Science.gov

Sample records for magnetic launch assist

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. 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.

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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…

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  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. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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}.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. Multimaterial magnetically assisted 3D printing of composite materials

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

    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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Experimental and theoretical studies of implant assisted magnetic drug targeting

    NASA Astrophysics Data System (ADS)

    Aviles, Misael O.

    One way to achieve drug targeting in the body is to incorporate magnetic nanoparticles into drug carriers and then retain them at the site using an externally applied magnetic field. This process is referred to as magnetic drug targeting (MDT). However, the main limitation of MDT is that an externally applied magnetic field alone may not be able to retain a sufficient number of magnetic drug carrier particles (MDCPs) to justify its use. Such a limitation might not exist when high gradient magnetic separation (HGMS) principles are applied to assist MDT by means of ferromagnetic implants. It was hypothesized that an Implant Assisted -- MDT (IA-MDT) system would increase the retention of the MDCPs at a target site where an implant had been previously located, since the magnetic forces are produced internally. With this in mind, the overall objective of this work was to demonstrate the feasibility of an IA-MDT system through mathematical modeling and in vitro experimentation. The mathematical models were developed and used to demonstrate the behavior and limitations of IA-MDT, and the in vitro experiments were designed and used to validate the models and to further elucidate the important parameters that affect the performance of the system. IA-MDT was studied with three plausible implants, ferromagnetic stents, seed particles, and wires. All implants were studied theoretically and experimentally using flow through systems with polymer particles containing magnetite nanoparticles as MDCPs. In the stent studies, a wire coil or mesh was simply placed in a flow field and the capture of the MDCPs was studied. In the other cases, a porous polymer matrix was used as a surrogate capillary tissue scaffold to study the capture of the MDCPs using wires or particle seeds as the implant, with the seeds either fixed within the polymer matrix or captured prior to capturing the MDCPs. An in vitro heart tissue perfusion model was also used to study the use of stents. In general, all

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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%.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. NPP Launch

    NASA Video Gallery

    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 ...

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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).

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  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. 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.

  17. 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.

  18. 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.

  19. 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).

  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. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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…

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. Test controller design, implementation, and performance for a magnetic suspension continuous flow ventricular assist device.

    PubMed

    Hilton, E F; Allaire, P E; Wei, N; Baloh, M J; Bearnson, G; Olsen, D B; Khanwilkar, P

    1999-08-01

    A new continuous flow ventricular assist device using full magnetic suspension has been designed, constructed, and tested. The magnetic suspension centers the centrifugal pump impeller within the clearance passages in the pump, thus avoiding any form of contact. The noncontact operation is designed to give very high expected mechanical reliability, large clearances, low hemolysis, and a relatively small size compared to current pulsatile devices. A unique configuration of magnetic actuators on the inlet side and exit sides of the impeller provides full 5 axis control and suspension of the impeller. The bearing system is divided into segments which allow for 3 displacement axes and 2 angular control axes. The controller chosen for the first suspension tests consists of a decentralized set of 5 proportional integral derivative (PID) controllers. This document describes both the controller and an overview of some results pertaining to the magnetic bearing performance. The pump has been successfully operated in both water and blood under design conditions suitable for use as a ventricular assist device.

  5. 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

  6. 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.

  7. 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.

  8. 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%.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Magnetic suspension controls for a new continuous flow ventricular assist device.

    PubMed

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

    1997-01-01

    A new continuous flow ventricular assist device (CFVAD III) using a full magnetic suspension has been constructed. The magnetic suspension centers the centrifugal impeller within the clearance passages in the pump, thus avoiding any contact. This noncontact operation gives very high expected mechanical reliability, large clearances, low hemolysis, low thrombosis, and relatively small size compared with current pulsatile devices. A unique configuration of a system of magnetic actuators on the inlet side and exit sides of the impeller gives full five axis control and suspension of the impeller. The bearing system is divided into segments that allow for three displacement axes and two angular control axes. For the first suspension tests, a decentralized set of proportional, derivative, and integral (PID) controllers acting along the modal coordinates are used to suspend the impeller. The controller design takes into account the blood forces acting on the magnetically suspended impeller, the unbalance forces on the impeller and gravitational loads during various body motions. In the final design, the bearing control axes will be coupled together through fluidic forces so the electronic feedback controller is a centralized multiple input, multiple output controller. The control system design must be robust against these types of externally imposed loads to keep the impeller centered and avoid blood damage. This article discusses the dynamic model, controller, and controller implementation for the magnetic suspension controller of CFVAD III.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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).

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  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. 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

  15. 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.

  16. 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.

  17. 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.

  18. Towers for Earth Launch

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Lyons, Valerie J. (Technical Monitor)

    2002-01-01

    This report lists some characteristics of a hypothetical 15 kilometer tower for launching spacecraft, the advantages of launching from high altitude, and some equations pertaining to launch from a 15 kilometer tower.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  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. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. IRIS Launch Animation

    NASA Video Gallery

    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...

  1. Shuttle Era: Launch Directors

    NASA Video Gallery

    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...

  2. Space Launch System Animation

    NASA Video Gallery

    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...

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. GPM: Waiting for Launch

    NASA Video Gallery

    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, ...

  19. Expedition 28 Launch

    NASA Video Gallery

    Three new Expedition 28 flight engineers -- NASA astronaut Mike Fossum, Russian cosmonaut Sergei Volkov and Japan Aerospace Exploration Agency astronaut Satoshi Furukawa -- launch from the Baikonur...

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  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. 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.

  12. 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

  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. 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.

  16. 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.

  17. 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.

  18. Launch of Juno!

    NASA Video Gallery

    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...

  19. IRVE 3 Launch

    NASA Video Gallery

    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...

  20. Hi-C Launch

    NASA Video Gallery

    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...

  1. GPM Launch Coverage

    NASA Video Gallery

    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...

  2. NASA Now: Glory Launch

    NASA Video Gallery

    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 ...

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. GPM Core Observatory Launch Animation

    NASA Video Gallery

    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....

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Canadian Space Launch: Exploiting Northern Latitudes For Efficient Space Launch

    DTIC Science & Technology

    2015-04-01

    launch. As such, it should be advantageous to move farther away from the equator. Plane changes which alter the orbital inclination of a...a plane change will not be as efficient as others. Launches Between the Equator and 45 o Launches for orbital inclinations which are less than the...highly inclined orbits (HIOs). Compared to launches which take place from facilities at lower latitudes, it is more efficient to launch HIOs from

  1. 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.

  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. 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).

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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).

  9. 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.

  10. STS-91 Mission Specialist Chang-Diaz suits up for launch

    NASA Technical Reports Server (NTRS)

    1998-01-01

    STS-91 Mission Specialist Franklin R. Chang- Diaz gets assistance from a suit technician as he dons his flight suit in the Operations and Checkout (O&C) Building. The fitting takes place prior to the crew walkout and transport to Launch Pad 39A. He is on his sixth space flight. Chang-Diaz holds a doctorate in applied plasma physics and is director of the Advanced Space Propulsion Laboratory at the University of Houston. Franklin'''s background will serve him well during the mission, since he will be primarily responsible for crew activities in support of the of the Alpha Magnetic Spectrometer. He will also back up Lawrence with the mideck experiments and Kavandi with SPACEHAB operations. STS-91 is scheduled to be launched on June 2 with a launch window opening around 6:10 p.m. EDT. The mission will feature the ninth and final Shuttle docking with the Russian Space Station Mir, the first Mir docking for 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 return to Earth as a STS-91 crew member after living more than four months aboard Mir.

  11. 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.

  12. Astronaut Jean-Francois Clervoy in white room on launch pad 39B

    NASA Technical Reports Server (NTRS)

    1994-01-01

    In the white room at Launch Pad 39B, STS-66 mission specialist Jean-Francois Clervoy is assisted with his partial pressure launch/entry suit by close-out crew members Travis Thompson and Danny Wyatt (background) before entering the Space Shuttle Atlantis for its November 3 launch.

  13. NLS Advanced Development - Launch operations

    NASA Technical Reports Server (NTRS)

    Parrish, Carrie L.

    1992-01-01

    Attention is given to Autonomous Launch Operations (ALO), one of a number of the USAF's National Launch System (NLS) Launch Operations projects whose aim is to research, develop and apply new technologies and more efficient approaches toward launch operations. The goal of the ALO project is to develop generic control and monitor software for launch operation subsystems. The result is enhanced reliability of system design, and reduced software development and retention of expert knowledge throughout the life-cycle of the system.

  14. The Personnel Launch System

    NASA Technical Reports Server (NTRS)

    Piland, William M.; Talay, Theodore A.; Stone, Howard W.

    1990-01-01

    NASA has begun to study candidate vehicles for manned access to space in support of the Space Station or other future missions requiring on-demand transportation of people to and from earth orbit. One such system, which would be used to complement the present Shuttle or an upgraded version, is the Personnel Launch System (PLS), which is envisioned as a reusable priority vehicle to place people and small payloads into orbit using an experimental launch vehicle. The design of the PLS is based on a Space Station crew changeout requirement whereby eight passengers and two crew members are flown to the station and a like number are returned within a 72 hour mission duration. Experimental and computational aerothermodynamic heating studies have been conducted using a new two-color thermographic technique that involved coating the model with a phosphor that radiates at varying color intensities as a function of temperature when illuminated with UV light. A full-scale model, the HL-20, has been produced and will be used for man-machine research. Three launch vehicle concepts are being considered, a Titan IV, the Advanced Launch System, and a Shuttle equipped with liquid rocket boosters.

  15. AST Launch Vehicle Acoustics

    NASA Technical Reports Server (NTRS)

    Houston, Janice; Counter, D.; Giacomoni, D.

    2015-01-01

    The liftoff phase induces acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are then used in the prediction of internal vibration responses of the vehicle and components which result in the qualification levels. Thus, predicting these liftoff acoustic (LOA) environments is critical to the design requirements of any launch vehicle. If there is a significant amount of uncertainty in the predictions or if acoustic mitigation options must be implemented, a subscale acoustic test is a feasible pre-launch test option to verify the LOA environments. The NASA Space Launch System (SLS) program initiated the Scale Model Acoustic Test (SMAT) to verify the predicted SLS LOA environments and to determine the acoustic reduction with an above deck water sound suppression system. The SMAT was conducted at Marshall Space Flight Center and the test article included a 5% scale SLS vehicle model, tower and Mobile Launcher. Acoustic and pressure data were measured by approximately 250 instruments. The SMAT liftoff acoustic results are presented, findings are discussed and a comparison is shown to the Ares I Scale Model Acoustic Test (ASMAT) results.

  16. 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.

  17. 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%).

  18. 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

  19. 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).

  20. 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.

  1. Atomic hydrogen as a launch vehicle propellant

    SciTech Connect

    Palaszewski, B.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 lb{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 hydrogen matrix. The magnetic field strength was estimated to be 30 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.

  2. 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 lb(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 hydrogen matrix. The magnetic field strength was estimated to be 30 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.

  3. 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

  4. 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.

  5. Cassini launch contingency effort

    NASA Astrophysics Data System (ADS)

    Chang, Yale; O'Neil, John M.; McGrath, Brian E.; Heyler, Gene A.; Brenza, Pete T.

    2002-01-01

    On 15 October 1997 at 4:43 AM EDT, the Cassini spacecraft was successfully launched on a Titan IVB/Centaur on a mission to explore the Saturnian system. It carried three Radioisotope Thermoelectric Generators (RTGs) and 117 Light Weight Radioisotope Heater Units (LWRHUs). As part of the joint National Aeronautics and Space Administration (NASA)/U.S. Department of Energy (DoE) safety effort, a contingency plan was prepared to address the unlikely events of an accidental suborbital reentry or out-of-orbital reentry. The objective of the plan was to develop procedures to predict, within hours, the Earth impact footprints (EIFs) for the nuclear heat sources released during the atmospheric reentry. The footprint predictions would be used in subsequent notification and recovery efforts. As part of a multi-agency team, The Johns Hopkins University Applied Physics Laboratory (JHU/APL) had the responsibility to predict the EIFs of the heat sources after a reentry, given the heat sources' release conditions from the main spacecraft. (No ablation burn-through of the heat sources' aeroshells was expected, as a result of earlier testing.) JHU/APL's other role was to predict the time of reentry from a potential orbital decay. The tools used were a three degree-of-freedom trajectory code, a database of aerodynamic coefficients for the heat sources, secure links to obtain tracking data, and a high fidelity special perturbation orbit integrator code to predict time of spacecraft reentry from orbital decay. In the weeks and days prior to launch, all the codes and procedures were exercised. Notional EIFs were derived from hypothetical reentry conditions. EIFs predicted by JHU/APL were compared to those by JPL and US SPACECOM, and were found to be in good agreement. The reentry time from orbital decay for a booster rocket for the Russian Progress M-36 freighter, a cargo ship for the Mir space station, was predicted to within 5 minutes more than two hours before reentry. For the

  6. 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.

  7. 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

  8. 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...Engineering Center Summary The goal of this project was to explore physics, materials and surface chemistry behind the polymer -based route towards...and colloidal stability. To improve these qualities we performed the surface modification of the particles by grafting polymer layerson the NiNP

  9. 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.

  10. 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.

  11. 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).

  12. 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.

  13. Russian Soyuz in Launch Position

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Soyuz TM-31 launch vehicle is shown in the vertical position for its launch from Baikonur, carrying the first resident crew to the International Space Station. The Russian Soyuz launch vehicle is an expendable spacecraft that evolved out of the original Class A (Sputnik). From the early 1960s until today, the Soyuz launch vehicle has been the backbone of Russia's marned and unmanned space launch fleet. Today, the Soyuz launch vehicle is marketed internationally by a joint Russian/French consortium called STARSEM. As of August 2001, there have been ten Soyuz missions under the STARSEM banner.

  14. 32. Launch Control Center, commander's console. Note launch key at ...

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

    32. Launch Control Center, commander's console. Note launch key at right. Lyon - Whiteman Air Force Base, Oscar O-1 Minuteman Missile Alert Facility, Southeast corner of Twelfth & Vendenberg Avenues, Knob Noster, Johnson County, MO

  15. 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.

  16. STS-121 Launch

    NASA Technical Reports Server (NTRS)

    2006-01-01

    Space Shuttle Discovery and its seven-member crew launched at 2:38 p.m. (EDT) to begin the two-day journey to the International Space Station (ISS) on the historic Return to Flight STS-121 mission. The shuttle made history as it was the first human-occupying spacecraft to launch on Independence Day. During its 12-day mission, this utilization and logistics flight delivered a multipurpose logistics module (MPLM) to the ISS with several thousand pounds of new supplies and experiments. In addition, some new orbital replacement units (ORUs) were delivered and stowed externally on the ISS on a special pallet. These ORUs are spares for critical machinery located on the outside of the ISS. During this mission the crew also carried out testing of Shuttle inspection and repair hardware, as well as evaluated operational techniques and concepts for conducting on-orbit inspection and repair.

  17. 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.

  18. Launch of Zoological Letters.

    PubMed

    Fukatsu, Takema; Kuratani, Shigeru

    2016-02-01

    A new open-access journal, Zoological Letters, was launched as a sister journal to Zoological Science, in January 2015. The new journal aims at publishing topical papers of high quality from a wide range of basic zoological research fields. This review highlights the notable reviews and research articles that have been published in the first year of Zoological Letters, providing an overview on the current achievements and future directions of the journal.

  19. Space Probe Launch

    NASA Technical Reports Server (NTRS)

    1970-01-01

    Managed by Marshall Space Flight Center, the Space Tug was a reusable multipurpose space vehicle designed to transport payloads to different orbital inclinations. Utilizing mission-specific combinations of its three primary modules (crew, propulsion, and cargo) and a variety of supplementary kits, the Space Tug was capable of numerous space applications. This 1970 artist's concept depicts the Tug's propulsion module launching a space probe into lunar orbit.

  20. Space Shuttle Endeavour launch

    NASA Technical Reports Server (NTRS)

    1992-01-01

    A smooth countdown culminated in a picture-perfect launch as the Space Shuttle Endeavour (STS-47) climbed skyward atop a ladder of billowing smoke. Primary payload for the plarned seven-day flight was Spacelab-J science laboratory. The second flight of Endeavour marks a number of historic firsts: the first space flight of an African-American woman, the first Japanese citizen to fly on a Space Shuttle, and the first married couple to fly in space.

  1. Space Logistics: Launch Capabilities

    NASA Technical Reports Server (NTRS)

    Furnas, Randall B.

    1989-01-01

    The current maximum launch capability for the United States are shown. The predicted Earth-to-orbit requirements for the United States are presented. Contrasting the two indicates the strong National need for a major increase in Earth-to-orbit lift capability. Approximate weights for planned payloads are shown. NASA is studying the following options to meet the need for a new heavy-lift capability by mid to late 1990's: (1) Shuttle-C for near term (include growth versions); and (2) the Advanced Lauching System (ALS) for the long term. The current baseline two-engine Shuttle-C has a 15 x 82 ft payload bay and an expected lift capability of 82,000 lb to Low Earth Orbit. Several options are being considered which have expanded diameter payload bays. A three-engine Shuttle-C with an expected lift of 145,000 lb to LEO is being evaluated as well. The Advanced Launch System (ALS) is a potential joint development between the Air Force and NASA. This program is focused toward long-term launch requirements, specifically beyond the year 2000. The basic approach is to develop a family of vehicles with the same high reliability as the Shuttle system, yet offering a much greater lift capability at a greatly reduced cost (per pound of payload). The ALS unmanned family of vehicles will provide a low end lift capability equivalent to Titan IV, and a high end lift capability greater than the Soviet Energia if requirements for such a high-end vehicle are defined.In conclusion, the planning of the next generation space telescope should not be constrained to the current launch vehicles. New vehicle designs will be driven by the needs of anticipated heavy users.

  2. Expendable launch vehicle propulsion

    NASA Technical Reports Server (NTRS)

    Fuller, Paul N.

    1991-01-01

    The current status is reviewed of the U.S. Expendable Launch Vehicle (ELV) fleet, the international competition, and the propulsion technology of both domestic and foreign ELVs. The ELV propulsion technology areas where research, development, and demonstration are most needed are identified. These propulsion technology recommendations are based on the work performed by the Commercial Space Transportation Advisory Committee (COMSTAC), an industry panel established by the Dept. of Transportation.

  3. 73. VIEW OF LAUNCH OPERATOR AND LAUNCH ANAYLST PANELS LOCATED ...

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

    73. VIEW OF LAUNCH OPERATOR AND LAUNCH ANAYLST PANELS LOCATED NEAR CENTER OF SOUTH WALL OF SLC-3E CONTROL ROOM. FROM LEFT TO RIGHT ON WALL IN BACKGROUND: COMMUNICATIONS HEADSET AND FOOT PEDAL IN FORGROUND. ACCIDENT REPORTING EMERGENCY NOTIFICATION SYSTEM TELEPHONE, ATLAS H FUEL COUNTER, AND DIGITAL COUNTDOWN CLOCK. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  4. 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.

  5. 25. Corridor between the Launch Control Center and the Launch ...

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

    25. Corridor between the Launch Control Center and the Launch Control Equipment Room, view from Launch Control Center. Thalheimer - Whiteman Air Force Base, Oscar O-1 Minuteman Missile Alert Facility, Southeast corner of Twelfth & Vendenberg Avenues, Knob Noster, Johnson County, MO

  6. 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.

  7. 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.

  8. SMAP Launch and Deployment Sequence

    NASA Video Gallery

    This video combines file footage of a Delta II rocket and computer animation to depict the launch and deployment of NASA's Soil Moisture Active Passive satellite. SMAP is scheduled to launch on Nov...

  9. Launch Vehicle Control Center Architectures

    NASA Technical Reports Server (NTRS)

    Watson, Michael D.; Epps, Amy; Woodruff, Van; Vachon, Michael Jacob; Monreal, Julio; Williams, Randall; McLaughlin, Tom

    2014-01-01

    This analysis is a survey of control center architectures of the NASA Space Launch System (SLS), United Launch Alliance (ULA) Atlas V and Delta IV, and the European Space Agency (ESA) Ariane 5. Each of these control center architectures have similarities in basic structure, and differences in functional distribution of responsibilities for the phases of operations: (a) Launch vehicles in the international community vary greatly in configuration and process; (b) Each launch site has a unique processing flow based on the specific configurations; (c) Launch and flight operations are managed through a set of control centers associated with each launch site, however the flight operations may be a different control center than the launch center; and (d) The engineering support centers are primarily located at the design center with a small engineering support team at the launch site.

  10. 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.

  11. 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.

  12. 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.

  13. Intelsat satellite scheduled for launch

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The launch schedule for Intelsat 5-B, the prime Intelsat satellite to provide communications services between the Americas, Europe, the Middle East, and Africa, is presented. The planned placement of the satellite into an elliptical transfer orbit, and circularization of the orbit at geosynchronous altitude over the equator are described. Characteristics of the Atlas Centaur launch vehicle, AC-56, are given. The launch operation is summarized and the launch sequence presented. The Intelsat team and contractors are listed.

  14. Apollo 11 astronaut Neil Armstrong suits up before launch

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Apollo 11 Commander Neil Armstrong prepares to put on his helmet with the assistance of a spacesuit technician during suiting operations in the Manned Spacecraft Operations Building (MSOB) prior to the astronauts' departure to Launch Pad 39A. The three astronauts, Edwin E. Aldrin Jr., Neil A Armstrong and Michael Collins, will then board the Saturn V launch vehicle, scheduled for a 9:32 a.m. EDT liftoff, for the first manned lunar landing mission.

  15. Launch summary for 1978 - 1982

    NASA Astrophysics Data System (ADS)

    Hills, H. K.

    1984-01-01

    Data pertinent to the launching of space probes, soundings rockets, and satellites presented in tables include launch date, time, and site; agency rocket identification; sponsoring country or countries; instruments carried for experiments; the peak altitude achieved by the rockets; and the apoapsis and periapsis for satellites. The experimenter or institution involved in the launching is also cited.

  16. Launch Vehicle Control Center Architectures

    NASA Technical Reports Server (NTRS)

    Watson, Michael D.; Epps, Amy; Woodruff, Van; Vachon, Michael Jacob; Monreal, Julio; Levesque, Marl; Williams, Randall; Mclaughlin, Tom

    2014-01-01

    Launch vehicles within the international community vary greatly in their configuration and processing. Each launch site has a unique processing flow based on the specific launch vehicle configuration. Launch and flight operations are managed through a set of control centers associated with each launch site. Each launch site has a control center for launch operations; however flight operations support varies from being co-located with the launch site to being shared with the space vehicle control center. There is also a nuance of some having an engineering support center which may be co-located with either the launch or flight control center, or in a separate geographical location altogether. A survey of control center architectures is presented for various launch vehicles including the NASA Space Launch System (SLS), United Launch Alliance (ULA) Atlas V and Delta IV, and the European Space Agency (ESA) Ariane 5. Each of these control center architectures shares some similarities in basic structure while differences in functional distribution also exist. The driving functions which lead to these factors are considered and a model of control center architectures is proposed which supports these commonalities and variations.

  17. Experimental Studies on Flexible Forming of Sheet Metals Assisted by Magnetic Force Transfer Medium

    NASA Astrophysics Data System (ADS)

    Li, Feng; Zhou, Fu Jian; Wang, Mo Nan; Xu, Peng; Jin, Cheng Chuang

    2016-08-01

    To improve the thickness uniformity and increase the forming limit of sheets to enhance their overall quality, a magnetorheological fluid (MRF) was injected into the punch cavity to act as the force transfer medium and fulfill the function of flexible pressing during the sheet bulging process. The rheological properties of the MRF were changed under the influence of a magnetic field produced by loading different currents, which allowed variation of stress states and deformation modes in the 0.75-mm-thick 304 stainless steel sheets. With increasing current (up to 3.5 A), the sheet-forming limit increased by 16.13% at most, and the fracture morphology experienced a certain change. Additionally, both the bulge height and the wall thickness distribution had obvious changes with a punch stroke of 10 mm. According to the experimental analysis, the MRF can be used successfully as a pressure-carrying medium in the sheet forming process.

  18. Trigger finger following partial flexor tendon laceration: Magnetic resonance imaging-assisted diagnosis

    PubMed Central

    Couceiro, Jose; Fraga, Javier; Sanmartin, Marcos

    2015-01-01

    Introduction Post-traumatic trigger finger is considerably rarer than normal trigger finger. The diagnosis is usually made on a clinical basis. This can be obscured; however, by concurrent pathological conditions. We report a case of post-traumatic trigger finger in which diagnosis was aided by magnetic resonance imaging (MRI). Presentation of case Our patient is a 32-year-old male who had a previous laceration with a subsequent surgery for infectious tenosynovitis. The MRI showed the impinging tendon tag. Surgical excision of the tag successfully solved the case. Discussion The use of imaging studies for the diagnosis of post-traumatic trigger finger has been previously reported, the authors described a variation on the contour of the pulley system. The full lacerated tendon tag can be seen on our patient's MRI. Conclusion On this case, the use of MRI was a useful aid for the differential diagnosis of post-traumattic trigger finger. PMID:25765739

  19. STS-115 Launch

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The Space Shuttle Atlantis and its six-member crew launched at 11:15 a.m. (EDT) on September 9, 2006 to begin the two-day journey to the International Space Station (ISS) on the STS-115 mission. During the 11-day mission, the STS-115 crew of six, along with station crews and ground teams, resumed construction of the ISS with the installation of a girder-like structure, known as the P3/P4 truss. The 35,000-pound piece includes a set of giant solar arrays, batteries and associated electronics. The arrays eventually will double the power capability of the Station.

  20. Apollo 13 Launch

    NASA Technical Reports Server (NTRS)

    1970-01-01

    The third marned lunar landing mission, Apollo 13 (SA-508), with three astronauts: Mission commander James A. Lovell Jr., Lunar Module pilot Fred W. Haise Jr., and Command Module pilot John L. Swigert Jr., lifted off from the Kennedy Space Center launch complex 39A on April 11, 1970. The mission was aborted after 56 hours of flight, 205,000 miles from Earth, when an oxygen tank in the service module exploded. The Command Module, Odyssey, carrying the three astronauts, safely splashed down in the Pacific Ocean at 1:08 p.m. EST, April 17, 1970.

  1. STS-39 Launch

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Launched aboard the Space Shuttle Discovery on April 28, 1991 at 7:33:14 am (EDT), STS-39 was a Department of Defense (DOD) mission. The crew included seven astronauts: Michael L. Coats, commander; L. Blaine Hammond, pilot; Guion S. Buford, Jr., mission specialist 1; Gregory J. Harbaugh, mission specialist 2; Richard J. Hieb, mission specialist 3; Donald R. McMonagle, mission specialist 4; and Charles L. Veach, mission specialist 5. The primary unclassified payload included the Air Force Program 675 (AFP-675), the Infrared Background Signature Survey (IBSS), and the Shuttle Pallet Satellite II (SPAS II).

  2. The continuing challenge of electromagnetic launch

    SciTech Connect

    Cowan, M.; Cnare, E.C.; Duggin, B.W.; Kaye, R.J.; Marder, B.M.; Shokair, I.R.

    1993-07-01

    Interest in launching payloads through the atmosphere to ever higher velocity is robust. For hundreds of years, guns and rockets have been improved for this purpose until they are now considered to be near to their performance limits. While the potential of electromagnetic technology to increase launch velocity has been known since late in the nineteenth century, it was not until about 1980 that a sustained and large-scale effort was started to exploit it. Electromagnetic launcher technology is restricted here to mean only that technology which establishes both a current density, J, and a magnetic field, B, within a part of the launch package, called the armature, so that J {times} B integrated over the volume of the armature is the launching force. Research and development activity was triggered by the discovery that high velocity can be produced with a simple railgun which uses an arc for its armature. This so called ``plasma-armature railgun`` has been the launcher technology upon which nearly all of the work has focused. Still, a relatively small parallel effort has also been made to explore the potential of electromagnetic launchers which do not use sliding contacts on stationary rails to establish current in the armature. One electromagnetic launcher of this type is called an induction coilgun because armature current is established by electromagnetic induction. In this paper, we first establish terminology which we will use not only to specify requirements for successful endoatmospheric launch but also to compare different launcher types. Then, we summarize the statuses of the railgun and induction coilgun technologies and discuss the issues which must be resolved before either of these launchers can offer substantial advantage for endoatomospheric launch.

  3. A Comparison of Magnetic Resonance Angiography Techniques for the Evaluation of Intracranial Aneurysms Treated With Stent-assisted Coil Embolization

    PubMed Central

    Cockroft, Kevin; Agarwal, Amit K; Sabat, Shyam; Kalapos, Paul

    2016-01-01

    Aim To identify the effective magnetic resonance angiography (MRA) technique to monitor intracranial aneurysms treated with stent-assisted coiling. Materials and Methods Retrospective analysis of various MRA techniques was performed in 42 patients. Three neuroradiologists independently compared non-contrast time of flight (ncTOF) MRA of the head, contrast-enhanced time of flight (cTOF) MRA of the head and dynamic contrast-enhanced MRA (CEMRA) of the head and neck or of the head. Digital subtraction angiography (DSA) was available for comparison in 32 cases. Inter-rater agreement (kappa statistic) was assessed. Results Artifactual in-stent severe stenosis or flow gap was identified by ncTOF MRA in 23 of 42 cases (55%) and by cTOF MRA in 23 of 38 cases (60%). DSA excluded in-stent stenosis or occlusion in all 32 cases. No difference was noted between ncTOF and cTOF in the demonstration of neck remnants or residual aneurysms in three cases each. CEMRA of the head and neck or of the head was rated superior to ncTOF and cTOF MRA by all three investigators in seven out of eight cases. In one case, all three techniques demonstrated signifcant artifacts due to double stent placement during coiling. The kappa statistic revealed 0.8 agreement between investigators. Conclusions In the assessment of stent-assisted coiling of intracranial aneurysm, both ncTOF and cTOF MRA show similar results. CEMRA tends to show better flow signals in stent and residual aneurysm. PMID:28083453

  4. Influence of MgO underlayers on the structure and magnetic properties of FePt-C nanogranular films for heat-assisted magnetic recording media

    NASA Astrophysics Data System (ADS)

    Shiroyama, T.; Varaprasad, B. S. D. Ch. S.; Takahashi, Y. K.; Hono, K.

    2016-10-01

    In order to optimize the nanogranular structure of FePt-C for heat-assisted magnetic recording media, we investigated the influence of MgO underlayers on the growth of FePt grains in the FePt-C layer. The FePt-C layer was deposited by using the alternating sputtering method, by which FePt and FePt-C layers were alternately deposited. To understand the growth mechanism of the FePt-C layer on the MgO underlayers deposited under various conditions, detailed plan-view and cross sectional transmission electron microscopy observations were made for different film thicknesses. We found that columnar FePt grains grow only when the deposition conditions of the MgO underlayer are optimal. Direct TEM observation of the growth process of the FePt-C layer revealed that the number density of nuclei is sufficient in the initial stage of the film deposition; however, coarsening of the grains after grain impingement causes a substantial decrease in the number density of the FePt grains.

  5. First Stage of a Highly Reliable Reusable Launch System

    NASA Technical Reports Server (NTRS)

    Kloesel, Kurt J.; Pickrel, Jonathan B.; Sayles, Emily L.; Wright, Michael; Marriott, Darin; Holland, Leo; Kuznetsov, Stephen

    2009-01-01

    Electromagnetic launch assist has the potential to provide a highly reliable reusable first stage to a space access system infrastructure at a lower overall cost. This paper explores the benefits of a smaller system that adds the advantages of a high specific impulse air-breathing stage and supersonic launch speeds. The method of virtual specific impulse is introduced as a tool to emphasize the gains afforded by launch assist. Analysis shows launch assist can provide a 278-s virtual specific impulse for a first-stage solid rocket. Additional trajectory analysis demonstrates that a system composed of a launch-assisted first-stage ramjet plus a bipropellant second stage can provide a 48-percent gross lift-off weight reduction versus an all-rocket system. The combination of high-speed linear induction motors and ramjets is identified, as the enabling technologies and benchtop prototypes are investigated. The high-speed response of a standard 60 Hz linear induction motor was tested with a pulse width modulated variable frequency drive to 150 Hz using a 10-lb load, achieving 150 mph. A 300-Hz stator-compensated linear induction motor was constructed and static-tested to 1900 lbf average. A matching ramjet design was developed for use on the 300-Hz linear induction motor.

  6. Launch of STS-134

    NASA Video Gallery

    Space Shuttle Endeavour lifts off from NASA's Kennedy Space Center in Florida on its final mission. Commander Mark Kelly and crew will deliver the Alpha Magnetic Spectrometer to the International S...

  7. STS-114: Discovery Launch Postponement Press Briefing

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This press briefing addresses the problem that occurred prior to the launch of the STS-114. Dean Acosta, Deputy Assistant Administrator of Public Affairs, introduces the panel which consists of Dr. Michael Griffin, NASA Administrator, William Readdy, Associate Administrator for Space Operations, Wayne Hale, Space Shuttle Program Deputy Manager, Steve Poulas, Orbiter Project Manager, Mike Leinbach, NASA Launch Director, and Bill Parsons, Space Shuttle Program Manager. Wayne Hale expresses that a problem occurred with one of the low level sensors in the hydrogen tank and that the cause of the problem must be identified and rectified. Steve Poulos talks about establishing a troubleshooting plan as a part of the scrub effort and Mike Leinbach describes the process of draining the external tank. Wayne Hale answers questions about the sensors and if the Space Shuttle Discovery is safe to fly and Steve Poulos answers questions about the possible suspects for this problem.

  8. Telesat-G/Delta post launch report

    NASA Technical Reports Server (NTRS)

    Mahon, J. B.; Abrahamson, J. A.

    1983-01-01

    The Canadiari Telesat-G (ANIK-D1) commercial communications satellite was launched successfully from the Eastern space and Missile Center (ESMC) at 7:10 p.m., EDT, on August 25, 1982, by a Delta 3920 Vehicle, Mission Number 164. Performance of the two stage Delta launch vehicle was nominal and placed the payload in a low circular orbit as planned. The Payload Assist Module (PAM-D), which is part of the payload, also performed nominally. The synchronous transfer orbital elements achieved by Delta/PAM, compared with the nominal expected, are provided. The satellite performed satisfactorily during the transfer orbit, and the ABM was fired successfully at 5:29 p.m., EDT, on August 29, 1982. The satellite was maneuvered to a position 104 degrees West Longitude above the equator. Satellite status is satisfactory and it has entered service.

  9. New Product Launching Ideas

    NASA Astrophysics Data System (ADS)

    Kiruthika, E.

    2012-09-01

    Launching a new product can be a tense time for a small or large business. There are those moments when you wonder if all of the work done to develop the product will pay off in revenue, but there are many things are can do to help increase the likelihood of a successful product launch. An open-minded consumer-oriented approach is imperative in todayís diverse global marketplace so a firm can identify and serve its target market, minimize dissatisfaction, and stay ahead of competitors. Final consumers purchase for personal, family, or household use. Finally, the kind of information that the marketing team needs to provide customers in different buying situations. In high-involvement decisions, the marketer needs to provide a good deal of information about the positive consequences of buying. The sales force may need to stress the important attributes of the product, the advantages compared with the competition; and maybe even encourage ìtrialî or ìsamplingî of the product in the hope of securing the sale. The final stage is the post-purchase evaluation of the decision. It is common for customers to experience concerns after making a purchase decision. This arises from a concept that is known as ìcognitive dissonance

  10. A new device for magnetic stirring-assisted dispersive liquid-liquid microextraction of UV filters in environmental water samples.

    PubMed

    Zhang, Ping-Ping; Shi, Zhi-Guo; Yu, Qiong-Wei; Feng, Yu-Qi

    2011-02-15

    A new method based on dispersive liquid-liquid microextraction (DLLME) in combination with high-performance liquid chromatography (HPLC) has been developed for the analysis of UV filters. A specially designed flask, which has two narrow open necks with one of them having a capillary tip, was employed to facilitate the DLLME process. By adopting such a device, the extraction and subsequent phase separation were conveniently achieved. A binary solvent system of water sample and low-density extraction solvent (1-octanol) was used for the DLLME and no disperser solvent was involved. The extraction was accelerated by magnetic agitation of the two phases. After extraction, phase separation of the extraction solvent from the aqueous sample was easily achieved by leaving the extraction system statically for a while. No centrifugation step involving in classical DLLME was necessary. The analyte-enriched phase, floating above the sample solution, was elevated and concentrated into the narrow open tip of the flask by adding pure water into it via the other port, which was withdrawn with a microsyringe for the subsequent HPLC analysis. Under the optimized conditions, the limits of detection for the analytes were in range of 0.2-0.8ngmL(-1) .The linearity ranges were 8-20,000 ng mL(-1) for HB, 7-20,000 ng mL(-1) for DB, 8-10,000 ng mL(-1) for BP and 5-20,000 ng mL(-1) for HMB, respectively. Enrichment factors ranging from 59 to 107 folders were obtained for the analytes. The relative standard deviations (n=3) at a spiked level of 80 ng mL(-1) were between 1.4 and 4.8%. The proposed magnetic stirring-assisted DLLME method was successfully applied to the analysis of lake water samples.

  11. Highly Reusable Space Transportation System Concept Evaluation (The Argus Launch Vehicle)

    NASA Technical Reports Server (NTRS)

    Olds, John R.; Bellini, Peter X.

    1998-01-01

    This paper summarizes the results of a conceptual design study that was performed in support of NASA's recent Highly Reusable Space Transportation study. The Argus concept uses a Maglifter magnetic-levitation sled launch assist system to accelerate it to a takeoff ground speed of 800 fps on its way to delivering a payload of 20,000 lb. to low earth orbit. Main propulsion is provided by two supercharged ejector rocket engines. The vehicle is autonomous and is fully reusable. A conceptual design exercise determined the vehicle gross weight to be approximately 597,250 lb. and the dry weight to be 75,500 lb. Aggressive weight and operations cost assumptions were used throughout the design process consistent with a second-generation reusable system that might be deployed in 10-15 years. Drawings, geometry, and weight of the concept are included. Preliminary development, production, and operations costs along with a business scenario assuming a price-elastic payload market are also included. A fleet of three Argus launch vehicles flying a total of 149 flights per year is shown to have a financial internal rate of return of 28%. At $169/lb., the recurring cost of Argus is shown to meet the study goal of $100/lb.-$200/lb., but optimum market price results in only a factor of two to five reduction compared to today's launch systems.

  12. Diffusion-assisted selective dynamical recoupling: A new approach to measure background gradients in magnetic resonance

    SciTech Connect

    Álvarez, Gonzalo A.; Shemesh, Noam; Frydman, Lucio

    2014-02-28

    Dynamical decoupling, a generalization of the original NMR spin-echo sequence, is becoming increasingly relevant as a tool for reducing decoherence in quantum systems. Such sequences apply non-equidistant refocusing pulses for optimizing the coupling between systems, and environmental fluctuations characterized by a given noise spectrum. One such sequence, dubbed Selective Dynamical Recoupling (SDR) [P. E. S. Smith, G. Bensky, G. A. Álvarez, G. Kurizki, and L. Frydman, Proc. Natl. Acad. Sci. 109, 5958 (2012)], allows one to coherently reintroduce diffusion decoherence effects driven by fluctuations arising from restricted molecular diffusion [G. A. Álvarez, N. Shemesh, and L. Frydman, Phys. Rev. Lett. 111, 080404 (2013)]. The fully-refocused, constant-time, and constant-number-of-pulses nature of SDR also allows one to filter out “intrinsic” T{sub 1} and T{sub 2} weightings, as well as pulse errors acting as additional sources of decoherence. This article explores such features when the fluctuations are now driven by unrestricted molecular diffusion. In particular, we show that diffusion-driven SDR can be exploited to investigate the decoherence arising from the frequency fluctuations imposed by internal gradients. As a result, SDR presents a unique way of probing and characterizing these internal magnetic fields, given an a priori known free diffusion coefficient. This has important implications in studies of structured systems, including porous media and live tissues, where the internal gradients may serve as fingerprints for the system's composition or structure. The principles of this method, along with full analytical solutions for the unrestricted diffusion-driven modulation of the SDR signal, are presented. The potential of this approach is demonstrated with the generation of a novel source of MRI contrast, based on the background gradients active in an ex vivo mouse brain. Additional features and limitations of this new method are discussed.

  13. Diffusion-assisted selective dynamical recoupling: A new approach to measure background gradients in magnetic resonance

    NASA Astrophysics Data System (ADS)

    Álvarez, Gonzalo A.; Shemesh, Noam; Frydman, Lucio

    2014-02-01

    Dynamical decoupling, a generalization of the original NMR spin-echo sequence, is becoming increasingly relevant as a tool for reducing decoherence in quantum systems. Such sequences apply non-equidistant refocusing pulses for optimizing the coupling between systems, and environmental fluctuations characterized by a given noise spectrum. One such sequence, dubbed Selective Dynamical Recoupling (SDR) [P. E. S. Smith, G. Bensky, G. A. Álvarez, G. Kurizki, and L. Frydman, Proc. Natl. Acad. Sci. 109, 5958 (2012)], allows one to coherently reintroduce diffusion decoherence effects driven by fluctuations arising from restricted molecular diffusion [G. A. Álvarez, N. Shemesh, and L. Frydman, Phys. Rev. Lett. 111, 080404 (2013)]. The fully-refocused, constant-time, and constant-number-of-pulses nature of SDR also allows one to filter out "intrinsic" T1 and T2 weightings, as well as pulse errors acting as additional sources of decoherence. This article explores such features when the fluctuations are now driven by unrestricted molecular diffusion. In particular, we show that diffusion-driven SDR can be exploited to investigate the decoherence arising from the frequency fluctuations imposed by internal gradients. As a result, SDR presents a unique way of probing and characterizing these internal magnetic fields, given an a priori known free diffusion coefficient. This has important implications in studies of structured systems, including porous media and live tissues, where the internal gradients may serve as fingerprints for the system's composition or structure. The principles of this method, along with full analytical solutions for the unrestricted diffusion-driven modulation of the SDR signal, are presented. The potential of this approach is demonstrated with the generation of a novel source of MRI contrast, based on the background gradients active in an ex vivo mouse brain. Additional features and limitations of this new method are discussed.

  14. Hypersonic Interplanetary Flight: Aero Gravity Assist

    NASA Technical Reports Server (NTRS)

    Bowers, Al; Banks, Dan; Randolph, Jim

    2006-01-01

    The use of aero-gravity assist during hypersonic interplanetary flights is highlighted. Specifically, the use of large versus small planet for gravity asssist maneuvers, aero-gravity assist trajectories, launch opportunities and planetary waverider performance are addressed.

  15. eLaunch Hypersonics: An Advanced Launch System

    NASA Technical Reports Server (NTRS)

    Starr, Stanley

    2010-01-01

    This presentation describes a new space launch system that NASA can and should develop. This approach can significantly reduce ground processing and launch costs, improve reliability, and broaden the scope of what we do in near earth orbit. The concept (not new) is to launch a re-usable air-breathing hypersonic vehicle from a ground based electric track. This vehicle launches a final rocket stage at high altitude/velocity for the final leg to orbit. The proposal here differs from past studies in that we will launch above Mach 1.5 (above transonic pinch point) which further improves the efficiency of air breathing, horizontal take-off launch systems. The approach described here significantly reduces cost per kilogram to orbit, increases safety and reliability of the boost systems, and reduces ground costs due to horizontal-processing. Finally, this approach provides significant technology transfer benefits for our national infrastructure.

  16. Launch vehicle selection model

    NASA Technical Reports Server (NTRS)

    Montoya, Alex J.

    1990-01-01

    Over the next 50 years, humans will be heading for the Moon and Mars to build scientific bases to gain further knowledge about the universe and to develop rewarding space activities. These large scale projects will last many years and will require large amounts of mass to be delivered to Low Earth Orbit (LEO). It will take a great deal of planning to complete these missions in an efficient manner. The planning of a future Heavy Lift Launch Vehicle (HLLV) will significantly impact the overall multi-year launching cost for the vehicle fleet depending upon when the HLLV will be ready for use. It is desirable to develop a model in which many trade studies can be performed. In one sample multi-year space program analysis, the total launch vehicle cost of implementing the program reduced from 50 percent to 25 percent. This indicates how critical it is to reduce space logistics costs. A linear programming model has been developed to answer such questions. The model is now in its second phase of development, and this paper will address the capabilities of the model and its intended uses. The main emphasis over the past year was to make the model user friendly and to incorporate additional realistic constraints that are difficult to represent mathematically. We have developed a methodology in which the user has to be knowledgeable about the mission model and the requirements of the payloads. We have found a representation that will cut down the solution space of the problem by inserting some preliminary tests to eliminate some infeasible vehicle solutions. The paper will address the handling of these additional constraints and the methodology for incorporating new costing information utilizing learning curve theory. The paper will review several test cases that will explore the preferred vehicle characteristics and the preferred period of construction, i.e., within the next decade, or in the first decade of the next century. Finally, the paper will explore the interaction

  17. Establishment of Magnetic Microparticles-Assisted Time-Resolved Fluoroimmunoassay for Determinating Biomarker Models in Human Serum

    PubMed Central

    Ren, Zhi-Qi; Liu, Tian-Cai; Zhuang, Si-Hui; Lin, Guan-Feng; Hou, Jing-Yuan; Wu, Ying-Song

    2015-01-01

    In order to early screen and detect suspected biomarkers from pathogens and the human body itself, tracers or reaction strategies that can act as signal enhancers have been proposed forth at purpose. In this paper, we discussed the applicability of magnetic microparticles-assisted time-resolved fluoroimmunoassay (MMPs-TRFIA) for sensitive determination of potential analytes. Hepatitis B e antigen, antibody to hepatitis B surface antigen and free triiodothyronine were used as biomarker models to explore the reliability of the method. By coupling with bioprobes, MMPs were used as immunoassay carriers to capture target molecules. Under optimal condition, assay performance, including accuracy, precision and specificity, was outstanding and demonstrated satisfactory. To further evaluate the performance of the MMPs-TRFIA in patients, a total of 728 serum samples from hospital were analyzed for three biomarkers in parallel with the proposed method and chemiluminescence immunoassay kit commercially available. Fairly good agreements are obtained between the two methods via data analysis. Not only that but the reliability of MMPs-TRFIA has also been illustrated by three different reaction models. It is confirmed that the novel method modified with MMPs has been established and showed great potential applications in both biological detection and clinical diagnosis, including big molecule protein and low molecular weight haptens. PMID:26103625

  18. Development of an alternating magnetic-field-assisted finishing process for microelectromechanical systems micropore x-ray optics.

    PubMed

    Riveros, Raul E; Yamaguchi, Hitomi; Mitsuishi, Ikuyuki; Takagi, Utako; Ezoe, Yuichiro; Kato, Fumiki; Sugiyama, Susumu; Yamasaki, Noriko; Mitsuda, Kazuhisa

    2010-06-20

    X-ray astronomy research is often limited by the size, weight, complexity, and cost of functioning x-ray optics. Micropore optics promises an economical alternative to traditional (e.g., glass or foil) x-ray optics; however, many manufacturing difficulties prevent micropore optics from being a viable solution. Ezoe et al. introduced microelectromechanical systems (MEMS) micropore optics having curvilinear micropores in 2008. Made by either deep reactive ion etching or x-ray lithography, electroforming, and molding (LIGA), MEMS micropore optics suffer from high micropore sidewall roughness (10-30nmrms) which, by current standards, cannot be improved. In this research, a new alternating magnetic-field-assisted finishing process was developed using a mixture of ferrofluid and microscale abrasive slurry. A machine was built, and a set of working process parameters including alternating frequency, abrasive size, and polishing time was selected. A polishing experiment on a LIGA-fabricated MEMS micropore optic was performed, and a change in micropore sidewall roughness of 9.3+/-2.5nmrms to 5.7+/-0.7nmrms was measured. An improvement in x-ray reflectance was also seen. This research shows the feasibility and confirms the effects of this new polishing process on MEMS micropore optics.

  19. Generation of Aptamers from A Primer-Free Randomized ssDNA Library Using Magnetic-Assisted Rapid Aptamer Selection.

    PubMed

    Tsao, Shih-Ming; Lai, Ji-Ching; Horng, Horng-Er; Liu, Tu-Chen; Hong, Chin-Yih

    2017-04-03

    Aptamers are oligonucleotides that can bind to specific target molecules. Most aptamers are generated using random libraries in the standard systematic evolution of ligands by exponential enrichment (SELEX). Each random library contains oligonucleotides with a randomized central region and two fixed primer regions at both ends. The fixed primer regions are necessary for amplifying target-bound sequences by PCR. However, these extra-sequences may cause non-specific bindings, which potentially interfere with good binding for random sequences. The Magnetic-Assisted Rapid Aptamer Selection (MARAS) is a newly developed protocol for generating single-strand DNA aptamers. No repeat selection cycle is required in the protocol. This study proposes and demonstrates a method to isolate aptamers for C-reactive proteins (CRP) from a randomized ssDNA library containing no fixed sequences at 5' and 3' termini using the MARAS platform. Furthermore, the isolated primer-free aptamer was sequenced and binding affinity for CRP was analyzed. The specificity of the obtained aptamer was validated using blind serum samples. The result was consistent with monoclonal antibody-based nephelometry analysis, which indicated that a primer-free aptamer has high specificity toward targets. MARAS is a feasible platform for efficiently generating primer-free aptamers for clinical diagnoses.

  20. Development of an alternating magnetic-field-assisted finishing process for microelectromechanical systems micropore x-ray optics

    SciTech Connect

    Riveros, Raul E.; Yamaguchi, Hitomi; Mitsuishi, Ikuyuki; Takagi, Utako; Ezoe, Yuichiro; Kato, Fumiki; Sugiyama, Susumu; Yamasaki, Noriko; Mitsuda, Kazuhisa

    2010-06-20

    X-ray astronomy research is often limited by the size, weight, complexity, and cost of functioning x-ray optics. Micropore optics promises an economical alternative to traditional (e.g., glass or foil) x-ray optics; however, many manufacturing difficulties prevent micropore optics from being a viable solution. Ezoe et al. introduced microelectromechanical systems (MEMS) micropore optics having curvilinear micropores in 2008. Made by either deep reactive ion etching or x-ray lithography, electroforming, and molding (LIGA), MEMS micropore optics suffer from high micropore sidewall roughness (10-30nmrms) which, by current standards, cannot be improved. In this research, a new alternating magnetic-field-assisted finishing process was developed using a mixture of ferrofluid and microscale abrasive slurry. A machine was built, and a set of working process parameters including alternating frequency, abrasive size, and polishing time was selected. A polishing experiment on a LIGA-fabricated MEMS micropore optic was performed, and a change in micropore sidewall roughness of 9.3{+-}2.5nmrms to 5.7{+-}0.7nmrms was measured. An improvement in x-ray reflectance was also seen. This research shows the feasibility and confirms the effects of this new polishing process on MEMS micropore optics.

  1. The effect of computer-assisted cognitive rehabilitation and repetitive transcranial magnetic stimulation on cognitive function for stroke patients

    PubMed Central

    Park, In-Seok; Yoon, Jung-Gyu

    2015-01-01

    [Purpose] This study investigated the effects of computer-assisted cognitive rehabilitation (CACR) and repetitive transcranial magnetic stimulation (rTMS) on cognitive function in patients with stroke. [Subjects and Methods] We enrolled 20 patients and divided them into CACR and rTMS groups. CACR and rTMS were performed thrice a week for 4 weeks. Cognitive function was measured with the Korean Mini-Mental State Examination (K-MMSE) and Lowenstein Occupational Therapy Cognitive Assessment-Geriatric (LOTCA-G) before and after treatment. The independent samples t-test was performed to test the homogeneity of K-MMSE and LOTCA-G before treatment and compare the differences in cognitive improvement between the CACR and rTMS groups. A paired samples t-test was used to compare cognitive function before and after treatment. [Results] Cognitive function of both the groups significantly improved after the intervention based on the K-MMSE and LOTCA-G scores. While the LOTCA-G score improved significantly more in the CACR group than in the rTMS group, no significant difference was seen in the K-MMSE scores. [Conclusion] We showed that CACR is more effective than rTMS in improving cognitive function after stroke. PMID:25931728

  2. Thyristor-based current-fed drive with direct power control for permanent magnet-assisted synchronous reluctance generator

    NASA Astrophysics Data System (ADS)

    Baek, J.; Kwak, S.-S.; Toliyat, H. A.

    2015-03-01

    This paper proposes a robust and simple direct power control (DPC) of a thyristor-based current-fed drive for generator applications. A current-fed drive and permanent magnet-assisted synchronous reluctance generator (PMa-SynRG) are investigated to deliver 3 kW power using a combustion engine. The current-fed drive utilises a thyristor-based three-phase rectifier to convert generator power to DC-link power and a single-phase current-fed inverter to supply a single-phase inductive load. In addition, a new control algorithm is developed based on DPC for the current-fed drive. The DC-link voltage-based DPC is proposed in order to directly control the output power. The goal of the DPC is to maintain the DC-link voltage at the required output power operating point. The DPC has advantages such as a simple algorithm for constant speed operation. Another feature of the developed current-fed drive is its inherent capability to provide generating action by making the PMa-SynRG operates as a generator, rectifying the phase voltages by means of the three-phase rectifier and feeding the power into the load. These features make the current-fed drive a good candidate for driving any type of synchronous generators including the proposed PMa-SynRG.

  3. The effect of computer-assisted cognitive rehabilitation and repetitive transcranial magnetic stimulation on cognitive function for stroke patients.

    PubMed

    Park, In-Seok; Yoon, Jung-Gyu

    2015-03-01

    [Purpose] This study investigated the effects of computer-assisted cognitive rehabilitation (CACR) and repetitive transcranial magnetic stimulation (rTMS) on cognitive function in patients with stroke. [Subjects and Methods] We enrolled 20 patients and divided them into CACR and rTMS groups. CACR and rTMS were performed thrice a week for 4 weeks. Cognitive function was measured with the Korean Mini-Mental State Examination (K-MMSE) and Lowenstein Occupational Therapy Cognitive Assessment-Geriatric (LOTCA-G) before and after treatment. The independent samples t-test was performed to test the homogeneity of K-MMSE and LOTCA-G before treatment and compare the differences in cognitive improvement between the CACR and rTMS groups. A paired samples t-test was used to compare cognitive function before and after treatment. [Results] Cognitive function of both the groups significantly improved after the intervention based on the K-MMSE and LOTCA-G scores. While the LOTCA-G score improved significantly more in the CACR group than in the rTMS group, no significant difference was seen in the K-MMSE scores. [Conclusion] We showed that CACR is more effective than rTMS in improving cognitive function after stroke.

  4. Nuclear Magnetic Resonance-Assisted Prediction of Secondary Structure for RNA: Incorporation of Direction-Dependent Chemical Shift Constraints.

    PubMed

    Chen, Jonathan L; Bellaousov, Stanislav; Tubbs, Jason D; Kennedy, Scott D; Lopez, Michael J; Mathews, David H; Turner, Douglas H

    2015-11-17

    Knowledge of RNA structure is necessary to determine structure-function relationships and to facilitate design of potential therapeutics. RNA secondary structure prediction can be improved by applying constraints from nuclear magnetic resonance (NMR) experiments to a dynamic programming algorithm. Imino proton walks from NOESY spectra reveal double-stranded regions. Chemical shifts of protons in GH1, UH3, and UH5 of GU pairs, UH3, UH5, and AH2 of AU pairs, and GH1 of GC pairs were analyzed to identify constraints for the 5' to 3' directionality of base pairs in helices. The 5' to 3' directionality constraints were incorporated into an NMR-assisted prediction of secondary structure (NAPSS-CS) program. When it was tested on 18 structures, including nine pseudoknots, the sensitivity and positive predictive value were improved relative to those of three unrestrained programs. The prediction accuracy for the pseudoknots improved the most. The program also facilitates assignment of chemical shifts to individual nucleotides, a necessary step for determining three-dimensional structure.

  5. Generation of Aptamers from A Primer-Free Randomized ssDNA Library Using Magnetic-Assisted Rapid Aptamer Selection

    PubMed Central

    Tsao, Shih-Ming; Lai, Ji-Ching; Horng, Horng-Er; Liu, Tu-Chen; Hong, Chin-Yih

    2017-01-01

    Aptamers are oligonucleotides that can bind to specific target molecules. Most aptamers are generated using random libraries in the standard systematic evolution of ligands by exponential enrichment (SELEX). Each random library contains oligonucleotides with a randomized central region and two fixed primer regions at both ends. The fixed primer regions are necessary for amplifying target-bound sequences by PCR. However, these extra-sequences may cause non-specific bindings, which potentially interfere with good binding for random sequences. The Magnetic-Assisted Rapid Aptamer Selection (MARAS) is a newly developed protocol for generating single-strand DNA aptamers. No repeat selection cycle is required in the protocol. This study proposes and demonstrates a method to isolate aptamers for C-reactive proteins (CRP) from a randomized ssDNA library containing no fixed sequences at 5′ and 3′ termini using the MARAS platform. Furthermore, the isolated primer-free aptamer was sequenced and binding affinity for CRP was analyzed. The specificity of the obtained aptamer was validated using blind serum samples. The result was consistent with monoclonal antibody-based nephelometry analysis, which indicated that a primer-free aptamer has high specificity toward targets. MARAS is a feasible platform for efficiently generating primer-free aptamers for clinical diagnoses. PMID:28367958

  6. The Launch Systems Operations Cost Model

    NASA Technical Reports Server (NTRS)

    Prince, Frank A.; Hamaker, Joseph W. (Technical Monitor)

    2001-01-01

    One of NASA's primary missions is to reduce the cost of access to space while simultaneously increasing safety. A key component, and one of the least understood, is the recurring operations and support cost for reusable launch systems. In order to predict these costs, NASA, under the leadership of the Independent Program Assessment Office (IPAO), has commissioned the development of a Launch Systems Operations Cost Model (LSOCM). LSOCM is a tool to predict the operations & support (O&S) cost of new and modified reusable (and partially reusable) launch systems. The requirements are to predict the non-recurring cost for the ground infrastructure and the recurring cost of maintaining that infrastructure, performing vehicle logistics, and performing the O&S actions to return the vehicle to flight. In addition, the model must estimate the time required to cycle the vehicle through all of the ground processing activities. The current version of LSOCM is an amalgamation of existing tools, leveraging our understanding of shuttle operations cost with a means of predicting how the maintenance burden will change as the vehicle becomes more aircraft like. The use of the Conceptual Operations Manpower Estimating Tool/Operations Cost Model (COMET/OCM) provides a solid point of departure based on shuttle and expendable launch vehicle (ELV) experience. The incorporation of the Reliability and Maintainability Analysis Tool (RMAT) as expressed by a set of response surface model equations gives a method for estimating how changing launch system characteristics affects cost and cycle time as compared to today's shuttle system. Plans are being made to improve the model. The development team will be spending the next few months devising a structured methodology that will enable verified and validated algorithms to give accurate cost estimates. To assist in this endeavor the LSOCM team is part of an Agency wide effort to combine resources with other cost and operations professionals to

  7. The Launch of an Atlas/Centaur Launch Vehicle

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The launch of an Atlas/Centaur launch vehicle is shown in this photograph. The Atlas/Centaur, launched on November 13, 1978, carried the High Energy Astronomy Observatory (HEAO)-2 into the required orbit. The second observatory, the HEAO-2 (nicknamed the Einstein Observatory in honor of the centernial of the birth of Albert Einstein) carried the first telescope capable of producing actual photographs of x-ray objects.

  8. KSC Vertical Launch Site Evaluation

    NASA Technical Reports Server (NTRS)

    Phillips, Lynne V.

    2007-01-01

    RS&H was tasked to evaluate the potential available launch sites for a combined two user launch pad. The Launch sites were to be contained entirely within current Kennedy Space Center property lines. The user launch vehicles to be used for evaluation are in the one million pounds of first stage thrust range. Additionally a second evaluation criterion was added early on in the study. A single user launch site was to be evaluated for a two million pound first stage thrust vehicle. Both scenarios were to be included in the report. To provide fidelity to the study criteria, a specific launch vehicle in the one million pound thrust range was chosen as a guide post or straw-man launch vehicle. The RpK K-1 vehicle is a current Commercial Orbital Transportation System (COTS), contract awardee along with the SpaceX Falcon 9 vehicle. SpaceX, at the time of writing, is planning to launch COTS and possibly other payloads from Cx-40 on Cape Canaveral Air Force Station property. RpK has yet to declare a specific launch site as their east coast US launch location. As such it was deemed appropriate that RpK's vehicle requirements be used as conceptual criteria. For the purposes of this study those criteria were marginally generalized to make them less specifiC.

  9. STS-92 Discovery Launch

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Viewed from across the waters of Banana Creek, clouds of smoke and steam are illuminated by the flames from Space Shuttle Discovery'''s perfect on-time launch at 7:17 p.m. EDT. Discovery carries a crew of seven on a construction flight to the International Space Station. Discovery also carries a payload that includes the Integrated Truss Structure Z-1, first of 10 trusses that will form the backbone of the Space Station, and the third Pressurized Mating Adapter that will provide a Shuttle docking port for solar array installation on the sixth Station flight and Lab installation on the seventh Station flight. Discovery'''s landing is expected Oct. 22 at 2:10 p.m. EDT.

  10. STS-120 Launch

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The Space Shuttle Discovery and its seven-member STS-120 crew headed toward Earth-orbit and a scheduled linkup with the International Space Station (ISS). Liftoff from Kennedy Space Center's launch pad 39A occurred at 11:38:19 a.m. (EDT) on October 23, 2007. Onboard were astronauts Pam Melroy, commander; George Zamka, pilot; Scott Parazynski, Stephanie Wilson, Doug Wheelock, European Space Agency's (ESA) Paolo Nespoli and Daniel Tani, all mission specialists. Discovery linked up with the station for a joint mission of continued construction, The mission delivered the Italian-built U.S. Node 2, named Harmony. During the 14-day mission, the crew installed Harmony, and moved and deployed the P6 solar arrays to their permanent position.

  11. STS-120 Launch

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The Space Shuttle Discovery and its seven-member STS-120 crew headed toward Earth-orbit and a scheduled linkup with the International Space Station (ISS). Liftoff from Kennedy Space Center's launch pad 39A occurred at 11:38:19 a.m. (EDT) on October 23, 2007. Onboard were astronauts Pam Melroy, commander; George Zamka, pilot; Scott Parazynski, Stephanie Wilson, Doug Wheelock, European Space Agency's (ESA) Paolo Nespoli, and Daniel Tani, all mission specialists. Discovery linked up with the station for a joint mission of continued construction. The mission delivered the Italian-built U.S. Node 2, named Harmony. During the 14-day mission, the crew installed Harmony, and moved and deployed the P6 solar arrays to their permanent position.

  12. STS-120 Launch

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The Space Shuttle Discovery and its seven-member STS-120 crew headed toward Earth-orbit and a scheduled linkup with the International Space Station (ISS). Liftoff from Kennedy Space Center's launch pad 39A occurred at 11:38:19 a.m. (EDT) on October 23, 2007. Onboard were astronauts Pam Melroy, commander; George Zamka, pilot; Scott Parazynski, Stephanie Wilson, Doug Wheelock, European Space Agency's (ESA) Paolo Nespoli and Daniel Tani, all mission specialists. Discovery linked up with the station for a joint mission of continued construction. The mission delivered the Italian-built U.S. Node 2, named Harmony. During the 14-day mission, the crew installed Harmony, moved and deployed the P6 solar arrays to their permanent position.

  13. STS-112 Launch

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Space Shuttle Orbiter Atlantis hurdles toward space from Launch Pad 39B at Kennedy Space Center in Florida for the STS-112 mission. Liftoff occurred at 3:46pm EDT, October 7, 2002. Atlantis carried the Starboard-1 (S1) Integrated Truss Structure and the Crew and Equipment Translation Aid (CETA) Cart A. The S1 was the second truss structure installed on the International Space Station (ISS). It was attached to the S0 truss which was previously installed by the STS-110 mission. The CETA is the first of two human-powered carts that ride along the ISS railway, providing mobile work platforms for future space walking astronauts. The 11 day mission performed three space walks to attach the S1 truss.

  14. Payload Launch Lock Mechanism

    NASA Technical Reports Server (NTRS)

    Young, Ken (Inventor); Hindle, Timothy (Inventor)

    2014-01-01

    A payload launch lock mechanism includes a base, a preload clamp, a fastener, and a shape memory alloy (SMA) actuator. The preload clamp is configured to releasibly restrain a payload. The fastener extends, along an axis, through the preload clamp and into the base, and supplies a force to the preload clamp sufficient to restrain the payload. The SMA actuator is disposed between the base and the clamp. The SMA actuator is adapted to receive electrical current and is configured, upon receipt of the electrical current, to supply a force that causes the fastener to elongate without fracturing. The preload clamp, in response to the fastener elongation, either rotates or pivots to thereby release the payload.

  15. Personnel Launch System definition

    NASA Astrophysics Data System (ADS)

    Piland, William M.; Talay, Theodore A.; Stone, Howard W.

    1990-10-01

    A lifting-body Personnel Launch System (PLS) is defined for assured manned access to space for future U.S. space missions. The reusable craft described is configured for reliable and safe operations, maintainability, affordability, and improved operability, and could reduce life-cycle costs associated with placing personnel into orbit. Flight simulations show the PLS to be a very flyable vehicle with very little control and propellant expenditure required during entry. The attention to crew safety has resulted in the design of a system that provides protection for the crew throughout the mission profile. However, a new operations philosophy for manned space vehicles must be adopted to fully achieve low-cost, manned earth-to-orbit transportation.

  16. Personnel Launch System definition

    NASA Technical Reports Server (NTRS)

    Piland, William M.; Talay, Theodore A.; Stone, Howard W.

    1990-01-01

    A lifting-body Personnel Launch System (PLS) is defined for assured manned access to space for future U.S. space missions. The reusable craft described is configured for reliable and safe operations, maintainability, affordability, and improved operability, and could reduce life-cycle costs associated with placing personnel into orbit. Flight simulations show the PLS to be a very flyable vehicle with very little control and propellant expenditure required during entry. The attention to crew safety has resulted in the design of a system that provides protection for the crew throughout the mission profile. However, a new operations philosophy for manned space vehicles must be adopted to fully achieve low-cost, manned earth-to-orbit transportation.

  17. Launch of Russian reactor postponed

    SciTech Connect

    Not Available

    1993-02-05

    Astronomers and weapons scientists seemed heated on a collision course a few months ago over the military's plans to send a Russian nuclear reactor into space. But an agreement reached in late January has prevented a pile-up, at least for 6 months. The astronomers, led by Donald Lamb of the University of Chicago, were objecting to plans by the Strategic Defense Initiative Office (SDIO) to launch Topaz 2, an experimental Russian nuclear reactor, arguing that rogue particles from it might ruin sensitive gamma ray experiments. The reactor is designed to propel itself in space with a jet of xenon ions. One worry was that leaking gamma rays and positrons, which can travel in the earth's magnetic field and pop up in the darndest places, might cause false signals in gamma ray monitors (Science, 18 December 1992, p. 1878). The worry has abated now that SDI officials will postpone choosing a rocket and mission altitutde for Topaz 2 for 6 months, while experts study how its emissions at various altitudes might affect instruments aboard the Gamma Ray Observatory and other satellites. In effect, the SDIO has agreed to an environmental impact study for space, following an unusual meeting organized by former Russian space official Roald Sagdeev at the University of Maryland on 19 January. There the Russian designers of Topaz 2, its new owners at the SDIO, and critics in the astronomy community achieved common ground: that more study was needed.

  18. Launch area theodolite system

    NASA Astrophysics Data System (ADS)

    Bradley, Lester M.; Corriveau, John P.; Tindal, Nan E.

    1991-08-01

    White Sands Missile Range has developed a Launch Area Theodolite (LAT) optical tracking system that provides improved Time-Space-Position-Information (TSPI) for the new class of hyper-velocity missiles being developed by the Army. The LAT system consists of a high- performance optical tracking mount equipped with an 8-12 micrometers Forward Looking Infrared (FLIR) sensor, a newly designed full-frame pin-registered 35-mm film camera, and an auto- focused 50-in. focal length lens. The FLIR has been integrated with the WSMR in-house developed statistical based automatic video tracker to yield a powerful system for the automatic tracking of missiles from a short standoff distance. The LAT has been designed to replace large fixed-camera arrays for test programs on short-range anti-tank missiles. New tracking techniques have been developed to deal with angular tracking rates that exceed one radian in both velocity and acceleration. Special techniques have been developed to shock the tracking mount at the missile launch to match the target motion. An adaptive servo control technique allows a Type III servo to be used to compensate for the high angular accelerations that are generated by the placement of the LAT mounts along the missile flight path. An automated mode selection adjustment is employed as the missile passes a point perpendicular to the tracking mount to compensate for the requirement to rapidly decelerate the tracking mount and keep the target in the field-of-view of the data camera. This paper covers the design concept for a network of eight LAT mounts, the techniques of automatic video tracking using a FLIR sensor, and the architecture of the servo control algorithms that have allowed the LAT system to produce results to a degree never before achieved at White Sands Missile Range.

  19. NASA to launch second business communications satellite

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The two stage Delta 3910 launch vehicle was chosen to place the second small business satellite (SBS-B) into a transfer orbit with an apogee of 36,619 kilometers and a perigee of 167 km, at an inclination of 27.7 degrees to Earth's equator. The firing and separation sequence and the inertial guidance system are described as well as the payload assist module. Facilities and services for tracking and control by NASA, COMSAT, Intelsat, and SBS are outlined and prelaunch operations are summarized.

  20. FePt : Al2O3 nanocomposite thin films synthesized by magnetic trapping assisted pulsed laser deposition with reduced intergranular exchange coupling

    NASA Astrophysics Data System (ADS)

    Lin, J. J.; Pan, Z. Y.; Karamat, S.; Mahmood, S.; Lee, P.; Tan, T. L.; Springham, S. V.; Rawat, R. S.

    2008-05-01

    FePt : Al2O3 nanocomposite thin films synthesized by magnetic trapping (MT) assisted pulsed laser deposition (PLD) were found to have lower transition temperature for L10 face-centred-tetragonal (fct) phase due to higher concentration of defects. The low phase transition temperature together with non-magnetic matrix materials helps to reduce grain growth and agglomeration during annealing. Small remanence ratio and coercive squareness for nanocomposite thin films annealed at 300 °C to fct phase confirm that the main intergranular interaction is magnetostatic interaction rather than exchange coupling. The MT assisted PLD can synthesize fct-FePt : Al2O3 nanocomposite thin films with reduced intergranular exchange coupling.

  1. Advanced small launch vehicle study

    NASA Technical Reports Server (NTRS)

    Reins, G. E.; Alvis, J. F.

    1972-01-01

    A conceptual design study was conducted to determine the most economical (lowest cost/launch) approach for the development of an advanced small launch vehicle (ASLV) for use over the next decade. The ASLV design objective was to place a 340 kg (750 lb) payload into a 556 km (300 n.mi.) circular orbit when launched due east from Wallops Island, Virginia. The investigation encompassed improvements to the current Scout launch vehicle; use of existing military and NASA launch vehicle stages; and new, optionally staged vehicles. Staging analyses included use of liquid, solid, and hybrid propellants. Improvements in guidance, controls, interstages, telemetry, and payload shroud were also considered. It was concluded that the most economical approach is to progressively improve the Scout launch vehicle in three phased steps which are discussed.

  2. 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

    Lutdka, G. M.; Chourey, A.

    2010-05-12

    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.

  3. Launch Processing System operations with a future look to Operations Analyst (OPERA)

    NASA Technical Reports Server (NTRS)

    Heard, Astrid E.

    1987-01-01

    The Launch Processing System architecture and the ground support operations required to provide Shuttle System engineers with the capability to safely process and launch an Orbiter are described. The described ground operations are the culmination of eleven years of experience and redesign. Some of the 'lessons learned' are examined, and problem areas which ground support operations have identified over the years as the Shuttle and Launch Processing Systems continue to grow in complexity are discussed. The Operational Analyst for Distributed Systems (OPERA), a proposed set of expert systems for the Launch Processing System Operational assistance, is discussed along with its extensions to prospective future configurations and components for the Launch Processing System.

  4. Peer Review of Launch Environments

    NASA Technical Reports Server (NTRS)

    Wilson, Timmy R.

    2011-01-01

    Catastrophic failures of launch vehicles during launch and ascent are currently modeled using equivalent trinitrotoluene (TNT) estimates. This approach tends to over-predict the blast effect with subsequent impact to launch vehicle and crew escape requirements. Bangham Engineering, located in Huntsville, Alabama, assembled a less-conservative model based on historical failure and test data coupled with physical models and estimates. This white paper summarizes NESC's peer review of the Bangham analytical work completed to date.

  5. Launch of STS-63 Discovery

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This wide lux image of the Space Shuttle Discovery as it began its race to catch up with Russia's Mir Space Station shows the base of the launch pad as well as the orbiter just clearing the gantry. Liftoff from Launch Pad 39B, Kennedy Space Center (KSC) occurred at 12:22:04 (EST) February 3, 1995. Discovery is the first in the current fleet of four space shuttle vehicles to make 20 launches.

  6. Launch of STS-63 Discovery

    NASA Technical Reports Server (NTRS)

    1995-01-01

    A 35mm camera was used to expose this image of the Space Shuttle Discovery as it began its race to catch up with Russia's Mir Space Station. Liftoff from Launch Pad 39B, Kennedy Space Center (KSC) occurred at 12:22:04 (EST) February 3, 1995. Discovery is the first in the current fleet of four space shuttle vehicles to make 20 launches. The launch pad and orbiter can be seen reflected in the water directly in front of it.

  7. Launch of STS-63 Discovery

    NASA Technical Reports Server (NTRS)

    1995-01-01

    A 70mm camera was used to expose this image of the Space Shuttle Discovery as it began its race to catch up with Russia's Mir Space Station. Liftoff from Launch Pad 39B, Kennedy Space Center (KSC) occurred at 12:22:04 (EST) February 3, 1995. Discovery is the first in the current fleet of four space shuttle vehicles to make 20 launches. The launch pad and orbiter can be seen reflected in the water directly in front of it.

  8. 14 CFR 415.121 - Launch schedule.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Launch schedule. 415.121 Section 415.121... TRANSPORTATION LICENSING LAUNCH LICENSE Safety Review and Approval for Launch of an Expendable Launch Vehicle From a Non-Federal Launch Site § 415.121 Launch schedule. An applicant's safety review document...

  9. 14 CFR 415.121 - Launch schedule.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Launch schedule. 415.121 Section 415.121... TRANSPORTATION LICENSING LAUNCH LICENSE Safety Review and Approval for Launch of an Expendable Launch Vehicle From a Non-Federal Launch Site § 415.121 Launch schedule. An applicant's safety review document...

  10. Rocket Launch Trajectory Simulations Mechanism

    NASA Technical Reports Server (NTRS)

    Margasahayam, Ravi; Caimi, Raoul E.; Hauss, Sharon; Voska, N. (Technical Monitor)

    2002-01-01

    The design and development of a Trajectory Simulation Mechanism (TSM) for the Launch Systems Testbed (LST) is outlined. In addition to being one-of-a-kind facility in the world, TSM serves as a platform to study the interaction of rocket launch-induced environments and subsequent dynamic effects on the equipment and structures in the close vicinity of the launch pad. For the first time, researchers and academicians alike will be able to perform tests in a laboratory environment and assess the impact of vibroacoustic behavior of structures in a moving rocket scenario on ground equipment, launch vehicle, and its valuable payload or spacecraft.

  11. The Titan Space Launch System

    NASA Astrophysics Data System (ADS)

    Keeley, J. T.

    1981-04-01

    The Titan III Space Launch Vehicle (SLV) System providing reliable fast response booster capability is discussed. Early Titans, including Titans I and II and the Gemini launch vehicle are described, and the elements of the Titan III, including the upper stages, payload fairings, and launch facilities are presented. The liquid boost module for STS performance augmentation and the Titan 34D SLV System are also discussed. The Titan III SLV System demonstrates excellent versatility while maintaining a high reliability record during thirteen years of operational flights, and provides optional use of solid thrust augmentation and launch sites on both Coasts.

  12. Influence of cooling rate in planar thermally assisted magnetic random access memory: Improved writeability due to spin-transfer-torque influence

    SciTech Connect

    Chavent, A.; Ducruet, C.; Portemont, C.; Creuzet, C.; Alvarez-Hérault, J.; Vila, L.; Sousa, R. C.; Prejbeanu, I. L.; Dieny, B.

    2015-09-14

    This paper investigates the effect of a controlled cooling rate on magnetic field reversal assisted by spin transfer torque (STT) in thermally assisted magnetic random access memory. By using a gradual linear decrease of the voltage at the end of the write pulse, the STT decays more slowly or at least at the same rate as the temperature. This condition is necessary to make sure that the storage layer magnetization remains in the desired written direction during cooling of the cell. The influence of the write current pulse decay rate was investigated on two exchange biased synthetic ferrimagnet (SyF) electrodes. For a NiFe based electrode, a significant improvement in writing reproducibility was observed using a gradual linear voltage transition. The write error rate decreases by a factor of 10 when increasing the write pulse fall-time from ∼3 ns to 70 ns. For comparison, a second CoFe/NiFe based electrode was also reversed by magnetic field assisted by STT. In this case, no difference between sharp and linear write pulse fall shape was observed. We attribute this observation to the higher thermal stability of the CoFe/NiFe electrode during cooling. In real-time measurements of the magnetization reversal, it was found that Ruderman-Kittel-Kasuya-Yosida (RKKY) coupling in the SyF electrode vanishes for the highest pulse voltages that were used due to the high temperature reached during write. As a result, during the cooling phase, the final state is reached through a spin-flop transition of the SyF storage layer.

  13. Launched electrons in plasma opening switches

    NASA Astrophysics Data System (ADS)

    Mendel, C. W., Jr.; Rochau, G. E.; Sweeney, M. A.; McDaniel, D. H.; Quintenz, J. P.; Savage, M. E.; Lindman, E. L.; Kindel, J. M.

    Plasma opening switches have provided a means to improve the characteristics of super-power pulse generators. Recent advances involving plasma control with fast and slow magnetic fields have made these switches more versatile, allowing for improved switch uniformity, triggering, and opening current levels that are set by the level of auxiliary fields. Such switches necessarily involve breaks in the translational symmetry of the transmission line geometry and therefore affect the electron flow characteristics of the line. These symmetry breaks are the result of high electric field regions caused by plasma conductors remaining in the transmission line, ion beams crossing the line, or auxilliary magnetic field regions. Symmetry breaks cause the canonical momentum of the electrons to change, thereby moving them away from the cathode. Additional electrons are pulled from the cathode into the magnetically insulated flow, resulting in an excess of electron flow over that expected for the voltage and line current downstream of the switch. These electrons are called launched electrons. Unless they are recaptured at the cathode or else are fed into the load and used beneficially, they cause a large power loss downstream. Examples are shown of SuperMite and PBFA II data showing these losses, the tools used to study them are explained, and the mechanisms employed to mitigate the problem are discussed. The losses will be reduced primarily by reducing the amount of launched electron flow.

  14. Launch Vehicle Assessment for Space Solar Power

    NASA Technical Reports Server (NTRS)

    Olds, John R.

    1998-01-01

    A recently completed study at Georgia Tech examined various launch vehicle options for deploying a future constellation of Space Solar Power satellites of the Suntower configuration. One of the motivations of the study was to determine whether the aggressive $400/kg launch price goal established for SSP package delivery would result in an attractive economic scenario for a future RLV developer. That is, would the potential revenue and traffic to be derived from a large scale SSP project be enough of an economic "carrot" to attract an RLV company into developing a new, low cost launch vehicle to address this market. Preliminary results presented in the attached charts show that there is enough economic reward for RLV developers, specifically in the case of the latest large GEO-based Suntower constellations (over 15,500 MT per year delivery for 30 years). For that SSP model, internal rates of return for the 30 year economic scenario exceed 22%. However, up-front government assistance to the RLV developer in terms of ground facilities, operations technologies, guaranteed low-interest rate loans, and partial offsets of some vehicle development expenses is necessary to achieve these positive results. This white paper is meant to serve as a companion to the data supplied in the accompanying charts. It's purpose is to provide more detail on the vehicles and design processes used, to highlight key decisions and issues, and to emphasize key results from each phase of the Georgia Tech study.

  15. Launch Support Video Site

    NASA Technical Reports Server (NTRS)

    OFarrell, Zachary L.

    2013-01-01

    The goal of this project is to create a website that displays video, countdown clock, and event times to customers during launches, without needing to be connected to the internal operations network. The requirements of this project are to also minimize the delay in the clock and events to be less than two seconds. The two parts of this are the webpage, which will display the data and videos to the user, and a server to send clock and event data to the webpage. The webpage is written in HTML with CSS and JavaScript. The JavaScript is responsible for connecting to the server, receiving new clock data, and updating the webpage. JavaScript is used for this because it can send custom HTTP requests from the webpage, and provides the ability to update parts of the webpage without having to refresh the entire page. The server application will act as a relay between the operations network, and the open internet. On the operations network side, the application receives multicast packets that contain countdown clock and events data. It will then parse the data into current countdown times and events, and create a packet with that information that can be sent to webpages. The other part will accept HTTP requests from the webpage, and respond to them with current data. The server is written in C# with some C++ files used to define the structure of data packets. The videos for the webpage will be shown in an embedded player from UStream.

  16. Development and evaluation of an algorithm for the computer-assisted segmentation of the human hypothalamus on 7-Tesla magnetic resonance images.

    PubMed

    Schindler, Stephanie; Schönknecht, Peter; Schmidt, Laura; Anwander, Alfred; Strauß, Maria; Trampel, Robert; Bazin, Pierre-Louis; Möller, Harald E; Hegerl, Ulrich; Turner, Robert; Geyer, Stefan

    2013-01-01

    Post mortem studies have shown volume changes of the hypothalamus in psychiatric patients. With 7T magnetic resonance imaging this effect can now be investigated in vivo in detail. To benefit from the sub-millimeter resolution requires an improved segmentation procedure. The traditional anatomical landmarks of the hypothalamus were refined using 7T T1-weighted magnetic resonance images. A detailed segmentation algorithm (unilateral hypothalamus) was developed for colour-coded, histogram-matched images, and evaluated in a sample of 10 subjects. Test-retest and inter-rater reliabilities were estimated in terms of intraclass-correlation coefficients (ICC) and Dice's coefficient (DC). The computer-assisted segmentation algorithm ensured test-retest reliabilities of ICC≥.97 (DC≥96.8) and inter-rater reliabilities of ICC≥.94 (DC = 95.2). There were no significant volume differences between the segmentation runs, raters, and hemispheres. The estimated volumes of the hypothalamus lie within the range of previous histological and neuroimaging results. We present a computer-assisted algorithm for the manual segmentation of the human hypothalamus using T1-weighted 7T magnetic resonance imaging. Providing very high test-retest and inter-rater reliabilities, it outperforms former procedures established at 1.5T and 3T magnetic resonance images and thus can serve as a gold standard for future automated procedures.

  17. Initial Experience with Magnetic Resonance-Guided Vacuum-Assisted Biopsy in Korean Women with Breast Cancer

    PubMed Central

    Jung, Hye Na; Ko, Eun Young; Shin, Jung Hee

    2014-01-01

    Purpose The aim of this study is to describe our initial experience with magnetic resonance (MR)-guided biopsy and to determine the malignancy rate of additional lesions identified by MR only in Korean women with breast cancer. Methods A retrospective review identified 22 consecutive patients with breast cancer who had undergone MR-guided vacuum-assisted biopsies (VAB) of MR-only identified lesions from May 2009 to October 2011.We evaluated the rate of compliance, the technical success for MR-guided VAB and the MR imaging findings of the target lesions. VAB histology was compared with surgical histology and follow-up imaging findings. Results The biopsy recommendations for MR-only identified lesions were accepted in 46.8% (22/47) of patients. One of 22 procedures failed due to the target's posterior location. Among 21 MR-guided VAB procedures, the target lesions were considered as a mass in 12 cases and a nonmass enhancement in nine cases. VAB histology revealed malignancies in 14% (3/21) of cases, high-risk lesions in 24% (5/21) and benign lesions in 62% (13/21). Eleven cases (52%, 11/21) had a positive surgical correlation, and one of them was upgraded from atypical ductal hyperplasia to invasive ductal carcinoma. In the remaining 10 lesions, follow-up breast ultrasound and mammography were available (range, 15-44 months; mean, 32.1 months) and did not show suspicious lesions. The final malignancy rate was 19% (4/21). Conclusion MR-guided VAB for MR-only identified lesions yielded a 19% malignancy rate in Korean women with breast cancer. MR-guided VAB helps surgeons avoid an unnecessary wide excision or additional excisional biopsy. PMID:25320626

  18. Outcome Analysis of 9-Gauge Magnetic Resonance Imaging-Guided Vacuum-Assisted Core Needle Breast Biopsies

    PubMed Central

    Rauch, Gaiane M.; Dogan, Basak E.; Smith, Taletha B.; Liu, Ping; Yang, Wei T.

    2014-01-01

    Purpose To correlate 9-gauge Magnetic Resonance imaging-guided Vacuum-Assisted breast Biopsy (MRVAB) with surgical histology to determine the upgrade rate and to correlate the frequency of MRVAB cancer diagnosis with breast MRI indications and enhancement characteristics of targeted lesions. Materials and Methods The HIPAA compliant study was approved by the institutional review board. A database search was performed of all MRVABs performed from January 1, 2005 to September 31, 2010. The breast MRI indications, history, age, risk factors, lesion size, enhancement characteristics, pathology at MRVAB and at surgery were documented. Fisher's exact test and Analysis of Variance were used for statistical analysis. Results A total of 218 lesions underwent MRVAB in 197 women (mean age 52 years, range 28 - 76 years), of which 85 (39%) had surgical correlation. (R1, #3) There were 48/218 (22%) malignant, 133/218 (61%) benign, and 37/218 (17%) high-risk lesions at MRVAB. Ten (12%) of 85 lesions were upgraded to malignancy at surgery, with a final malignancy rate of 25%. The frequency of malignancy was significantly higher in patients presenting for diagnostic (50/177, 28%) versus screening (4/41, 10%, P<0.05) evaluation, patients with ipsilateral cancer (22/49, 45%, P<0.001), lesions with washout kinetics (34/103, 33%, P < 0.05); and relatively higher in lesions with non-mass-like enhancement (26/76, 34%, P=0.07), which represented ductal carcinoma in situ in the majority (17/26, 65%, P<0.005). Conclusion Patients with ipsilateral cancer who have additional suspicious lesions identified on MRI require careful evaluation and biopsy to exclude additional sites of cancer that may impact surgical management. PMID:22268171

  19. Adsorption of Cu2+ ions using chitosan-modified magnetic Mn ferrite nanoparticles synthesized by microwave-assisted hydrothermal method

    NASA Astrophysics Data System (ADS)

    Meng, Yuying; Chen, Deyang; Sun, Yitao; Jiao, Dongling; Zeng, Dechang; Liu, Zhongwu

    2015-01-01

    Chitosan-modified Mn ferrite nanoparticles were synthesized by a one-step microwave-assisted hydrothermal method. These Mn ferrite magnetic composite nanoparticles were employed to absorb Cu2+ ions in water. XRD verified the spinel structure of the MnFe2O4 nanoparticles. Chitosan modification does not result in any phase change of MnFe2O4. FTIR and zeta potentials curves for all samples suggest that chitosan can be successfully coated on the Mn ferrites. TEM characterization showed that the modified MnFe2O4 nanoparticles have a cubic shape with a mean diameter of ∼100 nm. For adsorption behavior, the effects of experiment parameters such as solution pH value, contact time and initial Cu2+ ions concentration on the adsorption efficiency were systematically investigated. The results showed that increasing solution pH value and extending contact time are favorable for improving adsorption efficiency. Especially, adsorption efficiency can reach up to 100% and 96.7% after 500 min adsorption at pH 6.5 for the solutions with initial Cu2+ ions concentration of 50 mg/L and 100 mg/L. Adsorption data fits well with the Langmuir isotherm models with a maximum adsorption capacity (qm) and a Langmuir adsorption equilibrium constant (K) of 65.1 mg/g and 0.090 L/mg, respectively. The adsorption kinetic agrees well with pseudo second order model with the pseudo second rate constants (K2) of 0.0468 and 0.00189 g/mg/min for solutions with initial Cu2+ ions of 50 and 100 mg/L, respectively.

  20. Synthesis of Bifunctional Fe3O4@SiO2-Ag Magnetic-Plasmonic Nanoparticles by an Ultrasound Assisted Chemical Method

    NASA Astrophysics Data System (ADS)

    Chu, Dung Tien; Sai, Doanh Cong; Luu, Quynh Manh; Tran, Hong Thi; Quach, Truong Duy; Kim, Dong Hyun; Nguyen, Nam Hoang

    2017-03-01

    Bifunctional magnetic-plasmonic nanoparticles (NPs)—Fe3O4@SiO2-Ag were successfully synthesized by an ultrasound assisted chemical method. Silver ions were absorbed and then reduced by sodium borohydride on the surface of 3-aminopropyltriethoxysilane (APTES) functionalized silica-coated magnetic NPs, then they were reduced under the influence of a 200 W ultrasonic wave for 60 min. When the amount of precursor silver ions increased, the relative intensity of diffraction peaks of silver crystals in all samples increased with the atomic ratio of silver/iron increasing from 0.208 to 0.455 and saturation magnetization (M s) decreasing from 44.68 emu/g to 34.74 emu/g. The NPs have superparamagnetic properties and strong surface plasmon absorption at 420 nm, which make these particles promising for biomedical applications.

  1. Refinement and growth enhancement of Al2Cu phase during magnetic field assisting directional solidification of hypereutectic Al-Cu alloy

    PubMed Central

    Wang, Jiang; Yue, Sheng; Fautrelle, Yves; Lee, Peter D.; Li, Xi; Zhong, Yunbo; Ren, Zhongming

    2016-01-01

    Understanding how the magnetic fields affect the formation of reinforced phase during solidification is crucial to tailor the structure and therefor the performance of metal matrix in situ composites. In this study, a hypereutectic Al-40 wt.%Cu alloy has been directionally solidified under various axial magnetic fields and the morphology of Al2Cu phase was quantified in 3D by means of high resolution synchrotron X-ray tomography. With rising magnetic fields, both increase of Al2Cu phase’s total volume and decrease of each column’s transverse section area were found. These results respectively indicate the growth enhancement and refinement of the primary Al2Cu phase in the magnetic field assisting directional solidification. The thermoelectric magnetic forces (TEMF) causing torque and dislocation multiplication in the faceted primary phases were thought dedicate to respectively the refinement and growth enhancement. To verify this, a real structure based 3D simulation of TEMF in Al2Cu column was carried out, and the dislocations in the Al2Cu phase obtained without and with a 10T high magnetic field were analysed by the transmission electron microscope. PMID:27091383

  2. Refinement and growth enhancement of Al2Cu phase during magnetic field assisting directional solidification of hypereutectic Al-Cu alloy

    NASA Astrophysics Data System (ADS)

    Wang, Jiang; Yue, Sheng; Fautrelle, Yves; Lee, Peter D.; Li, Xi; Zhong, Yunbo; Ren, Zhongming

    2016-04-01

    Understanding how the magnetic fields affect the formation of reinforced phase during solidification is crucial to tailor the structure and therefor the performance of metal matrix in situ composites. In this study, a hypereutectic Al-40 wt.%Cu alloy has been directionally solidified under various axial magnetic fields and the morphology of Al2Cu phase was quantified in 3D by means of high resolution synchrotron X-ray tomography. With rising magnetic fields, both increase of Al2Cu phase’s total volume and decrease of each column’s transverse section area were found. These results respectively indicate the growth enhancement and refinement of the primary Al2Cu phase in the magnetic field assisting directional solidification. The thermoelectric magnetic forces (TEMF) causing torque and dislocation multiplication in the faceted primary phases were thought dedicate to respectively the refinement and growth enhancement. To verify this, a real structure based 3D simulation of TEMF in Al2Cu column was carried out, and the dislocations in the Al2Cu phase obtained without and with a 10T high magnetic field were analysed by the transmission electron microscope.

  3. Launch Vehicle Dynamics Demonstrator Model

    NASA Technical Reports Server (NTRS)

    1963-01-01

    Launch Vehicle Dynamics Demonstrator Model. The effect of vibration on launch vehicle dynamics was studied. Conditions included three modes of instability. The film includes close up views of the simulator fuel tank with and without stability control. [Entire movie available on DVD from CASI as Doc ID 20070030984. Contact help@sti.nasa.gov

  4. Commercial expendable launch vehicle liability

    NASA Astrophysics Data System (ADS)

    Hearings before a subcommittee of the House Committee on Commerce, Science, and Transportation are presented. Cost and availability of insurance for commercial launch providers was discussed. The contribution of the domestic launch industry to the Space Program is examined. All written testimony and submittals for the record are also included.

  5. Small Space Launch: Origins & Challenges

    NASA Astrophysics Data System (ADS)

    Freeman, T.; Delarosa, J.

    2010-09-01

    The United States Space Situational Awareness capability continues to be a key element in obtaining and maintaining the high ground in space. Space Situational Awareness satellites are critical enablers for integrated air, ground and sea operations, and play an essential role in fighting and winning conflicts. The United States leads the world space community in spacecraft payload systems from the component level into spacecraft, and in the development of constellations of spacecraft. In the area of launch systems that support Space Situational Awareness, despite the recent development of small launch vehicles, the United States launch capability is dominated by an old, unresponsive and relatively expensive set of launchers in the Expandable, Expendable Launch Vehicles (EELV) platforms; Delta IV and Atlas V. The United States directed Air Force Space Command to develop the capability for operationally responsive access to space and use of space to support national security, including the ability to provide critical space capabilities in the event of a failure of launch or on-orbit capabilities. On 1 Aug 06, Air Force Space Command activated the Space Development & Test Wing (SDTW) to perform development, test and evaluation of Air Force space systems and to execute advanced space deployment and demonstration projects to exploit new concepts and technologies, and rapidly migrate capabilities to the warfighter. The SDTW charged the Launch Test Squadron (LTS) with the mission to develop the capability of small space launch, supporting government research and development space launches and missile defense target missions, with operationally responsive spacelift for Low-Earth-Orbit Space Situational Awareness assets as a future mission. This new mission created new challenges for LTS. The LTS mission tenets of developing space launches and missile defense target vehicles were an evolution from the squadrons previous mission of providing sounding rockets under the Rocket

  6. No Launch Before Its Time

    NASA Technical Reports Server (NTRS)

    Townsend, Bill

    2004-01-01

    Aura is an Earth-observing satellite developed to help us study the quality of the air we breathe. It will look at the state of the ozone and the atmospheric composition in regards to the Earth's changing climate. I headed to California on July 5, 2004. The plan was that the satellite would launch on the tenth, but we had a few problems getting it off. This was the fifty-ninth launch of my career, and it was also a little different than most of my previous launches. Most of the time it's weather that postpones a launch; there aren't usually that many technical issues this late in the game. This time. however, we had several problems, equally split between the launch vehicle and the spacecraft. I remember a member of the crew asking me, 'Is this normal?' And in my experience, it wasn't.

  7. Pioneer Launch on Delta Vehicle

    NASA Technical Reports Server (NTRS)

    1969-01-01

    NASA launches the last in the series of interplanetary Pioneer spacecraft, Pioneer 10 from Cape Kennedy, Florida. The long-tank Delta launch vehicle placed the spacecraft in a solar orbit along the path of Earth's orbit. The spacecraft then passed inside and outside Earth's orbit, alternately speeding up and slowing down relative to Earth. The Delta launch vehicle family started development in 1959. The Delta was composed of parts from the Thor, an intermediate-range ballistic missile, as its first stage, and the Vanguard as its second. The first Delta was launched from Cape Canaveral on May 13, 1960 and was powerful enough to deliver a 100-pound spacecraft into geostationary transfer orbit. Delta has been used to launch civil, commercial, and military satellites into orbit. For more information about Delta, please see Chapter 3 in Roger Launius and Dennis Jenkins' book To Reach the High Frontier published by The University Press of Kentucky in 2002.

  8. STS-51 Launch

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Space Shuttle Discovery takes off from Launch Pad 39B at the Kennedy Space Center, Florida, to begin Mission STS-51 on 12 September 1993. The 57th shuttle mission began at 7:45 a.m. EDT, and lasted 9 days, 20 hours, 11 minutes, 11 seconds, while traveling a total distance of 4,106,411 miles. The Advanced Communications Technology Satellite (ACTS) was one of the projects deployed. This satellite serves as a test bed for advanced experimental communications satellite concepts and technology. Another payload on this mission was the Orbiting Retrievable Far and Extreme Ultraviolet Spectrometer (ORFEUS) telescope mounted on the Shuttle Pallet Satellite (SPAS) payload carrier. ORFEUS was designed to investigate very hot and very cold matter in the universe. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into

  9. The Air Force’s Evolved Expendable Launch Vehicle Competitive Procurement

    DTIC Science & Technology

    2014-03-04

    with ULA, committing the government to buy 35 launch vehicle booster cores over a five-year period, and the associated capability to launch them.2...EELV programmatic forecast dated June 2012. 2 The booster core is the main body of a launch vehicle. In the EELV program, common booster cores are...contributors to this report were Art Gallegos, Assistant Director; Peter Anderson, Claire Buck , Raj Chitikila, Desiree Cunningham, Laura Hook, John

  10. STS-26 Commander Hauck, wearing launch and entry suit, trains in JSC mockup

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Commander Frederick H. Hauck, wearing the orange launch and entry suit (LES) and launch and entry helmet (LEH), gets assistance from a suit technician prior to participating in a training exercise in JSC Mockup and Integration Laboratory Bldg 9A crew compartment trainer (CCT). During the exercise, the LES, a partial pressure suit to be worn during launch and entry phases of the space shuttle flight, was evaluated and checked out.

  11. Launch Order, Launch Separation, and Loiter in the Constellation 1 1/2-Launch Solution

    NASA Technical Reports Server (NTRS)

    Stromgren, Chel; Cates, Grant; Cirillo, William

    2009-01-01

    The NASA Constellation Program (CxP) is developing a two-element Earth-to-Orbit launch system to enable human exploration of the Moon. The first element, Ares I, is a human-rated system that consists of a first stage based on the Space Shuttle Program's solid rocket booster (SRB) and an upper stage that consists of a four-crew Orion capsule, a service module, and a Launch Escape System. The second element, Ares V, is a Saturn V-plus category launch system that consists of the core stage with a cluster of six RS-68B engines and augmented with two 5.5-segment SRBs, a Saturn-derived J-2X engine powering an Earth Departure Stage (EDS), and the lunar-lander vehicle payload, Altair. Initial plans called for the Ares V to be launched first, followed the next day by the Ares I. After the EDS performs the final portion of ascent and subsequent orbit circularization, the Orion spacecraft then performs a rendezvous and docks with the EDS and its Altair payload. Following checkout, the integrated stack loiters in low Earth orbit (LEO) until the appropriate Trans-Lunar Injection (TLI) window opportunity opens, at which time the EDS propels the integrated Orion Altair to the Moon. Successful completion of this 1 1/2-launch solution carries risks related to both the orbital lifetime of the assets and the probability of achieving the launch of the second vehicle within the orbital lifetime of the first. These risks, which are significant in terms of overall system design choices and probability of mission success, dictated a thorough reevaluation of the launch strategy, including the order of vehicle launch and the planned time period between launches. The goal of the effort described in this paper was to select a launch strategy that would result in the greatest possible expected system performance, while accounting for launch risks and the cost of increased orbital lifetime. Discrete Event Simulation (DES) model of the launch strategies was created to determine the probability

  12. School Indoor Air Quality Assessments Go Mobile / EPA Launches School IAQ Assessment Mobile App

    EPA Pesticide Factsheets

    WASHINGTON -- The U.S. Environmental Protection Agency (EPA) today launched a new mobile app to assist schools and school districts with performing comprehensive indoor air quality (IAQ) facility assessments to protect the health of children and sch

  13. Study on Alternative Cargo Launch Options from the Lunar Surface

    SciTech Connect

    Cheryl A. Blomberg; Zamir A. Zulkefli; Spencer W. Rich; Steven D. Howe

    2013-07-01

    In the future, there will be a need for constant cargo launches from Earth to Mars in order to build, and then sustain, a Martian base. Currently, chemical rockets are used for space launches. These are expensive and heavy due to the amount of necessary propellant. Nuclear thermal rockets (NTRs) are the next step in rocket design. Another alternative is to create a launcher on the lunar surface that uses magnetic levitation to launch cargo to Mars in order to minimize the amount of necessary propellant per mission. This paper investigates using nuclear power for six different cargo launching alternatives, as well as the orbital mechanics involved in launching cargo to a Martian base from the moon. Each alternative is compared to the other alternative launchers, as well as compared to using an NTR instead. This comparison is done on the basis of mass that must be shipped from Earth, the amount of necessary propellant, and the number of equivalent NTR launches. Of the options, a lunar coil launcher had a ship mass that is 12.7% less than the next best option and 17 NTR equivalent launches, making it the best of the presented six options.

  14. STS Derived Exploration Launch Operations

    NASA Technical Reports Server (NTRS)

    Best, Joel; Sorge, L.; Siders, J.; Sias, Dave

    2004-01-01

    A key aspect of the new space exploration programs will be the approach to optimize launch operations. A STS Derived Launch Vehicle (SDLV) Program can provide a cost effective, low risk, and logical step to launch all of the elements of the exploration program. Many benefits can be gained by utilizing the synergy of a common launch site as an exploration spaceport as well as evolving the resources of the current Space Shuttle Program (SSP) to meet the challenges of the Vision for Space Exploration. In particular, the launch operation resources of the SSP can be transitioned to the exploration program and combined with the operations efficiencies of unmanned EELVs to obtain the best of both worlds, resulting in lean launch operations for crew and cargo missions of the exploration program. The SDLV Program would then not only capture the extensive human space flight launch operations knowledge, but also provide for the safe fly-out of the SSP through continuity of system critical skills, manufacturing infrastructure, and ability to maintain and attract critical skill personnel. Thus, a SDLV Program can smoothly transition resources from the SSP and meet the transportation needs to continue the voyage of discovery of the space exploration program.

  15. Vertical La0.7Ca0.3MnO3 nanorods tailored by high magnetic field assisted pulsed laser deposition

    PubMed Central

    Zhang, Kejun; Dai, Jianming; Zhu, Xuebin; Zhu, Xiaoguang; Zuo, Xuzhong; Zhang, Peng; Hu, Ling; Lu, Wenjian; Song, Wenhai; Sheng, Zhigao; Wu, Wenbin; Sun, Yuping; Du, Youwei

    2016-01-01

    La0.7Ca0.3MnO3 (LCMO) thin films on (LaAlO3)0.3(Sr2AlTaO6)0.7 (001) [LSAT (001)] single crystal substrates have been prepared by high magnetic field assisted pulsed laser deposition (HMF-PLD) developed by ourselves. Uniformly sized and vertically aligned nanorod structures can be obtained under an applied high magnetic field above 5 T, and the dimension size of the nanorods can be manipulated by varying the applied magnetic field. It is found that the magnetic anisotropy is strongly correlated to the dimension size of the nanorods. A significantly enhanced low-field magnetoresistance (LFMR) of −36% under 0.5 T at 100 K can be obtained due to the enhanced carrier scattering at the vertical grain boundaries between the nanorods for the LCMO films. The growth mechanism of the nanorods has been also discussed, which can be attributed to the variation of deposition rate, adatom surface diffusion, and nucleation induced by the application of a high magnetic field in the film processing. The successful achievements of such vertical nanorod structures will provide an instructive route to investigate the physical nature of these nanostructures and achieve nanodevice manipulation. PMID:26778474

  16. Nanosecond-Timescale Low Energy Switching of In-Plane Magnetic Tunnel Junctions through Dynamic Oersted-Field-Assisted Spin Hall Effect.

    PubMed

    Aradhya, S V; Rowlands, G E; Oh, J; Ralph, D C; Buhrman, R A

    2016-10-12

    We investigate fast-pulse switching of in-plane-magnetized magnetic tunnel junctions (MTJs) within 3-terminal devices in which spin-transfer torque is applied to the MTJ by the giant spin Hall effect. We measure reliable switching, with write error rates down to 10(-5), using current pulses as short as just 2 ns in duration. This represents the fastest reliable switching reported to date for any spin-torque-driven magnetic memory geometry and corresponds to a characteristic time scale that is significantly shorter than predicted possible within a macrospin model for in-plane MTJs subject to thermal fluctuations at room temperature. Using micromagnetic simulations, we show that in the three-terminal spin-Hall devices the Oersted magnetic field generated by the pulse current strongly modifies the magnetic dynamics excited by the spin-Hall torque, enabling this unanticipated performance improvement. Our results suggest that in-plane MTJs controlled by Oersted-field-assisted spin-Hall torque are a promising candidate for both cache memory applications requiring high speed and for cryogenic memories requiring low write energies.

  17. Fabrication of Au nanoparticles supported on CoFe2O4 nanotubes by polyaniline assisted self-assembly strategy and their magnetically recoverable catalytic properties

    NASA Astrophysics Data System (ADS)

    Zhang, Zhen; Jiang, Yanzhou; Chi, Maoqiang; Yang, Zezhou; Nie, Guangdi; Lu, Xiaofeng; Wang, Ce

    2016-02-01

    This article reports the fabrication of magnetically responsive Au nanoparticles supported on CoFe2O4 nanotubes through polyaniline (PANI) assisted self-assembly strategy which can be used as an efficient magnetically recoverable nanocatalyst. The central magnetic CoFe2O4 nanotubes possess a strong magnetic response under an externally magnetic field, enabling an easy and efficient separation from the reaction system for reuse. The thorn-like PANI layer on the surface of CoFe2O4 nanotubes provides large surface area for supporting Au nanocatalysts due to the electrostatic interactions. The as-prepared CoFe2O4/PANI/Au nanotube assemblies exhibit a high catalytic activity for the hydrogenation of 4-nitrophenol by sodium borohydride (NaBH4) at room temperature, with an apparent kinetic rate constant (Kapp) of about 7.8 × 10-3 s-1. Furthermore, the composite nanocatalyst shows a good recoverable property during the catalytic process. This work affords a reliable way in developing multifunctional nanocomposite for catalysis and other potential applications in many fields.

  18. Mars Pathfinder Status at Launch

    NASA Technical Reports Server (NTRS)

    Spear, A. J.; Freeman, Delma C., Jr.; Braun, Robert D.

    1996-01-01

    The Mars Pathfinder Flight System is in final test, assembly and launch preparations at the Kennedy Space Center in Florida. Launch is scheduled for 2 Dec. 1996. The Flight System development, in particular the Entry, Descent, and Landing (EDL) system, was a major team effort involving JPL, other NASA centers and industry. This paper provides a summary Mars Pathfinder description and status at launch. In addition, a section by NASA's Langley Research Center, a key EDL contributor, is provided on their support to Mars Pathfinder. This section is included as an example of the work performed by Pathfinder team members outside JPL.

  19. Assessment of Advanced Logistics Delivery System (ALDS) Launch Systems Concepts

    DTIC Science & Technology

    2004-10-01

    roller coasters . They have also been included in preliminary EMALS / EARS launch system designs; however, ALDS launcher system accelerations and path...is based on a permanent magnet linear motor design incorporating high temperature superconducting materials in the rotor, stator windings, and...linear induction motor concept similar to the Electro- Magnetic Aircraft Launcher System (EMALS) that is currently under development for use as a

  20. BARREL Team Launching 20 Balloons

    NASA Video Gallery

    A movie made by the NASA-Funded Balloon Array for Radiation belt Relativistic Electron Losses, or BARREL, team on their work launching 20 balloons in Antarctica during the Dec. 2013/Jan. 2014 campa...

  1. Nanosatellite Launch Adapter System (NLAS)

    NASA Technical Reports Server (NTRS)

    Yost, Bruce D.; Hines, John W.; Agasid, Elwood F.; Buckley, Steven J.

    2010-01-01

    The utility of small spacecraft based on the University cubesat standard is becoming evident as more and more agencies and organizations are launching or planning to include nanosatellites in their mission portfolios. Cubesats are typically launched as secondary spacecraft in enclosed, containerized deployers such as the CalPoly Poly Picosat Orbital Deployer (P-POD) system. The P-POD allows for ease of integration and significantly reduces the risk exposure to the primary spacecraft and mission. NASA/ARC and the Operationally Responsive Space office are collaborating to develop a Nanosatellite Launch Adapter System (NLAS), which can accommodate multiple cubesat or cubesat-derived spacecraft on a single launch vehicle. NLAS is composed of the adapter structure, P-POD or similar spacecraft dispensers, and a sequencer/deployer system. This paper describes the NLAS system and it s future capabilities, and also provides status on the system s development and potential first use in space.

  2. Genomic Data Commons launches - TCGA

    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.

  3. Launch Abort System Pathfinder Arrival

    NASA Video Gallery

    The Orion Launch Abort System, or LAS, pathfinder returned home to NASA Langley on Oct. 18 on its way to NASA's Kennedy Space Center. The hardware was built at Langley and was used in preparation f...

  4. Lighting the Sky: ATREX Launches

    NASA Video Gallery

    NASA successfully launched five suborbital sounding rockets early March 27, 2012 from its Wallops Flight Facility in Virginia as part of a study of the upper level jet stream. The first rocket was ...

  5. STS-135 Fused Launch Video

    NASA Video Gallery

    Imaging experts funded by the Space Shuttle Program and located at NASA's Ames Research Center prepared this video of the STS-135 launch by merging images taken by a set of six cameras capturing fi...

  6. Launch Commit Criteria Monitoring Agent

    NASA Technical Reports Server (NTRS)

    Semmel, Glenn S.; Davis, Steven R.; Leucht, Kurt W.; Rowe, Dan A.; Kelly, Andrew O.; Boeloeni, Ladislau

    2005-01-01

    The Spaceport Processing Systems Branch at NASA Kennedy Space Center has developed and deployed a software agent to monitor the Space Shuttle's ground processing telemetry stream. The application, the Launch Commit Criteria Monitoring Agent, increases situational awareness for system and hardware engineers during Shuttle launch countdown. The agent provides autonomous monitoring of the telemetry stream, automatically alerts system engineers when predefined criteria have been met, identifies limit warnings and violations of launch commit criteria, aids Shuttle engineers through troubleshooting procedures, and provides additional insight to verify appropriate troubleshooting of problems by contractors. The agent has successfully detected launch commit criteria warnings and violations on a simulated playback data stream. Efficiency and safety are improved through increased automation.

  7. Re-entry Experiment Launch

    NASA Video Gallery

    On August 10, 2009, NASA successfully launched the Inflatable Re-entry Vehicle Experiment (IRVE) and proved that spacecraft can use inflatable heat shields to reduce speed and provide protection du...

  8. Space Launch System: Future Frontier

    NASA Video Gallery

    Featuring NASA Marshall’s Foundations of Influence, Relationships, Success & Teamwork (FIRST) employees and student interns, "Future Frontier" discusses the new Space Launch System (SLS) heavy-li...

  9. Environmentally-Preferable Launch Coatings

    NASA Technical Reports Server (NTRS)

    Kessel, Kurt R.

    2015-01-01

    The Ground Systems Development and Operations (GSDO) Program at NASA Kennedy Space Center (KSC), Florida, has the primary objective of modernizing and transforming the launch and range complex at KSC to benefit current and future NASA programs along with other emerging users. Described as the launch support and infrastructure modernization program in the NASA Authorization Act of 2010, the GSDO Program will develop and implement shared infrastructure and process improvements to provide more flexible, affordable, and responsive capabilities to a multi-user community. In support of NASA and the GSDO Program, the objective of this project is to determine the feasibility of environmentally friendly corrosion protecting coatings for launch facilities and ground support equipment (GSE). The focus of the project is corrosion resistance and survivability with the goal to reduce the amount of maintenance required to preserve the performance of launch facilities while reducing mission risk. The project compares coating performance of the selected alternatives to existing coating systems or standards.

  10. Robonaut 2 Readied for Launch

    NASA Video Gallery

    Robonaut 2 is being prepared for its history making launch to the International Space Station on STS-133. The robot, known as R2, will be the first humanoid machine to work in orbit. With a upper t...

  11. Advanced Launch Development Program status

    NASA Technical Reports Server (NTRS)

    Colgrove, Roger

    1990-01-01

    The Advanced Launch System is a joint NASA - Air Force program originally directed to define the concept for a modular family of launch vehicles, to continue development programs and preliminary design activities focused primarily on low cost to orbit, and to offer maturing technologies to existing systems. The program was restructed in the spring of 1990 as a result of funding reductions and renamed the Advanced Launch Development Program. This paper addresses the program's status following that restructuring and as NASA and the Air Force commence a period of deliberation over future space launch needs and the budgetary resources available to meet those needs. The program is currently poised to protect a full-scale development decision in the mid-1990's through the appropriate application of program resources. These resources are concentrated upon maintaining the phase II system contractor teams, continuing the Space Transportation Engine development activity, and refocusing the Advanced Development Program demonstrated activities.

  12. New Horizons Launch Contingency Effort

    NASA Astrophysics Data System (ADS)

    Chang, Yale; Lear, Matthew H.; McGrath, Brian E.; Heyler, Gene A.; Takashima, Naruhisa; Owings, W. Donald

    2007-01-01

    On 19 January 2006 at 2:00 PM EST, the NASA New Horizons spacecraft (SC) was launched from the Cape Canaveral Air Force Station (CCAFS), FL, onboard an Atlas V 551/Centaur/STAR™ 48B launch vehicle (LV) on a mission to explore the Pluto Charon planetary system and possibly other Kuiper Belt Objects. It carried a single Radioisotope Thermoelectric Generator (RTG). As part of the joint NASA/US Department of Energy (DOE) safety effort, contingency plans were prepared to address the unlikely events of launch accidents leading to a near-pad impact, a suborbital reentry, an orbital reentry, or a heliocentric orbit. As the implementing organization. The Johns Hopkins University Applied Physics Laboratory (JHU/APL) had expanded roles in the New Horizons launch contingency effort over those for the Cassini mission and Mars Exploration Rovers missions. The expanded tasks included participation in the Radiological Control Center (RADCC) at the Kennedy Space Center (KSC), preparation of contingency plans, coordination of space tracking assets, improved aerodynamics characterization of the RTG's 18 General Purpose Heat Source (GPHS) modules, and development of spacecraft and RTG reentry breakup analysis tools. Other JHU/APL tasks were prediction of the Earth impact footprints (ElFs) for the GPHS modules released during the atmospheric reentry (for purposes of notification and recovery), prediction of the time of SC reentry from a potential orbital decay, pre-launch dissemination of ballistic coefficients of various possible reentry configurations, and launch support of an Emergency Operations Center (EOC) on the JHU/APL campus. For the New Horizons launch, JHU/APL personnel at the RADCC and at the EOC were ready to implement any real-time launch contingency activities. A successful New Horizons launch and interplanetary injection precluded any further contingency actions. The New Horizons launch contingency was an interagency effort by several organizations. This paper

  13. Saturn IB AS-202 Launch

    NASA Technical Reports Server (NTRS)

    1966-01-01

    AS-202, the second Saturn IB launch vehicle developed by the Marshall Space Flight Center, lifts off from Cape Canaveral, Florida, August 25, 1966. Primary mission objectives included the confirmation of projected launch loads, demonstration of spacecraft component separation, and verification of heat shield adequacy at high reentry rates. In all, nine Saturn IB flights were made, ending with the Apollo-Soyuz Test Project (ASTP) in July 1975.

  14. Evolved Expendable Launch Vehicle (EELV)

    DTIC Science & Technology

    2013-12-01

    for the Orbital Sciences Corporation Antares, and Space Exploration Technologies Corporation ( SpaceX ) Falcon Heavy Statements of Intent. The New...The Space and Missile Systems Center Launch Systems Directorate (SMC/LR) and SpaceX tailored NECG requirements for the Falcon 9 version 1.1 and...preparation for the upcoming Phase 1A competitive launch service awards, two early integration studies will be performed for the SpaceX Falcon 9 v1.1

  15. Vertical Launch System Loadout Planner

    DTIC Science & Technology

    2015-03-01

    Submarine Rocket (ASROC): Ship -launched rocket used in ASW.  RIM-174 SM6: Advanced version of a ship -launched SM2 missile capable of over-the...Operational planners strive to fmd ways to load missiles on Vertical Latmch System (VLS) ships to meet mission requit·ements in theit· AI·ea of...Responsibility (AOR). Requirements are variable: there are missions requiting specific types of missiles; each ship may have distinct capability or capacity to

  16. NROL-41 Go for Launch

    DTIC Science & Technology

    2013-06-01

    57  Figure 34.  Cryogenic Tanking Prior to Launch ...............................................................58  Figure 35.  NROL-41...Tower rolls away from the launch vehicle, when cryogenic tanking operations begin, and when the vehicle is about to proceed into the final two...Tower Roll As the figure shows, there are many technicians still working near the vehicle up until the vehicle is ready to begin cryogenic tanking . Due

  17. STS-53 Launch and Landing

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Footage of various stages of the STS-53 Discovery launch is shown, including shots of the crew at breakfast, getting suited up, and departing to board the Orbiter. The launch is seen from many vantage points, as is the landing. On-orbit activities show the crew performing several medical experiments, such as taking a picture of the retina and measuring the pressure on the eyeball. One crewmember demonstrates how to use the rowing machine in an antigravity environment.

  18. Infrasound Detection of Rocket Launches

    DTIC Science & Technology

    2000-09-01

    were examined for 14 VAFB launches in 1999 at SGAR (680 km) and DLIAR (1300 km). Detections were seen for a Titan IVB launched 5/22/99 and a Delta II...size. Upper atmospheric wind conditions should have been favorable for several of the detections, however noise levels were often high at SGAR and...phase velocities are consistent with stratospheric propagation and nominal infrasound travel times to SGAR (2340 s) and DLIAR (4440 s). The signals were

  19. Launch of STS-63 Discovery

    NASA Technical Reports Server (NTRS)

    1995-01-01

    A 35mm camera was used to expose this close-up image of the Space Shuttle Discovery as it began its race to catch up with Russia's Mir Space Station. Liftoff from Launch Pad 39B, Kennedy Space Center (KSC) occurred at 12:22:04 (EST) February 3, 1995. Discovery is the first in the current fleet of four space shuttle vehicles to make 20 launches.

  20. CubeSat Launch Initiative

    NASA Technical Reports Server (NTRS)

    Higginbotham, Scott

    2016-01-01

    The National Aeronautics and Space Administration (NASA) recognizes the tremendous potential that CubeSats (very small satellites) have to inexpensively demonstrate advanced technologies, collect scientific data, and enhance student engagement in Science, Technology, Engineering, and Mathematics (STEM). The CubeSat Launch Initiative (CSLI) was created to provide launch opportunities for CubeSats developed by academic institutions, non-profit entities, and NASA centers. This presentation will provide an overview of the CSLI, its benefits, and its results.

  1. Micromagnetic model analysis of integrated single-pole-type head with tilted spin-torque oscillator for high-frequency microwave-assisted magnetic recording

    SciTech Connect

    Katayama, Takuto; Kanai, Yasushi; Yoshida, Kazuetsu; Greaves, Simon; Muraoka, Hiroaki

    2015-05-07

    The spin-torque oscillator (STO) is the most important component in microwave-assisted magnetic recording. Some requirements for the STO are: large amplitude and stable oscillation, small injected current, and oscillation at a frequency that excites resonance in a recording medium. It is also necessary for the STO oscillation to closely follow the head coil current. In this paper, STOs were integrated into write heads and micromagnetic analyses carried out to obtain a write head structure with stable STO oscillation that could follow a high-frequency head coil current.

  2. Spark-plasma-sintering magnetic field assisted compaction of Co{sub 80}Ni{sub 20} nanowires for anisotropic ferromagnetic bulk materials

    SciTech Connect

    Ouar, Nassima; Schoenstein, Frédéric; Mercone, Silvana; Farhat, Samir; Jouini, Noureddine; Villeroy, Benjamin; Leridon, Brigitte

    2013-10-28

    We developed a two-step process showing the way for sintering anisotropic nanostructured bulk ferromagnetic materials. A new reactor has been optimized allowing the synthesis of several grams per batch of nanopowders via a polyol soft chemistry route. The feasibility of the scale-up has been successfully demonstrated for Co{sub 80}Ni{sub 20} nanowires and a massic yield of ∼97% was obtained. The thus obtained nanowires show an average diameter of ∼6 nm and a length of ∼270 nm. A new bottom-up strategy allowed us to compact the powder into a bulk nanostructured system. We used a spark-plasma-sintering technique under uniaxial compression and low temperature assisted by a permanent magnetic field of 1 T. A macroscopic pellet of partially aligned nanowire arrays has been easily obtained. This showed optimized coercive properties along the direction of the magnetic field applied during compaction (i.e., the nanowires' direction)

  3. Effects of assisted magnetic field to an atmospheric-pressure plasma jet on radical generation at the plasma-surface interface and bactericidal function

    NASA Astrophysics Data System (ADS)

    Liu, Chih-Tung; Kumakura, Takumi; Ishikawa, Kenji; Hashizume, Hiroshi; Takeda, Keigo; Ito, Masafumi; Hori, Masaru; Wu, Jong-Shinn

    2016-12-01

    A configuration of magnetic-assisted-plasma (MAP) on helium-based atmospheric-pressure plasma jet (APPJ) with an axial magnetic-field of 0.587 T is proposed, which provides good ability for killing bacteria Escherichia coli on the agar surface. Optically, we confirmed that the MAP increased approximately 2.4 times in the electron density estimated by the Stark broadening of H β line emission, and approximately 1.5 times enhancement of atomic oxygen concentration measured by vacuum ultraviolet absorption spectroscopy (VUVAS). Moreover, the generation of hydroxyl radical in the water increased 1.5 times, confirmed by the spin-trapping electron spin-resonance technique. In addition, the bactericidal experiments demonstrated 2.4 times higher for E. coli by the MAP treatment. The MAP configuration is proposed to be highly useful for future bio-medical applications by enhancing the radical generation at the plasma/substrate interface region.

  4. Structural and magnetic studies of tin doped α-Fe2O3 (α-SnxFe2-xO3) nanoparticles prepared by microwave assisted synthesis

    NASA Astrophysics Data System (ADS)

    K., Bindu; Chowdhury, P.; Ajith K., M.; Nagaraja, H. S.

    2016-05-01

    Hematite (α-Fe2O3) doped with tetravalent ions have potential applications in various fields such as gas sensors, memories, energy storage devices because of their electrical and magnetic properties. Microwave assisted synthesis was used to prepare Tin doped α-Fe2O3 [α-SnxFe2-xO3]. The structural and morphological studies were investigated using X-ray diffraction (XRD) and Scanning electron microscopy (SEM). XRD patterns revealed that α-Fe2O3 and α-SnxFe2-xO3 were having rhombohedral structure. The compositional study was done by Energy dispersive X-ray Spectroscopy (EDS). The magnetic properties were studied by Vibrating Sample Magnetometry (VSM). Results shows that the prepared samples were found to be antiferromagnetic in nature and the results are discussed in detail.

  5. NASA's Space Launch System: Momentum Builds Towards First Launch

    NASA Technical Reports Server (NTRS)

    May, Todd; Lyles, Garry

    2014-01-01

    NASA's Space Launch System (SLS) is gaining momentum programmatically and technically toward the first launch of a new exploration-class heavy lift launch vehicle for international exploration and science initiatives. The SLS comprises an architecture that begins with a vehicle capable of launching 70 metric tons (t) into low Earth orbit. Its first mission will be the launch of the Orion Multi-Purpose Crew Vehicle (MPCV) on its first autonomous flight beyond the Moon and back. SLS will also launch the first Orion crewed flight in 2021. SLS can evolve to a 130-t lift capability and serve as a baseline for numerous robotic and human missions ranging from a Mars sample return to delivering the first astronauts to explore another planet. Managed by NASA's Marshall Space Flight Center, the SLS Program formally transitioned from the formulation phase to implementation with the successful completion of the rigorous Key Decision Point C review in 2014. At KDP-C, the Agency Planning Management Council determines the readiness of a program to go to the next life-cycle phase and makes technical, cost, and schedule commitments to its external stakeholders. As a result, the Agency authorized the Program to move forward to Critical Design Review, scheduled for 2015, and a launch readiness date of November 2018. Every SLS element is currently in testing or test preparations. The Program shipped its first flight hardware in 2014 in preparation for Orion's Exploration Flight Test-1 (EFT-1) launch on a Delta IV Heavy rocket in December, a significant first step toward human journeys into deep space. Accomplishments during 2014 included manufacture of Core Stage test articles and preparations for qualification testing the Solid Rocket Boosters and the RS-25 Core Stage engines. SLS was conceived with the goals of safety, affordability, and sustainability, while also providing unprecedented capability for human exploration and scientific discovery beyond Earth orbit. In an environment

  6. Magnetic field-assisted synthesis of wire-like Co{sub 3}O{sub 4} nanostructures: Electrochemical and photocatalytic studies

    SciTech Connect

    Zhao, Xiubin; Pang, Zhanwen; Wu, Mingzai; Liu, Xiansong; Zhang, Hui; Ma, Yongqing; Sun, Zhaoqi; Zhang, Lide; Chen, Xiaoshuang

    2013-01-15

    Graphical abstract: Schematic illustration for the magnetic field-assisted growth of wire-like Co{sub 3}O{sub 4} nanostructure. Display Omitted Highlights: ► Co{sub 3}O{sub 4} nanowires are prepared by magnetic field hydrothermal reduction and annealing. ► These Co{sub 3}O{sub 4} nanowires possess enhanced capacitance. ► The Co{sub 3}O{sub 4} nanowires have a good photocatalytic activity for methyl orange. -- Abstract: Wire-like Co{sub 3}O{sub 4} nanostructures were prepared by the combination of magnetic field-assisted hydrothermal reduction of cobalt ions and the subsequent ambient annealing at 500 °C. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the structure and morphological evolution of the products. The results show that the wire-like nanostructures possess diameters about 250 nm and lengths over 10 μm. The possible formation mechanism of the wire-like Co{sub 3}O{sub 4} nanostructures is also proposed based on the SEM results. Galvanostatic methods were used to characterize the electrochemical properties. The measurements indicate that the wire-like Co{sub 3}O{sub 4} nanostructures show larger discharge and charge capacities than that of spherical Co{sub 3}O{sub 4} nanoparticles prepared in the absence of magnetic field. In addition, the photocatalytic activity of the products was investigated by measuring the photodegradation of methyl orange solution under ultraviolet radiation, which shows that both the wire-like and spherical products have a good photocatalytic activity.

  7. Magnetic properties and coercivity mechanism of Sm1-xPrxCo5 (x=0-0.6) nanoflakes prepared by surfactant-assisted ball milling

    NASA Astrophysics Data System (ADS)

    Xu, M. L.; Yue, M.; Wu, Q.; Li, Y. Q.; Lu, Q. M.

    2016-05-01

    Sm1-xPrxCo5 (x=0-0.6) nanoflakes with CaCu5 structure were successfully prepared by surfactant-assisted high-energy ball milling (SAHEBM). The crystal structure and magnetic properties of Sm1-xPrxCo5 (x=0-0.6) nanoflakes were studied by X-ray diffraction and vibrating sample magnetometer. Effects of Pr addition on the structure, magnetic properties and coercivity mechanism of Sm1-xPrxCo5 nanoflakes were systematically investigated. XRD results show that all the nanoflakes have a hexagonal CaCu5-type (Sm, Pr)1Co5 main phase and the (Sm, Pr)2Co7 impurity phase, and all of the samples exhibit a strong (00l) texture after magnetic alignment. As the Pr content increases, remanence firstly increases, then slightly reduced, while anisotropy field (HA) and Hci of decrease monotonically. Maximum energy product [(BH)max] of the flakes increases first, peaks at 24.4 MGOe with Pr content of x = 0.4, then drops again. Magnetization behavior analysis indicate that the coercivity mechanism is mainly controlled by inhomogeneous domain wall pinning, and the pinning strength weakens with the increased Pr content, suggesting the great influence of HA on the coercivity of flakes.

  8. Apollo 11 Facts Project [Pre-Launch Activities and Launch

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The crewmembers of Apollo 11, Commander Neil A. Armstrong, Command Module Pilot Michael Collins, and Lunar Module Pilot Edwin E. Aldrin, Jr., are seen during various stages of preparation for the launch of Apollo 11, including suitup, breakfast, and boarding the spacecraft. They are also seen during mission training, including preparation for extravehicular activity on the surface of the Moon. The launch of Apollo 11 is shown. The ground support crew is also seen as they wait for the spacecraft to approach the Moon.

  9. ESA to launch six scientific satellites

    NASA Astrophysics Data System (ADS)

    1995-09-01

    The Infrared Space Observatory, ISO, will lead the trio into space. It will be launched on an Ariane 4 rocket in early November from the European launch site at Kourou, French Guiana. It will be followed in mid-December by SOHO, the Solar and Heliospheric Observatory, which will be launched by an Atlas IIAS rocket from Cape Canaveral, USA. Finally, in mid-January the four Cluster probes will be carried into space on the inaugural flight of Ariane 5. ISO is the world's only orbiting infrared observatory and is the most sophisticated ever. Its sensitive detectors will be cooled to below -270 degrees C, allowing it to observe cool objects in space, invisible through ordinary telescopes. ISO's many scientific goals include studying newly formed stars and planets, investigating the aging process of galaxies and search for the universe's elusive 'dark matter' that is believed to outweigh visible stars and galaxies. The SOHO observatory will provide scientists with a comprehensive study of the sun, the nuclear powerhouse in the centre of our solar system. Its twelve experiments, developed by scientists from Europe and the United States, will investigate the sun from its core outwards -from the very inner workings of the star, to the solar wind which blows through the solar system. The four identical Cluster spacecraft will focus on studying the interaction of the sun with plasmas of the Earth and the magnetic field in a region known as the magnetosphere. The four probes, flying in formation, will allow scientists to build up a three-dimensional picture of the battle between the sun's streams of wind and the Earth's protective magnetic field. These missions represent years of work by scientists across Europe and around the world. The data they gather will provide us with a greater understanding of our own solar neighbourhood and deep space. SPACECRAFT STATUS AS AT 1 SEPTEMBER 95 ISO The ISO satellite, together with all the associated equipment, was transported in June by

  10. STS-120 on Launch Pad

    NASA Technical Reports Server (NTRS)

    2007-01-01

    A photographer used a fisheye lens attached to an electronic still camera to record a series of photos of the Space Shuttle Discovery at the launch pad while the STS-120 crew was at Kennedy Space Center for the Terminal Countdown Demonstration Test in October 2007. The STS-120 mission launched from Kennedy Space Center's launch pad 39A at 11:38:19 a.m. (EDT) on October 23, 2007. The crew included Scott E. Parazynski, Douglas H. Wheelock, Stephanie D. Wilson, all mission specialists; George D. Zamka, pilot; Pamela A. Melroy, commander; Daniel M. Tani, Expedition 16 flight engineer; and Paolo A. Nespoli, mission specialist representing the European Space Agency (ESA). Major objectives included the installation of the P6 solar array of the port truss and delivery and installment of Harmony, the Italian-built U.S. Node 2 on the International Space Station (ISS).

  11. Launch Pad in a Box

    NASA Technical Reports Server (NTRS)

    Mantovani, J. G.; Tamasy, G. J.; Mueller, R. P.; Townsend, I. I.; Sampson, J. W.; Lane, M. A.

    2016-01-01

    NASA Kennedy Space Center (KSC) is developing a new deployable launch system capability to support a small class of launch vehicles for NASA and commercial space companies to test and launch their vehicles. The deployable launch pad concept was first demonstrated on a smaller scale at KSC in 2012 in support of NASA Johnson Space Center's Morpheus Lander Project. The main objective of the Morpheus Project was to test a prototype planetary lander as a vertical takeoff and landing test-bed for advanced spacecraft technologies using a hazard field that KSC had constructed at the Shuttle Landing Facility (SLF). A steel pad for launch or landing was constructed using a modular design that allowed it to be reconfigurable and expandable. A steel flame trench was designed as an optional module that could be easily inserted in place of any modular steel plate component. The concept of a transportable modular launch and landing pad may also be applicable to planetary surfaces where the effects of rocket exhaust plume on surface regolith is problematic for hardware on the surface that may either be damaged by direct impact of high speed dust particles, or impaired by the accumulation of dust (e.g., solar array panels and thermal radiators). During the Morpheus free flight campaign in 2013-14, KSC performed two studies related to rocket plume effects. One study compared four different thermal ablatives that were applied to the interior of a steel flame trench that KSC had designed and built. The second study monitored the erosion of a concrete landing pad following each landing of the Morpheus vehicle on the same pad located in the hazard field. All surfaces of a portable flame trench that could be directly exposed to hot gas during launch of the Morpheus vehicle were coated with four types of ablatives. All ablative products had been tested by NASA KSC and/or the manufacturer. The ablative thicknesses were measured periodically following the twelve Morpheus free flight tests

  12. Evolved Expendable Launch Vehicle (EELV)

    DTIC Science & Technology

    2015-12-15

    potential NSS mission processing timelines. SpaceX is now eligible for an award of specified NSS missions to include the GPS III-2 launch service... SpaceX has also evolved their Falcon 9v1.1 configuration into the Falcon 9 Upgrade. To update the certification baseline, SpaceX and AF built Joint Work...9 v1.1 commercial launch experienced an in-flight mishap resulting in loss of vehicle on June 28, 2015. An official investigation was led by a SpaceX

  13. Personnel Launch System (PLS) study

    NASA Technical Reports Server (NTRS)

    Ehrlich, Carl F., Jr.

    1991-01-01

    NASA is currently studying a personnel launch system (PLS) approach to help satisfy the crew rotation requirements for the Space Station Freedom. Several concepts from low L/D capsules to lifting body vehicles are being examined in a series of studies as a potential augmentation to the Space Shuttle launch system. Rockwell International Corporation, under contract to NASA, analyzed a lifting body concept to determine whether the lifting body class of vehicles is appropriate for the PLS function. The results of the study are given.

  14. Performance assessment of planetary missions as launched from an orbiting space station

    NASA Technical Reports Server (NTRS)

    Friedlander, A.

    1982-01-01

    Results presented are intended to assist planners and the mission analysis community in assessing the performance impact (pro or con) of launching planetary missions from an orbiting space station as compared to the usual, ground-based Shuttle launch of such missions. The analyses comprising this assessment include: (1) a basic understanding and description of the space station launch problem; (2) examination of alternative injection strategies and selection of the most appropriate strategy for minimizing performance penalties; and (3) quantitative comparison of station-launched and Shuttle-launched performance over a wide energy/mass range of planetary mission opportunities. Data for each mission covers a full 360 deg of possible nodal location of the space station orbit. The main results are that planetary missions can be launched from a space station within acceptable penalty bounds, and that the station serving as a staging base/propellant depot can benefit some missions requiring large payload mass or high injection energy.

  15. Reusable Reentry Satellite (RRS): Launch tradeoff study

    NASA Technical Reports Server (NTRS)

    1990-01-01

    A goal of the Phase B study is to define the launch system interfaces for the reusable reentry satellite (RRS) program. The focus of the launch tradeoff study, documented in this report, is to determine which expendable launch vehicles (ELV's) are best suited for the RRS application by understanding the impact of all viable launch systems on RRS design and operation.

  16. Intelsat communications satellite scheduled for launch

    NASA Technical Reports Server (NTRS)

    1983-01-01

    To be placed into a highly elliptical transfer orbit by the Atlas Centaur (AC-61) launch vehicle, the INTELSAT V-F satellite has 12,000 voice circuits and 2 color television channels and incorporates a maritime communication system for ship to shore communications. The stages of the launch vehicle and the launch operations are described. A table shows the launch sequence.

  17. 46 CFR 199.120 - Launching stations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Launching stations. 199.120 Section 199.120 Shipping... LIFESAVING SYSTEMS FOR CERTAIN INSPECTED VESSELS Requirements for All Vessels § 199.120 Launching stations. (a) Each launching station must be positioned to ensure safe launching with clearance from...

  18. 46 CFR 199.120 - Launching stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Launching stations. 199.120 Section 199.120 Shipping... LIFESAVING SYSTEMS FOR CERTAIN INSPECTED VESSELS Requirements for All Vessels § 199.120 Launching stations. (a) Each launching station must be positioned to ensure safe launching with clearance from...

  19. 46 CFR 133.120 - Launching stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Launching stations. 133.120 Section 133.120 Shipping... Requirements for All OSVs § 133.120 Launching stations. (a) Each launching station must be positioned to ensure safe launching with clearance from— (1) The propeller; and (2) The steeply overhanging portions of...

  20. 46 CFR 133.120 - Launching stations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Launching stations. 133.120 Section 133.120 Shipping... Requirements for All OSVs § 133.120 Launching stations. (a) Each launching station must be positioned to ensure safe launching with clearance from— (1) The propeller; and (2) The steeply overhanging portions of...

  1. Rapid ionic liquid-based ultrasound assisted dual magnetic microextraction to preconcentrate and separate cadmium-4-(2-thiazolylazo)-resorcinol complex from environmental and biological samples.

    PubMed

    Khan, Sumaira; Kazi, Tasneem Gul; Soylak, Mustafa

    2014-04-05

    A rapid and innovative microextraction technique named as, ionic liquid-based ultrasound-assisted dual magnetic microextraction (IL-UA-DMME) was developed for the preconcentration and extraction of trace cadmium from environmental and biological samples, prior to analyzed by flame atomic absorption spectrometry (FAAS). The proposed method has many obvious advantages, including evading the use of organic solvents and achieved high extraction yields by the combination of dispersive liquid-liquid microextraction (DLLME) and magnetic mediated-solid phase extraction (MM-SPE). In this approach ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6] play an important role to extract the cadmium-4-(2-thiazolylazo)-resorcinol (Cd-TAR) complex from acid digested sample solutions and ultrasonic irradiation was applied to assist emulsification. After then, dispersed small amount of Fe3O4 magnetic nanoparticles (MNPs) in sample solutions to salvaged the IL and complete phase separation was attained. Some analytical parameters that influencing the efficiency of proposed (IL-UA-DMME) method, such as pH, volume of IL, ligand concentration, ultra-sonication time, amount of Fe3O4 MNPs, sample volume and matrix effect were optimized. Limit of detection (LOD) and enrichment factor (EF) of the method under optimal experimental conditions were found to be 0.40μgL(-1) and 100, respectively. The relative standard deviation (RSD) of 50μgL(-1) Cd was 4.29%. The validity and accuracy of proposed method, was assessed to analyzed certified reference materials of fortified lake water TMDA-54.4, SPS-WW2 waste water, spinach leaves 1570a and also checked by standard addition method. The obtained values showed good agreement with the certified values and sufficiently high recovery were found in the range of 98.1-101% for Cd. The proposed method was facile, rapid and successfully applied for the determination of Cd in environmental and different biological samples.

  2. Pegasus air-launched space booster

    NASA Astrophysics Data System (ADS)

    Lindberg, Robert E.; Mosier, Marty R.

    The launching of small satellites with the mother- aircraft-launched Pegasus booster yields substantial cost improvements over ground launching and enhances operational flexibility, since it allows launches to be conducted into any orbital inclination. The Pegasus launch vehicle is a three-stage solid-rocket-propelled system with delta-winged first stage. The major components of airborne support equipment, located on the mother aircraft, encompass a launch panel operator console, an electronic pallet, and a pylon adapter. Alternatives to the currently employed B-52 launch platform aircraft have been identified for future use. Attention is given to the dynamic, thermal, and acoustic environments experienced by the payload.

  3. Launch site integration of Liquid Rocket Boosters

    NASA Technical Reports Server (NTRS)

    Scott, Leland P.; Dickinson, William J.

    1989-01-01

    The impacts of introducing Liquid Rocket Boosters (LRB) into the STS/KSC launch environment are identified and evaluated. Proposed ground systems configurations are presented along with a launch site requirements summary. Pre-launch processing scenarios are described and the required facility modifications and new facility requirements are analyzed. Flight vehicle design recommendations to enhance launch processing are discussed. Processing approaches to integrate LRB with existing STS launch operations are evaluated. The key features and significance of launch site transition to a new STS configuration in parallel with ongoing launch activities are enumerated.

  4. 16-Inch Gun-Launched Anti-Satellite Weapon

    DTIC Science & Technology

    1982-06-01

    public release, distribution unlimited 16-Inch Gun-Launched Anti-Satellite Weapon by Joseph John Natale Lieutenant, United States Navy B.A., University...w N L- UN H LLWIrNO0W CCT’. W W W ww WuflswrSx’x 0 ma. 63 I I I IZ I - I M w I I I lIL, I-.. CI =1 w I 1 1--* CL M~ WW OD 0 CL CL CL ODV CL a It...Dr. L. V. Schmidt Assistant Secretary of the Navy Assistant for Engineering Technology (R. E. and S) Pentagon SE731 Washington, D.C. 20350 6

  5. STS-77 Launch (front view fisheye closeup)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A flawless countdown culminates with an on-time liftoff as the Space Shuttle Endeavour lights up the morning sky. Endeavour was launched on Mission STS-77 from Pad 39B at 6:30:00 a.m. EDT, May 19. The fourth Shuttle mission of 1996 is devoted to the continuing effort to help open the commercial space frontier. Heading up the six-member crew is Commander John H. Casper. Curtis L. Brown Jr. is the pilot and there are four mission specialists on board: Daniel W. Bursch, Mario Runco Jr., Andrew S. W. Thomas and Marc Garneau, who represents the Canadian Space Agency. During the approximately 10-day mission, the astronauts will perform a variety of payload activities, including microgravity research aboard the SPACEHAB-4 module, deployment and retrieval of the Spartan 207 carrying the Inflatable Antenna Experiment (IAE) and deployment and rendezvous with the Passive Aerodynamically-Stabilized Magnetically-Damped Satellite (PAMS).

  6. STS-77 Endeavour Launch (side view closeup)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A flawless countdown culminates with an on-time liftoff as the Space Shuttle Endeavour lights up the morning sky. Endeavour was launched on Mission STS-77 from Pad 39B at 6:30:00 a.m. EDT, May 19. The fourth Shuttle mission of 1996 is devoted to the continuing effort to help open the commercial space frontier. Heading up the six-member crew is Commander John H. Casper. Curtis L. Brown Jr. is the pilot and there are four mission specialists on board: Daniel W. Bursch, Mario Runco Jr., Andrew S. W. Thomas and Marc Garneau, who represents the Canadian Space Agency. During the approximately 10-day mission, the astronauts will perform a variety of payload activities, including microgravity research aboard the SPACEHAB-4 module, deployment and retrieval of the Spartan 207 carrying the Inflatable Antenna Experiment (IAE) and deployment and rendezvous with the Passive Aerodynamically-Stabilized Magnetically-Damped Satellite (PAMS).

  7. STS-77 Launch (front view across water)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A flawless countdown culminates with an on-time liftoff as the Space Shuttle Endeavour lights up the morning sky. Endeavour was launched on Mission STS-77 from Pad 39B at 6:30:00 a.m. EDT, May 19. The fourth Shuttle mission of 1996 is devoted to the continuing effort to help open the commercial space frontier. Heading up the six-member crew is Commander John H. Casper. Curtis L. Brown Jr. is the pilot and there are four mission specialists on board: Daniel W. Bursch, Mario Runco Jr., Andrew S. W. Thomas and Marc Garneau, who represents the Canadian Space Agency. During the approximately 10-day mission, the astronauts will perform a variety of payload activities, including microgravity research aboard the SPACEHAB-4 module, deployment and retrieval of the Spartan 207 carrying the Inflatable Antenna Experiment (IAE) and deployment and rendezvous with the Passive Aerodynamically-Stabilized Magnetically-Damped Satellite (PAMS).

  8. STS-77 Endeavour Launch (below SRB closeup)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A flawless countdown culminates with an on-time liftoff as the Space Shuttle Endeavour lights up the morning sky. Endeavour was launched on Mission STS-77 from Pad 39B at 6:30:00 a.m. EDT, May 19. The fourth Shuttle mission of 1996 is devoted to the continuing effort to help open the commercial space frontier. Heading up the six-member crew is Commander John H. Casper. Curtis L. Brown Jr. is the pilot and there are four mission specialists on board: Daniel W. Bursch, Mario Runco Jr., Andrew S. W. Thomas and Marc Garneau, who represents the Canadian Space Agency. During the approximately 10-day mission, the astronauts will perform a variety of payload activities, including microgravity research aboard the SPACEHAB-4 module, deployment and retrieval of the Spartan 207 carrying the Inflatable Antenna Experiment (IAE) and deployment and rendezvous with the Passive Aerodynamically-Stabilized Magnetically-Damped Satellite (PAMS).

  9. STS-77 Launch (from right thru palms)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A flawless countdown culminates with an on-time liftoff as the Space Shuttle Endeavour lights up the morning sky. Endeavour was launched on Mission STS-77 from Pad 39B at 6:30:00 a.m. EDT, May 19. The fourth Shuttle mission of 1996 is devoted to the continuing effort to help open the commercial space frontier. Heading up the six-member crew is Commander John H. Casper. Curtis L. Brown Jr. is the pilot and there are four mission specialists on board: Daniel W. Bursch, Mario Runco Jr., Andrew S. W. Thomas and Marc Garneau, who represents the Canadian Space Agency. During the approximately 10-day mission, the astronauts will perform a variety of payload activities, including microgravity research aboard the SPACEHAB-4 module, deployment and retrieval of the Spartan 207 carrying the Inflatable Antenna Experiment (IAE) and deployment and rendezvous with the Passive Aerodynamically-Stabilized Magnetically-Damped Satellite (PAMS).

  10. STS-77 Launch (below side view)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A flawless countdown culminates with an on-time liftoff as the Space Shuttle Endeavour lights up the morning sky. Endeavour was launched on Mission STS-77 from Pad 39B at 6:30:00 a.m. EDT, May 19. The fourth Shuttle mission of 1996 is devoted to the continuing effort to help open the commercial space frontier. Heading up the six-member crew is Commander John H. Casper. Curtis L. Brown Jr. is the pilot and there are four mission specialists on board: Daniel W. Bursch, Mario Runco Jr., Andrew S. W. Thomas and Marc Garneau, who represents the Canadian Space Agency. During the approximately 10-day mission, the astronauts will perform a variety of payload activities, including microgravity research aboard the SPACEHAB-4 module, deployment and retrieval of the Spartan 207 carrying the Inflatable Antenna Experiment (IAE) and deployment and rendezvous with the Passive Aerodynamically-Stabilized Magnetically-Damped Satellite (PAMS).

  11. Global Precipitation Measurement Mission Launch and Commissioning

    NASA Technical Reports Server (NTRS)

    Davis, Nikesha; Deweese, Keith; Vess, Missie; Welter, Gary; O'Donnell, James R., Jr.

    2015-01-01

    During launch and early operation of the Global Precipitation Measurement (GPM) Mission, the Guidance, Navigation and Control (GNC) analysis team encountered four main on orbit anomalies. These include: (1) unexpected shock from Solar Array deployment, (2) momentum buildup from the Magnetic Torquer Bars (MTBs) phasing errors, (3) transition into Safehold due to albedo-induced Course Sun Sensor (CSS) anomaly, and (4) a flight software error that could cause a Safehold transition due to a Star Tracker occultation. This paper will discuss ways GNC engineers identified and tracked down the root causes. Flight data and GNC on board models will be shown to illustrate how each of these anomalies were investigated and mitigated before causing any harm to the spacecraft. On May 29, 2014, GPM was handed over to the Mission Flight Operations Team after a successful commissioning period. Currently, GPM is operating nominally on orbit, collecting meaningful scientific data that will significantly improve our understanding of the Earth's climate and water cycle.

  12. Use of magnetic effervescent tablet-assisted ionic liquid dispersive liquid-liquid microextraction to extract fungicides from environmental waters with the aid of experimental design methodology.

    PubMed

    Yang, Miyi; Wu, Xiaoling; Jia, Yuhan; Xi, Xuefei; Yang, Xiaoling; Lu, Runhua; Zhang, Sanbing; Gao, Haixiang; Zhou, Wenfeng

    2016-02-04

    In this work, a novel effervescence-assisted microextraction technique was proposed for the detection of four fungicides. This method combines ionic liquid-based dispersive liquid-liquid microextraction with the magnetic retrieval of the extractant. A magnetic effervescent tablet composed of Fe3O4 magnetic nanoparticles, sodium carbonate, sodium dihydrogen phosphate and 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonimide) was used for extractant dispersion and retrieval. The main factors affecting the extraction efficiency were screened by a Plackett-Burman design and optimized by a central composite design. Under the optimum conditions, good linearity was obtained for all analytes in pure water model and real water samples. Just for the pure water, the recoveries were between 84.6% and 112.8%, the limits of detection were between 0.02 and 0.10 μg L(-1) and the intra-day precision and inter-day precision both are lower than 4.9%. This optimized method was successfully applied in the analysis of four fungicides (azoxystrobin, triazolone, cyprodinil, trifloxystrobin) in environmental water samples and the recoveries ranged between 70.7% and 105%. The procedure promising to be a time-saving, environmentally friendly, and efficient field sampling technique.

  13. Electromagnetic launch of lunar material

    NASA Technical Reports Server (NTRS)

    Snow, William R.; Kolm, Henry H.

    1992-01-01

    Lunar soil can become a source of relatively inexpensive oxygen propellant for vehicles going from low Earth orbit (LEO) to geosynchronous Earth orbit (GEO) and beyond. This lunar oxygen could replace the oxygen propellant that, in current plans for these missions, is launched from the Earth's surface and amounts to approximately 75 percent of the total mass. The reason for considering the use of oxygen produced on the Moon is that the cost for the energy needed to transport things from the lunar surface to LEO is approximately 5 percent the cost from the surface of the Earth to LEO. Electromagnetic launchers, in particular the superconducting quenchgun, provide a method of getting this lunar oxygen off the lunar surface at minimal cost. This cost savings comes from the fact that the superconducting quenchgun gets its launch energy from locally supplied, solar- or nuclear-generated electrical power. We present a preliminary design to show the main features and components of a lunar-based superconducting quenchgun for use in launching 1-ton containers of liquid oxygen, one every 2 hours. At this rate, nearly 4400 tons of liquid oxygen would be launched into low lunar orbit in a year.

  14. Space Shuttle Launch: STS-129

    NASA Video Gallery

    STS-129. Space shuttle Atlantis and its six-member crew began an 11-day delivery flight to the International Space Station on Monday, Nov 16, 2009, with a 2:28 p.m. EST launch from NASA's Kennedy S...

  15. STS-1 Pre-Launch

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A timed exposure of the Space Shuttle, STS-1, at Launch Pad A, Complex 39, turns the space vehicle and support facilities into a night- time fantasy of light. Structures to the left of the Shuttle are the fixed and the rotating service structure.

  16. VEGA, a small launch vehicle

    NASA Astrophysics Data System (ADS)

    Duret, François; Fabrizi, Antonio

    1999-09-01

    Several studies have been performed in Europe aiming to promote the full development of a small launch vehicle to put into orbit one ton class spacecrafts. But during the last ten years, the european workforce was mainly oriented towards the qualification of the heavy class ARIANE 5 launch vehicle.Then, due also to lack of visibility on this reduced segment of market, when comparing with the geosatcom market, no proposal was sufficiently attractive to get from the potentially interrested authorities a clear go-ahead, i.e. a financial committment. The situation is now rapidly evolving. Several european states, among them ITALY and FRANCE, are now convinced of the necessity of the availability of such a transportation system, an important argument to promote small missions, using small satellites. Application market will be mainly scientific experiments and earth observation; some telecommunications applications may be also envisaged such as placement of little LEO constellation satellites, or replacement after failure of big LEO constellation satellites. FIAT AVIO and AEROSPATIALE have proposed to their national agencies the development of such a small launch vehicle, named VEGA. The paper presents the story of the industrial proposal, and the present status of the project: Mission spectrum, technical definition, launch service and performance, target development plan and target recurring costs, as well as the industrial organisation for development, procurement, marketing and operations.

  17. Nighttime Launch at NASA Wallops

    NASA Video Gallery

    A U.S. Air Force Minotaur 1 rocket carrying the Department of Defense Operationally Responsive Space office’s ORS-1 satellite was successfully launched at 11:09 p.m. EDT, June 29, 2011, from NASA...

  18. Healthy Border 2020 Embassy Launch

    Cancer.gov

    The U.S.-Mexico Border Health Commission launched the Healthy Border 2020 at the Mexican Embassy in the United States on June 24, 2015. This new initiative aims to strengthening what was accomplished on the previous plan of action entitled Healthy Border 2010.

  19. NASA's Space Launch System: Momentum Builds Toward First Launch

    NASA Technical Reports Server (NTRS)

    May, Todd A.; Lyles, Garry M.

    2014-01-01

    NASA's Space Launch System (SLS) is gaining momentum toward the first launch of a new exploration-class heavy lift launch vehicle for international exploration and science initiatives. The SLS comprises an architecture that begins with a vehicle capable of launching 70 metric tons (t) into low Earth orbit. It will launch the Orion Multi-Purpose Crew Vehicle (MPCV) on its first autonomous flight beyond the Moon and back in December 2017. Its first crewed flight follows in 2021. SLS can evolve to a130-t lift capability and serve as a baseline for numerous robotic and human missions ranging from a Mars sample return to delivering the first astronauts to explore another planet. The SLS Program formally transitioned from the formulation phase to implementation with the successful completion of the rigorous Key Decision Point C review in 2014. As a result, the Agency authorized the Program to move forward to Critical Design Review, scheduled for 2015. In the NASA project life cycle process, SLS has completed 50 percent of its major milestones toward first flight. Every SLS element manufactured development hardware for testing over the past year. Accomplishments during 2013/2014 included manufacture of core stage test articles, preparations for qualification testing the solid rocket boosters and the RS-25 main engines, and shipment of the first flight hardware in preparation for the Exploration Flight Test-1 (EFT-1) in 2014. SLS was conceived with the goals of safety, affordability, and sustainability, while also providing unprecedented capability for human exploration and scientific discovery beyond Earth orbit. In an environment of economic challenges, the SLS team continues to meet ambitious budget and schedule targets through the studied use of hardware, infrastructure, and workforce investments the United States made in the last half century, while selectively using new technologies for design, manufacturing, and testing, as well as streamlined management approaches

  20. Large Diameter Shuttle Launched-AEM (LDSL-AEM) study

    NASA Technical Reports Server (NTRS)

    1976-01-01

    A technical description of a Large Diameter Shuttle Launched-AEM (LDSL-AEM), an AEM base module adapted to carry 5 ft diameter payloads in the shuttle with propulsion for carrying payloads to higher altitude orbits from a 150 NM shuttle orbit, is described. The AEM is designed for launch on the scout launch vehicle. Onboard equipment provides capability to despin, acquire the earth, and control the vehicle in an earth pointing mode using reaction wheels for torque with magnets for all attitude acquisition, wheel desaturation, and nutation damping. Earth sensors in the wheels provide pitch and roll attitude. This system provides autonomous control capability to 1 degree in pitch and roll and 2 degrees in yaw. The attitude can be determined to .5 degrees in pitch and roll and 2 degrees in yaw.

  1. Optical-lattice-assisted magnetic phase transition in a spin-orbit-coupled Bose-Einstein condensate

    NASA Astrophysics Data System (ADS)

    Martone, Giovanni I.; Ozawa, Tomoki; Qu, Chunlei; Stringari, Sandro

    2016-10-01

    We investigate the effect of a periodic potential generated by a one-dimensional optical lattice on the magnetic properties of an S =1 /2 spin-orbit-coupled Bose gas. By increasing the lattice strength one can achieve a magnetic phase transition between a polarized and an unpolarized Bloch wave phase, characterized by a significant enhancement of the contrast of the density fringes. If the wave vector of the periodic potential is chosen close to the roton momentum, the transition could take place at very small lattice intensities, revealing the strong enhancement of the response of the system to a weak density perturbation. By solving the Gross-Pitaevskii equation in the presence of a three-dimensional trapping potential, we shed light on the possibility of observing the magnetic phase transition in currently available experimental conditions.

  2. Plasma-assisted synthesis and high-resolution characterization of anisotropic elemental and bimetallic core-shell magnetic nanoparticles.

    PubMed

    Hennes, M; Lotnyk, A; Mayr, S G

    2014-01-01

    Magnetically anisotropic as well as magnetic core-shell nanoparticles (CS-NPs) with controllable properties are highly desirable in a broad range of applications. With this background, a setup for the synthesis of heterostructured magnetic core-shell nanoparticles, which relies on (optionally pulsed) DC plasma gas condensation has been developed. We demonstrate the synthesis of elemental nickel nanoparticles with highly tunable sizes and shapes and Ni@Cu CS-NPs with an average shell thickness of 10 nm as determined with scanning electron microscopy, high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy measurements. An analytical model that relies on classical kinetic gas theory is used to describe the deposition of Cu shell atoms on top of existing Ni cores. Its predictive power and possible implications for the growth of heterostructured NP in gas condensation processes are discussed.

  3. 14 CFR 417.17 - Launch reporting requirements and launch specific updates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... specific updates. 417.17 Section 417.17 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL... Conditions § 417.17 Launch reporting requirements and launch specific updates. (a) General. A launch operator must satisfy the launch reporting requirements and launch specific updates required by this section...

  4. Inductive Sustainment of Oblate FRCs with the Assistance of Magnetic Diffusion, Shaping and Finite-Lamor Radius Stabilization

    SciTech Connect

    Gerhardt, S.; Belova, E. V.; Yamada, M.; Ji, H.; Inomoto, M.; Jacobson, C. M.; Maqueda, R.; McGeehan, B.; Y., Ren

    2008-07-31

    Oblate field-reversed configurations FRCs have been sustained for >300 µs, or >15 magnetic diffusion times, through the use of an inductive solenoid. These argon FRCs can have their poloidal flux sustained or increased, depending on the timing and strength of the induction. An inward pinch is observed during sustainment, leading to a peaking of the pressure profile and maintenance of the FRC equilibrium. The good stability observed in argon (and krypton) does not transfer to lighter gases, which develop terminal co-interchange instabilities. The stability in argon and krypton is attributed to a combination of external field shaping, magnetic diffusion, and finite-Larmor radius effects.

  5. MAGNETS

    DOEpatents

    Hofacker, H.B.

    1958-09-23

    This patent relates to nmgnets used in a calutron and more particularly to means fur clamping an assembly of magnet coils and coil spacers into tightly assembled relation in a fluid-tight vessel. The magnet comprises windings made up of an assembly of alternate pan-cake type coils and spacers disposed in a fluid-tight vessel. At one end of the tank a plurality of clamping strips are held firmly against the assembly by adjustable bolts extending through the adjacent wall. The foregoing arrangement permits taking up any looseness which may develop in the assembly of coils and spacers.

  6. Rapid Design of Gravity Assist Trajectories

    NASA Technical Reports Server (NTRS)

    Carrico, J.; Hooper, H. L.; Roszman, L.; Gramling, C.

    1991-01-01

    Several International Solar Terrestrial Physics (ISTP) missions require the design of complex gravity assisted trajectories in order to investigate the interaction of the solar wind with the Earth's magnetic field. These trajectories present a formidable trajectory design and optimization problem. The philosophy and methodology that enable an analyst to design and analyse such trajectories are discussed. The so called 'floating end point' targeting, which allows the inherently nonlinear multiple body problem to be solved with simple linear techniques, is described. The combination of floating end point targeting with analytic approximations with a Newton method targeter to achieve trajectory design goals quickly, even for the very sensitive double lunar swingby trajectories used by the ISTP missions, is demonstrated. A multiconic orbit integration scheme allows fast and accurate orbit propagation. A prototype software tool, Swingby, built for trajectory design and launch window analysis, is described.

  7. Dynamic Tow Maneuver Orbital Launch Technique

    NASA Technical Reports Server (NTRS)

    Rutan, Elbert L. (Inventor)

    2014-01-01

    An orbital launch system and its method of operation use a maneuver to improve the launch condition of a booster rocket and payload. A towed launch aircraft, to which the booster rocket is mounted, is towed to a predetermined elevation and airspeed. The towed launch aircraft begins the maneuver by increasing its lift, thereby increasing the flight path angle, which increases the tension on the towline connecting the towed launch aircraft to a towing aircraft. The increased tension accelerates the towed launch aircraft and booster rocket, while decreasing the speed (and thus the kinetic energy) of the towing aircraft, while increasing kinetic energy of the towed launch aircraft and booster rocket by transferring energy from the towing aircraft. The potential energy of the towed launch aircraft and booster rocket is also increased, due to the increased lift. The booster rocket is released and ignited, completing the launch.

  8. Space Launch System Development Status

    NASA Technical Reports Server (NTRS)

    Lyles, Garry

    2014-01-01

    Development of NASA's Space Launch System (SLS) heavy lift rocket is shifting from the formulation phase into the implementation phase in 2014, a little more than three years after formal program approval. Current development is focused on delivering a vehicle capable of launching 70 metric tons (t) into low Earth orbit. This "Block 1" configuration will launch the Orion Multi-Purpose Crew Vehicle (MPCV) on its first autonomous flight beyond the Moon and back in December 2017, followed by its first crewed flight in 2021. SLS can evolve to a130-t lift capability and serve as a baseline for numerous robotic and human missions ranging from a Mars sample return to delivering the first astronauts to explore another planet. Benefits associated with its unprecedented mass and volume include reduced trip times and simplified payload design. Every SLS element achieved significant, tangible progress over the past year. Among the Program's many accomplishments are: manufacture of Core Stage test panels; testing of Solid Rocket Booster development hardware including thrust vector controls and avionics; planning for testing the RS-25 Core Stage engine; and more than 4,000 wind tunnel runs to refine vehicle configuration, trajectory, and guidance. The Program shipped its first flight hardware - the Multi-Purpose Crew Vehicle Stage Adapter (MSA) - to the United Launch Alliance for integration with the Delta IV heavy rocket that will launch an Orion test article in 2014 from NASA's Kennedy Space Center. Objectives of this Earth-orbit flight include validating the performance of Orion's heat shield and the MSA design, which will be manufactured again for SLS missions to deep space. The Program successfully completed Preliminary Design Review in 2013 and Key Decision Point C in early 2014. NASA has authorized the Program to move forward to Critical Design Review, scheduled for 2015 and a December 2017 first launch. The Program's success to date is due to prudent use of proven

  9. NASA's Space Launch System: Moving Toward the Launch Pad

    NASA Technical Reports Server (NTRS)

    Creech, Stephen D.; May, Todd

    2013-01-01

    The National Aeronautics and Space Administration's (NASA's) Space Launch System (SLS) Program, managed at the Marshall Space Flight Center, is making progress toward delivering a new capability for human space flight and scientific missions beyond Earth orbit. Developed with the goals of safety, affordability, and sustainability in mind, the SLS rocket will launch the Orion Multi-Purpose Crew Vehicle (MPCV), equipment, supplies, and major science missions for exploration and discovery. Supporting Orion's first autonomous flight to lunar orbit and back in 2017 and its first crewed flight in 2021, the SLS will evolve into the most powerful launch vehicle ever flown, via an upgrade approach that will provide building blocks for future space exploration and development. NASA is working to develop this new capability in an austere economic climate, a fact which has inspired the SLS team to find innovative solutions to the challenges of designing, developing, fielding, and operating the largest rocket in history. This paper will summarize the planned capabilities of the vehicle, the progress the SLS program has made in the 2 years since the Agency formally announced its architecture in September 2011, and the path the program is following to reach the launch pad in 2017 and then to evolve the 70 metric ton (t) initial lift capability to 130-t lift capability. The paper will explain how, to meet the challenge of a flat funding curve, an architecture was chosen which combines the use and enhancement of legacy systems and technology with strategic new development projects that will evolve the capabilities of the launch vehicle. This approach reduces the time and cost of delivering the initial 70 t Block 1 vehicle, and reduces the number of parallel development investments required to deliver the evolved version of the vehicle. The paper will outline the milestones the program has already reached, from developmental milestones such as the manufacture of the first flight

  10. NASA's Space Launch System: Moving Toward the Launch Pad

    NASA Technical Reports Server (NTRS)

    Creech, Stephen D.; May, Todd A.

    2013-01-01

    The National Aeronautics and Space Administration's (NASA's) Space Launch System (SLS) Program, managed at the Marshall Space Flight Center (MSFC), is making progress toward delivering a new capability for human space flight and scientific missions beyond Earth orbit. Designed with the goals of safety, affordability, and sustainability in mind, the SLS rocket will launch the Orion Multi-Purpose Crew Vehicle (MPCV), equipment, supplies, and major science missions for exploration and discovery. Supporting Orion's first autonomous flight to lunar orbit and back in 2017 and its first crewed flight in 2021, the SLS will evolve into the most powerful launch vehicle ever flown via an upgrade approach that will provide building blocks for future space exploration. NASA is working to deliver this new capability in an austere economic climate, a fact that has inspired the SLS team to find innovative solutions to the challenges of designing, developing, fielding, and operating the largest rocket in history. This paper will summarize the planned capabilities of the vehicle, the progress the SLS Program has made in the 2 years since the Agency formally announced its architecture in September 2011, the path it is following to reach the launch pad in 2017 and then to evolve the 70 metric ton (t) initial lift capability to 130-t lift capability after 2021. The paper will explain how, to meet the challenge of a flat funding curve, an architecture was chosen that combines the use and enhancement of legacy systems and technology with strategic new developments that will evolve the launch vehicle's capabilities. This approach reduces the time and cost of delivering the initial 70 t Block 1 vehicle, and reduces the number of parallel development investments required to deliver the evolved 130 t Block 2 vehicle. The paper will outline the milestones the program has already reached, from developmental milestones such as the manufacture of the first flight hardware, to life

  11. The temperature and electromagnetic field distributions of heat-assisted magnetic recording for bit-patterned media at ultrahigh areal density

    NASA Astrophysics Data System (ADS)

    Pituso, K.; Kaewrawang, A.; Buatong, P.; Siritaratiwat, A.; Kruesubthaworn, A.

    2015-05-01

    In this paper, the temperature and electromagnetic field distributions for bit-patterned media (BPM) with heat-assisted writing technology at areal density of 6.54-17.92 Tb/in2 are investigated by the finite integral technique method. We have found that the BPM can confine temperature better than continuous media. The temperature ratio of neighbor bits to heating bit of BPM at areal density of 6.54-7.69 Tb/in2 is lower than 65% and increases with increasing areal density. The electric field direction is toward the bit and the magnetic field circulates around the heating bit. In addition, the electric field of BPM is the same pattern as continuous media at areal density of 13.17 Tb/in2 or above.

  12. Russian Soyuz Moves to Launch Pad

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Soyuz TM-31 launch vehicle, which carried the first resident crew to the International Space Station, moves toward the launch pad at the Baikonur complex in Kazakhstan. The Russian Soyuz launch vehicle is an expendable spacecraft that evolved out of the original Class A (Sputnik). From the early 1960' until today, the Soyuz launch vehicle has been the backbone of Russia's marned and unmanned space launch fleet. Today, the Soyuz launch vehicle is marketed internationally by a joint Russian/French consortium called STARSEM. As of August 2001, there have been ten Soyuz missions under the STARSEM banner.

  13. A triple-amplification colorimetric assay for antibiotics based on magnetic aptamer-enzyme co-immobilized platinum nanoprobes and exonuclease-assisted target recycling.

    PubMed

    Miao, Yangbao; Gan, Ning; Ren, Hong-Xia; Li, Tianhua; Cao, Yuting; Hu, Futao; Yan, Zhongdan; Chen, Yinji

    2015-11-21

    Herein, an ultrasensitive and selective colorimetric assay for antibiotics, using chloramphenicol (CAP) as the model analyte, was developed based on magnetic aptamer-HRP-platinum composite probes and exonuclease-assisted target recycling. The composite probes were prepared through immunoreactions between the double stranded DNA antibody (anti-DNA) labeled on core-shell Fe3O4@Au nanoparticles (AuMNP-anti-DNA) as the capture probe, and the double stranded aptamer (aptamer hybrid with its complementary oligonucleotides) labeled on Pt@HRP nanoparticles as the nanotracer (ds-Apt-HRP-PtNPs). When the CAP samples were incubated with the probes for 30 min at room temperature, they could be captured by the aptamer to form a nanotracer-CAP complex, which was then released into the supernatant after magnetic separation. This is because the anti-DNA on the capture probes cannot recognize the single strand aptamer-CAP complex. The exonuclease I (Exo I) added into the supernatant can further digest the aptamer-CAP from the 3'-end of the aptamer and the CAP in the aptamer-CAP complex can be released again, which can further participate in a new cycling process to react with the probes. Pt and HRP in the nanotracer could both catalyze and dual amplify the absorbance at 650 nm ascribed to the 3,3',5,5'-tetramethylbenzidine (TMB)-H2O2 system. Moreover, Exo I can assist the target recycling, which can further amplify the signal. Thus, the triple amplified signal can be quantified by ultraviolet-visible spectroscopy. The experimental results showed that the CAP detection possessed a linear range of 0.001-10 ng mL(-1) and a detection limit of 0.0003 ng mL(-1) (S/N = 3). The assay was successfully employed to detect CAP in milk, which is much more facile, time saving, and sensitive than the commercial ELISA kits.

  14. Aqua 10 Years After Launch

    NASA Technical Reports Server (NTRS)

    Parkinson, Claire L.

    2013-01-01

    A little over ten years ago, in the early morning hours of May 4, 2002, crowds of spectators stood anxiously watching as the Delta II rocket carrying NASA's Aqua spacecraft lifted off from its launch pad at Vandenberg Air Force Base in California at 2:55 a.m. The rocket quickly went through a low-lying cloud cover, after which the main portion of the rocket fell to the waters below and the rockets second stage proceeded to carry Aqua south across the Pacific, onward over Antarctica, and north to Africa, where the spacecraft separated from the rocket 59.5 minutes after launch. Then, 12.5 minutes later, the solar array unfurled over Europe, and Aqua was on its way in the first of what by now have become over 50,000 successful orbits of the Earth.

  15. Minuteman 2 launched small satellite

    NASA Technical Reports Server (NTRS)

    Chan, Sunny; Hinders, Kriss; Martin, Trent; Mcmillian, Shandy; Sharp, Brad; Vajdos, Greg

    1994-01-01

    The goal of LEOSat Industries' Spring 1994 project was to design a small satellite that has a strong technology demonstration or scientific justification and incorporates a high level of student involvement. The satellite is to be launched into low earth orbit by the converted Minuteman 2 satellite launcher designed by Minotaur Designs, Inc. in 1993. The launch vehicle shroud was modified to a height of 90 inches, a diameter of 48 inches at the bottom and 35 inches at the top for a total volume of 85 cubic feet. The maximum allowable mass of the payload is about 1100 lb., depending on the launch site, orbit altitude, and inclination. The satellite designed by LEOSat Industries is TerraSat, a remote-sensing satellite that will provide information for use in space-based earth studies. It will consist of infrared and ultraviolet/visible sensors similar to the SDI-developed sensors being tested on Clementine. The sensors will be mounted on the Defense Systems, Inc. Standard Satellite-1 spacecraft bus. LEOSat has planned for two satellites orbiting the Earth with trajectories similar to that of LANDSAT 5. The semi-major axis is 7080 kilometers, the eccentricity is 0, and the inclination is 98.2 degrees. The estimated mass of TerraSat is 145 kilograms and the estimated volume is 1.8 cubic meters. The estimated cost of TerraSat is $13.7 million. The projected length of time from assembly of the sensors to launch of the spacecraft is 13 months.

  16. Minuteman 2 launched small satellite

    NASA Astrophysics Data System (ADS)

    Chan, Sunny; Hinders, Kriss; Martin, Trent; McMillian, Shandy; Sharp, Brad; Vajdos, Greg

    1994-05-01

    The goal of LEOSat Industries' Spring 1994 project was to design a small satellite that has a strong technology demonstration or scientific justification and incorporates a high level of student involvement. The satellite is to be launched into low earth orbit by the converted Minuteman 2 satellite launcher designed by Minotaur Designs, Inc. in 1993. The launch vehicle shroud was modified to a height of 90 inches, a diameter of 48 inches at the bottom and 35 inches at the top for a total volume of 85 cubic feet. The maximum allowable mass of the payload is about 1100 lb., depending on the launch site, orbit altitude, and inclination. The satellite designed by LEOSat Industries is TerraSat, a remote-sensing satellite that will provide information for use in space-based earth studies. It will consist of infrared and ultraviolet/visible sensors similar to the SDI-developed sensors being tested on Clementine. The sensors will be mounted on the Defense Systems, Inc. Standard Satellite-1 spacecraft bus. LEOSat has planned for two satellites orbiting the Earth with trajectories similar to that of LANDSAT 5. The semi-major axis is 7080 kilometers, the eccentricity is 0, and the inclination is 98.2 degrees. The estimated mass of TerraSat is 145 kilograms and the estimated volume is 1.8 cubic meters. The estimated cost of TerraSat is $13.7 million. The projected length of time from assembly of the sensors to launch of the spacecraft is 13 months.

  17. Saturn IB Launch Vehicle - Cutaway

    NASA Technical Reports Server (NTRS)

    1968-01-01

    This 1968 cutaway drawing illustrates the Saturn IB launch vehicle with its two booster stages, the S-IB and S-IVB. 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 mission.

  18. Saturn IB Launch Vehicle Cutaway

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This undated cutaway drawing illustrates the Saturn IB launch vehicle with its two booster stages, the S-IB and S-IVB. 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.

  19. SMART-1 launch date confirmed

    NASA Astrophysics Data System (ADS)

    2003-09-01

    The 'launch window' will be 8:02 p.m. to 8:21 p.m. on Saturday, 27 September, local time in Kourou, French Guiana, and 1:02 a.m. to 1:21 a.m. on Sunday, 28 September, CEST. The SMART-1 spacecraft is now on board its Ariane 5 launcher inside the Final Assembly Building (BAF) at the Kourou spaceport in French Guiana.

  20. Inflatable Launch and Recovery System

    DTIC Science & Technology

    2014-07-31

    and air line connections. Inflatable arch shaped tubes and spacer fabric form the ramp structure from which the tow body can be launched and...also includes power electronics and software controllers. [0015] Multiple, inflatable, arch shaped tubes and spacer fabric form the ramp structure...this manner maintain their shapes when inflated. The panel 36 can be fabricated of woven spacer fabrics, also known as drop stitch fabrics. Such

  1. Atmosphere Explorer set for launch

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The Atmosphere Explorer-D (Explorer-54) is described which will explore in detail an area of the earth's outer atmosphere where important energy transfer, atomic and molecular processes, and chemical reactions occur that are critical to the heat balance of the atmosphere. Data are presented on the mission facts, launch vehicle operations, AE-D/Delta flight events, spacecraft description, scientific instruments, tracking, and data acquisition.

  2. Launch Options for the Future

    DTIC Science & Technology

    1988-01-01

    before 2010 and explores the costs of meet- ing different demand levels for launching humans and spacecraft to orbit. It also discusses the importance...programs: Deploy the Space Station by the mid-90s while maintain- ing an aggressive NASA science program: Send humans to Mars or es- tablish a base on...program goals, they must be made in a highly uncertain environ- ment. A decision to deploy SDI, or to send humans to Mars, would call for space

  3. National Security Space Launch Report

    DTIC Science & Technology

    2006-01-01

    Company Clayton Mowry, President, Arianespace Inc., North American—“Launch Solutions” Elon Musk , CEO and CTO, Space Exploration Technologies (SpaceX...Core Booster powered by the Russian-built RD-180 engine; it began oper- ations in August 2002 and has completed eight successful flights with no...failures. Boeing’s Delta IV family is built around a Common Booster Core powered by the Pratt & Whitney Rocketdyne RS-68 engine; it began operations in

  4. [X-33 Launch and Landing Facilities

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sverdrup is responsible for the design, construction and activation of the X-33 Flight Operations Center at Edwards Air Force Base and for providing assistance in activating the X-33 Landing Sites. The past year has seen the completion of the construction of the X-33 Flight Operations Center. Construction was completed in December of 1998, with systems checkout and testing continuing into early 1999. Integration of the site with LMCMS and other partner-supplied systems began in December and will continue through rollout of the X-33 vehicle. The construction of the X-33 Launch Complex has been performed within the Edwards AFB and Air Force Research Laboratory (AFRL) systems with no substantial interference to either parties. A high level of cooperation exists between Sverdrup, Edwards AFB, and the Air Force Research Laboratory in the areas of access, training, security, and operations. There have been no conflicts between programs that have not been accommodated. Development of the landing sites is progressing with many of the modifications necessary underway. GSE commitments are in place. The personnel training program developed by Sverdrup for persons entering the launch site construction areas, was modified by Lockheed for use in training and access control to the Center during flight operations to maximize safety and minimize intrusion upon the environment. Close cooperation between Sverdrup, the construction workers, and the environmental biologist permitted construction to proceed in a timely fashion without harm to the wildlife, in particular, the Desert Tortoise. Although the entire X-33 site encompasses approximately 50 acres including a new access road, only the areas directly impacted by the construction were cleared to minimize the impact on the environment. A total of about 30 acres was actually disturbed.

  5. Preparation of Gd(OH){sub 3} large single crystals by solid KOH assisted hydrothermal method and their luminescent and magnetic properties

    SciTech Connect

    Wu, Hai; Zhang, Youjin Zhou, Maozhong; Yao, Chengpeng; Ge, Xianjin

    2016-08-15

    Highlights: • Gd(OH){sub 3} large single crystals were prepared by solid KOH assisted hydrothermal method. • The possible growth mechanism of Gd(OH){sub 3} large single crystals was proposed. • The Gd(OH){sub 3} samples emitted a strong narrow-band ultraviolet B (NB-UVB) light. • The Gd(OH){sub 3} samples showed good paramagnetic properties. - Abstract: Large single crystals of gadolinium hydroxide [Gd(OH){sub 3}] in the length of several millimeters were successfully prepared by using solid KOH assisted hydrothermal method. Gd(OH){sub 3} samples were characterized by X-ray diffraction (XRD), 4-circle single-crystal diffraction, Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). FESEM image shows hexagonal prism morphology for the Gd(OH){sub 3} large crystals. The possible growth mechanism of Gd(OH){sub 3} large single crystals was proposed. The photoluminescence and magnetic properties of Gd(OH){sub 3} species were investigated.

  6. Voice command weapons launching system

    NASA Astrophysics Data System (ADS)

    Brown, H. E.

    1984-09-01

    This abstract discloses a voice-controlled weapons launching system for use by a pilot of an aircraft against a plurality of simultaneously appearing (i.e., existing) targets, such as two or more aggressor aircraft (or tanks, or the like) attacking more aggressor aircraft. The system includes, in combination, a voice controlled input device linked to and controlling a computer; apparatus (such as a television camera, receiver, and display), linked to and actuated by the computer by a voice command from the pilot, for acquiring and displaying an image of the multi-target area; a laser, linked to and actuated by the computer by a voice command from the pilot to point to (and to lock on to) any one of the plurality of targets, with the laser emitting a beam toward the designated (i.e., selected) target; and a plurality of laser beam-rider missiles, with a different missile being launched toward and attacking each different designated target by riding the laser beam to that target. Unlike the prior art, the system allows the pilot to use his hands full-time to fly and to control the aircraft, while also permitting him to launch each different missile in rapid sequence by giving a two-word spoken command after he has visually selected each target of the plurality of targets, thereby making it possible for the pilot of a single defender aircraft to prevail against the plurality of simultaneously attacking aircraft, or tanks, or the like.

  7. Switching time in laser pulse heat-assisted magnetic recording using L1{sub 0}-FePt nanoparticles

    SciTech Connect

    Lyberatos, A.; Weller, D.; Parker, G. J.

    2015-04-07

    Atomistic spin model simulations using Langevin dynamics are performed to study the factors that determine the thermomagnetic recording time window in FePt media. The onset of thermomagnetic writing occurs at a temperature T{sub o} larger than the Curie temperature T{sub c} as a result of the finite time of relaxation of the magnetization by the linear reversal mode. The Bloch relaxation rate of magnetization growth during cooling below T{sub c} is independent on the write field, provided the field is stronger than some threshold value. Application of a strong write field reduces switching time through better spin alignment in the paramagnetic regime. Finite size effects on the probability distribution of freezing temperatures T{sub f} and the free energy provide insight on the thermomagnetic reversal mechanism. Constraints on the “pulse-mode” of recording when the head field reverses direction during cooling are also considered.

  8. Interfacial spin-filter assisted spin transfer torque effect in Co/BeO/Co magnetic tunnel junction

    SciTech Connect

    Tang, Y.-H. Chu, F.-C.

    2015-03-07

    The first-principles calculation is employed to demonstrate the spin-selective transport properties and the non-collinear spin-transfer torque (STT) effect in the newly proposed Co/BeO/Co magnetic tunnel junction. The subtle spin-polarized charge transfer solely at O/Co interface gives rise to the interfacial spin-filter (ISF) effect, which can be simulated within the tight binding model to verify the general expression of STT. This allows us to predict the asymmetric bias behavior of non-collinear STT directly via the interplay between the first-principles calculated spin current densities in collinear magnetic configurations. We believe that the ISF effect, introduced by the combination between wurtzite-BeO barrier and the fcc-Co electrode, may open a new and promising route in semiconductor-based spintronics applications.

  9. Three-dimensional magnetic resonance imaging overlay to assist with percutaneous transhepatic access at the time of cardiac catheterization

    PubMed Central

    Whiteside, Wendy; Christensen, Jason; Zampi, Jeffrey D

    2015-01-01

    Multimodality image overlay is increasingly used for complex interventional procedures in the cardiac catheterization lab. We report a case in which three-dimensional magnetic resonance imaging (3D MRI) overlay onto live fluoroscopic imaging was utilized to safely obtain transhepatic access in a 12-year-old patient with prune belly syndrome, complex and distorted abdominal anatomy, and a vascular mass within the liver. PMID:26085770

  10. Preparation and characterization of magnetic allylamine modified graphene oxide-poly(vinyl acetate-co-divinylbenzene) nanocomposite for vortex assisted magnetic solid phase extraction of some metal ions.

    PubMed

    Khan, Mansoor; Yilmaz, Erkan; Sevinc, Basak; Sahmetlioglu, Ertugrul; Shah, Jasmin; Jan, Muhammad Rasul; Soylak, Mustafa

    2016-01-01

    Magnetic allylamine modified graphene oxide-poly(vinyl acetate-co-divinylbenzene) (MGO-DVB-VA) was synthesized and used for magnetic solid phase extraction of Pb(II), Cd(II), Cu(II), Ni(II) and Co(II) prior to their determination by flame atomic absorption spectroscopy. The adsorbent surface functional group was characterized by using FT-IR and Raman spectroscopy. XRD pattern was used to determine the layers of GO. Surface morphology and elemental composition of the adsorbent were evaluated by using SEM and EDX analysis. Various parameters, effecting adsorption efficiency like initial solution pH, adsorbent dose, type and volume of eluent, volume of sample and diverse ions effects were optimized. The preconcentration factor (PF) is 40 for all the metals and the limits of detection for Pb, Cd, Cu, Ni and Co are in the range of 0.37-2.39 µg L(-1) and relative standard deviation below 3.1%. The method was validated by using the method for certified reference materials (Tobacco Leaves (INCT-OBTL-5), Tomato Leaves (1573a), Certified Water (SPS-ww2) and Certified Water (TMDA 64-2)). The method was successfully applied for natural water and food samples.

  11. NASA Crew Launch Vehicle Overview

    NASA Technical Reports Server (NTRS)

    Dumbacher, Daniel L.

    2006-01-01

    The US. Vision for Space Exploration, announced January 2004, outlines the National Aeronautics and Space Administration s (NASA) strategic goals and objectives. These include: 1) Flying the Shuttle as safely as possible until its retirement, not later than 2010. 2) Bringing a new Crew Exploration Vehicle (CEV) into service as soon as possible after Shuttle retirement. 3) Developing a balanced overall program of science, exploration, and aeronautics at NASA, consistent with the redirection of the human spaceflight program to focus on exploration. 4) Completing the International Space Station (ISS) in a manner consistent with international partner commitments and the needs of human exploration. 5) Encouraging the pursuit of appropriate partnerships with the emerging commercial space sector. 6) Establishing a lunar return program having the maximum possible utility for later missions to Mars and other destinations. Following the confirmation of the new NASA Administrator in April 2005, the Agency commissioned a team of aerospace subject matter experts from government and industry to perform the Exploration Systems Architecture Study (ESAS), which provided in-depth information for selecting the follow-on launch vehicle designs to enable these goals, The ESAS team analyzed a number of potential launch systems, with a focus on: (1) a human-rated launch vehicle for crew transport and (2) a heavy lift launch vehicle (HLLV) to carry cargo. After several months of intense study utilizing technical performance, budget, and schedule objectives, the results showed that the optimum architecture to meet the challenge of safe, reliable crew transport is a two-stage variant of the Space Shuttle propulsion system - utilizing the reusable Solid Rocket Booster (SRB) as the first stage, along with a new upper stage that uses a derivative of the RS-25 Space Shuttle Main Engine to deliver 25 metric tons to low-Earth orbit. The CEV that this new Crew Launch Vehicle (CLV) lofts into space

  12. Ultrasonication-assisted one-step self-assembly preparation of biocompatible fluorescent-magnetic nanobeads for rare cancer cell detection

    NASA Astrophysics Data System (ADS)

    Guo, Shan; Chen, Yu-Qi; Lu, Ning-Ning; Wang, Xue-Ying; Xie, Min; Sui, Wei-Ping

    2014-12-01

    Multifunctional nanomaterials simultaneously possessing attractive properties, such as strong fluorescent intensity, excellent superparamagnetic behavior, easy modification and good biocompatibility, are always desired in a wide range of applications. In this work, we present a facile ultrasonication-assisted one-step self-assembly strategy for the fabrication of smart fluorescent-magnetic nanobeads (FMNBs) without using a matrix. Via one-step ultrasonication, organic-soluble superparamagnetic nanoparticles (MNPs) and quantum dots (QDs) were automatically encapsulated by amphiphilic (2-hydroxyl-3-dodecanoxyl) propylcarboxymethylchitosans (HDP-CMCHSs) through hydrophobic interaction to form hydrophilic FMNBs, presenting a good QD fluorescent property and a strong MNP magnetic response. The outer surface of the FMNBs was derived from natural biopolymer chitosans, enabling FMNBs with good biocompatibility and convenience for biological modification. As-prepared FMNBs can be easily modified with streptavidin, facilitating bioconjugation with biotin-labeled human epidermal growth factor (hEGF). hEGF-functionalized FMNBs are able to specifically recognize and capture rare target cells spiked in white blood cells, and the recovered cells can be further cultured for a long time. All of these excellent properties make nanobeads promising for circulating tumor cell (CTC) detection.

  13. Phase constituents and magnetic properties of the CoFe2O4 nanoparticles prepared by polyvinylpyrrolidone (PVP)-assisted hydrothermal route

    NASA Astrophysics Data System (ADS)

    Jalalian, M.; Mirkazemi, S. M.; Alamolhoda, S.

    2016-09-01

    In this research, nanoparticles of cobalt ferrite were synthesized by a simple hydrothermal process at 190 °C using different treatment durations with the assistance of polyvinylpyrrolidone (PVP) surfactant. The synthesized powders were characterized using X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscope and vibration sample magnetometer techniques. The quantitative values of phase constituents and also inversion parameter of cobalt ferrite spinel structure were calculated by Rietveld method using XRD results. XRD results show formation of cobalt ferrite as the main phase in all samples and also the presence of small amounts of Co3O4 lateral phase in some cases. Raman spectroscopies also confirm the presence of this lateral phase. Microstructural studies represent formation of nanoparticles with a narrow particle size distribution. Magnetic measurements represent that maximum magnetization ( M max) values are in the range of 25-57 emu/g with changes in the hydrothermal treatment duration. Intrinsic coercivity force values ( i H c ) change from 0 to 487 Oe in different samples. The highest M max value of 57 emu/g was obtained in the sample after 3 h of hydrothermal treatment with PVP addition. The i H c value of this sample was 35 Oe, while without PVP addition, the high M max value of 60 emu/g is observed in a sample that has i H c value equal to 320 Oe.

  14. Bare and protein-conjugated Fe3O4 ferromagnetic nanoparticles for utilization in magnetically assisted hemodialysis: biocompatibility with human blood cells

    NASA Astrophysics Data System (ADS)

    Stamopoulos, D.; Manios, E.; Gogola, V.; Benaki, D.; Bouziotis, P.; Niarchos, D.; Pissas, M.

    2008-12-01

    Magnetically assisted hemodialysis is a development of conventional hemodialysis and is based on the circulation of ferromagnetic nanoparticle-targeted binding substance conjugates (FN-TBS Cs) in the bloodstream of the patient and their eventual removal by means of a 'magnetic dialyzer'. Presented here is an in vitro investigation on the biocompatibility of bare Fe3O4 FNs and Fe3O4-bovine serum albumin Cs with blood cells, namely red blood cells (RBCs), white blood cells (WBCs) and platelets (Plts). Atomic force microscopy (AFM) and optical microscopy (OM) enabled the examination of blood cells at the nanometer and micrometer level, respectively. The observations made on FN- and C-maturated blood samples are contrasted to those obtained on FN- and C-free reference blood samples subjected to exactly the same maturation procedure. Qualitatively, both AFM and OM revealed no changes in the overall shape of RBCs, WBCs and Plts. Incidents where bare FNs or Cs were bound onto the surface of RBCs or internalized by WBCs were very rare. Detailed examination by means of OM proved that impaired coagulation of Plts is not initiated/promoted either by FNs or Cs. Quantitatively, the statistical analysis of the obtained AFM images from RBC surfaces clearly revealed that the mean surface roughness of RBCs maturated with bare FNs or Cs was identical to the one of reference RBCs.

  15. Quantitative transmission electron microscopy analysis of multi-variant grains in present L1{sub 0}-FePt based heat assisted magnetic recording media

    SciTech Connect

    Ho, Hoan; Zhu, Jingxi; Kulovits, Andreas; Laughlin, David E.; Zhu, Jian-Gang

    2014-11-21

    We present a study on atomic ordering within individual grains in granular L1{sub 0}-FePt thin films using transmission electron microscopy techniques. The film, used as a medium for heat assisted magnetic recording, consists of a single layer of FePt grains separated by non-magnetic grain boundaries and is grown on an MgO underlayer. Using convergent-beam techniques, diffraction patterns of individual grains are obtained for a large number of crystallites. The study found that although the majority of grains are ordered in the perpendicular direction, more than 15% of them are multi-variant, or of in-plane c-axis orientation, or disordered fcc. It was also found that these multi-variant and in-plane grains have always grown across MgO grain boundaries separating two or more MgO grains of the underlayer. The in-plane ordered portion within a multi-variant L1{sub 0}-FePt grain always lacks atomic coherence with the MgO directly underneath it, whereas, the perpendicularly ordered portion is always coherent with the underlying MgO grain. Since the existence of multi-variant and in-plane ordered grains are severely detrimental to high density data storage capability, the understanding of their formation mechanism obtained here should make a significant impact on the future development of hard disk drive technology.

  16. Ultrasound-assisted magnetic solid-phase extraction for the determination of some transition metals in Orujo spirit samples by capillary electrophoresis.

    PubMed

    Peña Crecente, Rosa M; Lovera, Carlha Gutiérrez; García, Julia Barciela; Latorre, Carlos Herrero; Martín, Sagrario García

    2016-01-01

    Ultrasound-assisted magnetic solid-phase extraction coupled to capillary electrophoresis was optimized for the preconcentration and determination of Zn(II), Cu(II), Mn(II) and Cd(II) as their complexes with 1,10-phenanthroline (Phen). Both pre- and on-capillary complexations were employed to obtain stable metal-Phen complexes. The parameters that have an influence on the electrophoretic separation and the MSPE process were studied and optimized using different experimental designs. Metals were extracted from 10 mL of sample at pH 5 using 3mg of magnetic particles functionalized with carboxylic groups. The metals were eluted as metal-Phen complexes and analyzed by capillary electrophoresis. The method showed low limits of detection for metals 0.49-2.19 μg L(-1), and high preconcentration factors, 39-44, The efficiencies of the extraction method were in the range 77.1-87.5% and the precision (RSD < 10%) and accuracy were between 98.2% and 101.6%. The method was applied to the determination of the aforementioned metals in Galician Orujo spirit samples.

  17. Postediting prostate magnetic resonance imaging segmentation consistency and operator time using manual and computer-assisted segmentation: multiobserver study.

    PubMed

    Shahedi, Maysam; Cool, Derek W; Romagnoli, Cesare; Bauman, Glenn S; Bastian-Jordan, Matthew; Rodrigues, George; Ahmad, Belal; Lock, Michael; Fenster, Aaron; Ward, Aaron D

    2016-10-01

    Prostate segmentation on T2w MRI is important for several diagnostic and therapeutic procedures for prostate cancer. Manual segmentation is time-consuming, labor-intensive, and subject to high interobserver variability. This study investigated the suitability of computer-assisted segmentation algorithms for clinical translation, based on measurements of interoperator variability and measurements of the editing time required to yield clinically acceptable segmentations. A multioperator pilot study was performed under three pre- and postediting conditions: manual, semiautomatic, and automatic segmentation. We recorded the required editing time for each segmentation and measured the editing magnitude based on five different spatial metrics. We recorded average editing times of 213, 328, and 393 s for manual, semiautomatic, and automatic segmentation respectively, while an average fully manual segmentation time of 564 s was recorded. The reduced measured postediting interoperator variability of semiautomatic and automatic segmentations compared to the manual approach indicates the potential of computer-assisted segmentation for generating a clinically acceptable segmentation faster with higher consistency. The lack of strong correlation between editing time and the values of typically used error metrics ([Formula: see text]) implies that the necessary postsegmentation editing time needs to be measured directly in order to evaluate an algorithm's suitability for clinical translation.

  18. Launch Services, a Proven Model

    NASA Astrophysics Data System (ADS)

    Trafton, W. C.; Simpson, J.

    2002-01-01

    From a commercial perspective, the ability to justify "leap frog" technology such as reusable systems has been difficult to justify because the estimated 5B to 10B investment is not supported in the current flat commercial market coupled with an oversupply of launch service suppliers. The market simply does not justify investment of that magnitude. Currently, next generation Expendable Launch Systems, including Boeing's Delta IV, Lockheed Martin's Atlas 5, Ariane V ESCA and RSC's H-IIA are being introduced into operations signifying that only upgrades to proven systems are planned to meet the changes in anticipated satellite demand (larger satellites, more lifetime, larger volumes, etc.) in the foreseeable future. We do not see a new fleet of ELVs emerging beyond that which is currently being introduced, only continuous upgrades of the fleet to meet the demands. To induce a radical change in the provision of launch services, a Multinational Government investment must be made and justified by World requirements. The commercial market alone cannot justify such an investment. And if an investment is made, we cannot afford to repeat previous mistakes by relying on one system such as shuttle for commercial deployment without having any back-up capability. Other issues that need to be considered are national science and security requirements, which to a large extent fuels the Japanese, Chinese, Indian, Former Soviet Union, European and United States space transportation entries. Additionally, this system must support or replace current Space Transportation Economies with across-the-board benefits. For the next 10 to 20 years, Multinational cooperation will be in the form of piecing together launch components and infrastructure to supplement existing launch systems and reducing the amount of non-recurring investment while meeting the future requirements of the End-User. Virtually all of the current systems have some form of multinational participation: Sea Launch

  19. Effectivity of atmospheric electricity on launch availability

    NASA Technical Reports Server (NTRS)

    Ernst, John A.

    1991-01-01

    Thunderstorm days at KSC; percentage of frequency of thunderstorms (1957-1989); effect of lightning advisory on ground operations; Shuttle launch history; Shuttle launch weather history; applied meteorology unit; and goals/operational benefits. This presentation is represented by viewgraphs.

  20. Delta launch vehicle inertial guidance system (DIGS)

    NASA Technical Reports Server (NTRS)

    Duck, K. I.

    1973-01-01

    The Delta inertial guidance system, part of the Delta launch vehicle improvement effort, has been flown on three launches and was found to perform as expected for a variety of mission profiles and vehicle configurations.