Sample records for fighter maneuverability efm
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X-31 in flight, Herbst maneuver
NASA Technical Reports Server (NTRS)
1990-01-01
Two X-31 Enhanced Fighter Maneuverability (EFM) demonstrators were flown at the Rockwell International Palmdale, California, facility and the NASA Dryden Flight Research Center, Edwards, California, to obtain data that may apply to the design of highly-maneuverable next-generation fighters. The program had its first flight on October 11, 1990, in Palmdale; it ended in June 1995. The X-31 program demonstrated the value of thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems, to provide controlled flight during close-in air combat at very high angles of attack. The result of this increased maneuverability is an aircraft with a significant advantage over conventional fighters. 'Angle-of-attack' (alpha) is an engineering term to describe the angle of an aircraft body and wings relative to its actual flight path. During maneuvers, pilots often fly at extreme angles of attack--with the nose pitched up while the aircraft continues in its original direction. This can lead to loss of control and result in the loss of the aircraft, or both. Three thrust-vectoring paddles made of graphite epoxy mounted on the X-31 aircraft exhaust nozzle directed the exhaust flow to provide control in pitch (up and down) and yaw (right and left) to improve control. The paddles can sustain heat of up to 1,500 degrees centigrade for extended periods of time. In addition the X-31 aircraft were configured with movable forward canards and fixed aft strakes. The canards were small wing-like structures set on the wing line between the nose and the leading edge of the wing. The strakes were set on the same line between the trailing edge of the wing and the engine exhaust. Both supplied additional control in tight maneuvering situations. The X-31 research program produced technical data at high angles of attack. This information is giving engineers and aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. This is expected to lead to design methods that provide better maneuverability in future high performance aircraft and make them safer to fly. An international test organization of about 110 people, managed by the Advanced Research Projects Agency (ARPA), conducted the flight operations at NASA Dryden. The ARPA had requested flight research for the X-31 aircraft be moved there in February 1992. In addition to ARPA and NASA, the International Test Organization (ITO) included the U.S. Navy, the U.S. Air Force, Rockwell International, the Federal Republic of Germany, and Daimler-Benz Aerospace (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace). NASA was responsible for flight research operations, aircraft maintenance, and research engineering once the program moved to Dryden. The No. 1 X-31 aircraft was lost in an accident Jan. 19, 1995. The pilot, Karl Heinz-Lang, of the Federal Republic of Germany, ejected safely before the aircraft crashed in an unpopulated desert area just north of Edwards. The X-31 program logged an X-plane record of 580 flights during the program, including 555 research missions and 21 in Europe for the 1995 Paris Air Show. A total of 14 pilots representing all agencies of the ITO flew the aircraft. In this 40-second movie clip the X-31 aircraft is shown performing the 'Herbst maneuver,' which is a rapid, minimum-180-degree turn using a post-stall maneuver flying well beyond the aerodynamic limits of any conventional aircraft. Named after Wolfgang Herbst a proponent of using post-stall flight in air-to-air combat.
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X-31 in flight - Double Reversal
NASA Technical Reports Server (NTRS)
1995-01-01
Two X-31 Enhanced Fighter Maneuverability (EFM) demonstrators were flown at the Rockwell International facility, Palmdale, California, and the NASA Dryden Flight Research Center, Edwards, California, to obtain data that may apply to the design of highly-maneuverable next-generation fighters. The program had its first flight on October 11, 1990, in Palmdale; it ended in June 1995. The X-31 program demonstrated the value of thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems, to provide controlled flight during close-in air combat at very high angles of attack. The result of this increased maneuverability is an airplane with a significant advantage over conventional fighters. 'Angle-of-attack' (alpha) is an engineering term to describe the angle of an aircraft body and wings relative to its actual flight path. During maneuvers, pilots often fly at extreme angles of attack -- with the nose pitched up while he aircraft continues in its original direction. This can lead to loss of control and result in the loss of the aircraft, pilot or both. Three thrust-vectoring paddles made of graphite epoxy mounted on the exhaust nozzle of the X-31 aircraft directed the exhaust flow to provide control in pitch (up and down) and yaw (right and left) to improve control. The paddles can sustain heat of up to 1,500 degrees centigrade for extended periods of time. In addition the X-31 aircraft were configured with movable forward canards and fixed aft strakes. The canards were small wing-like structures set on the wing line between the nose and the leading edge of the wing. The strakes were set on the same line between the trailing edge of the wing and the engine exhaust. Both supplied additional control in tight maneuvering situations. The X-31 research program produced technical data at high angles of attack. This information is giving engineers and aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. This understanding is expected to lead to design methods that provide better maneuverability in future high performance aircraft and make them safer to fly. An international test organization of about 110 people, managed by the Advanced Research Projects Agency (ARPA), conducted the flight operations at NASA Dryden. The ARPA had requested flight research for the X-31 aircraft be moved there in February 1992. In addition to ARPA and NASA, the international test organization (ITO) included the U.S. Navy, the U.S. Air Force, Rockwell International, the Federal Republic of Germany, and Daimler-Benz Aerospace (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace). NASA was responsible for flight research operations, aircraft maintenance, and research engineering once the program moved to Dryden. The No. 1 X-31 aircraft was lost in an accident Jan. 19, 1995. The pilot, Karl Heinz-Lang, of the Federal Republic of Germany, ejected safely before the aircraft crashed in an unpopulated desert area just north of Edwards. The X-31 program logged an X-plane record of 580 flights during the program, including 555 research missions and 21 in Europe for the 1995 Paris Air Show. A total of 14 pilots representing all agencies of the ITO flew the aircraft. This 39-second clip begins as the X-31 performs a short loop at the top of a stall maneuver, then quickly reverses its course first left, then right by means of thrust vectoring -- thereby gaining a tactical advantage over a putative opponent in air-to-air combat.
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NASA Technical Reports Server (NTRS)
1995-01-01
Two X-31 Enhanced Fighter Maneuverability (EFM) demonstrators were flown at the Rockwell International facility, Palmdale, California, and the NASA Dryden Flight Research Center, Edwards, California, to obtain data that may apply to the design of highly-maneuverable next-generation fighters. The program had its first flight on October 11, 1990, in Palmdale; it ended in June 1995. The X-31 program demonstrated the value of thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems, to provide controlled flight during close-in air combat at very high angles of attack. The result of this increased maneuverability is an airplane with a significant advantage over conventional fighters. 'Angle-of-attack' (alpha) is an engineering term to describe the angle of an aircraft's body and wings relative to its actual flight path. During maneuvers, pilots often fly at extreme angles of attack -- with the nose pitched up while the aircraft continues in its original direction. This can lead to loss of control and result in the loss of the aircraft, pilot or both. Three thrust vectoring paddles made of graphite epoxy mounted on the exhaust nozzle of the X-31 aircraft directed the exhaust flow to provide control in pitch (up and down) and yaw (right and left) to improve control. The paddles can sustain heat of up to 1,500 degrees centigrade for extended periods of time. In addition the X-31 aircraft were configured with movable forward canards and fixed aft strakes. The canards were small wing-like structures set on the wing line between the nose and the leading edge of the wing. The strakes were set on the same line between the trailing edge of the wing and the engine exhaust. Both supplied additional control in tight maneuvering situations. The X-31 research program produced technical data at high angles of attack. This information is giving engineers and aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. This understanding is expected to lead to design methods that provide better maneuverability in future high performance aircraft and make them safer to fly. An international test organization of about 110 people, managed by the Advanced Research Projects Agency (ARPA), conducted the flight operations at NASA Dryden. The ARPA had requested flight research for the X-31 aircraft be moved there in February 1992. In addition to ARPA and NASA, the international test organization (ITO) included the U.S. Navy, the U.S. Air Force, Rockwell International, the Federal Republic of Germany, and Daimler-Benz Aerospace (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace). NASA was responsible for flight research operations, aircraft maintenance, and research engineering once the program moved to Dryden. The No. 1 X-31 aircraft was lost in an accident January 19, 1995. The pilot, Karl Heinz-Lang, of the Federal Republic of Germany, ejected safely before the aircraft crashed in an unpopulated desert area just north of Edwards. The X-31 program logged an X-plane record of 580 flights during the program, including 555 research missions and 21 in Europe for the 1995 Paris Air Show. A total of 14 pilots representing all agencies of the ITO flew the aircraft. The X-31 aircraft shown on approach with a high angle of attack, touches down with its speed brakes, which can be seen extended just above and behind the wing. The aircraft then begins to rotate the nosegear down to runway contact and deploys a braking parachute that assists in slowing the aircraft after landing.
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X-31 in flight - Post Stall Maneuver
NASA Technical Reports Server (NTRS)
1995-01-01
Two X-31 Enhanced Fighter Maneuverability (EFM) demonstrators were flown at Rockwell International's Palmdale, Calif., facility and the NASA Dryden Flight Research Center, Edwards, Calif., to obtain data that may apply to the design of highly-maneuverable next-generation fighters. The program had its first flight on Oct. 11, 1990, in Palmdale; it ended in June 1995. The X-31 program demonstrated the value of thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems, to provide controlled flight during close-in air combat at very high angles of attack. The result of this increased maneuverability is a significant advantage over conventional fighters. 'Angle-of-attack' (alpha) is an engineering term to describe the angle of an aircraft's body and wings relative to its actual flight path. During maneuvers, pilots often fly at extreme angles of attack -- with the nose pitched up while the aircraft continues in its original direction. This can lead to loss of control and result in the loss of the aircraft, pilot or both. Three thrust vectoring paddles made of graphite epoxy mounted on the X-31's exhaust nozzle directed the exhaust flow to provide control in pitch (up and down) and yaw (right and left) to improve control. The paddles can sustain heat of up to 1,500 degrees centigrade for extended periods of time. In addition the X-31s were configured with movable forward canards and fixed aft strakes. The canards were small wing-like structures set on the wing line between the nose and the leading edge of the wing. The strakes were set on the same line between the trailing edge of the wing and the engine exhaust. Both supplyied additional control in tight maneuvering situations. The X-31 research program produced technical data at high angles of attack. This information is giving engineers and aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. This is expected to lead to design methods providing better maneuverability in future high performance aircraft and make them safer to fly. An international test organization of about 110 people, managed by the Advanced Research Projects Agency (ARPA), conducted the flight operations at Dryden, to which flight research was moved in February 1992 at the request of the Advanced Research Projects Agency (ARPA). In addition to ARPA and NASA, the International Test Organization (ITO) included the U.S. Navy, the U.S. Air Force, Rockwell International, the Federal Republic of Germany, and Daimler-Benz Aerospace (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace). NASA was responsible for flight research operations, aircraft maintenance, and research engineering once the program moved to Dryden. The No. 1 X-31 aircraft was lost in an accident Jan. 19, 1995. The pilot, Karl Heinz-Lang, of the Federal Republic of Germany, ejected safely before the aircraft crashed in an unpopulated desert area just north of Edwards. The X-31 program logged an X-plane record of 580 flights during the program, including 555 research missions and 21 in Europe for the 1995 Paris Air Show. A total of 14 pilots representing all agencies of the ITO flew the aircraft. This 34-second movie clip shows the aircraft as it slides backwards, thrust vectoring the tail over the top, turning the stall into a loop in which the aircraft then reverses it's heading and resumes level flight.
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NASA Technical Reports Server (NTRS)
1995-01-01
Two X-31 Enhanced Fighter Maneuverability (EFM) demonstrators were flown at the Rockwell International facility, Palmdale, California, and the NASA Dryden Flight Research Center, Edwards, California, to obtain data that may apply to the design of highly-maneuverable next-generation fighters. The program had its first flight on October 11, 1990, in Palmdale; it ended in June 1995. The X-31 program demonstrated the value of thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems, to provide controlled flight during close-in air combat at very high angles of attack. The result of this increased maneuverability is an airplane with a significant advantage over conventional fighters. 'Angle-of-attack' (alpha) is an engineering term to describe the angle of an aircraft body and wings relative to its actual flight path. During maneuvers, pilots often fly at extreme angles of attack -- with the nose pitched up while the aircraft continues in its original direction. This can lead to loss of control and result in the loss of the aircraft, pilot or both. Three thrust-vectoring paddles made of graphite epoxy mounted on the exhaust nozzle of the X-31 aircraft directed the exhaust flow to provide control in pitch (up and down) and yaw (right and left) to improve control. The paddles can sustain heat of up to 1,500 degrees centigrade for extended periods of time. In addition the X-31 aircraft were configured with movable forward canards and fixed aft strakes. The canards were small wing-like structures set on the wing line between the nose and the leading edge of the wing. The strakes were set on the same line between the trailing edge of the wing and the engine exhaust. Both supplied additional control in tight maneuvering situations. The X-31 research program produced technical data at high angles of attack. This information is giving engineers and aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. This understanding is expected to lead to design methods that provide better maneuverability in future high performance aircraft and make them safer to fly. An international test organization of about 110 people, managed by the Advanced Research Projects Agency (ARPA), conducted the flight operations at NASA Dryden. The ARPA had requested flight research for the X-31 aircraft be moved there in February 1992. In addition to ARPA and NASA, the international test organization (ITO) included the U.S. Navy, the U.S. Air Force, Rockwell International, the Federal Republic of Germany, and Daimler-Benz Aerospace (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace). NASA was responsible for flight research operations, aircraft maintenance, and research engineering once the program moved to Dryden. The No. 1 X-31 aircraft was lost in an accident January 19, 1995. The pilot, Karl Heinz-Lang, of the Federal Republic of Germany, ejected safely before the aircraft crashed in an unpopulated desert area just north of Edwards. The X-31 program logged an X-plane record of 580 flights during the program, including 555 research missions and 21 in Europe for the 1995 Paris Air Show. A total of 14 pilots representing all agencies of the ITO flew the aircraft. This 32-second clip shows the aircraft at the top of a stall and then thrust vectoring itself around to attain a new heading, thereby allowing the aircraft to gain the advantage over a putative opponent in air-to-air combat. This maneuver is also known as a 'J turn.'
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X-31 Unloading Returning from Paris Air Show
NASA Technical Reports Server (NTRS)
1995-01-01
After being flown in the Paris Air Show in June 1995, the X-31 Enhanced Fighter Maneuverability Technology Demonstrator Aircraft, based at the NASA Dryden Flight Research Center, Edwards Air Force Base, California, is off-loaded from an Air Force Reserve C-5 transport after the ferry flight back to Edwards. At the air show, the X-31 demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems to provide controlled flight at very high angles of attack. The X-31 Enhanced Fighter Maneuverability (EFM) demonstrator flew at the Ames- Dryden Flight Research Facility, Edwards, California (redesignated the Dryden Flight Research Center in 1994) from February 1992 until 1995 and before that at the Air Force's Plant 42 in Palmdale, California. The goal of the project was to provide design information for the next generation of highly maneuverable fighter aircraft. This program demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with an advanced flight control system to provide controlled flight to very high angles of attack. The result was a significant advantage over most conventional fighters in close-in combat situations. The X-31 flight program focused on agile flight within the post-stall regime, producing technical data to give aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. Stall is a condition of an airplane or an airfoil in which lift decreases and drag increases due to the separation of airflow. Thrust vectoring compensates for the loss of control through normal aerodynamic surfaces that occurs during a stall. Post-stall refers to flying beyond the normal stall angle of attack, which in the X-31 was at a 30-degree angle of attack. During Dryden flight testing, the X-31 aircraft established several milestones. On November 6, 1992, the X-31 achieved controlled flight at a 70-degree angle of attack. On April 29, 1993, the second X-31 successfully executed a rapid minimum-radius, 180-degree turn using a post-stall maneuver, flying well beyond the aerodynamic limits of any conventional aircraft. This revolutionary maneuver has been called the 'Herbst Maneuver' after Wolfgang Herbst, a German proponent of using post-stall flight in air-to-air combat. It is also called a 'J Turn' when flown to an arbitrary heading change. The aircraft was flown in tactical maneuvers against an F/A-18 and other tactical aircraft as part of the test flight program. During November and December 1993, the X-31 reached a supersonic speed of Mach 1.28. In 1994, the X-31 program installed software to demonstrate quasi-tailless operation. The X-31 flight test program was conducted by an international test organization (ITO) managed by the Advanced Research Projects Office (ARPA), known as the Defense Advanced Research Projects Office (DARPA) before March 1993. The ITO included the U.S. Navy and U.S. Air Force, Rockwell Aerospace, the Federal Republic of Germany, Daimler-Benz (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace), and NASA. Gary Trippensee was the ITO director and NASA Project Manager. Pilots came from participating organizations. The X-31 was 43.33 feet long with a wingspan of 23.83 feet. It was powered by a single General Electric P404-GE-400 turbofan engine that produced 16,000 pounds of thrust in afterburner.
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Results of recent NASA studies on automatic spin prevention for fighter aircraft
NASA Technical Reports Server (NTRS)
Chambers, J. R.; Nguyen, L. T.
1976-01-01
A broad based research program was developed to eliminate or minimize inadvertent spins for advanced military aircraft. Recent piloted simulator studies and airplane flight tests have demonstrated that the automatic control systems in use on current fighters can be tailored to provide a high degree of spin resistance for some configurations without restrictions to maneuverability. Such systems result in greatly increased tactical effectiveness, safety, and pilot confidence.
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X-31 in flight - Mongoose Maneuver
NASA Technical Reports Server (NTRS)
1995-01-01
Two X-31 Enhanced Fighter Maneuverability (EFM) demonstrators were flown at the Rockwell International facility, Palmdale, California, and the NASA Dryden Flight Research Center, Edwards, California, to obtain data that may apply to the design of highly-maneuverable next-generation fighters. The program had its first flight on October 11, 1990, in Palmdale; it ended in June 1995. The X-31 program demonstrated the value of thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems, to provide controlled flight during close-in air combat at very high angles of attack. The result of this increased maneuverability is an aircraft with a significant advantage over conventional fighters. 'Angle-of-attack' (alpha) is an engineering term to describe the angle of an aircraft body and wings relative to its actual flight path. During maneuvers, pilots often fly at extreme angles of attack -- with the nose pitched up while the aircraft continues in its original direction. This can lead to loss of control and result in the loss of the aircraft, pilot or both. Three thrust-vectoring paddles made of graphite epoxy mounted on the exhaust nozzle of the X-31 aircraft directed the exhaust flow to provide control in pitch (up and down) and yaw (right and left) to improve control. The paddles can sustain heat of up to 1,500 degrees centigrade for extended periods of time. In addition the X-31 aircraft were configured with movable forward canards and fixed aft strakes. The canards were small wing-like structures set on the wing line between the nose and the leading edge of the wing. The strakes were set on the same line between the trailing edge of the wing and the engine exhaust. Both supplied additional control in tight maneuvering situations. The X-31 research program produced technical data at high angles of attack. This information is giving engineers and aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. This understanding is expected to lead to design methods which provide better maneuverability in future high performance aircraft and make them safer to fly. An international test organization of about 110 people, managed by the Advanced Research Projects Agency (ARPA), conducted the flight operations at NASA Dryden. The ARPA had requested flight research for the X-31 aircraft be moved there in February 1992. In addition to ARPA and NASA, the international test organization (ITO) included the U.S. Navy, the U.S. Air Force, Rockwell International, the Federal Republic of Germany, and Daimler-Benz Aerospace (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace). NASA was responsible for flight research operations, aircraft maintenance, and research engineering once the program moved to Dryden. The No. 1 X-31 aircraft was lost in an accident January 19, 1995. The pilot, Karl Heinz-Lang, of the Federal Republic of Germany, ejected safely before the aircraft crashed in an unpopulated desert area just north of Edwards. The X-31 program logged an X-plane record of 580 flights during the program, including 555 research missions and 21 in Europe for the 1995 Paris Air Show. A total of 14 pilots representing all agencies of the ITO flew the aircraft. In this 36-second clip we see the X-31 performing the 'Mongoose maneuver,' beginning in a tight left hand turn, then pulling the aircraft into a high-angle-of-attack stall/tail-stand maneuver in which the aircraft remains in the vertical for several seconds, then pushes over to resume normal flight. This maneuver is in response to the Sukoi SU-27 'Flanker' test pilot Victor Georgievich Pugachev's 'Cobra maneuver' or 'Pugachev's cobra,' in which the aircraft, like the X-31, is stood on its tail to give the pilot a tactical advantage in air-to-air combat by essentially stopping and pointing the aircraft weapons toward the opponent.
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X-31 in flight - Post Stall Maneuver
NASA Technical Reports Server (NTRS)
1995-01-01
Two X-31 Enhanced Fighter Maneuverability (EFM) demonstrators were flown at the Rockwell International facility, Palmdale, California, and the NASA Dryden Flight Research Center, Edwards, California, to obtain data that may apply to the design of highly-maneuverable next-generation fighters. The program had its first flight on October 11, 1990, in Palmdale; it ended in June 1995. The X-31 program demonstrated the value of thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems, to provide controlled flight during close-in air combat at very high angles of attack. The result of this increased maneuverability is an aircraft with a significant advantage over conventional fighters. 'Angle-of-attack' (alpha) is an engineering term to describe the angle of an aircraft body and wings relative to its actual flight path. During maneuvers, pilots often fly at extreme angles of attack -- with the nose pitched up while the aircraft continues in its original direction. This can lead to loss of control and result in the loss of the aircraft, pilot or both. Three thrust vectoring paddles made of graphite epoxy mounted on the exhaust nozzle of the X-31 aircraft directed the exhaust flow to provide control in pitch (up and down) and yaw (right and left) to improve control. The paddles can sustain heat of up to 1,500 degrees centigrade for extended periods of time. In addition the X-31 aircraft were configured with movable forward canards and fixed aft strakes. The canards were small wing-like structures set on the wing line between the nose and the leading edge of the wing. The strakes were set on the same line between the trailing edge of the wing and the engine exhaust. Both supplied additional control in tight maneuvering situations. The X-31 research program produced technical data at high angles of attack. This information is giving engineers and aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. This understanding is expected to lead to design methods that can provide better maneuverability in future high performance aircraft and make them safer to fly. An international test organization of about 110 people, managed by the Advanced Research Projects Agency (ARPA), conducted the flight operations at NASA Dryden. The ARPA had requested flight research for the X-31 aircraft be moved there in February 1992. In addition to ARPA and NASA, the international test organization (ITO) included the U.S. Navy, the U.S. Air Force, Rockwell International, the Federal Republic of Germany, and Daimler-Benz Aerospace (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace). NASA was responsible for flight research operations, aircraft maintenance, and research engineering once the program moved to Dryden. The No. 1 X-31 aircraft was lost in an accident January 19, 1995. The pilot, Karl Heinz-Lang, of the Federal Republic of Germany, ejected safely before the aircraft crashed in an unpopulated desert area just north of Edwards. The X-31 program logged an X-plane record of 580 flights during the program, including 555 research missions and 21 in Europe for the 1995 Paris Air Show. A total of 14 pilots representing all agencies of the ITO flew the aircraft. This movie clip runs 1 minute, 6 seconds in length and shows the X-31 rotating at takeoff and climbing into a stall maneuver. The aircraft then slides backwards thrust vectoring the tail over the top, turning the stall into a loop in which the aircraft then reverses its heading and resumes level flight.
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Stability Result For Dynamic Inversion Devised to Control Large Flexible Aircraft
NASA Technical Reports Server (NTRS)
Gregory, Irene M.
2001-01-01
High performance aircraft of the future will be designed lighter, more maneuverable, and operate over an ever expanding flight envelope. One of the largest differences from the flight control perspective between current and future advanced aircraft is elasticity. Over the last decade, dynamic inversion methodology has gained considerable popularity in application to highly maneuverable fighter aircraft, which were treated as rigid vehicles. This paper is an initial attempt to establish global stability results for dynamic inversion methodology as applied to a large, flexible aircraft. This work builds on a previous result for rigid fighter aircraft and adds a new level of complexity that is the flexible aircraft dynamics, which cannot be ignored even in the most basic flight control. The results arise from observations of the control laws designed for a new generation of the High-Speed Civil Transport aircraft.
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NASA Technical Reports Server (NTRS)
1995-01-01
The X-31 Enhanced Fighter Maneuverability Technology Demonstrator Aircraft, based at the NASA Dryden Flight Research Center, Edwards Air Force Base, California, is secured inside the fuselage of an Air Force Reserve C-5 transport. The C-5 was used to ferry the X-31 from Europe back to Edwards, after being flown in the Paris Air Show in June 1995. The X-31's right wing, removed so the aircraft could fit inside the C-5, is in the shipping container in the foreground. At the air show, the X-31 demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems to provide controlled flight at very high angles of attack. The X-31 Enhanced Fighter Maneuverability (EFM) demonstrator flew at the Ames- Dryden Flight Research Facility, Edwards, California (redesignated the Dryden Flight Research Center in 1994) from February 1992 until 1995 and before that at the Air Force's Plant 42 in Palmdale, California. The goal of the project was to provide design information for the next generation of highly maneuverable fighter aircraft. This program demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with an advanced flight control system to provide controlled flight to very high angles of attack. The result was a significant advantage over most conventional fighters in close-in combat situations. The X-31 flight program focused on agile flight within the post-stall regime, producing technical data to give aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. Stall is a condition of an airplane or an airfoil in which lift decreases and drag increases due to the separation of airflow. Thrust vectoring compensates for the loss of control through normal aerodynamic surfaces that occurs during a stall. Post-stall refers to flying beyond the normal stall angle of attack, which in the X-31 was at a 30-degree angle of attack. During Dryden flight testing, the X-31 aircraft established several milestones. On November 6, 1992, the X-31 achieved controlled flight at a 70-degree angle of attack. On April 29, 1993, the second X-31 successfully executed a rapid minimum-radius, 180-degree turn using a post-stall maneuver, flying well beyond the aerodynamic limits of any conventional aircraft. This revolutionary maneuver has been called the 'Herbst Maneuver' after Wolfgang Herbst, a German proponent of using post-stall flight in air-to-air combat. It is also called a 'J Turn' when flown to an arbitrary heading change. The aircraft was flown in tactical maneuvers against an F/A-18 and other tactical aircraft as part of the test flight program. During November and December 1993, the X-31 reached a supersonic speed of Mach 1.28. In 1994, the X-31 program installed software to demonstrate quasi-tailless operation. The X-31 flight test program was conducted by an international test organization (ITO) managed by the Advanced Research Projects Office (ARPA), known as the Defense Advanced Research Projects Office (DARPA) before March 1993. The ITO included the U.S. Navy and U.S. Air Force, Rockwell Aerospace, the Federal Republic of Germany, Daimler-Benz (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace), and NASA. Gary Trippensee was the ITO director and NASA Project Manager. Pilots came from participating organizations. The X-31 was 43.33 feet long with a wingspan of 23.83 feet. It was powered by a single General Electric P404-GE-400 turbofan engine that produced 16,000 pounds of thrust in afterburner.
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NASA Technical Reports Server (NTRS)
Gingrich, P. B.; Child, R. D.; Panageas, G. N.
1977-01-01
The aerodynamic development of the highly maneuverable aircraft technology remotely piloted research vehicle (HiMAT/RPRV) from the conceptual design to the final configuration is presented. The design integrates several advanced concepts to achieve a high degree of transonic maneuverability, and was keyed to sustained maneuverability goals while other fighter typical performance characteristics were maintained. When tests of the baseline configuration indicated deficiencies in the technology integration and design techniques, the vehicle was reconfigured to satisfy the subcritical and supersonic requirements. Drag-due-to-lift levels only 5 percent higher than the optimum were obtained for the wind tunnel model at a lift coefficient of 1 for Mach numbers of up to 0.8. The transonic drag rise was progressively lowered with the application of nonlinear potential flow analyses coupled with experimental data.
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Control-system techniques for improved departure/spin resistance for fighter aircraft
NASA Technical Reports Server (NTRS)
Nguyen, L. T.; Gilbert, W. P.; Ogburn, M. E.
1980-01-01
Some fundamental information on control system effects on controllability of highly maneuverable aircraft at high angles of attack are summarized as well as techniques for enhancing fighter aircraft departure/spin resistance using control system design. The discussion includes: (1) a brief review of pertinent high angle of attack phenomena including aerodynamics, inertia coupling, and kinematic coupling; (2) effects of conventional stability augmentation systems at high angles of attack; (3) high angle of attack control system concepts designed to enhance departure/spin resistance; and (4) the outlook for applications of these concepts to future fighters, particularly those designs which incorporate relaxed static stability.
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Design of a fifth generation air superiority fighter
NASA Astrophysics Data System (ADS)
Atique, Md. Saifuddin Ahmed; Barman, Shuvrodeb; Nafi, Asif Shahriar; Bellah, Masum; Salam, Md. Abdus
2016-07-01
Air Superiority Fighter is considered to be an effective dogfighter which is stealthy & highly maneuverable to surprise enemy along with improve survivability against the missile fire. This new generation fighter aircraft requires fantastic aerodynamics design, low wing loading (W/S), high thrust to weight ratio (T/W) with super cruise ability. Conceptual design is the first step to design an aircraft. In this paper conceptual design of an Air Superiority Fighter Aircraft is proposed to carry 1 crew member (pilot) that can fly at maximum Mach No of 2.3 covering a range of 1500 km with maximum ceiling of 61,000 ft. Payload capacity of this proposed aircraft is 6000 lb that covers two advanced missiles & one advanced gun. The Air Superiority Fighter Aircraft was designed to undertake all the following missions like: combat air petrol, air to air combat, maritime attack, close air support, suppression, destruction of enemy air defense and reconnaissance.
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1980-12-30
A close-up view of the Highly Maneuverable Aircraft Technology (HiMAT) research vehicle attached to a wing pylon on NASA’s B-52 mothership during a 1980 test flight. The HiMAT used sharply swept-back wings and a canard configuration to test possible technology for advanced fighters.
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Schweinfurt Raids and the Pause in Daylight Strategic Bombing
2008-06-13
fundamentally flawed doctrine based upon faulty assumptions and the end result was the heavy loss of aircrew and aircraft. The Schweinfurt missions...maneuverable German fighters due to the Lightning’s turbochargers performing badly at higher altitudes in the high humidity and colder temperatures. The P-38
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1980-12-30
The HiMAT (Highly Maneuverable Aircraft Technology) subscale research vehicle, seen here during a research flight, was flown by the NASA Dryden Flight Research Center, Edwards, California, from mid 1979 to January 1983. The aircraft demonstrated advanced fighter technologies that have been used in the development of many modern high performance military aircraft.
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1980-12-30
The HiMAT (Highly Maneuverable Aircraft Technology) subscale research vehicle, seen here during a research flight, was flown by the NASA Dryden Flight Research Center, Edwards, California, from mid 1979 to January 1983. The aircraft demonstrated advanced fighter technologies that have been used in the development of many modern high performance military aircraft.
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Forebody/Inlet of the Joint Strike Fighter Tested at Low Speeds
NASA Technical Reports Server (NTRS)
Johns, Albert L.
1998-01-01
As part of a national cooperative effort to develop a multinational fighter aircraft, a model of a Joint Strike Fighter concept was tested in several NASA Lewis Research Center wind tunnels at low speeds over a range of headwind velocities and model attitudes. This Joint Strike Fighter concept, which is scheduled to go into production in 2005, will greatly improve the range, capability, maneuverability, and survivability of fighter aircraft, and the production program could ultimately be worth $100 billion. The test program was a team effort between Lewis and Lockheed Martin Tactical Aircraft Systems. Testing was completed in September 1997, several weeks ahead of schedule, allowing Lockheed additional time to review the results and analysis data before the next test and resulting in significant cost savings for Lockheed. Several major milestones related to dynamic and steady-state data acquisition and overall model performance were reached during this model test. Results from this program will contribute to both the concept demonstration phase and the production aircraft.
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A technique for the assessment of fighter aircraft precision controllability
NASA Technical Reports Server (NTRS)
Sisk, T. R.
1978-01-01
Today's emerging fighter aircraft are maneuvering as well at normal accelerations of 7 to 8 g's as their predecessors did at 4 to 5 g's. This improved maneuvering capability has significantly expanded their operating envelope and made the task of evaluating handling qualities more difficult. This paper describes a technique for assessing the precision controllability of highly maneuverable aircraft, a technique that was developed to evaluate the effects of buffet intensity on gunsight tracking capability and found to be a useful tool for the general assessment of fighter aircraft handling qualities. It has also demonstrated its usefulness for evaluating configuration and advanced flight control system refinements. This technique is believed to have application to future aircraft dynamics and pilot-vehicle interface studies.
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NASA Technical Reports Server (NTRS)
Foss, W. E., Jr.
1981-01-01
A computer technique to determine the mission radius and maneuverability characteristics of combat aircraft was developed. The technique was used to determine critical operational requirements and the areas in which research programs would be expected to yield the most beneficial results. In turn, the results of research efforts were evaluated in terms of aircraft performance on selected mission segments and for complete mission profiles. Extensive use of the technique in evaluation studies indicates that the calculated performance is essentially the same as that obtained by the proprietary programs in use throughout the aircraft industry.
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1980-01-03
The HiMAT (Highly Maneuverable Aircraft Technology) subscale research vehicle, seen here after landing to conclude a research flight, was flown by the NASA Dryden Flight Research Center, Edwards, California, from mid 1979 to January 1983. The aircraft demonstrated advanced fighter technologies that have been used in the development of many modern high performance military aircraft.
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1980-12-30
The HiMAT (Highly Maneuverable Aircraft Technology) subscale research vehicle, seen here during a research flight, was flown by the NASA Dryden Flight Research Center, Edwards, California, from mid 1979 to January 1983. The aircraft demonstrated advanced fighter technologies that have been used in the development of many modern high performance military aircraft.
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Calculated performance, stability and maneuverability of high-speed tilting-prop-rotor aircraft
NASA Technical Reports Server (NTRS)
Johnson, Wayne; Lau, Benton H.; Bowles, Jeffrey V.
1986-01-01
The feasibility of operating tilting-prop-rotor aircraft at high speeds is examined by calculating the performance, stability, and maneuverability of representative configurations. The rotor performance is examined in high-speed cruise and in hover. The whirl-flutter stability of the coupled-wing and rotor motion is calculated in the cruise mode. Maneuverability is examined in terms of the rotor-thrust limit during turns in helicopter configuration. Rotor airfoils, rotor-hub configuration, wing airfoil, and airframe structural weights representing demonstrated advance technology are discussed. Key rotor and airframe parameters are optimized for high-speed performance and stability. The basic aircraft-design parameters are optimized for minimum gross weight. To provide a focus for the calculations, two high-speed tilt-rotor aircraft are considered: a 46-passenger, civil transport and an air-combat/escort fighter, both with design speeds of about 400 knots. It is concluded that such high-speed tilt-rotor aircraft are quite practical.
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NASA Technical Reports Server (NTRS)
Griffin, S. A.; Madsen, A. P.; Mcclain, A. A.
1984-01-01
The feasibility of designing advanced technology, highly maneuverable, fighter aircraft models to achieve full scale Reynolds number in the National Transonic Facility (NTF) is examined. Each of the selected configurations are tested for aeroelastic effects through the use of force and pressure data. A review of materials and material processes is also included.
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1980-12-30
The Highly Maneuverable Aircraft Technology (HiMAT) research vehicle is shown here mated to a wing pylon on NASA’s B-52 mothership aircraft. The HiMAT was a technology demonstrator to test structures and configurations for advanced fighter concepts. Over the course of more than 40 years, the B-52 proved a valuable workhorse for NASA’s Dryden Flight Research Center (under various names), launching a wide variety of vehicles and conducting numerous other research flights.
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A Study on Aircraft Engine Control Systems for Integrated Flight and Propulsion Control
NASA Astrophysics Data System (ADS)
Yamane, Hideaki; Matsunaga, Yasushi; Kusakawa, Takeshi; Yasui, Hisako
The Integrated Flight and Propulsion Control (IFPC) for a highly maneuverable aircraft and a fighter-class engine with pitch/yaw thrust vectoring is described. Of the two IFPC functions the aircraft maneuver control utilizes the thrust vectoring based on aerodynamic control surfaces/thrust vectoring control allocation specified by the Integrated Control Unit (ICU) of a FADEC (Full Authority Digital Electronic Control) system. On the other hand in the Performance Seeking Control (PSC) the ICU identifies engine's various characteristic changes, optimizes manipulated variables and finally adjusts engine control parameters in cooperation with the Engine Control Unit (ECU). It is shown by hardware-in-the-loop simulation that the thrust vectoring can enhance aircraft maneuverability/agility and that the PSC can improve engine performance parameters such as SFC (specific fuel consumption), thrust and gas temperature.
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Modified Dynamic Inversion to Control Large Flexible Aircraft: What's Going On?
NASA Technical Reports Server (NTRS)
Gregory, Irene M.
1999-01-01
High performance aircraft of the future will be designed lighter, more maneuverable, and operate over an ever expanding flight envelope. One of the largest differences from the flight control perspective between current and future advanced aircraft is elasticity. Over the last decade, dynamic inversion methodology has gained considerable popularity in application to highly maneuverable fighter aircraft, which were treated as rigid vehicles. This paper explores dynamic inversion application to an advanced highly flexible aircraft. An initial application has been made to a large flexible supersonic aircraft. In the course of controller design for this advanced vehicle, modifications were made to the standard dynamic inversion methodology. The results of this application were deemed rather promising. An analytical study has been undertaken to better understand the nature of the made modifications and to determine its general applicability. This paper presents the results of this initial analytical look at the modifications to dynamic inversion to control large flexible aircraft.
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NASA Technical Reports Server (NTRS)
Foster, John V.; Ross, Holly M.; Ashley, Patrick A.
1993-01-01
Designers of the next-generation fighter and attack airplanes are faced with the requirements of good high-angle-of-attack maneuverability as well as efficient high speed cruise capability with low radar cross section (RCS) characteristics. As a result, they are challenged with the task of making critical design trades to achieve the desired levels of maneuverability and performance. This task has highlighted the need for comprehensive, flight-validated lateral-directional control power design guidelines for high angles of attack. A joint NASA/U.S. Navy study has been initiated to address this need and to investigate the complex flight dynamics characteristics and controls requirements for high-angle-of-attack lateral-directional maneuvering. A multi-year research program is underway which includes ground-based piloted simulation and flight validation. This paper will give a status update of this program that will include a program overview, description of test methodology and preliminary results.
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NASA Technical Reports Server (NTRS)
Foster, John V.; Ross, Holly M.; Ashley, Patrick A.
1993-01-01
Designers of the next-generation fighter and attack airplanes are faced with the requirements of good high angle-of-attack maneuverability as well as efficient high speed cruise capability with low radar cross section (RCS) characteristics. As a result, they are challenged with the task of making critical design trades to achieve the desired levels of maneuverability and performance. This task has highlighted the need for comprehensive, flight-validated lateral-directional control power design guidelines for high angles of attack. A joint NASA/U.S. Navy study has been initiated to address this need and to investigate the complex flight dynamics characteristics and controls requirements for high angle-of-attack lateral-directional maneuvering. A multi-year research program is underway which includes groundbased piloted simulation and flight validation. This paper will give a status update of this program that will include a program overview, description of test methodology and preliminary results.
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NASA Technical Reports Server (NTRS)
Freymuth, Peter
1992-01-01
Aims for improvement of fighter aircraft pursued by the unsteady flow community are high agility (the ability of the aircraft to make close turns in a low-speed regime) and super maneuverability (the ability of the aircraft to operate at high angles of attack in a post stall regime during quick maneuvers in a more extended speed range). High agility requires high lift coefficients at low speeds in a dynamic situation and this requirement can be met by dynamically forced separation or by quasistatic stall control. The competing methods will be assessed based on the known physics. Maneuvering into the post stall regime also involves dynamic separation but because even fast maneuvers involving the entire aircraft are 'aerodynamically slow' the resulting dynamic vortex structures should be considered 'elicited' rather than 'forced.' More work seems to be needed in this area of elicited dynamic separation.
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Impact of emerging technologies on future combat aircraft agility
NASA Technical Reports Server (NTRS)
Nguyen, Luat T.; Gilert, William P.
1990-01-01
The foreseeable character of future within-visual-range air combat entails a degree of agility which calls for the integration of high-alpha aerodynamics, thrust vectoring, intimate pilot/vehicle interfaces, and advanced weapons/avionics suites, in prospective configurations. The primary technology-development programs currently contributing to these goals are presently discussed; they encompass the F-15 Short Takeoff and Landing/Maneuver Technology Demonstrator Program, the Enhanced Fighter Maneuverability Program, the High Angle-of-Attack Technology Program, and the X-29 Technology Demonstrator Program.
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1980-07-02
View of the cockpit of NASA's F-14, tail number 991. This aircraft was the first of a series of post-Vietnam fighters, followed by the F-15, F-16, and F-18. They were designed for maneuverability in air-to-air combat. The F-14s had a spin problem that posed problems for its ability to engage successfully in a dogfight, since it tended to depart from controlled flight at the high angles of attack that frequently occur in close-in engagements.
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X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden
NASA Technical Reports Server (NTRS)
1996-01-01
The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft in it's hangar at NASA Dryden Flight Research Center, Edwards, California, following its arrival on July 2, 1996. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden
NASA Technical Reports Server (NTRS)
1996-01-01
NASA and McDonnell Douglas Corporation (MDC) personnel remove protective covers from the newly arrived NASA/McDonnell Douglas Corporation X-36 Tailless Fighter Agility Research Aircraft. It arrived at NASA Dryden Flight Research Center, Edwards, California, on July 2, 1996. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden
NASA Technical Reports Server (NTRS)
1996-01-01
NASA and McDonnell Douglas Corporation (MDC) personnel wait to attach a hoist to the X-36 Tailless Fighter Agility Research Aircraft, which arrived at NASA Dryden Flight Research Center, Edwards, California, on July 2, 1996. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 Tailless Fighter Agility Research Aircraft on lakebed during high-speed taxi tests
NASA Technical Reports Server (NTRS)
1996-01-01
The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft undergoes high-speed taxi tests on Rogers Dry Lake at NASA Dryden Flight Research Center, Edwards, California, on October 17, 1996. The aircraft was tested at speeds up to 85 knots. Normal takeoff speed would be 110 knots. More taxi and radio frequency tests were slated before it's first flight would be made. This took place on May 17, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 Tailless Fighter Agility Research Aircraft on lakebed during high-speed taxi tests
NASA Technical Reports Server (NTRS)
1996-01-01
The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft undergoes high-speed taxi tests on Rogers Dry Lake at NASA Dryden Flight Research Center, Edwards, California, on October 17, 1996. The aircraft was tested at speeds up to 85 knots. Normal takeoff speed would be 110 knots. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden
NASA Technical Reports Server (NTRS)
1996-01-01
The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft is steered to it's hangar at NASA Dryden Flight Research Center, Edwards, California, following arrival on July 2, 1996. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 Tailless Fighter Agility Research Aircraft in flight
NASA Technical Reports Server (NTRS)
1997-01-01
The X-36 technology demonstrator shows off its distinctive shape as the remotely piloted aircraft flies a research mission over the Southern California desert on October 30, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 Taking off during First Flight
NASA Technical Reports Server (NTRS)
1997-01-01
The remotely-piloted X-36 Tailless Fighter Agility Research Aircraft lifts off from Rogers Dry Lake at the Dryden Flight Research Center on its first flight on May 17, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 Tailless Fighter Agility Research Aircraft in flight
NASA Technical Reports Server (NTRS)
1997-01-01
The tailless X-36 technology demonstrator research aircraft cruises over the California desert at low altitude during a 1997 research flight. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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Lauritzsen, Lars P; Pfitzner, John
2003-04-01
The purpose of this brief review is to outline the past and present use of pressure breathing, not by patients but by fighter pilots. Of the historical and recent references quoted, most are from aviation-medicine journals that are not often readily available to anesthesiologists. Pressure breathing at moderate levels of airway pressure gave World War II fighter pilots a tactical altitude advantage. With today's fast and highly maneuverable jet fighters, very much higher airway pressures of the order of 8.0 kPa (identical with 60 mmHg) are used. They are used in conjunction with a counterpressure thoracic vest and an anti-G suit for the abdomen and lower body. Pressurization is activated automatically in response to +Gz accelerations, and to a potentially catastrophic loss of cabin pressurization at altitude. During +Gz accelerations, pressure breathing has been shown to maintain cerebral perfusion by raising the systemic arterial pressure, so increasing the level of G-tolerance that is afforded by the use of anti-G suits and seat tilt-back angles alone. This leaves the pilot less reliant on rigorous, and potentially distracting, straining maneuvers. With loss of cabin pressurization at altitude, pressure breathing of 100% oxygen at high airway pressures enables the pilot's alveolar PO(2) to be maintained at a safe level during emergency descent. Introduced in military aviation, pressure breathing for G-tolerance and pressure breathing for altitude presented as concepts that may be of general physiological interest to many anesthesiologists.
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F-22 cockpit avionics: a systems integration success story
NASA Astrophysics Data System (ADS)
Greeley, Kevin W.; Schwartz, Richard J.
2000-08-01
The F-22 'Raptor' is being developed and manufactured as multi-role fighter aircraft for the 'air dominance' mission. The F-22 team is led by Lockheed Martin, with Boeing and Pratt & Whitney as partners. The F-22 weapons system combines supersonic cruise, maneuverability, stealth, and an extensive suite of tightly integrated sensors to achieve a high level of lethality and invulnerability against current and projected threat systems such as fighter aircraft and surface to air missiles. Despite high automation of the complex systems installed in the F-22, the pilot is heavily tasked for air battle management. Response timelines are compressed due to supersonic cruise velocities. These factors challenge the Pilot Vehicle Interface (PVI) design. This paper discusses the team's response to these challenges, describing the physical cockpit layout, its controls and displays, and the hardware architecture, software tools, and development process used to mature the F-22 'Raptor' weapons system, including a review of Human Factors design considerations for F-22 displays.
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The X-31A quasi-tailless flight test results
NASA Technical Reports Server (NTRS)
Bosworth, John T.; Stoliker, P. C.
1996-01-01
A quasi-tailless flight investigation was launched using the X-31A enhanced fighter maneuverability airplane. In-flight simulations were used to assess the effect of partial to total vertical tail removal. The rudder control surface was used to cancel the stabilizing effects of the vertical tail, and yaw thrust vector commands were used to restabilize and control the airplane. The quasi-tailless mode was flown supersonically with gentle maneuvering and subsonically in precision approaches and ground attack profiles. Pilot ratings and a full set of flight test measurements were recorded. This report describes the results obtained and emphasizes the lessons learned from the X-31A flight test experiment. Sensor-related issues and their importance to a quasi-tailless simulation and to ultimately controlling a directionally unstable vehicle are assessed. The X-31A quasi-tailless flight test experiment showed that tailless and reduced tail fighter aircraft are definitely feasible. When the capability is designed into the airplane from the beginning, the benefits have the potential to outweigh the added complexity required.
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Consideration of dynamic loads on the vertical tail by the theory of flat yawing maneuvers
NASA Technical Reports Server (NTRS)
Boshar, John; Davis, Philip
1946-01-01
Dynamic yawing effects on vertical tail loads are considered by a theory of flat yawing maneuvers. A comparison is shown between computed loads and the loads measured in flight in a fighter airplane. The dynamic effects were investigated on a large flying boat for both an abrupt rudder deflection and a sinusoidal rudder deflection. Only a moderate amount of control deflection was found to be necessary to attain the ultimate design load on the tail. In order to take into account dynamic effects in design, specifications of yawing maneuverability or control movement are needed.
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NASA Technical Reports Server (NTRS)
Gilbert, W. P.; Nguyen, L. T.; Vangunst, R. W.
1976-01-01
A piloted, fixed-base simulation was conducted to study the effectiveness of some automatic control system features designed to improve the stability and control characteristics of fighter airplanes at high angles of attack. These features include an angle-of-attack limiter, a normal-acceleration limiter, an aileron-rudder interconnect, and a stability-axis yaw damper. The study was based on a current lightweight fighter prototype. The aerodynamic data used in the simulation were measured on a 0.15-scale model at low Reynolds number and low subsonic Mach number. The simulation was conducted on the Langley differential maneuvering simulator, and the evaluation involved representative combat maneuvering. Results of the investigation show the fully augmented airplane to be quite stable and maneuverable throughout the operational angle-of-attack range. The angle-of-attack/normal-acceleration limiting feature of the pitch control system is found to be a necessity to avoid angle-of-attack excursions at high angles of attack. The aileron-rudder interconnect system is shown to be very effective in making the airplane departure resistant while the stability-axis yaw damper provided improved high-angle-of-attack roll performance with a minimum of sideslip excursions.
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Pilot Human Factors in Stall/Spin Accidents of Supersonic Fighter Aircraft
NASA Technical Reports Server (NTRS)
Anderson, S. B.; Enevoldson, E. K.; Nguyen, L. T.
1983-01-01
A study has been made of pilot human factors related to stall/spin accidents of supersonic fighter aircraft. The military specifications for flight at high angles of attack are examined. Several pilot human factors problems related to stall/spin are discussed. These problems include (1) unsatisfactory nonvisual warning cues; (2) the inability of the pilot to quickly determine if the aircraft is spinning out of control, or to recognize the type of spin; (3) the inability of the pilot to decide on and implement the correct spin recovery technique; (4) the inability of the pilot to move, caused by high angular rotation; and (5) the tendency of pilots to wait too long in deciding to abandon the irrecoverable aircraft. Psycho-physiological phenomena influencing pilot's behavior in stall/spin situations include (1) channelization of sensory inputs, (2) limitations in precisely controlling several muscular inputs, (3) inaccurate judgment of elapsed time, and (4) disorientation of vestibulo-ocular inputs. Results are given of pilot responses to all these problems in the F14A, F16/AB, and F/A-18A aircraft. The use of departure spin resistance and automatic spin prevention systems incorporated on recent supersonic fighters are discussed. These systems should help to improve the stall/spin accident record with some compromise in maneuverability.
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X-36 Being Prepared on Lakebed for First Flight
NASA Technical Reports Server (NTRS)
1997-01-01
Lit by the rays of the morning sunrise on Rogers Dry Lake, adjacent to NASA's Dryden Flight Research Center, Edwards, California, technicians prepare the remotely-piloted X-36 Tailless Fighter Agility Research Aircraft for its first flight in May 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 on Ground after Radio and Telemetry Tests
NASA Technical Reports Server (NTRS)
1996-01-01
A UH-1 helicopter lowers the X-36 Tailless Fighter Agility Research Aircraft to the ground after radio frequency and telemetry tests above Rogers Dry Lake at NASA Dryden Flight Research Center, Edwards, California, in November 1996. The purpose of taking the X-36 aloft for the radio and telemetry system checkouts was to test the systems more realistically while airborne. More taxi and radio frequency tests were conducted before the aircraft's first flight in early 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 in Flight over Mojave Desert during 5th Flight
NASA Technical Reports Server (NTRS)
1997-01-01
The unusual lines of the X-36 Tailless Fighter Agility Research Aircraft contrast sharply with the desert floor as the remotely-piloted aircraft flies over the Mojave Desert on a June 1997 research flight. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 Carried Aloft by Helicopter during Radio and Telemetry Tests
NASA Technical Reports Server (NTRS)
1996-01-01
A Bell UH-1 helicopter lifts the X-36 Tailless Fighter Agility Research Aircraft off the ground for radio frequency and telemetry tests above Rogers Dry Lake at NASA Dryden Flight Research Center, Edwards, California, in November 1996. The purpose of taking the X-36 aloft for the radio and telemetry system checkouts was to test the systems more realistically while airborne. More taxi and radio frequency tests were conducted before the aircraft's first flight in early 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed/ high angles of attack and at high speed/low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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NASA Technical Reports Server (NTRS)
1997-01-01
The remotely-piloted X-36 Tailless Fighter Agility Research Aircraft climbs out from Rogers Dry Lake at the Dryden Flight Research Center on its first flight in May 1997. The aircraft flew for five minutes and reached an altitude of approximately 4,900 feet. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 in Flight near Edge of Rogers Dry Lake during 5th Flight
NASA Technical Reports Server (NTRS)
1997-01-01
This photo shows the X-36 Tailless Fighter Agility Research Aircraft passing over the edge of Rogers Dry Lake as the remotely-piloted aircraft flies over Edwards Air Force Base on a June 1997 research flight. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 Being Prepared on Lakebed for First Flight
NASA Technical Reports Server (NTRS)
1997-01-01
Lit by the rays of the morning sunrise on Rogers Dry Lake, adjacent to NASA's Dryden Flight Research Center, Edwards, California, a technician prepares the remotely-piloted X-36 Tailless Fighter Agility Research Aircraft for its first flight on May 17, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 on Ramp Viewed from Above
NASA Technical Reports Server (NTRS)
1997-01-01
This look-down view of the X-36 Tailless Fighter Agility Research Aircraft on the ramp at NASA's Dryden Flight Research Center, Edwards, California, clearly shows the unusual wing and canard design of the remotely-piloted aircraft. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 Being Prepared on Lakebed for First Flight
NASA Technical Reports Server (NTRS)
1997-01-01
Lit by the rays of the morning sunrise on Rogers Dry Lake, adjacent to NASA's Dryden Flight Research Center, Edwards, California, technicians prepares the remotely-piloted X-36 Tailless Fighter Agility Research Aircraft for its first flight on May 17, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 Carried Aloft by Helicopter during Radio and Telemetry Tests
NASA Technical Reports Server (NTRS)
1996-01-01
A Bell UH-1 helicopter lifts the X-36 Tailless Fighter Agility Research Aircraft off the ground for radio frequency and telemetry tests above Rogers Dry Lake at NASA Dryden Flight Research Center, Edwards, California, in November 1996. The purpose of taking the X-36 aloft for the radio and telemetry system checkouts was to test the systems more realistically while airborne. More taxi and radio frequency tests were conducted before the aircraft's first flight in early 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 Being Prepared on Lakebed for First Flight
NASA Technical Reports Server (NTRS)
1997-01-01
As the sun creeps above the horizon of Rogers Dry Lake at NASA's Dryden Flight Research Center, Edwards, California, technicians make final preparations for the first flight of the X-36 Tailless Fighter Agility Research Aircraft. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 Tailless Fighter Agility Research Aircraft in flight
NASA Technical Reports Server (NTRS)
1997-01-01
The lack of a vertical tail on the X-36 technology demonstrator is evident as the remotely piloted aircraft flies a low-altitude research flight above Rogers Dry Lake at Edwards Air Force Base in the California desert on October 30, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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NASA Technical Reports Server (NTRS)
1996-01-01
NASA and McDonnell Douglas Corporation (MDC) personnel steady the X-36 Tailless Fighter Agility Research Aircraft following arrival at NASA Dryden Flight Research Center, Edwards, California, on July 2, 1996. The aircraft is being hoisted out of it's shipping crate. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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NASA Technical Reports Server (NTRS)
Mann, M. J.; Mercer, C. E.
1986-01-01
A transonic computational analysis method and a transonic design procedure have been used to design the wing and the canard of a forward-swept-wing fighter configuration for good transonic maneuver performance. A model of this configuration was tested in the Langley 16-Foot Transonic Tunnel. Oil-flow photographs were obtained to examine the wind flow patterns at Mach numbers from 0.60 to 0.90. The transonic theory gave a reasonably good estimate of the wing pressure distributions at transonic maneuver conditions. Comparison of the forward-swept-wing configuration with an equivalent aft-swept-wing-configuration showed that, at a Mach number of 0.90 and a lift coefficient of 0.9, the two configurations have the same trimmed drag. The forward-swept wing configuration was also found to have trimmed drag levels at transonic maneuver conditions which are comparable to those of the HiMAT (highly maneuverable aircraft technology) configuration and the X-29 forward-swept-wing research configuration. The configuration of this study was also tested with a forebody strake.
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NASA Technical Reports Server (NTRS)
Howe, Dennis G.
1993-01-01
Just prior to its being EFM modulated (i.e., converted to eight-to-fourteen channel data by the EFM encoder) and written to a Compact Disc (CD), information that passes through the CIRC Block Encoder is grouped into 33-byte blocks referred to as EFM frames. Twenty four of the bytes that make up a given EFM frame are user data that was input into the CIRC encoder at various (different) times, 4 of the bytes of this same EFM frame were created by the C2 ECC encoder (each at a different time), and another 4 were created by the C1 ECC encoder (again, each at a different time). The one remaining byte of the given EFM frame, which is known as the EFM frame C&D (for Control & Display) byte, carries information that identifies which portion of the current disc program track the given EFM frame belongs to and also specifies the location of the given EFM frame on the disc (in terms of a time stamp that has a resolution of l/75th second, or 98 EFM frames). (Note: since the program track and time information is stored as a 98-byte word, a logical group consisting of 98 consecutive EFM frames must be read, and their respective C&D bytes must be catenated and decoded, before the program track identification and time position information that pertains to the entire block of 98 EFM frames can be obtained.) The C&D byte is put at the start (0th byte) of an EFM frame in real time; its placement completes the construction of the EFM frame - it is assigned just before the EFM frame enters the EFM encoder. Four distinct blocks of data are referred to: 24-byte User Input Data Blocks; 28-byte C2 words; 32-byte C1 words; and 33-byte EFM frames.
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A Study on Aircraft Engine Control Systems for Integrated Flight and Propulsion Control
NASA Astrophysics Data System (ADS)
Yamane, Hideaki; Matsunaga, Yasushi; Kusakawa, Takeshi
A flyable FADEC system engineering model incorporating Integrated Flight and Propulsion Control (IFPC) concept is developed for a highly maneuverable aircraft and a fighter-class engine. An overview of the FADEC system and functional assignments for its components such as the Engine Control Unit (ECU) and the Integrated Control Unit (ICU) are described. Overall system reliability analysis, convex analysis and multivariable controller design for the engine, fault detection/redundancy management, and response characteristics of a fuel system are addressed. The engine control performance of the FADEC is demonstrated by hardware-in-the-loop simulation for fast acceleration and thrust transient characteristics.
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Application of MCT Failure Criterion using EFM
2010-03-26
because HELIUS:MCT™ does not facilitate this. Attempts have been made to use ABAQUS native thermal expansion model combined in addition to Helius-MCT... ABAQUS using a user defined element subroutine EFM. Comparisons have been made between the analysis results using EFM-MCT code and HELIUS:MCT™ code...using the Element-Failure Method (EFM) in ABAQUS . The EFM-MCT has been implemented in ABAQUS using a user defined element subroutine EFM. Comparisons
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X-36 in Flight over Mojave Desert
NASA Technical Reports Server (NTRS)
1997-01-01
The unusual lines of the X-36 technology demonstrator contrast sharply with the desert floor as the remotely piloted aircraft scoots across the California desert at low altitude during a research flight on October 30, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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X-36 Taking off During First Flight
NASA Technical Reports Server (NTRS)
1997-01-01
The X-36 remotely piloted aircraft lifts off on its first flight, May 17, 1997, at NASA's Dryden Flight Research Center, Edwards, California. The aircraft flew for five minutes and reached an altitude of approximately 4,900 feet. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.
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Characterization of Enterococcus faecium bacteriophage IME-EFm5 and its endolysin LysEFm5.
Gong, Pengjuan; Cheng, Mengjun; Li, Xinwei; Jiang, Haiyan; Yu, Chuang; Kahaer, Nadire; Li, Juecheng; Zhang, Lei; Xia, Feifei; Hu, Liyuan; Sun, Changjiang; Feng, Xin; Lei, Liancheng; Han, Wenyu; Gu, Jingmin
2016-05-01
Due to the worldwide prevalence of antibiotic resistant strains, phages therapy has been revitalized recently. In this study, an Enterococcus faecium phage named IME-EFm5 was isolated from hospital sewage. Whole genomic sequence analysis demonstrated that IME-EFm5 belong to the Siphoviridae family, and has a double-stranded genome of 42,265bp (with a 35.51% G+C content) which contains 70 putative coding sequences. LysEFm5, the endolysin of IME-EFm5, contains an amidase domain in its N-terminal and has a wider bactericidal spectrum than its parental phage IME-EFm5, including 7 strains of vancomycin-resistant E. faecium. The mutagenesis analysis revealed that the zinc ion binding residues (H27, H132, and C140), E90, and T138 are required for the catalysis of LysEFm5. However, the antibacterial activity of LysEFm5 is zinc ion independent, which is inconsistent with most of other amidase members. The phage lysin LysEFm5 might be an alternative treatment strategy for infections caused by multidrug-resistant E. faecium. Copyright © 2016 Elsevier Inc. All rights reserved.
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NASA Astrophysics Data System (ADS)
Ishii, M.; Rigopoulos, N.; Poolton, N. R. J.; Hamilton, B.
2007-02-01
A new technique named X-EFM that measures the x-ray absorption fine structure (XAFS) of nanometer objects was developed. In X-EFM, electrostatic force microscopy (EFM) is used as an x-ray absorption detector, and photoionization induced by x-ray absorption of surface electron trapping sites is detected by EFM. An EFM signal with respect to x-ray photon energy provides the XAFS spectra of the trapping sites. We adopted X-EFM to observe Si oxide thin films. An edge jump shift intrinsic to the X-EFM spectrum was found, and it was explained with a model where an electric field between the trapping site and probe deepens the energy level of the inner-shell. A scanning probe under x-rays with fixed photon energy provided the chemical state mapping on the surface.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
J.H. Frantz Jr; K.G. Brown; W.K. Sawyer
2006-03-01
This report summarizes the work performed under contract DE-FC26-03NT41743. The primary objective of this study was to develop tools that would allow Underground Gas Storage (UGS) operators to use wellhead electronic flow measurement (EFM) data to quickly and efficiently identify trends in well damage over time, thus aiding in the identification of potential causes of the damage. Secondary objectives of this work included: (1) To assist UGS operators in the evaluation of hardware and software requirements for implementing an EFM system similar to the one described in this report, and (2) To provide a cost-benefit analysis framework UGS operators canmore » use to evaluate economic benefits of installing wellhead EFM systems in their particular fields. Assessment of EFM data available for use, and selection of the specific study field are reviewed. The various EFM data processing tasks, including data collection, organization, extraction, processing, and interpretation are discussed. The process of damage assessment via pressure transient analysis of EFM data is outlined and demonstrated, including such tasks as quality control, semi-log analysis, and log-log analysis of pressure transient test data extracted from routinely collected EFM data. Output from pressure transient test analyses for 21 wells is presented, and the interpretation of these analyses to determine the timing of damage development is demonstrated using output from specific study wells. Development of processing and interpretation modules to handle EFM data interpretation in horizontal wells is also a presented and discussed. A spreadsheet application developed to aid underground gas storage operators in the selection of EFM equipment is presented, discussed, and used to determine the cost benefit of installing EFM equipment in a gas storage field. Recommendations for future work related to EFM in gas storage fields are presented and discussed.« less
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Electronic Freight Management (EFM) Governance
DOT National Transportation Integrated Search
2012-03-01
The Electronic Freight Management (EFM) initiative is a USDOT-sponsored project that applies web technologies to improve data and message transmissions between supply chain partners. This report describes a new EFM Governance Model and the necessary ...
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F-18 simulation with Simulation Group Lead Martha Evans at the controls
NASA Technical Reports Server (NTRS)
1993-01-01
Simulation Group Leader Martha Evans is seen here at the controls of the F-18 aircraft simulator at NASA's Dryden Flight Research Center, Edwards, California. Simulators offer a safe and economical alternative to actual flights to gather data, as well as being excellent facilities for pilot practice and training. The highly modified F-18 airplane flew 383 flights over a nine year period and demonstrated concepts that greatly increase fighter maneuverability. Among concepts proven in the aircraft is the use of paddles to direct jet engine exhaust in cases of extreme altitudes where conventional control surfaces lose effectiveness. Another concept, developed by NASA Langley Research Center, is a deployable wing-like surface installed on the nose of the aircraft for increased right and left (yaw) control on nose-high flight angles.
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Riel, Jonathan M.; Yamauchi, Yasuhiro; Huang, Thomas T.F.; Grove, John; Ward, Monika A.
2011-01-01
Previous attempts to maintain human spermatozoa without freezing were based on short-term storage in component-rich medium and led to fast decline in motility and increased incidence of chromosome breaks. Here we report a new method in which sperm are maintained without freezing in an electrolyte-free medium (EFM) composed of glucose and bovine serum albumin. Human sperm were stored in EFM or human tubal fluid medium (HTFM) or were cryopreserved, and their motility, viability, and DNA integrity were examined at different intervals. Cryopreservation led to significant decline in sperm motility and viability and induced DNA fragmentation. Sperm stored in EFM maintained motility and viability for up to 4 and 7 wk, respectively, much longer than sperm stored in HTFM (<2 and <4 wk, respectively). DNA integrity, assessed with comet assay, was also maintained significantly better in EFM than in HTFM. One-week storage in EFM yielded motility and viability similar to that of cryopreserved sperm, but DNA integrity was significantly higher, resembling that of fresh sperm. After several weeks of storage in EFM, sperm were able to activate oocytes, undergo chromatin remodeling, and form normal zygotic chromosomes after intracytoplasmic sperm injection. This study demonstrated that human spermatozoa can be stored in EFM without freezing for several weeks while maintaining motility, viability, and chromatin integrity and that 1-wk storage in EFM offers better protection of sperm DNA integrity than cryopreservation. Sperm storage in EFM may become a viable option for the physicians working in assisted reproduction technology clinics, which would avoid cryodamage. PMID:21593474
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Freitas, Ana R.; Tedim, Ana P.; Novais, Carla; Ruiz-Garbajosa, Patricia; Werner, Guido; Laverde-Gomez, Jenny A.; Cantón, Rafael; Peixe, Luísa; Baquero, Fernando; Coque, Teresa M.
2010-01-01
Enterococcus faecium has increasingly been reported as a nosocomial pathogen since the early 1990s, presumptively associated with the expansion of a human-associated Enterococcus faecium polyclonal subcluster known as clonal complex 17 (CC17) that has progressively acquired different antibiotic resistance (ampicillin and vancomycin) and virulence (espEfm, hylEfm, and fms) traits. We analyzed the presence and the location of a putative glycoside hydrolase hylEfm gene among E. faecium strains obtained from hospitalized patients (255 patients; outbreak, bacteremic, and/or disseminated isolates from 23 countries and five continents; 1986 to 2009) and from nonclinical origins (isolates obtained from healthy humans [25 isolates], poultry [30], swine [90], and the environment [55]; 1999 to 2007). Clonal relatedness was established by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Plasmid analysis included determination of content and size (S1-PFGE), transferability (filter mating), screening of Rep initiator proteins (PCR), and location of vanA, vanB, ermB, and hylEfm genes (S1/I-CeuI hybridization). Most E. faecium isolates contained large plasmids (>150 kb) and showed variable contents of van, hylEfm, or espEfm. The hylEfm gene was associated with megaplasmids (170 to 375 kb) of worldwide spread (ST16, ST17, and ST18) or locally predominant (ST192, ST203, ST280, and ST412) ampicillin-resistant CC17 clones collected in the five continents since the early 1990s. All but one hylEfm-positive isolate belonged to the CC17 polyclonal subcluster. The presence of hylEfm megaplasmids among CC17 from Europe, Australia, Asia, and Africa since at least the mid-1990s was documented. This study further demonstrates the pandemic expansion of particular CC17 clones before acquisition of vancomycin resistance and putative virulence traits and describes the presence of megaplasmids in most of the contemporary E. faecium isolates with different origins. PMID:20385861
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How important is thermodynamics for identifying elementary flux modes?
Peres, Sabine; Jolicœur, Mario; Moulin, Cécile
2017-01-01
We present a method for computing thermodynamically feasible elementary flux modes (tEFMs) using equilibrium constants without need of internal metabolite concentrations. The method is compared with the method based on a binary distinction between reversible and irreversible reactions. When all reactions are reversible, adding the constraints based on equilibrium constants reduces the number of elementary flux modes (EFMs) by a factor of two. Declaring in advance some reactions as irreversible, based on reliable biochemical expertise, can in general reduce the number of EFMs by a greater factor. But, even in this case, computing tEFMs can rule out some EFMs which are biochemically irrelevant. We applied our method to two published models described with binary distinction: the monosaccharide metabolism and the central carbon metabolism of Chinese hamster ovary cells. The results show that the binary distinction is in good agreement with biochemical observations. Moreover, the suppression of the EFMs that are not consistent with the equilibrium constants appears to be biologically relevant. PMID:28222104
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Shape memory alloy TiNi actuators for twist control of smart wing designs
NASA Astrophysics Data System (ADS)
Jardine, A. Peter; Kudva, Jayanth N.; Martin, Christopher A.; Appa, Kari
1996-05-01
On high performance military aircraft, small changes in both wing twist and wing camber have the potential to provide substantial payoffs in terms of additional lift and enhanced maneuverability. To achieve the required wing shape, actuators made of smart materials are currently being studied under an ARPA/WL contract for a subscale model of a fighter aircraft. The use of the shape memory alloy TiNi for wing twist actuation was investigated using shape memory effect (SME) torque tube actuator configurations. The actuator configurations were sized to fit inside a 16% scale model of an aircraft wing and the torque's supplied to the wing were similarly calculated from full-scale requirements. The actuator systems were tested in a conventional laboratory setting. Design and calibration of the actuators for wing twist are discussed.
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A half century of electronic fetal monitoring and bioethics: silence speaks louder than words.
Sartwelle, Thomas P; Johnston, James C; Arda, Berna
2017-01-01
Bioethics abolished the prevailing Hippocratic tenet instructing physicians to make treatment decisions, replacing it with autonomy through informed consent. Informed consent allows the patient to choose treatment after options are explained by the physician. The appearance of bioethics in 1970 coincided with the introduction of electronic fetal monitoring (EFM), which evolved to become the fetal surveillance modality of choice for virtually all women in labor. Autonomy rapidly pervaded all medical procedures, but there was a clear exemption for EFM. Even today, EFM remains immune to the doctrine of informed consent despite continually mounting evidence which proves the procedure is nothing more than myth, illusion and junk science that subjects mothers and babies alike to increased risks of morbidity and mortality. And ethicists have remained utterly silent through a half century of EFM misuse. Our article explores this egregious ethical failure by reviewing EFM's lack of clinical efficacy, discussing the EFM related harm to mothers and babies, and focusing on the reasons that this obstetrical procedure eluded the revolutionary change from the Hippocratic tradition to autonomy through informed consent.
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Surface potential extraction from electrostatic and Kelvin-probe force microscopy images
NASA Astrophysics Data System (ADS)
Xu, Jie; Chen, Deyuan; Li, Wei; Xu, Jun
2018-05-01
A comprehensive comparison study of electrostatic force microscopy (EFM) and Kelvin probe force microscopy (KPFM) is conducted in this manuscript. First, it is theoretically demonstrated that for metallic or semiconductor samples, both the EFM and KPFM signals are a convolution of the sample surface potential with their respective transfer functions. Then, an equivalent point-mass model describing cantilever deflection under distributed loads is developed to reevaluate the cantilever influence on detection signals, and it is shown that the cantilever has no influence on the EFM signal, while it will affect the KPFM signal intensity but not change the resolution. Finally, EFM and KPFM experiments are carried out, and the surface potential is extracted from the EFM and KPFM images by deconvolution processing, respectively. The extracted potential intensity is well consistent with each other and the detection resolution also complies with the theoretical analysis. Our work is helpful to perform a quantitative analysis of EFM and KPFM signals, and the developed point-mass model can also be used for other cantilever beam deflection problems.
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Miller, Lisa A; Miller, David A
2013-01-01
Intrapartum electronic fetal monitoring (EFM) is one of the most common procedures in obstetrics. Current consensus statements provide clinicians with a common language for EFM as well as provide a basis for a simplified approach to interpretation and management. This article presents a summary of the content and implementation of a statewide initiative in interdisciplinary EFM education and training designed to give clinicians of all backgrounds a shared mental model in EFM. Challenges to implementation at individual institutions may include physician and nursing engagement as well as time and cost constraints.
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Ogunyemi, Dotun; Jovanovski, Andrew; Friedman, Perry; Sweatman, Brittany; Madan, Ichchha
2018-04-06
The objective of this study is to evaluate the associations of electronic fetal heart rate monitoring (EFM) patterns and adverse neonatal outcomes Study design: From 2013 to 2016; 12,067 term, singleton deliveries in labor ≥2 h with abnormal EFM defined as absent accelerations, variable, late or prolonged decelerations, tachycardia, bradycardia, or minimal variability were analyzed as any documentation during labor, in first hour and last hour of labor. Outcomes were composite neonatal adverse outcomes, neonatal intensive care unit (NICU) admission, neonatal hypoxia, neonatal hypoglycemia, umbilical artery pH, and base excess. Independent associations were ascertained using regression analysis. Significant independent associations occurred between any abnormal EFM during the last hour and five adverse neonatal outcomes; between abnormal EFM at any time and one adverse neonatal outcome while there was none with the first hour of labor. In the last hour, accelerations had significant negative associations with three adverse neonatal outcomes, while prolonged decelerations, late decelerations, tachycardia, and bradycardia had significant positive associations with three adverse neonatal outcomes. Throughout labor, increasing accelerations events were significantly negatively correlated with all adverse neonatal outcomes, while increasing frequency of late, variable, and prolonged decelerations were positively associated with five adverse neonatal outcomes. Hierarchical analysis showed that bradycardia/tachycardia contributed only 0.8%, while all EFM periodic changes contributed 1%; the addition of the frequencies of abnormal EFM events contributed 0.6% to the variance in umbilical artery pH and base excess. Terminal EFM patterns are independently associated with neonatal outcomes. Accelerations are protective of adverse neonatal outcomes. Increasing frequency of EFM patterns overtime contributes to neonatal outcome.
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Klamt, Steffen; Regensburger, Georg; Gerstl, Matthias P; Jungreuthmayer, Christian; Schuster, Stefan; Mahadevan, Radhakrishnan; Zanghellini, Jürgen; Müller, Stefan
2017-04-01
Elementary flux modes (EFMs) emerged as a formal concept to describe metabolic pathways and have become an established tool for constraint-based modeling and metabolic network analysis. EFMs are characteristic (support-minimal) vectors of the flux cone that contains all feasible steady-state flux vectors of a given metabolic network. EFMs account for (homogeneous) linear constraints arising from reaction irreversibilities and the assumption of steady state; however, other (inhomogeneous) linear constraints, such as minimal and maximal reaction rates frequently used by other constraint-based techniques (such as flux balance analysis [FBA]), cannot be directly integrated. These additional constraints further restrict the space of feasible flux vectors and turn the flux cone into a general flux polyhedron in which the concept of EFMs is not directly applicable anymore. For this reason, there has been a conceptual gap between EFM-based (pathway) analysis methods and linear optimization (FBA) techniques, as they operate on different geometric objects. One approach to overcome these limitations was proposed ten years ago and is based on the concept of elementary flux vectors (EFVs). Only recently has the community started to recognize the potential of EFVs for metabolic network analysis. In fact, EFVs exactly represent the conceptual development required to generalize the idea of EFMs from flux cones to flux polyhedra. This work aims to present a concise theoretical and practical introduction to EFVs that is accessible to a broad audience. We highlight the close relationship between EFMs and EFVs and demonstrate that almost all applications of EFMs (in flux cones) are possible for EFVs (in flux polyhedra) as well. In fact, certain properties can only be studied with EFVs. Thus, we conclude that EFVs provide a powerful and unifying framework for constraint-based modeling of metabolic networks.
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Klamt, Steffen; Gerstl, Matthias P.; Jungreuthmayer, Christian; Mahadevan, Radhakrishnan; Müller, Stefan
2017-01-01
Elementary flux modes (EFMs) emerged as a formal concept to describe metabolic pathways and have become an established tool for constraint-based modeling and metabolic network analysis. EFMs are characteristic (support-minimal) vectors of the flux cone that contains all feasible steady-state flux vectors of a given metabolic network. EFMs account for (homogeneous) linear constraints arising from reaction irreversibilities and the assumption of steady state; however, other (inhomogeneous) linear constraints, such as minimal and maximal reaction rates frequently used by other constraint-based techniques (such as flux balance analysis [FBA]), cannot be directly integrated. These additional constraints further restrict the space of feasible flux vectors and turn the flux cone into a general flux polyhedron in which the concept of EFMs is not directly applicable anymore. For this reason, there has been a conceptual gap between EFM-based (pathway) analysis methods and linear optimization (FBA) techniques, as they operate on different geometric objects. One approach to overcome these limitations was proposed ten years ago and is based on the concept of elementary flux vectors (EFVs). Only recently has the community started to recognize the potential of EFVs for metabolic network analysis. In fact, EFVs exactly represent the conceptual development required to generalize the idea of EFMs from flux cones to flux polyhedra. This work aims to present a concise theoretical and practical introduction to EFVs that is accessible to a broad audience. We highlight the close relationship between EFMs and EFVs and demonstrate that almost all applications of EFMs (in flux cones) are possible for EFVs (in flux polyhedra) as well. In fact, certain properties can only be studied with EFVs. Thus, we conclude that EFVs provide a powerful and unifying framework for constraint-based modeling of metabolic networks. PMID:28406903
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Historical background and design evolution of the transonic aircraft technology supercritical wing
NASA Technical Reports Server (NTRS)
Ayers, T. G.; Hallissy, J. B.
1981-01-01
Two dimensional wind tunnel test results obtained for supercritical airfoils indicated that substantial improvements in aircraft performance at high subsonic speeds could be achieved by shaping the airfoil to improve the supercritical flow above the upper surface. Significant increases in the drag divergence Mach number, the maximum lift coefficient for buffer onset, and the Mach number for buffet onset at a given lift coefficient were demonstrated for the supercritical airfoil, as compared with a NACA 6 series airfoil of comparable thickness. These trends were corroborated by results from three dimensional wind tunnel and flight tests. Because these indicated extensions of the buffet boundaries could provide significant improvements in the maneuverability of a fighter airplane, an exploratory wind tunnel investigation was initiated which demonstrated that significant aerodynamic improvements could be achieved from the direct substitution of a supercritical airfoil on a variable wing sweep multimission airplane model.
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Application of smart materials for improved flight performance of military aircraft
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kudva, J.; Appa, K.; Martin, C.
1995-12-31
This paper discusses on-going work under an ARPA/WL contract to Northrop Grumman entitled {open_quotes}Smart Structures and Materials Development - Smart Wing.{close_quotes} The contract addresses the application of smart materials and smart Structures concepts to enhance the aerodynamic and maneuver performance of military aircraft. Various concepts for adaptive wing and control surfaces are being studied. Specifically, (a) wing span-wise twist control using built-in shape- memory alloy torquing mechanism and (b) cambered leading edge and trailing edge control surfaces using hybrid piezoelectric and SMA actuation, are being evaluated for a 20% model of a modem day fighter aircraft. The potential benefits ofmore » the designs include increased lift for short take-offs, improved high-speed maneuverability, and enhanced control surface effectiveness. These benefits will be quantified by testing the sub-scale model in a transonic wind tunnel next year.« less
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Perpetuating Myths, Fables, and Fairy Tales: A Half Century of Electronic Fetal Monitoring
Sartwelle, Thomas P.; Johnston, James C.; Arda, Berna
2015-01-01
Electronic fetal monitoring (EFM) entered clinical medical practice at the same time bioethics became reality. Bioethics changed the medical ethics landscape by replacing the traditional Hippocratic benign paternalism with patient autonomy, informed consent, beneficence, and nonmaleficence. But EFM use represents the polar opposite of bioethics' revered principles—it has been documented for half a century to be completely ineffectual, used without informed consent, and harmful to mothers and newborns alike. Despite EFM's ethical misuse, there has been no outcry from the bioethical world. Why? This article answers that question, discussing EFM's history and the reasons it was issued an ethics pass. And it explores the reason that even today mothers are still treated with blatant medical paternalism, deprived of autonomy and informed consent, and subjected to real medical risks under the guise that EFM is an essential safety device when in fact it is used almost solely to protect physicians and hospitals from cerebral palsy lawsuits. PMID:28824967
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Characterization of Dielectric Nanocomposites with Electrostatic Force Microscopy
El Khoury, D.; Fedorenko, V.; Castellon, J.; Laurentie, J.-C.; Fréchette, M.; Ramonda, M.
2017-01-01
Nanocomposites physical properties unexplainable by general mixture laws are usually supposed to be related to interphases, highly present at the nanoscale. The intrinsic dielectric constant of the interphase and its volume need to be considered in the prediction of the effective permittivity of nanodielectrics, for example. The electrostatic force microscope (EFM) constitutes a promising technique to probe interphases locally. This work reports theoretical finite-elements simulations and experimental measurements to interpret EFM signals in front of nanocomposites with the aim of detecting and characterizing interphases. According to simulations, we designed and synthesized appropriate samples to verify experimentally the ability of EFM to characterize a nanoshell covering nanoparticles, for different shell thicknesses. This type of samples constitutes a simplified electrostatic model of a nanodielectric. Experiments were conducted using either DC or AC-EFM polarization, with force gradient detection method. A comparison between our numerical model and experimental results was performed in order to validate our predictions for general EFM-interphase interactions. PMID:29109811
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A depth-first search algorithm to compute elementary flux modes by linear programming.
Quek, Lake-Ee; Nielsen, Lars K
2014-07-30
The decomposition of complex metabolic networks into elementary flux modes (EFMs) provides a useful framework for exploring reaction interactions systematically. Generating a complete set of EFMs for large-scale models, however, is near impossible. Even for moderately-sized models (<400 reactions), existing approaches based on the Double Description method must iterate through a large number of combinatorial candidates, thus imposing an immense processor and memory demand. Based on an alternative elementarity test, we developed a depth-first search algorithm using linear programming (LP) to enumerate EFMs in an exhaustive fashion. Constraints can be introduced to directly generate a subset of EFMs satisfying the set of constraints. The depth-first search algorithm has a constant memory overhead. Using flux constraints, a large LP problem can be massively divided and parallelized into independent sub-jobs for deployment into computing clusters. Since the sub-jobs do not overlap, the approach scales to utilize all available computing nodes with minimal coordination overhead or memory limitations. The speed of the algorithm was comparable to efmtool, a mainstream Double Description method, when enumerating all EFMs; the attrition power gained from performing flux feasibility tests offsets the increased computational demand of running an LP solver. Unlike the Double Description method, the algorithm enables accelerated enumeration of all EFMs satisfying a set of constraints.
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Lilliu, S; Maragliano, C; Hampton, M; Elliott, M; Stefancich, M; Chiesa, M; Dahlem, M S; Macdonald, J E
2013-11-27
We report a simple technique for mapping Electrostatic Force Microscopy (EFM) bias sweep data into 2D images. The method allows simultaneous probing, in the same scanning area, of the contact potential difference and the second derivative of the capacitance between tip and sample, along with the height information. The only required equipment consists of a microscope with lift-mode EFM capable of phase shift detection. We designate this approach as Scanning Probe Potential Electrostatic Force Microscopy (SPP-EFM). An open-source MATLAB Graphical User Interface (GUI) for images acquisition, processing and analysis has been developed. The technique is tested with Indium Tin Oxide (ITO) and with poly(3-hexylthiophene) (P3HT) nanowires for organic transistor applications.
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A depth-first search algorithm to compute elementary flux modes by linear programming
2014-01-01
Background The decomposition of complex metabolic networks into elementary flux modes (EFMs) provides a useful framework for exploring reaction interactions systematically. Generating a complete set of EFMs for large-scale models, however, is near impossible. Even for moderately-sized models (<400 reactions), existing approaches based on the Double Description method must iterate through a large number of combinatorial candidates, thus imposing an immense processor and memory demand. Results Based on an alternative elementarity test, we developed a depth-first search algorithm using linear programming (LP) to enumerate EFMs in an exhaustive fashion. Constraints can be introduced to directly generate a subset of EFMs satisfying the set of constraints. The depth-first search algorithm has a constant memory overhead. Using flux constraints, a large LP problem can be massively divided and parallelized into independent sub-jobs for deployment into computing clusters. Since the sub-jobs do not overlap, the approach scales to utilize all available computing nodes with minimal coordination overhead or memory limitations. Conclusions The speed of the algorithm was comparable to efmtool, a mainstream Double Description method, when enumerating all EFMs; the attrition power gained from performing flux feasibility tests offsets the increased computational demand of running an LP solver. Unlike the Double Description method, the algorithm enables accelerated enumeration of all EFMs satisfying a set of constraints. PMID:25074068
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Hoerst, B J; Fairman, J
2000-06-01
Electronic fetal monitoring (EFM) is one example of a biomedical technology that rapidly diffused from an experimental innovation into a standard medical practice. First developed in the 1950s, EFM became commercially available in the early 1970s and quickly transformed intrapartum obstetrical practice. Assessments and interventions, which practitioners had previously based primarily on laboring women's subjective reports of bodily sensations, were now being based on quantifiable objective data from uterine activity and fetal heart rate transducers. Despite concerns of over-medicalization of the natural event of birth, iatrogenesis related to the increased incidence of operative deliveries, and escalating costs, EFM became widely accepted as routine and necessary by both practitioners and patients. By presenting the confident expectations and cautious reservations of various practitioners and patients to EFM, this article explores the rapid diffusion of EFM within the social context of the 1970s. A special focus is given to the perspective of intrapartum obstetrical nurses, because they have been the primary users of this perinatal technology since its introduction.
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HIMAT Inlet Model in the 8- by 6-Foot Supersonic Wind Tunnel
1979-02-21
A Highly Maneuverable Aircraft Technology (HiMAT) inlet model installed in the test section of the 8- by 6-Foot Supersonic Wind Tunnel at the National Aeronautics and Space Administration (NASA) Lewis Research Center. Engineers at the Ames Research Center, Dryden Flight Research Center, and Rockwell International designed two pilotless subscale HiMAT vehicles in the mid-1970s to study new design concepts for fighter aircraft in the transonic realm without risking the lives of test pilots. The aircraft used sophisticated technologies such as advanced aerodynamics, composite materials, digital integrated propulsion control, and digital fly-by-wire control systems. In late 1977 NASA Lewis studied the HiMAT’s General Electric J85-21 jet engine in the Propulsion Systems Laboratory. The researchers charted the inlet quality with various combinations anti-distortion screens. HiMAT employed a relatively short and curved inlet compared to actual fighter jets. In the spring of 1979, Larry Smith led an in-depth analysis of the HiMAT inlet in the 8- by 6 tunnel. The researchers installed vortex generators to battle flow separation in the diffuser. The two HiMAT aircraft performed 11 hours of flying over the course of 26 missions from mid-1979 to January 1983 at Dryden and Ames. Although the HiMAT vehicles were considered to be overly complex and expensive, the program yielded a wealth of data that would validate computer-based design tools.
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An Active Smart Material Control System for F/A-18 Buffet Alleviation
NASA Technical Reports Server (NTRS)
Sheta, Essam F.; Moses, Robert W.; Huttsell, Lawrence J.; Harrand, Vincent J.
2003-01-01
The vertical tail buffet problem of fighter aircraft occurs at high angles of attack when the vortical flow breaks down ahead of the vertical tails resulting in unsteady and unbalanced pressure loads on the vertical tails. The buffet loads imposed upon the vertical tails resulted in a premature fatigue failure of the tails, and consequently limits the performance and super maneuverability of twin-tail fighter aircraft. An active smart material control system using distributed piezoelectric actuators has been developed for buffet alleviation and is presented. The inboard and outboard surfaces of the vertical tail are equipped with piezoelectric actuators to control the buffet responses in the first bending and torsion modes. The electrodynamics of the piezoelectric actuators are expressed with a three-dimensional finite-element model. A single-input-single-output controller is designed to drive the active piezoelectric actuators. High-fidelity multidisciplinary analysis modules for the fluid dynamics, structure dynamics, electrodynamics of the piezoelectric actuators, control law, fluid structure interfacing, and grid motion are integrated into a multidisciplinary computing environment that controls the temporal synchronization of the analysis modules. At 30 degree angle of attack, RMS values of tip acceleration are reduced by as much as 12%. The peak values of the power spectral density of tail-tip acceleration are reduced by as much as 22% in the first bending mode and by as much as 82% in the first torsion mode. The actively controlled piezoelectric actuators were also effective in adding damping at wide range of angles of attack.
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Electronic freight management (EFM) standards strategy
DOT National Transportation Integrated Search
2006-04-01
The EFM initiative is a U.S. Department of Transportation (DOT)-sponsored research effort aimed at improving the operating efficiency, safety, and security of freight movement. The initiative involves conducting a deployment test using Web services t...
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Xing, Hua; Zhang, Lirong; Ma, Jinshu; Liu, Zhen; Song, Changlong; Liu, Yuxia
2018-01-01
Lapatinib and capecitabine have been widely used in the therapy of breast cancer. However, long-term use of lapatinib and capecitabine often causes the most common side effect diarrhea, which limit the medicine use. Fructus mume (F. mume) has been proved to be effective to treat chronic diarrhea with few side effects. The compounds from F. mume were extracted by using an ethanol method. Extracts of F. mume (EFM) were analyzed by HPLC. We investigated the protective effects of EFM on the diarrhea caused by lapatinib and capecitabine. From March 1st, 2016 to June 1st, 2017, 208 breast cancer patients with diarrhea caused by lapatinib and capecitabine were recruited. The patients were evenly assigned into two groups: EG group (the patients took 100 mg EFM daily) and CG group (the patients took placebo daily). The effects of EFM on diarrhea and gastrointestinal symptoms were measured by a semiquantitative method seven-point Likert scale. Overall quality of life was measured by SF-36 questionnaire and Hospital Anxiety and Depression Scale (HADS). The HPLC analysis showed that there were three components in EFM, including citric acid, 5-hydroxymethylfurfural (5-HMF), and chlorogenic acid. Breast cancer types were observed by using Hematoxylin and eosin (H&E) stain. The breast cancer can be divided into leaflet, gland and fibroblast types. Patient age, skin metastases, treatment, and grade 1 diarrhea were significant risk factors associated with for grade 2 diarrhea. EFM reduced diarrhea and gastrointestinal symptoms by reducing the average scores of the diarrhea symptom and seven-point Likert scale, and improved life quality of patients significantly by improving SF-36 scores and reducing HADS scores when compared to that in the CG group after 6-week therapy and further 4-week follow-up (P < 0.05). EFM may be a potential choice for the diarrhea therapy in breast cancer patients. PMID:29875660
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Electronic Freight Management Case Studies : a Summary of Results
DOT National Transportation Integrated Search
2012-04-01
The Electronic Freight Management (EFM) initiative is a USDOT-sponsored project that applies Web technologies that improve data and message transmissions between supply chain partners. The EFM implementation case studies contained in this document ex...
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DOT National Transportation Integrated Search
2009-03-01
Effective innovation in information technology (IT) may be the most important tool for the private and public sectors to respond to international supply chain capacity constraints and congestion. Electronic Freight Management (EFM) technologies are m...
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Performance Evaluation Method for Dissimilar Aircraft Designs
NASA Technical Reports Server (NTRS)
Walker, H. J.
1979-01-01
A rationale is presented for using the square of the wingspan rather than the wing reference area as a basis for nondimensional comparisons of the aerodynamic and performance characteristics of aircraft that differ substantially in planform and loading. Working relationships are developed and illustrated through application to several categories of aircraft covering a range of Mach numbers from 0.60 to 2.00. For each application, direct comparisons of drag polars, lift-to-drag ratios, and maneuverability are shown for both nondimensional systems. The inaccuracies that may arise in the determination of aerodynamic efficiency based on reference area are noted. Span loading is introduced independently in comparing the combined effects of loading and aerodynamic efficiency on overall performance. Performance comparisons are made for the NACA research aircraft, lifting bodies, century-series fighter aircraft, F-111A aircraft with conventional and supercritical wings, and a group of supersonic aircraft including the B-58 and XB-70 bomber aircraft. An idealized configuration is included in each category to serve as a standard for comparing overall efficiency.
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NASA Technical Reports Server (NTRS)
1995-01-01
This photos shows the remains of the number one X-31 following a mishap on 19 January 1995. Two X-31A demonstartor aircraft were built to explore Enhanced Fighter Manueverability (EFM). The aircraft demonstrated techniques to allow close-in aerial combat beyond normal flight envelope parameters. The X-31 EFM demonstrator program was the first international effort to buid an X-plane. The aircraft was designed and funded jointly by the U.S. Defense Advanced Research Projects Agency (DARPA) and the German Ministry of Defense. Design and construction of components and systems was split between Rockwell International in the United States and Messerschmitt-Bolkow-Blohm (MBB) in the Federal Republic of Germany. Other participants included the U.S. Air Force, U.S. Navy, and NASA. Fianl assembly took place at Rockwell's North American Aircraft Division. The flight test progarm included an international team of pilots from Rockwell, MBB, and the U.S. and German armed forces. The demonstrator aircraft were designed for subsonic flight only. Overall program costs were reduced by using as amny off-the-shelf components as possible. The weight of the airframe was reduced through extensive use of graphite/epoxy thermosplastics in construction of aerodynamic surfaces and the forward fuselage. the design included fully movable canards, thrust-vectoring paddles, and a cranked composite delta wing. The first X-31A (Bu. No. 164584) was rolled out from Rockwell's Palmdale, Californai facility on 1 March 1990. Rockwell chief test pilot Norman 'Ken' Dyson made the first flight on 11 October 1990. Aircraft 584 completed a total of 292 flights during the EFM test program. Aircraft 584 was lost on 19 January 1995 while returning to Edwards Air Force Base on its third flight of the day. German test pilot Karl-Heinz Langwas nearing the end of a one-hour mission to measure aircraft parameters. The aircraft was flying at 21,000 feet and 141 knots in straight and level flight with the thrust-vectoring and high angle-of-attack (AOA) flight control mode turned off. Lang noticed erroneous airspeed readings (207 knots indicated airspeed at 20 degrees AOA). About a minute later, while executing the pre-landing checklist, the X-31 began a rapidly increasing series of pitch oscillations, ending up at about 20 degrees past vertical. This was followed by a sharp roll. Lang ejected at 18,050 feet, and parachuted to safety with some injuries. The X-31 crashed in a sparsely-populated area a mile and a half north of the base boundary. Investigators later determined that ice in the air data probe caused the erroneous readings that led to the accident.
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GPU-accelerated element-free reverse-time migration with Gauss points partition
NASA Astrophysics Data System (ADS)
Zhou, Zhen; Jia, Xiaofeng; Qiang, Xiaodong
2018-06-01
An element-free method (EFM) has been demonstrated successfully in elasticity, heat conduction and fatigue crack growth problems. We present the theory of EFM and its numerical applications in seismic modelling and reverse time migration (RTM). Compared with the finite difference method and the finite element method, the EFM has unique advantages: (1) independence of grids in computation and (2) lower expense and more flexibility (because only the information of the nodes and the boundary of the concerned area is required). However, in EFM, due to improper computation and storage of some large sparse matrices, such as the mass matrix and the stiffness matrix, the method is difficult to apply to seismic modelling and RTM for a large velocity model. To solve the problem of storage and computation efficiency, we propose a concept of Gauss points partition and utilise the graphics processing unit to improve the computational efficiency. We employ the compressed sparse row format to compress the intermediate large sparse matrices and attempt to simplify the operations by solving the linear equations with CULA solver. To improve the computation efficiency further, we introduce the concept of the lumped mass matrix. Numerical experiments indicate that the proposed method is accurate and more efficient than the regular EFM.
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Electronic fetal monitoring: a Canadian survey.
Davies, B L; Niday, P A; Nimrod, C A; Drake, E R; Sprague, A E; Trépanier, M J
1993-01-01
OBJECTIVES: To determine the current status of electronic fetal monitoring (EFM) in Canadian teaching and nonteaching hospitals, to review the medical and nursing standards of practice for EFM and to determine the availability of EFM educational programs. DESIGN: National survey in 1989. PARTICIPANTS: The directors of nursing at the 737 hospitals providing obstetric care were sent a questionnaire and asked to have it completed by the most appropriate staff member. The response rate was 80.5% (593/737); 44 hospitals did not have deliveries in 1988 and were excluded. The remaining hospitals varied in size from 8 to 1800 (mean 162.1) beds and had 1 to 7500 (mean 617.1) births in 1988; 18.8% were teaching hospitals. RESULTS: Of the 549 hospitals 419 (76.3%) reported having at least 1 monitor (range 1 to 30; mean 2.6); the mean number of monitors per hospital was higher in the teaching hospitals than in the nonteaching hospitals (6.2 v. 1.7). Manitoba had the lowest mean number of monitors per hospital (1.1) and Ontario the highest (3.7). In 71.8% of the hospitals with monitors almost all of the obstetric patients were monitored at some point during labour. However, 21.6% of the hospitals with monitors had no policy on EFM practice. The availability of EFM educational programs for physicians and nurses varied according to hospital size, type and region. CONCLUSIONS: Most Canadian hospitals providing obstetric services have electronic fetal monitors and use them frequently. Although substantial research has questioned the benefits of EFM, further definitive research is required. In the meantime, a national committee should be established to develop multidisciplinary guidelines for intrapartum fetal assessment. PMID:8485677
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Wu, C D; Wang, L; Hu, C X; He, M H
2013-01-01
The single-solute and bisolute sorption behaviour of phenol and trichloroethylene, two organic compounds with different structures, onto cetyltrimethylammonium bromide (CTAB)-montmorillonite was studied. The monolayer Langmuir model (MLM) and empirical Freundlich model (EFM) were applied to the single-solute sorption of phenol or trichloroethylene from water onto monolayer or multilayer CTAB-montmorillonite. The parameters contained in the MLM and EFM were determined for each solute by fitting to the single-solute isotherm data, and subsequently utilized in binary sorption. The extended Langmuir model (ELM) coupled with the single-solute MLM and the ideal adsorbed solution theory (IAST) coupled with the single-solute EFM were used to predict the binary sorption of phenol and trichloroethylene onto CTAB-montmorillonite. It was found that the EFM was better than the MLM at describing single-solute sorption from water onto CTAB-montmorillonite, and the IAST was better than the ELM at describing the binary sorption from water onto CTAB-montmorillonite.
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Georgieva, Antoniya; Payne, Stephen J; Moulden, Mary; Redman, Christopher W G
2011-01-01
We applied computerized methods to assess the Electronic Fetal Monitoring (EFM) in labor. We analyzed retrospectively the last hour of EFM for 1,370 babies, delivered by emergency Cesarean sections before the onset of pushing (data collected at the John Radcliffe Hospital, Oxford, UK). There were two cohorts according to the reason for intervention: (a) fetal distress, n(1) = 524 and (b) failure to progress and/or malpresentation, n(2) = 846. The cohorts were compared in terms of classical EFM features (baseline, decelerations, variability and accelerations), computed by a dedicated Oxford system for automated analysis--OxSys. In addition, OxSys was employed to simulate current clinical guidelines for the classification of fetal monitoring, i.e. providing in real time a three-tier grading system of the EFM (normal, indeterminate, or abnormal). The computerized features and the simulated guidelines corresponded well to the clinical management and to the actual labor outcome (measured by umbilical arterial pH).
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Update on Fetal Monitoring: Overview of Approaches and Management of Category II Tracings.
Raghuraman, Nandini; Cahill, Alison G
2017-12-01
Electronic fetal monitoring (EFM) is widely used to assess fetal status in labor. Use of intrapartum continuous EFM is associated with a lower risk of neonatal seizures but a higher risk of cesarean or operative delivery. Category II fetal heart tracings (FHTs) are indeterminate in their ability to predict fetal acidemia. Certain patterns of decelerations and variability within this category may be predictive of neonatal morbidity. Adjunct tests of fetal well-being can be used during labor to further triage patients. Intrauterine resuscitation techniques should target the suspected etiology of intrapartum fetal hypoxia. Clinical factors play a role in the interpretation of EFM. Copyright © 2017 Elsevier Inc. All rights reserved.
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Energy measurement using flow computers and chromatography
DOE Office of Scientific and Technical Information (OSTI.GOV)
Beeson, J.
1995-12-01
Arkla Pipeline Group (APG), along with most transmission companies, went to electronic flow measurement (EFM) to: (1) Increase resolution and accuracy; (2) Real time correction of flow variables; (3) Increase speed in data retrieval; (4) Reduce capital expenditures; and (5) Reduce operation and maintenance expenditures Prior to EFM, mechanical seven day charts were used which yielded 800 pressure and differential pressure readings. EFM yields 1.2-million readings, a 1500 time improvement in resolution and additional flow representation. The total system accuracy of the EFM system is 0.25 % compared with 2 % for the chart system which gives APG improved accuracy.more » A typical APG electronic measurement system includes a microprocessor-based flow computer, a telemetry communications package, and a gas chromatograph. Live relative density (specific gravity), BTU, CO{sub 2}, and N{sub 2} are updated from the chromatograph to the flow computer every six minutes which provides accurate MMBTU computations. Because the gas contract length has changed from years to monthly and from a majority of direct sales to transports both Arkla and its customers wanted access to actual volumes on a much more timely basis than is allowed with charts. The new electronic system allows volumes and other system data to be retrieved continuously, if EFM is on Supervisory Control and Data Acquisition (SCADA) or daily if on dial up telephone. Previously because of chart integration, information was not available for four to six weeks. EFM costs much less than the combined costs of telemetry transmitters, pressure and differential pressure chart recorders, and temperature chart recorder which it replaces. APG will install this equipment on smaller volume stations at a customers expense. APG requires backup measurement on metering facilities this size. It could be another APG flow computer or chart recorder, or the other companies flow computer or chart recorder.« less
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Panesso, Diana; Reyes, Jinnethe; Rincón, Sandra; Díaz, Lorena; Galloway-Peña, Jessica; Zurita, Jeannete; Carrillo, Carlos; Merentes, Altagracia; Guzmán, Manuel; Adachi, Javier A.; Murray, Barbara E.; Arias, Cesar A.
2010-01-01
Enterococcus faecium has emerged as an important nosocomial pathogen worldwide, and this trend has been associated with the dissemination of a genetic lineage designated clonal cluster 17 (CC17). Enterococcal isolates were collected prospectively (2006 to 2008) from 32 hospitals in Colombia, Ecuador, Perú, and Venezuela and subjected to antimicrobial susceptibility testing. Genotyping was performed with all vancomycin-resistant E. faecium (VREfm) isolates by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. All VREfm isolates were evaluated for the presence of 16 putative virulence genes (14 fms genes, the esp gene of E. faecium [espEfm], and the hyl gene of E. faecium [hylEfm]) and plasmids carrying the fms20-fms21 (pilA), hylEfm, and vanA genes. Of 723 enterococcal isolates recovered, E. faecalis was the most common (78%). Vancomycin resistance was detected in 6% of the isolates (74% of which were E. faecium). Eleven distinct PFGE types were found among the VREfm isolates, with most belonging to sequence types 412 and 18. The ebpAEfm-ebpBEfm-ebpCEfm (pilB) and fms11-fms19-fms16 clusters were detected in all VREfm isolates from the region, whereas espEfm and hylEfm were detected in 69% and 23% of the isolates, respectively. The fms20-fms21 (pilA) cluster, which encodes a putative pilus-like protein, was found on plasmids from almost all VREfm isolates and was sometimes found to coexist with hylEfm and the vanA gene cluster. The population genetics of VREfm in South America appear to resemble those of such strains in the United States in the early years of the CC17 epidemic. The overwhelming presence of plasmids encoding putative virulence factors and vanA genes suggests that E. faecium from the CC17 genogroup may disseminate in the region in the coming years. PMID:20220167
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Wang, Yaohui; Ural, Ani
2018-06-01
A key length scale of interest in assessing the fracture resistance of bone is the submicroscale which is composed of mineralized collagen fibrils (MCF) and extra-fibrillar matrix (EFM). Although the processes through which the submicroscale constituents of bone contribute to the fracture resistance in bone have been identified, the extent of the modifications in submicroscale mechanical response due to the changes in individual properties of MCFs and EFM has not been determined. As a result, this study aims to quantify the influence of individual MCF and EFM material property modifications on the mechanical behavior (elastic modulus, ultimate strength, and resistance to failure) of bone at the submicroscale using a novel finite element modeling approach that incorporate 3D networks of MCFs with three different orientations as well as explicit representation of EFM. The models were evaluated under tensile loading in transverse (representing MCF separation) and longitudinal (representing MCF rupture) directions. The results showed that the apparent elastic modulus at the submicroscale under both loading directions for all orientations was only affected by the change in the elastic modulus of MCFs. MCF separation and rupture strengths were mainly dependent on the ultimate strength of EFM and MCFs, respectively, with minimal influence of other material properties. The extent of damage during MCF separation increased with increasing ultimate strength of EFM and decreased with increasing fracture energy of EFM with minimal contribution from elastic modulus of MCFs. For MCF rupture, there was an almost one-to-one linear relationship between the percent change in fracture energy of MCFs and the percent change in the apparent submicroscale fracture energy. The ultimate strength and elastic modulus of MCFs had moderate to limited influence on the MCF rupture fracture energy. The results of this study quantified the extent of changes that may be seen in the energy dissipation processes during MCF rupture and separation relative to the changes in the individual constituents of the tissue. This new knowledge significantly contributes to improving the understanding of how the material property alterations at the submicroscale that can occur due to diseases, age-related changes, and treatments affect the fracture processes at larger length scales. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Buffet induced structural/flight-control system interaction of the X-29A aircraft
NASA Technical Reports Server (NTRS)
Voracek, David F.; Clarke, Robert
1991-01-01
High angle-of-attack flight regime research is currently being conducted for modern fighter aircraft at the NASA Ames Research Center's Dryden Flight Research Facility. This flight regime provides enhanced maneuverability to fighter pilots in combat situations. Flight research data are being acquired to compare and validate advanced computational fluid dynamic solutions and wind-tunnel models. High angle-of-attack flight creates unique aerodynamic phenomena including wing rock and buffet on the airframe. These phenomena increase the level of excitation of the structural modes, especially on the vertical and horizontal stabilizers. With high gain digital flight-control systems, this structural response may result in an aeroservoelastic interaction. A structural interaction on the X-29A aircraft was observed during high angle-of-attack flight testing. The roll and yaw rate gyros sensed the aircraft's structural modes at 11, 13, and 16 Hz. The rate gyro output signals were then amplified through the flight-control laws and sent as commands to the flaperons and rudder. The flight data indicated that as the angle of attack increased, the amplitude of the buffet on the vertical stabilizer increased, which resulted in more excitation to the structural modes. The flight-control system sensors and command signals showed this increase in modal power at the structural frequencies up to a 30 degree angle-of-attack. Beyond a 30 degree angle-of-attack, the vertical stabilizer response, the feedback sensor amplitude, and control surface command signal amplitude remained relatively constant. Data are presented that show the increased modal power in the aircraft structural accelerometers, the feedback sensors, and the command signals as a function of angle of attack. This structural interaction is traced from the aerodynamic buffet to the flight-control surfaces.
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F-18 HARV research pilot Dana Purifoy
NASA Technical Reports Server (NTRS)
1996-01-01
Dana D. Purifoy is an aerospace research pilot at NASA's Dryden Flight Research Center, Edwards, California. He joined NASA in August 1994. Purifoy is a former Air Force test pilot who served as a project pilot in the joint NASA/Air Force X-29 Forward Swept Wing research program conducted at Dryden from 1984 to 1991. His most recent assignment in the Air Force was flying U-2 aircraft as a test pilot at Air Force Plant 42, Palmdale, CA. In addition to flying the X-29 at Dryden as an Air Force pilot, Purifoy also served as project pilot and joint test force director with the AFTI F-16 (Advanced Fighter Technology Integration/F-16) program, also located at Dryden. Before his assignments as project pilot on the X-29 and AFTI/F-16 aircraft, Purifoy was chief of the Academics Systems Branch at the Air Force Test Pilot School at Edwards. Prior to becoming a test pilot, he flew F-111 and F-16 aircraft in Great Britain and Germany. He has accumulated 3800 hours of flying time in his career. The final flight for the F-18 High Alpha Research Vehicle (HARV) took place at NASA Dryden on May 29, 1996. The highly modified F-18 airplane flew 383 flights over a nine year period and demonstrated concepts that greatly increase fighter maneuverability. Among concepts proven in the aircraft is the use of paddles to direct jet engine exhaust in cases of extreme altitudes where conventional control surfaces lose effectiveness. Another concept, developed by NASA Langley Research Center, is a deployable wing-like surface installed on the nose of the aircraft for increased right and left (yaw) control on nose-high flight angles.
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ERIC Educational Resources Information Center
Banta, H. David; Thacker, Stephen B.
This report focuses on electronic fetal monitoring (EFM)--a technology that was developed during the 1960s and has rapidly spread into use in clinical obstetrics. The report includes a review of the extensive published literature on EFM and related subjects. It also contains original calculations concerning the technique's specificity and…
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Actuated forebody strake controls for the F-18 high alpha research vehicle
NASA Technical Reports Server (NTRS)
Murri, Daniel G.; Shah, Gautam H.; Dicarlo, Daniel J.; Trilling, Todd W.
1993-01-01
A series of ground-based studies have been conducted to develop actuated forebody strake controls for flight test evaluations using the NASA F-18 High-Alpha Research Vehicle. The actuated forebody strake concept has been designed to provide increased levels of yaw control at high angles of attack where conventional rudders become ineffective. Results are presented from tests conducted with the flight-test strake design, including static and dynamic wind-tunnel tests, transonic wind-tunnel tests, full-scale wind-tunnel tests, pressure surveys, and flow visualization tests. Results from these studies show that a pair of conformal actuated forebody strakes applied to the F-18 HARV can provide a powerful and precise yaw control device at high angles of attack. The preparations for flight testing are described, including the fabrication of flight hardware and the development of aircraft flight control laws. The primary objectives of the flight tests are to provide flight validation of the groundbased studies and to evaluate the use of this type of control to enhance fighter aircraft maneuverability.
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A modified elastic foundation contact model for application in 3D models of the prosthetic knee.
Pérez-González, Antonio; Fenollosa-Esteve, Carlos; Sancho-Bru, Joaquín L; Sánchez-Marín, Francisco T; Vergara, Margarita; Rodríguez-Cervantes, Pablo J
2008-04-01
Different models have been used in the literature for the simulation of surface contact in biomechanical knee models. However, there is a lack of systematic comparisons of these models applied to the simulation of a common case, which will provide relevant information about their accuracy and suitability for application in models of the implanted knee. In this work a comparison of the Hertz model (HM), the elastic foundation model (EFM) and the finite element model (FEM) for the simulation of the elastic contact in a 3D model of the prosthetic knee is presented. From the results of this comparison it is found that although the nature of the EFM offers advantages when compared with that of the HM for its application to realistic prosthetic surfaces, and when compared with the FEM in CPU time, its predictions can differ from FEM in some circumstances. These differences are considerable if the comparison is performed for prescribed displacements, although they are less important for prescribed loads. To solve these problems a new modified elastic foundation model (mEFM) is proposed that maintains basically the simplicity of the original model while producing much more accurate results. In this paper it is shown that this new mEFM calculates pressure distribution and contact area with accuracy and short computation times for toroidal contacting surfaces. Although further work is needed to confirm its validity for more complex geometries the mEFM is envisaged as a good option for application in 3D knee models to predict prosthetic knee performance.
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Yan, Ying; Zhao, Hui; Chen, Cuihua; Zou, Lisi; Liu, Xunhong; Chai, Chuan; Wang, Chengcheng; Shi, Jingjing; Chen, Shuyu
2018-03-13
Eucommia ulmoides Oilv. (EU), also called Du-zhong, is a classical traditional Chinese medicine. Its bark, leaf, and male flower are all used for medicinal purposes, called Eucommiae Cortex (EC), Eucommiae Folium (EF), and Eucommiae Flos Male (EFM). In order to study the difference in synthesis and the accumulation of metabolites in different parts of EU, a reliable method based on ultra-fast liquid chromatography tandem triple quadrupole mass spectrometry (UFLC-QTRAP-MS/MS) was developed for the simultaneous determination of a total of 21 constituents, including two lignans, 6 iridoids, 6 penylpropanoids, 6 flavonoids, and one phenol in the samples (EC, EF, and EFM). Furthermore, principal component analysis (PCA) was performed to evaluate and classify the samples according to the contents of these 21 constituents. All of the results demonstrated that the chemical compositions in EC, EF, and EFM were significantly different and the differential constituents (i.e., aucubin, geniposidic acid, chlorogenic acid, pinoresinol-di- O -β-d-glucopyranoside, geniposide, cryptochlorogenic acid, rutin, and quercetin) were remarkably associated with sample classifications. The research will provide the basic information for revealing the laws of metabolite accumulation in EC, EF, and EFM from the same origin.
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Occhipinti, Andrea; Maffei, Massimo E
2013-10-01
Chlorophyll and chlorophyll degradation products were observed in the two-spotted spider mite (Tetranychus urticae) using epifluorescence microscopy (EFM) and confocal laser scanning microscopy (CLSM). A clear red fluorescence (EFM) and a fluorescence induced by a laser wavelength of 650 nm (CLSM) were observed. In the lateral caeca, in the ventriculus and in the excretory organ, a bright light blue fluorescence was observed in close association with chlorophyll by using EFM. The same material can be localized with CLSM by using a laser with a wavelength of 488 nm. By comparison with synthetic guanine, this bright fluorescence is supposed to be guanine. The presence of guanine fluorescence in the mite pellets confirms this hypothesis. A possible mechanism for guanine formation is discussed.
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Extra-fibrillar matrix mechanics of annulus fibrosus in tension and compression.
Cortes, Daniel H; Elliott, Dawn M
2012-07-01
The annulus fibrosus (AF) of the disk is a highly nonlinear and anisotropic material that undergoes a complex combination of loads in multiple orientations. The tensile mechanical behavior of AF in the lamellar plane is dominated by collagen fibers and has been accurately modeled using exponential functions. On the other hand, AF mechanics perpendicular to the lamella, in the radial direction, depend on the properties of the ground matrix with little to no fiber contribution. The ground matrix is mainly composed of proteoglycans (PG), which are negatively charged macromolecules that maintain the tissue hydration via osmotic pressure. The mechanical response of the ground matrix can be divided in the contribution of osmotic pressure and an elastic solid part known as extra-fibrillar matrix (EFM). Mechanical properties of the ground matrix have been measured using tensile and confined compression tests. However, EFM mechanics have not been measured directly. The objective of this study was to measure AF nonlinear mechanics of the EFM in tension and compression. To accomplish this, a combination of osmotic swelling and confined compression in disk radial direction, perpendicular to the lamella, was used. For this type of analysis, it was necessary to define a stress-free reference configuration. Thus, a brief analysis on residual stress in the disk and a procedure to estimate the reference configuration are presented. The proposed method was able to predict similar swelling deformations when using different loading protocols and models for the EFM, demonstrating its robustness. The stress-stretch curve of the EFM was linear in the range 0.9 < λ₃ < 1.3 with an aggregate modulus of 10.18±3.32 kPa; however, a significant nonlinearity was observed for compression below 0.8. The contribution of the EFM to the total aggregate modulus of the AF decreased from 70 to 30% for an applied compression of 50% of the initial thickness. The properties obtained in this study are essential for constitutive and finite element models of the AF and disk and can be applied to differentiate between functional degeneration effects such as PG loss and stiffening due to cross-linking.
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Galloway-Peña, Jessica R.; Nallapareddy, Sreedhar R.; Arias, Cesar A.; Eliopoulos, George M.; Murray, Barbara E.
2009-01-01
Background The Enterococcus faecium genogroup, referred to as clonal complex 17 (CC17), seems to possess multiple determinants that increase its ability to survive and cause disease in nosocomial environments. Methods Using 53 clinical and geographically diverse US E. faecium isolates dating from 1971 to 1994 we determined the multi-locus sequence type, the presence of 16 putative virulence genes (hylEfm, espEfm and fms genes), resistance to ampicillin (AMPR), vancomycin (VANR) and high-levels of gentamicin and streptomycin. Results Overall, 16 different sequence types (STs), mostly CC17 isolates, were identified in 9 different regions of the US. The earliest CC17 isolates were part of an outbreak in 1982 in Richmond, VA. Characteristics of CC17 isolates included increases in AMPR, the presence of hylEfm and espEfm, emergence of VANR and the presence of at least 13/14 fms genes. Eight out of forty-one of the early AMPR isolates, however, were not within CC17. Conclusions While not all early US AMPR isolates were clonally related, E. faecium CC17 isolates have been circulating in the US since at least 1982 and appear to have progressively acquired additional virulence and antibiotic resistance determinants, perhaps explaining the recent success of this species in the hospital environment. PMID:19821720
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Eden, Robert D; Evans, Mark I; Evans, Shara M; Schifrin, Barry S
2018-01-01
Electronic fetal monitoring (EFM) correlates poorly with neonatal outcome. We present a new metric: the "Fetal Reserve Index" (FRI), formally incorporating EFM with maternal, obstetrical, fetal risk factors, and excessive uterine activity for assessment of risk for cerebral palsy (CP). We performed a retrospective, case-control series of 50 term CP cases with apparent intrapartum neurological injury and 200 controls. All were deemed neurologically normal on admission. We compared the FRI against ACOG Category (I-III) system and long-term outcome parameters against ACOG monograph (NEACP) requirements for labor-induced fetal neurological injury. Abnormal FRI's identified 100% of CP cases and did so hours before injury. ACOG Category III identified only 44% and much later. Retrospective ACOG monograph criteria were found in at most 30% of intrapartum-acquired CP patients; only 27% had umbilical or neonatal pH <7.0. In this initial, retrospective trial, an abnormal FRI identified all cases of labor-related neurological injury more reliably and earlier than Category III, which may allow fetal therapy by intrauterine resuscitation. The combination of traditional EFM with maternal, obstetrical, and fetal risk factors creating the FRI performed much better as a screening test than EFM alone. Our quantified screening system needs further evaluation in prospective trials. © 2017 S. Karger AG, Basel.
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Neldam, S; Osler, M; Hansen, P K; Nim, J; Smith, S F; Hertel, J
1986-10-01
In a prospective clinical randomized investigation 487 women had the condition of the fetus during labour supervised by means of stethoscope (AUS), while 482 women went through labour under surveillance of electronic fetal monitoring, cardiotocography (EFM). 349 women refused to participate in the investigation (NAI) and had delivery conducted according to the normal procedures of the department (70% AUS, 30% EFM). Significantly more pathological fetal heart rate patterns (FHR) were found in the EFM group compared to the AUS group in both the first and the second stage of labour. As a result significantly more vacuum extractions were performed in the EFM group than in the AUS group, while no statistical difference was found between the groups in the incidence of acute cesarean sections carried out for asphyxia. One case of intrapartum death occurred in the AUS group. No differences were found in Apgar scores after 1 and 5 min or in neonatal morbidity at examination on the 2nd and 5th days after delivery. A tendency towards more biochemically compromised children was found in the AUS group. The specificity for both methods was found to be acceptably high (80%), while the predictive value for both methods was low (50%). More research is therefore urgently needed to evaluate supplementary investigations and parameters for the evaluation of the intrapartum fetal condition.
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Identification of aerodynamic models for maneuvering aircraft
NASA Technical Reports Server (NTRS)
Chin, Suei; Lan, C. Edward
1990-01-01
Due to the requirement of increased performance and maneuverability, the flight envelope of a modern fighter is frequently extended to the high angle-of-attack regime. Vehicles maneuvering in this regime are subjected to nonlinear aerodynamic loads. The nonlinearities are due mainly to three-dimensional separated flow and concentrated vortex flow that occur at large angles of attack. Accurate prediction of these nonlinear airloads is of great importance in the analysis of a vehicle's flight motion and in the design of its flight control system. A satisfactory evaluation of the performance envelope of the aircraft may require a large number of coupled computations, one for each change in initial conditions. To avoid the disadvantage of solving the coupled flow-field equations and aircraft's motion equations, an alternate approach is to use a mathematical modeling to describe the steady and unsteady aerodynamics for the aircraft equations of motion. Aerodynamic forces and moments acting on a rapidly maneuvering aircraft are, in general, nonlinear functions of motion variables, their time rate of change, and the history of maneuvering. A numerical method was developed to analyze the nonlinear and time-dependent aerodynamic response to establish the generalized indicial function in terms of motion variables and their time rates of change.
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HARV ANSER Flight Test Data Retrieval and Processing Procedures
NASA Technical Reports Server (NTRS)
Yeager, Jessie C.
1997-01-01
Under the NASA High-Alpha Technology Program the High Alpha Research Vehicle (HARV) was used to conduct flight tests of advanced control effectors, advanced control laws, and high-alpha design guidelines for future super-maneuverable fighters. The High-Alpha Research Vehicle is a pre-production F/A-18 airplane modified with a multi-axis thrust-vectoring system for augmented pitch and yaw control power and Actuated Nose Strakes for Enhanced Rolling (ANSER) to augment body-axis yaw control power. Flight testing at the Dryden Flight Research Center (DFRC) began in July 1995 and continued until May 1996. Flight data will be utilized to evaluate control law performance and aircraft dynamics, determine aircraft control and stability derivatives using parameter identification techniques, and validate design guidelines. To accomplish these purposes, essential flight data parameters were retrieved from the DFRC data system and stored on the Dynamics and Control Branch (DCB) computer complex at Langley. This report describes the multi-step task used to retrieve and process this data and documents the results of these tasks. Documentation includes software listings, flight information, maneuver information, time intervals for which data were retrieved, lists of data parameters and definitions, and example data plots.
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NASA Technical Reports Server (NTRS)
Boyalakuntla, Kishore; Soni, Bharat K.; Thornburg, Hugh J.; Yu, Robert
1996-01-01
During the past decade, computational simulation of fluid flow around complex configurations has progressed significantly and many notable successes have been reported, however, unsteady time-dependent solutions are not easily obtainable. The present effort involves unsteady time dependent simulation of temporally deforming geometries. Grid generation for a complex configuration can be a time consuming process and temporally varying geometries necessitate the regeneration of such grids for every time step. Traditional grid generation techniques have been tried and demonstrated to be inadequate to such simulations. Non-Uniform Rational B-splines (NURBS) based techniques provide a compact and accurate representation of the geometry. This definition can be coupled with a distribution mesh for a user defined spacing. The present method greatly reduces cpu requirements for time dependent remeshing, facilitating the simulation of more complex unsteady problems. A thrust vectoring nozzle has been chosen to demonstrate the capability as it is of current interest in the aerospace industry for better maneuverability of fighter aircraft in close combat and in post stall regimes. This current effort is the first step towards multidisciplinary design optimization which involves coupling the aerodynamic heat transfer and structural analysis techniques. Applications include simulation of temporally deforming bodies and aeroelastic problems.
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Flight test of the X-29A at high angle of attack: Flight dynamics and controls
NASA Technical Reports Server (NTRS)
Bauer, Jeffrey E.; Clarke, Robert; Burken, John J.
1995-01-01
The NASA Dryden Flight Research Center has flight tested two X-29A aircraft at low and high angles of attack. The high-angle-of-attack tests evaluate the feasibility of integrated X-29A technologies. More specific objectives focus on evaluating the high-angle-of-attack flying qualities, defining multiaxis controllability limits, and determining the maximum pitch-pointing capability. A pilot-selectable gain system allows examination of tradeoffs in airplane stability and maneuverability. Basic fighter maneuvers provide qualitative evaluation. Bank angle captures permit qualitative data analysis. This paper discusses the design goals and approach for high-angle-of-attack control laws and provides results from the envelope expansion and handling qualities testing at intermediate angles of attack. Comparisons of the flight test results to the predictions are made where appropriate. The pitch rate command structure of the longitudinal control system is shown to be a valid design for high-angle-of-attack control laws. Flight test results show that wing rock amplitude was overpredicted and aileron and rudder effectiveness were underpredicted. Flight tests show the X-29A airplane to be a good aircraft up to 40 deg angle of attack.
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X-31 Wing Storage for Shipping
1995-05-18
The right wing of the X-31 Enhanced Fighter Maneuverability Technology Demonstrator Aircraft is seen here being put into a shipping container May 18, 1995, at NASA's Dryden Flight Research Center, Edwards, California, by U.S. and German members of the program. To fit inside an Air Force Reserve C-5 transport, which was used to ferry the X-31 to Europe on May 22, 1995, the right wing had to be removed. Manching, Germany, was used as a staging base to prepare the aircraft for participation in the Paris Air Show. At the air show on June 11 through the 18th, the X-31 demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems to provide controlled flight at very high angles of attack. The aircraft arrived back at Edwards in an Air Force Reserve C-5 on June 25, 1995, and off loaded at Dryden the 27th. The X-31 aircraft was developed jointly by Rockwell International's North American Aircraft Division (now part of Boeing) and Daimler-Benz Aerospace (formerly Messerschmitt-Bolkow-Blohm), under sponsorship by the U.S. Department of Defense and the German Federal Ministry of Defense.
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Use of a Mobile Device Simulation as a Preclass Active Learning Exercise.
Keegan, Robert D; Oliver, M Cecile; Stanfill, Teresa J; Stevens, Kevin V; Brown, Gary R; Ebinger, Michael; Gay, John M
2016-01-01
Research shows that preclass activities introducing new material can increase student performance. In an effort to engage students in an active learning, preclass activity, the authors developed a mobile application. Eighty-four nursing students were assigned a preclass reading exercise, whereas 32 students completed the preclass simulation scenario on their mobile device. All students completed the same electronic fetal monitoring (EFM) quiz 1 week following the lecture. The effects of reading or simulation on student quiz performance was evaluated with a student's paired t test, using an alpha of .05. Students completing the preclass simulation scored higher on the EFM quiz, compared with students assigned the preclass reading (85% versus 70% correct answers, p = .01). Student survey data indicated that the mobile device simulation was perceived as an engaging and desirable instructional tool. Nursing students completing the mobile device EFM preclass simulation outperformed the students who were given the traditional reading assignment. Copyright 2016, SLACK Incorporated.
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Exploring metabolic pathways in genome-scale networks via generating flux modes.
Rezola, A; de Figueiredo, L F; Brock, M; Pey, J; Podhorski, A; Wittmann, C; Schuster, S; Bockmayr, A; Planes, F J
2011-02-15
The reconstruction of metabolic networks at the genome scale has allowed the analysis of metabolic pathways at an unprecedented level of complexity. Elementary flux modes (EFMs) are an appropriate concept for such analysis. However, their number grows in a combinatorial fashion as the size of the metabolic network increases, which renders the application of EFMs approach to large metabolic networks difficult. Novel methods are expected to deal with such complexity. In this article, we present a novel optimization-based method for determining a minimal generating set of EFMs, i.e. a convex basis. We show that a subset of elements of this convex basis can be effectively computed even in large metabolic networks. Our method was applied to examine the structure of pathways producing lysine in Escherichia coli. We obtained a more varied and informative set of pathways in comparison with existing methods. In addition, an alternative pathway to produce lysine was identified using a detour via propionyl-CoA, which shows the predictive power of our novel approach. The source code in C++ is available upon request.
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Reynolds Number Effects at High Angles of Attack
NASA Technical Reports Server (NTRS)
Fisher, David F.; Cobleigh, Brent R.; Banks, Daniel W.; Hall, Robert M.; Wahls, Richard A.
1998-01-01
Lessons learned from comparisons between ground-based tests and flight measurements for the high-angle-of-attack programs on the F-18 High Alpha Research Vehicle (HARV), the X-29 forward-swept wing aircraft, and the X-31 enhanced fighter maneuverability aircraft are presented. On all three vehicles, Reynolds number effects were evident on the forebodies at high angles of attack. The correlation between flight and wind tunnel forebody pressure distributions for the F-18 HARV were improved by using twin longitudinal grit strips on the forebody of the wind-tunnel model. Pressure distributions obtained on the X-29 wind-tunnel model at flight Reynolds numbers showed excellent correlation with the flight data up to alpha = 50 deg. Above (alpha = 50 deg. the pressure distributions for both flight and wind tunnel became asymmetric and showed poorer agreement, possibly because of the different surface finish of the model and aircraft. The detrimental effect of a very sharp nose apex was demonstrated on the X-31 aircraft. Grit strips on the forebody of the X-31 reduced the randomness but increased the magnitude of the asymmetry. Nose strakes were required to reduce the forebody yawing moment asymmetries and the grit strips on the flight test noseboom improved the aircraft handling qualities.
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1995-05-18
U.S. and German personnel of the X-31 Enhanced Fighter Maneuverability Technology Demonstrator aircraft program removing the right wing of the aircraft, which was ferried from Edwards Air Force Base, California, to Europe on May 22, 1995 aboard an Air Force Reserve C-5 transport. The X-31, based at the NASA Dryden Flight Research Center was ferried to Europe and flown in the Paris Air Show in June. The wing of the X-31 was removed on May 18, 1995, to allow the aircraft to fit inside the C-5 fuselage. Officials of the X-31 project used Manching, Germany, as a staging base to prepare the aircraft for the flight demonstration. At the air show, the X-31 demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems to provide controlled flight at very high angles of attack. The aircraft arrived back at Edwards in a Air Force Reserve C-5 on June 25, 1995 and off loaded at Dryden June 27. The X-31 aircraft was developed jointly by Rockwell International's North American Aircraft Division (now part of Boeing) and Daimler-Benz Aerospace (formerly Messerschmitt-Bolkow-Blohm), under sponsorship by the U.S. Department of Defense and the German Federal Ministry of Defense.
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Mechanical Removal and Rescreening of Local Screening Charges on Ferroelectric Surfaces
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tong, Sheng; Park, Woon Ik; Choi, YoonYoung
2015-01-20
We report the kinetics of screening charge removal and rescreening on periodically poled lithium niobate using charge-gradient microscopy and electrostatic force microscopy (EFM). A minimum pressure needs to be applied to initiate mechanical screening charge removal, and increasing the pressure leads to further removal of charge until a threshold is reached when all screening charges are removed. We fit all rescreening EFM contrast curves under various pressures into a universal exponential decay. The findings imply that we can control the screening degree of ferroelectric surfaces by mechanical means without affecting the polarization underneath.
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Mechanical Removal and Rescreening of Local Screening Charges at Ferroelectric Surfaces
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tong, Sheng; Park, Woon Ik; Choi, Yoon-Young
2015-01-20
In this paper, we report the kinetics of screening charge removal and rescreening on periodically poled lithium niobate using charge-gradient microscopy and electrostatic force microscopy (EFM). A minimum pressure needs to be applied to initiate mechanical screening charge removal, and increasing the pressure leads to further removal of charge until a threshold is reached when all screening charges are removed. We fit all rescreening EFM contrast curves under various pressures into a universal exponential decay. Finally, the findings imply that we can control the screening degree of ferroelectric surfaces by mechanical means without affecting the polarization underneath.
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Noguchi, Remi; Sekizawa, Yoichi; So, Mirai; Yamaguchi, Sosei; Shimizu, Eiji
2017-03-04
Notwithstanding a high expectation for internet-based cognitive behavioral therapy (iCBT) for reducing depressive symptoms, many of iCBT programs have limitations such as temporary effects and high drop-out rates, possibly due to their complexity. We examined the effects of a free, simplified, 5-minute iCBT program by comparing it with a simplified emotion-focused mindfulness (sEFM) exercise and with a waiting list control group. A total of 974 participants, who were recruited using the website of a market research company, were randomly assigned to the iCBT group, the sEFM group, and the control group. Those in the intervention arms performed each exercise for 5 weeks. The primary outcome measure was the Center for Epidemiological Studies Depression scale (CES-D) at postintervention. Secondary outcome measures were the Patient Health Questionnaire-9 (PHQ-9) and the Generalized Anxiety Disorder-7 scale (GAD-7). Intention-to-treat analyses were conducted. During postintervention assessment, there were no significant differences between the intervention arms and the control group in the CES-D, although the difference between the iCBT arm and control group was close to significance (p = 0.05) in favor of iCBT. There was a significant difference in the PHQ-9 in favor of the sEFM group compared with the control group. There were no significant differences in outcome measures between the three groups at the 6-week follow-up. Although both iCBT and sEFM have the potential to temporarily reduce depressive symptoms, substantial improvements are required to enhance and maintain their effects. This trial is registered with the UMIN Clinical Trial Registry (UMIN-CTR) (ID: UMIN000015097 ) on 1 October 2014.
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Nutritional value of enzyme- or sodium hydroxide-treated feathers from dead hens.
Kim, W K; Patterson, P H
2000-04-01
Two feather digestion processes to remove the feathers from the carcasses of dead hens were evaluated for their impact on the nutritional quality of the resulting feather meal. There were three treatments: control (untreated feathers), a feather-digesting enzyme, and NaOH treatment. Both enzyme- and NaOH-treated feathers were easily separated from the hen carcasses. The CP level of enzyme-treated feathers after autoclaving (49.90%) was significantly less than the control and NaOH-treated feathers (94.48 and 87.31%, respectively) because of elevated ether extract levels resulting from skin and abdominal fat release during the 12-h enzyme incubation. Before autoclaving, pepsin digestibilities of enzyme- and NaOH-treated feathers were significantly higher than the control. However, after autoclaving, no significant difference was found in pepsin digestibility between the control and enzyme treatments or control and NaOH treatments. The typical limiting amino acids, methionine, lysine, and histidine, in feathers were present at greater levels in the resulting enzyme-feather meal (E-FM) compared with the NaOH-feather meal (N-FM) or control-feather meal (C-FM) on a percentage of CP basis. Cystine levels, however, were significantly lower in the E-FM and N-FM compared with that of the C-FM. In chick bioassays, no significant differences were found in protein efficiency ratio (PER) and net protein ratio (NPR) among C-FM, E-FM, and N-FM. The AMEn of E-FM (4.52 kcal/g) was significantly higher than the C-FM (3.58) or N-FM (2.79). These findings indicated that although enzyme treatment could improve the nutritional quality of feathers from dead hens, NaOH treatment was a more rapid means of separating feathers from the carcass.
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Paganelli, Fernanda L.; Willems, Rob J. L.; Jansen, Pamela; Hendrickx, Antoni; Zhang, Xinglin; Bonten, Marc J. M.; Leavis, Helen L.
2013-01-01
ABSTRACT Enterococcus faecium is an important multidrug-resistant nosocomial pathogen causing biofilm-mediated infections in patients with medical devices. Insight into E. faecium biofilm pathogenesis is pivotal for the development of new strategies to prevent and treat these infections. In several bacteria, a major autolysin is essential for extracellular DNA (eDNA) release in the biofilm matrix, contributing to biofilm attachment and stability. In this study, we identified and functionally characterized the major autolysin of E. faecium E1162 by a bioinformatic genome screen followed by insertional gene disruption of six putative autolysin genes. Insertional inactivation of locus tag EfmE1162_2692 resulted in resistance to lysis, reduced eDNA release, deficient cell attachment, decreased biofilm, decreased cell wall hydrolysis, and significant chaining compared to that of the wild type. Therefore, locus tag EfmE1162_2692 was considered the major autolysin in E. faecium and renamed atlAEfm. In addition, AtlAEfm was implicated in cell surface exposure of Acm, a virulence factor in E. faecium, and thereby facilitates binding to collagen types I and IV. This is a novel feature of enterococcal autolysins not described previously. Furthermore, we identified (and localized) autolysin-independent DNA release in E. faecium that contributes to cell-cell interactions in the atlAEfm mutant and is important for cell separation. In conclusion, AtlAEfm is the major autolysin in E. faecium and contributes to biofilm stability and Acm localization, making AtlAEfm a promising target for treatment of E. faecium biofilm-mediated infections. PMID:23592262
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NASA Astrophysics Data System (ADS)
Waddell, J.; Ou, R.; Capozzi, C. J.; Gupta, S.; Parker, C. A.; Gerhardt, R. A.; Seal, K.; Kalinin, S. V.; Baddorf, A. P.
2009-12-01
Composite specimens possessing polyhedral segregated network microstructures require a very small amount of nanosize filler, <1 vol %, to reach percolation because percolation occurs by accumulation of the fillers along the edges of the deformed polymer matrix particles. In this paper, electrostatic force microscopy (EFM) and conductive atomic force microscopy (C-AFM) were used to confirm the location of the nanosize fillers and the corresponding percolating paths in polymethyl methacrylate/carbon black composites. The EFM and C-AFM images revealed that the polyhedral polymer particles were coated with filler, primarily on the edges as predicted by the geometric models provided.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Yang, I. K.; Jeong, Y. H., E-mail: yhj@postech.ac.kr; Kim, Jeehoon
2015-04-13
LuFe{sub 2}O{sub 4} is a multiferroic system which exhibits charge order, ferroelectricity, and ferrimagnetism simultaneously below ∼230 K. The ferroelectric/charge order domains of LuFe{sub 2}O{sub 4} are imaged with both piezoresponse force microscopy (PFM) and electrostatic force microscopy (EFM), while the magnetic domains are characterized by magnetic force microscopy (MFM). Comparison of PFM and EFM results suggests that the proposed ferroelectricity in LuFe{sub 2}O{sub 4} is not of usual displacive type but of electronic origin. Simultaneous characterization of ferroelectric/charge order and magnetic domains by EFM and MFM, respectively, on the same surface of LuFe{sub 2}O{sub 4} reveals that both domains havemore » irregular patterns of similar shape, but the length scales are quite different. The domain size is approximately 100 nm for the ferroelectric domains, while the magnetic domain size is much larger and gets as large as 1 μm. We also demonstrate that the origin of the formation of irregular domains in LuFe{sub 2}O{sub 4} is not extrinsic but intrinsic.« less
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Barnard, R J; Gardner, G W; Diaco, N V; Kattus, A A
1975-11-01
Near-maximal ECG stress testing and coronary artery disease risk factor analysis including blood pressure, serum cholesterol and smoking habits were conducted on a randomly selected group (N=90) of Los Angeles City Fire Fighters ranging in age from 40 to 59 yrs. The data obtained from the fire fighters were compared to data previously reported for a group of Los Angeles insurance underwriters of the same age range. Only 12% of the fire fighters had cholesterol values greater than 260 mg% while 18% of the insurance executives fell into this category. Only 2% of the fire fighters had blood pressure values greater than 160/90 mm Hg while 25% of the insurance executives were hypertensive. Thirty-two percent of the fire fighters were smokers at the time of testing as compared to 26% for the insurance executives. Only one fire fighter had all three risk factors elevated and only five had two risk factors elevated. Forty-seven of the fire fighters had no risk factors elevated. Ten percent of the fire fighters had ischemic stress tests as compared to 8% for the insurance executives. Of the nine fire fighters with ischemic stress tests one was hypertensive, one had elevated serum triglycerides, and three were smokers at the time of testing. Since the fire fighters are a medically-selected population with low risk factors for CHD, the observed incidence of ischemic stress tests is surprising and suggests that ischemic heart disease may be job associated.
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NASA Astrophysics Data System (ADS)
Oh, Y. J.; Jo, W.; Yang, Y.; Park, S.
2007-04-01
The authors report growth media dependence of electrostatic force characteristics in Escherichia coli O157:H7 biofilm through local measurement by electrostatic force microscopy (EFM). The difference values of electrostatic interaction between the bacterial surface and the abiotic surface show an exponential decay behavior during biofilm development. In the EFM data, the biofilm in the low nutrient media shows a faster decay than the biofilm in the rich media. The surface potential in the bacterial cells was changed from 957to149mV. Local characterization of extracellular materials extracted from the bacteria reveals the progress of the biofilm formation and functional complexities.
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Passive appendages improve the maneuverability of fish-like robots
NASA Astrophysics Data System (ADS)
Pollard, Beau; Tallapragada, Phanindra
2017-11-01
It is known that the passive mechanics of fish appendages play a role in the high efficiency of their swimming. A well known example of this is the experimental demonstration that a dead fish could swim upstream. However little is known about the role if any of passive deformations of a fish-like body that could aid in its maneuverability. Part of the difficulty investigating this lies in clearly separating the role of actuated body deformations and passive deformations in response to the fluid structure interaction. In this paper we compare the maneuverability of several fish shaped robotic models that possess varying numbers of passive appendages with a fish shaped robot that has no appendages. All the robots are propelled by the oscillations of an internal momentum wheel thereby eliminating any active deformations of the body. Our experiments clearly reveal the significant improvement in maneuverability of robots with passive appendages. In the broader context of swimming robots our experiments show that passive mechanisms could be useful to provide mechanical feedback that can help maneuverability and obstacle avoidance along with propulsive efficiency. This work was partly supported by a Grant from the NSF CMMI 1563315.
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Jung, Kyung-Won; Park, Dae-Seon; Hwang, Min-Jin; Ahn, Kyu-Hong
2015-09-01
In this study, the decolorization of Acid Orange 7 (AO-7) with intensified performance was obtained using hydrodynamic cavitation (HC) combined with an electric field (graphite electrodes). As a preliminary step, various HC systems were compared in terms of decolorization, and, among them, the electric field-assisted modified orifice plate HC (EFM-HC) system exhibited perfect decolorization performance within 40 min of reaction time. Interestingly, when H2O2 was injected into the EFM-HC system as an additional oxidant, the reactor performance gradually decreased as the dosing ratio increased; thus, the remaining experiments were performed without H2O2. Subsequently, an optimization process was conducted using response surface methodology with a Box-Behnken design. The inlet pressure, initial pH, applied voltage, and reaction time were chosen as operational key factors, while decolorization was selected as the response variable. The overall performance revealed that the selected parameters were either slightly interdependent, or had significant interactive effects on the decolorization. In the verification test, complete decolorization was observed under statistically optimized conditions. This study suggests that EFM-HC is a useful method for pretreatment of dye wastewater with positive economic and commercial benefits. Copyright © 2015 Elsevier B.V. All rights reserved.
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Tercjak, A; Garcia, I; Mondragon, I
2008-07-09
Novel well-defined nanostructured thermosetting systems were prepared by modification of a diglicydylether of bisphenol-A epoxy resin (DGEBA) with 10 or 15 wt% amphiphilic poly(styrene-b-ethylene oxide) block copolymer (PSEO) and 30 or 40 wt% low molecular weight liquid crystal 4'-(hexyl)-4-biphenyl-carbonitrile (HBC) using m-xylylenediamine (MXDA) as a curing agent. The competition between well-defined nanostructured materials and the ability for alignment of the liquid crystal phase in the materials obtained has been studied by atomic and electrostatic force microscopy, AFM and EFM, respectively. Based on our knowledge, this is the first time that addition of an adequate amount (10 wt%) of a block copolymer to 40 wt% HBC-(DGEBA/MXDA) leads to a well-organized nanostructured thermosetting system (between a hexagonal and worm-like ordered structure), which is also electro-responsive with high rate contrast. This behavior was confirmed using electrostatic force microscopy (EFM), by means of the response of the HBC liquid crystal phase to the voltage applied to the EFM tip. In contrast, though materials containing 15 wt% PSEO and 30 wt% HBC also form a well-defined nanostructured thermosetting system, they do not show such a high contrast between the uncharged and charged surface.
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Overview of the ARPA/WL Smart Structures and Materials Development-Smart Wing contract
NASA Astrophysics Data System (ADS)
Kudva, Jayanth N.; Jardine, A. Peter; Martin, Christopher A.; Appa, Kari
1996-05-01
While the concept of an adaptive aircraft wing, i.e., a wing whose shape parameters such as camber, wing twist, and thickness can be varied to optimize the wing shape for various flight conditions, has been extensively studied, the complexity and weight penalty of the actuation mechanisms have precluded their practical implementation. Recent development of sensors and actuators using smart materials could potentially alleviate the shortcomings of prior designs, paving the way for a practical, `smart' adaptive wing which responds to changes in flight and environmental conditions by modifying its shape to provide optimal performance. This paper presents a summary of recent work done on adaptive wing designs under an on-going ARPA/WL contract entitled `Smart Structures and Materials Development--Smart Wing.' Specifically, the design, development and planned wind tunnel testing of a 16% model representative of a fighter aircraft wing and incorporating the following features, are discussed: (1) a composite wing torque box whose span-wise twist can be varied by activating built-in shape memory alloy (SMA) torque tubes to provide increased lift and enhanced maneuverability at multiple flight conditions, (2) trailing edge control surfaces deployed using composite SMA actuators to provide smooth, hingeless aerodynamic surfaces, and (3) a suite of fiber optic sensors integrated into the wing skin which provide real-time strain and pressure data to a feedback control system.
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Electrical Measurements and Nanomechanics Using Scanning Probe Microscopy
NASA Astrophysics Data System (ADS)
Chang, Yong
2002-10-01
In the early 1980s, G. Binnig et al. invented the Scanning Tunneling Microscopy (STM) [1], making it possible to obtain atomic resolution images of conducting surfaces. After that, many different types of Scanning Probe Microscopy (SPM) were invented and some of the most useful representatives are Atomic Force Microscopy (AFM) [2], Electrostatic Force Microscopy (EFM) [3] and Kelvin Probe Force Microscopy (KPFM) [4,5]. In 1985, G. Binnig et al. [2] invented the AFM, which now is used as a fundamental tool in many fields of research. Developed from AFM, Y. Martin et al. [3] invented EFM in 1987. The development of AC mode AFM allows the detection of weak long-range forces. EFM has also been used to study other systems and phenomena, such as thin liquid films on solid surfaces [6], electrically stressed gold nanowires [7], and spatial charge distribution in quantum wires [8]. In 1991, M. Nonnenmacher et al. [5] invented Kelvin Probe Force Microscopy. KPFM is used to study any property that affects the tip-surface Contact Potential Difference (CPD), such as voltage signals in integrated circuits (IC) [9], charged grain boundaries in polycrystalline silicon [10] and surface potential variations in multilayer semiconductor devices [11]. The aim of this poster is to discuss the application of SPM to electrical measurements. The theory of SPM was presented. The AFM was firstly introduced as it was developed before the other two. The design and theory were discussed. The force-distance curve was introduced. After this EFM was presented. EFM was developed from AC mode AFM. The technique was achieved by applying a DC voltage between the tip and the sample. The design, theory and features of it were surveyed. KPFM was also discussed. KPFM was developed from EFM. The central part of this technique is to measure the CPD. Experimental measurements of SPM were described after theory part. Research work using AFM was presented. The newest technique of AFM, UHV-AFM has been used in investigating the nano-mechanical properties of different materials. Normally common AFM has shortcomings as it has either strict limit resolution or difficulties in interpreting the data from the measurements. In order to solve these problems, Ultra High Vacuum (UHV) conditions were applied to acquire quantitative results. A typical UHV-AFM uses a cantilever whose spring constant is relatively high (>100 N/m) to obtain high-resolution image. Experimental measurements using KPFM was presented after AFM. Researchers are using KPFM to acquire the topography and measuring the CPD of semiconductor or metal surfaces. Similarly as in AFM, KPFM works best in UHV environment. A typical UHV-KPFM also uses a cantilever whose spring constant is relatively high. A UHV-KPFM may be able to achieve a high resolution in CPD images. In the past 20 years many different kinds of SPM were invented and used. AFM, EFM, and KPFM are representatives of them. Researchers are still developing new techniques. However, in recent years, they pay more attention in improving the measurement accuracy instead of trying to invent new SPM. These three SPM continue to be frequently used. The current capabilities of SPM do not satisfy us completely. We still cant measure the Electrical field directly. We actually measure the capacitance gradient. There are also some other questions. This is because the electrostatic force depends very strongly on the geometry of the probe at all length scales, so any model is subject to two big problems. First, the geometry is not known with complete accuracy; and second, the tip shape can change during an experiment due to wear. In the future, maybe the problems could be overcome by using a tip with a very well defined shape, such as a carbon nanotube, for which a realistic geometrical model could be more easily constructed, and the wear could be avoided or reduced.
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Review of manual control methods for handheld maneuverable instruments.
Fan, Chunman; Dodou, Dimitra; Breedveld, Paul
2013-06-01
By the introduction of new technologies, surgical procedures have been varying from free access in open surgery towards limited access in minimal access surgery. Improving access to difficult-to-reach anatomic sites, e.g. in neurosurgery or percutaneous interventions, needs advanced maneuverable instrumentation. Advances in maneuverable technology require the development of dedicated methods enabling surgeons to stay in direct, manual control of these complex instruments. This article gives an overview of the state-of-the-art in the development of manual control methods for handheld maneuverable instruments. It categorizes the manual control methods in three levels: a) number of steerable segments, b) number of Degrees Of Freedom (DOF), and c) coupling between control motion of the handle and steering motion of the tip. The literature research was completed by using Web of Science, Scopus and PubMed. The study shows that in controlling single steerable segments, direct as well as indirect control methods have been developed, whereas in controlling multiple steerable segments, a gradual shift can be noticed from parallel and serial control to integrated control. The development of multi-segmented maneuverable instruments is still at an early stage, and an intuitive and effective method to control them has to become a primary focus in the domain of minimal access surgery.
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Hodous, T; Pizatella, T; Braddee, R; Castillo, D
2004-01-01
Objective: To review the causes of all fire fighter line-of-duty-deaths from 1998 through 2001, and present recommendations for preventing fatalities within the specific subgroup of structure related events. Methods: Fire fighter fatality data from the United States Fire Administration were reviewed and classified into three main categories of injury. Investigations conducted through the National Institute for Occupational Safety and Health (NIOSH) Fire Fighter Fatality Investigation and Prevention Program provided the basis for the recommendations presented in this paper. Results: During the time period from 1998–2001, there were 410 line-of-duty deaths among fire fighters in the United States, excluding the 343 fire fighters who died at the World Trade Center on 11 September 2001. The 410 fatalities included 191 medical (non-traumatic) deaths (47%), 75 motor vehicle related fatalities (18%), and 144 other traumatic fatalities (35%). The latter group included 68 fatalities that were associated with structures which commonly involved structural collapse, rapid fire progression, and trapped fire fighters. Conclusions: Structural fires pose particular hazards to fire fighters. Additional efforts must be directed to more effectively use what we have learned through the NIOSH investigations and recommendations from published experts in the safety community, consensus standards, and national fire safety organizations to reduce fire fighter fatalities during structural fire fighting. PMID:15314049
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Chinese Arms Production and Sales for the Third World
1991-01-01
Egypt J-6 fighter 60 Guinea Shanghai-class patrol boat 4 Kampuchea (Khmer Rouge) Type-59 MBT NA HJ-73 ATGW 200+ J-5 fighter 4 J-6 fighter 16 North Korea...Shanghai-class patrol boat 6 Tunisia Shanghai-class patrol boat 2 Zaire T-62 light tank 50 Type-56/-59/- 60 /-63 arty 80 Huanchen-class FAC(T) 4 Zambia T-59...fighter 75+ J-7 fighter 60 Chaho-class patrol boat 3 HY-2/FL-1 antishipping missile 72+ C-801 antishipping missile 100 Iraq Type-59 MBT 1000 Type-69 MBT
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Which subgroups of fire fighters are more prone to work-related diminished health requirements?
Plat, Marie-Christine J; Frings-Dresen, Monique H W; Sluiter, Judith K
2012-10-01
To determine whether certain subgroups of fire fighters are prone to work-related diminished health requirements. The health requirements for fire-fighting were tested in a workers' health surveillance (WHS) setting. These health requirements included psychological, physical and sense-related components as well as cardiovascular risk factors. The odds ratio (OR) and 95% confidence interval (95% CI) for the presence of the diminished health requirements were calculated for the subgroups of gender, professionalism and age. The prevalence of diminished psychological requirements was equivalent among the subgroups, and no significant high-risk group was identified. As compared to men fire fighters, women fire fighters were more likely to have diminished physical requirements (OR 28.5; 95% CI 12.1-66.9) and less likely to have cardiovascular risk factors (OR 0.3; 0.1-0.5). As compared to volunteer fire fighters, professionals were less likely to have diminished physical requirements (OR 0.5; 0.3-0.9), but professionals had a higher prevalence of cardiovascular risk factors with an odds ratio of 1.9 (1.1-3.2). As compared to the youngest fire fighters, the oldest fire fighters were more likely to have diminished sense-related requirements (OR 7.1; 3.4-15.2); a similar comparison could be made between oldest and middle-aged fire fighters (OR 5.1; 2.5-10.5). In addition, the oldest fire fighters were more likely to have cardiovascular risk factors when compared to the youngest (OR 4.4; 1.7-11.1) and to the middle-aged fire fighters (OR 3.1; 1.2-7.9). Subgroups (gender, professionalism and age) of fire fighters are prone to at least one specific work-related diminished health requirement. Therefore, parts of the WHS could be applied with more attention to these high-risk groups.
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Measuring wildland fire fighter performance with wearable technology.
Parker, Richard; Vitalis, Antonios; Walker, Robyn; Riley, David; Pearce, H Grant
2017-03-01
Wildland (rural) fire fighting is a physically demanding and hazardous occupation. An observational study was conducted to explore the use of new technologies for the field study of fire fighters at wildfires and to understand the work pressures of wildland fire fighting. The research was carried out with two fire fighters at real fires wearing microphones, miniature video cameras, heart rate monitors and GPS units to record their actions and location at wildfire events. The fire fighters were exposed to high physiological workloads (heart rates of up to 180 beats per minute) and walked considerable distances at the fires. Results from this study have been used in presentations to fire fighters and non-operational fire personnel to understand the pressures fire fighters are under and how others complete the fire fighting tasks. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Dehydration and acute weight gain in mixed martial arts fighters before competition.
Jetton, Adam M; Lawrence, Marcus M; Meucci, Marco; Haines, Tracie L; Collier, Scott R; Morris, David M; Utter, Alan C
2013-05-01
The purpose of this study was to characterize the magnitude of acute weight gain (AWG) and dehydration in mixed martial arts (MMA) fighters before competition. Urinary measures of hydration status and body mass were determined approximately 24 hours before and then again approximately 2 hours before competition in 40 MMA fighters (mean ± SE, age: 25.2 ± 0.65 years, height: 1.77 ± 0.01 m, body mass: 75.8 ± 1.5 kg). The AWG was defined as the amount of body weight the fighters gained in the approximately 22-hour period between the official weigh-in and the actual competition. On average, the MMA fighters gained 3.40 ± 2.2 kg or 4.4% of their body weight in the approximately 22-hour period before competition. Urine specific gravity significantly decreased (p < 0.001) from 1.028 ± 0.001 to 1.020 ± 0.001 during the approximately 22-hour rehydration period. Results demonstrated that 39% of the MMA fighters presented with a Usg of >1.021 immediately before competition indicating significant or serious dehydration. The MMA fighters undergo significant dehydration and fluctuations in body mass (4.4% avg.) in the 24-hour period before competition. Urinary measures of hydration status indicate that a significant proportion of MMA fighters are not successfully rehydrating before competition and subsequently are competing in a dehydrated state. Weight management guidelines to prevent acute dehydration in MMA fighters are warranted to prevent unnecessary adverse health events secondary to dehydration.
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Development and flight test of an experimental maneuver autopilot for a highly maneuverable aircraft
NASA Technical Reports Server (NTRS)
Duke, Eugene L.; Jones, Frank P.; Roncoli, Ralph B.
1986-01-01
This report presents the development of an experimental flight test maneuver autopilot (FTMAP) for a highly maneuverable aircraft. The essence of this technique is the application of an autopilot to provide precise control during required flight test maneuvers. This newly developed flight test technique is being applied at the Dryden Flight Research Facility of NASA Ames Research Center. The FTMAP is designed to increase the quantity and quality of data obtained in test flight. The technique was developed and demonstrated on the highly maneuverable aircraft technology (HiMAT) vehicle. This report describes the HiMAT vehicle systems, maneuver requirements, FTMAP development process, and flight results.
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Webcam autofocus mechanism used as a delay line for the characterization of femtosecond pulses.
Castro-Marín, Pablo; Kapellmann-Zafra, Gabriel; Garduño-Mejía, Jesús; Rosete-Aguilar, Martha; Román-Moreno, Carlos J
2015-08-01
In this work, we present an electromagnetic focusing mechanism (EFM), from a commercial webcam, implemented as a delay line of a femtosecond laser pulse characterization system. The characterization system consists on a second order autocorrelator based on a two-photon-absorption detection. The results presented here were performed for two different home-made femtosecond oscillators: Ti:sapph @ 820 nm and highly chirped pulses generated with an Erbium Doped Fiber @ 1550 nm. The EFM applied as a delay line represents an excellent alternative due its performance in terms of stability, resolution, and long scan range up to 3 ps. Due its low power consumption, the device can be connected through the Universal Serial Bus (USB) port. Details of components, schematics of electronic controls, and detection systems are presented.
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Webcam autofocus mechanism used as a delay line for the characterization of femtosecond pulses
NASA Astrophysics Data System (ADS)
Castro-Marín, Pablo; Kapellmann-Zafra, Gabriel; Garduño-Mejía, Jesús; Rosete-Aguilar, Martha; Román-Moreno, Carlos J.
2015-08-01
In this work, we present an electromagnetic focusing mechanism (EFM), from a commercial webcam, implemented as a delay line of a femtosecond laser pulse characterization system. The characterization system consists on a second order autocorrelator based on a two-photon-absorption detection. The results presented here were performed for two different home-made femtosecond oscillators: Ti:sapph @ 820 nm and highly chirped pulses generated with an Erbium Doped Fiber @ 1550 nm. The EFM applied as a delay line represents an excellent alternative due its performance in terms of stability, resolution, and long scan range up to 3 ps. Due its low power consumption, the device can be connected through the Universal Serial Bus (USB) port. Details of components, schematics of electronic controls, and detection systems are presented.
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2016-04-01
in 2017. Recall from the previous retention section that there is nearly a 50% drop in the total AC fighter pilot inventory available to separate...8 Figure 3. Total Fighter Pilots by Year Group ...................................................................11 Figure 4...important for the Total Force to find an equitable balance and refine the forcing functions to produce, absorb, and sustain the dwindling fighter
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Adel, Youssef; Hilkhuysen, Gaston; Noreña, Arnaud; Cazals, Yves; Roman, Stéphane; Macherey, Olivier
2017-06-01
Electrical stimulation of auditory nerve fibers using cochlear implants (CI) shows psychophysical forward masking (pFM) up to several hundreds of milliseconds. By contrast, recovery of electrically evoked compound action potentials (eCAPs) from forward masking (eFM) was shown to be more rapid, with time constants no greater than a few milliseconds. These discrepancies suggested two main contributors to pFM: a rapid-recovery process due to refractory properties of the auditory nerve and a slow-recovery process arising from more central structures. In the present study, we investigate whether the use of different maskers between eCAP and psychophysical measures, specifically single-pulse versus pulse train maskers, may have been a source of confound.In experiment 1, we measured eFM using the following: a single-pulse masker, a 300-ms low-rate pulse train masker (LTM, 250 pps), and a 300-ms high-rate pulse train masker (HTM, 5000 pps). The maskers were presented either at same physical current (Φ) or at same perceptual (Ψ) level corresponding to comfortable loudness. Responses to a single-pulse probe were measured for masker-probe intervals ranging from 1 to 512 ms. Recovery from masking was much slower for pulse trains than for the single-pulse masker. When presented at Φ level, HTM produced more and longer-lasting masking than LTM. However, results were inconsistent when LTM and HTM were compared at Ψ level. In experiment 2, masked detection thresholds of single-pulse probes were measured using the same pulse train masker conditions. In line with our eFM findings, masked thresholds for HTM were higher than those for LTM at Φ level. However, the opposite result was found when the pulse trains were presented at Ψ level.Our results confirm the presence of slow-recovery phenomena at the level of the auditory nerve in CI users, as previously shown in animal studies. Inconsistencies between eFM and pFM results, despite using the same masking conditions, further underline the importance of comparing electrophysiological and psychophysical measures with identical stimulation paradigms.
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Handling qualities related to stall/spin accidents of supersonic fighter aircraft
NASA Technical Reports Server (NTRS)
Anderson, S. B.
1984-01-01
This paper reviews the handling qualities which influence the high angle of attack (AOA) behavior of supersonic fighter aircraft in order to obtain a clearer understanding of the causes of stall/spin accidents. The results show that, because modern fighters suffer more serious consequences when control is lost, good handling qualities are essential for safe operation at high AOA. Relaxed static stability used on some fighter aircraft can result in control problems at high AOA owing to inertia coupling and the difficulty of a recovery from a deep stall. Indications are that the use of departure/spin resistance and an automatic spin prevention system will greatly improve the safety record for modern supersonic fighters.
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[ROLE OF THE SYMPATHOADRENOMEDULLARY SYSTEM IN FORMATION OF PILOT'S ADAPTATION TO FLIGHT LOADS].
Sukhoterin, A F; Pashchenko, P S; Plakhov, N N; Zhuravlev, A G
2015-01-01
Purpose of the work was to evaluate the sympathoadrenomedullary functions and associated psychophysiological reactions of pilots as a function of flight hours on highly maneuverable aircraft. Volunteers to the investigation were 78 pilots (41 pilots of maneuverable aircraft and 37 pilots of bombers and transporters). Selected methods were to enable comprehensive evaluation of the body functioning against flight loads. Our results evidence that piloting of high maneuverable aircraft but not of bombing and transporting aircrafts activates the sympathoadrenomedullary system significantly. This is particularly common to young pilots with the total flying time less than 1000 hours. Adaptive changes to flight factors were noted to develop with age and experience.
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Estimation of weapon-radius versus maneuverability trade-off for air-to-air combat
NASA Technical Reports Server (NTRS)
Kelley, H. J.; Lefton, L.
1977-01-01
A chase in a horizontal plane between a pursuer with a large capture radius and a more maneuverable evading vehicle is examined with constant-speed vehicle models. An approximation to the 'sidestepping' maneuver of the Homicidal Chauffeur Game is modified to account for the effect of evader turning rate, and an estimate of capture radius required is so obtained which agrees remarkably well with Cockayne's point-capture result. The maneuver assumes central importance for barrier surfaces appearing in the Game of Two Cars. Results are given for required weapon capture-radius in terms of the maneuverability of the two vehicles. Some calculations of capture radius are presented.
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Stability control of a flexible maneuverable tethered space net robot
NASA Astrophysics Data System (ADS)
Zhang, Fan; Huang, Panfeng
2018-04-01
As a promising solution for active space debris capture and removal, a maneuverable Tethered Space Net Robot (TSNR) is proposed as an improved Space Tethered Net (TSN). In addition to the advantages inherit to the TSN, the TSNR's maneuverability expands the capture's potential. However, oscillations caused by the TSNR's flexibility and elasticity of make higher requests of the control scheme. Based on the dynamics model, a modified adaptive super-twisting sliding mode control scheme is proposed in this paper for TSNR stability control. The proposed continuous control force can effectively suppress oscillations. Theoretical verification and numerical simulations demonstrate that the desired trajectory can be tracked steadily and efficiently by employing the proposed control scheme.
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A knowledge-based system design/information tool for aircraft flight control systems
NASA Technical Reports Server (NTRS)
Mackall, Dale A.; Allen, James G.
1991-01-01
Research aircraft have become increasingly dependent on advanced electronic control systems to accomplish program goals. These aircraft are integrating multiple disciplines to improve performance and satisfy research objective. This integration is being accomplished through electronic control systems. Systems design methods and information management have become essential to program success. The primary objective of the system design/information tool for aircraft flight control is to help transfer flight control system design knowledge to the flight test community. By providing all of the design information and covering multiple disciplines in a structured, graphical manner, flight control systems can more easily be understood by the test engineers. This will provide the engineers with the information needed to thoroughly ground test the system and thereby reduce the likelihood of serious design errors surfacing in flight. The secondary object is to apply structured design techniques to all of the design domains. By using the techniques in the top level system design down through the detailed hardware and software designs, it is hoped that fewer design anomalies will result. The flight test experiences are reviewed of three highly complex, integrated aircraft programs: the X-29 forward swept wing; the advanced fighter technology integration (AFTI) F-16; and the highly maneuverable aircraft technology (HiMAT) program. Significant operating technologies, and the design errors which cause them, is examined to help identify what functions a system design/informatin tool should provide to assist designers in avoiding errors.
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A Collection of Nonlinear Aircraft Simulations in MATLAB
NASA Technical Reports Server (NTRS)
Garza, Frederico R.; Morelli, Eugene A.
2003-01-01
Nonlinear six degree-of-freedom simulations for a variety of aircraft were created using MATLAB. Data for aircraft geometry, aerodynamic characteristics, mass / inertia properties, and engine characteristics were obtained from open literature publications documenting wind tunnel experiments and flight tests. Each nonlinear simulation was implemented within a common framework in MATLAB, and includes an interface with another commercially-available program to read pilot inputs and produce a three-dimensional (3-D) display of the simulated airplane motion. Aircraft simulations include the General Dynamics F-16 Fighting Falcon, Convair F-106B Delta Dart, Grumman F-14 Tomcat, McDonnell Douglas F-4 Phantom, NASA Langley Free-Flying Aircraft for Sub-scale Experimental Research (FASER), NASA HL-20 Lifting Body, NASA / DARPA X-31 Enhanced Fighter Maneuverability Demonstrator, and the Vought A-7 Corsair II. All nonlinear simulations and 3-D displays run in real time in response to pilot inputs, using contemporary desktop personal computer hardware. The simulations can also be run in batch mode. Each nonlinear simulation includes the full nonlinear dynamics of the bare airframe, with a scaled direct connection from pilot inputs to control surface deflections to provide adequate pilot control. Since all the nonlinear simulations are implemented entirely in MATLAB, user-defined control laws can be added in a straightforward fashion, and the simulations are portable across various computing platforms. Routines for trim, linearization, and numerical integration are included. The general nonlinear simulation framework and the specifics for each particular aircraft are documented.
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Air Weapon Systems in the Third World: A Combat Potential Assessment Technique.
1986-06-01
VALUE LABEL BMAT BOMBER-GROUND ATTACK FTAT FIGHTER-GROUND ATTACK FTTA FIGHTER/TRAINER-GROUND ATTACK FTIN FIGHTER-INTERCEPTOR FTTI FIGHTER/TRAINER...260 2.91 10900 5440 17720 24540 TORADV FTIN 46 400 5.20 31500 15632 41392 60000 TORIDS FTAT 46 400 5.20 31065 14000 47985 60000 TU16AG BMAT 108 1772...6.58 82000 56870 130235 158730 TU22BD BMAT 91 1451 5. 69 80400 81600 147650 185000 ACFT MAXPWR TWPWR ASPD SPECENA LSPD SPECENS CSPD SCEI ALPHAMSI 5952
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The Electronic Freight Management Initiative
DOT National Transportation Integrated Search
2006-04-01
This report discusses the Electronic Freight Management initiative, a U.S. Department of Transportation (DOT) sponsored research effort that partners with industry to improve the operating efficiencies, safety, and security of goods movement. The EFM...
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Webcam autofocus mechanism used as a delay line for the characterization of femtosecond pulses
DOE Office of Scientific and Technical Information (OSTI.GOV)
Castro-Marín, Pablo; Kapellmann-Zafra, Gabriel; Garduño-Mejía, Jesús, E-mail: jesus.garduno@ccadet.unam.mx
2015-08-15
In this work, we present an electromagnetic focusing mechanism (EFM), from a commercial webcam, implemented as a delay line of a femtosecond laser pulse characterization system. The characterization system consists on a second order autocorrelator based on a two-photon-absorption detection. The results presented here were performed for two different home-made femtosecond oscillators: Ti:sapph @ 820 nm and highly chirped pulses generated with an Erbium Doped Fiber @ 1550 nm. The EFM applied as a delay line represents an excellent alternative due its performance in terms of stability, resolution, and long scan range up to 3 ps. Due its low powermore » consumption, the device can be connected through the Universal Serial Bus (USB) port. Details of components, schematics of electronic controls, and detection systems are presented.« less
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Flight Dynamic Simulation of Fighter In the Asymmetric External Store Release Process
NASA Astrophysics Data System (ADS)
Safi’i, Imam; Arifianto, Ony; Nurohman, Chandra
2018-04-01
In the fighter design, it is important to evaluate and analyze the flight dynamic of the aircraft earlier in the development process. One of the case is the dynamics of external store release process. A simulation tool can be used to analyze the fighter/external store system’s dynamics in the preliminary design stage. This paper reports the flight dynamics of Jet Fighter Experiment (JF-1 E) in asymmetric Advance Medium Range Air to Air Missile (AMRAAM) release process through simulations. The JF-1 E and AIM 120 AMRAAAM models are built by using Advanced Aircraft Analysis (AAA) and Missile Datcom software. By using these softwares, the aerodynamic stability and control derivatives can be obtained and used to model the dynamic characteristic of the fighter and the external store. The dynamic system is modeled by using MATLAB/Simulink software. By using this software, both the fighter/external store integration and the external store release process is simulated, and the dynamic of the system can be analyzed.
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The sharing of radiological images by professional mixed martial arts fighters on social media.
Rahmani, George; Joyce, Cormac W; McCarthy, Peter
2017-06-01
Mixed martial arts is a sport that has recently enjoyed a significant increase in popularity. This rise in popularity has catapulted many of these "cage fighters" into stardom and many regularly use social media to reach out to their fans. An interesting result of this interaction on social media is that athletes are sharing images of their radiological examinations when they sustain an injury. To review instances where mixed martial arts fighters shared images of their radiological examinations on social media and in what context they were shared. An Internet search was performed using the Google search engine. Search terms included "MMA," "mixed martial arts," "injury," "scan," "X-ray," "fracture," and "break." Articles which discussed injuries to MMA fighters were examined and those in which the fighter themselves shared a radiological image of their injury on social media were identified. During our search, we identified 20 MMA fighters that had shared radiological images of their injuries on social media. There were 15 different types of injury, with a fracture of the mid-shaft of the ulna being the most common. The most popular social media platform was Twitter. The most common imaging modality X-ray (71%). The majority of injuries were sustained during competition (81%) and 35% of these fights resulted in a win for the fighter. Professional mixed martial artists are sharing radiological images of their injuries on social media. This may be in an attempt to connect with fans and raise their profile among other fighters.
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Charting a New Path: Modernizing the U.S. Air Force Fighter Pilots Career Development
2015-12-01
truly provides no new incentives for undecided fighter pilots and is proving to be an antiquated attempt to maintain the fighter pilot force...growing technological requirements. Weapons shops are responsible for a growing number of responsibilities to support combat operations. Crypto
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Making the Soldier Decisive on Future Battlefields
2013-01-01
mostly real. They are also affected by physical stressors ranging from the exertion while carrying a load and extreme temperatures to the effects ...Military Effects , 36 Lethality, 36 Stability and Humanitarian Effects , 38 Maneuverability, 40 Sustainability, 41 Power and Energy, 41...Integration Priorities, 100 Balancing TSU Maneuverability, Military Effects , and Survivability, 105 Soldiers Carry Too Much to Move Quickly, Act
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High Maneuverability Airframe: Investigation of Fin and Canard Sizing for Optimum Maneuverability
2014-09-01
overset grids (unified- grid); 5) total variation diminishing discretization based on a new multidimensional interpolation framework; 6) Riemann solvers to...Aerodynamics .........................................................................................3 3.1.1 Solver ...describes the methodology used for the simulations. 3.1.1 Solver The double-precision solver of a commercially available code, CFD ++ v12.1.1, 9
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ERIC Educational Resources Information Center
New England Board of Higher Education, Wellesley, MA.
Issues in the improvement of training for fire fighters and officer personnel were taken up in ten symposium papers. Session 1 covered legal and other constraints that affect what a fire fighter should know; and current practices in volunteer, rural, and municipal fire fighter training in the United States. Papers from the other sessions dealt…
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76 FR 31613 - NIOSH Fire Fighter Fatality Investigation and Prevention Program (FFFIPP)
Federal Register 2010, 2011, 2012, 2013, 2014
2011-06-01
... NIOSH-063B] NIOSH Fire Fighter Fatality Investigation and Prevention Program (FFFIPP) AGENCY: The... Fire Fighter Fatality Investigation and Prevention Program (FFFIPP). NIOSH is seeking stakeholder input on the FFFIPP to ensure that the program is meeting the needs and expectations of the U.S. fire...
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Learning amongst Norwegian Fire-Fighters
ERIC Educational Resources Information Center
Sommer, Morten; Nja, Ove
2011-01-01
Purpose: The purpose of this study is to reveal and analyse dominant learning processes in emergency response work from the fire-fighters' point of view, and how fire-fighters develop their competence. Design/methodology/approach: This study adopted an explorative approach using participant observation. The objective of this open-minded approach…
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Program Fighter: An Evaluation.
ERIC Educational Resources Information Center
Hull, David G.; Fowler, Wallace T.
A computer program for the sizing of subsonic and supersonic fighter planes was adapted for use in an aerospace engineering course at the University of Texas at Austin. FIGHTER uses classroom notation and separate subroutines for different disciplines to implement the conceptual design process. Input consists of a set of design variables and a set…
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Electrochemical degradation, kinetics & performance studies of solid oxide fuel cells
NASA Astrophysics Data System (ADS)
Das, Debanjan
Linear and Non-linear electrochemical characterization techniques and equivalent circuit modelling were carried out on miniature and sub-commercial Solid Oxide Fuel Cell (SOFC) stacks as an in-situ diagnostic approach to evaluate and analyze their performance under the presence of simulated alternative fuel conditions. The main focus of the study was to track the change in cell behavior and response live, as the cell was generating power. Electrochemical Impedance Spectroscopy (EIS) was the most important linear AC technique used for the study. The distinct effects of inorganic components usually present in hydrocarbon fuel reformates on SOFC behavior have been determined, allowing identification of possible "fingerprint" impedance behavior corresponding to specific fuel conditions and reaction mechanisms. Critical electrochemical processes and degradation mechanisms which might affect cell performance were identified and quantified. Sulfur and siloxane cause the most prominent degradation and the associated electrochemical cell parameters such as Gerisher and Warburg elements are applied respectively for better understanding of the degradation processes. Electrochemical Frequency Modulation (EFM) was applied for kinetic studies in SOFCs for the very first time for estimating the exchange current density and transfer coefficients. EFM is a non-linear in-situ electrochemical technique conceptually different from EIS and is used extensively in corrosion work, but rarely used on fuel cells till now. EFM is based on exploring information obtained from non-linear higher harmonic contributions from potential perturbations of electrochemical systems, otherwise not obtained by EIS. The baseline fuel used was 3 % humidified hydrogen with a 5-cell SOFC sub-commercial planar stack to perform the analysis. Traditional methods such as EIS and Tafel analysis were carried out at similar operating conditions to verify and correlate with the EFM data and ensure the validity of the obtained information. The obtained values closely range from around 11 mA cm-2 - 16 mA cm -2 with reasonable repeatability and excellent accuracy. The potential advantages of EFM compared to traditional methods were realized and our primary aim at demonstrating this technique on a SOFC system are presented which can act as a starting point for future research efforts in this area. Finally, an approach based on in-situ State of Health tests by EIS was formulated and investigated to understand the most efficient fuel conditions for suitable long term operation of a solid oxide fuel cell stack under power generation conditions. The procedure helped to reflect the individual effects of three most important fuel characteristics CO/H2 volumetric ratio, S/C ratio and fuel utilization under the presence of a simulated alternative fuel at 0.4 A cm-2. Variation tests helped to identify corresponding electrochemical/chemical processes, narrow down the most optimum operating regimes considering practical behavior of simulated reformer-SOFC system arrangements. At the end, 8 different combinations of the optimized parameters were tested long term with the stack, and the most efficient blend was determined.
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Why Adolescents Fight: A Qualitative Study of Youth Perspectives on Fighting and Its Prevention
Shetgiri, Rashmi; Lee, Simon C.; Tillitski, John; Wilson, Connie; Flores, Glenn
2014-01-01
Objective Identify risk factors for fighting, factors that protect against fighting, and strategies to prevent fighting, among adolescents who fight and those uninvolved in fighting. Methods Focus groups were conducted with middle and high-school students, stratified by fighting (fighter/non-fighter) status, race/ethnicity, and gender. Groups were audiotaped, transcribed, and analyzed using margin coding and thematic content analysis. Themes were independently identified by three coders; disagreements were resolved by consensus. Results The 65 participants in the 12 focus groups were 13–17 years old. Reasons for fighting include self-defense, to gain/maintain respect, or due to anger; having goals for the future is protective. Non-fighters state that their parents condone fighting only when physically attacked, and teach adolescents strategies to avoid fighting. Fighters describe mixed messages from parents, and pro-fighting attitudes and modeling of aggressive behavior among some family members. Non-fighters avoid fighting by ignoring insults or walking away. Fighters feel unable to use nonviolent conflict-resolution methods effectively. Peers may instigate or encourage fights. Suggested prevention strategies include anger-management and conflict-resolution programs, relationships with caring adults, and physicians counseling youth about the consequences of fighting. Conclusions Non-fighters use various strategies to avoid fighting, whereas fighters are aware of few alternatives to fighting. Conflicting parental messages about fighting may enhance the likelihood of fighting. Physicians can counsel youth about the negative consequences of fighting. Interventions that teach anger management and conflict resolution, promote adolescent self-efficacy for using non-violent strategies, and address parental attitudes about fighting may be effective in preventing fighting. PMID:25528128
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Methodology to improve design of accelerated life tests in civil engineering projects.
Lin, Jing; Yuan, Yongbo; Zhou, Jilai; Gao, Jie
2014-01-01
For reliability testing an Energy Expansion Tree (EET) and a companion Energy Function Model (EFM) are proposed and described in this paper. Different from conventional approaches, the EET provides a more comprehensive and objective way to systematically identify external energy factors affecting reliability. The EFM introduces energy loss into a traditional Function Model to identify internal energy sources affecting reliability. The combination creates a sound way to enumerate the energies to which a system may be exposed during its lifetime. We input these energies into planning an accelerated life test, a Multi Environment Over Stress Test. The test objective is to discover weak links and interactions among the system and the energies to which it is exposed, and design them out. As an example, the methods are applied to the pipe in subsea pipeline. However, they can be widely used in other civil engineering industries as well. The proposed method is compared with current methods.
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Bootstrapping conformal field theories with the extremal functional method.
El-Showk, Sheer; Paulos, Miguel F
2013-12-13
The existence of a positive linear functional acting on the space of (differences between) conformal blocks has been shown to rule out regions in the parameter space of conformal field theories (CFTs). We argue that at the boundary of the allowed region the extremal functional contains, in principle, enough information to determine the dimensions and operator product expansion (OPE) coefficients of an infinite number of operators appearing in the correlator under analysis. Based on this idea we develop the extremal functional method (EFM), a numerical procedure for deriving the spectrum and OPE coefficients of CFTs lying on the boundary (of solution space). We test the EFM by using it to rederive the low lying spectrum and OPE coefficients of the two-dimensional Ising model based solely on the dimension of a single scalar quasiprimary--no Virasoro algebra required. Our work serves as a benchmark for applications to more interesting, less known CFTs in the near future.
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Time-resolved electric force microscopy of charge traps in polycrystalline pentacene films
NASA Astrophysics Data System (ADS)
Jaquith, Michael; Muller, Erik; Marohn, John
2006-03-01
The microscopic mechanisms by which charges trap in organic electronic materials are poorly understood. Muller and Marohn recently showed that electric force microscopy (EFM) can be used to image trapped charge in working pentacene thin-film transistors [E. M. Muller et al, Adv. Mater. 17 1410 (2005)]. We have extended their work by imaging trapped charge in pentacene films with much larger grains. In contrast to the previous study in which charge was found to trap inhomogeneously throughout the transistor gap, we find microscopic evidence for a new trapping mechanism in which charges trap predominantly at the pentacene/metal interface in large-grained devices. We have also made localized measurements of the trap growth over time by performing pulsed-gate EFM experiments. Integrated-rate kinetics data supports a charge trap mechanism which is second order in holes, e.g., holes trap in pairs, although the charge-trapping rate appears to depend on gate voltage.
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-14
... NIOSH 141-A] Preventing Deaths and Injuries of Fire Fighters Using Risk Management Principles at Structure Fires AGENCY: National Institute for Occupational Safety and Health (NIOSH) of the Centers for... publication entitled ``Preventing Deaths and Injuries of Fire Fighters Using Risk Management Principles at...
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ERIC Educational Resources Information Center
Pribyl, Paul F.
Practical skills tests are provided for fire fighter trainees in the Wisconsin Fire Service Certification Series, Fire Fighter Levels I, II, and III. A course introduction appears first and contains this information: recommended instructional sequence, required facilities, instructional methodology, requirements for certification, course…
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2004-05-01
Environmental Assessment for Employment of a Mobile Laser Evaluator System (LES-M) for the 20th Fighter Wing at Shaw Air Force Base, South Carolina...Mobile Laser Evaluator System (LES-M) for the 20th Fighter Wing at Shaw Air Force Base, South Carolina 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...a Mobile Laser Evaluator System (LES-M) for the 20’’ Fighter Wing (20 fW) at Shaw Air Force Base (AFB), South Carolir.a DESCRIPTION OF THE PROPOSED
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Putting the "ecology" into environmental flows: ecological dynamics and demographic modelling.
Shenton, Will; Bond, Nicholas R; Yen, Jian D L; Mac Nally, Ralph
2012-07-01
There have been significant diversions of water from rivers and streams around the world; natural flow regimes have been perturbed by dams, barriers and excessive extractions. Many aspects of the ecological 'health' of riverine systems have declined due to changes in water flows, which has stimulated the development of thinking about the maintenance and restoration of these systems, which we refer to as environmental flow methodologies (EFMs). Most existing EFMs cannot deliver information on the population viability of species because they: (1) use habitat suitability as a proxy for population status; (2) use historical time series (usually of short duration) to forecast future conditions and flow sequences; (3) cannot, or do not, handle extreme flow events associated with climate variability; and (4) assume process stationarity for flow sequences, which means the past sequences are treated as good indicators of the future. These assumptions undermine the capacity of EFMs to properly represent risks associated with different flow management options; assumption (4) is untenable given most climate-change predictions. We discuss these concerns and advocate the use of demographic modelling as a more appropriate tool for linking population dynamics to flow regime change. A 'meta-species' approach to demographic modelling is discussed as a useful step from habitat based models towards modelling strategies grounded in ecological theory when limited data are available on flow-demographic relationships. Data requirements of demographic models will undoubtedly expose gaps in existing knowledge, but, in so doing, will strengthen future efforts to link changes in river flows with their ecological consequences.
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Putting the "Ecology" into Environmental Flows: Ecological Dynamics and Demographic Modelling
NASA Astrophysics Data System (ADS)
Shenton, Will; Bond, Nicholas R.; Yen, Jian D. L.; Mac Nally, Ralph
2012-07-01
There have been significant diversions of water from rivers and streams around the world; natural flow regimes have been perturbed by dams, barriers and excessive extractions. Many aspects of the ecological `health' of riverine systems have declined due to changes in water flows, which has stimulated the development of thinking about the maintenance and restoration of these systems, which we refer to as environmental flow methodologies (EFMs). Most existing EFMs cannot deliver information on the population viability of species because they: (1) use habitat suitability as a proxy for population status; (2) use historical time series (usually of short duration) to forecast future conditions and flow sequences; (3) cannot, or do not, handle extreme flow events associated with climate variability; and (4) assume process stationarity for flow sequences, which means the past sequences are treated as good indicators of the future. These assumptions undermine the capacity of EFMs to properly represent risks associated with different flow management options; assumption (4) is untenable given most climate-change predictions. We discuss these concerns and advocate the use of demographic modelling as a more appropriate tool for linking population dynamics to flow regime change. A `meta-species' approach to demographic modelling is discussed as a useful step from habitat based models towards modelling strategies grounded in ecological theory when limited data are available on flow-demographic relationships. Data requirements of demographic models will undoubtedly expose gaps in existing knowledge, but, in so doing, will strengthen future efforts to link changes in river flows with their ecological consequences.
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Sneaker Males Affect Fighter Male Body Size and Sexual Size Dimorphism in Salmon.
Weir, Laura K; Kindsvater, Holly K; Young, Kyle A; Reynolds, John D
2016-08-01
Large male body size is typically favored by directional sexual selection through competition for mates. However, alternative male life-history phenotypes, such as "sneakers," should decrease the strength of sexual selection acting on body size of large "fighter" males. We tested this prediction with salmon species; in southern populations, where sneakers are common, fighter males should be smaller than in northern populations, where sneakers are rare, leading to geographical clines in sexual size dimorphism (SSD). Consistent with our prediction, fighter male body size and SSD (fighter male∶female size) increase with latitude in species with sneaker males (Atlantic salmon Salmo salar and masu salmon Oncorhynchus masou) but not in species without sneakers (chum salmon Oncorhynchus keta and pink salmon Oncorhynchus gorbuscha). This is the first evidence that sneaker males affect SSD across populations and species, and it suggests that alternative male mating strategies may shape the evolution of body size.
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NASA Technical Reports Server (NTRS)
1971-01-01
The Apollo hardware jammed into the F-8C. The computer is partially visible in the avionics bay at the top of the fuselage behind the cockpit. Note the display and keyboard unit in the gun bay. To carry the computers and other equipment, the F-8 DFBW team removed the aircraft's guns and ammunition boxes. The F-8 Digital Fly-By-Wire (DFBW) flight research project validated the principal concepts of all-electric flight control systems now used on nearly all modern high-performance aircraft and on military and civilian transports. The first flight of the 13-year project was on May 25, 1972, with research pilot Gary E. Krier at the controls of a modified F-8C Crusader that served as the testbed for the fly-by-wire technologies. The project was a joint effort between the NASA Flight Research Center, Edwards, California, (now the Dryden Flight Research Center) and Langley Research Center. It included a total of 211 flights. The last flight was December 16, 1985, with Dryden research pilot Ed Schneider at the controls. The F-8 DFBW system was the forerunner of current fly-by-wire systems used in the space shuttles and on today's military and civil aircraft to make them safer, more maneuverable, and more efficient. Electronic fly-by-wire systems replaced older hydraulic control systems, freeing designers to design aircraft with reduced in-flight stability. Fly-by-wire systems are safer because of their redundancies. They are more maneuverable because computers can command more frequent adjustments than a human pilot can. For airliners, computerized control ensures a smoother ride than a human pilot alone can provide. Digital-fly-by-wire is more efficient because it is lighter and takes up less space than the hydraulic systems it replaced. This either reduces the fuel required to fly or increases the number of passengers or pounds of cargo the aircraft can carry. Digital fly-by-wire is currently used in a variety of aircraft ranging from F/A-18 fighters to the Boeing 777. The DFBW research program is considered one of the most significant and most successful NASA aeronautical programs since the inception of the agency. F-8 aircraft were built originally for the U.S. Navy by LTV Aerospace of Dallas, Texas. The aircraft had a wingspan of 35 feet, 2 inches; was 54 feet, 6 inches long; and was powered by a Pratt & Whitney J57 turbojet engine.
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Integrated Unit Deployments: Rethinking Air National Guard Fighter Mobilizations
2016-06-01
INTEGRATED UNIT DEPLOYMENTS: RETHINKING AIR NATIONAL GUARD FIGHTER MOBILIZATIONS BY MAJOR ANDREW P. JACOB A THESIS...This study comprises an analysis of the mobilization and deployment of Air National Guard fighter aircraft units in a search for an efficient and... mobilization . This thesis suggests that Integrated Unit Deployments will provide the balance between Air National Guard overseas deployments and
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-22
... Tactics Development and Evaluation (TD&E) Program. Multiple munitions (bombs, missiles, and gunner rounds... laser-guided Mk-84 bomb F-16C fighter aircraft. GBU-24 laser-guided Mk-84 bomb F-16C+ fighter aircraft... bomb. GBU-12 laser-guided Mk-82 bomb A-10 fighter aircraft. GBU-38 Joint Direct Attack Munition, global...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-04
...) Program. Multiple munitions (bombs, missiles, and gunner rounds) and aircraft would be used to meet the... with Munitions specific munitions) GBU-10 laser-guided Mk-84 bomb F-16C fighter aircraft. GBU-24 laser-guided Mk-84 bomb F-16C+ fighter aircraft. GBU-31 Joint Direct Attack Munition, F-15E fighter aircraft...
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Training and Education in the Fire Services (Proceedings of a Symposium, April 8-9 1970).
ERIC Educational Resources Information Center
National Academy of Sciences-National Research Council, Washington, DC. Div. of Engineering.
Issues in the improvement of training for fire fighters and officer personnel were taken up in ten symposium papers. Session I covered legal and other constraints that affect what a fire fighter should know; and current practices in volunteer, rural, and municipal fire fighter training in the United States. Papers from the other sessions dealt…
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A knowledge-based system design/information tool for aircraft flight control systems
NASA Technical Reports Server (NTRS)
Mackall, Dale A.; Allen, James G.
1989-01-01
Research aircraft have become increasingly dependent on advanced control systems to accomplish program goals. These aircraft are integrating multiple disciplines to improve performance and satisfy research objectives. This integration is being accomplished through electronic control systems. Because of the number of systems involved and the variety of engineering disciplines, systems design methods and information management have become essential to program success. The primary objective of the system design/information tool for aircraft flight control system is to help transfer flight control system design knowledge to the flight test community. By providing all of the design information and covering multiple disciplines in a structured, graphical manner, flight control systems can more easily be understood by the test engineers. This will provide the engineers with the information needed to thoroughly ground test the system and thereby reduce the likelihood of serious design errors surfacing in flight. The secondary objective is to apply structured design techniques to all of the design domains. By using the techniques in the top level system design down through the detailed hardware and software designs, it is hoped that fewer design anomalies will result. The flight test experiences of three highly complex, integrated aircraft programs are reviewed: the X-29 forward-swept wing, the advanced fighter technology integration (AFTI) F-16, and the highly maneuverable aircraft technology (HiMAT) program. Significant operating anomalies and the design errors which cause them, are examined to help identify what functions a system design/information tool should provide to assist designers in avoiding errors.
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The geometry of high angle of attack maneuvers and the implications for Gy-induced neck injuries.
Newman, David G; Ostler, David
2011-08-01
Modern super agile fighter aircraft have significantly expanded maneuverability envelopes, often involving very high angles of attack (AOA) in the post-stall region. One such maneuver is the high AOA velocity vector roll. The geometry of this flight maneuver is such that during the roll there is a significant lateral C load imposed on the unrestrained head-neck complex of the pilot. A mathematical analysis of the geometric relationship determining the magnitude of +/- Gy acceleration during high AOA maneuvering was conducted. This preliminary mathematical model is able to predict the Gy load imposed on the head-neck complex of the pilot for a given set of flight maneuver parameters. The analysis predicts that at an AOA of 700 and with a roll rate of 100 degrees x s(-1), the lateral G developed will be approximately 3.5 Gy. Increasing the roll rate increases the lateral G component: at 200 degrees x s(-1) the Gy, load is more than 6 Gy. There are serious potential implications of super agile maneuvers on the neck of the pilot. The G environment experienced by the pilot of super agile aircraft is increasingly multiaxial, involving +/- Gx, +/- Gy, and +/- Gz. The level of lateral G developed during these dynamic flight maneuvers should not be underestimated, as such G loads can potentially lead to neck injuries. While aircraft become ever more capable, a full understanding of the biodynamic effects on the pilot while exploiting the agility of the aircraft still needs to be developed.
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2013-09-01
including the interaction effects between the fins and canards. 2. Solution Technique 2.1 Computational Aerodynamics The double-precision solver of a...and overset grids (unified-grid). • Total variation diminishing discretization based on a new multidimensional interpolation framework. • Riemann ... solvers to provide proper signal propagation physics including versions for preconditioned forms of the governing equations. • Consistent and
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2014-10-01
Resource JSF Joint Strike Fighter JPATS Joint Primary Aircraft Training System USMC United States Marine Corps USAF United States Air Force LIST...Surface Anthropometry Resource (CAESAR) was developed for the Joint Strike Fighter (JSF) program. The ACSS was intended to replace the JSF-CAESAR...an aircrew sample was made in 2003 by Hudson et al. They extracted a subset, named JSF CAESAR (Joint Strike Fighter), from the Civilian American and
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Preliminary design of a supersonic Short-Takeoff and Vertical-Landing (STOVL) fighter aircraft
NASA Technical Reports Server (NTRS)
1990-01-01
A preliminary study of a supersonic short takeoff and vertical landing (STOVL) fighter is presented. Three configurations (a lift plus lift/cruise concept, a hybrid fan vectored thrust concept, and a mixed flow vectored thrust concept) were initially investigated with one configuration selected for further design analysis. The selected configuration, the lift plus lift/cruise concept, was successfully integrated to accommodate the powered lift short takeoff and vertical landing requirements as well as the demanding supersonic cruise and point performance requirements. A supersonic fighter aircraft with a short takeoff and vertical landing capability using the lift plus lift/cruise engine concept seems a viable option for the next generation fighter.
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Determinants of maximal oxygen uptake (VO2 max) in fire fighter testing.
Vandersmissen, G J M; Verhoogen, R A J R; Van Cauwenbergh, A F M; Godderis, L
2014-07-01
The aim of this study was to evaluate current daily practice of aerobic capacity testing in Belgian fire fighters. The impact of personal and test-related parameters on the outcome has been evaluated. Maximal oxygen uptake (VO2 max) results of 605 male fire fighters gathered between 1999 and 2010 were analysed. The maximal cardio respiratory exercise tests were performed at 22 different centres using different types of tests (tread mill or bicycle), different exercise protocols and measuring equipment. Mean VO2 max was 43.3 (SD = 9.8) ml/kg.min. Besides waist circumference and age, the type of test, the degree of performance of the test and the test centre were statistically significant determinants of maximal oxygen uptake. Test-related parameters have to be taken into account when interpreting and comparing maximal oxygen uptake tests of fire fighters. It highlights the need for standardization of aerobic capacity testing in the medical evaluation of fire fighters. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.
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Shen, Yue; Wang, Ying; Zhou, Yuan; Hai, Chunxi; Hu, Jun; Zhang, Yi
2018-01-01
Electrostatic force spectroscopy (EFS) is a method for monitoring the electrostatic force microscopy (EFM) phase with high resolution as a function of the electrical direct current bias applied either to the probe or sample. Based on the dielectric constant difference of graphene oxide (GO) sheets (reduced using various methods), EFS can be used to characterize the degree of reduction of uniformly reduced one-atom-thick GO sheets at the nanoscale. In this paper, using thermally or chemically reduced individual GO sheets on mica substrates as examples, we characterize their degree of reduction at the nanoscale using EFS. For the reduced graphene oxide (rGO) sheets with a given degree of reduction (sample n), the EFS curve is very close to a parabola within a restricted area. We found that the change in parabola opening direction (or sign the parabola opening value) indicates the onset of reduction on GO sheets. Moreover, the parabola opening value, the peak bias value (tip bias leads to the peak or valley EFM phases) and the EFM phase contrast at a certain tip bias less than the peak value can all indicate the degree of reduction of rGO samples, which is positively correlated with the dielectric constant. In addition, we gave the ranking of degree for reduction on thermally or chemically reduced GO sheets and evaluated the effects of the reducing conditions. The identification of the degree of reduction of GO sheets using EFS is important for reduction strategy optimization and mass application of GO, which is highly desired owing to its mechanical, thermal, optical and electronic applications. Furthermore, as a general and quantitative technique for evaluating the small differences in the dielectric properties of nanomaterials, the EFS technique will extend and facilitate its nanoscale electronic devices applications in the future.
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Forecasting Demand for KC-135 Sorties: Deploy to Dwell Impacts
2013-06-01
fighter movements from individual units are rampant (6 OSS/ OSOS , 2013). However, TACC directed missions in this category are scarce, if not non...existent (6 OSS/ OSOS , 2013). Recent TACC tasked missions that appear to support CONUS fighter movements were training related: pre-deployment preparation...and large scale exercises directed by the Joint Staff (6 OSS/ OSOS , 2013). Anecdotal evidence that AMC supports CONUS fighter movements was flawed
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2010-03-18
1 Filling the Fighter Gap by Major Justin DeMarco, USAF The purpose of this paper is to suggest how the Air Force can mitigate the...estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services...SUBTITLE Filling the Fighter Gap 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER
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Cherepkova, Elena V; Maksimov, Vladimir N; Kushnarev, Alexandr P; Shakhmatov, Igor I; Aftanas, Lyubomir I
2017-09-12
Variable-number tandem repeat (VNTR) polymorphisms of DRD4 and DAT genes were studied in the Russian and Chechen men convicted of crimes, and two control groups comprised of the MMA fighters and a sample of general population. A group of MMA fighters included only the subjects without history of antisocial behaviour. DNA was isolated by phenol-chloroform extraction from the blood. Genotyping VNTR polymorphisms of the DRD4 and DAT genes were performed by PCR on published methods. Among those convicted of felonies and most grave crimes, carriers of DRD4 long alleles are found more frequently, similarly to the cohort of MMA fighters (lacking criminal record in both paternal lines). The 9/9 DAT genotype carriers are more frequently encountered among the habitual offenders. A frequency of the combination of the DRD4 genotype 4/7 and DAT genotype 10/10 is clearly higher among the convicts of violent crimes and the MMA fighters. One can speculate the presence of a 'controlled aggression' without a predisposition to pathological violence in the MMA fighters. Our study supports the hypothesis of genetic predisposition to different variants of extreme behaviour mediated by genetic determinants involved in the functioning of neuromediator systems including those controlling dopamine pathways.
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NASA Astrophysics Data System (ADS)
Rahaman, Md. Mashiur; Islam, Hafizul; Islam, Md. Tariqul; Khondoker, Md. Reaz Hasan
2017-12-01
Maneuverability and resistance prediction with suitable accuracy is essential for optimum ship design and propulsion power prediction. This paper aims at providing some of the maneuverability characteristics of a Japanese bulk carrier model, JBC in calm water using a computational fluid dynamics solver named SHIP Motion and OpenFOAM. The solvers are based on the Reynolds average Navier-Stokes method (RaNS) and solves structured grid using the Finite Volume Method (FVM). This paper comprises the numerical results of calm water test for the JBC model with available experimental results. The calm water test results include the total drag co-efficient, average sinkage, and trim data. Visualization data for pressure distribution on the hull surface and free water surface have also been included. The paper concludes that the presented solvers predict the resistance and maneuverability characteristics of the bulk carrier with reasonable accuracy utilizing minimum computational resources.
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NASA Astrophysics Data System (ADS)
Wang, Zhaoyong; Hu, Xing; Yao, Ning
2015-03-01
At the optimized deposition parameters, Cu film was deposited by the direct current magnetron sputtering (DMS) technique and the energy filtrating magnetron sputtering (EFMS) technique. The nano-structure was charactered by x-ray diffraction. The surface morphology of the film was observed by atomic force microscopy. The optical properties of the film were measured by spectroscopic ellipsometry. The refractive index, extinction coefficient and the thickness of the film were obtained by the fitted spectroscopic ellipsometry data using the Drude-Lorentz oscillator optical model. Results suggested that a Cu film with different properties was fabricated by the EFMS technique. The film containing smaller particles is denser and the surface is smoother. The average transmission coefficient, the refractive index and the extinction coefficients are higher than those of the Cu film deposited by the DMS technique. The average transmission coefficient (400-800 nm) is more than three times higher. The refractive index and extinction coefficient (at 550 nm) are more than 36% and 14% higher, respectively.
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Gomila, G; Esteban-Ferrer, D; Fumagalli, L
2013-12-20
We analyze by means of finite-element numerical calculations the polarization force between a sharp conducting tip and a non-spherical uncharged dielectric nanoparticle with the objective of quantifying its dielectric constant from electrostatic force microscopy (EFM) measurements. We show that for an oblate spheroid nanoparticle of given height the strength of the polarization force acting on the tip depends linearly on the eccentricity, e, of the nanoparticle in the small eccentricity and low dielectric constant regimes (1 < e < 2 and 1 < ε(r) < 10), while for higher eccentricities (e > 2) the dependence is sub-linear and finally becomes independent of e for very large eccentricities (e > 30). These results imply that a precise account of the nanoparticle shape is required to quantify EFM data and obtain the dielectric constants of non-spherical dielectric nanoparticles. Experimental results obtained on polystyrene, silicon dioxide and aluminum oxide nanoparticles and on single viruses are used to illustrate the main findings.
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Methodology to Improve Design of Accelerated Life Tests in Civil Engineering Projects
Lin, Jing; Yuan, Yongbo; Zhou, Jilai; Gao, Jie
2014-01-01
For reliability testing an Energy Expansion Tree (EET) and a companion Energy Function Model (EFM) are proposed and described in this paper. Different from conventional approaches, the EET provides a more comprehensive and objective way to systematically identify external energy factors affecting reliability. The EFM introduces energy loss into a traditional Function Model to identify internal energy sources affecting reliability. The combination creates a sound way to enumerate the energies to which a system may be exposed during its lifetime. We input these energies into planning an accelerated life test, a Multi Environment Over Stress Test. The test objective is to discover weak links and interactions among the system and the energies to which it is exposed, and design them out. As an example, the methods are applied to the pipe in subsea pipeline. However, they can be widely used in other civil engineering industries as well. The proposed method is compared with current methods. PMID:25111800
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Roy-Gobeil, Antoine; Miyahara, Yoichi; Grutter, Peter
2015-04-08
We present theoretical and experimental studies of the effect of the density of states of a quantum dot (QD) on the rate of single-electron tunneling that can be directly measured by electrostatic force microscopy (e-EFM) experiments. In e-EFM, the motion of a biased atomic force microscope cantilever tip modulates the charge state of a QD in the Coulomb blockade regime. The charge dynamics of the dot, which is detected through its back-action on the capacitavely coupled cantilever, depends on the tunneling rate of the QD to a back-electrode. The density of states of the QD can therefore be measured through its effect on the energy dependence of tunneling rate. We present experimental data on individual 5 nm colloidal gold nanoparticles that exhibit a near continuous density of state at 77 K. In contrast, our analysis of already published data on self-assembled InAs QDs at 4 K clearly reveals discrete degenerate energy levels.
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Alternatives for Modernizing U.S. Fighter Forces
2009-05-01
Plans for Modernizing Fighter Forces xS -2. The Possible Role of the F-22 Program in Mitigating the Air Force’s Projected Inventory Shortfall xvi1- 1 ... Northrop Grumman won that competition with its proposal for an aircraft based on the RQ-4 Global Hawk. 38 ALTERNATIVES FOR MODERNIZING U.S. FIGHTER...flyable demonstrator for exploring technologies that could lead to an operational UCAV-N, was rolled out by Northrop Grumman in December 2008. Its
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Design and analysis of a supersonic penetration/maneuvering fighter
NASA Technical Reports Server (NTRS)
Child, R. D.
1975-01-01
The design of three candidate air combat fighters which would cruise effectively at freestream Mach numbers of 1.6, 2.0, and 2.5 while maintaining good transonic maneuvering capability, is considered. These fighters were designed to deliver aerodynamically controlled dogfight missiles at the design Mach numbers. Studies performed by Rockwell International in May 1974 and guidance from NASA determined the shape and size of these missiles. The principle objective of this study is the aerodynamic design of the vehicles; however, configurations are sized to have realistic structures, mass properties, and propulsion systems. The results of this study show that air combat fighters in the 15,000 to 23,000 pound class would cruise supersonically on dry power and still maintain good transonic maneuvering performance.
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NASA Technical Reports Server (NTRS)
Spearman, M. L.; Sawyer, W. C.
1974-01-01
Some criteria for external carriage of missiles for fighter aircraft intended for aerial combat missions and for fighter-interceptor missions are considered. The mission requirements discussed include the short-range fighter-interceptor, the short-range interceptor, the medium-range interceptor, and the long-range interceptor. Missiles types considered to be compatible with the various point mission designs include the short-range missile, the medium-range missile, and the long-range missile. From the study, it appears that point mission design aircraft can be arranged in such a way that the required external-store arrangement will not impair the stability of the aircraft. An extensive reference list of NASA external store research is included.
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Wagner, Norbert L; Berger, Jürgen; Flesch-Janys, Dieter; Koch, Peter; Köchel, Anja; Peschke, Michel; Ossenbach, Trude
2006-01-01
Background The healthy worker effect may hide adverse health effects in hazardous jobs, especially those where physical fitness is required. Fire fighters may serve as a good example because they sometimes are severely exposed to hazardous substances while on the other hand their physical fitness and their strong health surveillance by far exceeds that of comparable persons from the general population. Methods To study this effect a historic cohort study was conducted to assess mortality and life expectancy of professional fire fighters of the City of Hamburg, Germany. Fire departments and trade unions questioned the validity of existing studies from outside Germany because of specific differences in the professional career. No mortality study had been conducted so far in Germany and only few in Europe. Information on all active and retired fire fighters was extracted from personnel records. To assure completeness of data the cohort was restricted to all fire fighters being active on January 1, 1950 or later. Follow up of the cohort ended on June 30th 2000. Vital status was assessed by personnel records, pension fund records and the German residence registries. Mortality of fire fighters was compared to mortality of the Hamburg and German male population by means of standardized mortality ratios. Life expectancy was calculated using life table analysis. Multivariate proportional hazard models were used to assess the effect of seniority, time from first employment, and other occupational characteristics on mortality. Results The cohort consists of 4640 fire fighters accumulating 111796 person years. Vital status could be determined for 98.2% of the cohort. By the end of follow up 1052 person were deceased. Standardized Mortality Ratio (SMR) for the total cohort was 0.79 (95% CI, 0.74–0.84) compared to Hamburg reference data and 0.78 (95% CI, 0.74–0.83) compared to National German reference data. Conditional life expectancy of a 30 year old fire fighter was 45.3 years as compared to 42.9 year of a German male in normal population. Job tasks, rank status and early retirement negatively influenced mortality. For fire fighters with comparably short duration of employment the mortality advantage diminished with longer time since first employment. SMR of persons who retired early was 1.25 (95% CI, 1.13–1.60) in reference to the general German population and the SMR of 1.71 (1.18–2.50) in the multivariate regression model. Conclusion A strong healthy worker effect was observed for the cohort, which diminished with longer time since first employment for fire fighters with shorter duration of employment, as expected. The negative effects on mortality of job tasks, rank status and in particular early retirement indicate the presence of undetermined and specific risks related to occupational hazards of fire fighters. PMID:17020604
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Xu, Xianrong; Ma, Xiaoli; Zhang, Yang; Xiong, Wei
2012-01-01
To comparatively analyze the disease data of nasal sinus between helicopter and (strike) fighter pilots under flying qualification, and then to provide references for aeromedical support as a significant part of new logistics service union in army, The CT data of nasal sinus in 138 pilots who accepted physical examination for change to new-type aircraft, were collected included 46 cases of helicopter pilots and 92 cases of (strike)fighter pilots). The incidence of chronic sinusitis and cyst of nasal sinus were computed respectively in helicopter pilots and (strike)fighter pilots. (1) Fourteen cases suffered from chronic sinusitis (6 cases of maxillary sinusitis, 4 cases of ethmoiditis and 4 cases of maxillary sinusitis and ethmoiditis) in helicopter pilots whose incidence rate of chronic sinusitis was 30.4% (14/46). Of which, 3 cases of antracele were treated. Twelve cases suffered from chronic sinusitis (8 cases of maxillary sinusitis, 1 case of ethmoiditis, 3 cases of maxillary sinusitis and ethmoiditis) in (strike)fighter pilots whose incidence of chronic sinusitis was 13.0% (12/92). Of which, 1 case of antracele was treated. The incidence of chronic sinusitis was higher in helicopter pilots than (strike) fighters pilots (Chi2 = 6.07, P < 0.05). (2) Four cases suffered from unilateral mucosa cysts in maxillary sinus in helicopter pilots whose incidence of cyst of nasal sinus was 8.7% (4/46). Ten cases suffered from mucosa cysts in maxillary sinus (unilateral 8 cases and bilateral 2 cases) in (strike) fighters pilots whose incidence of cyst of nasal sinus was 10.87% (10/92). The difference of the incidence of cyst of nasal sinus was not statistically significant between the helicopter pilots and(strike)fighters pilots. The cysts of nasal sinus did not need treatment in 14 cases of this group data. The incidence of symptomless chronic sinusitis and cyst of nasal sinus are high in pilots. It is related with repeatedly changes of atmosphere pressure during flying. But most chronic sinusitis and cyst of nasal sinus do not need treatment. The incidence of chronic sinusitis is higher in helicopter pilots than(strike)fighter pilots. It may be related with the environment of helicopter which have unclosed cockpit and load other aircrew.
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The sharing of radiological images by professional mixed martial arts fighters on social media
Joyce, Cormac W; McCarthy, Peter
2017-01-01
Background Mixed martial arts is a sport that has recently enjoyed a significant increase in popularity. This rise in popularity has catapulted many of these “cage fighters” into stardom and many regularly use social media to reach out to their fans. An interesting result of this interaction on social media is that athletes are sharing images of their radiological examinations when they sustain an injury. Purpose To review instances where mixed martial arts fighters shared images of their radiological examinations on social media and in what context they were shared. Material and Methods An Internet search was performed using the Google search engine. Search terms included “MMA,” “mixed martial arts,” “injury,” “scan,” “X-ray,” “fracture,” and “break.” Articles which discussed injuries to MMA fighters were examined and those in which the fighter themselves shared a radiological image of their injury on social media were identified. Results During our search, we identified 20 MMA fighters that had shared radiological images of their injuries on social media. There were 15 different types of injury, with a fracture of the mid-shaft of the ulna being the most common. The most popular social media platform was Twitter. The most common imaging modality X-ray (71%). The majority of injuries were sustained during competition (81%) and 35% of these fights resulted in a win for the fighter. Conclusion Professional mixed martial artists are sharing radiological images of their injuries on social media. This may be in an attempt to connect with fans and raise their profile among other fighters. PMID:28717518
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GPU-accelerated Modeling and Element-free Reverse-time Migration with Gauss Points Partition
NASA Astrophysics Data System (ADS)
Zhen, Z.; Jia, X.
2014-12-01
Element-free method (EFM) has been applied to seismic modeling and migration. Compared with finite element method (FEM) and finite difference method (FDM), it is much cheaper and more flexible because only the information of the nodes and the boundary of the study area are required in computation. In the EFM, the number of Gauss points should be consistent with the number of model nodes; otherwise the accuracy of the intermediate coefficient matrices would be harmed. Thus when we increase the nodes of velocity model in order to obtain higher resolution, we find that the size of the computer's memory will be a bottleneck. The original EFM can deal with at most 81×81 nodes in the case of 2G memory, as tested by Jia and Hu (2006). In order to solve the problem of storage and computation efficiency, we propose a concept of Gauss points partition (GPP), and utilize the GPUs to improve the computation efficiency. Considering the characteristics of the Gaussian points, the GPP method doesn't influence the propagation of seismic wave in the velocity model. To overcome the time-consuming computation of the stiffness matrix (K) and the mass matrix (M), we also use the GPUs in our computation program. We employ the compressed sparse row (CSR) format to compress the intermediate sparse matrices and try to simplify the operations by solving the linear equations with the CULA Sparse's Conjugate Gradient (CG) solver instead of the linear sparse solver 'PARDISO'. It is observed that our strategy can significantly reduce the computational time of K and Mcompared with the algorithm based on CPU. The model tested is Marmousi model. The length of the model is 7425m and the depth is 2990m. We discretize the model with 595x298 nodes, 300x300 Gauss cells and 3x3 Gauss points in each cell. In contrast to the computational time of the conventional EFM, the GPUs-GPP approach can substantially improve the efficiency. The speedup ratio of time consumption of computing K, M is 120 and the speedup ratio time consumption of RTM is 11.5. At the same time, the accuracy of imaging is not harmed. Another advantage of the GPUs-GPP method is its easy applications in other numerical methods such as the FEM. Finally, in the GPUs-GPP method, the arrays require quite limited memory storage, which makes the method promising in dealing with large-scale 3D problems.
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Paganelli, Fernanda L; Willems, Rob J L; Jansen, Pamela; Hendrickx, Antoni; Zhang, Xinglin; Bonten, Marc J M; Leavis, Helen L
2013-04-16
Enterococcus faecium is an important multidrug-resistant nosocomial pathogen causing biofilm-mediated infections in patients with medical devices. Insight into E. faecium biofilm pathogenesis is pivotal for the development of new strategies to prevent and treat these infections. In several bacteria, a major autolysin is essential for extracellular DNA (eDNA) release in the biofilm matrix, contributing to biofilm attachment and stability. In this study, we identified and functionally characterized the major autolysin of E. faecium E1162 by a bioinformatic genome screen followed by insertional gene disruption of six putative autolysin genes. Insertional inactivation of locus tag EfmE1162_2692 resulted in resistance to lysis, reduced eDNA release, deficient cell attachment, decreased biofilm, decreased cell wall hydrolysis, and significant chaining compared to that of the wild type. Therefore, locus tag EfmE1162_2692 was considered the major autolysin in E. faecium and renamed atlAEfm. In addition, AtlAEfm was implicated in cell surface exposure of Acm, a virulence factor in E. faecium, and thereby facilitates binding to collagen types I and IV. This is a novel feature of enterococcal autolysins not described previously. Furthermore, we identified (and localized) autolysin-independent DNA release in E. faecium that contributes to cell-cell interactions in the atlAEfm mutant and is important for cell separation. In conclusion, AtlAEfm is the major autolysin in E. faecium and contributes to biofilm stability and Acm localization, making AtlAEfm a promising target for treatment of E. faecium biofilm-mediated infections. IMPORTANCE Nosocomial infections caused by Enterococcus faecium have rapidly increased, and treatment options have become more limited. This is due not only to increasing resistance to antibiotics but also to biofilm-associated infections. DNA is released in biofilm matrix via cell lysis, caused by autolysin, and acts as a matrix stabilizer. In this study, we identified and characterized the major autolysin in E. faecium, which we designated AtlAEfm. atlAEfm disruption resulted in resistance to lysis, reduced extracellular DNA (eDNA), deficient cell attachment, decreased biofilm, decreased cell wall hydrolysis, and chaining. Furthermore, AtlAEfm is associated with Acm cell surface localization, resulting in less binding to collagen types I and IV in the atlAEfm mutant. We also identified AtlAEfm-independent eDNA release that contributes to cell-cell interactions in the atlAEfm mutant. These findings indicate that AtlAEfm is important in biofilm and collagen binding in E. faecium, making AtlAEfm a promising target for treatment of E. faecium infections.
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NASA Astrophysics Data System (ADS)
Cox, Phillip Alexander
With power conversion efficiencies on the rise, organic photovoltaics (OPVs) hold promise as a next-generation thin-film solar technology. However, both device performance and stability are inextricably linked to local film structure. Methods capable of probing nanoscale electronic properties as a function of film structure are thus a crucial component of the rational design of efficient and robust devices. This dissertation describes the use of three scanning probe methods for studying local charge generation and photodegradation in polymer/fullerene solar cells. First, we show that time-resolved electrostatic force microscopy (trEFM) is capable of resolving local photocurrent from sub-bandgap excitation down to attoampere level currents, a result unattainable by traditional contact-mode methods. We find that the local charging rates measured with trEFM are proportional to external quantum efficiency (EQE) measurements made on completed devices, making trEFM images equivalent to local EQE maps across the entire solar spectrum. For both phase-segregated and well-mixed MDMO-PPV:PCBM film morphologies, we show that the local distribution of photocurrent is invariant to excitation wavelength, providing local evidence for the controversial result that the probability of generating separated charge carriers does not depend on whether excitons are formed at the singlet state or charge transfer state. Next, we describe how local dissipation imaging can be performed with commercially-available frequency-modulated electrostatic force microscopy (FM-EFM) and show that dissipation maps are highly sensitive to photo-oxidative effects in organic semiconductors. We show that photo-oxidation induced changes in cantilever energy dissipation are proportional to device performance losses. We further develop dissipation imaging by implementing ringdown imaging, which directly measures the quality factor of the cantilever, enabling quantitative dissipation mapping. Using organic photovoltaic materials as a testbed, we study macroscopic device degradation as a function of photooxidation for three different film morphologies. According to EQE measurements, we find that the stability of the macroscopic devices is very sensitive to processing conditions, with films processed with the solvent additive 1,8-diiodooctane being the most stable. At the microscopic level, we compare the evolution of cantilever power dissipation as a function of photochemical degradation for three different polymer/fullerene blend morphologies, and show that the evolution of local power dissipation correlates with device stability. Lastly, we show that cantilever power dissipation increases more rapidly over large fullerene aggregates than in well-mixed polymer/fullerene regions, suggesting that local photochemistry on the fullerene contributes strongly to the dissipation signal.
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2016-12-01
Fighter Travel, 6. 16 Ibid., 6–15. 17 Ibid., 13. 5 United States failed to stop Americans from going abroad to become foreign fighters, and made 32...ethnicity only possess meaning because they connect people socially.130 The different categories that American Muslims classify themselves demonstrate the...Identity.” 133 Ibid., 66. 34 An example is found in American Muslims; they identify all Americans as part of their national in-group, but when
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1979-06-01
significantly higher.2 Also femin - inity3 as measured by the Minnesota Multiphasic Personality Inventory (MMPI) and the California Personality Inventory (CPI) L...question of women in combat. The fighters had participated in more activities, hobbies and sports than had non-fighters (19 activities as compared to...15). They tended to prefer body contact sports and had partici- pated in them longer and more frequently than had non-fighters. The activities that
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1949-07-25
RAND 1 RESEARCH MEMORANDUM c: . A BOMBER FIGHTER DUEL (II) David Blackwell and Max Shiffiaan HM-193 • 25 July 1949 Copy No./c^JZ. . Thi...II) David Blackwell and Max Shiffman 0. Summary. This memorandum completes the study’of the fighteir- bomber duel described in RM-l65i» The... duel is one in which a fighter fires a single rocket burst at a bomber, which has limited ammunition, and defends itself by intermittent firing. It
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Medical evaluation of fire fighters: How fit are they for duty?
Davis, P O; Biersner, R J; Barnard, R J; Schamadan, J
1982-08-01
Aside from the obvious dangers to life and limb associated with the job, fire fighting subjects the body to environmental and physical stressors that can adversely affect various systems. In fact, the effects of these stressors on the cardiovascular system have made coronary heart disease a greater killer among fire fighters than among other occupational groups. The approach to medical evaluation of fire fighters presented here is based on an appreciation of these stressors.
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Fire fighting and its influence on the body.
Rossi, René
2003-08-15
Working conditions for fire fighters can be described according to the environment temperature and the incident radiant heat flux. Measurements for this study in buildings for fire fighting training have shown that fire fighters are typically exposed to radiant heat fluxes of between 5 and 10 kWm(-2) during this kind of exercise. The heat load can nevertheless be much higher. In one case, 42 kWm(-2) was measured. The temperatures reached between 100 and 190 degrees C at 1 m above ground, going up to 278 degrees C in one case. Human trials have been performed with 17 fire fighters. After exercises (about 15 min) in a heated room, the mean core temperature of the fire fighters rose by 0.6 degrees C with a surrounding temperature of 31 degrees C and 1.0 degrees C with 38 degrees C. The sweat production varied from 0.7 to 2.1 lh(-1); 16% to 45% of sweat remained in the clothing layers. During the exercises in the training buildings, a mean of 48 degrees C has been measured between fire fighters' clothing and workwear. These conditions lead to an increase of the relative humidity in all the jackets up to 100%. When the fire fighters came out of the fire, the humidity remained at this level in the PVC coated jackets while it was in some cases strongly reduced in breathable jackets.
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Psychological distress and alcohol use among fire fighters.
Boxer, P A; Wild, D
1993-04-01
Few studies have investigated stressors to which fire fighters are subjected and the potential psychological consequences. One hundred and forty-five fire fighters were studied to enumerate potential occupational stressors, assess psychological distress and problems with alcohol use, and determine whether a relationship exists between these measures and self-reported stressors. Hearing that children are in a burning building was the highest ranked stressor. According to three self-report instruments, between 33 and 41% of the fire fighters were experiencing significant psychological distress, and 29% had possible or probable problems with alcohol use. These figures are significantly higher than would be expected in a typical community or working population. In a logistic regression analysis, no relationship was found between measures of psychological distress and alcohol use and the 10 most highly ranked work stressors.
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The Caliphates Global Workforce: An Inside Look at the Islamic States Foreign Fighter Paper Trail
2016-04-01
The Caliphate’s Global Workforce: An Inside Look at the Islamic State’s Foreign Fighter Paper Trail Brian Dodwell Daniel Milton Don Rassler The...Caliphate’s Global Workforce: An Inside Look at the Islamic State’s Foreign Fighter Paper Trail Brian Dodwell Daniel Milton Don Rassler Combating...Terrorism Center at West Point April 2016 Cover Photo: Image taken from the Islamic State’s Dabiq magazine United States Military Academy www.ctc.usma.edu
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High Energy Laser on the Joint Strike Fighter: A Reality in 2025?
2007-02-26
10 October 2006. 19. Siegman , A.E., Nemes, G., Serna, J. “How to (Maybe) Measure Laser Beam Quality,” in DPSS (Diode Pumped Solid State) Lasers ...AIR WAR COLLEGE AIR UNIVERSITY HIGH ENERGY LASER ON THE JOINT STRIKE FIGHTER A REALITY IN 2025? by Jeffrey A. Hausmann, Lt Col, USAF A...00-00-2007 to 00-00-2007 4. TITLE AND SUBTITLE High Energy Laser on the Joint Strike Fighter a Reality in 2025? 5a. CONTRACT NUMBER 5b. GRANT
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The Debate is Over: Close Air Support in Korea and Vietnam
2011-05-03
F4U Corsair became Marine aviation’s plane of choice. Early models of the Corsair were formidable fighter aircraft best suited for the air...superiority role. By 1944, the Marine Corps made a deliberate effort to transform the Corsair from a fighter to a multi-role fighter- bomber. As such, the F4U...installation of a ten-channel radio facilitated better communications with ground forces. The upgraded Corsair was such an effective ground attack platform
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The Search for an Advanced Fighter: A History from the XF-108 to the Advanced Tactical Fighter
1986-04-01
V, ,tt AIR COMMAND AND- STAFF COLLEGE STUDENT REPORT THE SEARCH FOR AN ADVANCED FIGHTER, A HISTORY FROM THE XF-108 TO THE &ELECTE j - MAJOR ROBERT P...expressed in this document are those of the author. They are- J not intended and should not be thought to represent official ideas, attitudes, or policies of...the general public. A loan copy of the document may be obtained from the Air University Interlibrary Loan Service (AULILDEX, Maxwell AFB, Alabama
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Exceptional Family Member Program EFM
1996-01-01
official. A legible copy of the most current Individualized Education Plan ( IEP ) must be submitted with NA\\’PERS 1754/4. SNAVPERS 1754/3 and 1754/4 must be...Center National Easter Seal Society (Mobiltv / Hearing /Sight) iEarlv Intervention) 1-800-833 3232 - * 1-800-221-6821 -- (312) 726-6200 Autism
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Segre, Paolo S; Dakin, Roslyn; Zordan, Victor B; Dickinson, Michael H; Straw, Andrew D; Altshuler, Douglas L
2015-01-01
Despite recent advances in the study of animal flight, the biomechanical determinants of maneuverability are poorly understood. It is thought that maneuverability may be influenced by intrinsic body mass and wing morphology, and by physiological muscle capacity, but this hypothesis has not yet been evaluated because it requires tracking a large number of free flight maneuvers from known individuals. We used an automated tracking system to record flight sequences from 20 Anna's hummingbirds flying solo and in competition in a large chamber. We found that burst muscle capacity predicted most performance metrics. Hummingbirds with higher burst capacity flew with faster velocities, accelerations, and rotations, and they used more demanding complex turns. In contrast, body mass did not predict variation in maneuvering performance, and wing morphology predicted only the use of arcing turns and high centripetal accelerations. Collectively, our results indicate that burst muscle capacity is a key predictor of maneuverability. DOI: http://dx.doi.org/10.7554/eLife.11159.001 PMID:26583753
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The life and death of ATR/sensor fusion and the hope for resurrection
NASA Astrophysics Data System (ADS)
Rogers, Steven K.; Sadowski, Charles; Bauer, Kenneth W.; Oxley, Mark E.; Kabrisky, Matthew; Rogers, Adam; Mott, Stephen D.
2008-04-01
For over half a century, scientists and engineers have worked diligently to advance computational intelligence. One application of interest is how computational intelligence can bring value to our war fighters. Automatic Target Recognition (ATR) and sensor fusion efforts have fallen far short of the desired capabilities. In this article we review the capabilities requested by war fighters. When compared to our current capabilities, it is easy to conclude current Combat Identification (CID) as a Family of Systems (FoS) does a lousy job. The war fighter needed capable, operationalized ATR and sensor fusion systems ten years ago but it did not happen. The article reviews the war fighter needs and the current state of the art. The article then concludes by looking forward to where we are headed to provide the capabilities required.
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Famous head injuries of the first aerial war: deaths of the "Knights of the Air".
Koul, Prateeka; Mau, Christine; Sabourin, Victor M; Gandhi, Chirag D; Prestigiacomo, Charles J
2015-07-01
World War I advanced the development of aviation from the concept of flight to the use of aircraft on the battlefield. Fighter planes advanced technologically as the war progressed. Fighter pilot aces Francesco Baracca and Manfred von Richthofen (the Red Baron) were two of the most famous pilots of this time period. These courageous fighter aces skillfully maneuvered their SPAD and Albatros planes, respectively, while battling enemies and scoring aerial victories that contributed to the course of the war. The media thrilled the public with their depictions of the heroic feats of fighter pilots such as Baracca and the Red Baron. Despite their aerial prowess, both pilots would eventually be shot down in combat. Although the accounts of their deaths are debated, it is undeniable that both were victims of traumatic head injury.
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The effect of smoke inhalation on lung function and airway responsiveness in wildland fire fighters
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, D.; Tager, I.B.; Balmes, J.R.
1992-12-01
The current study was undertaken to evaluate the effect of smoke on forced expiratory volumes and airway responsiveness in wildland fire fighters during a season of active fire fighting. Sixty-three seasonal and full-time wildland fire fighters from five U.S. Department of Agriculture Forest Service (USDAFS) Hotshot crews in Northern California and Montana completed questionnaires, spirometry, and methacholine challenge testing before and after an active season of fire fighting in 1989. There were significant mean individual declines of 0.09, 0.15, and 0.44 L/s in postseason values of FVC, FEV1, and FEF25-75, respectively, compared with preseason values. There were no consistent significantmore » relationships between mean individual declines of the spirometric parameters and the covariates: sex, smoking history, history of asthma or allergies, years as a fire fighter, upper/lower respiratory symptoms, or membership in a particular Hotshot crew. There was a statistically significant increase in airway responsiveness when comparing preseason methacholine dose-response slopes (DRS) with postseason dose-response slopes (p = 0.02). The increase in airway responsiveness appeared to be greatest in fire fighters with a history of lower respiratory symptoms or asthma, but it was not related to smoking history. These data suggest that wildland fire fighting is associated with decreases in lung function and increases in airway responsiveness independent of a history of cigarette smoking. Our findings are consistent with the results of previous studies of municipal fire fighters.« less
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Physics of forebody flow control
NASA Technical Reports Server (NTRS)
Font, Gabriel I.
1993-01-01
Performance in the high angle of attack regime is required by many different types of aircraft. Military aircraft, such as fighters, utilize flight in this regime to improve maneuverability. Civilian aircraft, such as supersonic or hypersonic transports, will also need to operate in this regime during take off and landing, due to their small highly swept wings. Flight at high angles of attack is problematic due to the vortices being created on the nose of the aircraft. The vortices tend to become asymmetric and produce side forces. At the same time, the rudders are less effective because they are becoming immersed in the flow separating from the wings and fuselage. Consequently, the side force produced by the vortices on the nose tend to destabilize the aircraft. This situation may be corrected through the use of a forebody flow control system such as tangential slot blowing. In this concept, a jet is blown from the nose in an effort to alter the flow field around the nose and diminish the destabilizing side force. Alternately, the jet may be used to create a side force which could be used to augment the rudders. This would allow the size of the rudders to be decreased which would, in turn, diminish the cruise drag. Therefore, the use of a tangential slot blowing system has the potential for improving both the maneuver performance and the cruise performance of an aircraft. The present study was conducted to explore the physics of forebody flow control. The study consisted of two major thrusts: (1) exploration of forebody flow control with tangential slot blowing; (2) investigation of flow and field response to a general perturbation.
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Future Jet Technologies. Part B. F-35 Future Risks v. JS-Education of Pilots & Engineers
NASA Astrophysics Data System (ADS)
Gal-Or, Benjamin
2011-09-01
Design of “Next-Generation” airframes based on supermarket-jet-engine-components is nowadays passé. A novel integration methodology [Gal-Or, “Editorial-Review, Part A”, 2011, Gal-Or, “Vectored Propulsion, Supermaneuverability and Robot Aircraft”, Springer Verlag, Gal-Or, Int'l. J. of Thermal and Fluid Sciences 7: 1-6, 1998, “Introduction”, 2011] is nowadays in. For advanced fighter aircraft it begins with JS-based powerplant, which takes up to three times longer to mature vis-à-vis the airframe, unless “committee's design” enforces a dormant catastrophe. Jet Steering (JS) or Thrust Vectoring Flight Control, is a classified, integrated engine-airframe technology aimed at maximizing post-stall-maneuverability, flight safety, efficiency and flight envelopes of manned and unmanned air vehicles, especially in the “impossible-to-fly”, post-stall flight domains where the 100+ years old, stall-spin-limited, Conventional Flight Control fails. Worldwide success in adopting the post-stall, JS-revolution, opens a new era in aviation, with unprecedented design variables identified here for a critical review of F-35 future risks v. future fleets of jet-steered, pilotless vehicles, like the X-47B/C. From the educational point of view, it is also instructive to comprehend the causes of long, intensive opposition to adopt post-stall, JS ideas. A review of such debates may also curb a future opposition to adopt more advanced, JS-based technologies, tests, strategies, tactics and missions within the evolving air, marine and land applications of JS. Most important, re-education of pilots and engineers requires adding post-stall, JS-based studies to curriculum & R&D.
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NASA Astrophysics Data System (ADS)
Kus, Orcun; Kocaman, Ibrahim; Topcu, Yucel; Karaca, Volkan
2012-05-01
The problem of defending a specific airspace is among the main issues a military commander to solve. Proper protection of own airspace is crucial for mission success at the battlefield. The military doctrines of most world armed forces involve two main options of defending the airspace. One of them is utilizing formations of fighter aircraft, which is a flexible choice. The second option is deploying modern SAM (Surface to Air Missile) systems, which is more expansive. On the other hand the decision makers are to cope with miscellaneous restrictions such as the budgeting problems. This study defines air defense concept according to modern air warfare doctrine. It considers an air defense scenario over an arbitrary airspace and compares the performance and cost-effectiveness of employing fighter aircraft and SAM systems. It also presents SWOT (Strenghts - Weakness - Opportunities - Threats) analyses of air defense by fighter aircraft and by modern SAMs and tries to point out whichever option is better. We conclude that deploying SAMs has important advantages over using fighter aircraft by means of interception capacity within a given time period and is cost-effective.
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Patent foramen ovale and asymptomatic brain lesions in military fighter pilots.
Kang, Kyung Wook; Kim, Joon-Tae; Choi, Won-Ho; Park, Won-Ju; Shin, Young Ho; Choi, Kang-Ho
2014-10-01
Previous studies have reported higher incidence of white matter lesions (WMLs) in military pilots. The anti-gravity straining maneuver, which fighter military pilots perform numerously during a flight is identical to the valsalva maneuver. We sought to investigate the prevalence of right-to-left shunt (RLS) associated with WMLs in military pilots. A prospective study was performed involving military pilots who visited the Airomedical Center. The pilots underwent brain magnetic resonance imaging (MRI) scan and transcranial Doppler (TCD) with intravenous injection of agitated saline solution for the detection of RLS. Periventricular WMLs (PVWMLs) on MRI were graded using Fazeka's scale, and deep WMLs (DWMLs) were graded using Scheltens's scale. This study included 81 military pilots. RLS on TCD was observed less frequently in non-fighter pilots than in fighter pilots (35.5% vs. 64.5%, p=0.011). Fighter pilot was an independently associated factor with RLS on the TCD. DWMLs were independently associated with RLSs through a patent foramen ovale (PFO) (OR 3.507, 95% CI 1.223-10.055, p=0.02). The results suggest that DWMLs in military pilots may significantly be associated with RLS via PFO. Additional investigations are warranted. Copyright © 2014 Elsevier B.V. All rights reserved.
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Former WWII Fighter Pilot Finds New Home Near Family
... Navigation Bar Home Current Issue Past Issues Feature: Senior Living Former WWII Fighter Pilot Finds New Home ... in Kalispell, Mont. Advice On a Move to Senior Living: Investigate your new surroundings. Talk to those ...
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Multi-Level Scenario Module 1: 7th Division
2009-03-01
MQ1B Recon Sq 1x RC135S Recon Sq 5x RC135VW Cythera Paros Shaw Peterson Fighter Sq 24x F16CD BLK-50 Fighter Sq 24x F15E Fighter Sq 24x A/0A10A Airlift Sq...Mountain Home Amphibious Assault Ship, Multipurpose (LHD) Amphibious Transport Dock (LPD) Dock Landing Ship ( LSD ) Guided Missile Cruiser (CG...Destroyer (DDG) x2 Submarine, Nuclear Powered (SSN) x 6 Guided Missile Submarine, Nuclear Powered (SSGN) Cythera Paros Shaw Peterson Guided
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Overwhelming Force, Indecisive Victory: The German Invasion of Yugoslavia, 1941
1993-05-13
It was a system of large units that depended primarily on animal draft power for transportation that resulted in low march speed and lack of...STUBOL* 12 3D BOMBER REGT SKOPLJE* 13 63D BOMBER GROUP PZTROVAC 30 D017 13 64TH BOMBER GROUP PSTROVAC 30 DOl0 14 5TH FIGHTER RIGT NIS* 15 35TH...FIGHTER GROUP KOSANCIC 15 HAWKER FURY 16 36TH FIGHTER GROUP REZANOVACKA KOSA 15 HAWKER FURY 17 4TH BOMBER AIR BDE LJUBIC* 18 1ST BOMBER RIGT NOVI SAD* 19
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NASA Technical Reports Server (NTRS)
Dudley, Michael R.
2016-01-01
In the 1980s NASA Aeronautics was actively involved in full-scale wind tunnel testing of promising VSTOL aircraft concepts. This presentation looks at two, a multi-role fighter and a subsonic tactical transport. Their strengths and weaknesses are discussed with some of the rationale that ultimately led to the selection of competing concepts for production, namely the V-22 Osprey and the F-35 Lightning. The E7-A STOVL multi-role fighter was the product of an aircraft development program in the late 1980s by NASA, the Defense Advanced Research Projects Agency (DARPA), the Canadian Department of Industry Science and Technology (DIST), and industry partners General Dynamics and Boeing Dehavilland. The program was conducted an in response to increasing US-UK interest in supersonic STOVL fighters. The objective was to design an aircraft that could replace most existing close air support-air combat fighters with a single aircraft that had some of the qualities of an air superiority fighter and the deployment flexibility of a VSTOL aircraft. The resulting E7-A concept was a delta-wing supersonic fighter that used a fuselage-mounted thrust augmenting ejector and a ventral deflecting jet nozzle for vertical lift. The Grumman Aircraft Company, the Navy, and NASA developed the Design-698 (D-698) subsonic tactical transport in response to the Navy's Type A VSTOL utility aircraft requirement. The objective was to develop a subsonic utility transport with the operational flexibility of a helicopter, but with greater speed and range. The D-698 employs two high-bypass turbofan engines mounted on a dumbbell that rotates through ninety degrees for vertical takeoff and cruise flight. Movable vanes positioned in the exhaust flow provide control in hover with the need for reaction control jets. The presentations concluding comments suggest that technology advances in the last thirty-years may justify the value of revisiting some of these concepts.
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Applying Total Quality Leadership to an Aviation Squadron
1991-12-01
was developed in 1950 by Professor Kaoru Ishikawa . (Juran,1988,pp.22.37) It was developed to show the relationship between some fail point or desired...AND-EFmECT DIAGRAM 1. Description of Cause-and-Effect Diagram The cause-and-effect diagram (also known as the Ishikawa diagram or the fishbone diagram
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University of Maryland MRSEC - Facilities: SEM/STM/AFM
MRSEC Templates Opportunities Search Home » Facilities » SEM/STM/AFM Shared Experimental Facilities conducting and non conducting samples. The sample stage permits electronic device imaging under operational Specifications: Image Modes - STM, STS, MFM, EFM, SKPM, contact- and non-contact AFM Three Sample Contacts 0.1 nm
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Jung, Kyung-Won; Hwang, Min-Jin; Yun, Yeo-Myeong; Cha, Min-Jung; Ahn, Kyu-Hong
2014-09-01
In this current study, we present a modified hydrodynamic cavitation device that combines an electric field to substitute for the chemical addition. A modified HC system is basically an orifice plate and crisscross pipe assembly, in which the crisscross pipe imparts some turbulence, which creates collision events. This study shows that for maximizing disintegration, combining HC system, which called electric field-assisted modified orifice plate hydrodynamic cavitation (EFM-HC) in this study, with an electric field is important. Various HC systems were compared in terms of disintegration of WAS, and, among them, the EFM-HC system exhibited the best performance with the highest disintegration efficiency of 47.0±2.0% as well as the destruction of WAS morphological characteristics. The experimental results clearly show that a conventional HC system was successfully modified. In addition, electric field has a great potential for efficient disintegration of WAS for as a additional option in a combination treatment. This study suggests continued research in this field may lead to an appropriate design for commercial use. Copyright © 2014 Elsevier B.V. All rights reserved.
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Zou, Tianhua; Qin, Xiaoying; Zhang, Yongsheng; Li, Xiaoguang; Zeng, Zhi; Li, Di; Zhang, Jian; Xin, Hongxing; Xie, Wenjie; Weidenkaff, Anke
2015-12-15
It is a major challenge to elevate the thermoelectric figure of merit ZT of materials through enhancing their power factor (PF) and reducing the thermal conductivity at the same time. Experience has shown that engineering of the electronic density of states (eDOS) and the energy filtering mechanism (EFM) are two different effective approaches to improve the PF. However, the successful combination of these two methods is elusive. Here we show that the PF of β-Zn4Sb3 can greatly benefit from both effects. Simultaneous resonant distortion in eDOS via Pb-doping and energy filtering via introduction of interface potentials result in a ~40% increase of PF and an approximately twofold reduction of the lattice thermal conductivity due to interface scattering. Accordingly, the ZT of β-Pb0.02Zn3.98Sb3 with 3 vol.% of Cu3SbSe4 nanoinclusions reaches a value of 1.4 at 648 K. The combination of eDOS engineering and EFM would potentially facilitate the development of high-performance thermoelectric materials.
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1991-01-01
1 L)if I M4’) 100 < of ICO 1a" 0..( crI of ) " i X I- H 011 WCN I(A z EfmE 1 3 I4 o 0f mIi I mcON I’ ~0L4C0L0O)0AIC)0’NLN-C.4)-4CCLC)4)00~C ofI z...00n Inn~~U~f Gn)fUU U o LU L) NLL a 00 4N N m oo---444444--.4- COO- - -4 4 4 4- - - - 0.o0 04o- 4M 100 NO moo0 0 j IX N11- 10000c N 4 0000 4 -ON -0)000...2j O il to N I ciI- $._ I 1-4_ J ZN 100 N13 U 11 wo x IN4 0 Na (0, 21 - 4co()0r na >c4r-I 0- o ni 7 .- - 4ɘ . D 0 0 $_r 044 81 CN NfC)0 Y o - * 4r 0
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Time Resolved Microscopy of Charge Trapping in Polycrystalline Pentacene
NASA Astrophysics Data System (ADS)
Jaquith, Michael; Muller, Erik; Marohn, John
2007-03-01
The microscopic mechanisms by which charges trap in organic electronic materials are poorly understood. Muller and Marohn recently showed that electric force microscopy (EFM) can be used to image trapped charge in working pentacene thin-film transistors [E. M. Muller et al., Adv. Mater. 17 1410 (2005)]. We have made a new discovery by imaging trapped charge in pentacene films with much larger grains. In contrast to the previous study in which charge was found to trap inhomogeneously throughout the transistor gap, we find microscopic evidence for a new trapping mechanism in which charges trap predominantly at the pentacene/metal interface in large-grained devices. We conclude that at least two charge trapping mechanisms are at play in polycrystalline pentacene. We have made localized measurements of the trap growth over time by performing pulsed-gate EFM experiments. Trap formation is not instantaneous, taking up to a second to complete. Furthermore, the charge-trapping rate depends strongly on gate voltage (or hole concentration). This kinetics data is consistent with the hypothesis that traps form by chemical reaction.
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NASA Astrophysics Data System (ADS)
Zhao, Mengmeng
2017-12-01
The thermal protective performance of the fire fighter protective clothing is of vital importance for fire fighters. In the study fabrics treated by phase change materials (PCMs) were applied in the multi-layered fabrics of the fire fighter protective clothing ensemble. The PCM fabrics were placed at the different layers of the clothing and their thermal protective performance were measured by a TPP tester. Results show that with the application of the PCM fabrics the thermal protection of the multi-layered fabrics was greatly increased. The time to reach a second degree burn was largely reduced. The location of the PCM fabrics at the different layers did not affect much on the thermal protective performance. The higher amount of the PCM adds on, the higher thermal protection was brought. The fabrics with PCMs of a higher melting temperature could contribute to higher thermal protection.
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Control strategy for a dual-arm maneuverable space robot
NASA Technical Reports Server (NTRS)
Wang, P. K. C.
1987-01-01
A simple strategy for the attitude control and arm coordination of a maneuverable space robot with dual arms is proposed. The basic task for the robot consists of the placement of marked rigid solid objects with specified pairs of gripping points and a specified direction of approach for gripping. The strategy consists of three phases each of which involves only elementary rotational and translational collision-free maneuvers of the robot body. Control laws for these elementary maneuvers are derived by using a body-referenced dynamic model of the dual-arm robot.
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Bernick, Charles; Zetterberg, Henrik; Shan, Guogen; Banks, Sarah; Blennow, Kaj
2018-04-02
The objective of this study is to evaluate longitudinal change in plasma neurofilament light (NF-L) and tau levels in relationship to clinical and radiological measures in professional fighters. Participants (active and retired professional fighters and control group) underwent annual blood sampling, 3 Tesla MRI brain imaging, computerized cognitive testing, and assessment of exposure to head trauma. Plasma tau and NF-L concentrations were measured using Simoa assays. Multiple linear regression models were used to compare the difference across groups in regard to baseline measurements, while mixed linear models was used for the longitudinal data with multiple measurements for each participant. Plasma samples were available on 471 participants. Baseline NF-L measures differed across groups (F_3,393=6.99, p=0.0001), with the active boxers having the highest levels. Higher NF-L levels at baseline were correlated with lower baseline MRI regional volumes and lower cognitive scores. The number of sparring rounds completed by the active fighters was correlated with NF-L (95% CI 0.0116-0.4053, p=0.0381), but not tau, levels. Among 126 subjects having multiple yearly samples, there was a significant difference in average yearly percentage change in tau across groups (F_3,83=3.87, p=0.0121).). We conclude that plasma NF-L and tau behave differently in a group of active and retired fighters; NF-L better reflects acute exposure whereas the role of plasma tau levels in signifying chronic change in brain structure over time requires further study.
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Professional fighters brain health study: rationale and methods.
Bernick, Charles; Banks, Sarah; Phillips, Michael; Lowe, Mark; Shin, Wanyong; Obuchowski, Nancy; Jones, Stephen; Modic, Michael
2013-07-15
Repetitive head trauma is a risk factor for Alzheimer's disease and is the primary cause of chronic traumatic encephalopathy. However, little is known about the natural history of, and risk factors for, chronic traumatic encephalopathy or about means of early detection and intervention. The Professional Fighters Brain Health Study is a longitudinal study of active professional fighters (boxers and mixed martial artists), retired professional fighters, and controls matched for age and level of education. The main objective of the Professional Fighters Brain Health Study is to determine the relationships between measures of head trauma exposure and other potential modifiers and changes in brain imaging and neurological and behavioral function over time. The study is designed to extend over 5 years, and we anticipate enrollment of more than 400 boxers and mixed martial artists. Participants will undergo annual evaluations that include 3-tesla magnetic resonance imaging scanning, computerized cognitive assessments, speech analysis, surveys of mood and impulsivity, and blood sampling for genotyping and exploratory biomarker studies. Statistical models will be developed and validated to predict early and progressive changes in brain structure and function. A composite fight exposure index, developed as a summary measure of cumulative traumatic exposure, shows promise as a predictor of brain volumes and cognitive function.
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Preliminary design of a supersonic Short Takeoff and Vertical Landing (STOVL) fighter aircraft
NASA Technical Reports Server (NTRS)
Cox, Brian; Borchers, Paul; Gomer, Charlie; Henderson, Dean; Jacobs, Tavis; Lawson, Todd; Peterson, Eric; Ross, Tweed, III; Bellmard, Larry
1990-01-01
The preliminary design study of a supersonic Short Takeoff and Vertical Landing (STOVL) fighter is presented. A brief historical survey of powered lift vehicles was presented, followed by a technology assessment of the latest supersonic STOVL engine cycles under consideration by industry and government in the U.S. and UK. A survey of operational fighter/attack aircraft and the modern battlefield scenario were completed to develop, respectively, the performance requirements and mission profiles for the study. Three configurations were initially investigated with the following engine cycles: a hybrid fan vectored thrust cycle, a lift+lift/cruise cycle, and a mixed flow vectored thrust cycle. The lift+lift/cruise aircraft configuration was selected for detailed design work which consisted of: (1) a material selection and structural layout, including engine removal considerations, (2) an aircraft systems layout, (3) a weapons integration model showing the internal weapons bay mechanism, (4) inlet and nozzle integration, (5) an aircraft suckdown prediction, (6) an aircraft stability and control analysis, including a takeoff, hover, and transition control analysis, (7) a performance and mission capability study, and (8) a life cycle cost analysis. A supersonic fighter aircraft with STOVL capability with the lift+lift/cruise engine cycle seems a viable option for the next generation fighter.
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Effects of fire fighter protective ensembles on mobility and performance.
Coca, Aitor; Williams, W Jon; Roberge, Raymond J; Powell, Jeffrey B
2010-07-01
Many studies have shown that fire fighter turnout gear and equipment may restrict mobility. The restriction of movement is usually due to a decrease in range of motion (ROM). It is important to know how much the decrease in ROM affects performance. The aim of this study was to determine the effects of fire fighter protective ensembles on mobility and performance by measuring static and dynamic range of motion (ROM) and job-related tasks. Eight healthy adults (5 males, 3 females), aged 20-40 years, participated in this study. The study consisted of measuring a battery of motions and fire fighter specific tasks while wearing a standard fire fighter ensemble (SE) or regular light clothing (baseline or BL). Several BL ROM tests were significantly (p < 0.05) different from the SE test, including a decrease in shoulder flexion, cervical rotation and flexion, trunk lateral flexion, and stand and reach. There was a significant decrease in time from SE to baseline performing the one-arm search task and object lift. These overall findings support the need for a comprehensive ergonomic evaluation of protective clothing systems to ascertain human factors issues. The development of a Standard Ergonomics Test Practice for further use in laboratories that conduct personal protective systems evaluations using human test subjects is recommended. Published by Elsevier Ltd.
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A comparative framework for maneuverability and gust tolerance of aerial microsystems
NASA Astrophysics Data System (ADS)
Campbell, Renee
Aerial microsystems have the potential of navigating low-altitude, cluttered environments such as urban corridors and building interiors. Reliable systems require both agility and tolerance to gusts. While many platform designs are under development, no framework currently exists to quantitatively assess these inherent bare airframe characteristics which are independent of closed loop controllers. This research develops a method to quantify the maneuverability and gust tolerance of vehicles using reachability and disturbance sensitivity sets. The method is applied to a stable flybar helicopter and an unstable flybarless helicopter, whose state space models were formed through system identification. Model-based static H∞ controllers were also implemented on the vehicles and tested in the lab using fan-generated gusts. It is shown that the flybar restricts the bare airframe's ability to maneuver in translational velocity directions. As such, the flybarless helicopter proved more maneuverable and gust tolerant than the flybar helicopter. This approach was specifically applied here to compare stable and unstable helicopter platforms; however, the framework may be used to assess a broad range of aerial microsystems.
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NASA Astrophysics Data System (ADS)
Cowan, Noah; Sefati, Shahin; Neveln, Izaak; Roth, Eatai; Mitchell, Terence; Snyder, James; Maciver, Malcolm; Fortune, Eric
A surprising feature of animal locomotion is that organisms typically produce substantial forces in directions other than what is necessary to move the animal through its environment, such as perpendicular to, or counter to, the direction of travel. The effect of these forces has been difficult to observe because they are often mutually opposing and therefore cancel out. Using a combination of robotic physical modeling, computational modeling, and biological experiments, we discovered that these forces serve an important role: to simplify and enhance the control of locomotion. Specifically, we examined a well-suited model system, the glass knifefish Eigenmannia virescens, which produces mutually opposing forces during a hovering behavior. By systematically varying the locomotor parameters of our biomimetic robot, and measuring the resulting forces and kinematics, we demonstrated that the production and differential control of mutually opposing forces is a strategy that generates passive stabilization while simultaneously enhancing maneuverability. Mutually opposing forces during locomotion are widespread across animal taxa, and these results indicate that such forces can eliminate the tradeoff between stability and maneuverability, thereby simplifying robotic and neural control.
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Air Force Medical Service > Resources > Suicide Prevention
Air Force Medical Service Air Force Medical Service Join the Air Force Home Your Healthcare Healthy Videos MHS Genesis AFMS Priorities Trusted Care Vision Air Force Medical Home Full Spectrum Medical ) Air Force EFMP Who is an EFM? Who must enroll? EFMP-Medical EFMP-M Objectives Family Criteria EFMP-M
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Practical application of AMLCDs for tactical fighter aircraft
NASA Astrophysics Data System (ADS)
McClaskey, Paul; Craddock, Roger
1995-06-01
Development and testing of an AMLCD-display to replace a dichroic display in a fighter aircraft environment has presented a unique set of technical challenges. This paper addresses design concepts used on the Engine Fuel Display and proposes design guidelines generally applicable for AMLCD projects.
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Study of aerodynamic technology for VSTOL fighter attack aircraft
NASA Technical Reports Server (NTRS)
Burhans, W., Jr.; Crafta, V. J., Jr.; Dannenhoffer, N.; Dellamura, F. A.; Krepski, R. E.
1978-01-01
Vertical short takeoff aircraft capability, supersonic dash capability, and transonic agility were investigated for the development of Fighter/attack aircraft to be accommodated on ships smaller than present aircraft carriers. Topics covered include: (1) description of viable V/STOL fighter/attack configuration (a high wing, close-coupled canard, twin-engine, control configured aircraft) which meets or exceeds specified levels of vehicle performance; (2) estimates of vehicle aerodynamic characteristics and the methodology utilized to generate them; (3) description of propulsion system characteristics and vehicle mass properties; (4) identification of areas of aerodynamic uncertainty; and (5) a test program to investigate the areas of aerodynamic uncertainty in the conventional flight mode.
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Paillard, Thierry
2011-12-01
The article by Del Vecchio, et al. (2011) provides relevant information to trainers about the effort-pause ratio during mixed martial arts matches. Taking into account the physiological profiles of fighters would increase interest in these findings.
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HiMAT Subscale Research Vehicle Mated to B-52 Mothership in Flight
NASA Technical Reports Server (NTRS)
1980-01-01
The Highly Maneuverable Aircraft Technology (HiMAT) research vehicle is shown here mated to a wing pylon on NASA's B-52 mothership aircraft. The HiMAT was a technology demonstrator to test structures and configurations for advanced fighter concepts. Over the course of more than 40 years, the B-52 proved a valuable workhorse for NASA's Dryden Flight Research Center (under various names), launching a wide variety of vehicles and conducting numerous other research flights. NASA B-52, Tail Number 008, is an air launch carrier aircraft, 'mothership,' as well as a research aircraft platform that has been used on a variety of research projects. The aircraft, a 'B' model built in 1952 and first flown on June 11, 1955, is the oldest B-52 in flying status and has been used on some of the most significant research projects in aerospace history. Some of the significant projects supported by B-52 008 include the X-15, the lifting bodies, HiMAT (highly maneuverable aircraft technology), Pegasus, validation of parachute systems developed for the space shuttle program (solid-rocket-booster recovery system and the orbiter drag chute system), and the X-38. The B-52 served as the launch vehicle on 106 X-15 flights and flew a total of 159 captive-carry and launch missions in support of that program from June 1959 to October 1968. Information gained from the highly successful X-15 program contributed to the Mercury, Gemini, and Apollo human spaceflight programs as well as space shuttle development. Between 1966 and 1975, the B-52 served as the launch aircraft for 127 of the 144 wingless lifting body flights. In the 1970s and 1980s, the B-52 was the launch aircraft for several aircraft at what is now the Dryden Flight Research Center, Edwards, California, to study spin-stall, high-angle-of attack, and maneuvering characteristics. These included the 3/8-scale F-15/spin research vehicle (SRV), the HiMAT (Highly Maneuverable Aircraft Technology) research vehicle, and the DAST (drones for aerodynamic and structural testing). The aircraft supported the development of parachute recovery systems used to recover the space shuttle solid rocket booster casings. It also supported eight orbiter (space shuttle) drag chute tests in 1990. In addition, the B-52 served as the air launch platform for the first six Pegasus space boosters. During its many years of service, the B-52 has undergone several modifications. The first major modification was made by North American Aviation (now part of Boeing) in support of the X-15 program. This involved creating a launch-panel-operator station for monitoring the status of the test vehicle being carried, cutting a large notch in the right inboard wing flap to accommodate the vertical tail of the X-15 aircraft, and installing a wing pylon that enables the B-52 to carry research vehicles and test articles to be air-launched/dropped. Located on the right wing, between the inboard engine pylon and the fuselage, this wing pylon was subjected to extensive testing prior to its use. For each test vehicle the B-52 carried, minor changes were made to the launch-panel operator's station. Built originally by the Boeing Company, the NASA B-52 is powered by eight Pratt & Whitney J57-19 turbojet engines, each of which produce 12,000 pounds of thrust. The aircraft's normal launch speed has been Mach 0.8 (about 530 miles per hour) and its normal drop altitude has been 40,000 to 45,000 feet. It is 156 feet long and has a wing span of 185 feet. The heaviest load it has carried was the No. 2 X-15 aircraft at 53,100 pounds. Project manager for the aircraft is Roy Bryant.
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HiMAT Subscale Research Vehicle Mated to B-52 Mothership in Flight, Close-up View
NASA Technical Reports Server (NTRS)
1980-01-01
A close-up view of the Highly Maneuverable Aircraft Technology (HiMAT) research vehicle attached to a wing pylon on NASA's B-52 mothership during a 1980 test flight. The HiMAT used sharply swept-back wings and a canard configuration to test possible technology for advanced fighters. NASA B-52, Tail Number 008, is an air launch carrier aircraft, 'mothership,' as well as a research aircraft platform that has been used on a variety of research projects. The aircraft, a 'B' model built in 1952 and first flown on June 11, 1955, is the oldest B-52 in flying status and has been used on some of the most significant research projects in aerospace history. Some of the significant projects supported by B-52 008 include the X-15, the lifting bodies, HiMAT (highly maneuverable aircraft technology), Pegasus, validation of parachute systems developed for the space shuttle program (solid-rocket-booster recovery system and the orbiter drag chute system), and the X-38. The B-52 served as the launch vehicle on 106 X-15 flights and flew a total of 159 captive-carry and launch missions in support of that program from June 1959 to October 1968. Information gained from the highly successful X-15 program contributed to the Mercury, Gemini, and Apollo human spaceflight programs as well as space shuttle development. Between 1966 and 1975, the B-52 served as the launch aircraft for 127 of the 144 wingless lifting body flights. In the 1970s and 1980s, the B-52 was the launch aircraft for several aircraft at what is now the Dryden Flight Research Center, Edwards, California, to study spin-stall, high-angle-of attack, and maneuvering characteristics. These included the 3/8-scale F-15/spin research vehicle (SRV), the HiMAT (Highly Maneuverable Aircraft Technology) research vehicle, and the DAST (drones for aerodynamic and structural testing). The aircraft supported the development of parachute recovery systems used to recover the space shuttle solid rocket booster casings. It also supported eight orbiter (space shuttle) drag chute tests in 1990. In addition, the B-52 served as the air launch platform for the first six Pegasus space boosters. During its many years of service, the B-52 has undergone several modifications. The first major modification was made by North American Aviation (now part of Boeing) in support of the X-15 program. This involved creating a launch-panel-operator station for monitoring the status of the test vehicle being carried, cutting a large notch in the right inboard wing flap to accommodate the vertical tail of the X-15 aircraft, and installing a wing pylon that enables the B-52 to carry research vehicles and test articles to be air-launched/dropped. Located on the right wing, between the inboard engine pylon and the fuselage, this wing pylon was subjected to extensive testing prior to its use. For each test vehicle the B-52 carried, minor changes were made to the launch-panel operator's station. Built originally by the Boeing Company, the NASA B-52 is powered by eight Pratt & Whitney J57-19 turbojet engines, each of which produce 12,000 pounds of thrust. The aircraft's normal launch speed has been Mach 0.8 (about 530 miles per hour) and its normal drop altitude has been 40,000 to 45,000 feet. It is 156 feet long and has a wing span of 185 feet. The heaviest load it has carried was the No. 2 X-15 aircraft at 53,100 pounds. Project manager for the aircraft is Roy Bryant.
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The Fighters of Lashkar-e-Taiba: Recruitment, Training, Deployment and Death
2013-04-01
false. First, the vast majority of LeT fighters are Pakistani and most are Punjabi , not Kashmiri. It is noteworthy that there is...this database died in Indian‐administered Kashmir. This truth, taken with the predominantly Pakistani‐ Punjabi origins of the fighters...2002. RESIDENCE AND RECRUITMENT Scholars have long claimed that LeT is primarily a Punjabi organization and that its membership is
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Influence of maneuverability on helicopter combat effectiveness
NASA Technical Reports Server (NTRS)
Falco, M.; Smith, R.
1982-01-01
A computational procedure employing a stochastic learning method in conjunction with dynamic simulation of helicopter flight and weapon system operation was used to derive helicopter maneuvering strategies. The derived strategies maximize either survival or kill probability and are in the form of a feedback control based upon threat visual or warning system cues. Maneuverability parameters implicit in the strategy development include maximum longitudinal acceleration and deceleration, maximum sustained and transient load factor turn rate at forward speed, and maximum pedal turn rate and lateral acceleration at hover. Results are presented in terms of probability of skill for all combat initial conditions for two threat categories.
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Aoi, Shinya; Tanaka, Takahiro; Fujiki, Soichiro; Funato, Tetsuro; Senda, Kei; Tsuchiya, Kazuo
2016-01-01
Multilegged locomotion improves the mobility of terrestrial animals and artifacts. Using many legs has advantages, such as the ability to avoid falling and to tolerate leg malfunction. However, many intrinsic degrees of freedom make the motion planning and control difficult, and many contact legs can impede the maneuverability during locomotion. The underlying mechanism for generating agile locomotion using many legs remains unclear from biological and engineering viewpoints. The present study used a centipede-like multilegged robot composed of six body segments and twelve legs. The body segments are passively connected through yaw joints with torsional springs. The dynamic stability of the robot walking in a straight line changes through a supercritical Hopf bifurcation due to the body axis flexibility. We focused on a quick turning task of the robot and quantitatively investigated the relationship between stability and maneuverability in multilegged locomotion by using a simple control strategy. Our experimental results show that the straight walk instability does help the turning maneuver. We discuss the importance and relevance of our findings for biological systems and propose a design principle for a simple control scheme to create maneuverable locomotion of multilegged robots. PMID:27444746
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Combined design of structures and controllers for optimal maneuverability
NASA Technical Reports Server (NTRS)
Ling, Jer; Kabamba, Pierre; Taylor, John
1990-01-01
Approaches to the combined design of structures and controllers for achieving optimal maneuverability are presented. A maneuverability index which directly reflects the minimum time required to perform a given set of maneuvers is introduced. By designing the flexible appendages, the maneuver time of the spacecraft is minimized under the constraints of structural properties, and post maneuver spillover is kept within a specified bound. The spillover reduction is achieved by making use of an appropriate reduced order model. The distributed parameter design problem is approached using assumed shape functions, and finite element analysis with dynamic reduction. Solution procedures have been investigated. Approximate design methods have been developed to overcome the computational difficulties. Some new constraints on the modal frequencies of the spacecraft are introduced in the original optimization problem to facilitate the solution process. It is shown that the global optimal design may be obtained by tuning the natural frequencies to satisfy specific constraints. Researchers quantify the difference between a lower bound to the solution for maneuver time associated with the original problem and the estimate obtained from the modified problem, for a specified application requirement. Numerical examples are presented to demonstrate the capability of this approach.
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2013-12-01
is critical to establishing his heroic identity . Authority Issues: Whether portrayed via confrontation (e.g., Fighter Squadron, The Dawn Patrol...traits throughout the subject’s cinema history has solidified the archetype into the public’s subconscious. Some combination of youthfulness
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Calculation of High Angle of Attack Aerodynamics of Fighter Configurations. Volume 1. Steady
1991-04-01
patterns are now well known qualitatively for fighter configurations from extensive wind and water tunnel tests. However, development of quantitative ...Illustration of Flow Features Predicted in the Present Method -55- z -I1 Figure 2. Difinition of Airplane Coordinate Systems -56- zz T .. l y vy.y Mean
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Program Fighter - An Evaluation.
ERIC Educational Resources Information Center
Hull, David G.; Fowler, Wallace T.
Described is a computer program for the sizing of subsonic and supersonic fighters which has been adapted for use in an aerospace engineering design course. Following a description of the program, an evaluation of its use in the university is presented. It is concluded that computer programs for the conceptual design of aerospace vehicles can play…
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Development and analysis of a STOL supersonic cruise fighter concept
NASA Technical Reports Server (NTRS)
Dollyhigh, S. M.; Foss, W. E., Jr.; Morris, S. J., Jr.; Walkley, K. B.; Swanson, E. E.; Robins, A. W.
1984-01-01
The application of advanced and emerging technologies to a fighter aircraft concept is described. The twin-boom fighter (TBF-1) relies on a two dimensional vectoring/reversing nozzle to provide STOL performance while also achieving efficient long range supersonic cruise. A key feature is that the propulsion package is placed so that the nozzle hinge line is near the aircraft center-of-gravity to allow large vector angles and, thus, provide large values of direct lift while minimizing the moments to be trimmed. The configurations name is derived from the long twin booms extending aft of the engine to the twin vertical tails which have a single horizontal tail mounted atop and between them. Technologies utilized were an advanced engine (1985 state-of-the-art), superplastic formed/diffusion bonded titanium structure, advanced controls/avionics/displays, supersonic wing design, and conformal weapons carriage. The integration of advanced technologies into this concept indicate that large gains in takeoff and landing performance, maneuver, acceleration, supersonic cruise speed, and range can be acieved relative to current fighter concepts.
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Wing planform effects at supersonic speeds for an advanced fighter configuration
NASA Technical Reports Server (NTRS)
Wood, R. M.; Miller, D. S.
1984-01-01
Four advanced fighter configurations, which differed in wing planform and airfoil shape, were investigated in the Langley Unitary Plan Wind Tunnel at Mach numbers of 1.60, 1.80, 2.00, and 2.16. Supersonic data were obtained on the four uncambered wings, which were each attached to a single fighter fuselage. The fuselage geometry varied in cross-sectional shape and had two side-mounted, flow-through, half-axisymmetric inlets. Twin vertical tails were attached to the fuselage. The four planforms tested were a 65 deg delta wing, a combination of a 20 deg trapezoidal wing and a 45 deg horizontal tail, a 70 deg/30 deg cranked wing, and a 70 deg/66 deg crank wing, where the angle values refer to the leading-edge sweep angle of the lifting-surface planform. Planform effects on a single fuselage representative of an advanced fighter aircraft were studied. Results show that the highly swept cranked wings exceeded the aerodynamic performance levels, at low lift coefficients, of the 65 deg delta wing and the 20 deg trapezoidal wing at trimmed and untrimmed conditions.
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Giguère, Denis; Marchand, Denis
2005-01-01
Injuries related to emergency vehicles represent 19% of compensated work accidents for fire fighters, 37% of which occur while stepping down from their vehicles. This study compared the impact forces, the use of upper limbs and the perception of danger of fire fighters as they step down from five different locations on fire trucks. The results show that stepping down from the crew cab facing the street produces impact forces averaging 3.2 times the subject's body weight, but is also perceived as the safest way to descend in one of the two groups of fire fighters that participated in the study. Stepping down from the same location, but facing the truck, produced significantly less impact force and a better distribution of the energy over time. This may be achieved through better control of the descending leg, ankle flexion, and the use of grab bars. A re-design of the access to emergency vehicles should take into account both the safety needs and reduction in biomechanical stress of fire fighters.
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Shiri, Rahman; Frilander, Heikki; Sainio, Markku; Karvala, Kirsi; Sovelius, Roope; Vehmas, Tapio; Viikari-Juntura, Eira
2015-02-01
To assess the associations of acceleration force indicators (aircraft type and flight hours) with cervical and lumbar pain and radiological degeneration among fighter pilots. The PubMed, Embase, Scopus and Web of Science databases were searched until October 2013. Twenty-seven studies were included in the review and 20 in the meta-analysis. There were no differences in the prevalence of neck pain (pooled OR=1.07, 95% CI 0.87 to 1.33), cervical disc degeneration (OR=1.26, CI 0.81 to 1.96), low back pain (OR=0.80, CI 0.47 to 1.38) or lumbar disc degeneration (OR=0.87, CI 0.67 to 1.13) between fighter pilots and helicopter or transport/cargo pilots. Moreover, the prevalence of cervical (OR=1.14, CI 0.61 to 2.16) or lumbar (OR=1.05, CI 0.49 to 2.26) disc degeneration did not differ between fighter pilots and non-flying personnel. Most studies did not control their estimates for age and other potential confounders. Among high-performance aircraft pilots, exposure to the highest G-forces was associated with a higher prevalence of neck pain compared with exposure to lower G-forces (pooled OR=3.12, CI 2.08 to 4.67). The studies on the association between flight hours and neck pain reported inconsistent findings. Moreover, looking back over the shoulder (check six) was the most common posture associated with neck pain. Fighter pilots exposed to high G-forces may be at a greater risk for neck pain than those exposed to low G-forces. This finding should be confirmed with better control for confounding. Awkward neck posture may be an important factor in neck pain among fighter pilots. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
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Strategic Forum. Number 254, February 2010. U.S.-Mexico Homeland Defense: A Compatible Interface
2010-02-01
United States, and the creation of a Mexican P–47 Thunderbolt fighter squadron called the “ Aztec Eagles.” The 201st Mexican Fighter Squadron, Mexican... decline in trade started in 2001 and continued through 2003, with substantial recovery in 2005 and 2006. These trade fig- ures make clear that an
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NASA Technical Reports Server (NTRS)
Graham, A. B.
1977-01-01
Small- and large-scale models of supersonic cruise fighter vehicles were used to determine the effectiveness of airframe/propulsion integration concepts for improved low-speed performance and stability and control characteristics. Computer programs were used for engine/airframe sizing studies to yield optimum vehicle performance.
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ERIC Educational Resources Information Center
Florida State Dept. of Education, Tallahassee. Div. of Vocational, Adult, and Community Education.
Florida's community college and school district postsecondary adult vocational programs in fire fighter training and fire science technology were subjected to a statewide program review. Efforts were made to reach Florida's entire community of career and volunteer fire fighters. Data were collected in the following ways: site interviews with…
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McDonnell XF-88B Experimental Jet Fighter
1955-08-10
91,591 Overhead view. McDonnell XF-88B Experimental Jet Fighter. Langley used this aircraft in the mid-1950s to explore the potential of a supersonic propeller. Photographed in Engineer in Charge A History of the Langley Aeronautical Laboratory, 1917-1958 by James R. Hansen. Page 508. **Note see L57-2259 for eye level view.
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56TH Fighter Group: ’Wolfpack’ Operations - Air Battle for Berlin.
1988-04-01
A pilot from the 63rd FS later reported seeing a yellow nosed fighter attacked and blown up by a Me-109. The 63rd FS pilot subsequently downed that...places one of its aircraft at my disposal by order of the Commanding Officer. Specht and I take off together, with Feldwebel Hauptmann and Sergeant
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Inspection. Fire Service Certification Series. Unit FSCS-FF-17-81.
ERIC Educational Resources Information Center
Pribyl, Paul F.
This training unit on inspection is part of a 17-unit course package written to aid instructors in the development, teaching, and evaluation of fire fighters in the Wisconsin Fire Service Certification Series. The purpose stated for the 4.5-hour unit is to give the fire fighters an insight into their responsibilities concerning fire prevention and…
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Flight control systems development of highly maneuverable aircraft technology /HiMAT/ vehicle
NASA Technical Reports Server (NTRS)
Petersen, K. L.
1979-01-01
The highly maneuverable aircraft technology (HiMAT) program was conceived to demonstrate advanced technology concepts through scaled-aircraft flight tests using a remotely piloted technique. Closed-loop primary flight control is performed from a ground-based cockpit, utilizing a digital computer and up/down telemetry links. A backup flight control system for emergency operation resides in an onboard computer. The onboard systems are designed to provide fail-operational capabilities and utilize two microcomputers, dual uplink receiver/decoders, and redundant hydraulic actuation and power systems. This paper discusses the design and validation of the primary and backup digital flight control systems as well as the unique pilot and specialized systems interfaces.
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Highly Maneuverable Aircraft Technology (HiMAT) flight-flutter test program
NASA Technical Reports Server (NTRS)
Kehoe, M. W.
1984-01-01
The highly maneuverable aircraft technology (HiMAT) vehicle was evaluated in a joint NASA and Air Force flight test program. The HiMAT vehicle is a remotely piloted research vehicle. Its design incorporates the use of advanced composite materials in the wings, and canards for aeroelastic tailoring. A flight-flutter test program was conducted to clear a sufficient flight envelope to allow for performance, stability and control, and loads testing. Testing was accomplished with and without flight control-surface dampers. Flutter clearance of the vehicle indicated satisfactory damping and damping trends for the structural modes of the HiMAT vehicle. The data presented include frequency and damping plotted as a function of Mach number.
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Shin, W; Mahmoud, S Y; Sakaie, K; Banks, S J; Lowe, M J; Phillips, M; Modic, M T; Bernick, C
2014-02-01
Traumatic brain injury is common in fighting athletes such as boxers, given the frequency of blows to the head. Because DTI is sensitive to microstructural changes in white matter, this technique is often used to investigate white matter integrity in patients with traumatic brain injury. We hypothesized that previous fight exposure would predict DTI abnormalities in fighting athletes after controlling for individual variation. A total of 74 boxers and 81 mixed martial arts fighters were included in the analysis and scanned by use of DTI. Individual information and data on fight exposures, including number of fights and knockouts, were collected. A multiple hierarchical linear regression model was used in region-of-interest analysis to test the hypothesis that fight-related exposure could predict DTI values separately in boxers and mixed martial arts fighters. Age, weight, and years of education were controlled to ensure that these factors would not account for the hypothesized effects. We found that the number of knockouts among boxers predicted increased longitudinal diffusivity and transversal diffusivity in white matter and subcortical gray matter regions, including corpus callosum, isthmus cingulate, pericalcarine, precuneus, and amygdala, leading to increased mean diffusivity and decreased fractional anisotropy in the corresponding regions. The mixed martial arts fighters had increased transversal diffusivity in the posterior cingulate. The number of fights did not predict any DTI measures in either group. These findings suggest that the history of fight exposure in a fighter population can be used to predict microstructural brain damage.
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Fighter Pilot Ejection Study as an Educational Tool
ERIC Educational Resources Information Center
Robinson, Garry; Jovanoski, Zlatko
2010-01-01
In this article, we apply the well-known equations of projectile motion to the case of a fighter pilot ejecting from an aircraft, the aim being to establish under what conditions there is danger of impact with the rear vertical stabilizer. The drag force on the pilot after ejection is assumed to vary as the velocity squared and the aircraft motion…
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Challenging the New World Order: The Arms Transfer Policies of the Russian Republic
1993-10-01
SU-22 fighter, SU-24 and SU-25 ground attack planes, MiG-29, MiG-31 fighters, 11-76 transports, " secondhand " AN-24 and Yak-40 passenger aircraft, i.e...notably in the Third World, and is the author of a forthcoming study of the Soviet Commissariat of Nationalities and editor of books on Soviet
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-10
... DEPARTMENT OF DEFENSE Department of the Air Force Record of Decision for the F-15 Aircraft Conversion, 144th Fighter Wing, California Air National Guard, Fresno-Yosemite International Airport Final... May 31, 2013, the United States Air Force signed the ROD for the F-15 Aircraft Conversion for the...
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Sprinklers/Standpipes/Detection Systems. Fire Service Certification Series. Unit FSCS-FF-11-80.
ERIC Educational Resources Information Center
Pribyl, Paul F.
This training unit on sprinklers, standpipes, and detection systems is part of a 17-unit course package written to aid instructors in the development, teaching, and evaluation of fire fighters in the Wisconsin Fire Service Certification Series. The purpose stated for the 6-hour unit is to provide the fire fighter with an understanding of the…
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CFD validation experiments at McDonnell Aircraft Company
NASA Technical Reports Server (NTRS)
Verhoff, August
1987-01-01
Information is given in viewgraph form on computational fluid dynamics (CFD) validation experiments at McDonnell Aircraft Company. Topics covered include a high speed research model, a supersonic persistence fighter model, a generic fighter wing model, surface grids, force and moment predictions, surface pressure predictions, forebody models with 65 degree clipped delta wings, and the low aspect ratio wing/body experiment.
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Defense.gov Special Report: Travels With Hagel
Force base on the Florida panhandle, talking to pilots from the 33rd Fighter Wing, meeting with and in an F-35 fighter. Troop Event At Eglin Air Force Base More Video Hagel Troop Event Kings Bay Travel Locations Map of Hagel's Trip Naval Submarine Base Kings Bay, Georgia. Eglin Air Force Base, Florida. Fort
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Some effects of external stores on the static stability of fighter airplanes
NASA Technical Reports Server (NTRS)
Spearman, M. L.
1972-01-01
Fighter airplanes may have a seemingly limitless number of external store arrangements. Some practical considerations and some aerodynamic considerations must be taken into account in the arrangements of the external stores. The nature of the problems concerning the type of store arrangement involved and the type of airplane on which the stores are installed are reported.
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Fire Streams. Fire Service Certification Series. Unit FSCS-FF-10-80.
ERIC Educational Resources Information Center
Pribyl, Paul F.
This training unit on fire streams is part of a 17-unit course package written to aid instructors in the development, teaching, and evaluation of fire fighters in the Wisconsin Fire Service Certification Series. The purpose stated for the 8-hour unit is to provide the fire fighters with an understanding of the characteristics, use, and application…
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2009-02-12
features an Active Electronic Scan Array ( ASEA ) radar and improved electronics to enhance the capability of current front line fighter aircraft to...equipped with the APG-79 ASEA radar and selected squadrons of Air Force F-16 and F-15E have been approved for ASEA upgrades. Next generation fighter
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Maneuverability and chemotaxis of Caenorhabditis elegans in three-dimensional environments
NASA Astrophysics Data System (ADS)
Blawzdziewicz, Jerzy; Bilbao, Alejandro; Patel, Amar; Vanapalli, Siva
2015-11-01
Locomotion of the nematode C. elegans in water and complex fluids has recently been investigated to gain insight into neuromuscular control of locomotion and to shed light on nematode evolutionary adaptation to environments with varying mechanical properties. Previous studies focused mainly on locomotion efficiency and on adaptation of the nematode gait to the surrounding medium. Much less attention has been devoted to nematode maneuverability, in spite of its crucial role in the survival of the animal. Recently we have provided a quantitative analysis of turning maneuvers of crawling and swimming nematodes on flat surfaces and in 2D fluid layers. Based on this work, we follow with the first full 3D description of how C. elegans moves in complex 3D environments. We show that by superposing body twist and 2D undulations, a burrowing or swimming nematode can rotate the undulation plane and change the direction of motion within that plane by varying undulation-wave parameters. A combination of these corkscrew maneuvers and 2D turns allows the nematode to explore 3D space. We conclude by analyzing 3D chemotaxis of nematodes burrowing in gel and swimming in water, which demonstrates an important application of our maneuverability model. This work was supported by NSF grant CBET-1059745.
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NASA Astrophysics Data System (ADS)
Oliveira, Camilla; Matos, Matheus; Mazzoni, Mário; Chacham, Hélio; Neves, Bernardo
2013-03-01
Hexagonal boron nitride (h-BN) is a two-dimensional compound from III-V family, with the atoms of boron and nitrogen arranged in a honeycomb lattice, similar to graphene. Unlike graphene though, h-BN is an insulator material, with a gap larger than 5 eV. Here, we use Electric Force Microscopy (EFM) to study the electrical response of mono and few-layers of h-BN to an electric field applied by the EFM tip. Our results show an anomalous behavior in the dielectric response for h-BN for different bias orientation: for a positive bias applied to the tip, h-BN layers respond with a larger dielectric constant than the dielectric constant of the silicon dioxide substrate; while for a negative bias, the h-BN dielectric constant is smaller than the dielectric constant of the substrate. Based on first-principles calculations, we showed that this anomalous response may be interpreted as a macroscopic consequence of confinement of a thin water layer between h-BN and substrate. These results were confirmed by sample annealing and also also by a comparative analysis with h-BN on a non-polar substrate. All the authors acknowledge financial support from CNPq, Fapemig, Rede Nacional de Pesquisa em Nanotubos de Carbono and INCT-Nano-Carbono.
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Recent research related to prediction of stall/spin characteristics of fighter aircraft
NASA Technical Reports Server (NTRS)
Nguyen, L. T.; Anglin, E. L.; Gilbert, W. P.
1976-01-01
The NASA Langley Research Center is currently engaged in a stall/spin research program to provide the fundamental information and design guidelines required to predict the stall/spin characteristics of fighter aircraft. The prediction methods under study include theoretical spin prediction techniques and piloted simulation studies. The paper discusses the overall status of theoretical techniques including: (1) input data requirements, (2) math model requirements, and (3) correlation between theoretical and experimental results. The Langley Differential Maneuvering Simulator (DMS) facility has been used to evaluate the spin susceptibility of several current fighters during typical air combat maneuvers and to develop and evaluate the effectiveness of automatic departure/spin prevention concepts. The evaluation procedure is described and some of the more significant results of the studies are presented.
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2008-11-07
CAPE CANAVERAL, Fla. – Standing next to a Starfighter aircraft at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, retired U.S. Air Force Lt. Col. Lee A. Archer Jr., one of the Tuskegee Airmen, shares his experiences as a combat fighter pilot. Earlier, Archer made a special presentation to the Kennedy work force, talking about his years as a combat fighter pilot, civil rights leader and business executive. Archer is the only Tuskegee Airmen fighter pilot to receive the honor “Ace” for shooting down five enemy aircraft during WWII. He retired as Air Force Command Pilot after 30 years of military service, 1941-1971. Archer is at Kennedy to serve as Military Marshall of the 2008 KSC Space & Air Show, Nov. 8-9. Photo credit: NASA/Kim Shiflett
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Rivera, Gabriel; Rivera, Angela R V; Dougherty, Erin E; Blob, Richard W
2006-11-01
The ability to capture prey and avoid predation in aquatic habitats depends strongly on the ability to perform unsteady maneuvers (e.g. turns), which itself depends strongly on body flexibility. Two previous studies of turning performance in rigid-bodied taxa have found either high maneuverability or high agility, but not both. However, examinations of aquatic turning performance in rigid-bodied animals have had limited taxonomic scope and, as such, the effects of many body shapes and designs on aquatic maneuverability and agility have yet to be examined. Turtles represent the oldest extant lineage of rigid-bodied vertebrates and the only aquatic rigid-bodied tetrapods. We evaluated the aquatic turning performance of painted turtles, Chrysemys picta (Schneider, 1783) using the minimum length-specific radius of the turning path (R/L) and the average turning rate (omega(avg)) as measures of maneuverability and agility, respectively. We filmed turtles conducting forward and backward turns in an aquatic arena. Each type of turn was executed using a different pattern of limb movements. During forward turns, turtles consistently protracted the inboard forelimb and held it stationary into the flow, while continuing to move the outboard forelimb and both hindlimbs as in rectilinear swimming. The limb movements of backward turns were more complex than those of forward turns, but involved near simultaneous retraction and protraction of contralateral fore- and hindlimbs, respectively. Forward turns had a minimum R/L of 0.0018 (the second single lowest value reported from any animal) and a maximum omega(avg) of 247.1 degrees. Values of R/L for backward turns (0.0091-0.0950 L) were much less variable than that of forward turns (0.0018-1.0442 L). The maneuverability of turtles is similar to that recorded previously for rigid-bodied boxfish. However, several morphological features of turtles (e.g. shell morphology and limb position) appear to increase agility relative to the body design of boxfish.
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Venus Atmospheric Maneuverable Platform (VAMP) - A Low Cost Venus Exploration Concept
NASA Astrophysics Data System (ADS)
Lee, G.; Polidan, R. S.; Ross, F.
2015-12-01
The Northrop Grumman Aerospace Systems and L-Garde team has been developing an innovative mission concept: a long-lived, maneuverable platform to explore the Venus upper atmosphere. This capability is an implementation of our Lifting Entry Atmospheric Flight (LEAF) system concept, and the Venus implementation is called the Venus Atmospheric Maneuverable Platform (VAMP). The VAMP concept utilizes an ultra-low ballistic coefficient (< 50 Pa), semi-buoyant aircraft that deploys prior to entering the Venus atmosphere, enters without an aeroshell, and provides a long-lived (months to a year) maneuverable vehicle capable of carrying science instruments to explore the Venus upper atmosphere. In this presentation we provide an update on the air vehicle design and a low cost pathfinder mission concept that can be implemented in the near-term. The presentation also provides an overview of our plans for future trade studies, analyses, and prototyping to advance and refine the concept. We will discuss the air vehicle's entry concepts of operations (CONOPs) and atmospheric science operations. We will present a strawman concept of a VAMP pathfinder, including ballistic coefficient, planform area, percent buoyancy, wing span, vehicle mass, power supply, propulsion, materials considerations, structural elements, and instruments accommodation. In this context, we will discuss the following key factors impacting the design and performance of VAMP: Entry into the Venus atmosphere, including descent profile, heating rate, total heat load, stagnation, and acreage temperatures Impact of maximum altitude on air vehicle design and entry heating Candidate thermal protection system (TPS) requirements We will discuss the interdependencies of the above factors and the manner in which the VAMP pathfinder concept's characteristics affect the CONOPs and the science objectives. We will show how the these factors provide constraints as well as enable opportunities for novel long duration scientific studies of the Venus upper atmosphere that support Venus science goals. We will also discuss how the VAMP platform itself can facilitate some of these science measurements.
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Libyan Former Foreign Fighters and Their Effects on the Libyan Revolution
2012-03-23
Glocal organizations; Arab Spring; Sinjar Papers; CJSOTF 120; 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF PAGES 52...the Libyan Islamic Fighting Group (LIFG) ........................................................................ 13 LIFG and Al Qaeda: A “ Glocal ...to be specifically targeted.(27) LIFG and Al Qaeda Connections: A “ Glocal ” Operation(28) FORMER FOREIGN FIGHTERS AND THEIR EFFECTS ON THE LIBYAN
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Seri Rama: converting a shadow play puppet to Street Fighter.
Ghani, D B A
2012-01-01
Shadow puppet plays, a traditional Malaysian theater art, is slowly losing its appeal to adolescents, who prefer computer games. To help reverse this decline, the authors incorporated the traditional Seri Rama character into the Street Fighter video game. Using modeling, texturing, and animation, they developed a 3D Seri Rama prototype. Users can control Seri Rama with a PlayStation game controller.
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National Nanotechnology Initiative: The Initiative and Its Implementation Plan
2000-07-01
precisely controlled size and composition and then to assemble them into larger structures with unique properties and functions will revolutionize...thousand pounds could be stripped from a pilotless fighter aircraft , resulting in longer missions, and fighter agility could be dramatically improved...societal impact: $12 million. e. Major themes and new programs in FY 2001 include : • Nano-biotechnology: biosystems, bio-mimetics and composites (priority
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-15
... Environmental Impact Statement (EIS) for Proposed Conversion to the F-15 Aircraft for the 144th Fighter Wing... conversion to the F-15 aircraft at the 144th Fighter Wing (144 FW) installation at Fresno-Yosemite... action alternatives analyzed will be a conversion from 18 F-16 PAA to 18 F-15 PAA; or conversion to 24 F...
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William W. Momyer: A Biography of an Airpower Mind
2013-06-01
Europe to the Mediterranean and Soviet Union 1935-45 ( Helion and Company, West Midlands, England, 2010), 169. 22 Richard G. Davis, Carl A. Spaatz and... Helion and Company, West Midlands, England, 2010), 169. 31 60th Fighter Squadron History, 62-63; 58th Fighter Squadron History, 131; Craven and... Energy Commission (AEC) to recommend, “an intensification of efforts to make atomic weapons available for
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Joint Strike Figher Acquisition: Mature Critical Technologies Needed to Reduce Risks
2001-10-01
Reduce Risks GAO-02-39 Report Documentation Page Report Date 00OCT2001 Report Type N/A Dates Covered (from... to) - Title and Subtitle JOINT STRIKE...FIGHTER ACQUISITION: Mature Critical Technologies Needed to Reduce Risks Contract Number Grant Number Program Element Number Author(s) Project...1Joint Strike Fighter Acquisition: Development Schedule Should Be Changed to Reduce Risks (GAO/T-NSIAD-00-132
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Fire Fighter Trainer Environmental Considerations
1981-01-08
established by the Environmental Protection Agency and various state and local ordinances. At present, the Navy’s fire fighter train- ing facilities use...necessary. All operational capabilities for military communications equipment have been retained. Each training compartment has a local communications...the state or local air pollution-control agencies on a case-by-case basis. 4.2.4 Japanese Air Pollution-Control Regulations. The Japanese Air Quality
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Defeating Violent Nonstate Actors
2013-01-01
Chiefs of Staff, December 19, 2012), 38, 39. 4 Ibid. 5 Odierno, Amos, and McRaven, Strategic Landpower, 3. Fighting irregulAr Fighters Defeating...or Ringing Hollow?” Army, August 2013, 18-20. Fighting irregular Fighters Bunker 59 and corruption capability. Organized into private armies...the state. Via one process, the synergistic employment of violence and corruption, plato o plomo (silver or lead in Spanish), results in areas of
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German Foreign Fighters in Syria and Iraq
2016-03-01
players of a Saudi semi-professional soccer team mobilized as a group to travel and fight in Iraq.47 Yet the Saudi soccer squad is not the only...as their biographical availability and integration into German society. The study finds that German foreign fighters are primarily mobilized through...MASTER OF ARTS IN SECURITY STUDIES (MIDDLE EAST, SOUTH ASIA, SUB-SAHARAN AFRICA) from the NAVAL POSTGRADUATE SCHOOL March 2016
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Evans, Mark I; Eden, Robert D; Britt, David W; Evans, Shara M; Schifrin, Barry S
2018-02-28
Even key opinion leaders now concede that electronic fetal monitoring (EFM) cannot reliably identify fetal acidemia which many vouch as the only labor mediated pathophysiologic precursor for cerebral palsy (CP). We have developed the "Fetal Reserve Index" - an algorithm combining five dynamic components of EFM (1. Rate, 2. Variability, 3. Accelerations, 4. Decelerations, and 5. Excessive uterine activity) considered individually that are combined with the presence of: 6. maternal, 7. obstetrical, and 8. fetal risk factors. Here, we compare this 8-point fetal reserve index (FRI) against the performance of ACOG monograph criteria and ACOG Category systems for predicting risk for both CP and the need for emergency operative delivery (EOD). We then studied how varied management for screen positives (Red zone-defined below) impacts the outcome of such cases. Four hundred twenty term patients were studied: all entered labor with normal EFMs and no apparent cause of harm except events of labor and delivery. Sixty subsequently developed CP, and 360 were apparently normal controls. An FRI, normal on all eight parameters scored 100%, 4 of the 8 was 50%, etc. We divided cases into Green zone >50%, Yellow 50-26%, and Red ≤25%. An FRI in the Red zone was considered a positive screen. We then compared performance metrics for the three evaluation schemes and differences between controls that reached Red against those controls whose worst scores were Green/Yellow. For detection of injury during labor, the FRI performed much better than the ACOG Category criteria (sensitivity 28%), and Category III (45%) (p < .001). All CP cases reached Red zone and were Red for a minimum of 2 hours (mean = 5.35 hours). Twenty-four% of controls reached Red, but were only Red for average of 1 hr. The incidence of low Apgar's, pH, FRI, and Lowest FRI increased progressively from Green/Yellow controls to red controls to CP cases. Irrespective, CP cases met ACOG Monograph criteria for labor injury less than 50% of the time. Only half of CP babies had umbilical artery pH values <7.00, and less than 50% showed Category III patterns. The earlier in labor the Red zone was reached, the more likely for a baby to develop CP or the mother to require an EOD regardless of fetal outcome. Successful intrauterine resuscitations (IR) diminished time spent in the Red zone and the need for EODs. FRI shows better discrimination for adverse fetal outcome and EOD than traditional EFM interpretation. The Category system is a very poor, subjective screening method as the vast majority of CP babies never reach the "action point" result of Category III. While reaching the Red zone does not ordain a bad outcome, how it is managed, does. Compared to CP cases, Red controls were delivered faster, had higher FRIs, and often had prompt management including IR maneuvers, which improved the FRI and lowered the risk of EODs even for cases with normal outcomes. With further study and validation, the quantitative FRI approach may replace the current, very subjective interpretation with a quantitative "lab test" approach.
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Cross-sectional study of neck pain and cervical sagittal alignment in air force pilots.
Moon, Bong Ju; Choi, Kyong Ho; Yun, Chul; Ha, Yoon
2015-05-01
There is a high prevalence of neck pain in air force pilots; however, the causes are not clear and are considered work-related. Kyphotic changes in the cervical spine have been known to cause neck pain. In this study, we investigated the association between neck pain and cervical kyphosis in air force pilots. This is a cross-sectional study of 63 Republic of South Korea Air Force pilots. We examined the C2-7 absolute rotation angle (ARA) using the posterior tangent method and other radiologic parameters on whole spine lateral radiographs. We divided the participants into a neck pain group (N = 32) and no neck pain group (N = 31), and subsequently analyzed the difference in radiographic parameters and clinical data between the two groups. There were no significant differences found in age, body mass index, total flight time, or aerobic or anaerobic exercise between the neck pain and control groups. The fighter pilots had higher 1-yr prevalence of neck pain than nonfighter pilots (84.4% vs. 15.6%). The lower C2-7 ARA (OR = 0.91, 95% CI 0.846, 0.979) and fighter type aircrafts (OR = 3.93, 95% CI 1.104, 13.989) were associated with neck pain. Fighter pilots experienced neck pain more frequently than the nonfighter pilots. Those fighter pilots suffering from neck pain were shown to have more kyphotic changes in the cervical spine than control pilots through evaluation of whole spine lateral radiographs using the posterior tangent method. These key findings suggest that the forces involved in flying a fighter type aircraft may affect cervical alignment and neck pain.
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Home Cervical Traction to Reduce Neck Pain in Fighter Pilots.
Chumbley, Eric M; O'Hair, Nicole; Stolfi, Adrienne; Lienesch, Christopher; McEachen, James C; Wright, Bruce A
2016-12-01
Most fighter pilots report cervical pain during their careers. Recommendations for remediation lack evidence. We sought to determine whether regular use of a home cervical traction device could decrease reported cervical pain in F-15C pilots. An institutional review board-approved, Health Insurance Portability and Accountability Act-compliant, controlled crossover study was undertaken with 21 male F-15C fighter pilots between February and June 2015. Of the 21 subjects, 12 completed 6 wk each of traction and control, while logging morning, postflying, and post-traction pain. Pain was compared with paired t-tests between the periods, from initial pain scores to postflying, and postflying to post-traction. In the traction phase, initial pain levels increased postflight, from 1.2 (0.7) to 1.6 (1.0) Subsequent post-traction pain levels decreased to 1.3 (0.9), with a corresponding linear decrease in pain relative to pain reported postflight. The difference in pain levels after traction compared to initial levels was not significant, indicating that cervical traction was effective in alleviating flying-related pain. Control pain increased postflight from 1.4 (0.9) to 1.9 (1.3). Daily traction phase pain was lower than the control, but insignificant. To our knowledge, this is the first study of home cervical traction to address fighter pilots' cervical pain. We found a small but meaningful improvement in daily pain rating when using cervical traction after flying. These results help inform countermeasure development for pilots flying high-performance aircraft. Further study should clarify the optimal traction dose and timing in relation to flying.Chumbley EM, O'Hair N, Stolfi A, Lienesch C, McEachen JC, Wright BA. Home cervical traction to reduce neck pain in fighter pilots. Aerosp Med Hum Perform. 2016; 87(12):1010-1015.
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Development of infrared scene projectors for testing fire-fighter cameras
NASA Astrophysics Data System (ADS)
Neira, Jorge E.; Rice, Joseph P.; Amon, Francine K.
2008-04-01
We have developed two types of infrared scene projectors for hardware-in-the-loop testing of thermal imaging cameras such as those used by fire-fighters. In one, direct projection, images are projected directly into the camera. In the other, indirect projection, images are projected onto a diffuse screen, which is then viewed by the camera. Both projectors use a digital micromirror array as the spatial light modulator, in the form of a Micromirror Array Projection System (MAPS) engine having resolution of 800 x 600 with mirrors on a 17 micrometer pitch, aluminum-coated mirrors, and a ZnSe protective window. Fire-fighter cameras are often based upon uncooled microbolometer arrays and typically have resolutions of 320 x 240 or lower. For direct projection, we use an argon-arc source, which provides spectral radiance equivalent to a 10,000 Kelvin blackbody over the 7 micrometer to 14 micrometer wavelength range, to illuminate the micromirror array. For indirect projection, an expanded 4 watt CO II laser beam at a wavelength of 10.6 micrometers illuminates the micromirror array and the scene formed by the first-order diffracted light from the array is projected onto a diffuse aluminum screen. In both projectors, a well-calibrated reference camera is used to provide non-uniformity correction and brightness calibration of the projected scenes, and the fire-fighter cameras alternately view the same scenes. In this paper, we compare the two methods for this application and report on our quantitative results. Indirect projection has an advantage of being able to more easily fill the wide field of view of the fire-fighter cameras, which typically is about 50 degrees. Direct projection more efficiently utilizes the available light, which will become important in emerging multispectral and hyperspectral applications.
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NASA Astrophysics Data System (ADS)
Schastlivtsev, A. I.; Borzenko, V. I.
2017-11-01
The comparative feasibility study of the energy storage technologies showed good applicability of hydrogen-oxygen steam generators (HOSG) based energy storage systems with large-scale hydrogen production. The developed scheme solutions for the use of HOSGs for thermal power (TPP) and nuclear power plants (NPP), and the feasibility analysis that have been carried out have shown that their use makes it possible to increase the maneuverability of steam turbines and provide backup power supply in the event of failure of the main steam generating equipment. The main design solutions for the integration of hydrogen-oxygen steam generators into the main power equipment of TPPs and NPPs, as well as their optimal operation modes, are considered.
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NASA Technical Reports Server (NTRS)
Kauffman, William M; Liddell, Charles J , Jr; Smith, Allan; Van Dyke, Rudolph D , Jr
1949-01-01
An apparatus for varying effective dihedral in flight by means of servo actuation of the ailerons in response to sideslip angle is described. The results of brief flight tests of the apparatus on a conventional fighter airplane are presented and discussed. The apparatus is shown to have satisfactory simulated a wide range of effective dihedral under static and dynamic conditions. The effects of a small amount of servo lag are shown to be measurable when the apparatus is simulating small negative values of dihedral. However, these effects were not considered by the pilots to give the airplane an artificial feel. The results of an investigation employing the apparatus to determine the tolerable (safe for normal fighter operation) range of effective dihedral on the test airplane are presented.
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What boxing tells us about repetitive head trauma and the brain.
Bernick, Charles; Banks, Sarah
2013-01-01
Boxing and other combat sports may serve as a human model to study the effects of repetitive head trauma on brain structure and function. The initial description of what is now known as chronic traumatic encephalopathy (CTE) was reported in boxers in 1928. In the ensuing years, studies examining boxers have described the clinical features of CTE, its relationship to degree of exposure to fighting, and an array of radiologic findings. The field has been hampered by issues related to study design, lack of longitudinal follow-up, and absence of agreed-upon clinical criteria for CTE. A recently launched prospective cohort study of professional fighters, the Professional Fighters Brain Health Study, attempts to overcome some of the problems in studying fighters. Here, we review the cross-sectional results from the first year of the project.
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Historical development of worldwide supersonic aircraft
NASA Technical Reports Server (NTRS)
Spearman, M. L.
1979-01-01
Aerodynamic problems in the development of supersonic aircraft, their solutions, and innovative design features are presented. Studies of compressibility, introduction of jets, supersonic phenomena, transonic drag and lift, longitudinal and directional stability, dynamic pressure fields, and advent of the supersonic fighter are discussed. The flight research aircraft such as the Bell X-1 and the Douglas-558, the century series models, reconnaissance aircraft, the multimission tactical fighter, and the current generation fighters such as F-16 and F-18 are described. The SCAT program is considered, along with supersonic developments in Great Britain, France, and USSR. It is concluded that the sonic boom still appears to be an inherent problem of supersonic flight that particularly affects overland commercial flight, and efforts continue for increased efficiency for economic and performance gains and increased safety for military and civilian aircraft.
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Missouri River Recovery Management Plan and Environmental Impact Statement
2014-04-11
Proficient in hydrologic and hydraulic engineering computer models, particularly ResSim and HEC - RAS ; working experience with large river systems including...to help study teams determine ecosystem responses to changes in the flow regime of a river or connected wetland. HEC -EFM analyses involve: 1...Description of the Model and How It Will Be Applied in the Study Approval Status HEC - RAS The function of this model is to conduct one-dimensional hydraulic
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1976-09-01
1 dB into 50 ohm load, output VSWR less than 1.5. Phase variation relative to the optical pulse train less than +A.5 Rod Temperature...design of the PSQM laser. All phases of design, mechanical, electronic and optical , borrowed heavily from the EFM lamp pumped laser...opnical power input change for the germanium device is twice that for the silicon device, its random phase noise for a typical in- put of 1 mW optical
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ERIC Educational Resources Information Center
Aviation/Space, 1982
1982-01-01
Current aeronautical research is highlighted, focusing on tilt rotor aircraft, quiet short-haul jets, HiMAT (Highly Maneuverable Aircraft Technology), pivoting wing aircraft, energy absorption tests, and lightning research. (JN)
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Assessment of aerodynamic performance of V/STOL and STOVL fighter aircraft
NASA Technical Reports Server (NTRS)
Nelms, W. P.
1984-01-01
The aerodynamic performance of V/STOL and STOVL fighter/attack aircraft was assessed. Aerodynamic and propulsion/airframe integration activities are described and small and large scale research programs are considered. Uncertainties affecting aerodynamic performance that are associated with special configuration features resulting from the V/STOL requirement are addressed. Example uncertainties relate to minimum drag, wave drag, high angle of attack characteristics, and power induced effects.
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2010-06-01
138- 143 . 36 advancing bomber versus pursuit technology took on greater significance. The need to establish a balanced force was just one more...54 Watson, 138- 143 . 55 AAF Statistical Digest: World War II, December 1945, Table 79. The percentage...72 William Wolf American Fighter-Bombers in World War II: USAAF Jabos in the MTO and ETO (Atglen, PA: Schiffer
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A Communication Protocol for CyAMS and the Cyber Fighter Associate Interface
2015-05-01
by David Harman , Scott Brown, Brian Henz, and Lisa M Marvel Approved for public release; distribution unlimited...Laboratory A Communication Protocol for CyAMS and the Cyber Fighter Associate Interface by David Harman College Qualified Leaders Student...CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) David Harman , Scott Brown, Brian Henz, and Lisa M Marvel 5d. PROJECT
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Price vs. Performance: The Value of Next Generation Fighter Aircraft
2007-03-01
forms. Both the semi-log and log-log forms were plagued with heteroskedasticity (according to the Breusch - Pagan /Cook-Weisberg test ). The RDT&E models...from 1949-present were used to construct two models – one based on procurement costs and one based on research, design, test , and evaluation (RDT&E...fighter aircraft hedonic models include several different categories of variables. Aircraft procurement costs and research, design, test , and
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Reducing Air Force Fighter Pilot Shortages
2015-12-31
that active-component fighter pilot requirements (particularly nonflying staff requirements) exceed its capacity to train and provide initial...pilots in the reserve components. This research was sponsored by four elements of the U.S. Air Force: the Deputy Chief of Staff for Operations (AF/A3...the Deputy Chief of Staff for Manpower, Personnel and Services (AF/A1); the Commander, Air Force Reserve Command (AFRC/CC); and the Director, Air
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Signaling the End of Deterrence Afforded by Dual Capable Aircraft
2017-04-06
INTRODUCTION For more than 60 years, the Unites States and Europe relied on fighter aircraft capable of executing conventional and nuclear strike...missions. Known as dual-capable aircraft (DCA), these fighters were an integral part of the US extended nuclear deterrence strategy in Asia and Europe...force structure, sustainment and modernization by the US and Allied nations allowed tactical nuclear forces to atrophy. Starting in 2010, the US and
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Planning for Recall of Maintenance Manpower
2015-09-01
per hour as the MT supporting the reserve unit (assuming no premium is paid for hazard duty or locale adjustment). All tasks assigned to the MTs...fighter aircraft. Under certain conditions, the placement of these technicians in their roles as reserve personnel creates disproportionate economic...loss for the parent unit and the reserve unit. The results of an analysis of the F-15D fighter aircraft indicate that the organization costs of the
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Acute spinal injury after centrifuge training in asymptomatic fighter pilots.
Kang, Kyung-Wook; Shin, Young Ho; Kang, Seungcheol
2015-04-01
Many countries have hypergravity training centers using centrifuges for pilots to cope with a high gravity (G) environment. The high G training carries potential risk for the development of spinal injury. However, no studies evaluated the influence of centrifuge training on the spines of asymptomatic fighter pilots on a large scale. Study subjects were 991 male fighter pilots with high G training at one institution. Subject variables included information about physical characteristics, flight hours of pilots prior to the training, and G force exposure related factors during training. The two dependent variables were whether the pilots developed acute spinal injury after training and the severity of the injury (major/minor). The incidence of acute spinal injury after high G training was 2.3% (23 of 991 subjects). There were 19 subjects who developed minor injury and 4 subjects who developed a herniated intervertebral disc, which is considered a major injury. In multivariate analysis, only the magnitude of G force during training was significantly related to the development of acute spinal injury. However, there was no significant factor related to the severity of the injury. These results suggest that high G training could cause negative effects on fighter pilots' spines. The magnitude of G force during training seemed to be the most significant factor affecting the occurrence of acute spinal injury.
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Candidate control design metrics for an agile fighter
NASA Technical Reports Server (NTRS)
Murphy, Patrick C.; Bailey, Melvin L.; Ostroff, Aaron J.
1991-01-01
Success in the fighter combat environment of the future will certainly demand increasing capability from aircraft technology. These advanced capabilities in the form of superagility and supermaneuverability will require special design techniques which translate advanced air combat maneuvering requirements into design criteria. Control design metrics can provide some of these techniques for the control designer. Thus study presents an overview of control design metrics and investigates metrics for advanced fighter agility. The objectives of various metric users, such as airframe designers and pilots, are differentiated from the objectives of the control designer. Using an advanced fighter model, metric values are documented over a portion of the flight envelope through piloted simulation. These metric values provide a baseline against which future control system improvements can be compared and against which a control design methodology can be developed. Agility is measured for axial, pitch, and roll axes. Axial metrics highlight acceleration and deceleration capabilities under different flight loads and include specific excess power measurements to characterize energy meneuverability. Pitch metrics cover both body-axis and wind-axis pitch rates and accelerations. Included in pitch metrics are nose pointing metrics which highlight displacement capability between the nose and the velocity vector. Roll metrics (or torsion metrics) focus on rotational capability about the wind axis.
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Light weight escape capsule for fighter aircraft
NASA Technical Reports Server (NTRS)
Robert, James A.
1988-01-01
Emergency crew escape capabilities have been less than adequate for fighter aircraft since before WW II. From the over-the-side bailout of those days through the current ejection seat with a rocket catapult, escaping from a disabled aircraft has been risky at best. Current efforts are underway toward developing a high-tech, smart ejection seat that will give fighter pilots more room to live in the sky, but an escape capsule is needed to meet current and future fighter envelopes. Escape capsules have a bad reputation due to past examples of high weight, poor performance and great complexity. However, the advantages available demand that a capsule be developed. This capsule concept will minimize the inherent disavantages and incorporate the benefits while integrating all aspects of crew station design. The resulting design is appropriate for a crew station of the year 2010 and includes improved combat acceleration protection, chemical or biological combat capability, improved aircraft to escape system interaction, and the highest level of escape performance achievable. The capsule is compact, which can allow a reduced aircraft size and weighs only 1200 lb. The escape system weight penalty is only 120 lb higher than that for the next ejection seat and the capsule has a corresponding increase in performance.
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Life-history differences favor evolution of male dimorphism in competitive games.
Smallegange, Isabel M; Johansson, Jacob
2014-02-01
Many species exhibit two discrete male morphs: fighters and sneakers. Fighters are large and possess weapons but may mature slowly. Sneakers are small and have no weapons but can sneak matings and may mature quickly to start mating earlier in life than fighters. However, how differences in competitive ability and life history interact to determine male morph coexistence has not yet been investigated within a single framework. Here we integrate demography and game theory into a two-sex population model to study the evolution of strategies that result in the coexistence of fighters and sneakers. We incorporate differences in maturation time between the morphs and use a mating-probability matrix analogous to the classic hawk-dove game. Using adaptive dynamics, we show that male dimorphism evolves more easily in our model than in classic game theory approaches. Our results also revealed an interaction between life-history differences and sneaker competitiveness, which shows that demography and competitive games should be treated as interlinked mechanisms to understand the evolution of male dimorphism. Applying our approach to empirical data on bulb mites (Rhizoglyphus robini), coho salmon (Oncorhynchus kisutch), and bullhorned dung beetles (Onthophagus taurus) indicates that observed occurrences of male dimorphism are in general agreement with model predictions.
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Carter, Gerald; Schoeppler, Diana; Manthey, Marie; Knörnschild, Mirjam; Denzinger, Annette
2015-01-01
Many birds and mammals produce distress calls when captured. Bats often approach speakers playing conspecific distress calls, which has led to the hypothesis that bat distress calls promote cooperative mobbing. An alternative explanation is that approaching bats are selfishly assessing predation risk. Previous playback studies on bat distress calls involved species with highly maneuverable flight, capable of making close passes and tight circles around speakers, which can look like mobbing. We broadcast distress calls recorded from the velvety free-tailed bat, Molossus molossus, a fast-flying aerial-hawker with relatively poor maneuverability. Based on their flight behavior, we predicted that, in response to distress call playbacks, M. molossus would make individual passing inspection flights but would not approach in groups or approach within a meter of the distress call source. By recording responses via ultrasonic recording and infrared video, we found that M. molossus, and to a lesser extent Saccopteryx bilineata, made more flight passes during distress call playbacks compared to noise. However, only the more maneuverable S. bilineata made close approaches to the speaker, and we found no evidence of mobbing in groups. Instead, our findings are consistent with the hypothesis that single bats approached distress calls simply to investigate the situation. These results suggest that approaches by bats to distress calls should not suffice as clear evidence for mobbing. PMID:26353118
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Carter, Gerald; Schoeppler, Diana; Manthey, Marie; Knörnschild, Mirjam; Denzinger, Annette
2015-01-01
Many birds and mammals produce distress calls when captured. Bats often approach speakers playing conspecific distress calls, which has led to the hypothesis that bat distress calls promote cooperative mobbing. An alternative explanation is that approaching bats are selfishly assessing predation risk. Previous playback studies on bat distress calls involved species with highly maneuverable flight, capable of making close passes and tight circles around speakers, which can look like mobbing. We broadcast distress calls recorded from the velvety free-tailed bat, Molossus molossus, a fast-flying aerial-hawker with relatively poor maneuverability. Based on their flight behavior, we predicted that, in response to distress call playbacks, M. molossus would make individual passing inspection flights but would not approach in groups or approach within a meter of the distress call source. By recording responses via ultrasonic recording and infrared video, we found that M. molossus, and to a lesser extent Saccopteryx bilineata, made more flight passes during distress call playbacks compared to noise. However, only the more maneuverable S. bilineata made close approaches to the speaker, and we found no evidence of mobbing in groups. Instead, our findings are consistent with the hypothesis that single bats approached distress calls simply to investigate the situation. These results suggest that approaches by bats to distress calls should not suffice as clear evidence for mobbing.
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Quantification of Viral and Prokaryotic Production Rates in Benthic Ecosystems: A Methods Comparison
Rastelli, Eugenio; Dell’Anno, Antonio; Corinaldesi, Cinzia; Middelboe, Mathias; Noble, Rachel T.; Danovaro, Roberto
2016-01-01
Viruses profoundly influence benthic marine ecosystems by infecting and subsequently killing their prokaryotic hosts, thereby impacting the cycling of carbon and nutrients. Previously conducted studies, based on different methodologies, have provided widely differing estimates of the relevance of viruses on benthic prokaryotes. There has been no attempt so far to compare these independent approaches, including contextual comparisons among different approaches for sample manipulation (i.e., dilution or not of the sediments during incubations), between methods based on epifluorescence microscopy (EFM) or radiotracers, and between the use of different radiotracers. Therefore, it has been difficult to identify the most suitable methodologies and protocols to be used as standard approaches for the quantification of viral infections of prokaryotes. Here, we compared for the first time different methods for determining viral and prokaryotic production rates in marine sediments collected at two benthic sites, differing in depth and environmental conditions. We used a highly replicated experimental design, testing the potential biases associated to the incubation of sediments as diluted or undiluted. In parallel, we also compared EFM counts with the 3H-thymidine incubations for the determination of viral production rates, and the use of 3H-thymidine versus 3H-leucine radiotracers for the determination of prokaryotic production. We show here that, independent from sediment dilution, EFM-based values of viral production ranged from 1.4 to 4.6 × 107 viruses g-1 h-1, and were similar but overall less variable compared to those obtained by the 3H-thymidine method (0.3 to 9.0 × 107 viruses g-1h-1). In addition, the prokaryotic production rates were not affected by sediment dilution, and the use of different radiotracers provided very consistent estimates (10.3–35.1 and 9.3–34.6 ngC g-1h-1 using the 3H-thymidine or 3H-leucine method, respectively). These results indicated that viral lysis was responsible for the abatement of 55–81% of the prokaryotic heterotrophic production, corroborating previous findings of the major role of viruses in benthic deep-sea ecosystems. Moreover, our methodological comparison for the analysis of viral production in marine sediments suggests that microscopy-based approaches are simpler and more cost-effective than those based on radiotracers. These approaches also reduce time to results and overcome issues related to generation of radioactive waste. PMID:27713739
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Living Expert System (LEXSYS). Volume 6
1989-05-15
NOT CONSIDER A FAST MOVER A THREAT UNLESS YOU ARE THINKING ABOUT THE FLOT AREA. AWAY FROM THE FLOT DEFENSIVE ARRAY FIGHTERS HAVE THE LUXURY TO FLY...HIGHER, INCREASING THEIR RADAR COVERAGE AND DENYING YOUR EFFECTIVE USE OF MASKING. I WOULD AGREE THAT AROUND THE FLOT FIGHTERS ARE MOVING TO FAST AND...SAY THAT AFTER IT COMES OFF THE RAIL, COUNTERMEASURES ARE FEW AND FAR BETWEEN. IN DAYLIGHT, HIGH ANGLE STRAFE IS VERY EFFECTIVE AGAINST HELOS BECAUSE
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2016-09-01
severe. Chapter III begins the first part of the comparative case study analysis by focusing on Canada’s current foreign fighter issues, propaganda...violence in their home countries. Through an extensive comparative case study analysis of recent ISIL-related violent incidents and plots in the United...overseas, decided instead to alter their targeting trajectory and commit violence in their home countries. Through an extensive comparative case study
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2013-12-01
equity employed). Customer measures, such as customer satisfaction , are intended to measure the company’s performance from the customer’s perspective...link between a non-financial measure and a firm’s financial performance. For example, one could meet objectives relating to customer satisfaction ... customer satisfaction . Who then is the customer of a strike fighter squadron? Kaplan and Norton (2004) write extensively about 61 the value
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Neil Armstrong Family Memorial Service
2012-08-31
U.S. Navy F/A-18 jets from Strike Fighter Squadron (VFA) 106 and Strike Fighter Squadron (VFA) 34, from Naval Air Station Oceana (Va.) fly in a "Missing Man" formation over the Camargo Club following a memorial service celebrating the life of Neil Armstrong, Friday, Aug. 31, 2012, in Cincinnati. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit: (NASA/Bill Ingalls)
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Air Base Attacks and Defensive Counters: Historical Lessons and Future Challenges
2015-01-01
I. Reid, Murray Scot Tanner, and Barry Wilson, A Question of Balance: Political Context and Military Aspects of the China–Taiwan Dispute, Santa...this case, Ramstein AB, Germany) placed fighter shelters on loops in woods . Although the shelters are clearly visible from directly overhead in...this image, placing them in woods would have made target acquisition and attack more difficult for Warsaw Pact fighters. That is because, in the 1970s
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DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1996-01-01
Decision Document for IRP Site No. 3 - Storage Area at the USMC Sublease Area, California Air National Guard, 144th Fighter Wing, Fresno Air Terminal, Fresno, California. This report documents the data, conclusion, and recommendation to support a No Further Remedial Action Planned decision at Site 3 under the IRP.
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Historic Properties Report: Stratford Army Engine Plant, Connecticut.
1984-07-01
aircraft, Pan American began flights to Argentina, Hawaii, and New Zealand , and by August 1934 the Sikorsky S-42 airplane had set world records for...384;or a lengthy discussion of the Corsair , see William Green, Famous Fighters of the Second World War (Garden City, New York: Doubleday), pp. 79-92...manufacture the Corsair fighter plane. Presently, the Avco Lycoming Division uses the facility to develop and manufacture gas turbine engines. There are
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NASA Technical Reports Server (NTRS)
Roskam, J.; Hamler, F. R.; Reynolds, D.
1972-01-01
The procedures used to establish the mass matrices characteristics for the fighter type wings studied are given. A description of the procedure used to find the mass associated with a specific aerodynamic panel is presented and some examples of the application of the procedure are included.
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Effects of UAV Supervisory Control on F-18 Formation Flight Performance in a Simulator Environment
2013-03-01
words) Continual advances in technology, along with increased cockpit workload— particularly the shift from two- seat to single- seat fighters to save...INTENTIONALLY LEFT BLANK v ABSTRACT Continual advances in technology, along with increased cockpit workload— particularly the shift from two- seat to...single- seat fighters to save money and reduce risk to life—push the limits of human mental capacity. Additionally, there is interest within the
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Environmental Assessment for a Fighter Detachment Facility, Shaw Air Force Base, South Carolina
2005-04-01
provides for the protection and propagation of fish, shellfish, wildlife, and recreation in and on the water. The US Army Corps of Engineers (USACE) is...scirpoides Long-beaked baldrush - SC Floating mats in ponds; pond margins. Ruellia caroliniensis A petunia - SC Woods and wood margins. Sagittaria...supply after conventional treatment, fishing, and the survival and propagation of a balanced indigenous aquatic Final EA for a Fighter Detachment
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NASA Technical Reports Server (NTRS)
Malcolm, G. N.; Schiff, L. B.
1985-01-01
Two rotary balance apparatuses were developed for testing airplane models in a coning motion. A large scale apparatus, developed for use in the 12-Foot Pressure Wind tunnel primarily to permit testing at high Reynolds numbers, was recently used to investigate the aerodynamics of 0.05-scale model of the F-15 fighter aircraft. Effects of Reynolds number, spin rate parameter, model attitude, presence of a nose boom, and model/sting mounting angle were investigated. A smaller apparatus, which investigates the aerodynamics of bodies of revolution in a coning motion, was used in the 6-by-6 foot Supersonic Wind Tunnel to investigate the aerodynamic behavior of a simple representation of a modern fighter, the Standard Dynamic Model (SDM). Effects of spin rate parameter and model attitude were investigated. A description of the two rigs and a discussion of some of the results obtained in the respective test are presented.
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Development and flight test experiences with a flight-crucial digital control system
NASA Technical Reports Server (NTRS)
Mackall, Dale A.
1988-01-01
Engineers and scientists in the advanced fighter technology integration (AFTI) F-16 program investigated the integration of emerging technologies into an advanced fighter aircraft. AFTI's three major technologies included: flight-crucial digital control, decoupled aircraft flight control, and integration of avionics, flight control, and pilot displays. In addition to investigating improvements in fighter performance, researchers studied the generic problems confronting the designers of highly integrated flight-crucial digital control. An overview is provided of both the advantages and problems of integration digital control systems. Also, an examination of the specification, design, qualification, and flight test life-cycle phase is provided. An overview is given of the fault-tolerant design, multimoded decoupled flight control laws, and integrated avionics design. The approach to qualifying the software and system designs is discussed, and the effects of design choices on system qualification are highlighted.
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NASA Technical Reports Server (NTRS)
Tomek, W. G.; Hall, R. M.; Wahls, R. A.; Luckring, J. M.; Owens, L. R.
2002-01-01
A wind tunnel test of a generic fighter configuration was tested in the National Transonic Facility through a cooperative agreement between NASA Langley Research Center and McDonnell Douglas. The primary purpose of the test was to assess Reynolds number scale effects on a thin-wing, fighter-type configuration up to full-scale flight conditions (that is, Reynolds numbers of the order of 60 million). The test included longitudinal and lateral/directional studies at subsonic and transonic conditions across a range of Reynolds numbers from that available in conventional wind tunnels to flight conditions. Results are presented for three Mach numbers (0.6, 0.8, and 0.9) and three configurations: (1) Fuselage/Wing; (2) Fuselage/Wing/Centerline Vertical Tail/Horizontal Tail; and (3) Fuselage/Wing/Trailing-Edge Extension/Twin Vertical Tails. Reynolds number effects on the longitudinal aerodynamic characteristics are presented herein.
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NASA Technical Reports Server (NTRS)
Nelms, W. P., Jr.; Axelson, J. A.
1974-01-01
A computerized synthesis program has been used to assess the effects of various vehicle and mission parameters on the performance of a highly maneuverable remotely piloted vehicle (RPV) for the air-to-air combat role. The configuration used in the study is a trapezoidal-wing and body concept, with forward-mounted stabilizing and control surfaces. The study mission consists of an outbound cruise, an acceleration phase, a series of subsonic and supersonic turns, and a return cruise. Performance is evaluated in terms of both the required vehicle weight to accomplish this mission and combat effectiveness as measured by turning and acceleration capability. The report describes the synthesis program, the mission, the vehicle, and the results of sensitivity and trade studies.
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Informedia at TRECVID2014: MED and MER, Semantic Indexing, Surveillance Event Detection
2014-11-10
multiple ranked lists for a given system query. Our system incorporates various retrieval methods such as Vector Space Model, tf-idf, BM25, language...separable space before applying the linear classifier. As the EFM is an approximation, we run the risk of a slight drop in performance. Figure 4 shows...validation set are fused. • CMU_Run3: After removing junk shots (by the junk /black frame detectors), MultiModal Pseudo Relevance Feedback (MMPRF) [12
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Exercise capacity, muscle strength and fatigue in sarcoidosis.
Marcellis, R G J; Lenssen, A F; Elfferich, M D P; De Vries, J; Kassim, S; Foerster, K; Drent, M
2011-09-01
The aim of this case-control study was to investigate the prevalence of exercise intolerance, muscle weakness and fatigue in sarcoidosis patients. Additionally, we evaluated whether fatigue can be explained by exercise capacity, muscle strength or other clinical characteristics (lung function tests, radiographic stages, prednisone usage and inflammatory markers). 124 sarcoidosis patients (80 males) referred to the Maastricht University Medical Centre (Maastricht, the Netherlands) were included (mean age 46.6±10.2 yrs). Patients performed a 6-min walk test (6MWT) and handgrip force (HGF), elbow flexor muscle strength (EFMS), quadriceps peak torque (QPT) and hamstring peak torque (HPT) tests. Maximal inspiratory pressure (P(I,max)) was recorded. All patients completed the Fatigue Assessment Scale (FAS) questionnaire. The 6MWT was reduced in 45% of the population, while HGF, EFMS, QPT and HPT muscle strength were reduced in 15, 12, 27 and 18%, respectively. P(I,max) was reduced in 43% of the population. The majority of the patients (81%) reported fatigue (FAS ≥22). Patients with reduced peripheral muscle strength of the upper and/or lower extremities were more fatigued and demonstrated impaired lung functions, fat-free mass, P(I,max), 6MWT and quality of life. Fatigue was neither predicted by exercise capacity, nor by muscle strength. Besides fatigue, exercise intolerance and muscle weakness are frequent problems in sarcoidosis. We therefore recommend physical tests in the multidisciplinary management of sarcoidosis patients, even in nonfatigued patients.
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Mapping nanometric electronic property changes induced by an aryl diazonium sub-monolayer on HOPG.
González, M C R; Carro, P; Vázquez, L; Creus, A H
2016-10-26
The morphology as well as the electric and electronic properties of aryl diazonium, in particular 4-nitrobenzene-diazonium (NBD), films on HOPG surfaces have been studied at the nanoscale level. By controlling the 2,2-diphenyl-1-picrylhydrazyl concentration during the NBD film growth, we have been able to control the thickness of the layer. The implications of NBD submonolayer adsorption on the electrical properties of this system have been analysed through Density Functional Theory (DFT) calculations, Atomic Force (AFM), Electric Force (EFM) and Kelvin Probe Force (KPFM) microscopies. DFT simulations showed that the NBD molecule adsorbs almost perpendicularly to the HOPG surface, which was confirmed experimentally through AFM imaging in the dynamic mode. In addition, DFT calculations showed that the adsorbed NBD has an appreciable dipole moment directed towards the HOPG surface and along the vertical direction of the HOPG surface. The existence of this dipole is the origin of the EFM contrast observed between the NBD-free and NBD-covered regions when a bias of -2 V was applied to the tip. Besides, the KPFM measurements show that the NBD adsorption leads to higher work function values, which is in agreement with the DFT calculations. Noticeably, our studies show that the KPFM signal is sensitive to the partial NBD coverage of the HOPG surface below the monolayer level.
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Apollo display and keyboard unit (DSKY) used on F-8 DFBW
NASA Technical Reports Server (NTRS)
1996-01-01
The display and keyboard (DSKY) unit used on the F-8 Digital Fly-By-Wire (DFBW) aircraft during Phase I of the fly-by-wire program. Warning lights are in the upper left section, displays in the upper right, and the keyboard is in the lower section. The Apollo flight-control system used in Phase I of the DFBW program had been used previously on the Lunar Module and was incredibly reliable. The DSKY was one element of the system. Also part of the fly-by-wire control system was the inertial platform. Both the computer and the inertial platform required a cooling system that used liquid nitrogen to keep the system within temperature limits. Should the primary flight control system fail, a backup system using three analog computers would automatically take over. The F-8 DFBW had no manual backup. The F-8 Digital Fly-By-Wire (DFBW) flight research project validated the principal concepts of all-electric flight control systems now used on nearly all modern high-performance aircraft and on military and civilian transports. The first flight of the 13-year project was on May 25, 1972, with research pilot Gary E. Krier at the controls of a modified F-8C Crusader that served as the testbed for the fly-by-wire technologies. The project was a joint effort between the NASA Flight Research Center, Edwards, California, (now the Dryden Flight Research Center) and Langley Research Center. It included a total of 211 flights. The last flight was December 16, 1985, with Dryden research pilot Ed Schneider at the controls. The F-8 DFBW system was the forerunner of current fly-by-wire systems used in the space shuttles and on today's military and civil aircraft to make them safer, more maneuverable, and more efficient. Electronic fly-by-wire systems replaced older hydraulic control systems, freeing designers to design aircraft with reduced in-flight stability. Fly-by-wire systems are safer because of their redundancies. They are more maneuverable because computers can command more frequent adjustments than a human pilot can. For airliners, computerized control ensures a smoother ride than a human pilot alone can provide. Digital-fly-by-wire is more efficient because it is lighter and takes up less space than the hydraulic systems it replaced. This either reduces the fuel required to fly or increases the number of passengers or pounds of cargo the aircraft can carry. Digital fly-by-wire is currently used in a variety of aircraft ranging from F/A-18 fighters to the Boeing 777. The DFBW research program is considered one of the most significant and most successful NASA aeronautical programs since the inception of the agency. F-8 aircraft were built originally for the U.S. Navy by LTV Aerospace of Dallas, Texas. The aircraft had a wingspan of 35 feet, 2 inches; was 54 feet, 6 inches long; and was powered by a Pratt & Whitney J57 turbojet engine.
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Study of aerodynamic technology for single-cruise-engine V/STOL fighter/attack aircraft
NASA Technical Reports Server (NTRS)
Hess, J. R.; Bear, R. L.
1982-01-01
A viable, single engine, supersonic V/STOL fighter/attack aircraft concept was defined. This vectored thrust, canard wing configuration utilizes an advanced technology separated flow engine with fan stream burning. The aerodynamic characteristics of this configuration were estimated and performance evaluated. Significant aerodynamic and aerodynamic propulsion interaction uncertainties requiring additional investigation were identified. A wind tunnel model concept and test program to resolve these uncertainties and validate the aerodynamic prediction methods were defined.
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Communicating Why: Aligning the Air Force Message
2015-02-17
innovation as the Air Force’s HOW, after all the service could not have demonstrated its WHY without it. For example, Lt Col Jimmy Doolittle ...the Doolittle Raid.54 Later in the war, General Doolittle’s first order as the newly appointed commander of the 8th Air Force was to free the...fighters from their strict bomber tether so they could go on the offensive against the German fighters.55 As Doolittle later noted, the German General of
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2017-06-09
of strategic bombing . Douhet’s theory of airpower rested on four principles. First, the inherent strength of the defense on land would result in...Douhet envisioned the destruction of both the enemy’s airpower and economic capability to produce airpower through strategic bombing .6 While admitting...340-444. 3 fighter aircraft, Douhet believed that fighters were vulnerable to bombing and that their effectiveness after the initial stages of
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F-35 Joint Strike Fighter Aircraft (F-35)
2015-12-01
Selected Acquisition Report ( SAR ) RCS: DD-A&T(Q&A)823-198 F-35 Joint Strike Fighter Aircraft (F-35) As of FY 2017 President’s Budget Defense...Acquisition Management Information Retrieval (DAMIR) March 21, 2016 08:47:09 UNCLASSIFIED F-35 December 2015 SAR March 21, 2016 08:47:09 UNCLASSIFIED 2...Document OSD - Office of the Secretary of Defense O&S - Operating and Support PAUC - Program Acquisition Unit Cost F-35 December 2015 SAR March 21
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Dynamic Function Allocation in Fighter Cockpits.
1987-06-30
their ability to play the video game simulation used in this study. This was done in an attempt to conceptually match the subject’s skills to those of...highly trained Air Force pilots. 4 Apparatus Simulation. A single seat fighter cockpit environment was simulated using the F-15 Strike Eagle video game developed...simulator containing three color CRTs. The video game was presented on the CRT located in the HUD position. The subjects controlled the game through a
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Viper NHEXS Program: A Viper Pilot Neck Health & Conditioning Guide
2012-11-01
recommended in this manual. The Neck vs. Gs Problem At least one acute neck pain episode is reported to occur in an estimated 85% of all pilots flying...high-performance fighter type aircraft, with the yearly prevalence of neck-related pain for all pilots at 56% [1]. Vandebeek reported over 50% of...72% of fighter pilots experience neck pain in relation to flying, while 35% experience some low back pain . The reported average G level for acute
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STOCHASTIC DUELS OF LIMITED TIME-DURATION,
This paper continues the development of the theory of stochastic duels to include the case where there is a time limitation on the duration of the... duel . An example of this situation is fighter-bomber combat in which the fighter has a very limited fuel supply. In this duel , two contestants (with...variable or (2) constant. The duel proceeds until one or both of the contestants are killed or until the time limit is exceeded. The time limit is either
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2007-02-01
which is used by the model to drive the normal activities of the crew (Figure C.1-2). These routines consist of a sequential list of high- level...separately. Figure C.1-3: Resources & Logic Sheet C.1.1.4 Scenario The scenario that is performed during a model run is a sequential list of all...were marked with a white fore and aft lineup stripe on both landing spots. Current Sea Fighter design does not provide a hangar; however, there
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Smart Power: The United States, Iran, and a Nuclear Deal
2014-05-22
fighter aircraft to the Arabian Peninsula.2 1Aljazeera, “Iranian fighters ’fired on US drone in Gulf’,” http://www.aljazeera.com /news/middleeast...declared the Anglo-Iranian Oil Company (AIOC) nationalized on May 1, and in return promised compensation . He set up the National Iranian Oil...Italy, Japan, and the United States. 23Bill, 16. 24William O. Beeman, The “Great Satan” vs. the “ Mad Mullahs (Westport, CT: Greenwood Publishing
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Bernick, Charles; Banks, Sarah J; Shin, Wanyong; Obuchowski, Nancy; Butler, Sam; Noback, Michael; Phillips, Michael; Lowe, Mark; Jones, Stephen; Modic, Michael
2015-01-01
Objectives Cumulative head trauma may alter brain structure and function. We explored the relationship between exposure variables, cognition and MRI brain structural measures in a cohort of professional combatants. Methods 224 fighters (131 mixed martial arts fighters and 93 boxers) participating in the Professional Fighters Brain Health Study, a longitudinal cohort study of licensed professional combatants, were recruited, as were 22 controls. Each participant underwent computerised cognitive testing and volumetric brain MRI. Fighting history including years of fighting and fights per year was obtained from self-report and published records. Statistical analyses of the baseline evaluations were applied cross-sectionally to determine the relationship between fight exposure variables and volumes of the hippocampus, amygdala, thalamus, caudate, putamen. Moreover, the relationship between exposure and brain volumes with cognitive function was assessed. Results Increasing exposure to repetitive head trauma measured by number of professional fights, years of fighting, or a Fight Exposure Score (FES) was associated with lower brain volumes, particularly the thalamus and caudate. In addition, speed of processing decreased with decreased thalamic volumes and with increasing fight exposure. Higher scores on a FES used to reflect exposure to repetitive head trauma were associated with greater likelihood of having cognitive impairment. Conclusions Greater exposure to repetitive head trauma is associated with lower brain volumes and lower processing speed in active professional fighters. PMID:25633832
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14 CFR 29.143 - Controllability and maneuverability.
Code of Federal Regulations, 2010 CFR
2010-01-01
... occurs with maximum continuous power and critical weight. No corrective action time delay for any... pilot reaction time (whichever is greater); and (ii) For any other condition, normal pilot reaction time...
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Maneuvers during legged locomotion
NASA Astrophysics Data System (ADS)
Jindrich, Devin L.; Qiao, Mu
2009-06-01
Maneuverability is essential for locomotion. For animals in the environment, maneuverability is directly related to survival. For humans, maneuvers such as turning are associated with increased risk for injury, either directly through tissue loading or indirectly through destabilization. Consequently, understanding the mechanics and motor control of maneuverability is a critical part of locomotion research. We briefly review the literature on maneuvering during locomotion with a focus on turning in bipeds. Walking turns can use one of several different strategies. Anticipation can be important to adjust kinematics and dynamics for smooth and stable maneuvers. During running, turns may be substantially constrained by the requirement for body orientation to match movement direction at the end of a turn. A simple mathematical model based on the requirement for rotation to match direction can describe leg forces used by bipeds (humans and ostriches). During running turns, both humans and ostriches control body rotation by generating fore-aft forces. However, whereas humans must generate large braking forces to prevent body over-rotation, ostriches do not. For ostriches, generating the lateral forces necessary to change movement direction results in appropriate body rotation. Although ostriches required smaller braking forces due in part to increased rotational inertia relative to body mass, other movement parameters also played a role. Turning performance resulted from the coordinated behavior of an integrated biomechanical system. Results from preliminary experiments on horizontal-plane stabilization support the hypothesis that controlling body rotation is an important aspect of stable maneuvers. In humans, body orientation relative to movement direction is rapidly stabilized during running turns within the minimum of two steps theoretically required to complete analogous maneuvers. During straight running and cutting turns, humans exhibit spring-mass behavior in the horizontal plane. Changes in the horizontal projection of leg length were linearly related to changes in horizontal-plane leg forces. Consequently, the passive dynamic stabilization associated with spring-mass behavior may contribute to stability during maneuvers in bipeds. Understanding the mechanics of maneuverability will be important for understanding the motor control of maneuvers and also potentially be useful for understanding stability.
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Effect of wood smoke exposure on vascular function and thrombus formation in healthy fire fighters.
Hunter, Amanda L; Unosson, Jon; Bosson, Jenny A; Langrish, Jeremy P; Pourazar, Jamshid; Raftis, Jennifer B; Miller, Mark R; Lucking, Andrew J; Boman, Christoffer; Nyström, Robin; Donaldson, Kenneth; Flapan, Andrew D; Shah, Anoop S V; Pung, Louis; Sadiktsis, Ioannis; Masala, Silvia; Westerholm, Roger; Sandström, Thomas; Blomberg, Anders; Newby, David E; Mills, Nicholas L
2014-12-09
Myocardial infarction is the leading cause of death in fire fighters and has been linked with exposure to air pollution and fire suppression duties. We therefore investigated the effects of wood smoke exposure on vascular vasomotor and fibrinolytic function, and thrombus formation in healthy fire fighters. In a double-blind randomized cross-over study, 16 healthy male fire fighters were exposed to wood smoke (~1 mg/m³ particulate matter concentration) or filtered air for one hour during intermittent exercise. Arterial pressure and stiffness were measured before and immediately after exposure, and forearm blood flow was measured during intra-brachial infusion of endothelium-dependent and -independent vasodilators 4-6 hours after exposure. Thrombus formation was assessed using the ex vivo Badimon chamber at 2 hours, and platelet activation was measured using flow cytometry for up to 24 hours after the exposure. Compared to filtered air, exposure to wood smoke increased blood carboxyhaemoglobin concentrations (1.3% versus 0.8%; P < 0.001), but had no effect on arterial pressure, augmentation index or pulse wave velocity (P > 0.05 for all). Whilst there was a dose-dependent increase in forearm blood flow with each vasodilator (P < 0.01 for all), there were no differences in blood flow responses to acetylcholine, sodium nitroprusside or verapamil between exposures (P > 0.05 for all). Following exposure to wood smoke, vasodilatation to bradykinin increased (P = 0.003), but there was no effect on bradykinin-induced tissue-plasminogen activator release, thrombus area or markers of platelet activation (P > 0.05 for all). Wood smoke exposure does not impair vascular vasomotor or fibrinolytic function, or increase thrombus formation in fire fighters. Acute cardiovascular events following fire suppression may be precipitated by exposure to other air pollutants or through other mechanisms, such as strenuous physical exertion and dehydration.
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Feedback Control of Rotor Overspeed
NASA Technical Reports Server (NTRS)
Churchill, G. B.
1984-01-01
Feedback system for automatically governing helicopter rotor speed promises to lessen pilot's workload, enhance maneuverability, and protect airframe. With suitable modifications, concept applied to control speed of electrical generators, automotive engines and other machinery.
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14 CFR 27.143 - Controllability and maneuverability.
Code of Federal Regulations, 2010 CFR
2010-01-01
... failure occurs with maximum continuous power and critical weight. No corrective action time delay for any... pilot reaction time (whichever is greater); and (ii) For any other condition, normal pilot reaction time...
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Study of aerodynamic technology for single-cruise-engine VSTOL fighter/attack aircraft, phase 1
NASA Technical Reports Server (NTRS)
Foley, W. H.; Sheridan, A. E.; Smith, C. W.
1982-01-01
A conceptual design and analysis on a single engine VSTOL fighter/attack aircraft is completed. The aircraft combines a NASA/deHavilland ejector with vectored thrust and is capable of accomplishing the mission and point performance of type Specification 169, and a flight demonstrator could be built with an existing F101/DFE engine. The aerodynamic, aero/propulsive, and propulsive uncertainties are identified, and a wind tunnel program is proposed to address those uncertainties associated with wing borne flight.
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Accurate Modeling of Stability and Control Properties for Fighter Aircraft from CFD
2012-03-01
first an aircraft to flight test which is not until late in the design phase where millions if not billions of dollars have already been invested. It...of an aircraft and even late in the design phase there are often large gaps in data due to budget cuts to flight testing and limitations to maneuvers...early in the design cycle has been the source of many costly fixes to fighter aircraft after flight testing begins. Early prediction of these nonlinear
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1988-02-01
capabilities at the start of a programme. ,Z _ 1. Introduction The flight manoeuvre loads are major design criteria for agile aircraft (aerobatic...E. Van Patten, Ph.D. Armstrong Aerospace Medical Research Laboratory Wright-Patterson AFB, OH 45433-6573 USA INTRODUCTION ~ urrent Fighter...anticipated usage. Also, compliance with each condition mit he verified by analysis, model test, or full scale measurement. INTRODUCTION During the
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Combat Leadership: 56th Fighter Group 1943-1944.
1986-04-01
September-October 1970, pp. 30-35. Meyer, John C ., Col, USAF. "What Makes a Jet Ace?" Air Trails, October 1952, p. 21. Ritchey, Russell V. "Identifying...A-Ri68 864 COMBAT LEADERSHIP: 56TH FIGHTER GROUP i947-1944(U) AIR 1/1 COMMAND AND STAFF COLL MAXWELL RFB RL T L LENTZ APR 86I ACSC-86-1525...Interlibrary Loan Service (AUL/LDEX, Maxwell AFB, Alabama, 36112) or the Defense Technical Information Center. Request 4 must include the author’s name and
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2014-10-01
Arming and Refueling Points for Fighter Aircraft Feature Fifth-Generation Doolittle Raid If we should have to fight, we should be prepared to do so from...the neck up instead of from the neck down. —Gen Jimmy Doolittle The famous Doolittle Raid during World War II offers a superb exam- ple of how an...innovative concept can lead to strategic effects. On 18 April 1942, just four months after the Japanese attack on Pearl Harbor, Lt Col Jimmy Doolittle
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1986-06-01
PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGANIZATION (Ii’ ppticable) Sc. ADDRESS (City, State and ZIP Code) 10. SOURCE OF FUNDING NOS...total of 60 KC-10s were available to support the fighter deployment. This number represented the projected KC-10 procurement for the year 1990 as...search for relevant government studies was accomplished through the Defense Technical Information Center (DTIC). All their 3-9 research related to
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Then and Now: Comparing the Flow of Foreign Fighters to AQI and the Islamic State
2016-12-01
State during separate blocks of time . Second, it provides insight into the local travel and flow of foreign fighters across time , and the mobilization...who joined the Islamic State during that latter time period also traveled alone more frequently. When they didn’t travel alone, they arrived in...arriving at the caliphate are larger than they were during the time period covered by the Sinjar records. A couple of cases of group travel to Syria
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Western Foreign Fighters in Syria: An Empirical Analysis of Recruitment and Mobilization Mechanisms
2015-06-01
Malet, Foreign Fighters, 5. 16 Ibid., 4–6. 17 See for example Ines von Behr, Anaïs Reding , Charlie Edwards, and Luke Gribbon, “Radicalization in the...summary see Ines von Behr, Anaïs Reding , Charlie Edwards, and Luke Gribbon, “Radicalization in the Digital Era: The Use of the Internet in 15 Cases of...12; <http://www.lexisnexis.com.libproxy.nps.edu/hottopics/lnacademic> [April 11, 2015]. 134 von Behr, Reding , Edwards, and Gribbon
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1979-11-01
to-?ir kills, especially since we will probably be atle to field only a relatively small number of fighter pilots in future wars. Fighter pilots have...Education and Training, Information, And Legal, too many colonel positlons were allocated. Overall, many jobs wer found to be undergraded, especially at the...t preparing the final eppmntice progress/status report, 4e avy C :-vs educacion specialist will regard previous work experience as distri±xtnd
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1991-02-05
finance , insurance and real estate FL flight level ft feet FWS U.S. Fish and Wildlife Service FWW Fighter Weapon Wing FY fiscal year GAF German Air Force...three locations are related to socioeconomics. Potential effects of the realignment on employment, income, public finance , housing, and local economic...Manufacturing 89 107 1 Transportation, communications, and utilities 135 202 2 * Wholesale and retail tradeb 514 594 5 3 Finance , insurance, and real estate 216
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Air Force F-22 Fighter Program: Background and Issues for Congress
2009-12-22
comprises a large share of their overall business.23 The Air Force in 2007 estimated that of about 1,000 first-tier F-22 supplier firms, roughly 110, or...fighter.37 In addition, Boeing, the manufacturer of the F-15, is offering for sale on the international market an upgraded version of the F-15 called...Personally I have no interest in the Silent Eagle because it is only stealthy from the front,” Hirata says, referencing a limitation shared by the
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The F-35 JSF: Beginning of the End for Blue-Water Ops?
2010-04-06
DAMAGED BY INGESTING DEBRIS, THE RESULT OF SWITCHING TO A SINGLE-ENGINE AIRCRAFT FOR THE NAW’S PRIMARY FIGHTER. THE LOCKHEED MARTIN F-35 LIGHTNING II JOINT...States Navy Thesis: Single-engine aircraft have long been considered unsuitable for Naval Aviation, but now the future of blue-water operations is...dependent on the success and reliability of an aircraft · powered by a single engine, the Lockheed -Martin F-35Lightning II Joint Strike Fighter
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The Future of the Fighter Pilot ... Will There Be a 6th Generation Fighter?
2012-02-02
tndudtng suggestioos lor r &ducing this burden to Washington Headquarters Service, Directorate ror Information Operations and Reports, 1215 Jefferson DaviS...replacement. 22 The concept of spreading R &D risk in this manner at the same time as pre-signing a wide number of future customers was designed to...aviationweek.com/aw/generic/story_channel.jsp ?channel=Defense &id=news/ awst /2011/03/21/AW_03 _21_2011_p27297530.xml&headline=null&next=20>. 33 Ibid
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2010-06-01
Jr (Bomber) o Seventh Air Force, LTG Jeffrey A. Remington (Fighter) o Eleventh Air Force, LTG Dana T. Atkins (Fighter) o Thirteenth Air Force, LTG...Acculturation.‖ In Handbook of Socialization: Theory and Research, edited by Joan E. Grusec, and Paul D. Hastings, 543-560. New York, NY: Guilford...Philip. ―Determinism and Indeterminacy in the History of Technology.‖ In Does Technology Drive History?, edited by Merritt Roe Smith, and Leo Marx
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Systems Engineering Processes for the Acquisition of Prognostic and Health Management Systems
2012-09-01
INTRODUCTION A. BACKGROUND Prior to the F-35 Joint Strike Fighter (JSF) Program, the A-7 Corsair II was the last single engine fighter in the Navy...first fielded on the A-7 Corsair to the CBM+ systems being developed for the F-35 JSF. It also identified the DoD directive that mandates the...LEFT BLANK 55 LIST OF REFERENCES [1] A-7 Corsair II. (2011, July 7). GlobalSecurity.org. [Online]. Available: http://www.globalsecurity.org
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Fire Fighter Trainer Environmental Considerations. Phase II.
1981-07-31
NL* 2ffffffffffff m0 h~ hEhI J- L 2 2 * S * MICROCOP Y RI SOLM IION Ii SI CI AN I ’If Conrct No. 1111339-79-C-10011, Mod. No. P0007( i SFIRE FIGHTER...Phosphoric and polyphosphoric acids pose a disposal problem because phosphate compounds are environmentally controlled. Because these compounds do not meet the...acidity from use of these compounds in-a firefight- ing situation do not meet the health and safety criteria for an AFFF substitute; therefore, we
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Clinical Utility and Pitfalls of Ultrasound Guided Foreign Body Removal in War Fighters
2015-12-01
1 AD_________________ AWARD NUMBER: W81XWH-08-2-0162 TITLE: Clinical Utility and Pitfalls of Ultrasound Guided Foreign Body Removal in War...Clinical Utility and Pitfalls of Ultrasound Guided Foreign Body Removal in War Fighters 5a. CONTRACT NUMBER 5b. GRANT NUMBER: W81XWH-08-2-0162 5c...Purpose: To demonstrate that 1) ultrasound guided foreign body removal (USFBR) is superior to conventional surgery in the cadaver model, 2) USFBR can be
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The DTIC Review. Unmanned Aerial Vehicles. Volume 4, Number 2
1998-09-01
is likely that today’s fighter force will be retired by 2018 , the 14 F-22 will begin entering retirement in 2025, and that there will be further...Vietarn War Ends Berlin Wall Falls 300 Downsizing axi0 World Wide Recession of 2018 1500 10%0 500"- Figure 3-2. Fighter Force Projection for 2025...Reconnaisance Vehicle UAV’ Enem HQ/Control Command Post JFACC Ig 3700nrm Figure 6-2. StrikeStar C2 Architecture Former Vice Chairman of the Joint
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DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1999-09-01
This report explains the explosion/BLEVE that took place on April 9, 1998, at the Herrig Brothers Feather Creek Farm, located in Albert City, Iowa. Two volunteer fire fighters were killed and seven other emergency response personnel were injured. Safety issues covered in the report include protection of propane storage tanks and piping, state regulatory oversight of such installations, and fire fighter response to propane storage tank fires.
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Should the Australian Army Adopt the Concept of Effects-Based Operations?
2003-06-06
militray effect (Echevarria, 2001). 2 John Boyd was a US Air Force Fighter pilot who developed a model of decision making based on his experiences in the...this cycle, the decision maker (initially a fighter pilot ) would try to reduce the time it took him to go through the cycle. The speed of the decision...cycle was relative, but ultimately, the pilot who could reduce his cycle enough to be “inside”‘ his adversary’s cycle would eventually win. The BOYD
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Personnel Management in the Military: Effects of Retirement Policies on the Retention of Personnel.
1986-01-01
observable characteristics as education level, AFQT scores, and promotion speed, see Ward and Tan (1984). 2 7EFMS is a decision support system being developed...34’For an operationalization of the concept of "quality" by looking at such observable characteristics as education level, AFQT scores, and * ’.,promotion...probabilities would have to deal with predicting the test scores for airmen by using information on entry characteristics such as education level and
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Surface Transportation Weather Decision Support Requirements - Executive Summary, Version 1.0
DOT National Transportation Integrated Search
1999-12-16
WEATHER: IT AFFECTS THE VISIBILITY, TRACTABILITY, MANEUVERABILITY, VEHICLE STABILITY, EXHAUST EMISSIONS AND STRUCTURAL INTEGRITY OF THE SURFACE TRANSPORTATION SYSTEM. THEREBY WEATHER AFFECTS THE SAFETY, MOBILITY, PRODUCTIVITY AND ENVIRONMENTAL IMPACT...
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A concept of highly maneuverable experimental space (HIMES) vehicle
NASA Astrophysics Data System (ADS)
Nagatomo, M.; Naruo, Y.; Inatani, Y.
1985-10-01
The development of a highly maneuverable experimental space (HIMES) vehicle is proposed. This reusable sounding rocket is to be propelled by a liquid hydrogen/LOX engine, and have a maximum payload mass of 500 kg at an altitude of 300 km. The main subsystems of HIMES, the fuselage and wing structure, propulsion, and navigation, guidance, and control system, are described and a diagram is provided. The operational features of HIMES are defined by three mission models. In the first model the vehicle is used as a stable platform of low velocity relative to the environment; model two represents the suborbital flight of sounding rockets, and model three is used for orbital reentry experiments and the testing of a new system of winged space vehicles. Typical mission profiles for the three models are presented. A cost estimation of the HIMES vehicle is given.
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Movable Ground Based Recovery System for Reuseable Space Flight Hardware
NASA Technical Reports Server (NTRS)
Sarver, George L. (Inventor)
2013-01-01
A reusable space flight launch system is configured to eliminate complex descent and landing systems from the space flight hardware and move them to maneuverable ground based systems. Precision landing of the reusable space flight hardware is enabled using a simple, light weight aerodynamic device on board the flight hardware such as a parachute, and one or more translating ground based vehicles such as a hovercraft that include active speed, orientation and directional control. The ground based vehicle maneuvers itself into position beneath the descending flight hardware, matching its speed and direction and captures the flight hardware. The ground based vehicle will contain propulsion, command and GN&C functionality as well as space flight hardware landing cushioning and retaining hardware. The ground based vehicle propulsion system enables longitudinal and transverse maneuverability independent of its physical heading.
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Utah State University's T2 ODV mobility analysis
NASA Astrophysics Data System (ADS)
Davidson, Morgan E.; Bahl, Vikas; Wood, Carl G.
2000-07-01
In response to ultra-high maneuverability vehicle requirements, Utah State University (USU) has developed an autonomous vehicle with unique mobility and maneuverability capabilities. This paper describes a study of the mobility of the USU T2 Omni-Directional Vehicle (ODV). The T2 vehicle is a mid-scale (625 kg), second-generation ODV mobile robot with six independently driven and steered wheel assemblies. The six wheel, independent steering system is capable of unlimited steering rotation, presenting a unique solution to enhanced vehicle mobility requirements. This mobility study focuses on energy consumption in three basic experiments, comparing two modes of steering: Ackerman and ODV. The experiments are all performed on the same vehicle without any physical changes to the vehicle itself, providing a direct comparison these two steering methodologies. A computer simulation of the T2 mechanical and control system dynamics is described.
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Geometry definition and grid generation for a complete fighter aircraft
NASA Technical Reports Server (NTRS)
Edwards, T. A.
1986-01-01
Recent advances in computing power and numerical solution procedures have enabled computational fluid dynamicists to attempt increasingly difficult problems. In particular, efforts are focusing on computations of complex three-dimensional flow fields about realistic aerodynamic bodies. To perform such computations, a very accurate and detailed description of the surface geometry must be provided, and a three-dimensional grid must be generated in the space around the body. The geometry must be supplied in a format compatible with the grid generation requirements, and must be verified to be free of inconsistencies. This paper presents a procedure for performing the geometry definition of a fighter aircraft that makes use of a commercial computer-aided design/computer-aided manufacturing system. Furthermore, visual representations of the geometry are generated using a computer graphics system for verification of the body definition. Finally, the three-dimensional grids for fighter-like aircraft are generated by means of an efficient new parabolic grid generation method. This method exhibits good control of grid quality.
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Low-speed wind-tunnel test of a STOL supersonic-cruise fighter concept
NASA Technical Reports Server (NTRS)
Coe, Paul L., Jr.; Riley, Donald R.
1988-01-01
A wind-tunnel investigation was conducted to examine the low-speed static stability and control characteristics of a 0.10 scale model of a STOL supersonic cruise fighter concept. The concept, referred to as a twin boom fighter, was designed as a STOL aircraft capable of efficient long range supersonic cruise. The configuration name is derived from the long twin booms extending aft of the engine to the twin vertical tails which support a high center horizontal tail. The propulsion system features a two dimensional thrust vectoring exhaust nozzle which is located so that the nozzle hinge line is near the aircraft center of gravity. This arrangement is intended to allow large thrust vector angles to be used to obtain significant values of powered lift, while minimizing pitching moment trim changes. Low speed stability and control information was obtained over an angle of attack range including the stall. A study of jet induced power effects was included.
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Miller, Justin B.; Rissman, Robert A.; Bernick, Charles B.
2017-01-01
Abstract The role of the apolipoprotein e4 allele in moderating cognitive and neuroanatomical degeneration following repeated traumatic brain injury is controversial. Here we sought to establish the presence or absence of such a moderating relationship in a prospective study of active and retired boxers and mixed martial arts fighters. Fighters (n = 193) underwent cognitive evaluations, interviews regarding fight history, MRI of the brain, and genetic testing. We used a series of moderator analyses to test for any relationship of apolipoprotein genotype on structural volumes of brain regions previously established to be smaller in those with the most fight exposure, and on cognitive abilities also established to be sensitive to fight exposure. No moderating relationship was detected in any of the analyses. The results of this study suggest that there is no impact of apolipoprotein genotype on the apparent negative association between exposure to professional fighting and brain structure volume or aspects of cognition. PMID:27245878
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NASA Technical Reports Server (NTRS)
Tomek, W. G.; Wahls, R. A.; Owens, L. R.; Burner, A. B.; Graves, S. S.; Luckring, J. M.
2003-01-01
Two wind tunnel tests of a generic fighter configuration have been completed in the National Transonic Facility. The primary purpose of the tests was to assess Reynolds number scale effects on a thin-wing, fighter-type configuration up to full-scale flight conditions (that is, Reynolds numbers of the order of 60 million). The tests included longitudinal and lateral/directional studies at subsonic and transonic conditions across a range of Reynolds numbers from that available in conventional wind tunnels to flight conditions. Results are presented for three Mach numbers (0.6, 0.8, and 0.9) and three configurations: 1) Fuselage / Wing, 2) Fuselage / Wing / Centerline Vertical Tail / Horizontal Tail, and 3) Fuselage / Wing / Trailing-Edge Extension / Twin Vertical Tails. Reynolds number effects on the lateral-directional aerodynamic characteristics are presented herein, along with longitudinal data demonstrating the effects of fixing the boundary layer transition location for low Reynolds number conditions. In addition, an improved model videogrammetry system and results are discussed.
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Geometry definition and grid generation for a complete fighter aircraft
NASA Technical Reports Server (NTRS)
Edwards, Thomas A.
1986-01-01
Recent advances in computing power and numerical solution procedures have enabled computational fluid dynamicists to attempt increasingly difficult problems. In particular, efforts are focusing on computations of complex three-dimensional flow fields about realistic aerodynamic bodies. To perform such computations, a very accurate and detailed description of the surface geometry must be provided, and a three-dimensional grid must be generated in the space around the body. The geometry must be supplied in a format compatible with the grid generation requirements, and must be verified to be free of inconsistencies. A procedure for performing the geometry definition of a fighter aircraft that makes use of a commercial computer-aided design/computer-aided manufacturing system is presented. Furthermore, visual representations of the geometry are generated using a computer graphics system for verification of the body definition. Finally, the three-dimensional grids for fighter-like aircraft are generated by means of an efficient new parabolic grid generation method. This method exhibits good control of grid quality.
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Injuries to volunteer fire fighters in West Virginia.
Magnetti, S M; Wyant, W D; Greenwood, J; Roder, N J; Linton, J C; Ducatman, A M
1999-02-01
The distribution and characteristics of workplace injuries for West Virginia volunteer fire fighters (VFFs) are described using 1992 workers' compensation data. Most of the injuries occurred in VFFs who were less than 30 years of age (62%). The most common type of injuries were those in the category of lacerations and contusions (28.9%), with a notable percentage of injuries due to smoke inhalation and respiratory problems (13.7%). The proportional rates related to falls in VFFs were almost twice the national figures for the same year (39.3% versus 22.3%). County population density was found to be directly associated with injury rates, even when adjusted for number of responses. Claims statistics mirror a similar geographical trend in overall workers' compensation claims for all injuries in West Virginia. The results of this study provide a foundation for additional follow-up studies in order to develop improved occupational safety policies and target educational programs aimed at the prevention of injuries in volunteer fire fighters. Several findings have already resulted in programmatic recommendations.
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NASA Technical Reports Server (NTRS)
Erickson, Gary E.; Brandon, Jay M.
1987-01-01
An exploratory investigation was conducted of the nonlinear aerodynamic and stability characteristics of a tailless generic fighter configuration featuring a chine-shaped forebody coupled to a slender cropped delta wing in the NASA Langley Research Center's 12-Foot Low-Speed Wind Tunnel. Forebody and wing vortex flow mechanisms were identified through off-body flow visualizations to explain the trends in the longitudinal and lateral-directional characteristics at extreme attitudes (angles of attack and sideslip). The interactions of the vortical motions with centerline and wing-mounted vertical tail surfaces were studied and the flow phenomena were correlated with the configuration forces and moments. Single degree of freedom, free-to-roll tests were used to study the wing rock susceptibility of the generic fighter model. Modifications to the nose region of the chine forebody were examined and fluid mechanisms were established to account for their ineffectiveness in modulating the highly interactive forebody and wing vortex systems.
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High angle-of-attack aerodynamics of a strake-canard-wing V/STOL fighter configuration
NASA Technical Reports Server (NTRS)
Durston, D. A.; Schreiner, J. A.
1983-01-01
High angle-of-attack aerodynamic data are analyzed for a strake-canard-wing V/STOL fighter configuration. The configuration represents a twin-engine supersonic V/STOL fighter aircraft which uses four longitudinal thrust-augmenting ejectors to provide vertical lift. The data were obtained in tests of a 9.39 percent scale model of the configuration in the NASA Ames 12-Foot Pressure Wind Tunnel, at a Mach number of 0.2. Trimmed aerodynamic characteristics, longitudinal control power, longitudinal and lateral/directional stability, and effects of alternate strake and canard configurations are analyzed. The configuration could not be trimmed (power-off) above 12 deg angle of attack because of the limited pitch control power and the high degree of longitudinal instability (28 percent) at this Mach number. Aerodynamic center location was found to be controllable by varying strake size and canard location without significantly affecting lift and drag. These configuration variations had relatively little effect on the lateral/directional stability up to 10 deg angle of attack.
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Perceived aggressiveness predicts fighting performance in mixed-martial-arts fighters.
Trebicky, Vít; Havlícek, Jan; Roberts, S Craig; Little, Anthony C; Kleisner, Karel
2013-09-01
Accurate assessment of competitive ability is a critical component of contest behavior in animals, and it could be just as important in human competition, particularly in human ancestral populations. Here, we tested the role that facial perception plays in this assessment by investigating the association between both perceived aggressiveness and perceived fighting ability in fighters' faces and their actual fighting success. Perceived aggressiveness was positively associated with the proportion of fights won, after we controlled for the effect of weight, which also independently predicted perceived aggression. In contrast, perception of fighting ability was confounded by weight, and an association between perceived fighting ability and actual fighting success was restricted to heavyweight fighters. Shape regressions revealed that aggressive-looking faces are generally wider and have a broader chin, more prominent eyebrows, and a larger nose than less aggressive-looking faces. Our results indicate that perception of aggressiveness and fighting ability might cue different aspects of success in male-male physical confrontation.
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Park, Myunghwan; Yoo, Seunghoon; Seol, Hyeongju; Kim, Cheonyoung; Hong, Youngseok
2015-04-01
While the factors affecting fighter pilots' G level tolerance have been widely accepted, the factors affecting fighter pilots' G duration tolerance have not been well understood. Thirty-eight subjects wearing anti-G suits were exposed to sustained high G forces using a centrifuge. The subjects exerted AGSM and decelerated the centrifuge when they reached the point of loss of peripheral vision. The G profile consisted of a +2.3 G onset rate, +7.3 G single plateau, and -1.6 G offset rate. Each subject's G tolerance time was recorded and the relationship between the tolerance time and the subject's anthropometric and physiological factors were analyzed. The mean tolerance time of the 38 subjects was 31.6 s, and the min and max tolerance times were 20 s and 58 s, respectively. The correlation analysis indicated that none of the factors had statistically significant correlations with the subjects' G duration tolerance. Stepwise multiple regression analysis showed that G duration tolerance was not dependent on any personal factors of the subjects. After the values of personal factors were simplified into 0 or 1, the t-test analysis showed that subjects' heights were inversely correlated with G duration tolerance at a statistically significant level. However, a logistic regression analysis suggested that the effect of the height factor to a pilot's G duration tolerance was too weak to be used as a predictor of a pilot's G tolerance. Fighter pilots' G duration tolerance could not be predicted by pilots' anthropometric and physiological factors.
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NASA Astrophysics Data System (ADS)
Jana, S.; Chakraborty, R.; Maitra, A.
2017-12-01
Nowcasting of lightning activities during intense convective events using a single electric field monitor (EFM) has been carried out at a tropical location, Kolkata (22.65oN, 88.45oE). Before and at the onset of heavy lightning, certain changes of electric field (EF) can be related to high liquid water content (LWC) and low cloud base height (CBH). The present study discusses the utility of EF observation to show a few aspects of convective events. Large convective cloud showed by high LWC and low CBH can be detected from EF variation which could be a precursor of upcoming convective events. Suitable values of EF gradient can be used as an indicator of impending lightning events. An EF variation of 0.195 kV/m/min can predict lightning within 17.5 km radius with a probability of detection (POD) of 91% and false alarm rate (FAR) of 8% with a lead time of 45 min. The total number of predicted lightning strikes is nearly 9 times less than that measured by the lightning detector. This prediction technique can, therefore, give an estimate of cloud to ground (CG) and intra cloud (IC) lighting occurrences within the surrounding area. This prediction technique involving POD, FAR and lead time information shows a better prediction capability compared to the techniques reported earlier. Thus an EFM can be effectively used for prediction of lightning events at a tropical location.
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Stable, inflatable life raft for high seas rescue operations
NASA Technical Reports Server (NTRS)
Barnett, J. H., Jr.; Harrison, F.; Marak, R.; Radnofsky, M. I.
1971-01-01
Raft is easily deployed and highly maneuverable in water. It has false bottom of water ballast containers attached to underside, making it exceptionally stable platform from which swimmers can operate. Raft is attachable to external moorings.
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Cara Status and Upcoming Enhancements
NASA Technical Reports Server (NTRS)
Newman, Lauri
2015-01-01
RIC Miss Values in Summary TableTabular presentation of miss vector in Summary Section RIC Uncertainty Values in Details SectionNumerical presentation of miss component uncertainty values in Details SectionGreen Events with Potentially Maneuverable Secondary ObjectsAll potentially maneuverable secondary objects will be reported out to 7-days prior to TCA for LEO events and 10-days for NONLEO events, regardless of risk (relates to MOWG Action Item 1309-11) All green events with potentially active secondary objects included in Summary ReportsAllows more time for contacting other OOBlack Box FixSometimes a black square appeared in the summary report where the ASW RIC time history plot should beAppendix Orbit RegimeMission Name MismatchPc 0 Plotting BugAll Pc points less than 1e-10 (zero) are now plotted as 1e-10 (instead of not at all)Maneuver Indication FixManeuver indicator now present even if maneuver was in the past.
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Thomas, Louise; Borisoff, Jaimie; Sparrey, Carolyn J
2017-07-01
In general, manual wheelchairs are designed with a fixed frame, which is not optimal for every situation. Adjustable on the fly seating allow users to rapidly adapt their wheelchair configuration to suit different tasks. These changes move the center of gravity (CoG) of the system, altering the wheelchair stability and maneuverability. To assess these changes, a computer simulation of a manual wheelchair was created with adjustable seat, backrest, rear axle position and user position, and validated with experimental testing. The stability of the wheelchair was most affected by the position of the rear axle, but adjustments to the backrest and seat angles also result in stability improvements that could be used when wheeling in the community. These findings describe the most influential parameters for wheelchair stability and maneuverability, as well as provide quantitative guidelines for the use of manual wheelchairs with on the fly adjustable seats.
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The evaluation of partial binocular overlap on car maneuverability: A pilot study
NASA Technical Reports Server (NTRS)
Tsou, Brian H.; Rogers-Adams, Beth M.; Goodyear, Charles D.
1992-01-01
An engineering approach to enlarge the helmet mounted display (HMD) field of view (FOV) and maintain resolution and weight by partially overlapping the binocular FOV has received renewed interest among human factors scientists. It is evident, based on the brief literature review, that any panoramic display with a binocular overlap, less than a minimum amount, annoys the viewer, degrades performance, and elicits undesirable behavior. The major finding is that across the 60 deg conditions, subjects moved their heads a greater distance (by about 5 degs on each side) than in the 180 deg condition, presumably to compensate for the lack of FOV. It is quite clear that the study, based on simple car maneuverability and two subjects, reveals differences in FOV, but nothing significant between binocular overlap levels and configurations. This tentatively indicates that some tradeoffs of binocular vision for a larger overall display FOV are acceptable.
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A comparison of theoretical and experimental pressure distributions for two advanced fighter wings
NASA Technical Reports Server (NTRS)
Haney, H. P.; Hicks, R. M.
1981-01-01
A comparison was made between experimental pressure distributions measured during testing of the Vought A-7 fighter and the theoretical predictions of four transonic potential flow codes. Isolated wind and three wing-body codes were used for comparison. All comparisons are for transonic Mach numbers and include both attached and separate flows. In general, the wing-body codes gave better agreement with the experiment than did the isolated wing code but, because of the greater complexity of the geometry, were found to be considerably more expensive and less reliable.
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1992-01-01
29 echelon of XII Fighter Command; the Moroccan Composite Wing operated in Morocco . All wings were activated 26 January 1943. XII Fighter Command’s...satellites, would raise Allied morale, and would encourage those ele - ments in the Axis-occupied countries which were working as best they could toward...news of the invasion, in order to fore- stall an Allied breaching of the southern coast of France, to establish submarine and air bases , and to control
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NASA Technical Reports Server (NTRS)
Taylor, Robert T.
1959-01-01
A 0.10-scale model of a swept-wing fighter airplane was tested in the Langley high-speed 7- by 10-foot tunnel at Mach numbers from 0.60 to 0.92 to determine the effects of adding underfuselage speed brakes. The results of brief spoiler-aileron lateral control tests also are included. The tests show acceptable trim and drag increments when the speed brakes are installed at the 32-71-inch fuselage station.
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Computer-automated opponent for manned air-to-air combat simulations
NASA Technical Reports Server (NTRS)
Hankins, W. W., III
1979-01-01
Two versions of a real-time digital-computer program that operates a fighter airplane interactively against a human pilot in simulated air combat were evaluated. They function by replacing one of two pilots in the Langley differential maneuvering simulator. Both versions make maneuvering decisions from identical information and logic; they differ essentially in the aerodynamic models that they control. One is very complete, but the other is much simpler, primarily characterizing the airplane's performance (lift, drag, and thrust). Both models competed extremely well against highly trained U.S. fighter pilots.
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Effectiveness of brief VR treatment for PTSD in war-fighters: a case study.
Miyahira, Sarah D; Folen, Raymond A; Hoffman, Hunter G; Garcia-Palacios, Azucena; Schaper, Kim M
2010-01-01
War-fighters exposed to combat are at high risk for developing posttraumatic stress disorder (PTSD), a complex and challenging condition to treat. Cognitive behavioral therapies (CBT) have been empirically validated as effective treatments for PTSD resulting from sexual assault, vehicular accidents, and disasters. Exposure, imaginal or in vivo, to the traumatic event is a central component of successful CBT treatment. Early studies indicate that CBT with brief virtual reality exposure (VRE) is beneficial in treating PTSD. The case study examined the effectiveness of brief VRE in treating combat-related PTSD.
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Design of a V/STOL propulsion system for a large-scale fighter model
NASA Technical Reports Server (NTRS)
Willis, W. S.
1981-01-01
Modifications were made to the existing Large-Scale STOL fighter model to simulate a V/STOL configuration. Modifications include the substitutions of two dimensional lift/cruise exhaust nozzles in the nacelles, and the addition of a third J97 engine in the fuselage to suppy a remote exhaust nozzle simulating a Remote Augmented Lift System. A preliminary design of the inlet and exhaust ducting for the third engine was developed and a detailed design was completed of the hot exhaust ducting and remote nozzle.
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Study of aerodynamic technology for VSTOL fighter/attack aircraft: Horizontal attitude concept
NASA Technical Reports Server (NTRS)
Brown, S. H.
1978-01-01
A horizontal attitude VSTOL (HAVSTOL) supersonic fighter attack aircraft powered by RALS turbofan propulsion system is analyzed. Reaction control for subaerodynamic flight is obtained in pitch and yaw from the RALS and roll from wingtip jets powered by bleed air from the RALS duct. Emphasis is placed on the development of aerodynamic characteristics and the identification of aerodynamic uncertainties. A wind tunnel program is shown to resolve some of the uncertainties. Aerodynamic data developed are static characteristics about all axes, control effectiveness, drag, propulsion induced effects and reaction control characteristics.
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F-35 Joint Strike Fighter (JSF) Program: Background, Status, and Issues
2007-07-19
Buy ‘Hundreds’ of STOVL Joint Strike Fighters,” Inside the Air Force. September 17, 2004. 6 Marc Selinger. “Jumper Confirms Air Force Plans to Cut...concluded that some 230 of the Navy’s projected buy of 480 JSFs could instead be F/A-18E/Fs, depending on the progress of the JSF program and the price of...18E/F Buy Depends on JSF Progress,’Cohen Tells SASC,” Aerospace Daily, May 21, 1997: 285, 288. See also CRS Issue Brief IB93041, C- 17 Cargo
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Scanning Probe Microscopy of Organic Solar Cells
NASA Astrophysics Data System (ADS)
Reid, Obadiah G.
Nanostructured composites of organic semiconductors are a promising class of materials for the manufacture of low-cost solar cells. Understanding how the nanoscale morphology of these materials affects their efficiency as solar energy harvesters is crucial to their eventual potential for large-scale deployment for primary power generation. In this thesis we describe the use of optoelectronic scanning-probe based microscopy methods to study this efficiency-structure relationship with nanoscale resolution. In particular, our objective is to make spatially resolved measurements of each step in the power conversion process from photons to an electric current, including charge generation, transport, and recombination processes, and correlate them with local device structure. We have achieved two aims in this work: first, to develop and apply novel electrically sensitive scanning probe microscopy experiments to study the optoelectronic materials and processes discussed above; and second, to deepen our understanding of the physics underpinning our experimental techniques. In the first case, we have applied conductive-, and photoconductive atomic force (cAFM & pcAFM) microscopy to measure both local photocurrent collection and dark charge transport properties in a variety of model and novel organic solar cell composites, including polymer/fullerene blends, and polymer-nanowire/fullerene blends, finding that local heterogeneity is the rule, and that improvements in the uniformity of specific beneficial nanostructures could lead to large increases in efficiency. We have used scanning Kelvin probe microscopy (SKPM) and time resolved-electrostatic force microscopy (trEFM) to characterize all-polymer blends, quantifying their sensitivity to photochemical degradation and the subsequent formation of local charge traps. We find that while trEFM provides a sensitive measure of local quantum efficiency, SKPM is generally unsuited to measurements of efficiency, less sensitive than trEFM, and of greater utility in identifying local changes in steady-state charge density that can be associated with charge trapping. In the second case, we have developed a new understanding of charge transport between a sharp AFM tip and planar substrates applicable to conductive and photoconductive atomic force microscopy, and shown that hole-only transport characteristics can be easily obtained including quantitative values of the charge carrier mobility. Finally, we have shown that intensity-dependent photoconductive atomic force microscopy measurements can be used to infer the 3D structure of organic photovoltaic materials, and gained new insight into the influence vertical composition of the these devices can have on their open-circuit voltage and its intensity dependence.
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An investigation of fighter aircraft agility
NASA Technical Reports Server (NTRS)
Valasek, John; Downing, David R.
1993-01-01
This report attempts to unify in a single document the results of a series of studies on fighter aircraft agility funded by the NASA Ames Research Center, Dryden Flight Research Facility and conducted at the University of Kansas Flight Research Laboratory during the period January 1989 through December 1993. New metrics proposed by pilots and the research community to assess fighter aircraft agility are collected and analyzed. The report develops a framework for understanding the context into which the various proposed fighter agility metrics fit in terms of application and testing. Since new metrics continue to be proposed, this report does not claim to contain every proposed fighter agility metric. Flight test procedures, test constraints, and related criteria are developed. Instrumentation required to quantify agility via flight test is considered, as is the sensitivity of the candidate metrics to deviations from nominal pilot command inputs, which is studied in detail. Instead of supplying specific, detailed conclusions about the relevance or utility of one candidate metric versus another, the authors have attempted to provide sufficient data and analyses for readers to formulate their own conclusions. Readers are therefore ultimately responsible for judging exactly which metrics are 'best' for their particular needs. Additionally, it is not the intent of the authors to suggest combat tactics or other actual operational uses of the results and data in this report. This has been left up to the user community. Twenty of the candidate agility metrics were selected for evaluation with high fidelity, nonlinear, non real-time flight simulation computer programs of the F-5A Freedom Fighter, F-16A Fighting Falcon, F-18A Hornet, and X-29A. The information and data presented on the 20 candidate metrics which were evaluated will assist interested readers in conducting their own extensive investigations. The report provides a definition and analysis of each metric; details of how to test and measure the metric, including any special data reduction requirements; typical values for the metric obtained using one or more aircraft types; and a sensitivity analysis if applicable. The report is organized as follows. The first chapter in the report presents a historical review of air combat trends which demonstrate the need for agility metrics in assessing the combat performance of fighter aircraft in a modern, all-aspect missile environment. The second chapter presents a framework for classifying each candidate metric according to time scale (transient, functional, instantaneous), further subdivided by axis (pitch, lateral, axial). The report is then broadly divided into two parts, with the transient agility metrics (pitch lateral, axial) covered in chapters three, four, and five, and the functional agility metrics covered in chapter six. Conclusions, recommendations, and an extensive reference list and biography are also included. Five appendices contain a comprehensive list of the definitions of all the candidate metrics; a description of the aircraft models and flight simulation programs used for testing the metrics; several relations and concepts which are fundamental to the study of lateral agility; an in-depth analysis of the axial agility metrics; and a derivation of the relations for the instantaneous agility and their approximations.
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Ercan, Serdar; Scerrati, Alba; Wu, Phengfei; Zhang, Jun; Ammirati, Mario
2017-07-01
OBJECTIVE The subtemporal approach is one of the surgical routes used to reach the interpeduncular fossa. Keyhole subtemporal approaches and zygomatic arch osteotomy have been proposed in an effort to decrease the amount of temporal lobe retraction. However, the effects of these modified subtemporal approaches on temporal lobe retraction have never been objectively validated. METHODS A keyhole and a classic subtemporal craniotomy were executed in 4 fresh-frozen silicone-injected cadaver heads. The target was defined as the area bordered by the superior cerebellar artery, the anterior clinoid process, supraclinoid internal carotid artery, and the posterior cerebral artery. Once the target was fully visualized, the authors evaluated the amount of temporal lobe retraction by measuring the distance between the base of the middle fossa and the temporal lobe. In addition, the volume of the surgical and anatomical corridors was assessed as well as the surgical maneuverability using navigation and 3D moldings. The same evaluation was conducted after a zygomatic osteotomy was added to the two approaches. RESULTS Temporal lobe retraction was the same in the two approaches evaluated while the surgical corridor and the maneuverability were all greater in the classic subtemporal approach. CONCLUSIONS The zygomatic arch osteotomy facilitates the maneuverability and the surgical volume in both approaches, but the temporal lobe retraction benefit is confined to the lateral part of the middle fossa skull base and does not result in the retraction necessary to expose the selected target.
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Mountcastle, Andrew M.; Combes, Stacey A.
2015-01-01
Bumblebee foragers spend a significant portion of their lives transporting nectar and pollen, often carrying loads equivalent to more than half their body mass. Whereas nectar is stored in the abdomen near the bee’s center of mass, pollen is carried on the hind legs, farther from the center of mass. We examine how load position changes the rotational moment of inertia in bumblebees and whether this affects their flight maneuverability and/or stability. We applied simulated pollen or nectar loads of equal mass to Bombus impatiens bumblebees and examined flight performance in a wind tunnel under three conditions: flight in unsteady flow, tracking an oscillating flower in smooth flow, and flower tracking in unsteady flow. Using an inertial model, we estimated that carrying a load on the legs rather than in the abdomen increases a bee’s moment of inertia about the roll and yaw axes but not the pitch axis. Consistent with these predictions, we found that bees carrying a load on their legs displayed slower rotations about their roll and yaw axes, regardless of whether these rotations were driven by external perturbations or self-initiated steering maneuvers. This allowed pollen-loaded bees to maintain a more stable body orientation and higher median flight speed in unsteady flow but reduced their performance when tracking a moving flower, supporting the concept of a tradeoff between stability and maneuverability. These results demonstrate that the types of resources collected by bees affect their flight performance and energetics and suggest that wind conditions may influence resource selection. PMID:26240364
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Stolzenburg, Jens-Uwe; Kallidonis, Panagiotis; Oh, Min-A; Ghulam, Nabi; Do, Minh; Haefner, Tim; Dietel, Anja; Till, Holger; Sakellaropoulos, George; Liatsikos, Evangelos N
2010-02-01
Laparoendoscopic single-site surgery (LESS) represents the latest innovation in laparoscopic surgery. We compare in dry and animal laboratory the efficacy of recently introduced pre-bent instruments with conventional laparoscopic and flexible instruments in terms of time requirement, maneuverability, and ease of handling. Participants of varying laparoscopic experience were included in the study and divided in groups according to their experience. The participants performed predetermined tasks in dry laboratory using all sets of instruments. An experienced laparoscopic surgeon performed 24 nephrectomies in 12 pigs using all sets of instruments. Single port was used for all instrument sets except for the conventional instruments, which were inserted through three ports. The time required for the performance of dry laboratory tasks and the porcine nephrectomies was recorded. Errors in the performance of dry laboratory tasks of each instrument type were also recorded. Pre-bent instruments had a significant advantage over flexible instruments in terms of time requirement to accomplish tasks and procedures as well as maneuverability. Flexible instruments were more time consuming in comparison to the conventional laparoscopic instruments during the performance of the tasks. There were no significant differences in the time required for the accomplishment of dry laboratory tasks or steps of nephrectomy using conventional instruments through appropriate number of ports in comparison to pre-bent instruments through single port. Pre-bent instruments were less time consuming and with better maneuverability in comparison to flexible instruments in experimental single-port access surgery. Further clinical investigations would elucidate the efficacy of pre-bent instruments.
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Stability-maneuverability trade-offs during lateral steps.
Acasio, Julian; Wu, Mengnan/Mary; Fey, Nicholas P; Gordon, Keith E
2017-02-01
Selecting a specific foot placement strategy to perform walking maneuvers requires the management of several competing factors, including: maintaining stability, positioning oneself to actively generate impulses, and minimizing mechanical energy requirements. These requirements are unlikely to be independent. Our purpose was to determine the impact of lateral foot placement on stability, maneuverability, and energetics during walking maneuvers. Ten able-bodied adults performed laterally-directed walking maneuvers. Mediolateral placement of the "Push-off" foot during the maneuvers was varied, ranging from a cross-over step to a side-step. We hypothesized that as mediolateral foot placement became wider, passive stability in the direction of the maneuver, the lateral impulse generated to create the maneuver, and mechanical energy cost would all increase. We also hypothesized that subjects would prefer an intermediate step width reflective of trade-offs between stability vs. both maneuverability and energy. In support of our first hypothesis, we found that as Push-off step width increased, lateral margin of stability, peak lateral impulse, and total joint work all increased. In support of our second hypothesis, we found that when subjects had no restrictions on their mediolateral foot placement, they chose a foot placement between the two extreme positions. We found a significant relationship (p<0.05) between lateral margin of stability and peak lateral impulse (r=0.773), indicating a trade-off between passive stability and the force input required to maneuver. These findings suggest that during anticipated maneuvers people select foot placement strategies that balance competing costs to maintain stability, actively generate impulses, and minimize mechanical energy costs. Published by Elsevier B.V.
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Maloney, Michael A; Renshaw, Ian; Headrick, Jonathon; Martin, David T; Farrow, Damian
2018-01-01
Enhancing practice design is critical to facilitate transfer of learning. Considerable research has focused on the role of perceptual information in practice simulation, yet has neglected how affect and cognition are shaped by practice environments and whether this influences the fidelity of behavior (Headrick et al., 2015). This study filled this gap by examining the fidelity of individual (cognition, affect, and actions) and interpersonal behavior of 10 highly skilled Australian Taekwondo athletes fighting in training compared to competition. Interpersonal behavior was assessed by tracking location coordinates to analyze distance-time coordination tendencies of the fighter-fighter system. Individual actions were assessed through notational analysis and approximate entropy calculations of coordinate data to quantify the (un)predictability of movement displacement. Affect and cognition were assessed with mixed-methods that included perceptual scales measuring anxiety, arousal, and mental effort, and post-fight video-facilitated confrontational interviews to explore how affect and cognitions might differ. Quantitative differences were assessed with mixed models and dependent t -tests. Results reveal that individual and interpersonal behavior differed between training and competition. In training, individuals attacked less ( d = 0.81, p < 0.05), initiated attacks from further away ( d = -0.20, p < 0.05) and displayed more predictable movement trajectories ( d = 0.84, p < 0.05). In training, fighters had lower anxiety ( d = -1.26, p < 0.05), arousal ( d = -1.07, p < 0.05), and mental effort ( d = -0.77, p < 0.05). These results were accompanied by changes in interpersonal behavior, with larger interpersonal distances generated by the fighter-fighter system in training ( d = 0.80, p < 0.05). Qualitative data revealed the emergence of cognitions and affect specific to the training environment, such as reductions in pressure, arousal, and mental challenge. Findings highlight the specificity of performer-environment interactions. Fighting in training affords reduced affective and cognitive demands and a decrease in action fidelity compared to competition. In addition to sampling information, representative practice needs to consider modeling the cognitions and affect of competition to enhance transfer.
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Incidence of injury in professional mixed martial arts competitions.
Bledsoe, Gregory H; Hsu, Edbert B; Grabowski, Jurek George; Brill, Justin D; Li, Guohua
2006-01-01
Mixed Martial Arts (MMA) competitions were introduced in the United States with the first Ultimate Fighting Championship (UFC) in 1993. In 2001, Nevada and New Jersey sanctioned MMA events after requiring a series of rule changes. The purpose of this study was to determine the incidence of injury in professional MMA fighters. Data from all professional MMA events that took place between September 2001 and December 2004 in the state of Nevada were obtained from the Nevada Athletic Commission. Medical and outcome data from events were analyzed based on a pair-matched case-control design. Both conditional and unconditional logistic regression models were used to assess risk factors for injury. A total of 171 MMA matches involving 220 different fighters occurred during the study period. There were a total of 96 injuries to 78 fighters. Of the 171 matches fought, 69 (40.3%) ended with at least one injured fighter. The overall injury rate was 28.6 injuries per 100 fight participations or 12.5 injuries per 100 competitor rounds. Facial laceration was the most common injury accounting for 47.9% of all injuries, followed by hand injury (13.5%), nose injury (10.4%), and eye injury (8.3%). With adjustment for weight and match outcome, older age was associated with significantly increased risk of injury. The most common conclusion to a MMA fight was a technical knockout (TKO) followed by a tap out. The injury rate in MMA competitions is compatible with other combat sports involving striking. The lower knockout rates in MMA compared to boxing may help prevent brain injury in MMA events. Key PointsMixed martial arts (MMA) has changed since the first MMA matches in the United States and now has increased safety regulations and sanctioning.MMA competitions have an overall high rate of injury.There have been no MMA deaths in the United States.The knockout (KO) rate in MMA appears to be lower than the KO rate of boxing matches.MMA must continue to be supervised by properly trained medical professionals and referees to ensure fighter safety in the future.
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Violence against women during the Liberian civil conflict.
Swiss, S; Jennings, P J; Aryee, G V; Brown, G H; Jappah-Samukai, R M; Kamara, M S; Schaack, R D; Turay-Kanneh, R S
1998-02-25
Civilians were often the casualties of fighting during the recent Liberian civil conflict. Liberian health care workers played a crucial role in documenting violence against women by soldiers and fighters during the war. To document women's experiences of violence, including rape and sexual coercion, from a soldier or fighter during 5 years of the Liberian civil war from 1989 through 1994. Interview and survey. High schools, markets, displaced persons camps, and urban communities in Monrovia, Liberia, in 1994. A random sample of 205 women and girls between the ages of 15 and 70 years (88% participation rate). One hundred (49%) of 205 participants reported experiencing at least 1 act of physical or sexual violence by a soldier or fighter. Survey participants reported being beaten, tied up, or detained in a room under armed guard (17%); strip-searched 1 or more times (32%); and raped, subjected to attempted rape, or sexually coerced (15%). Women who were accused of belonging to a particular ethnic group or fighting faction or who were forced to cook for a soldier or fighter were at increased risk for physical and sexual violence. Of the 106 women and girls accused of belonging to an ethnic group or faction, 65 (61%) reported that they were beaten, locked up, strip-searched, or subjected to attempted rape, compared with 27 (27%) of the 99 women who were not accused (P< or =.02, .07, .001, and .06, respectively). Women and girls who were forced to cook for a soldier or fighter were more likely to report experiencing rape, attempted rape, or sexual coercion than those who were not forced to cook (55% vs 10%; P< or =.001, .06, and .001, respectively). Young women (those younger than 25 years) were more likely than women 25 years or older to report experiencing attempted rape and sexual coercion (18% vs 4%, P=.02 and .04, respectively). This collaborative research allowed Liberian women to document wartime violence against women in their own communities and to develop a unique program to address violence against women in Liberia.
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Incidence of Injury in Professional Mixed Martial Arts Competitions
Bledsoe, Gregory H.; Hsu, Edbert B.; Grabowski, Jurek George; Brill, Justin D.; Li, Guohua
2006-01-01
Mixed Martial Arts (MMA) competitions were introduced in the United States with the first Ultimate Fighting Championship (UFC) in 1993. In 2001, Nevada and New Jersey sanctioned MMA events after requiring a series of rule changes. The purpose of this study was to determine the incidence of injury in professional MMA fighters. Data from all professional MMA events that took place between September 2001 and December 2004 in the state of Nevada were obtained from the Nevada Athletic Commission. Medical and outcome data from events were analyzed based on a pair-matched case-control design. Both conditional and unconditional logistic regression models were used to assess risk factors for injury. A total of 171 MMA matches involving 220 different fighters occurred during the study period. There were a total of 96 injuries to 78 fighters. Of the 171 matches fought, 69 (40.3%) ended with at least one injured fighter. The overall injury rate was 28.6 injuries per 100 fight participations or 12.5 injuries per 100 competitor rounds. Facial laceration was the most common injury accounting for 47.9% of all injuries, followed by hand injury (13.5%), nose injury (10.4%), and eye injury (8.3%). With adjustment for weight and match outcome, older age was associated with significantly increased risk of injury. The most common conclusion to a MMA fight was a technical knockout (TKO) followed by a tap out. The injury rate in MMA competitions is compatible with other combat sports involving striking. The lower knockout rates in MMA compared to boxing may help prevent brain injury in MMA events. Key Points Mixed martial arts (MMA) has changed since the first MMA matches in the United States and now has increased safety regulations and sanctioning. MMA competitions have an overall high rate of injury. There have been no MMA deaths in the United States. The knockout (KO) rate in MMA appears to be lower than the KO rate of boxing matches. MMA must continue to be supervised by properly trained medical professionals and referees to ensure fighter safety in the future. PMID:24357986
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2009-12-22
b) From top to bottom, (i) AFM topograph of the p-i-n SiNW, (ii) plot of EFM phase-shift vs . position recorded along the nanowire axis and (iii...c) Current vs . applied voltage curve for a typical SiNW p-i-n junction at room temperature. (d) Current vs . applied reverse voltage data of a p-i...incident laser power. Iph vs . laser power (Figure 3c) measured at 22, 20 and 18 V show linear dependences with slopes of 1.16, 0.94 and 0.72 nA/μW
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Design and Calibration of the NBS Isotropic Electric-Field Monitor (EFM- 5), 0.2 to 1000 MHz
1981-03-01
34 "’" ^^ Up t0 about 5° ™<<« (316 V/m). and a There are th * "P t0 M dBV/m (10°° V/m)’ teen designated "IT"’"’ ^^^ ^^ *""* ’" the meter1n9 un1t...investigation. However, NBS personnel have analyzed •v ■ v" .*U^O> IV ***» • ts* M .h jnj hjve nude preliminary evaluations of new types of
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Fighter pilots' heart rate, heart rate variation and performance during instrument approaches.
Mansikka, Heikki; Simola, Petteri; Virtanen, Kai; Harris, Don; Oksama, Lauri
2016-10-01
Fighter pilots' heart rate (HR), heart rate variation (HRV) and performance during instrument approaches were examined. The subjects were required to fly instrument approaches in a high-fidelity simulator under various levels of task demand. The task demand was manipulated by increasing the load on the subjects by reducing the range at which they commenced the approach. HR and the time domain components of HRV were used as measures of pilot mental workload (PMWL). The findings of this study indicate that HR and HRV are sensitive to varying task demands. HR and HRV were able to distinguish the level of PMWL after which the subjects were no longer able to cope with the increasing task demands and their instrument landing system performance fell to a sub-standard level. The major finding was the HR/HRV's ability to differentiate the sub-standard performance approaches from the high-performance approaches. Practitioner Summary: This paper examined if HR and HRV were sensitive to varying task demands in a fighter aviation environment and if these measures were related to variations in pilot's performance.
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Physiological parameters monitoring of fire-fighters by means of a wearable wireless sensor system
NASA Astrophysics Data System (ADS)
Stelios, M.; Mitilineos, Stelios A.; Chatzistamatis, Panagiotis; Vassiliadis, Savvas; Primentas, Antonios; Kogias, Dimitris; Michailidis, Emmanouel T.; Rangoussi, Maria; Kurşun Bahadir, Senem; Atalay, Özgür; Kalaoğlu, Fatma; Sağlam, Yusuf
2016-03-01
Physiological parameter monitoring may be useful in many different groups of the population, such as infants, elderly people, athletes, soldiers, drivers, fire-fighters, police etc. This can provide a variety of information ranging from health status to operational readiness. In this article, we focus on the case of first responders and specifically fire-fighters. Firefighters can benefit from a physiological monitoring system that is used to extract multiple indications such as the present position, the possible life risk level, the stress level etc. This work presents a wearable wireless sensor network node, based on low cost, commercial-off- the-self (COTS) electronic modules, which can be easily attached on a standard fire-fighters’ uniform. Due to the low frequency wired interface between the selected electronic components, the proposed solution can be used as a basis for a textile system where all wired connections will be implemented by means of conductive yarn routing in the textile structure, while some of the standard sensors can be replaced by textile ones. System architecture is described in detail, while indicative samples of acquired signals are also presented.
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NASA Technical Reports Server (NTRS)
Ngan, Angelen; Biezad, Daniel
1996-01-01
A study has been conducted to develop and to analyze a FORTRAN computer code for performing agility analysis on fighter aircraft configurations. This program is one of the modules of the NASA Ames ACSYNT (AirCraft SYNThesis) design code. The background of the agility research in the aircraft industry and a survey of a few agility metrics are discussed. The methodology, techniques, and models developed for the code are presented. The validity of the existing code was evaluated by comparing with existing flight test data. A FORTRAN program was developed for a specific metric, PM (Pointing Margin), as part of the agility module. Example trade studies using the agility module along with ACSYNT were conducted using a McDonnell Douglas F/A-18 Hornet aircraft model. Tile sensitivity of thrust loading, wing loading, and thrust vectoring on agility criteria were investigated. The module can compare the agility potential between different configurations and has capability to optimize agility performance in the preliminary design process. This research provides a new and useful design tool for analyzing fighter performance during air combat engagements in the preliminary design.
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Development of an agility assessment module for preliminary fighter design
NASA Technical Reports Server (NTRS)
Ngan, Angelen; Bauer, Brent; Biezad, Daniel; Hahn, Andrew
1996-01-01
A FORTRAN computer program is presented to perform agility analysis on fighter aircraft configurations. This code is one of the modules of the NASA Ames ACSYNT (AirCraft SYNThesis) design code. The background of the agility research in the aircraft industry and a survey of a few agility metrics are discussed. The methodology, techniques, and models developed for the code are presented. FORTRAN programs were developed for two specific metrics, CCT (Combat Cycle Time) and PM (Pointing Margin), as part of the agility module. The validity of the code was evaluated by comparing with existing flight test data. Example trade studies using the agility module along with ACSYNT were conducted using Northrop F-20 Tigershark and McDonnell Douglas F/A-18 Hornet aircraft models. The sensitivity of thrust loading and wing loading on agility criteria were investigated. The module can compare the agility potential between different configurations and has the capability to optimize agility performance in the preliminary design process. This research provides a new and useful design tool for analyzing fighter performance during air combat engagements.
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The southpaw advantage? Lateral preference in mixed martial arts.
Baker, Joseph; Schorer, Jörg
2013-01-01
Performers with a left-orientation have a greater likelihood of obtaining elite levels of performance in many interactive sports. This study examined whether combat stance orientation was related to skill and success in Mixed Martial Arts fighters. Data were extracted for 1468 mixed martial artists from a reliable and valid online data source. Measures included fighting stance, win percentage and an ordinal measure of skill based on number of fights. The overall analysis revealed that the fraction of fighters using a southpaw stance was greater than the fraction of left-handers in the general population, but the relationship between stance and hand-preference is not well-understood. Furthermore, t-tests found no statistically significant relationship between laterality and winning percentage, although there was a significant difference between stances for number of fights. Southpaw fighters had a greater number of fights than those using an orthodox stance. These results contribute to an expanding database on the influence of laterality on sport performance and a relatively limited database on variables associated with success in mixed martial arts.
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NASA Technical Reports Server (NTRS)
Howell, G. A.; Crosthwait, E. L.; Witte, M. C.
1981-01-01
A STOL fighter model employing the vectored-engine-over wing concept was tested at low speeds in the NASA/Ames 40 by 80-foot wind tunnel. The model, approximately 0.75 scale of an operational fighter, was powered by two General Electric J-97 turbojet engines. Limited pressure and thermal instrumentation were provided to measure power effects (chordwise and spanwise blowing) and control-surface-deflection effects. An indepth study of the pressure and temperature data revealed many flow field features - the foremost being wing and canard leading-edge vortices. These vortices delineated regions of attached and separated flow, and their movements were often keys to an understanding of flow field changes caused by power and control-surface variations. Chordwise blowing increased wing lift and caused a modest aft shift in the center of pressure. The induced effects of chordwise blowing extended forward to the canard and significantly increased the canard lift when the surface was stalled. Spanwise blowing effectively enhanced the wing leading-edge vortex, thereby increasing lift and causing a forward shift in the center of pressure.
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NASA Technical Reports Server (NTRS)
1991-01-01
The AFTI F-16 flying at high angle of attack, shown in the final configuration and paint finish. Dummy Sidewinder air-to-air missles are attached to the wing tips. The white objects visible on the wing racks represent practice bomb dispensers, used in weapon tests. During the 1980s and 1990s, NASA and the U.S. Air Force participated in a joint program to integrate and demonstrate new avionics technologies to improve close air support capabilities in next-generation aircraft. The testbed aircraft, seen here in flight over the desert at NASA's Dryden Flight Research Center, Edwards, California, was called the Advanced Fighter Technology Integration (AFTI) F-16. The tests demonstrated technologies to improve navigation and the pilot's ability to find and destroy enemy ground targets day or night, including adverse weather. The aircraft--an F-16A Fighting Falcon (Serial #75-0750)--underwent numerous modifications. A relatively low-cost testbed, it evaluated the feasability of advanced, intergrated-sensor, avionics, and flight control technologies. During the first phase of the AFTI/F-16 program, which began in 1983, the aircraft demonstrated voice-actuated commands, helmet-mounted sights, flat turns, and selective fuselage pointing using forward-mounted canards and a triplex digital flight control computer system. The second phase of research, which began in the summer of 1991, demonstrated advanced technologies and capabilities to find and destroy ground targets day or night, and in adverse weather while using maneuverability and speed at low altitude. This phase was known as the close air support and battlefield air interdiction (CAS/BAI) phase. Finally, the aircraft was used to assess the Automatic Ground Collision Avoidance System (Auto - GCAS), a joint project with the Swedish Government. For these tests, the pilot flew the aircraft directly toward the ground, simulating a total loss of control. The GCAS was designed to take command in such emergencies and bring the aircraft back to level flight. The AFTI F-16 program ended at Dryden on November 4, 1997 after 15 years and over 700 research flights. The USAF continued to fly the aircraft until retiring it to the Air Force Museum on January 9, 2001.
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AFTI/F-16 50th flight team photo
NASA Technical Reports Server (NTRS)
1983-01-01
An early (1983) photograph of the AFTI F-16 team, commemorating the aircraft's 50th flight. It shows the initial configuration and paint finish of the AFTI F-16, as well as the forward mounted canards and the spin chute. During the 1980s and 1990s, NASA and the U.S. Air Force participated in a joint program to integrate and demonstrate new avionics technologies to improve close air support capabilities in next-generation aircraft. The testbed aircraft, seen here in flight over the desert at NASA's Dryden Flight Research Center, Edwards, California, was called the Advanced Fighter Technology Integration (AFTI) F-16. The tests demonstrated technologies to improve navigation and the pilot's ability to find and destroy enemy ground targets day or night, including adverse weather. The aircraft--an F-16A Fighting Falcon (Serial #75-0750)--underwent numerous modifications. A relatively low-cost testbed, it evaluated the feasability of advanced, intergrated-sensor, avionics, and flight control technologies. During the first phase of the AFTI/F-16 program, which began in 1983, the aircraft demonstrated voice-actuated commands, helmet-mounted sights, flat turns, and selective fuselage pointing using forward-mounted canards and a triplex digital flight control computer system. The second phase of research, which began in the summer of 1991, demonstrated advanced technologies and capabilities to find and destroy ground targets day or night, and in adverse weather while using maneuverability and speed at low altitude. This phase was known as the close air support and battlefield air interdiction (CAS/BAI) phase. Finally, the aircraft was used to assess the Automatic Ground Collision Avoidance System (Auto - GCAS), a joint project with the Swedish Government. For these tests, the pilot flew the aircraft directly toward the ground, simulating a total loss of control. The GCAS was designed to take command in such emergencies and bring the aircraft back to level flight. The AFTI F-16 program ended at Dryden on November 4, 1997 after 15 years and over 700 research flights. The USAF continued to fly the aircraft until retiring it to the Air Force Museum on January 9, 2001.
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NASA Technical Reports Server (NTRS)
1989-01-01
This photo depicts the AFTI F-16 in the configuration used midway through the program. The sensor pods were added to the fuselage, but the chin canards remained in place. Painted in non-standard gray tones, it carried Sidewinder air-to-air missles on its wingtips. During the 1980s and 1990s, NASA and the U.S. Air Force participated in a joint program to integrate and demonstrate new avionics technologies to improve close air support capabilities in next-generation aircraft. The testbed aircraft, seen here in flight over the desert at NASA's Dryden Flight Research Center, Edwards, California, was called the Advanced Fighter Technology Integration (AFTI) F-16. The tests demonstrated technologies to improve navigation and the pilot's ability to find and destroy enemy ground targets day or night, including adverse weather. The aircraft--an F-16A Fighting Falcon (Serial #75-0750)--underwent numerous modifications. A relatively low-cost testbed, it evaluated the feasability of advanced, intergrated-sensor, avionics, and flight control technologies. During the first phase of the AFTI/F-16 program, which began in 1983, the aircraft demonstrated voice-actuated commands, helmet-mounted sights, flat turns, and selective fuselage pointing using forward-mounted canards and a triplex digital flight control computer system. The second phase of research, which began in the summer of 1991, demonstrated advanced technologies and capabilities to find and destroy ground targets day or night, and in adverse weather while using maneuverability and speed at low altitude. This phase was known as the close air support and battlefield air interdiction (CAS/BAI) phase. Finally, the aircraft was used to assess the Automatic Ground Collision Avoidance System (Auto - GCAS), a joint project with the Swedish Government. For these tests, the pilot flew the aircraft directly toward the ground, simulating a total loss of control. The GCAS was designed to take command in such emergencies and bring the aircraft back to level flight. The AFTI F-16 program ended at Dryden on November 4, 1997 after 15 years and over 700 research flights. The USAF continued to fly the aircraft until retiring it to the Air Force Museum on January 9, 2001.
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NASA Technical Reports Server (NTRS)
1992-01-01
The AFTI F-16 in its final configuration, flying in the vicinity of Edwards Air Force Base, California. During this phase, the two forward infrared turrets were added ahead of the cockpit, the chin canards were removed, and the aircraft was repainted in a standard Air Force scheme. A fuel drop tank is visible below the wing. During the 1980s and 1990s, NASA and the U.S. Air Force participated in a joint program to integrate and demonstrate new avionics technologies to improve close air support capabilities in next-generation aircraft. The testbed aircraft, seen here in flight over the desert at NASA's Dryden Flight Research Center, Edwards, California, was called the Advanced Fighter Technology Integration (AFTI) F-16. The tests demonstrated technologies to improve navigation and the pilot's ability to find and destroy enemy ground targets day or night, including adverse weather. The aircraft--an F-16A Fighting Falcon (Serial #75-0750)--underwent numerous modifications. A relatively low-cost testbed, it evaluated the feasability of advanced, intergrated-sensor, avionics, and flight control technologies. During the first phase of the AFTI/F-16 program, which began in 1983, the aircraft demonstrated voice-actuated commands, helmet-mounted sights, flat turns, and selective fuselage pointing using forward-mounted canards and a triplex digital flight control computer system. The second phase of research, which began in the summer of 1991, demonstrated advanced technologies and capabilities to find and destroy ground targets day or night, and in adverse weather while using maneuverability and speed at low altitude. This phase was known as the close air support and battlefield air interdiction (CAS/BAI) phase. Finally, the aircraft was used to assess the Automatic Ground Collision Avoidance System (Auto - GCAS), a joint project with the Swedish Government. For these tests, the pilot flew the aircraft directly toward the ground, simulating a total loss of control. The GCAS was designed to take command in such emergencies and bring the aircraft back to level flight. The AFTI F-16 program ended at Dryden on November 4, 1997 after 15 years and over 700 research flights. The USAF continued to fly the aircraft until retiring it to the Air Force Museum on January 9, 2001.
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50 CFR 404.4 - Access to Monument.
Code of Federal Regulations, 2010 CFR
2010-10-01
... INTERIOR AND NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT... defects or deficiencies that restrict maneuverability or impair normal navigation. (11) Any pollution.... (4) Any pollution incident or goods lost overboard within the Monument, the reporting area, or the U...
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Simulation Model for the Piper PA-30 Light Maneuverable Aircraft in the Final Approach
DOT National Transportation Integrated Search
1971-07-01
The report describes the Piper PA-30 'Twin Comanche' aircraft and a representative autopilot during the final approach configuration for simulation purposes. The aircraft is modeled by linearized six-degree-of-freedom perturbation equations reference...
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Study of aerodynamic technology for single-cruise engine V/STOL fighter/attack aircraft
NASA Technical Reports Server (NTRS)
Driggers, H. H.; Powers, S. A.; Roush, R. T.
1982-01-01
A conceptual design analysis is performed on a single engine V/STOL supersonic fighter/attack concept powered by a series flow tandem fan propulsion system. Forward and aft mounted fans have independent flow paths for V/STOL operation and series flow in high speed flight. Mission, combat and V/STOL performance is calculated. Detailed aerodynamic estimates are made and aerodynamic uncertainties associated with the configuration and estimation methods identified. A wind tunnel research program is developed to resolve principal uncertainties and establish a data base for the baseline configuration and parametric variations.
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Air National Guard Fighters the Total Force (Maxwell Paper, Number 1)
1996-05-01
child abuse cases, 9 percent rise in spousal abuse reports, and an 11 percent rise in alcohol abuse. While these figures represent only one fighter wing, they highlight some of the potential problems that may be encountered by other active duty units as they too struggle under an ever increasing workload. These problems and a growing belief that long-term readiness may soon suffer if the workload is not reduced, convinced Defense Secretary William Perry to direct a greater role for the Air National Guard in peacetime contingency operations. The Air National Guard is no
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Subsonic characteristics of a twin-jet swept-wing fighter model with maneuvering devices
NASA Technical Reports Server (NTRS)
Ray, E. J.; Hollingsworth, E. G.
1973-01-01
An investigation has been conducted at Mach numbers ranging from 0.06 to 0.94 to determine the effects of various combinations of leading-edge slat devices on the static aerodynamic characteristics of a twin-jet swept-wing fighter model. The study also included a determination of the effects of wing leading-edge droop, trailing-edge chord-extensions, wing fences, and wing-planform and camber modifications. The angle-of-attack range generally extended from about minus 2 deg to 24 deg and the sideslip angles ranged from about minus 6 deg to 13 deg.
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McDonald XP-85 Airplane in 40x80 foot Wind Tunnel.
1948-04-08
Front View of McDonald XP-85 Plan Model. Parasite Airplane designed to be carried in the B-36 bombay (never built) At the time it was the smallest Jet powered airplane. The McDonnell XF-85 Goblin was an American prototype fighter aircraft conceived during World War II by McDonnell Aircraft. It was intended to be deployed from the bomb bay of the giant Convair B-36 bomber as a parasite fighter. The XF-85's intended role was to defend bombers from hostile interceptor aircraft, a need demonstrated during World War II
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NASA Technical Reports Server (NTRS)
Morris, O. A.
1977-01-01
A wind tunnel investigation has been conducted to determine the longitudinal and lateral aerodynamic characteristics of a model of a supersonic cruise fighter configuration with a design Mach number of 2.60. The configuration is characterized by a highly swept arrow wing twisted and cambered to minimize supersonic drag due to lift, twin wing mounted vertical tails, and an aft mounted integral underslung duel-engine pod. The investigation also included tests of the configuration with larger outboard vertical tails and with small nose strakes.
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Measurement and Analysis of Wing and Tail Buffeting Loads on a Fighter Airplane
NASA Technical Reports Server (NTRS)
Huston, Wilber B; Skopinski, T H
1955-01-01
The buffeting loads measured on the wing and tail of a fighter airplane during 194 maneuvers are given in tabular form, along with the associated flight conditions. Measurements were made at altitudes of 30,000 to 10,000 feet and at speeds up to a Mach number of 0.8. Least-squares methods have been used for a preliminary analysis of the data. The agreement between the results of this analysis and the loads measured in stalls is sufficiently good to suggest the examination of the buffeting of other airplanes on the same basis.
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NASA Technical Reports Server (NTRS)
Neuhart, Dan H.; Rhode, Matthew N.
1990-01-01
A test was conducted in the NASA Langley 16- by 24-Inch Water Tunnel to study alleviation of the adverse interactions of inlet spillage flow on the external stores of a fighter aircraft. A 1/48-scale model of a fighter aircraft was used to simulate the flow environment around the aircraft inlets and on the downstream underside of the fuselage. A controlled inlet mass flow was simulated by drawing water into the inlets. Various flow control devices were used on the underside of the aircraft model to manipulate the vortical inlet spillage flow.
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HiMAT highly maneuverable aircraft technology, flight report
NASA Technical Reports Server (NTRS)
1982-01-01
Flight verification of a primary flight control system, designed to control the unstable HiMAT aircraft is presented. The initial flight demonstration of a maneuver autopilot in the level cruise mode and the gathering of a limited amount of airspeed calibration data.
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NASA Technical Reports Server (NTRS)
Smallcombe, Richard D.
1994-01-01
Captive bolt installed, removed, and reinstalled easily, even with heavily gloved hands depriving technicians of feeling of engagement of threads. Has two threads with different diameters but same pitch. Engages either housing or mating part. Useful in construction in environments where visibility, tactility, and/or maneuverability poor.
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The Mobility Decision. 1990 Wheelchair Guide.
ERIC Educational Resources Information Center
Henke, Cliff
1990-01-01
This article presents tips for parents shopping for wheelchairs for children with special mobility needs. Manual versus power chairs, dimensions, maneuverability, weight, transportability, durability, adaptability, maximum/minimum speeds, battery life (for power chairs), climbing angle, and other features are discussed. Factors to consider in…
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NASA Astrophysics Data System (ADS)
Sebald, Thomas; Rider, Gavin
2009-04-01
It has recently been reported [1] that production reticles are subject to progressive CD degradation during use and intense study is under way to try and identify the causes of it. One damage mechanism which has already been identified and quantified [2] is electric field induced migration of chrome (EFM). This can be caused by electric fields that are more than 100x weaker than those that cause ESD. Such low level electric fields can be experienced by a reticle during normal handling and processing steps, as well as coming from external sources during transportation and storage. The field strength of concern is lower than most electrostatic field meters are designed to measure and it can be difficult or impossible to measure such fields inside the cramped environment of equipment. To measure this risk a new sensor device ("E-Reticle") has been developed having the same materials of construction and form factor as a standard chrome-on-quartz reticle. It allows the electric field that a reticle would experience during normal use and handling to be measured and recorded. Results from testing of this device in a semiconductor production facility are reported, showing that certain processes like reticle washing are inherently hazardous. It also enables identification of problems with electrostatic protection measures inside equipment, such as unbalanced ionizers or poor load port grounding. The device is shown to be capable of recording electric fields in the reticle handling environment that are below the recommended maximum that is being proposed for the 2009 ITRS guidelines.
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NASA Astrophysics Data System (ADS)
Ankudinov, A.; Titkov, A. N.; Evtikhiev, Vadim P.; Kotelnikov, Eugeny Y.; Bazhenov, N.; Zegrya, Georgy G.; Huhtinen, H.; Laiho, R.
2003-06-01
One of the important factors that restricts the power limit of semiconductor lasers is a catastrophic optical mirror damage. This process is significantly suppressed through decreasing the optical power density due to its redistribution over the broad transverse waveguide (BW). Recently it was shown that record-breaking values of the quasicontinuous and continuous-wave (QWC and CW) output power for 100-μm-wide-aperture devices can be achieved by incorporating a broad transverse waveguide into 0.97 μm emitting Al-free InGaAs(P)/InGaP/GaAs and Al-containing InGaAs/AlGaAs/GaAs separate confinement heterostructure quantum-well lasers (SCH-QWL). Another important factor limiting the CW output power is the Joule overheating of a laser diode due to an extra serial resistance. Traditionally, a decrease in the resistance is achieved by development of the contacts, whereas a voltage distribution across the device structure is not analyzed properly. At high operating currents the applied voltage can drop not only across the n-p-junction, but also at certain additional regions of the laser structure depending on a particular design of the device. Electrostatic force microscopy (EFM) provides a very promising method to study the voltage distribution across an operating device with a nanometer space resolution. An application of EFM for diagnostics of III-V laser diodes without and under applied biases have been recently demonstrated. However, the most interesting range of the biases, the lazing regime, has not been studied yet.
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Flight experience and the perception of pitch angular displacements in a gondola centrifuge.
Tribukait, Arne; Eiken, Ola
2012-05-01
It has been shown that flight experience may induce an adaptation of the vestibular system. The aim of the present work was to elucidate whether pilots, in comparison with non-pilots, have an increased responsiveness to angular displacement canal stimuli in the pitch plane during a conflict between the otolith organs and the semicircular canals. In a large swing-out gondola centrifuge, eight non-pilots, eight fighter pilots, and eight helicopter pilots underwent three runs (2 G, 5 min) heading forward, centripetally, and centrifugally. The direction of the gravitoinertial force was constant with respect to the subject. The visually perceived eye level (VPEL) was measured in darkness by means of an adjustable luminous dot. In the forward position the three groups produced similar results. After acceleration there was a sensation of backward tilt and an increasing depression of VPEL. This effect was smaller in the centripetal position and larger in the centrifugal position. The difference in VPEL between the opposite positions constitutes a measure of the ability to sense the pitch angular displacement canal stimulus related to the swing out of the gondola (60 degrees). This difference was most pronounced initially at the 2-G plateau (mean +/- SD): 13.5 +/- 12.9 degrees (non-pilots), 41.6 +/- 21.1 degrees (fighter pilots), and 19.5 +/- 14.0 degrees (helicopter pilots). There was no significant difference between non-pilots and helicopter pilots. Fighter pilots differed significantly from both non-pilots and helicopter pilots. Vestibular learning effects of flying may be revealed in a centrifuge. Fighter pilots had an increased ability, as compared to non-pilots and helicopter pilots, to perceive pitch angular displacements.
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Tayebi Meybodi, Ali; Benet, Arnau; Rodriguez Rubio, Roberto; Yousef, Sonia; Lawton, Michael T
2018-03-03
The orbitozygomatic approach is generally advocated over the pterional approach for basilar apex aneurysms. However, the impact of the extensions of the pterional approach on the obtained maneuverability over multiple vascular targets (relevant to basilar apex surgery) has not been studied before. To analyze the patterns of surgical freedom change across the basilar bifurcation between the pterional, orbitopterional, and orbitozygomatic approaches. Surgical freedom was assessed for 3 vascular targets important in basilar apex aneurysm surgery (ipsilateral and contralateral P1-P2 junctions, and basilar apex), and compared between the pterional, orbitopterional, and orbitozygomatic approaches in 10 cadaveric specimens. Transitioning from the pterional to orbitopterional approach, the surgical freedom increased significantly at all 3 targets (P < .05). However, the gain in surgical freedom declined progressively from the most superficial target (60% for ipsilateral P1-P2 junction) to the deepest target (35% for contralateral P1-P2 junction). Conversely, transitioning from the orbitopterional to the orbitozygomatic approach, the gain in surgical freedom was minimal for the ipsilateral P1-P2 and basilar apex (<4%), but increased dramatically to 19% at the contralateral P1-P2 junction. The orbitopterional approach provides a remarkable increase in surgical maneuverability compared to the pterional approach for the basilar apex target and the relevant adjacent arterial targets. However, compared to the orbitopterional, the orbitozygomatic approach adds little maneuverability except for the deepest target (ie, contralateral P1-P2 junction). Therefore, the orbitozygomatic approach may be most efficacious with larger basilar apex aneurysms limiting the control over of the contralateral P1 PCA.
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Design features that affect the maneuverability of wheelchairs and scooters.
Koontz, Alicia M; Brindle, Eric D; Kankipati, Padmaja; Feathers, David; Cooper, Rory A
2010-05-01
To determine the minimum space required for wheeled mobility device users to perform 4 maneuverability tasks and to investigate the impact of selected design attributes on space. Case series. University laboratory, Veterans Affairs research facility, vocational training center, and a national wheelchair sport event. The sample of convenience included manual wheelchair (MWC; n=109), power wheelchair (PWC; n=100), and scooter users (n=14). A mock environment was constructed to create passageways to form an L-turn, 360 degrees -turn in place, and a U-turn with and without a barrier. Passageway openings were increased in 5-cm increments until the user could successfully perform each task without hitting the walls. Structural dimensions of the device and user were collected using an electromechanical probe. Mobility devices were grouped into categories based on design features and compared using 1-way analysis of variance and post hoc pairwise Bonferroni-corrected tests. Minimum passageway widths for the 4 maneuverability tasks. Ultralight MWCs with rear axles posterior to the shoulder had the shortest lengths and required the least amount of space compared with all other types of MWCs (P<.05). Mid-wheel-drive PWCs required the least space for the 360 degrees -turn in place compared with front-wheel-drive and rear-wheel-drive PWCs (P<.01) but performed equally as well as front-wheel-drive models on all other turning tasks. PWCs with seat functions required more space to perform the tasks. Between 10% and 100% of users would not be able to maneuver in spaces that meet current Accessibility Guidelines for Buildings and Facilities specifications. This study provides data that can be used to support wheelchair prescription and home modifications and to update standards to improve the accessibility of public areas.
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Enhancement of roll maneuverability using post-reversal design
NASA Astrophysics Data System (ADS)
Li, Wei-En
This dissertation consists of three main parts. The first part is to discuss aileron reversal problem for a typical section with linear aerodynamic and structural analysis. The result gives some insight and ideas for this aeroelastic problem. Although the aileron in its post-reversal state will work the opposite of its design, this type of phenomenon as a design root should not be ruled out on these grounds alone, as current active flight-control systems can compensate for this. Moreover, one can get considerably more (negative) lift for positive flap angle in this unusual regime than positive lift for positive flap angle in the more conventional setting. This may have important implications for development of highly maneuverable aircraft. The second part is to involve the nonlinear aerodynamic and structural analyses into the aileron reversal problem. Two models, a uniform cantilevered lifting surface and a rolling aircraft with rectangular wings, are investigated here. Both models have trailing-edge control surfaces attached to the main wings. A configuration that reverses at a relatively low dynamic pressure and flies with the enhanced controls at a higher level of effectiveness is demonstrated. To evaluate how reliable for the data from XFOIL, the data for the wing-aileron system from advanced CFD codes and experiment are used to compare with that from XFOIL. To enhance rolling maneuverability for an aircraft, the third part is to search for the optimal configuration during the post-reversal regime from a design point of view. Aspect ratio, hinge location, airfoil dimension, inner structure of wing section, composite skin, aeroelastic tailoring, and airfoil selection are investigated for cantilevered wing and rolling aircraft models, respectively. Based on these parametric structural designs as well as the aerodynamic characteristics of different airfoils, recommendations are given to expand AAW flight program.
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Lien, Gi-Shih; Wu, Ming-Shun; Chen, Chun-Nan; Liu, Chih-Wen; Suk, Fat-Moon
2018-04-01
Current capsule endoscopy procedures are ineffective for upper gastrointestinal (GI) tract examination because they do not allow for operator-controlled navigation of the capsule. External controllability of a capsule endoscope with an applied magnetic field is a possible solution to this problem. We developed a novel magnetic-assisted capsule endoscope (MACE) system to visualize the entire upper GI tract. The present study evaluated the safety and feasibility of the MACE system for the examination of the upper GI tract, including the esophagus, stomach, and duodenum. The present open clinical study enrolled ten healthy volunteers. All participants swallowed a MACE, and an external magnetic field navigator was used for magnetic capsule manipulation in the upper GI tract. We assessed the maneuverability of the magnetic capsule and completeness of the MACE examination as well as the safety and tolerability of the procedure. The present study enrolled ten healthy volunteers with a mean age and body mass index of 47.7 years and 25.6 kg/m 2 , respectively. One volunteer withdrew because of difficulty in swallowing the capsule. In total, nine volunteers underwent the MACE examination. The average examination time was 27.1 min. The maneuverability of the capsule was assessed as good and fair in 55.6 and 44.4% of the participants, respectively. The overall completeness of the examination in the esophagus, stomach, and duodenum was 100, 85.2, and 86.1%, respectively. No severe adverse events occurred during this study. All participants exhibited satisfactory tolerance of the MACE examination. The MACE system has satisfactory maneuverability and visualization completeness with excellent acceptance and tolerance.
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NASA Astrophysics Data System (ADS)
Du, Peng; Ouahsine, Abdellatif; Sergent, Philippe
2018-05-01
Ship maneuvering in the confined inland waterway is investigated using the system-based method, where a nonlinear transient hydrodynamic model is adopted and confinement models are implemented to account for the influence of the channel bank and bottom. The maneuvering model is validated using the turning circle test, and the confinement model is validated using the experimental data. The separation distance, ship speed, and channel width are then varied to investigate their influences on ship maneuverability. With smaller separation distances and higher speeds near the bank, the ship's trajectory deviates more from the original course and the bow is repelled with a larger yaw angle, which increase the difficulty of maneuvering. Smaller channel widths induce higher advancing resistances on the ship. The minimum distance to the bank are extracted and studied. It is suggested to navigate the ship in the middle of the channel and with a reasonable speed in the restricted waterway.
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Optimization of a tensegrity wing for biomimetic applications
NASA Astrophysics Data System (ADS)
Moored, Keith W., III; Taylor, Stuart A.; Bart-Smith, Hilary
2006-03-01
Current attempts to build fast, efficient, and maneuverable underwater vehicles have looked to nature for inspiration. However, they have all been based on traditional propulsive techniques, i.e. rotary motors. In the current study a promising and potentially revolutionary approach is taken that overcomes the limitations of these traditional methods-morphing structure concepts with integrated actuation and sensing. Inspiration for this work comes from the manta ray (Manta birostris) and other batoid fish. These creatures are highly maneuverable but are also able to cruise at high speeds over long distances. In this paper, the structural foundation for the biomimetic morphing wing is a tensegrity structure. A preliminary procedure is presented for developing morphing tensegrity structures that include actuating elements. A shape optimization method is used that determines actuator placement and actuation amount necessary to achieve the measured biological displacement field of a ray. Lastly, an experimental manta ray wing is presented that measures the static and dynamic pressure field acting on the ray's wings during a normal flapping cycle.
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Sun, Zhen-Jun; Ye, Bo; Sun, Yi; Zhang, Hong-Hai; Liu, Sheng
2014-07-01
This article describes a novel magnetically maneuverable capsule endoscope system with direction reference for image navigation. This direction reference was employed by utilizing a specific magnet configuration between a pair of external permanent magnets and a magnetic shell coated on the external capsule endoscope surface. A pair of customized Cartesian robots, each with only 4 degrees of freedom, was built to hold the external permanent magnets as their end-effectors. These robots, together with their external permanent magnets, were placed on two opposite sides of a "patient bed." Because of the optimized configuration based on magnetic analysis between the external permanent magnets and the magnetic shell, a simplified control strategy was proposed, and only two parameters, yaw step angle and moving step, were necessary for the employed robotic system. Step-by-step experiments demonstrated that the proposed system is capable of magnetically maneuvering the capsule endoscope while providing direction reference for image navigation. © IMechE 2014.
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NASA Technical Reports Server (NTRS)
Mineck, R. E.; Margason, R. J.
1974-01-01
A wind-tunnel investigation has been conducted in the Langley V/STOL tunnel with a vectored-thrust V/STOL fighter configuration to obtain detailed pressure measurements on the body and on the wing in the transition-speed range. The vectored-thrust jet exhaust induced a region of negative pressure coefficients on the lower surface of the wing and on the bottom of the fuselage. The location of the jet exhaust relative to the wing was a major factor in determining the extent of the region of negative pressure coefficients.
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A NASA study of the impact of technology on future carrier based tactical aircraft - Overview
NASA Technical Reports Server (NTRS)
Wilson, S. B., III
1992-01-01
This paper examines the impact of technology on future carrier based tactical aircraft. The results were used in the Center for Naval Analysis Future Carrier Study. The NASA Team designed three classes of aircraft ('Fighter', 'Attack', and 'Multimission') with two different technology levels. The Multimission aircraft were further analyzed by examining the penalty on the aircraft for both catapult launch/arrested landing recovery (Cat/trap) and short take-off/vertical landing (STOVL). The study showed the so-called STOVL penalty was reduced by engine technology and the next generation Strike Fighter will pay more penalty for Cat/trap than for STOVL capability.
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NASA Technical Reports Server (NTRS)
Osher, S.
1984-01-01
The construction of a reliable, shock capturing finite difference method to solve the Euler equations for inviscid, supersonic flow past fighter and missile type configurations is highly desirable. The numerical method must have a firm theoretical foundation and must be robust and efficient. It should be able to treat subsonic pockets in a predominantly supersonic flow. The method must also be easily applicable to the complex topologies of the aerodynamic configuration under consideration. The ongoing approach to this task is described and for steady supersonic flows is presented. This scheme is the basic numerical method. Results of work obtained during previous years are presented.
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NASA Technical Reports Server (NTRS)
Ogburn, Marilyn E.; Foster, John V.; Hoffler, Keith D.
2005-01-01
This paper reviews the use of piloted simulation at Langley Research Center as part of the NASA High-Angle-of-Attack Technology Program (HATP), which was created to provide concepts and methods for the design of advanced fighter aircraft. A major research activity within this program is the development of the design processes required to take advantage of the benefits of advanced control concepts for high-angle-of-attack agility. Fundamental methodologies associated with the effective use of piloted simulation for this research are described, particularly those relating to the test techniques, validation of the test results, and design guideline/criteria development.
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The minimization of pylon-mounted store effects on air combat capability
NASA Technical Reports Server (NTRS)
Spearman, M. L.
1983-01-01
Some effects of pylon-mounted missiles on aft-tail delta wing supersonic fighter concepts have been investigated. Whereas minimum drag penalties do occur with the addition of missiles, the effects at higher lifts, corresponding to maneuvering flight, are less severe and often favorable. Lower speeds and altitudes enhance the maneuvering capability and one-on-one air combat would probably tend to degenerate to subsonic speeds even though the combatants may be flying supersonic fighters. Higher speed (supersonic) flight might best be reserved for interceptors with long-range missiles where the weapon carriage effects at low angles of attack are of prime importance.
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NASA Technical Reports Server (NTRS)
Hamer, Harold A.; Mayo, Alton P.
1953-01-01
Preliminary results of one phase of a control-motion study program involving several jet fighter-type airplanes are presented in time-history form and are summarized as maximum measured quantities plotted against indicated airspeed. The results pertain to approximately 1,000 maneuvers performed by a Republic F-84G jet-fighter airplane during squadron operational training. The data include most tactical maneuvers of which the F-84G airplane is capable. Maneuvers were performed at pressure altitudes of 0 to 30,000 feet with indicated airspeeds ranging from the stalling speed to approximately 515 knots.
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NASA Technical Reports Server (NTRS)
Chamberlin, R.
1974-01-01
A circular-arc - conic boattail nozzle, typical of those used on a twin engine fighter, was tested on an underwing nacelle mounted on an F-106B aircraft. The boattail had a radius ratio r/r sub c of 0.41 and a terminal boattail angle of approximately 19 deg. The gas generator was a J85-GE-13 turbojet engine. The effects of Reynolds number and angle of attack on boattail pressure drag and boattail pressure profiles were investigated. Increasing Reynolds number resulted in reduced boattail drag at both Mach numbers of 0.6 and 0.9.
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NASA Technical Reports Server (NTRS)
Fox, C. H., Jr.
1978-01-01
A general research fighter model was tested in the Langley 7 by 10 foot high speed tunnel at a Mach number of 0.3. Strakes with exposed semi-spans of 10 percent, 20 percent, and 30 percent of the wing reference semi-span were tested in combination with wings having leading edge sweep angles of 30, 44, and 60 degrees. The angle of attack range was from -4 degrees to approximately 48 degrees at sideslip angles of 0, -5, and 5 degrees. The data are presented without analysis in order to expedite publication.
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NASA Technical Reports Server (NTRS)
Shanks, Robert E.
1958-01-01
A theoretical method is presented for predicting the dynamic lateral stability characteristics of an airplane towed in tandem by a much larger airplane. Values of period and time to damp to one-half amplitude and rolling motions calculated by an analog computer have been correlated with results of two experimental investigations conducted in the Langley free-flight tunnel which were part of a U.S. Air Force program (Project FICON) to develop a satisfactory arrangement by which a bomber could tow a parasite fighter. In general, the theoretical results agree with the experimental results.
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Combative Sports Injuries: An Edmonton Retrospective.
Karpman, Shelby; Reid, Patrick; Phillips, Leah; Qin, Ziling; Gross, Douglas P
2016-07-01
Mixed martial arts (MMA) is an increasingly popular combative sport involving aggressive techniques that present substantial injury risk. We examined the incidence and types of injuries sustained in MMA fights and compared this with injuries sustained in boxing matches. Consecutive Case Series. We used data from post-fight medical examinations on all bouts in Edmonton, Canada, between 2000 and 2013. The participants were 1181 MMA competitors and 550 boxers. The attending physician conducted a mandatory post-fight examination of all fighters and documented the nature of injuries sustained. Boxers were significantly more likely not to experience injury (49.8% vs 59.4%, P < 0.001), whereas MMA fighters were significantly more likely to experience 1 injury (typically contusion/bruising, P < 0.001). Boxers were more likely to experience loss of consciousness (7.1% vs 4.2%, P = 0.01) and serious eye injury (1.1% vs 0.3%, P = 0.02). The overall injury incidence in MMA competitors appears slightly higher than for boxers, but MMA fighters experience more minor contusion/bruising injuries. Boxers are more likely to experience serious injury such as concussion/head trauma involving loss of consciousness or eye injury such as retinal detachment.
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Analysis of Idaho fire service education
NASA Astrophysics Data System (ADS)
Roberts, Walter O.
1999-01-01
Becoming a career fire fighter in the state of Idaho requires specialized knowledge and training. Fire science education at Idaho colleges and universities is available only to people who are affiliated with a fire department. Law enforcement curriculum, on the other hand, is available to any interested persons. A student in law enforcement can attend the Police Officers Standards and Training (POST) academy or participate in classes in one of Idaho's institutions for higher education. There are no fire academies in Idaho. Applicants wanting to become professional fire fighters in Idaho are required to compete with applicants from other states; many of whom have had prior fire education and training. Resident Idaho fire fighter applicants are at a disadvantage when applying for Idaho fire fighting positions. Because of this apparent need, I surveyed the Idaho fire chiefs, using a research instrument I developed in a graduate field research class. I wrote the research instrument to determine the educational needs of the Idaho fire service. The College of Southern Idaho (CSI) and the Idaho Fire Chiefs Association (IFCA) were the recipients of this survey. This report, Analysis of Idaho Fire Service Education, describes that research process from beginning to end.
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Predicting Tail Buffet Loads of a Fighter Airplane
NASA Technical Reports Server (NTRS)
Moses, Robert W.; Pototzky, Anthony S.
2006-01-01
Buffet loads on aft aerodynamic surfaces pose a recurring problem on most twin-tailed fighter airplanes: During maneuvers at high angles of attack, vortices emanating from various surfaces on the forward parts of such an airplane (engine inlets, wings, or other fuselage appendages) often burst, immersing the tails in their wakes. Although these vortices increase lift, the frequency contents of the burst vortices become so low as to cause the aft surfaces to vibrate destructively. Now, there exists a new analysis capability for predicting buffet loads during the earliest design phase of a fighter-aircraft program. In effect, buffet pressures are applied to mathematical models in the framework of a finite-element code, complete with aeroelastic properties and working knowledge of the spatiality of the buffet pressures for all flight conditions. The results of analysis performed by use of this capability illustrate those vibratory modes of a tail fin that are most likely to be affected by buffet loads. Hence, the results help in identifying the flight conditions during which to expect problems. Using this capability, an aircraft designer can make adjustments to the airframe and possibly the aerodynamics, leading to a more robust design.
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Advanced simulation noise model for modern fighter aircraft
NASA Astrophysics Data System (ADS)
Ikelheimer, Bruce
2005-09-01
NoiseMap currently represents the state of the art for military airfield noise analysis. While this model is sufficient for the current fleet of aircraft, it has limits in its capability to model the new generation of fighter aircraft like the JSF and the F-22. These aircraft's high-powered engines produce noise with significant nonlinear content. Combining this with their ability to vector the thrust means they have noise characteristics that are outside of the basic modeling assumptions of the currently available noise models. Wyle Laboratories, Penn State University, and University of Alabama are in the process of developing a new noise propagation model for the Strategic Environmental Research and Development Program. Source characterization will be through complete spheres (or hemispheres if there is not sufficient data) for each aircraft state (including thrust vector angles). Fixed and rotor wing aircraft will be included. Broadband, narrowband, and pure tone propagation will be included. The model will account for complex terrain and weather effects, as well as the effects of nonlinear propagation. It will be a complete model capable of handling a range of noise sources from small subsonic general aviation aircraft to the latest fighter aircraft like the JSF.
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Del Vecchio, Fabrício Boscolo; Gondim, Denis Foster; Arruda, Antonio Carlos Pereira
2016-08-01
Boscolo Del Vecchio, F, Foster, D, and Arruda, A. Functional movement screening performance of Brazilian jiu-jitsu athletes from Brazil: differences considering practice time and combat style. J Strength Cond Res 30(8): 2341-2347, 2016-Brazilian jiu-jitsu (BJJ) is a grappling combat sport that athletes, lying (guard fighter) or kneeling (pass fighter) on the mat, attempt to force their opponents to submit. Brazilian jiu-jitsu practices may result in muscular imbalances, which increase the risk of injury. Instead, the Functional Movement Screen (FMS) is an evaluation routine that could be related to injury incidence and seeks to detect muscular imbalance and movement dysfunction. Thus, the aim of the study was to investigate the injury profile and the FMS score and their relationship, with consideration for the BJJ fight style. Sports injuries were recorded in the last 12 months of 33 BJJ athletes, and the statistical analyses were applied to a routine evaluation FMS and a score of 14 points or less was considered low performance in FMS. We used a logistic regression; the effect size (ES) was calculated, and 5% was assumed as the statistical significance level. Pass fighters showed a higher percentage of injuries on the thorax (24.24%) than did guard fighters (6.67%, p = 0.01). Upper limbs were the most injured part of the body (χ = 36.7; p < 0.001), and they were 79% of the injuries that occurred in training sessions (χ = 14.53; p < 0.001). Despite the lack of statistical differences in the FMS performance between guard and pass fighters (t = 1.97; p = 0.05), its magnitude was considered medium (ES = 0.77). There was an association between FMS and presence of injury (χ = 4.95; p = 0.03). Considering the FMS score as a predictor and the presence or absence of injury as the dependent variable, the data met a Wald coefficient of 4.55, p = 0.03 and Exp (B) = 5.71. The study found that almost half of the sample had injuries in the upper limbs and a quarter had injuries in the lower limbs in the last year. A poor FMS score was observed, and lower scores in the FMS were associated with a higher risk of injury in BJJ athletes.
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Real-time high-resolution PC-based system for measurement of errors on compact disks
NASA Astrophysics Data System (ADS)
Tehranchi, Babak; Howe, Dennis G.
1994-10-01
Hardware and software utilities are developed to directly monitor the Eight-to-Fourteen (EFM) demodulated data bytes at the input of a CD player's Cross-Interleaved Reed-Solomon Code (CIRC) block decoder. The hardware is capable of identifying erroneous data with single-byte resolution in the serial data stream read from a Compact Disc by a CDD 461 Philips CD-ROM drive. In addition, the system produces graphical maps that show the physical location of the measured errors on the entire disc, or via a zooming and planning feature, on user selectable local disc regions.
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Fetal Monitoring: Creating a Culture of Safety With Informed Choice
Heelan, Lisa
2013-01-01
The dominant culture in labor and birth is the medical model, not the midwifery model of woman-centered care. Consensus among professional and governmental groups is that, based on the evidence, intermittent auscultation is safer to use in healthy women with uncomplicated pregnancies than electronic fetal monitoring (EFM). Barriers impact the laboring woman’s ability to give informed choice regarding fetal monitoring. Lack of informed choice denies a woman her right to be in control of her birth experience, and is in opposition to a woman’s right to autonomy and self-determination. PMID:24868127
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2007-08-01
An increasing variety of sensors are becoming available for use onboard autonomous vehicles . Given these enhanced sensing capabilities, scientific...and military personnel are interested in exploiting autonomous vehicles for increasingly complex missions. Most of these missions require the vehicle to
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2011-09-01
CHALLENGES ............................66 1. Radar Processing Gain ........................66 2. High Sensitivity Requirement .................68 B...Relationship Between Network Space and Challenges .....................................127 Figure 42. Maneuverability................................129...virtually any kind of terrain. It has five modes: Normal, Weather, ECCM, LPI, and Very Low Clearance ( VLC ). Pictures of the LANTIRN pod aboard and F-16
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14 CFR 23.147 - Directional and lateral control.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Directional and lateral control. 23.147... Controllability and Maneuverability § 23.147 Directional and lateral control. (a) For each multiengine airplane... regain full control of the airplane without exceeding a bank angle of 45 degrees, reaching a dangerous...
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14 CFR 23.147 - Directional and lateral control.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Directional and lateral control. 23.147... Controllability and Maneuverability § 23.147 Directional and lateral control. (a) For each multiengine airplane... regain full control of the airplane without exceeding a bank angle of 45 degrees, reaching a dangerous...
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14 CFR 23.147 - Directional and lateral control.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Directional and lateral control. 23.147... Controllability and Maneuverability § 23.147 Directional and lateral control. (a) For each multiengine airplane... regain full control of the airplane without exceeding a bank angle of 45 degrees, reaching a dangerous...
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14 CFR 23.147 - Directional and lateral control.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Directional and lateral control. 23.147... Controllability and Maneuverability § 23.147 Directional and lateral control. (a) For each multiengine airplane... regain full control of the airplane without exceeding a bank angle of 45 degrees, reaching a dangerous...
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14 CFR 23.155 - Elevator control force in maneuvers.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Elevator control force in maneuvers. 23.155 Section 23.155 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Controllability and Maneuverability § 23.155 Elevator control force in maneuvers. (a) The elevator control force...
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14 CFR 23.155 - Elevator control force in maneuvers.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Elevator control force in maneuvers. 23.155 Section 23.155 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Controllability and Maneuverability § 23.155 Elevator control force in maneuvers. (a) The elevator control force...
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14 CFR 23.155 - Elevator control force in maneuvers.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Elevator control force in maneuvers. 23.155 Section 23.155 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Controllability and Maneuverability § 23.155 Elevator control force in maneuvers. (a) The elevator control force...
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14 CFR 23.155 - Elevator control force in maneuvers.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Elevator control force in maneuvers. 23.155 Section 23.155 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Controllability and Maneuverability § 23.155 Elevator control force in maneuvers. (a) The elevator control force...
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14 CFR 23.155 - Elevator control force in maneuvers.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Elevator control force in maneuvers. 23.155 Section 23.155 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Controllability and Maneuverability § 23.155 Elevator control force in maneuvers. (a) The elevator control force...
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Theory, Guidance, and Flight Control for High Maneuverability Projectiles
2014-01-01
estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining...2.8 Linear System Modeling with Time Delay ...................................................................22 2.9 Linear System Modeling Without... Time Delay .............................................................23 3. Guidance and Flight Control 24 3.1 Proportional Navigation Guidance Law
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Baloon-lofted pollutant sampling of open burning and open detonation: abstract
The U.S. EPA has developed a balloon-lofted, ~10 kg instrument pack for sampling open burning (OB) and open detonation (OD) events for pollutants. The instrument pack, termed the “Flyer,” and its accompanying maneuverable balloon system, are intended to sample OB/OD plumes to de...
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Report of the Analysis of the Joint Medium Range Air to Surface Missile Program.
1980-01-23
contractors will continue to be an integral source of these type procurements, especially such firms as Veda , Flight Systems, Inc., Maxfield Associates...available. ($200,000) Contract with VEDA to assess the compatibility of the current on-board radars with the range, maneuverability, and speed
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A Review and Reappraisal of Adaptive Human-Computer Interfaces in Complex Control Systems
2006-08-01
maneuverability measures. The cost elements were expressed as fuzzy membership functions. Figure 9 shows the flowchart of the route planner. A fuzzy navigator...and updating of the user model, which contains information about three generic stereotypes ( beginner , intermediate and expert users) plus an
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46 CFR 117.210 - Rescue boats.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Rescue boats. 117.210 Section 117.210 Shipping COAST... Number and Type of Survival Craft § 117.210 Rescue boats. (a) Each vessel must carry at least one rescue boat unless the cognizant OCMI determines that: (1) The vessel is sufficiently maneuverable, arranged...
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46 CFR 117.210 - Rescue boats.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Rescue boats. 117.210 Section 117.210 Shipping COAST... Number and Type of Survival Craft § 117.210 Rescue boats. (a) Each vessel must carry at least one rescue boat unless the cognizant OCMI determines that: (1) The vessel is sufficiently maneuverable, arranged...
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46 CFR 117.210 - Rescue boats.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Rescue boats. 117.210 Section 117.210 Shipping COAST... Number and Type of Survival Craft § 117.210 Rescue boats. (a) Each vessel must carry at least one rescue boat unless the cognizant OCMI determines that: (1) The vessel is sufficiently maneuverable, arranged...
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46 CFR 117.210 - Rescue boats.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Rescue boats. 117.210 Section 117.210 Shipping COAST... Number and Type of Survival Craft § 117.210 Rescue boats. (a) Each vessel must carry at least one rescue boat unless the cognizant OCMI determines that: (1) The vessel is sufficiently maneuverable, arranged...
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The Wonders of Interactive Whiteboards
ERIC Educational Resources Information Center
Starkman, Neal
2006-01-01
This article discusses the advantages of using interactive whiteboards in the classroom. Developed by Smart Technologies, the Smart Board is one of several interactive whiteboards on the market today. Through Smart Board, starters can write, erase, and perform mouse functions with their finger, a pen, or anything with a maneuverable, firm surface.…
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14 CFR 27.143 - Controllability and maneuverability.
Code of Federal Regulations, 2013 CFR
2013-01-01
... gravity; (3) Critical rotor r.p.m.; and (4) Power off (except for helicopters demonstrating compliance...; with— (i) Critical Weight; (ii) Critical center of gravity; (iii) Critical rotor r.p.m.; (2) For...; (ii) Critical center of gravity; and (iii) Critical rotor r.p.m. (d) Wind velocities from zero to at...
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14 CFR 27.143 - Controllability and maneuverability.
Code of Federal Regulations, 2012 CFR
2012-01-01
... gravity; (3) Critical rotor r.p.m.; and (4) Power off (except for helicopters demonstrating compliance...; with— (i) Critical Weight; (ii) Critical center of gravity; (iii) Critical rotor r.p.m.; (2) For...; (ii) Critical center of gravity; and (iii) Critical rotor r.p.m. (d) Wind velocities from zero to at...
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14 CFR 27.143 - Controllability and maneuverability.
Code of Federal Regulations, 2014 CFR
2014-01-01
... gravity; (3) Critical rotor r.p.m.; and (4) Power off (except for helicopters demonstrating compliance...; with— (i) Critical Weight; (ii) Critical center of gravity; (iii) Critical rotor r.p.m.; (2) For...; (ii) Critical center of gravity; and (iii) Critical rotor r.p.m. (d) Wind velocities from zero to at...
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14 CFR 27.143 - Controllability and maneuverability.
Code of Federal Regulations, 2011 CFR
2011-01-01
... with paragraph (f) of this section) and power on. (c) Wind velocities from zero to at least 17 knots...; (iii) Level flight; (iv) Turning flight; (v) Autorotation; (vi) Landing (power on and power off); and (vii) Recovery to power-on flight from a balked autorotative approach. (b) The margin of cyclic control...
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14 CFR 29.143 - Controllability and maneuverability.
Code of Federal Regulations, 2011 CFR
2011-01-01
...) Critical weight; (2) Critical center of gravity; (3) Critical rotor r.p.m.; and (4) Power off (except for helicopters demonstrating compliance with paragraph (f) of this section) and power on. (c) Wind velocities...; (iii) Level flight; (iv) Turning flight; (v) Autorotation; and (vi) Landing (power on and power off...
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Sinel, Clara; Cacaci, Margherita; Meignen, Pierrick; Guérin, François; Davies, Bryan W.; Sanguinetti, Maurizio; Giard, Jean-Christophe
2017-01-01
ABSTRACT Enterococcus faecium has emerged as a major opportunistic pathogen for 2 decades with the spread of hospital-adapted multidrug-resistant clones. As members of the intestinal microbiota, they are subjected to numerous bacterial stresses, including antibiotics at subinhibitory concentrations (SICs). Since fluoroquinolones are extensively prescribed, SICs are very likely to occur in vivo, with potential effects on bacterial metabolism with subsequent modulation of opportunistic traits. The aim of this study was to evaluate globally the impact of SICs of ciprofloxacin on antimicrobial resistance and pathogenicity of E. faecium. Transcriptomic analysis was performed by RNA sequencing (RNA-seq) (HiSeq 2500; Illumina) using the vanB-positive reference strain E. faecium Aus0004 in the absence or presence of ciprofloxacin SIC (0.38 mg/liter, i.e., 1/8 of the MIC). Several genetic and phenotypic tests were used for validation. In the presence of ciprofloxacin SIC, 196 genes were significantly induced, whereas 286 genes were significantly repressed, meaning that 16.8% of the E. faecium genome was altered. Among upregulated genes, EFAU004_02294 (fold change, 14.3) encoded a protein (Qnr of E. faecium [EfmQnr]) homologue of Qnr proteins involved in quinolone resistance in Gram-negative bacilli. Its implication in intrinsic and adaptive fluoroquinolone (FQ) resistance in E. faecium was experimentally ascertained. Moreover, EFAU004_02292, coding for the collagen adhesin Acm, was also induced by the SIC of ciprofloxacin (fold change, 8.2), and higher adhesion capabilities were demonstrated phenotypically. Both EfmQnr and Acm determinants may play an important role in the transition from a commensal to a pathogenic state of E. faecium that resides in the gut of patients receiving fluoroquinolone therapy. PMID:28193670
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Sinel, Clara; Cacaci, Margherita; Meignen, Pierrick; Guérin, François; Davies, Bryan W; Sanguinetti, Maurizio; Giard, Jean-Christophe; Cattoir, Vincent
2017-05-01
Enterococcus faecium has emerged as a major opportunistic pathogen for 2 decades with the spread of hospital-adapted multidrug-resistant clones. As members of the intestinal microbiota, they are subjected to numerous bacterial stresses, including antibiotics at subinhibitory concentrations (SICs). Since fluoroquinolones are extensively prescribed, SICs are very likely to occur in vivo , with potential effects on bacterial metabolism with subsequent modulation of opportunistic traits. The aim of this study was to evaluate globally the impact of SICs of ciprofloxacin on antimicrobial resistance and pathogenicity of E. faecium Transcriptomic analysis was performed by RNA sequencing (RNA-seq) (HiSeq 2500; Illumina) using the vanB -positive reference strain E. faecium Aus0004 in the absence or presence of ciprofloxacin SIC (0.38 mg/liter, i.e., 1/8 of the MIC). Several genetic and phenotypic tests were used for validation. In the presence of ciprofloxacin SIC, 196 genes were significantly induced, whereas 286 genes were significantly repressed, meaning that 16.8% of the E. faecium genome was altered. Among upregulated genes, EFAU004_02294 (fold change, 14.3) encoded a protein (Qnr of E. faecium [EfmQnr]) homologue of Qnr proteins involved in quinolone resistance in Gram-negative bacilli. Its implication in intrinsic and adaptive fluoroquinolone (FQ) resistance in E. faecium was experimentally ascertained. Moreover, EFAU004_02292, coding for the collagen adhesin Acm, was also induced by the SIC of ciprofloxacin (fold change, 8.2), and higher adhesion capabilities were demonstrated phenotypically. Both EfmQnr and Acm determinants may play an important role in the transition from a commensal to a pathogenic state of E. faecium that resides in the gut of patients receiving fluoroquinolone therapy. Copyright © 2017 American Society for Microbiology.
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Development of an ultra-portable echo device connected to USB port.
Saijo, Yoshifumi; Nitta, Shin-ichi; Kobayashi, Kazuto; Arai, Hitoshi; Nemoto, Yukiko
2004-04-01
In practical cardiology, a stethoscope based auscultation has been used to reveal the patient's clinical status. Recently, several hand-held echo devices are going on market and they are expected to play a role as "visible" auscultation instead of stethoscope. We have developed a portable and inexpensive echo device which can be used for screening of cardiac function. Two single element transducers were attached 180 degrees apart to a rotor with 14-mm diameter. The mechanical scanner, integrated circuits for transmitting and receiving ultrasonic signals and an A/D converter were encapsulated in a 150 x 40 mm probe weighing 200 g. The scan was started and the image was displayed on a Windows based personal computer (PC) as soon as the probe was connected to USB 2.0 port of the PC. The central frequency was available between 2.5 and 7.5 MHz, the image depth was 15 cm and the frame rate was 30/s. The estimated price of this ultra-portable ultrasound is about 3000 US dollars with software. For 69 cardiac patients with informed consent, image quality was compared with those obtained with basic range diagnostic echo machines. Left ventricular ejection fraction (EF) derived from normal M-mode image of standard machines (EFm) were compared with visual EF of the ultra-portable ultrasound device (EFv). The image quality was comparable to the basic range diagnostic echo machines although short axis view of aortic root was not clearly visualized because the probe was too large for intercostal approach. EFv agreed well with EFm. The ultra-portable ultrasound may provide useful information on screening and health care.
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Gysin, Urs; Glatzel, Thilo; Schmölzer, Thomas; Schöner, Adolf; Reshanov, Sergey; Bartolf, Holger; Meyer, Ernst
2015-01-01
The resolution in electrostatic force microscopy (EFM), a descendant of atomic force microscopy (AFM), has reached nanometre dimensions, necessary to investigate integrated circuits in modern electronic devices. However, the characterization of conducting or semiconducting power devices with EFM methods requires an accurate and reliable technique from the nanometre up to the micrometre scale. For high force sensitivity it is indispensable to operate the microscope under high to ultra-high vacuum (UHV) conditions to suppress viscous damping of the sensor. Furthermore, UHV environment allows for the analysis of clean surfaces under controlled environmental conditions. Because of these requirements we built a large area scanning probe microscope operating under UHV conditions at room temperature allowing to perform various electrical measurements, such as Kelvin probe force microscopy, scanning capacitance force microscopy, scanning spreading resistance microscopy, and also electrostatic force microscopy at higher harmonics. The instrument incorporates beside a standard beam deflection detection system a closed loop scanner with a scan range of 100 μm in lateral and 25 μm in vertical direction as well as an additional fibre optics. This enables the illumination of the tip-sample interface for optically excited measurements such as local surface photo voltage detection. We present Kelvin probe force microscopy (KPFM) measurements before and after sputtering of a copper alloy with chromium grains used as electrical contact surface in ultra-high power switches. In addition, we discuss KPFM measurements on cross sections of cleaved silicon carbide structures: a calibration layer sample and a power rectifier. To demonstrate the benefit of surface photo voltage measurements, we analysed the contact potential difference of a silicon carbide p/n-junction under illumination.
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Costa, Maria L; Cecatti, Jose G; Milanez, Helaine M; Souza, Joao P; Gülmezoglu, Metin
2009-01-01
To assess the effects of audit and feedback on the practice of professionals in obstetrics. Before-after intervention study. Obstetric unit of a university hospital in Brazil. Before the intervention the prevalence rates of six evidence-based interventions were assessed. Seminars and workshops were administered, with the baseline results and also the main contents from systematic reviews on the topics studied, followed by detailed discussion of each topic, based on the Reproductive Health Library. After four months, the same practices were measured again and compared with the pre-intervention period. Selective episiotomy; continuous electronic fetal monitoring (EFM) during labor of low-risk pregnant women; antibiotic prophylaxis in cesarean section; active management of third stage of labor; routine induction of labor at 41 weeks for uncomplicated pregnancies; and continuous support for women during childbirth. Both periods showed a similar number and mode of deliveries. There was a significant reduction in episiotomies (RR = 0.84; 0.73-0.97) and an increase in continuous support for women during childbirth by a companion (RR = 1.42; 1.24-1.63). Although there was not a significant change in the use of oxytocin during the third stage of labor, there was a shift to the internationally recommended dosage of 10 IU (p<0.0001). There was no significant change in the use of antibiotic prophylaxis for cesarean section, continuous EFM, or routine induction of labor at 41 weeks for uncomplicated pregnancies. Audit and feedback can be used as a tool to improve obstetrical practice, at least for some interventions and when the medical staff is open and receptive to change.
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NASA Technical Reports Server (NTRS)
Parrish, R. V.; Steinmetz, G. G.
1972-01-01
A method of parameter extraction for stability and control derivatives of aircraft from flight test data, implementing maximum likelihood estimation, has been developed and successfully applied to actual lateral flight test data from a modern sophisticated jet fighter. This application demonstrates the important role played by the analyst in combining engineering judgment and estimator statistics to yield meaningful results. During the analysis, the problems of uniqueness of the extracted set of parameters and of longitudinal coupling effects were encountered and resolved. The results for all flight runs are presented in tabular form and as time history comparisons between the estimated states and the actual flight test data.
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NASA Technical Reports Server (NTRS)
Paulson, J. W., Jr.; Thomas, J. L.
1979-01-01
Investigations of the low speed longitudinal characteristics of two powered close coupled wing-canard fighter configurations are discussed. Data obtained at angles of attack from -2 deg to 42 deg, Mach numbers from 0.12 to 0.20, nozzle and flap deflections from 0 deg to 40 deg, and thrust coefficients from 0 to 2.0, to represent both high angle of attack subsonic maneuvering characteristics and conventional takeoff and landing characteristics are examined. Data obtained with the nozzles deflected either 60 deg or 90 deg and the flaps deflected 60 deg to represent vertical or short takeoff and landing characteristics are discussed.
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Study of aerodynamic technology for VSTOL fighter/attack aircraft, phase 1
NASA Technical Reports Server (NTRS)
Driggers, H. H.
1978-01-01
A conceptual design study was performed of a vertical attitude takeoff and landing (VATOL) fighter/attack aircraft. The configuration has a close-coupled canard-delta wing, side two-dimensional ramp inlets, and two augmented turbofan engines with thrust vectoring capability. Performance and sensitivities to objective requirements were calculated. Aerodynamic characteristics were estimated based on contractor and NASA wind tunnel data. Computer simulations of VATOL transitions were performed. Successful transitions can be made, even with series post-stall instabilities, if reaction controls are properly phased. Principal aerodynamic uncertainties identified were post-stall aerodynamics, transonic aerodynamics with thrust vectoring and inlet performance in VATOL transition. A wind tunnel research program was recommended to resolve the aerodynamic uncertainties.
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NASA Technical Reports Server (NTRS)
Huffman, J. K.; Fox, C. H., Jr.; Ziegler, H.
1978-01-01
A configuration concept for developing vortex lift, which replaces the physical wing strake with a jet sheet generated fluid strake, was investigated on a general research fighter model. The vertical and horizontal location of the jet sheet with respect to the wing leading edge was studied over a momentum coefficient range from 0 to 0.24 in the Langley 7- by 10-foot high speed tunnel over a Mach number range from 0.3 to 0.8. The angle of attack range studied was from -2 to 30 deg at sideslip angles of 0, -5, and 5 deg. Test data are presented without analysis.
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Al-Qa’ida’s Foreign Fighters in Iraq: A First Look at the Sinjar Records
2007-12-01
synchronization of earlier analyses suggests that the pattern of immigration to Iraq has simply shifted over time. In an admittedly small sample, 76.9...military: 5) to the bizarre (massage therapist : 1). Figure 11: Occupation of Fighters25 0 20 40 60 80 Number of Records TEACHER STUDENT SKILLED...merchant and weapons merchant. “Other” includes free jobs, employee, artist, painter, fitness trainer, massage therapist , bombmaker, and farmer. “Skilled
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Study of aerodynamic technology for single-cruise-engine V/STOL fighter/attack aircraft
NASA Technical Reports Server (NTRS)
Mark, L.
1982-01-01
Conceptual designs and analyses were conducted on two V/STOL supersonic fighter/attack aircraft. These aircraft feature low footprint temperature and pressure thrust augmenting ejectors in the wings for vertical lift, combined with a low wing loading, low wave drag airframe for outstanding cruise and supersonic performance. Aerodynamic, propulsion, performance, and mass properties were determined and are presented for each aircraft. Aerodynamic and Aero/Propulsion characteristics having the most significant effect on the success of the up and away flight mode were identified, and the certainty with which they could be predicted was defined. A wind tunnel model and test program are recommended to resolve the identified uncertainties.
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Analysis of Effect of Rolling Pull-Outs on Wing and Aileron Loads of a Fighter Airplane
NASA Technical Reports Server (NTRS)
Pearson, Henry A.; Aiken, William S.
1946-01-01
An analysis was made to determine the effect of rolling pull-out maneuvers on the wing and aileron loads of a typical fighter airplane, the P-47B. The results obtained indicate that higher loads are imposed upon wings and ailerons because of the rolling pull-out maneuver, than would be obtained by application of the loading requirements to which the airplane was designed. An increase of 102 lb or 15 percent of wing weight would be required if the wing were designed for rolling pull-out maneuver. It was also determined that the requirements by which the aileron was originally designed were inadequate.
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New rotation-balance apparatus for measuring airplane spin aerodynamics in the wind tunnel
NASA Technical Reports Server (NTRS)
Malcolm, G. N.
1978-01-01
An advanced rotation-balance apparatus has been developed for the Ames 12-ft pressure tunnel to study the effects of spin rate, angles of attack and sideslip, and, particularly, Reynolds number on the aerodynamics of fighter and general aviation aircraft in a steady spin. Angles of attack to 100 deg and angles of sideslip to 30 deg are possible with spin rates to 42 rad/sec (400 rpm) and Reynolds numbers to 30 million/m on fighter models with wing spans that are typically 0.7 m. A complete description of the new rotation-balance apparatus, the sting/balance/model assembly, and the operational capabilities is given.