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Sample records for magnetic launch assist

  1. Magnetic Launch Assist

    NASA Technical Reports Server (NTRS)

    Perez, Jose

    2000-01-01

    The objectives of this program are to: (1) To develop a safe, reliable, inexpensive, and minimum operation launch assist system for sending payloads into orbit using ground powered, magnetic suspension and propulsion technologies; (2) Improve safety, reliability, operability for third generation Reusable Launch Vehicles (RLV); (3) Reduce vehicle weight and increase payload capacity; and (4) Support operational testing of Rocket Based Combine Cycle (RBCC) engines.

  2. Magnetic Launch Assist

    NASA Technical Reports Server (NTRS)

    Jacobs, W. A.

    2000-01-01

    With the ever-increasing cost of getting to space and the need for safe, reliable, and inexpensive ways to access space, NASA is taking a look at technologies that will get us there. One of these technologies is Magnetic Launch Assist (MagLev). This is the concept of using both magnetic levitation and magnetic propulsion to provide an initial velocity by using electrical power from ground sources. The use of ground based power can significantly reduce operational costs over the consumables necessary to attain the same velocity. The technologies to accomplish this are both old and new. The concept of MagLev has been around for a long time and several MagLev Trains have already been made. Where NASA's MagLev diverges from the traditional train is in the immense power required to propel this vehicle to 600 feet per second in less than 10 seconds. New technologies or the upgrade of existing technologies will need to be investigated in areas of energy storage and power switching. Plus the separation of a very large mass (the space vehicle) and the aerodynamics of that vehicle while on the carrier are also of great concern and require considerable study and testing. NASA's plan is to mature these technologies in the next 10 years to achieve our goal of launching a full sized space vehicle off a MagLev rail.

  3. Magnetic Launch Assist System Demonstration

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This Quick Time movie demonstrates the Magnetic Launch Assist system, previously referred to as the Magnetic Levitation (Maglev) system, for space launch using a 5 foot model of a reusable Bantam Class launch vehicle on a 50 foot track that provided 6-g acceleration and 6-g de-acceleration. Overcoming the grip of Earth's gravity is a supreme challenge for engineers who design rockets that leave the planet. Engineers at the Marshall Space Flight Center have developed and tested Magnetic Launch Assist technologies that could levitate and accelerate a launch vehicle along a track at high speeds before it leaves the ground. Using electricity and magnetic fields, a Magnetic Launch Assist system would drive a spacecraft along a horizontal track until it reaches desired speeds. A full-scale, operational track would be about 1.5-miles long and capable of accelerating a vehicle to 600 mph in 9.5 seconds. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the takeoff, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  4. Magnetic Launch Assist System Demonstration

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This Quick Time movie demonstrates the Magnetic Launch Assist system, previously referred to as the Magnetic Levitation (Maglev) system, for space launch using a 5 foot model of a reusable Bantam Class launch vehicle on a 50 foot track that provided 6-g acceleration and 6-g de-acceleration. Overcoming the grip of Earth's gravity is a supreme challenge for engineers who design rockets that leave the planet. Engineers at the Marshall Space Flight Center have developed and tested Magnetic Launch Assist technologies that could levitate and accelerate a launch vehicle along a track at high speeds before it leaves the ground. Using electricity and magnetic fields, a Magnetic Launch Assist system would drive a spacecraft along a horizontal track until it reaches desired speeds. A full-scale, operational track would be about 1.5-miles long and capable of accelerating a vehicle to 600 mph in 9.5 seconds. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the takeoff, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  5. Magnetic Launch Assist Demonstration Test

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image shows a 1/9 subscale model vehicle clearing the Magnetic Launch Assist System, formerly referred to as the Magnetic Levitation (MagLev), test track during a demonstration test conducted at the Marshall Space Flight Center (MSFC). Engineers at MSFC have developed and tested Magnetic Launch Assist technologies. To launch spacecraft into orbit, a Magnetic Launch Assist System would use magnetic fields to levitate and accelerate a vehicle along a track at very high speeds. Similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway, a launch-assist system would electromagnetically drive a space vehicle along the track. A full-scale, operational track would be about 1.5-miles long and capable of accelerating a vehicle to 600 mph in 9.5 seconds. This track is an advanced linear induction motor. Induction motors are common in fans, power drills, and sewing machines. Instead of spinning in a circular motion to turn a shaft or gears, a linear induction motor produces thrust in a straight line. Mounted on concrete pedestals, the track is 100-feet long, about 2-feet wide and about 1.5-feet high. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  6. Magnetic Launch Assist Demonstration Test

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image shows a 1/9 subscale model vehicle clearing the Magnetic Launch Assist System, formerly referred to as the Magnetic Levitation (MagLev), test track during a demonstration test conducted at the Marshall Space Flight Center (MSFC). Engineers at MSFC have developed and tested Magnetic Launch Assist technologies. To launch spacecraft into orbit, a Magnetic Launch Assist System would use magnetic fields to levitate and accelerate a vehicle along a track at very high speeds. Similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway, a launch-assist system would electromagnetically drive a space vehicle along the track. A full-scale, operational track would be about 1.5-miles long and capable of accelerating a vehicle to 600 mph in 9.5 seconds. This track is an advanced linear induction motor. Induction motors are common in fans, power drills, and sewing machines. Instead of spinning in a circular motion to turn a shaft or gears, a linear induction motor produces thrust in a straight line. Mounted on concrete pedestals, the track is 100-feet long, about 2-feet wide and about 1.5-feet high. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  7. Magnetic Launch Assist Experimental Track

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In this photograph, a futuristic spacecraft model sits atop a carrier on the Magnetic Launch Assist System, formerly known as the Magnetic Levitation (MagLev) System, experimental track at the Marshall Space Flight Center (MSFC). Engineers at MSFC have developed and tested Magnetic Launch Assist technologies that would use magnetic fields to levitate and accelerate a vehicle along a track at very high speeds. Similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway, a Magnetic Launch Assist system would electromagnetically drive a space vehicle along the track. A full-scale, operational track would be about 1.5-miles long and capable of accelerating a vehicle to 600 mph in 9.5 seconds. This track is an advanced linear induction motor. Induction motors are common in fans, power drills, and sewing machines. Instead of spinning in a circular motion to turn a shaft or gears, a linear induction motor produces thrust in a straight line. Mounted on concrete pedestals, the track is 100-feet long, about 2-feet wide, and about 1.5-feet high. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  8. Magnetic Launch Assist Experimental Track

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In this photograph, a futuristic spacecraft model sits atop a carrier on the Magnetic Launch Assist System, formerly known as the Magnetic Levitation (MagLev) System, experimental track at the Marshall Space Flight Center (MSFC). Engineers at MSFC have developed and tested Magnetic Launch Assist technologies that would use magnetic fields to levitate and accelerate a vehicle along a track at very high speeds. Similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway, a Magnetic Launch Assist system would electromagnetically drive a space vehicle along the track. A full-scale, operational track would be about 1.5-miles long and capable of accelerating a vehicle to 600 mph in 9.5 seconds. This track is an advanced linear induction motor. Induction motors are common in fans, power drills, and sewing machines. Instead of spinning in a circular motion to turn a shaft or gears, a linear induction motor produces thrust in a straight line. Mounted on concrete pedestals, the track is 100-feet long, about 2-feet wide, and about 1.5-feet high. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  9. Magnetic Launch Assist System-Artist's Concept

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This illustration is an artist's concept of a Magnetic Launch Assist System, formerly referred as the Magnetic Levitation (Maglev) system, for space launch. Overcoming the grip of Earth's gravity is a supreme challenge for engineers who design rockets that leave the planet. Engineers at the Marshall Space Flight Center have developed and tested Magnetic Launch Assist System technologies that could levitate and accelerate a launch vehicle along a track at high speeds before it leaves the ground. Using electricity and magnetic fields, a Magnetic Launch Assist system would drive a spacecraft along a horizontal track until it reaches desired speeds. A full-scale, operational track would be about 1.5-miles long and capable of accelerating a vehicle to 600 mph in 9.5 seconds. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, landing gear and the wing size, as well as the elimination of propellant weight resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  10. Magnetic Launch Assist System-Artist's Concept

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This illustration is an artist's concept of a Magnetic Launch Assist System, formerly referred as the Magnetic Levitation (Maglev) system, for space launch. Overcoming the grip of Earth's gravity is a supreme challenge for engineers who design rockets that leave the planet. Engineers at the Marshall Space Flight Center have developed and tested Magnetic Launch Assist System technologies that could levitate and accelerate a launch vehicle along a track at high speeds before it leaves the ground. Using electricity and magnetic fields, a Magnetic Launch Assist system would drive a spacecraft along a horizontal track until it reaches desired speeds. A full-scale, operational track would be about 1.5-miles long and capable of accelerating a vehicle to 600 mph in 9.5 seconds. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, landing gear and the wing size, as well as the elimination of propellant weight resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  11. Magnetic Launch Assist Vehicle-Artist's Concept

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This artist's concept depicts a Magnetic Launch Assist vehicle clearing the track and shifting to rocket engines for launch into orbit. The system, formerly referred as the Magnetic Levitation (MagLev) system, is a launch system developed and tested by Engineers at the Marshall Space Flight Center (MSFC) that could levitate and accelerate a launch vehicle along a track at high speeds before it leaves the ground. Using an off-board electric energy source and magnetic fields, a Magnetic Launch Assist system would drive a spacecraft along a horizontal track until it reaches desired speeds. The system is similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway. A full-scale, operational track would be about 1.5-miles long, capable of accelerating a vehicle to 600 mph in 9.5 seconds, and the vehicle would then shift to rocket engines for launch into orbit. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  12. Magnetic Launch Assist Vehicle-Artist's Concept

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This artist's concept depicts a Magnetic Launch Assist vehicle clearing the track and shifting to rocket engines for launch into orbit. The system, formerly referred as the Magnetic Levitation (MagLev) system, is a launch system developed and tested by Engineers at the Marshall Space Flight Center (MSFC) that could levitate and accelerate a launch vehicle along a track at high speeds before it leaves the ground. Using an off-board electric energy source and magnetic fields, a Magnetic Launch Assist system would drive a spacecraft along a horizontal track until it reaches desired speeds. The system is similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway. A full-scale, operational track would be about 1.5-miles long, capable of accelerating a vehicle to 600 mph in 9.5 seconds, and the vehicle would then shift to rocket engines for launch into orbit. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  13. Tabletop Experimental Track for Magnetic Launch Assist

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Marshall Space Flight Center's (MSFC's) Advanced Space Transportation Program has developed the Magnetic Launch Assist System, formerly known as the Magnetic Levitation (MagLev) technology that could give a space vehicle a running start to break free from Earth's gravity. A Magnetic Launch Assist system would use magnetic fields to levitate and accelerate a vehicle along a track at speeds up to 600 mph. The vehicle would shift to rocket engines for launch into orbit. Similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway, a Magnetic Launch Assist system would electromagnetically propel a space vehicle along the track. The tabletop experimental track for the system shown in this photograph is 44-feet long, with 22-feet of powered acceleration and 22-feet of passive braking. A 10-pound carrier with permanent magnets on its sides swiftly glides by copper coils, producing a levitation force. The track uses a linear synchronous motor, which means the track is synchronized to turn the coils on just before the carrier comes in contact with them, and off once the carrier passes. Sensors are positioned on the side of the track to determine the carrier's position so the appropriate drive coils can be energized. MSFC engineers have conducted tests on the indoor track and a 50-foot outdoor track. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  14. Tabletop Experimental Track for Magnetic Launch Assist

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Marshall Space Flight Center's (MSFC's) Advanced Space Transportation Program has developed the Magnetic Launch Assist System, formerly known as the Magnetic Levitation (MagLev) technology that could give a space vehicle a running start to break free from Earth's gravity. A Magnetic Launch Assist system would use magnetic fields to levitate and accelerate a vehicle along a track at speeds up to 600 mph. The vehicle would shift to rocket engines for launch into orbit. Similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway, a Magnetic Launch Assist system would electromagnetically propel a space vehicle along the track. The tabletop experimental track for the system shown in this photograph is 44-feet long, with 22-feet of powered acceleration and 22-feet of passive braking. A 10-pound carrier with permanent magnets on its sides swiftly glides by copper coils, producing a levitation force. The track uses a linear synchronous motor, which means the track is synchronized to turn the coils on just before the carrier comes in contact with them, and off once the carrier passes. Sensors are positioned on the side of the track to determine the carrier's position so the appropriate drive coils can be energized. MSFC engineers have conducted tests on the indoor track and a 50-foot outdoor track. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  15. Magnetic Launch Assist System Demonstration Test

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Engineers at the Marshall Space Flight Center (MSFC) have been testing Magnetic Launch Assist Systems, formerly known as Magnetic Levitation (MagLev) technologies. To launch spacecraft into orbit, a Magnetic Launch Assist system would use magnetic fields to levitate and accelerate a vehicle along a track at a very high speed. Similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway, the launch-assist system would electromagnetically drive a space vehicle along the track. A full-scale, operational track would be about 1.5-miles long and capable of accelerating a vehicle to 600 mph in 9.5 seconds. This photograph shows a subscale model of an airplane running on the experimental track at MSFC during the demonstration test. This track is an advanced linear induction motor. Induction motors are common in fans, power drills, and sewing machines. Instead of spinning in a circular motion to turn a shaft or gears, a linear induction motor produces thrust in a straight line. Mounted on concrete pedestals, the track is 100-feet long, about 2-feet wide, and about 1.5- feet high. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  16. Magnetic Launch Assist System Demonstration Test

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Engineers at the Marshall Space Flight Center (MSFC) have been testing Magnetic Launch Assist Systems, formerly known as Magnetic Levitation (MagLev) technologies. To launch spacecraft into orbit, a Magnetic Launch Assist system would use magnetic fields to levitate and accelerate a vehicle along a track at a very high speed. Similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway, the launch-assist system would electromagnetically drive a space vehicle along the track. A full-scale, operational track would be about 1.5-miles long and capable of accelerating a vehicle to 600 mph in 9.5 seconds. This photograph shows a subscale model of an airplane running on the experimental track at MSFC during the demonstration test. This track is an advanced linear induction motor. Induction motors are common in fans, power drills, and sewing machines. Instead of spinning in a circular motion to turn a shaft or gears, a linear induction motor produces thrust in a straight line. Mounted on concrete pedestals, the track is 100-feet long, about 2-feet wide, and about 1.5- feet high. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  17. Artist's Concept of Magnetic Launch Assisted Air-Breathing Rocket

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This artist's concept depicts a Magnetic Launch Assist vehicle in orbit. Formerly referred to as the Magnetic Levitation (Maglev) system, the Magnetic Launch Assist system is a launch system developed and tested by engineers at the Marshall Space Flight Center (MSFC) that could levitate and accelerate a launch vehicle along a track at high speeds before it leaves the ground. Using electricity and magnetic fields, a Magnetic Launch Assist system would drive a spacecraft along a horizontal track until it reaches desired speeds. The system is similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway. A full-scale, operational track would be about 1.5-miles long, capable of accelerating a vehicle to 600 mph in 9.5 seconds, and the vehicle would then shift to rocket engines for launch into orbit. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  18. Artist's Concept of Magnetic Launch Assisted Air-Breathing Rocket

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This artist's concept depicts a Magnetic Launch Assist vehicle in orbit. Formerly referred to as the Magnetic Levitation (Maglev) system, the Magnetic Launch Assist system is a launch system developed and tested by engineers at the Marshall Space Flight Center (MSFC) that could levitate and accelerate a launch vehicle along a track at high speeds before it leaves the ground. Using electricity and magnetic fields, a Magnetic Launch Assist system would drive a spacecraft along a horizontal track until it reaches desired speeds. The system is similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway. A full-scale, operational track would be about 1.5-miles long, capable of accelerating a vehicle to 600 mph in 9.5 seconds, and the vehicle would then shift to rocket engines for launch into orbit. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  19. Magnetic Launch Assist: NASA's Vision for the Future

    NASA Technical Reports Server (NTRS)

    Jacobs, William A.; Montenegro, Justino (Technical Monitor)

    2000-01-01

    With the ever-increasing cost of getting to space and the need for safe, reliable, and inexpensive ways to access space. The National Aeronautics and Space Administration (NASA) is taking a look at technologies that will get us there. One of these technologies is Magnetic Launch Assist (MagLev). This is the concept of using both magnetic levitation and magnetic propulsion to provide an initial velocity by using electrical power from ground sources. The use of ground generated electricity can significantly reduce operational costs over the consumables necessary to attain the same velocity. The technologies to accomplish this are both old and new. The concept of MagLev has been around for a long time and several MagLev Trains have been developed. Where NASA's MagLev diverges from the traditional train is in the immense amount of power required to propel this vehicle to 183 meters per second in less than 10 seconds. New technologies or the upgrade of existing technologies will need to be investigated in the areas of energy storage and power switching. An added difficulty is the separation of a very large mass (the space vehicle) from the track and the aerodynamics of that vehicle while on the track. These are of great concern and require considerable study and testing. NASA's plan is to mature these technologies in the next 25 years to achieve our goal of launching a full sized space vehicle for under $300 a kilogram.

  20. Developments in Understanding Stability as Applied to Magnetic Levitated Launch Assist

    NASA Technical Reports Server (NTRS)

    Gering, James A.

    2002-01-01

    Magnetic levitation is a promising technology, with the potential of constituting the first stage of a third generation space transportation system. Today, the Space Shuttle burns on the order of one million pounds of solid rocket propellant to bring the orbiter and external tank to nearly Mach 1 (1,000 kph). Imagine the reductions in launch vehicle weight, complexity and risk if an aerospace vehicle could be accelerated to the same speed utilizing about $1,000 of off-board electrical energy stored in flywheels. After over two decades of development, maglev trains travel on full-scale demonstration tracks in Germany and Japan reaching speeds approaching 500 kph. Encouraging as this may appear, the energy and power required to accelerate a 1 million pound launch vehicle to 1,000 kph would radically redefine the state-of-the-art in electrical energy storage and delivery. Reaching such a goal will require levitation with sufficient stability to withstand an operating environment fundamentally different from that of a high-speed train. Recently NASA let contracts for the construction of three maglev demonstration tracks. This construction and several associated trade studies represent a first-order investigation into the feasibility of maglev launch assist. This report provides a review of these efforts, other government sponsored maglev projects and additional technical literature pertinent to maglev stability. This review brings to light details and dimensions of the maglev stability problem which are not found in previous NASA-sponsored trade studies and which must be addressed in order to realize magnetic levitation as a launch assist technology.

  1. 65. DETAIL OF ASSISTANT LAUNCH CONTROLLER AND LAUNCH CONTROLLER PANELS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    65. DETAIL OF ASSISTANT LAUNCH CONTROLLER AND LAUNCH CONTROLLER PANELS LOCATED NEAR CENTER OF SLC-3E CONTROL ROOM. NOTE 30-CHANNEL COMMUNICATIONS PANELS. PAYLOAD ENVIRONMENTAL CONTROL AND MONITORING PANELS (LEFT) AND LAUNCH OPERATORS PANEL (RIGHT) IN BACKGROUND. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  2. Throttleable GOX/ABS launch assist hybrid rocket motor for small scale air launch platform

    NASA Astrophysics Data System (ADS)

    Spurrier, Zachary S.

    Aircraft-based space-launch platforms allow operational flexibility and offer the potential for significant propellant savings for small-to-medium orbital payloads. The NASA Armstrong Flight Research Center's Towed Glider Air-Launch System (TGALS) is a small-scale flight research project investigating the feasibility for a remotely-piloted, towed, glider system to act as a versatile air launch platform for nano-scale satellites. Removing the crew from the launch vehicle means that the system does not have to be human rated, and offers a potential for considerable cost savings. Utah State University is developing a small throttled launch-assist system for the TGALS platform. This "stage zero" design allows the TGALS platform to achieve the required flight path angle for the launch point, a condition that the TGALS cannot achieve without external propulsion. Throttling is required in order to achieve and sustain the proper launch attitude without structurally overloading the airframe. The hybrid rocket system employs gaseous-oxygen and acrylonitrile butadiene styrene (ABS) as propellants. This thesis summarizes the development and testing campaign, and presents results from the clean-sheet design through ground-based static fire testing. Development of the closed-loop throttle control system is presented.

  3. The Feasibility of Railgun Horizontal-Launch Assist

    NASA Technical Reports Server (NTRS)

    Youngquist, Robert C.; Cox, Robert B.

    2011-01-01

    Railguns typically operate for a few milliseconds, supplying thousands of G's of acceleration to a small projectile, resulting in exceptional speeds. This paper argues through analysis and experiment, that this "standard" technology can be modified to provide 2-3 G's acceleration to a relatively heavy launch vehicle for a time period exceeding several seconds, yielding a launch assist velocity in excess of Mach 1. The key insight here is that an efficient rail gun operates at a speed approximately given by the system resistance divided by the inductance gradient, which can be tailored because recent MOSFET and ultra-capacitor advances allow very low total power supply resistances with high capacitance and augmented railgun architectures provide a scalable inductance gradient. Consequently, it should now be possible to construct a horizontal launch assist system utilizing railgun based architecture.

  4. Vehicle Dynamics due to Magnetic Launch Propulsion

    NASA Technical Reports Server (NTRS)

    Galaboff, Zachary J.; Jacobs, William; West, Mark E.; Montenegro, Justino (Technical Monitor)

    2000-01-01

    The field of Magnetic Levitation Lind Propulsion (MagLev) has been around for over 30 years, primarily in high-speed rail service. In recent years, however, NASA has been looking closely at MagLev as a possible first stage propulsion system for spacecraft. This approach creates a variety of new problems that don't currently exist with the present MagLev trains around the world. NASA requires that a spacecraft of approximately 120,000 lbs be accelerated at two times the acceleration of gravity (2g's). This produces a greater demand on power over the normal MagLev trains that accelerate at around 0.1g. To be able to store and distribute up to 3,000 Mega Joules of energy in less than 10 seconds is a technical challenge. Another problem never addressed by the train industry and, peculiar only to NASA, is the control of a lifting body through the acceleration of and separation from the MagLev track. Very little is understood about how a lifting body will react with external forces, Such as wind gusts and ground effects, while being propelled along on soft springs such as magnetic levitators. Much study needs to be done to determine spacecraft control requirements as well as what control mechanisms and aero-surfaces should be placed on the carrier. Once the spacecraft has been propelled down the track another significant event takes place, the separation of the spacecraft from the carrier. The dynamics involved for both the carrier and the spacecraft are complex and coupled. Analysis of the reaction of the carrier after losing, a majority of its mass must be performed to insure control of the carrier is maintained and a safe separation of the spacecraft is achieved. The spacecraft angle of attack required for lift and how it will affect the carriage just prior to separation, along with the impacts of around effect and aerodynamic forces at ground level must be modeled and analyzed to define requirements on the launch vehicle design. Mechanisms, which can withstand the

  5. Vehicle Dynamics due to Magnetic Launch Propulsion

    NASA Technical Reports Server (NTRS)

    Galaboff, Zachary J.; Jacobs, William; West, Mark E.; Montenegro, Justino (Technical Monitor)

    2000-01-01

    The field of Magnetic Levitation Lind Propulsion (MagLev) has been around for over 30 years, primarily in high-speed rail service. In recent years, however, NASA has been looking closely at MagLev as a possible first stage propulsion system for spacecraft. This approach creates a variety of new problems that don't currently exist with the present MagLev trains around the world. NASA requires that a spacecraft of approximately 120,000 lbs be accelerated at two times the acceleration of gravity (2g's). This produces a greater demand on power over the normal MagLev trains that accelerate at around 0.1g. To be able to store and distribute up to 3,000 Mega Joules of energy in less than 10 seconds is a technical challenge. Another problem never addressed by the train industry and, peculiar only to NASA, is the control of a lifting body through the acceleration of and separation from the MagLev track. Very little is understood about how a lifting body will react with external forces, Such as wind gusts and ground effects, while being propelled along on soft springs such as magnetic levitators. Much study needs to be done to determine spacecraft control requirements as well as what control mechanisms and aero-surfaces should be placed on the carrier. Once the spacecraft has been propelled down the track another significant event takes place, the separation of the spacecraft from the carrier. The dynamics involved for both the carrier and the spacecraft are complex and coupled. Analysis of the reaction of the carrier after losing, a majority of its mass must be performed to insure control of the carrier is maintained and a safe separation of the spacecraft is achieved. The spacecraft angle of attack required for lift and how it will affect the carriage just prior to separation, along with the impacts of around effect and aerodynamic forces at ground level must be modeled and analyzed to define requirements on the launch vehicle design. Mechanisms, which can withstand the

  6. Aero-Assisted Pre-Stage for Ballistic and Aero-Assisted Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Ustinov, Eugene A.

    2012-01-01

    A concept of an aero-assisted pre-stage is proposed, which enables launch of both ballistic and aero-assisted launch vehicles from conventional runways. The pre-stage can be implemented as a delta-wing with a suitable undercarriage, which is mated with the launch vehicle, so that their flight directions are coaligned. The ample wing area of the pre-stage combined with the thrust of the launch vehicle ensure prompt roll-out and take-off of the stack at airspeeds typical for a conventional jet airliner. The launch vehicle is separated from the pre-stage as soon as safe altitude is achieved, and the desired ascent trajectory is reached. Nominally, the pre-stage is non-powered. As an option, to save the propellant of the launch vehicle, the pre-stage may have its own short-burn propulsion system, whereas the propulsion system of the launch vehicle is activated at the separation point. A general non-dimensional analysis of performance of the pre-stage from roll-out to separation is carried out and applications to existing ballistic launch vehicle and hypothetical aero-assisted vehicles (spaceplanes) are considered.

  7. Preliminary Design of a Ramjet for Integration with Ground-Based Launch Assist

    NASA Technical Reports Server (NTRS)

    Sayles, Emily L.

    2008-01-01

    This viewgraph presentation reviews the preliminary design of a ramjet for integration with a ground based launch assist. The reasons for the use of ground-based launch assist and the proposed mechanism for a system are reviewed. The use of a Optimal Trajectory by Implicit Simulation (OTIS), to model the flight and comparison with an actual rocket trajectory is given. The OTIS system is reviewed, The benefits of a launch assist system are analyzed concluding that a launch assist can provide supersonic speeds thus allowing ignition of ramjet without an onboard compressor. This means a further reduction in total launch weight. The Ramjet study is reviewed next. This included a review of the ONX simulations, the verification of the ONX results with the use of Holloman Sled experiment data as derived from the Feasibility of Ramjet Engine Test Capability on The Holloman AFB Sled Track. The conclusion was that the ONX system was not sufficient to meet the needs for the modeling required. The GECAT (Graphical Engine Cycle Analysis Tool) is examined. The results of the GECAT simulations was verified with data from Stataltex and D21 flights. The Next steps are: to create a GECAT Model of a launch assist ramjet, to adjust the geometry to produce the desired thrust, and to survey the ramjet's performance over a range of Mach numbers. The assumptions and requirements of a launch assist ramjet are given, and the acceptable flight regimes are reviewed.

  8. 75 FR 9777 - Magnet Schools Assistance Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-04

    ... CFR Part 280 RIN 1855-AA07 Magnet Schools Assistance Program AGENCY: Office of Innovation and... amends the regulations governing the Magnet Schools Assistance Program (MSAP) to provide greater... classifications and prohibit the creation of magnet schools that result in minority group enrollments in...

  9. Simulation Assisted Risk Assessment Applied to Launch Vehicle Conceptual Design

    NASA Technical Reports Server (NTRS)

    Mathias, Donovan L.; Go, Susie; Gee, Ken; Lawrence, Scott

    2008-01-01

    A simulation-based risk assessment approach is presented and is applied to the analysis of abort during the ascent phase of a space exploration mission. The approach utilizes groupings of launch vehicle failures, referred to as failure bins, which are mapped to corresponding failure environments. Physical models are used to characterize the failure environments in terms of the risk due to blast overpressure, resulting debris field, and the thermal radiation due to a fireball. The resulting risk to the crew is dynamically modeled by combining the likelihood of each failure, the severity of the failure environments as a function of initiator and time of the failure, the robustness of the crew module, and the warning time available due to early detection. The approach is shown to support the launch vehicle design process by characterizing the risk drivers and identifying regions where failure detection would significantly reduce the risk to the crew.

  10. Aero-assisted trajectories for direct launch systems

    NASA Astrophysics Data System (ADS)

    McInnes, Colin R.

    The dynamics of direct launch systems are investigated using the method of matched asymptotic expansions. Using this methodology, analytic solutions are obtained for both ballistic and lifting projectile motion. It is then shown, using parametric optimization, that the required orbital injection impulse is lower for a lifting projectile. Larger launch elevations may be used so that the atmospheric path length, and so drag loss, is lower than for a ballistic projectile. The aerodynamic lift acceleration also induces trajectory curvature to ensure a low flight path angle, and so large transverse velocity, on exit from the atmosphere. The reduction in orbital injection impulse can lead to a greatly increased payload mass fraction for the system.

  11. Magnetic Assisted Colloidal Pattern Formation

    NASA Astrophysics Data System (ADS)

    Yang, Ye

    photoacids, which stabilized the structures after the external field was removed. This approach has potential applications in the fabrication of advanced materials. My thesis is arranged as follows. In Chapter 1, I present a brief background of general pattern formation and why I chose to investigate patterns formed in colloidal systems. I also provide a brief review of field-assisted manipulation techniques in order to motivate why I selected magnetic and acoustic field to study colloidal patterns. In chapter 2, I present the theoretical background of magnetic manipulation, which is the main technique used in my research. In this chapter, I will introduce the basic knowledge on magnetic materials and theories behind magnetic manipulation. The underlining thermodynamic mechanisms and theoretical/computational approaches in colloidal pattern formation are also briefly reviewed. In Chapter 3, I focus on using these concepts to study adhesion forces between particle and surfaces. In Chapter 4, I focus on exploring the ground states of colloidal patterns formed from the anti-ferromagnetic interactions of mixtures of particles, as a function of the particle volume fractions. In Chapter 5, I discuss my research on phase transformations of the well-ordered checkerboard phase formed from the equimolar mixture of magnetic and non-magnetic beads in ferrofluid, and I focus mainly on phase transformations in a slowly varying magnetic field. In Chapter 6, I discuss my work on the superimposed magnetic and acoustic field to study patterns formed from monocomponent colloidal suspensions under vertical confinement. Finally, I conclude my thesis in Chapter 7 and discuss future directions and open questions that can be explored in magnetic field directed self-organization in colloidal systems.

  12. 75 FR 21506 - Magnet Schools Assistance Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-26

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF EDUCATION 34 CFR Part 280 RIN 1855-AA07 Magnet Schools Assistance Program AGENCY: Office of Innovation and... requested comments on that rule for the Magnet Schools Assistance Program (MSAP). The rule became...

  13. Magnet Schools Assistance Program (MSAP). Evaluation Report.

    ERIC Educational Resources Information Center

    Johnson, Janet; Donley, Jan

    The Magnet Schools Assistance Program (MSAP) was designed to eliminate and prevent minority group isolation in targeted magnet schools in the Wake County (North Carolina) Public School System; this evaluation report examines factors that relate to achieving the MSAP goals and objectives. Parent survey data were used to determine whether increased…

  14. Dynamics of Magnetized Plasma Jets and Bubbles Launched into a Background Magnetized Plasma

    NASA Astrophysics Data System (ADS)

    Wallace, B.; Zhang, Y.; Fisher, D. M.; Gilmore, M.

    2016-10-01

    The propagation of dense magnetized plasma, either collimated with mainly azimuthal B-field (jet) or toroidal with closed B-field (bubble), in a background plasma occurs in a number of solar and astrophysical cases. Such cases include coronal mass ejections moving in the background solar wind and extragalactic radio lobes expanding into the extragalactic medium. Understanding the detailed MHD behavior is crucial for correctly modeling these events. In order to further the understanding of such systems, we are investigating the injection of dense magnetized jets and bubbles into a lower density background magnetized plasma using a coaxial plasma gun and a background helicon or cathode plasma. In both jet and bubble cases, the MHD dynamics are found to be very different when launched into background plasma or magnetic field, as compared to vacuum. In the jet case, it is found that the inherent kink instability is stabilized by velocity shear developed due to added magnetic tension from the background field. In the bubble case, rather than directly relaxing to a minimum energy Taylor state (spheromak) as in vacuum, there is an expansion asymmetry and the bubble becomes Rayleigh-Taylor unstable on one side. Recent results will be presented. Work supported by the Army Research Office Award No. W911NF1510480.

  15. Spatially Assisted Schwinger Mechanism and Magnetic Catalysis

    NASA Astrophysics Data System (ADS)

    Copinger, Patrick; Fukushima, Kenji

    2016-08-01

    Using the worldline formalism we compute an effective action for fermions under a temporally modulated electric field and a spatially modulated magnetic field. It is known that the former leads to an enhanced Schwinger mechanism, while we find that the latter can also result in enhanced particle production and even cause a reorganization of the vacuum to acquire a larger dynamical mass in equilibrium which spatially assists the magnetic catalysis.

  16. Automated Assistance for Designing Active Magnetic Bearings

    NASA Technical Reports Server (NTRS)

    Imlach, Joseph

    2008-01-01

    MagBear12 is a computer code that assists in the design of radial, heteropolar active magnetic bearings (AMBs). MagBear12 was developed to help in designing the system described in "Advanced Active-Magnetic-Bearing Thrust-Measurement System". Beyond this initial application, MagBear12 is expected to be useful for designing AMBs for a variety of rotating machinery. This program incorporates design rules and governing equations that are also implemented in other, proprietary design software used by AMB manufacturers. In addition, this program incorporates an advanced unpublished fringing-magnetic-field model that increases accuracy beyond that offered by the other AMB-design software.

  17. Magnetic mesocrystal-assisted magnetoresistance in manganite.

    PubMed

    Yang, Jan-Chi; He, Qing; Zhu, Yuan-Min; Lin, Jheng-Cyuan; Liu, Heng-Jui; Hsieh, Ying-Hui; Wu, Ping-Chun; Chen, Yen-Lin; Lee, Shang-Fan; Chin, Yi-Ying; Lin, Hong-Ji; Chen, Chien-Te; Zhan, Qian; Arenholz, Elke; Chu, Ying-Hao

    2014-11-12

    Mesocrystal, a new class of crystals as compared to conventional and well-known single crystals and polycrystalline systems, has captured significant attention in the past decade. Recent studies have been focused on the advance of synthesis mechanisms as well as the potential on device applications. In order to create further opportunities upon functional mesocrystals, we fabricated a self-assembled nanocomposite composed of magnetic CoFe2O4 mesocrystal in Sr-doped manganites. This combination exhibits intriguing structural and magnetic tunabilities. Furthermore, the antiferromagnetic coupling of the mesocrystal and matrix has induced an additional magnetic perturbation to spin-polarized electrons, resulting in a significantly enhanced magnetoresistance in the nanocomposite. Our work demonstrates a new thought toward the enhancement of intrinsic functionalities assisted by mesocrystals and advanced design of novel mesocrystal-embedded nanocomposites.

  18. Closed end launch tube (CELT)

    NASA Astrophysics Data System (ADS)

    Lueck, Dale E.; Parrish, Clyde F.

    2001-02-01

    As an alternative to magnetic propulsion for launch assist, the authors propose a pneumatic launch assist system. Using off-the-shelf components, coupled with familiar steel and concrete construction, a launch assist system can be brought from the initial feasibility stage, through a flight capable 5000 kg demonstrator to a deployed full size launch assist system in 10 years. The final system would be capable of accelerating a 450,000 kg vehicle to 270 ms-1. The CELT system uses commercially available compressors and valves to build a fail-safe system in less than half the time of a full Mag-Lev (magnetic levitation) system, and at a small fraction of the development cost. The resulting system could be ready in time to support some Gen 2 (Generation 2) vehicles, as well as the proposed Gen 3 vehicle. .

  19. Closed End Launch Tube (CELT)

    NASA Technical Reports Server (NTRS)

    Lueck, Dale E.; Parrish, Clyde F.; Delgado, H. (Technical Monitor)

    2000-01-01

    As an alternative to magnetic propulsion for launch assist, the authors propose a pneumatic launch assist system. Using off the shelf components, coupled with familiar steel and concrete construction, a launch assist system can be brought from the initial feasibility stage, through a flight capable 5000 kg. demonstrator to a deployed full size launch assist system in 10 years. The final system would be capable of accelerating a 450,000 kg. vehicle to 270 meters per second. The CELT system uses commercially available compressors and valves to build a fail-safe system in less than half the time of a full Mag-Lev (magnetic levitation) system, and at a small fraction of the development cost. The resulting system could be ready in time to support some Gen 2 (generation 2) vehicles, as well as the proposed Gen 3 vehicle.

  20. BIPOLAR JETS LAUNCHED FROM MAGNETICALLY DIFFUSIVE ACCRETION DISKS. I. EJECTION EFFICIENCY VERSUS FIELD STRENGTH AND DIFFUSIVITY

    SciTech Connect

    Sheikhnezami, Somayeh; Fendt, Christian; Porth, Oliver; Vaidya, Bhargav; Ghanbari, Jamshid E-mail: fendt@mpia.de

    2012-09-20

    We investigate the launching of jets and outflows from magnetically diffusive accretion disks. Using the PLUTO code, we solve the time-dependent resistive magnetohydrodynamic equations taking into account the disk and jet evolution simultaneously. The main question we address is which kind of disks launch jets and which kind of disks do not? In particular, we study how the magnitude and distribution of the (turbulent) magnetic diffusivity affect mass loading and jet acceleration. We apply a turbulent magnetic diffusivity based on {alpha}-prescription, but also investigate examples where the scale height of diffusivity is larger than that of the disk gas pressure. We further investigate how the ejection efficiency is governed by the magnetic field strength. Our simulations last for up to 5000 dynamical timescales corresponding to 900 orbital periods of the inner disk. As a general result, we observe a continuous and robust outflow launched from the inner part of the disk, expanding into a collimated jet of superfast-magnetosonic speed. For long timescales, the disk's internal dynamics change, as due to outflow ejection and disk accretion the disk mass decreases. For magnetocentrifugally driven jets, we find that for (1) less diffusive disks, (2) a stronger magnetic field, (3) a low poloidal diffusivity, or (4) a lower numerical diffusivity (resolution), the mass loading of the outflow is increased-resulting in more powerful jets with high-mass flux. For weak magnetization, the (weak) outflow is driven by the magnetic pressure gradient. We consider in detail the advection and diffusion of magnetic flux within the disk and we find that the disk and outflow magnetization may substantially change in time. This may have severe impact on the launching and formation process-an initially highly magnetized disk may evolve into a disk of weak magnetization which cannot drive strong outflows. We further investigate the jet asymptotic velocity and the jet rotational velocity in

  1. Bipolar Jets Launched from Magnetically Diffusive Accretion Disks. I. Ejection Efficiency versus Field Strength and Diffusivity

    NASA Astrophysics Data System (ADS)

    Sheikhnezami, Somayeh; Fendt, Christian; Porth, Oliver; Vaidya, Bhargav; Ghanbari, Jamshid

    2012-09-01

    We investigate the launching of jets and outflows from magnetically diffusive accretion disks. Using the PLUTO code, we solve the time-dependent resistive magnetohydrodynamic equations taking into account the disk and jet evolution simultaneously. The main question we address is which kind of disks launch jets and which kind of disks do not? In particular, we study how the magnitude and distribution of the (turbulent) magnetic diffusivity affect mass loading and jet acceleration. We apply a turbulent magnetic diffusivity based on α-prescription, but also investigate examples where the scale height of diffusivity is larger than that of the disk gas pressure. We further investigate how the ejection efficiency is governed by the magnetic field strength. Our simulations last for up to 5000 dynamical timescales corresponding to 900 orbital periods of the inner disk. As a general result, we observe a continuous and robust outflow launched from the inner part of the disk, expanding into a collimated jet of superfast-magnetosonic speed. For long timescales, the disk's internal dynamics change, as due to outflow ejection and disk accretion the disk mass decreases. For magnetocentrifugally driven jets, we find that for (1) less diffusive disks, (2) a stronger magnetic field, (3) a low poloidal diffusivity, or (4) a lower numerical diffusivity (resolution), the mass loading of the outflow is increased—resulting in more powerful jets with high-mass flux. For weak magnetization, the (weak) outflow is driven by the magnetic pressure gradient. We consider in detail the advection and diffusion of magnetic flux within the disk and we find that the disk and outflow magnetization may substantially change in time. This may have severe impact on the launching and formation process—an initially highly magnetized disk may evolve into a disk of weak magnetization which cannot drive strong outflows. We further investigate the jet asymptotic velocity and the jet rotational velocity in

  2. Ultimate Limits to Thermally Assisted Magnetic Recording

    NASA Astrophysics Data System (ADS)

    McDaniel, Terry

    2004-03-01

    The application of thermal energy to enable recording on extremely high anisotropy magnetic media appears to be a viable means of extending the density of stored information. The central physical issue facing the technology is what gain can be realized in writability along with long- term data stability using imaginable media materials. We reasonably expect the material properties M(T) and H_k(T) to determine this, since a stability metric for media with characteristic magnetization switching unit volume V is MVH_k/2kT. This matter is controversial owing to still open questions related to thermomagnetic recording with temperature elevation above the Curie point and optimal cooling rates. There are indications that multi-component magnetic media may offer advantages in achieving performance goals. Beyond the physical issues lie engineering matters related to the correct system architecture to yield a practical storage device to meet future customer expectations. Here one must address a detailed means of delivering localized heating to the magnetic medium to perform efficient recording. To date, magnetic recording devices have been highly mechanical systems, so it is natural to inquire how a need for an aggressively heated head-medium interface could impact the evolution of future systems. Eventually elements of thermally assisted recording could be combined with patterned media approaches such as self-organized magnetic arrays to push toward ultimate limits where the thermal instability of bits overtakes engineered media materials. Finally, a practical recording system cannot be realized unless a means of finding, following, and reading the smallest bits with a usable signal-to-noise ratio exists - engineering issues separate from an ability to reliably record those bits.

  3. Blazar Variability from Turbulence in Jets Launched by Magnetically Arrested Accretion Flows

    NASA Astrophysics Data System (ADS)

    O' Riordan, Michael; Pe'er, Asaf; McKinney, Jonathan C.

    2017-07-01

    Blazars show variability on timescales ranging from minutes to years, the former being comparable to and in some cases even shorter than the light-crossing time of the central black hole. The observed γ-ray light curves can be described by a power-law power density spectrum (PDS), with a similar index for both BL Lacs and flat-spectrum radio quasars. We show that this variability can be produced by turbulence in relativistic jets launched by magnetically arrested accretion flows (MADs). We perform radiative transport calculations on the turbulent, highly magnetized jet launching region of a MAD with a rapidly rotating supermassive black hole. The resulting synchrotron and synchrotron self-Compton emission, originating from close to the black hole horizon, is highly variable. This variability is characterized by PDS, which is remarkably similar to the observed power-law spectrum at frequencies less than a few per day. Furthermore, turbulence in the jet launching region naturally produces fluctuations in the plasma on scales much smaller than the horizon radius. We speculate that similar turbulent processes, operating in the jet at large radii (and therefore a high bulk Lorentz factor), are responsible for blazar variability over many decades in frequency, including on minute timescales.

  4. Feasibility study on linear-motor-assisted take-off (LMATO) of winged launch vehicle

    NASA Astrophysics Data System (ADS)

    Nagatomo, Makoto; Kyotani, Yoshihiro

    1987-11-01

    Application of technology of magnetically levitated transportation to horizontal take-off of an experimental space vehicle has been studied. An experimental system of linear-motor-assisted take-off (LMATO) consists of the HIMES space vehicle and a magnetically levitated and propelled sled which is a modified MLU model developed by the JNR. The original MLU model is a train of three cars which weighs 30 tons and is driven by a thrust of 15 tons. The maximum speed is 400 km/h. The highest speed of 517 km/h has been obtained by the first JNR linear motor car. Since the take-off speed of the HIMES vehicle with the initial mass of 14 tons is 470 km/h, the existing technology can be used for the LMATO of the vehicle. The concept of the HIMES/LMATO is to use the MLU vehicles to accelerate the HIMES vehicle at 0.33 g on a 5 km guide track until the speed reaches 300 km/h, when the rocket engines of the space vehicle are started to increase the acceleration up to 1 g. The total system will take the final checkout for take-off during the acceleration phase and the speed exceeds 470 km/h which is large enough to aerodynamically lift the space vehicle, then the fastening mechanism is unlocked to separate the vehicles. The experimental system can be applied for initial acceleration of a vehicle with air-breathing propulsion.

  5. 3-D MHD modeling and stability analysis of jet and spheromak plasmas launched into a magnetized plasma

    NASA Astrophysics Data System (ADS)

    Fisher, Dustin; Zhang, Yue; Wallace, Ben; Gilmore, Mark; Manchester, Ward; Arge, C. Nick

    2016-10-01

    The Plasma Bubble Expansion Experiment (PBEX) at the University of New Mexico uses a coaxial plasma gun to launch jet and spheromak magnetic plasma configurations into the Helicon-Cathode (HelCat) plasma device. Plasma structures launched from the gun drag frozen-in magnetic flux into the background magnetic field of the chamber providing a rich set of dynamics to study magnetic turbulence, force-free magnetic spheromaks, and shocks. Preliminary modeling is presented using the highly-developed 3-D, MHD, BATS-R-US code developed at the University of Michigan. BATS-R-US employs an adaptive mesh refinement grid that enables the capture and resolution of shock structures and current sheets, and is particularly suited to model the parameter regime under investigation. CCD images and magnetic field data from the experiment suggest the stabilization of an m =1 kink mode trailing a plasma jet launched into a background magnetic field. Results from a linear stability code investigating the effect of shear-flow as a cause of this stabilization from magnetic tension forces on the jet will be presented. Initial analyses of a possible magnetic Rayleigh Taylor instability seen at the interface between launched spheromaks and their entraining background magnetic field will also be presented. Work supported by the Army Research Office Award No. W911NF1510480.

  6. Low launch-energy trajectories to the outer solar system via Venus and earth gravity-assist flybys

    NASA Technical Reports Server (NTRS)

    Diehl, Roger; Belbruno, Edward; Bender, David; Myers, Mark; Stetson, Douglas

    1988-01-01

    Recent cancellation of the program to develop a Centaur upper stage for use in the Space Transportation System (STS) has motivated considerable interest in trajectory modes with low launch-energy requirements to the outer solar system. Flyby encounters of the inner planets, especially Venus and earth, may be used to enable missions to Jupiter, Saturn, and a restricted class of comets. An examination of mission opportunities to these targets is presented through the end of this century using gravity-assist trajectories.

  7. The role of magnetic reconnection on astrophysical jets launching and particle acceleration

    NASA Astrophysics Data System (ADS)

    De Gouveia Dal Pino, Elisabete

    2012-07-01

    Magnetic reconnection events like those associated to solar flares can be also a very powerful mechanism operating on accretion disk/jet systems. We have recently found that the magnetic power released in fast reconnection flares is more than sufficient to accelerate relativistic plasmons and produce the observed radio luminosity of the nuclear jets associated both to galactic stellar mass black holes and low luminous active galactic nuclei (AGNs). The famous observed correlation between the radio luminosity and the black hole mass of these sources, spanning ^10^9 orders of magnitude in mass, can be naturally explained in this model as simply due to the magnetic reconnection activity at the jet launching region of the accretion disk coronae of these sources. A similar process may explain the observed x-ray flares in young stars (YSOs) as well. In this talk, we review this mechanism and show results of numerical MHD tests of its validity. Also, particle acceleration in the magnetic reconnection sites of these sources can be rather efficient . In this talk, we will also discuss this acceleration process showing the energy distribution evolution of several thousands of test particles injected in a three-dimensional MHD domain of magnetic reconnection with embedded turbulence. The particle acceleration rate, which depends on the reconnection rate, is highly enhanced in this case. This is because reconnection becomes fast and independent of magnetic resistivity in the presence of turbulence and allows the formation of a thick volume in the current sheet filled with multiple, simultaneously reconnecting magnetic fluxes. The particles trapped within this volume then suffer several head-on scatterings with the contracting magnetic fluctuations in a first-order Fermi process. Particles are thus exponentially accelerated to energies which are several orders of magnitude larger than their injected energy.

  8. Field assisted spin switching in magnetic random access memory

    NASA Astrophysics Data System (ADS)

    Jeong, W. C.; Park, J. H.; Oh, J. H.; Koh, G. H.; Jeong, G. T.; Jeong, H. S.; Kim, Kinam

    2006-04-01

    A switching method called by field assisted spin switching has been investigated. A field assisted spin switching consists of a metal line induced magnetic field and a spin switching through a magnetic tunnel junction. It is a variation of a current induced switching and assisted by the magnetic field induced by the current-carrying metal line. Various current paths have been tested to investigate how and how much the spin switching contributes to the overall switching and the results will be explained. A computer simulation has been complemented to measure the degree of the thermal effect in the switching.

  9. The Great Equalizer: Assistive Technology Launches a New Era in Inclusion.

    ERIC Educational Resources Information Center

    Wyer, Kathy

    2001-01-01

    Describes how assistive technology can be used to facilitate the mainstreaming of students with disabilities, focusing on: different types of technology that are useful; the importance of mainstreaming; how to learn what assistive choices are available; and how inclusive education is enhanced by assistive technology in one California school…

  10. The Great Equalizer: Assistive Technology Launches a New Era in Inclusion.

    ERIC Educational Resources Information Center

    Wyer, Kathy

    2001-01-01

    Describes how assistive technology can be used to facilitate the mainstreaming of students with disabilities, focusing on: different types of technology that are useful; the importance of mainstreaming; how to learn what assistive choices are available; and how inclusive education is enhanced by assistive technology in one California school…

  11. 34 CFR 280.1 - What is the Magnet Schools Assistance Program?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 1 2012-07-01 2012-07-01 false What is the Magnet Schools Assistance Program? 280.1... SECONDARY EDUCATION, DEPARTMENT OF EDUCATION MAGNET SCHOOLS ASSISTANCE PROGRAM General § 280.1 What is the Magnet Schools Assistance Program? The Magnet Schools Assistance Program provides grants to...

  12. 34 CFR 280.1 - What is the Magnet Schools Assistance Program?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 1 2011-07-01 2011-07-01 false What is the Magnet Schools Assistance Program? 280.1... SECONDARY EDUCATION, DEPARTMENT OF EDUCATION MAGNET SCHOOLS ASSISTANCE PROGRAM General § 280.1 What is the Magnet Schools Assistance Program? The Magnet Schools Assistance Program provides grants to...

  13. 34 CFR 280.1 - What is the Magnet Schools Assistance Program?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 1 2013-07-01 2013-07-01 false What is the Magnet Schools Assistance Program? 280.1... SECONDARY EDUCATION, DEPARTMENT OF EDUCATION MAGNET SCHOOLS ASSISTANCE PROGRAM General § 280.1 What is the Magnet Schools Assistance Program? The Magnet Schools Assistance Program provides grants to...

  14. 34 CFR 280.1 - What is the Magnet Schools Assistance Program?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 1 2014-07-01 2014-07-01 false What is the Magnet Schools Assistance Program? 280.1... SECONDARY EDUCATION, DEPARTMENT OF EDUCATION MAGNET SCHOOLS ASSISTANCE PROGRAM General § 280.1 What is the Magnet Schools Assistance Program? The Magnet Schools Assistance Program provides grants to...

  15. 34 CFR 280.1 - What is the Magnet Schools Assistance Program?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false What is the Magnet Schools Assistance Program? 280.1... SECONDARY EDUCATION, DEPARTMENT OF EDUCATION MAGNET SCHOOLS ASSISTANCE PROGRAM General § 280.1 What is the Magnet Schools Assistance Program? The Magnet Schools Assistance Program provides grants to...

  16. Electric-field-assisted switching in magnetic tunnel junctions.

    PubMed

    Wang, Wei-Gang; Li, Mingen; Hageman, Stephen; Chien, C L

    2011-11-13

    The advent of spin transfer torque effect accommodates site-specific switching of magnetic nanostructures by current alone without magnetic field. However, the critical current density required for usual spin torque switching remains stubbornly high around 10(6)-10(7) A cm(-2). It would be fundamentally transformative if an electric field through a voltage could assist or accomplish the switching of ferromagnets. Here we report electric-field-assisted reversible switching in CoFeB/MgO/CoFeB magnetic tunnel junctions with interfacial perpendicular magnetic anisotropy, where the coercivity, the magnetic configuration and the tunnelling magnetoresistance can be manipulated by voltage pulses associated with much smaller current densities. These results represent a crucial step towards ultralow energy switching in magnetic tunnel junctions, and open a new avenue for exploring other voltage-controlled spintronic devices.

  17. Launching Cosmic-Ray-driven Outflows from the Magnetized Interstellar Medium

    NASA Astrophysics Data System (ADS)

    Girichidis, Philipp; Naab, Thorsten; Walch, Stefanie; Hanasz, Michał; Mac Low, Mordecai-Mark; Ostriker, Jeremiah P.; Gatto, Andrea; Peters, Thomas; Wünsch, Richard; Glover, Simon C. O.; Klessen, Ralf S.; Clark, Paul C.; Baczynski, Christian

    2016-01-01

    We present a hydrodynamical simulation of the turbulent, magnetized, supernova (SN)-driven interstellar medium (ISM) in a stratified box that dynamically couples the injection and evolution of cosmic rays (CRs) and a self-consistent evolution of the chemical composition. CRs are treated as a relativistic fluid in the advection-diffusion approximation. The thermodynamic evolution of the gas is computed using a chemical network that follows the abundances of H+, H, H2, CO, C+, and free electrons and includes (self-)shielding of the gas and dust. We find that CRs perceptibly thicken the disk with the heights of 90% (70%) enclosed mass reaching ≳ 1.5 {kpc} (≳ 0.2 {kpc}). The simulations indicate that CRs alone can launch and sustain strong outflows of atomic and ionized gas with mass loading factors of order unity, even in solar neighborhood conditions and with a CR energy injection per SN of {10}50 {erg}, 10% of the fiducial thermal energy of an SN. The CR-driven outflows have moderate launching velocities close to the midplane (≲ 100 {km} {{{s}}}-1) and are denser (ρ ˜ 10-24-10-26 g cm-3), smoother, and colder than the (thermal) SN-driven winds. The simulations support the importance of CRs for setting the vertical structure of the disk as well as the driving of winds.

  18. Design of permanent magnet eddy current brake for a small scaled electromagnetic launch model

    NASA Astrophysics Data System (ADS)

    Zhou, Shigui; Yu, Haitao; Hu, Minqiang; Huang, Lei

    2012-04-01

    A variable pole-pitch double-sided permanent magnet (PM) linear eddy current brake (LECB) is proposed for a small scaled electromagnetic launch model. A two-dimensional (2D) analytical steady state model is presented for the double-sided PM-LECB, and the expression for the braking force is derived. Based on the analytical model, the material and eddy current skin effect of the conducting plate are analyzed. Moreover, a variable pole-pitch double-sided PM-LECB is proposed for the effective braking of the moving plate. In addition, the braking force is predicted by finite element (FE) analysis, and the simulated results are in good agreement with the analytical model. Finally, a prototype is presented to test the braking profile for validation of the proposed design.

  19. Study of the reduced magnetic field required for thermally assisted magnetization reversal

    NASA Astrophysics Data System (ADS)

    Firdausi, H. F. Y.; Utari; Purnama, B.

    2016-11-01

    The reduced magnetic field required for thermally magnetization reversal discussed in this paper. Study of thermally assisted magnetization reversal conduct by using micromagnetic simulation. The magnetic dot size of the simulation was 50 nm × 50 nm × 20 nm. The perpendicularly anisotropy constant was 2 × 106 erg/cm3. Initial condition was set single domain configuration. Then a sufficiently thermal pulse was used to get stochastic effect so that the magnetization along to the induce field direction for pico second duration. The results show that the reduced magnetic field mechanism seem to be temporary antiferromagnetic configuration before single domain configuration in alinging along to field direction. The same mechanims observed for modify of thickness dot particles. The require magnetic field of 145 Oe in thermally assisted magnetization reversal open a posibility for MRAM application.

  20. Magnetorelaxometry assisting biomedical applications of magnetic nanoparticles.

    PubMed

    Wiekhorst, Frank; Steinhoff, Uwe; Eberbeck, Dietmar; Trahms, Lutz

    2012-05-01

    Due to their biocompatibility and small size, iron oxide magnetic nanoparticles (MNP) can be guided to virtually every biological environment. MNP are susceptible to external magnetic fields and can thus be used for transport of drugs and genes, for heat generation in magnetic hyperthermia or for contrast enhancement in magnetic resonance imaging of biological tissue. At the same time, their magnetic properties allow one to develop sensitive and specific measurement methods to non-invasively detect MNP, to quantify MNP distribution in tissue and to determine their binding state. In this article, we review the application of magnetorelaxometry (MRX) for MNP detection. The underlying physical properties of MNP responsible for the generation of the MRX signal with its characteristic parameters of relaxation amplitude and relaxation time are described. Existing single and multi-channel MRX devices are reviewed. Finally, we thoroughly describe some applications of MRX to cellular MNP quantification, MNP organ distribution and MNP-based binding assays. Providing specific MNP signals, a detection limit down to a few nanogram MNP, in-vivo capability in conscious animals and measurement times of a few seconds, MRX is a valuable tool to improve the application of MNP for diagnostic and therapeutic purposes.

  1. Electrical detection of microwave assisted magnetization reversal by spin pumping

    SciTech Connect

    Rao, Siddharth; Subhra Mukherjee, Sankha; Elyasi, Mehrdad; Singh Bhatia, Charanjit; Yang, Hyunsoo

    2014-03-24

    Microwave assisted magnetization reversal has been investigated in a bilayer system of Pt/ferromagnet by detecting a change in the polarity of the spin pumping signal. The reversal process is studied in two material systems, Pt/CoFeB and Pt/NiFe, for different aspect ratios. The onset of the switching behavior is indicated by a sharp transition in the spin pumping voltage. At a threshold value of the external field, the switching process changes from partial to full reversal with increasing microwave power. The proposed method provides a simple way to detect microwave assisted magnetization reversal.

  2. Assisted Writing in Spin Transfer Torque Magnetic Tunnel Junctions

    NASA Astrophysics Data System (ADS)

    Ganguly, Samiran; Ahmed, Zeeshan; Datta, Supriyo; Marinero, Ernesto E.

    2015-03-01

    Spin transfer torque driven MRAM devices are now in an advanced state of development, and the importance of reducing the current requirement for writing information is well recognized. Different approaches to assist the writing process have been proposed such as spin orbit torque, spin Hall effect, voltage controlled magnetic anisotropy and thermal excitation. In this work,we report on our comparative study using the Spin-Circuit Approach regarding the total energy, the switching speed and energy-delay products for different assisted writing approaches in STT-MTJ devices using PMA magnets.

  3. Magnetically Assisted Bilayer Composites for Soft Bending Actuators

    PubMed Central

    Jang, Sung-Hwan; Na, Seon-Hong; Park, Yong-Lae

    2017-01-01

    This article presents a soft pneumatic bending actuator using a magnetically assisted bilayer composite composed of silicone polymer and ferromagnetic particles. Bilayer composites were fabricated by mixing ferromagnetic particles to a prepolymer state of silicone in a mold and asymmetrically distributed them by applying a strong non-uniform magnetic field to one side of the mold during the curing process. The biased magnetic field induces sedimentation of the ferromagnetic particles toward one side of the structure. The nonhomogeneous distribution of the particles induces bending of the structure when inflated, as a result of asymmetric stiffness of the composite. The bilayer composites were then characterized with a scanning electron microscopy and thermogravimetric analysis. The bending performance and the axial expansion of the actuator were discussed for manipulation applications in soft robotics and bioengineering. The magnetically assisted manufacturing process for the soft bending actuator is a promising technique for various applications in soft robotics. PMID:28773007

  4. Critical damping constant of microwave-assisted magnetization switching

    NASA Astrophysics Data System (ADS)

    Yamaji, Toshiki; Arai, Hiroko; Matsumoto, Rie; Imamura, Hiroshi

    2016-02-01

    Microwave-assisted switching of magnetization in a perpendicularly magnetized disk was theoretically studied and special attention was paid to the effect of a damping constant on the switching field. We found that there exists a critical damping constant above which the switching field suddenly increases. We derived an analytical expression of the critical damping constant and showed that it decreases with increasing frequency of the microwave field, while it increases with increasing amplitude of the microwave field and the effective anisotropy field.

  5. Transcranial magnetic stimulation assisted by neuronavigation of magnetic resonance images

    NASA Astrophysics Data System (ADS)

    Viesca, N. Angeline; Alcauter, S. Sarael; Barrios, A. Fernando; González, O. Jorge J.; Márquez, F. Jorge A.

    2012-10-01

    Technological advance has improved the way scientists and doctors can learn about the brain and treat different disorders. A non-invasive method used for this is Transcranial Magnetic Stimulation (TMS) based on neuron excitation by electromagnetic induction. Combining this method with functional Magnetic Resonance Images (fMRI), it is intended to improve the localization technique of cortical brain structures by designing an extracranial localization system, based on Alcauter et al. work.

  6. Renormalized anisotropic exchange for representing heat assisted magnetic recording media

    SciTech Connect

    Jiao, Yipeng; Liu, Zengyuan; Victora, R. H.

    2015-05-07

    Anisotropic exchange has been incorporated in a description of magnetic recording media near the Curie temperature, as would be found during heat assisted magnetic recording. The new parameters were found using a cost function that minimized the difference between atomistic properties and those of renormalized spin blocks. Interestingly, the anisotropic exchange description at 1.5 nm discretization yields very similar switching and magnetization behavior to that found at 1.2 nm (and below) discretization for the previous isotropic exchange. This suggests that the increased accuracy of anisotropic exchange may also reduce the computational cost during simulation.

  7. Magnetic logic based on diode-assisted magnetoresistance

    NASA Astrophysics Data System (ADS)

    Luo, Zhaochu; Zhang, Xiaozhong

    2017-05-01

    Conventional computer suffers from the von Neumann performance bottleneck due to its hardware architecture that non-volatile memory and logic are separated. The new emerging magnetic logic coupling the extra dimension of spin, shows the potential to overcome this performance bottleneck. Here, we propose a novel category of magnetic logic based on diode-assisted magnetoresistance. By coupling Hall effect and nonlinear transport property in silicon, all four basic Boolean logic operations including AND, NAND, OR and NOR, can be programmed at room temperature with high output ratio in one silicon-based device. Further introducing anomalous Hall effect of magnetic material into magnetic logic, we achieve perpendicular magnetic anisotropy-based magnetic logic which combines the advantages of both high output ratio (>103 %) and low work magnetic field (˜1 mT). Integrated with non-volatile magnetic memory, our logic device with unique magnetoelectric properties has the advantages of current-controlled reconfiguration, zero refresh consumption, instant-on performance and would bridge the processor-memory gap. Our findings would pave the way in magnetic logic and offer a feasible platform to build a new kind of magnetic microprocessor with potential of high performance.

  8. Strong permanent magnet-assisted electromagnetic undulator

    DOEpatents

    Halbach, Klaus

    1988-01-01

    This invention discloses an improved undulator comprising a plurality of electromagnet poles located along opposite sides of a particle beam axis with alternate north and south poles on each side of the beam to cause the beam to wiggle or undulate as it travels generally along the beam axis and permanent magnets spaced adjacent the electromagnetic poles on each side of the axis of said particle beam in an orientation sufficient to reduce the saturation of the electromagnet poles whereby the field strength of the electromagnet poles can be increased beyond the normal saturation levels of the electromagnetic poles.

  9. Microwave-assisted magnetization reversal in a Co/Pd multilayer with perpendicular magnetic anisotropy

    NASA Astrophysics Data System (ADS)

    Nozaki, Yukio; Narita, Naoyuki; Tanaka, Terumitsu; Matsuyama, Kimihide

    2009-08-01

    Microwave-assisted magnetization reversal in a rectangle of a Co/Pd multilayer with a perpendicular magnetic anisotropy is examined using vector network analyzer ferromagnetic resonance (FMR) spectroscopy. A microwave field is applied along the in-plane direction of the rectangle together with a negative dc easy-axis field smaller than the coercive field. Broadening or splitting of the peak profile in the FMR spectrum suggesting the formation of multidomain structure appears after the microwave field is applied. The dominance of microwave-assisted nucleation of magnetization is supported by the frequency dependence of the probability with which the multidomain structure appears.

  10. Magnetic-Field-Assisted Assembly of Anisotropic Superstructures by Iron Oxide Nanoparticles and Their Enhanced Magnetism.

    PubMed

    Jiang, Chengpeng; Leung, Chi Wah; Pong, Philip W T

    2016-12-01

    Magnetic nanoparticle superstructures with controlled magnetic alignment and desired structural anisotropy hold promise for applications in data storage and energy storage. Assembly of monodisperse magnetic nanoparticles under a magnetic field could lead to highly ordered superstructures, providing distinctive magnetic properties. In this work, a low-cost fabrication technique was demonstrated to assemble sub-20-nm iron oxide nanoparticles into crystalline superstructures under an in-plane magnetic field. The gradient of the applied magnetic field contributes to the anisotropic formation of micron-sized superstructures. The magnitude of the applied magnetic field promotes the alignment of magnetic moments of the nanoparticles. The strong dipole-dipole interactions between the neighboring nanoparticles lead to a close-packed pattern as an energetically favorable configuration. Rod-shaped and spindle-shaped superstructures with uniform size and controlled spacing were obtained using spherical and polyhedral nanoparticles, respectively. The arrangement and alignment of the superstructures can be tuned by changing the experimental conditions. The two types of superstructures both show enhancement of coercivity and saturation magnetization along the applied field direction, which is presumably associated with the magnetic anisotropy and magnetic dipole interactions of the constituent nanoparticles and the increased shape anisotropy of the superstructures. Our results show that the magnetic-field-assisted assembly technique could be used for fabricating nanomaterial-based structures with controlled geometric dimensions and enhanced magnetic properties for magnetic and energy storage applications.

  11. Magnetic gold nanotriangles by microwave-assisted polyol synthesis

    NASA Astrophysics Data System (ADS)

    Yu, Siming; Hachtel, Jordan A.; Chisholm, Matthew F.; Pantelides, Sokrates T.; Laromaine, Anna; Roig, Anna

    2015-08-01

    Simple approaches to synthesize hybrid nanoparticles with magnetic and plasmonic functionalities, with high control of their shape and avoiding cytotoxic reactants, to target biomedical applications remain a huge challenge. Here, we report a facile, fast and bio-friendly microwave-assisted polyol route for the synthesis of a complex multi-material consisting of monodisperse gold nanotriangles around 280 nm in size uniformly decorated by superparamagnetic iron oxide nanoparticles of 5 nm. These nanotriangles are readily dispersible in water, display a strong magnetic response (10 wt% magnetic fraction) and exhibit a localized surface plasmon resonance band in the NIR region (800 nm). Moreover, these hybrid particles can be easily self-assembled at the liquid-air interfaces.Simple approaches to synthesize hybrid nanoparticles with magnetic and plasmonic functionalities, with high control of their shape and avoiding cytotoxic reactants, to target biomedical applications remain a huge challenge. Here, we report a facile, fast and bio-friendly microwave-assisted polyol route for the synthesis of a complex multi-material consisting of monodisperse gold nanotriangles around 280 nm in size uniformly decorated by superparamagnetic iron oxide nanoparticles of 5 nm. These nanotriangles are readily dispersible in water, display a strong magnetic response (10 wt% magnetic fraction) and exhibit a localized surface plasmon resonance band in the NIR region (800 nm). Moreover, these hybrid particles can be easily self-assembled at the liquid-air interfaces. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03113c

  12. Space Shuttle Discovery Launch

    NASA Image and Video Library

    2008-05-31

    NASA Shuttle Launch Director Michael Leinbach, left, STS-124 Assistant Launch Director Ed Mango, center, and Flow Director for Space Shuttle Discovery Stephanie Stilson clap in the the Launch Control Center after the main engine cut off and successful launch of the Space Shuttle Discovery (STS-124) Saturday, May 31, 2008, at the Kennedy Space Center in Cape Canaveral, Fla. The Shuttle lifted off from launch pad 39A at 5:02 p.m. EDT. Photo Credit: (NASA/Bill Ingalls)

  13. Laser frequency stabilization by magnetically assisted rotation spectroscopy

    NASA Astrophysics Data System (ADS)

    Krzemień, Leszek; Brzozowski, Krzysztof; Noga, Andrzej; Witkowski, Marcin; Zachorowski, Jerzy; Zawada, Michał; Gawlik, Wojciech

    2011-03-01

    We present a method of Doppler-free laser frequency stabilization based on magnetically assisted rotation spectroscopy (MARS) which combines the Doppler-free velocity-selective optical pumping (VSOP) and magnetic rotation spectroscopy. The stabilization is demonstrated for the atomic rubidium transitions at 780 nm. The proposed method is largely independent of stray magnetic fields and does not require any modulation of the laser frequency. Moreover, the discussed method allows one to choose between locking the laser exactly to the line center, or with a magnetically-controlled shift to an arbitrary frequency detuned by up to several natural linewidths. This feature is useful in many situations, e.g. for laser cooling experiments. In addition to presenting the principle of the method, its theoretical background and peculiarities inherent to the repopulation VSOP are discussed.

  14. Analytical expression for critical frequency of microwave assisted magnetization switching

    NASA Astrophysics Data System (ADS)

    Arai, Hiroko; Imamura, Hiroshi

    2016-02-01

    The microwave-assisted switching (MAS) of magnetization in a perpendicularly magnetized circular disk is studied based on the macrospin model in a rotating frame. The analytical expression for the critical frequency of MAS is derived by analyzing the presence of a quasiperiodic mode. The critical frequency is expressed as a function of the radio frequency (rf) field Hrf and the effective anisotropy field H\\text{k}\\text{eff}. For a small rf field such that H\\text{rf} \\ll H\\text{k}\\text{eff}, the critical frequency is approximately equal to (γ /π )\\root 3 \\of{\\smash{H\\text{k}\\text{eff}H\\text{rf}2}\\mathstrut}.

  15. Erasure temperature measurements of heat assisted magnetic recording media

    NASA Astrophysics Data System (ADS)

    Chen, Y. J.; Yang, H. Z.; Leong, S. H.; Cher, K. M.; Hu, J. F.; Sethi, P.; Lew, W. S.

    2015-05-01

    For heat assisted magnetic recording (HAMR) media development, measurement of erasure temperature (Te) is interesting and important for practical HAMR testing and applications. Here, we present an investigation on Te measurements of L10 ordered FePt granular HAMR media made using a Laser Heating (LH) method on a home-built HAMR write test system versus that from a bulk heating approach. The HAMR write test system provides HAMR writing, micro-MOKE (magneto-optical Kerr effect) signal detection, and MOKE imaging functions at the same testing spot in one single system. Magnetic force microscopy (MFM) and magnetic Kerr microscopy observations of the scanning laser induced degradation/erasure/demagnetization of the pre-recorded magnetic patterns on disk media (over a wide area of a few hundreds of μm2) show that the magnetic (MFM and Kerr signal) amplitude of the pre-recorded magnetic patterns decreases slowly with increasing laser power (Pw) (/temperature rise) for Pw ≲ 66 mW and then drops sharply to nearly zero for Pw ≥ ˜72 mW (the laser power corresponding to complete thermal erasure when the media temperature is ˜Te). It was further found that this trend of magnetic amplitude reduction with increased Pw is similar to that from magnetic amplitude decrease of pre-recorded magnetic patterns with increased bulk heating temperature. The temperature for complete erasure at laser power, Pw = 72 mW for the LH method, corresponds therefore to ˜650 K (≈Te) for the bulk heating methods. Besides fast measurement, LH (as a comparable and viable approach for erasure measurement) is dynamic, localized, and has time scales closer to practical HAMR situation.

  16. Prototype ventricular assist device supported on magnetic bearings

    SciTech Connect

    Allaire, P.E.; Maslen, E.H.; Kim, H.C.; Olsen, D.B.; Bearnson, G.D.

    1995-12-31

    Mechanical artificial hearts are now expected to be used as assist or total replacements for failing human hearts, if a reliable, anatomically appropriate design is developed. Initially, ventricular assist or total replacement devices were pulsatile air driven units containing a flexing polymeric diaphragm and two valves for each ventricle. Many reliability problems were encountered. Recently, attention has been focused on axial or centrifugal continuous flow blood pumps. Magnetic bearings employed in such devices offer the advantages of no required lubrication and large operating clearances. This paper describes a prototype continuous flow pump supported in magnetic bearings. The pump performance was measured in a simulated adult human circulation system. It delivered 6 liters/min of flow at 100 mm Hg differential head operating at 2,400 rpm in water. The pump is totally magnetically supported in four magnetic bearings - two radial and two thrust. The geometry and other properties of the bearings are described. Bearing parameters such as load capacity, current gains, and open loop stiffness are discussed. Bearing coil currents were measured during operation in air and water. The rotor was operated in various orientations to determine the actuator current gains. These values were then used to estimate the radial and thrust forces acting on the rotor in both air and water.

  17. Patterning Graphene Film by Magnetic-assisted UV Ozonation

    PubMed Central

    Wu, Yixuan; Tao, Haihua; Su, Shubin; Yue, Huan; Li, Hao; Zhang, Ziyu; Ni, Zhenhua; Chen, Xianfeng

    2017-01-01

    Developing an alternative method for fabricating microscale graphene patterns that overcomes the obstacles of organic contamination, linewidth resolution, and substrate damaging is paramount for applications in optoelectronics. Here we propose to pattern chemical vapor deposition grown graphene film through a stencil mask by magnetic-assisted ultraviolet (UV) ozonation under irradiation of a xenon excimer lamp. In this process, the paramagnetic oxygen molecules and photochemically generated oxygen radicals are magnetized and attracted in an inhomogenous external magnetic field. As a consequence, their random motions convert into directional, which can greatly modify or enhance the quality of graphene patterns. Using a ferromagnetic steel mask, an approximately vertical magnetic-field-assisted UV ozonation (BZ = 0.31 T, ∇BZ = 90 T · m−1) has a capability of patterning graphene microstructures with a line width of 29 μm and lateral under-oxidation less than 4 μm. Our approach is applicable to patterning graphene field-effect transistor arrays, and it can be a promising solution toward resist-free, substrate non-damaging, and cost effective microscale patterning of graphene film. PMID:28422180

  18. Micromagnetic simulation of electric-field-assisted magnetization switching in perpendicular magnetic tunnel junction

    NASA Astrophysics Data System (ADS)

    Yoshida, Chikako; Noshiro, Hideyuki; Yamazaki, Yuichi; Sugii, Toshihiro; Tanaka, Tomohiro; Furuya, Atsushi; Uehara, Yuji

    2017-05-01

    The feasibility of a voltage assisted unipolar switching in perpendicular magnetic tunnel junction (MTJ) has been studied using a micromagnetic simulation. Assuming a linear modulation of anisotropy field with voltage, both parallel (P) to anti-parallel (AP) and AP to P switchings were observed by application of unipolar voltage pulse without external magnetic field assistance. In latter case, the final P state can only be achieved with an ultrashort voltage pulse which vanishes before spin transfer torque (STT) becomes dominant to restore the initial AP state. In addition, it was found that the larger change in anisotropy field is required for the MTJ with smaller diameter.

  19. Multimaterial magnetically assisted 3D printing of composite materials.

    PubMed

    Kokkinis, Dimitri; Schaffner, Manuel; Studart, André R

    2015-10-23

    3D printing has become commonplace for the manufacturing of objects with unusual geometries. Recent developments that enabled printing of multiple materials indicate that the technology can potentially offer a much wider design space beyond unusual shaping. Here we show that a new dimension in this design space can be exploited through the control of the orientation of anisotropic particles used as building blocks during a direct ink-writing process. Particle orientation control is demonstrated by applying low magnetic fields on deposited inks pre-loaded with magnetized stiff platelets. Multimaterial dispensers and a two-component mixing unit provide additional control over the local composition of the printed material. The five-dimensional design space covered by the proposed multimaterial magnetically assisted 3D printing platform (MM-3D printing) opens the way towards the manufacturing of functional heterogeneous materials with exquisite microstructural features thus far only accessible by biological materials grown in nature.

  20. Wiggler magnetic field assisted second harmonic generation in clusters

    NASA Astrophysics Data System (ADS)

    Aggarwal, Munish; Vij, Shivani; Kant, Niti

    2015-06-01

    Wiggler magnetic field assisted second harmonic generation in clusters has been investigated theoretically. An intense short-pulse laser propagating through a gas embedded with atomic clusters, converts it into hot plasma balls. For clusters with radius less than one tenth of the laser wavelength, the nonlinear restoration force dominates, which leads to second harmonic generation. The magnetic wiggler provides the uncompensated momentum to second harmonic photon, to make the process of harmonic generation resonant. We explore the impact of laser intensity and cluster size on the efficiency of second harmonic generation. Pulse slippage of second harmonic pulse out of the domain of fundamental laser pulse has been observed on account of group velocity mismatch between the fundamental and second harmonic pulse. Enhancement in the efficiency of the second harmonic is seen for the optimum values of wiggler magnetic field.

  1. Multimaterial magnetically assisted 3D printing of composite materials

    PubMed Central

    Kokkinis, Dimitri; Schaffner, Manuel; Studart, André R.

    2015-01-01

    3D printing has become commonplace for the manufacturing of objects with unusual geometries. Recent developments that enabled printing of multiple materials indicate that the technology can potentially offer a much wider design space beyond unusual shaping. Here we show that a new dimension in this design space can be exploited through the control of the orientation of anisotropic particles used as building blocks during a direct ink-writing process. Particle orientation control is demonstrated by applying low magnetic fields on deposited inks pre-loaded with magnetized stiff platelets. Multimaterial dispensers and a two-component mixing unit provide additional control over the local composition of the printed material. The five-dimensional design space covered by the proposed multimaterial magnetically assisted 3D printing platform (MM-3D printing) opens the way towards the manufacturing of functional heterogeneous materials with exquisite microstructural features thus far only accessible by biological materials grown in nature. PMID:26494528

  2. Magnetic gold nanotriangles by microwave-assisted polyol synthesis

    SciTech Connect

    Yu, Siming; Hachtel, Jordan A.; Chisholm, Matthew F.; Pantelides, Sokrates T.; Laromaine, Anna; Roig, Anna

    2015-07-21

    Our simple approach to synthesize hybrid nanoparticles with magnetic and plasmonic functionalities, with high control of their shape and avoiding cytotoxic reactants, to target biomedical applications remains a huge challenge. We report a facile, fast and bio-friendly microwave-assisted polyol route for the synthesis of a complex multi-material consisting of monodisperse gold nanotriangles around 280 nm in size uniformly decorated by superparamagnetic iron oxide nanoparticles of 5 nm. Moreover, these nanotriangles are readily dispersible in water, display a strong magnetic response (10 wt% magnetic fraction) and exhibit a localized surface plasmon resonance band in the NIR region (800 nm). Moreover, these hybrid particles can be easily self-assembled at the liquid–air interfaces.

  3. Magnetic nanoparticle and magnetic field assisted siRNA delivery in vitro.

    PubMed

    Mykhaylyk, Olga; Sanchez-Antequera, Yolanda; Vlaskou, Dialechti; Cerda, Maria Belen; Bokharaei, Mehrdad; Hammerschmid, Edelburga; Anton, Martina; Plank, Christian

    2015-01-01

    This chapter describes how to design and conduct experiments to deliver siRNA to adherent cell cultures in vitro by magnetic force-assisted transfection using self-assembled complexes of small interfering RNA (siRNA) and cationic lipids or polymers that are associated with magnetic nanoparticles (MNPs). These magnetic complexes are targeted to the cell surface by the application of a gradient magnetic field. A further development of the magnetic drug-targeting concept is combining it with an ultrasound-triggered delivery using magnetic microbubbles as a carrier for gene or drug delivery. For this purpose, selected MNPs, phospholipids, and siRNAs are assembled in the presence of perfluorocarbon gas into flexible formulations of magnetic lipospheres (microbubbles). Methods are described how to accomplish the synthesis of magnetic nanoparticles for magnetofection and how to test the association of siRNA with the magnetic components of the transfection vector. A simple method is described to evaluate magnetic responsiveness of the magnetic siRNA transfection complexes and estimate the complex loading with magnetic nanoparticles. Procedures are provided for the preparation of magnetic lipoplexes and polyplexes of siRNA as well as magnetic microbubbles for magnetofection and downregulation of the target gene expression analysis with account for the toxicity determined using an MTT-based respiration activity test. A modification of the magnetic transfection triplexes with INF-7, fusogenic peptide, is described resulting in reporter gene silencing improvement in HeLa, Caco-2, and ARPE-19 cells. The methods described can also be useful for screening vector compositions and novel magnetic nanoparticle preparations for optimized siRNA transfection by magnetofection in any cell type.

  4. Magnetic properties of TbFe2 particles prepared by magnetic field assisted ball milling

    NASA Astrophysics Data System (ADS)

    Arout Chelvane, J.; Palit, Mithun; Basumatary, Himalay; Pandian, S.

    2013-10-01

    The alloy of TbFe2 was studied by ball milling with and without the presence of external magnetic field. While the structure and powder morphology of the alloy were investigated using scanning electron microscope and X-ray diffraction, the magnetization was investigated using vibrating sample and superconducting quantum interference device magnetometers. The rate of particle reduction with ball milling is comparatively higher in the presence of external magnetic field than without it. Consequently, owing to a large fraction of particles acquiring near single domain configuration under the field assisted milling condition, the coercivity derived from these particles are as high as 6500 Oe than that of particles obtained without the aid of external magnetic field which is around 3850 Oe. The field cooled low temperature magnetization exhibits a large coercivity and skew in the shape of the magnetization curve due to the large anisotropy.

  5. Magnetic-stress-assisted damping of magnetization precession in multilayered metallic films

    NASA Astrophysics Data System (ADS)

    Bastrukov, Sergey; Yong Khoo, Jun; Lukianchuk, Boris; Molodtsova, Irina

    2013-09-01

    Micromagnetic dynamics of spin relaxation in multilayered metallic films of stacked microelectronic devices is modeled by a modified Landau-Lifshitz-Gilbert equation with a newly introduced form of damping torque owing its origin to coupling between precessing magnetization-vector and stress-tensor of combined intrinsic and extrinsic magnetic anisotropy. Based on the magnetization energy loss equation, the exponential relaxation time as a function of precession frequency and angle of applied rf-field is obtained, depending upon two parameters of intrinsic and extrinsic damping torques acting on precessing magnetization. It is shown that theoretically obtained from the Gabor uncertainty relation the FMR linewidth, originating from the above magnetic-stress-assisted damping of magnetization precession, provides proper account for the empirical non-linear linewidth-vs-frequency curves deduced from recent in-plane FMR measurements on multilayered ultrathin films of ferromagnetic metals.

  6. Ablation modeling of electro-magnetically launched projectile for access to space

    NASA Astrophysics Data System (ADS)

    Gosse, Ryan C.

    It has been proposed to study and identify the technical issues involved in the launch to space of micro-satellite payloads using an airborne electromagnetic launcher (AEML). A computational fluid dynamics (CFD) computer code was developed to help characterize the aerothermal issues involved with the flight of the projectile as it exits the Earth's atmosphere. Conceptual geometries were chosen to evaluate the feasibility of launching to orbit from an aircraft. Due to expected high heating fluxes, carboncarbon material was selected for the thermal protection system (TPS). Results of the conceptual study are presented and used to evaluate the practicality of the AEML concept.

  7. Magnetic Launching And Collimation Of Jets From The Disk-magnetosphere Boundary: 2.5D MHD Simulations

    NASA Astrophysics Data System (ADS)

    Lii, Patrick; Romanova, M.; Lovelace, R.

    2011-05-01

    We use axisymmetric magnetohydrodynamics (MHD) to investigate the launching and collimation of jets emerging from the disk-magnetosphere boundary of accreting magnetized stars. Our analysis shows that the emergence of a collimated jet is a two-step process: first, the matter is accelerated along field lines extending up from the disk by the magnetic pressure force. Then, the matter is collimated by the toroidal magnetic field in the stellar corona. The jet emerges from the disk-magnetosphere boundary and is weakly matter dominated. The matter in the jet crosses the Alfven and fast magnetosonic surfaces a few stellar radii above the disk. Even far from the disk, the magnetic force continues to accelerate and collimate the jet. We observe a matter ejection-to-accretion ratio of 0.25 in steady state. A high accretion rate can generate the strong magnetic pressure which drives the matter from the disk and as such, these simulations may apply to EXor and FUOR class stars which undergo episodes of enhanced accretion. In general, the models can be applied to many types of magnetized stars--white dwarfs, neutron stars, and brown dwarfs--which exhibit periods of enhanced accretion.

  8. Dynamic compact model of thermally assisted switching magnetic tunnel junctions

    NASA Astrophysics Data System (ADS)

    El Baraji, M.; Javerliac, V.; Guo, W.; Prenat, G.; Dieny, B.

    2009-12-01

    The general purpose of spin electronics is to take advantage of the electron's spin in addition to its electrical charge to build innovative electronic devices. These devices combine magnetic materials which are used as spin polarizer or analyzer together with semiconductors or insulators, resulting in innovative hybrid CMOS/magnetic (Complementary MOS) architectures. In particular, magnetic tunnel junctions (MTJs) can be used for the design of magnetic random access memories [S. Tehrani, Proc. IEEE 91, 703 (2003)], magnetic field programmable gate arrays [Y. Guillement, International Journal of Reconfigurable Computing, 2008], low-power application specific integrated circuits [S. Matsunaga, Appl. Phys. Express 1, 091301 (2008)], and rf oscillators. The thermally assisted switching (TAS) technology requires heating the MTJ before writing it by means of an external field. It reduces the overall power consumption, solves the data writing selectivity issues, and improves the thermal stability of the written information for high density applications. The design of hybrid architectures requires a MTJ compact model, which can be used in standard electrical simulators of the industry. As a result, complete simulations of CMOS/MTJ hybrid circuits can be performed before experimental realization and testing. This article presents a highly accurate model of the MTJ based on the TAS technology. It is compatible with the Spectre electrical simulator of Cadence design suite.

  9. Current induced perpendicular-magnetic-anisotropy racetrack memory with magnetic field assistance

    SciTech Connect

    Zhang, Y.; Klein, J.-O.; Chappert, C.; Ravelosona, D.; Zhao, W. S.

    2014-01-20

    High current density is indispensable to shift domain walls (DWs) in magnetic nanowires, which limits the using of racetrack memory (RM) for low power and high density purposes. In this paper, we present perpendicular-magnetic-anisotropy (PMA) Co/Ni RM with global magnetic field assistance, which lowers the current density for DW motion. By using a compact model of PMA RM and 40 nm design kit, we perform mixed simulation to validate the functionality of this structure and analyze its density potential. Stochastic DW motion behavior has been taken into account and statistical Monte-Carlo simulations are carried out to evaluate its reliability performance.

  10. Employee and Family Assistance Video Counseling Program: A Post Launch Retrospective Comparison With In-Person Counseling Outcomes

    PubMed Central

    2014-01-01

    Background Access to technologically mediated information and services under the umbrella of mental and physical health has become increasingly available to clients via Internet modalities, according to a recent study. In May 2010, video counseling was added to the counseling services offered through the Employee and Family Assistance Program at Shepell·fgi as a pilot project with a full operational launch in September 2011. Objective The objective of this study was to conduct a retrospective post launch examination of the video counseling service through an analysis of the reported clinical outcomes of video and in-person counseling modalities. Methods A chronological sample of 68 video counseling (VC) cases and 68 in-person (IP) cases were collected from a pool of client clinical files closed in 2012. To minimize the variables impacting the study and maintain as much clinical continuity as possible, the IP and the VC clients must have attended clinical sessions with any one of six counselors who provided both the VC and the IP services. The study compared the two counseling modalities along the following data points (see glossary of terms): (1) client demographic profiles (eg, age, gender, whether the sessions involved individuals or conjoint sessions with couples or families, etc), (2) presenting issue, (3) average session hours, (4) client rating of session helpfulness, (5) rates of goal completion, (6) client withdrawal rates, (7) no show and late cancellation rates, and (8) pre/post client self-assessment. Specific to VC, we examined client geographic location. Results Data analysis demonstrates that the VC and the IP showed a similar representation of presenting issues with nearly identical outcomes for client ratings of session helpfulness, rates of goal completion, pre/post client self-assessment, average session duration, and client geographic location. There were no statistically significant differences in the rates of withdrawal from counseling, no

  11. Embedding magnetic nanoparticles into polysaccharide-based hydrogels for magnetically assisted bioseparation.

    PubMed

    Liang, Yuan-Yuan; Zhang, Li-Ming; Jiang, Wei; Li, Wei

    2007-11-12

    Based on the preparation of biocompatible polysaccharide-based hydrogels with stimuli-responsive properties by the copolymerization of maleilated carboxymethyl chitosan with N-isopropylacrylamide, novel magnetic hybrid hydrogels were fabricated by the in situ embedding of magnetic iron oxide nanoparticles into the porous hydrogel networks. Scanning electron microscopy (SEM) and thermogravimetric (TG) analyses showed that the size, morphology, and content of the iron oxide nanoparticles formed could be modulated by controlling the amount of maleilated carboxymethyl chitosan. As confirmed by X-ray diffractometry (XRD), equilibrium swelling ratio, and differential scanning calorimetry (DSC) measurements, the embedding process did not induce a phase change of the magnetic iron oxide nanoparticles, and the resultant hybrid hydrogels could retain the pH- and temperature-responsive characteristics of their hydrogel precursors. By investigating the partition coefficients of bovine serum albumin as a model protein, this magnetic hydrogel material was found to hold a potential application in magnetically assisted bioseparation.

  12. Subnanosecond microwave-assisted magnetization switching in a circularly polarized microwave magnetic field

    NASA Astrophysics Data System (ADS)

    Suto, Hirofumi; Kanao, Taro; Nagasawa, Tazumi; Kudo, Kiwamu; Mizushima, Koichi; Sato, Rie

    2017-06-01

    We study microwave-assisted magnetization switching (MAS) of a perpendicularly magnetized nanomagnet with a diameter of 50 nm in a circularly polarized microwave magnetic field. The MAS effect appears when the rotation direction of the microwave field matches that of the ferromagnetic resonance excitation, and a large switching field decrease from 7.1 kOe to 1.5 kOe is demonstrated. In comparison with a linearly polarized microwave magnetic field, the circularly polarized microwave field induces the same MAS effect at half the microwave field amplitude, thereby showing its efficiency. We also examine MAS in the subnanosecond region and show that the magnetization switching can be induced by a microwave field with the duration of 0.2 ns.

  13. Magnetic domain wall depinning assisted by spin wave bursts

    NASA Astrophysics Data System (ADS)

    Woo, Seonghoon; Delaney, Tristan; Beach, Geoffrey S. D.

    2017-01-01

    Spin waves (SWs) in magnetic structures could potentially be exploited for high-speed, low-power magnonic devices for signal transmission and magnetic logic applications. The short wavelengths and high frequencies of dipole-exchange-mode SWs in metallic ferromagnets make them particularly suitable for nanoscale devices. However, these same characteristics make generation and detection challenging due to the length-scale mismatch of conventional SW interfaces such as microwave striplines. Here we show numerically and experimentally that colliding domain walls (DWs) release energetic spin wave bursts that can couple to and assist depinning of nearby DWs. Hence, DWs can be used as stationary reservoirs of exchange energy that can be efficiently generated, manipulated, and used to release SWs on demand, which can subsequently be detected again using DWs. This work highlights a route towards integrating DWs and SWs for enhanced functionality in spintronics applications.

  14. TOPICAL REVIEW: Ultimate limits to thermally assisted magnetic recording

    NASA Astrophysics Data System (ADS)

    McDaniel, Terry W.

    2005-02-01

    The application of thermal energy to enable recording on extremely high anisotropy magnetic media appears to be a viable means of extending the density of stored information. The central physical issue facing the technology is what gain can be realized in writability along with long-term data stability using imaginable media materials. We reasonably expect the material properties M(T) and Hk(T) to determine this, since a stability metric for media with characteristic magnetization switching unit volume V is MV Hk/2kBT. This matter is controversial owing to still open questions related to thermomagnetic recording with temperature elevation above the Curie point and optimal cooling rates. There are indications that multi-component magnetic media may offer advantages in achieving performance goals. Beyond the physical issues lie engineering matters related to the correct system architecture to yield a practical storage device to meet future customer expectations. Here one must address a detailed means of delivering localized heating to the magnetic medium to perform efficient recording. To date, magnetic recording devices have been highly mechanical systems, so it is natural to inquire how a need for an aggressively heated head-medium interface could impact the evolution of future systems. Eventually elements of thermally assisted recording could be combined with patterned media approaches such as self-organized magnetic arrays to push toward ultimate limits where the thermal instability of bits overtakes engineered media materials. Finally, a practical recording system cannot be realized unless a means of finding, following, and reading the smallest bits with a usable signal-to-noise ratio exists—engineering issues separate from an ability to reliably record those bits. This paper is based on an invited presentation of the same title given at the meeting of the American Physical Society, 22-26 March 2004, in Montreal, Quebec, Canada.

  15. Magnetic design for the PediaFlow ventricular assist device.

    PubMed

    Noh, Myounggyu D; Antaki, James F; Ricci, Michael; Gardiner, Jeff; Paden, Dave; Wu, Jingchun; Prem, Ed; Borovetz, Harvey; Paden, Bradley E

    2008-02-01

    This article describes a design process for a new pediatric ventricular assist device, the PediaFlow. The pump is embodied in a magnetically levitated turbodynamic design that was developed explicitly based on the requirements for chronic support of infants and small children. The procedure entailed the consideration of multiple pump topologies, from which an axial mixed-flow configuration was chosen for further development. The magnetic design includes permanent-magnet (PM) passive bearings for radial support of the rotor, an actively controlled thrust actuator for axial support, and a brushless direct current (DC) motor for rotation. These components are closely coupled both geometrically and magnetically, and were therefore optimized in parallel, using electromagnetic, rotordynamic models and fluid models, and in consideration of hydrodynamic requirements. Multiple design objectives were considered, including efficiency, size, and margin between critical speeds to operating speed. The former depends upon the radial and yaw stiffnesses of the PM bearings. Analytical expressions for the stiffnesses were derived and verified through finite element analysis (FEA). A toroidally wound motor was designed for high efficiency and minimal additional negative radial stiffness. The design process relies heavily on optimization at the component level and system level. The results of this preliminary design optimization yielded a pump design with an overall stability margin of 15%, based on a pressure rise of 100 mm Hg at 0.5 lpm running at 16,000 rpm.

  16. Magnetic Field Assisted sub-THz Quantum Cascade Lasers

    NASA Astrophysics Data System (ADS)

    Wade, A.; Kim, Y.; Smirnov, D.; Kumar, S.; Hu, Q.; Williams, B. S.; Reno, J.

    2009-03-01

    In THz QCLs radiative transitions take place between closely-spaced 2D electronic subbands (1THz ˜ 4meV) of a multi-QW semiconductor system. THz quantum cascade lasers now cover the frequency range from 1.2 THz to 5 THz, though cryogenic cooling is still required. Further progress towards the realization of devices emitting at longer wavelengths (sub-THz QCLs) and higher temperatures may be realized in a system with additional lateral confinement. Here we use strong magnetic fields to achieve quasi-0D confinement in THz QCL based on the resonance phonon design. We studied two designs: (a) 2-well injector/2 well active region, emitting at 3 THz at B=0; and (b) 1-well injector/3-well active region, emitting at 2 THz at B=0 T. By applying the appropriate electrical bias and strong magnetic fields, we achieved laser emission at 0.8-0.9 THz at B>16 T [1], and 0.6 THz at B˜17 T, from devices a and b respectively. The ability to achieve sub-THz lasing is due to magnetic field enhanced population inversion in a quasi-0D QCL. [1] Wade, A et. al., Magnetic field assisted Terahertz quantum cascade laser operating up to 225K, Accepted for publication Nature Photonics (2009)

  17. Magnetic launching and collimation of jets from the disc-magnetosphere boundary: 2.5D MHD simulations

    NASA Astrophysics Data System (ADS)

    Lii, Patrick; Romanova, Marina; Lovelace, Richard

    2012-03-01

    We use axisymmetric magnetohydrodynamic simulations to investigate the launching and collimation of jets emerging from the disc-magnetosphere boundary of accreting magnetized stars. Our analysis shows that the matter flows into the jet from the inner edge of the accretion disc. It is magnetically accelerated along field lines extending up from the disc and simultaneously collimated by the magnetic pinch force. In the reference run which we use for analysis, the matter in the jet crosses the Alfvén surface a few R* above the disc and the fast magnetosonic surface ˜13R* above the disc. At larger distances, the magnetic pressure is a few times smaller than the total matter pressure, but the magnetic force continues to accelerate and collimate the jet. In steady state, we observe a matter ejection-to-accretion ratio of ˜0.2. Across different simulation runs, we measure a range of half-opening angles between Θ≈ 4° and 20° at the top of the simulation region, depending on the degree of magnetization in the outflow. We consider the case of stars undergoing epochs of high accretion [such as EX Lupi (EXors), FU Orionis (FUORs) and Classical T Tauri Stars (CTTSs)] where the stellar magnetosphere is strongly compressed by the incoming accretion disc. For a typical EXor (mass 0.8 M⊙, radius 2 R⊙) accreting at ˜10-5 M⊙ yr-1, we measure poloidal velocities in the jet ranging from 30 km s-1 on the outer edge of the jet to more than 260 km s-1 on the inner edge. In general, the models can be applied to a variety of magnetized stars - white dwarfs, neutron stars and brown dwarfs - which exhibit periods of high accretion.

  18. Magnetic Resonance Imaging Guided Vacuum Assisted and Core Needle Biopsies.

    PubMed

    Kılıç, Fahrettin; Eren, Abdulkadir; Tunç, Necmettin; Velidedeoğlu, Mehmet; Bakan, Selim; Aydoğan, Fatih; Çelik, Varol; Gazioğlu, Ertuğrul; Yılmaz, Mehmet Halit

    2016-01-01

    The purpose of this study to present the results of Magnetic resonance imaging (MRI) guided cutting needle biopsy procedures of suspicious breast lesions that can be solely detected on Magnetic resonance (MR) examination. The study included 48 patients with 48 lesions which were solely be observed in breast MRI, indistinguishable in ultrasonography and mammography, for MR guided vacuum-assisted cutting needle biopsy and 42 patients with 42 lesions for MR guided cutting needle biopsy for the lesions of the same nature. MR imaging was performed using a 1.5-Tesla MRI device. Acquired MR images were determined and biopsy protocol was performed using computer-aided diagnosis system on the workstation. Vacuum biopsies were performed using 10 G or 12 G automatic biopsy systems, cutting needle biopsy procedures were performed using fully automated 12 G biopsy needle. All biopsy procedures were finalized successfully without major complications. The lesions were 54 mass (60%), 28 were non-mass contrast enhancement (31%) and 8 were foci (9%) in the MR examination. Histopathological evaluation revealed 18 malignant (invasive, in-situ ductal carcinoma and lobular carcinoma), 66 benign (apocrine metaplasia, fibrosis, fibroadenomatoid lesion, sclerosing adenosis, fibrocystic disease and mild-to-severe epithelial proliferation) and 6 high-risk (atypical ductal hyperplasia, intraductal papilloma, radial scar) lesions. Magnetic resonance guided vacuum and cutting needle biopsy methods are successful methods fort he evaluation of solely MRI detected suspicious breast lesions. There are several advantages relative to each other in both methods.

  19. Electric field assisted magnetization reversal in FePt films.

    NASA Astrophysics Data System (ADS)

    Lukashev, Pavel; Belashchenko, Kirill; Sabirianov, Renat

    2008-03-01

    We propose to use strain assisted reduction in anisotropy of FePt in order to make magnetization reversal easier in the writing of the magnetic storage devices. We performed first-principles calculations of the magnetocrystalline anisotropy of FePt under bi-axial stress using full-potential LAPW implemented in FLEUR code. Magnetocrystalline anisotropy decreases by 25% with application of 1.5% tensile biaxial strain. This is partially due to the reduction of the c/a ratio by about 1.5% (calculated Poisson ratio is 0.33) in the tetragonal cell and partially due to the increase in volume by about 1.5%. Biaxial strain can be obtained by placing piezoelectric film under FePt layer, and by applying electric field on the system. Modern ferroelectric systems can provide stress up to 2%. Besides, we propose using thin ferroelectric films with asymmetric interfaces, which provides a simple way to generate bias field in the polarization reversal and related properties. The existence of the polar interfaces results in a different average polarization in the film upon reversal. As a result, the strain in the film depends on the direction of polarization. This asymmetric strain can be used do modulate magnetic properties.

  20. Magnetic activated cell sorting (MACS): utility in assisted reproduction.

    PubMed

    Makker, Kartikeya; Agarwal, Ashok; Sharma, Rakesh K

    2008-07-01

    Assisted reproductive techniques (ART) have now been extensively incorporated in the management of infertile couples. But even after rapid methodological and technological advances the success rates of these procedures have been below expectations. This has led to development of many sperm preparation protocols to obtain an ideal semen sample for artificial reproduction. Sperm apoptosis has been heavily linked to failures in reproductive techniques. One of the earliest changes shown by apoptotic spermatozoa is externalization of phosphatidyl serine. Magnetic activated cell sorting (MACS) is a novel sperm preparation technique that separates apoptotic and non-apoptotic spermatozoa based on the expression of phosphatidylserine. This has led to the incorporation of MACS as a sperm preparation technique. The review highlights the principle and mechanism of this novel technique and enumerates its advantages as a sperm preparation technique. Its utility in ART as an efficient tool for sperm recovery and its application in cryopreservation of semen samples is also explained.

  1. Optical modeling of media for heat assisted magnetic recording

    NASA Astrophysics Data System (ADS)

    Ghoreyshi, Ali; Victora, R. H.

    2016-02-01

    The validity of effective medium theory for modeling nanocomposite thin films interacting with a plasmonic nanoantenna has been investigated using an optical circuit model and finite-difference time-domain simulations. We show that in the regime where the size of the optical beam generated by the nanoantenna is comparable to the feature size inside the thin film, the effective medium theory is not valid anymore. We demonstrate that using effective medium theory can cause a dramatic error in the performance analysis of applications such as heat assisted magnetic recording that work at this regime. Therefore, we develop a theoretical framework based on circuit theory at optical frequencies to study and design nanocomposite thin films for these applications.

  2. Spin-orbit torque-assisted switching in magnetic insulator thin films with perpendicular magnetic anisotropy

    NASA Astrophysics Data System (ADS)

    Li, Peng; Liu, Tao; Chang, Houchen; Kalitsov, Alan; Zhang, Wei; Csaba, Gyorgy; Li, Wei; Richardson, Daniel; Demann, August; Rimal, Gaurab; Dey, Himadri; Jiang, J. S.; Porod, Wolfgang; Field, Stuart B.; Tang, Jinke; Marconi, Mario C.; Hoffmann, Axel; Mryasov, Oleg; Wu, Mingzhong

    2016-09-01

    As an in-plane charge current flows in a heavy metal film with spin-orbit coupling, it produces a torque on and thereby switches the magnetization in a neighbouring ferromagnetic metal film. Such spin-orbit torque (SOT)-induced switching has been studied extensively in recent years and has shown higher efficiency than switching using conventional spin-transfer torque. Here we report the SOT-assisted switching in heavy metal/magnetic insulator systems. The experiments used a Pt/BaFe12O19 bilayer where the BaFe12O19 layer exhibits perpendicular magnetic anisotropy. As a charge current is passed through the Pt film, it produces a SOT that can control the up and down states of the remnant magnetization in the BaFe12O19 film when the film is magnetized by an in-plane magnetic field. It can reduce or increase the switching field of the BaFe12O19 film by as much as about 500 Oe when the film is switched with an out-of-plane field.

  3. Spin-orbit torque-assisted switching in magnetic insulator thin films with perpendicular magnetic anisotropy.

    PubMed

    Li, Peng; Liu, Tao; Chang, Houchen; Kalitsov, Alan; Zhang, Wei; Csaba, Gyorgy; Li, Wei; Richardson, Daniel; DeMann, August; Rimal, Gaurab; Dey, Himadri; Jiang, J S; Porod, Wolfgang; Field, Stuart B; Tang, Jinke; Marconi, Mario C; Hoffmann, Axel; Mryasov, Oleg; Wu, Mingzhong

    2016-09-01

    As an in-plane charge current flows in a heavy metal film with spin-orbit coupling, it produces a torque on and thereby switches the magnetization in a neighbouring ferromagnetic metal film. Such spin-orbit torque (SOT)-induced switching has been studied extensively in recent years and has shown higher efficiency than switching using conventional spin-transfer torque. Here we report the SOT-assisted switching in heavy metal/magnetic insulator systems. The experiments used a Pt/BaFe12O19 bilayer where the BaFe12O19 layer exhibits perpendicular magnetic anisotropy. As a charge current is passed through the Pt film, it produces a SOT that can control the up and down states of the remnant magnetization in the BaFe12O19 film when the film is magnetized by an in-plane magnetic field. It can reduce or increase the switching field of the BaFe12O19 film by as much as about 500 Oe when the film is switched with an out-of-plane field.

  4. Spin–orbit torque-assisted switching in magnetic insulator thin films with perpendicular magnetic anisotropy

    DOE PAGES

    Li, Peng; Liu, Tao; Chang, Houchen; ...

    2016-09-01

    As an in-plane charge current flows in a heavy metal film with spin-orbit coupling, it produces a torque on and thereby switches the magnetization in a neighbouring ferromagnetic metal film. Such spin-orbit torque (SOT)-induced switching has been studied extensively in recent years and has shown higher efficiency than switching using conventional spin-transfer torque. Here we report the SOT-assisted switching in heavy metal/magnetic insulator systems. The experiments used a Pt/BaFe12O19 bilayer where the BaFe12O19 layer exhibits perpendicular magnetic anisotropy. As a charge current is passed through the Pt film, it produces a SOT that can control the up and down statesmore » of the remnant magnetization in the BaFe12O19 film when the film is magnetized by an in-plane magnetic field. Furthermore, it can reduce or increase the switching field of the BaFe12O19 film by as much as about 500 Oe when the film is switched with an out-of-plane field.« less

  5. Spin–orbit torque-assisted switching in magnetic insulator thin films with perpendicular magnetic anisotropy

    SciTech Connect

    Li, Peng; Liu, Tao; Chang, Houchen; Kalitsov, Alan; Zhang, Wei; Csaba, Gyorgy; Li, Wei; Richardson, Daniel; DeMann, August; Rimal, Gaurab; Dey, Himadri; Jiang, J. S.; Porod, Wolfgang; Field, Stuart B.; Tang, Jinke; Marconi, Mario C.; Hoffmann, Axel; Mryasov, Oleg; Wu, Mingzhong

    2016-09-01

    As an in-plane charge current flows in a heavy metal film with spin-orbit coupling, it produces a torque on and thereby switches the magnetization in a neighbouring ferromagnetic metal film. Such spin-orbit torque (SOT)-induced switching has been studied extensively in recent years and has shown higher efficiency than switching using conventional spin-transfer torque. Here we report the SOT-assisted switching in heavy metal/magnetic insulator systems. The experiments used a Pt/BaFe12O19 bilayer where the BaFe12O19 layer exhibits perpendicular magnetic anisotropy. As a charge current is passed through the Pt film, it produces a SOT that can control the up and down states of the remnant magnetization in the BaFe12O19 film when the film is magnetized by an in-plane magnetic field. Furthermore, it can reduce or increase the switching field of the BaFe12O19 film by as much as about 500 Oe when the film is switched with an out-of-plane field.

  6. Spin–orbit torque-assisted switching in magnetic insulator thin films with perpendicular magnetic anisotropy

    PubMed Central

    Li, Peng; Liu, Tao; Chang, Houchen; Kalitsov, Alan; Zhang, Wei; Csaba, Gyorgy; Li, Wei; Richardson, Daniel; DeMann, August; Rimal, Gaurab; Dey, Himadri; Jiang, J. S.; Porod, Wolfgang; Field, Stuart B.; Tang, Jinke; Marconi, Mario C.; Hoffmann, Axel; Mryasov, Oleg; Wu, Mingzhong

    2016-01-01

    As an in-plane charge current flows in a heavy metal film with spin–orbit coupling, it produces a torque on and thereby switches the magnetization in a neighbouring ferromagnetic metal film. Such spin–orbit torque (SOT)-induced switching has been studied extensively in recent years and has shown higher efficiency than switching using conventional spin-transfer torque. Here we report the SOT-assisted switching in heavy metal/magnetic insulator systems. The experiments used a Pt/BaFe12O19 bilayer where the BaFe12O19 layer exhibits perpendicular magnetic anisotropy. As a charge current is passed through the Pt film, it produces a SOT that can control the up and down states of the remnant magnetization in the BaFe12O19 film when the film is magnetized by an in-plane magnetic field. It can reduce or increase the switching field of the BaFe12O19 film by as much as about 500 Oe when the film is switched with an out-of-plane field. PMID:27581060

  7. Polymer-assisted iron oxide magnetic nanoparticle immobilized keratinase

    NASA Astrophysics Data System (ADS)

    Konwarh, Rocktotpal; Karak, Niranjan; Rai, Sudhir Kumar; Mukherjee, Ashis Kumar

    2009-06-01

    Nanotechnology holds the prospect for avant-garde changes to improve the performance of materials in various sectors. The domain of enzyme biotechnology is no exception. Immobilization of industrially important enzymes onto nanomaterials, with improved performance, would pave the way to myriad application-based commercialization. Keratinase produced by Bacillus subtilis was immobilized onto poly(ethylene glycol)-supported Fe3O4 superparamagnetic nanoparticles. The optimization process showed that the highest enzyme activity was noted when immobilized onto cyanamide-activated PEG-assisted MNP prepared under conditions of 25 °C and pH 7.2 of the reaction mixture before addition of H2O2 (3% w/w), 2% (w/v) PEG6000 and 0.062:1 molar ratio of PEG to FeCl2·4H2O. Further statistical optimization using response surface methodology yielded an R2 value that could explain more than 94% of the sample variations. Along with the magnetization studies, the immobilization of the enzyme onto the PEG-assisted MNP was characterized by UV, XRD, FTIR and TEM. The immobilization process had resulted in an almost fourfold increase in the enzyme activity over the free enzyme. Furthermore, the immobilized enzyme exhibited a significant thermostability, storage stability and recyclability. The leather-industry-oriented application of the immobilized enzyme was tested for the dehairing of goat-skin.

  8. Observation of molecular assisted recombination in the magnetized sheet plasma

    NASA Astrophysics Data System (ADS)

    Tonegawa, Akira; Ogawa, Hironori; Yazawa, Hiroyuki; Ono, Masataka; Kawamura, Kazutaka

    2003-10-01

    Molecular assisted recombination (MAR) with vibrational hydorogen molecular has been observed to enhance the reduction of ion particle flux in a high density magnetized sheet plasma device (TPDSHEET-IV). There are two main paths for MAR: (1) H2(v) + e=> H- + H (dissociated attachment) followed by H- + H+ =>H + H (mutual neutralization), and (2) H2(v) + A+ => (AH)+ + H (ion conversion) followed by (AH)+ + e => A + H (dissociative recombination) , where A+(A) is a hydrogen or an impurity ion (atom) existing in the plasma. The value of H+, H2+ and H3+ are observed in the mid-plane region with hot electron(Te= 10-15 eV) by a mass-analyzer. On the other hand, negative ions of hydrogen atom H- is localized in the circumference of existing cold electrons (Te= 3-5 eV) by a probe assisted laser photodetachment method. A small amount of secondary hydrogen gas puffing into a hydrogen plasma decreased gradually the density of H2+, H3+ and increased rapidly H- in the plasma, while the conventional radiation and three-body recombination (EIR) processes were disappeared. These results can be well explained by taking the MAR in the plasma into account.

  9. Microwave assisted magnetization switching in Co/Pt multilayer

    SciTech Connect

    Okamoto, S.; Kikuchi, N.; Kitakami, O.; Shimatsu, T.; Aoi, H.

    2011-04-01

    In this study, we have experimentally investigated the microwave assisted magnetization by switching (MAS) on the microstructured Co/Pt multilayer. The sample exhibits the typical magnetization curve peculiar to perpendicular anisotropy films, that is, a steep reversal initiated by nucleation of a reversed domain followed by its subsequent gradual expansion by the domain wall displacement. By applying microwaves with the frequency of GHz order, the nucleation field H{sub n} is significantly reduced at three frequencies. Taking into account the effective anisotropy field of our sample, the first dip of H{sub n} at the lowest frequency probably corresponds to the Kittel mode excitation, and the other two dips at higher frequencies correspond to unidentified excitation modes other than the Kittel mode. Among them, the last dip of H{sub n} at the highest frequency reaches about 1/3 of that without microwave application. These results suggest the existence of more effective excitation modes for MAS than the Kittel mode.

  10. Magnetically launched flyer plate technique for probing electrical conductivity of compressed copper

    NASA Astrophysics Data System (ADS)

    Cochrane, K. R.; Lemke, R. W.; Riford, Z.; Carpenter, J. H.

    2016-03-01

    The electrical conductivity of materials under extremes of temperature and pressure is of crucial importance for a wide variety of phenomena, including planetary modeling, inertial confinement fusion, and pulsed power based dynamic materials experiments. There is a dearth of experimental techniques and data for highly compressed materials, even at known states such as along the principal isentrope and Hugoniot, where many pulsed power experiments occur. We present a method for developing, calibrating, and validating material conductivity models as used in magnetohydrodynamic (MHD) simulations. The difficulty in calibrating a conductivity model is in knowing where the model should be modified. Our method isolates those regions that will have an impact. It also quantitatively prioritizes which regions will have the most beneficial impact. Finally, it tracks the quantitative improvements to the conductivity model during each incremental adjustment. In this paper, we use an experiment on Sandia National Laboratories Z-machine to isentropically launch multiple flyer plates and, with the MHD code ALEGRA and the optimization code DAKOTA, calibrated the conductivity such that we matched an experimental figure of merit to +/-1%.

  11. Magnetically launched flyer plate technique for probing electrical conductivity of compressed copper

    DOE PAGES

    Cochrane, Kyle R.; Lemke, Raymond W.; Riford, Z.; ...

    2016-03-11

    The electrical conductivity of materials under extremes of temperature and pressure is of crucial importance for a wide variety of phenomena, including planetary modeling, inertial confinement fusion, and pulsed power based dynamic materialsexperiments. There is a dearth of experimental techniques and data for highly compressed materials, even at known states such as along the principal isentrope and Hugoniot, where many pulsed power experiments occur. We present a method for developing, calibrating, and validating material conductivity models as used in magnetohydrodynamic(MHD) simulations. The difficulty in calibrating a conductivity model is in knowing where the model should be modified. Our method isolatesmore » those regions that will have an impact. It also quantitatively prioritizes which regions will have the most beneficial impact. Finally, it tracks the quantitative improvements to the conductivity model during each incremental adjustment. In this study, we use an experiment on Sandia National Laboratories Z-machine to isentropically launch multiple flyer plates and, with the MHD code ALEGRA and the optimization code DAKOTA, calibrated the conductivity such that we matched an experimental figure of merit to +/–1%.« less

  12. Magnetic Resonance Imaging Guided Vacuum Assisted and Core Needle Biopsies

    PubMed Central

    Kılıç, Fahrettin; Eren, Abdulkadir; Tunç, Necmettin; Velidedeoğlu, Mehmet; Bakan, Selim; Aydoğan, Fatih; Çelik, Varol; Gazioğlu, Ertuğrul; Yılmaz, Mehmet Halit

    2016-01-01

    Objective The purpose of this study to present the results of Magnetic resonance imaging (MRI) guided cutting needle biopsy procedures of suspicious breast lesions that can be solely detected on Magnetic resonance (MR) examination. Materials and Methods The study included 48 patients with 48 lesions which were solely be observed in breast MRI, indistinguishable in ultrasonography and mammography, for MR guided vacuum-assisted cutting needle biopsy and 42 patients with 42 lesions for MR guided cutting needle biopsy for the lesions of the same nature. MR imaging was performed using a 1.5-Tesla MRI device. Acquired MR images were determined and biopsy protocol was performed using computer-aided diagnosis system on the workstation. Vacuum biopsies were performed using 10 G or 12 G automatic biopsy systems, cutting needle biopsy procedures were performed using fully automated 12 G biopsy needle. Results All biopsy procedures were finalized successfully without major complications. The lesions were 54 mass (60%), 28 were non-mass contrast enhancement (31%) and 8 were foci (9%) in the MR examination. Histopathological evaluation revealed 18 malignant (invasive, in-situ ductal carcinoma and lobular carcinoma), 66 benign (apocrine metaplasia, fibrosis, fibroadenomatoid lesion, sclerosing adenosis, fibrocystic disease and mild-to-severe epithelial proliferation) and 6 high-risk (atypical ductal hyperplasia, intraductal papilloma, radial scar) lesions. Conclusion Magnetic resonance guided vacuum and cutting needle biopsy methods are successful methods fort he evaluation of solely MRI detected suspicious breast lesions. There are several advantages relative to each other in both methods. PMID:28331727

  13. KENNEDY SPACE CENTER, FLA. - STS-83 Payload Commander Janice E. Voss prepares to enter the Space Shuttle Columbia at Launch Pad 39A after getting assistance from the White Room closeout crew that included Bob Saulnier (right).

    NASA Image and Video Library

    1997-04-04

    KENNEDY SPACE CENTER, FLA. - STS-83 Payload Commander Janice E. Voss prepares to enter the Space Shuttle Columbia at Launch Pad 39A after getting assistance from the White Room closeout crew that included Bob Saulnier (right).

  14. Upward propagation and subsequent steepening of transverse waves launched by small-scale magnetic reconnection in the chromosphere

    NASA Astrophysics Data System (ADS)

    He, Jiansen; Marsch, Eckart; Tu, Chuanyi; Tian, Hui

    SOT observations of chromospheric spicules have revealed that Alfven-like transverse oscilla-tions on the spicules are prevalent in the chromosphere. But the propagation features, e.g., the phase speed and the propagation direction, have not been derived directly from observations. It is still not clear how these transverse waves are generated. Here we aim at identifying the propagation feature of the transverse wave, studying its ampli-tude evolution as well as its generation by magnetic reconnection underneath. The phase speed is estimated to range between 20 and 150 km/s, based on time lags between different transverse oscillation profiles at various heights along the dynamic spicule. The transverse fluctuation is found to originate at the cusp of an inverted Y-shaped emission structure, where apparently magnetic reconnection occurred. The transverse wave steepened with height probably due to density rarefaction in the stratified atmosphere, and evolved into a nonlinear state with a large relative disturbance, yielding a relative velocity-amplitude (dV/Vph) of 0.21 at 5.5 Mm. The nonlinear transverse wave seems to be damped in velocity amplitude beyond 5.5 Mm, with the transverse-fluctuation energy possibly being converted to the longitudinal-motion energy. We also estimate the energy flux density carried by the transverse wave, and find it is still sufficient, in spite of possible attenuation in the transition region, for heating the quiet corona or driving the solar wind. In another case, we find that upward propagation (launched by magnetic recon-nection) is subsequently followed by clear downward propagation, which may indicate possible wave reflection at some height in the transition region. Our findings shed new light on future modelling of coronal heating and solar wind acceleration, involving magnetic reconnection in the chromosphere. References: [1]. He, J.-S., Marsch, E., Tu, C.-Y., Tian, H., Excitation of kink waves due to small-scale magnetic

  15. Magnetic-Assisted Noncontact Triboelectric Nanogenerator Converting Mechanical Energy into Electricity and Light Emissions.

    PubMed

    Huang, Long-Biao; Bai, Gongxun; Wong, Man-Chung; Yang, Zhibin; Xu, Wei; Hao, Jianhua

    2016-04-13

    A magnetic-assisted noncontact triboelectric nanogenerator (TENG) is developed by combining a magnetic responsive layer with a TENG. The novel TENG device is applied to harvest mechanical energy which can be converted into electricity and light emissions. This work has potential for energy harvesting, magnetic sensors, self-powered electronics and optoelectronics applications.

  16. Launch Services Safety Overview

    NASA Technical Reports Server (NTRS)

    Loftin, Charles E.

    2008-01-01

    NASA/KSC Launch Services Division Safety (SA-D) services include: (1) Assessing the safety of the launch vehicle (2) Assessing the safety of NASA ELV spacecraft (S/C) / launch vehicle (LV) interfaces (3) Assessing the safety of spacecraft processing to ensure resource protection of: - KSC facilities - KSC VAFB facilities - KSC controlled property - Other NASA assets (4) NASA personnel safety (5) Interfacing with payload organizations to review spacecraft for adequate safety implementation and compliance for integrated activities (6) Assisting in the integration of safety activities between the payload, launch vehicle, and processing facilities

  17. Strain-assisted current-induced magnetization reversal in magnetic tunnel junctions: A micromagnetic study with phase-field microelasticity

    SciTech Connect

    Huang, H. B.; Hu, J. M.; Yang, T. N.; Chen, L. Q.; Ma, X. Q.

    2014-09-22

    Effect of substrate misfit strain on current-induced in-plane magnetization reversal in CoFeB-MgO based magnetic tunnel junctions is investigated by combining micromagnetic simulations with phase-field microelasticity theory. It is found that the critical current density for in-plane magnetization reversal decreases dramatically with an increasing substrate strain, since the effective elastic field can drag the magnetization to one of the four in-plane diagonal directions. A potential strain-assisted multilevel bit spin transfer magnetization switching device using substrate misfit strain is also proposed.

  18. Phase Dependence of Microwave-Assisted Switching of a Single Magnetic Nanoparticle

    NASA Astrophysics Data System (ADS)

    Piquerel, R.; Gaier, O.; Bonet, E.; Thirion, C.; Wernsdorfer, W.

    2014-03-01

    Microwave-assisted switching of the magnetization is an efficient way to reduce the magnetic field required to reverse the magnetization of nanostructures. Here, the phase sensitivity of microwave-assisted switching of an individual cobalt nanoparticle is studied using a pump-probe technique. The pump microwave pulse prepares an initial state of the magnetization, and the probe pulse tests its stability against switching. Precession states are established, which are stable against switching. Their basin of attraction is measured and is in qualitative agreement with numerical macrospin calculations. The damping parameter is evaluated using the variable delay pump-probe technique.

  19. Magnetic properties of Fe-Mn-Pt for heat assisted magnetic recording applications

    NASA Astrophysics Data System (ADS)

    Park, Jihoon; Hong, Yang-Ki; Kim, Seong-Gon; Gao, Li; Thiele, Jan-Ulrich

    2015-02-01

    We calculate the electronic structures of FePt and Fe0.5Mn0.5Pt using first-principles calculations based on density functional theory within the local-spin-density approximation. The Curie temperature (Tc) was calculated by mean field approximation. Composition dependence of the Cure temperature (Tc(x)) of Fe1-xMnxPt was used to identify a composition to meet the desired Tc in the range of 600-650 K. The identified composition (0.0294 ≤ x ≤ 0.0713) gives saturation magnetization (Ms) in the range of 1041-919 emu/cm3 and magnetocrystalline anisotropy constant (K) in the range of 9.96-8.36 × 106 J/m3 at 0 K. Temperature dependent M(T) and K(T) of Fe1-xMnxPt (0.0294 ≤ x ≤ 0.0713) were calculated using the Brillouin function and Callen-Callen experimental relation, respectively. Fe1-xMnxPt (0.0294 ≤ x ≤ 0.0713) shows 930-800 emu/cm3 of Ms and 7.18-5.61 × 106 J/m3 of K at 300 K, thereby satisfying desired magnetic properties for heat-assisted magnetic recording media to achieve 4 Tb/in.2 areal density.

  20. Alternative material study for heat assisted magnetic recording transducer application

    SciTech Connect

    Xu, B. X. Cen, Z. H.; Hu, J. F.; Tsai, J. W. H.

    2015-05-07

    In heat assisted magnetic recording (HAMR), optical near field transducer (NFT) is a key component. Au is currently used as NFT material because of its strong surface plasmon effect. Due to the soft property of Au material, reliability of Au NFT becomes a key issue for realizing HAMR production. In this paper, the possibility of alternative materials, including transition metal nitrides (TMNs) and transparent conducting oxides (TCOs) to replace Au is studied. The results show that all of the listed TMN and TCO materials can meet the mechanical requirements at room temperature in terms of hardness and thermal expansion. An optical model, which includes optical waveguide, NFT and FePt media, is used to simulate NFT performances. The results indicate that the resonant wavelengths for NFT with TCO materials are longer than 1500 nm, which is not suitable for HAMR application. TMN materials are suitable for NFT application at wavelength band of around 800 nm. But the NFT efficiency is very low. ZrN is the best material among TMN materials and the efficiency of ZrN NFT is only 13% of the Au NFT's efficiency. Reducing refractive index (n) and increasing extinction coefficient (k) will both lead to efficiency increase. Increasing k contributes more in the efficiency increase, while reducing n has a relatively low NFT absorption. For materials with the same figure of merit, the NFT with larger k material has higher efficiency. Doping materials to increase the material conduction electron density and growing film with larger size grain may be the way to increase k and reduce n.

  1. Nanopatterning reconfigurable magnetic landscapes via thermally assisted scanning probe lithography.

    PubMed

    Albisetti, E; Petti, D; Pancaldi, M; Madami, M; Tacchi, S; Curtis, J; King, W P; Papp, A; Csaba, G; Porod, W; Vavassori, P; Riedo, E; Bertacco, R

    2016-06-01

    The search for novel tools to control magnetism at the nanoscale is crucial for the development of new paradigms in optics, electronics and spintronics. So far, the fabrication of magnetic nanostructures has been achieved mainly through irreversible structural or chemical modifications. Here, we propose a new concept for creating reconfigurable magnetic nanopatterns by crafting, at the nanoscale, the magnetic anisotropy landscape of a ferromagnetic layer exchange-coupled to an antiferromagnetic layer. By performing localized field cooling with the hot tip of a scanning probe microscope, magnetic structures, with arbitrarily oriented magnetization and tunable unidirectional anisotropy, are reversibly patterned without modifying the film chemistry and topography. This opens unforeseen possibilities for the development of novel metamaterials with finely tuned magnetic properties, such as reconfigurable magneto-plasmonic and magnonic crystals. In this context, we experimentally demonstrate spatially controlled spin wave excitation and propagation in magnetic structures patterned with the proposed method.

  2. Influence of intergrain interactions and thermal agitation on microwave-assisted magnetization switching behavior of granular magnetic film

    NASA Astrophysics Data System (ADS)

    Okamoto, Satoshi; Kikuchi, Nobuaki; Kitakami, Osamu; Shimatsu, Takehito

    2017-02-01

    Microwave-assisted magnetization switching (MAS) in a granular magnetic film is examined by computer simulation. Contrary to the macrospin calculation and the experiments on single magnetic dots reported so far, in which the switching field linearly decreases with increasing rf frequency and then sharply increases at the critical frequency, the granular film exhibits considerably broad MAS behavior against the rf frequency. This broad MAS behavior is mainly caused by the dispersion of magnetic properties and thermal agitation. On the other hand, intergrain dipolar and exchange interactions enhance the MAS effect in the granular film and suppress the MAS broadening.

  3. Plasma plume dynamics in magnetically assisted pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Haverkamp, J. D.; Bourham, M. A.; Du, S.; Narayan, J.

    2009-01-01

    The expansion of a laser produced plasma perpendicular to a magnetic field is studied with a quadruple Langmuir probe and a B-dot probe. In regions where the kinetic beta is less than one, we find plume deceleration and weak displacement of the magnetic field. As the plume expands into regions of weak magnetic field, plume deceleration stops and the displacement of the magnetic field is large. The diffusion time of the magnetic field lines was consistent with anomalously large resistivity driven by the presence of an instability. Electron temperatures are larger than in the field-free case due to Ohmic heating mediated by the anomalously large resistivity.

  4. Magnetic carbon nanostructures: microwave energy-assisted pyrolysis vs. conventional pyrolysis.

    PubMed

    Zhu, Jiahua; Pallavkar, Sameer; Chen, Minjiao; Yerra, Narendranath; Luo, Zhiping; Colorado, Henry A; Lin, Hongfei; Haldolaarachchige, Neel; Khasanov, Airat; Ho, Thomas C; Young, David P; Wei, Suying; Guo, Zhanhu

    2013-01-11

    Magnetic carbon nanostructures from microwave assisted- and conventional-pyrolysis processes are compared. Unlike graphitized carbon shells from conventional heating, different carbon shell morphologies including nanotubes, nanoflakes and amorphous carbon were observed. Crystalline iron and cementite were observed in the magnetic core, different from a single cementite phase from the conventional process.

  5. Magnetic actuator intended for left ventricular assist system

    NASA Astrophysics Data System (ADS)

    Saotome, H.; Okada, T.

    2006-04-01

    With the goal of developing an artificial heart, the authors fabricated a prototype pump employing a linear motion magnetic actuator, and carried out performance tests. The actuator is composed of two disk-shaped Nd-Fe-B magnets having a diameter of 80 mm and a thickness of 7 mm. The disks are magnetized in the direction normal to the circular surface, and are formed by semicircular pieces; one semicircle serves as a N pole and the other as a S pole. The magnets face each other in the actuator. One magnet is limited to spin around its axis while the second magnet is limited to move in linear motion along its axis. In this way, the circumferential rotation of one of the magnets produces reciprocating forces on the other magnet, causing it to move back and forth. This coupled action produces a pumping motion. Because the two magnets are magnetically coupled without any mechanical contact, the rotating magnet does not have to be implanted and should be placed outside the body. The rotating magnet is driven by a motor. The motor power is magnetically conveyed, via the rotating magnet, to the implanted linear motion magnet through the skin. The proposed system yields no problems with infection that would otherwise require careful treatment in a system employing a tube penetrating the skin for power transmission. Comparison of the proposed system with another system using a transcutaneous transformer shows that our system has good potential to occupy a smaller space in the body, because it obviates implantation of a secondary part of the transformer, a power supply, and armature windings. The dimensions of the trial pump are designed in accordance with the fluid mechanical specifications of a human left ventricle, by computing magnetic fields that provide the magnetic forces on the magnets. The output power of the trial pump, 1.0 W at 87 beats/min, is experimentally obtained under the pressure and flow conditions of water, 100 mm Hg and 4.5 l/min.

  6. New vibration-assisted magnetic abrasive polishing (VAMAP) method for microstructured surface finishing.

    PubMed

    Guo, Jiang; Kum, Chun Wai; Au, Ka Hing; Tan, Zhi'En Eddie; Wu, Hu; Liu, Kui

    2016-06-13

    In order to polish microstructured surface without deteriorating its profile, we propose a new vibration-assisted magnetic abrasive polishing (VAMAP) method. In this method, magnetic force guarantees that the magnetic abrasives can well contact the microstructured surface and access the corners of microstructures while vibration produces a relative movement between microstructures and magnetic abrasives. As the vibration direction is parallel to the microstructures, the profile of the microstructures will not be deteriorated. The relation between vibration and magnetic force was analyzed and the feasibility of this method was experimentally verified. The results show that after polishing, the surface finish around microstructures was significantly improved while the profile of microstructures was well maintained.

  7. Magnetic properties of Fe-Mn-Pt for heat assisted magnetic recording applications

    SciTech Connect

    Park, Jihoon; Hong, Yang-Ki; Kim, Seong-Gon; Gao, Li; Thiele, Jan-Ulrich

    2015-02-07

    We calculate the electronic structures of FePt and Fe{sub 0.5}Mn{sub 0.5}Pt using first-principles calculations based on density functional theory within the local-spin-density approximation. The Curie temperature (T{sub c}) was calculated by mean field approximation. Composition dependence of the Cure temperature (T{sub c}(x)) of Fe{sub 1−x}Mn{sub x}Pt was used to identify a composition to meet the desired T{sub c} in the range of 600–650 K. The identified composition (0.0294 ≤ x ≤ 0.0713) gives saturation magnetization (M{sub s}) in the range of 1041–919 emu/cm{sup 3} and magnetocrystalline anisotropy constant (K) in the range of 9.96–8.36 × 10{sup 6 }J/m{sup 3} at 0 K. Temperature dependent M(T) and K(T) of Fe{sub 1−x}Mn{sub x}Pt (0.0294 ≤ x ≤ 0.0713) were calculated using the Brillouin function and Callen-Callen experimental relation, respectively. Fe{sub 1−x}Mn{sub x}Pt (0.0294 ≤ x ≤ 0.0713) shows 930–800 emu/cm{sup 3} of M{sub s} and 7.18–5.61 × 10{sup 6 }J/m{sup 3} of K at 300 K, thereby satisfying desired magnetic properties for heat-assisted magnetic recording media to achieve 4 Tb/in.{sup 2} areal density.

  8. A study: Effect of Students Peer Assisted Learning on Magnetic Field Achievement

    NASA Astrophysics Data System (ADS)

    Mueanploy, Wannapa

    2016-04-01

    This study is the case study of Physic II Course for students of Pathumwan Institute of Technology. The purpose of this study is: 1) to develop cooperative learning method of peer assisted learning (PAL), 2) to compare the learning achievement before and after studied magnetic field lesson by cooperative learning method of peer assisted learning. The population was engineering students of Pathumwan Institute of Technology (PIT’s students) who registered Physic II Course during year 2014. The sample used in this study was selected from the 72 students who passed in Physic I Course. The control groups learning magnetic fields by Traditional Method (TM) and experimental groups learning magnetic field by method of peers assisted learning. The students do pretest before the lesson and do post-test after the lesson by 20 items achievement tests of magnetic field. The post-test higher than pretest achievement significantly at 0.01 level.

  9. Time-resolved imaging of pulse-induced magnetization reversal with a microwave assist field

    PubMed Central

    Rao, Siddharth; Rhensius, Jan; Bisig, Andre; Mawass, Mohamad-Assaad; Weigand, Markus; Kläui, Mathias; Bhatia, Charanjit S.; Yang, Hyunsoo

    2015-01-01

    The reversal of the magnetization under the influence of a field pulse has been previously predicted to be an incoherent process with several competing phenomena such as domain wall relaxation, spin wave-mediated instability regions, and vortex-core mediated reversal dynamics. However, there has been no study on the direct observation of the switching process with the aid of a microwave signal input. We report a time-resolved imaging study of magnetization reversal in patterned magnetic structures under the influence of a field pulse with microwave assistance. The microwave frequency is varied to demonstrate the effect of resonant microwave-assisted switching. We observe that the switching process is dominated by spin wave dynamics generated as a result of magnetic instabilities in the structures, and identify the frequencies that are most dominant in magnetization reversal. PMID:26023723

  10. Nanomaterial-assisted PCR based on thermal generation from magnetic nanoparticles under high-frequency AC magnetic fields

    NASA Astrophysics Data System (ADS)

    Higashi, Toshiaki; Minegishi, Hiroaki; Echigo, Akinobu; Nagaoka, Yutaka; Fukuda, Takahiro; Usami, Ron; Maekawa, Toru; Hanajiri, Tatsuro

    2015-08-01

    Here the authors present a nanomaterial-assisted PCR technique based on the use of thermal generation from magnetic nanoparticles (MNPs) under AC magnetic fields. In this approach, MNPs work as internal nano thermal generators to realize PCR thermal cycling. In order to suppress the non-specific absorption of DNA synthetic enzymes, MNPs are decorated with bovine serum albumin (BSA), forming BSA/MNP complexes. Under high-frequency AC magnetic fields, these complexes work as internal nano thermal generators, thereby producing the typical temperature required for PCR thermal cycling, and perform all the reaction processes of PCR amplification in the place of conventional PCR thermal cyclers.

  11. Microbially assisted recording of the Earth's magnetic field in sediment

    PubMed Central

    Zhao, Xiangyu; Egli, Ramon; Gilder, Stuart A.; Müller, Sebastian

    2016-01-01

    Sediments continuously record variations of the Earth's magnetic field and thus provide an important archive for studying the geodynamo. The recording process occurs as magnetic grains partially align with the geomagnetic field during and after sediment deposition, generating a depositional remanent magnetization (DRM) or post-DRM (PDRM). (P)DRM acquisition mechanisms have been investigated for over 50 years, yet many aspects remain unclear. A key issue concerns the controversial role of bioturbation, that is, the mechanical disturbance of sediment by benthic organisms, during PDRM acquisition. A recent theory on bioturbation-driven PDRM appears to solve many inconsistencies between laboratory experiments and palaeomagnetic records, yet it lacks experimental proof. Here we fill this gap by documenting the important role of bioturbation-induced rotational diffusion for (P)DRM acquisition, including the control exerted on the recorded inclination and intensity, as determined by the equilibrium between aligning and perturbing torques acting on magnetic particles. PMID:26864428

  12. Microbially assisted recording of the Earth's magnetic field in sediment.

    PubMed

    Zhao, Xiangyu; Egli, Ramon; Gilder, Stuart A; Müller, Sebastian

    2016-02-11

    Sediments continuously record variations of the Earth's magnetic field and thus provide an important archive for studying the geodynamo. The recording process occurs as magnetic grains partially align with the geomagnetic field during and after sediment deposition, generating a depositional remanent magnetization (DRM) or post-DRM (PDRM). (P)DRM acquisition mechanisms have been investigated for over 50 years, yet many aspects remain unclear. A key issue concerns the controversial role of bioturbation, that is, the mechanical disturbance of sediment by benthic organisms, during PDRM acquisition. A recent theory on bioturbation-driven PDRM appears to solve many inconsistencies between laboratory experiments and palaeomagnetic records, yet it lacks experimental proof. Here we fill this gap by documenting the important role of bioturbation-induced rotational diffusion for (P)DRM acquisition, including the control exerted on the recorded inclination and intensity, as determined by the equilibrium between aligning and perturbing torques acting on magnetic particles.

  13. Electric field assisted switching in magnetic tunnel junctions

    NASA Astrophysics Data System (ADS)

    Wang, Weigang; Li, Mingen; Hagemen, Stephen; Chien, C. L.

    2012-02-01

    It is of great interest to acquire large effects of electric field on magnetic properties, partly driven by the premise that voltage-controlled magnetization reversal would be far more energy efficient and be compatible with the ubiquitous voltage-controlled semiconductor devices. Normally the effect of electric field in metallic systems is negligible because the electric field can only penetrate into the materials by a few monolayers due to screening by the free electrons. Here we report the pronounced effects of electric field in magnetic tunnel junctions (MTJs) with very thin CoFeB electrodes, where the magnetic anisotropy originates solely from the CoFeB/MgO interfaces. The MTJs have the key structure of Co40Fe40B20(1.2-1.3nm)/MgO(1.2-2nm)/Co40Fe40B20(1.6nm) and the tunneling magnetoresistance in all junctions is in excess of 100%. Due to the redistribution of electrons among the different 3d orbitals of Fe and Co, the perpendicular magnetic anisotropy of the CoFeB electrodes can be significantly modified by an applied electric field. As a result, the coercivity, the magnetic configuration, and the tunneling magnetoresistance of the MTJs can be manipulated by voltage pulses, such that the high and low resistance states of the MTJ can be reversibly controlled by voltages less than 1.5 V in magnitude and with much smaller current densities.

  14. Synthesis of magnetic nanoparticles by atmospheric-pressure glow discharge plasma-assisted electrolysis

    NASA Astrophysics Data System (ADS)

    Shirai, Naoki; Yoshida, Taketo; Uchida, Satoshi; Tochikubo, Fumiyoshi

    2017-07-01

    For the synthesis of magnetic nanoparticles (NPs), we used plasma-assisted electrolysis in which atmospheric-pressure DC glow discharge using a liquid electrode is combined with electrolysis. The solution surface is exposed to positive ions or electrons in plasma. To synthesize magnetic NPs, aqueous solutions of FeCl2 or an iron electrode immersed in liquid was used to supply iron ions in the liquid. Magnetic NPs were synthesized at the plasma-liquid interface upon the electron irradiation of the liquid surface. In the case of using aqueous solutions of FeCl2, the condition of magnetic NP synthesis depended on the gas species of plasma and the chemical agent in the liquid for controlling oxidization. The amount of magnetic NPs synthesized using plasma is not very large. On the other hand, in the case of using an iron electrode immersed in NaCl solution, magnetic NPs were synthesized without using FeCl2 solutions. When plasma-assisted electrolysis was operated, the iron electrode eluted Fe cations, resulting in the formation of magnetic NPs at the plasma-liquid interface. Magnetic NP synthesis depended on the concentration of NaCl solution and discharge current. The magnetic NPs were identified to be magnetite. By using this method, more magnetite NPs were synthesized than in the case of plasma-assisted electrolysis with FeCl2 aqueous solutions. The pH of the liquid used in plasma-assisted electrolysis was important for the synthesis of magnetite NPs.

  15. Microscopic and magnetic properties of template assisted electrodeposited iron nanowires

    NASA Astrophysics Data System (ADS)

    Irshad, M. I.; Ahmad, F.; Mohamed, N. M.; Abdullah, M. Z.; Yar, A.

    2015-07-01

    Nanowires of magnetic materials such as Iron, nickel, cobalt, and alloys of them are one of the most widely investigated structures because of their possible applications in high density magnetic recording media, sensor elements, and building blocks in biological transport systems. In this work, Iron nanowires have been prepared by electrodeposition technique using Anodized Aluminium Oxide (AAO) templates. The electrolyte used consisted of FeSO4.6H2O buffered with H3BO3 and acidized by dilute H2SO4. FESEM analysis shows that the asdeposited nanowires are parallel to one another and have high aspect ratio with a reasonably high pore-filing factor. To fabricate the working electrode, a thin film of copper (˜ 220 nm thick) was coated on back side of AAO template by e-beam evaporation system to create electrical contact with the external circuit. The TEM results show that electrodeposited nanowires have diameter around 100 nm and are polycrystalline in structure. Magnetic properties show the existence of anisotropy for in and out of plane configuration. These nanowires have potential applications in magnetic data storage, catalysis and magnetic sensor applications.

  16. Microscopic and magnetic properties of template assisted electrodeposited iron nanowires

    SciTech Connect

    Irshad, M. I. Mohamed, N. M. Yar, A.; Ahmad, F. Abdullah, M. Z.

    2015-07-22

    Nanowires of magnetic materials such as Iron, nickel, cobalt, and alloys of them are one of the most widely investigated structures because of their possible applications in high density magnetic recording media, sensor elements, and building blocks in biological transport systems. In this work, Iron nanowires have been prepared by electrodeposition technique using Anodized Aluminium Oxide (AAO) templates. The electrolyte used consisted of FeSO{sub 4.}6H{sub 2}O buffered with H{sub 3}BO{sub 3} and acidized by dilute H{sub 2}SO{sub 4}. FESEM analysis shows that the asdeposited nanowires are parallel to one another and have high aspect ratio with a reasonably high pore-filing factor. To fabricate the working electrode, a thin film of copper (∼ 220 nm thick) was coated on back side of AAO template by e-beam evaporation system to create electrical contact with the external circuit. The TEM results show that electrodeposited nanowires have diameter around 100 nm and are polycrystalline in structure. Magnetic properties show the existence of anisotropy for in and out of plane configuration. These nanowires have potential applications in magnetic data storage, catalysis and magnetic sensor applications.

  17. In vitro characterization of a magnetically suspended continuous flow ventricular assist device.

    PubMed

    Kim, H C; Bearnson, G B; Khanwilkar, P S; Olsen, D B; Maslen, E H; Allaire, P E

    1995-01-01

    A magnetically suspended continuous flow ventricular assist device using magnetic bearings was developed aiming at an implantable ventricular assist device. The main advantage of this device includes no mechanical wear and minimal chance of blood trauma such, as thrombosis and hemolysis, because there is no mechanical contact between the stationary and rotating parts. The total system consists of two subsystems: the centrifugal pump and the magnetic bearing. The centrifugal pump is comprised of a 4 vane logarithmic spiral radial flow impeller and a brushless DC motor with slotless stator, driven by the back emf commutation scheme. Two radial and one thrust magnetic bearing that dynamically controls the position of the rotor in a radial and axial direction, respectively, contains magnetic coils, the rotor's position sensors, and feedback electronic control system. The magnetic bearing system was able to successfully suspend a 365.5g rotating part in space and sustain it for up to 5000 rpm of rotation. Average force-current square factor of the magnetic bearing was measured as 0.48 and 0.44 (kg-f/Amp2) for radial and thrust bearing, respectively. The integrated system demonstrated adequate performance in mock circulation tests by providing a 6 L/min flow rate against 100 mmHg differential pressure at 2300 rpm. Based on these in vitro performance test results, long-term clinical application of the magnetically suspended continuous flow ventricular assist device is very promising after system optimization with a hybrid system using both active (electromagnet) and passive (permanent magnets) magnet bearings.

  18. Iron oxide nanoparticles for magnetically assisted patterned coatings

    NASA Astrophysics Data System (ADS)

    Dodi, Gianina; Hritcu, Doina; Draganescu, Dan; Popa, Marcel I.

    2015-08-01

    Iron oxide nanoparticles able to magnetically assemble during the curing stage of a polymeric support to create micro-scale surface protuberances in a controlled manner were prepared and characterized. The bare Fe3O4 particles were obtained by two methods: co-precipitation from an aqueous solution containing Fe3+/Fe2+ ions with a molar ratio of 2:1 and partial oxidation of ferrous ions in alkaline conditions. The products were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and magnetization measurement. They were subsequently functionalized using oleic acid, sodium oleate, or non-ionic surfactant mixtures with various hydrophilic to lipophilic balance (HLB) values. Composite nanoparticle-polymer films prepared by spraying were deposited and cured by drying on glass slides under a static magnetic field in the range of 1.5-5.5 mT. Magnetic field generated surface roughness was evidenced by optical and scanning electron microscopy. The optimum hierarchical patterning was obtained with the nanoparticles produced by partial oxidation and functionalized with hydrophobic surfactants. Possible applications may include ice-phobic composite coatings.

  19. Magnetic field concentration assisted by epsilon-near-zero media.

    PubMed

    Liberal, Iñigo; Li, Yue; Engheta, Nader

    2017-03-28

    Strengthening the magnetic response of matter at optical frequencies is of fundamental interest, as it provides additional information in spectroscopy, as well as alternative mechanisms to manipulate light at the nanoscale. Here, we demonstrate theoretically that epsilon-near-zero (ENZ) media can enhance the magnetic field concentration capabilities of dielectric resonators. We demonstrate that the magnetic field enhancement factor is unbounded in theory, and it diverges as the size of the ENZ host increases. In practice, the maximal enhancement factor is limited by dissipation losses in the host, and it is found via numerical simulations that ENZ hosts with moderate losses can enhance the performance of a circular dielectric rod resonator by around one order of magnitude. The physical mechanism behind this process is the strongly inhomogeneous magnetic field distributions induced by ENZ media in neighbouring dielectrics. We show that this is an intrinsic property of ENZ media, and that the occurrence of resonant enhancement is independent of the shape of the host. These results might find applications in spectroscopy, in sensing, in light emission and, in general, in investigating light-matter interactions beyond electric dipole transitions.This article is part of the themed issue 'New horizons for nanophotonics'. © 2017 The Author(s).

  20. Development of a prototype magnetically suspended rotor ventricular assist device.

    PubMed

    Bearnson, G B; Maslen, E H; Olsen, D B; Allaire, P E; Khanwilkar, P S; Long, J W; Kim, H C

    1996-01-01

    A continuous flow centrifugal blood pump with magnetically suspended impeller has been designed, constructed, and tested. The system can be functionally divided into three subsystem designs: 1) centrifugal pump and flow paths, 2) magnetic bearings, and 3) brushless DC motor. The centrifugal pump is a Francis vane type design with a designed operating point of 6 L/min flow and 100 mmHg pressure rise at 2,300 RPM. Peak hydraulic efficiency is over 50%. The magnetic bearing system is an all active design with five axes of control. Rotor position sensors were developed as part of the system to provide feedback to a proportional-integral-derivative controller. The motor is a sensorless brushless DC motor. Back electromotive force voltage generated by the motor is used to provide commutation for the motor. No slots are employed in the motor design in order to reduce the radial force that the bearings must generate. Tests pumping blood in vitro were very encouraging; an index of hemolysis of 0.0086 +/- 0.0012 was measured. Further design refinement is needed to reduce power dissipation and size of the device. The concept of using magnetic bearings in a blood pump shows promise in a long-term implantable blood pump.

  1. Performance of a continuous flow ventricular assist device: magnetic bearing design, construction, and testing.

    PubMed

    Allaire, P; Hilton, E; Baloh, M; Maslen, E; Bearnson, G; Noh, D; Khanwilkar, P; Olsen, D

    1998-06-01

    A new centrifugal continuous flow ventricular assist device, the CFVAD III, which is fully magnetic bearing suspended, has been developed. It has only one moving part (the impeller), has no contact (magnetic suspension), is compact, and has minimal heating. A centrifugal impeller of 2 inch outer diameter is driven by a permanent magnet brushless DC motor. This paper discusses the design, construction, testing, and performance of the magnetic bearings in the unit. The magnetic suspension consists of an inlet side magnetic bearing and an outlet side magnetic bearing, each divided into 8 pole segments to control axial and radial displacements as well as angular displacements. The magnetic actuators are composed of several different materials to minimize size and weight while having sufficient load capacity to support the forces on the impeller. Flux levels in the range of 0.1 T are employed in the magnetic bearings. Self sensing electronic circuits (without physical sensors) are employed to determine the impellar position and provide the feedback control signal needed for the magnetic bearing control loops. The sensors provide position sensitivity of approximately 0.025 mm. A decentralized 5 axis controller has been developed using modal control techniques. Proportional integral derivative controls are used for each axis to levitate the magnetically supported impeller.

  2. Ulysses Launch

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Ulysses is a joint mission between the United States National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) to explore the heliosphere over the full range of solar latitudes, especially in the polar regions. The goal of the Ulysses mission is to provide an accurate assessment of our total solar environment. This collaborative ESA/NASA mission will, for the first time, explore the heliosphere -- the region of space that is dominated by the Sun-- within a few astronomical units of the Sun over the full range of heliographic latitudes. The path followed by the spacecraft, using a Jupiter gravity-assist to achieve a trajectory extending to high solar latitudes, will enable the highly sophisticated scientific instruments on board to make measurements in the uncharted third dimension of the heliosphere. The Ulysses spacecraft will carry nine scientific instruments to measure the properties of the solar corona, the solar wind, the Sun/wind interface, the heliospheric magnetic field, solar radio bursts, plasma waves, solar X-rays, solar and galactic cosmic rays, and the interplanetary/interstellar neutral gas and dust. Scientists will take advantage of the enormous distance between the spacecraft and the Earth to perform astrophysical measurements and to search for gravitational waves. In conjunction with instrumentation on Earth-orbiting spacecraft, Ulysses will help to precisely locate the mysterious sources of cosmic gamma bursts. The results obtained will help to solve outstanding problems in solar and heliospheric physics, while undoubtedly revealing new and unanticipated phenomena.

  3. Launch Vehicles

    NASA Image and Video Library

    2007-09-09

    Under the goals of the Vision for Space Exploration, Ares I is a chief component of the cost-effective space transportation infrastructure being developed by NASA's Constellation Program. This transportation system will safely and reliably carry human explorers back to the moon, and then onward to Mars and other destinations in the solar system. Launch Pad 39B of the Kennedy Space Flight Center (KSC), currently used for Space Shuttle launches, will be revised to host the Ares launch vehicles. The fixed and rotating service structures standing at the pad will be dismantled sometime after the Ares I-X test flight. A new launch tower for Ares I will be built onto a new mobile launch platform. The gantry for the shuttle doesn't reach much higher than the top of the four segments of the solid rocket booster. Pad access above the current shuttle launch pad structure will not be required for Ares I-X because the stages above the solid rocket booster are inert. For the test scheduled in 2012 or for the crewed flights, workers and astronauts will need access to the highest levels of the rocket and capsule. When the Ares I rocket rolls out to the launch pad on the back of the same crawler-transporters used now, its launch gantry will be with it. The mobile launchers will nestle under three lightning protection towers to be erected around the pad area. Ares time at the launch pad will be significantly less than the three weeks or more the shuttle requires. This “clean pad” approach minimizes equipment and servicing at the launch pad. It is the same plan NASA used with the Saturn V rockets and industry employs it with more modern launchers. The launch pad will also get a new emergency escape system for astronauts, one that looks very much like a roller coaster. Cars riding on a rail will replace the familiar baskets hanging from steel cables. This artist's concept illustrates the Ares I on launch pad 39B.

  4. Launch vehicle

    NASA Astrophysics Data System (ADS)

    Rutledge, William S.

    1994-06-01

    Concentrated efforts by NASA and the DOD to begin development of a new large launch vehicle have been under way for over a decade. Options include the National Launch System, Advanced Launch System, a heavy lift vehicle, a Shuttle-derived vehicle, a Titan-derived vehicle, Single stage To Orbit, NASP and Spacelifter, to name a few. All initially promised low operations costs achieved at development costs in the $5 billion - $10 billion range. However, none has obtained approval for development, primarily because it became apparent that these cost goals could not realistically be met.

  5. Magnetic flux assisted thermospin transport in a Rashba ring

    NASA Astrophysics Data System (ADS)

    Feng, Liang; Benling, Gao; Yu, Gu

    2016-10-01

    The electron transport through a Rashba ring with a magnetic flux and driven by a temperature difference is investigated. It is found that the spin interference effect induced by the Rashba spin-orbit interaction and by the magnetic flux can break the balance between the spin-up and spin-down component currents in the thermally driven charge current and thus result in a spin current. The analytical derivation and numerical calculations reveal that the magnitude, sign, peaks and spin-polarization of the generated spin current can be readily modulated by the system parameters. In particular, with some choices of the parameters, the spin polarization of the generated spin current can reach 100%, that is, a fully spin-polarized thermospin current can be produced. These results may help the use of the spin-dependent Seebeck effect to generate and manipulate a spin current. Project supported by the National Natural Science Foundation of China (No.11404142).

  6. Giant thermal spin-torque-assisted magnetic tunnel junction switching.

    PubMed

    Pushp, Aakash; Phung, Timothy; Rettner, Charles; Hughes, Brian P; Yang, See-Hun; Parkin, Stuart S P

    2015-05-26

    Spin-polarized charge currents induce magnetic tunnel junction (MTJ) switching by virtue of spin-transfer torque (STT). Recently, by taking advantage of the spin-dependent thermoelectric properties of magnetic materials, novel means of generating spin currents from temperature gradients, and their associated thermal-spin torques (TSTs), have been proposed, but so far these TSTs have not been large enough to influence MTJ switching. Here we demonstrate significant TSTs in MTJs by generating large temperature gradients across ultrathin MgO tunnel barriers that considerably affect the switching fields of the MTJ. We attribute the origin of the TST to an asymmetry of the tunneling conductance across the zero-bias voltage of the MTJ. Remarkably, we estimate through magneto-Seebeck voltage measurements that the charge currents that would be generated due to the temperature gradient would give rise to STT that is a thousand times too small to account for the changes in switching fields that we observe.

  7. Plasma instabilities in magnetically assisted pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Haverkamp, J. D.; Bourham, M. A.; Du, S.; Narayan, J.

    2008-06-01

    The laser ablation of a carbon target in a transverse magnetic field is studied using a quadruple Langmuir probe. Ion saturation signals indicate the presence of wavelike behaviour not found in field-free laser ablation of carbon. Results are discussed in terms of the lower-hybrid drift instability and the electron-ion hybrid instability. The results are found to be most consistent with the electron-ion hybrid instability.

  8. Prototype continuous flow ventricular assist device supported on magnetic bearings.

    PubMed

    Allaire, P E; Kim, H C; Maslen, E H; Olsen, D B; Bearnson, G B

    1996-06-01

    This article describes a prototype continuous flow pump (CFVAD2) fully supported in magnetic bearings. The pump performance was measured in a simulated adult human circulation system. The pump delivered 6 L/min of flow at 100 mm Hg of differential pressure head operating at 2,400 rpm in water. The pump is totally supported in 4 magnetic bearings: 2 radial and 2 thrust. Magnetic bearings offer the advantages of no required lubrication and large operating clearances. The geometry and other properties of the bearings are described. Bearing parameters such as load capacity and current gains are discussed. Bearing coil currents were measured during operation in air and water. The rotor was operated in various orientations to determine the actuator current gains. These values were then used to estimate the radial and thrust forces acting on the rotor in both air and water. Much lower levels of force were found than were expected, allowing for a very significant reduction in the size of the next prototype. Hemolysis levels were measured in the prototype pump and found not to indicate damage to the blood cells.

  9. NPP Launch

    NASA Image and Video Library

    NASA's National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP) spacecraft was launched aboard a Delta II rocket at 5:48 a.m. EDT today, on a mission to measure ...

  10. Numerical analysis of thermally assisted spin-transfer torque magnetization reversal in synthetic ferrimagnetic free layers

    SciTech Connect

    Shen, J.; Shi, M.; Tanaka, T. Matsuyama, K.

    2015-05-07

    The spin transfer torque magnetization reversal of synthetic ferrimagnetic free layers under pulsed temperature rise was numerically studied by solving the Landau–Lifshitz–Gilbert equation, taking into account the stochastic random fields, the temperature dependence of magnetic parameters, and the spin torque terms. The anti-parallel magnetization configuration was retained at the elevated temperature, due to interlayer dipole coupling. A significant thermal assistance effect, resulting in a 40% reduction in the switching current, was demonstrated during a nanosecond pulsed temperature rise up to 77% of the Curie temperature.

  11. Effects of a spin-polarized current assisted Ørsted field in magnetization patterning

    SciTech Connect

    Volkov, Oleksii M. Sheka, Denis D.; Kravchuk, Volodymyr P.; Gaididei, Yuri; Mertens, Franz G.

    2015-06-07

    A spin-polarized electrical current leads to a variety of periodical magnetic structures in nanostripes. In the presence of the Ørsted field, which always assists an electrical current, the basic types of magnetic structures, i.e., a vortex-antivortex crystal and cross-tie domain walls, survive. The Ørsted field prevents saturation of the nanostripe and a longitudinal domain wall appears instead. Possible magnetization structures in stripes with different geometrical and material properties are studied numerically and analytically.

  12. Orion Launch

    NASA Image and Video Library

    2014-12-05

    A Delta IV Heavy rocket lifts off from Space Launch Complex 37 at Cape Canaveral Air Force Station in Florida carrying NASA's Orion spacecraft on an unpiloted flight test to Earth orbit. Liftoff was at 7:05 a.m. EST. During the two-orbit, four-and-a-half hour mission, engineers will evaluate the systems critical to crew safety, the launch abort system, the heat shield and the parachute system.

  13. Finite Larmor radius assisted velocity shear stabilization of the interchange instability in magnetized plasmas

    SciTech Connect

    Ng Sheungwah; Hassam, A.B.

    2005-06-15

    Finite Larmor radius (FLR) effects, originally shown to stabilize magnetized plasma interchange modes at short wavelength, are shown to assist velocity shear stabilization of long wavelength interchanges. It is shown that the FLR effects result in stabilization with roughly the same efficacy as the stabilization from dissipative (resistive and viscous) effects found earlier.

  14. Magnet Schools Assistance Program. Final Regulations. Federal Register, Department of Education, 34 CFR Part 280

    ERIC Educational Resources Information Center

    National Archives and Records Administration, 2007

    2007-01-01

    The Secretary amends the regulations governing the Magnet Schools Assistance Program (MSAP) in 34 CFR part 280. These amendments allow the MSAP to use an approach similar to that in section 75.200 for establishing selection criteria in grant competitions. Under this approach the MSAP has the flexibility to use selection criteria from its program…

  15. Electric-field assisted switching of magnetization in perpendicularly magnetized (Ga,Mn)As films at high temperatures

    NASA Astrophysics Data System (ADS)

    Wang, Hailong; Ma, Jialin; Yu, Xueze; Yu, Zhifeng; Zhao, Jianhua

    2017-01-01

    The electric-field effects on the magnetism in perpendicularly magnetized (Ga,Mn)As films at high temperatures have been investigated. An electric-field as high as 0.6 V nm-1 is applied by utilizing a solid-state dielectric Al2O3 film as a gate insulator. The coercive field, saturation magnetization and magnetic anisotropy have been clearly changed by the gate electric-field, which are detected via the anomalous Hall effect. In terms of the Curie temperature, a variation of about 3 K is observed as determined by the temperature derivative of the sheet resistance. In addition, electrical switching of the magnetization assisted by a fixed external magnetic field at 120 K is demonstrated, employing the gate-controlled coercive field. The above experimental results have been attributed to the gate voltage modulation of the hole density in (Ga,Mn)As films, since the ferromagnetism in (Ga,Mn)As is carrier-mediated. The limited modulation magnitude of magnetism is found to result from the strong charge screening effect introduced by the high hole concentration up to 1.10  ×  1021 cm-3, while the variation of the hole density is only about 1.16  ×  1020 cm-3.

  16. A strong permanent magnet-assisted electromagnetic undulator

    DOEpatents

    Halbach, K.

    1987-01-30

    This invention discloses an improved undulator comprising a plurality of electromagnet poles located along opposite sides of a particle beam axis with alternate north and south poles on each side of the beam to cause the beam to wiggle or undulate as it travels generally along the beam axis and permanent magnets spaced adjacent the electromagnetic poles on each side of the axis of said particle beam in an orientation sufficient to reduce the saturation of the electromagnet poles whereby the field strength of the electromagnet poles can be increased beyond the normal saturation levels of the electromagnetic poles. 4 figs.

  17. Magnetic bead assisted labeling of antibodies at nanogram scale.

    PubMed

    Dezfouli, Mahya; Vickovic, Sanja; Iglesias, Maria Jesus; Nilsson, Peter; Schwenk, Jochen M; Ahmadian, Afshin

    2014-01-01

    There are currently several initiatives that aim to produce binding reagents for proteome-wide analysis. To enable protein detection, visualization, and target quantification, covalent coupling of reporter molecules to antibodies is essential. However, current labeling protocols recommend considerable amount of antibodies, require antibody purity and are not designed for automation. Given that small amounts of antibodies are often sufficient for downstream analysis, we developed a labeling protocol that combines purification and modification of antibodies at submicrogram quantities. With the support of magnetic microspheres, automated labeling of antibodies in parallel using biotin or fluorescent dyes was achieved. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Giant thermal spin torque assisted magnetic tunnel junction switching

    NASA Astrophysics Data System (ADS)

    Pushp, Aakash

    Spin-polarized charge-currents induce magnetic tunnel junction (MTJ) switching by virtue of spin-transfer-torque (STT). Recently, by taking advantage of the spin-dependent thermoelectric properties of magnetic materials, novel means of generating spin-currents from temperature gradients, and their associated thermal-spin-torques (TSTs) have been proposed, but so far these TSTs have not been large enough to influence MTJ switching. Here we demonstrate significant TSTs in MTJs by generating large temperature gradients across ultrathin MgO tunnel barriers that considerably affect the switching fields of the MTJ. We attribute the origin of the TST to an asymmetry of the tunneling conductance across the zero-bias voltage of the MTJ. Remarkably, we estimate through magneto-Seebeck voltage measurements that the charge-currents that would be generated due to the temperature gradient would give rise to STT that is a thousand times too small to account for the changes in switching fields that we observe. Reference: A. Pushp*, T. Phung*, C. Rettner, B. P. Hughes, S.-H. Yang, S. S. P. Parkin, 112, 6585-6590 (2015).

  19. Magnetically assisted slip casting of bioinspired heterogeneous composites.

    PubMed

    Le Ferrand, Hortense; Bouville, Florian; Niebel, Tobias P; Studart, André R

    2015-11-01

    Natural composites are often heterogeneous to fulfil functional demands. Manufacturing analogous materials remains difficult, however, owing to the lack of adequate and easily accessible processing tools. Here, we report an additive manufacturing platform able to fabricate complex-shaped parts exhibiting bioinspired heterogeneous microstructures with locally tunable texture, composition and properties, as well as unprecedentedly high volume fractions of inorganic phase (up to 100%). The technology combines an aqueous-based slip-casting process with magnetically directed particle assembly to create programmed microstructural designs using anisotropic stiff platelets in a ceramic, metal or polymer functional matrix. Using quantitative tools to control the casting kinetics and the temporal pattern of the applied magnetic fields, we demonstrate that this approach is robust and can be exploited to design and fabricate heterogeneous composites with thus far inaccessible microstructures. Proof-of-concept examples include bulk composites with periodic patterns of microreinforcement orientation, and tooth-like bilayer parts with intricate shapes exhibiting site-specific composition and texture.

  20. Giant thermal spin-torque–assisted magnetic tunnel junction switching

    PubMed Central

    Pushp, Aakash; Phung, Timothy; Rettner, Charles; Hughes, Brian P.; Yang, See-Hun; Parkin, Stuart S. P.

    2015-01-01

    Spin-polarized charge currents induce magnetic tunnel junction (MTJ) switching by virtue of spin-transfer torque (STT). Recently, by taking advantage of the spin-dependent thermoelectric properties of magnetic materials, novel means of generating spin currents from temperature gradients, and their associated thermal-spin torques (TSTs), have been proposed, but so far these TSTs have not been large enough to influence MTJ switching. Here we demonstrate significant TSTs in MTJs by generating large temperature gradients across ultrathin MgO tunnel barriers that considerably affect the switching fields of the MTJ. We attribute the origin of the TST to an asymmetry of the tunneling conductance across the zero-bias voltage of the MTJ. Remarkably, we estimate through magneto-Seebeck voltage measurements that the charge currents that would be generated due to the temperature gradient would give rise to STT that is a thousand times too small to account for the changes in switching fields that we observe. PMID:25971730

  1. Magnetically assisted slip casting of bioinspired heterogeneous composites

    NASA Astrophysics Data System (ADS)

    Le Ferrand, Hortense; Bouville, Florian; Niebel, Tobias P.; Studart, André R.

    2015-11-01

    Natural composites are often heterogeneous to fulfil functional demands. Manufacturing analogous materials remains difficult, however, owing to the lack of adequate and easily accessible processing tools. Here, we report an additive manufacturing platform able to fabricate complex-shaped parts exhibiting bioinspired heterogeneous microstructures with locally tunable texture, composition and properties, as well as unprecedentedly high volume fractions of inorganic phase (up to 100%). The technology combines an aqueous-based slip-casting process with magnetically directed particle assembly to create programmed microstructural designs using anisotropic stiff platelets in a ceramic, metal or polymer functional matrix. Using quantitative tools to control the casting kinetics and the temporal pattern of the applied magnetic fields, we demonstrate that this approach is robust and can be exploited to design and fabricate heterogeneous composites with thus far inaccessible microstructures. Proof-of-concept examples include bulk composites with periodic patterns of microreinforcement orientation, and tooth-like bilayer parts with intricate shapes exhibiting site-specific composition and texture.

  2. STS-124 Space Shuttle Discovery Launch

    NASA Image and Video Library

    2008-05-30

    NASA Shuttle Launch Director Michael Leinbach, left, STS-124 Assistant Launch Director Ed Mango, center, and Flow Director for Space Shuttle Discovery Stephanie Stilson clap in the the Launch Control Center after the main engine cut off and successful launch of the Space Shuttle Discovery (STS-124) Saturday, May 31, 2008, at the Kennedy Space Center in Cape Canaveral, Fla. The Shuttle lifted off from launch pad 39A at 5:02 p.m. EDT. Photo Credit: (NASA/Bill Ingalls)

  3. Strain-assisted magnetization reversal in Co/Ni multilayers with perpendicular magnetic anisotropy.

    PubMed

    Gopman, D B; Dennis, C L; Chen, P J; Iunin, Y L; Finkel, P; Staruch, M; Shull, R D

    2016-06-14

    Multifunctional materials composed of ultrathin magnetic films with perpendicular magnetic anisotropy combined with ferroelectric substrates represent a new approach toward low power, fast, high density spintronics. Here we demonstrate Co/Ni multilayered films with tunable saturation magnetization and perpendicular anisotropy grown directly on ferroelectric PZT [Pb(Zr0.52Ti0.48)O3] substrate plates. Electric fields up to ±2 MV/m expand the PZT by 0.1% and generate at least 0.02% in-plane compression in the Co/Ni multilayered film. Modifying the strain with a voltage can reduce the coercive field by over 30%. We also demonstrate that alternating in-plane tensile and compressive strains (less than 0.01%) can be used to propagate magnetic domain walls. This ability to manipulate high anisotropy magnetic thin films could prove useful for lowering the switching energy for magnetic elements in future voltage-controlled spintronic devices.

  4. Strain-assisted magnetization reversal in Co/Ni multilayers with perpendicular magnetic anisotropy

    NASA Astrophysics Data System (ADS)

    Gopman, D. B.; Dennis, C. L.; Chen, P. J.; Iunin, Y. L.; Finkel, P.; Staruch, M.; Shull, R. D.

    2016-06-01

    Multifunctional materials composed of ultrathin magnetic films with perpendicular magnetic anisotropy combined with ferroelectric substrates represent a new approach toward low power, fast, high density spintronics. Here we demonstrate Co/Ni multilayered films with tunable saturation magnetization and perpendicular anisotropy grown directly on ferroelectric PZT [Pb(Zr0.52Ti0.48)O3] substrate plates. Electric fields up to ±2 MV/m expand the PZT by 0.1% and generate at least 0.02% in-plane compression in the Co/Ni multilayered film. Modifying the strain with a voltage can reduce the coercive field by over 30%. We also demonstrate that alternating in-plane tensile and compressive strains (less than 0.01%) can be used to propagate magnetic domain walls. This ability to manipulate high anisotropy magnetic thin films could prove useful for lowering the switching energy for magnetic elements in future voltage-controlled spintronic devices.

  5. Strain-assisted magnetization reversal in Co/Ni multilayers with perpendicular magnetic anisotropy

    PubMed Central

    Gopman, D. B.; Dennis, C. L.; Chen, P. J.; Iunin, Y. L.; Finkel, P.; Staruch, M.; Shull, R. D.

    2016-01-01

    Multifunctional materials composed of ultrathin magnetic films with perpendicular magnetic anisotropy combined with ferroelectric substrates represent a new approach toward low power, fast, high density spintronics. Here we demonstrate Co/Ni multilayered films with tunable saturation magnetization and perpendicular anisotropy grown directly on ferroelectric PZT [Pb(Zr0.52Ti0.48)O3] substrate plates. Electric fields up to ±2 MV/m expand the PZT by 0.1% and generate at least 0.02% in-plane compression in the Co/Ni multilayered film. Modifying the strain with a voltage can reduce the coercive field by over 30%. We also demonstrate that alternating in-plane tensile and compressive strains (less than 0.01%) can be used to propagate magnetic domain walls. This ability to manipulate high anisotropy magnetic thin films could prove useful for lowering the switching energy for magnetic elements in future voltage-controlled spintronic devices. PMID:27297638

  6. Novel microwave assisted chemical synthesis of Nd₂Fe₁₄B hard magnetic nanoparticles.

    PubMed

    Swaminathan, Viswanathan; Deheri, Pratap Kumar; Bhame, Shekhar Dnyaneswar; Ramanujan, Raju Vijayaraghavan

    2013-04-07

    The high coercivity and excellent energy product of Nd2Fe14B hard magnets have led to a large number of high value added industrial applications. Chemical synthesis of Nd2Fe14B nanoparticles is challenging due to the large reduction potential of Nd(3+) and the high tendency for Nd2Fe14B oxidation. We report the novel synthesis of Nd2Fe14B nanoparticles by a microwave assisted combustion process. The process consisted of Nd-Fe-B mixed oxide preparation by microwave assisted combustion, followed by the reduction of the mixed oxide by CaH2. This combustion process is fast, energy efficient and offers facile elemental substitution. The coercivity of the resulting powders was ∼8.0 kOe and the saturation magnetization was ∼40 emu g(-1). After removal of CaO by washing, saturation magnetization increased and an energy product of 3.57 MGOe was obtained. A range of magnetic properties was obtained by varying the microwave power, reduction temperature and Nd to Fe ratio. A transition from soft to exchange coupled to hard magnetic properties was obtained by varying the composition of NdxFe1-xB8 (x varies from 7% to 40%). This synthesis procedure offers an inexpensive and facile platform to produce exchange coupled hard magnets.

  7. Bit patterned media with composite structure for microwave assisted magnetic recording

    NASA Astrophysics Data System (ADS)

    Eibagi, Nasim

    Patterned magnetic nano-structures are under extensive research due to their interesting emergent physics and promising applications in high-density magnetic data storage, through magnetic logic to bio-magnetic functionality. Bit-patterned media is an example of such structures which is a leading candidate to reach magnetic densities which cannot be achieved by conventional magnetic media. Patterned arrays of complex heterostructures such as exchange-coupled composites are studied in this thesis as a potential for next generation of magnetic recording media. Exchange-coupled composites have shown new functionality and performance advantages in magnetic recording and bit patterned media provide unique capability to implement such architectures. Due to unique resonant properties of such structures, their possible application in spin transfer torque memory and microwave assisted switching is also studied. This dissertation is divided into seven chapters. The first chapter covers the history of magnetic recording, the need to increase magnetic storage density, and the challenges in the field. The second chapter introduces basic concepts of magnetism. The third chapter explains the fabrication methods for thin films and various lithographic techniques that were used to pattern the devices under study for this thesis. The fourth chapter introduces the exchanged coupled system with the structure of [Co/Pd] / Fe / [Co/Pd], where the thickness of Fe is varied, and presents the magnetic properties of such structures using conventional magnetometers. The fifth chapter goes beyond what is learned in the fourth chapter and utilizes polarized neutron reflectometry to study the vertical exchange coupling and reversal mechanism in patterned structures with such structure. The sixth chapter explores the dynamic properties of the patterned samples, and their reversal mechanism under microwave field. The final chapter summarizes the results and describes the prospects for future

  8. ARES I-X Launch

    NASA Image and Video Library

    2009-10-27

    NASA Ares I-X Launch Director Ed Mango, left, laughs as NASA Ares I-X Assistant Launch Director Pete Nickolenko looks out the window of Firing Room One of the Launch Control Center (LCC) at the Kennedy Space Center prior to the launch of the Ares I-X rocket from pad 39b at the Kennedy Space Center in Cape Canaveral, Fla., Wednesday, Oct. 28, 2009. The flight test of Ares I-X will provide NASA with an early opportunity to test and prove flight characteristics, hardware, facilities and ground operations associated with the Ares I. Photo Credit: (NASA/Bill Ingalls)

  9. Launch Vehicles

    NASA Image and Video Library

    1961-01-01

    This is a comparison illustration of the Redstone, Jupiter-C, and Mercury Redstone launch vehicles. The Redstone ballistic missile was a high-accuracy, liquid-propelled, surface-to-surface missile. Originally developed as a nose cone re-entry test vehicle for the Jupiter intermediate range ballistic missile, the Jupiter-C was a modification of the Redstone missile and successfully launched the first American Satellite, Explorer-1, in orbit on January 31, 1958. The Mercury Redstone lifted off carrying the first American, astronaut Alan Shepard, in his Mercury spacecraft Freedom 7, on May 5, 1961.

  10. Reducing, Eliminating, and Preventing Minority Isolation in American Schools: The Impact of the Magnet Schools Assistance Program.

    ERIC Educational Resources Information Center

    Steele, Lauri; Eaton, Marian

    The Magnet Schools Assistance Program (MSAP) was begun in 1984 to provide Federal support for magnet schools that are part of an approved voluntary or court-ordered desegregation plan. This report examines the impact of federally supported magnet schools on school desegregation, focusing specifically on schools supported through the MSAP in fiscal…

  11. STS-133 launch

    NASA Image and Video Library

    2011-02-24

    STS133-S-067 (24 Feb. 2011) --- In Firing Room 4 of the Launch Control Center at NASA's Kennedy Space Center in Florida, NASA's Discovery Flow Director Stephanie Stilson, left, STS-133 Assistant Shuttle Launch Director and lead NASA Test Director Charlie Blackwell-Thompson and Shuttle Launch Director Mike Leinbach watch space shuttle Discovery head toward Earth orbit on the STS-133 mission to the International Space Station. Discovery and its six-member crew are on a mission to deliver the Permanent Multipurpose Module, packed with supplies and critical spare parts, as well as Robonaut 2, the dexterous humanoid astronaut helper, to the orbiting outpost. Discovery is making its 39th mission and is scheduled to be retired following STS-133. This is the 133rd Space Shuttle Program mission and the 35th shuttle voyage to the space station. Photo credit: NASA or National Aeronautics and Space Administration

  12. Launch of Vanguard

    NASA Technical Reports Server (NTRS)

    1955-01-01

    Launch of a three-stage Vanguard (SLV-7) from Cape Canaveral, Florida, September 18, 1959. Designated Vanguard III, the 100-pound satellite was used to study the magnetic field and radiation belt. In September 1955, the Department of Defense recommended and authorized the new program, known as Project Vanguard, to launch Vanguard booster to carry an upper atmosphere research satellite in orbit. The Vanguard vehicles were used in conjunction with later booster vehicle such as the Thor and Atlas, and the technique of gimbaled (movable) engines for directional control was adapted to other rockets.

  13. In vivo experiment leading to clinical application of an electrohydraulic ventricular assist device with magnetic coupling.

    PubMed

    Kim, W G; Choi, J S; Won, Y S; Jo, Y H; Park, S K; Chung, C I; Kim, J; Min, B G; Ahn, H; Rho, J R

    1999-01-01

    We developed an electrohydraulic ventricular assist device with magnetic coupling. The integrated system consists of a blood pump, a water conduit for pressure transmission, a bellows type pumping sac, an actuator for transforming the circular motion of a motor to the linear motion of a pusher plate attached to the pumping sac with magnetic coupling, and a controller. The purpose of the coupling was to prevent excessive sucking against the atrial wall. Number 21 Medtronic Hall (Irvine, CA) mechanical valves were used in the inflow and outflow ports of the blood pump. Maximum dynamic stroke volume was 48 ml, and against a mean afterload of 100 mm Hg, maximum pump output was 7 L/min. Chronic in vivo experiments were performed in three sheep, and during these evaluations the system showed no noticeable problems related to mechanical or electronic devices. When left atrial pressure decreased below 0 mm Hg, the magnetic coupling system decoupled the pumping sac and pusher plate with satisfactory reliability. The device was clinically applied in a postoperative patient with chronic dilating cardiomyopathy, and no significant device related problems ensued. These results prove that the electrohydraulic ventricular assist system with magnetic coupling is a suitable ventricular assist device.

  14. Haemolytic index and performance of a magnetically coupled rotary pulsatile pump with potential for ventricular assist.

    PubMed

    Ostberg, B; Southwell, J

    2000-09-01

    A novel magnetically coupled rotary vane pump is described which has the potential to be used as a ventricular assist device. The pump has an excellent haemodynamic performance. When tested, pumping blood, against a range of pressures from 20 to 100 mm Hg the volumetric output varied within reasonable limits. The pump could deliver 5.1 litres per minute against a pressure of 180 mm Hg before the magnetic coupling disengaged. With specially moulded magnets improved coupling can be achieved. The haemolytic index was determined using a circuit conforming to ASTM: F04-40-101. The NIH (normalised index of haemolysis) was found to be 0.3 and the MIH (modified index of haemolysis) 0.26 which is unacceptably high for long term perfusion. The pump has several outstanding features, it is hermetically sealed, it needs no valving, a desirable property in a ventricular assist pump, and it has a pulsatile action. In a non magnetically coupled form it performed satisfactorily in left ventricular assist mode and as a total cardiopulmonary bypass pump in short term experiments with dogs.

  15. Magnetic-Nanoflocculant-Assisted Water-Nonpolar Solvent Interface Sieve for Microalgae Harvesting.

    PubMed

    Lee, Kyubock; Na, Jeong-Geol; Seo, Jung Yoon; Shim, Tae Soup; Kim, Bohwa; Praveenkumar, Ramasamy; Park, Ji-Yeon; Oh, You-Kwan; Jeon, Sang Goo

    2015-08-26

    Exploitation of magnetic flocculants is regarded as a very promising energy-saving approach to microalgae harvesting. However, its practical applicability remains limited, mainly because of the problem of the postharvest separation of magnetic flocculants from microalgal flocs, which is crucial both for magnetic-flocculant recycling and high-purity microalgal biomasses, but which is also a very challenging and energy-consuming step. In the present study, we designed magnetic nanoflocculants dually functionalizable by two different organosilane compounds, (3-aminopropyl)triethoxysilane (APTES) and octyltriethoxysilane (OTES), which flocculate negatively charged microalgae and are readily detachable at the water-nonpolar organic solvent (NOS) interface only by application of an external magnetic field. APTES functionalization imparts a positive zeta potential charge (29.6 mV) to magnetic nanoflocculants, thereby enabling microalgae flocculation with 98.5% harvesting efficiency (with a dosage of 1.6 g of dMNF/g of cells). OTES functionalization imparts lipophilicity to magnetic nanoflocculants to make them compatible with NOS, thus effecting efficient separation of magnetic flocculants passing through the water-NOS interface sieve from hydrophilic microalgae. Our new energy-saving approach to microalgae harvesting concentrates microalgal cultures (∼1.5 g/L) up to 60 g/L, which can be directly connected to the following process of NOS-assisted wet lipid extraction or biodiesel production, and therefore provides, by simplifying multiple downstream processes, a great potential cost reduction in microalgae-based biorefinement.

  16. Biodegradable nanocomposite magnetite stent for implant-assisted magnetic drug targeting

    NASA Astrophysics Data System (ADS)

    Mangual, Jan O.; Li, Shigeng; Ploehn, Harry J.; Ebner, Armin D.; Ritter, James A.

    2010-10-01

    This study shows, for the first time, the fabrication of a biodegradable polymer nanocomposite magnetic stent and the feasibility of its use in implant-assisted-magnetic drug targeting (IA-MDT). The nanocomposite magnetic stent was made from PLGA, a biodegradable copolymer, and iron oxide nanopowder via melt mixing and extrusion into fibers. Degradation and dynamic mechanical thermal analyses showed that the addition of the iron oxide nanopowder increased the polymer's glass transition temperature ( Tg) and its modulus but had no notable effect on its degradation rate in PBS buffer solution. IA-MDT in vitro experiments were carried out with the nanocomposite magnetic fiber molded into a stent coil. These stent prototypes were used in the presence of a homogeneous magnetic field of 0.3 T to capture 100 nm magnetic drug carrier particles (MDCPs) from an aqueous solution. Increasing the amount of magnetite in the stent nanocomposite (0, 10 and 40 w/w%) resulted in an increase in the MDCP capture efficiency (CE). Reducing the MDCP concentrations (0.75 and 1.5 mg/mL) in the flowing fluid and increasing the fluid velocities (20 and 40 mL/min) both resulted in decrease in the MDCP CE. These results show that the particle capture performance of PLGA-based, magnetic nanocomposite stents are similar to those exhibited by a variety of different non-polymeric magnetic stent materials studied previously.

  17. Calibration and measurement of the thermal reflection coefficient of heat assisted magnetic recording media

    NASA Astrophysics Data System (ADS)

    Yang, H. Z.; Chen, Y. J.; Leong, S. H.; An, C. W.; Ye, K. D.; Hu, J. F.

    2015-08-01

    With increased interest in heat assisted magnetic recording (HAMR), the thermal reflection coefficient of HAMR media becomes more important, as it is related to the change of optical parameters of the media at different temperatures and can potentially be used for non-contact temperature measurement. In this report, we introduce a method to calibrate the thermal reflection coefficient of magnetic thin films by in situ measurement of the thermal reflectance as well as the magneto-optic Kerr effect (MOKE) signal from the media. In the measurement, we use one beam to locally heat up the media, while using a second beam, whose diameter and intensity is much smaller, to measure in situ the MOKE and thermal reflectance signal of the heated media. We characterize the media temperature by heating up the magnetic media with prewritten magnetic patterns in an ultra-high vacuum system and the resulting magnetic remanence in the prewritten area is measured by magnetic force microscopy. Thus the thermal reflection coefficient is measured by performing a pump-probe experiment, with the temperature calibrated at the zero thermoremanence temperature of the HAMR media, at which temperature all grains under test have reached Curie temperature. This method can be extended to comparative studies of the thermo-optical properties of magnetic thin films, whose magnetic properties are sensitive to temperature.

  18. A study on dynamic heat assisted magnetization reversal mechanisms under insufficient reversal field conditions

    NASA Astrophysics Data System (ADS)

    Chen, Y. J.; Yang, H. Z.; Leong, S. H.; Wu, B. L.; Asbahi, M.; Yu Ko, Hnin Yu; Yang, J. K. W.; Ng, V.

    2014-10-01

    We report an experimental study on the dynamic thermomagnetic (TM) reversal mechanisms at around Curie temperature (Tc) for isolated 60 nm pitch single-domain [Co/Pd] islands heated by a 1.5 μm spot size laser pulse under an applied magnetic reversal field (Hr). Magnetic force microscopy (MFM) observations with high resolution MFM tips clearly showed randomly trapped non-switched islands within the laser irradiated spot after dynamic TM reversal process with insufficient Hr strength. This observation provides direct experimental evidence by MFM of a large magnetization switching variation due to increased thermal fluctuation/agitation over magnetization energy at the elevated temperature of around Tc. The average percentage of non-switched islands/magnetization was further found to be inversely proportional to the applied reversal field Hr for incomplete magnetization reversal when Hr is less than 13% of the island coercivity (Hc), showing an increased switching field distribution (SFD) at elevated temperature of around Tc (where main contributions to SFD broadening are from Tc distribution and stronger thermal fluctuations). Our experimental study and results provide better understanding and insight on practical heat assisted magnetic recording (HAMR) process and recording performance, including HAMR writing magnetization dynamics induced SFD as well as associated DC saturation noise that limits areal density, as were previously observed and investigated by theoretical simulations.

  19. A study on dynamic heat assisted magnetization reversal mechanisms under insufficient reversal field conditions

    SciTech Connect

    Chen, Y. J.; Yang, H. Z.; Leong, S. H.; Yu Ko, Hnin Yu; Wu, B. L.; Ng, V.; Asbahi, M.; Yang, J. K. W.

    2014-10-20

    We report an experimental study on the dynamic thermomagnetic (TM) reversal mechanisms at around Curie temperature (Tc) for isolated 60 nm pitch single-domain [Co/Pd] islands heated by a 1.5 μm spot size laser pulse under an applied magnetic reversal field (Hr). Magnetic force microscopy (MFM) observations with high resolution MFM tips clearly showed randomly trapped non-switched islands within the laser irradiated spot after dynamic TM reversal process with insufficient Hr strength. This observation provides direct experimental evidence by MFM of a large magnetization switching variation due to increased thermal fluctuation/agitation over magnetization energy at the elevated temperature of around Tc. The average percentage of non-switched islands/magnetization was further found to be inversely proportional to the applied reversal field Hr for incomplete magnetization reversal when Hr is less than 13% of the island coercivity (Hc), showing an increased switching field distribution (SFD) at elevated temperature of around Tc (where main contributions to SFD broadening are from Tc distribution and stronger thermal fluctuations). Our experimental study and results provide better understanding and insight on practical heat assisted magnetic recording (HAMR) process and recording performance, including HAMR writing magnetization dynamics induced SFD as well as associated DC saturation noise that limits areal density, as were previously observed and investigated by theoretical simulations.

  20. A machine vision assisted system for fluorescent magnetic particle inspection of railway wheelsets

    NASA Astrophysics Data System (ADS)

    Ma, Tao; Sun, Zhenguo; Zhang, Wenzeng; Chen, Qiang

    2016-02-01

    Fluorescent magnetic particle inspection is a conventional non-destructive evaluation process for detecting surface and slightly subsurface cracks of the wheelsets. Using machine vision instead of workers' direct observation could remarkably improve the working condition and repeatability of the inspection. This paper presents a machine vision assisted automatic fluorescent magnetic particle inspection system for surface defect inspection of railway wheelsets. The system setup of it is composed of a semiautomatic fluorescent magnetic particle inspection machine, a vision system and an industrial computer. The detection of magnetic particle indications of quantitative quality indicators and cracks is studied: the detection of quantitative quality indicators is achieved by mathematical morphology, Otsu's thresholding and a RANSAC based ellipse fitting algorithm; the crack detection algorithm is a multiscale algorithm using Gaussian blur, mathematical morphology and several shape and color descriptors. Tests show that the algorithms are able to detect the indications of the quantitative quality indicators and the cracks precisely.

  1. Animal trials of a Magnetically Levitated Left-Ventricular Assist Device

    NASA Technical Reports Server (NTRS)

    Paden, Brad; Antaki, James; Groom, Nelson

    2000-01-01

    The University of Pittsburgh/Magnetic Moments mag-lev left-ventricular assist devices (LVADs), the Streamliner HG3b and HG3c, have successfully been implanted in calves. The first was implanted for 4 hours on July 10, 1998 and the second for 34 days on August 24, 1999 respectively. The tests confirmed the feasibility of low power levitation (1.5 watts coil power) and very low blood damage in a mag-lev ventricular assist device. In this paper, we describe the unique geometry of this pump and its design. Key features of this LVAD concept are the passive radial suspension and active voice-coil thrust bearing.

  2. Launching "Dunno"

    ERIC Educational Resources Information Center

    Inson, Peter

    2005-01-01

    This article, written in response to an invitation from "CLE," describes the origins and controversial content of "dunno," a first novel, self-published by Peter Inson, a former teacher and headmaster. Inson considers influences upon his writing, the thinking which led him towards self-publication and the process of personally launching and…

  3. Ion beam assisted deposition of MgO barriers for magnetic tunnel junctions

    SciTech Connect

    Cardoso, S.; Macedo, R. J.; Ferreira, R.; Augusto, A.; Wisniowski, P.; Freitas, P. P.

    2008-04-01

    This work reports for the first time results on MgO tunnel junctions prepared by ion beam. The MgO barrier was deposited from a ceramic MgO target using an assisted beam, following the deposition and assisted beam phase diagram which relate the beam profile with the current and energy. The deposition rate for MgO is calculated with and without assisted beam, and compared with the experimental values. The MgO film growth on Ta/CoFeB/MgO simple stacks was optimized aiming at a (002) preferred orientation for the MgO growth, measured by x-ray diffraction. The optimum assist beam energy was tuned for each deposition beam condition (+800,+1000,+1200 V), using assist beams of 40 mA ({approx}130 {mu}A/cm{sup 2}) with 0 to +600 V. Without assist beam, no texture is observed for the MgO, while the (002) orientation appears for assisted deposition. The optimum range of assist voltages is large, being limited by the onset of etching at high voltages, reducing the deposition rate. Magnetic tunnel junctions were deposited with the structure Ta 50 A/Ru 200 A/Ta 50 A/Mn{sub 78}Ir{sub 22} 150 A/Co{sub 90}Fe{sub 10} 30 A/Ru 8 A/Co{sub 56}Fe{sub 24}B{sub 20} 40 A/MgO t/Co{sub 56}Fe{sub 24}B{sub 20} 30 A/Ru 30 A/Ta 50 A, with the MgO barrier deposited with the conditions optimized by x rays. The effect of the assist beam energy on the junction properties (magnetoresistance and magnetization) are discussed. Tunnel magnetoresistance values up to 110%, with RA products of 100-400 {omega} {mu}m{sup 2}, for 11 A thick MgO barriers are obtained using assisted deposition with a +100 V assist beam, which is a major improvement of the {approx}30% of TMR, if no beam is used.

  4. Review and evaluation of extractants for strontium removal using magnetically assisted chemical separation

    SciTech Connect

    Bauer, C.B.; Rogers, R.D.; Nunez, L.; Ziemer, M.D.; Pleune, T.T.; Vandegrift, G.F.

    1995-11-01

    A literature review on extractants for strontium removal was initially performed at Northern Illinois University to assess their potential in magnetically assisted chemical separation. A series of potential strontium extractants was systematically evaluated there using radioanalytical methods. Initial experiments were designed to test the uptake of strontium from nitric acid using several samples of magnetic extractant particles that were coated with various crown ether ligands. High partition coefficient (K{sub d}) values for stimulant tank waste were obtained. Further studies demonstrated that the large partitioning was due to uncoated particles.

  5. Single axis controlled hybrid magnetic bearing for left ventricular assist device: hybrid core and closed magnetic circuit.

    PubMed

    da Silva, Isaias; Horikawa, Oswaldo; Cardoso, Jose R; Camargo, Fernando A; Andrade, Aron J P; Bock, Eduardo G P

    2011-05-01

    In previous studies, we presented main strategies for suspending the rotor of a mixed-flow type (centrifugal and axial) ventricular assist device (VAD), originally presented by the Institute Dante Pazzanese of Cardiology (IDPC), Brazil. Magnetic suspension is achieved by the use of a magnetic bearing architecture in which the active control is executed in only one degree of freedom, in the axial direction of the rotor. Remaining degrees of freedom, excepting the rotation, are restricted only by the attraction force between pairs of permanent magnets. This study is part of a joint project in development by IDPC and Escola Politecnica of São Paulo University, Brazil. This article shows advances in that project, presenting two promising solutions for magnetic bearings. One solution uses hybrid cores as electromagnetic actuators, that is, cores that combine iron and permanent magnets. The other solution uses actuators, also of hybrid type, but with the magnetic circuit closed by an iron core. After preliminary analysis, a pump prototype has been developed for each solution and has been tested. For each prototype, a brushless DC motor has been developed as the rotor driver. Each solution was evaluated by in vitro experiments and guidelines are extracted for future improvements. Tests have shown good results and demonstrated that one solution is not isolated from the other. One complements the other for the development of a single-axis-controlled, hybrid-type magnetic bearing for a mixed-flow type VAD. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  6. Processing of magnetically anisotropic MnBi particles by surfactant assisted ball milling

    NASA Astrophysics Data System (ADS)

    Kanari, K.; Sarafidis, C.; Gjoka, M.; Niarchos, D.; Kalogirou, O.

    2017-03-01

    MnBi particles are obtained from bulk MnBi using mechanochemical processing. The structure and magnetic properties of the MnBi particles are investigated by means of X-ray diffraction analysis, scanning electron microscopy and magnetometry. Surfactant assisted high energy ball milling results to the samples' degradation even after one hour of milling. In the case of surfactant assisted low energy ball milling the increase of ball milling duration decreases the average particle size while the particles seem to be more separated. The saturation magnetization (Ms) was found to decrease for large milling times beginning from 61 Am2/kg, while the coercivity (μ0Hc) increases with the increase of ball milling duration up to 35 min where it reaches 1.62 T and thereafter it decreases.

  7. Strong magnetic field-assisted growth of carbon nanofibers and its microstructural transformation mechanism

    PubMed Central

    Luo, Chengzhi; Fu, Qiang; Pan, Chunxu

    2015-01-01

    It is well-known that electric and magnetic fields can control the growth direction, morphology and microstructure of one-dimensional carbon nanomaterials (1-DCNMs), which plays a key role for its potential applications in micro-nano-electrics and devices. In this paper, we introduce a novel process for controlling growth of carbon nanofibers (CNFs) with assistance of a strong magnetic field (up to 0.5 T in the center) in a chemical vapor deposition (CVD) system. The results reveal that: 1) The CNFs get bundled when grown in the presence of a strong magnetic field and slightly get aligned parallel to the direction of the magnetic field; 2) The CNFs diameter become narrowed and homogenized with increase of the magnetic field; 3) With the increase of the magnetic field, the microstructure of CNFs is gradually changed, i.e., the strong magnetic field makes the disordered “solid-cored” CNFs transform into a kind of bamboo-liked carbon nanotubes; 4) We propose a mechanism that the reason for these variations and transformation is due to diamagnetic property of carbon atoms, so that it has direction selectivity in the precipitation process. PMID:25761381

  8. Structural and magnetic studies of thin Fe57 films formed by ion beam assisted deposition

    NASA Astrophysics Data System (ADS)

    Lyadov, N. M.; Bazarov, V. V.; Vagizov, F. G.; Vakhitov, I. R.; Dulov, E. N.; Kashapov, R. N.; Noskov, A. I.; Khaibullin, R. I.; Shustov, V. A.; Faizrakhmanov, I. A.

    2016-08-01

    Thin Fe57 films with the thickness of 120 nm have been prepared on glass substrates by using the ion-beam-assisted deposition technique. X-ray diffraction, electron microdiffraction and Mössbauer spectroscopy studies have shown that as-deposited films are in a stressful nanostructured state containing the nanoscaled inclusions of α-phase iron with the size of ∼10 nm. Room temperature in-plane and out-of-plane magnetization measurements confirmed the presence of the magnetic α-phase in the iron film and indicated the strong effect of residual stresses on magnetic properties of the film as well. Subsequent thermal annealing of iron films in vacuum at the temperature of 450 °C stimulates the growth of α-phase Fe crystallites with the size of up to 20 nm. However, electron microdiffraction and Mössbauer spectroscopic data have shown the partial oxidation and carbonization of the iron film during annealing. The stress disappeared after annealing of the film. The magnetic behaviour of the annealed samples was characterized by the magnetic hysteresis loop with the coercive field of ∼10 mT and the saturation magnetization decreased slightly in comparison with the α-phase Fe magnetization due to small oxidation of the film.

  9. Magnetic-field-assisted synthesis of Co3O4 nanoneedles with superior electrochemical capacitance

    NASA Astrophysics Data System (ADS)

    Zhu, Tao; Xie, Yan; Zhang, Guoxiong; He, Zhenni; Lu, Yisheng; Guo, Haibo; Lin, Chuan; Chen, Yigang

    2015-12-01

    Nanostructured Co3O4 films have been deposited on nickel foam in a magnetic-field-assisted hydrothermal process followed by annealing in air. The magnetic field strength is varied to study its relationship with nanostructures, morphology, and electrochemical properties of the Co3O4 electrodes. The Co3O4 films synthesized in the weak magnetic fields consist of dispersed nanoneedles, which are different from clustered nanoneedles when the magnetic field is absent. Moreover, the magnetic fields (of several millitesla) induced substantial changes in the nanostructures and electrochemical properties of the Co3O4 films. A possible formation mechanism of Co3O4 nanoneedles is proposed by comparing the morphologies and nanostructures of the films synthesized with and without the magnetic fields. Among these electrodes, the optimal one has a high specific capacitance (970.8 F g-1 at 0.5 A g-1), good power capability (847.5 F g-1 at 6.0 A g-1), and an excellent retention ratio (93.7 % over 1000 cycles). All these impressive results demonstrate that magnetic fields may be an economic and effective tool in hydrothermal synthesis of Co3O4 electrodes for high-performance supercapacitors.

  10. Strong magnetic field-assisted growth of carbon nanofibers and its microstructural transformation mechanism

    NASA Astrophysics Data System (ADS)

    Luo, Chengzhi; Fu, Qiang; Pan, Chunxu

    2015-03-01

    It is well-known that electric and magnetic fields can control the growth direction, morphology and microstructure of one-dimensional carbon nanomaterials (1-DCNMs), which plays a key role for its potential applications in micro-nano-electrics and devices. In this paper, we introduce a novel process for controlling growth of carbon nanofibers (CNFs) with assistance of a strong magnetic field (up to 0.5 T in the center) in a chemical vapor deposition (CVD) system. The results reveal that: 1) The CNFs get bundled when grown in the presence of a strong magnetic field and slightly get aligned parallel to the direction of the magnetic field; 2) The CNFs diameter become narrowed and homogenized with increase of the magnetic field; 3) With the increase of the magnetic field, the microstructure of CNFs is gradually changed, i.e., the strong magnetic field makes the disordered ``solid-cored'' CNFs transform into a kind of bamboo-liked carbon nanotubes; 4) We propose a mechanism that the reason for these variations and transformation is due to diamagnetic property of carbon atoms, so that it has direction selectivity in the precipitation process.

  11. Thermally assisted electric field control of magnetism in flexible multiferroic heterostructures

    PubMed Central

    Liu, Yiwei; Zhan, Qingfeng; Dai, Guohong; Zhang, Xiaoshan; Wang, Baomin; Liu, Gang; Zuo, Zhenghu; Rong, Xin; Yang, Huali; Zhu, Xiaojian; Xie, Yali; Chen, Bin; Li, Run-Wei

    2014-01-01

    Thermal and electrical control of magnetic anisotropy were investigated in flexible Fe81Ga19 (FeGa)/Polyvinylidene fluoride (PVDF) multiferroic heterostructures. Due to the large anisotropic thermal deformation of PVDF (α1 = −13 × 10−6 K−1 and α2 = −145 × 10−6 K−1), the in-plane uniaxial magnetic anisotropy (UMA) of FeGa can be reoriented 90° by changing the temperature across 295 K where the films are magnetically isotropic. Thus, the magnetization of FeGa can be reversed by the thermal cycling between 280 and 320 K under a constant magnetic field lower than coercivity. Moreover, under the assistance of thermal deformation with slightly heating the samples to the critical temperature, the electric field of ± 267 kV cm−1 can well align the UMA along the two orthogonal directions. The new route of combining thermal and electrical control of magnetic properties realized in PVDF-based flexible multiferroic materials shows good prospects in application of flexible thermal spintronic devices and flexible microwave magnetic materials. PMID:25370605

  12. The Cassini spacecraft is mated to the launch vehicle adapter in the PHSF

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Flight mechanics from NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., secure the Cassini spacecraft to its launch vehicle adapter in KSC's Payload Hazardous Servicing Facility. The adapter will later be mated to a Titan IV/Centaur expendable launch vehicle that will lift Cassini into space. The mechanic in the crane lift at right is assisting in exact positioning of the spacecraft for precise fitting. Scheduled for launch in October, the Cassini mission seeks insight into the origins and evolution of the early solar system. Scientific instruments carried aboard the spacecraft will study Saturn's atmosphere, magnetic field, rings, and several moons. JPL is managing the Cassini project for NASA.

  13. Launch vehicles

    NASA Astrophysics Data System (ADS)

    Moss, J. B.

    The basic principles which determine launcher design and hence constrain the spacecraft payload are determined. Some key features of the principal launcher alternatives in Europe and the U.S., namely, the unmanned, expendable Ariane and the manned, substantially reusable, Space Shuttle, are outlined. The equations of motion of the rocket are specialized to the vertical plane, parallel and normal to the flight direction, and to the motion of the center of mass and the pitch rotation. A typical Ariane 2 flight profile for transfer into GTO is illustrated. Some representative mission requirements for spacecraft launches are reviewed. Launch vehicle burnout velocities for spacecraft emplacement are given. Geostationary orbit emplacement, orbital mission performance, and configuration interactions are discussed.

  14. LADEE Launch

    NASA Image and Video Library

    2013-09-07

    NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE) observatory launches aboard the Minotaur V rocket from the Mid-Atlantic Regional Spaceport (MARS) at NASA's Wallops Flight Facility, Friday, Sept. 6, 2013 in Virginia. LADEE is a robotic mission that will orbit the moon where it will provide unprecedented information about the environment around the moon and give scientists a better understanding of other planetary bodies in our solar system and beyond. Photo Credit: (NASA/Carla Cioffi)

  15. Launch Vehicles

    NASA Image and Video Library

    2004-04-15

    The Titan II liftoff. The Titan II launch vehicle was used for carrying astronauts on the Gemini mission. The Gemini Program was an intermediate step between the Project Mercury and the Apollo Program. The major objectives were to subject are two men and supporting equipment to long duration flights, to effect rendezvous and docking with other orbiting vehicle, and to perfect methods of reentry, and landing the spacecraft.

  16. Launch Vehicles

    NASA Image and Video Library

    2007-07-09

    Under the goals of the Vision for Space Exploration, Ares I is a chief component of the cost-effective space transportation infrastructure being developed by NASA's Constellation Program. This transportation system will safely and reliably carry human explorers back to the moon, and then onward to Mars and other destinations in the solar system. The Ares I effort includes multiple project element teams at NASA centers and contract organizations around the nation, and is managed by the Exploration Launch Projects Office at NASA's Marshall Space Flight Center (MFSC). ATK Launch Systems near Brigham City, Utah, is the prime contractor for the first stage booster. ATK's subcontractor, United Space Alliance of Houston, is designing, developing and testing the parachutes at its facilities at NASA's Kennedy Space Center in Florida. NASA's Johnson Space Center in Houston hosts the Constellation Program and Orion Crew Capsule Project Office and provides test instrumentation and support personnel. Together, these teams are developing vehicle hardware, evolving proven technologies, and testing components and systems. Their work builds on powerful, reliable space shuttle propulsion elements and nearly a half-century of NASA space flight experience and technological advances. Ares I is an inline, two-stage rocket configuration topped by the Crew Exploration Vehicle, its service module, and a launch abort system. In this HD video image, an Ares I x-test involves the upper stage separating from the first stage. This particular test was conducted at the NASA Langley Research Center in July 2007. (Highest resolution available)

  17. One-dimensional zinc ferrite nano-chains synthesis by chemical self-assembly assistant by magnetic field

    NASA Astrophysics Data System (ADS)

    Kou, Zhaoxia; Zhang, Wen; Wang, Yukun; Johnny Wong, Ping Kwan; Huang, Haibo; Ji, Cheng; Yue, Jinjin; Zhang, Dong; Zhai, Ya; Zhai, Hongru

    2014-05-01

    A series of zinc ferrite chains have been synthesized successfully by using the self-assembly method in different synthesizing magnetic fields. The particle chains are arranged in order on the Si substrate under the assistant magnetic field. The zinc ferrite chains show various length-to-radius aspect ratio, saturation magnetization Ms, remanent magnetization Mr, and coercivity Hc in the corresponding synthesizing magnetic fields. Using X-ray magnetic circular dichroism, the Zn substitution mechanism in the ferrite chains has been analyzed and discussed.

  18. Magnetic properties and texture of NdFeB magnets fabricated by current-applied-pressure-assisted process

    NASA Astrophysics Data System (ADS)

    Kim, H. T.; Kim, Y. B.; Kim, H. S.

    2001-03-01

    The current-applied-pressure-assisted (CAPA) process has been applied to obtain full dense isotropic and anisotropic NdFeB magnets from melt spun NdFeB alloy (MQP-A). The energy product of isotropic magnets obtained by this process was 120-135 kJ/m 3(15-17 MGOe) and the remanence was 0.8-0.9 T(8-9 kG). These isotropic magnets were deformed with different thickness reduction ratio by CAPA process. The energy product obtained by this procedure was in excess of 320 kJ/m 3(40 MGOe), and the best magnetic properties obtained were B r=1.36 T(13.6 kG) , iH c=868 kA/m(10.9 kOe) and (BH) max=352 kJ/m 3(44.2 MGOe) . The effect of deformation by CAPA process on texture was examined using pole figures. The (1 0 5) texture was dominant up to the thickness reduction ratio of 74%, whereas the (0 0 6) texture was dominant at the thickness reduction ratio of 81%.

  19. Simulation of Magnetic Field Assisted Finishing (MFAF) Process Utilizing Smart MR Polishing Tool

    NASA Astrophysics Data System (ADS)

    Barman, Anwesa; Das, Manas

    2016-05-01

    Magnetic field assisted finishing process is an advanced finishing process. This process is capable of producing nanometer level surface finish. In this process magnetic field is applied to control the finishing forces using magnetorheological polishing medium. In the current study, permanent magnet is used to provide the required magnetic field in the finishing zone. The working gap between the workpiece and the magnet is filled with MR fluid which is used as the polishing brush to remove surface undulations from the top surface of the workpiece. In this paper, the distribution of magnetic flux density on the workpiece surface and behaviour of MR polishing medium during finishing are analyzed using commercial finite element packages (Ansys Maxwell® and Comsol®). The role of magnetic force in the indentation of abrasive particles on the workpiece surface is studied. A two-dimensional simulation study of the steady, laminar, and incompressible MR fluid flow behaviour during finishing process is carried out. The material removal and surface roughness modelling of the finishing process are also presented. The indentation force by a single active abrasive particle on the workpiece surface is modelled during simulation. The velocity profile of MR fluid with and without application of magnetic field is plotted. It shows non-Newtonian property without application of magnetic field. After that the total material displacement due to one abrasive particle is plotted. The simulated roughness profile is in a good agreement with the experimental results. The conducted study will help in understanding the fluid behavior and the mechanism of finishing during finishing process. Also, the modelling and simulation of the process will help in achieving better finishing performance.

  20. Isolated swine heart ventricle perfusion model for implant assisted-magnetic drug targeting.

    PubMed

    Avilés, Misael O; Mangual, Jan O; Ebner, Armin D; Ritter, James A

    2008-09-01

    An isolated swine heart ventricle perfusion model was developed and used under physiologically relevant conditions to study implant assisted-magnetic drug targeting (IA-MDT). A stent coil was fabricated from a ferromagnetic SS 430 wire and used to capture 100-nm diameter magnetite particles that mimicked magnetic drug carrier particles (MDCPs). Four key cases were studied: (1) no stent and no magnet (control), (2) no magnet but with a stent, (3) no stent but with a magnet (traditional MDT), and (4) with a stent and a magnet (IA-MDT). When applied, the magnetic field was fixed at 0.125T. The performance of the system was based on the capture efficiency (CE) of the magnetite nanoparticles. The experiments done in the absence of the magnetic field showed minimal retention of any nanoparticles whether the stent was present or not. The experiments done in the presence of the magnetic field showed a statistically significant increase in the retention of the nanoparticles, with a marked difference between the traditional and IA-MDT cases. Compared to the control case, in one case there was nearly an 11-fold increase in CE for the IA-MDT case compared to only a threefold increase in CE for the traditional MDT case. This enhanced performance by the IA-MDT case was typical of all the experiments. Histology images of the cross-section of the coronary artery revealed that the nanoparticles were captured mainly in the vicinity of the stent. Overall, the IA-MDT results from this work with actual tissue were very encouraging and similar to those obtained from other non-tissue and theoretical studies; but, they did point to the need for further studies of IA-MDT.

  1. Simulation of Magnetic Field Assisted Finishing (MFAF) Process Utilizing Smart MR Polishing Tool

    NASA Astrophysics Data System (ADS)

    Barman, Anwesa; Das, Manas

    2017-02-01

    Magnetic field assisted finishing process is an advanced finishing process. This process is capable of producing nanometer level surface finish. In this process magnetic field is applied to control the finishing forces using magnetorheological polishing medium. In the current study, permanent magnet is used to provide the required magnetic field in the finishing zone. The working gap between the workpiece and the magnet is filled with MR fluid which is used as the polishing brush to remove surface undulations from the top surface of the workpiece. In this paper, the distribution of magnetic flux density on the workpiece surface and behaviour of MR polishing medium during finishing are analyzed using commercial finite element packages (Ansys Maxwell® and Comsol®). The role of magnetic force in the indentation of abrasive particles on the workpiece surface is studied. A two-dimensional simulation study of the steady, laminar, and incompressible MR fluid flow behaviour during finishing process is carried out. The material removal and surface roughness modelling of the finishing process are also presented. The indentation force by a single active abrasive particle on the workpiece surface is modelled during simulation. The velocity profile of MR fluid with and without application of magnetic field is plotted. It shows non-Newtonian property without application of magnetic field. After that the total material displacement due to one abrasive particle is plotted. The simulated roughness profile is in a good agreement with the experimental results. The conducted study will help in understanding the fluid behavior and the mechanism of finishing during finishing process. Also, the modelling and simulation of the process will help in achieving better finishing performance.

  2. Magnetic-Field-Assisted Fabrication and Manipulation of Nonspherical Polymer Particles in Ferrofluid-Based Droplet Microfluidics.

    PubMed

    Zhu, Taotao; Cheng, Rui; Sheppard, Gareth R; Locklin, Jason; Mao, Leidong

    2015-08-11

    We report a novel magnetic-field-assisted method for the fabrication and manipulation of nonspherical polymer particles within a ferrofluid-based droplet microfluidic device. Shape control and chain assembly of droplets with tunable lengths have been achieved.

  3. Current and future role of magnetically assisted gastric capsule endoscopy in the upper gastrointestinal tract

    PubMed Central

    Ching, Hey-Long; Hale, Melissa Fay; McAlindon, Mark Edward

    2016-01-01

    Capsule endoscopy first captivated the medical world when it provided a means to visualize the small bowel, which was previously out of endoscopic reach. In the subsequent decade and a half we continue to learn of the true potential that capsule endoscopy has to offer. Of particular current interest is whether capsule endoscopy has any reliable investigative role in the upper gastrointestinal tract. Much research has already been dedicated to enhancing the diagnostic and indeed therapeutic properties of capsule endoscopy. Specific modifications to tackle the challenges of the gut have already been described in the current literature. In the upper gastrointestinal tract, the capacious anatomy of the stomach represents one of many challenges that capsule endoscopy must overcome. One solution to improving diagnostic yield is to utilize external magnetic steering of a magnetically receptive capsule endoscope. Notionally this would provide a navigation system to direct the capsule to different areas of the stomach and allow complete gastric mucosal examination. To date, several studies have presented promising data to support the feasibility of this endeavour. However the jury is still out as to whether this system will surpass conventional gastroscopy, which remains the gold standard diagnostic tool in the foregut. Nevertheless, a minimally invasive and patient-friendly alternative to gastroscopy remains irresistibly appealing, warranting further studies to test the potential of magnetically assisted capsule endoscopy. In this article the authors would like to share the current state of magnetically assisted capsule endoscopy and anticipate what is yet to come. PMID:27134661

  4. Penetration and screening of perpendicularly launched electromagnetic waves through bounded supercritical plasma confined in multicusp magnetic field

    NASA Astrophysics Data System (ADS)

    Dey, Indranuj; Bhattacharjee, Sudeep

    2011-02-01

    The question of electromagnetic wave penetration and screening by a bounded supercritical (ωp>ω with ωp and ω being the electron-plasma and wave frequencies, respectively) plasma confined in a minimum B multicusp field, for waves launched in the k ⊥Bo mode, is addressed through experiments and numerical simulations. The scale length of radial plasma nonuniformity (|ne/(∂ne/∂r)|) and magnetostatic field (Bo) inhomogeneity (|Bo/(∂Bo/∂r)|) are much smaller than the free space (λo) and guided wavelengths (λg). Contrary to predictions of plane wave dispersion theory and the Clemow-Mullaly-Allis (CMA) diagram, for a bounded plasma a finite propagation occurs through the central plasma regions where αp2=ωp2/ω2≥1 and βc2=ωce2/ω2≪1(˜10-4), with ωce being the electron cyclotron frequency. Wave screening, as predicted by the plane wave model, does not remain valid due to phase mixing and superposition of reflected waves from the conducting boundary, leading to the formation of electromagnetic standing wave modes. The waves are found to satisfy a modified upper hybrid resonance (UHR) relation in the minimum B field and are damped at the local electron cyclotron resonance (ECR) location.

  5. Reversible Control of Interfacial Magnetism through Ionic-Liquid-Assisted Polarization Switching

    DOE PAGES

    Herklotz, Andreas; Guo, Er-Jia; Wong, Anthony T.; ...

    2017-02-06

    The ability to control magnetism of materials via electric field enables a myriad of technological innovations in information storage, sensing, and computing. In this paper, we use ionic-liquid-assisted ferroelectric switching to demonstrate reversible modulation of interfacial magnetism in a multiferroic heterostructure composed of ferromagnetic (FM) La0.8Sr0.2MnO3 and ferroelectric (FE) PbZr0.2Ti0.8O3. It is shown that ionic liquids can be used to persistently and reversibly switch a large area of a FE film. Finally, this is a prerequisite for polarized neutron reflectometry (PNR) studies that are conducted to directly probe magnetoelectric coupling of the FE polarization to the interfacial magnetization.

  6. Reversible Control of Interfacial Magnetism through Ionic-Liquid-Assisted Polarization Switching.

    PubMed

    Herklotz, Andreas; Guo, Er-Jia; Wong, Anthony T; Meyer, Tricia L; Dai, Sheng; Ward, T Zac; Lee, Ho Nyung; Fitzsimmons, Michael R

    2017-03-08

    The ability to control magnetism of materials via electric field enables a myriad of technological innovations in information storage, sensing, and computing. We use ionic-liquid-assisted ferroelectric switching to demonstrate reversible modulation of interfacial magnetism in a multiferroic heterostructure composed of ferromagnetic (FM) La0.8Sr0.2MnO3 and ferroelectric (FE) PbZr0.2Ti0.8O3. It is shown that ionic liquids can be used to persistently and reversibly switch a large area of a FE film. This is a prerequisite for polarized neutron reflectometry (PNR) studies that are conducted to directly probe magnetoelectric coupling of the FE polarization to the interfacial magnetization.

  7. Calcium-assisted reduction of cobalt ferrite nanoparticles for nanostructured iron cobalt with enhanced magnetic performance

    NASA Astrophysics Data System (ADS)

    Qi, B.; Andrew, J. S.; Arnold, D. P.

    2017-03-01

    This paper demonstrates the potential of a calcium-assisted reduction process for synthesizing fine-grain ( 100 nm) metal alloys from metal oxide nanoparticles. To demonstrate the process, an iron cobalt alloy (Fe66Co34) is obtained by hydrogen annealing 7-nm cobalt ferrite (CoFe2O4) nanoparticles in the presence of calcium granules. The calcium serves as a strong reducing agent, promoting the phase transition from cobalt ferrite to a metallic iron cobalt alloy, while maintaining high crystallinity. Magnetic measurements demonstrate the annealing temperature is the dominant factor of tuning the grain size and magnetic properties. Annealing at 700 °C for 1 h maximizes the magnetic saturation, up to 2.4 T (235 emu/g), which matches that of bulk iron cobalt.

  8. Measurement of Curie temperature distribution relevant to heat assisted magnetic recording

    NASA Astrophysics Data System (ADS)

    Chernyshov, Alex; Le, Thanh; Livshitz, Boris; Mryasov, Oleg; Miller, Charles; Acharya, Ram; Treves, David

    2015-05-01

    Heat-Assisted Magnetic Recording (HAMR) is a likely successor of Perpendicular Magnetic Recording (PMR) in the Hard disk drive industry. In PMR, recording performance is strongly affected by the following distributions in magnetic granular media: magnetic anisotropy field (HK), volume/grain size, and interaction field from neighboring grains. Since HAMR writing occurs in a narrow temperature region below Curie point (Tc), additional grain-to-grain Tc variation would strongly affect HAMR recording performance. Thus, Tc distribution should be examined for successful HAMR media development. In this paper, we demonstrate a new approach of extracting HK and Tc distributions (σHK and σTc) from thermo-remanence measurements. During the measurement process, a thin film is magnetically saturated, laser heated to specific peak temperature (for a time typically of 5 μs), then cooled to room temperature and magnetic thermo-remanence is measured. Analytical fit to the experimental curves enables independent evaluation of both σTc (±0.5% absolute) and σHK (±2% absolute). Parameters of the analytical statistical model include: temperature dependencies Ms(T), HK(T); mean field effective demagnetization factor N; grain size, HK; and Tc distributions. Thermal fluctuations are taken into account using Arrhenius-Neel formalism. Here, we report experimental σTc values as a function of grain volume. Increase of σTc with grain size reduction might be a limiting factor for HAMR extendibility.

  9. Magnetic-field-assisted fabrication of micro-convex domes using long pulse laser

    NASA Astrophysics Data System (ADS)

    Wang, Xingsheng; Xu, Weiteng; Liu, Lu; Zhang, Zhengwei; Jin, Meifu; Kang, Min

    2017-09-01

    Surfaces with mimic micro-convex domes offer superior functions such as superhydrophobicity, self-cleaning, anti-wear and drag reduction. In this paper, magnetic-filed-assisted laser surface texturing (LST) using long pulse laser was employed to create micro-convex domes on 304L stainless steel. Spherical cap shaped domes with ripples around the bottom were fabricated through LST. The effects of laser power and magnetic flux density on surface morphologies of the created convex domes were investigated. It was found that the height and diameter of the created convex dome increased with the increment of the laser power without magnetic field. Moreover, the height of the created convex dome grew up gradually with the increase of magnetic flux density due to the induced Lorentz force. The height of the convex dome was increased by as much as 14.5% as compared to LST without the applied magnetic field at a laser power of 54 W. However, the applied magnetic field had no evident effect on the diameter of the created convex dome.

  10. Spin transfer torque in a graphene lateral spin valve assisted by an external magnetic field.

    PubMed

    Lin, Chia-Ching; Penumatcha, Ashish Verma; Gao, Yunfei; Diep, Vinh Quang; Appenzeller, Joerg; Chen, Zhihong

    2013-11-13

    Spin-based devices are widely discussed for post-complementary metal-oxide-semiconductor (CMOS) applications. A number of spin device ideas propose using spin current to carry information coherently through a spin channel and transfering it to an output magnet by spin transfer torque. Graphene is an ideal channel material in this context due to its long spin diffusion length, gate-tunable carrier density, and high carrier mobility. However, spin transfer torque has not been demonstrated in graphene or any other semiconductor material as of yet. Here, we report the first experimental measurement of spin transfer torque in graphene lateral nonlocal spin valve devices. Assisted by an external magnetic field, the magnetization reversal of the ferromagnetic receiving magnet is induced by pure spin diffusion currents from the input magnet. The magnetization switching is reversible between parallel and antiparallel configurations, depending on the polarity of the applied charged current. The presented results are an important step toward developing graphene-based spin logic and understanding spin-transfer torque in systems with tunneling barriers.

  11. Monte Carlo simulation for thermal assisted reversal process of micro-magnetic torus ring with bistable closure domain structure

    NASA Astrophysics Data System (ADS)

    Terashima, Kenichi; Suzuki, Kenji; Yamaguchi, Katsuhiko

    2016-04-01

    Monte Carlo simulations were performed for temperature dependences of closure domain parameter for a magnetic micro-torus ring cluster under magnetic field on limited temperature regions. Simulation results show that magnetic field on tiny limited temperature region can reverse magnetic closure domain structures when the magnetic field is applied at a threshold temperature corresponding to intensity of applied magnetic field. This is one of thermally assisted switching phenomena through a self-organization process. The results show the way to find non-wasteful pairs between intensity of magnetic field and temperature region for reversing closure domain structure by temperature dependence of the fluctuation of closure domain parameter. Monte Carlo method for this simulation is very valuable to optimize the design of thermally assisted switching devices.

  12. High velocity flyer plates launched by magnetic pressure on pulsed power generator CQ-4 and applied in shock Hugoniot experiments

    NASA Astrophysics Data System (ADS)

    Zhang, Xuping; Wang, Guiji; Zhao, Jianheng; Tan, Fuli; Luo, Binqiang; Sun, Chengwei

    2014-05-01

    High velocity flyer plates with good flatness and some thickness have being widely used to the field of shock physics for characterizations of materials under dynamical loading. The techniques of magnetically driven high-velocity flyer plates are further researched based on our pulsed power generators CQ-4 and some good results got on Sandia's Z machine. With large current of several mega-amperes, the loading surface of electrode panel will suffer acute phase transitions caused from magnetic diffusion and Joule heating, and the thickness and flatness of the flyer plates will change with time. In order to obtain the flyer plates with high performances for shock physics, some researches on electrode panels were done by means of LS-DYNA980 software with electro-magnetic package. Two typical configurations for high velocity flyer plates were compared from distribution uniformity of magnetic field in simulation. The results show that the configuration with counter-bore with "notch" and "ear" is better than the other. Then, with the better configuration panels, some experiments were designed and done to validate the simulation results and obtain high velocity flyer plates with good flatness for one-dimensional strain shock experiments on CQ-4. The velocity profiles of the flyer plates were measured by displacement interferometer systems for any reflectors. And the planarity of flyer plates was measured by using the optical fiber pins array for recording the flyer arrival time. The peak velocities of 8.7 km/s with initial dimension of 10 × 7.2 × 0.62 mm for aluminum flyer plates have been achieved. And the flyer plate with initial size of 12 × 9.2 × 0.73 mm was accelerated to velocity of 6.5 km/s with the flatness of less than 11 ns in the central region of 6 mm in diameter and the effective thickness of about 0.220 mm. Based on these work, the symmetrical impact experiments were performed to obtain the high accuracy Hugoniot data of OFHC (oxygen free high conductance

  13. High velocity flyer plates launched by magnetic pressure on pulsed power generator CQ-4 and applied in shock Hugoniot experiments.

    PubMed

    Zhang, Xuping; Wang, Guiji; Zhao, Jianheng; Tan, Fuli; Luo, Binqiang; Sun, Chengwei

    2014-05-01

    High velocity flyer plates with good flatness and some thickness have being widely used to the field of shock physics for characterizations of materials under dynamical loading. The techniques of magnetically driven high-velocity flyer plates are further researched based on our pulsed power generators CQ-4 and some good results got on Sandia's Z machine. With large current of several mega-amperes, the loading surface of electrode panel will suffer acute phase transitions caused from magnetic diffusion and Joule heating, and the thickness and flatness of the flyer plates will change with time. In order to obtain the flyer plates with high performances for shock physics, some researches on electrode panels were done by means of LS-DYNA980 software with electro-magnetic package. Two typical configurations for high velocity flyer plates were compared from distribution uniformity of magnetic field in simulation. The results show that the configuration with counter-bore with "notch" and "ear" is better than the other. Then, with the better configuration panels, some experiments were designed and done to validate the simulation results and obtain high velocity flyer plates with good flatness for one-dimensional strain shock experiments on CQ-4. The velocity profiles of the flyer plates were measured by displacement interferometer systems for any reflectors. And the planarity of flyer plates was measured by using the optical fiber pins array for recording the flyer arrival time. The peak velocities of 8.7 km/s with initial dimension of 10 × 7.2 × 0.62 mm for aluminum flyer plates have been achieved. And the flyer plate with initial size of 12 × 9.2 × 0.73 mm was accelerated to velocity of 6.5 km/s with the flatness of less than 11 ns in the central region of 6 mm in diameter and the effective thickness of about 0.220 mm. Based on these work, the symmetrical impact experiments were performed to obtain the high accuracy Hugoniot data of OFHC (oxygen free high conductance

  14. Launch Vehicles

    NASA Image and Video Library

    2007-08-09

    Under the goals of the Vision for Space Exploration, Ares I is a chief component of the cost-effective space transportation infrastructure being developed by NASA's Constellation Program. This transportation system will safely and reliably carry human explorers back to the moon, and then onward to Mars and other destinations in the solar system. The Ares I effort includes multiple project element teams at NASA centers and contract organizations around the nation, and is managed by the Exploration Launch Projects Office at NASA's Marshall Space Flight Center (MFSC). ATK Launch Systems near Brigham City, Utah, is the prime contractor for the first stage booster. ATK's subcontractor, United Space Alliance of Houston, is designing, developing and testing the parachutes at its facilities at NASA's Kennedy Space Center in Florida. NASA's Johnson Space Center in Houston hosts the Constellation Program and Orion Crew Capsule Project Office and provides test instrumentation and support personnel. Together, these teams are developing vehicle hardware, evolving proven technologies, and testing components and systems. Their work builds on powerful, reliable space shuttle propulsion elements and nearly a half-century of NASA space flight experience and technological advances. Ares I is an inline, two-stage rocket configuration topped by the Crew Exploration Vehicle, its service module, and a launch abort system. This HD video image depicts the preparation and placement of a confidence ring for friction stir welding used in manufacturing aluminum panels that will fabricate the Ares I upper stage barrel. The aluminum panels are manufactured and subjected to confidence tests during which the bent aluminum is stressed to breaking point and thoroughly examined. The panels are manufactured by AMRO Manufacturing located in El Monte, California. (Highest resolution available)

  15. Launch Vehicles

    NASA Image and Video Library

    2006-09-09

    Under the goals of the Vision for Space Exploration, Ares I is a chief component of the cost-effective space transportation infrastructure being developed by NASA's Constellation Program. This transportation system will safely and reliably carry human explorers back to the moon, and then onward to Mars and other destinations in the solar system. The Ares I effort includes multiple project element teams at NASA centers and contract organizations around the nation, and is managed by the Exploration Launch Projects Office at NASA's Marshall Space Flight Center (MFSC). ATK Launch Systems near Brigham City, Utah, is the prime contractor for the first stage booster. ATK's subcontractor, United Space Alliance of Houston, is designing, developing and testing the parachutes at its facilities at NASA's Kennedy Space Center in Florida. NASA's Johnson Space Center in Houston hosts the Constellation Program and Orion Crew Capsule Project Office and provides test instrumentation and support personnel. Together, these teams are developing vehicle hardware, evolving proven technologies, and testing components and systems. Their work builds on powerful, reliable space shuttle propulsion elements and nearly a half-century of NASA space flight experience and technological advances. Ares I is an inline, two-stage rocket configuration topped by the Crew Exploration Vehicle, its service module, and a launch abort system. In this HD video image, the first stage reentry parachute drop test is conducted at the Yuma, Arizona proving ground. The parachute tests demonstrated a three-stage deployment sequence that included the use of an Orbiter drag chute to properly stage the unfurling of the main chute. The parachute recovery system for Orion will be similar to the system used for Apollo command module landings and include two drogue, three pilot, and three main parachutes. (Highest resolution available)

  16. Launch Vehicles

    NASA Image and Video Library

    2007-09-09

    Under the goals of the Vision for Space Exploration, Ares I is a chief component of the cost-effective space transportation infrastructure being developed by NASA's Constellation Program. This transportation system will safely and reliably carry human explorers back to the moon, and then onward to Mars and other destinations in the solar system. The Ares I effort includes multiple project element teams at NASA centers and contract organizations around the nation, and is managed by the Exploration Launch Projects Office at NASA's Marshall Space Flight Center (MFSC). ATK Launch Systems near Brigham City, Utah, is the prime contractor for the first stage booster. ATK's subcontractor, United Space Alliance of Houston, is designing, developing and testing the parachutes at its facilities at NASA's Kennedy Space Center in Florida. NASA's Johnson Space Center in Houston hosts the Constellation Program and Orion Crew Capsule Project Office and provides test instrumentation and support personnel. Together, these teams are developing vehicle hardware, evolving proven technologies, and testing components and systems. Their work builds on powerful, reliable space shuttle propulsion elements and nearly a half-century of NASA space flight experience and technological advances. Ares I is an inline, two-stage rocket configuration topped by the Crew Exploration Vehicle, its service module, and a launch abort system. In this HD video image, the first stage reentry parachute drop test is conducted at the Yuma, Arizona proving ground. The parachute tests demonstrated a three-stage deployment sequence that included the use of an Orbiter drag chute to properly stage the unfurling of the main chute. The parachute recovery system for Orion will be similar to the system used for Apollo command module landings and include two drogue, three pilot, and three main parachutes. (Highest resolution available)

  17. Launch Vehicles

    NASA Image and Video Library

    2007-08-09

    Under the goals of the Vision for Space Exploration, Ares I is a chief component of the cost-effective space transportation infrastructure being developed by NASA's Constellation Program. This transportation system will safely and reliably carry human explorers back to the moon, and then onward to Mars and other destinations in the solar system. The Ares I effort includes multiple project element teams at NASA centers and contract organizations around the nation, and is managed by the Exploration Launch Projects Office at NASA's Marshall Space Flight Center (MFSC). ATK Launch Systems near Brigham City, Utah, is the prime contractor for the first stage booster. ATK's subcontractor, United Space Alliance of Houston, is designing, developing and testing the parachutes at its facilities at NASA's Kennedy Space Center in Florida. NASA's Johnson Space Center in Houston hosts the Constellation Program and Orion Crew Capsule Project Office and provides test instrumentation and support personnel. Together, these teams are developing vehicle hardware, evolving proven technologies, and testing components and systems. Their work builds on powerful, reliable space shuttle propulsion elements and nearly a half-century of NASA space flight experience and technological advances. Ares I is an inline, two-stage rocket configuration topped by the Crew Exploration Vehicle, its service module, and a launch abort system. In this HD video image, processes for upper stage barrel fabrication are talking place. Aluminum panels are manufacturing process demonstration articles that will undergo testing until perfected. The panels are built by AMRO Manufacturing located in El Monte, California. (Largest resolution available)

  18. Launch Vehicles

    NASA Image and Video Library

    2007-08-09

    Under the goals of the Vision for Space Exploration, Ares I is a chief component of the cost-effective space transportation infrastructure being developed by NASA's Constellation Program. This transportation system will safely and reliably carry human explorers back to the moon, and then onward to Mars and other destinations in the solar system. The Ares I effort includes multiple project element teams at NASA centers and contract organizations around the nation, and is managed by the Exploration Launch Projects Office at NASA's Marshall Space Flight Center (MFSC). ATK Launch Systems near Brigham City, Utah, is the prime contractor for the first stage booster. ATK's subcontractor, United Space Alliance of Houston, is designing, developing and testing the parachutes at its facilities at NASA's Kennedy Space Center in Florida. NASA's Johnson Space Center in Houston hosts the Constellation Program and Orion Crew Capsule Project Office and provides test instrumentation and support personnel. Together, these teams are developing vehicle hardware, evolving proven technologies, and testing components and systems. Their work builds on powerful, reliable space shuttle propulsion elements and nearly a half-century of NASA space flight experience and technological advances. Ares I is an inline, two-stage rocket configuration topped by the Crew Exploration Vehicle, its service module, and a launch abort system. This HD video image depicts the manufacturing of aluminum panels that will be used to form the Ares I barrel. The panels are manufacturing process demonstration articles that will undergo testing until perfected. The panels are built by AMRO Manufacturing located in El Monte, California. (Highest resolution available)

  19. Launch Vehicles

    NASA Image and Video Library

    2007-08-09

    Under the goals of the Vision for Space Exploration, Ares I is a chief component of the cost-effective space transportation infrastructure being developed by NASA's Constellation Program. This transportation system will safely and reliably carry human explorers back to the moon, and then onward to Mars and other destinations in the solar system. The Ares I effort includes multiple project element teams at NASA centers and contract organizations around the nation, and is managed by the Exploration Launch Projects Office at NASA's Marshall Space Flight Center (MFSC). ATK Launch Systems near Brigham City, Utah, is the prime contractor for the first stage booster. ATK's subcontractor, United Space Alliance of Houston, is designing, developing and testing the parachutes at its facilities at NASA's Kennedy Space Center in Florida. NASA's Johnson Space Center in Houston hosts the Constellation Program and Orion Crew Capsule Project Office and provides test instrumentation and support personnel. Together, these teams are developing vehicle hardware, evolving proven technologies, and testing components and systems. Their work builds on powerful, reliable space shuttle propulsion elements and nearly a half-century of NASA space flight experience and technological advances. Ares I is an inline, two-stage rocket configuration topped by the Crew Exploration Vehicle, its service module, and a launch abort system. This HD video image depicts friction stir welding used in manufacturing aluminum panels that will fabricate the Ares I upper stage barrel. The panels are subjected to confidence tests in which the bent aluminum is stressed to breaking point and thoroughly examined. The panels are manufactured by AMRO Manufacturing located in El Monte, California. (Highest resolution available)

  20. Launch Vehicles

    NASA Image and Video Library

    2007-08-09

    Under the goals of the Vision for Space Exploration, Ares I is a chief component of the cost-effective space transportation infrastructure being developed by NASA's Constellation Program. This transportation system will safely and reliably carry human explorers back to the moon, and then onward to Mars and other destinations in the solar system. The Ares I effort includes multiple project element teams at NASA centers and contract organizations around the nation, and is managed by the Exploration Launch Projects Office at NASA's Marshall Space Flight Center (MFSC). ATK Launch Systems near Brigham City, Utah, is the prime contractor for the first stage booster. ATK's subcontractor, United Space Alliance of Houston, is designing, developing and testing the parachutes at its facilities at NASA's Kennedy Space Center in Florida. NASA's Johnson Space Center in Houston hosts the Constellation Program and Orion Crew Capsule Project Office and provides test instrumentation and support personnel. Together, these teams are developing vehicle hardware, evolving proven technologies, and testing components and systems. Their work builds on powerful, reliable space shuttle propulsion elements and nearly a half-century of NASA space flight experience and technological advances. Ares I is an inline, two-stage rocket configuration topped by the Crew Exploration Vehicle, its service module, and a launch abort system. This HD video image, depicts a manufactured aluminum panel, that will be used to fabricate the Ares I upper stage barrel, undergoing a confidence panel test. In this test, the bent aluminum is stressed to breaking point and thoroughly examined. The panels are manufactured by AMRO Manufacturing located in El Monte, California. (Highest resolution available)

  1. Launch Vehicles

    NASA Image and Video Library

    2006-08-08

    Under the goals of the Vision for Space Exploration, Ares I is a chief component of the cost-effective space transportation infrastructure being developed by NASA's Constellation Program. This transportation system will safely and reliably carry human explorers back to the moon, and then onward to Mars and other destinations in the solar system. The Ares I effort includes multiple project element teams at NASA centers and contract organizations around the nation, and is managed by the Exploration Launch Projects Office at NASA's Marshall Space Flight Center (MFSC). ATK Launch Systems near Brigham City, Utah, is the prime contractor for the first stage booster. ATK's subcontractor, United Space Alliance of Houston, is designing, developing and testing the parachutes at its facilities at NASA's Kennedy Space Center in Florida. NASA's Johnson Space Center in Houston hosts the Constellation Program and Orion Crew Capsule Project Office and provides test instrumentation and support personnel. Together, these teams are developing vehicle hardware, evolving proven technologies, and testing components and systems. Their work builds on powerful, reliable space shuttle propulsion elements and nearly a half-century of NASA space flight experience and technological advances. Ares I is an inline, two-stage rocket configuration topped by the Crew Exploration Vehicle, its service module, and a launch abort system. This HD video image depicts a manufactured aluminum panel that will be used to fabricate the Ares I upper stage barrel, undergoing a confidence panel test. In this test, the bent aluminum is stressed to breaking point and thoroughly examined. The panels are manufactured by AMRO Manufacturing located in El Monte, California. (Highest resolution available)

  2. Launch Vehicles

    NASA Image and Video Library

    2007-08-09

    Under the goals of the Vision for Space Exploration, Ares I is a chief component of the cost-effective space transportation infrastructure being developed by NASA's Constellation Program. This transportation system will safely and reliably carry human explorers back to the moon, and then onward to Mars and other destinations in the solar system. The Ares I effort includes multiple project element teams at NASA centers and contract organizations around the nation, and is managed by the Exploration Launch Projects Office at NASA's Marshall Space Flight Center (MFSC). ATK Launch Systems near Brigham City, Utah, is the prime contractor for the first stage booster. ATK's subcontractor, United Space Alliance of Houston, is designing, developing and testing the parachutes at its facilities at NASA's Kennedy Space Center in Florida. NASA's Johnson Space Center in Houston hosts the Constellation Program and Orion Crew Capsule Project Office and provides test instrumentation and support personnel. Together, these teams are developing vehicle hardware, evolving proven technologies, and testing components and systems. Their work builds on powerful, reliable space shuttle propulsion elements and nearly a half-century of NASA space flight experience and technological advances. Ares I is an inline, two-stage rocket configuration topped by the Crew Exploration Vehicle, its service module, and a launch abort system. This HD video image depicts confidence testing of a manufactured aluminum panel that will fabricate the Ares I upper stage barrel. In this test, bent aluminum is stressed to breaking point and thoroughly examined. The panels are manufactured by AMRO Manufacturing located in El Monte, California. (Highest resolution available)

  3. Launch Vehicles

    NASA Image and Video Library

    2006-08-09

    Under the goals of the Vision for Space Exploration, Ares I is a chief component of the cost-effective space transportation infrastructure being developed by NASA's Constellation Program. This transportation system will safely and reliably carry human explorers back to the moon, and then onward to Mars and other destinations in the solar system. The Ares I effort includes multiple project element teams at NASA centers and contract organizations around the nation, and is managed by the Exploration Launch Projects Office at NASA's Marshall Space Flight Center (MFSC). ATK Launch Systems near Brigham City, Utah, is the prime contractor for the first stage booster. ATK's subcontractor, United Space Alliance of Houston, is designing, developing and testing the parachutes at its facilities at NASA's Kennedy Space Center in Florida. NASA's Johnson Space Center in Houston hosts the Constellation Program and Orion Crew Capsule Project Office and provides test instrumentation and support personnel. Together, these teams are developing vehicle hardware, evolving proven technologies, and testing components and systems. Their work builds on powerful, reliable space shuttle propulsion elements and nearly a half-century of NASA space flight experience and technological advances. Ares I is an inline, two-stage rocket configuration topped by the Crew Exploration Vehicle, its service module, and a launch abort system. This HD video image depicts a manufactured aluminum panel, that will fabricate the Ares I upper stage barrel, undergoing a confidence panel test. In this test, bent aluminum is stressed to breaking point and thoroughly examined. The panels are manufactured by AMRO Manufacturing located in El Monte, California. (Highest resolution available)

  4. Launch Vehicles

    NASA Image and Video Library

    2007-08-09

    Under the goals of the Vision for Space Exploration, Ares I is a chief component of the cost-effective space transportation infrastructure being developed by NASA's Constellation Program. This transportation system will safely and reliably carry human explorers back to the moon, and then onward to Mars and other destinations in the solar system. The Ares I effort includes multiple project element teams at NASA centers and contract organizations around the nation, and is managed by the Exploration Launch Projects Office at NASA's Marshall Space Flight Center (MFSC). ATK Launch Systems near Brigham City, Utah, is the prime contractor for the first stage booster. ATK's subcontractor, United Space Alliance of Houston, is designing, developing and testing the parachutes at its facilities at NASA's Kennedy Space Center in Florida. NASA's Johnson Space Center in Houston hosts the Constellation Program and Orion Crew Capsule Project Office and provides test instrumentation and support personnel. Together, these teams are developing vehicle hardware, evolving proven technologies, and testing components and systems. Their work builds on powerful, reliable space shuttle propulsion elements and nearly a half-century of NASA space flight experience and technological advances. Ares I is an inline, two-stage rocket configuration topped by the Crew Exploration Vehicle, its service module, and a launch abort system. This HD video image depicts a manufactured aluminum panel, that will fabricate the Ares I upper stage barrel, undergoing a confidence panel test. In this test, the bent aluminum is stressed to breaking point and thoroughly examined. The panels are manufactured by AMRO Manufacturing located in El Monte, California. (Highest resolution available)

  5. A multi-functional testing instrument for heat assisted magnetic recording media

    SciTech Connect

    Yang, H. Z. Chen, Y. J.; Leong, S. H.; An, C. W.; Ye, K. D.; Hu, J. F.; Yin, M. J.

    2014-05-07

    With recent developments in heat assisted magnetic recording (HAMR), characterization of HAMR media is becoming very important. We present a multi-functional instrument for testing HAMR media, which integrates HAMR writing, reading, and a micro-magneto-optic Kerr effect (μ-MOKE) testing function. A potential application of the present instrument is to make temperature dependent magnetic property measurement using a pump-probe configuration. In the measurement, the media is heated up by a heating (intense) beam while a testing (weak) beam is overlapped with the heating beam for MOKE measurement. By heating the media with different heating beam power, magnetic measurements by MOKE at different temperatures can be performed. Compared to traditional existing tools such as the vibrating sample magnetometer, the present instrument provides localized and efficient heating at the measurement spot. The integration of HAMR writing and μ-MOKE system can also facilitate a localized full investigation of the magnetic media by potential correlation of HAMR head independent write/read performance to localized magnetic properties.

  6. Magnetism-assisted modification of screen printed electrode with magnetic multi-walled carbon nanotubes for electrochemical determination of dopamine.

    PubMed

    Zhang, Yong-Mei; Xu, Pei-Li; Zeng, Qiong; Liu, Yi-Ming; Liao, Xun; Hou, Mei-Fang

    2017-05-01

    A simple and sensitive dopamine (DA) electrochemical sensor was fabricated based on magnetism-assisted modification of screen printed electrode (SPE) with magnetic multi-walled carbon nanotubes (mMWCNTs). The mMWCNTs modified electrodes (mMWCNTs/SPE) combines the advantages of SPE and the simultaneous contribution of magnetic nanoparticles (MNPs) and MWCNTs, increasing sensitivity and selectivity of DA detection. The linearity was found between 5μM to 180μM, with the limit of detection (LOD) of 0.43μM. In the mean time, this modified electrode exhibited excellent selectivity for DA detection with almost no interference from ascorbic acid (AA), which co-exists with DA in many bio-samples and causes common interference. Finally, this novel electrode has been applied to determine DA concentration in spiked human blood serum and satisfactory recovery was found in the range of 97.43-102.94% with the RSDs of less than 2.27%. This work developed a sensitive and reliable electrochemical analytical method based on mMWCNTs/SPE, which exhibits great potential for diagnosis of the diseases related to DA.

  7. Magnetic-assisted triboelectric nanogenerators as self-powered visualized omnidirectional tilt sensing system

    NASA Astrophysics Data System (ADS)

    Han, Mengdi; Zhang, Xiao-Sheng; Sun, Xuming; Meng, Bo; Liu, Wen; Zhang, Haixia

    2014-04-01

    The triboelectric nanogenerator (TENG) is a promising device in energy harvesting and self-powered sensing. In this work, we demonstrate a magnetic-assisted TENG, utilizing the magnetic force for electric generation. Maximum power density of 541.1 mW/m2 is obtained at 16.67 MΩ for the triboelectric part, while the electromagnetic part can provide power density of 649.4 mW/m2 at 16 Ω. Through theoretical calculation and experimental measurement, linear relationship between the tilt angle and output voltage at large angles is observed. On this basis, a self-powered omnidirectional tilt sensor is realized by two magnetic-assisted TENGs, which can measure the magnitude and direction of the tilt angle at the same time. For visualized sensing of the tilt angle, a sensing system is established, which is portable, intuitive, and self-powered. This visualized system greatly simplifies the measure process, and promotes the development of self-powered systems.

  8. Perpendicular-anisotropy magnetic tunnel junction switched by spin-Hall-assisted spin-transfer torque

    NASA Astrophysics Data System (ADS)

    Wang, Zhaohao; Zhao, Weisheng; Deng, Erya; Klein, Jacques-Olivier; Chappert, Claude

    2015-02-01

    We investigate the magnetization switching induced by spin-Hall-assisted spin-transfer torque (STT) in a three-terminal device consisting of a perpendicular-anisotropy magnetic tunnel junction (MTJ) and an β-W strip. Magnetization dynamics in free layer of MTJ is simulated by solving numerically a modified Landau-Lifshitz-Gilbert equation. The influences of spin-Hall write current (density, duration and direction) on the STT switching are evaluated. We find that the switching speed of a STT-MTJ can be significantly improved (reduced to <1 ns) by using a sufficiently large spin-Hall write current density (~25 MA cm-2) with an appropriate duration (~0.5 ns). Finally we develop an electrical model of three-terminal MTJ/β-W device with Verilog-A language and perform transient simulation of switching a 4 T/1MTJ/1β-W memory cell with Spectre simulator. Simulation results demonstrate that spin-Hall-assisted STT-MTJ has advantages over conventional STT-MTJ in write speed and energy.

  9. Magnetic-assisted triboelectric nanogenerators as self-powered visualized omnidirectional tilt sensing system

    PubMed Central

    Han, Mengdi; Zhang, Xiao-Sheng; Sun, Xuming; Meng, Bo; Liu, Wen; Zhang, Haixia

    2014-01-01

    The triboelectric nanogenerator (TENG) is a promising device in energy harvesting and self-powered sensing. In this work, we demonstrate a magnetic-assisted TENG, utilizing the magnetic force for electric generation. Maximum power density of 541.1 mW/m2 is obtained at 16.67 MΩ for the triboelectric part, while the electromagnetic part can provide power density of 649.4 mW/m2 at 16 Ω. Through theoretical calculation and experimental measurement, linear relationship between the tilt angle and output voltage at large angles is observed. On this basis, a self-powered omnidirectional tilt sensor is realized by two magnetic-assisted TENGs, which can measure the magnitude and direction of the tilt angle at the same time. For visualized sensing of the tilt angle, a sensing system is established, which is portable, intuitive, and self-powered. This visualized system greatly simplifies the measure process, and promotes the development of self-powered systems. PMID:24770490

  10. Magnetic-assisted triboelectric nanogenerators as self-powered visualized omnidirectional tilt sensing system.

    PubMed

    Han, Mengdi; Zhang, Xiao-Sheng; Sun, Xuming; Meng, Bo; Liu, Wen; Zhang, Haixia

    2014-04-28

    The triboelectric nanogenerator (TENG) is a promising device in energy harvesting and self-powered sensing. In this work, we demonstrate a magnetic-assisted TENG, utilizing the magnetic force for electric generation. Maximum power density of 541.1 mW/m(2) is obtained at 16.67 MΩ for the triboelectric part, while the electromagnetic part can provide power density of 649.4 mW/m(2) at 16 Ω. Through theoretical calculation and experimental measurement, linear relationship between the tilt angle and output voltage at large angles is observed. On this basis, a self-powered omnidirectional tilt sensor is realized by two magnetic-assisted TENGs, which can measure the magnitude and direction of the tilt angle at the same time. For visualized sensing of the tilt angle, a sensing system is established, which is portable, intuitive, and self-powered. This visualized system greatly simplifies the measure process, and promotes the development of self-powered systems.

  11. Magnetic-Field-Assisted Terahertz Quantum Cascade Laser Operating up to 225 K

    NASA Technical Reports Server (NTRS)

    Wade, A.; Fedorov, G.; Smirnov, D.; Kumar, S.; Williams, B. S.; Hu, Q.; Reno, J. L.

    2008-01-01

    Advances in semiconductor bandgap engineering have resulted in the recent development of the terahertz quantum cascade laser1. These compact optoelectronic devices now operate in the frequency range 1.2-5 THz, although cryogenic cooling is still required2.3. Further progress towards the realization of devices operating at higher temperatures and emitting at longer wavelengths (sub-terahertz quantum cascade lasers) is difficult because it requires maintaining a population inversion between closely spaced electronic sub-bands (1 THz approx. equals 4 meV). Here, we demonstrate a magnetic-field-assisted quantum cascade laser based on the resonant-phonon design. By applying appropriate electrical bias and strong magnetic fields above 16 T, it is possible to achieve laser emission from a single device over a wide range of frequencies (0.68-3.33 THz). Owing to the suppression of inter-landau-level non-radiative scattering, the device shows magnetic field assisted laser action at 1 THz at temperatures up to 215 K, and 3 THz lasing up to 225 K.

  12. Magnetic levitation assisted aircraft take-off and landing (feasibility study - GABRIEL concept)

    NASA Astrophysics Data System (ADS)

    Rohacs, Daniel; Rohacs, Jozsef

    2016-08-01

    The Technology Roadmap 2013 developed by the International Air Transport Association envisions the option of flying without an undercarriage to be in operation by 2032. Preliminary investigations clearly indicate that magnetic levitation technology (MagLev) might be an appealing solution to assist the aircraft take-off and landing. The EU supported research project, abbreviated as GABRIEL, was dealing with (i) the concept development, (ii) the identification, evaluation and selection of the deployable magnetic levitation technology, (iii) the definition of the core system elements (including the required aircraft modifications, the ground-based system and airport elements, and the rendezvous control system), (iv) the analysis of the safety and security aspects, (v) the concept validation and (vi) the estimation of the proposed concept impact in terms of aircraft weight, noise, emission, cost-benefit). All results introduced here are compared to a medium size hypothetic passenger aircraft (identical with an Airbus A320). This paper gives a systematic overview of (i) the applied methods, (ii) the investigation of the possible use of magnetic levitation technology to assist the commercial aircraft take-off and landing processes and (iii) the demonstrations, validations showing the feasibility of the radically new concept. All major results are outlined.

  13. Magnetic-Field-Assisted Terahertz Quantum Cascade Laser Operating up to 225 K

    NASA Technical Reports Server (NTRS)

    Wade, A.; Fedorov, G.; Smirnov, D.; Kumar, S.; Williams, B. S.; Hu, Q.; Reno, J. L.

    2008-01-01

    Advances in semiconductor bandgap engineering have resulted in the recent development of the terahertz quantum cascade laser1. These compact optoelectronic devices now operate in the frequency range 1.2-5 THz, although cryogenic cooling is still required2.3. Further progress towards the realization of devices operating at higher temperatures and emitting at longer wavelengths (sub-terahertz quantum cascade lasers) is difficult because it requires maintaining a population inversion between closely spaced electronic sub-bands (1 THz approx. equals 4 meV). Here, we demonstrate a magnetic-field-assisted quantum cascade laser based on the resonant-phonon design. By applying appropriate electrical bias and strong magnetic fields above 16 T, it is possible to achieve laser emission from a single device over a wide range of frequencies (0.68-3.33 THz). Owing to the suppression of inter-landau-level non-radiative scattering, the device shows magnetic field assisted laser action at 1 THz at temperatures up to 215 K, and 3 THz lasing up to 225 K.

  14. (001) Oriented L10 FeCuPt for Heat-Assisted Magnetic Recording

    NASA Astrophysics Data System (ADS)

    Liu, Kai

    2015-03-01

    High magnetic anisotropy materials are critical to key technologies such as ultrahigh density magnetic recording and permanent magnets. Among them, ordered FePt alloys in the L10 phase are particularly sought after, for the emerging heat-assisted magnetic recording (HAMR) media. However, the highly desirable properties are associated with the tetragonal L10 phase. Key challenges exist in the high annealing temperature necessary to transform the as-deposited disordered cubic A1 phase into the ordered tetragonal L10 phase and the ability to maintain the magnetic easy axis perpendicular to the film. We have achieved (001) oriented L10 FeCuPt thin films, with magnetic anisotropy up to 3.6 x 107 erg/cm3, using atomic-scale multilayer sputtering and rapid thermal annealing (RTA) at 400 °C for 10 seconds, which is much more benign compared to earlier studies. The artificial ordering in the multilayer structure and a significant tensile stress exerted by the underlying Si/SiO2 during RTA facilitate the formation of (001) oriented L10 phase. The A1 to L10 phase transformation has been investigated by x-ray diffraction and the first-order reversal curve (FORC) method. The L10 ordering takes place via a nucleation-and-growth mode. Traditional x-ray diffraction is not always reliable in generating a true order parameter, due to non-ideal crystallinity of the A1 phase in some of the samples. A magnetization-based L10 phase fraction is extracted, providing a quantitative measure of the L10 phase homogeneity. This work has been done in collaboration with D. A. Gilbert, J. W. Liao, L. W. Wang, J. W. Lau, T. J Klemmer, J. U. Thiele, and C. H. Lai, supported by the NSF (DMR-1008791).

  15. Magnetically-Assisted Remote Controlled Microcatheter Tip Deflection under Magnetic Resonance Imaging.

    PubMed

    Hetts, Steven W; Saeed, Maythem; Martin, Alastair; Lillaney, Prasheel; Losey, Aaron; Yee, Erin Jeannie; Sincic, Ryan; Do, Loi; Evans, Lee; Malba, Vincent; Bernhardt, Anthony F; Wilson, Mark W; Patel, Anand; Arenson, Ronald L; Caton, Curtis; Cooke, Daniel L

    2013-04-04

    X-ray fluoroscopy-guided endovascular procedures have several significant limitations, including difficult catheter navigation and use of ionizing radiation, which can potentially be overcome using a magnetically steerable catheter under MR guidance. The main goal of this work is to develop a microcatheter whose tip can be remotely controlled using the magnetic field of the MR scanner. This protocol aims to describe the procedures for applying current to the microcoil-tipped microcatheter to produce consistent and controllable deflections. A microcoil was fabricated using laser lathe lithography onto a polyimide-tipped endovascular catheter. In vitro testing was performed in a waterbath and vessel phantom under the guidance of a 1.5-T MR system using steady-state free precession (SSFP) sequencing. Various amounts of current were applied to the coils of the microcatheter to produce measureable tip deflections and navigate in vascular phantoms. The development of this device provides a platform for future testing and opportunity to revolutionize the endovascular interventional MRI environment.

  16. Novel microwave-assisted digestion by trypsin-immobilized magnetic nanoparticles for proteomic analysis.

    PubMed

    Lin, Shuang; Yun, Dong; Qi, Dawei; Deng, Chunhui; Li, Yan; Zhang, Xiangmin

    2008-03-01

    In this study, a novel microwave-assisted protein digestion method was developed using trypsin-immobilized magnetic nanoparticles (TIMNs). The magnetic nanoparticles worked as not only substrate for enzyme immobilization, but also excellent microwave irradiation absorber and, thus, improved the efficiency of microwave-assisted digestion greatly. Three standard proteins, bovine serum albumin (BSA), myoglobin, and cytochrome c, were used to optimize the conditions of this novel digestion method. With the optimized conditions, peptide fragments produced in very short time (only 15 s) could be identified successfully by MALDI-TOF-MS. When it was compared to the conventional in-solution digestion (12 h), equivalent or better digestion efficiency was observed. Even when protein quantity was as low as micrograms, this novel digestion method still could digest proteins successfully, while the same samples by conventional in-solution digestion failed. Moreover, with an external magnetic field, the enzyme could be removed easily and reused. It was verified that, after 4 replicate runs, the TIMNs still kept high activity. To further confirm the efficiency of this rapid digestion method for proteome analysis, it was applied to the protein extract of rat liver. Without any preparation and prefractionation processing, the entire proteome digested by TIMNs in 15 s went through LC-ESI-MS/MS direct analysis. The whole shotgun proteomic experiment was finished in only 1 h with the identification of 313 proteins ( p < 0.01). This new application of TIMNs in microwave-assisted protein digestion really opens a route for large-scale proteomic analysis.

  17. Serial dilution via surface energy trap-assisted magnetic droplet manipulation.

    PubMed

    Zhang, Yi; Shin, Dong Jin; Wang, Tza-Huei

    2013-12-21

    This paper demonstrates a facile method of generating precise serial dilutions in the form of droplets on an open surface platform. The method relies on the use of surface energy traps (SETs), etched areas of high surface energy on a Teflon coated glass substrate, to assist in the magnetic manipulation of droplets to meter and dispense liquid of defined volumes for the preparation of serial dilutions. The volume of the dispensed liquid can be precisely controlled by the size of the SETs, facilitating generation of concentration profiles of high linearity. We have applied this approach to the generation of serial dilutions of antibiotics for anti-microbial susceptibility testing (AST).

  18. Porous cobalt spheres for high temperature gradient magnetically assisted fluidized beds

    NASA Technical Reports Server (NTRS)

    Atwater, James E.; Akse, James R.; Jovanovic, Goran N.; Wheeler, Richard R Jr; Sornchamni, Thana

    2003-01-01

    Porous metallic cobalt spheres have been prepared as high temperature capable media for employment in gradient magnetically assisted fluidization and filtration technologies. Cobalt impregnated alginate beads are first formed by extrusion of an aqueous suspension of Co3O4 into a Co(II) chloride solution. The organic polymer is thermally decomposed yielding cobalt oxide spheres, followed by reduction to the metallic state, and densification. Cobalt beads have been produced with porosities ranging between 10 and 50%, depending upon sintering conditions. The product media have been characterized by scanning electron microscopy (SEM), nitrogen adsorption porosimetry, and vibrating sample magnetometry. c2003 Elsevier Science Ltd. All rights reserved.

  19. Porous cobalt spheres for high temperature gradient magnetically assisted fluidized beds

    SciTech Connect

    Atwater, James E.; Akse, James R.; Jovanovic, Goran N.; Wheeler, Richard R.; Sornchamni, Thana

    2003-02-20

    Porous metallic cobalt spheres have been prepared as high temperature capable media for employment in gradient magnetically assisted fluidization and filtration technologies. Cobalt impregnated alginate beads are first formed by extrusion of an aqueous suspension of Co{sub 3}O{sub 4} into a Co(II) chloride solution. The organic polymer is thermally decomposed yielding cobalt oxide spheres, followed by reduction to the metallic state, and densification. Cobalt beads have been produced with porosities ranging between 10 and 50%, depending upon sintering conditions. The product media have been characterized by scanning electron microscopy (SEM), nitrogen adsorption porosimetry, and vibrating sample magnetometry.

  20. Porous cobalt spheres for high temperature gradient magnetically assisted fluidized beds

    NASA Technical Reports Server (NTRS)

    Atwater, James E.; Akse, James R.; Jovanovic, Goran N.; Wheeler, Richard R Jr; Sornchamni, Thana

    2003-01-01

    Porous metallic cobalt spheres have been prepared as high temperature capable media for employment in gradient magnetically assisted fluidization and filtration technologies. Cobalt impregnated alginate beads are first formed by extrusion of an aqueous suspension of Co3O4 into a Co(II) chloride solution. The organic polymer is thermally decomposed yielding cobalt oxide spheres, followed by reduction to the metallic state, and densification. Cobalt beads have been produced with porosities ranging between 10 and 50%, depending upon sintering conditions. The product media have been characterized by scanning electron microscopy (SEM), nitrogen adsorption porosimetry, and vibrating sample magnetometry. c2003 Elsevier Science Ltd. All rights reserved.

  1. Porous cobalt spheres for high temperature gradient magnetically assisted fluidized beds.

    PubMed

    Atwater, James E; Akse, James R; Jovanovic, Goran N; Wheeler, Richard R; Sornchamni, Thana

    2003-02-20

    Porous metallic cobalt spheres have been prepared as high temperature capable media for employment in gradient magnetically assisted fluidization and filtration technologies. Cobalt impregnated alginate beads are first formed by extrusion of an aqueous suspension of Co3O4 into a Co(II) chloride solution. The organic polymer is thermally decomposed yielding cobalt oxide spheres, followed by reduction to the metallic state, and densification. Cobalt beads have been produced with porosities ranging between 10 and 50%, depending upon sintering conditions. The product media have been characterized by scanning electron microscopy (SEM), nitrogen adsorption porosimetry, and vibrating sample magnetometry.

  2. Photon-assisted tunneling in a Fe8 single-molecule magnet

    NASA Astrophysics Data System (ADS)

    Sorace, L.; Wernsdorfer, W.; Thirion, C.; Barra, A.-L.; Pacchioni, M.; Mailly, D.; Barbara, B.

    2003-12-01

    The low-temperature spin dynamics of a Fe8 single-molecule magnet was studied under circularly polarized electromagnetic radiation allowing us to establish clearly photon-assisted tunneling. This effect, while linear at low power, becomes highly nonlinear above a relatively low-power threshold. Heating due to phonon emission, spin-spin interactions, and coherent emission/absorption of photons might lead to the observed nonlinearity. These results are of importance if such systems are to be used as quantum computers.

  3. Microwave-Assisted Synthesis, Microstructure, and Magnetic Properties of Rare-Earth Cobaltites.

    PubMed

    Gutiérrez Seijas, Julia; Prado-Gonjal, Jesús; Ávila Brande, David; Terry, Ian; Morán, Emilio; Schmidt, Rainer

    2017-01-03

    The series of perovskite rare-earth (RE) doped cobaltites (RE)CoO3 (RE = La-Dy) was prepared by microwave-assisted synthesis. The crystal structure undergoes a change of symmetry depending on the size of the RE cation. LaCoO3 is rhombohedral, S.G. R3̅c (No. 167), while, for the rest of the RE series (Pr-Dy), the symmetry is orthorhombic, S.G. Pnma (No. 62). The crystal structure obtained by X-ray diffraction was confirmed by high-resolution transmission electron microscopy, which yielded a good match between experimental and simulated images. It is further shown that the well-known magnetism in LaCoO3, which involves a thermally induced Co(3+) (d(6)) low spin to intermediate or high spin state transition, is strongly modified by the RE cation, and a rich variety of magnetic order has been detected across the series.

  4. Nanoscale heat transfer in the head-disk interface for heat assisted magnetic recording

    NASA Astrophysics Data System (ADS)

    Wu, Haoyu; Xiong, Shaomin; Canchi, Sripathi; Schreck, Erhard; Bogy, David

    2016-02-01

    Laser heating has been introduced in heat-assisted magnetic recording in order to reduce the magnetic coercivity and enable data writing. However, the heat flow inside a couple of nanometers head-disk gap is still not well understood. An experimental stage was built for studying heat transfer in the head-disk interface (HDI) and the heat-induced instability of the HDI. A laser heating system is included to produce a heated spot on the disk at the position of the slider. A floating air bearing slider is implemented in the stage for sensing the temperature change of the slider due to the heat transfer from the disk by the use of an embedded contact sensor, and the gap between the two surfaces is controlled by the use of a thermal fly-height control actuator. By using this system, we explore the dependency of the heat transfer on the gap spacing as well as the disk temperature.

  5. Using hybrid magnetic bearings to completely suspend the impeller of a ventricular assist device.

    PubMed

    Khanwilkar, P; Olsen, D; Bearnson, G; Allaire, P; Maslen, E; Flack, R; Long, J

    1996-06-01

    Clinically available blood pumps and those under development suffer from poor mechanical reliability and poor biocompatibility related to anatomic fit, hemolysis, and thrombosis. To alleviate these problems concurrently in a long-term device is a substantial challenge. Based on testing the performance of a prototype, and on our judgment of desired characteristics, we have configured an innovative ventricular assist device, the CFVAD4, for long-term use. The design process and its outcome, the CFVAD4 system configuration, is described. To provide unprecedented reliability and biocompatibility, magnetic bearings completely suspend the rotating pump impeller. The CFVAD4 uses a combination of passive (permanent) and active (electric) magnetic bearings, a mixed flow impeller, and a slotless 3-phase brushless DC motor. These components are shaped, oriented, and integrated to provide a compact, implantable, pancake-shaped unit for placement in the left upper abdominal quadrant of adult humans.

  6. Analysis of self-heating of thermally assisted spin-transfer torque magnetic random access memory

    SciTech Connect

    Deschenes, Austin; Muneer, Sadid; Akbulut, Mustafa; Gokirmak, Ali; Silva, Helena

    2016-11-11

    Thermal assistance has been shown to significantly reduce the required operation power for spin torque transfer magnetic random access memory (STT-MRAM). Proposed heating methods include modified material stack compositions that result in increased self-heating or external heat sources. Here, we analyze the self-heating process of a standard perpendicular magnetic anisotropy STT-MRAM device through numerical simulations in order to understand the relative contributions of Joule, thermoelectric Peltier and Thomson, and tunneling junction heating. A 2D rotationally symmetric numerical model is used to solve the coupled electro-thermal equations including thermoelectric effects and heat absorbed or released at the tunneling junction. We compare self-heating for different common passivation materials, positive and negative electrical current polarity, and different device thermal anchoring and boundaries resistance configurations. The variations considered are found to result in significant differences in maximum temperatures reached. Average increases of 3 K, 10 K, and 100 K for different passivation materials, positive and negative polarity, and different thermal anchoring configurations, respectively, are observed. Furthermore, the highest temperatures, up to 424 K, are obtained for silicon dioxide as the passivation material, positive polarity, and low thermal anchoring with thermal boundary resistance configurations. Interestingly it is also found that due to the tunneling heat, Peltier effect, device geometry, and numerous interfacial layers around the magnetic tunnel junction (MTJ), most of the heat is dissipated on the lower potential side of the magnetic junction. We have observed this asymmetry in heating and is important as thermally assisted switching requires heating of the free layer specifically and this will be significantly different for the two polarity operations, set and reset.

  7. Analysis of self-heating of thermally assisted spin-transfer torque magnetic random access memory

    DOE PAGES

    Deschenes, Austin; Muneer, Sadid; Akbulut, Mustafa; ...

    2016-11-11

    Thermal assistance has been shown to significantly reduce the required operation power for spin torque transfer magnetic random access memory (STT-MRAM). Proposed heating methods include modified material stack compositions that result in increased self-heating or external heat sources. Here, we analyze the self-heating process of a standard perpendicular magnetic anisotropy STT-MRAM device through numerical simulations in order to understand the relative contributions of Joule, thermoelectric Peltier and Thomson, and tunneling junction heating. A 2D rotationally symmetric numerical model is used to solve the coupled electro-thermal equations including thermoelectric effects and heat absorbed or released at the tunneling junction. We comparemore » self-heating for different common passivation materials, positive and negative electrical current polarity, and different device thermal anchoring and boundaries resistance configurations. The variations considered are found to result in significant differences in maximum temperatures reached. Average increases of 3 K, 10 K, and 100 K for different passivation materials, positive and negative polarity, and different thermal anchoring configurations, respectively, are observed. Furthermore, the highest temperatures, up to 424 K, are obtained for silicon dioxide as the passivation material, positive polarity, and low thermal anchoring with thermal boundary resistance configurations. Interestingly it is also found that due to the tunneling heat, Peltier effect, device geometry, and numerous interfacial layers around the magnetic tunnel junction (MTJ), most of the heat is dissipated on the lower potential side of the magnetic junction. We have observed this asymmetry in heating and is important as thermally assisted switching requires heating of the free layer specifically and this will be significantly different for the two polarity operations, set and reset.« less

  8. Analysis of self-heating of thermally assisted spin-transfer torque magnetic random access memory.

    PubMed

    Deschenes, Austin; Muneer, Sadid; Akbulut, Mustafa; Gokirmak, Ali; Silva, Helena

    2016-01-01

    Thermal assistance has been shown to significantly reduce the required operation power for spin torque transfer magnetic random access memory (STT-MRAM). Proposed heating methods include modified material stack compositions that result in increased self-heating or external heat sources. In this work we analyze the self-heating process of a standard perpendicular magnetic anisotropy STT-MRAM device through numerical simulations in order to understand the relative contributions of Joule, thermoelectric Peltier and Thomson, and tunneling junction heating. A 2D rotationally symmetric numerical model is used to solve the coupled electro-thermal equations including thermoelectric effects and heat absorbed or released at the tunneling junction. We compare self-heating for different common passivation materials, positive and negative electrical current polarity, and different device thermal anchoring and boundaries resistance configurations. The variations considered are found to result in significant differences in maximum temperatures reached. Average increases of 3 K, 10 K, and 100 K for different passivation materials, positive and negative polarity, and different thermal anchoring configurations, respectively, are observed. The highest temperatures, up to 424 K, are obtained for silicon dioxide as the passivation material, positive polarity, and low thermal anchoring with thermal boundary resistance configurations. Interestingly it is also found that due to the tunneling heat, Peltier effect, device geometry, and numerous interfacial layers around the magnetic tunnel junction (MTJ), most of the heat is dissipated on the lower potential side of the magnetic junction. This asymmetry in heating, which has also been observed experimentally, is important as thermally assisted switching requires heating of the free layer specifically and this will be significantly different for the two polarity operations, set and reset.

  9. Analysis of self-heating of thermally assisted spin-transfer torque magnetic random access memory

    PubMed Central

    Muneer, Sadid; Akbulut, Mustafa; Gokirmak, Ali; Silva, Helena

    2016-01-01

    Thermal assistance has been shown to significantly reduce the required operation power for spin torque transfer magnetic random access memory (STT-MRAM). Proposed heating methods include modified material stack compositions that result in increased self-heating or external heat sources. In this work we analyze the self-heating process of a standard perpendicular magnetic anisotropy STT-MRAM device through numerical simulations in order to understand the relative contributions of Joule, thermoelectric Peltier and Thomson, and tunneling junction heating. A 2D rotationally symmetric numerical model is used to solve the coupled electro-thermal equations including thermoelectric effects and heat absorbed or released at the tunneling junction. We compare self-heating for different common passivation materials, positive and negative electrical current polarity, and different device thermal anchoring and boundaries resistance configurations. The variations considered are found to result in significant differences in maximum temperatures reached. Average increases of 3 K, 10 K, and 100 K for different passivation materials, positive and negative polarity, and different thermal anchoring configurations, respectively, are observed. The highest temperatures, up to 424 K, are obtained for silicon dioxide as the passivation material, positive polarity, and low thermal anchoring with thermal boundary resistance configurations. Interestingly it is also found that due to the tunneling heat, Peltier effect, device geometry, and numerous interfacial layers around the magnetic tunnel junction (MTJ), most of the heat is dissipated on the lower potential side of the magnetic junction. This asymmetry in heating, which has also been observed experimentally, is important as thermally assisted switching requires heating of the free layer specifically and this will be significantly different for the two polarity operations, set and reset. PMID:28144517

  10. Ultra-sensitive magnetic field sensor with resolved temperature cross-sensitivity employing microfiber-assisted modal interferometer integrated with magnetic fluids

    NASA Astrophysics Data System (ADS)

    Liu, Haifeng; Zhang, Hao; Liu, Bo; Song, Binbin; Wu, Jixuan; Lin, Lie

    2016-07-01

    A compact and ultra-sensitive magnetic field sensor has been proposed by exploiting a microfiber-assisted Mach-Zehnder interferometer functionalized by magnetic fluids. We have experimentally investigated the transmission spectral responses of the proposed sensor to the variation of applied magnetic field intensity and environmental temperature. The interference dips exhibit a magnetic field sensitivity as large as -1.193 nm/Oe for a low magnetic field intensity range of 3 Oe to 21 Oe. By using the sensing matrix containing the magnetic field as well as temperature sensitivities for different interference dips, the temperature cross-sensitivity issue could be effectively resolved. Our proposed sensor is anticipated to find potential applications in weak magnetic field detection, and moreover, the immunity to temperature cross-sensitivity effect ensures its applicability in temperature-fluctuated environments.

  11. Microgravity and Hypogravity Compatible Methods for the Destruction of Solid Wastes by Magnetically Assisted Gasification

    NASA Technical Reports Server (NTRS)

    Atwater, James E.; Akse, James R.; Wheeler, Richard R., Jr.; Jovanovic, Goran N.; Pinto-Espinoza, Joaquin; Reed, Brian; Sornchamni, Thana

    2003-01-01

    This report summarizes a three-year collaborative effort between researchers at UMPQUA Research Company (URC) and the Chemical Engineering Department at Oregon State University (OSU). The Magnetically Assisted Gasification (MAG) concept was originally conceived as a microgravity and hypogravity compatible means for the decomposition of solid waste materials generated aboard spacecraft, lunar and planetary habitations, and for the recovery of potentially valuable resources. While a number of methods such as supercritical water oxidation (SCW0), fluidized bed incineration, pyrolysis , composting and related biological processes have been demonstrated for the decomposition of solid wastes, none of these methods are particularly well- suited for employment under microgravity or hypogravity conditions. For example, fluidized bed incineration relies upon a balance between drag forces which the flowing gas stream exerts upon the fluidization particles and the opposing force of gravity. In the absence of gravity, conventional fluidization cannot take place. Hypogravity operation can also be problematic for conventional fluidized bed reactors, because the various factors which govern fluidization phenomena do not all scale linearly with gravity. For this reason it may be difficult to design and test fluidized bed reactors in lg, which are intended to operate under different gravitational conditions. However, fluidization can be achieved in microgravity (and hypogravity) if a suitable replacement force to counteract the forces between fluid and particles can be found. Possible alternatives include: centripetal force, electric fields, or magnetic fields. Of these, magnetic forces created by the action of magnetic fields and magnetic field gradients upon ferromagnetic media offer the most practical approach. The goal of this URC-OSU collaborative effort was to develop magnetic hardware and methods to control the degree of fluidization (or conversely consolidation) of granular

  12. Magnetic suspension of the rotor of a ventricular assist device of mixed flow type.

    PubMed

    Horikawa, Oswaldo; de Andrade, Aron José Pazin; da Silva, Isaías; Bock, Eduardo Guy Perpetuo

    2008-04-01

    This work presents results of preliminary studies concerning application of magnetic bearing in a ventricular assist device (VAD) being developed by Dante Pazzanese Institute of Cardiology-IDPC (São Paulo, Brazil). The VAD-IDPC has a novel architecture that distinguishes from other known VADs. In this, the rotor has a conical geometry with spiral impellers, showing characteristics that are intermediate between a centrifugal VAD and an axial VAD. The effectiveness of this new type of blood pumping principle was showed by tests and by using it in heart surgery for external blood circulation. However, the developed VAD uses a combination of ball bearings and mechanical seals, limiting the life for some 10 h, making impossible its long-term use or its use as an implantable VAD. As a part of development of an implantable VAD, this work aims at the replacement of ball bearings by a magnetic bearing. The most important magnetic bearing principles are studied and the magnetic bearing developed by Escola Politécnica of São Paulo University (EPUSP-MB) is elected because of its very simple architecture. Besides presenting the principle of the EPUSP-MB, this work presents one possible alternative for applying the EPUSP-MB in the IDPC-VAD.

  13. Magnetically assisted chemical separation (MACS) process: Preparation and optimization of particles for removal of transuranic elements

    SciTech Connect

    Nunez, L.; Kaminski, M.; Bradley, C.; Buchholz, B.A.; Aase, S.B.; Tuazon, H.E.; Vandegrift, G.F.; Landsberger, S.

    1995-05-01

    The Magnetically Assisted Chemical Separation (MACS) process combines the selectivity afforded by solvent extractants with magnetic separation by using specially coated magnetic particles to provide a more efficient chemical separation of transuranic (TRU) elements, other radionuclides, and heavy metals from waste streams. Development of the MACS process uses chemical and physical techniques to elucidate the properties of particle coatings and the extent of radiolytic and chemical damage to the particles, and to optimize the stages of loading, extraction, and particle regeneration. This report describes the development of a separation process for TRU elements from various high-level waste streams. Polymer-coated ferromagnetic particles with an adsorbed layer of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) diluted with tributyl phosphate (TBP) were evaluated for use in the separation and recovery of americium and plutonium from nuclear waste solutions. Due to their chemical nature, these extractants selectively complex americium and plutonium contaminants onto the particles, which can then be recovered from the solution by using a magnet. The partition coefficients were larger than those expected based on liquid[liquid extractions, and the extraction proceeded with rapid kinetics. Extractants were stripped from the particles with alcohols and 400-fold volume reductions were achieved. Particles were more sensitive to acid hydrolysis than to radiolysis. Overall, the optimization of a suitable NMCS particle for TRU separation was achieved under simulant conditions, and a MACS unit is currently being designed for an in-lab demonstration.

  14. Interfering lipoproteins in magnetic field-assisted agglutination of superparamagnetic particles immunoassay.

    PubMed

    Cauet, Gilles; Daynès, Aurélien; Temurok, Nevzat

    2016-04-01

    The technology of magnetic field-assisted immuno-agglutination of superparamagnetic particles allows sensitive detection of biomarkers in whole blood. However, we observed non-specific agglutination (NSA), due to interfering plasma proteins, that negatively affects C-reactive protein immunoassay. The objective of the study was to identify the plasma proteins involved and to eliminate these interferences. Plasma was fractionated by size exclusion HPLC and each fraction was tested for non-specific agglutination. In addition, plasma proteins bound to magnetic particles were analyzed by SDS-gel electrophoresis and identified by mass spectrometry. We found that NSA was due to the binding of some lipoproteins to the particles. NSA was observed in the presence of purified LDL and VLDL but not HDL. NSA was mediated by the binding of ApoB100 to magnetic particles through its heparin binding sites. These interferences could be eliminated by addition of heparin or other polyanions like dextran sulfate to the assay buffer. NSA results from the binding of some plasma lipoproteins to magnetic particles. The use of a polyanion to eliminate these interferences allows the formulation of a stable reagent.

  15. Super-paramagnetic nanoparticles synthesis in a thermal plasma reactor assisted by magnetic bottle

    NASA Astrophysics Data System (ADS)

    Cartaya, R.; Puerta, J.; Martín, P.

    2015-03-01

    The present work is a study of the synthesis of super-paramagnetic particles. A preliminary study based on thermodynamic diagrams of Gibbs free energy minimization, was performed with the CSIRO Thermochemical System. In this way, the synthesis of magnetite nanoparticles from precursor powder of ore iron in a thermal reactor, was performed. Then the process was simulated mathematically using magnetohydrodynamic and kinetic equations, in order to predict the synthesis process. A cylindrical reactor assisted by magnetic mirrors was used. The peak intensity of 0.1 tesla (1000 Gauss) was measured at the end of the solenoid. A PlazjetTM 105/15 thermal plasma torch was used. The precursor powder was iron oxide and the plasma gas, nitrogen. The magnetite powder was magnetized whit rare-earth super-magnets, alloy of neodymium-iron boron (NdFeB) grade N-42. The synthesized nanoparticles diameters was measured with a scanning electron microscope LECO and the permanent magnetization with a YOKOGAWA gauss meter, model 325i. Our experimental results show that it is possible the synthesis of super-paramagnetic nanoparticles in thermal plasma reactors.

  16. Initial experience with magnet-assisted single trocar appendectomy in children.

    PubMed

    Padilla, Benjamin E; Dominguez, Guillermo; Millan, Carolina; Bignon, Horacio; Buela, Enrique; Bellia, Gaston; Elias, Maria Eugenia; Albertal, Mariano; Martinez-Ferro, Marcelo

    2013-05-01

    Single-incision laparoscopic surgery (SILS) is increasingly being used to treat acute appendicitis. Existing SILS techniques suffer from inefficient triangulation and poor ergonomics. In an effort to improve on existing SILS techniques, we developed the magnet-assisted single trocar (MAST) appendectomy. We retrospectively analyzed all MAST appendectomies performed between March 2010 and February 2011. Outcomes included demographics, diagnosis, operative time, hospital stay, and complications. Twenty-three MAST appendectomies were performed in 10 boys and 13 girls. The mean age at operation was 12.22 years (range, 5-19 years), and the mean weight was 46.5 kg (range, 25-82 kg). At presentation the mean white blood cell count was 15,000 with 74% polymorphonuclear neutrophils. The mean operative time was 61 minutes (range, 20-105 minutes), and length of stay was 3.6 days (range, 1-7 days). In total, 4 operations (17%) required one additional 5-mm trocar to complete the operation, and none was converted to an open operation. There were no intraoperative complications, nor were there any wound infections. MAST appendectomy is safe and effective in children. Magnetic instruments provide excellent triangulation and improve ergonomics. This technique uses a single 12-mm trocar and can be performed without the aid of a surgical assistant.

  17. Thermal effects on transducer material for heat assisted magnetic recording application

    NASA Astrophysics Data System (ADS)

    Ji, Rong; Xu, Baoxi; Cen, Zhanhong; Ying, Ji Feng; Toh, Yeow Teck

    2015-05-01

    Heat Assisted Magnetic Recording (HAMR) is a promising technology for next generation hard disk drives with significantly increased data recording capacities. In HAMR, an optical near-field transducer (NFT) is used to concentrate laser energy on a magnetic recording medium to fulfill the heat assist function. The key components of a NFT are transducer material, cladding material, and adhesion material between the cladding and the transducer materials. Since transducer materials and cladding materials have been widely reported, this paper focuses on the adhesion materials between the Au transducer and the Al2O3 cladding material. A comparative study for two kinds of adhesion material, Ta and Cr, has been conducted. We found that Ta provides better thermal stability to the whole transducer than Cr. This is because after thermal annealing, chromium forms oxide material at interfaces and chromium atoms diffuse remarkably into the Au layer and react with Au to form Au alloy. This study also provides insights on the selection of adhesion material for HAMR transducer.

  18. Thermal effects on transducer material for heat assisted magnetic recording application

    SciTech Connect

    Ji, Rong Xu, Baoxi; Cen, Zhanhong; Ying, Ji Feng; Toh, Yeow Teck

    2015-05-07

    Heat Assisted Magnetic Recording (HAMR) is a promising technology for next generation hard disk drives with significantly increased data recording capacities. In HAMR, an optical near-field transducer (NFT) is used to concentrate laser energy on a magnetic recording medium to fulfill the heat assist function. The key components of a NFT are transducer material, cladding material, and adhesion material between the cladding and the transducer materials. Since transducer materials and cladding materials have been widely reported, this paper focuses on the adhesion materials between the Au transducer and the Al{sub 2}O{sub 3} cladding material. A comparative study for two kinds of adhesion material, Ta and Cr, has been conducted. We found that Ta provides better thermal stability to the whole transducer than Cr. This is because after thermal annealing, chromium forms oxide material at interfaces and chromium atoms diffuse remarkably into the Au layer and react with Au to form Au alloy. This study also provides insights on the selection of adhesion material for HAMR transducer.

  19. Launch Control Network Engineer

    NASA Technical Reports Server (NTRS)

    Medeiros, Samantha

    2017-01-01

    The Spaceport Command and Control System (SCCS) is being built at the Kennedy Space Center in order to successfully launch NASA’s revolutionary vehicle that allows humans to explore further into space than ever before. During my internship, I worked with the Network, Firewall, and Hardware teams that are all contributing to the huge SCCS network project effort. I learned the SCCS network design and the several concepts that are running in the background. I also updated and designed documentation for physical networks that are part of SCCS. This includes being able to assist and build physical installations as well as configurations. I worked with the network design for vehicle telemetry interfaces to the Launch Control System (LCS); this allows the interface to interact with other systems at other NASA locations. This network design includes the Space Launch System (SLS), Interim Cryogenic Propulsion Stage (ICPS), and the Orion Multipurpose Crew Vehicle (MPCV). I worked on the network design and implementation in the Customer Avionics Interface Development and Analysis (CAIDA) lab.

  20. ARES I-X Launch Prep

    NASA Image and Video Library

    2009-10-26

    NASA Ares I-X Assistant Launch Director Pete Nickolenko, left, and NASA Ares I-X Launch Director Ed Mango monitor the launch countdown from Firing Room One of the Launch Control Center (LCC) at the Kennedy Space Center during the planned launch of the Ares I-X rocket from pad 39b at the Kennedy Space Center in Cape Canaveral, Fla., Tuesday, Oct. 27, 2009. The flight test of Ares I-X will provide NASA with an early opportunity to test and prove flight characteristics, hardware, facilities and ground operations associated with the Ares I. Photo Credit: (NASA/Bill Ingalls)

  1. Fully Magnetically Levitated Left Ventricular Assist System for Treating Advanced HF: A Multicenter Study.

    PubMed

    Netuka, Ivan; Sood, Poornima; Pya, Yuriy; Zimpfer, Daniel; Krabatsch, Thomas; Garbade, Jens; Rao, Vivek; Morshuis, Michiel; Marasco, Silvana; Beyersdorf, Friedhelm; Damme, Laura; Schmitto, Jan D

    2015-12-15

    The HeartMate 3 left ventricular assist system (LVAS) is intended to provide long-term support to patients with advanced heart failure. The centrifugal flow pump is designed for enhanced hemocompatibility by incorporating a magnetically levitated rotor with wide blood-flow paths and an artificial pulse. The aim of this single-arm, prospective, multicenter study was to evaluate the performance and safety of this LVAS. The primary endpoint was 6-month survival compared with INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support)-derived performance goal. Patients were adults with ejection fraction ≤ 25%, cardiac index ≤ 2.2 l/min/m(2) without inotropes or were inotrope-dependent on optimal medical management, or listed for transplant. Fifty patients were enrolled at 10 centers. The indications for LVAS support were bridge to transplantation (54%) or destination therapy (46%). At 6 months, 88% of patients continued on support, 4% received transplants, and 8% died. Thirty-day mortality was 2% and 6-month survival 92%, which exceeded the 88% performance goal. Support with the fully magnetically levitated LVAS significantly reduced mortality risk by 66% compared with the Seattle Heart Failure Model-predicted survival of 78% (p = 0.0093). Key adverse events included reoperation for bleeding (14%), driveline infection (10%), gastrointestinal bleeding (8%), and debilitating stroke (modified Rankin Score > 3) (8%). There were no pump exchanges, pump malfunctions, pump thrombosis, or hemolysis events. New York Heart Association classification, 6-min walk test, and quality-of-life scores showed progressive and sustained improvement. The results show that the fully magnetically levitated centrifugal-flow chronic LVAS is safe, with high 30-day and 6-month survival rates, a favorable adverse event profile, and improved quality of life and functional status. (HeartMate 3™ CE Mark Clinical Investigation Plan [HM3 CE Mark]; NCT02170363). Copyright

  2. Areal density optimizations for heat-assisted magnetic recording of high-density media

    NASA Astrophysics Data System (ADS)

    Vogler, Christoph; Abert, Claas; Bruckner, Florian; Suess, Dieter; Praetorius, Dirk

    2016-06-01

    Heat-assisted magnetic recording (HAMR) is hoped to be the future recording technique for high-density storage devices. Nevertheless, there exist several realization strategies. With a coarse-grained Landau-Lifshitz-Bloch model, we investigate in detail the benefits and disadvantages of a continuous and pulsed laser spot recording of shingled and conventional bit-patterned media. Additionally, we compare single-phase grains and bits having a bilayer structure with graded Curie temperature, consisting of a hard magnetic layer with high TC and a soft magnetic one with low TC, respectively. To describe the whole write process as realistically as possible, a distribution of the grain sizes and Curie temperatures, a displacement jitter of the head, and the bit positions are considered. For all these cases, we calculate bit error rates of various grain patterns, temperatures, and write head positions to optimize the achievable areal storage density. Within our analysis, shingled HAMR with a continuous laser pulse moving over the medium reaches the best results and thus has the highest potential to become the next-generation storage device.

  3. Synthesis and characterization of carbon-encapsulated magnetic nanoparticles via arc-plasma assisted CVD.

    PubMed

    Li, Zhentao; Hu, Chao; Yu, Chang; Qiu, Jieshan

    2009-12-01

    Carbon-encapsulated magnetic nanoparticles (CEMNs) were fabricated on a large scale by arc-plasma assisted CVD in acetylene. The coal-derived metal-containing (Fe, Co and Ni) carbon rods were used as anodes, while a high-purity graphite rod was used as a cathode that remained unchanged during the arcing process. The CEMNs obtained were characterized by TEM, XRD, Raman spectroscopy, N2 adsorption isotherms and VSM. The diameter distribution of the obtained CEMNs varies from 10 to 70 nm, of which the metal cores are proximately 5-50 nm. The core phases in Fe(C) nanoparticles are body-centered cubic Fe and orthorhombic Fe3C while Co(C) nanoparticles and Ni(C) nanoparticles show the characteristic of a face-centered cubic structure. The Fe(C), Co(C) and Ni(C) nanoparticles with well-ordered graphitic shells have the surface area of 89 m2/g, 72 m2/g and 75 m2/g, respectively. The CEMNs show ferromagnetic of which was characterized by a ratio of remnant magnetization (MR) to saturation magnetization (MS).

  4. A novel permanently magnetised high gradient magnetic filter using assisted capture for fine particles

    SciTech Connect

    Watson, J.H.P.

    1995-02-01

    This paper describes the structure and properties of a novel permanently magnetised magnetic filter for fine friable radioactive material. Previously a filter was described and tested. This filter was designed so that the holes in the filter are left open as capture proceeds which means the pressure drop builds up only slowly. This filter is not suitable for friable composite particles which can be broken by mechanical forces. The structure of magnetic part of the second filter has been changed so as to strongly capture particles composed of fine particles weakly bound together which tend to break when captured. This uses a principle of assisted-capture in which coarse particles aid the capture of the fine fragments. The technique has the unfortunate consequence that the pressure drop across the filter rises faster as capture capture proceeds than the filter described previously. These filters have the following characteristics: (1) No external magnet is required. (2) No external power is required. (3) Small is size and portable. (4) Easily interchangeable. (5) Can be cleaned without demagnetising.

  5. Microwave Assisted Synthesis of Ferrite Nanoparticles: Effect of Reaction Temperature on Particle Size and Magnetic Properties.

    PubMed

    Kalyani, S; Sangeetha, J; Philip, John

    2015-08-01

    The preparation of ferrite magnetic nanoparticles of different particle sizes by controlling the reaction temperature using microwave assisted synthesis is reported. The iron oxide nanoparticles synthesized at two different temperatures viz., 45 and 85 °C were characterized using techniques such as X-ray diffraction (XRD), small angle X-ray scattering (SAXS), vibrating sample magnetometry (VSM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The average size of iron oxide nanoparticles synthesized at 45 and 85 °C is found to be 10 and 13.8 nm, respectively, and the nanoparticles exhibited superparamagantic behavior at room temperature. The saturation magnetization values of nanoparticles synthesized at 45 and 85 °C were found to be 67 and 72 emu/g, respectively. The increase in particle size and saturation magnetization values with increase in incubation temperature is attributed to a decrease in supersaturation at elevated temperature. The Curie temperature was found to be 561 and 566 0C for the iron oxide nanoparticles synthesized at 45 and 85 °C, respectively. The FTIR spectrum of the iron oxide nanoparticles synthesized at different temperatures exhibited the characteristic peaks that corresponded to the stretching of bonds between octahedral and tetrahedral metal ions to oxide ions. Our results showed that the ferrite nanoparticle size can be varied by controlling the reaction temperature inside a microwave reactor.

  6. Vertical Si nanowire arrays fabricated by magnetically guided metal-assisted chemical etching

    NASA Astrophysics Data System (ADS)

    Chun, Dong Won; Kim, Tae Kyoung; Choi, Duyoung; Caldwell, Elizabeth; Kim, Young Jin; Paik, Jae Cheol; Jin, Sungho; Chen, Renkun

    2016-11-01

    In this work, vertically aligned Si nanowire arrays were fabricated by magnetically guided metal-assisted directional chemical etching. Using an anodized aluminum oxide template as a shadow mask, nanoscale Ni dot arrays were fabricated on an Si wafer to serve as a mask to protect the Si during the etching. For the magnetically guided chemical etching, we deposited a tri-layer metal catalyst (Au/Fe/Au) in a Swiss-cheese configuration and etched the sample under the magnetic field to improve the directionality of the Si nanowire etching and increase the etching rate along the vertical direction. After the etching, the nanowires were dried with minimal surface-tension-induced aggregation by utilizing a supercritical CO2 drying procedure. High-resolution transmission electron microscopy (HR-TEM) analysis confirmed the formation of single-crystal Si nanowires. The method developed here for producing vertically aligned Si nanowire arrays could find a wide range of applications in electrochemical and electronic devices.

  7. Vertical Si nanowire arrays fabricated by magnetically guided metal-assisted chemical etching.

    PubMed

    Chun, Dong Won; Kim, Tae Kyoung; Choi, Duyoung; Caldwell, Elizabeth; Kim, Young Jin; Paik, Jae Cheol; Jin, Sungho; Chen, Renkun

    2016-11-11

    In this work, vertically aligned Si nanowire arrays were fabricated by magnetically guided metal-assisted directional chemical etching. Using an anodized aluminum oxide template as a shadow mask, nanoscale Ni dot arrays were fabricated on an Si wafer to serve as a mask to protect the Si during the etching. For the magnetically guided chemical etching, we deposited a tri-layer metal catalyst (Au/Fe/Au) in a Swiss-cheese configuration and etched the sample under the magnetic field to improve the directionality of the Si nanowire etching and increase the etching rate along the vertical direction. After the etching, the nanowires were dried with minimal surface-tension-induced aggregation by utilizing a supercritical CO2 drying procedure. High-resolution transmission electron microscopy (HR-TEM) analysis confirmed the formation of single-crystal Si nanowires. The method developed here for producing vertically aligned Si nanowire arrays could find a wide range of applications in electrochemical and electronic devices.

  8. KENNEDY SPACE CENTER, FLA. - NASA's Lunar Prospector spacecraft launched successfully on its way to the Moon from Launch Complex 46 (LC46) at Cape Canaveral Air Station on Jan. 6 at 9:38 p.m. EST. It was the inaugural launch of Lockheed Martin's Athena II launch vehicle and the first launch from LC46, operated by Spaceport Florida Authority. Lunar Prospector, built for the NASA Ames Research Center by Lockheed Martin, is a spin-stabilized spacecraft designed to provide NASA with the first global maps of the Moon's surface and its gravitational magnetic fields, as well as look for the possible presence of ice near the lunar poles. It will orbit the Moon at an altitude of approximately 63 miles during a one-year mission.

    NASA Image and Video Library

    1998-01-06

    KENNEDY SPACE CENTER, FLA. - NASA's Lunar Prospector spacecraft launched successfully on its way to the Moon from Launch Complex 46 (LC46) at Cape Canaveral Air Station on Jan. 6 at 9:38 p.m. EST. It was the inaugural launch of Lockheed Martin's Athena II launch vehicle and the first launch from LC46, operated by Spaceport Florida Authority. Lunar Prospector, built for the NASA Ames Research Center by Lockheed Martin, is a spin-stabilized spacecraft designed to provide NASA with the first global maps of the Moon's surface and its gravitational magnetic fields, as well as look for the possible presence of ice near the lunar poles. It will orbit the Moon at an altitude of approximately 63 miles during a one-year mission.

  9. The Operation of Magnetically Assisted Fluidized Bed in Microgravity and Variable Gravity: Experiment and Theory

    NASA Astrophysics Data System (ADS)

    Sornchamni, T.; Jovanovic, G.; Atwater, J.; Akse, J.; Wheeler, R.

    Typically, the operation of a conventional fluidized bed relies on the balance of gravitational, buoyancy, and drag forces. In the absence of normal gravity, or under microgravity and variable gravity conditions, the gravitational force must be replaced with an alternative force to restore fluidization. Our work has shown that, given a suitable variable magnetic field design, the resulting magnetic field gradient can create sufficient magnetic force acting upon the ferromagnetic particles to replace or supplement the gravitational force. Therefore, the ferromagnetic granular media can be fluidized in either microgravity or hypogravity. In this paper, we present our experimental and theoretical work leading to a) development of theoretical model based on fundamental principles for the design of the Gradient Magnetically Assisted Fluidized Bed (G-MAFB), and b) practical implementation of the G-MAFB in the filtration and destruction of solid biowaste particles from liquid streams. The G-MAFB system consists of a fluidization column and series of Helmholtz electromagnetic coils, with DC power supply. Each Helmholtz ring is powered and controlled separately. Experiments are performed in both 0g (on board NASA KC- 135) and 1g (laboratory) environments. The experiments in 0g are conducted in a two-dimensional, square cross-section, tapered fluidization column. The tapered shape is introduced to provide additional stability to the fluidization particles. The experiments in 0g prove that the magnetic force has a significant role in keeping the particles from extruding out of the bed. Without the magnetic force, it is impossible to have fluidization in space. Solid waste destruction technologies are needed to support long duration human habitation in space. The current technologies, including supercritical water oxidation (SCWO), microwave powered combustion and fluidized bed incineration, have been applied to the destruction of solid wastes, but none are compatible with

  10. Influence of magnetic resonance imaging in the decision to preserve or resect neurovascular bundles at robotic assisted laparoscopic radical prostatectomy.

    PubMed

    Park, Bong Hee; Jeon, Hwang Gyun; Jeong, Byong Chang; Seo, Seong Il; Lee, Hyun Moo; Choi, Han Yong; Jeon, Seong Soo

    2014-07-01

    We evaluated the accuracy of preoperative multiparametric 3.0-T magnetic resonance imaging for local staging of prostate cancer and its influence in the decision to preserve neurovascular bundles at robotic assisted laparoscopic radical prostatectomy. The study included 353 patients who had confirmed prostate cancer and underwent preoperative magnetic resonance imaging and robotic assisted laparoscopic radical prostatectomy between 2008 and 2011. The extent of neurovascular bundle sparing was initially determined on the basis of the clinical information and the nerve sparing surgical plan was reevaluated after review of the magnetic resonance imaging report. The value of preoperative magnetic resonance imaging in the prediction of extracapsular extension and in the decision of surgical plan according to D'Amico risk classification was analyzed. The magnetic resonance imaging performed correct staging, over staging and under staging in 261 (73.9%), 43 (12.2%), and 49 (13.9%) patients, respectively. After review of the magnetic resonance imaging reports, the initial surgical plan was not changed in 260 patients (74%) and was changed in 93 patients (26%). Robotic assisted laparoscopic radical prostatectomy was changed to a more preservable neurovascular bundle sparing procedure in 53 patients (57%) and changed to a more aggressive neurovascular bundle resecting procedure in 40 patients (43%). For the patients with a change to more conservative surgery, the appropriateness was 91%. The sensitivity of magnetic resonance imaging in predicting extracapsular extension showed a tendency to increase from low to high risk groups (33%, 46%, 80%, respectively, p <0.001). In intermediate and high risk groups, there was a surgical plan change in 40 patients (of 129, 31%) and 27 patients (of 67, 40%), respectively. Preoperative magnetic resonance imaging significantly improves the decision making to preserve or resect the neurovascular bundle at robotic assisted laparoscopic

  11. Fluid force predictions and experimental measurements for a magnetically levitated pediatric ventricular assist device.

    PubMed

    Throckmorton, Amy L; Untaroiu, Alexandrina; Lim, D Scott; Wood, Houston G; Allaire, Paul E

    2007-05-01

    The latest generation of artificial blood pumps incorporates the use of magnetic bearings to levitate the rotating component of the pump, the impeller. A magnetic suspension prevents the rotating impeller from contacting the internal surfaces of the pump and reduces regions of stagnant and high shear flow that surround fluid or mechanical bearings. Applying this third-generation technology, the Virginia Artificial Heart Institute has developed a ventricular assist device (VAD) to support infants and children. In consideration of the suspension design, the axial and radial fluid forces exerted on the rotor of the pediatric VAD were estimated using computational fluid dynamics (CFD) such that fluid perturbations would be counterbalanced. In addition, a prototype was built for experimental measurements of the axial fluid forces and estimations of the radial fluid forces during operation using a blood analog mixture. The axial fluid forces for a centered impeller position were found to range from 0.5 +/- 0.01 to 1 +/- 0.02 N in magnitude for 0.5 +/- 0.095 to 3.5 +/- 0.164 Lpm over rotational speeds of 6110 +/- 0.39 to 8030 +/- 0.57% rpm. The CFD predictions for the axial forces deviated from the experimental data by approximately 8.5% with a maximum difference of 18% at higher flow rates. Similarly for the off-centered impeller conditions, the maximum radial fluid force along the y-axis was found to be -0.57 +/- 0.17 N. The maximum cross-coupling force in the x direction was found to be larger with a maximum value of 0.74 +/- 0.22 N. This resulted in a 25-35% overestimate of the radial fluid force as compared to the CFD predictions; this overestimation will lead to a far more robust magnetic suspension design. The axial and radial forces estimated from the computational results are well within a range over which a compact magnetic suspension can compensate for flow perturbations. This study also serves as an effective and novel design methodology for blood pump

  12. Photonic crystal membrane reflectors by magnetic field-guided metal-assisted chemical etching

    NASA Astrophysics Data System (ADS)

    Balasundaram, Karthik; Mohseni, Parsian K.; Shuai, Yi-Chen; Zhao, Deyin; Zhou, Weidong; Li, Xiuling

    2013-11-01

    Metal-assisted chemical etching (MacEtch) is a simple etching method that uses metal as the catalyst for anisotropic etching of semiconductors. However, producing nano-structures using MacEtch from discrete metal patterns, in contrast to interconnected ones, has been challenging because of the difficulties in keeping the discrete metal features in close contact with the semiconductor. We report the use of magnetic field-guided MacEtch (h-MacEtch) to fabricate periodic nanohole arrays in silicon-on-insulator (SOI) wafers for high reflectance photonic crystal membrane reflectors. This study demonstrates that h-MacEtch can be used in place of conventional dry etching to produce ordered nanohole arrays for photonic devices.

  13. Preparation of magnetic Ni@graphene nanocomposites and efficient removal organic dye under assistance of ultrasound

    NASA Astrophysics Data System (ADS)

    Zhao, Chuang; Guo, Jianhui; Yang, Qing; Tong, Lei; Zhang, Jingwei; Zhang, Jiwei; Gong, Chunhong; Zhou, Jingfang; Zhang, Zhijun

    2015-12-01

    In this article, we report a facile one-step synthesis of Ni@graphene nanocomposite microspheres (NGs) in hydrazine hydrate solution under ultrasound conditions. During the ultrasonic process, graphene oxide (GO) was reduced effectively under mild conditions and Ni nanoparticles were simultaneously formed and anchored on graphene sheets, which act as spacers to keep the neighboring sheets separated. The target products exhibit excellent performance for fast and efficient removal of dye contaminants, rhodamine B (RhB) in aqueous solution, under assistance of ultrasound. Finally, the nanocomposites can be easily separated from solution by a magnet. Furthermore, higher content of graphene can be produced under sonication, which facilitates faster and more efficient removal of organic contaminates in the solution. The nanocomposites were also characterized by scanning electron microscopy, Raman spectroscopy, Fourier transformed infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray powder diffraction and thermogravimetric analysis.

  14. Operation of magnetically assisted fluidized beds in microgravity and variable gravity: experiment and theory

    NASA Technical Reports Server (NTRS)

    Sornchamni, T.; Jovanovic, G. N.; Reed, B. P.; Atwater, J. E.; Akse, J. R.; Wheeler, R. R.

    2004-01-01

    The conversion of solid waste into useful resources in support of long duration manned missions in space presents serious technological challenges. Several technologies, including supercritical water oxidation, microwave powered combustion and fluidized bed incineration, have been tested for the conversion of solid waste. However, none of these technologies are compatible with microgravity or hypogravity operating conditions. In this paper, we present the gradient magnetically assisted fluidized bed (G-MAFB) as a promising operating platform for fluidized bed operations in the space environment. Our experimental and theoretical work has resulted in both the development of a theoretical model based on fundamental principles for the design of the G-MAFB, and also the practical implementation of the G-MAFB in the filtration and destruction of solid biomass waste particles from liquid streams. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  15. Operation of magnetically assisted fluidized beds in microgravity and variable gravity: experiment and theory

    NASA Technical Reports Server (NTRS)

    Sornchamni, T.; Jovanovic, G. N.; Reed, B. P.; Atwater, J. E.; Akse, J. R.; Wheeler, R. R.

    2004-01-01

    The conversion of solid waste into useful resources in support of long duration manned missions in space presents serious technological challenges. Several technologies, including supercritical water oxidation, microwave powered combustion and fluidized bed incineration, have been tested for the conversion of solid waste. However, none of these technologies are compatible with microgravity or hypogravity operating conditions. In this paper, we present the gradient magnetically assisted fluidized bed (G-MAFB) as a promising operating platform for fluidized bed operations in the space environment. Our experimental and theoretical work has resulted in both the development of a theoretical model based on fundamental principles for the design of the G-MAFB, and also the practical implementation of the G-MAFB in the filtration and destruction of solid biomass waste particles from liquid streams. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  16. Fabrication of a glucose biosensor based on citric acid assisted cobalt ferrite magnetic nanoparticles.

    PubMed

    Krishna, Rahul; Titus, Elby; Chandra, Sudeshna; Bardhan, Neel Kanth; Krishna, Rohit; Bahadur, Dhirendra; Gracio, José

    2012-08-01

    A novel and practical glucose biosensor was fabricated with immobilization of Glucose oxidase (GOx) enzyme on the surface of citric acid (CA) assisted cobalt ferrite (CF) magnetic nanoparticles (MNPs). This innovative sensor was constructed with glassy carbon electrode which is represented as (GOx)/CA-CF/(GCE). An explicit high negative zeta potential value (-22.4 mV at pH 7.0) was observed on the surface of CA-CF MNPs. Our sensor works on the principle of detection of H2O2 which is produced by the enzymatic oxidation of glucose to gluconic acid. This sensor has tremendous potential for application in glucose biosensing due to the higher sensitivity 2.5 microA/cm2-mM and substantial increment of the anodic peak current from 0.2 microA to 10.5 microA.

  17. Mechanisms of heat transport across a nano-scale gap in heat assisted magnetic recording

    NASA Astrophysics Data System (ADS)

    Budaev, Bair V.; Bogy, David B.

    2012-06-01

    This paper compares different mechanisms of heat transport across nano-scale gaps and discusses the role of electromagnetic phenomena in heat transport in general nano-scale layered structures. The results of the analysis suggest that heat transfer across sub-5 nm gaps like that appearing in prototypes of heat assisted magnetic recording (HAMR) systems is dominated by direct intermolecular interactions between the separated bodies and is little affected by electromagnetic radiation. The analysis further suggests that local heating for HAMR with sub-5 nm spacing can be more efficiently achieved by a Joule heater that is simpler to fabricate than laser-based optical systems and is less destructive for the nano-scale transducers than laser radiation, which may lead to their structural damage and short duration life of nanoscale transducers.

  18. Performance characterization of a rotary centrifugal left ventricular assist device with magnetic suspension.

    PubMed

    Jahanmir, Said; Hunsberger, Andrew Z; Heshmat, Hooshang; Tomaszewski, Michael J; Walton, James F; Weiss, William J; Lukic, Branka; Pae, William E; Zapanta, Conrad M; Khalapyan, Tigran Z

    2008-05-01

    The MiTiHeart (MiTiHeart Corporation, Gaithersburg, MD, USA) left ventricular assist device (LVAD), a third-generation blood pump, is being developed for destination therapy for adult heart failure patients of small to medium frame that are not being served by present pulsatile devices. The pump design is based on a novel, patented, hybrid passive/active magnetic bearing system with backup hydrodynamic thrust bearing and exhibits low power loss, low vibration, and low hemolysis. Performance of the titanium alloy prototype was evaluated in a series of in vitro tests with blood analogue to map out the performance envelop of the pump. The LVAD prototype was implanted in a calf animal model, and the in vivo pump performance was evaluated. The animal's native heart imparted a strong pulsatility to the flow rate. These tests confirmed the efficacy of the MiTiHeart LVAD design and confirmed that the pulsatility does not adversely affect the pump performance.

  19. Operation of magnetically assisted fluidized beds in microgravity and variable gravity: experiment and theory.

    PubMed

    Sornchamni, T; Jovanovic, G N; Reed, B P; Atwater, J E; Akse, J R; Wheeler, R R

    2004-01-01

    The conversion of solid waste into useful resources in support of long duration manned missions in space presents serious technological challenges. Several technologies, including supercritical water oxidation, microwave powered combustion and fluidized bed incineration, have been tested for the conversion of solid waste. However, none of these technologies are compatible with microgravity or hypogravity operating conditions. In this paper, we present the gradient magnetically assisted fluidized bed (G-MAFB) as a promising operating platform for fluidized bed operations in the space environment. Our experimental and theoretical work has resulted in both the development of a theoretical model based on fundamental principles for the design of the G-MAFB, and also the practical implementation of the G-MAFB in the filtration and destruction of solid biomass waste particles from liquid streams. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  20. Synthesis of magnetic nickel spinel ferrite nanospheres by a reverse emulsion-assisted hydrothermal process

    SciTech Connect

    Zhang Jilin; Shi Jianxin; Gong Menglian

    2009-08-15

    Nickel ferrite nanospheres were successfully synthesized by a reverse emulsion-assisted hydrothermal method. The reverse emulsion was composed of water, cetyltrimethyl ammonium bromide, polyoxyethylene(10)nonyl phenyl ether, iso-amyl alcohol and hexane. During the hydrothermal process, beta-FeO(OH) and Ni{sub 0.75}Fe{sub 0.25}(CO{sub 3}){sub 0.125}(OH){sub 2}.0.38H{sub 2}O (INCHH) nanorods formed first and then transformed into nickel spinel ferrite nanospheres. The phase transformation mechanism is proposed based on the results of X-ray powder diffraction, transmission electron microscopy and energy-dispersive X-ray spectroscopy, etc. Nickel ferrite may form at the end of the INCHH nanorods or from the solution accompanied by the dissolution of beta-FeO(OH) and INCHH nanorods. The X-ray photoelectron spectroscopy analysis shows that a few Fe{sup 3+} ions have been reduced to Fe{sup 2+} ions during the formation of nickel ferrite. The maximum magnetization of the nickel ferrite nanospheres obtained after hydrothermal reaction for 30 h is 55.01 emu/g, which is close to that of bulk NiFe{sub 2}O{sub 4}. - Graphical abstract: Nickel ferrite nanospheres were obtained through a reverse emulsion-assisted hydrothermal process. The phase transformation as a function of reaction time was studied based on the XRD, TEM and EDS analyses.

  1. HeartQuest ventricular assist device magnetically levitated centrifugal blood pump.

    PubMed

    Bearnson, Gill B; Jacobs, Gordon B; Kirk, John; Khanwilkar, Pratap S; Nelson, Karl E; Long, James W

    2006-05-01

    Improvements in implantable ventricular assist device (VAD) performance will be required to obtain patient outcomes that are comparable with those of heart transplantation. The HeartQuest VAD (WorldHeart, Oakland, CA, U.S.A.) is an advanced device, with full magnetic suspension of the rotor, designed to address specific clinical shortcomings in existing devices and to maximize margins of safety and performance for an implantable assist device. The device dimensions are 35 x 75 mm, with a total weight of 440 g. The system was designed using extensive computer modeling of device function; a total of two iterations of device prototypes were built before building the clinical version. Animal study results have been very promising, with over 30 calf studies completed. Plasma-free hemoglobin levels returned to preoperative levels, and other hematology results were in the normal ranges. Highlights include clean surfaces seen in a 116-day experiment with no anticoagulation after day 43. Feasibility clinical trials are planned to start in 2006.

  2. Venture Class Launch Services

    NASA Technical Reports Server (NTRS)

    Wiese, Mark

    2016-01-01

    Provide an introduction to the Launch Services Program, and specifically the strategic initiative that drove the Venture Class Launch Services contracts. Provide information from the VCLS request for proposals, as well as the Agency's CubeSat Launch Initiative.

  3. Launch summary for 1978

    NASA Technical Reports Server (NTRS)

    Vostreys, R. W.

    1978-01-01

    Sounding rocket, satellite, and space probe launchings are presented. Time, date, and location of the launches are provided. The sponsoring countries and the institutions responsible for the launch are listed.

  4. Measurement of FePt thermal properties relevant to heat-assisted magnetic recording

    NASA Astrophysics Data System (ADS)

    Chernyshov, Alex; Treves, David; Le, Thanh; Zong, Fenghua; Ajan, Antony; Acharya, Ramamurthy

    2014-05-01

    Heat-assisted magnetic recording (HAMR) is the likely successor of the conventional perpendicular magnetic recording. Due to its high anisotropy, graded L10 ordered FePt is widely used as a HAMR recording layer. Electrically insulating MgO under-layer is essential for growing FePt in HAMR media. Experimentally, we observe very low thermal conductivity of FePt and significant thermal boundary resistance between FePt and MgO, whose magnitudes affect the HAMR thermal gradient. Realistic granular FePt media has >30% segregation, and, experimentally, we observe that FePt thermal properties are affected by segregation. We utilized time domain thermo-reflectance (TDTR) technique for studying FePt thermal conductivity and boundary resistance in realistic HAMR media stack. 1D finite element heat transport model was used for fitting experimental TDTR data and extracting thermal conductivities and related thermal boundary resistances. We found best fit thermal conductivity value for non-segregated FePt is as low as 13 W/mK. When reasonable amount of segregation (30%) is added, thermal conductivity reduces from 13 W/mK to 6 W/mK, and thermal boundary resistance to MgO reduces from 3.5 × 10-9 m2K/W to 0.7 × 10-9 m2K/W.

  5. Antithrombogenic properties of a monopivot magnetic suspension centrifugal pump for circulatory assist.

    PubMed

    Yamane, Takashi; Maruyama, Osamu; Nishida, Masahiro; Kosaka, Ryo; Chida, Takahiro; Kawamura, Hiroshi; Kuwana, Katsuyuki; Ishihara, Kazuhiko; Sankai, Yoshiyuki; Matsuzaki, Mio; Shigeta, Osamu; Enomoto, Yoshiharu; Tsutsui, Tatsuo

    2008-06-01

    The National Institute of Advanced Industrial Science and Technology (AIST) monopivot magnetic suspension centrifugal pump (MC105) was developed for open-heart surgery and several weeks of circulatory assist. The monopivot centrifugal pump has a closed impeller of 50 mm in diameter, supported by a single pivot bearing, and is driven through a magnetic coupling to widen the fluid gap. Design parameters such as pivot length and tongue radius were determined through flow visualization experiments, and the effectiveness was verified in preliminary animal experiments. The maximum overall pump efficiency reached 18%, and the normalized index of hemolysis tested with bovine blood was as low as 0.0013 g/100 L. Animal experiments with MC105 were conducted in sheep for 3, 15, 29, and 35 days in a configuration of left ventricle bypass. No thrombus was formed around the pivot bearing except when the pump speed was reduced by 20% of normal operational speed, which reduced the pump flow by 40% to avoid inlet suction. Subsequently, the antithrombogenic design was verified in animal experiments for 5 weeks at a minimum rotational speed of greater than 1500 rpm and a minimum pump flow greater than 1.0 L/min; no thrombus formation was observed under these conditions.

  6. Use of an embedded contact sensor to study nanoscale heat transfer in heat assisted magnetic recording

    NASA Astrophysics Data System (ADS)

    Wu, Haoyu; Bogy, David

    2017-01-01

    A near field transducer is employed in the heat assisted magnetic recording technology in order to focus the light energy into a nanoscale spot on the disk. This is necessary to heat the high coercivity magnetic media to their Curie temperature, so the write transducer can record the data. However, the heat transfer mechanism across the head disk interface (HDI) is still not well understood. The current perpendicular media recording systems have a thermal fly-height control means in the air bearing slider near the read/write transducers for placing the transducers within 1 to 2 nm of the rotating disk. In order to monitor this near contact spacing, this system also uses an embedded contact sensor (ECS). Here, we investigate how this ECS can be used to study the heat transfer across the nanoscale gap between the read/write transducer and the disk. This study shows that the self heating effect of the ECS is strong when its current bias is too high. But this self heating effect can be isolated from other heat sources, which allows us to use the ECS for the desired heat transfer measurements. The experiments show that the heat transfer across the HDI is a strong function of the head-disk spacing.

  7. Magnetic-field-assisted photothermal therapy of cancer cells using Fe-doped carbon nanoparticles

    NASA Astrophysics Data System (ADS)

    Gu, Ling; Vardarajan, Vijaylakshmi; Koymen, Ali R.; Mohanty, Samarendra K.

    2012-01-01

    Photothermal therapy with assistance of nanoparticles offers a solution for the destruction of cancer cells without significant collateral damage to otherwise healthy cells. However, minimizing the required number of injected nanoparticles is a major challenge. Here, we introduce the use of magnetic carbon nanoparticles (MCNPs), localizing them in a desired region by applying an external magnetic-field, and irradiating the targeted cancer cells with a near-infrared laser beam. The MCNPs were prepared in benzene, using an electric plasma discharge, generated in the cavitation field of an ultrasonic horn. The CNPs were made ferromagnetic by use of Fe-electrodes to dope the CNPs, as confirmed by magnetometry. Transmission electron microscopy measurements showed the size distribution of these MCNPs to be in the range of 5 to 10 nm. For photothermal irradiation, a tunable continuous wave Ti: Sapphire laser beam was weakly focused on to the cell monolayer under an inverted fluorescence microscope. The response of different cell types to photothermal irradiation was investigated. Cell death in the presence of both MCNPs and laser beam was confirmed by morphological changes and propidium iodide fluorescence inclusion assay. The results of our study suggest that MCNP based photothermal therapy is a promising approach to remotely guide photothermal therapy.

  8. DuraHeart™ magnetically levitated left ventricular assist device: Osaka University experience.

    PubMed

    Sakaguchi, Taichi; Matsumiya, Goro; Yoshioka, Daisuke; Miyagawa, Shigeru; Nishi, Hiroyuki; Yoshikawa, Yasushi; Fukushima, Satsuki; Saito, Shunsuke; Ueno, Takayoshi; Sawa, Yoshiki

    2013-01-01

    The DuraHeart left ventricular assist device (LVAD) is the world's first approved magnetically levitated implantable centrifugal pump. We report our initial experience with the DuraHeart as a bridge to heart transplantation. Between 2008 and 2011, 23 patients (17 males; mean age 35 years, range 16-53 years) with endstage heart failure underwent implantation with the DuraHeart LVAD at Osaka University Hospital. Of those, 7 underwent conversion surgery from a Nipro paracorporeal LVAD to the DuraHeart. There were no deaths during the mean support period of 559±241 days (176-999 days). In total, 17 patients (74%) remain with the LVAD and 5 (22%) underwent heart transplantation after 580±302 days (176-982 days) of support. Major adverse events included 8 (34%) driveline/pocket infections, 4 (17%) cerebrovascular accidents, 4 (17%) right heart failures requiring mechanical support, and 3 (13%) mechanical device failures (magnetic levitation failure caused by driveline fracture). Of the 5 patients who developed pump pocket infection, 3 underwent previous conversion surgery from the Nipro LVAD. Our initial experience with the DuraHeart LVAD in Japan demonstrated excellent long-term survival with acceptable rates of adverse events. With refinement of the system, including mechanical durability, this pump will further enhance the quality of life for patients who require long-term mechanical circulatory support.

  9. Enhancement of in-plane uniaxial magnetic anisotropy for patterned nanoparticle films fabricated by electric field-assisted deposition

    NASA Astrophysics Data System (ADS)

    Ou, Xiulong; He, Jun; Xia, Zhenjun; An, Jing; Hao, Jiazheng; He, Shuli; Zhao, Dongliang

    2017-08-01

    The patterned FeNi nanoparticle films with strip width 60 μm were prepared by electric field-assisted deposition technique. Application of electric field drove the accelerating deposition of the condensed nanoparticles, promoting the formation of the films with high stacking density. Besides the excellent soft magnetic characteristics, the samples showed an obvious enhancement of in-plane uniaxial magnetic anisotropy when they were annealed in vacuum environment at proper temperatures. The increase of in-plane uniaxial magnetic anisotropy, which is due to the release of stress with increasing temperature, is also confirmed by scanning microwave permeability spectra in GHz range. The experimental results imply that optimization of in-plane uniaxial magnetic anisotropy is particularly attractive for the application of electric field deposited soft magnetic nanoparticle films in the high-temperature processing electromagnetic devices.

  10. ARES I-X Launch Prep

    NASA Image and Video Library

    2009-10-26

    Mission managers, from left, NASA Ares I-X Assistant Launch Director Pete Nickolenko, Ground Operations Manager Philip "Pepper" Phillips, Ares I-X Launch Director Ed Mango, and Constellation Program manager Jeff Hanley review the latest weather radar from Firing Room One of the Launch Control Center (LCC) at the Kennedy Space Center during the launch countdown of the Ares I-X rocket in Cape Canaveral, Fla., Tuesday, Oct. 27, 2009. The flight test of Ares I-X will provide NASA with an early opportunity to test and prove flight characteristics, hardware, facilities and ground operations associated with the Ares I. Photo Credit: (NASA/Bill Ingalls)

  11. STS-120 launch

    NASA Image and Video Library

    2007-10-23

    STS120-S-026 (23 Oct. 2007) --- In the firing room of the Kennedy Space Center in Florida, NASA Shuttle Launch Director Michael Leinbach (second right) and launch managers watch the 11:38 a.m. (EDT) launch of Space Shuttle Discovery. Discovery launched Oct. 23 on a 14-day construction mission to the International Space Station. Photo credit: NASA/Bill Ingalls

  12. Fast and efficient proteolysis by microwave-assisted protein digestion using trypsin-immobilized magnetic silica microspheres.

    PubMed

    Lin, Shuang; Yao, Guoping; Qi, Dawei; Li, Yan; Deng, Chunhui; Yang, Pengyuan; Zhang, Xiangmin

    2008-05-15

    A fast and efficient proteolysis approach of microwave-assisted protein digestion was developed by using trypsin-immobilized magnetic silica (MS) microspheres. In the work, immobilization of the enzyme onto MS microspheres was very simple and only through a one-step reaction with 3-glycidoxypropyltrimethoxysilane (GLYMO) which provides the epoxy group as a reactive spacer. Considering that the magnetic particles are excellent microwave absorbers, we developed a novel microwave-assisted digestion method based on the easily prepared trypsin-immobilized MS microspheres. This novel digestion method combined the advantages of immobilized trypsin and the rapid-fashion of microwave-assisted digestion, which resulted in high digestion efficiency. BSA and myoglobin were used as model proteins to optimize the conditions of this method. Peptide fragments produced in 15 s could be confidently identified by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) analysis. Equivalent or better digestion efficiency was observed comparing to current in-solution digestion. Besides, because of the unique magnetic responsivity, the immobilized trypsin can be isolated easily with the help of an external magnet and thus used repeatedly. High activity was obtained even after seven runs of the trypsin-immobilized MS microspheres. To further verify its efficiency in proteome analysis, one reversed-phase liquid chromatography (RPLC) fraction of rat liver extract was applied. After 15 s incubation, 16 totally unique peptides corresponding to two proteins were identified. Finally, the rat liver sample was used to evaluate its worth for the application. With analysis by liquid chromatography-electrospray-tandem mass spectrometry (LC-ESI-MS/MS), comparable digestion efficiency was observed with typical in-solution digestion but the incubation time was largely shortened. This new microwave-assisted digestion method will hasten the application of the proteome

  13. HEOS-1 SATELLITE LIFTS OFF FROM LAUNCH COMPLEX 17B BY A DELTA LAUNCH VEHICLE

    NASA Technical Reports Server (NTRS)

    1968-01-01

    HEOS-1 SATELLITE LIFTS OFF FROM LAUNCH COMPLEX 17B BY A DELTA LAUNCH VEHICLE KSC-68P-0572.01 102-KSC-68P-572.1, P-19020, ARCHIVE-04091 A HEOS satellite [Highly Eccentric Orbit Satellite] was launched aboard a 92-foot-high Delta rocket from Cape Kennedy's Launch Complex 17B at 1:55 P.M.EST December 5, 1968. It will study cosmic radiation, solar winds and magnetic fields, two-thirds the distance from the Earth to the Moon. The Kennedy Space Center launched the 238-pound satellite for the 10-nation European Space Research Organization [ESRO].

  14. Launching and propagation of protostellar jets

    NASA Astrophysics Data System (ADS)

    Fendt, Christian; Sheikhnezami, Somayeh

    2013-07-01

    We present resistive MHD simulations of jet launching and propagation using the PLUTO code. The main question we address is which kind of disks launch jets and which kind of disks do not? We investigate the jet-disk interaction applying different profiles of the disk magnetic diffusivity and derive the corresponding accretion and ejection rates for bipolar outflows. We determine the launching disk area of the fast component of protostellar jets. We further investigate numerically symmetry aspects of jet and counter jet. Finally, we present a model explaining the observationally indicated jet rotation by MHD shocks of the helical magnetic field in the propagating jet.

  15. Electromagnetic Aircraft Launching System: Do the Benefits Outweigh the Costs?

    DTIC Science & Technology

    2010-03-29

    atg.ga.com/EM/defense/emals/index.php (accessed October 09, 2009). 19 M. Doyle, G. Sulich and L. Lebron , "The Benefits of Electro magnetically Launching...34 IEEE Transtions on Magnetics, Vol. 31, 15 April, 1995. 21 M. Doyle, G. Sulich and L. Lebron , "The Benefits of Electro magnetically Launching Aircraft...George Sulich, and Lynne Lebron . "The Benefits ofElectromagnetically Launching Aircraft." Naval Engineers Journal, May 2000: 78-82

  16. Thermal modeling of head disk interface system in heat assisted magnetic recording

    SciTech Connect

    Vemuri, Sesha Hari; Seung Chung, Pil; Jhon, Myung S.; Min Kim, Hyung

    2014-05-07

    A thorough understanding of the temperature profiles introduced by the heat assisted magnetic recording is required to maintain the hotspot at the desired location on the disk with minimal heat damage to other components. Here, we implement a transient mesoscale modeling methodology termed lattice Boltzmann method (LBM) for phonons (which are primary carriers of energy) in the thermal modeling of the head disk interface (HDI) components, namely, carbon overcoat (COC). The LBM can provide more accurate results compared to conventional Fourier methodology by capturing the nanoscale phenomena due to ballistic heat transfer. We examine the in-plane and out-of-plane heat transfer in the COC via analyzing the temperature profiles with a continuously focused and pulsed laser beam on a moving disk. Larger in-plane hotspot widening is observed in continuously focused laser beam compared to a pulsed laser. A pulsed laser surface develops steeper temperature gradients compared to continuous hotspot. Furthermore, out-of-plane heat transfer from the COC to the media is enhanced with a continuous laser beam then a pulsed laser, while the temperature takes around 140 fs to reach the bottom surface of the COC. Our study can lead to a realistic thermal model describing novel HDI material design criteria for the next generation of hard disk drives with ultra high recording densities.

  17. FePt-C granular thin film for heat-assisted magnetic recording (HAMR) media

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Xue, S.-X.; Li, Z.-G.; Liu, Y.-P.; Chen, W.-P.

    2014-09-01

    We studied a FePt-C granular film for ultra-high density perpendicular recording media towards 1 Tbits/in.2 because of strong magnetocrystalline anisotropy at its L10-phase. We deposit a Fe52Pt48-C50 % (6.7 nm) film on oxidized silicon substrates at 400 °C and 0.50 Pa Ar pressure. The perpendicular anisotropy of the film is 20 kOe, with a perfect squareness of 1. Bright-field transmission electron microscopy (TEM) images display that the FePt granular film has small and uniform grains of 6.4 ± 1.5 nm. Further work on high-resolution TEM imaging demonstrates excellent L10 ordering for this FePt granular film, which is consistent with the texture measurement by X-ray diffraction. Thus, we prove that FePt granular film is a promising candidate for high-density heat-assisted magnetic recording media.

  18. DuraHeart magnetically levitated centrifugal left ventricular assist system for advanced heart failure patients.

    PubMed

    Morshuis, Michiel; Schoenbrodt, Michael; Nojiri, Chisato; Roefe, Daniela; Schulte-Eistrup, Sebastian; Boergermann, Jochen; Gummert, Jan F; Arusoglu, Latif

    2010-03-01

    The implantable left ventricular assist system (LVAS) using pulsatile pump technology has become an established therapeutic option for advanced heart failure patients. However, there have been technological limitations in some older designs, including a high incidence of infection and mechanical failures associated with moving parts, and the large size of both implantable pump and percutaneous cable. A smaller rotary blood pump emerged as a possible alternative to a large pulsatile pump to overcome some of these limitations. The technological advancement that defines the third-generation LVAS was the elimination of all mechanical contacts between the impeller and the drive mechanism. The DuraHeart LVAS is the world's first third-generation implantable LVAS to obtain market approval (CE-mark), which combines a centrifugal pump and active magnetic levitation. The initial clinical experience with the DuraHeart LVAS in Europe demonstrated that it provided significantly improved survival (85% at 6 months and 79% at 1 year), reduced adverse event rates and long-term device reliability (freedom from device replacement at 2 years: 96 +/- 3%) over pulsatile LVAS.

  19. Implant-assisted magnetic drug targeting in permeable microvessels: Comparison of two-fluid statistical transport model with experiment

    NASA Astrophysics Data System (ADS)

    ChiBin, Zhang; XiaoHui, Lin; ZhaoMin, Wang; ChangBao, Wang

    2017-03-01

    In experiments and theoretical analyses, this study examines the capture efficiency (CE) of magnetic drug carrier particles (MDCPs) for implant-assisted magnetic drug targeting (IA-MDT) in microvessels. It also proposes a three-dimensional statistical transport model of MDCPs for IA-MDT in permeable microvessels, which describes blood flow by the two-fluid (Casson and Newtonian) model. The model accounts for the permeable effect of the microvessel wall and the coupling effect between the blood flow and tissue fluid flow. The MDCPs move randomly through the microvessel, and their transport state is described by the Boltzmann equation. The regulated changes and factors affecting the CE of the MDCPs in the assisted magnetic targeting were obtained by solving the theoretical model and by experimental testing. The CE was negatively correlated with the blood flow velocity, and positively correlated with the external magnetic field intensity and microvessel permeability. The predicted CEs of the MDCPs were consistent with the experimental results. Additionally, under the same external magnetic field, the predicted CE was 5-8% higher in the IA-MDT model than in the model ignoring the permeability effect of the microvessel wall.

  20. Hybrid Magnetoelectric Nanowires for Nanorobotic Applications: Fabrication, Magnetoelectric Coupling, and Magnetically Assisted In Vitro Targeted Drug Delivery.

    PubMed

    Chen, Xiang-Zhong; Hoop, Marcus; Shamsudhin, Naveen; Huang, Tianyun; Özkale, Berna; Li, Qian; Siringil, Erdem; Mushtaq, Fajer; Di Tizio, Luca; Nelson, Bradley J; Pané, Salvador

    2017-02-01

    An FeGa@P(VDF-TrFE) wire-shaped magnetoelectric nanorobot is designed and fabricated to demonstrate a proof-of-concept integrated device, which features wireless locomotion and on-site triggered therapeutics with a single external power source (i.e., a magnetic field). The device can be precisely steered toward a targeted location wirelessly by rotating magnetic fields and perform on-demand magnetoelectrically assisted drug release to kill cancer cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Heat assisted magnetic recording with patterned FePt recording media using a lollipop near field transducer

    SciTech Connect

    Ghoreyshi, Ali; Victora, R. H.

    2014-05-07

    In heat-assisted magnetic recording, optical energy is transferred to a small optical spot on the recording media using a near field transducer. In this study, a scattered field finite difference time domain simulation is used to analyze the performance of a lollipop transducer in heat assisted magnetic recording on both a patterned FePt media and a continuous thin film. To represent wear, sharp corners of the peg are approximated with curved ones, which are found to narrow the track width without excessive loss of intensity. Compared with continuous media, the patterned media exhibits higher energy efficiency and a better concentrated optical beam spot. This effect is due to the near field effects of patterned media on the performance of the transducer.

  2. Modelling and simulation of the lubricant depletion process induced by laser heating in heat-assisted magnetic recording system

    NASA Astrophysics Data System (ADS)

    Wu, Lin

    2007-05-01

    A model for lubricant flow dynamics under a scanning laser beam has been constructed for a heat-assisted magnetic recording system. The effects of evaporation, thermocapillary stress and thermoviscosity on the lubricant depletion on both glass and aluminium disks are systematically studied. Our results indicate that both evaporation and thermocapillary stress are able to deplete non-negligible amount of Z-type PFPE lubricants with a low molecular weight from the disk surface within nanoseconds. Evaporation is the dominant lubricant removal mechanism when low molecular weight lubricant is used. Evaporation is significantly reduced when high molecular weight PFPE lubricants are used. Our simulations show that the performance of head/disk interface of heat-assisted magnetic recording systems may be significantly deteriorated when lubricants with improper properties are used.

  3. A novel magnetic field-assisted polishing method using magnetic compound slurry and its performance in mirror surface finishing of miniature V-grooves

    NASA Astrophysics Data System (ADS)

    Wang, Youliang; Wu, Yongbo; Mitsuyoshi, Nomura

    2016-05-01

    A novel magnetic field-assisted polishing technique was proposed for finishing 3D structured surface using a magnetic compound (MC) slurry. The MC slurry was prepared by blending carbonyl-iron-particles, abrasive grains and α-cellulose into a magnetic fluid which contains nano-scale magnetite particles. An experimental setup was constructed firstly by installing an oscillation worktable and a unit onto a polishing machine. Then, experimental investigations were conducted on oxygen-free copper workpiece with parallel distributed linear V-grooves to clarify the influence of the polishing time and abrasive impact angle on the grooves surface qualities. It was found that (1) the groove form accuracy, i.e. the form retention rate η varied with the polishing locations. Although the form retention rate η deteriorated during the polishing process, the final η was greater than 99.4%; (2) the effective impact angle θm affected the material removal and form accuracy seriously. An increase of the absolute value θm resulted with an increase of material removal rate and a decrease of the form accuracy; (3) the work-surface roughness decreased more than 6 times compared with the original surface after MC slurry polishing. These results confirmed the performance of the proposed new magnetic field-assisted polishing method in the finishing of 3D-structured surface.

  4. Heat-Assisted Magnetic Recording: Fundamental Limits to Inverse Electromagnetic Design

    NASA Astrophysics Data System (ADS)

    Bhargava, Samarth

    In this dissertation, we address the burgeoning fields of diffractive optics, metals-optics and plasmonics, and computational inverse problems in the engineering design of electromagnetic structures. We focus on the application of the optical nano-focusing system that will enable Heat-Assisted Magnetic Recording (HAMR), a higher density magnetic recording technology that will fulfill the exploding worldwide demand of digital data storage. The heart of HAMR is a system that focuses light to a nano- sub-diffraction-limit spot with an extremely high power density via an optical antenna. We approach this engineering problem by first discussing the fundamental limits of nano-focusing and the material limits for metal-optics and plasmonics. Then, we use efficient gradient-based optimization algorithms to computationally design shapes of 3D nanostructures that outperform human designs on the basis of mass-market product requirements. In 2014, the world manufactured ˜1 zettabyte (ZB), ie. 1 Billion terabytes (TBs), of data storage devices, including ˜560 million magnetic hard disk drives (HDDs). Global demand of storage will likely increase by 10x in the next 5-10 years, and manufacturing capacity cannot keep up with demand alone. We discuss the state-of-art HDD and why industry invented Heat-Assisted Magnetic Recording (HAMR) to overcome the data density limitations. HAMR leverages the temperature sensitivity of magnets, in which the coercivity suddenly and non-linearly falls at the Curie temperature. Data recording to high-density hard disks can be achieved by locally heating one bit of information while co-applying a magnetic field. The heating can be achieved by focusing 100 microW of light to a 30nm diameter spot on the hard disk. This is an enormous light intensity, roughly ˜100,000,000x the intensity of sunlight on the earth's surface! This power density is ˜1,000x the output of gold-coated tapered optical fibers used in Near-field Scanning Optical Microscopes

  5. Heat assisted recording on bottom layer of dual recording layer perpendicular magnetic recording media for two and a half dimensional (2.5D) magnetic data storage

    NASA Astrophysics Data System (ADS)

    Chen, Y. J.; Yang, H. Z.; Leong, S. H.; Santoso, B.; Shi, J. Z.; Xu, B. X.; Tsai, J. W. H.

    2015-05-01

    In this paper, we present a study on two and a half dimensional (2.5D) perpendicular magnetic recording (PMR) media consisting of dual hard magnetic recording layers (RL) with 1st or top RL1 used for conventional data storage and 2nd or bottom RL2 used for dedicated servo with lower linear densities or DC servo patterns with focus on the writability issue of the bottom servo layer (RL2). We demonstrate experimentally the feasibility to magnetically erase, write, and re-write RL2 by laser assist on a home built heat-assisted-magnetic-recording writing test system. Experimental data (by magnetic force microscopy measurements) show that the signal amplitudes of the pre-recorded magnetic patterns for both RL1 and RL2 decrease at almost the same rate with thermal erasure using scanning laser power (Pw) from 13 mW to 23 mW, clearly indicating equally effective laser heating and close temperature rise for RL1 and RL2 for far field laser heating with laser pulse duration in sub-μs and μs range. This is further verified by theoretical simulations of the thermal distribution and the temperature rise depth profile in dual layer media by laser heating. Simulations indicate very little temperature difference of less than 6 K (˜1% of maximum temperature rise) between RL1 and RL2 because the main mechanism of temperature rises in RL1 and RL2 is due to the effective thermal conduction from the top layers to lower layers. These experimental and theoretical study results could provide useful understanding and insights into servo writing methods of 2.5D PMR media.

  6. Fifth FLTSATCOM to be launched

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Launch of the FLTSATOOM-E, into an elliptical orbit by the Atlas Centaur launch vehicle is announced. The launch and relevant launch operations are described. A chart of the launch sequence for FLTSATCOM-E communication satellite is given.

  7. Amphiphilic block copolymer modified magnetic nanoparticles for microwave-assisted extraction of polycyclic aromatic hydrocarbons in environmental water.

    PubMed

    Li, Nan; Qi, Li; Shen, Ying; Li, Yaping; Chen, Yi

    2013-11-05

    In this work, amphiphilic block copolymer poly(tert-butyl methacrylate)-block-poly(glycidyl methacrylate) (PtBMA-b-PGMA) modified Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) were synthesized, and served as an adsorbent for microwave-assisted extraction of polycyclic aromatic hydrocarbons (PAHs). The PtBMA-b-PGMA block copolymers with different block ratios were prepared by two-step atom transfer radical polymerization (ATRP) and the extraction abilities of their corresponding Fe3O4@PtBMA-b-PGMA were investigated. The key factors affecting the extraction efficiency of the adsorbent, including microwave conditions, amount of adsorbent, type and volume of desorption solvent, were studied in detail. In comparison with vortex, which is a conventional method used for assisting extraction, the proposed microwave-assisted method allowed better extraction efficiency and required a shorter extraction time. The calibration curves of PAHs were obtained in the range of 0.05-120 μg/L (r>0.9985) and the limits of detection (S/N=3) were in the range of 2.4-6.3 ng/L. The recoveries of PAHs spiked in environmental water samples were between 62.5% and 104% with relative standard deviations (RSDs) ranging from 0.84% to 9.02%. The proposed technique combining microwave-assisted extraction and magnetic separation was demonstrated to be a fast, convenient and sensitive pretreating method for PAHs.

  8. IRIS Launch Animation

    NASA Image and Video Library

    This animation demonstrates the launch and deployment of NASA's Interface Region Imaging Spectrograph (IRIS) mission satellite via a Pegasus rocket. The launch is scheduled for June 26, 2013 from V...

  9. Shuttle Era: Launch Directors

    NASA Image and Video Library

    A space shuttle launch director is the leader of the complex choreography that goes into a shuttle liftoff. Ten people have served as shuttle launch directors, making the final decision whether the...

  10. Space Launch System Animation

    NASA Image and Video Library

    NASA is ready to move forward with the development of the Space Launch System -- an advanced heavy-lift launch vehicle that will provide an entirely new national capability for human exploration be...

  11. One-pot laser-assisted synthesis of porous carbon with embedded magnetic cobalt nanoparticles

    NASA Astrophysics Data System (ADS)

    Ghimbeu, Camélia Matei; Sopronyi, Mihai; Sima, Felix; Delmotte, Luc; Vaulot, Cyril; Zlotea, Claudia; Paul-Boncour, Valérie; Le Meins, Jean-Marc

    2015-05-01

    A novel one-pot laser-assisted approach is reported herein for the synthesis of ordered carbons with embedded cobalt nanoparticles. The process is based on a UV pulsed laser exposure of an ethanolic solution consisting of green carbon precursors, a structure directing agent and a cobalt salt. Very short irradiation times (5 to 30 min) are only required to polymerize and cross-link carbon precursors (i.e. phloroglucinol and glyoxylic acid) independent of a catalyst presence. The influence of three metallic salts (acetate, nitrate and chloride) on the phenolic resin and carbon characteristics (structure, texture and particle size/distribution) was systematically studied. When exposed to UV laser, the metallic salt exhibited a strong influence on the particle size and distribution in the carbon matrix rather than on the textural carbon properties. Using cobalt acetate, very small (3.5 nm) and uniformly dispersed particles were obtained by this simple, fast and green one-pot synthesis approach. An original combined 13C CP-MAS and DP-DEC solid state NMR spectroscopy analysis allowed to determine the structure of phenolic resins as well as the location of the cobalt salt in the resin. Complementarily, the 1H solid-state and relaxation NMR provided unique insights into the rigidity (cross-linking) of the phenolic resin and dispersion of the cobalt salt. The magnetic properties of cobalt nanoparticles were found to be size-dependent: large Co nanoparticles (~50 nm) behave as bulk Co whereas small Co nanoparticles are superparamagnetic.A novel one-pot laser-assisted approach is reported herein for the synthesis of ordered carbons with embedded cobalt nanoparticles. The process is based on a UV pulsed laser exposure of an ethanolic solution consisting of green carbon precursors, a structure directing agent and a cobalt salt. Very short irradiation times (5 to 30 min) are only required to polymerize and cross-link carbon precursors (i.e. phloroglucinol and glyoxylic acid

  12. STS-135 Atlantis Launch

    NASA Image and Video Library

    2011-07-07

    NASA Administrator Charles Bolden, right, participates in the post launch traditional beans and cornbread at the NASA Kennedy Space Center, Launch Control Center (LCC) shortly after the space shuttle Atlantis, STS-135, launched on Friday, July 8, 2011, in Cape Canaveral, Fla. The launch of Atlantis is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  13. Launch Vehicle Operations Simulator

    NASA Technical Reports Server (NTRS)

    Blackledge, J. W.

    1974-01-01

    The Saturn Launch Vehicle Operations Simulator (LVOS) was developed for NASA at Kennedy Space Center. LVOS simulates the Saturn launch vehicle and its ground support equipment. The simulator was intended primarily to be used as a launch crew trainer but it is also being used for test procedure and software validation. A NASA/contractor team of engineers and programmers implemented the simulator after the Apollo XI lunar landing during the low activity periods between launches.

  14. STS-135 Atlantis Launch

    NASA Image and Video Library

    2011-07-07

    NASA Photographer Kim Shiflett, left, and Videographer Glenn Benson capture a group photo of the launch team in Firing Room Four of the NASA Kennedy Space Center Launch Control Center (LCC) shortly after the space shuttle Atlantis, STS-135, launched on Friday, July 8, 2011, in Cape Canaveral, Fla. The launch of Atlantis is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  15. STS-135 Atlantis Launch

    NASA Image and Video Library

    2011-07-07

    NASA Kennedy Space Center worker Dwayne Hutcheson sweeps the Launch Control Center (LCC) lobby floor in preparation for the post launch tradition of corn bread and beans after a successful launch of the space shuttle Atlantis from pad 39A on Friday, July 8, 2011, in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  16. A new concentric double prosthesis for sutureless, magnetic-assisted aortic arch inclusion.

    PubMed

    Cirillo, Marco

    2016-04-01

    Acute dissection of the ascending aorta is a life-threatening condition in which the aortic wall develops one or more tears of the intima associated with intramural rupture of the media layer with subsequent formation of a two lumina vessel. The remaining outer layer is just the adventitia, with high risk of complete rupture. Vital organs may be under-perfused. Mortality rate in this acute event is about 50% if an emergent surgical procedure is not performed as soon as possible to replace the tract affected by the primary rupture. Nevertheless, the emergent surgical procedure is affected by high risk of mortality or severe neurologic sequelae, due to the need for deep hypothermia and cardiocirculatory arrest and different methods of cerebral protection. If the patient survives the acute event, a frequent outcome is the establishment of a chronic aortic dissection in the remaining aorta and late chronic dissecting aneurysm, usually starting from the surgical suture itself. Traumatism of surgical stitches and of direct blood flow pressure on weak aortic wall can be important contributing factors of the chronic disease. In conclusions, the majority of these patients undergoes a high risk operation without a complete solution of the disease. We hypothesize that excluding the aortic layers from the blood direct flow and using an anastomotic technique which does not include surgical stitches could help to significantly reduce the recurrence of aortic dissection after the acute event and shorten hypothermic arrest duration. We devised a double tubular prosthesis consisting of two concentric artificial tubes between which the aortic wall is confined and excluded from direct blood flow. We also devised a magnetic assisted sutureless anastomotic technique that seals the aortic tissue between the two prostheses and avoids the perforation of the fragile aortic wall with surgical stitches. We are presenting here this new prototype and draw a few different models. Both acute and

  17. One-pot laser-assisted synthesis of porous carbon with embedded magnetic cobalt nanoparticles.

    PubMed

    Ghimbeu, Camélia Matei; Sopronyi, Mihai; Sima, Felix; Delmotte, Luc; Vaulot, Cyril; Zlotea, Claudia; Paul-Boncour, Valérie; Le Meins, Jean-Marc

    2015-06-14

    A novel one-pot laser-assisted approach is reported herein for the synthesis of ordered carbons with embedded cobalt nanoparticles. The process is based on a UV pulsed laser exposure of an ethanolic solution consisting of green carbon precursors, a structure directing agent and a cobalt salt. Very short irradiation times (5 to 30 min) are only required to polymerize and cross-link carbon precursors (i.e. phloroglucinol and glyoxylic acid) independent of a catalyst presence. The influence of three metallic salts (acetate, nitrate and chloride) on the phenolic resin and carbon characteristics (structure, texture and particle size/distribution) was systematically studied. When exposed to UV laser, the metallic salt exhibited a strong influence on the particle size and distribution in the carbon matrix rather than on the textural carbon properties. Using cobalt acetate, very small (3.5 nm) and uniformly dispersed particles were obtained by this simple, fast and green one-pot synthesis approach. An original combined (13)C CP-MAS and DP-DEC solid state NMR spectroscopy analysis allowed to determine the structure of phenolic resins as well as the location of the cobalt salt in the resin. Complementarily, the (1)H solid-state and relaxation NMR provided unique insights into the rigidity (cross-linking) of the phenolic resin and dispersion of the cobalt salt. The magnetic properties of cobalt nanoparticles were found to be size-dependent: large Co nanoparticles (∼50 nm) behave as bulk Co whereas small Co nanoparticles are superparamagnetic.

  18. Launch Summary for 1979

    NASA Technical Reports Server (NTRS)

    Vostreys, R. W.

    1980-01-01

    Spacecraft launching for 1979 are identified and listed under the categories of (1) sounding rockets, and (2) artificial Earth satellites and space probes. The sounding rockets section includes a listing of the experiments, index of launch sites and tables of the meanings and codes used in the launch listing.

  19. LAUNCH Health Forum

    NASA Image and Video Library

    2010-10-30

    Tom Kalil, Deputy Director of the White House Office of Science and Technology Policy, opens the LAUNCH: Health forum at NASA's Kennedy Space Center in Florida on Saturday, Oct. 30, 2010. LAUNCH: Health provides a forum to discuss accelerating innovation for a sustainable future. LAUNCH: Health partners include NASA, USAID and Nike. Photo Credit: (NASA/Bill Ingalls)

  20. Magnetic and Structural Properties of Cobalt- and Zinc-Substituted Nickel Ferrite Synthesized by Microwave-Assisted Hydrothermal Method

    NASA Astrophysics Data System (ADS)

    Sinfrônio, F. S. M.; Santana, P. Y. C.; Coelho, S. F. N.; Silva, F. C.; de Menezes, A. S.; Sharma, S. K.

    2017-02-01

    Ceramic spinel-based ferrites of cobalt, nickel and zinc were prepared by means of the microwave-assisted hydrothermal method. All samples were thoroughly characterized using different techniques for their structural, compositional, phonic and magnetic properties. The Rietveld analysis of x-ray powder diffraction data revealed the crystallinity as well single-phase partially inverse spinel structure. Wavelength dispersive x-ray fluorescence measurement indicates a good correlation between the empirical stoichiometry. The estimated average crystallite size varies between 9 nm and 13 nm (XRPD) and 6 and 14 nm for high-resolution transmission electron microscopy measurements. In addition, the observed micro-strain varies in the range of 0.01-0.6%. All samples show a quasi-spherical morphology and slight agglomeration. Infrared and Raman data spectra exhibit characteristic modes for spinel-based ferrites. Direct current magnetic measurements indicate behavior typical of magnetically soft materials system at 300 K.

  1. High-End Concept Based on Hypersonic Two-Stage Rocket and Electro-Magnetic Railgun to Launch Micro-Satellites Into Low-Earth

    NASA Astrophysics Data System (ADS)

    Bozic, O.; Longo, J. M.; Giese, P.; Behren, J.

    2005-02-01

    The electromagnetic railgun technology appears to be an interesting alternative to launch small payloads into Low Earth Orbit (LEO), as this may introduce lower launch costs. A high-end solution, based upon present state of the art technology, has been investigated to derive the technical boundary conditions for the application of such a new system. This paper presents the main concept and the design aspects of such propelled projectile with special emphasis on flight mechanics, aero-/thermodynamics, materials and propulsion characteristics. Launch angles and trajectory optimisation analyses are carried out by means of 3 degree of freedom simulations (3DOF). The aerodynamic form of the projectile is optimised to provoke minimum drag and low heat loads. The surface temperature distribution for critical zones is calculated with DLR developed Navier-Stokes codes TAU, HOTSOSE, whereas the engineering tool HF3T is used for time dependent calculations of heat loads and temperatures on project surface and inner structures. Furthermore, competing propulsions systems are considered for the rocket engines of both stages. The structural mass is analysed mostly on the basis of carbon fibre reinforced materials as well as classical aerospace metallic materials. Finally, this paper gives a critical overview of the technical feasibility and cost of small rockets for such missions. Key words: micro-satellite, two-stage-rocket, railgun, rocket-engines, aero/thermodynamic, mass optimization

  2. A portable magnetic field of >3 T generated by the flux jump assisted, pulsed field magnetization of bulk superconductors

    NASA Astrophysics Data System (ADS)

    Zhou, Difan; Ainslie, Mark D.; Shi, Yunhua; Dennis, Anthony R.; Huang, Kaiyuan; Hull, John R.; Cardwell, David A.; Durrell, John H.

    2017-02-01

    A trapped magnetic field of greater than 3 T has been achieved in a single grain GdBa2Cu3O7-δ (GdBaCuO) bulk superconductor of diameter 30 mm by employing pulsed field magnetization. The magnet system is portable and operates at temperatures between 50 K and 60 K. Flux jump behaviour was observed consistently during magnetization when the applied pulsed field, Ba, exceeded a critical value (e.g., 3.78 T at 60 K). A sharp dBa/dt is essential to this phenomenon. This flux jump behaviour enables the magnetic flux to penetrate fully to the centre of the bulk superconductor, resulting in full magnetization of the sample without requiring an applied field as large as that predicted by the Bean model. We show that this flux jump behaviour can occur over a wide range of fields and temperatures, and that it can be exploited in a practical quasi-permanent magnet system.

  3. Launch summary for 1980

    NASA Technical Reports Server (NTRS)

    Vostreys, R. W.

    1981-01-01

    Sounding rockets, artificial Earth satellites, and space probes launched betweeen January 1 and December 31, 1980 are listed. Data tabulated for the rocket launchings show launching site, instruments carried, date of launch, agency rocket identification, sponsoring country, experiment discipline, peak altitude, and the experimenter or institution responsible. Tables for satellites and space probes show COSPAR designation, spacecraft name, country, launch date, epoch date, orbit type, apoapsis, periapsis and inclination period. The functions and responsibilities of the World Data Center and the areas of scientific interest at the seven subcenters are defined. An alphabetical listing of experimenters using the sounding rockets is also provided.

  4. Usefulness of magnetic resonance imaging-guided vacuum-assisted breast biopsy in Korean women: a pilot study.

    PubMed

    An, Yeong; Kim, Sung; Kang, Bong; Lee, Jae

    2013-08-16

    Magnetic resonance imaging (MRI)-guided vacuum-assisted biopsy is the technique of choice for lesions that are visible only with breast MRI. The purpose of this study was to report our clinical experience with MRI-guided vacuum-assisted biopsy in Korean women. A total of 13 patients with 15 lesions for MRI-guided vacuum-assisted biopsy were prospectively entered into this study between September 2009 and November 2011. Biopsy samples were obtained in a 3-T magnet using a 9-guage MRI-compatible vacuum-assisted biopsy device. We evaluated clinical indications for biopsy, lesion characteristics on prebiopsy MRI, pathologic results, and postbiopsy complication status. The clinical indications for MRI-guided vacuum-assisted biopsy were as follows: abnormalities in patients with interstitial mammoplasty on screening MRI (n = 10); preoperative evaluation of patients with a recently diagnosed cancer (n = 3); and suspicious recurrence on follow-up MRI after cancer surgery (n = 1) or chemotherapy (n = 1). All lesions have morphologic features suspicious or highly suggestive of malignancy by the American College of Radiology Breast Imaging Reporting and Data System category of MRI (C4a = 12, C4b = 2, C5 = 1). In two of the 15 lesions (13.3%, <6 mm), MRI-guided 9-gauge vacuum-assisted breast biopsy was deferred due to nonvisualization of the MRI findings that led to biopsy and the lesions were stable or disappeared on follow up so were considered benign. Of 13 biopsied lesions, pathology revealed four malignancies (4/13, 30.8%; mean size 15.5 mm) and nine benign lesions (9/13, 69.2%; size 14.2 mm). Immediate postprocedural hematoma (mean size 23.5 mm) was observed in eight out of 13 patients (61.5%) and was controlled conservatively. Our initial experience of MRI-guided vacuum-assisted biopsy showed a success rate of 86.7% and a cancer diagnosis rate of 30.8%, which was quite satisfactory. MRI-guided vacuum-assisted breast biopsy is a safe and effective tool for the workup of

  5. Usefulness of magnetic resonance imaging-guided vacuum-assisted breast biopsy in Korean women: a pilot study

    PubMed Central

    2013-01-01

    Background Magnetic resonance imaging (MRI)-guided vacuum-assisted biopsy is the technique of choice for lesions that are visible only with breast MRI. The purpose of this study was to report our clinical experience with MRI-guided vacuum-assisted biopsy in Korean women. Methods A total of 13 patients with 15 lesions for MRI-guided vacuum-assisted biopsy were prospectively entered into this study between September 2009 and November 2011. Biopsy samples were obtained in a 3-T magnet using a 9-guage MRI-compatible vacuum-assisted biopsy device. We evaluated clinical indications for biopsy, lesion characteristics on prebiopsy MRI, pathologic results, and postbiopsy complication status. Results The clinical indications for MRI-guided vacuum-assisted biopsy were as follows: abnormalities in patients with interstitial mammoplasty on screening MRI (n = 10); preoperative evaluation of patients with a recently diagnosed cancer (n = 3); and suspicious recurrence on follow-up MRI after cancer surgery (n = 1) or chemotherapy (n = 1). All lesions have morphologic features suspicious or highly suggestive of malignancy by the American College of Radiology Breast Imaging Reporting and Data System category of MRI (C4a = 12, C4b = 2, C5 = 1). In two of the 15 lesions (13.3%, <6 mm), MRI-guided 9-gauge vacuum-assisted breast biopsy was deferred due to nonvisualization of the MRI findings that led to biopsy and the lesions were stable or disappeared on follow up so were considered benign. Of 13 biopsied lesions, pathology revealed four malignancies (4/13, 30.8%; mean size 15.5 mm) and nine benign lesions (9/13, 69.2%; size 14.2 mm). Immediate postprocedural hematoma (mean size 23.5 mm) was observed in eight out of 13 patients (61.5%) and was controlled conservatively. Conclusions Our initial experience of MRI-guided vacuum-assisted biopsy showed a success rate of 86.7% and a cancer diagnosis rate of 30.8%, which was quite satisfactory. MRI-guided vacuum-assisted breast biopsy is a

  6. The Rockot launch system

    NASA Astrophysics Data System (ADS)

    Stamerjohanns, G.; Kinnersley, M.

    1999-09-01

    EUROCKOT Launch Services GmbH has been founded by Daimler-Benz Aerospace of Germany and Khrunichev State Research and Production Space Center of Russia to offer world-wide cost effective launch services on the Rockot launch system. The Rockot commercial program is described. Rockot can launch satellites weighing up to 1850 kg into polar and other low earth (LEO) orbits. The Rockot launch vehicle is based on the former Russian SS-19 strategic missile. The first and second stages are inherited from the SS-19, the third stage named Breeze is newly developed and has multiple ignition capability. The Rockot launch system is flight proven. In addition to the currently adapted Rockot launch site Plesetsk for high inclinations, EUROCKOT is in the process to also adapt the Baykonur cosmodrome as their complementary Rockot launch site for lower inclinations. The wide range of Rockot performance is provided. The first commercial launch is foreseen in the middle of 1999. The expected launch capacity for Plesetsk and Baykonur will exceed 10 launches per year. The complete Rockot system including performance is presented.

  7. Electron launching voltage monitor

    DOEpatents

    Mendel, Clifford W.; Savage, Mark E.

    1992-01-01

    An electron launching voltage monitor measures MITL voltage using a relationship between anode electric field and electron current launched from a cathode-mounted perturbation. An electron launching probe extends through and is spaced from the edge of an opening in a first MITL conductor, one end of the launching probe being in the gap between the MITL conductor, the other end being adjacent a first side of the first conductor away from the second conductor. A housing surrounds the launching probe and electrically connects the first side of the first conductor to the other end of the launching probe. A detector detects the current passing through the housing to the launching probe, the detected current being representative of the voltage between the conductors.

  8. Electron launching voltage monitor

    DOEpatents

    Mendel, C.W.; Savage, M.E.

    1992-03-17

    An electron launching voltage monitor measures MITL voltage using a relationship between anode electric field and electron current launched from a cathode-mounted perturbation. An electron launching probe extends through and is spaced from the edge of an opening in a first MITL conductor, one end of the launching probe being in the gap between the MITL conductor, the other end being adjacent a first side of the first conductor away from the second conductor. A housing surrounds the launching probe and electrically connects the first side of the first conductor to the other end of the launching probe. A detector detects the current passing through the housing to the launching probe, the detected current being representative of the voltage between the conductors. 5 figs.

  9. Rapid microwave-assisted regeneration of magnetic carbon nanotubes loaded with p-nitrophenol

    NASA Astrophysics Data System (ADS)

    Cui, Chunyue; Zheng, Qingzhu; Han, Yanhe; Xin, Yanjun

    2015-08-01

    A novel magnetic carbon nanotubes (CNTs) adsorbent with good sorption, magnetic separability, and microwave (MW) regeneration properties was prepared successfully using thermal decomposition. The magnetic CNTs were characterized using transmission electron microscopy, energy dispersive X-ray, nitrogen adsorption (Brunauer-Emmett-Teller surface area), and X-ray diffraction and their magnetic properties were measured using a vibrating sample magnetometer. Magnetic nanoparticles (≈10 nm diameter) were dispersed uniformly on the CNTs with a magnetic CNTs surface area of 146.7 m2 g-1 and a saturation magnetization of 21.11 emu g-1. When the magnetic CNTs were used in the sorption of p-nitrophenol, the equilibrium time was 20 min and the sorption isotherms fit the Freundlich isotherm well. The spent magnetic CNTs could be separated magnetically and be regenerated by MW irradiation. After six adsorption and MW regeneration cycles (at 850 W for 180 s), the adsorption capacity of the magnetic CNTs was higher than that of the virgin magnetic CNTs with a low carbon loss.

  10. Thermally assisted interlayer magnetic coupling through Ba0.05Sr0.95TiO3 barriers

    NASA Astrophysics Data System (ADS)

    Carreira, Santiago J.; Avilés Félix, Luis; Sirena, Martín; Alejandro, Gabriela; Steren, Laura B.

    2016-08-01

    We report on the interlayer exchange coupling across insulating barriers observed on Ni80Fe20/Ba0.05Sr0.95TiO3/La0.66Sr0.33MnO3 (Py/BST0.05/LSMO) trilayers. The coupling mechanism has been analyzed in terms of the barrier thickness, samples' substrate, and temperature. We examined the effect of MgO (MGO) and SrTiO3 (STO) (001) single-crystalline substrates on the magnetic coupling and also on the magnetic anisotropies of the samples in order to get a deeper understanding of the magnetism of the structures. We measured a weak coupling mediated by spin-dependent tunneling phenomena whose sign and strength depend on barrier thickness and substrate. An antiferromagnetic (AF) exchange prevails for most of the samples and smoothly increases with the barrier thicknesses as a consequence of the screening effects of the BST0.05. The coupling monotonically increases with temperature in all the samples and this behavior is attributed to thermally assisted mechanisms. The magnetic anisotropy of both magnetic components has a cubic symmetry that in the case of permalloy is added to a small uniaxial component.

  11. COSMOS Launch Services

    NASA Astrophysics Data System (ADS)

    Kalnins, Indulis

    2002-01-01

    COSMOS-3M is a two stage launcher with liquid propellant rocket engines. Since 1960's COSMOS has launched satellites of up to 1.500kg in both circular low Earth and elliptical orbits with high inclination. The direct SSO ascent is available from Plesetsk launch site. The very high number of 759 launches and the achieved success rate of 97,4% makes this space transportation system one of the most reliable and successful launchers in the world. The German small satellite company OHB System co-operates since 1994 with the COSMOS manufacturer POLYOT, Omsk, in Russia. They have created the joint venture COSMOS International and successfully launched five German and Italian satellites in 1999 and 2000. The next commercial launches are contracted for 2002 and 2003. In 2005 -2007 COSMOS will be also used for the new German reconnaissance satellite launches. This paper provides an overview of COSMOS-3M launcher: its heritage and performance, examples of scientific and commercial primary and piggyback payload launches, the launch service organization and international cooperation. The COSMOS launch service business strategy main points are depicted. The current and future position of COSMOS in the worldwide market of launch services is outlined.

  12. Vortex-assisted magnetic dispersive solid-phase microextraction for rapid screening and recognition of dicofol residues in tea products.

    PubMed

    Cheng, Xiaoling; Yan, Hongyuan; Wang, Xiaoling; Sun, Ning; Qiao, Xiaoqiang

    2014-11-01

    A simple and rapid vortex-assisted magnetic dispersive solid-phase microextraction (VAMDSME) method coupled with gas chromatography-electronic capture detection was developed for rapid screening and selective recognition of dicofol in tea products. The magnetic molecularly imprinted microspheres (mag-MIMs) synthesised by aqueous suspension polymerisation using dichlorodiphenyltrichloroethane (DDT) as a dummy template showed high selectivity and affinity to dicofol in aqueous solution and were successfully applied as special adsorbents of VAMDSME for rapid isolation of dicofol from complex tea matrix. Good linearity was obtained in a range of 0.2-160 ng g(-1) and the limit of detection based on a signal to noise ratio of 3 was 0.05 ng g(-1). The recoveries at three spiked levels ranged from 83.6% to 94.5% with the related standard deviations (RSD) ⩽ 5.0%. The VAMDSME-GC protocol, which took advantages of the selective adsorption of molecularly imprinted microspheres and rapid magnetic phase separation, as well as the short equilibrium time by vortex-assisted, could avoid the time-consuming procedures related to other traditional extraction methods.

  13. Magnetization reversal assisted by half antivortex states in nanostructured circular cobalt disks

    SciTech Connect

    Lara, A.; Aliev, F. G.; Dobrovolskiy, O. V.; Prieto, J. L.; Huth, M.

    2014-11-03

    The half antivortex, a fundamental topological structure which determines magnetization reversal of submicron magnetic devices with domain walls, has been suggested also to play a crucial role in spin torque induced vortex core reversal in circular disks. Here, we report on magnetization reversal in circular disks with nanoholes through consecutive metastable states with half antivortices. In-plane anisotropic magnetoresistance and broadband susceptibility measurements accompanied by micromagnetic simulations reveal that cobalt (Co) disks with two and three linearly arranged nanoholes directed at 45° and 135° with respect to the external magnetic field show reproducible step-like changes in the anisotropic magnetoresistance and magnetic permeability due to transitions between different intermediate states mediated by vortices and half antivortices confined to the dot nanoholes and edges, respectively. Our findings are relevant for the development of multi-hole based spintronic and magnetic memory devices.

  14. Integrated simulation of magnetic-field-assist fast ignition laser fusion

    NASA Astrophysics Data System (ADS)

    Johzaki, T.; Nagatomo, H.; Sunahara, A.; Sentoku, Y.; Sakagami, H.; Hata, M.; Taguchi, T.; Mima, K.; Kai, Y.; Ajimi, D.; Isoda, T.; Endo, T.; Yogo, A.; Arikawa, Y.; Fujioka, S.; Shiraga, H.; Azechi, H.

    2017-01-01

    To enhance the core heating efficiency in fast ignition laser fusion, the concept of relativistic electron beam guiding by external magnetic fields was evaluated by integrated simulations for FIREX class targets. For the cone-attached shell target case, the core heating performance deteriorates by applying magnetic fields since the core is considerably deformed and most of the fast electrons are reflected due to the magnetic mirror formed through the implosion. On the other hand, in the case of a cone-attached solid ball target, the implosion is more stable under the kilo-tesla-class magnetic field. In addition, feasible magnetic field configuration is formed through the implosion. As a result, the core heating efficiency doubles by magnetic guiding. The dependence of core heating properties on the heating pulse shot timing was also investigated for the solid ball target.

  15. Antares Rocket Test Launch

    NASA Image and Video Library

    2013-04-21

    The Orbital Sciences Corporation Antares rocket is seen as it launches from Pad-0A of the Mid-Atlantic Regional Spaceport (MARS) at the NASA Wallops Flight Facility in Virginia, Sunday, April 21, 2013. The test launch marked the first flight of Antares and the first rocket launch from Pad-0A. The Antares rocket delivered the equivalent mass of a spacecraft, a so-called mass simulated payload, into Earth's orbit. Photo Credit: (NASA/Bill Ingalls)

  16. STS-135 Atlantis Launch

    NASA Image and Video Library

    2011-07-07

    NASA Administrator Charles Bolden speaks to visitors at the NASA Kennedy Space Center Banana Creek viewing site prior to going to the Launch Control Center (LCC) for the planned launch of the space shuttle Atlantis from pad 39A on Friday, July 8, 2011, in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  17. Launch the Litening Pod!

    DTIC Science & Technology

    2008-02-19

    Launch the LITENING Pod ! EWS Contemporary Issue Paper Submitted by Captain Fausett, Brian M. to Major G.A. Thiele, CG 2 19...TITLE AND SUBTITLE Launch the Litening Pod ! 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e...ABSTRACT unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 2 “Launch the LITENING pod

  18. MAVEN Atlas V Launch

    NASA Image and Video Library

    2013-11-18

    The United Launch Alliance Atlas V rocket with NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft launches from the Cape Canaveral Air Force Station Space Launch Complex 41, Monday, Nov. 18, 2013, Cape Canaveral, Florida. NASA’s Mars-bound spacecraft, the Mars Atmosphere and Volatile EvolutionN, or MAVEN, is the first spacecraft devoted to exploring and understanding the Martian upper atmosphere. Photo Credit: (NASA/Bill Ingalls)

  19. LAUNCH - STS-4 - KSC

    NASA Image and Video Library

    1982-07-06

    S82-33288 (27 June 1982) --- This horizontal view of the space shuttle Columbia captures the flight of water birds disturbed by the activity at launch Pad 39A. Launch occurred at 10:59:59 a.m. (EDT), June 27, 1982. Astronauts Thomas K. Mattingly II and Henry W. Hartsfield Jr. are aboard for NASA's final orbital flight test before launching into a new space era with the first operational flight planned for fall of this year. Photo credit: NASA

  20. MAVEN Atlas V Launch

    NASA Image and Video Library

    2013-11-18

    The United Launch Alliance Atlas V rocket with NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft launches from the Cape Canaveral Air Force Station Space Launch Complex 41, Monday, Nov. 18, 2013, Cape Canaveral, Florida. NASA’s Mars-bound spacecraft, the Mars Atmosphere and Volatile EvolutioN, or MAVEN, is the first spacecraft devoted to exploring and understanding the Martian upper atmosphere. Photo Credit: (NASA/Bill Ingalls)

  1. Expedition 27 Launch

    NASA Image and Video Library

    2010-04-01

    The Soyuz TMA-21 launches from the Baikonur Cosmodrome in Kazakhstan on Tuesday, April 5, 2011 carrying Expedition 27 Soyuz Commander Alexander Samokutyaev, NASA Flight Engineer Ron Garan and Russian Flight Engineer Andrey Borisenko to the International Space Station. The Soyuz, which has been dubbed "Gagarin", is launching one week shy of the 50th anniversary of the launch of Yuri Gagarin from the same launch pad in Baikonur on April 12, 1961 to become the first human to fly in space. Photo Credit: (NASA/Victor Zelentsov)

  2. Expedition 27 Launch

    NASA Image and Video Library

    2011-04-04

    The Soyuz TMA-21 launches from the Baikonur Cosmodrome in Kazakhstan on Tuesday, April 5, 2011 carrying Expedition 27 Soyuz Commander Alexander Samokutyaev, NASA Flight Engineer Ron Garan and Russian Flight Engineer Andrey Borisenko to the International Space Station. The Soyuz, which has been dubbed "Gagarin", is launching one week shy of the 50th anniversary of the launch of Yuri Gagarin from the same launch pad in Baikonur on April 12, 1961 to become the first human to fly in space. Photo Credit: (NASA/Carla Cioffi)

  3. Antares Rocket Test Launch

    NASA Image and Video Library

    2013-04-21

    NASA Administrator Charles Bolden congratulates the Orbital Sciences Corporation launch team and management in the Range Control Center at the NASA Wallops Flight Facility after the successful launch of the Orbital Sciences Antares rocket from the Mid-Atlantic Regional Spaceport (MARS) in Virginia, Sunday, April 21, 2013. The test launch marked the first flight of Antares and the first rocket launch from Pad-0A. The Antares rocket delivered the equivalent mass of a spacecraft, a so-called mass simulated payload, into Earth's orbit. Photo Credit: (NASA/Bill Ingalls)

  4. GPM: Waiting for Launch

    NASA Image and Video Library

    The Global Precipitation Measurement mission's Core Observatory is poised for launch from the Japan Aerospace Exploration Agency's Tanegashima Space Center, scheduled for the afternoon of Feb. 27, ...

  5. Kestrel balloon launch system

    SciTech Connect

    Newman, M.J.

    1991-10-01

    Kestrel is a high-altitude, Helium-gas-filled-balloon system used to launch scientific payloads in winds up to 20 knots, from small platforms or ships, anywhere over land or water, with a minimal crew and be able to hold in standby conditions. Its major components consist of two balloons (a tow balloon and a main balloon), the main deployment system, helium measurement system, a parachute recovery unit, and the scientific payload package. The main scope of the launch system was to eliminate the problems of being dependent of launching on long airfield runways, low wind conditions, and long launch preparation time. These objectives were clearly met with Kestrel 3.

  6. Mechanism of coercivity enhancement by Ag addition in FePt-C granular films for heat assisted magnetic recording media

    NASA Astrophysics Data System (ADS)

    Varaprasad, B. S. D. Ch. S.; Takahashi, Y. K.; Wang, J.; Ina, T.; Nakamura, T.; Ueno, W.; Nitta, K.; Uruga, T.; Hono, K.

    2014-06-01

    We investigated the Ag distribution in a FePtAg-C granular film that is under consideration for a heat assisted magnetic recording medium by aberration-corrected scanning transmission electron microscope-energy dispersive X-ray spectroscopy and X-ray absorption fine structure. Ag is rejected from the core of FePt grains during the deposition, forming Ag-enriched shell surrounding L10-ordered FePt grains. Since Ag has no solubility in both Fe and Pt, the rejection of Ag induces atomic diffusions thereby enhancing the kinetics of the L10-order in the FePt grains.

  7. Room Temperature Magnetic Behavior In Nanocrystalline Ni-Doped Zro2 By Microwave-Assisted Polyol Synthesis

    NASA Astrophysics Data System (ADS)

    Parimita Rath, Pragyan; Parhi, Pankaj Kumar; Ranjan Panda, Sirish; Priyadarshini, Barsharani; Ranjan Sahoo, Tapas

    2017-08-01

    This article, deals with a microwave-assisted polyol method to demonstrate a low temperature route < 250°C, to prepare a high temperature cubic zirconia phase. Powder XRD pattern shows broad diffraction peaks suggesting nanometric size of the particles. Magnetic behavior of 1-5 at% Ni doped samples show a threshold for substitutional induced room temperature ferromagnetism up to 3 at% of Ni. TGA data reveals that Ni-doped ZrO2 polyol precursors decompose exothermically below 300°C. IR data confirms the reduction of Zr(OH)4 precipitates to ZrO2, in agreement with the conclusions drawn from the TGA analysis.

  8. A compact model for magnetic tunnel junction (MTJ) switched by thermally assisted Spin transfer torque (TAS + STT).

    PubMed

    Zhao, Weisheng; Duval, Julien; Klein, Jacques-Olivier; Chappert, Claude

    2011-04-28

    Thermally assisted spin transfer torque [TAS + STT] is a new switching approach for magnetic tunnel junction [MTJ] nanopillars that represents the best trade-off between data reliability, power efficiency and density. In this paper, we present a compact model for MTJ switched by this approach, which integrates a number of physical models such as temperature evaluation and STT dynamic switching models. Many experimental parameters are included directly to improve the simulation accuracy. It is programmed in the Verilog-A language and compatible with the standard IC CAD tools, providing an easy parameter configuration interface and allowing high-speed co-simulation of hybrid MTJ/CMOS circuits.

  9. A compact model for magnetic tunnel junction (MTJ) switched by thermally assisted Spin transfer torque (TAS + STT)

    PubMed Central

    2011-01-01

    Thermally assisted spin transfer torque [TAS + STT] is a new switching approach for magnetic tunnel junction [MTJ] nanopillars that represents the best trade-off between data reliability, power efficiency and density. In this paper, we present a compact model for MTJ switched by this approach, which integrates a number of physical models such as temperature evaluation and STT dynamic switching models. Many experimental parameters are included directly to improve the simulation accuracy. It is programmed in the Verilog-A language and compatible with the standard IC CAD tools, providing an easy parameter configuration interface and allowing high-speed co-simulation of hybrid MTJ/CMOS circuits. PMID:21711868

  10. Beating oscillation and Fano resonance in the laser assisted electron transmission through graphene δ-function magnetic barriers

    NASA Astrophysics Data System (ADS)

    Biswas, R.; Maity, S.; Sinha, C.

    2016-10-01

    We investigate theoretically the transmission of electrons through a pair of δ-function magnetic barriers in graphene in presence of external monochromatic, linearly polarized and CW laser field. The transmission coefficients are calculated in the framework of non-perturbative Floquet theory using the transfer matrix method. It is noted that the usual Fabry-Perot oscillations in transmission through the graphene magnetic barriers with larger inter barrier separation takes the shape of beating oscillations in presence of the external laser field. The laser assisted transmission spectra are also found to exhibit the characteristic Fano resonances (FR) for smaller values of the inter barrier separation. The appearance of the perfect node in the beating oscillation and the asymmetric Fano line shape can be controlled by varying the intensity of the laser field. The above features could provide some useful and potential information about the light - matter interactions and may be utilized in the graphene based optoelectronic device applications.

  11. Design of plasmonic near-field transducers in heat-assisted magnetic recording: 1D Fourier approach

    NASA Astrophysics Data System (ADS)

    Gan, C. H.; Fernandez-Garcia, R.; Hardy, M. J.; Neira, A.; Bance, S.; Gubbins, M. A.

    2016-09-01

    Heat-assisted magnetic recording (HAMR) is a potential enabling technology for ultrahigh density data storage systems. In HAMR, a near-field transducer (NFT) delivers a subdiffraction heat spot to record bits of data on a high-anisotropy magnetic media. We developed an intuitive 1D Fourier model that expedites the analysis and design of the NFT. Among other strengths, the simple model predicts rather surprisingly and in agreement with 3D simulations, that for metallic nanoresonators the longitudinal component of the electric field dominates the heat transfer to the media. The proposed Fourier model serves well as a platform to study electromagnetic behavior such as field confinement and heat spot generation of 3D NFT designs.

  12. Magnetocrystalline anisotropy and its electric-field-assisted switching of Heusler-compound-based perpendicular magnetic tunnel junctions

    NASA Astrophysics Data System (ADS)

    Bai, Zhaoqiang; Shen, Lei; Cai, Yongqing; Wu, Qingyun; Zeng, Minggang; Han, Guchang; Feng, Yuan Ping

    2014-10-01

    Employing density functional theory combined with the non-equilibrium Green's function formalism, we systematically investigate the structural, magnetic and magnetoelectric properties of the Co2FeAl(CFA)/MgO interface, as well as the spin-dependent transport characteristics of the CFA/MgO/CFA perpendicular magnetic tunnel junctions (p-MTJs). We find that the structure of the CFA/MgO interface with the oxygen-top FeAl termination has high thermal stability, which is protected by the thermodynamic equilibrium limit. Furthermore, this structure is found to have perpendicular magnetocrystalline anisotropy (MCA). Giant electric-field-assisted modifications of this interfacial MCA through magnetoelectric coupling are demonstrated with an MCA coefficient of up to 10-7 erg V-1 cm. In addition, our non-collinear spin transport calculations of the CFA/MgO/CFA p-MTJ predict a good magnetoresistance performance of the device.

  13. Synthesis and magnetic properties of (Eu-Ni) substituted Y-type hexaferrite by surfactant assisted co-precipitation method

    NASA Astrophysics Data System (ADS)

    Ali, Irshad; Islam, M. U.; sadiq, Imran; Karamat, Nazia; Iftikhar, Aisha; khan, M. Azhar; Shah, Afzal; Athar, Muhammad; Shakir, Imran; Ashiq, Muhammad Naeem

    2015-07-01

    A series of (Eu-Ni) substituted Y-type hexaferrite with composition Sr2Co(2-x)NixEuyFe(12-y)O22 (x=0.0-1, Y=0.0-0.1) were prepared by the surfactant assisted co-precipitation method. The present samples were sintered at 1050 °C for 8 h. The shape of the particles is plate-like which is very advantageous for various applications and the grain size varies from 73 to 269 nm. The values of saturation magnetization (Ms), remanent magnetization (Mr) and magnetic moment (nB) were found to decrease which are attributed to the weakening of super exchange interactions. The values of in-plane Squareness ratios (Mr/Ms) ranging from 0.41 to 0.65 whereas in case of out of plane measurement it varies from 0.30 to 0.62.The investigated samples can be used in perpendicular recording media (PRM) due to high value of coercivity 2300 Oe which is analogous to the those of M-type and W-type hard magnetic.

  14. Impedance spectroscopy assisted by magnetic nanoparticles as a potential biosensor principle for breast cancer cells in suspension.

    PubMed

    Silva, Jesús G; Cárdenas, Rey A; Quiróz, Alan R; Sánchez, Virginia; Lozano, Lucila M; Pérez, Nadia M; López, Jaime; Villanueva, Cleva; González, César A

    2014-06-01

    Breast cancer (BC) is the leading cause of cancer death in women worldwide, with a higher mortality reported in undeveloped countries. Ideal adjuvant therapeutic strategies require the continuous monitoring of patients by regular blood tests to detect circulating cancer cells, in order to determine whether additional treatment is necessary to prevent cancer dissemination. This circumstance requires a non-complex design of tumor cell biosensor in whole blood with feasibility for use in poor regions. In this work we have evaluated an inexpensive and simple technique of relative bioimpedance measurement, assisted by magnetic nanoparticles, as a potential biosensor of BC cells in suspension. Measurements represent the relative impedance changes caused by the magnetic holding of an interphase of tumor cells versus a homogenous condition in the frequency range of 10-100 kHz. The results indicate that use of a magnet to separate tumor cells in suspension, coupled to magnetic nanoparticles, is a feasible technique to fix an interphase of tumor cells in close proximity to gold electrodes. Relative impedance changes were shown to have potential value as a biosensor method for BC cells in whole blood, at frequencies around 20 kHz. Additional studies are warranted with respect to electrode design and sensitivity at micro-scale levels, according to the proposed technique.

  15. One-step microwave-assisted synthesis of water-dispersible Fe3O4 magnetic nanoclusters for hyperthermia applications

    NASA Astrophysics Data System (ADS)

    Sathya, Ayyappan; Kalyani, S.; Ranoo, Surojit; Philip, John

    2017-10-01

    To realize magnetic hyperthermia as an alternate stand-alone therapeutic procedure for cancer treatment, magnetic nanoparticles with optimal performance, within the biologically safe limits, are to be produced using simple, reproducible and scalable techniques. Herein, we present a simple, one-step approach for synthesis of water-dispersible magnetic nanoclusters (MNCs) of superparamagnetic iron oxide by reducing of Fe2(SO4)3 in sodium acetate (alkali), poly ethylene glycol (capping ligand), and ethylene glycol (solvent and reductant) in a microwave reactor. The average size and saturation magnetization of the MNC's are tuned from 27 to 52 nm and 32 to 58 emu/g by increasing the reaction time from 10 to 600 s. Transmission electron microscopy images reveal that each MNC composed of large number of primary Fe3O4 nanoparticles. The synthesised MNCs show excellent colloidal stability in aqueous phase due to the adsorbed PEG layer. The highest SAR value of 215 ± 10 W/gFe observed in 52 nm size MNC at a frequency of 126 kHz and field of 63 kA/m suggest the potential use of these MNC in hyperthermia applications. This study further opens up the possibilities to develop metal ion-doped MNCs with tunable sizes suitable for various biomedical applications using microwave assisted synthesis.

  16. Microwave-assisted synthesis and high dechlorination activity of magnetic FeNi broom-like nanostructures.

    PubMed

    Peng, Jin; Wen, Ming; Wang, Chenxiang; Wu, Qingsheng; Sun, Yuzhen

    2013-06-28

    A three-dimensional (3D) broom-like nanostructured magnetic FeNi catalyst was synthesized using inexpensive Fe and Ni as precursors in a controllable microwave-assisted route. In this 3D broom-like nanostructure, the length of an FeNi nanorod, which serves as a building block, depends on the molar content of Fe. With a decrease in the Fe content from 100 to 45% in the Fe(x)Ni(96-x) system, the length varies from 8 μm to 1 μm, which is corroborated by SEM, TEM, XRD, EDS and XPS. The magnetic behavior measurement results show that the magnetic saturation and coercivity are strongly influenced by the length of the nanorods and the Fe content. The sample of Fe nanorods gives a maximum magnetization saturation at 196 emu g(-1), and a maximum coercivity of 241.23 Oe is obtained for Fe78Ni22. These economical 3D FeNi broom-like nanostructures, with large surface areas and dispersed active sites, can dramatically facilitate the diffusion and transportation of a reactant to improve the reactivity. In particular, Fe89Ni11 broom-like nanostructures exert an excellent reactivity towards the reductive dechlorination of 1,1,2,2-tetrachloroethane.

  17. Expedition 24 Launch Day

    NASA Image and Video Library

    2010-06-14

    Expedition 24 NASA Flight Engineer Shannon Walker has her Russian Sokol suit prepared for launch by technicians at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Tuesday, June 15, 2010. Walker, Soyuz Commander Fyodor Yurchikhin and Flight Engineer Doug Wheelock launched in their Soyuz TMA-19 rocket from the Baikonur Cosmodrome in Kazakhstan on Wednesday, June 16, 2010. (Photo Credit: NASA/Carla Cioffi)

  18. Expedition 24 Launch Day

    NASA Image and Video Library

    2010-06-14

    Expedition 24 NASA Flight Engineer Doug Wheelock, center, has his Russian Sokol suit prepared for launch by a technician at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Tuesday, June 15, 2010. Wheelock, Soyuz Commander Fyodor Yurchikhin and Flight Engineer Shannon Walker launched in their Soyuz TMA-19 rocket from the Baikonur Cosmodrome in Kazakhstan on Wednesday, June 16, 2010. (Photo Credit: NASA/Carla Cioffi)

  19. Expedition 24 Launch Day

    NASA Image and Video Library

    2010-06-14

    Expedition 24 NASA Flight Engineer Doug Wheelock has his Russian Sokol suit prepared for launch by a technician at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Tuesday, June 15, 2010. Wheelock, Soyuz Commander Fyodor Yurchikhin and Flight Engineer Shannon Walker launched in their Soyuz TMA-19 rocket from the Baikonur Cosmodrome in Kazakhstan on Wednesday, June 16, 2010. (Photo Credit: NASA/Carla Cioffi)

  20. Saturn IB Launch

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The Saturn IB launch vehicle lifting off from Launch Complex 39B at 9:01 a.m. EST. The Skylab 4 astronauts Gerald P. Carr, Dr. Edward G. Gibson, and William R. Pogue, were onboard for the third and final mission to the orbiting space station.

  1. Saturn IB Launch Summary

    NASA Technical Reports Server (NTRS)

    1973-01-01

    This chart provides a launch summary of the Saturn IB launch vehicle as of 1973. Developed by the Marshall Space Flight Center (MSFC) as an interim vehicle in MSFC's 'building block' approach to the Saturn rocket development, the Saturn IB utilized Saturn I technology to further develop and refine the larger boosters and the Apollo spacecraft capabilities required for the marned lunar missions.

  2. Expedition 8 Launch Briefing

    NASA Image and Video Library

    2003-10-15

    Expedition 8 Soyuz Commander and Flight Engineer Alexander Kaleri and European Space Agency astronaut Pedro Duque of Spain are briefed on launch procedures from a Russian trainer at their crew quarters in Baikonur, Kazakhstan, Wednesday, Oct. 15, 2003 as they prepare for launch Oct. 18 in a Soyuz TMA-3 vehicle to the International Space Station. Photo Credit (NASA/Bill Ingalls)

  3. Launch Collision Probability

    NASA Technical Reports Server (NTRS)

    Bollenbacher, Gary; Guptill, James D.

    1999-01-01

    This report analyzes the probability of a launch vehicle colliding with one of the nearly 10,000 tracked objects orbiting the Earth, given that an object on a near-collision course with the launch vehicle has been identified. Knowledge of the probability of collision throughout the launch window can be used to avoid launching at times when the probability of collision is unacceptably high. The analysis in this report assumes that the positions of the orbiting objects and the launch vehicle can be predicted as a function of time and therefore that any tracked object which comes close to the launch vehicle can be identified. The analysis further assumes that the position uncertainty of the launch vehicle and the approaching space object can be described with position covariance matrices. With these and some additional simplifying assumptions, a closed-form solution is developed using two approaches. The solution shows that the probability of collision is a function of position uncertainties, the size of the two potentially colliding objects, and the nominal separation distance at the point of closest approach. ne impact of the simplifying assumptions on the accuracy of the final result is assessed and the application of the results to the Cassini mission, launched in October 1997, is described. Other factors that affect the probability of collision are also discussed. Finally, the report offers alternative approaches that can be used to evaluate the probability of collision.

  4. STS-135 Atlantis Launch

    NASA Image and Video Library

    2011-07-08

    Space shuttle Atlantis is seen as it launches from pad 39A on Friday, July 8, 2011, at NASA's Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  5. STS-114: Post Launch Press Conference

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Dean Acosta, Deputy Assistant Administrator for Public Affairs hosted this post launch press conference. Present were Mike Griffin, NASA Administrator; William Ready, Associate Administrator for Space Operations; Bill Parsons, Space Shuttle Program Manager; Mike Leinbach, NASA Launch Director; and Wayne Hill, Deputy Program Manager for Space Shuttle Program. Each expressed thanks to all of NASA Officials and employees, contractors, vendors and the crew for their hard work the past two and a half years that resulted the successful and pristine launch of Space Shuttle Discovery. The Panel emphasized that through extensive technical analysis, thorough planning and tremendous amount of public support brought them full circle again to return to flight. Flight safety, debris during rocket separation, sensors, observations from the mission control, launch conditions were some of the topics discussed with the News media.

  6. Optimization of Magnetic Field-Assisted Synthesis of Carbon Nanotubes for Sensing Applications

    PubMed Central

    Raniszewski, Grzegorz; Pyc, Marcin; Kolacinski, Zbigniew

    2014-01-01

    One of the most effective ways of synthesizing carbon nanotubes is the arc discharge method. This paper describes a system supported by a magnetic field which can be generated by an external coil. An electric arc between two electrodes is stabilized by the magnetic field following mass flux stabilization from the anode to the cathode. In this work four constructions are compared. Different configurations of cathode and coils are calculated and presented. Exemplary results are discussed. The paper describes attempts of magnetic field optimization for different configurations of electrodes. PMID:25295922

  7. Fabrication of nano-sized magnetic tunnel junctions using lift-off process assisted by atomic force probe tip.

    PubMed

    Jung, Ku Youl; Min, Byoung-Chul; Ahn, Chiyui; Choi, Gyung-Min; Shin, Il-Jae; Park, Seung-Young; Rhie, Kungwon; Shin, Kyung-Ho

    2013-09-01

    We present a fabrication method for nano-scale magnetic tunnel junctions (MTJs), employing e-beam lithography and lift-off process assisted by the probe tip of atomic force microscope (AFM). It is challenging to fabricate nano-sized MTJs on small substrates because it is difficult to use chemical mechanical planarization (CMP) process. The AFM-assisted lift-off process enables us to fabricate nano-sized MTJs on small substrates (12.5 mm x 12.5 mm) without CMP process. The e-beam patterning has been done using bi-layer resist, the poly methyl methacrylate (PMMA)/ hydrogen silsesquioxane (HSQ). The PMMA/HSQ resist patterns are used for both the etch mask for ion milling and the self-aligned mask for top contact formation after passivation. The self-aligned mask buried inside a passivation oxide layer, is readily lifted-off by the force exerted by the probe tip. The nano-MTJs (160 nm x 90 nm) fabricated by this method show clear current-induced magnetization switching with a reasonable TMR and critical switching current density.

  8. Magnetic Property in large array cobalt antidot thin film using polymer-assisted nanosphere lithography

    NASA Astrophysics Data System (ADS)

    Lee, Wei-Li; Ho, Chi-Chih; Hsieh, Yung-Wu; Juan, Wen-Tau; Lin, Keng-Hui

    2010-03-01

    We have developed a new method to prepare monolayer of close- packed nanospheres (NSs) over large area onto a substrate of any kind utilizing polymer bridging effect. The NSs packing domain can be as large as 1 cmx1 cm which is demonstrated from its diffraction pattern. It was then used as a template to fabricate series of cobalt antidot thin films with different antidot diameter ranging from 100nm to 180nm. Because of the good periodicity and less defects in our nanostructured samples, we would be able to not only qualitatively study their magnetic properties but also quantitatively. As the antidot diameter increases, the surface to bulk volume fraction increases and the surface magnetism becomes more prominent. We found a systematic increase in magnetic coercivity with the antidote diameter, while the saturation magnetization drops at large antidote diameter. Detailed analysis and their implication will be discussed.

  9. Magnetic Field-Assisted Perovskite Film Preparation for Enhanced Performance of Solar Cells.

    PubMed

    Wang, Haoxu; Lei, Jie; Gao, Fei; Yang, Zhou; Yang, Dong; Jiang, Jiexuan; Li, Juan; Hu, Xihong; Ren, Xiaodong; Liu, Bin; Liu, Jing; Lei, Hairui; Liu, Zhike; Liu, Shengzhong Frank

    2017-07-05

    Perovskite solar cells (PSCs) are promising low-cost photovoltaic technologies with high power conversion efficiency (PCE). The crystalline quality of perovskite materials is crucial to the photovoltaic performance of the PSCs. Herein, a simple approach is introduced to prepare high-quality CH3NH3PbI3 perovskite films with larger crystalline grains and longer carriers lifetime by using magnetic field to control the nucleation and crystal growth. The fabricated planar CH3NH3PbI3 solar cells have an average PCE of 17.84% and the highest PCE of 18.56% using an optimized magnetic field at 80 mT. In contrast, the PSCs fabricated without the magnetic field give an average PCE of 15.52% and the highest PCE of 16.72%. The magnetic field action produces an ordered arrangement of the perovskite ions, improving the crystallinity of the perovskite films and resulting in a higher PCE.

  10. Positioning and aligning CNTs by external magnetic field to assist localised epoxy cure

    NASA Astrophysics Data System (ADS)

    Ariu, G.; Hamerton, I.; Ivanov, D.

    2016-01-01

    This work focuses on the generation of conductive networks through the localised alignment of nano fillers, such as multi-walled carbon nanotubes (MWCNTs). The feasibility of alignment and positioning of functionalised MWCNTs by external DC magnetic fields was investigated. The aim of this manipulation is to enhance resin curing through AC induction heating due to hysteresis losses from the nanotubes. Experimental analyses focused on in-depth assessment of the nanotube functionalisation, processing and characterisation of magnetic, rheological and cure kinetics properties of the MWCNT solution. The study has shown that an external magnetic field has great potential for positioning and alignment of CNTs. The study demonstrated potential for creating well-ordered architectures with an unprecedented level of control of network geometry. Magnetic characterisation indicated cobalt-plated nanotubes to be the most suitable candidate for magnetic alignment due to their high magnetic sensitivity. Epoxy/metal-plated CNT nanocomposite systems were validated by thermal analysis as induction heating mediums. The curing process could therefore be optimised by the use of dielectric resins. This study offers a first step towards the proof of concept of this technique as a novel repair technology.

  11. Development of microwave-assisted protein digestion based on trypsin-immobilized magnetic microspheres for highly efficient proteolysis followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis.

    PubMed

    Lin, Shuang; Lin, Zhenxin; Yao, Guoping; Deng, Chunhui; Yang, Pengyuan; Zhang, Xiangmin

    2007-01-01

    In this study, very easily prepared trypsin-immobilized magnetic microspheres were applied in microwave-assisted protein digestion and firstly applied for proteome analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Magnetic microspheres with small size were synthesized and modified by 3-glycidoxypropyltrimethoxysilane (GLYMO). Trypsin was immobilized onto magnetic microspheres through only a one-step reaction of its amine group with GLYMO. When these easily prepared trypsin-immobilized magnetic microspheres were applied in microwave-assisted protein digestion, the magnetic microspheres not only functionalized as substrate for trypsin immobilization, but also as an excellent microwave absorber and thus improved the efficiency of microwave-assisted digestion greatly. Cytochrome c was used as a model protein to verify its digestion efficiency. Without any additives such as organic solvents or urea, peptide fragments produced in 15 s could be confidently identified by MALDI-TOF-MS and better digestion efficiency was obtained comparing to conventional in-solution digestion (12 h). Besides, with an external magnet, trypsin could be used repeatedly and at the same time no contaminants were introduced into the sample solution. It was verified that the enzyme maintained high activity after seven runs. Furthermore, reversed-phase liquid chromatography (RPLC) fractions of rat liver extract were also successfully processed using this novel method. These results indicated that this fast and efficient digestion method, which combined the advantages of immobilized trypsin and microwave-assisted protein digestion, will greatly hasten the application of top-down proteomic techniques for large-scale analysis in biological and clinical research.

  12. Antares Rocket Test Launch

    NASA Image and Video Library

    2013-04-21

    NASA Deputy Administrator Lori Garver and other guests react after having watched the successful launch of the Orbital Sciences Corporation Antares rocket from the Mid-Atlantic Regional Spaceport (MARS) at the NASA Wallops Flight Facility in Virginia, Sunday, April 21, 2013. The test launch marked the first flight of Antares and the first rocket launch from Pad-0A. The Antares rocket delivered the equivalent mass of a spacecraft, a so-called mass simulated payload, into Earth's orbit. Photo Credit: (NASA/Bill Ingalls)

  13. Antares Rocket Test Launch

    NASA Image and Video Library

    2013-04-21

    NASA Administrator Charles Bolden and NASA Deputy Administrator Lori Garver and other guests react after having watched the successful launch of the Orbital Sciences Corporation Antares rocket from the Mid-Atlantic Regional Spaceport (MARS) at the NASA Wallops Flight Facility in Virginia, Sunday, April 21, 2013. The test launch marked the first flight of Antares and the first rocket launch from Pad-0A. The Antares rocket delivered the equivalent mass of a spacecraft, a so-called mass simulated payload, into Earth's orbit. Photo Credit: (NASA/Bill Ingalls)

  14. STS-135 Launch Day

    NASA Image and Video Library

    2011-07-07

    NASA Chief, Astronaut Office, Johnson Space Center Peggy Whitson deals cards during a traditional game that is played at the NASA Kennedy Space Center Operations and Checkout Building with the shuttle crew prior to them leaving for the launch pad, on Friday, July 8, 2011 in Cape Canaveral, Fla. The point of the game is that the commander must use up all his or her bad luck before launch, so the crew can only leave for the pad after the commander loses. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Jerry Ross)

  15. STS-135 Atlantis Launch

    NASA Image and Video Library

    2011-07-08

    Space shuttle Atlantis is seen through the window of a Shuttle Training Aircraft (STA) as it launches from launch pad 39A at Kennedy Space Center on the STS-135 mission, Friday, July 8, 2011 in Cape Canaveral, Fla. Atlantis launched on the final flight of the shuttle program on a 12-day mission to the International Space Station. The STS-135 crew will deliver the Raffaello multipurpose logistics module containing supplies and spare parts for the space station. Photo Credit: (NASA/Dick Clark)

  16. Development of a Hybrid Piezo Natural Rubber Piezoelectricity and Piezoresistivity Sensor with Magnetic Clusters Made by Electric and Magnetic Field Assistance and Filling with Magnetic Compound Fluid

    PubMed Central

    Shimada, Kunio; Saga, Norihiko

    2017-01-01

    Piezoelements used in robotics require large elasticity and extensibility to be installed in an artificial robot skin. However, the piezoelements used until recently are vulnerable to large forces because of the thin solid materials employed. To resolve this issue, we utilized a natural rubber and applied our proposed new method of aiding with magnetic and electric fields as well as filling with magnetic compound fluid (MCF) and doping. We have verified the piezoproperties of the resulting MCF rubber. The effect of the created magnetic clusters is featured in a new two types of multilayered structures of the piezoelement. By measuring the piezoelectricity response to pressure, the synergetic effects of the magnetic clusters, the doping and the electric polymerization on the piezoelectric effect were clarified. In addition, by examining the relation between the piezoelectricity and the piezoresistivity created in the MCF piezo element, we propose a hybrid piezoelement. PMID:28208625

  17. Development of a Hybrid Piezo Natural Rubber Piezoelectricity and Piezoresistivity Sensor with Magnetic Clusters Made by Electric and Magnetic Field Assistance and Filling with Magnetic Compound Fluid.

    PubMed

    Shimada, Kunio; Saga, Norihiko

    2017-02-10

    Piezoelements used in robotics require large elasticity and extensibility to be installed in an artificial robot skin. However, the piezoelements used until recently are vulnerable to large forces because of the thin solid materials employed. To resolve this issue, we utilized a natural rubber and applied our proposed new method of aiding with magnetic and electric fields as well as filling with magnetic compound fluid (MCF) and doping. We have verified the piezoproperties of the resulting MCF rubber. The effect of the created magnetic clusters is featured in a new two types of multilayered structures of the piezoelement. By measuring the piezoelectricity response to pressure, the synergetic effects of the magnetic clusters, the doping and the electric polymerization on the piezoelectric effect were clarified. In addition, by examining the relation between the piezoelectricity and the piezoresistivity created in the MCF piezo element, we propose a hybrid piezoelement.

  18. AC magnetic field-assisted method to develop porous carbon nanotube/conducting polymer composites for application in thermoelectric materials

    NASA Astrophysics Data System (ADS)

    Chuang, Chun-Yu; Yang, Shu-Chian; Chang, Su-Hua; Yang, Ta-I.

    2015-04-01

    Thermoelectric materials are very effective in converting waste heat sources into useful electricity. Researchers are continuing to develop new polymeric thermoelectric materials. The segregated-network carbon nanotube (CNT)- polymer composites are most promising. Thus, the goal of this study is to develop novel porous CNT -polymer composites with improved thermoelectric properties. The research efforts focused on modifying the surface of the CNT with magnetic nanoparticles so that heat was released when subjecting to an AC magnetic field. Subsequently, polymers covered on the surface of the CNT were crosslinked. The porous CNT -polymer composites can be obtained by removing the un-crosslinked polymers. Polydimethylsiloxane polymer was utilized to investigate the effect of porosity and electrical conductivity on the thermoelectric properties of the composites. This AC magnetic field-assisted method to develop porous carbon nanotube/polymer composites for application in thermoelectric materials is introduced for the first time. The advantage of this method is that the electrical conductivity of the composites was high since we can easily to manipulate the CNT to form a conducting path. Another advantage is that the high porosity significantly reduced the thermal conductivity of the composites. These two advantages enable us to realize the polymer composites for thermoelectric applications. We are confident that this research will open a new avenue for developing polymer thermoelectric materials.

  19. Synthesis and application of magnetic deep eutectic solvents: Novel solvents for ultrasound assisted liquid-liquid microextraction of thiophene.

    PubMed

    Khezeli, Tahere; Daneshfar, Ali

    2017-09-01

    Two novel magnetic deep eutectic solvents (MDESs), comprised of cheap and simple components named [choline chloride/phenol] [FeCl4] and [choline chloride/ethylene glycol] [FeCl4] were prepared and characterized by CHN elemental analysis, proton nuclear magnetic resonance ((1)H NMR), vibrating sample magnetometery (VSM), Raman, Fourier transform-infrared (FT-IR) and UV-Vis spectrometery. The extraction efficiency of the prepared MDESs has been investigated in ultrasound assisted liquid-liquid microextraction based MDES (UALLME-MDES). Briefly, MDESs were added to n-heptan containing thiophene. Then, MDESs were dispersed in n-heptane by sonication. After that, microdroplets of MDESs were collected by a magnet and the remained concentration of thiophene in n-heptane phase was analyzed by GC-FID. The results indicated that [choline chloride/phenol] [FeCl4] has higher extraction efficiency than [choline chloride/ethylene glycol] [FeCl4]. This work opens a new way to the application of MDESs. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. NASA Launches Rocket Into Active Auroras

    NASA Image and Video Library

    2017-09-28

    A test rocket is launched the night of Feb. 17 from the Poker Flat Research Range in Alaska. Test rockets are launched as part of the countdown to test out the radar tracking systems. NASA is launching five sounding rockets from the Poker Range into active auroras to explore the Earth's magnetic environment and its impact on Earth’s upper atmosphere and ionosphere. The launch window for the four remaining rockets runs through March 3. Credit: NASA/Terry Zaperach NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  1. Delta II THEMIS Pre-Launch

    NASA Image and Video Library

    2002-01-01

    The Delta II rocket with the THEMIS spacecraft atop sits ready for launch on Pad 17-B at Cape Canaveral Air Force Station in this aerial view of the launch complex area as the mobile service tower begins to move away. THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, consists of five identical probes that will track violent, colorful eruptions near the North Pole. This will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. The THEMIS mission aims to unravel the mystery behind auroral substorms, an avalanche of magnetic energy powered by the solar wind that intensifies the northern and southern lights. The mission will investigate what causes auroras in the Earth’s atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of bright color. Launch is scheduled for 6:05 p.m.

  2. STS-90 Pilot Scott Altman in white room before launch

    NASA Technical Reports Server (NTRS)

    1998-01-01

    STS-90 Pilot Scott Altman is assisted by NASA and USA closeout crew members immediately preceding launch for the nearly 17-day Neurolab mission. Investigations during the Neurolab mission will focus on the effects of microgravity on the nervous system. Linnehan and six fellow crew members will shortly enter the orbiter at KSC's Launch Pad 39B, where the Space Shuttle Columbia will lift off during a launch window that opens at 2:19 p.m. EDT, April 17.

  3. Magnetic assistance highly sensitive protein assay based on surface-enhanced resonance Raman scattering.

    PubMed

    Chen, Lei; Hong, Wonjin; Guo, Zhinan; Sa, Youngjo; Wang, Xu; Jung, Young Mee; Zhao, Bing

    2012-02-15

    A simple and effective surface-enhanced Raman scattering (SERS)-based protocol for the detection of protein-small molecule interactions has been developed. We employed silver-coated magnetic particles (AgMNPs), which can provide high SERS activity as a protein carrier to capture a small molecule. Combining magnetic separation and the SERS method for protein detection, highly reproducible SERS spectra of a protein-small molecule complex can be obtained with high sensitivity. This time-saving method employs an external magnetic field to induce the AgMNPs to aggregate to increase the amount of atto610-biotin/avidin complex in a unit area with the SERS enhancement. Because of the contribution of the AgMNP aggregation to the SERS, this protocol has great potential for practical high-throughput detection of the protein-small molecule complex and the antigen-antibody immunocomplex.

  4. Integrated head design using a nanobeak antenna for thermally assisted magnetic recording.

    PubMed

    Matsumoto, Takuya; Akagi, Fumiko; Mochizuki, Masafumi; Miyamoto, Harukazu; Stipe, Barry

    2012-08-13

    We propose a near-field optical transducer using a triangular antenna and a thin film structure (wing) to efficiently generate an optical near-field near a magnetic head. A finite-difference time-domain calculation showed that the near-field was efficiently generated at the apex of the antenna when the dimensions of the wing were optimized for efficient delivery of the surface plasmon excited on the wing to the antenna. The calculated light utilization efficiency (ratio between the absorbed power in the recording medium and the input power) was 8%. The temperature distribution on the medium, magnetic field distribution, and magnetization pattern were calculated; the proposed recording head may be capable of an areal recording density of 2.5 Tb/in.(2).

  5. Surfactant-assisted epitaxial growth and magnetism of Fe films on Cu(111).

    PubMed

    Niño, M A; Camarero, J; Gómez, L; Ferrón, J; de Miguel, J J; Miranda, R

    2008-07-02

    The magnetic properties of thin epitaxial layers of Fe grown on Cu(111) depend sensitively on the films' structure and morphology. A combination of experiments and numerical simulations reveals that the use of a surfactant monolayer (ML) of Pb during molecular beam epitaxy (MBE) growth at room temperature reduces the amount of interdiffusion at the Cu-Fe interface, retards the fcc-to-bcc transformation by about 2 ML and substantially increases the films' coercivity. The origin of all these alterations to the magnetic behavior can be traced back to the structural modifications provoked by the surfactant during the early growth stages. These results open the way for the controlled fabrication of custom-designed materials with specific magnetic characteristics.

  6. Launch of Juno!

    NASA Image and Video Library

    An Atlas V rocket lofted the Juno spacecraft toward Jupiter from Space Launch Complex-41. The 4-ton Juno spacecraft will take five years to reach Jupiter on a mission to study its structure and dec...

  7. Anchor Trial Launch

    Cancer.gov

    NCI has launched a multicenter phase III clinical trial called the ANCHOR Study -- Anal Cancer HSIL (High-grade Squamous Intraepithelial Lesion) Outcomes Research Study -- to determine if treatment of HSIL in HIV-infected individuals can prevent anal canc

  8. Genomic Data Commons launches

    Cancer.gov

    The Genomic Data Commons (GDC), a unified data system that promotes sharing of genomic and clinical data between researchers, launched today with a visit from Vice President Joe Biden to the operations center at the University of Chicago.

  9. Hi-C Launch

    NASA Image and Video Library

    The High resolution Coronal Imager (Hi-C) was launched on a NASA Black Brant IX two-stage rocket from White Sands Missile Range in New Mexico July 11, 2012. The experiment reached a maximum velocit...

  10. Launch - STS-6 - KSC

    NASA Image and Video Library

    1983-04-12

    S83-30222 (4 April 1983) --- The second reusable spacecraft in history successfully launches from Launch Pad 39A at 1:30:00:88 p.m. (EST) on April 4, 1983, and heads for its history making five-day mission in Earth orbit. The space shuttle Challenger, its two solid rocket boosters (SRB), and a new lightweight?external fuel tank were captured on film by an automatically-tripped camera in a protected station nearer to the launch pad than human beings are able to be at launch time. Onboard the spacecraft are astronauts Paul J. Wietz, Karol J. Bobko, Dr. Story Musgrave and Donald H. Peterson. Photo credit: NASA

  11. First Accessible Boat Launch

    EPA Pesticide Factsheets

    This is a story about how the Northwest Indiana urban waters partnership location supported the process to create and open the first handicap accessible canoe and kayak launch in the state of Indiana.

  12. IRVE 3 Launch

    NASA Image and Video Library

    The Inflatable Reentry Vehicle Experiment, or IRVE-3, launched on July 23, 2012, from NASA's Wallops Flight Facility. The purpose of the IRVE-3 test was to show that a space capsule can use an infl...

  13. GPM Launch Coverage

    NASA Image and Video Library

    A Japanese H-IIA rocket with the NASA-Japan Aerospace Exploration Agency (JAXA) Global Precipitation Measurement (GPM) Core Observatory aboard, launched from the Tanegashima Space Center in Japan o...

  14. NASA Now: Glory Launch

    NASA Image and Video Library

    In this episode of NASA Now, Dr. Hal Maring joins us to explain why the upcoming launch of the Glory satellite is so important to further our understanding of climate change. He also will speak on ...

  15. RICK BURT AND ANDY SCHORR WITH LAUNCH VEHICLE STAGE ADAPTER

    NASA Image and Video Library

    2016-09-23

    RICK BURT, RIGHT, DIRECTOR OF SAFETY AND MISSION ASSURANCE TALKS WITH ANDY SCHORR, ASSISTANT MANAGER OF THE SPACE LAUNCH SYSTEM'S SPACECRAFT PAYLOAD INTEGRATION AND EVOLUTION OFFICE. BEHIND THEM IS THE LAUNCH VEHICLE STAGE ADAPTOR, WHICH WAS DESIGNED AND MANUFACTURED AT MARSHALL AND WILL CONNECT TWO MAJOR SLS UPPER SECTIONS

  16. Vertical Launch Alignment Transfer Apparatus.

    DTIC Science & Technology

    A launch mechanism for vertically launching missiles carried in launch tubes disposed in a pod . The launch mechanism includes apparatus for... pod and v-groove elements are secured in the launch tubes and oriented to the northfinder. Rods are secured on opposite sides of each missile and are

  17. 33. Launch Control Center, close view of launch key inserted ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    33. Launch Control Center, close view of launch key inserted in the launch panel. Lyon - Whiteman Air Force Base, Oscar O-1 Minuteman Missile Alert Facility, Southeast corner of Twelfth & Vendenberg Avenues, Knob Noster, Johnson County, MO

  18. Surface modification by nonthermal plasma induced by using magnetic-field-assisted gliding arc discharge

    NASA Astrophysics Data System (ADS)

    Feng, Zongbao; Saeki, Noboru; Kuroki, Tomoyuki; Tahara, Mitsuru; Okubo, Masaaki

    2012-07-01

    The authors report on the introduction of a magnetic field to gliding arc discharge (GD) in order to enhance surface modification by nonthermal plasma at atmospheric-pressure. The GD is induced between two wire electrodes by using a pulse high-voltage power supply with peak-to-peak voltage of 5 kV. When a magnetic field of 0.25 T is applied, the GD enlarged and a 19-cm-long stretch of plasma is excited. The surface treatment of polyethylene terephthalate and polytetrafluoroethylene films is performed. The adhesion improved by up to ˜30 times due to the enhanced chemical activity in the films.

  19. Experiences with Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Dumbacher, Daniel L.

    2006-01-01

    The presentation "NASA Experience with Launch Vehicles" is a compilation of Mr. Dumbacher's career experiences with the Space Shuttle Program, the Delta - Clipper Experimental flight test project, the X-33 demonstrator project, and recent experiences with the Orbital Spaceplane Program agd the current NASA effort on Exploration Launch Systems. Mr. Dumbacher will discuss his personal experiences and provide lessons learned from each program. The accounts provided by Mr. Dumbacher are his own and do not necessarily represent the official NASA position.

  20. STS-130 Launch Attempt

    NASA Image and Video Library

    2010-02-07

    NASA Associate Administrator for Space Operations Bill Gerstenmaier, center, reacts to an updated weather report during the countdown of the launch of the space shuttle Endeavour and the start of the STS-130 mission at NASA Kennedy Space Center in Cape Canaveral, Fla. on Sunday Feb. 7, 2010. Space shuttle Endeavour's launch attempt was scrubbed due to a low cloud ceiling over Kennedy Space Center. Photo Credit: (NASA/Bill Ingalls)

  1. STS-132 Launch Tweetup

    NASA Image and Video Library

    2010-05-12

    Jon Cowart @Rocky_Sci, orbiter engineering manager, Space Shuttle Program, interacts with Tweetup participant, Jen Vargas, @jenvargus, as he speaks to participants at the two-day STS-132 Launch Tweetup at Kennedy Space Center, Thursday, May 13, 2010, in Cape Canaveral, Fla. NASA Twitter followers in attendance will have the opportunity to take a tour of NASA's Kennedy Space Center, view the space shuttle launch and speak with shuttle technicians, engineers, astronauts and managers. Photo Credit: (NASA/Paul E. Alers)

  2. Expedition 23 Launch Day

    NASA Image and Video Library

    2010-04-01

    Expedition 23 Flight Engineer Mikhail Kornienko of the Russia has his Russian Sokol suit prepared for launch by a technician at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Friday, April 2, 2010. Kornienko and fellow Expedition 23 crewmembers Soyuz Commander Alexander Skvortsov and NASA Flight Engineer Tracy Caldwell Dyson of the U.S. launched in their Soyuz TMA-18 rocket from the Baikonur Cosmodrome in Kazakhstan on Friday, April 2, 2010. Photo Credit: (NASA/Carla Cioffi)

  3. Expedition 23 Launch Day

    NASA Image and Video Library

    2010-04-01

    Expedition 23 Soyuz Commander Alexander Skvortsov has his Russian Sokol suit prepared for launch by a technician at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Friday, April 2, 2010. Skvortsov and fellow Expedition 23 crewmembers Flight Engineer Mikhail Kornienko of the Russia and NASA Flight Engineer Tracy Caldwell Dyson of the U.S. launched in their Soyuz TMA-18 rocket from the Baikonur Cosmodrome in Kazakhstan on Friday, April 2, 2010. Photo Credit: (NASA/Carla Cioffi)

  4. Expedition 22 Launch Day

    NASA Image and Video Library

    2009-12-20

    Expedition 22 Flight Engineer Soichi Noguchi of Japan has his Russian Sokol suit prepared for launch by a technician at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Sunday, Dec. 20, 2009. Soichi and fellow Expedition 22 crew members NASA Flight Engineer Timothy J. Creamer of the U.S., Soyuz Commander Oleg Kotov of Russia launched in their Soyuz TMA-17 rocket from the Baikonur Cosmodrome in Kazakhstan on Monday, Dec. 21, 2009. (Photo Credit: NASA/Bill Ingalls)

  5. Expedition 23 Launch Day

    NASA Image and Video Library

    2010-04-01

    Expedition 23 NASA Flight Engineer Tracy Caldwell Dyson, left, talks with Soyuz Commander Alexander Skvortsov of Russia, while Flight Engineer Mikhail Kornienko of Russia has his Russian Sokol suit prepared for launch at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Friday, April 2, 2010. The Expedition 23 crew members launched in their Soyuz TMA-18 rocket from the Baikonur Cosmodrome in Kazakhstan on Friday, April 2, 2010. (Photo Credit: NASA/Bill Ingalls)

  6. Expedition 23 Launch Day

    NASA Image and Video Library

    2010-04-01

    Expedition 23 NASA Flight Engineer Tracy Caldwell Dyson of the U.S. has her Russian Sokol suit prepared for launch by a technician at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Friday, April 2, 2010. Caldwell Dyson and fellow Expedition 23 crew members Soyuz Commander Alexander Skvortsov and Flight Engineer Mikhail Kornienko of Russia launched in their Soyuz TMA-18 rocket from the Baikonur Cosmodrome in Kazakhstan on Friday, April 2, 2010. Photo Credit: (NASA/Carla Cioffi)

  7. Expedition 25 Launch

    NASA Image and Video Library

    2010-10-07

    Expedition 25 NASA Flight Engineer Scott Kelly of the U.S. has his Russian Sokol suit prepared for launch by a technician at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Friday, Oct. 8, 2010. Kelly and fellow Expedition 25 crew members Soyuz Commander Alexander Kaleri and Flight Engineer Oleg Skripochka launched in their Soyuz TMA-01M at 5:10 a.m. Friday morning. (Photo Credit: NASA/Carla Cioffi)

  8. Expedition 25 Launch

    NASA Image and Video Library

    2010-10-07

    The Soyuz TMA-01M rocket launches from the Baikonur Cosmodrome in Kazakhstan on Friday, October 8, 2010 carrying Expedition 25 Soyuz Commander Alexander Kaleri of Russia, NASA Flight Engineer Scott J. Kelly and Russian Flight Engineer Oleg Skripochka to the International Space Station. Their Soyuz TMA-01M rocket launched at 5:10 a.m Kazakhstan time. (Photo Credit: NASA/Carla Cioffi)

  9. Expedition 25 Launch

    NASA Image and Video Library

    2010-10-07

    Expedition 25 NASA Flight Engineer Scott Kelly of the U.S. has his Russian Sokol suit prepared for launch by a technician at the Baikonur Cosmodrome in Kazakhstan, Friday, Oct. 8, 2010. Kelly and fellow Expedition 25 crew members Soyuz Commander Alexander Kaleri and Flight Engineer Oleg Skripochka launched in their Soyuz TMA-01M at 5:10 a.m. Friday morning. (Photo Credit: NASA/Carla Cioffi)

  10. STS-64 launch view

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Passing through some of the trailer clouds of an overcast sky which temporarily postponed its launch, the Space Shuttle Discovery heads for its 19th Earth orbital flight. Several kilometers away, astronaut John H. Casper, Jr., who took this picture, was piloting the Shuttle Training Aircraft (STA) from which the launch and landing area weather was being monitored. Onboard Discovery were astronauts Richard N. Richards, L. Blaine Hammond, Jr., Mark C. Lee, Carl J. Meade, Susan J. Helms, and Jerry M. Linenger.

  11. Orion EFT-1 Launch

    NASA Image and Video Library

    2014-12-05

    A Delta IV Heavy rocket lifts off from Space Launch Complex 37 at Cape Canaveral Air Force Station in Florida carrying NASA's Orion spacecraft on an unpiloted flight test to Earth orbit. Liftoff was at 7:05 a.m. EST. During the two-orbit, four-and-a-half hour mission, engineers will evaluate the systems critical to crew safety, the launch abort system, the heat shield and the parachute system.

  12. Expedition 22 Launch Day

    NASA Image and Video Library

    2009-12-21

    Expedition 22 Soyuz Commander Oleg Kotov of Russia, left, NASA Flight Engineer Timothy J. Creamer of the U.S., back center, and Flight Engineer Soichi Noguchi of Japan are walked from their bus to the soyuz rocket at the launch pad at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Monday, Dec. 21, 2009. Kotov, Creamer and Noguchi launched in their Soyuz TMA-17 rocket from the Baikonur Cosmodrome in Kazakhstan on Monday, Dec. 21, 2009. (Photo Credit: NASA/Bill Ingalls)

  13. Expedition 22 Launch Day

    NASA Image and Video Library

    2009-12-20

    Expedition 22 Soyuz Commander Oleg Kotov of Russia, center, has his Russian Sokol suit prepared for launch while NASA Flight Engineer Timothy J. Creamer of the U.S., left, and Flight Engineer Soichi Noguchi of Japan wait at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Sunday, Dec. 20, 2009. The Expedition 22 crew members launched in their Soyuz TMA-17 rocket from the Baikonur Cosmodrome in Kazakhstan on Monday, Dec. 21, 2009. (Photo Credit: NASA/Bill Ingalls)

  14. Expedition 22 Launch Day

    NASA Image and Video Library

    2009-12-20

    Expedition 22 NASA Flight Engineer Timothy J. Creamer of the U.S. has his Russian Sokol suit prepared for launch by a technician at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Sunday, Dec. 20, 2009. Creamer and fellow Expedition 22 crew members, Soyuz Commander Oleg Kotov of Russia, Flight Engineer Soichi Noguchi of Japan launched in their Soyuz TMA-17 rocket from the Baikonur Cosmodrome in Kazakhstan on Monday, Dec. 21, 2009. (Photo Credit: NASA/Bill Ingalls)

  15. Expedition 22 Launch Day

    NASA Image and Video Library

    2009-12-20

    Expedition 22 NASA Flight Engineer Timothy J. Creamer of the U.S., left, talks with Soyuz Commander Oleg Kotov of Russia, right, while Flight Engineer Soichi Noguchi of Japan has his Russian Sokol suit prepared for launch at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Sunday, Dec. 20, 2009. The Expedition 22 crew members launched in their Soyuz TMA-17 rocket from the Baikonur Cosmodrome in Kazakhstan on Monday, Dec. 21, 2009. (Photo Credit: NASA/Bill Ingalls)

  16. STS-132 Launch Tweetup

    NASA Image and Video Library

    2010-05-12

    Kendal Van Dyke, a database professional that is followed on Twitter @twitter.com/sqldba, takes part in the two-day STS-132 Launch Tweetup at Kennedy Space Center, Thursday, May 13, 2010, in Cape Canaveral, Fla. NASA Twitter followers in attendance will have the opportunity to take a tour of NASA's Kennedy Space Center, view the space shuttle launch and speak with shuttle technicians, engineers, astronauts and managers. Photo Credit: (NASA/Paul E. Alers)

  17. Expedition 8 Launch Day

    NASA Image and Video Library

    2003-10-18

    Technicians conduct a leak check on the spacesuit of Expedition 8 Soyuz Commander Alexander Kaleri at the Baikonur Cosmodrome, Saturday, Oct. 18, 2003, prior to his departure for the launch pad with Expedition 8 Commander and NASA Science Officer Mike Foale and European Space Agency astronaut Pedro Duque of Spain. The trio were launched on a Soyuz TMA-3 vehicle to the International Space Station, arriving on Oct. 20. Photo Credit (NASA/Bill Ingalls)

  18. Expedition 8 Launch Day

    NASA Image and Video Library

    2003-10-18

    Technicians conduct a leak check on the spacesuit of European Space Agency astronaut Pedro Duque of Spain at the Baikonur Cosmodrome, Saturday, Oct. 18, 2003, prior to his departure for the launch pad with Expedition 8 Commander and NASA Science Officer Mike Foale and Soyuz Commander Alexander Kaleri. The trio were launched on a Soyuz TMA-3 vehicle to the International Space Station, arriving on Oct. 20. Photo Credit (NASA/Bill Ingalls)

  19. Expedition 8 Launch Day

    NASA Image and Video Library

    2003-10-18

    Expedition 8 Commander and NASA Science Officer Michael Foale completes suiting up at the Baikonur Cosmodrome in Kazakhstan, Saturday, Oct. 18, 2003, prior to departing for the launch pad with Expedition 8 Soyuz Commander Alexander Kaleri and European Space Agency astronaut Pedro Duque of Spain. The trio were launched on the Soyuz TMA-3 vehicle to the International Space Station, arriving on Oct. 20. Photo Credit (NASA/Bill Ingalls)

  20. Launch Vehicle Communications

    NASA Technical Reports Server (NTRS)

    Welch, Bryan; Greenfeld, Israel

    2005-01-01

    As the National Aeronautics and Space Administration's (NASA) planning for updated launch vehicle operations progresses, there is a need to consider improved methods. This study considers the use of phased array antennas mounted on launch vehicles and transmitting data to either NASA's Tracking and Data Relay Satellite System (TDRSS) satellites or to the commercial Iridium, Intelsat, or Inmarsat communications satellites. Different data rate requirements are analyzed to determine size and weight of resulting antennas.

  1. STS-135 Atlantis Launch

    NASA Image and Video Library

    2011-07-08

    Guests look on from the terrace of Operations Support Building II as space shuttle Atlantis launches from launch pad 39A on the STS-135 mission Friday, July 8, 2011, at Kennedy Space Center in Cape Canaveral, Fla. Atlantis and its crew will deliver to the International Space Station the Raffaello multipurpose logistics module containing supplies and spare parts for the space station. Photo Credit: (NASA/Carla Cioffi)

  2. STS-135 Atlantis Launch

    NASA Image and Video Library

    2011-07-08

    Space shuttle Atlantis, STS-135, launches skyward on a 12-day mission to the International Space Station (ISS), Friday, July 8, 2011, at NASA's Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis is the final flight of the shuttle program and will carry the Raffaello multipurpose logistics module containing supplies and spare parts for the space station. Photo Credit: (NASA/Paul E. Alers)

  3. Orion EFT-1 Launch

    NASA Image and Video Library

    2014-12-05

    A Delta IV Heavy rocket roars to life at Space Launch Complex 37 at Cape Canaveral Air Force Station in Florida. The launch vehicle is carrying NASA's Orion spacecraft on an unpiloted flight test to Earth orbit. Liftoff was at 7:05 a.m. EST. The flight will send Orion 3,600 miles in altitude beyond the Earth's surface on a four-and-a-half hour mission.

  4. STS-132 Launch Tweetup

    NASA Image and Video Library

    2010-05-12

    Ron Woods, an equipment specialist, who has been a space suit designer from Mercury to now speaks to participants at the two-day STS-132 Launch Tweetup at Kennedy Space Center, Thursday, May 13, 2010, in Cape Canaveral, Fla. NASA Twitter followers in attendance will have the opportunity to take a tour of NASA's Kennedy Space Center, view the space shuttle launch and speak with shuttle technicians, engineers, astronauts and managers. Photo Credit: (NASA/Paul E. Alers)

  5. 3850:..At the Cosmonaut Hotel crew quarters in Baikonur, Kazakhstan, Expedition 44 prime crewmember Kjell Lindgren of NASA (right) plants a tree in his name in a traditional pre-launch ceremony July 15. Assisting are crewmates Kimiya Yui of the Japan Aerospace Exploration Agency (left) and Oleg Kononenko of the Russian Federal Space Agency (Roscosmos, center), Yui, Kononenko and Lindgren will launch July 23, Kazakh time on the Soyuz TMA-17M spacecraft from the Baikonur Cosmodrome for a five-month mission on the International Space Station...Credit: Gagarin Cosmonaut Training Center.

    NASA Image and Video Library

    2015-07-15

    3850: At the Cosmonaut Hotel crew quarters in Baikonur, Kazakhstan, Expedition 44 prime crewmember Kjell Lindgren of NASA (right) plants a tree in his name in a traditional pre-launch ceremony July 15. Assisting are crewmates Kimiya Yui of the Japan Aerospace Exploration Agency (left) and Oleg Kononenko of the Russian Federal Space Agency (Roscosmos, center), Yui, Kononenko and Lindgren will launch July 23, Kazakh time on the Soyuz TMA-17M spacecraft from the Baikonur Cosmodrome for a five-month mission on the International Space Station. Credit: Gagarin Cosmonaut Training Center

  6. Electromagnetic Launch to Space

    NASA Astrophysics Data System (ADS)

    McNab, I. R.

    Many advances in electromagnetic (EM) propulsion technology have occurred in recent years. Linear motor technology for low-velocity and high-mass applications is being developed for naval catapults. Such technology could serve as the basis for a first-stage booster launch--as suggested by the US National Aeronautics and Space Administration (NASA) in the Maglifter concept. Using railguns, laboratory experiments have demonstrated launch velocities of 2-3 km/s and muzzle energies > 8 MJ. The extension of this technology to the muzzle velocities ( 7500 m/s) and energies ( 10 GJ) needed for the direct launch of payloads into orbit is very challenging but may not be impossible. For launch to orbit, even long launchers (> 1000 m) would need to operate at accelerations > 1000 G to reach the required velocities, so it would only be possible to launch rugged payloads, such as fuel, water, and materiel. Interest is being shown in such concepts by US, European, Russian, and Chinese researchers. An intermediate step proposed in France could be to launch payloads to sounding rocket altitudes for ionospheric research.

  7. Comparison of the Effectiveness of Water-Based Extraction of Substances from Dry Tea Leaves with the Use of Magnetic Field Assisted Extraction Techniques.

    PubMed

    Zaguła, Grzegorz; Bajcar, Marcin; Saletnik, Bogdan; Czernicka, Maria; Puchalski, Czesław; Kapusta, Ireneusz; Oszmiański, Jan

    2017-10-03

    This article presents the findings of a study investigating the feasibility of using a magnetic field assisted technique for the water-based extraction of mineral components, polyphenols, and caffeine from dry black and green tea leaves. The authors present a concept of applying constant and variable magnetic fields in the process of producing water-based infusions from selected types of tea. Analyses investigating the effectiveness of the proposed technique in comparison with conventional infusion methods assessed the contents of selected mineral components-i.e., Al, Ca, Cu, K, Mg, P, S, and Zn-which were examined with the use of ICP-OES. The contents of caffeine and polyphenolic compounds were assessed using the HPLC. A changing magnetic field permitted an increased effectiveness of extraction of the mineral components, caffeine, and polyphenols. The findings support the conclusion that a changing magnetic field assisted extraction method is useful for obtaining biologically valuable components from tea infusions.

  8. Magnetic-field-assisted assembly of layered double hydroxide/metal porphyrin ultrathin films and their application for glucose sensors.

    PubMed

    Shao, Mingfei; Xu, Xiangyu; Han, Jingbin; Zhao, Jingwen; Shi, Wenying; Kong, Xianggui; Wei, Min; Evans, David G; Duan, Xue

    2011-07-05

    The ordered ultrathin films (UTFs) based on CoFe-LDH (layered double hydroxide) nanoplatelets and manganese porphyrin (Mn-TPPS) have been fabricated on ITO substrates via a magnetic-field-assisted (MFA) layer-by-layer (LBL) method and were demonstrated as an electrochemical sensor for glucose. The XRD pattern for the film indicates a long-range stacking order in the normal direction of the substrate. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) images of the MFA LDH/Mn-TPPS UTFs reveal a continuous and uniform surface morphology. Cyclic voltammetry, impedance spectroscopy, and chronoamperometry were used to evaluate the electrochemical performance of the film, and the results show that the MFA-0.5 (0.5 T magnetic field) CoFe-LDH/Mn-TPPS-modified electrode displays the strongest redox current peaks and fastest electron transfer process compared with those of MFA-0 (without magnetic-field) and MFA-0.15 (0.15 T magnetic field). Furthermore, the MFA-0.5 CoFe-LDH/Mn-TPPS exhibits remarkable electrocatalytic activity toward the oxidation of glucose with a linear response range (0.1-15 mM; R(2) = 0.999), low detection limit (0.79 μM) and high sensitivity (66.3 μA mM(-1) cm(-2)). In addition, the glucose sensor prepared by the MFA LBL method also shows good selectivity and reproducibility as well as resistance to poisoning in a chloride ion solution. Therefore, the novel strategy in this work creates new opportunities for the fabrication of nonenzyme sensors with prospective applications in practical detection.

  9. Magnetic effervescent tablet-assisted ionic liquid dispersive liquid-liquid microextraction of selenium for speciation in foods and beverages.

    PubMed

    Wang, Xiaojun; Wu, Long; Cao, Jiaqi; Hong, Xincheng; Ye, Rui; Chen, Weiji; Yuan, Ting

    2016-07-01

    A novel, simple and rapid method based on magnetic effervescent tablet-assisted ionic liquid dispersive liquid-liquid microextraction (MEA-IL-DLLME) followed by graphite furnace atomic absorption spectrometry (GFAAS) determination was established for the speciation of selenium in various food and beverage samples. In the procedure, a special magnetic effervescent tablet containing CO2 sources (sodium carbonate and sodium dihydrogenphosphate), ionic liquids and Fe3O4 magnetic nanoparticles (MNPs) was used to combine extractant dispersion and magnetic recovery procedures into a single step. The parameters influencing the microextraction efficiency, such as pH of the sample solution, volume of ionic liquid, amount of MNPs, concentration of the chelating agent, salt effect and matrix effect were investigated and optimised. Under the optimised conditions, the limits of detection (LODs) for Se(IV) were 0.021 μg l(-)(1) and the linear dynamic range was 0.05-5.0 μg l(-)(1). The relative standard deviation for seven replicate measurements of 1.0 μg l(-)(1) of Se(IV) was 2.9%. The accuracy of the developed method was evaluated by analysis of the standard reference materials (GBW10016 tea, GBW10017 milk powder, GBW10043 Liaoning rice, GBW10046 Henan wheat, GBW10048 celery). The proposed method was successfully applied to food and beverage samples including black tea, milk powder, mushroom, soybean, bamboo shoots, energy drink, bottled water, carbonated drink and mineral water for the speciation of Se(IV) and Se(VI) with satisfactory relative recoveries (92.0-108.1%).

  10. Head-disk Interface Study for Heat Assisted Magnetic Recording (HAMR) and Plasmonic Nanolithography for Patterned Media

    NASA Astrophysics Data System (ADS)

    Xiong, Shaomin

    The magnetic storage areal density keeps increasing every year, and magnetic recording-based hard disk drives provide a very cheap and effective solution to the ever increasing demand for data storage. Heat assisted magnetic recording (HAMR) and bit patterned media have been proposed to increase the magnetic storage density beyond 1 Tb/in2. In HAMR systems, high magnetic anisotropy materials are recommended to break the superparamagnetic limit for further scaling down the size of magnetic bits. However, the current magnetic transducers are not able to generate strong enough field to switch the magnetic orientations of the high magnetic anisotropy material so the data writing is not able to be achieved. So thermal heating has to be applied to reduce the coercivity for the magnetic writing. To provide the heating, a laser is focused using a near field transducer (NFT) to locally heat a ~(25 nm)2 spot on the magnetic disk to the Curie temperature, which is ~ 400 C-600°C, to assist in the data writing process. But this high temperature working condition is a great challenge for the traditional head-disk interface (HDI). The disk lubricant can be depleted by evaporation or decomposition. The protective carbon overcoat can be graphitized or oxidized. The surface quality, such as its roughness, can be changed as well. The NFT structure is also vulnerable to degradation under the large number of thermal load cycles. The changes of the HDI under the thermal conditions could significantly reduce the robustness and reliability of the HAMR products. In bit patterned media systems, instead of using the continuous magnetic granular material, physically isolated magnetic islands are used to store data. The size of the magnetic islands should be about or less than 25 nm in order to achieve the storage areal density beyond 1 Tb/in2. However, the manufacture of the patterned media disks is a great challenge for the current optical lithography technology. Alternative lithography

  11. Designing a Poly (N-isopropylacrylamide) Nanocapsule for Magnetic Field-assisted Drug Delivery

    NASA Astrophysics Data System (ADS)

    Denmark, Daniel; Mukherjee, Pritish; Witanachchi, Sarath

    2014-03-01

    The method of synthesis and the characteristics of polymer based nanocapsules as biomedical drug delivery systems are presented. Magnetic iron oxide nanoparticles have been incorporated into these capsules for effective guidance with external magnetic fields to transport therapeutic compounds to various parts of the human body. Once they have reached their destination they can be stimulated to release the drug to the target tissue through externally applied fields. The polymeric material that constitutes the capsules is specifically designed to melt away with the external stimuli to deliver the therapeutic bio agents near the target tissue. In this work we use nebulization to create aqueous poly (N-isopropylacrylamide) nanoparticles that decompose after being heated beyond their transition temperature. Transmission Electron Microscopic imaging (TEM) and dynamic light scattering (DLS) experiments have been conducted to study the decomposition of the capsules under external stimuli. Distribution of the magnetic nanoparticles within the capsules and their role in delivering the bio agents have been investigated by the Magnetic Force Microscopy (MFM).

  12. 77 FR 77056 - Applications for New Awards; Magnet Schools Assistance Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-31

    ... than through academic examination. Priority 4--Promoting Science, Technology, Engineering, and... Grants.gov under News and Events on the Department's G5 system home page at www.G5.gov . You will not... magnet school, e.g. women and girls in mathematics, science, or technology courses, and disabled students...

  13. A new magnetic compound fluid slurry and its performance in magnetic field-assisted polishing of oxygen-free copper

    NASA Astrophysics Data System (ADS)

    Wang, Youliang; Wu, Yongbo; Guo, Huiru; Fujimoto, Masakazu; Nomura, Mitsuyoshi; Shimada, Kunio

    2015-05-01

    In nano-precision surface finishing of engineering materials using MCF (magnetic compound fluid) slurry, the water-based MCF slurry is preferable from the viewpoint of the environmental issue and the running cost of cleaning workpiece and equipment. However, the uncoated-CIPs (carbonyl-iron-powders) within the conventional MCF slurry have low ability against aqueous corrosion, leading to the performance deterioration and working life shortening of the conventional MCF slurry. This study proposed a new MCF slurry containing ZrO2-coated CIPs instead of the uncoated CIPs. Its performance in the polishing of oxygen-free copper was compared experimentally with that of the conventional one. The results showed that the work-surface finish polished with the new slurry was in the same level as that with the conventional one when the slurry was used soon after prepared, i.e., the settling time was 0 min; however, as the settling time increased the uncoated-CIPs got rusty, leading to a deterioration in the slurry performance. By contrast, no rust was observed on ZrO2-coated CIPs even the settling time reached several days, indicating the employment of ZrO2-coated CIPs prolonged the working-life of the MCF slurry greatly.

  14. STS-119 Astronaut White Room Launch Prep

    NASA Image and Video Library

    2009-03-15

    STS119-S-014 (15 March 2009) --- In the White Room on launch pad 39A at NASA's Kennedy Space Center in Florida, astronaut Joseph Acaba, STS-119 mission specialist, attired in his shuttle launch and entry suit, dons his harness, which includes a parachute pack, before crawling through the open hatch into Space Shuttle Discovery. The White Room is at the end of the orbiter access arm on the fixed service structure and provides access into the shuttle. Members of the closeout crew assisted Acaba. Liftoff is scheduled for 7:43 p.m. (EDT) on March 15, 2009.

  15. STS-119 Astronaut White Room Launch Prep

    NASA Image and Video Library

    2009-03-15

    STS119-S-011 (15 March 2009) --- In the White Room on launch pad 39A at NASA's Kennedy Space Center in Florida, astronaut John Phillips, STS-119 mission specialist, attired in his shuttle launch and entry suit, dons his harness, which includes a parachute pack, before crawling through the open hatch into Space Shuttle Discovery. The White Room is at the end of the orbiter access arm on the fixed service structure and provides access into the shuttle. Members of the closeout crew assisted Phillips. Liftoff is scheduled for 7:43 p.m. (EDT) on March 15, 2009.

  16. STS-119 Astronaut White Room Launch Prep

    NASA Image and Video Library

    2009-03-15

    STS119-S-017 (15 March 2009) --- In the White Room on launch pad 39A at NASA's Kennedy Space Center in Florida, astronaut Steve Swanson, STS-119 mission specialist, attired in his shuttle launch and entry suit, dons his harnesses, which includes a parachute pack, before crawling through the open hatch into Space Shuttle Discovery. The White Room is at the end of the orbiter access arm on the fixed service structure and provides access into the shuttle. Members of the closeout crew assisted Swanson. Liftoff is scheduled for 7:43 p.m. (EDT) on March 15, 2009.

  17. Electromagnetic launch, then lessening chemical thrust over time as laser beam powered ion thrust grows—to any orbit

    NASA Astrophysics Data System (ADS)

    Morse, Thomas M.

    1996-03-01

    The ElectroMagnetic (EM) Launch Tube (LT), using High-Temp SuperConduction (HTSC) EM launch coils if developed, will be built in a tall building, or, if not, at a steep angle up the west slope of an extinct volcano. The Reusable Launch Vehicle (RLV) exits the LT at such high velocity that the otherwise violent entry into the atmosphere is made possible by Special-Laser-Launch-Assist (SLLA), which ionizes and expands the atmosphere immediately ahead of the RLV. At first a brief period of chemical thrust is followed by a long period of ion thrust during ascent to orbit. As decades pass and greater ion thrust is developed, the period of chemical thrust shortens until it is no longer needed. The RLV's ion thrusters are powered by laser/maser, beamed first from the launch site, then from two large Solar-Power-Satellites (SPS) 180° apart in Medium Earth Orbit (MEO) orbit. In orbit, the RLV is limited in where it can go only by the amount of propellant it carries or is stored in various orbits. The RLV can land at a launch site on Earth by using both chemical and ion thrust at first, and later by ion thrust alone as developments cause a far lighter RLV to carry no chemical engines/fuel/tanks.

  18. Observation of Tunneling-Assisted Highly Forbidden Single-Photon Transitions in a Ni4 Single-Molecule Magnet

    NASA Astrophysics Data System (ADS)

    Chen, Yiming; Ashkezari, Mohammad D.; Collett, Charles A.; Allão Cassaro, Rafael A.; Troiani, Filippo; Lahti, Paul M.; Friedman, Jonathan R.

    2016-10-01

    Forbidden transitions between energy levels typically involve violation of selection rules imposed by symmetry and/or conservation laws. A nanomagnet tunneling between up and down states violates angular momentum conservation because of broken rotational symmetry. Here we report observations of highly forbidden transitions between spin states in a Ni4 single-molecule magnet in which a single photon can induce the spin to change by several times ℏ, nearly reversing the direction of the spin. These observations are understood as tunneling-assisted transitions that lift the standard Δ m =±1 selection rule for single-photon transitions. These transitions are observed at low applied fields, where tunneling is dominated by the molecule's intrinsic anisotropy and the field acts as a perturbation. Such transitions can be exploited to create macroscopic superposition states that are not typically accessible through single-photon Δ m =±1 transitions.

  19. Personnel in LCC watch STS-130 Launch

    NASA Image and Video Library

    2010-02-08

    STS130-S-025 (8 Feb. 2010) --- From left, Mike Leinbach, shuttle launch director; Pete Nickolenko, assistant launch director; and Dana Hutcherson, flow director for space shuttle Endeavour, watch the liftoff of Endeavour through the windows of Firing Room 4 in the Launch Control Center at NASA's Kennedy Space Center in Florida. Launch of Endeavour on the STS-130 mission to the International Space Station was at 4:14 a.m. (EST) on Feb. 8, 2010. This was the second launch attempt for Endeavour's STS-130 crew and the final scheduled space shuttle night launch. The first attempt on Feb. 7 was scrubbed due to unfavorable weather. The primary payload for the STS-130 mission to the International Space Station is the Tranquility node, a pressurized module that will provide additional room for crew members and many of the station's life support and environmental control systems. Attached to one end of Tranquility is the Cupola, a unique work area with six windows on its sides and one on top. The Cupola resembles a circular bay window and will provide a vastly improved view of the station's exterior. The multi-directional view will allow the crew to monitor spacewalks and docking operations, as well as provide a spectacular view of Earth and other celestial objects. The module was built in Turin, Italy, by Thales Alenia Space for the European Space Agency.

  20. Magnetically Assisted Remote-controlled Endovascular Catheter for Interventional MR Imaging: In Vitro Navigation at 1.5 T versus X-ray Fluoroscopy

    PubMed Central

    Losey, Aaron D.; Lillaney, Prasheel; Martin, Alastair J.; Cooke, Daniel L.; Wilson, Mark W.; Thorne, Bradford R. H.; Sincic, Ryan S.; Arenson, Ronald L.; Saeed, Maythem

    2014-01-01

    Purpose To compare in vitro navigation of a magnetically assisted remote-controlled (MARC) catheter under real-time magnetic resonance (MR) imaging with manual navigation under MR imaging and standard x-ray guidance in endovascular catheterization procedures in an abdominal aortic phantom. Materials and Methods The 2-mm-diameter custom clinical-grade microcatheter prototype with a solenoid coil at the distal tip was deflected with a foot pedal actuator used to deliver 300 mA of positive or negative current. Investigators navigated the catheter into branch vessels in a custom cryogel abdominal aortic phantom. This was repeated under MR imaging guidance without magnetic assistance and under conventional x-ray fluoroscopy. MR experiments were performed at 1.5 T by using a balanced steady-state free precession sequence. The mean procedure times and percentage success data were determined and analyzed with a linear mixed-effects regression analysis. Results The catheter was clearly visible under real-time MR imaging. One hundred ninety-two (80%) of 240 turns were successfully completed with magnetically assisted guidance versus 144 (60%) of 240 turns with nonassisted guidance (P < .001) and 119 (74%) of 160 turns with standard x-ray guidance (P = .028). Overall mean procedure time was shorter with magnetically assisted than with nonassisted guidance under MR imaging (37 seconds ± 6 [standard error of the mean] vs 55 seconds ± 3, P < .001), and time was comparable between magnetically assisted and standard x-ray guidance (37 seconds ± 6 vs 44 seconds ± 3, P = .045). When stratified by angle of branch vessel, magnetic assistance was faster than nonassisted MR guidance at turns of 45°, 60°, and 75°. Conclusion In this study, a MARC catheter for endovascular navigation under real-time MR imaging guidance was developed and tested. For catheterization of branch vessels arising at large angles, magnetically assisted catheterization was faster than manual catheterization

  1. First experimental demonstration of magnetic-field assisted fast heating of a dense plasma core

    NASA Astrophysics Data System (ADS)

    Fujioka, Shinsuke; Sakata, Shohei; Lee, Seung Ho; Matsuo, Kazuki; Sawada, Hiroshi; Iwasa, Yuki; Law, King Fai Farley; Morita, Hitoki; Kojima, Sadaoki; Abe, Yuki; Yao, Akira; Hata, Masayasu; Johzaki, Tomoyuki; Sunahara, Atsushi; Ozaki, Tetsuo; Sakagami, Hitoshi; Morace, Alessio; Arikawa, Yasunobu; Yogo, Akifumi; Nishimura, Hiroaki; Nakai, Mitsuo; Shiraga, Hiroyuki; Sentoku, Yasuhiko; Nagatomo, Hideo; Azechi, Hiroshi; Firex Project Team

    2016-10-01

    Fast heating of a dense plasma core by an energetic electron beam is being studied on GEKKO-LFEX laser facility. Here, we introduce a laser-driven kilo-tesla external magnetic field to guide the diverging electron beam to the dense plasma core. This involve placing a spherical target in the magnetic field, compressing it with the GEKKO-XII laser beams and then using the LFEX laser beams injected into the dense plasma to generate the electron beam which do the fast heating. Cu-Ka emission is used to visualize transport or heating processes of a dense plasma. X-ray spectrum from a highly ionized Cu ions indicates several keV of the temperature increment induced by the LFEX.

  2. GPM Core Observatory Launch Animation

    NASA Image and Video Library

    This animation depicts the launch of the Global Precipitation Measurement (GPM) Core Observatory satellite from Tanegashima Space Center, Japan. The launch is currently scheduled for Feb. 27, 2014....

  3. An integrated computer-controlled system for assisting researchers in cortical excitability studies by using transcranial magnetic stimulation.

    PubMed

    Giordano, D; Kavasidis, I; Spampinato, C; Bella, R; Pennisi, G; Pennisi, M

    2012-07-01

    Transcranial magnetic stimulation (TMS) is the most important technique currently available to study cortical excitability. Additionally, TMS can be used for therapeutic and rehabilitation purposes, replacing the more painful transcranial electric stimulation (TES). In this paper we present an innovative and easy-to-use tool that enables neuroscientists to design, carry out and analyze scientific studies based on TMS experiments for both diagnostic and research purposes, assisting them not only in the practicalities of administering the TMS but also in each step of the entire study's workflow. One important aspect of this tool is that it allows neuroscientists to specify research designs at will, enabling them to define any parameter of a TMS study starting from data acquisition and sample group definition to automated statistical data analysis and RDF data storage. It also supports the diagnosing process by using on-line support vector machines able to learn incrementally from the diseases instances that are continuously added into the system. The proposed system is a neuroscientist-centred tool where the protocols being followed in TMS studies are made explicit, leaving to the users flexibility in exploring and sharing the results, and providing assistance in managing the complexity of the final diagnosis. This type of tool can make the results of medical experiments more easily exploitable, thus accelerating scientific progress. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Does magnetically assisted capsule endoscopy improve small bowel capsule endoscopy completion rate? A randomised controlled trial

    PubMed Central

    Hale, Melissa F.; Drew, Kaye; Sidhu, Reena; McAlindon, Mark E.

    2016-01-01

    Background and study aims: Delayed gastric emptying is a significant factor in incomplete small bowel capsule examinations. Gastric transit could be hastened by external magnetic control of the capsule. We studied the feasibility of this approach to improve capsule endoscopy completion rates. Patients and methods: Prospective, single-center, randomized controlled trial involving 122 patients attending for small bowel capsule endoscopy using MiroCam Navi. Patients were randomized to either the control group (mobilisation for 30 minutes after capsule ingestion, followed by intramuscular metoclopramide 10 mg if the capsule failed to enter the small bowel) or the intervention group (1000 mL of water prior to capsule ingestion, followed by positional change and magnetic steering). Outcome measures were capsule endoscopy completion rate, gastric clarity and distention, relationship of body habitus to capsule endoscopy completion rate (CECR), and patient comfort scores. Results: 122 patients were recruited (61 each to the control and intervention groups: mean age 49 years [range 21 – 85], 61 females). There was no significant difference in CECR between the two groups (P = 0.39). Time to first pyloric image was significantly shorter in the intervention group (P = 0.03) but there was no difference in gastric transit times (P = 0.12), suggesting that magnetic control hastens capsular transit to the gastric antrum but does not influence duodenal passage. Gastric clarity and distention were significantly better in the intervention group (P < 0.0001 and P < 0.0001 respectively). Conclusions: Magnetic steering of a small bowel capsule is unable to overcome pyloric contractions to enhance gastric emptying and improve capsule endoscope completion rate. Excellent mucosal visualisation within the gastric cavity suggests this technique could be harnessed for capsule examination of the stomach. PMID:26878053

  5. Magnetic-Field-Assisted Assembly of Ordered Multifunctional Ceramic Nanocomposites for Extreme Environments

    DTIC Science & Technology

    2016-04-01

    project was to explore physics, materials and surface chemistry behind the polymer-based route towards creation of magnetic ceramic composites out of...Department of Material Science and Engineering, Clemson University kkornev@clemson.edu In collaboration with Jeffery Owens, Tyndall Air Force Civil...Engineering Center Summary The goal of this project was to explore physics, materials and surface chemistry behind the polymer-based route towards

  6. The Use of a Software-Assisted Method to Estimate Fetal Weight at and Near Term Using Magnetic Resonance Imaging.

    PubMed

    Kadji, Caroline; De Groof, Maxime; Camus, Margaux F; De Angelis, Riccardo; Fellas, Stéphanie; Klass, Magdalena; Cecotti, Vera; Dütemeyer, Vivien; Barakat, Elie; Cannie, Mieke M; Jani, Jacques C

    2017-01-01

    The aim of this study was to apply a semi-automated calculation method of fetal body volume and, thus, of magnetic resonance-estimated fetal weight (MR-EFW) prior to planned delivery and to evaluate whether the technique of measurement could be simplified while remaining accurate. MR-EFW was calculated using a semi-automated method at 38.6 weeks of gestation in 36 patients and compared to the picture archiving and communication system (PACS). Per patient, 8 sequences were acquired with a slice thickness of 4-8 mm and an intersection gap of 0, 4, 8, 12, 16, or 20 mm. The median absolute relative errors for MR-EFW and the time of planimetric measurements were calculated for all 8 sequences and for each method (assisted vs. PACS), and the difference between the methods was calculated. The median delivery weight was 3,280 g. The overall median relative error for all 288 MR-EFW calculations was 2.4% using the semi-automated method and 2.2% for the PACS method. Measurements did not differ between the 8 sequences using the assisted method (p = 0.313) or the PACS (p = 0.118), while the time of planimetric measurement decreased significantly with a larger gap (p < 0.001) and in the assisted method compared to the PACS method (p < 0.01). Our simplified MR-EFW measurement showed a dramatic decrease in time of planimetric measurement without a decrease in the accuracy of weight estimates. © 2017 S. Karger AG, Basel.

  7. Magnetically-assisted impedimetric detection of bacteria using phage-modified carbon microarrays.

    PubMed

    Shabani, Arghavan; Marquette, Christophe A; Mandeville, Rosemonde; Lawrence, Marcus F

    2013-11-15

    This study presents an investigation on the possibility of improving the detection limit of bacteria with an inexpensive electrochemical, impedimetric sensor platform, by integrating the sensor with magnetic manipulation. The approach uses T4 bacteriophage coated Dynabeads to selectively capture and concentrate E. coli K12 cells from samples, to increase the sensitivity of detection at the surface of functionalized screen-printed carbon microarrays. Fluorescence and flow cytometry measurements indicate that the surface modification of the magnetic beads, with phages, and binding with the bacteria, were successful. Integration of the screen-printed carbon-based impedimetric sensor, with a magnetic manipulation system, was found to improve the sensitivity of the device, decreasing the limit of detection of E. coli K12 from 10(4) to 10(3) cfu/mL. We have also demonstrated that this approach provides for more specific detection of bacteria, enabling the operator to account for non-specific adsorption, and detection of bacteria in more complex (real) samples (milk).

  8. Crystalline magnetic carbon nanoparticle assisted photothermal delivery into cells using CW near-infrared laser beam

    NASA Astrophysics Data System (ADS)

    Gu, Ling; Koymen, Ali R.; Mohanty, Samarendra K.

    2014-05-01

    Efficient and targeted delivery of impermeable exogenous material such as small molecules, proteins, and plasmids into cells in culture as well as in vivo is of great importance for drug, vaccine and gene delivery for different therapeutic strategies. Though advent of optoporation by ultrafast laser microbeam has allowed spatial targeting in cells, the requirement of high peak power to create holes on the cell membrane is not practical and also challenging in vivo. Here, we report development and use of uniquely non-reactive crystalline magnetic carbon nanoparticles (CMCNPs) for photothermal delivery (PTD) of impermeable dyes and plasmids encoding light-sensitive proteins into cells using low power continuous wave near-infrared (NIR) laser beam. Further, we utilized the magnetic nature of these CMCNPs to localize them in desired region by external magnetic field, thus minimizing the required number of nanoparticles. We discovered that irradiation of the CMCNPs near the desired cell(s) with NIR laser beam leads to temperature rise that not only stretch the cell-membrane to ease delivery, it also creates fluid flow to allow mobilization of exogenous substances to the delivery. Due to significant absorption properties of the CMCNPs in the NIR therapeutic window, PTD under in vivo condition is highly possible.

  9. Crystalline magnetic carbon nanoparticle assisted photothermal delivery into cells using CW near-infrared laser beam.

    PubMed

    Gu, Ling; Koymen, Ali R; Mohanty, Samarendra K

    2014-05-29

    Efficient and targeted delivery of impermeable exogenous material such as small molecules, proteins, and plasmids into cells in culture as well as in vivo is of great importance for drug, vaccine and gene delivery for different therapeutic strategies. Though advent of optoporation by ultrafast laser microbeam has allowed spatial targeting in cells, the requirement of high peak power to create holes on the cell membrane is not practical and also challenging in vivo. Here, we report development and use of uniquely non-reactive crystalline magnetic carbon nanoparticles (CMCNPs) for photothermal delivery (PTD) of impermeable dyes and plasmids encoding light-sensitive proteins into cells using low power continuous wave near-infrared (NIR) laser beam. Further, we utilized the magnetic nature of these CMCNPs to localize them in desired region by external magnetic field, thus minimizing the required number of nanoparticles. We discovered that irradiation of the CMCNPs near the desired cell(s) with NIR laser beam leads to temperature rise that not only stretch the cell-membrane to ease delivery, it also creates fluid flow to allow mobilization of exogenous substances to the delivery. Due to significant absorption properties of the CMCNPs in the NIR therapeutic window, PTD under in vivo condition is highly possible.

  10. Synthesis and neuro-cytocompatibility of magnetic Zn-ferrite nanorods via peptide-assisted process.

    PubMed

    Zou, Yuanwen; Huang, Zhongbing; Deng, Min; Yin, Guangfu; Chen, Xianchun; Liu, Juan; Wang, Yan; Yan, Li; Gu, Jianwen

    2013-10-15

    In order to obtain magnetic nanorods (MNRs) with the neuro-cytocompatibility, silk-fibroin (SF)-coated Zn-ferrite NRs are successfully prepared via a mineralization process, and their saturation magnetization is 32emu g(-)(1). After the mineralization of 2d and 4d in the mixed solution of the concentrations of 15w/w% SF and 0.01M HCl, the lengths of NRs are ∼220nm and ∼2μm, respectively. Cell tests of NRs with 220nm length showed that the as-prepared Zn-ferrite NRs hardly produced toxicity on Escherichiacoli, Staphylococcusaureus, L929, and PC12 cells. The results of the outgrown neurites from PC12 cells indicated that the neurite length and the number of neurites were not significantly decreased at the low concentrations of SF-coated NRs (less than 0.25mg mL(-)(1)) in 1-5d culture time. TEM images of cell ultrathin sections indicated that, although Zn-ferrite NRs were split in the cytosol for 5d at the NR concentrations of 0.125mg mL(-)(1), some integrated mitochondria in a neurite suggested that SF-coated NRs inside cells did not influence the extension activity of neurites. Based on the good neuro-cytocompatibility and magnetic property of Zn-ferrite NRs, their potential applications in safe cell manipulation and axon guidance can be envisioned.

  11. STS-91 Launch of Discovery from Launch Pad 39-A

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Startled by the thunderous roar of the Space Shuttle Discovery's engines as it lifts off, several birds hurriedly leave the Launch Pad 39A area for a more peaceful site. Liftoff time for STS-91, the 91st Shuttle launch and last Shuttle-Mir mission, was 6:06:24 p.m. EDT June 2. On board Discovery are Mission Commander Charles J. Precourt; Pilot Dominic L. Gorie; and Mission Specialists Wendy B. Lawrence, Franklin R. Chang-Diaz, Janet Lynn Kavandi and Valery Victorovitch Ryumin. The nearly 10-day mission will feature the ninth and final Shuttle docking with the Russian space station Mir, the first Mir docking for the Space Shuttle orbiter Discovery, the first on-orbit test of the Alpha Magnetic Spectrometer (AMS), and the first flight of the new Space Shuttle super lightweight external tank. Astronaut Andrew S. W. Thomas will be returning to Earth as an STS-91 crew member after living more than four months aboard Mir.

  12. STS-91 Launch of Discovery from Launch Pad 39-A

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Startled by the thunderous roar of the Space Shuttle Discovery'''s engines as it lifts off, a bird hurriedly leaves the Launch Pad 39A area for a more peaceful site. Liftoff time for the 91st Shuttle launch and last Shuttle-Mir mission was 6:06:24 p.m. EDT June 2. On board Discovery are Mission Commander Charles J. Precourt; Pilot Dominic L. Gorie; and Mission Specialists Wendy B. Lawrence, Franklin R. Chang-Diaz, Janet Lynn Kavandi and Valery Victorovitch Ryumin. The nearly 10-day mission will feature the ninth and final Shuttle docking with the Russian space station Mir, the first Mir docking for the Space Shuttle orbiter Discovery, the first on-orbit test of the Alpha Magnetic Spectrometer (AMS), and the first flight of the new Space Shuttle super lightweight external tank. Astronaut Andrew S. W. Thomas will be returning to Earth as a STS-91 crew member after living more than four months aboard Mir.

  13. Animal magnetocardiography using superconducting quantum interference device gradiometers assisted with magnetic nanoparticle injection: A sensitive method for early detecting electromagnetic changes induced by hypercholesterolemia

    NASA Astrophysics Data System (ADS)

    Wu, C. C.; Hong, B. F.; Wu, B. H.; Yang, S. Y.; Horng, H. E.; Yang, H. C.; Tseng, W. Y. Isaac; Tseng, W. K.; Liu, Y. B.; Lin, L. C.; Lu, L. S.; Lee, Y. H.

    2007-01-01

    In this work, the authors used a superconducting quantum interference device (SQUID) magnetocardiography (MCG) system consisted of 64-channel low-transition-temperature SQUID gradiometers to detect the MCG signals of hepercholesterolemic rabbits. In addition, the MCG signals were recorded before and after the injection of magnetic nanoparticles into the rabbits' ear veins to investigate the effects of magnetic nanoparticles on the MCG signals. These MCG data were compared to those of normal rabbits to reveal the feasibility for early detection of the electromagnetic changes induced by hypercholesterolemia using MCG with the assistance of magnetic nanoparticle injection.

  14. XMCD and XMCD-PEEM Studies on Magnetic-Field-Assisted Self-Assembled 1D Nanochains of Spherical Ferrite Particles

    DOE PAGES

    Zhang, Wen; Wong, Ping Kwan Johnny; Zhang, Dong; ...

    2017-05-30

    Quasi-1D nanochains of spherical magnetic ferrite particles with a homogeneous particle size of ≈200 nm and a micrometer-sized chain length are fabricated in this paper via a self-assembly method under an external magnetic field. This assisting magnetic field (Hassist), applied during synthesis, significantly modifies the distribution of the Fe2+Oh, Fe3+Td, and Fe3+Oh cations in the chains, as demonstrated by X-ray magnetic circular dichroism (XMCD) combined with theoretical analysis. This provides direct evidence of the nontrivial role of external synthetic conditions for defining the crystal chemistry of nanoscale ferrites and in turn their magnetic properties, providing an extra degree of freedommore » for intentional control over the performances of 1D magnetic nanodevices for various applications. Magnetic imaging, performed via XMCD in photoemission electron microscopy, further shows the possibility of creating and trapping a series of adjacent magnetic domain walls in a single chain, suggesting that there is great application potential for these nanochains in 1D magnetic nanodevices, as determined by field- or current-driven domain wall motions. Finally, practical control over the magnetic properties of the nanochains is also achieved by extrinsic dopants of cobalt and zinc, which are observed to occupy the ferrite ionic sites in a selective manner.« less

  15. A Study to Develop an Industrial-Scale, Computer-Controlled High Magnetic Field Processing (HMFP) System to Assist in Commercializing the Novel, Enabling HMFP Manufacturing Technology

    SciTech Connect

    Ludtka, Gail Mackiewicz-; Chourey, Aashish

    2010-08-01

    As the original magnet designer and manufacturer of ORNL s 9T, 5-inch ID bore magnet, American Magnetics Inc. (AMI) has collaborated with ORNL s Materials Processing Group s and this partnership has been instrumental in the development of our unique thermo-magnetic facilities and expertise. Consequently, AMI and ORNL have realized that the commercial implementation of the High Magnetic Field Processing (HMFP) technology will require the evolution of robust, automated superconducting (SC) magnet systems that will be cost-effective and easy to operate in an industrial environment. The goal of this project and CRADA is to significantly expedite the timeline for implementing this revolutionary and pervasive cross-cutting technology for future US produced industrial components. The successful completion of this project is anticipated to significantly assist in the timely commercialization and licensing of our HMFP intellectual property for a broad spectrum of industries; and to open up a new market for AMI. One notable outcome of this project is that the ThermoMagnetic Processing Technology WON a prestigious 2009 R&D 100 Awards. This award acknowledges and recognizes our TMP Technology as one of the top 100 innovative US technologies in 2009. By successfully establishing the design requirements for a commercial scale magnetic processing system, this project effort has accomplished a key first step in facilitating the building and demonstration of a superconducting magnetic processing coil, enabling the transition of the High Magnetic Field Processing Technology beyond a laboratory novelty into a commercially viable and industrially scalable Manufacturing Technology.

  16. Materials investigation for thermally-assisted magnetic random access memory robust against 400 °C temperatures

    NASA Astrophysics Data System (ADS)

    Annunziata, A. J.; Trouilloud, P. L.; Bandiera, S.; Brown, S. L.; Gapihan, E.; O'Sullivan, E. J.; Worledge, D. C.

    2015-05-01

    Magnetic materials are investigated in order to enable a new type of Thermally Assisted Magnetic Random Access Memory (TAS-MRAM). A TAS-MRAM materials stack that is robust against the 400 °C process temperatures required for embedded integration with complementary metal oxide silicon processes is demonstrated. In unpatterned sheet film stacks, a stable resistance-area product, tunneling magnetoresistance (MR) > 100%, and temperature-dependent exchange bias of 1500 Oe after 400 °C anneal are shown for this stack. It is further shown that by doping the sense and storage layers with Ta using thin laminations of Ta/CoFeB, the moment of each layer can be reduced by more than 40% without a major reduction in MR. In patterned nanopillar devices, it is shown that by reducing the moment of the sense and storage layers with laminations of Ta, and by adding a second MgO barrier, the resistance versus applied field loop quality is maintained, while the read field is reduced by more than 40% and devices survive 108 write cycles without breakdown or significant degradation.

  17. Fluidic assisted thin-film device heterogeneous integration: Surface tension as driving force and magnetic as guiding force

    NASA Astrophysics Data System (ADS)

    Xiao, Jing; Ray Chaudhuri, Ritesh; Seo, Sang-Woo

    2015-10-01

    This paper demonstrates a fluidic assisted heterogeneous integration of optical thin-film device using surface tension as driving force and magnetic field as guiding force. Thin-film devices can be auto-aligned and integrated using surface tension onto their predesigned locations on a host substrate due to minimization of interfacial energy. By inserting a layer of nickel (Ni) into device metallization step, magnetic force was employed to increase mobility and contact probability of thin-film devices to their binding sites on the host substrate. A thin-film gallium arsenide (GaAs) inverted Metal-Semiconductor-Metal (MSM) photodetector (PD) has been successfully integrated onto a silicon host substrate with the proposed integration approach. The influence of the nickel layer to the PD performance was also investigated. Due to the self-assembly capability and thin-film format of the device, the proposed method has potential for wafer-scale implementation and is compatible with the matured silicon-based CMOS technology. This is a critical step towards a scalable manufacturing process to create advanced photonic/optoelectronic systems that are low-cost, compact, high performance, and complex in multi-material functionality.

  18. Suspending test masses in terrestrial millihertz gravitational-wave detectors: a case study with a magnetic assisted torsion pendulum

    NASA Astrophysics Data System (ADS)

    Thrane, Eric; Anderson, Russell P.; Levin, Yuri; Turner, L. D.

    2017-05-01

    Current terrestrial gravitational-wave detectors operate at frequencies above 10 Hz. There is strong astrophysical motivation to construct low-frequency gravitational-wave detectors capable of observing 10 mHz-10 Hz signals. While space-based detectors provide one means of achieving this end, one may also consider terretrial detectors. However, there are numerous technological challenges. In particular, it is difficult to isolate test masses so that they are both seismically isolated and freely falling under the influence of gravity at millihertz frequencies. We investigate the challenges of low-frequency suspension in a hypothetical terrestrial detector. As a case study, we consider a magnetically assisted gravitational-wave pendulum intorsion (MAGPI) suspension design. We construct a noise budget to estimate some of the required specifications. In doing so, we identify what are likely to be a number of generic limiting noise sources for terrestrial millihertz gravitational-wave suspension systems (as well as some peculiar to the MAGPI design). We highlight significant experimental challenges in order to argue that the development of millihertz suspensions will be a daunting task. Any system that relies on magnets faces even greater challenges. Entirely mechanical designs such as Zöllner pendulums may provide the best path forward.

  19. Magnetic resonance imaging (MRI)-assisted laparoscopic anorectoplasty for imperforate anus: a single center experience.

    PubMed

    Thomas, Tina T; Teitelbaum, Daniel H; Smith, Ethan A; Dillman, Jonathan R; Vellody, Ranjith; Jarboe, Marcus D

    2017-01-01

    Surgical procedures for high imperforate anus have ranged from the posterior sagittal anorectoplasty (PSARP) to laparoscopic-assisted anorectoplasty (LAARP). PSARP bisects the sphincter muscle complex, introducing muscle injury and scarring. LAARP uses a straight trocar to traverse an often non-linear sphincter muscle complex. MRI-assisted LAARP (MRI-LAARP) guides the neorectum precisely through the middle of the entire sphincter complex along its trajectory. We present our experience utilizing MRI intraoperatively during LAARP. Ten children underwent MRI-LAARP procedures. Intraoperative MRI was performed to delineate the sphincter complex, and to guide the advancement of an MRI-compatible needle through the center of the complex from skin to the peritoneal cavity. The remainder of the procedure was completed using the standard LAARP technique. All had successful MRI needle placement through the sphincter complex. Nine patients had successful laparoscopic pull-through procedures; one was converted to open due to severe intraperitoneal adhesions. Postoperative stay averaged 5.4 ± 4.4 days. Out of the ten patients, one child had mild dehiscence of the anal anastomosis requiring revision 11 days postoperatively. The theoretical advantage of the MRI-LAARP is placing the neorectum through the entire sphincter complex without transecting the muscle. Follow-up of these patients shows good short-term results; however, long-term follow-up will be needed to best assess sphincter and bowel function.

  20. Ares Launch Vehicles Overview

    NASA Technical Reports Server (NTRS)

    Vanhooser, Teresa

    2009-01-01

    Since 2005, the Ares Projects have been building the nation s next generation of crew and cargo launch vehicles. As part of the Constellation Program, the Ares vehicles will enable astronauts in the Orion crew exploration vehicle and Altair lunar lander to reach the Moon and beyond. These vehicles draw upon hardware and experienced developed over 50 years of exploration, while also incorporating technology and management practices from today. Ares is concentrating on building the Ares I crew launch vehicle to ensure America s continued ability to send crews to the International Space Station. Progress has been made on design, fabrication, and testing for the first stage, upper stage, upper stage engine, and integrated vehicle. This presentation will provide an overview of the Ares launch vehicles architecture, milestone progress, and top project risks.

  1. STS-135 Launch Day

    NASA Image and Video Library

    2011-07-07

    NASA Chief, Astronaut Office, Johnson Space Center Peggy Whitson, center, STS-135 Astronauts, Rex Walheim, left, and Commander Chris Ferguson are seen as the entire crew plays a traditional card game at the NASA Kennedy Space Center Operations and Checkout Building prior to them leaving for the launch pad, on Friday, July 8, 2011 in Cape Canaveral, Fla. The point of the game is that the commander must use up all his or her bad luck before launch, so the crew can only leave for the pad after the commander loses. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Jerry Ross)

  2. Antares Rocket Test Launch

    NASA Image and Video Library

    2013-04-21

    NASA Deputy Administrator Lori Garver talks with CEO and President of Orbital Sciences Corporation David Thompson, left, Executive Vice President and Chief Technical Officer, Orbital Sciences Corporation Antonio Elias, second from left, and Executive Director, Va. Commercial Space Flight Authority Dale Nash, background, in the Range Control Center at the NASA Wallops Flight Facility after the successful launch of the Orbital Sciences Antares rocket from the Mid-Atlantic Regional Spaceport (MARS) in Virginia, Sunday, April 21, 2013. The test launch marked the first flight of Antares and the first rocket launch from Pad-0A. The Antares rocket delivered the equivalent mass of a spacecraft, a so-called mass simulated payload, into Earth's orbit. Photo Credit: (NASA/Bill Ingalls)

  3. AXONOMETRIC, LAUNCH DOOR AND DOOR CYLINDER, LAUNCH PLATFORM ROLLER GUIDE, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    AXONOMETRIC, LAUNCH DOOR AND DOOR CYLINDER, LAUNCH PLATFORM ROLLER GUIDE, CRIB SUSPENSION SHOCK STRUT, LAUNCH PLATFORM - Dyess Air Force Base, Atlas F Missle Site S-8, Launch Facility, Approximately 3 miles east of Winters, 500 feet southwest of Highway 1770, center of complex, Winters, Runnels County, TX

  4. Atomic hydrogen as a launch vehicle propellant

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan A.

    1990-01-01

    An analysis of several atomic hydrogen launch vehicles was conducted. A discussion of the facilities and the technologies that would be needed for these vehicles is also presented. The Gross Liftoff Weights (GLOW) for two systems were estimated; their specific impulses (I sub sp) were 750 and 1500 lb (sub f)/s/lb(sub m). The atomic hydrogen launch vehicles were also compared to the currently planned Advanced Launch System design concepts. Very significant GLOW reductions of 52 to 58 percent are possible over the Advanced Launch System designs. Applying atomic hydrogen propellants to upper stages was also considered. Very high I(sub sp) (greater than 750 1b(sub f)/s/lb(sub m) is needed to enable a mass savings over advanced oxygen/hydrogen propulsion. Associated with the potential benefits of high I(sub sp) atomic hydrogen are several challenging problems. Very high magnetic fields are required to maintain the atomic hydrogen in a solid kilogauss (3 Tesla). Also the storage temperature of the propellant is 4 K. This very low temperature will require a large refrigeration facility for the launch vehicle. The design considerations for a very high recombination rate for the propellant are also discussed. A recombination rate of 210 cm/s is predicted for atomic hydrogen. This high recombination rate can produce very high acceleration for the launch vehicle. Unique insulation or segmentation to inhibit the propellant may be needed to reduce its recombination rate.

  5. Launch Period Development for the Juno Mission to Jupiter

    NASA Technical Reports Server (NTRS)

    Kowalkowski, Theresa D.; Johannesen, Jennie R.; Lam, Try

    2008-01-01

    The Juno mission to Jupiter is targeted to launch in 2011 and would reach the giant planet about five years later. The interplanetary trajectory is planned to include two large deep space maneuvers and an Earth gravity assist a little more than two years after launch. In this paper, we describe the development of a 21-day launch period for Juno with the objective of keeping overall launch energy and delta-V low while meeting constraints imposed on Earth departure, the deep space maneuvers' timing and geometry, and Jupiter arrival.

  6. Launch Period Development for the Juno Mission to Jupiter

    NASA Technical Reports Server (NTRS)

    Kowalkowski, Theresa D.; Johannesen, Jennie R.; Lam, Try

    2008-01-01

    The Juno mission to Jupiter is targeted to launch in 2011 and would reach the giant planet about five years later. The interplanetary trajectory is planned to include two large deep space maneuvers and an Earth gravity assist a little more than two years after launch. In this paper, we describe the development of a 21-day launch period for Juno with the objective of keeping overall launch energy and delta-V low while meeting constraints imposed on Earth departure, the deep space maneuvers' timing and geometry, and Jupiter arrival.

  7. Simultaneous in situ derivatization and ultrasound-assisted dispersive magnetic solid phase extraction for thiamine determination by spectrofluorimetry.

    PubMed

    Tarigh, Ghazale Daneshvar; Shemirani, Farzaneh

    2014-06-01

    A simple and rapid method for the simultaneous in situ derivatizaion, preconcentration and extraction of thiamine (vitamin B1) as a model analyte was developed by a novel quantitative method, namely ultrasound-assisted dispersive magnetic solid phase extraction spectrofluorimetry (USA-DMSPE-FL) from different real samples. This method consists of sample preparation, in situ derivatization, exhaustive extraction and clean up by a single process. High extraction efficiency and in situ derivatization in a short period of time is the main advantages of this procedure. For this purpose, the reusable magnetic multi-wall carbon nanotube (MMWCNT) nanocomposite was used as an adsorbent for preconcentration and determination of thiamine. Thiamine was, simultaneously, in situ derivatized as thiochrome by potassium hexacyanoferrate (III) and adsorbed on MMWCNT in an ultrasonic water bath. The MMWCNTs were then collected using an external magnetic field. Subsequently, the extracted thiochrome was washed from the surface of the adsorbent and determined by spectrofluorimetry. The developed method, which has been analytically characterized under its optimal operating conditions, allows the detection of the analyte in the samples with method detection limits of 0.37 µg L(-1). The repeatability of the method, expressed as the relative standard deviation (RSD, n=6), varies between 2.0% and 4.8% in different real samples, while the enhancement factor is 197. The proposed procedure has been applied for the determination of thiamine in biological (serum and urine), pharmaceutical (multivitamin tablet and B complex syrup) and foodstuff samples (cereal, wheat flour, banana and honey) with the good recoveries in the range from 90% to 105%. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Quantum-memory-assisted entropic uncertainty relation in a Heisenberg XYZ chain with an inhomogeneous magnetic field

    NASA Astrophysics Data System (ADS)

    Wang, Dong; Huang, Aijun; Ming, Fei; Sun, Wenyang; Lu, Heping; Liu, Chengcheng; Ye, Liu

    2017-06-01

    The uncertainty principle provides a nontrivial bound to expose the precision for the outcome of the measurement on a pair of incompatible observables in a quantum system. Therefore, it is of essential importance for quantum precision measurement in the area of quantum information processing. Herein, we investigate quantum-memory-assisted entropic uncertainty relation (QMA-EUR) in a two-qubit Heisenberg \\boldsymbol{X}\\boldsymbol{Y}\\boldsymbol{Z} spin chain. Specifically, we observe the dynamics of QMA-EUR in a realistic model there are two correlated sites linked by a thermal entanglement in the spin chain with an inhomogeneous magnetic field. It turns out that the temperature, the external inhomogeneous magnetic field and the field inhomogeneity can lift the uncertainty of the measurement due to the reduction of the thermal entanglement, and explicitly higher temperature, stronger magnetic field or larger inhomogeneity of the field can result in inflation of the uncertainty. Besides, it is found that there exists distinct dynamical behaviors of the uncertainty for ferromagnetism \\boldsymbol{}≤ft(\\boldsymbol{J}<\\boldsymbol{0}\\right) and antiferromagnetism \\boldsymbol{}≤ft(\\boldsymbol{J}>\\boldsymbol{0}\\right) chains. Moreover, we also verify that the measuring uncertainty is dramatically anti-correlated with the purity of the bipartite spin system, the greater purity can result in the reduction of the measuring uncertainty, vice versa. Therefore, our observations might provide a better understanding of the dynamics of the entropic uncertainty in the Heisenberg spin chain, and thus shed light on quantum precision measurement in the framework of versatile systems, particularly solid states.

  9. Fundamental limits in heat-assisted magnetic recording and methods to overcome it with exchange spring structures

    SciTech Connect

    Suess, D.; Abert, C.; Bruckner, F.; Windl, R.; Vogler, C.; Breth, L.; Fidler, J.

    2015-04-28

    The switching probability of magnetic elements for heat-assisted recording with pulsed laser heating was investigated. It was found that FePt elements with a diameter of 5 nm and a height of 10 nm show, at a field of 0.5 T, thermally written-in errors of 12%, which is significantly too large for bit-patterned magnetic recording. Thermally written-in errors can be decreased if larger-head fields are applied. However, larger fields lead to an increase in the fundamental thermal jitter. This leads to a dilemma between thermally written-in errors and fundamental thermal jitter. This dilemma can be partly relaxed by increasing the thickness of the FePt film up to 30 nm. For realistic head fields, it is found that the fundamental thermal jitter is in the same order of magnitude of the fundamental thermal jitter in conventional recording, which is about 0.5–0.8 nm. Composite structures consisting of high Curie top layer and FePt as a hard magnetic storage layer can reduce the thermally written-in errors to be smaller than 10{sup −4} if the damping constant is increased in the soft layer. Large damping may be realized by doping with rare earth elements. Similar to single FePt grains in composite structure, an increase of switching probability is sacrificed by an increase of thermal jitter. Structures utilizing first-order phase transitions breaking the thermal jitter and writability dilemma are discussed.

  10. Expedition 18 Launch Day

    NASA Image and Video Library

    2008-10-11

    Expedition 18 Flight Engineer Yuri V. Lonchakov, bottom, Expedition 18 Commander Michael Fincke and American spaceflight participant Richard Garriott, top, wave farewell from the steps of the Soyuz launch pad prior to their launch in the Soyuz TMA-13 spacecraft, Sunday, Oct. 12, 2008 from the Baikonur Cosmodrome in Kazakhstan. The three crew members are scheduled to dock with the International Space Station on Oct. 14. Fincke and Lonchakov will spend six months on the station, while Garriott will return to Earth Oct. 24 with two of the Expedition 17 crew members currently on the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  11. LAUNCH - APOLLO 9 - CAPE

    NASA Image and Video Library

    1969-03-03

    S69-25862 (3 March 1969) --- Framed by palm trees in the foreground, the Apollo 9 (Spacecraft 104/Lunar Module 3/ Saturn 504) space vehicle is launched from Pad A, Launch Complex 39, Kennedy Space Center (KSC) at 11 a.m. (EST), March 3, 1969. Aboard the spacecraft are astronauts James A. McDivitt, commander; David R. Scott, command module pilot; and Russell L. Schweickart, lunar module pilot. The Apollo 9 mission will evaluate spacecraft lunar module systems performance during manned Earth-orbital flight. Apollo 9 is the second manned Saturn V mission.

  12. APOLLO VII - LAUNCH - KSC

    NASA Image and Video Library

    1968-10-11

    S68-48662 (11 Oct. 1968) --- The Apollo 7/Saturn IB space vehicle is launched from the Kennedy Space Center's Launch Complex 34 at 11:03 a.m. (EDT), Oct. 11, 1968. Apollo 7 (Spacecraft 101/Saturn 205) is the first of several manned flights aimed at qualifying the spacecraft for the half-million mile round trip to the moon. Aboard the Apollo spacecraft are astronauts Walter M. Schirra Jr., commander; Donn F. Eisele, command module pilot; and Walter Cunningham, lunar module pilot. (This view is framed by palm trees on either side).

  13. NPP Satellite Launch

    NASA Image and Video Library

    2011-10-28

    The Satellite Operations Facility of the National Oceanic and Atmospheric Administration (NOAA) is seen here minutes before the launch of the National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP) on Friday, Oct. 28, 2011 in Suitland, Md. NPP is a joint venture between NASA and NOAA, and is the nation's newest Earth-observing satellite, which will provide data on climate change science, allow for accurate weather forecasts and advance warning for severe weather. NPP was launched from Vandenberg Air Force Base in California. Photo Credit: (NASA/Carla Cioffi)

  14. NPP Satellite Launch

    NASA Image and Video Library

    2011-10-28

    Dr. Kathy Sullivan, center, Deputy Administrator of the National Oceanic and Atmospheric Administration (NOAA) and former NASA astronaut is interviewed by a local television network at NOAA's Satellite Operations Facility in Suitland, Md. after the successful launch of the National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP) on Friday, Oct. 28, 2011. NPP is a joint venture between NASA and NOAA, and is the nation's newest Earth-observing satellite, which will provide data on climate change science, allow for accurate weather forecasts and advance warning for severe weather. NPP was launched from Vandenberg Air Force Base in California. Photo Credit: (NASA/Carla Cioffi)

  15. NPP Satellite Launch

    NASA Image and Video Library

    2011-10-28

    NASA Deputy Administrator Lori Garver, left, watches the launch of the National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP) at the National Oceanic and Atmospheric Administration (NOAA) Satellite Operations Center on Friday, Oct. 28, 2011 in Suitland, Md. U.S Congresswoman Donna Edwards, D-Md., is seen next to Garver. NPP is a joint venture between NASA and NOAA, and is the nation's newest Earth-observing satellite, which will provide data on climate change science, allow for accurate weather forecasts and advance warning for severe weather. NPP was launched from Vandenberg Air Force Base in California. Photo Credit: (NASA/Carla Cioffi)

  16. Expedition 8 Launch Day

    NASA Image and Video Library

    2003-10-18

    With a throng of reporters looking on, the prime and backup crews for the Expedition 8 mission to the International Space Station and the prime and backup European Space Agency Astronauts receive final well-wishes from Russian and U.S. space officials at the Baikonur Cosmodrome in Kazakhstan, Saturday, Oct. 18, 2003, before heading to the launch pad. Expedition 8 Commander and NASA Science Officer Michael Foale, Expedition 8 Soyuz Commander Alexander Kaleri and ESA's Pedro Duque of Spain were launched on a Soyuz TMA-3 vehicle, arriving at the ISS on Oct. 20. Photo Credit (NASA/Bill Ingalls)

  17. LDSD Ready for Launch

    NASA Image and Video Library

    2015-06-05

    NASA's Low-Density Supersonic Decelerator (LDSD) hangs from a launch tower at U.S. Navy's Pacific Missile Range Facility in Kauai, Hawaii. The saucer-shaped vehicle will test two devices for landing heavy payloads on Mars: an inflatable donut-shaped device and a supersonic parachute. The launch tower helps link the vehicle to a balloon; once the balloon floats up, the vehicle is released from the tower and the balloon carries it to high altitudes. The vehicle's rocket takes it to even higher altitudes, to the top of the stratosphere, where the supersonic test begins. http://photojournal.jpl.nasa.gov/catalog/PIA19342

  18. STS-64 launch view

    NASA Technical Reports Server (NTRS)

    1994-01-01

    With a crew of six NASA astronauts aboard, the Space Shuttle Discovery heads for its nineteenth Earth-orbital mission. Launch was delayed because of weather, but all systems were 'go,' and the spacecraft left the launch pad at 6:23 p.m. (EDT) on September 9, 1994. Onboard were astronauts Richard N. Richards, L. Blaine Hammond, Carl J. Meade, Mark C. Lee, Susan J. Helms, and Jerry M. Linenger (051-2); Making a bright reflection in nearby marsh waters, the Space Shuttle Discovery heads for its 19th mission in earth orbit (053).

  19. STS-64 launch view

    NASA Technical Reports Server (NTRS)

    1994-01-01

    With a crew of six NASA astronauts aboard, the Space Shuttle Discovery heads for its nineteenth Earth-orbital mission. Launch was delayed because of weather, but all systems were 'go,' and the spacecraft left the launch pad at 6:23 p.m. (EDT) on September 9, 1994. Onboard were astronauts Richard N. Richards, L. Blaine Hammond, Carl J. Meade, Mark C. Lee, Susan J. Helms, and Jerry M. Linenger (051-2); Making a bright reflection in nearby marsh waters, the Space Shuttle Discovery heads for its 19th mission in earth orbit (053).

  20. Expedition 22 Launch Day

    NASA Image and Video Library

    2009-12-20

    Expedition 22 Flight Engineer Soichi Noguchi of Japan has his Russian Sokol suit prepared for launch by a technician while space agency photographers document the process at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Sunday, Dec. 20, 2009. Soichi and fellow Expedition 22 crew members NASA Flight Engineer Timothy J. Creamer of the U.S., Soyuz Commander Oleg Kotov of Russia launched in their Soyuz TMA-17 rocket from the Baikonur Cosmodrome in Kazakhstan on Monday, Dec. 21, 2009. (Photo Credit: NASA/Bill Ingalls)

  1. Launch - STS-6 - KSC

    NASA Image and Video Library

    1983-04-06

    S83-30134 (7 April 1983) --- Flare from the first launch of the space shuttle Challenger is reflected in the Atlantic Ocean?s Cape Canaveral beach waters shortly after 1:30 p.m. (EST) on April 7, 1983. Only the tips of the orbiter?s wings are visible in this south looking view, as the manned portion of the launch cluster is obscured by its new lightweight external fuel tank (ET) and two solid rocket boosters (SRB). Onboard the spacecraft are astronauts Paul J. Weitz, Karol J. Bobko, Dr. F. Story Musgrave and Donald H. Peterson. Photo credit: NASA

  2. STS-56 Launch

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The second try works like a charm as the Space Shuttle Discovery lifts off from Launch Pad 39B on Mission STS-56 at 1:29:00 a.m., EDT, April 8. First attempt to launch Discovery on its 16th space voyage was halted at T-11 seconds on April 6. Aboard for the second Space Shuttle mission of 1993 are a crew of five and the Atmospheric Laboratory for Applications and Science 2 (ATLAS 2), the second in a series of missions to study the sun's energy output and Earth's middle atmosphere chemical makeup, and how these factors affect levels of ozone.

  3. Synthesis, structural, dielectric and magnetic properties of polyol assisted copper ferrite nano particles

    NASA Astrophysics Data System (ADS)

    Pavithradevi, S.; Suriyanarayanan, N.; Boobalan, T.

    2017-03-01

    Nanocrystalline copper ferrite CuFe2O4 is synthesized by co-precipitation method in ethylene glycol as chelating agent, using sodium Hydroxide as precipitator at pH 8. The as synthesized CuFe2O4 is annealed at temperatures of 350 °C, 700 °C, and 1050 °C for 2 h respectively. The thermal analysis of the synthesized sample is done by TG technique. It is shown that at 260 °C ethylene glycol has evaporated completely and after 715 °C, spinel ferrite is formed with a cubic structure. The calculated lattice parameters are in agreement with the reported values. FTIR spectra of CuFe2O4 nano particles are as synthesized and annealed at 1050 °C and recorded between 400 cm-1 and 4000 cm-1. It shows that when the temperature increases ethylene glycol gradually evaporates. Finally, nano crystalline single phase spinel ferrite is obtained. X-ray diffraction (XRD) and electron diffraction (EDS) studies show that the sample is indexed as the face centered cubic spinel structure. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that the particles are flaky and spherical with the crystallite size in the range of 25-34 nm. From the dielectric studies, the dielectric constant decreases as the frequency increases. Low value of dielectric loss at higher frequencies suggests that the material is suitable for high frequency applications. AC conductivity increases with frequency. The magnetic properties of the samples are measured using a vibrating sample magnetometer (VSM) at room temperature, which shows that the sample exhibited a typical super paramagnetic behavior at low temperature. The saturation magnetization, remanant magnetism, and coercivity increases with applied field.

  4. Atlas V Rocket Launches with Juno Spacecraft

    NASA Image and Video Library

    2011-08-05

    An Atlas V rocket launches with the Juno spacecraft payload from Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida on Friday, August 5, 2011. The Juno spacecraft will make a five-year, 400-million-mile voyage to Jupiter, orbit the planet, investigate its origin and evolution with eight instruments to probe its internal structure and gravity field, measure water and ammonia in its atmosphere, map its powerful magnetic field and observe its intense auroras. Photo Credit: (NASA/Bill Ingalls)

  5. Railgun launch of small bodies

    SciTech Connect

    Drobyshevski, E.M.; Zhukov, B.G.; Sakharov, V.A.

    1995-01-01

    The small body launching using gas or plasma faces the fundamental problem caused by excess energy loss due to great wall surface/volume of the barrel ratio. That is why the efficiency of the plasma armature (PA) railgun acceleration is maximum for 8--10 mm-size bodies and drops as their size decreases. For the nuclear fusion applications, where {number_sign}1--2 mm-size pellets at 5--10 km/s velocity are desirable, one is forced to search for compromise between the body size (3--4 mm) and its velocity (3 km/s). Under these conditions, EM launchers did not demonstrate an advantage over the light-gas guns. When elaborating the {number_sign}1 mm railgun, the authors made use of the ideology of the body launching at constant acceleration close to the body strength or the electrode skin-layer explosion limits. That shortened the barrel length sufficiently. The system becomes highly compact thus permitting rapid test of new operation modes and different modifications of the design including the magnetic field augmentation. As a result of these refinements, the difficulties caused by the catastrophic supply of mass ablated from the electrodes were overcome and regimes of {number_sign}1 mm body non-sabot speed-up to 4.5 km/s were found. Potentialities of the small system created are far from being exhausted.

  6. Ritual and ceremony in intraoperative magnetic resonance imaging-assisted brain surgery.

    PubMed

    Gellert, Vance

    2012-01-01

    Previous photographic research into traditional and shamanic healing practices in Peru and Bolivia and a review of the literature suggested that all medical practices have cultural determined nonmedical activities as integral parts of the healing encounter. These include costume, ritual, ceremony, environment factors that were looked for in a western clinical encounter for this paper. A patient was followed through pre-op preparation and iMRI assisted brain surgery. All activities were photographed extensively and evaluated in a broader healing context. A number of activities were visually and metaphorically comparable with those seen in other practices. These are discussed as rituals of intention on the part of the caregivers to focus their skills on healing and also to mindfully engage the patient in the healing process. Artistic observation and analysis may be an effective way to identify these non quantifiable elements of the healing encounter and suggest directions for further research into the emotional components of the healing process.

  7. Development program for magnetically assisted chemical separation: Evaluation of cesium removal from Hanford tank supernatant

    SciTech Connect

    Nunez, L.; Buchholz, B.A.; Ziemer, M.; Dyrkacz, G.; Kaminski, M.; Vandegrift, G.F.; Atkins, K.J.; Bos, F.M.; Elder, G.R.; Swift, C.A.

    1994-12-01

    Magnetic particles (MAG*SEP{sup SM}) coated with various absorbents were evaluated for the separation and recovery of low concentrations of cesium from nuclear waste solutions. The MAG*SEP{sup SM} particles were coated with (1) clinoptilolite, (2) transylvanian volcanic tuff, (3) resorcinol formaldehyde, and (4) crystalline silico-titanate, and then were contacted with a Hanford supernatant simulant. Particles coated with the crystalline silico-titanate were identified by Bradtec as having the highest capacity for cesium removal under the conditions tested (variation of pH, ionic strength, cesium concentration, and absorbent/solution ratio). The MAG*SEP{sup SM} particles coated with resorcinol formaldehyde had high distribution ratios values and could also be used to remove cesium from Hanford supernant simulant. Gamma irradiation studies were performed on the MAG*SEP{sup SM} particles with a gamma dose equivalent to 100 cycles of use. This irradiation decreased the loading capacity and distribution ratios for the particles by greater than 75%. The particles demonstrated high sensitivity to radiolytic damage due to the degradation of the polymeric regions. These results were supported by optical microscopy measurements. Overall, use of magnetic particles for cesium separation under nuclear waste conditions was found to be marginally effective.

  8. Innovative fluorescent magnetic albumin microbead-assisted cell labeling and intracellular imaging of glioblastoma cells.

    PubMed

    Wang, Xueqin; Wei, Fang; Yan, Shuang; Zhang, Huiru; Tan, Xiaorong; Zhang, Lu; Zhou, Guangzhou; Cui, Liuqing; Li, Cuixiang; Wang, Liang; Li, Yatao

    2014-04-15

    Superparamagnetic nanoparticle-based polymer microbeads utilized as carriers are attractive materials widely applied in the biomedical field. However, the deficiency of toxicity, biocompatibility, and biodegradability for polymer materials often limits the application of these microbeads. In the present study, magnetic albumin microbeads (MAMbs), i.e., human serum albumin-coated γ-Fe2O3 nanoparticles, are synthesized to label human U251 glioblastoma multiforme cells. The effects of MAMbs on the biological behavior of U251 glioblastoma cells, including their proliferation, cell viability, cytoskeletal structure, cell cycle, and apoptosis rate, are investigated. Moreover, fluorescein isothiocyanate (FITC)-MAMbs are fabricated by reaction with fluorescent dye FITC used for intracellular imaging of U251 glioblastoma cells. MAMbs possess undetectable cytotoxicity and excellent biocompatibility with U251 glioblastoma cells, as demonstrated by the biological behavior and morphology of U251 cells exposed to MAMbs. Furthermore, the constructed fluorescent MAMbs allow effective intracellular imaging, as illustrated by fluorescence microscopic analysis. The fabricated fluorescent MAMbs have promising perspectives in biomedical research, especially in cell-targeted labeling and intracellular fluorescence magnetic dual-mode imaging in cancer-targeted diagnosis and therapy. © 2013 Published by Elsevier B.V.

  9. Microwave-assisted preparation of poly(ionic liquids)-modified magnetic nanoparticles for pesticide extraction.

    PubMed

    Zhang, Ruizhe; Su, Ping; Yang, Lu; Yang, Yi

    2014-06-01

    Novel poly(ionic liquids) were synthesized and immobilized on prepared magnetic nanoparticles, which were used to extract pesticides from fruit and vegetable samples by dispersive solid-phase extraction prior to high-performance liquid chromatography analysis. Compared with monomeric ionic liquids, poly(ionic liquids) have a larger effective contact area and higher viscosity, so they can achieve higher extraction efficiency and be used repeatedly without a decrease in analyte recovery. The immobilized poly(ionic liquids) were rapidly separated from the sample matrix, providing a simple approach for sample pretreatment. The nature and volume of the desorption solvent and amount of poly(ionic liquid)-modified magnetic material were optimized for the extraction process. Under optimum conditions, calibration curves were linear (R(2) > 0.9988) for pesticide concentrations in the range of 0.100-10.000 μg/L. The relative standard deviations for repeated determinations of the four analytes were 2.29-3.31%. The limits of detection and quantification were 0.29-0.88 and 0.97-2.93 μg/L, respectively. Our results demonstrate that the developed poly(ionic liquid)-modified material is an effective absorbent to extract pesticides from fruit and vegetable samples.

  10. Microwave assisted synthesis, spectral, magnetic and bioevolution of few Mn (II)-amide complexes

    SciTech Connect

    Joshi, Gaurav; Verma, K. K.; Gudesaria, D. D.; Bhojak, N.

    2016-05-06

    The importance and versatility of amide group containing ligands have promoted the selection of this class of ligands and their complexes for the study. The present work describes the synthesis, spectral and biological investigations on the complexes of amides derived from heterocyclic amines with Mn (II) ions. Four ligands derived 2-aminopyridine and their complexes with Mn (II) have been synthesized. A method for the synthesis of complexes has been developed by the use of microwave irradiation which is in agreement to Green chemistry approach. The complexes have been characterized on the basis of elemental analysis, infrared, electronic, ESR spectra and magnetic susceptibility studies. The diffuse reflectance spectrum of the complexes show bands in the region 20,000 cm{sup −1} to 26,000 cm{sup −1} assignable to {sup 6}A{sub 1g} → {sup 4}T{sub 2g} and {sup 6}A{sub 1g} → {sup 4}E{sub 1g} transitions. These are also typical of tetrahedral environment around the manganese. The magnetic moment (5.80 BM) of the complex indicates high spin tetrahedral environment. The microwave method of synthesis of complexes have been found easier, convenient and ecofriendly. Antimicrobial activities of compounds were also carried out against bacteria and fungi. Further minimal inhibitory concentration (MIC) was also determined for each compound.

  11. Microwave assisted synthesis, spectral, magnetic and bioevolution of few Mn (II)-amide complexes

    NASA Astrophysics Data System (ADS)

    Joshi, Gaurav; Verma, K. K.; Gudesaria, D. D.; Bhojak, N.

    2016-05-01

    The importance and versatility of amide group containing ligands have promoted the selection of this class of ligands and their complexes for the study. The present work describes the synthesis, spectral and biological investigations on the complexes of amides derived from heterocyclic amines with Mn (II) ions. Four ligands derived 2-aminopyridine and their complexes with Mn (II) have been synthesized. A method for the synthesis of complexes has been developed by the use of microwave irradiation which is in agreement to Green chemistry approach. The complexes have been characterized on the basis of elemental analysis, infrared, electronic, ESR spectra and magnetic susceptibility studies. The diffuse reflectance spectrum of the complexes show bands in the region 20,000 cm-1 to 26,000 cm-1 assignable to 6A1g → 4T2g and 6A1g → 4E1g transitions. These are also typical of tetrahedral environment around the manganese. The magnetic moment (5.80 BM) of the complex indicates high spin tetrahedral environment. The microwave method of synthesis of complexes have been found easier, convenient and ecofriendly. Antimicrobial activities of compounds were also carried out against bacteria and fungi. Further minimal inhibitory concentration (MIC) was also determined for each compound.

  12. NASA Launch Services Program Overview

    NASA Technical Reports Server (NTRS)

    Higginbotham, Scott

    2016-01-01

    The National Aeronautics and Space Administration (NASA) has need to procure a variety of launch vehicles and services for its unmanned spacecraft. The Launch Services Program (LSP) provides the Agency with a single focus for the acquisition and management of Expendable Launch Vehicle (ELV) launch services. This presentation will provide an overview of the LSP and its organization, approach, and activities.

  13. Voyager 1's Launch Vehicle

    NASA Image and Video Library

    1977-09-05

    The Titan/Centaur-6 launch vehicle was moved to Launch Complex 41 at Kennedy Space Center in Florida to complete checkout procedures in preparation for launch. The photo is dated January 1977. This launch vehicle carried Voyager 1 into space on September 5, 1977. https://photojournal.jpl.nasa.gov/catalog/PIA21739

  14. SPIDER Readied for Launch

    NASA Image and Video Library

    2015-01-22

    Prior to launch, the team laid out the parachute and hang lines in front of SPIDER, seen in the distance. The long-duration balloon that would carry SPIDER into the sky is attached to the end of the parachute shown here in the foreground. http://photojournal.jpl.nasa.gov/catalog/PIA19177

  15. NanoLaunch

    NASA Technical Reports Server (NTRS)

    Jones, Jonathan; Harris, Lawanna

    2015-01-01

    NASA's NanoLaunch effort will provide the framework to mature both Earth-to-orbit and on-orbit propulsion and avionics technologies while also providing affordable, dedicated access to low-Earth orbit for CubeSat-class payloads. The project will also serve as an early career personnel training opportunity with mentors to gain hands-on project experience.

  16. Expedition 23 Launch Day

    NASA Image and Video Library

    2010-04-01

    Expedition 23 Flight Engineer Tracy Caldwell Dyson performs the traditional door signing Friday, April 2, 2010 at the Cosmonaut Hotel in Baikonur, Kazakhstan. Caldwell Dyson was launched onboard the Soyuz rocket later that day with Expedition 23 Soyuz Commander Alexander Skvortsov and Flight Engineer Mikhail Kornienko on a mission to the International Space Station (ISS). Photo Credit: (NASA/Carla Cioffi)

  17. STS-120 launch

    NASA Image and Video Library

    2007-10-23

    STS120-S-025 (23 Oct. 2007) --- In the firing room at NASA's Kennedy Space Center, NASA Associate Administrator Chris Scolese and other managers watch the Space Shuttle Discovery launch of the STS-120 mission at 11:38 a.m. (EDT), Oct. 23, 2007. William Gerstenmaier is in right foreground. Photo credit: NASA/Bill Ingalls

  18. Expedition 8 Launch Briefing

    NASA Image and Video Library

    2003-10-12

    Backup Expedition 8 Commander Bill McArthur, left, and prime Expedition 8 Commander Michael Foale practice procedures with a satellite phone during final training at their crew quarters in Baikonur, Kazakhstan, Wednesday, Oct. 15, 2003, for launch on a Soyuz TMA-3 vehicle Oct. 18 to the International Space Station. Photo Credit (NASA/Bill Ingalls)

  19. Expedition 25 Launch

    NASA Image and Video Library

    2010-10-07

    Expedition 25 NASA Flight Engineer Scott Kelly of the U.S., left, Soyuz Commander Alexander Kaleri and Flight Engineer Oleg Skripochka, right, have their Russian Sokol suits prepared for launch by technicians at the Baikonur Cosmodrome in Kazakhstan, Friday, Oct. 8, 2010. (Photo Credit: NASA/Carla Cioffi)

  20. Expedition 25 Launch

    NASA Image and Video Library

    2010-10-07

    Expedition 25 crew members prepare to have their Russian Sokol Suits pressure checked at the Baikonur Cosmodrome in Kazakhstan on Friday, Oct. 8, 2010. Soyuz Commander Alexander Kaleri, NASA Flight Engineer Scott Kelly and Flight Engineer Oleg Skripochka launched in their Soyuz TMA-01M at 5:10 a.m. Friday morning. (Photo Credit: NASA/Carla Cioffi)