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Sample records for electrodynamic levitation system

  1. Magnetic Levitation Experiments with the Electrodynamic Wheel

    NASA Astrophysics Data System (ADS)

    Cordrey, Vincent; Gutarra-Leon, Angel; Gaul, Nathan; Majewski, Walerian

    Our experiments explored inductive magnetic levitation using circular Halbach arrays with the strong variable magnetic field on the outer rim of the ring. Such a system is usually called an Electrodynamic Wheel (EDW). Rotating this wheel around a horizontal axis above a flat conducting surface should induce eddy currents in said surface through the variable magnetic flux. The eddy currents produce, in turn, their own magnetic fields which interact with the magnets of the EDW. We constructed two Electrodynamic Wheels with different diameters and demonstrated that the magnetic interactions produce both lift and drag forces on the EDW which can be used for levitation and propulsion of the EDW. The focus of our experiments is the direct measurement of lift and drag forces to compare with theoretical models using wheels of two different radii. Supported by Grants from the Virginia Academy of Science, Society of Physics Students, Virginia Community College System, and the NVCC Educational Foundation.

  2. Study on figure-eight-shaped coil electrodynamic suspension magnetic levitation systems without cross-connection

    SciTech Connect

    Ribani, P.L.; Urbano, N.

    2000-01-01

    Two figure-eight-shaped coils for electrodynamic suspension (EDS) magnetic levitation (MAGLEV) systems without cross-connection are proposed and analyzed. The guideway coils are positioned under the MAGLEV vehicle; they are parallel to the horizontal plane. The interaction of a magnetic module on the vehicle, composed of three or four superconducting (SC) coils, with a guideway module, comprised of two figure-eight coils, is studied by means of the dynamic circuit theory. The currents in the SC coils are supposed to be constant in time while they move as a rigid body, with a constant velocity. Some results are presented and compared with those for a standard side-wall cross-connected system.

  3. Laboratory Scale Prototype of a Low-Speed Electrodynamic Levitation System Based on a Halbach Magnet Array

    ERIC Educational Resources Information Center

    Iniguez, J.; Raposo, V.

    2009-01-01

    In this paper we analyse the behaviour of a small-scale model of a magnetic levitation system based on the Inductrack concept. Drag and lift forces acting on our prototype, moving above a continuous copper track, are studied analytically following a simple low-speed approach. The experimental results are in good agreement with the theoretical…

  4. Propulsion and Levitation with a Large Electrodynamic Wheel

    NASA Astrophysics Data System (ADS)

    Gaul, Nathan; Lane, Hannah

    We constructed an electrodynamic wheel using a motorized bicycle wheel with a radius of 12 inches and 36 one-inch cube magnets attached to the rim of the wheel. The radial magnetic field on the outside of the wheel was maximized by arranging the magnets into a series of Halbach arrays which amplify the field on one side of the array and reduce it on the other side. Rotating the wheel produces a rapidly oscillating magnetic field. When a conductive metal ``track'' is placed in this area of strong magnetic flux, eddy currents are produced in the track. These eddy currents create magnetic fields that interact with the magnetic fields from the electrodynamic wheel. The interaction of the magnetic fields produces lift and drag forces on the track which were measured with force gauges. Measurements were taken at a variety of wheel speeds, and the results were compared to the theoretical prediction that there should be a linear relationship between the lift and drag forces with increasing wheel speed. Partial levitation was achieved with the current electrodynamic wheel. In the future, the wheel will be upgraded to include 72 magnets rather than 36 magnets. This will double the frequency at which the magnetic field oscillates, increasing the magnetic flux. Electrodynamic wheels have applications to the transportation industry, since multiple electrodynamic wheels could be used on a vehicle to produce a lift and propulsion force over a conductive track.

  5. Lift to Drag Ratio Analysis in Magnetic Levitation with an Electrodynamic Wheel

    NASA Astrophysics Data System (ADS)

    Gutarra-Leon, Angel; Cordrey, Vincent; Majewski, Walerian

    Our experiments explored inductive magnetic levitation (MagLev) using simple permanent magnets and conductive tracks. Our investigations used a circular Halbach array with a 1 Tesla variable magnetic field on the outer rim of the ring. Such a system is usually called an Electrodynamic Wheel (EDW). Rotating this wheel around a horizontal axis above or below a flat conducting surface should induce eddy currents in said surface through the variable magnetic flux. The eddy currents produce, in turn, their own magnetic fields, which interact with the magnets of the EDW. We constructed a four-inch diameter Electrodynamic Wheel using twelve Neodymium permanent magnets and demonstrated that the magnetic interactions produce both lift and drag forces on the EDW. These forces can be used for levitation and propulsion of the EDW to produce magnetic levitation without coils and complex control circuitry. We achieved full levitation of the non-magnetic aluminum and copper plates. Our results confirm the expected behavior of lift to drag ratio as proportional to (L/R) ω, with L and R being the inductance and resistance of the track plate, and ω being the angular velocity of the magnetic flux. Supported by grants from the Virginia Academy of Science, Society of Physics Students, Virginia Community College System, and the NVCC Educational Foundation.

  6. Electrodynamic Tether Propulsion System

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This picture is an artist's concept of an orbiting vehicle using the Electrodynamic Tethers Propulsion System. Relatively short electrodynamic tethers can use solar power to push against a planetary magnetic field to achieve propulsion without the expenditure of propellant.

  7. Perspectives of an acoustic electrostatic/electrodynamic hybrid levitator for small fluid and solid samples

    NASA Astrophysics Data System (ADS)

    Lierke, E. G.; Holitzner, L.

    2008-11-01

    The feasibility of an acoustic-electrostatic hybrid levitator for small fluid and solid samples is evaluated. A proposed design and its theoretical assessment are based on the optional implementation of simple hardware components (ring electrodes) and standard laboratory equipment into typical commercial ultrasonic standing wave levitators. These levitators allow precise electrical charging of drops during syringe- or ink-jet-type deployment. The homogeneous electric 'Millikan field' between the grounded ultrasonic transducer and the electrically charged reflector provide an axial compensation of the sample weight in an indifferent equilibrium, which can be balanced by using commercial optical position sensors in combination with standard electronic PID position control. Radial electrostatic repulsion forces between the charged sample and concentric ring electrodes of the same polarity provide stable positioning at the centre of the levitator. The levitator can be used in a pure acoustic or electrostatic mode or in a hybrid combination of both subsystems. Analytical evaluations of the radial-axial force profiles are verified with detailed numerical finite element calculations under consideration of alternative boundary conditions. The simple hardware modification with implemented double-ring electrodes in ac/dc operation is also feasible for an electrodynamic/acoustic hybrid levitator.

  8. Electrodynamic tether system study

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The purpose of this program is to define an Electrodynamic Tether System (ETS) that could be erected from the space station and/or platforms to function as an energy storage device. A schematic representation of the ETS concept mounted on the space station is presented. In addition to the hardware design and configuration efforts, studies are also documented involving simulations of the Earth's magnetic fields and the effects this has on overall system efficiency calculations. Also discussed are some preliminary computer simulations of orbit perturbations caused by the cyclic/night operations of the ETS. System cost estimates, an outline for future development testing for the ETS system, and conclusions and recommendations are also provided.

  9. Analysis of an electrodynamic maglev system

    SciTech Connect

    Davey, K.

    1999-09-01

    Electrodynamic systems (EDS's) for maglev have an advantage over electromagnetic systems (EMS's) in that the stability is built into the system. EDS's induce the currents used for levitation and guidance, while EMS's impose those currents with controlled feedback. The movement of a magnet over properly designed EDS coils results in forces to keep the system fixed in the lowest energy or null flux spot. In the past such systems have been examined through two-dimensional boundary element techniques. An approximation to the full three-dimensional time harmonic problem is obtained through LaPlace transform theory after using boundary element methods to predict the mutual coupling of the magnets with the track coils. The analytic solution offers helpful design and operation guidelines.

  10. Compact rf heating and levitation systems for the NASA modular electromagnetic levitator

    NASA Technical Reports Server (NTRS)

    Fox, R. J.

    1990-01-01

    The levitator demonstrates levitation of a 5 mm diam aluminum sphere at 1 G using a small, compact rf levitator operating from a small 12-V battery. This system is designed to levitate and melt niobium in space; however, the small battery unit limits the power for melting operations.

  11. Study of Japanese electrodynamic-suspension maglev systems

    NASA Astrophysics Data System (ADS)

    He, J. L.; Rote, D. M.; Coffey, H. T.

    1994-04-01

    This report presents the results of a study of the Japanese MLU magnetic levitation (maglev) system. The development of the MLU system is reviewed, and the dynamic circuit model then is introduced and applied to the figure-eight-shaped null-flux coil suspension system. Three different types of figure-eight-shaped null-flux suspension systems are discussed in detail: (1) the figure-eight-shaped null-flux coil suspension system without cross-connection; (2) the combined suspension and guidance system; and (3) the combined propulsion, levitation, and guidance system. The electrodynamic suspension maglev systems developed in Japan seem to be very promising and could result in a commercial application in the near future.

  12. Study of Japanese electrodynamic-suspension maglev systems

    SciTech Connect

    He, J.L.; Rote, D.M.; Coffey, H.T.

    1994-04-01

    This report presents the results of a study of the Japanese MLU magnetic-levitation (maglev) system. The development of the MLU system is reviewed, and the dynamic circuit model then is introduced and applied to the figure-eight-shaped null-flux coil suspension system. Three different types of figure-eight-shaped null-flux suspension systems are discussed in detail: (1) the figure-eight-shaped null-flux coil suspension system without cross-connection; (2) the combined suspension and guidance system; and (3) the combined propulsion, levitation, and guidance system. The electrodynamic-suspension maglev systems developed in Japan seem to be very promising and could result in a commercial application in the near future.

  13. Oscillation damping means for magnetically levitated systems

    DOEpatents

    Post, Richard F.

    2009-01-20

    The present invention presents a novel system and method of damping rolling, pitching, or yawing motions, or longitudinal oscillations superposed on their normal forward or backward velocity of a moving levitated system.

  14. Discontinuous hygroscopic growth of an aqueous surfactant/salt aerosol particle levitated in an electrodynamic balance

    NASA Astrophysics Data System (ADS)

    Soonsin, V.; Krieger, U. K.; Peter, T.

    2010-12-01

    Organic compounds are a major fraction of tropospheric aerosol. The organic fraction is usually internally mixed with inorganic salts. Surface-active organic matter or surfactants, enriched in the oceanic surface layer and transferred to the atmosphere by bubble-bursting processes, are the most likely candidates to contribute the observed organic fraction in sea salt aerosol [1, 2]. If the organic substance is a surfactant, it will lower the surface tension. In addition aggregates of the organic monomers, called micelles, will form if the concentration of the organic exceeds a certain limit (critical micelle concentration). These aggregates do have different morphology (spheres or globular or rod like micelles, or spherical bilayer vesicles etc.) and size, depending on the nature of the organic molecule, its concentration and the concentration of inorganic salts [3]. These aggregate may promote solubilisation of organic compounds in aqueous atmospheric aerosol. We performed measurements of ternary aqueous solution particles consisting of tetraethylene glycol monooctyl ether (C8E4) as organic surfactant and sodium chloride (NaCl) as inorganic salt and water (H2O) using single levitated aerosol particles in an electrodynamic balance. The particles can be stored contact-free in a temperature and humidity controlled chamber and optical resonance spectroscopy is used to monitor radius change [4]. Mie resonance spectra of ternary droplets show discontinuous growth with increasing relative humidity (RH) and also discontinuous shrinkage with decreasing relative humidity. We observe this behavior at temperatures and RHs at which the salt is completely deliquesced and the concentration of the organic surfactant is larger than the critical micelle concentration. Independent measurements of particle mass show also discontinuous water uptake. We speculate that this discontinuous, step-like, growth is caused by disaggregation of a micelle needed to conserve the monolayer of

  15. Characteristics of an electromagnetic levitation system using a bulk superconductor

    SciTech Connect

    Senba, A.; Kitahara, H.; Ohsaki, H.; Masada, E.

    1996-09-01

    It is beneficial to apply a high-Tc bulk superconductor as a large flux source to an electromagnetic levitation system, which needs large amounts of levitation force. The authors made an attractive-type electromagnetic levitation system using a hybrid magnet that mainly consisted of bulk superconductor and control coils to confirm the principle of the levitation, and obtained characteristics of its system by both experiment and numerical analysis with magnetic circuit calculation. This is applicable to maglev transportation systems.

  16. Magnetic levitation self-regulating systems

    SciTech Connect

    Tozoni, O.

    1993-06-08

    A magnet levitation self-regulating system is described comprising monotypic magnetic devices combined together by rigid nonmagnetic couplers; said magnetic device comprising two cylindrical parts extended along a cylinder generatrix: a. an iron core having a symmetrical C-shaped cross section and an air gap between its core shoes; and b. a permanent magnet having a rectangular cross-section disposed in said air gap; wherein all the iron cores of said magnetic devices are fixed on a common foundation by a first plurality of rigid nonmagnetic couplers and formed a stator assembly; all the permanent magnets of said magnetic devices are connected together by a second plurality of rigid non-magnetic couplers and form a levitator assembly; said permanent magnets of said levitator generate an original magnetic field and magnetize the stator cores; said stator cores create a secondary magnetic field; both said original and secondary magnetic fields create a magnetic levitation force that provides a stable hovering of said levitator in a resulting magnetic field of said system.

  17. Systems analysis of electrodynamic tethers

    SciTech Connect

    Samantha, R.I.; Hastings, D.E.; Ahedo, E. )

    1992-06-01

    A dynamic simulation model is developed and employed in a new system study to investigate the performance of electrodynamic tethers, both as power generators and thrusters. The electron collection performance of a contactor and a bare wire tether, both separately and in combination, are compared and contrasted. The power and thrust generated by a bare wire tether is found to have a higher dependence on the geomagnetic and ionospheric fluctuations. However, depending on the performance of the contactor, the combination of a bare tether and contactor can substantially boost performance for power generation. As a pure thruster, the contactor tether is examined at constant current, voltage, thrust, and power. It is found that the best mode of operation is with constant power, with resulting power/thrust ratios better than those for ion or magnetoplasmadynamic engines. It is concluded that tethers offer greater potential than previously envisioned. 13 refs.

  18. Electrostatic Liquid-Drop-Levitation System

    NASA Technical Reports Server (NTRS)

    Rhim, Won Kyu; Chung, San Kun; Hyson, Michael T.; Elleman, Daniel D.

    1988-01-01

    Electrostatic levitator has levitated drops of liquid up to 4 mm in diameter while maintaining spherical drop shapes. Stable levitation of spherical drops valuable in experiments involving super-cooling, solidification, and crystal growth.

  19. Knolle Magnetrans: A magnetically levitated train system

    NASA Technical Reports Server (NTRS)

    Knolle, Ernst G.

    1992-01-01

    The Knolle Magnetrans is a continuous transportation system featuring small cars traveling in rapid succession, levitated by permanent magnets in repulsion, and propelled by stationary linear induction motors. The vehicles' headway, speed, acceleration, and deceleration are designed into the system and mechanically enforced. Passengers board dynamically and controls consist of a simple on-off relay. This paper summarizes the system design goals, describes the system components and discusses related environmental issues.

  20. MSFC Electrostatic Levitator (ESL) Rapid Quench System

    NASA Technical Reports Server (NTRS)

    SanSoucie, Michael P.; Craven, Paul D.; Rogers, Jan R.

    2014-01-01

    The NASA Marshall Space Flight Center (MSFC) Electrostatic Levitator (ESL) Laboratory is a unique facility for investigators studying high-temperature materials. The laboratory boasts two levitators in which samples can be levitated, heated, melted, undercooled, and resolidified, all without the interference of a container or data-gathering instrument. The ESL main chamber has been upgraded with the addition of a rapid quench system. This system allows samples to be dropped into a quench vessel that can be filled with a low melting point material, such as a gallium or indium alloy. Thereby allowing rapid quenching of undercooled liquid metals. Up to 8 quench vessels can be loaded into the quench wheel, which is indexed with LabVIEW control software. This allows up to 8 samples to be rapidly quenched before having to open the chamber. The system has been tested successfully on several zirconium samples. Future work will be done with other materials using different quench mediums. Microstructural analysis will also be done on successfully quench samples.

  1. Effective method to control the levitation force and levitation height in a superconducting maglev system

    NASA Astrophysics Data System (ADS)

    Yang, Peng-Tao; Yang, Wan-Min; Wang, Miao; Li, Jia-Wei; Guo, Yu-Xia

    2015-11-01

    The influence of the width of the middle magnet in the permanent magnet guideways (PMGs) on the levitation force and the levitation height of single-domain yttrium barium copper oxide (YBCO) bulks has been investigated at 77 K under the zero field cooled (ZFC) state. It is found that the largest levitation force can be obtained in the system with the width of the middle magnet of the PMG equal to the size of the YBCO bulk when the gap between the YBCO bulk and PMG is small. Both larger levitation force and higher levitation height can be obtained in the system with the width of the middle magnet of the PMG larger than the size of the YBCO bulk. The stiffness of the levitation force between the PMG and the YBCO bulk is higher in the system with a smaller width of the middle magnet in the PMG. These results provide an effective way to control the levitation force and the levitation height for the superconducting maglev design and applications. Project supported by the National Natural Science Foundation of China (Grant Nos. 51342001 and 50872079), the Key-grant Project of Chinese Ministry of Education (Grant No. 311033), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120202110003), the Innovation Team in Shaanxi Province, China (Grant No. 2014KTC-18), and the Fundamental Research Funds for the Central Universities, China (Grant Nos. GK201101001 and GK201305014), and the Outstanding Doctoral Thesis Foundation Project of Shaanxi Normal University, China (Grant Nos. X2011YB08 and X2012YB05).

  2. Propulsion and stabilization system for magnetically levitated vehicles

    DOEpatents

    Coffey, Howard T.

    1993-06-29

    A propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and stabilized by a system which includes propulsion windings mounted above and parallel to vehicle-borne suspension magnets. A linear synchronous motor is part of the vehicle guideway and is mounted above and parallel to superconducting magnets attached to the magnetically levitated vehicle.

  3. Levitation properties of maglev systems using soft ferromagnets

    NASA Astrophysics Data System (ADS)

    Huang, Chen-Guang; Zhou, You-He

    2015-03-01

    Soft ferromagnets are widely used as flux-concentration materials in the design of guideways for superconducting magnetic levitation transport systems. In order to fully understand the influence of soft ferromagnets on the levitation performance, in this work we apply a numerical model based on the functional minimization method and the Bean’s critical state model to study the levitation properties of an infinitely long superconductor immersed in the magnetic field created by a guideway of different sets of infinitely long parallel permanent magnets with soft ferromagnets between them. The levitation force, guidance force, magnetic stiffness and magnetic pole density are calculated considering the coupling between the superconductor and soft ferromagnets. The results show that the levitation performance is closely associated with the permanent magnet configuration and with the location and dimension of the soft ferromagnets. Introducing the soft ferromagnet with a certain width in a few configurations always decreases the levitation force. However, for most configurations, the soft ferromagnets contribute to improve the levitation performance only when they have particular locations and dimensions in which the optimized location and thickness exist to increase the levitation force the most. Moreover, if the superconductor is laterally disturbed, the presence of soft ferromagnets can effectively improve the lateral stability for small lateral displacement and reduce the degradation of levitation force.

  4. Magnetic Levitation.

    ERIC Educational Resources Information Center

    Rossing, Thomas D.; Hull, John R.

    1991-01-01

    Discusses the principles of magnetic levitation presented in the physics classroom and applied to transportation systems. Topics discussed include three classroom demonstrations to illustrate magnetic levitation, the concept of eddy currents, lift and drag forces on a moving magnet, magnetic levitation vehicles, levitation with permanent magnets…

  5. Corridor guided transport system utilizing permanent magnet levitation

    SciTech Connect

    Geraghty, J.J.; Poland, A.P.; Lombardi, J.A.

    1995-07-01

    The invention relates to a corridor guided transport system including a guided goods conveyance container utilizing permanent magnet levitation. The transport system of the invention eliminates the need for the wheel and track arrangement presently required by known and utilized conventional train systems and also required by some conventional magnetic levitation transport systems and, as a result, is safer to operate and maintain than either of these known transportation systems.

  6. Control and dynamics of an anti-friction levitation system

    NASA Technical Reports Server (NTRS)

    Ih, C.-H. C.; Vivian, H.; Ahmed, A.; Wang, S. J.

    1992-01-01

    A novel anti-friction levitator concept has been devised and analytically evaluated to overcome support bearing friction and thereby minimize the structural damping of the Large Spacecraft Control Laboratory (LSCL) experiment structure at JPL. A dynamic model and controller design have been developed for the new levitation system. Simulation results show excellent system performance even when the system is subjected to significant measurement noise and hardware saturation effects.

  7. The electrodynamic and hydrodynamic phenomena in magnetically-levitated molten droplets. I - Steady state behavior

    NASA Technical Reports Server (NTRS)

    Zong, Jin-Ho; Li, Benqiang; Szekely, Julian

    1992-01-01

    A mathematical formulation is given and computed results are presented describing the behavior of electromagnetically-levitated metal droplets under the conditions of microgravity. In the formulation the electromagnetic force field is calculated using a modification of the volume integral method and these results are then combined with the FIDAP code to calculate the steady state melt velocities. The specific computational results are presented for the conditions corresponding to the planned IML-2 Space Shuttle experiment, using the TEMPUS device, which has separate 'heating' and 'positioning' coils. While the computed results are necessarily specific to the input conditions, some general conclusions may be drawn from this work. These include the fact that for the planned TEMPUS experiments to positioning coils will produce only a weak melt circulation, while the heating coils are like to produce a mildly turbulent recirculating flow pattern within the samples. The computed results also allow us to assess the effect of sample size, material properties and the applied current on these phenomena.

  8. Coarse-fine residual gravity cancellation system with magnetic levitation

    NASA Technical Reports Server (NTRS)

    Salcudean, S. E.; Davis, H.; Chen, C. T.; Goertz, D. E.; Tryggvason, B. V.

    1992-01-01

    Aircraft flight along parabolic trajectories have been proposed and executed in order to achieve low cost, near free fall conditions of moderate duration. This paper describes a six degree of freedom experiment isolation system designed to cancel out residual accelerations due to mechanical vibrations and errors in aircraft trajectory. The isolation system consists of a fine motion magnetic levitator whose stator is transported by a conventional coarse motion stage. The levitator uses wide gap voice coil actuators and has the dual purpose of isolating the experiment platform from aircraft vibrations and actively cancelling residual accelerations through feedback control. The course motion stage tracks the levitated platform in order to keep the levitator's coils centered within their matching magnetic gaps. Aspects of system design, an analysis of the proposed control strategy and simulation results are presented. Feasibility experiments are also discussed.

  9. Eddy damping effect of additional conductors in superconducting levitation systems

    NASA Astrophysics Data System (ADS)

    Jiang, Zhao-Fei; Gou, Xiao-Fan

    2015-12-01

    Passive superconducting levitation systems consisting of a high temperature superconductor (HTSC) and a permanent magnet (PM) have demonstrated several fascinating applications such as the maglev system, flywheel energy storage. Generally, for the HTSC-PM levitation system, the HTSC with higher critical current density Jc can obtain larger magnetic force to make the PM levitate over the HTSC (or suspended below the HTSC), however, the process of the vibration of the levitated PM, provides very limited inherent damping (essentially hysteresis). To improve the dynamic stability of the levitated PM, eddy damping of additional conductors can be considered as the most simple and effective approach. In this article, for the HTSC-PM levitation system with an additional copper damper attached to the HTSC, we numerically and comprehensively investigated the damping coefficient c, damping ratio, Joule heating of the copper damper, and the vibration frequency of the PM as well. Furthermore, we comparatively studied four different arrangements of the copper damper, on the comprehensive analyzed the damping effect, efficiency (defined by c/VCu, in which VCu is the volume of the damper) and Joule heating, and finally presented the most advisable arrangement.

  10. Change in the coil distribution of electrodynamic suspension system

    NASA Technical Reports Server (NTRS)

    Tanaka, Hisashi

    1992-01-01

    At the Miyazaki Maglev Test Center, the initial test runs were completed using a system design that required the superconducting coils to be parallel with the ground levitation coils. Recently, the coil distribution was changed to a system such that the two types of coils were perpendicular to each other. Further system changes will lead to the construction of a side wall levitation system. It is hoped that the development will culminate in a system whereby a superconducting coil will maintain all the functions: levitation, propulsion, and guidance.

  11. Dual-keel electrodynamic maglev system

    SciTech Connect

    He, J.; Wang, Z.; Rote, D.M.; Coffey, H.T.; Hull, J.R.; Mulcahy, T.M.; Cai, Y.

    1995-12-31

    A propulsion and stabilization system with a plurality of superconducting magnetic devices affixed to the dual-keels of a vehicle, where the superconducting magnetic devices produce a magnetic field when energized. The system also includes a plurality of figure-eight shaped null-flux coils affixed to opposing vertical sides of slots in a guideway. The figure-eight shaped null-flux coils are vertically oriented, laterally cross-connected in parallel, longitudinally connected in series, and continue the length of the vertical slots providing levitation and guidance force. An external power source energizes the figure-eight shaped null-flux coils to create a magnetic traveling wave that interacts with the magnetic field produced by the superconducting magnets to impart motion to the vehicle.

  12. Dual-keel electrodynamic maglev system

    DOEpatents

    He, Jianliang; Wang, Zian; Rote, Donald M.; Coffey, Howard T.; Hull, John R.; Mulcahy, Thomas M.; Cal, Yigang

    1996-01-01

    A propulsion and stabilization system with a plurality of superconducting magnetic devices affixed to the dual-keels of a vehicle, where the superconducting magnetic devices produce a magnetic field when energized. The system also includes a plurality of figure-eight shaped null-flux coils affixed to opposing vertical sides of slots in a guideway. The figure-eight shaped null-flux coils are vertically oriented, laterally cross-connected in parallel, longitudinally connected in series, and continue the length of the vertical slots providing levitation and guidance force. An external power source energizes the figure-eight shaped null-flux coils to create a magnetic traveling wave that interacts with the magnetic field produced by the superconducting magnets to impart motion to the vehicle.

  13. Dual-keel electrodynamic maglev system

    DOEpatents

    He, J.L.; Wang, Z.; Rote, D.M.; Coffey, H.T.; Hull, J.R.; Mulcahy, T.M.; Cal, Y.

    1996-12-24

    A propulsion and stabilization system is disclosed with a plurality of superconducting magnetic devices affixed to the dual-keels of a vehicle, where the superconducting magnetic devices produce a magnetic field when energized. The system also includes a plurality of figure-eight shaped null-flux coils affixed to opposing vertical sides of slots in a guideway. The figure-eight shaped null-flux coils are vertically oriented, laterally cross-connected in parallel, longitudinally connected in series, and continue the length of the vertical slots providing levitation and guidance force. An external power source energizes the figure-eight shaped null-flux coils to create a magnetic traveling wave that interacts with the magnetic field produced by the superconducting magnets to impart motion to the vehicle. 6 figs.

  14. Dual-keel electrodynamic Maglev system

    SciTech Connect

    He, Jianliang; Rote, D.M.; Wang, Zian; Coffey, H.T.

    1995-12-31

    This paper introduces a new concept for an electrodynamic-suspension maglev system that has a dual-keel arrangement. Each keel consists of a row of superconducting magnets aboard the vehicle. The keels move in troughs in the guideway that are each lined with pairs of figure-eight-shaped null-flux coils. Each pair of null-flux coils is cross-connected to produce null-flux suspension and guidance force. The cross-connected figure-eight null-flux coils in each trough are also energized by a three-phase power supply to produce propulsive force. Preliminary analysis shows that the new system has many advantages over other EDS systems in terms of system performance and dynamic stability.

  15. Magnetic Field Gradient Levitation System for Physics and Biophysics

    NASA Astrophysics Data System (ADS)

    Valles, James; Guevorkian, Karine

    2002-03-01

    We are developing a Magnetic Field Gradient Levitation (MFGL) apparatus as a ground based system for simulating a low or variable gravity environment for diamagnetic materials. The system consists of a superconducting solenoid with a room temperature bore that can generate a magnetic force strong enough to levitate or cancel the body force of gravity in common organic materials (e.g. water, proteins, polypropylene). We will describe the specifications and capabilities of the apparatus and our initial experimental studies of gravitational sensitivity in the biological systems, frog embryos and paramecium.

  16. Combination Solar Sail and Electrodynamic Tether Propulsion System

    NASA Technical Reports Server (NTRS)

    Johnson, Charles L. (Inventor); Matloff, Gregory L. (Inventor)

    2003-01-01

    A propulsion system for a spacecraft includes a solar sail system and an electrodynamic tether system is presented. The solar sail system is used to generate propulsion to propel the spacecraft through space using solar photons and the electrodynamic tether system is used to generate propulsion to steer the spacecraft into orbit and to perform orbital maneuvers around a planet using the planet's magnetic field. The electrodynamic tether system can also be used to generate power for the spacecraft using the planet's magnetic field.

  17. Magnetic levitation system for moving objects

    DOEpatents

    Post, R.F.

    1998-03-03

    Repelling magnetic forces are produced by the interaction of a flux-concentrated magnetic field (produced by permanent magnets or electromagnets) with an inductively loaded closed electric circuit. When one such element moves with respect to the other, a current is induced in the circuit. This current then interacts back on the field to produce a repelling force. These repelling magnetic forces are applied to magnetically levitate a moving object such as a train car. The power required to levitate a train of such cars is drawn from the motional energy of the train itself, and typically represents only a percent or two of the several megawatts of power required to overcome aerodynamic drag at high speeds. 7 figs.

  18. Magnetic levitation system for moving objects

    DOEpatents

    Post, Richard F.

    1998-01-01

    Repelling magnetic forces are produced by the interaction of a flux-concentrated magnetic field (produced by permanent magnets or electromagnets) with an inductively loaded closed electric circuit. When one such element moves with respect to the other, a current is induced in the circuit. This current then interacts back on the field to produce a repelling force. These repelling magnetic forces are applied to magnetically levitate a moving object such as a train car. The power required to levitate a train of such cars is drawn from the motional energy of the train itself, and typically represents only a percent or two of the several megawatts of power required to overcome aerodynamic drag at high speeds.

  19. Damping in high-temperature superconducting levitation systems

    DOEpatents

    Hull, John R.

    2009-12-15

    Methods and apparatuses for improved damping in high-temperature superconducting levitation systems are disclosed. A superconducting element (e.g., a stator) generating a magnetic field and a magnet (e.g. a rotor) supported by the magnetic field are provided such that the superconducting element is supported relative to a ground state with damped motion substantially perpendicular to the support of the magnetic field on the magnet. Applying this, a cryostat housing the superconducting bearing may be coupled to the ground state with high damping but low radial stiffness, such that its resonant frequency is less than that of the superconducting bearing. The damping of the cryostat may be substantially transferred to the levitated magnetic rotor, thus, providing damping without affecting the rotational loss, as can be derived applying coupled harmonic oscillator theory in rotor dynamics. Thus, damping can be provided to a levitated object, without substantially affecting the rotational loss.

  20. Analysis of the combined maglev levitation, propulsion, and guidance system

    SciTech Connect

    He, J.L.; Coffey, H.T.; Rote, D.M.

    1995-03-01

    An analysis of a Japanese maglev system that uses only one set of coils in the guideway for combined levitation, propulsion, and guidance functions is presented. This preliminary study, using the dynamic circuit approach, indicates that the system is very promising.

  1. Technical background for a demonstration magnetic levitation system

    NASA Technical Reports Server (NTRS)

    Britcher, Colin P.

    1987-01-01

    A preliminary technical assessment of the feasibility of a demonstration Magnetic Levitation system, required to support aerodynamic models with a specified clear air volume around them, is presented. Preliminary calculations of required sizes of electromagnets and power supplies are made, indicating that the system is practical. Other aspects, including model position sensing and controller design, are briefly addressed.

  2. NASA MSFC Electrostatic Levitator (ESL) Rapid Quench System

    NASA Technical Reports Server (NTRS)

    SanSoucie, Michael P.; Craven, Paul D.

    2014-01-01

    Electrostatic levitation, a form of containerless processing, is an important tool in materials research. Levitated specimens are free from contact with a container; therefore, heterogeneous nucleation on container walls is not possible. This allows studies of deeply undercooled melts. Furthermore, studies of high-temperature, highly reactive materials are also possible. Studies of the solidification and crystallization of undercooled melts is vital to the understanding of microstructure development, particularly the formation of alloys with unique properties by rapid solidification. The NASA Marshall Space Flight Center (MSFC) Electrostatic Levitator (ESL) lab has recently been upgraded to allow for rapid quenching of levitated materials. The ESL Rapid Quench System uses a small crucible-like vessel that can be partially filled with a low melting point material, such as a Gallium alloy, as a quench medium. An undercooled sample can be dropped into the vessel to rapidly quench the sample. A carousel with nine vessels sits below the bottom electrode assembly. This system allows up to nine rapid quenches before having to break vacuum and remove the vessels. This new Rapid Quench System will allow materials science studies of undercooled materials and new materials development. In this presentation, the system is described and initial results are presented.

  3. A new maglev system for magnetically levitated carrier system

    NASA Astrophysics Data System (ADS)

    Morishita, Mimpei; Azukizawa, Teruo; Kanda, Shuji; Tamura, Noburu; Yokoyama, Toyohiko

    1989-11-01

    A power-saving electromagnetic suspension system has been developed in which electromagnets with permanent magnets are used to suspend the vehicle. The electromagnets are controlled to maintain air gap length so that the attractive force by the permanent magnet always balances the total weight of the vehicle and its loads, based on modern control theory. This technology realizes a significantly power-saving electromagnetic suspension system in which the electromagnetic coil current required to keep a vehicle levitating was extremely small, ideally zero. The 8-kg weight test vehicle with 4-kg load could be levitated continuously over 8 h, without recharging the on-board 1300-mAh batteries. This technology realized a completely contact-free material transportation system when combined with a contact-free driving system using linear motors. The attractive force characteristics of a permanent magnet with control electromagnets and the newly developed electromagnet control system that can eliminate power collecting devices from the electromagnetic suspension system are described.

  4. Magnetic levitation/suspension system by high-temperature superconducting materials

    SciTech Connect

    Chen, I.; Hsu, J.; Jamn, G.; Lin, C.E.; Wu, M.K.

    1997-04-01

    Recently, with the advance of materials processing techniques, such as top-seeding and melt-texturing (TSMT) method, very large single-grained Y-Ba-Cu-O (YBCO) samples up to several centimeters in diameter can be produced. Each sample is capable of levitating over kilograms of weight. A HTS magnetic levitation (MagLev) transportation prototype has been constructed at National Cheng-Kung University (NCKU) to validate the concept of HTS-MagLev system based on Meissner effect. This HTS-MagLev is an inherent stable levitation system, unlike traditional MagLev system that requires sensors and feedback circuits to dynamically adjust its unstable levitation position. In this report, the results of various magnetic levitation parameters, such as different permanent magnet configurations, relative levitation stability, levitation force, etc., as well as magnetic field intensity and distribution will be discussed. {copyright} {ital 1997 American Institute of Physics.}

  5. Analysis of a high Tc superconducting levitation system with vibration isolation control

    SciTech Connect

    Nagaya, Kosuke

    1996-03-01

    This paper presents a method for controlling vibrations of a levitated high Tc superconducting body subjected to base disturbances. To have the control forces, an actuator consisting of a permanent magnet with an electromagnet was presented. The analytical solution for calculating levitation forces due to the permanent magnet and the control currents in the electromagnet was obtained. The levitation forces obtained coincide with the previously published results. The equation of motion of the levitated body subjected to base disturbances under the control was presented. Nonlinear vibrations of the body were first discussed; then the method of vibration isolation control using the direct disturbance cancellation combining the velocity feedback control was investigated. Numerical calculations were carried out for the levitation forces, with respect to the levitated body subjected to harmonic or pulse base excitations. It was clarified that the present method is valid for controlling nonlinear systems like the magnetic levitated superconducting body.

  6. Optical encoder feedback system for levitating rotor system

    NASA Astrophysics Data System (ADS)

    Khanna, Shrey; Ho, Joe N.; Irwen, Jonathan; Rakka, Gurjinder; Wang, Weichih

    2010-03-01

    This paper describes the design and fabrication of feedback control system for a three phase motor with a diamagnetically levitating rotor. The planar rotor described in this paper uses a triangular configuration of magnets that rotates due to nine electric coils evenly spaced around the rotor. An optical mechanical feedback system controls the frequency at which the rotor spins. The current input to the coil is controlled by a mechanical relay circuit which latches based on a DC pulse signal generated by a PID control algorithm. The mechanical relay circuit allows current to flow to each coils (the actuators of this system), which then produces a magnetic field strong enough to spin the rotor.

  7. Effect of the active damper coil system on the lateral displacement of the magnetically levitated bogie

    SciTech Connect

    Ohashi, S.; Ohsaki, H.; Masada, E.

    1999-09-01

    Numerical simulation of the superconducting magnetically levitated bogie (JR Maglev) has been studied. The active damper coil system is introduced. In this levitation system, the interaction between levitation and guidance is strong. This active damper coil system is designed for reducing the vertical vibration of the bogie. Using the numerical simulation, its effect on the lateral displacement of the bogie is assessed. The active damper coil system for the vertical vibration is shown to works as a passive damper for the lateral vibration.

  8. Improved optical feedback reference tracking for diamagnetically levitating motor system

    NASA Astrophysics Data System (ADS)

    Wang, Wei-Chih; Vu, Jefferey; Khanna, Shrey

    2011-04-01

    This paper describes the design and fabrication of an optical sensor to sense vertical displacement of a diamagnetically stabilized levitating rotor. The planar rotor described in this paper rotates due to nine electromagnetic coils evenly spaced around the rotor. A driving circuit allows current to flow through the coils one phase at a time. This produces a magnetic field strong enough to spin the rotor. However, instability due to a number of factors is prevalent in the present system. This instability is observed as vertical and horizontal displacement of the levitating rotor. The purpose of an additional optical sensor is to measure and record this vertical displacement and combine it with topsensing optical measurements in order to create a three-dimensional optical sensing mechanism around the rotor.

  9. Air jet levitation furnace system for observing glass microspheres during heating and melting

    NASA Technical Reports Server (NTRS)

    Ethridge, E. C.; Dunn, S. L.

    1982-01-01

    A collimated hole structure air jet levitation system has been developed which can be used to levitate hollow glass microspheres used in inertial confinement fusion studies. An ellipsoidal furnace has been added to the system to provide a heating source. A video camera and a 16 mm movie camera connected to a microsphere system provide real time observation as well as permanent documentation of the experiments. Microspheres have been levitated at temperatures over 1400 C for over 10 minutes at a time.

  10. New levitation scheme with AC superconducting magnet for EDS MAGLEV system

    SciTech Connect

    Kim, D.H.; Lee, J.K.; Hahn, S.Y.; Cha, G.

    1996-09-01

    This paper proposes a new magnetic levitation scheme which is able to generate levitation force for all speeds including a standstill. Auxiliary wheels which are needed in EDS MAGLEV vehicle can be eliminated. This scheme uses AC superconducting magnets to generate levitation force. In this paper, magnetic fields, forces and power dissipations generated by AC magnets moving above a conducting slab are calculated analytically. Results of calculation show characteristics of EDS system with AC magnet, such as levitation force and loss, are superior to those of EDS system with DC magnets for all speeds.

  11. Robust levitation control for maglev systems with guaranteed bounded airgap.

    PubMed

    Xu, Jinquan; Chen, Ye-Hwa; Guo, Hong

    2015-11-01

    The robust control design problem for the levitation control of a nonlinear uncertain maglev system is considered. The uncertainty is (possibly) fast time-varying. The system has magnitude limitation on the airgap between the suspended chassis and the guideway in order to prevent undesirable contact. Furthermore, the (global) matching condition is not satisfied. After a three-step state transformation, a robust control scheme for the maglev vehicle is proposed, which is able to guarantee the uniform boundedness and uniform ultimate boundedness of the system, regardless of the uncertainty. The magnitude limitation of the airgap is guaranteed, regardless of the uncertainty. PMID:26524957

  12. Development of magnetically levitated high speed transport system in Japan

    SciTech Connect

    Sawada, Kazuo

    1996-07-01

    In Japan, huge passenger traffic moves through the Tokyo-Osaka corridor and the demand is mounting on one more high speed line besides the Tokaido Shinkansen. A magnetically levitated vehicle (JR Maglev) using superconducting magnets has been developed for the Tokyo-Osaka superspeed express. JR Maglev has many advantages over conventional rail systems. This paper describes the necessity of one more high speed line in this corridor, the reason the author chose Maglev, the scheme of this system, history of the development and outline of the new Yamanashi test line project.

  13. A review of dynamic characteristics of magnetically levitated vehicle systems

    SciTech Connect

    Cai, Y.; Chen, S.S.

    1995-11-01

    The dynamic response of magnetically levitated (maglev) ground transportation systems has important consequences for safety and ride quality, guideway design, and system costs. Ride quality is determined by vehicle response and by environmental factors such as humidity and noise. The dynamic response of the vehicles is the key element in determining ride quality, while vehicle stability is an important safety-related element. To design a guideway that provides acceptable ride quality in the stable region, vehicle dynamics must be understood. Furthermore, the trade-off between guideway smoothness and levitation and control systems must be considered if maglev systems are to be economically feasible. The link between the guideway and the other maglev components is vehicle dynamics. For a commercial maglev system, vehicle dynamics must be analyzed and tested in detail. This report, which reviews various aspects of the dynamic characteristics, experiments and analysis, and design guidelines for maglev systems, discusses vehicle stability, motion dependent magnetic force components, guideway characteristics, vehicle/ guideway interaction, ride quality, suspension control laws, aerodynamic loads and other excitations, and research needs.

  14. Dynamic characteristics of magnetically-levitated vehicle systems.

    SciTech Connect

    Cai, Y.; Chen, S. S.; Energy Technology

    1997-11-01

    The dynamic response of magnetically levitated (maglev) ground transportation systems has important consequences for safety and ride quality, guideway design, and system costs. Ride quality is determined by vehicle response and by environmental factors such as humidity and noise. The dynamic response of the vehicles is the key element in determining ride quality, while vehicle stability is an important safety related element. To design a guideway that provides acceptable ride quality in the stable region, vehicle dynamics must be understood. Furthermore, the trade off between guideway smoothness and levitation and control systems must be considered if maglev systems are to be economically feasible. The link between the guideway and the other maglev components is vehicle dynamics. For a commercial maglev system, vehicle dynamics must be analyzed and tested in detail. This report, which reviews various aspects of the dynamic characteristics, experiments and analysis, and design guidelines for maglev systems, discusses vehicle stability, motion dependent magnetic force components, guideway characteristics, vehicle/ guideway interaction, ride quality, suspension control laws, aerodynamic loads and other excitations, and research needs.

  15. Damping and support in high-temperature superconducting levitation systems

    DOEpatents

    Hull, John R.; McIver, Carl R.; Mittleider, John A.

    2009-12-15

    Methods and apparatuses to provide improved auxiliary damping for superconducting bearings in superconducting levitation systems are disclosed. In a superconducting bearing, a cryostat housing the superconductors is connected to a ground state with a combination of a damping strip of material, a set of linkage arms to provide vertical support, and spring washers to provide stiffness. Alternately, the superconducting bearing may be supported by a cryostat connected to a ground state by posts constructed from a mesh of fibers, with the damping and stiffness controlled by the fiber composition, size, and mesh geometry.

  16. Characteristics on electodynamic suspension simulator with HTS levitation magnet

    NASA Astrophysics Data System (ADS)

    Lee, J.; Bae, D. K.; Sim, K.; Chung, Y. D.; Lee, Y.-S.

    2009-10-01

    High- Tc superconducting (HTSC) electrodynamic suspension (EDS) system basically consists of the HTSC levitation magnet and the ground conductor. The levitation force of EDS system is forms by the interaction between the moving magnetic field produced by the onboard levitation magnet and the induced magnetic field produced by eddy current in the ground conductor. This paper deals with the characteristics of the EDS simulators with high- Tc superconducting (HTS) levitation magnet. Two EDS simulator systems, rotating type EDS simulator and static type EDS simulator, were studied in this paper. The rotating type EDS simulator consists of a HTS levitation magnet and a 1.5 m diameter rotating ground conductor, a motor, the supporting structure and force measuring devices. In the static type EDS simulator, instead of moving magnetic field, AC current was applied to the fixed HTS levitation magnet to induce the eddy current. The static type EDS simulator consists of a HTS levitation magnet, a ground conductor, force measuring devices and supporting structure. The double-pancake type HTSC levitation magnet was designed, manufactured and tested in the EDS simulator.

  17. Output feedback control of a mechanical system using magnetic levitation.

    PubMed

    Beltran-Carbajal, F; Valderrabano-Gonzalez, A; Rosas-Caro, J C; Favela-Contreras, A

    2015-07-01

    This paper presents an application of a nonlinear magnetic levitation system to the problem of efficient active control of mass-spring-damper mechanical systems. An output feedback control scheme is proposed for reference position trajectory tracking tasks on the flexible mechanical system. The electromagnetically actuated system is shown to be a differentially flat nonlinear system. An extended state estimation approach is also proposed to obtain estimates of velocity, acceleration and disturbance signals. The differential flatness structural property of the system is then employed for the synthesis of the controller and the signal estimation approach presented in this work. Some experimental and simulation results are included to show the efficient performance of the control approach and the effective estimation of the unknown signals. PMID:25707718

  18. Expansion joint for guideway for magnetic levitation transportation system

    SciTech Connect

    Rossing, T.D.

    1991-12-31

    An expansion joint that allows a guideway of a magnetic levitation transportation system to expand and contract while minimizing transients occurring in the magnetic lift and drag forces acting on a magnetic levitation vehicle traveling over the joint includes an upper cut or recess extending downwardly from the upper surface of the guideway and a non-intersecting lower cut or recess that extends upwardly from the lower surface of the guideway. The sidewalls of the cuts can be parallel to each other and the vertical axis of the guideway; the depth of the lower cut can be greater than the depth of the upper cut; and the overall combined lengths of the cuts can be greater than the thickness of the guideway from the upper to lower surface so that the cuts will overlap, but be spaced apart from each other. The distance between the cuts can be determined on the basis of the force transients and the mechanical behavior of the guideway. A second pair of similarly configured upper and lower cuts may be disposed in the guideway; the expansion joint may consist of two upper cuts and one lower cut; or the cuts may have non-parallel, diverging sidewalls so that the cuts have a substantially dove-tail shape.

  19. Expansion joint for guideway for magnetic levitation transportation system

    DOEpatents

    Rossing, Thomas D.

    1993-01-01

    An expansion joint that allows a guideway of a magnetic levitation transportation system to expand and contract while minimizing transients occurring in the magnetic lift and drag forces acting on a magnetic levitation vehicle traveling over the joint includes an upper cut or recess extending downwardly from the upper surface of the guideway and a non-intersecting lower cut or recess that extends upwardly from the lower surface of the guideway. The sidewalls of the cuts can be parallel to each other and the vertical axis of the guideway; the depth of the lower cut can be greater than the depth of the upper cut; and the overall combined lengths of the cuts can be greater than the thickness of the guideway from the upper to lower surface so that the cuts will overlap, but be spaced apart from each other. The distance between the cuts can be determined on the basis of the force transients and the mechanical behavior of the guideway. A second pair of similarly configured upper and lower cuts may be disposed in the guideway; the expansion joint may consist of two upper cuts and one lower cut; or the cuts may have non-parallel, diverging sidewalls so that the cuts have a substantially dove-tail shape.

  20. Expansion joint for guideway for magnetic levitation transportation system

    DOEpatents

    Rossing, T.D.

    1993-02-09

    An expansion joint that allows a guideway of a magnetic levitation transportation system to expand and contract while minimizing transients occurring in the magnetic lift and drag forces acting on a magnetic levitation vehicle traveling over the joint includes an upper cut or recess extending downwardly from the upper surface of the guideway and a non-intersecting lower cut or recess that extends upwardly from the lower surface of the guideway. The side walls of the cuts can be parallel to each other and the vertical axis of the guideway; the depth of the lower cut can be greater than the depth of the upper cut; and the overall combined lengths of the cuts can be greater than the thickness of the guideway from the upper to lower surface so that the cuts will overlap, but be spaced apart from each other. The distance between the cuts can be determined on the basis of the force transients and the mechanical behavior of the guideway. A second pair of similarly configured upper and lower cuts may be disposed in the guideway; the expansion joint may consist of two upper cuts and one lower cut; or the cuts may have non-parallel, diverging side walls so that the cuts have a substantially dove-tail shape.

  1. Design, manufacture and performance evaluation of HTS electromagnets for the hybrid magnetic levitation system

    NASA Astrophysics Data System (ADS)

    Chu, S. Y.; Hwang, Y. J.; Choi, S.; Na, J. B.; Kim, Y. J.; Chang, K. S.; Bae, D. K.; Lee, C. Y.; Ko, T. K.

    2011-11-01

    A high speed electromagnetic suspension (EMS) maglev has emerged as the solution to speed limit problem that conventional high-speed railroad has. In the EMS maglev, small levitation gap needs uniform guide-way which leads to increase the construction cost. The large levitation gap can reduce the construction cost. However it is hard for normal conducting electromagnet to produce larger magneto-motive force (MMF) for generating levitation force as increased levitation gap. This is because normal conductors have limited rating current to their specific volume. Therefore, the superconducting electromagnet can be one of the solutions for producing both large levitation gap and sufficient MMF. The superconducting electromagnets have incomparably high allowable current density than what normal conductors have. In this paper, the prototype of high temperature superconducting (HTS) electromagnets were designed and manufactured applicable to hybrid electromagnetic suspension system (H-EMS). The H-EMS consists of control coils for levitation control and superconducting coils for producing MMF for levitation. The required MMF for generating given levitation force was calculated by both equations of ideal U-core magnet and magnetic field analysis using the finite element method (FEM). The HTS electromagnets were designed as double pancakes with Bi-2223/Ag tapes. Experiments to confirm its operating performance were performed in liquid nitrogen (LN 2).

  2. System and Method for Obtaining Simultaneous Levitation and Rotation of a Ferromagnetic Object

    NASA Astrophysics Data System (ADS)

    Banerjee, Subrata; Sarkar, Mrinal Kanti; Ghosh, Arnab

    2016-06-01

    In this work a practical demonstration for simultaneous levitation and rotation for a ferromagnetic cylindrical object is presented. A hollow steel cylinder has been arranged to remain suspended stably under I-core electromagnet utilizing dc attraction type levitation principle and then arranged to rotate the levitated object around 1000 rpm speed based on eddy current based energy meter principle. Since the object is to be rotating during levitated condition the device will be frictionless, energy-efficient and robust. This technology may be applied to frictionless energy meter, wind turbine, machine tool applications, precision instruments and many other devices where easy energy-efficient stable rotation will be required. The cascade lead compensation control scheme has been applied for stabilization of unstable levitation system. The proposed device is successfully tested in the laboratory and experimental results have been produced.

  3. Propulsion and stabilization system for magnetically levitated vehicles

    SciTech Connect

    Coffey, H.T.

    1993-06-29

    A magnetic levitation and propulsion system for a vehicle adapted to travel over a roadbed is described comprising: a guide way affixed to a support structure where the support structure is coupled to the roadbed, a plurality of superconducting magnet devices producing magnetic fields and affixed to the vehicle where the superconducting magnet devices are oriented parallel to one surface of the guide way to generate a repulsive force between the guide way and the magnetic devices, and a plurality of propulsion windings affixed to the support structure, where the propulsion windings are located above and parallel to the superconducting magnet devices and are energized by a power source to generate a vehicle propulsion force to propel the vehicle along the roadbed support structure.

  4. An advanced arrangement of the combined propulsion, levitation and guidance system of superconducting Maglev

    SciTech Connect

    Fujie, Junji

    1999-09-01

    The PLG (combined Propulsion, Levitation and Guidance) method was proposed for a more favorable Maglev ground coil system, combining the functions of propulsion, levitation, and guidance of the vehicle into one coil. Research and development is currently being conducted on this method. In this paper, the characteristics of a newly-structured system for the PLG method is examined. The discussed characteristics include propulsion, levitation-guidance, vehicle dynamics in the cases of problems with the superconducting magnets, and the magnetic field on board the vehicle.

  5. Mechanical resonance characteristics of a high-{Tc} superconducting levitation system

    SciTech Connect

    Sugiura, Toshihiko; Fujimori, Hideki

    1996-05-01

    This research deals with dynamic response of a permanent magnet freely levitated above an excited high-{Tc} superconductor. Evaluation of dynamic characteristics is required in mechanical design of high-{Tc} superconducting levitation systems. Their dynamics is coupled with Type-II superconducting phenomena. By a numerical approach based on some macroscopic models they evaluate mechanical resonance characteristics of a superconducting levitation system. Numerical results show some nonlinear properties and effect of the flux flow in Type-II superconductor, which are observed in experiments or predicted by analyses.

  6. A Superconducting Levitation Transport Model System for Dynamical and Didactical Studies

    NASA Astrophysics Data System (ADS)

    Rosenzweig, St.; Reich, E.; Neu, V.; Berger, D.; Peukert, K.; Holzapfel, B.; Schultz, L.; Pospiech, G.

    Superconducting levitation transport systems might become very attractive in the near future due to various reasons. The realisation of contactless systems allows e.g. extended maintenance-free operation with high efficiency since such a system only needs energy for cooling and propulsion. We established a small superconducting levitation transport model system called "SupraTrans Min" consisting of permanent magnetic rails and a levitated vehicle including four YBCO-bulk samples in a cryostat. The rail system consists of an oval shaped loop (2.90 m x 1.44 m), which was build up from individual linear and curved track modules. Inside the vehicle position variations of the superconductors are possible. By means of velocity, acceleration and temperature measurements different dynamical aspects of our complex levitation system can be investigated. We also show the broad applicability of the experimental setup for didactical studies in physics.

  7. Electrodynamic Bare Tether Systems as a Thruster for the Momentum-Exchange/Electrodynamic Reboost(MXER)Project

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Krivorutsky, E. N.; Gallagher, D. L.

    2006-01-01

    The concept of electrodynamic tether propulsion has a number of attractive features and has been widely discussed for different applications. Different system designs have been proposed and compared during the last 10 years. In spite of this, the choice of proper design for any particular mission is a unique problem. Such characteristics of tether performance as system acceleration, efficiency, etc., should be calculated and compared on the basis of the known capability of a tether to collect electrical current. We discuss the choice of parameters for circular and tape tethers with regard to the Momentum-Exchange/Electrodynamic Reboost (MXER) tether project.

  8. 13th International Conference on Magnetically Levitated Systems and Linear Drives

    SciTech Connect

    Not Available

    1993-09-01

    This report contains short papers on research being conducted throughout the world on magnetically levitated systems, mainly consisting of trains, and magnetic linear drives. These papers have been index separately elsewhere on the data base.

  9. Evaluation of a six-DOF electrodynamic shaker system.

    SciTech Connect

    Gregory, Danny Lynn; Smallwood, David Ora

    2009-03-01

    The paper describes the preliminary evaluation of a 6 degree of freedom electrodynamic shaker system. The 8 by 8 inch (20.3 cm) table is driven by 12 electrodynamic shakers producing motion in all 6 rigid body modes. A small electrodynamic shaker system suitable for small component testing is described. The principal purpose of the system is to demonstrate the technology. The shaker is driven by 12 electrodynamic shakers each with a force capability of about 50 lbs (220 N). The system was developed through an informal cooperative agreement between Sandia National Laboratories, Team Corp. and Spectral Dynamics Corporation. Sandia provided the laboratory space and some development funds. Team provided the mechanical system, and Spectral Dynamics provided the control system. Spectral Dynamics was chosen to provide the control system partly because of their experience in MIMO control and partly because Sandia already had part of the system in house. The shaker system was conceived and manufactured by TEAM Corp. Figure 1 shows the overall system. The vibration table, electrodynamic shakers, hydraulic pumps, and amplifiers are all housed in a single cabinet. Figure 2 is a drawing showing how the electrodynamic shakers are coupled to the table. The shakers are coupled to the table through a hydraulic spherical pad bearing providing 5 degrees of freedom and one stiff degree of freedom. The pad bearing must be preloaded with a static force as they are unable to provide any tension forces. The horizontal bearings are preloaded with steel springs. The drawing shows a spring providing the vertical preload. This was changed in the final design. The vertical preload is provided by multiple strands of an O-ring material as shown in Figure 4. Four shakers provide excitation in each of the three orthogonal axes. The specifications of the shaker are outlined in Table 1. Four shakers provide inputs in each of the three orthogonal directions. By choosing the phase relationships

  10. Dynamic stability of electrodynamic maglev systems

    SciTech Connect

    Cai, Y.; Chen, S.S.; Mulcahy, T.M.; Rote, D.M.

    1997-01-01

    Because dynamic instabilities are not acceptable in any commercial maglev system, it is important to consider dynamic instability in the development of all maglev systems. This study considers the stability of maglev systems based on mathematical models and experimental data. Divergence and flutter are obtained for coupled vibration of a three-degree-of-freedom maglev vehicle on a guideway consisting of double L-shaped aluminum segments. The theory and analysis for motion-dependent magnetic-force-induced instability developed in this study provides basic stability characteristics and identifies future research needs for maglev systems.

  11. Gravito-electrodynamics and the structure of planetary ring systems

    NASA Technical Reports Server (NTRS)

    Mendis, D. A.

    1984-01-01

    Recent spacecraft observations of the Saturnian and Jovian ring systems have highlighted a plethora of interesting new phenomena associated with those regions containing fine (micron and sub-micron sized) dust. Recognizing that these dust grains, by virtue of being immersed within the planetary magnetospheres, are electrostatically charged to the point that they experience comparable gravitational and electric forces, a new 'gravito-electrodynamic' theory has been developed to describe their dynamics. This theory has been successful in explaining all these phenomena in a systematic way. In this review, the basic model and its range of validity are outlined, and its application to the Saturnian and Jovian ring systems are discussed.

  12. Gravito-electrodynamics and the structure of planetary ring systems

    NASA Astrophysics Data System (ADS)

    Mendis, D. A.

    1984-08-01

    Recent spacecraft observations of the Saturnian and Jovian ring systems have highlighted a plethora of interesting new phenomena associated with those regions containing fine (micron and sub-micron sized) dust. Recognizing that these dust grains, by virtue of being immersed within the planetary magnetospheres, are electrostatically charged to the point that they experience comparable gravitational and electric forces, a new 'gravito-electrodynamic' theory has been developed to describe their dynamics. This theory has been successful in explaining all these phenomena in a systematic way. In this review, the basic model and its range of validity are outlined, and its application to the Saturnian and Jovian ring systems are discussed.

  13. Lyapunov Orbits in the Jupiter System Using Electrodynamic Tethers

    NASA Technical Reports Server (NTRS)

    Bokelmann, Kevin; Russell, Ryan P.; Lantoine, Gregory

    2013-01-01

    Various researchers have proposed the use of electrodynamic tethers for power generation and capture from interplanetary transfers. The effect of tether forces on periodic orbits in Jupiter-satellite systems are investigated. A perturbation force is added to the restricted three-body problem model and a series of simplifications allows development of a conservative system that retains the Jacobi integral. Expressions are developed to find modified locations of equilibrium positions. Modified families of Lyapunov orbits are generated as functions of tether size and Jacobi integral. Zero velocity curves and stability analyses are used to evaluate the dynamical properties of tether-modified orbits.

  14. Amplitude and frequency dependence of hysteresis loss in a magnet-superconductor levitation system

    SciTech Connect

    Yang, Z.J.; Hull, J.R.; Mulcahy, T.M.; Rossing, T.D.

    1995-08-01

    Using an electromagnetically controlled mechanical pendulum, we measured the energy loss for different amplitudes in a magnetic levitation system that contained high temperature superconductors (HTSs). Two procedures were followed to measure losses at 77 K for frequencies of 93.8 mHz to 80 Hz. In the first procedure, the distance between the permanent magnet and the HTS levitator was the same as that during (field) cooling. In the second procedure, the magnet was lowered (after cooling) closer to the HTS levitator before the measurements were performed. The experimental data show that these two procedures give essentially the same results at the same distance despite different cooling (and magnetization) histories for melt-textured YBaCuO levitators, and the frequency-independent energy loss is a power-law function of amplitude. We attribute the energy loss to magnetic hysteresis in the superconductor. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  15. Electrodynamics of strongly correlated electron systems

    NASA Astrophysics Data System (ADS)

    Dordevic, Sasa V.

    2002-09-01

    In this thesis we study a variety of condensed matter systems with strongly correlated electrons, i.e. systems in which the electron-electron interactions cannot be ignored like in conventional metals, (gold, aluminum, copper, etc.). Infrared spectroscopy has proven to be a powerful tool for studying such systems. The latter experimental technique probes all excitations is solids that have a dipole moment associated with them, such as gap excitations, interband transitions, phonons, polarons, magnons etc. Strong electron correlations lead to a variety of interesting physical phenomena at low temperatures. In copper ox ides superconductivity sets in below an unprecedently high critical temperature, Tc. The mechanism of this unusual phenomenon is still unclear. In this thesis we discuss energy scales from which the superconducting condensate is collected and the response of cuprates to an external magnetic field applied parallel to the CuO2 planes. In so-called heavy fermion metals a coherent ground state develops at low temperatures where the electrons appear to have large effective mass, typically 50--1,000 free electron masses. We show that magnetic interactions play an important role for the mass renormalization in heavy fermion metals. In transition metal dichalcogenides reduced dimensionality of the electron gas leads to significant anisotropy of the electron-phonon interaction.

  16. Spin Pumping in Electrodynamically Coupled Magnon-Photon Systems.

    PubMed

    Bai, Lihui; Harder, M; Chen, Y P; Fan, X; Xiao, J Q; Hu, C-M

    2015-06-01

    We use electrical detection, in combination with microwave transmission, to investigate both resonant and nonresonant magnon-photon coupling at room temperature. Spin pumping in a dynamically coupled magnon-photon system is found to be distinctly different from previous experiments. Characteristic coupling features such as modes anticrossing, linewidth evolution, peculiar line shape, and resonance broadening are systematically measured and consistently analyzed by a theoretical model set on the foundation of classical electrodynamic coupling. Our experimental and theoretical approach paves the way for pursuing microwave coherent manipulation of pure spin current via the combination of spin pumping and magnon-photon coupling. PMID:26196640

  17. Electrodynamic processes in the ring system of Saturn

    NASA Technical Reports Server (NTRS)

    Mendis, D. A.; Hill, J. R.; Ip, W.-H.; Goertz, C. K.; Gruen, E.

    1984-01-01

    A number of recently observed Saturn ring phenomena are discussed in terms of their electrodynamic implications. Voyager 1 and 2 observations of the rotating near-radial spokes in the B Ring, waves and braids of the F Ring, and discrete episodic bursts of broadband radio emission, claimed by some to originate in a ring, are addressed. Several other phenomena are considered, including the origin and evolution of the diffuse E Ring and G Ring (which appear to be composed of fine dust), as well as the existence of a number of sharp discontinuities in the main ring system, within the context of gravitoelectrodynamics of charged dust in the magnetosphere.

  18. Spin pumping in electrodynamically coupled magnon-photon systems

    NASA Astrophysics Data System (ADS)

    Bai, Lihui

    The electronics industry is quickly approaching the limitation of Moore's Law due to Joule heating in high density-integrated devices. To achieve new higher-speed devices and reduce energy consumption, researchers are turning to spintronics where the intrinsic spin, rather than the charge of electrons, is used to carry information in devices. Advances in spintronics have led to the discovery of giant magnetoresistance (GMR), spin transfer torque etc. Another subject, cavity electrodynamics, promises a completely new quantum algorithm by studying the properties of a single electron interacting with photons inside of a cavity. By merging both spintronics and cavity electrodynamics, a new cutting edge field called Cavity Spintronics is forming, which draws on the advantages of both subjects to develop new spintronics devices utilizing light-matter interaction. In this work, we use electrical detection, in combination with microwave transmission, to investigate both resonant and nonresonant magnon-photon coupling in a microwave cavity at room temperature. Spin pumping in a dynamically coupled magnon-photon system is found to be distinctly different from previous experiments. Characteristic coupling features such as modes anticrossing, linewidth evolution, peculiar line shape, and resonance broadening are systematically measured and consistently analyzed by a theoretical model set on the foundation of classical electrodynamic coupling. Our experimental and theoretical approach paves the way for pursuing microwave coherent manipulation of pure spin current via the combination of spin pumping and magnon-photon coupling. Co-authored with M. Harder, C.-M. Hu from University of Manitoba, Y. P. Chen, J. Q. Xiao from University of Delaware, and X. Fan from Univeristy of Denver.

  19. Effect of reciprocating motions around working points on levitation force of superconductor-magnet system

    NASA Astrophysics Data System (ADS)

    Xu, Jimin; Zhang, Fei; Sun, Tao; Yuan, Xiaoyang; Zhang, Cuiping

    2016-09-01

    In order to simulate vibration around working points in practical operation of superconducting levitation system, magnet in a simple superconductor-magnet system are conducted reciprocating motions around static height in this study. Two YBCO cylindrical samples with different grain orientations are used to investigate the effect of reciprocating motions of magnet on superconducting magnetic force. The c-axis of sample S1 is perpendicular to the top surface while sample S2 is parallel to the top surface. The initial cooling processes for the superconductors include zero-field-cooled (ZFC) and filed-cooled (FC). Compared to the levitation force before reciprocating motions, the ZFC levitation force at static height becomes smaller after reciprocating while the FC force presents opposite phenomenon. It is found that levitation force at static height tends to be stable after several times of reciprocating under ZFC and FC conditions and its time-decay phenomenon is suppressed in some extent, which is meaningful for the practical application of superconducting levitation system. Based on vortex dynamic, some physical discussions are presented to the experimental results.

  20. Effect of size on levitation force in a magnet/superconductor system

    SciTech Connect

    Yang, Z.J.; Hull, J.R.

    1996-03-01

    We consider a model system consisting of an infinitely long magnetic dipole line placed symmetrically above an infinitely long superconducting strip. Using the Meissner effect of superconductors, we derive analytical expressions of the levitation forces acting on the dipole line. At lowest-order approximation, we discuss the possible application of our model system to estimate the upper limit of the levitation forces in some magnetic bearing systems. In one example, the model correctly calculated the vertical vibration frequency of an experimental superconducting bearing.

  1. Apparatus and method for reducing inductive coupling between levitation and drive coils within a magnetic propulsion system

    DOEpatents

    Post, Richard F.

    2001-01-01

    An apparatus and method is disclosed for reducing inductive coupling between levitation and drive coils within a magnetic levitation system. A pole array has a magnetic field. A levitation coil is positioned so that in response to motion of the magnetic field of the pole array a current is induced in the levitation coil. A first drive coil having a magnetic field coupled to drive the pole array also has a magnetic flux which induces a parasitic current in the levitation coil. A second drive coil having a magnetic field is positioned to attenuate the parasitic current in the levitation coil by canceling the magnetic flux of the first drive coil which induces the parasitic current. Steps in the method include generating a magnetic field with a pole array for levitating an object; inducing current in a levitation coil in response to motion of the magnetic field of the pole array; generating a magnetic field with a first drive coil for propelling the object; and generating a magnetic field with a second drive coil for attenuating effects of the magnetic field of the first drive coil on the current in the levitation coil.

  2. Preliminary characterization of a one-axis acoustic system. [acoustic levitation for space processing

    NASA Technical Reports Server (NTRS)

    Oran, W. A.; Reiss, D. A.; Berge, L. H.; Parker, H. W.

    1979-01-01

    The acoustic fields and levitation forces produced along the axis of a single-axis resonance system were measured. The system consisted of a St. Clair generator and a planar reflector. The levitation force was measured for bodies of various sizes and geometries (i.e., spheres, cylinders, and discs). The force was found to be roughly proportional to the volume of the body until the characteristic body radius reaches approximately 2/k (k = wave number). The acoustic pressures along the axis were modeled using Huygens principle and a method of imaging to approximate multiple reflections. The modeled pressures were found to be in reasonable agreement with those measured with a calibrated microphone.

  3. Automatic gas-levitation system for vacuum deposition of laser-fusion targets

    SciTech Connect

    Jordan, C.W.; Cameron, G.R.; Krenik, R.M.; Crane, J.K.

    1981-09-08

    An improved simple system has been developed to gas-levitate microspheres during vacuum-deposition processes. The automatic operation relies on two effects: a lateral stabilizing force provided by a centering-ring; and an automatically incremented gas metering system to offset weight increases during coating.

  4. Performance analysis of the combined EDS maglev propulsion, levitation, and guidance system

    SciTech Connect

    He, J.L.; Coffey, H.T.; Rote, D.M.

    1993-10-01

    An analysis of the Japanese maglev system which uses only one set of coils in the guideway for combined levitation, propulsion, and guidance functions is presented in this paper. This preliminary study, using the dynamic circuit approach, indicates that the system is very promising.

  5. Robust dynamic sliding-mode control using adaptive RENN for magnetic levitation system.

    PubMed

    Lin, Faa-Jeng; Chen, Syuan-Yi; Shyu, Kuo-Kai

    2009-06-01

    In this paper, a robust dynamic sliding mode control system (RDSMC) using a recurrent Elman neural network (RENN) is proposed to control the position of a levitated object of a magnetic levitation system considering the uncertainties. First, a dynamic model of the magnetic levitation system is derived. Then, a proportional-integral-derivative (PID)-type sliding-mode control system (SMC) is adopted for tracking of the reference trajectories. Moreover, a new PID-type dynamic sliding-mode control system (DSMC) is proposed to reduce the chattering phenomenon. However, due to the hardware being limited and the uncertainty bound being unknown of the switching function for the DSMC, an RDSMC is proposed to improve the control performance and further increase the robustness of the magnetic levitation system. In the RDSMC, an RENN estimator is used to estimate an unknown nonlinear function of lumped uncertainty online and replace the switching function in the hitting control of the DSMC directly. The adaptive learning algorithms that trained the parameters of the RENN online are derived using Lyapunov stability theorem. Furthermore, a robust compensator is proposed to confront the uncertainties including approximation error, optimal parameter vectors, and higher order terms in Taylor series. Finally, some experimental results of tracking the various periodic trajectories demonstrate the validity of the proposed RDSMC for practical applications. PMID:19423437

  6. Magnetic Levitation Force Measurement System at Any Low Temperatures From 20 K To 300 K

    NASA Astrophysics Data System (ADS)

    Celik, Sukru; Guner, S. Baris; Coskun, Elvan

    2015-03-01

    Most of the magnetic levitation force measurements in previous studies were performed at liquid nitrogen temperatures. For the levitation force of MgB2 and iron based superconducting samples, magnetic levitation force measurement system is needed. In this study, magnetic levitation force measurement system was designed. In this system, beside vertical force versus vertical motion, lateral and vertical force versus lateral motion measurements, the vertical force versus temperature at the fixed distance between permanent magnet PM - superconducting sample SS and the vertical force versus time measurements were performed at any temperatures from 20 K to 300 K. Thanks to these measurements, the temperature dependence, time dependence, and the distance (magnetic field) and temperature dependences of SS can be investigated. On the other hand, the magnetic stiffness MS measurements can be performed in this system. Using the measurement of MS at different temperature in the range, MS dependence on temperature can be investigated. These measurements at any temperatures in the range help to the superconductivity properties to be characterized. This work was supported by TUBTAK-the Scientific and technological research council of Turkey under project of MFAG - 110T622. This system was applied to the Turkish patent institute with the Application Number of 2013/13638 on 22/11/2013.

  7. Electromagnetically levitated vibration isolation system for the manufacturing process of silicon monocrystals

    NASA Technical Reports Server (NTRS)

    Kanemitsu, Yoichi; Watanabe, Katsuhide; Yano, Kenichi; Mizuno, Takayuki

    1994-01-01

    This paper introduces a study on an Electromagnetically Levitated Vibration Isolation System (ELVIS) for isolation control of large-scale vibration. This system features no mechanical contact between the isolation table and the installation floor, using a total of four electromagnetic actuators which generate magnetic levitation force in the vertical and horizontal directions. The configuration of the magnet for the vertical direction is designed to prevent any generation of restoring vibratory force in the horizontal direction. The isolation system is set so that vibration control effects due to small earthquakes can be regulated to below 5(gal) versus horizontal vibration levels of the installation floor of up t 25(gal), and those in the horizontal relative displacement of up to 30 (mm) between the floor and levitated isolation table. In particular, studies on the relative displacement between the installation floor and the levitated isolation table have been made for vibration control in the horizontal direction. In case of small-scale earthquakes (Taft wave scaled: max. 25 gal), the present system has been confirmed to achieve a vibration isolation to a level below 5 gal. The vibration transmission ratio of below 1/10 has been achieved versus continuous micro-vibration (approx. one gal) in the horizontal direction on the installation floor.

  8. A Multi-Transducer Near Field Acoustic Levitation System for Noncontact Transportation of Large-Sized Planar Objects

    NASA Astrophysics Data System (ADS)

    Amano, Takafumi; Koike, Yoshikazu; Nakamura, Kentaro; Ueha, Sadayuki; Hashimoto, Yoshiki

    2000-05-01

    A new noncontact transportation system, which consists of multiple ultrasonic transducers and operates based on near-field acoustic levitation, is proposed to transport a large-sized planar object such as a glass substrate for liquid crystal devices. Using the proposed systems consisting of two and three transducers, the suspension characteristics of the levitated objects are studied as functions of both size difference and angles between the vibration systems and the levitated object. As a result, the holding force is proved to increase as the angle increases and is maximum when the horizontal dimensions of the system and the object coincide.

  9. Optimization of a superconducting linear levitation system using a soft ferromagnet

    NASA Astrophysics Data System (ADS)

    Agramunt-Puig, Sebastia; Del-Valle, Nuria; Navau, Carles; Sanchez, Alvaro

    2013-04-01

    The use of guideways that combine permanent magnets and soft ferromagnetic materials is a common practice in magnetic levitation transport systems (maglevs) with bulk high-temperature superconductors. Theoretical tools to simulate in a realistic way both the behavior of all elements (permanent magnets, soft ferromagnet and superconductor) and their mutual effects are helpful to optimize the designs of real systems. Here we present a systematic study of the levitation of a maglev with translational symmetry consisting of a superconducting bar and a guideway with two identic permanent magnets and a soft ferromagnetic material between them. The system is simulated with a numerical model based on the energy minimization method that allows to analyze the mutual interaction of the superconductor, assumed to be in the critical state, and a soft ferromagnet with infinite susceptibility. Results indicate that introducing a soft ferromagnet within the permanent magnets not only increases the levitation force but also improves the stability. Besides, an estimation of the relative sizes and shapes of the soft ferromagnet, permanent magnets and the superconductor in order to obtain large levitation force with full stability is provided.

  10. Study on control method of running velocity for the permanent magnet-HTSC hybrid magnetically levitated conveyance system

    NASA Astrophysics Data System (ADS)

    Nishio, R.; Ikeda, M.; Sasaki, R.; Ohashi, S.

    2011-11-01

    We have developed the magnetically levitated carrying system. In this system, pinning force of high temperature bulk super conductor (HTSC) is used for the levitation and guidance. Four HTSCs are installed on the carrier. The magnetic rail is set on the ground, and flux from the magnetic rail is pinned by HTSCs. To increase levitation force, repulsive force of the permanent magnet is used. The hybrid levitation system is composed. The permanent magnet is installed under the load stage of the carrier. Repulsive force by the permanent magnet between the load stage on the carrier and the magnetic rail on the ground is used to support the load weight. Levitation and guidance one by pinning effect of the YBaCuO HTSC in the carrier is used to levitate the carrier body. The load stage is separated from the carrier flame and can move freely for vertical direction levitation. For the propulsion system, electromagnet is installed on the surface of the magnetic rail. In this paper, control method of running velocity of the carrier is studied. Propulsion force is given as follows; Air core copper coils are installed on the magnetic rail. Interaction between current of these coils and permanent magnets on the carrier generates propulsion force. Running velocity is controlled by current of the propulsion coils. It is also changed by position of the carrier and the load weight. From the results, stability of the propulsion system is given, and propulsion characteristics are improved.

  11. Spontaneous and nonphotochemical laser-induced nucleation in levitated supersaturated microdroplets

    NASA Astrophysics Data System (ADS)

    Fang, Ke

    Research of nucleation in levitated supersaturated microdroplets was conducted in this dissertation. An unconventional crystallization system, levitated microdroplets, was utilized in this research. The microdroplet was levitated by an electrodynamic balance (EDB) constructed inside a vacuum chamber. EDB has the advantage of creating a containerless environment for the crystallization system. Spontaneous nucleation in levitated microdroplets was investigated. Spontaneous nucleation of aqueous microdroplets was caused by reducing the ambient relative humidity (RH) surrounding the solution droplets. Different polymorphs of glutaric acid and malonic acid are nucleated in levitated microdroplets when injected into a chamber maintained at different initial RH values. Effect of surfactant as additive is also investigated. A site-dependent evaporation-driven crystallization theory is established to explain the spontaneous nucleation phenomena in levitated aqueous microdroplets. Levitated microdroplets containing a solute and an organic solvent were also investigated. The crystallization behavior of glutaric acid methanol solutions and ethanol solutions was observed. ROY, a deca-polymorphic compound, was also studied from its DMSO solution microdroplets. Non-photochemical laser induced nucleation (NPLIN) was observed in levitated microdroplets of supersaturated potassium chloride (KCl) aqueous solution. A focused green (532 nm) pulsed laser with 1 ns pulse width was used to induce nucleation. Nucleation of levitated KCl microdroplet with high supersaturation was observed upon laser irradiation. A laser-induced charge loss phenomenon was also observed. A hypothesis of laser-induced electrostriction and corona discharge is discussed. Analysis with classical nucleation theory suggests that the NPLIN results in levitated microdroplets are consistent with previously published data on bulk samples.

  12. High fidelity microelectromechanical system electrodynamic micro-speaker characterization

    NASA Astrophysics Data System (ADS)

    Sturtzer, E.; Shahosseini, I.; Pillonnet, G.; Lefeuvre, E.; Lemarquand, G.

    2013-06-01

    This paper deals with the heterogeneous characterization of a microelectromechanical system (MEMS) electrodynamic micro-speaker. This MEMS micro-speaker consists of an optimized silicon structure based on a very light but very stiff membrane. The mobile part is suspended using soft suspension beams, also made of silicon, which enable large out-of-plane displacement. The electromagnetic motor is composed of a micro-assembly permanent ring magnet and of a deposit mobile planar coil fixed on the top of the silicon membrane. Previous publications have presented the MEMS as theoretically able to produce high fidelity and high efficiency over a wide bandwidth. The present study intends to validate the electrical, the mechanical, and the acoustic performance improvements. The characterization of the microfabricated micro-speaker showed that the electric impedance is flat over the entire audio bandwidth. Some results validates the performance improvements in terms of audio quality as compared to state of the art of the MEMS micro-speakers, such as the high out-of-plane membrane displacement over ±400 μm, the 80 dBSPL sound pressure level at 10 cm, the 2% maximal distortion level, and the useful bandwidth from 335 Hz to cutoff frequency.

  13. Quantum electrodynamics of resonance energy transfer in nanowire systems

    NASA Astrophysics Data System (ADS)

    Weeraddana, Dilusha; Premaratne, Malin; Andrews, David L.

    2016-02-01

    Nonradiative resonance energy transfer (RET) provides the ability to transfer excitation energy between contiguous nanowires (NWs) with high efficiency under certain conditions. Nevertheless, the well-established Förster formalism commonly used to represent RET was developed for energy transfer primarily between molecular blocks (i.e., from one molecule, or part of a molecule, to another). Although deviations from Förster theory for functional blocks such as NWs have been studied previously, the role of the relative distance, the orientation of transition dipole moment pairs, and the passively interacting matter on electronic energy transfer are to a large extent unknown. Thus, a comprehensive theory that models RET in NWs is required. In this context, analytical insights to give a deeper and more intuitive understanding of the distance and orientation dependence of RET in NWs is presented within the framework of quantum electrodynamics. Additionally, the influence of an included intermediary on the rate of excitation energy transfer is illustrated, embracing indirect energy transfer rate and quantum interference. The results deliver equations that afford new intuitions into the behavior of virtual photons. In particular, results indicate that RET efficiency in a NW system can be explicitly expedited or inhibited by a neighboring mediator, depending on the relative spacing and orientation of NWs.

  14. Safety of high speed magnetic levitation transportation systems. Preliminary safety review of the transrapid maglev system

    NASA Astrophysics Data System (ADS)

    Dorer, R. M.; Hathaway, W. T.

    1990-11-01

    The safety of various magnetically levitated trains under development for possible implementation in the United States is of direct concern to the Federal Railroad Administration. Safety issues are addressed related to a specific maglev technology. The Transrapid maglev system was under development by the German Government over the last 10 to 15 years and was evolved into the current system with the TR-07 vehicle. A technically based safety review was under way over the last year by the U.S. Department of Transportation. The initial results of the review are presented to identify and assess potential maglev safety issues.

  15. Optimization of guideway coil dimensions for a magnetic levitation system

    SciTech Connect

    Chen, Y.J.; Feng, J.

    1997-09-01

    A fast computer code that generates currents and forces for multiple magnetic levitation (MAGLEV) vehicle coils over a discrete guideway of arbitrary geometry has been developed, tested, and verified. A study of coil dimensions for overlapping loops, ladders, and discrete loops has been conducted to determine the optimal guideway design. A parameter known as figure of merit has been defined to assist in evaluating the level of merit for a particular track configuration. From this, it has been discovered that, for most cases, ladder tracks are a better configuration over both overlapping and discrete loops. On closer inspection, it was also discovered that an aspect ratio of unity for the dimensions of a ladder track yields the best overall results.

  16. Design framework of a teleoperating system for a magnetically levitated robot with force feedback

    NASA Astrophysics Data System (ADS)

    Tsuda, Naoaki; Kato, Norihiko; Nomura, Yoshihiko; Matsui, Hirokazu

    2002-02-01

    Precise works and manipulating micro objects are tough jobs for operators both mentally and physically. To execute these jobs smoothly without feeling wrongness, use of master-slave system is preferable because position and force are able to be scaled up and down as well under the system. In this study we develop a master-slave system where the size of a slave robot is very small and the slave robot is levitated by magnetic forces. In distinction from ordinary master- slave systems, the levitated robot does not get any other contact forces from outside. Thus we introduce a method using an impedance model for constructing the master-slave system. We confirmed the effectiveness of the positioning control algorithm through experiments.

  17. Acoustic levitation

    SciTech Connect

    2012-09-12

    Scientists at Argonne National Laboratory have discovered a way to use sound waves to levitate individual droplets of solutions containing different pharmaceuticals. While the connection between levitation and drug development may not be immediately apparent, a special relationship emerges at the molecular level. Read more: http://www.anl.gov/articles/no-magic-show-real-world-levitation-inspire-better-pharmaceuticals

  18. High temperature metal purification using a compact portable rf heating and levitation system on the wake shield

    NASA Technical Reports Server (NTRS)

    Hahs, C. A.

    1990-01-01

    The Wake Shield Facility (WSF) can provide an ideal vacuum environment for the purification of high temperature metals in space. The Modular Electromagnetic Levitator (MEL), will provide the opportunity to study undercooling of metals in space and allow to determine material properties in space. The battery powered rf levitation and heating system developed for the MEL demonstrated efficiency of 36 percent. This system is being considered to purify metals at temperatures below 3000 C.

  19. Integrated null-flux suspension and multiphase propulsion system for magnetically-levitated vehicles

    DOEpatents

    Rote, Donald M.; He, Jianliang; Johnson, Larry R.

    1994-01-01

    A propulsion and stabilization system comprising a series of FIG. 8 coils mounted vertically on the walls of the guideway to provide suspension, lateral guidance and propulsion of a magnetically levitated vehicle. This system further allows for altering the magnetic field effects by changing the relative position of the loops comprising the FIG. 8 coils either longitudinally and/or vertically with resulting changes in the propulsion, the vertical stability, and the suspension.

  20. Integrated null-flux suspension and multiphase propulsion system for magnetically-levitated vehicles

    DOEpatents

    Rote, D.M.; He, Jianliang; Johnson, L.R.

    1992-01-01

    This report discusses a propulsion and stabilization system comprising a series of figure 8 coils mounted vertically on the walls of the guideway to provide suspension, lateral guidance and propulsion of a magnetically levitated vehicle. This system further allows for altering the magnetic field effects by changing the relative position of the loops comprising the figure 8 coils either longitudinally and/or vertically with resulting changes in the propulsion, the vertical stability, and the suspension.

  1. Integrated null-flux suspension and multiphase propulsion system for magnetically-levitated vehicles

    DOEpatents

    Rote, D.M.; He, J.; Johnson, L.R.

    1994-01-04

    A propulsion and stabilization system are described comprising a series of coils mounted vertically on the walls of the guideway to provide suspension, lateral guidance, and propulsion of a magnetically levitated vehicle. This system further allows for altering the magnetic field effects by changing the relative position of the loops comprising the coils either longitudinally and/or vertically with resulting changes in the propulsion, the vertical stability, and the suspension. 8 figures.

  2. Leidenfrost levitation: beyond droplets

    PubMed Central

    Hashmi, Ali; Xu, Yuhao; Coder, Benjamin; Osborne, Paul A.; Spafford, Jonathon; Michael, Grant E.; Yu, Gan; Xu, Jie

    2012-01-01

    Friction is a major inhibitor in almost every mechanical system. Enlightened by the Leidenfrost effect – a droplet can be levitated by its own vapor layer on a sufficiently hot surface – we demonstrate for the first time that a small cart can also be levitated by Leidenfrost vapor. The levitated cart can carry certain amount of load and move frictionlessly over the hot surface. The maximum load that the cart can carry is experimentally tested over a range of surface temperatures. We show that the levitated cart can be propelled not only by gravitational force over a slanted flat surface, but also self-propelled over a ratchet shaped horizontal surface. In the end, we experimentally tested water consumption rate for sustaining the levitated cart, and compared the results to theoretical calculations. If perfected, this frictionless Leidenfrost cart could be used in numerous engineering applications where relative motion exists between surfaces. PMID:23150770

  3. Cavity quantum electrodynamics of nanoscale two-level systems

    NASA Astrophysics Data System (ADS)

    Sarabi, Bahman

    In this dissertation, I introduce a novel method for measuring individual nanoscale two-level systems (TLSs) in amorphous solids based on strong direct coupling between a TLS and a cavity. I describe power- and temperature-dependent analysis of individual TLSs using a theoretical model based on cavity quantum electrodynamics (CQED). This method allows for measuring individual TLSs in different insulators and over a wide range of film thicknesses. For a silicon nitride film at 25 mK and a lumped-element cavity resonance at 6.9 GHz, I find TLSs with coherence times on the order of microseconds which can potentially be used as coherent resources. Furthermore, I introduce a device which enables spectroscopy of TLSs in insulating films by DC-tuning the TLSs. I present measurement results on 60 TLSs accompanied by theoretical analysis and extraction of distribution statistics of the TLS parameters. I find evidence for at least two TLS dipole sizes. I also investigate the role of RF-induced DC bias voltage on the growth of titanium nitride films on silicon (100) substrates deposited by DC magnetron reactive sputtering. I present hybrid designs of TiN coplanar resonators which were fabricated with an aluminum transmission line to avoid impedance mismatches due to large kinetic inductance of TiN films. I observe remarkably large kinetic inductance at certain substrate DC bias voltages. Finally, I describe several trilayer resonators designed to measure TLS ensembles within atomic layer deposition (ALD) grown aluminum oxide. Each resonator is unique in trilayer capacitor perimeter and hence the alumina air-exposed cross section. I compare the measured loss tangents of the resonators and investigate the effect of the capacitor perimeter on TLS defect density at different temperatures.

  4. Time-delay control of a magnetic levitated linear positioning system

    NASA Technical Reports Server (NTRS)

    Tarn, J. H.; Juang, K. Y.; Lin, C. E.

    1994-01-01

    In this paper, a high accuracy linear positioning system with a linear force actuator and magnetic levitation is proposed. By locating a permanently magnetized rod inside a current-carrying solenoid, the axial force is achieved by the boundary effect of magnet poles and utilized to power the linear motion, while the force for levitation is governed by Ampere's Law supplied with the same solenoid. With the levitation in a radial direction, there is hardly any friction between the rod and the solenoid. The high speed motion can hence be achieved. Besides, the axial force acting on the rod is a smooth function of rod position, so the system can provide nanometer resolution linear positioning to the molecule size. Since the force-position relation is highly nonlinear, and the mathematical model is derived according to some assumptions, such as the equivalent solenoid of the permanently magnetized rod, so there exists unknown dynamics in practical application. Thus 'robustness' is an important issue in controller design. Meanwhile the load effect reacts directly on the servo system without transmission elements, so the capability of 'disturbance rejection; is also required. With the above consideration, a time-delay control scheme is chosen and applied. By comparing the input-output relation and the mathematical model, the time-delay controller calculates an estimation of unmodeled dynamics and disturbances and then composes the desired compensation into the system. Effectiveness of the linear positioning system and control scheme are illustrated with simulation results.

  5. Electric generator using a triangular diamagnetic levitating rotor system.

    PubMed

    Ho, Joe Nhut; Wang, Wei-Chih

    2009-02-01

    This paper describes a feasibility study of creating a small low friction and low maintenance generator using a diamagnetically stabilized levitating rotor. The planar rotor described in this paper uses a triangular configuration of magnets that generates emf by passing over coils placed below the rotor. Equations were developed to predict the generated emf from coils with two different coil geometries. Additionally, this paper provides a method for estimating optimal coil size and position for the planar rotor presented for both segmental arc and circular coils to obtain maximum power output. Experiments demonstrated that the emf generated in the coils matches well with the predicted wave forms for each case, and the optimization theory gives good prediction to outcome of induced waveforms. For the segmental arc coil design, the induced emf was 1.7 mV at a radial frequency of 21.8 rad/s. For the circular coil design, the emf was 1.25 mV at a radial frequency of 28.1 rad/s. PMID:19256668

  6. Optimization of levitation and guidance forces in a superconducting Maglev system

    NASA Astrophysics Data System (ADS)

    Yildizer, Irfan; Cansiz, Ahmet; Ozturk, Kemal

    2016-09-01

    Optimization of the levitation for superconducting Maglev systems requires effective use of vertical and guidance forces during the operation. In this respect the levitation and guidance forces in terms of various permanent magnet array configurations are analyzed. The arrangements of permanent magnet arrays interacting with the superconductor are configured for the purpose of increasing the magnetic flux density. According to configurations, modeling the interaction forces between the permanent magnet and the superconductor are established in terms of the frozen image model. The model is complemented with the analytical calculations and provides a reasonable agreement with the experiments. The agreement of the analytical calculation associated with the frozen image model indicates a strong case to establish an optimization, in which provides preliminary analysis before constructing more complex Maglev system.

  7. Magnetic levitation systems for future aeronautics and space research and missions

    NASA Technical Reports Server (NTRS)

    Blankson, Isaiah M.; Mankins, John C.

    1996-01-01

    The objectives, advantages, and research needs for several applications of superconducting magnetic levitation to aerodynamics research, testing, and space-launch are discussed. Applications include very large-scale magnetic balance and suspension systems for high alpha testing, support interference-free testing of slender hypersonic propulsion/airframe integrated vehicles, and hypersonic maglev. Current practice and concepts are outlined as part of a unified effort in high magnetic fields R&D within NASA. Recent advances in the design and construction of the proposed ground-based Holloman test track (rocket sled) that uses magnetic levitation are presented. It is protected that ground speeds of up to Mach 8 to 11 at sea-level are possible with such a system. This capability may enable supersonic combustor tests as well as ramjet-to-scramjet transition simulation to be performed in clean air. Finally a novel space launch concept (Maglifter) which uses magnetic levitation and propulsion for a re-usable 'first stage' and rocket or air-breathing combined-cycle propulsion for its second stage is discussed in detail. Performance of this concept is compared with conventional advanced launch systems and a preliminary concept for a subscale system demonstration is presented.

  8. Dynamical analysis to the levitated systems of high temperature superconductors with hysteresis

    NASA Astrophysics Data System (ADS)

    Zhou, You-He; Zhao, Xian-Feng

    2006-08-01

    Dynamic behavior and penetration history of shielding currents distribution associated with the hysteresis of magnetic levitation force are investigated to the vertically mechanical oscillation of a permanent magnet (PM) which is magnetically levitated over a YBCO superconductor based on Bean’s critical-state model and Ampére circulation theorem. After the shielding current distribution is analytically derived out from the Maxwell’s equations of the electromagnetic system to each monotonic procedure of the hysteresis, the dynamic differential equation of the levitation is solved to the damped free vibration of the system using the adaptive Runge-Kutta approach of order 4. The obtained results display that the partially wiping-out phenomenon of shielding currents always happens in the interior of the superconductor such that the PM experiences a damped vibration. It is found that the damping generated from the hysteresis in the superconductor is time-changeable in the whole response, and that the frequency of vibration or magnetic stiffness increases with time during the first four periods of the response, as well as that the maximum penetration depth, δp, of the shielding currents at the end of each procedure of the hysteresis decays with time or turning number, Ntur, i.e., δp=e where α0 and α1 are the fitting coefficients.

  9. Experiments with Electrodynamic Wheels

    NASA Astrophysics Data System (ADS)

    Gaul, Nathan; Corey, Daniel; Cordrey, Vincent; Majewski, Walerian

    2015-04-01

    Our experiments were involving inductive magnetic levitation. A Halbach array is a system in which a series of magnets is arranged in a manner such that the magnetic field is cancelled on one side of the array while strengthening the field on the other. We constructed two circular Halbach wheels, making the strong magnetic field on the outer rim of the ring. Such system is usually dubbed as an Electrodynamic Wheel (EDW). Rotating this wheel around a horizontal axis above a flat conducting surface should induce eddy currents in said surface through the variable magnetic flux. The eddy currents produce, in turn, their own magnetic fields which interact with the magnets of the EDW. We demonstrated that these interactions produce both drag and lift forces on the EDW which can theoretically be used for lift and propulsion of the EDW. The focus of our experiments is determining how to maximize the lift-to-drag ratio by the proper choice of the induction element. We will also describe our experiments with a rotating circular Halbach array having the strong magnetic field of about 1 T on the flat side of the ring, and acting as a hovercraft.

  10. A new electromagnetic levitation system for rapid transit and high speed transportation

    SciTech Connect

    Wang, T.C.; Tzeng, Y.K. . Dept. of Electrical Engineering)

    1994-11-01

    A Maglev system using permanent and electromagnet is described. Such a system offers the advantages of high lift force to magnet weight ratio and nearly zero ohmic loss of its control winding. However, it is more difficult to control. Also, unlike the conventional electromagnetic levitation system, the control current is always maintained at zero value even with load variations. Analysis shows that the size and weight of this system are smaller by a factor of three compared to the conventional Maglev system. Basic design criteria and control strategy using variable structure control method are given, together with experimental results of a small model to verify its feasibility and good dynamic response.

  11. Design and implementation of a 2-DOF PID compensation for magnetic levitation systems.

    PubMed

    Ghosh, Arun; Rakesh Krishnan, T; Tejaswy, Pailla; Mandal, Abhisek; Pradhan, Jatin K; Ranasingh, Subhakant

    2014-07-01

    This paper employs a 2-DOF (degree of freedom) PID controller for compensating a physical magnetic levitation system. It is shown that because of having a feedforward gain in the proposed 2-DOF PID control, the transient performance of the compensated system can be changed in a desired manner unlike the conventional 1-DOF PID control. It is also shown that for a choice of PID parameters, although the theoretical loop robustness is the same for both the compensated systems, in real-time, 2-DOF PID control may provide superior robustness if a suitable choice of the feedforward parameter is made. The results are verified through simulations and experiments. PMID:24947430

  12. Electrostatic Levitator Electrode Layout

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Schematic of Electrostatic Levitator (ESL) electrodes and controls system. The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  13. Design approaches and parameters for magnetically levitated transport systems. [Null flux suspension (Maglev)

    SciTech Connect

    Danby, G.T.; Powell, J.R.

    1988-01-01

    Mechanically levitated transport system approaches are assessed with regard to thrust power needs, track cost, suspension stability, and safety. The null flux suspension appears as the favored approach, having the least thrust power requirements, highest stability, and lowest amount of track material. Various null flux configurations are described together with their operating parameters. The Linear Synchronous Motor (LSM) propulsion system is also described for propelling the suspended vehicles. Cryogenics and superconductivity aspects are discussed and the effect of high T/sub c/ superconductors evaluated. 13 refs., 16 figs., 2 tabs.

  14. Investigation of the stability of AC repulsive force levitation systems for low-speed maglev.

    SciTech Connect

    He, J. L.; Wang, Z.; Rote, D. M.; Winkelman, S.; Energy Systems

    1992-09-01

    Discusses the stability of an AC induction levitation system, focusing on the analysis and optimum design of the secondary conductor. Several improved secondary conductor geometries are considered. A theoretical model with numerical results, as well as experimental observations and data are presented. Theoretical and experimental results indicate that only marginal stability can be achieved with a single-plate secondary conductor. Modifications of the single plate can enhance its stability at rest, but this design suffers from longitudinal instabilities when propelled. It is concluded that a double-plate secondary conductor is stable in all six degrees of freedom.

  15. Thermal properties of a cylindrical YBa2Cu3O x superconductor in a levitation system: triggered by nonlinear dynamics

    NASA Astrophysics Data System (ADS)

    Huang, Yi; Zhang, Xingyi; Zhou, You-He

    2016-07-01

    The vibration of a permanent magnet (PM) levitated upon a high temperature superconductor (HTS) shows anomalous motion under external disturbance. In this paper we construct a cantilevered beam experimental setup composed of a bulk PM and a thermally insulated cylindrical YBa2Cu3O x superconductor. When the levitation system is disturbed by vertical excitation, the thermal character of the superconductor surface could be measured directly. Our experiments on a clean and large single-domain superconductor show that a giant temperature spike appears once the levitated PM experiences period doubling oscillation. We develop a numerical simulation for the analysis of the nonlinear vibration of the levitated PM coupled with the nonlinear electromagnetic force between the PM and HTS, taking into account heat diffusion. Using this procedure, we explore the electromagnetic and thermal properties at the thermally insulated HTS surface when the levitated PM shows a period doubling vibration. We find a remarkable difference between the experimental results and simulation. In order to interpret this temperature difference, we suggest a type of flux motion triggered by the electromagnetic force when it is far larger than the pinning force of the superconductor. The quantitative approach is based on the analysis process of the partial flux jump as a result of the flux creep. Finally, the calculated result is shown to be very close to the experimental result.

  16. Electrodynamic Propulsion System Tether Experiment (T-REX)

    NASA Technical Reports Server (NTRS)

    Johnson, L.; Fujii, H. A.; Sanmartin, J. R.

    2010-01-01

    A Japanese-led international team is developing a suborbital test of orbital-motion-limited (OML) bare wire anode current collection for application to electrodynamic tether (EDT) propulsion. The tether is a tape with a width of 25 mm, thickness of 0.05 mm, and is 300 m in length. This will be the first space test of OML theory. The mission will launch in the summer of 2010 using an S520 Sounding Rocket. During ascent, and above approximately 100 km in attitude, the tape tether will be deployed at a rate of approximately8 m/s. Once deployed, the tape tether will serve as an anode, collecting ionospheric electrons. The electrons will be expelled into space by a hollow cathode device, thereby completing the circuit and allowing current to flow. The total amount of current collected will be used to assess the validity of OML theory. This paper will describe the objectives of the proposed mission, the technologies to be employed, and the application of the results to future space missions using EDTs for propulsion or power generation

  17. Development of ultrasonically levitated drops as microreactors for study of enzyme kinetics and potential as a universal portable analysis system

    NASA Astrophysics Data System (ADS)

    Scheeline, A.; Pierre, Z.; Field, C. R.; Ginsberg, M. D.

    2009-05-01

    Development of microfluidics has focused on carrying out chemical synthesis and analysis in ever-smaller volumes of solution. In most cases, flow systems are made of either quartz, glass, or an easily moldable polymer such as polydimethylsiloxane (Whitesides 2006). As the system shrinks, the ratio of surface area to volume increases. For studies of either free radical chemistry or protein chemistry, this is undesirable. Proteins stick to surfaces, biofilms grow on surfaces, and radicals annihilate on walls (Lewis et al. 2006). Thus, under those circumstances where small amounts of reactants must be employed, typical microfluidic systems are incompatible with the chemistry one wishes to study. We have developed an alternative approach. We use ultrasonically levitated microliter drops as well mixed microreactors. Depending on whether capillaries (to form the drop) and electrochemical sensors are in contact with the drop or whether there are no contacting solids, the ratio of solid surface area to volume is low or zero. The only interface seen by reactants is a liquid/air interface (or, more generally, liquid/gas, as any gas may be used to support the drop). While drop levitation has been reported since at least the 1940's, we are the second group to carry out enzyme reactions in levitated drops, (Weis; Nardozzi 2005) and have fabricated the lowest power levitator in the literature (Field; Scheeline 2007). The low consumption aspects of ordinary microfluidics combine with a contact-free determination cell (the levitated drop) that ensures against cross-contamination, minimizes the likelihood of biofilm formation, and is robust to changes in temperature and humidity (Lide 1992). We report kinetics measurements in levitated drops and explain how outgrowths of these accomplishments will lead to portable chemistry/biology laboratories well suited to detection of a wide range of chemical and biological agents in the asymmetric battlefield environment.

  18. Differential force balances during levitation

    NASA Astrophysics Data System (ADS)

    Todd, Paul

    The simplest arithmetic of inertial, buoyant, magnetic and electrokinetic levitation is explored in the context of a model living system with “acceleration-sensitive structures” in which motion, if allowed, produces a biological effect. The simple model is a finite-sized object enclosed within another finite-sized object suspended in an outer fluid (liquid or vapor) medium. The inner object has density and electrical and magnetic properties quantitatively different from those of the outer object and the medium. In inertial levitation (“weightlessness”) inertial accelerations are balanced, and the forces due to them are canceled in accordance with Newton’s third law. In the presence of inertial acceleration (gravity, centrifugal) motionlessness depends on a balance between the levitating force and the inertial force. If the inner and outer objects differ in density one or the other will be subjected to an unbalanced force when one object is levitated by any other force (buoyant, magnetic, electrokinetic). The requirements for motionlessness of the internal object in the presence of a levitating force are equality of density in the case of buoyant levitation, equality of magnetic susceptibility in the case of magnetic levitation, and equality of zeta potential and dielectric constant in the case of electrokinetic levitation. Examples of internal “acceleration-sensitive structures” are cellular organelles and the organs of advanced plants and animals. For these structures fundamental physical data are important in the interpretation of the effects of forces used for levitation.

  19. Stability of magnetic tip/superconductor levitation systems

    NASA Astrophysics Data System (ADS)

    K. Alqadi, M.

    2015-11-01

    The vertical stability of a magnetic tip over a superconducting material is investigated by using the critical state and the frozen image models. The analytical expressions of the stiffness and the vibration frequency about the equilibrium position are derived in term of the geometrical parameters of the magnet/superconductor system. It is found that the stability of the system depends on the shape of the superconductor as well as its thickness.

  20. A Shaftless Magnetically Levitated Multifunctional Spacecraft Flywheel Storage System

    NASA Technical Reports Server (NTRS)

    Stevens, Ken; Thornton, Richard; Clark, Tracy; Beaman, Bob G.; Dennehy, Neil; Day, John H. (Technical Monitor)

    2002-01-01

    Presently many types of spacecraft use a Spacecraft Attitude Control System (ACS) with momentum wheels for steering and electrochemical batteries to provide electrical power for the eclipse period of the spacecraft orbit. Future spacecraft will use Flywheels for combined use in ACS and Energy Storage. This can be done by using multiple wheels and varying the differential speed for ACS and varying the average speed for energy storage and recovery. Technology in these areas has improved since the 1990s so it is now feasible for flywheel systems to emerge from the laboratory for spacecraft use. This paper describes a new flywheel system that can be used for both ACS and energy storage. Some of the possible advantages of a flywheel system are: lower total mass and volume, higher efficiency, less thermal impact, improved satellite integration schedule and complexity, simplified satellite orbital operations, longer life with lower risk, less pointing jitter, and greater capability for high-rate slews. In short, they have the potential to enable new types of missions and provide lower cost. Two basic types of flywheel configurations are the Flywheel Energy Storage System (FESS) and the Integrated Power and Attitude Control System (IPACS).

  1. Design, implementation, and testing of a single axis levitation system for the suspension of a platform.

    PubMed

    Banerjee, Subrata; Prasad, Dinkar; Pal, Jayanta

    2007-04-01

    This paper describes the design and implementation of a single axis DC attraction type suspension system, where a platform (vehicle structure) of around 14 kg mass is made to remain suspended at the desired operating gap under a ferromagnetic guide-way. The prototype has four electromagnetic actuators of attraction type and four inductive gap sensors, all located at the corners of the platform. The four actuators are controlled independently through four identical controllers, and the stable levitation of the platform is achieved through the single input and single output (SISO) control of each air-gap. The emphasis of this work is on the design and development of the switched mode power amplifier cum controller unit for the four actuators. The proposed single switch-based power circuit simplifies the overall hardware, and it can be extended to any number of magnet-coils. A cascade lead compensation control scheme utilizing an inner current loop and outer position loop has been designed and implemented for the stabilization of such a highly unstable and strongly nonlinear system. The prototype has been successfully tested, and stable levitation was demonstrated with the desired operating gap. PMID:17350630

  2. Acoustic Translation of an Acoustically Levitated Sample

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Allen, J. L.

    1986-01-01

    Acoustic-levitation apparatus uses only one acoustic mode to move sample from one region of chamber to another. Sample heated and cooled quickly by translation between hot and cold regions of levitation chamber. Levitated sample is raised into furnace region by raising plunger. Frequency of sound produced by transducers adjusted by feedback system to maintain (102) resonant mode, which levitates sample midway between transducers and plunger regardless of plunger position.

  3. Electromagnet Weight Reduction in a Magnetic Levitation System for Contactless Delivery Applications

    PubMed Central

    Hong, Do-Kwan; Woo, Byung-Chul; Koo, Dae-Hyun; Lee, Ki-Chang

    2010-01-01

    This paper presents an optimum design of a lightweight vehicle levitation electromagnet, which also provides a passive guide force in a magnetic levitation system for contactless delivery applications. The split alignment of C-shaped electromagnets about C-shaped rails has a bad effect on the lateral deviation force, therefore, no-split positioning of electromagnets is better for lateral performance. This is verified by simulations and experiments. This paper presents a statistically optimized design with a high number of the design variables to reduce the weight of the electromagnet under the constraint of normal force using response surface methodology (RSM) and the kriging interpolation method. 2D and 3D magnetostatic analysis of the electromagnet are performed using ANSYS. The most effective design variables are extracted by a Pareto chart. The most desirable set is determined and the influence of each design variable on the objective function can be obtained. The generalized reduced gradient (GRG) algorithm is adopted in the kriging model. This paper’s procedure is validated by a comparison between experimental and calculation results, which shows that the predicted performance of the electromagnet designed by RSM is in good agreement with the simulation results. PMID:22163572

  4. Electromagnet weight reduction in a magnetic levitation system for contactless delivery applications.

    PubMed

    Hong, Do-Kwan; Woo, Byung-Chul; Koo, Dae-Hyun; Lee, Ki-Chang

    2010-01-01

    This paper presents an optimum design of a lightweight vehicle levitation electromagnet, which also provides a passive guide force in a magnetic levitation system for contactless delivery applications. The split alignment of C-shaped electromagnets about C-shaped rails has a bad effect on the lateral deviation force, therefore, no-split positioning of electromagnets is better for lateral performance. This is verified by simulations and experiments. This paper presents a statistically optimized design with a high number of the design variables to reduce the weight of the electromagnet under the constraint of normal force using response surface methodology (RSM) and the kriging interpolation method. 2D and 3D magnetostatic analysis of the electromagnet are performed using ANSYS. The most effective design variables are extracted by a Pareto chart. The most desirable set is determined and the influence of each design variable on the objective function can be obtained. The generalized reduced gradient (GRG) algorithm is adopted in the kriging model. This paper's procedure is validated by a comparison between experimental and calculation results, which shows that the predicted performance of the electromagnet designed by RSM is in good agreement with the simulation results. PMID:22163572

  5. Controlled sample orientation and rotation in an acoustic levitator

    NASA Technical Reports Server (NTRS)

    Barmatz, Martin B. (Inventor); Gaspar, Mark S. (Inventor); Trinh, Eugene H. (Inventor)

    1988-01-01

    A system is described for use with acoustic levitators, which can prevent rotation of a levitated object or control its orientation and/or rotation. The acoustic field is made nonsymmetrical about the axis of the levitator, to produce an orienting torque that resists sample rotation. In one system, a perturbating reflector is located on one side of the axis of the levitator, at a location near the levitated object. In another system, the main reflector surface towards which incoming acoustic waves are directed is nonsymmetrically curved about the axis of the levitator. The levitated object can be reoriented or rotated in a controlled manner by repositioning the reflector producing the nonsymmetry.

  6. Photon antibunching and bunching in a ring-resonator waveguide quantum electrodynamics system.

    PubMed

    Chen, Zihao; Zhou, Yao; Shen, Jung-Tsung

    2016-07-15

    We numerically investigate the photonic state generation and its nonclassical correlations in a ring-resonator waveguide quantum electrodynamics system. Specifically, we discuss photon antibunching and bunching in various scenarios, including the imperfect resonator with backscattering and dissipations. Our numerical results indicate that an imperfect ring resonator with backscattering can enhance the quality of antibunching. In addition, we also identify the quantum photonic halo phenomenon in the photon scattering dynamics and the shoulder effect in the second-order correlation function. PMID:27420523

  7. Electrostatic Levitator (ESL)

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Dr. Rulison of Space System LORAl working with the Electrostatic Levitation (ESL) prior to the donation. Space System/LORAL donated the electrostatic containerless processing system to NASA's Marshall Space Flight Center (MSFC). The official hand over took place in July 1998.

  8. No Drama Quantum Electrodynamics?

    NASA Astrophysics Data System (ADS)

    Akhmeteli, Andrey

    2015-03-01

    Is it possible to offer a ``no drama'' quantum electrodynamics, as simple (in principle) as classical electrodynamics - a theory described by a system of partial differential equations (PDE) in 3+1 dimensions, but reproducing unitary evolution of a quantum field theory in the Fock space? The following results suggest an affirmative answer: 1. The scalar field can be algebraically eliminated from scalar electrodynamics. 2. After introduction of a complex 4-potential (producing the same electromagnetic field (EMF) as the standard real 4-potential), the spinor field can be algebraically eliminated from spinor electrodynamics. 3. The resulting theories describe independent evolution of EMF and can be embedded into quantum field theories. Another fundamental result: in a general case, the Dirac equation is equivalent to a 4th order PDE for just one component, which can be made real by a gauge transform. Issues related to the Bell theorem and the connection with Barut's self-field electrodynamics are discussed.

  9. Optical-response properties in levitated optomechanical systems beyond the low-excitation limit

    NASA Astrophysics Data System (ADS)

    Nie, Wenjie; Chen, Aixi; Lan, Yueheng

    2016-02-01

    We investigate the optical-response properties of a levitated optomechanical cavity coupled to a higher order excited atomic medium. The cavity field driven through the atom-field interaction is responsible for trapping a dielectric nanosphere, whose steady-state position is biased by the Coulomb force between the nanosphere and the cavity wall. We show that the phenomena of optomechanically induced transparency (OMIT) and amplification can be generated from the output probe field in the presence of an effective optomechanical coupling between the nanosphere and the cavity field. Further, the width of the transparency window increases with increasing strength of the effective optomechanical coupling, which is controlled easily by varying the Coulomb interaction and the radius of the nanosphere. In particular, when the higher order excitation of the atomic medium is included, a large driving of the atomic ensemble but a relatively small atom-field detuning can be applied to help observe the OMIT behavior in the hybrid system.

  10. Airborne chemistry: acoustic levitation in chemical analysis.

    PubMed

    Santesson, Sabina; Nilsson, Staffan

    2004-04-01

    This review with 60 references describes a unique path to miniaturisation, that is, the use of acoustic levitation in analytical and bioanalytical chemistry applications. Levitation of small volumes of sample by means of a levitation technique can be used as a way to avoid solid walls around the sample, thus circumventing the main problem of miniaturisation, the unfavourable surface-to-volume ratio. Different techniques for sample levitation have been developed and improved. Of the levitation techniques described, acoustic or ultrasonic levitation fulfils all requirements for analytical chemistry applications. This technique has previously been used to study properties of molten materials and the equilibrium shape()and stability of liquid drops. Temperature and mass transfer in levitated drops have also been described, as have crystallisation and microgravity applications. The airborne analytical system described here is equipped with different and exchangeable remote detection systems. The levitated drops are normally in the 100 nL-2 microL volume range and additions to the levitated drop can be made in the pL-volume range. The use of levitated drops in analytical and bioanalytical chemistry offers several benefits. Several remote detection systems are compatible with acoustic levitation, including fluorescence imaging detection, right angle light scattering, Raman spectroscopy, and X-ray diffraction. Applications include liquid/liquid extractions, solvent exchange, analyte enrichment, single-cell analysis, cell-cell communication studies, precipitation screening of proteins to establish nucleation conditions, and crystallisation of proteins and pharmaceuticals. PMID:14762640

  11. Self-adjusting control system of the electrodynamic velocity transducer for Mössbauer spectrometer

    NASA Astrophysics Data System (ADS)

    Zekhtser, M. Yu.; Revyakin, A. S.; Sarychev, D. A.

    2016-08-01

    The novel control system has been developed on the basis of motion equation for the moving part of the electrodynamic velocity transducer of Mössbauer spectrometer. The motion equation coefficients are the parameters of its vibrating system. The square of cyclic eigenfrequency and damping factor are automatically determined by the control software for the spectrometer using the express analysis of free damped oscillations before any measurements are taken. The control system does not require manual adjustment of the spectrometer before the experiment. It exhibits accuracy of self-tuning and high degree of Doppler modulation stability in long-term experiments, providing high quality Mössbauer spectra.

  12. General theory based on fluctuational electrodynamics for van der Waals interactions in colloidal systems

    SciTech Connect

    Yannopapas, Vassilios

    2007-12-15

    A rigorous theory for the determination of the van der Waals interactions in colloidal systems is presented. The method is based on fluctuational electrodynamics and a multiple-scattering method which provides the electromagnetic Green's tensor. In particular, expressions for the Green's tensor are presented for arbitrary, finite collections of colloidal particles, for infinitely periodic or defected crystals, as well as for finite slabs of crystals. The presented formalism allows for ab initio calculations of the van der Waals interactions in colloidal systems since it takes fully into account retardation, many-body, multipolar, and near-field effects.

  13. An illuminated growth system for the study of Arabidopsis thaliana during diamagnetic levitation by a superconducting magnet

    NASA Astrophysics Data System (ADS)

    Lu, Y.; Ding, C.; Wang, J.; Shang, P.

    2015-01-01

    The effect of gravity on plant growth is an interesting topic in its own right, but it is also important because it impacts the possibility of long-term space travel. Plants may be grown in microgravity simulated by diamagnetic levitation within superconducting magnet, but this approach is limited by the size and other objective conditions of the superconducting magnet. Tremendous difficulties exist in evaluating the effects of simulated microgravity on plant seedling growth under lighting conditions. Therefore, we developed a lighting system and culturing system that can meet the demands of growing plant seedlings in a superconducting magnet. This system mainly consists of an illumination system, suitable containers and a method to cultivate Arabidopsis thaliana seedlings. In order to prove the suitability of this light-growing system, A. thaliana was cultured in a superconducting magnet for four days. The status of seedlings was recorded and total RNA was extracted for gene expression analysis. Our results showed that Arabidopsis seedlings could germinate and grow successfully in this light-growing system. In addition, it was observed that under diamagnetic levitation conditions, the seedling bended and gene expression of PGM and MOR1 decreased significantly compared to a control group. Nonetheless, there were no substantial differences between the diamagnetic levitation group and RPM group. Our results suggest that this light-growing system is expedient and beneficial for plants grown in a superconducting magnet. Our experiment also provides a way to utilize diamagnetic levitation in a superconducting magnet that simulates the conditions necessary to study plant physiology and biochemical responses in a microgravity environment.

  14. Nonlinear normal modes in electrodynamic systems: A nonperturbative approach

    NASA Astrophysics Data System (ADS)

    Kudrin, A. V.; Kudrina, O. A.; Petrov, E. Yu.

    2016-06-01

    We consider electromagnetic nonlinear normal modes in cylindrical cavity resonators filled with a nonlinear nondispersive medium. The key feature of the analysis is that exact analytic solutions of the nonlinear field equations are employed to study the mode properties in detail. Based on such a nonperturbative approach, we rigorously prove that the total energy of free nonlinear oscillations in a distributed conservative system, such as that considered in our work, can exactly coincide with the sum of energies of the normal modes of the system. This fact implies that the energy orthogonality property, which has so far been known to hold only for linear oscillations and fields, can also be observed in a nonlinear oscillatory system.

  15. An electrodynamic tether system for propulsion and power generation in a Jovian mission

    NASA Astrophysics Data System (ADS)

    Castronuovo, M. M.; Laneve, G.; Ulivieri, C.

    2002-01-01

    The paper concerns an innovative propulsive/power system exploiting the magnetic field and the charged atmosphere present on some planets of our solar system. In fact a conductive tether moving in the above mentioned environment is able to provide a low thrust for orbital control and/or power generation for on-board systems. This solution is considered particularly promising for the exploration of outer planets where the low solar luminosity makes the use of solar panels unsuitable. On the other end the use of radioactive thermoelectric generators (RTG) might be ruled out on future missions due to the finite risk of releasing plutonium into the terrestrial environment. The main objective of the present paper is the assessment of the feasibility and applicability of an electrodynamic tether system to missions devoted to the exploration of the Jovian system. Among the outer planets, at the present stage of knowledge, Jupiter is by far the most promising target for the proposed system application. In fact, it has a large and energetic magnetosphere ideally suited for electrodynamic tether operations and due to its rapid rotation, its magnetic field sweeps the tether rather than being swept by it (as in the Earth case). The net effect will be the increase of spacecraft momentum, thus allowing the raise of its orbit, and/or on-board power generation, without any expenditure of propellants. .

  16. Electrodynamic System of Earth in Moon and Solar Tides Investigation

    NASA Astrophysics Data System (ADS)

    Grunskaya, Lubov; Isakevich, Valiriy

    Since 2000 there has been working the united system of monitoring of electrical and geomagnetic fields of ELF range of the atmosphere boundary surface layer at the spaced apart stations: Vladimir State physical experimental ground; the station of RAS Institute of Sun and Earth physics at Lake Baikal; the station in Paratunka (Kamchatka); the station in Obninsk. There has been developed a programme-analytical system (PAS) to investigate signal structures in spectral and time series, caused by geophysical and astrophysical processes based on the method of eigen vectors. There has been developed a programme and analytical system to investigate the signal structure in the spectral and time series caused by geophysical processes. There has been estimated the amplitude and investigated the properties of the Earth atmosphere boundary layer electrical field components localized spectrally at the frequencies of the moon and solar tides. There has been exposed a method of determination of relative and absolute amplitudes of the main components of the eigen series. There has been investigated coherence of the spectral components at the frequencies of solar and moon tides. The work is carried out with supporting of RFFI № 14-07-97510, State Task to Universities on 2014-2016.

  17. Calculating the electromagnetic field on the earth due to an electrodynamic tethered system in the ionosphere

    NASA Technical Reports Server (NTRS)

    Estes, Robert D.

    1989-01-01

    A method is presented for calculating the electromagnetic wave field on the earth's surface associated with the operation of an electrodynamic tethered satellite system of constant or slowly varying current in the upper ionosphere. The wave field at the ionospheric boundary and on the earth's surface is obtained by numerical integration. The results suggest that the ionospheric waves do not propagate into the atmosphere and that the image of the Alfven wings from a steady-current tether should be greatly broadened on the earth's surface.

  18. Magnetic levitation of single cells.

    PubMed

    Durmus, Naside Gozde; Tekin, H Cumhur; Guven, Sinan; Sridhar, Kaushik; Arslan Yildiz, Ahu; Calibasi, Gizem; Ghiran, Ionita; Davis, Ronald W; Steinmetz, Lars M; Demirci, Utkan

    2015-07-14

    Several cellular events cause permanent or transient changes in inherent magnetic and density properties of cells. Characterizing these changes in cell populations is crucial to understand cellular heterogeneity in cancer, immune response, infectious diseases, drug resistance, and evolution. Although magnetic levitation has previously been used for macroscale objects, its use in life sciences has been hindered by the inability to levitate microscale objects and by the toxicity of metal salts previously applied for levitation. Here, we use magnetic levitation principles for biological characterization and monitoring of cells and cellular events. We demonstrate that each cell type (i.e., cancer, blood, bacteria, and yeast) has a characteristic levitation profile, which we distinguish at an unprecedented resolution of 1 × 10(-4) g ⋅ mL(-1). We have identified unique differences in levitation and density blueprints between breast, esophageal, colorectal, and nonsmall cell lung cancer cell lines, as well as heterogeneity within these seemingly homogenous cell populations. Furthermore, we demonstrate that changes in cellular density and levitation profiles can be monitored in real time at single-cell resolution, allowing quantification of heterogeneous temporal responses of each cell to environmental stressors. These data establish density as a powerful biomarker for investigating living systems and their responses. Thereby, our method enables rapid, density-based imaging and profiling of single cells with intriguing applications, such as label-free identification and monitoring of heterogeneous biological changes under various physiological conditions, including antibiotic or cancer treatment in personalized medicine. PMID:26124131

  19. Magnetic levitation of single cells

    PubMed Central

    Durmus, Naside Gozde; Tekin, H. Cumhur; Guven, Sinan; Sridhar, Kaushik; Arslan Yildiz, Ahu; Calibasi, Gizem; Davis, Ronald W.; Steinmetz, Lars M.; Demirci, Utkan

    2015-01-01

    Several cellular events cause permanent or transient changes in inherent magnetic and density properties of cells. Characterizing these changes in cell populations is crucial to understand cellular heterogeneity in cancer, immune response, infectious diseases, drug resistance, and evolution. Although magnetic levitation has previously been used for macroscale objects, its use in life sciences has been hindered by the inability to levitate microscale objects and by the toxicity of metal salts previously applied for levitation. Here, we use magnetic levitation principles for biological characterization and monitoring of cells and cellular events. We demonstrate that each cell type (i.e., cancer, blood, bacteria, and yeast) has a characteristic levitation profile, which we distinguish at an unprecedented resolution of 1 × 10−4 g⋅mL−1. We have identified unique differences in levitation and density blueprints between breast, esophageal, colorectal, and nonsmall cell lung cancer cell lines, as well as heterogeneity within these seemingly homogenous cell populations. Furthermore, we demonstrate that changes in cellular density and levitation profiles can be monitored in real time at single-cell resolution, allowing quantification of heterogeneous temporal responses of each cell to environmental stressors. These data establish density as a powerful biomarker for investigating living systems and their responses. Thereby, our method enables rapid, density-based imaging and profiling of single cells with intriguing applications, such as label-free identification and monitoring of heterogeneous biological changes under various physiological conditions, including antibiotic or cancer treatment in personalized medicine. PMID:26124131

  20. Oscillation propagating in non-contact linear piezoelectric ultrasonic levitation transporting system---from solid state to fluid media.

    PubMed

    Li, Xianghua; Sun, Yuntao; Chen, Chao; Zhao, Chunsheng

    2010-04-01

    Non-contact ultrasonic motors (USM) show potential for future use, especially in the industrial fields because of its simple structure and quick response. It is therefore important to comprehensively understand their theoretical background so as to push this research forward. In this study, we shall fully explain and deduce the driving mechanism of a linear ultrasonic levitation transporting system. Oscillation equations from the initial exciting Langevin transducer and flexural traveling wave propagation on the linear guide were first established. Then the squeezing fluid movement between the linear guide and the levitating slider was analyzed. Next, after being excited by the progressing wave under corresponding boundary conditions, the related tangential velocity of the middle flow field was obtained. Finally, the validated experiment was set up to test slider velocity. PMID:20378457

  1. Acoustic levitation

    NASA Astrophysics Data System (ADS)

    Hansen, Uwe J.

    2005-09-01

    A speaker, driven by an amplified audio signal is used to set up a standing wave in a 3b-ft-long, 4-in.-diam transparent tube. Initially the tube is oriented horizontally, and Styrofoam packing peanuts accumulate near the pressure nodes. When the tube is turned to a position with the axis oriented vertically, the peanuts drop slightly, until the gravitational force on the peanuts is balanced by the force due to the sound pressure, at which point levitation is observed. Sound-pressure level measurements are used to map the air column normal mode pattern. Similarly, standing waves are established between an ultrasonic horn and a metal reflector and millimeter size Styrofoam balls are levitated.

  2. Iterative methods for the solution of very large complex symmetric linear systems of equations in electrodynamics

    SciTech Connect

    Clemens, M.; Weiland, T.

    1996-12-31

    In the field of computational electrodynamics the discretization of Maxwell`s equations using the Finite Integration Theory (FIT) yields very large, sparse, complex symmetric linear systems of equations. For this class of complex non-Hermitian systems a number of conjugate gradient-type algorithms is considered. The complex version of the biconjugate gradient (BiCG) method by Jacobs can be extended to a whole class of methods for complex-symmetric algorithms SCBiCG(T, n), which only require one matrix vector multiplication per iteration step. In this class the well-known conjugate orthogonal conjugate gradient (COCG) method for complex-symmetric systems corresponds to the case n = 0. The case n = 1 yields the BiCGCR method which corresponds to the conjugate residual algorithm for the real-valued case. These methods in combination with a minimal residual smoothing process are applied separately to practical 3D electro-quasistatical and eddy-current problems in electrodynamics. The practical performance of the SCBiCG methods is compared with other methods such as QMR and TFQMR.

  3. Dynamics of an Electrodynamic Tether System in a Varying Space-Plasma Environment

    NASA Astrophysics Data System (ADS)

    Janeski, John A.

    Electrodynamic tethers have a wide range of proposed applications in the fields of satellite propulsion and space plasma research. The fundamental purpose of this dissertation is to improve the understanding of the behavior of an electrodynamic tether (EDT) system in Earth's ionosphere. An electrodynamic tether system consists of two satellites connected by a long tether that generates current to produce either power or thrust via the system's electromagnetic interaction with the space environment. Previous electrodynamic tether investigations decouple the interaction between the tether and the constantly changing plasma environment. The limiting factor inhibiting the development of a full system model that has an accurate characterization of the tether/plasma interaction is that the understanding of that interaction is not well developed over a wide range of system parameters. The EDT system model developed in this study uses a high fidelity dynamics model that includes a tether current described by an analytical current collection model whose plasma parameters are determine by the International Reference Ionosphere. It is first shown that new instabilities are induced in the system dynamics under a basic analytical current model versus a constant current model. A 2-D3v Particle-in-Cell (PIC) code has been developed to study the plasma dynamics near a positively charged EDT system end-body and their impact on the current collected. Simulations are run over a range of system parameters that occur throughout a LEO orbit. The azimuthal current structures observed during the TSS-1R mission are found to enhance the current collected by the satellite when the magnetic field is slightly off of perpendicular to the orbital velocity. When the in-plane component of the magnetic field becomes large, the electrons are not able to easily cross the field lines causing plasma lobes form above and below the satellite. The lobes limit the current arriving to the satellite and also

  4. Development of the sonic pump levitator

    NASA Technical Reports Server (NTRS)

    Dunn, S. A.

    1985-01-01

    The process and mechanism involved in producing glass microballoons (GMBs) of acceptable quality for laser triggered inertial fusion through use of glass jet levitation and manipulation are considered. The gas jet levitation device, called sonic pumps, provides positioning by timely and appropriate application of gas mementum from one or more of six sonic pumps which are arranged orthogonally in opposed pairs about the levitation region and are activated by an electrooptical, computer controlled, feedback system. The levitation device was fabricated and its associated control systems were assembled into a package and tested in reduced gravity flight regime of the NASA KC-135 aircraft.

  5. Velocity damper for electromagnetically levitated materials

    SciTech Connect

    Fox, R.J.

    1992-12-31

    A system for damping oscillatory and spinning motions induced in an electromagnetically levitated material. Two opposed field magnets are located orthogonally to the existing levitation coils for providing a DC quadrupole field (cusp field) around the material. The material used for generating the DC quadrupole field must be nonconducting to avoid eddy-current heating and of low magnetic permeability to avoid distorting the induction fields providing the levitation.

  6. Velocity damper for electromagnetically levitated materials

    DOEpatents

    Fox, Richard J.

    1994-01-01

    A system for damping oscillatory and spinning motions induced in an electromagnetically levitated material. Two opposed field magnets are located orthogonally to the existing levitation coils for providing a DC quadrupole field (cusp field) around the material. The material used for generating the DC quadrupole field must be nonconducting to avoid eddy-current heating and of low magnetic permeability to avoid distorting the induction fields providing the levitation.

  7. Velocity damper for electromagnetically levitated materials

    DOEpatents

    Fox, R.J.

    1994-06-07

    A system for damping oscillatory and spinning motions induced in an electromagnetically levitated material is disclosed. Two opposed field magnets are located orthogonally to the existing levitation coils for providing a DC quadrupole field (cusp field) around the material. The material used for generating the DC quadrupole field must be nonconducting to avoid eddy-current heating and of low magnetic permeability to avoid distorting the induction fields providing the levitation. 1 fig.

  8. Possibilities for Continuous Frequency Tuning in Terahertz Gyrotrons with Nontunable Electrodynamic Systems

    NASA Astrophysics Data System (ADS)

    Bratman, V. L.; Savilov, A. V.; Chang, T. H.

    2016-02-01

    Large ohmic losses in the cavities of terahertz gyrotrons may lead to the overlapping of the axial mode spectra. In a number of gyrotron experiments, this effect has been used to provide a fairly broadband frequency tuning by changing appropriately the operating magnetic field and/or accelerating voltage of the gyrotron. Similar to the systems with nonfixed axial structure of the RF electromagnetic field and low diffraction quality, which are due to weak reflections of the operating wave from the collector end of the electrodynamic system, this changing leads to a monotonic change in the axial index of the operating wave and transition from the gyrotron regime to the gyro-BWO regime. According to a theoretical comparison of these two methods performed on the basis of generalization of self-consistent gyrotron equations with allowance for variations in the axial electron momenta, low-reflection systems can provide a higher efficiency and monotonicity of the frequency tuning.

  9. Flux-canceling electrodynamic maglev suspension. Part 1: Test fixture design and modeling

    SciTech Connect

    Thompson, M.T.; Thornton, R.D.; Kondoleon, A.

    1999-05-01

    The design and analysis of a scale-model suspension test facility for magnetic levitation (maglev) is discussed. The authors describe techniques for the design, construction, and testing of a prototype electrodynamic suspension (EDS) levitation system. The viability of future high-temperature superconducting magnet designs for maglev has been investigated with regard to their application to active secondary suspensions. In order to test the viability of a new flux-canceling EDS suspension, a 1/5-scale suspension magnet and guideway was constructed. The suspension was tested by using a high-speed rotating test wheel facility with linear peripheral speed of up to 84 m/s (300 km/h). A set of approximate design tools and scaling laws has been developed in order to evaluate forces and critical velocities in the suspension.

  10. A portable Raman acoustic levitation spectroscopic system for the identification and environmental monitoring of algal cells.

    PubMed

    Wood, Bayden R; Heraud, Philip; Stojkovic, Slobodanka; Morrison, Danielle; Beardall, John; McNaughton, Don

    2005-08-01

    We report the coupling of a portable Raman spectrometer to an acoustic levitation device to enable environmental monitoring and the potential taxonomic identification of microalgae. Spectra of living cells were recorded at 785 nm using a fiber-optic probe coupled to a portable Raman spectrometer. The spectra exhibit an excellent signal-to-noise ratio and clearly show bands from chlorophyll a and beta-carotene. Spectra of levitated photobleached microalgae clearly show a reduction in chlorophyll a concentration relative to beta-carotene after 10 min of exposure to a quartz halogen lamp. Spectra recorded from levitated nitrogen-limited cells also show a significant reduction in bands associated with chlorophyll a, as compared to nitrogen-replete cells. To investigate the diagnostic capability of the technique, four species of microalgae were analyzed. Good quality spectra of all four species were obtained showing varying ratios of beta-carotene to chlorophyll. The combination of an acoustic levitation device and a portable Raman spectrometer shows potential as a taxonomic and environmental monitoring tool with direct application to field studies in remote environments. PMID:16053309

  11. Sound Waves Levitate Substrates

    NASA Technical Reports Server (NTRS)

    Lee, M. C.; Wang, T. G.

    1982-01-01

    System recently tested uses acoustic waves to levitate liquid drops, millimeter-sized glass microballoons, and other objects for coating by vapor deposition or capillary attraction. Cylindrical contactless coating/handling facility employs a cylindrical acoustic focusing radiator and a tapered reflector to generate a specially-shaped standing wave pattern. Article to be processed is captured by the acoustic force field under the reflector and moves as reflector is moved to different work stations.

  12. Improvement of the propulsion force for HTSC-permanent magnet hybrid magnetically levitated carrying system by using the pinned flux of HTSC

    NASA Astrophysics Data System (ADS)

    Ikeda, M.; Sasaki, R.; Ueno, T.; Ohashi, S.

    Magnetically levitated carrying system has been developed. In this system, pinning force of high temperature bulk superconductor (HTSC) is used for the levitation and guidance. The magnetic rail is set on the ground, and flux from the magnetic rail is pinned by HTSCs. To increase levitation force, repulsive force of the permanent magnet is used. For the propulsion system, electromagnets are installed on the surface of the magnetic rail. Improvement of the propulsion force is studied. In the previous system, only flux of the permanent magnet of the carrier is used for propulsion. To increase propulsion force, that of the HTSC of the carrier is also used. Using this excitation method, the propulsion force is improved even though total number of the excited coil is the same.

  13. High-temperature metal purification using a compact, portable rf heating and levitation system on the wake shield

    NASA Technical Reports Server (NTRS)

    Hahs, C. A.

    1990-01-01

    The potential use of a compact, battery-operated rf levitator and heating system to purify high-temperature melting materials in space is described. The wake shield now being fabricated for the Space Vacuum Epitaxy Center will provide an Ultra-high vacuum (10(exp -14) Torr hydrogen, 10(exp -14) Torr helium, 10(exp -30) Torr oxygen). The use of the wake shield to purify Nb, Ti, W, Ir, and other metals to a purity level not achievable on earth is described.

  14. Controlled levitation of a large magnet above superconductors

    SciTech Connect

    Takamori, T.; Boland, J.J.; Dove, D.B. )

    1990-07-01

    The levitation of a permanent magnet over a type-II superconductor may be modified and controlled by the addition of a variable magnetic field to the magnet-superconductor system. Using this scheme, levitation of a magnet of significantly larger mass was established by the direct interaction of the additonal field with the levitating magnet.

  15. No Drama Quantum Electrodynamics?

    NASA Astrophysics Data System (ADS)

    Akhmeteli, Andrey

    2014-03-01

    Is it possible to offer a ``no drama'' quantum electrodynamics, as simple (in principle) as classical electrodynamics - a theory described by a system of partial differential equations (PDE) in 3+1 dimensions, but reproducing unitary evolution of a quantum field theory in the Fock space? The following results suggest an affirmative answer: 1. The scalar field can be algebraically eliminated from scalar electrodynamics. 2. After introduction of a complex 4-potential (producing the same electromagnetic field (EMF) as the standard real 4-potential), the spinor field can be algebraically eliminated from spinor electrodynamics. 3. The resulting theories describe independent evolution of EMF and can be embedded into quantum field theories. Another fundamental result: in a general case, the Dirac equation is equivalent to a 4th order PDE for just one component, which can be made real by a gauge transform. Issues related to the Bell theorem and the connection with Barut's self-field electrodynamics are discussed. A. Akhmeteli, Int'l Journal of Quantum Information, Vol. 9, Suppl., 17-26 (2011) A. Akhmeteli, Journal of Mathematical Physics, Vol. 52, 082303 (2011) A. Akhmeteli, quant-ph/1111.4630 A. Akhmeteli, European Physical Journal C, Vol. 73, 2371 (2013) (open access)

  16. Calculation of levitation forces in permanent magnet-superconductor systems using finite element analysis

    SciTech Connect

    Camacho, D.; Mora, J.; Fontcuberta, J.; Obradors, X.

    1997-08-01

    In this paper we present calculations of levitation forces between a cylindrical permanent magnet and a cylindrical superconductor using a commercial finite element program. Force limits for zero field cooled and field cooled processes have been obtained using the Meissner effect and the perfect pinning hypothesis, respectively. Comparison of the experimentally determined forces with respect to these limits provides a simple estimation of the sample quality. The hysteretical behavior of the forces has been reproduced assuming a critical state model for the superconductor. Results are compared with experimental data. Excellent agreement has been found for forces measured after zero field cooled process thus allowing us to estimate the critical current of the samples. As a further exploitation of the software capabilities we have investigated the effects of the superconducting sample geometry and the effects of different strategies of flux conditioning to optimize the levitation forces. {copyright} {ital 1997 American Institute of Physics.}

  17. Solidification Studies from the Electrostatic Levitation System at the Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Rogers, Jan R.; Hyers, Robert W.; Robinson, Michael B.; Savage, Larry

    2000-01-01

    Electrostatic levitation (ESL) provides a means to study molten materials in a high-purity environment, free from contact with a container. Many phenomena important to materials science can be studied in the ESL. Solidification of metals, alloys and undercooled materials represent an important topic for research in the ESL. Recent studies of metals and alloys during solidification in the ESL are reported. Measurements include time, temperature and transformation of metallic glass-forming alloys, solidification velocities, and microstructure,

  18. Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

    DOEpatents

    Coffey, H.T.

    1993-10-19

    A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle levitation. 3 figures.

  19. Electrodynamics panel presentation

    NASA Technical Reports Server (NTRS)

    Mccoy, J.

    1986-01-01

    The Plasma Motor Generator (PMG) concept is explained in detail. The PMG tether systems being used to calculate the estimated performance data is described. The voltage drops and current contact geometries involved in the operation of an electrodynamic tether are displayed illustrating the comparative behavior of hollow cathodes, electron guns, and passive collectors for current coupling into the ionosphere. The basic PMG design involving the massive tether cable with little or no satellite mass at the far end(s) are also described. The Jupiter mission and its use of electrodynamic tethers are given. The need for demonstration experiments is stressed.

  20. Adipose Tissue Engineering in Three-Dimensional Levitation Tissue Culture System Based on Magnetic Nanoparticles

    PubMed Central

    Daquinag, Alexes C.; Souza, Glauco R.

    2013-01-01

    White adipose tissue (WAT) is becoming widely used in regenerative medicine/cell therapy applications, and its physiological and pathological importance is increasingly appreciated. WAT is a complex organ composed of differentiated adipocytes, stromal mesenchymal progenitors known as adipose stromal cells (ASC), as well as endothelial vascular cells and infiltrating leukocytes. Two-dimensional (2D) culture that has been typically used for studying adipose cells does not adequately recapitulate WAT complexity. Improved methods for reconstruction of functional WAT ex vivo are instrumental for understanding of physiological interactions between the composing cell populations. Here, we used a three-dimensional (3D) levitation tissue culture system based on magnetic nanoparticle assembly to model WAT development and growth in organoids termed adipospheres. We show that 3T3-L1 preadipocytes remain viable in spheroids for a long period of time, while in 2D culture, they lose adherence and die after reaching confluence. Upon adipogenesis induction in 3T3-L1 adipospheres, cells efficiently formed large lipid droplets typical of white adipocytes in vivo, while only smaller lipid droplet formation is achievable in 2D. Adiposphere-based coculture of 3T3-L1 preadipocytes with murine endothelial bEND.3 cells led to a vascular-like network assembly concomitantly with lipogenesis in perivascular cells. Adipocyte-depleted stromal vascular fraction (SVF) of mouse WAT cultured in 3D underwent assembly into organoids with vascular-like structures containing luminal endothelial and perivascular stromal cell layers. Adipospheres made from primary WAT cells displayed robust proliferation and complex hierarchical organization reflected by a matricellular gradient incorporating ASC, endothelial cells, and leukocytes, while ASC quickly outgrew other cell types in adherent culture. Upon adipogenesis induction, adipospheres derived from the SVF displayed more efficient lipid droplet

  1. The Wonders of Levitation

    ERIC Educational Resources Information Center

    French, M. M. J.

    2010-01-01

    I discuss some interesting classroom demonstrations of diamagnetism and how this effect can produce levitation. The possibilities for hands-on demonstrations of diamagnetic and superconducting levitation are discussed. To conclude I discuss some practical uses for levitation in daily life. (Contains 6 figures.)

  2. Isolation of crystallizing droplets by electrostatic levitation

    NASA Technical Reports Server (NTRS)

    Rhim, Won-Kyu; Chung, Sang K.

    1990-01-01

    The principles of electrostatic levitation where the positioning and stabilization of a sample are accomplished by applying appropriate electrostatic forces to a charged sample are outlined, and attention is focused on a feedback control algorithm, drop-launching method, and four-drop levitator. Drop levitation in 1-g is discussed, and crystal-growth experiments are presented. An experiment in which the protein concentration of a levitated drop is controlled by a feedback system is described. During levitation, the drop evaporation rate is controlled in a programmed way in order to acquire proper protein concentration levels for both nucleation and growth. The containerless approach of protein crystal growth when applied in the space environment is assessed.

  3. Improved Position Sensor for Feedback Control of Levitation

    NASA Technical Reports Server (NTRS)

    Hyers, Robert; Savage, Larry; Rogers, Jan

    2004-01-01

    An improved optoelectronic apparatus has been developed to provide the position feedback needed for controlling the levitation subsystem of a containerless-processing system. As explained, the advantage of this apparatus over prior optoelectronic apparatuses that have served this purpose stems from the use of an incandescent lamp, instead of a laser, to illuminate the levitated object. In containerless processing, a small object to be processed is levitated (e.g., by use of a microwave, low-frequency electromagnetic, electrostatic, or acoustic field) so that it is not in contact with the wall of the processing chamber or with any other solid object during processing. In the case of electrostatic or low-frequency electromagnetic levitation, real-time measurement of the displacement of the levitated object from its nominal levitation position along the vertical axis (and, in some cases, along one or two horizontal axes) is needed for feedback control of the levitating field.

  4. Flowfield characteristics of an aerodynamic acoustic levitator

    NASA Astrophysics Data System (ADS)

    Yarin, A. L.; Brenn, G.; Keller, J.; Pfaffenlehner, M.; Ryssel, E.; Tropea, C.

    1997-11-01

    A droplet held in a single-axis ultrasonic levitator will principally sustain a certain external blowing along the levitation axis, which introduces the possibility of investigating heat and/or mass transfer from the droplet under conditions which are not too remote from those in spray systems. The focus of the present work is on the influence of the acoustic field on the external flow. More specifically, an axisymmetric submerged gas jet in an axial standing acoustic wave is examined, both in the absence and presence of a liquid droplet. Flow visualization is first presented to illustrate the global flow effects and the operating windows of jet velocities and acoustic powers which are suitable for further study. An analytic and numeric solution, based on the parabolic boundary layer equations are then given for the case of no levitated droplet, providing quantitative estimates of the acoustic field/flow interaction. Detailed velocity measurements using a laser Doppler anemometer verify the analytic results and extend these to the case of a levitated droplet. Some unresolved discrepancy remains in predicting the maximum velocity attainable before the droplet is blown out of the levitator. Two methods are developed to estimate the sound pressure level in the levitator by comparing flowfield patterns with analytic results. These results and observations are used to estimate to what extent acoustic aerodynamic levitators can be used in the future for investigating transport properties of individual droplets.

  5. Mixing in colliding, ultrasonically levitated drops.

    PubMed

    Chainani, Edward T; Choi, Woo-Hyuck; Ngo, Khanh T; Scheeline, Alexander

    2014-02-18

    Lab-in-a-drop, using ultrasonic levitation, has been actively investigated for the last two decades. Benefits include lack of contact between solutions and an apparatus and a lack of sample cross-contamination. Understanding and controlling mixing in the levitated drop is necessary for using an acoustically levitated drop as a microreactor, particularly for studying kinetics. A pulsed electrostatic delivery system enables addition and mixing of a desired-volume droplet with the levitated drop. Measurement of mixing kinetics is obtained by high-speed video monitoring of a titration reaction. Drop heterogeneity is visualized as 370 nl of 0.25 M KOH (pH: 13.4) was added to 3.7 μL of 0.058 M HCl (pH: 1.24). Spontaneous mixing time is about 2 s. Following droplet impact, the mixed drop orbits the levitator axis at about 5 Hz during homogenization. The video's green channel (maximum response near 540 nm) shows the color change due to phenolphthalein absorption. While mixing is at least an order of magnitude faster in the levitated drop compared with three-dimensional diffusion, modulation of the acoustic waveform near the surface acoustic wave resonance frequency of the levitated drop does not substantially reduce mixing time. PMID:24460103

  6. Substorm electrodynamics

    NASA Technical Reports Server (NTRS)

    Stern, David P.

    1990-01-01

    The present one-dimensional model analysis of substorm electrodynamics proceeds from the standard scenario in which the plasma sheet collapses into a neutral sheet, and magnetic merging occurs between the two tail lobes; plasma flows into the neutral sheet from the lobes and the sides, undergoing acceleration in the dawn-dusk direction. The process is modified by the tendency of the accelerated plasma to unbalance charge neutrality, leading to an exchange of electrons with the ionosphere in order to maintain neutrality. The cross-tail current is weakened by the diversion: this reduces the adjacent lobe-field intensity, but without notable effects apart from a slight expansion of the tail boundary.

  7. On a modified electrodynamics

    PubMed Central

    Reiss, H.R.

    2012-01-01

    A modification of electrodynamics is proposed, motivated by previously unremarked paradoxes that can occur in the standard formulation. It is shown by specific examples that gauge transformations exist that radically alter the nature of a problem, even while maintaining the values of many measurable quantities. In one example, a system with energy conservation is transformed to a system where energy is not conserved. The second example possesses a ponderomotive potential in one gauge, but this important measurable quantity does not appear in the gauge-transformed system. A resolution of the paradoxes comes from noting that the change in total action arising from the interaction term in the Lagrangian density cannot always be neglected, contrary to the usual assumption. The problem arises from the information lost by employing an adiabatic cutoff of the field. This is not necessary. Its replacement by a requirement that the total action should not change with a gauge transformation amounts to a supplementary condition for gauge invariance that can be employed to preserve the physical character of the problem. It is shown that the adiabatic cutoff procedure can also be eliminated in the construction of quantum transition amplitudes, thus retaining consistency between the way in which asymptotic conditions are applied in electrodynamics and in quantum mechanics. The ‘gauge-invariant electrodynamics’ of Schwinger is shown to depend on an ansatz equivalent to the condition found here for maintenance of the ponderomotive potential in a gauge transformation. Among the altered viewpoints required by the modified electrodynamics, in addition to the rejection of the adiabatic cutoff, is the recognition that the electric and magnetic fields do not completely determine a physical problem, and that the electromagnetic potentials supply additional information that is required for completeness of electrodynamics. PMID:23105173

  8. Rapid crystallization from acoustically levitated droplets.

    PubMed

    Cao, Hui-Ling; Yin, Da-Chuan; Guo, Yun-Zhu; Ma, Xiao-Liang; He, Jin; Guo, Wei-Hong; Xie, Xu-Zhuo; Zhou, Bo-Ru

    2012-04-01

    This paper reports on an ultrasonic levitation system developed for crystallization from solution in a containerless condition. The system has been proven to be able to levitate droplets stably and grow crystals rapidly and freely from a levitated droplet. Crystals of four samples, including NaCl, NH(4)Cl, lysozyme, and proteinase K, were obtained successfully utilizing the system. The studies showed that the crystals obtained from the acoustically levitated droplets all exhibited higher growth rates, larger sizes, better shapes, fewer crystals, as well as fewer twins and shards, compared with the control on a vessel wall. The results indicated that containerless ultrasonic levitation could play a key role in improving the crystallization of both inorganic salts and proteins. The ultrasonic levitation system could be used as a ground-based microgravity simulation platform, which could swiftly perform crystallization and screening of crystallization conditions for space crystallization and other ground-based containerless techniques. Moreover, the approach could also be conveniently applied to researching the dynamics and mechanism of crystallization. In addition, the device could be used for the preparation of high-purity materials, analysis of minute or poisonous samples, study of living cells, environmental monitoring, and so on. PMID:22501088

  9. Electrostatic Levitator (ESL) Facility

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The Electrostatic Levitator (ESL) Facility established at Marshall Space Flight Center (MSFC) supports NASA's Microgravity Materials Science Research Program. NASA materials science investigations include ground-based, flight definition and flight projects. Flight definition projects, with demanding science concept review schedules, receive highest priority for scheduling experiment time in the Electrostatic Levitator (ESL) Facility.

  10. Photopolymerization Of Levitated Droplets

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan; Rhim, Won-Kyu; Hyson, Michael T.; Chang, Manchium

    1989-01-01

    Experimental containerless process combines two established techniques to make variety of polymeric microspheres. In single step, electrostatically-levitated monomer droplets polymerized by ultraviolet light. Faster than multiple-step emulsion polymerization process used to make microspheres. Droplets suspended in cylindrical quadrupole electrostatic levitator. Alternating electrostatic field produces dynamic potential along axis. Process enables tailoring of microspheres for medical, scientific, and industrial applications.

  11. Levitation properties of the YBa sub 2 Cu sub 3 O sub x and Tl-Ba-Ca-Cu-O superconducting systems

    SciTech Connect

    Weeks, D.E. )

    1989-12-25

    A torsion balance is used to measure the levitation force on a magnet as a function of height above bulk samples of the YBa{sub 2}Cu{sub 3}O{sub {ital x}} ({ital T}{sub {ital c}}{similar to}90 K) and Tl-Ba-Ca-Cu-O ({ital T}{sub {ital c}}{similar to}110--120 K) superconducting systems. Measurements of magnetic shielding and trapped magnetic fields are also made.

  12. The Inductrack concept: A new approach to magnetic levitation

    SciTech Connect

    Post, R.F.; Ryutov, D.

    1996-05-01

    This report describes theoretical and experimental investigations of a new approach to the problem of the magnetic levitation of a moving object. By contrast with previously studied levitation approaches, the Inductrack concept concept represents a simpler, potentially less expensive, and totally passive means of levitating a high-speed train. It may also be applicable to other areas where simpler magnetic levitation systems are needed, for example, high-speed test sleds for crash testing applications, or low-friction conveyer systems for industrial use.

  13. Magnetic levitation experiments in Sendai

    NASA Astrophysics Data System (ADS)

    Mogi, I.; Takahashi, K.; Awaji, S.; Watanabe, K.; Motokawa, M.

    2006-11-01

    A levitating apple in a hybrid magnet implies the presence of microgravity conditions under gradient magnetic fields. However, several unique behaviors were found, the orientation of levitating rice grains, the alignment of levitating bismuth particles, and the thermal convection in water under the levitation conditions. These are unlikely under the microgravity conditions in the space and are characteristic of the magnetic levitation. On the basis of the understanding of such behaviors, the magnetic levitation was applied to containerless materials processing, and such an attempt resulted in the development of a magnetic levitation furnace.

  14. Matrix method for acoustic levitation simulation.

    PubMed

    Andrade, Marco A B; Perez, Nicolas; Buiochi, Flavio; Adamowski, Julio C

    2011-08-01

    A matrix method is presented for simulating acoustic levitators. A typical acoustic levitator consists of an ultrasonic transducer and a reflector. The matrix method is used to determine the potential for acoustic radiation force that acts on a small sphere in the standing wave field produced by the levitator. The method is based on the Rayleigh integral and it takes into account the multiple reflections that occur between the transducer and the reflector. The potential for acoustic radiation force obtained by the matrix method is validated by comparing the matrix method results with those obtained by the finite element method when using an axisymmetric model of a single-axis acoustic levitator. After validation, the method is applied in the simulation of a noncontact manipulation system consisting of two 37.9-kHz Langevin-type transducers and a plane reflector. The manipulation system allows control of the horizontal position of a small levitated sphere from -6 mm to 6 mm, which is done by changing the phase difference between the two transducers. The horizontal position of the sphere predicted by the matrix method agrees with the horizontal positions measured experimentally with a charge-coupled device camera. The main advantage of the matrix method is that it allows simulation of non-symmetric acoustic levitators without requiring much computational effort. PMID:21859587

  15. 2013 Problem 5: Levitation

    NASA Astrophysics Data System (ADS)

    Ruan, Qiyuan; Zeng, Pei; Zhou, Huijun; Wang, Sihui

    2015-10-01

    In this work, we reproduce the phenomenon through a preliminary experiment. The main factors to optimize the system are identified as the mass of the ball, the flow velocity and distribution of the airstream. We propose a Gaussian velocity distribution model to describe the flow velocity field model quantitatively which is supported by COMSOL simulation and experimental data. Through force analysis, the supporting forces that balance the gravity of the ball are identified. Equation for the tilt angle has been found, from which the optimal tilt angle can be calculated and compared to experimental data. Our research also shows that levitation is more stable without rotation. So the method we used to adjust the mass of the ball by injecting water is also effective in preventing rotation and enhance stability. The theoretical result for the optimal tilt angle is consistent with experimental data.

  16. Magnetic Levitators With Superconductive Components

    NASA Technical Reports Server (NTRS)

    Dolgin, Benjamin P.

    1995-01-01

    Magnetic noncontact levitators that include superconductive components provide vibration-damping suspension for cryogenic instruments, according to proposal. Because superconductive components attached to levitated cryogenic instruments, no additional coolant liquid or refrigeration power needed. Also because vibration-damping components of levitators located outside cold chambers, in ambient environment, not necessary to waste coolant liquid or refrigeration power on dissipation of vibrational energy. At least three levitating magnets and three superconductors necessary for stable levitation.

  17. 3D positional control of magnetic levitation system using adaptive control: improvement of positioning control in horizontal plane

    NASA Astrophysics Data System (ADS)

    Nishino, Toshimasa; Fujitani, Yasuhiro; Kato, Norihiko; Tsuda, Naoaki; Nomura, Yoshihiko; Matsui, Hirokazu

    2012-01-01

    The objective of this paper is to establish a technique that levitates and conveys a hand, a kind of micro-robot, by applying magnetic forces: the hand is assumed to have a function of holding and detaching the objects. The equipment to be used in our experiments consists of four pole-pieces of electromagnets, and is expected to work as a 4DOF drive unit within some restricted range of 3D space: the three DOF are corresponding to 3D positional control and the remaining one DOF, rotational oscillation damping control. Having used the same equipment, Khamesee et al. had manipulated the impressed voltages on the four electric magnetics by a PID controller by the use of the feedback signal of the hand's 3D position, the controlled variable. However, in this system, there were some problems remaining: in the horizontal direction, when translating the hand out of restricted region, positional control performance was suddenly degraded. The authors propose a method to apply an adaptive control to the horizontal directional control. It is expected that the technique to be presented in this paper contributes not only to the improvement of the response characteristic but also to widening the applicable range in the horizontal directional control.

  18. Effect of the characteristics of a superconductor on the levitation properties of the magnet-superconductor system

    SciTech Connect

    Rudnev, I. A. Ermolaev, Yu. S.

    2007-07-15

    The results of the experimental and theoretical investigations of the magnetic levitation force appearing at the interaction of the multilayer superconducting block of the YBa{sub 2}Cu{sub 3}O{sub 7-x} melted textured ceramic and a permanent magnet are presented. The maximum repulsive force and maximum attractive force are determined as functions of the thickness of the superconducting block in the superconductor cooling regime in both zero and nonzero magnetic fields. The dependence of the levitation force on the geometric parameters and critical current of the superconductor is found.

  19. Studying Electrostatic Levitator Specimen

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Kevin Croat of Washington University in St. Louis, MO, examines samples processed in NASA/Marshall Space Flight Center's (MSFC)Electrostatic Levitator Facility. Croat is working with Prof. Kerneth Kelton in investigating undercooling of polytetrahedral phase-forming liquids.

  20. Levitation in physics.

    PubMed

    Brandt, E H

    1989-01-20

    Several physical effects allow free floatation of solid and even liquid matter. Materials may be levitated by a jet of gas, by intense sound waves, or by beams of laser light. In addition, conductors levitate in strong radio-frequency fields, charged particles in alternating electric fields, and magnets above superconductors or vice versa. Although levitation by means of ferromagnets is unstable, supper-conductors may be suspended both above and below a magnet as a result of flux pinning. Levitation is used for containerless processing and investigation of materials, for frictionless bearings and high-speed ground transportation, for spectroscopy of single atoms and microparticles, and for demonstrating superconductivity in the new oxide superconductors. PMID:17787252

  1. Understanding 1D Electrostatic Dust Levitation

    NASA Astrophysics Data System (ADS)

    Hartzell, C. M.; Scheeres, D. J.

    2011-12-01

    Electrostatically-dominated dust motion has been hypothesized since the Lunar Horizon Glow was observed by the Surveyor spacecraft. The hypothesized occurence of this phenomenon was naturally extended to asteroids due to their small gravities. Additionally, it has been suggested that the dust ponds observed on Eros by the NEAR mission may be created by electrostatically-dominated dust transport. Previous attempts to numerically model dust motion on the Moon and Eros have been stymied by poorly understood dust launching mechanisms. As a result, the initial velocity and charge of dust particles used in numerical simulations may or may not have any relevance to the actual conditions occurring in situ. It has been seen that properly tuned initial states (velocity and charge) result in dust particles levitating above the surface in both 1D and 2D simulations. Levitation is of interest to planetary scientists since it provides a way to quickly redistribute the surface dust particles over a body. However, there is currently no method to predict whether or not a certain initial state will result in levitation. We have developed a method to provide constraints on the initial states that result in levitation as a function of dust particle size and central body gravity. Additionally, our method can be applied to several models of the plasma sheath. Thus, we limit the guesswork involved in determining which initial conditions result in levitation. We provide a more detailed understanding of levitation phenomena couched in terms of the commonly recognized spring-mass system. This method of understanding dust motion removes the dependency on the launching mechanism, which remains fraught with controversy. Once a feasible dust launching mechanism is identified (be it micrometeoroid bombardment or electrostatic lofting), our method will allow the community to quickly ascertain if dust levitation will occur in situ or if it is simply a numerical artifact. In addition to

  2. Galilean limit of electrodynamics.

    NASA Astrophysics Data System (ADS)

    Reula, O. A.; Hamity, V. H.; Frittelli, S.

    The final interest of the authors' work is to study the Newtonian limit as an approximation to General Relativity. In this paper they show, using the Galilean limit of electrodynamics with external sources as a test model, some of the problems that they will be confronted with, and the techniques that are introduced to attack them. The crucial physical issue, to define an asymptotic expansion of a class of solutions, is the selection of initial data which results of imposing regularity conditions in the nonrelativistic limit. The authors' model is an example of a more general class of systems which includes, hopefully, the gravitational field plus matter.

  3. Limits on nonlinear electrodynamics

    NASA Astrophysics Data System (ADS)

    Fouché, M.; Battesti, R.; Rizzo, C.

    2016-05-01

    In this paper we set a framework in which experiments whose goal is to test QED predictions can be used in a more general way to test nonlinear electrodynamics (NLED) which contains low-energy QED as a special case. We review some of these experiments and we establish limits on the different free parameters by generalizing QED predictions in the framework of NLED. We finally discuss the implications of these limits on bound systems and isolated charged particles for which QED has been widely and successfully tested.

  4. Quantization of general linear electrodynamics

    SciTech Connect

    Rivera, Sergio; Schuller, Frederic P.

    2011-03-15

    General linear electrodynamics allow for an arbitrary linear constitutive relation between the field strength 2-form and induction 2-form density if crucial hyperbolicity and energy conditions are satisfied, which render the theory predictive and physically interpretable. Taking into account the higher-order polynomial dispersion relation and associated causal structure of general linear electrodynamics, we carefully develop its Hamiltonian formulation from first principles. Canonical quantization of the resulting constrained system then results in a quantum vacuum which is sensitive to the constitutive tensor of the classical theory. As an application we calculate the Casimir effect in a birefringent linear optical medium.

  5. Optics for five-dimensional measurement for correction of vertical displacement error due to attitude of floating body in superconducting magnetic levitation system

    NASA Astrophysics Data System (ADS)

    Shiota, Fuyuhiko; Morokuma, Tadashi

    2006-09-01

    An improved optical system for five-dimensional measurement has been developed for the correction of vertical displacement error due to the attitude change of a superconducting floating body that shows five degrees of freedom besides a vertical displacement of 10mm. The available solid angle for the optical measurement is extremely limited because of the cryogenic laser interferometer sharing the optical window of a vacuum chamber in addition to the basic structure of the cryogenic vessel for liquid helium. The aim of the design was to develop a more practical as well as better optical system compared with the prototype system. Various artifices were built into this optical system and the result shows a satisfactory performance and easy operation overcoming the extremely severe spatial difficulty in the levitation system. Although the system described here is specifically designed for our magnetic levitation system, the concept and each artifice will be applicable to the optical measurement system for an object in a high-vacuum chamber and/or cryogenic vessel where the available solid angle for an optical path is extremely limited.

  6. Livermore's 2004 R&D 100 Awards: Magnetically Levitated Train Takes Flight

    SciTech Connect

    Hazi, A

    2005-09-20

    within {+-}1 millimeter. Position sensors and electronic feedback systems are required to control the magnetic current and to compensate for the inherent instability. This requirement, plus the onboard source of emergency power required to ensure operational safety during a sudden power loss, increases the complexity of EMS trains. In contrast, in electrodynamic systems (EDS), large superconducting magnet coils mounted on the sides of the train generate high-intensity magnetic field poles. Interaction of the current between the coils and the track levitates the train. At operating speeds (above a liftoff speed of about 100 kilometers per hour), the magnetic levitation force balances the weight of the car at a stable position. EDS trains do not require the feedback control systems that EMS trains use to stabilize levitation. However, the superconducting magnetic coils must be kept at temperatures of only 5 kelvins, so costly electrically powered cryogenic equipment is required. Also, passengers, especially those with pacemakers, must be shielded from the high magnetic fields generated by the superconductors.

  7. Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

    DOEpatents

    Coffey, Howard T.

    1993-01-01

    A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle leviation.

  8. Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

    SciTech Connect

    Coffey, H.T.

    1992-12-31

    A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle leviation.

  9. Stable And Oscillating Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, Martin B.; Garrett, Steven L.

    1988-01-01

    Sample stability or instability determined by levitating frequency. Degree of oscillation of acoustically levitated object along axis of levitation chamber controlled by varying frequency of acoustic driver for axis above or below frequency of corresponding chamber resonance. Stabilization/oscillation technique applied in normal Earth gravity, or in absence of gravity to bring object quickly to rest at nominal levitation position or make object oscillate in desired range about that position.

  10. Variable-Position Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Stoneburner, J. D.; Jacobi, N.; Wang, T. G.

    1983-01-01

    Method of acoustic levitation supports objects at positions other than acoustic nodes. Acoustic force is varied so it balances gravitational (or other) force, thereby maintaining object at any position within equilibrium range. Levitation method applicable to containerless processing. Such objects as table-tennis balls, hollow plastic spheres, and balsa-wood spheres levitated in laboratory by new method.

  11. High-Temperature Electrostatic Levitator

    NASA Technical Reports Server (NTRS)

    Rhim, Won-Kyu; Chung, Sang K.

    1994-01-01

    High-temperature electrostatic levitator provides independent control of levitation and heating of sample in vacuum. Does not cause electromagnetic stirring in molten sample (such stirring causes early nucleation in undercooling). Maintenance of levitating force entails control of electrostatic field and electrical charge on sample.

  12. Levitated Duct Fan (LDF) Aircraft Auxiliary Generator

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.; Emerson, Dawn C.; Gallo, Christopher A.; Thompson, William K.

    2011-01-01

    This generator concept includes a novel stator and rotor architecture made from composite material with blades attached to the outer rotating shell of a ducted fan drum rotor, a non-contact support system between the stator and rotor using magnetic fields to provide levitation, and an integrated electromagnetic generation system. The magnetic suspension between the rotor and the stator suspends and supports the rotor within the stator housing using permanent magnets attached to the outer circumference of the drum rotor and passive levitation coils in the stator shell. The magnets are arranged in a Halbach array configuration.

  13. Levitation Technology in International Space Station Research

    NASA Technical Reports Server (NTRS)

    Guinart-Ramirez, Y.; Cooley, V. M.; Love, J. E.

    2016-01-01

    The International Space Station (ISS) is a unique multidisciplinary orbiting laboratory for science and technology research, enabling discoveries that benefit life on Earth and exploration of the universe. ISS facilities for containerless sample processing in Materials Science experiments include levitation devices with specimen positioning control while reducing containment vessel contamination. For example, ESA's EML (ElectroMagnetic Levitator), is used for melting and solidification of conductive metals, alloys, or semiconductors in ultra-high vacuum, or in high-purity gaseous atmospheres. Sample heating and positioning are accomplished through electromagnetic fields generated by a coil system. EML applications cover investigation of solidification and microstructural formation, evaluation of thermophysical properties of highly reactive metals (whose properties can be very sensitive to contamination), and examination of undercooled liquid metals to understand metastable phase convection and influence convection on structural changes. MSL utilization includes development of novel light-weight, high-performance materials. Another facility, JAXA's ELF (Electrostatic Levitation Furnace), is used to perform high temperature melting while avoiding chemical reactions with crucibles by levitating a sample through Coulomb force. ELF is capable of measuring density, surface tension, and viscosity of samples at high temperatures. One of the initial ELF investigations, Interfacial Energy-1, is aimed at clarification of interfacial phenomena between molten steels and oxide melts with industrial applications in control processes for liquid mixing. In addition to these Materials Science facilities, other ISS investigations that involve levitation employ it for biological research. For example, NASA's "Magnetic 3D Culturing and Bioprinting" investigation uses magnetic levitation for three-dimensional culturing and positioning of magnetized cells to generate spheroid assemblies

  14. Final Report: Levitated Dipole Experiment

    SciTech Connect

    Kesner, Jay; Mauel, Michael

    2013-03-10

    -field transport. We find levitation causes the central plasma density to increase dramatically and to significantly improve the confinement of thermal plasma [Boxer, Nature-Physics, v8, p. 949, 2010]. Several diagnostic systems have been used to measure plasma fluctuations, and these appear to represent low-frequency convection that may lead to adiabatic heating and strongly peaked pressure profiles. These experiments are remarkable, and the motivate wide-ranging studies of plasma found in space and confined for fusion energy. In the following report, we describe: (i) observations of the centrally-peaked density profile that appears naturally as a consequence of a strong turbulent pinch, (ii) observations of overall density and pressure increases that suggest large improvements to the thermal electron confinement time result occur during levitation, and (iii) the remarkable properties of low-frequency plasma fluctuations that cause magnetized plasma to "self-organize" into well-confined, centrally-peaked profiles that are relative to fusion and to space.

  15. Dimensionless Analysis and Mathematical Modeling of Electromagnetic Levitation (EML) of Metals

    NASA Astrophysics Data System (ADS)

    Gao, Lei; Shi, Zhe; Li, Donghui; Yang, Yindong; Zhang, Guifang; McLean, Alexander; Chattopadhyay, Kinnor

    2016-02-01

    Electromagnetic levitation (EML), a contactless metal melting method, can be used to produce ultra-pure metals and alloys. In the EML process, the levitation force exerted on the droplet is of paramount importance and is affected by many parameters. In this paper, the relationship between levitation force and parameters affecting the levitation process were investigated by dimensionless analysis. The general formula developed by dimensionless analysis was tested and evaluated by numerical modeling. This technique can be employed to design levitation systems for a variety of materials.

  16. Development of the sonic pump levitation

    NASA Technical Reports Server (NTRS)

    Dunn, S. A.

    1984-01-01

    A prototype levitating/positioning device termed the Sonic Pump Levitator was designed, built and successfully tested in full gravity and in the reduced gravity of the parabolic flight regime of the KC-135. Positioning is achieved by timely and appropriate application of gas momentum from one or more of six sonic pumps. The sonic pumps, which are arranged orthogonally in opposed pairs about the levitation region, are activated by an electro-optical, computer controlled, feedback system. The sonic pump is a transducer which is capable of converting sound energy into a directed flow of gas. It consists of a loudspeaker whose face is sealed by a closure perforated by one or more orifices. The diaphragm of the loudspeaker is the only moving part of the sonic pump, no valves being needed. This very low inertia electromechanical device was developed to provide the short response time necessary to keep pace with the demands of computerized position keeping.

  17. Remarks on nonlinear electrodynamics

    NASA Astrophysics Data System (ADS)

    Gaete, Patricio; Helayël-Neto, José

    2014-11-01

    We consider both generalized Born-Infeld and exponential electrodynamics. The field energy of a point-like charge is finite only for Born-Infeld-like electrodynamics. However, both Born-Infeld-type and exponential electrodynamics display the vacuum birefringence phenomenon. Subsequently, we calculate the lowest-order modifications to the interaction energy for both classes of electrodynamics, within the framework of the gauge-invariant path-dependent variables formalism. These are shown to result in long-range (-type) corrections to the Coulomb potential. Once again, for their noncommutative versions, the interaction energy is ultraviolet finite.

  18. Magnetic levitation for hard superconductors

    SciTech Connect

    Kordyuk, A.A.

    1998-01-01

    An approach for calculating the interaction between a hard superconductor and a permanent magnet in the field-cooled case is proposed. The exact solutions were obtained for the point magnetic dipole over a flat ideally hard superconductor. We have shown that such an approach is adaptable to a wide practical range of melt-textured high-temperature superconductors{close_quote} systems with magnetic levitation. In this case, the energy losses can be calculated from the alternating magnetic field distribution on the superconducting sample surface. {copyright} {ital 1998 American Institute of Physics.}

  19. Electron spin control of optically levitated nanodiamonds in vacuum

    NASA Astrophysics Data System (ADS)

    Hoang, Thai; Ahn, Jonghoon; Bang, Jaehoon; Li, Tongcang

    2016-05-01

    Electron spins of diamond nitrogen-vacancy (NV) centers are important quantum resources for nanoscale sensing and quantum information. Combining such NV spin systems with levitated optomechanical resonators will provide a hybrid quantum system for many novel applications. Here we optically levitate a nanodiamond and demonstrate electron spin control of its built-in NV centers in low vacuum. We observe that the strength of electron spin resonance (ESR) is enhanced when the air pressure is reduced. To better understand this novel system, we also investigate the effects of trap power and measure the absolute internal temperature of levitated nanodiamonds with ESR after calibration of the strain effect.

  20. Report of the Electrodynamic Interactions Panel

    NASA Technical Reports Server (NTRS)

    Stone, N. H.; Taylor, R. S.; Benford, S.; Binsack, J. H.; Dobrowolny, M.; Finnegan, P.; Grossi, M. D.; Hudson, M.; Intriligator, D.; Kaminskas, R.

    1985-01-01

    A wide range of opportunities is provided by the electrodynamic tether to more fully understand the generation of waves in plasmas, the behavior of field aligned currents, the behavior of large body-space plasma interactions, and for process simulation, using the electrodynamic tether to study processes and phenomena relevant to solar system and astrophysics plasma physics. The electrodynamic tether offers a means of study and experimentation in space which will provide a rich yield in new scientific results and will enhance the understanding of space plasma physics. It also has promising technological applications (e.g., the generation of electrical power and thrust) which may be highly significant to future space operations.

  1. The PROPEL Electrodynamic Tether Demonstration Mission

    NASA Technical Reports Server (NTRS)

    Bilen, Sven G.; Johnson, C. Les; Wiegmann, Bruce M.; Alexander, Leslie; Gilchrist, Brian E.; Hoyt, Robert P.; Elder, Craig H.; Fuhrhop, Keith P.; Scadera, Michael

    2012-01-01

    The PROPEL ("Propulsion using Electrodynamics") mission will demonstrate the operation of an electrodynamic tether propulsion system in low Earth orbit and advance its technology readiness level for multiple applications. The PROPEL mission has two primary objectives: first, to demonstrate the capability of electrodynamic tether technology to provide robust and safe, near-propellantless propulsion for orbit-raising, de-orbit, plane change, and station keeping, as well as to perform orbital power harvesting and formation flight; and, second, to fully characterize and validate the performance of an integrated electrodynamic tether propulsion system, qualifying it for infusion into future multiple satellite platforms and missions with minimal modification. This paper provides an overview of the PROPEL system and design reference missions; mission goals and required measurements; and ongoing PROPEL mission design efforts.

  2. A containerless levitation setup for liquid processing in a superconducting magnet.

    PubMed

    Lu, Hui-Meng; Yin, Da-Chuan; Li, Hai-Sheng; Geng, Li-Qiang; Zhang, Chen-Yan; Lu, Qin-Qin; Guo, Yun-Zhu; Guo, Wei-Hong; Shang, Peng; Wakayama, Nobuko I

    2008-09-01

    Containerless processing of materials is considered beneficial for obtaining high quality products due to the elimination of the detrimental effects coming from the contact with container walls. Many containerless processing methods are realized by levitation techniques. This paper describes a containerless levitation setup that utilized the magnetization force generated in a gradient magnetic field. It comprises a levitation unit, a temperature control unit, and a real-time observation unit. Known volume of liquid diamagnetic samples can be levitated in the levitation chamber, the temperature of which is controlled using the temperature control unit. The evolution of the levitated sample is observed in real time using the observation unit. With this setup, containerless processing of liquid such as crystal growth from solution can be realized in a well-controlled manner. Since the levitation is achieved using a superconducting magnet, experiments requiring long duration time such as protein crystallization and simulation of space environment for living system can be easily succeeded. PMID:19044425

  3. Cavity quantum electrodynamics using a near-resonance two-level system: Emergence of the Glauber state

    SciTech Connect

    Sarabi, B.; Ramanayaka, A. N.; Burin, A. L.; Wellstood, F. C.; Osborn, K. D.

    2015-04-27

    Random tunneling two-level systems (TLSs) in dielectrics have been of interest recently because they adversely affect the performance of superconducting qubits. The coupling of TLSs to qubits has allowed individual TLS characterization, which has previously been limited to TLSs within (thin) Josephson tunneling barriers made from aluminum oxide. Here, we report on the measurement of an individual TLS within the capacitor of a lumped-element LC microwave resonator, which forms a cavity quantum electrodynamics (CQED) system and allows for individual TLS characterization in a different structure and material than demonstrated with qubits. Due to the reduced volume of the dielectric (80 μm{sup 3}), even with a moderate dielectric thickness (250 nm), we achieve the strong coupling regime as evidenced by the vacuum Rabi splitting observed in the cavity spectrum. A TLS with a coherence time of 3.2 μs was observed in a film of silicon nitride as analyzed with a Jaynes-Cummings spectral model, which is larger than seen from superconducting qubits. As the drive power is increased, we observe an unusual but explicable set of continuous and discrete crossovers from the vacuum Rabi split transitions to the Glauber (coherent) state.

  4. Cavity quantum electrodynamics using a near-resonance two-level system: Emergence of the Glauber state

    NASA Astrophysics Data System (ADS)

    Sarabi, B.; Ramanayaka, A. N.; Burin, A. L.; Wellstood, F. C.; Osborn, K. D.

    2015-04-01

    Random tunneling two-level systems (TLSs) in dielectrics have been of interest recently because they adversely affect the performance of superconducting qubits. The coupling of TLSs to qubits has allowed individual TLS characterization, which has previously been limited to TLSs within (thin) Josephson tunneling barriers made from aluminum oxide. Here, we report on the measurement of an individual TLS within the capacitor of a lumped-element LC microwave resonator, which forms a cavity quantum electrodynamics (CQED) system and allows for individual TLS characterization in a different structure and material than demonstrated with qubits. Due to the reduced volume of the dielectric (80 μm3), even with a moderate dielectric thickness (250 nm), we achieve the strong coupling regime as evidenced by the vacuum Rabi splitting observed in the cavity spectrum. A TLS with a coherence time of 3.2 μs was observed in a film of silicon nitride as analyzed with a Jaynes-Cummings spectral model, which is larger than seen from superconducting qubits. As the drive power is increased, we observe an unusual but explicable set of continuous and discrete crossovers from the vacuum Rabi split transitions to the Glauber (coherent) state.

  5. Levitation Kits Demonstrate Superconductivity.

    ERIC Educational Resources Information Center

    Worthy, Ward

    1987-01-01

    Describes the "Project 1-2-3" levitation kit used to demonstrate superconductivity. Summarizes the materials included in the kit. Discusses the effect demonstrated and gives details on how to obtain kits. Gives an overview of the documentation that is included. (CW)

  6. Levitation of superconducting composites

    NASA Technical Reports Server (NTRS)

    Chiang, C. K.; Turchinskaya, M.; Swartzendruber, L. J.; Shull, R. D.; Bennett, L. H.

    1991-01-01

    The inverse levitation of a high temperature superconductor polymer composite consisting of powdered quench melt growth Ba2YCu3O(7-delta) and cyanoacrylate is reported. Magnetic hysteresis loop measurements for the composite are compared to those measured for the bulk material prior to powdering. Differences in the flux pining capability between the two material forms are small but significant.

  7. Studying Electrostatic Levitator Specimen

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Prof. Kerneth Kelton of Washington University in St. Lous, MO, (L) and Dr. Michael Robinson of NASA's Marshall Space Flight Center (MSFC) examine a titanium-iron silicate (TiFeSiO)sample processed in MSFC's Electrostatic Levitator (ESL) Facility (background). Kelton is investigating undercooling of polytetrahedral phase-forming liquids.

  8. Depinning of flux lines and AC losses in magnet-superconductor levitation system

    SciTech Connect

    Terentiev, A. N.; Hull, J. R.; De Long, L. E.

    1999-11-29

    The AC loss characteristics of a magnet-superconductor system were studied with the magnet fixed to the free end of an oscillating cantilever located near a stationary melt-textured YBCO pellet. Below a threshold AC field amplitude {approx}2Oe, the dissipation of the oscillator is amplitude-independent, characteristic of a linear, non-hysteretic regime. Above threshold,dissipation increases with amplitude, reflecting the depinning and hysteretic motion of flux lines. The threshold AC field is an order of magnitude higher than that measured for the same YBCO material via AC susceptometry in a uniform DC magnetic field, A partial lock-in of flux lines between YBCO ab planes is proposed as the mechanism for the substantial increase of the depinning threshold.

  9. Magnetically levitated space elevator to low-earth orbit.

    SciTech Connect

    Hull, J. R.; Mulcahy, T. M.

    2001-07-02

    The properties of currently available NbTi superconductor and carbon-fiber structural materials enable the possibility of constructing a magnetically levitated space elevator from the earth's surface up to an altitude of {approx} 200 km. The magnetic part of the elevator consists of a long loop of current-carrying NbTi, composed of one length that is attached to the earth's surface in an east-west direction and a levitated-arch portion. The critical current density of NbTi is sufficiently high that these conductors will stably levitate in the earth's magnetic field. The magnetic self-field from the loop increases the levitational force and for some geometries assists levitational stability. The 200-km maximum height of the levitated arch is limited by the allowable stresses of the structural material. The loop is cryogenically cooled with helium, and the system utilizes intermediate pumping and cooling stations along both the ground and the levitated portion of the loop, similar to other large terrestrial cryogenic systems. Mechanically suspended from the basic loop is an elevator structure, upon which mass can be moved between the earth's surface and the top of the loop by a linear electric motor or other mechanical or electrical means. At the top of the loop, vehicles may be accelerated to orbital velocity or higher by rocket motors, electromagnetic propulsion, or hybrid methods.

  10. Electrodynamic Tether

    NASA Technical Reports Server (NTRS)

    Johnson, Charles L. (Inventor); Ballance, Judy L. (Inventor); Welzyn, Kenneth J. (Inventor); Vaughn, Jason A. (Inventor); Lorenzini, Enrico (Inventor); Schuler, Peter S. (Inventor)

    2006-01-01

    A tether system for providing thrust to or power subsystems of an artificial satellite in a low earth orbit. The tether has three main sections, an insulated section connected to the satellite, a conducting section connected to the insulating section for drawing in and releasing electrons from the space plasma and a non-conducting section for providing a tension to the other sections of the tether. An oxygen resistant coating is applied to the bare wire of the conducting section as well as the insulated wires of the insulated section that prevents breakdown during tether operations in the space plasma. The insulated and bare wire sections also surround a high tensile flexible polymer core to prevent any debris from breaking the tether during use.

  11. The Inductrack Approach to Magnetic Levitation

    SciTech Connect

    Post, R.F.; Ryutov, D.D.

    2000-04-19

    Concepts developed during research on passive magnetic bearing systems at the Lawrence Livermore National Laboratory gave rise to a new approach to magnetic levitation, the Inductrack. A passive induced-current system employing permanent magnets on the moving vehicle, the Inductrack maximizes levitation forces by a combination of two elements. First, the permanent magnets on the vehicle are arranged in a ''Halbach array,'' a magnet configuration that optimally produces a periodic magnetic field below the array, while canceling the field above the array. Second, the track is made up of close-packed shorted electrical circuits. These circuits couple optimally to the magnetic field of the Halbach array. As a result, levitating forces of order 40 metric tonnes per square meter of Halbach array can be generated, using NdFeB magnets whose weight is a few percent of the levitated weight. Being an induced-current system, the levitation requires motion of the vehicle above a low transition speed. For maglev applications this speed is a few kilometers per hour, walking speed. At rest or in the station auxiliary wheels are needed. The Inductrack is thus fail-safe, that is, drive system failure would only result in the vehicle slowing down and finally settling on its auxiliary wheels. On the basis of theoretical analyses a small model vehicle and a 20-meter-long track was built and tested at speeds of order 12 meters per second. A second model, designed to achieve 10-g acceleration levels and much higher speeds, is under construction under NASA sponsorship, en route to the design of maglev-based launchers for rockets. Some of the presently perceived practical problems of implementing full-scale maglev systems based on the Inductrack concept will be discussed.

  12. A levitation instrument for containerless study of molten materials

    NASA Astrophysics Data System (ADS)

    Nordine, Paul C.; Merkley, Dennis; Sickel, Jeffrey; Finkelman, Steve; Telle, Rainer; Kaiser, Arno; Prieler, Robert

    2012-12-01

    A new aero-acoustic levitation instrument (AAL) has been installed at the Institute for Mineral Engineering at RWTH University in Aachen, Germany. The AAL employs acoustically stabilized gas jet levitation with laser-beam heating and melting to create a contact-free containerless environment for high temperature materials research. Contamination-free study of liquids is possible at temperatures in excess of 3000 °C and of undercooled liquids at temperatures far below the melting point. Digital control technology advances the art of containerless experiments to obtain long-term levitation stability, allowing new experiments in extreme temperature materials research and to study operation of the levitation instrument itself. Experiments with liquid Al2O3 at temperatures more than 3200 °C, 1200 °C above the melting point, and with liquid Y3Al5O12 far below the melting point are reported. Fast pyrometry and video recording instruments yield crystallization rates in undercooled liquid Al2O3 as a function of temperature. Levitation of dense liquid HfO2 at temperatures above 2900 °C is demonstrated. Capabilities are described for resonant frequency matching in the three-axis acoustic positioning system, acoustic control of sample spin, and position control of standing wave nodes to stabilize levitation under changing experimental conditions. Further development and application of the levitation technology is discussed based on the results of experiments and modeling of instrument operations.

  13. Experimental study of streaming flows associated with ultrasonic levitators

    NASA Astrophysics Data System (ADS)

    Trinh, E. H.; Robey, J. L.

    1994-11-01

    Steady-state acoustic streaming flow patterns have been observed during the operation of a variety of resonant single-axis ultrasonic levitators in a gaseous environment and in the 20-37 kHz frequency range. Light sheet illumination and scattering from smoke particles have revealed primary streaming flows which display different characteristics at low and high sound pressure levels. Secondary macroscopic streaming cells around levitated samples are superimposed on the primary streaming flow pattern generated by the standing wave. These recorded flows are quite reproducible, and are qualitatively the same for a variety of levitator physical geometries. An onset of flow instability can also be recorded in nonisothermal systems, such as levitated spot-heated samples when the resonance conditions are not exactly satisfied. A preliminary qualitative interpretation of these experimental results is presented in terms of the superposition of three discrete sets of circulation cells operating on different spatial scales. These relevant length scales are the acoustic wavelength, the levitated sample size, and finally the acoustic boundary layer thickness. This approach fails, however, to explain the streaming flow-field morphology around liquid drops levitated on Earth. Observation of the interaction between the flows cells and the levitated samples also suggests the existence of a steady-state torque induced by the streaming flows.

  14. A levitation instrument for containerless study of molten materials.

    PubMed

    Nordine, Paul C; Merkley, Dennis; Sickel, Jeffrey; Finkelman, Steve; Telle, Rainer; Kaiser, Arno; Prieler, Robert

    2012-12-01

    A new aero-acoustic levitation instrument (AAL) has been installed at the Institute for Mineral Engineering at RWTH University in Aachen, Germany. The AAL employs acoustically stabilized gas jet levitation with laser-beam heating and melting to create a contact-free containerless environment for high temperature materials research. Contamination-free study of liquids is possible at temperatures in excess of 3000 °C and of undercooled liquids at temperatures far below the melting point. Digital control technology advances the art of containerless experiments to obtain long-term levitation stability, allowing new experiments in extreme temperature materials research and to study operation of the levitation instrument itself. Experiments with liquid Al(2)O(3) at temperatures more than 3200 °C, 1200 °C above the melting point, and with liquid Y(3)Al(5)O(12) far below the melting point are reported. Fast pyrometry and video recording instruments yield crystallization rates in undercooled liquid Al(2)O(3) as a function of temperature. Levitation of dense liquid HfO(2) at temperatures above 2900 °C is demonstrated. Capabilities are described for resonant frequency matching in the three-axis acoustic positioning system, acoustic control of sample spin, and position control of standing wave nodes to stabilize levitation under changing experimental conditions. Further development and application of the levitation technology is discussed based on the results of experiments and modeling of instrument operations. PMID:23278026

  15. Simplified Rotation In Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Gaspar, M. S.; Trinh, E. H.

    1989-01-01

    New technique based on old discovery used to control orientation of object levitated acoustically in axisymmetric chamber. Method does not require expensive equipment like additional acoustic drivers of precisely adjustable amplitude, phase, and frequency. Reflecting object acts as second source of sound. If reflecting object large enough, close enough to levitated object, or focuses reflected sound sufficiently, Rayleigh torque exerted on levitated object by reflected sound controls orientation of object.

  16. Single mode levitation and translation

    NASA Technical Reports Server (NTRS)

    Barmatz, Martin B. (Inventor); Allen, James L. (Inventor)

    1988-01-01

    A single frequency resonance mode is applied by a transducer to acoustically levitate an object within a chamber. This process allows smooth movement of the object and suppression of unwanted levitation modes that would urge the object to a different levitation position. A plunger forms one end of the chamber, and the frequency changes as the plunger moves. Acoustic energy is applied to opposite sides of the chamber, with the acoustic energy on opposite sides being substantially 180 degrees out of phase.

  17. The effects of a realistic hollow cathode plasma contactor model on the simulation of bare electrodynamic tether systems

    NASA Astrophysics Data System (ADS)

    Blash, Derek M.

    The region known as Low-Earth Orbit (LEO) has become populated with artificial satellites and space debris since humanities initial venture into the region. This has turned LEO into a hazardous region. Since LEO is very valuable to many different countries, there has been a push to prevent further buildup and talk of even deorbiting spent satellites and debris already in LEO. One of the more attractive concepts available for deorbiting debris and spent satellites is a Bare Electrodynamic Tether (BET). A BET is a propellantless propulsion technique in which two objects are joined together by a thin conducting material. When these tethered objects are placed in LEO, the tether sweeps across the magnetic field lines of the Earth and induces an electromotive force (emf) along the tether. Current from the space plasma is collected on the bare tether under the action of the induced emf, and this current interacts with the Earth's magnetic field to create a drag force that can be used to deorbit spent satellites and space debris. A Plasma Contactor (PC) is used to close the electrical circuit between the BET and the ionospheric plasma. The PC requires a voltage and, depending on the device, a gas flow to emit electrons through a plasma bridge to the ionospheric plasma. The PC also can require a plasma discharge electrode and a heater to condition the PC for operation. These parameters as well as the PC performance are required to build an accurate simulation of a PC and, therefore, a BET deorbiting system. This thesis focuses on the development, validation, and implementation of a simulation tool to model the effects of a realistic hollow cathode PC system model on a BET deorbit system.

  18. Electron spin control of optically levitated nanodiamonds in vacuum.

    PubMed

    Hoang, Thai M; Ahn, Jonghoon; Bang, Jaehoon; Li, Tongcang

    2016-01-01

    Electron spins of diamond nitrogen-vacancy (NV) centres are important quantum resources for nanoscale sensing and quantum information. Combining NV spins with levitated optomechanical resonators will provide a hybrid quantum system for novel applications. Here we optically levitate a nanodiamond and demonstrate electron spin control of its built-in NV centres in low vacuum. We observe that the strength of electron spin resonance (ESR) is enhanced when the air pressure is reduced. To better understand this system, we investigate the effects of trap power and measure the absolute internal temperature of levitated nanodiamonds with ESR after calibration of the strain effect. We also observe that oxygen and helium gases have different effects on both the photoluminescence and the ESR contrast of nanodiamond NV centres, indicating potential applications of NV centres in oxygen gas sensing. Our results pave the way towards a levitated spin-optomechanical system for studying macroscopic quantum mechanics. PMID:27432560

  19. Electron spin control of optically levitated nanodiamonds in vacuum

    PubMed Central

    Hoang, Thai M.; Ahn, Jonghoon; Bang, Jaehoon; Li, Tongcang

    2016-01-01

    Electron spins of diamond nitrogen-vacancy (NV) centres are important quantum resources for nanoscale sensing and quantum information. Combining NV spins with levitated optomechanical resonators will provide a hybrid quantum system for novel applications. Here we optically levitate a nanodiamond and demonstrate electron spin control of its built-in NV centres in low vacuum. We observe that the strength of electron spin resonance (ESR) is enhanced when the air pressure is reduced. To better understand this system, we investigate the effects of trap power and measure the absolute internal temperature of levitated nanodiamonds with ESR after calibration of the strain effect. We also observe that oxygen and helium gases have different effects on both the photoluminescence and the ESR contrast of nanodiamond NV centres, indicating potential applications of NV centres in oxygen gas sensing. Our results pave the way towards a levitated spin–optomechanical system for studying macroscopic quantum mechanics. PMID:27432560

  20. The design considerations for a superconducting magnetic bearing system

    NASA Astrophysics Data System (ADS)

    Cansiz, Ahmet; Yildizer, Irfan

    2014-09-01

    In this paper a high temperature superconducting magnetic bearing is studied with various design considerations. The design of the bearing consists of a rotor with 7.5 kg mass. The stable levitation of the rotor is provided with the Evershed type and superconducting components. The dynamic stability of the rotor is strengthened with the electromagnetic and electrodynamic levitation techniques. The force on the rotor is predicted in terms of semi-analytical frozen image model. The designed driving system sustains stable levitation during the rotation of the rotor and achieves higher rotational speed than that of the torque driver. The results indicate that the designed rotor and driving system have potential solutions for the development of the superconducting flywheel energy storage.

  1. Magnetically levitated superconducting bearing

    SciTech Connect

    Weinberger, B.R.; Lynds, L. Jr.

    1993-10-26

    A magnetically levitated superconducting bearing includes a magnet mounted on a shaft that is rotatable around an axis of rotation and a Type II superconductor supported on a stator in proximity to the magnet. The superconductor is positioned so that when it is cooled to its superconducting state in the presence of a magnetic field, it interacts with the magnet to produce an attractive force that levitates the magnet and supports a load on the shaft. The interaction between the superconductor and magnet also produces surface screening currents that generate a repulsive force perpendicular to the load. The bearing also has means for maintaining the superconductor at a temperature below its critical temperature. The bearing could also be constructed so the magnet is supported on the stator and the superconductor is mounted on the shaft. The bearing can be operated by cooling the superconductor to its superconducting state in the presence of a magnetic field. 6 figures.

  2. Dust Levitation and Transport Near Surfaces

    NASA Astrophysics Data System (ADS)

    Sickafoose, A. A.; Colwell, J. E.; Horanyi, M.; Robertson, S.

    2002-12-01

    There are many examples of active dust transport near surfaces in the solar system: dust grains suspended above the lunar surface, spokes observed in Saturn's rings, and recent images of infilled craters from the NEAR spacecraft at Eros. Electrostatic dust levitation and transport have also been theorized to occur on Mercury, asteroids, and comets. Dusty regoliths are produced by the interplanetary micrometeoroid flux on nearly all airless bodies in the solar system. Therefore, understanding dust charging, levitation, and dynamics above surfaces is important for interpreting remote sensing data and analyzing the evolution of most planetary surfaces. Objects in a plasma, such as planetary bodies in the solar wind, charge to a floating potential determined by the balance between charging currents in the local plasma environment. The primary charging currents are due to collection of electrons and ions from the plasma, photoemission, and secondary electron emission. When photoemission is the dominant charging process, a photoelectron sheath forms near the surface of the object. Positively charged particles released from the surface can levitate above the surface at a height where the gravitational force is balanced by the electric force. In cases where secondary electron emission and photoemission are weak, objects will become negatively charged due to electron collection and will be surrounded by a plasma sheath. Negatively charged dust grains from these surfaces can levitate in the electric field created by the plasma sheath. Dust levitation and transport near surfaces in the solar system is thought to be primarily due to the interaction between charged dust particles and a photoelectron or plasma sheath on the surface. We report the results of experiments on the levitation and transport of dust particles in an argon plasma sheath above a flat, conducting surface. Levitation experiments are performed using monodisperse polystyrene DVB microbeads. Transport

  3. Dimensionless Analysis and Numerical Modeling of Rebalancing Phenomena During Levitation

    NASA Astrophysics Data System (ADS)

    Gao, Lei; Shi, Zhe; Li, Donghui; McLean, Alexander; Chattopadhyay, Kinnor

    2016-06-01

    Electromagnetic levitation (EML) has proved to be a powerful tool for research activities in areas pertaining to materials physics and engineering. The customized EML setups in various fields, ranging from solidification to nanomaterial manufacturing, require the designing of stable levitation systems. Since the elevated droplet is opaque, the most effective way to research on EML is mathematical modeling. In the present study, a 3D model was built to investigate the rebalancing phenomenon causing instabilities during droplet melting. A mathematical model modified based on Hooke's law (spring) was proposed to describe the levitation system. This was combined with dimensionless analysis to investigate the generation of levitation forces as it will significantly affect the behavior of the spring model.

  4. Galilean Podolsky Electrodynamics

    NASA Astrophysics Data System (ADS)

    Pompeia, P. J.; de Montigny, M.; Khanna, F. C.

    2009-09-01

    We analyze non-relativistic limits of Podolsky generalized electrodynamics in the context of the 5-dimensional Galilean formalism. The 'electric' and 'magnetic' limits are studied in analogy with the work of Le Bellac and Levy-Leblond (1973).

  5. Electrodynamic trapping and manipulation of particle clouds

    NASA Astrophysics Data System (ADS)

    Vehring, R.; Aardahl, C. L.; Davis, E. J.; Schweiger, G.; Covert, D. S.

    1997-01-01

    Apparatus and techniques were developed to electrodynamically trap and manipulate groups of microparticles. The equipment consists of a vibrating orifice aerosol generator, an inductive particle charger, a plenum chamber, and a double-ring electrodynamic balance. Salt particles (NaNO3) of controllable and measurable mass and charge were produced and introduced into the balance in nitrogen at flow rates up to 25 cm3/min. Ordered arrays of any number of particles up to 26 were assembled and manipulated. Methods for compressing the arrays are presented, and controlled ejection of single particles from a trapped array is demonstrated. Particles of opposite polarity were successfully levitated and kept apart, and aggregation of these particles was then induced by changing the electric field. Raman spectra were recorded for multiple salt particles, each having a diameter of 3.5 μm, by aligning them in a laser beam. The enhanced Raman signal is compared with that from a single particle isolated from the array. From the results, a detection limit of 0.4 pg per particle was estimated.

  6. Magnetic levitation of a flexible steel plate with a vibration suppressing magnet

    SciTech Connect

    Hayashiya, H.; Araki, N.; Paddison, J.E.; Ohsaki, H.; Masada, E.

    1996-09-01

    In the steel making process, the application of a magnetic levitation to the steel plate conveyance is expected. The advantages brought by introducing contactless support of a steel plate are improved quality of products, reduced maintenance cost of installations, increased productivity, and quieter operation. Here, a magnetic levitation system that has a vibration suppressing electromagnet which use only the velocity of the levitated object for the control has been studied. The proposed system has advantages of the stale levitation of a flexible steel plate which moves with time under the fixed electromagnets. The simulation of levitated plate`s response using finite element method and the magnetic levitation experiments using such a vibration suppressing magnet were carried out. The results show the vibration suppressing magnet is able to control the low frequency natural vibration effectively, and a notch filter is able to avoid the excitation of the high frequency natural vibration.

  7. Electromagnetic Levitation of a Disc

    ERIC Educational Resources Information Center

    Valle, R.; Neves, F.; de Andrade, R., Jr.; Stephan, R. M.

    2012-01-01

    This paper presents a teaching experiment that explores the levitation of a disc of ferromagnetic material in the presence of the magnetic field produced by a single electromagnet. In comparison to the classical experiment of the levitation of a sphere, the main advantage of the proposed laboratory bench is that the uniform magnetic field…

  8. Aerodynamic levitator for large-sized glassy material production.

    PubMed

    Yoda, Shinichi; Cho, Won-Seung; Imai, Ryoji

    2015-09-01

    Containerless aerodynamic levitation processing is a unique technology for the fabrication of bulk non-crystalline materials. Using conventional aerodynamic levitation, a high reflective index (RI) material (BaTi2O5 and LaO3/2-TiO2-ZrO2 system) was developed with a RI greater than approximately 2.2, which is similar to that of diamond. However, the glass size was small, approximately 3 mm in diameter. Therefore, it is essential to produce large sized materials for future optical materials applications, such as camera lenses. In this study, a new aerodynamic levitator was designed to produce non-crystalline materials with diameters larger than 6 mm. The concept of this new levitator was to set up a reduced pressure at the top of the molten samples without generating turbulent flow. A numerical simulation was also performed to verify the concept. PMID:26429456

  9. Experience on a cryogenic linear mechanism based on superconducting levitation

    NASA Astrophysics Data System (ADS)

    Serrano-Tellez, Javier; Romera-Juarez, Fernando; González-de-María, David; Lamensans, Mikel; Argelaguet-Vilaseca, Heribert; Pérez-Díaz, José-Luis; Sánchez-Casarrubios, Juan; Díez-Jiménez, Efrén.; Valiente-Blanco, Ignacio

    2012-09-01

    The instrumentation of many space missions requires operation in cryogenic temperatures. In all the cases, the use of mechanisms in this environment is a matter of concern, especially when long lifetime is required. With the aim of removing lifetime concerns and to benefit from the cryogenic environment, a cryogenic contactless linear mechanism has been developed. It is based on the levitation of a permanent magnet over superconductor disks. The mechanism has been designed, built, and tested to assess the performances of such technology. The levitation system solves the mechanical contact problems due to cold-welding effects, material degradation by fatigue, wearing, backlash, lubrication...etc, at cryogenic temperatures. In fact, the lower is the temperature the better the superconductor levitation systems work. The mechanism provides a wide stroke (18mm) and high resolution motion (1μm), where position is controlled by changing the magnetic field of its environment using electric-magnets. During the motion, the moving part of the mechanism levitates supported by the magnetic interaction with the high temperature type II superconductors after reaching the superconductor state down to 90K. This paper describes the results of the complete levitation system development, including extensive cryogenic testing to measure optically the motion range, resolution, run-outs and rotations in order to characterize the levitation mechanism and to verify its performance in a cryogenic environment.

  10. Electrodynamics on extrasolar giant planets

    SciTech Connect

    Koskinen, T. T.; Yelle, R. V.; Lavvas, P.; Cho, J. Y-K.

    2014-11-20

    Strong ionization on close-in extrasolar giant planets (EGPs) suggests that their atmospheres may be affected by ion drag and resistive heating arising from wind-driven electrodynamics. Recent models of ion drag on these planets, however, are based on thermal ionization only and do not include the upper atmosphere above the 1 mbar level. These models are also based on simplified equations of resistive magnetohydrodynamics that are not always valid in extrasolar planet atmospheres. We show that photoionization dominates over thermal ionization over much of the dayside atmosphere above the 100 mbar level, creating an upper ionosphere dominated by ionization of H and He and a lower ionosphere dominated by ionization of metals such as Na, K, and Mg. The resulting dayside electron densities on close-in exoplanets are higher than those encountered in any planetary ionosphere of the solar system, and the conductivities are comparable to the chromosphere of the Sun. Based on these results and assumed magnetic fields, we constrain the conductivity regimes on close-in EGPs and use a generalized Ohm's law to study the basic effects of electrodynamics in their atmospheres. We find that ion drag is important above the 10 mbar level where it can also significantly alter the energy balance through resistive heating. Due to frequent collisions of the electrons and ions with the neutral atmosphere, however, ion drag is largely negligible in the lower atmosphere below the 10 mbar level for a reasonable range of planetary magnetic moments. We find that the atmospheric conductivity decreases by several orders of magnitude in the night side of tidally locked planets, leading to a potentially interesting large-scale dichotomy in electrodynamics between the day and night sides. A combined approach that relies on UV observations of the upper atmosphere, phase curve and Doppler measurements of global dynamics, and visual transit observations to probe the alkali metals can potentially be

  11. Characterization of Acousto-Electric Cluster and Array Levitation and its Application to Evaporation

    NASA Technical Reports Server (NTRS)

    Robert E. Apfel; Zheng, Yibing

    2000-01-01

    An acousto-electric levitator has been developed to study the behavior of liquid drop and solid particle clusters and arrays. Unlike an ordinary acoustic levitator that uses only a standing acoustic wave to levitate a single drop or particle, this device uses an extra electric static field and the acoustic field simultaneously to generate and levitate charged drops in two-dimensional arrays in air without any contact to a solid surface. This cluster and array generation (CAG) instrument enables us to steadily position drops and arrays to study the behavior of multiple drop and particle systems such as spray and aerosol systems relevant to the energy, environmental, and material sciences.

  12. Recurrent Delocalization and Quasiequilibration of Photons in Coupled Systems in Circuit Quantum Electrodynamics

    NASA Astrophysics Data System (ADS)

    Hwang, Myung-Joong; Kim, M. S.; Choi, Mahn-Soo

    2016-04-01

    We explore the photon population dynamics in two coupled circuit QED systems. For a sufficiently weak intercavity photon hopping, as the photon-cavity coupling increases, the dynamics undergoes double transitions first from a delocalized to a localized phase and then from the localized to another delocalized phase. The latter delocalized phase is distinguished from the former one; instead of oscillating between the two cavities, the photons rapidly quasiequilibrate over the two cavities. These intriguing features are attributed to an interplay between two qualitatively distinctive nonlinear behaviors of the circuit QED systems in the utrastrong coupling regime, whose distinction has been widely overlooked.

  13. Recurrent Delocalization and Quasiequilibration of Photons in Coupled Systems in Circuit Quantum Electrodynamics.

    PubMed

    Hwang, Myung-Joong; Kim, M S; Choi, Mahn-Soo

    2016-04-15

    We explore the photon population dynamics in two coupled circuit QED systems. For a sufficiently weak intercavity photon hopping, as the photon-cavity coupling increases, the dynamics undergoes double transitions first from a delocalized to a localized phase and then from the localized to another delocalized phase. The latter delocalized phase is distinguished from the former one; instead of oscillating between the two cavities, the photons rapidly quasiequilibrate over the two cavities. These intriguing features are attributed to an interplay between two qualitatively distinctive nonlinear behaviors of the circuit QED systems in the utrastrong coupling regime, whose distinction has been widely overlooked. PMID:27127967

  14. Vibration converter with magnetic levitation

    NASA Astrophysics Data System (ADS)

    Gladilin, A. V.; Pirogov, V. A.; Golyamina, I. P.; Kulaev, U. V.; Kurbatov, P. A.; Kurbatova, E. P.

    2015-05-01

    The paper presents a mathematical model, the results of computational and theoretical research, and the feasibility of creating a vibration converter with full magnetic levitation in the suspension of a high-temperature superconductor (HTSC). The axial and radial stability of the active part of the converter is provided by the interaction of the magnetic field of ring-shaped permanent magnets and a hollow cylinder made of the ceramic HTSC material. The force is created by a system of current-carrying coils whose magnetic field is polarized by permanent magnets and interacts with induced currents in the superconducting cylinder. The case of transition to the superconducting state of HTSC material in the field of the permanent magnets (FC mode) is considered. The data confirm the outlook for the proposed technical solutions.

  15. Densitometry By Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Trinh, Eugene H.

    1989-01-01

    "Static" and "dynamic" methods developed for measuring mass density of acoustically levitated solid particle or liquid drop. "Static" method, unknown density of sample found by comparison with another sample of known density. "Dynamic" method practiced with or without gravitational field. Advantages over conventional density-measuring techniques: sample does not have to make contact with container or other solid surface, size and shape of samples do not affect measurement significantly, sound field does not have to be know in detail, and sample can be smaller than microliter. Detailed knowledge of acoustic field not necessary.

  16. Quantum electrodynamical time-dependent density functional theory for many-electron systems on a lattice

    NASA Astrophysics Data System (ADS)

    Farzanehpour, Mehdi; Tokatly, Ilya; Nano-Bio Spectroscopy Group; ETSF Scientific Development Centre Team

    2015-03-01

    We present a rigorous formulation of the time-dependent density functional theory for interacting lattice electrons strongly coupled to cavity photons. We start with an example of one particle on a Hubbard dimer coupled to a single photonic mode, which is equivalent to the single mode spin-boson model or the quantum Rabi model. For this system we prove that the electron-photon wave function is a unique functional of the electronic density and the expectation value of the photonic coordinate, provided the initial state and the density satisfy a set of well defined conditions. Then we generalize the formalism to many interacting electrons on a lattice coupled to multiple photonic modes and prove the general mapping theorem. We also show that for a system evolving from the ground state of a lattice Hamiltonian any density with a continuous second time derivative is locally v-representable. Spanish Ministry of Economy and Competitiveness (Grant No. FIS2013-46159-C3-1-P), Grupos Consolidados UPV/EHU del Gobierno Vasco (Grant No. IT578-13), COST Actions CM1204 (XLIC) and MP1306 (EUSpec).

  17. The Electrodynamics of Gradient Fields in Superconductive Magnetic Resonance Imaging Systems

    NASA Astrophysics Data System (ADS)

    Morich, Michael Andrew

    The eddy current problem associated with magnetic field gradients in superconductive magnetic resonance imaging (MRI) and spectroscopy (MRS) applications is well-known throughout the nuclear magnetic resonance (NMR) scientific and engineering community. The electromagnetic interaction of gradient field coils with surrounding cold (4.2 K to 80 K) and warm (300 K) metal structures from which the superconducting magnet systems are fabricated, nonetheless, has largely remained unstudied from a theoretical standpoint. There is a great need for a fundamental understanding of this interaction, which, it is fair to say, is a major determinant of imaging system performance due to its impact on gradient pulse fidelity. The work presented in this dissertation addresses this need and advances our knowledge and understanding of the gradient coil and cold shield interaction problem. It goes beyond the gross approximations of superconducting shell and skin-effect models used in present self-shielded and unshielded gradient coil design schemes. In essence, we take into account the fact that a typical gradient pulse spectrum spans DC to several kHz and, hence, skin-effect arguments are invalid. The work is largely theoretical in nature and provides solutions to canonical and more generalized problems involving axial (azimuthal separation constant m = 0) and distributed transverse (m = +/-1) gradient field coils which interact with cylindrical metallic shells of finite conductivity, various thicknesses and of infinite length. The electromagnetic boundary-value problems are developed and are then solved in the spectral domain, exclusive of the radial variable. The solutions are obtained directly in the spectral domain for three cases: (i) m = 0 and a single shell of infinite thickness, (ii) m = 0 and a single shell of finite thickness, and (iii) m = +/-1 and a single shell of infinite thickness. A normalized matrix solution is then developed for the general N-shell problem and is

  18. Method for identifying electromagnetically induced transparency in a tunable circuit quantum electrodynamics system

    NASA Astrophysics Data System (ADS)

    Liu, Qi-Chun; Li, Tie-Fu; Luo, Xiao-Qing; Zhao, Hu; Xiong, Wei; Zhang, Ying-Shan; Chen, Zhen; Liu, J. S.; Chen, Wei; Nori, Franco; Tsai, J. S.; You, J. Q.

    2016-05-01

    Electromagnetically induced transparency (EIT) has been realized in atomic systems, but fulfilling the EIT conditions for artificial atoms made from superconducting circuits is a more difficult task. Here we report an experimental observation of the EIT in a tunable three-dimensional transmon by probing the cavity transmission. To fulfill the EIT conditions, we tune the transmon to adjust its damping rates by utilizing the effect of the cavity on the transmon states. From the experimental observations, we clearly identify the EIT and Autler-Townes splitting (ATS) regimes as well as the transition regime in between. Also, the experimental data demonstrate that the threshold ΩAIC determined by the Akaike information criterion can describe the EIT-ATS transition better than the threshold ΩEIT given by the EIT theory.

  19. The effects of magnetization process on levitation characteristics of a superconducting bulk magnet

    NASA Astrophysics Data System (ADS)

    Jiang, J.; Gong, Y. M.; Li, Y. H.; Liang, G.; Yang, X. S.; Cheng, C. H.; Zhao, Y.

    2015-09-01

    In this paper, a bulk YBCO superconductor was magnetized in a chosen magnetic field generated from a superconducting magnet (SM) after field cooling process. The effects of magnetization process with different magnetization intensities on levitation forces and relaxation characteristics were investigated. From the results, it can be confirmed that the superconducting bulk magnet (SBM) magnetized with proper magnetization intensity was beneficial to improve the levitation characteristics of the magnetic levitation system. Nevertheless, when the magnetization intensity exceeded 0.85T, the levitation forces and the relaxation characteristics of the SBM attained saturation.

  20. System engineering study of electrodynamic tether as a spaceborne generator and radiator of electromagnetic waves in the ULF/ELF frequency band

    NASA Technical Reports Server (NTRS)

    Estes, Robert D.

    1987-01-01

    An electrodynamic tether deployed from a satellite in low-Earth orbit can perform, if properly instrumented, as a partially self-powered generator of electromagnetic waves in the ULF/ELF band, potentially at power levels high enough to be of practical use. Two basic problems are examined. The first is that of the level of wave power that the system can be expected to generate in the ULF/ELF radiation band. The second major question is whether an electrodynamic tethered satellite system for transmitting waves can be made partially self-powering so that power requirements for drag compensation can be met within economical constraints of mass, cost, and complexity. The theoretical developments and the system applications study are presented. The basic design criteria, the drag-compensation method, the effects on the propagation paths from orbit to Earth surface of high-altitude nuclear debris patches, and the estimate of masses and sizes are covered. An outline of recommended analytical work, to be performed as a follow-on to the present study, is contained.

  1. Leidenfrost levitated liquid tori

    NASA Astrophysics Data System (ADS)

    Perrard, Stéphane; Labousse, Matthieu; Fort, Emmanuel; Bush, John; Couder, Yves; Limat, Laurent

    2012-11-01

    A drop of water deposited on a surface hotter than 150°C can levitate without any contact with a solid container. Indeed the evaporation of the fluid generates a thin vapour film, which supports the drop's weight by lubrication forces (Leidenfrost effect). This effect was until now limited to droplets. We propose here an original substrate geometry, a circular brass through, that allows us to maintain in levitation any quantity of fluid. It could be a good tool to study wave propagation without solid boundary condition and thus very low friction. We report here one possible application, and our most striking observation : when the substrate temperature is high enough, convective motion appears in the liquid torus and its inner side becomes polygonal. This periodic deformation of large amplitude propagates along the azimuthal direction. The geometry, the flow and the shape appear very similar to the polygonal destabilization of an hydraulic jump. We propose here an experimental and theorical characterization of these rotating polygons having from three to twelve sides. Moreover, we have found a model describing the shape for any number of sides. It appears closely related to the Korteweg de Vries equation describing the propagation of solitonic waves in shallow water.

  2. Levitated micro-accelerometer.

    SciTech Connect

    Warne, Larry Kevin; Schmidt, Carrie Frances; Peterson, Kenneth Allen; Kravitz, Stanley H.; Renn, Rosemarie A.; Peter, Frank J.; Kinney, Ragon D.; Gilkey, Jeffrey C.

    2004-06-01

    The objective is a significant advancement in the state-of-the-art of accelerometer design for tactical grade (or better) applications. The design goals are <1 milli-G bias stability across environments and $200 cost. This quantum leap in performance improvement and cost reduction can only be achieved by a radical new approach, not incremental improvements to existing concepts. This novel levitated closed-loop accelerometer is implemented as a hybrid micromachine. The hybrid approach frees the designer from the limitations of any given monolithic process and dramatically expands the available design space. The design can be tailored to the dynamic range, resolution, bandwidth, and environmental requirements of the application while still preserving all of the benefits of monolithic MEMS fabrication - extreme precision, small size, low cost, and low power. An accelerometer was designed and prototype hardware was built, driving the successful development and refinement of several 'never been done before' fabrication processes. Many of these process developments are commercially valuable and are key enablers for the realization of a wide variety of useful micro-devices. While controlled levitation of a proof mass has yet to be realized, the overall design concept remains sound. This was clearly demonstrated by the stable and reliable closed-loop control of a proof mass at the test structure level. Furthermore, the hybrid MEMS implementation is the most promising approach for achieving the ambitious cost and performance targets. It is strongly recommended that Sandia remain committed to the original goal.

  3. Structure of Aristotelian electrodynamics

    NASA Astrophysics Data System (ADS)

    Jacobson, Ted

    2015-07-01

    Aristotelian electrodynamics (AE) describes the regime of a plasma with a very strong electric field that is not shorted out, with the charge current determined completely by pair production and the balance of the Lorentz 4-force against the curvature radiation reaction. Here it is shown how the principal null directions and associated eigenvalues of the field tensor govern AE, and how force-free electrodynamics arises smoothly from AE when the eigenvalues (and therefore the electric field in some frame) vanish. A criterion for validity of AE and force-free electrodynamics is proposed in terms of a pair of "field curvature scalars" formed from the first derivative of the principal null directions.

  4. First quantized electrodynamics

    SciTech Connect

    Bennett, A.F.

    2014-06-15

    The parametrized Dirac wave equation represents position and time as operators, and can be formulated for many particles. It thus provides, unlike field-theoretic Quantum Electrodynamics (QED), an elementary and unrestricted representation of electrons entangled in space or time. The parametrized formalism leads directly and without further conjecture to the Bethe–Salpeter equation for bound states. The formalism also yields the Uehling shift of the hydrogenic spectrum, the anomalous magnetic moment of the electron to leading order in the fine structure constant, the Lamb shift and the axial anomaly of QED. -- Highlights: •First-quantized electrodynamics of the parametrized Dirac equation is developed. •Unrestricted entanglement in time is made explicit. •Bethe and Salpeter’s equation for relativistic bound states is derived without further conjecture. •One-loop scattering corrections and the axial anomaly are derived using a partial summation. •Wide utility of semi-classical Quantum Electrodynamics is argued.

  5. Anomalous electrodynamic explosions in liquids

    SciTech Connect

    Aspden, H.

    1986-06-01

    The recently reported Graneau experiments on electrodynamic explosions in liquids, which reveal anomalous longitudinal electrodynamic forces of the order of 10/sup 4/ times greater than expected, verify the need for a term in the law of electrodynamics that corresponds to the ion/electron mass ratio. This confirms an earlier theoretical interpretation of the anomalous cathode reaction forces found in the vacuum arc.

  6. Electrodynamics, wind and temperature

    NASA Technical Reports Server (NTRS)

    Schmidlin, F. J.

    1988-01-01

    This RTOP provides for correlative meteorological wind and temperature measurements with atmospheric electrodynamic measurements. Meteorological rocketsondes were launched as part of a number of electrodynamic investigations in Alaska, Norway, Peru, Sweden, and at the Wallops Flight Facility, Wallops Island, Virginia. Measurements obtained as part of the MAC/Epsilon campaign during October 1987 from Andoya, Norway, were in conjunction with electric field, ion mobility, conductivity, and energy deposition studies. The measurements obtained between 30 and 90 km are to evaluate and correlate changes in the atmospheric electrical structure caused by the neutral wind and temperature, or changes in the neutral atmosphere resulting from electrical anomalies.

  7. Galilean conformal electrodynamics

    NASA Astrophysics Data System (ADS)

    Bagchi, Arjun; Basu, Rudranil; Mehra, Aditya

    2014-11-01

    Maxwell's Electrodynamics admits two distinct Galilean limits called the Electric and Magnetic limits. We show that the equations of motion in both these limits are invariant under the Galilean Conformal Algebra in D = 4, thereby exhibiting non-relativistic conformal symmetries. Remarkably, the symmetries are infinite dimensional and thus Galilean Electrodynamics give us the first example of an infinitely extended Galilean Conformal Field Theory in D > 2. We examine details of the theory by looking at purely non-relativistic conformal methods and also use input from the limit of the relativistic theory.

  8. Cavity cooling a single charged levitated nanosphere.

    PubMed

    Millen, J; Fonseca, P Z G; Mavrogordatos, T; Monteiro, T S; Barker, P F

    2015-03-27

    Optomechanical cavity cooling of levitated objects offers the possibility for laboratory investigation of the macroscopic quantum behavior of systems that are largely decoupled from their environment. However, experimental progress has been hindered by particle loss mechanisms, which have prevented levitation and cavity cooling in a vacuum. We overcome this problem with a new type of hybrid electro-optical trap formed from a Paul trap within a single-mode optical cavity. We demonstrate a factor of 100 cavity cooling of 400 nm diameter silica spheres trapped in vacuum. This paves the way for ground-state cooling in a smaller, higher finesse cavity, as we show that a novel feature of the hybrid trap is that the optomechanical cooling becomes actively driven by the Paul trap, even for singly charged nanospheres. PMID:25860743

  9. Levitation forces in bearingless permanent magnet motors

    SciTech Connect

    Amrhein, W.; Silber, S.; Nenninger, K.

    1999-09-01

    Bearingless motors combine brushless AC-motors with active magnetic bearings by the integration of two separate winding systems (torque and radial levitation force windings with different pole pairs) in one housing. This paper gives an insight into the influences of the motor design on the levitation force and torque generation. It is shown that especially for machines with small air gaps it can be very important to choose the right design parameters. Increasing the permanent magnet height in order to increase the motor torque can result in a remarkable reduction of radial forces. The interrelationships are discussed on the basis of Maxwell and Lorentz forces acting upon the stator surface. The investigations are presented for a bearingless low cost motor, suited for pump, fan or blower applications. The presented motor needs only four coils for operation.

  10. Aerodynamic levitation : an approach to microgravity.

    SciTech Connect

    Glorieux, B.; Saboungi, M.-L.; Millot, F.; Enderby, J.; Rifflet, J.-C.

    2000-12-05

    Measurements of the thermophysical and structural properties of liquid materials at high temperature have undergone considerable development in the past few years. Following improvements in electromagnetic levitation, aerodynamic levitation associated with laser heating has shown promise for assessing properties of different molten materials (metals, oxides, and semiconductors), preserving sample purity over a wide range of temperatures and under different gas environments. The density, surface tension and viscosity are measured with a high-speed video camera and an image analysis system. Results on nickel and alumina show that small droplets can be considered in the first approximation to be under microgravity conditions. Using a non-invasive contactless technique recently developed to measure electrical conductivity, results have been extended to variety of materials ranging from liquid metals and liquid semiconductors to ionically conducting materials. The advantage of this technique is the feasibility of monitoring changes in transport occurring during phase transitions and in deeply undercooled states.

  11. The tethered satellite electrodynamics experiment project

    NASA Technical Reports Server (NTRS)

    Price, John M.

    1988-01-01

    NASA and Italy's PSN have undertaken the Tethered Satellite Electrodynamics Experiment, in which two tethered bodies will be equipped with data-collecting scientific instruments, as the first stage of the development of the Tethered Satellite System that can be deployed by the Space Shuttle. The experiment will give attention to the electromagnetic interaction between the satellite/tether/orbiter system and the ambient space plasma, and should demonstrate the operation of both satellite- and Shuttle-borne electrodynamic instruments with a conductive tether.

  12. Safety of high speed magnetic levitation transportation systems. Comparison of US and foreign safety requirements for application to US maglev systems. Final report, April 1991-August 1993

    SciTech Connect

    Bing, A.J.; Parker, J.D.; Pristach, G.S.; Behara, C.; Gabriel, D.

    1993-09-01

    The use of magnetically levitated (maglev) vehicles for high-speed guided ground transportation has been proposed for passenger operations in the United States. As a result, a need exists for the assessment for the safety implications of this new form of technology to ensure passenger safety. This report contains the results of a detailed review of safety requirements to evaluate their suitability to maglev operations in the U.S. environment.

  13. Microwave Dielectrophoretic Levitation In Microgravity

    NASA Technical Reports Server (NTRS)

    Watkins, John L.; Jackson, Henry W.; Barmatz, Martin B.

    1993-01-01

    Two reports propose use of dielectrophoresis in microwave resonant cavities to levitate samples of materials for containerless processing in microgravity in vacuum or in any suitable atmosphere. Also describe experiments undertaken to verify feasibility of proposal.

  14. Causality in Classical Electrodynamics

    ERIC Educational Resources Information Center

    Savage, Craig

    2012-01-01

    Causality in electrodynamics is a subject of some confusion, especially regarding the application of Faraday's law and the Ampere-Maxwell law. This has led to the suggestion that we should not teach students that electric and magnetic fields can cause each other, but rather focus on charges and currents as the causal agents. In this paper I argue…

  15. Vertical Magnetic Levitation Force Measurement on Single Crystal YBaCuO Bulk at Different Temperatures

    NASA Astrophysics Data System (ADS)

    Celik, Sukru; Guner, Sait Baris; Ozturk, Kemal; Ozturk, Ozgur

    Magnetic levitation force measurements of HTS samples are performed with the use of liquid nitrogen. It is both convenient and cheap. However, the temperature of the sample cannot be changed (77 K) and there is problem of frost. So, it is necessary to build another type of system to measure the levitation force high Tc superconductor at different temperatures. In this study, we fabricated YBaCuO superconducting by top-seeding-melting-growth (TSMG) technique and measured vertical forces of them at FC (Field Cooling) and ZFC (Zero Field Cooling) regimes by using our new designed magnetic levitation force measurement system. It was used to investigate the three-dimensional levitation force and lateral force in the levitation system consisting of a cylindrical magnet and a permanent cylindrical superconductor at different temperatures (37, 47, 57, 67 and 77 K).

  16. Magnetic levitation technology and transportation strategies

    SciTech Connect

    Not Available

    1990-01-01

    This book contains the following topics: Benefits of magnetically levitated high speed transportation for the United States. Monorail MagLev, HSST magnetic levitation trains, past, present and future, a national vision for MagLev transit in America.

  17. Electrodynamic Tethers for Novel LEO Missions

    NASA Technical Reports Server (NTRS)

    Kantner, Michael; Hoyt, Robert; Scardera, Michael; Johnson, Charles

    2011-01-01

    The exponential increase of launch system size - and cost - with deltaV makes missions requiring large total impulse cost prohibitive. Northrop Grumman and partners have matured a fundamentally different method for generating propulsion using electrodynamic tethers (EDTs) that escapes the limitations of the rocket equation. With essentially unlimited delta V, we can perform new classes of missions that are currently unaffordable or unfeasible.

  18. Magnetic levitation transport of mining products. Report of investigations/1995

    SciTech Connect

    Geraghty, J.J.; Wright, W.E.; Lombardi, J.A.

    1995-07-01

    U.S. Bureau of Mines researchers have developed innovative magnetic levitation (mag-lev) technology that allows for noncontact, frictionless conveyance of materials within a dedicated transit corridor. A transport system incorporating this technology could improve the safety and reduce the cost of underground mining and materials handling. The mag-lev transport technology uses two types of permanent magnets. An array of neodymium-iron-boron magnets is contained in the base of each levitated materials container, and an array of ceramic-5 magnets lines the bottom of the transit corridor. The orientation of the magnets is such that the two arrays repel each other. An electronic position control system, located on the levitated materials containers, overcomes the inherent lateral instability of the repelling magnet arrays.

  19. Accretion disk electrodynamics

    NASA Technical Reports Server (NTRS)

    Coroniti, F. V.

    1985-01-01

    Accretion disk electrodynamic phenomena are separable into two classes: (1) disks and coronas with turbulent magnetic fields; (2) disks and black holes which are connected to a large-scale external magnetic field. Turbulent fields may originate in an alpha-omega dynamo, provide anomalous viscous transport, and sustain an active corona by magnetic buoyancy. The large-scale field can extract energy and angular momentum from the disk and black hole, and be dynamically configured into a collimated relativistic jet.

  20. On generalized logarithmic electrodynamics

    NASA Astrophysics Data System (ADS)

    Kruglov, S. I.

    2015-02-01

    The generalized logarithmic electrodynamics with two parameters and is considered. The indexes of refraction of light in the external magnetic field are calculated. In the case we come to results obtained by Gaete and Helayël-Neto (Eur Phys J C 74:2816, 2014). The bound on the values of , was obtained from the Biréfringence Magnétique du Vide (BMV) experiment. The symmetrical Belinfante energy-momentum tensor and dilatation current are found.

  1. Implementation Options for the PROPEL Electrodynamic Tether Demonstration Mission

    NASA Technical Reports Server (NTRS)

    Bilen, Sven G.; Johnson, Les; Gilchrist, Brian E.; Hoyt, Robert P.; Elder, Craig H.; Fuhrhop, Keith P.; Scadera, Michael P.; Stone, Nobie H.

    2014-01-01

    The PROPEL flight mission concept will demonstrate the safe use of an electrodynamic tether for generating thrust. PROPEL is being designed to be a versatile electrodynamic-tether system for multiple end users and to be flexible with respect to platform. As such, several implementation options are being explored, including a comprehensive mission design for PROPEL with a mission duration of six months; a space demonstration mission concept design with configuration of a pair of tethered satellites, one of which is the Japanese H-II Transfer Vehicle; and an ESPA-based system. We report here on these possible implementation options for PROPEL. electrodynamic tether; PROPEL demonstration mission; propellantless propulsion

  2. Nanomagnetic Levitation 3-D Cultures of Breast and Colorectal Cancers

    PubMed Central

    Bumpers, Harvey L.; Janagama, Dasharatham G.; Manne, Upender; Basson, Marc D.; Katkoori, Venkat

    2014-01-01

    Background Innovative technologies for drug discovery and development, cancer models, stem cell research, tissue engineering, and drug testing in various cell-based platforms require an application similar to the in vivo system. Materials and Methods We developed for the first time nanomagnetically levitated three dimensional (3-D) cultures of breast cancer (BC) and colorectal cancer (CRC) cells using carbon encapsulated cobalt magnetic nanoparticles. BC and CRC xenografts grown in severe combined immunodeficient (SCID) mice were evaluated for N-cadherin and Epidermal growth factor receptor (EGFR) expressions. These phenotypes were compared with 2-D cultures and 3-D cultures grown in a gel matrix. Results The BC and CRC cells grown by magnetic levitation formed microtissues. The levitated cultures had high viability and were maintained in culture for long periods of time. It has been observed that N-cadherin and EGFR activities were highly expressed in the levitated 3-D tumor spheres and xenografts of CRC and BC cells. Conclusions Nanomagnetically levitated 3-D cultures tend to form stable microtissues of BC and CRC and may be more feasible for a range of applications in drug discovery or regenerative medicine. PMID:25617973

  3. Experimental determination of the dynamics of an acoustically levitated sphere

    SciTech Connect

    Pérez, Nicolás; Andrade, Marco A. B.; Canetti, Rafael; Adamowski, Julio C.

    2014-11-14

    Levitation of solids and liquids by ultrasonic standing waves is a promising technique to manipulate materials without contact. When a small particle is introduced in certain areas of a standing wave field, the acoustic radiation force pushes the particle to the pressure node. This movement is followed by oscillations of the levitated particle. Aiming to investigate the particle oscillations in acoustic levitation, this paper presents the experimental and numerical characterization of the dynamic behavior of a levitated sphere. To obtain the experimental response, a small sphere is lifted by the acoustic radiation force. After the sphere lift, it presents a damped oscillatory behavior, which is recorded by a high speed camera. To model this behavior, a mass-spring-damper system is proposed. In this model, the acoustic radiation force that acts on the sphere is theoretically predicted by the Gor'kov theory and the viscous forces are modeled by two damping terms, one term proportional to the square of the velocity and another term proportional to the particle velocity. The proposed model was experimentally verified by using different values of sound pressure amplitude. The comparison between numerical and experimental results shows that the model can accurately describe the oscillatory behavior of the sphere in an acoustic levitator.

  4. Coil optimization for electromagnetic levitation using a genetic like algorithm

    NASA Astrophysics Data System (ADS)

    Royer, Z. L.; Tackes, C.; LeSar, R.; Napolitano, R. E.

    2013-06-01

    The technique of electromagnetic levitation (EML) provides a means for thermally processing an electrically conductive specimen in a containerless manner. For the investigation of metallic liquids and related melting or freezing transformations, the elimination of substrate-induced nucleation affords access to much higher undercooling than otherwise attainable. With heating and levitation both arising from the currents induced by the coil, the performance of any EML system depends on controlling the balance between lifting forces and heating effects, as influenced by the levitation coil geometry. In this work, a genetic algorithm is developed and utilized to optimize the design of electromagnetic levitation coils. The optimization is targeted specifically to reduce the steady-state temperature of the stably levitated metallic specimen. Reductions in temperature of nominally 70 K relative to that obtained with the initial design are achieved through coil optimization, and the results are compared with experiments for aluminum. Additionally, the optimization method is shown to be robust, generating a small range of converged results from a variety of initial starting conditions. While our optimization criterion was set to achieve the lowest possible sample temperature, the method is general and can be used to optimize for other criteria as well.

  5. Experimental determination of the dynamics of an acoustically levitated sphere

    NASA Astrophysics Data System (ADS)

    Pérez, Nicolás; Andrade, Marco A. B.; Canetti, Rafael; Adamowski, Julio C.

    2014-11-01

    Levitation of solids and liquids by ultrasonic standing waves is a promising technique to manipulate materials without contact. When a small particle is introduced in certain areas of a standing wave field, the acoustic radiation force pushes the particle to the pressure node. This movement is followed by oscillations of the levitated particle. Aiming to investigate the particle oscillations in acoustic levitation, this paper presents the experimental and numerical characterization of the dynamic behavior of a levitated sphere. To obtain the experimental response, a small sphere is lifted by the acoustic radiation force. After the sphere lift, it presents a damped oscillatory behavior, which is recorded by a high speed camera. To model this behavior, a mass-spring-damper system is proposed. In this model, the acoustic radiation force that acts on the sphere is theoretically predicted by the Gor'kov theory and the viscous forces are modeled by two damping terms, one term proportional to the square of the velocity and another term proportional to the particle velocity. The proposed model was experimentally verified by using different values of sound pressure amplitude. The comparison between numerical and experimental results shows that the model can accurately describe the oscillatory behavior of the sphere in an acoustic levitator.

  6. Controlling charge on levitating drops.

    PubMed

    Hilger, Ryan T; Westphall, Michael S; Smith, Lloyd M

    2007-08-01

    Levitation technologies are used in containerless processing of materials, as microscale manipulators and reactors, and in the study of single drops and particles. Presented here is a method for controlling the amount and polarity of charge on a levitating drop. The method uses single-axis acoustic levitation to trap and levitate a single, initially neutral drop with a diameter between 400 microm and 2 mm. This drop is then charged in a controllable manner using discrete packets of charge in the form of charged drops produced by a piezoelectric drop-on-demand dispenser equipped with a charging electrode. The magnitude of the charge on the dispensed drops can be adjusted by varying the voltage applied to the charging electrode. The polarity of the charge on the added drops can be changed allowing removal of charge from the trapped drop (by neutralization) and polarity reversal. The maximum amount of added charge is limited by repulsion of like charges between the drops in the trap. This charging scheme can aid in micromanipulation and the study of charged drops and particles using levitation. PMID:17580951

  7. Modeling and experimental study on near-field acoustic levitation by flexural mode.

    PubMed

    Liu, Pinkuan; Li, Jin; Ding, Han; Cao, Wenwu

    2009-12-01

    Near-field acoustic levitation (NFAL) has been used in noncontact handling and transportation of small objects to avoid contamination. We have performed a theoretical analysis based on nonuniform vibrating surface to quantify the levitation force produced by the air film and also conducted experimental tests to verify our model. Modal analysis was performed using ANSYS on the flexural plate radiator to obtain its natural frequency of desired mode, which is used to design the measurement system. Then, the levitation force was calculated as a function of levitation distance based on squeeze gas film theory using measured amplitude and phase distributions on the vibrator surface. Compared with previous fluid-structural analyses using a uniform piston motion, our model based on the nonuniform radiating surface of the vibrator is more realistic and fits better with experimentally measured levitation force. PMID:20040404

  8. Ion-induced nucleation in solution: promotion of solute nucleation in charged levitated droplets.

    PubMed

    Draper, Neil D; Bakhoum, Samuel F; Haddrell, Allen E; Agnes, George R

    2007-09-19

    We have investigated the nucleation and growth of sodium chloride in both single quiescent charged droplets and charged droplet populations that were levitated in an electrodynamic levitation trap (EDLT). In both cases, the magnitude of a droplet's net excess charge (ions(DNEC)) influenced NaCl nucleation and growth, albeit in different capacities. We have termed the phenomenon ion-induced nucleation in solution. For single quiescent levitated droplets, an increase in ions(DNEC) resulted in a significant promotion of NaCl nucleation, as determined by the number of crystals observed. For levitated droplet populations, a change in NaCl crystal habit, from regular cubic shapes to dome-shaped dendrites, was observed once a surface charge density threshold of -9 x 10(-4) e.nm(-2) was surpassed. Although promotion of NaCl nucleation was observed for droplet population experiments, this can be attributed in part to the increased rate of solvent evaporation observed for levitated droplet populations having a high net charge. Promotion of nucleation was also observed for two organic acids, 2,4,6-trihydroxyacetophenone monohydrate (THAP) and alpha-cyano-4-hydroxycinnamic acid (CHCA). These results are of direct relevance to processes that occur in both soft-ionization techniques for mass spectrometry and to a variety of industrial processes. To this end, we have demonstrated the use of ion-induced nucleation in solution to form ammonium nitrate particles from levitated droplets to be used in in vitro toxicology studies of ambient particle types. PMID:17718487

  9. Electrodynamic Dust Shield Demonstrator

    NASA Technical Reports Server (NTRS)

    Stankie, Charles G.

    2013-01-01

    The objective of the project was to design and manufacture a device to demonstrate a new technology developed by NASA's Electrostatics and Surface Physics Laboratory. The technology itself is a system which uses magnetic principles to remove regolith dust from its surface. This project was to create an enclosure that will be used to demonstrate the effectiveness of the invention to The Office of the Chief Technologist. ONE of the most important challenges of space exploration is actually caused by something very small and seemingly insignificant. Dust in space, most notably on the moon and Mars, has caused many unforeseen issues. Dirt and dust on Earth, while a nuisance, can be easily cleaned and kept at bay. However, there is considerably less weathering and erosion in space. As a result, the microscopic particles are extremely rough and abrasive. They are also electrostatically charged, so they cling to everything they make contact with. This was first noted to be a major problem during the Apollo missions. Dust would stick to the spacesuits, and could not be wiped off as predicted. Dust was brought back into the spacecraft, and was even inhaled by astronauts. This is a major health hazard. Atmospheric storms and other events can also cause dust to coat surfaces of spacecraft. This can cause abrasive damage to the craft. The coating can also reduce the effectiveness of thermal insulation and solar panels.' A group of engineers at Kennedy Space Center's Electrostatics and Surface Physics Laboratory have developed a new technology, called the Electrodynamic Dust Shield, to help alleviate these problems. It is based off of the electric curtain concept developed at NASA in 1967. "The EDS is an active dust mitigation technology that uses traveling electric fields to transport electrostatically charged dust particles along surfaces. To generate the traveling electric fields, the EDS consists of a multilayer dielectric coating with an embedded thin electrode grid

  10. Containerless processing using electromagnetic levitation

    NASA Technical Reports Server (NTRS)

    Gokhale, A. B.; Abbaschian, R.

    1990-01-01

    The theory and practice of containerless processing via electromagnetic (EM) levitation is reviewed briefly. The use of EM levitation for the processing of alloys is described with particular emphasis on the bulk melt supercooling phenomenon in a containerless environment. The various effects associated with rapid solidification via bulk melt supercooling are discussed with examples of Nb-Si alloys. It is suggested that a detailed analysis of such effects can be utilized to select the potentially most promising alloys for future space-based processing.

  11. Optical sample-position sensing for electrostatic levitation

    NASA Technical Reports Server (NTRS)

    Sridharan, G.; Chung, S.; Elleman, D.; Whim, W. K.

    1989-01-01

    A comparative study is conducted for optical position-sensing techniques applicable to micro-G conditions sample-levitation systems. CCD sensors are compared with one- and two-dimensional position detectors used in electrostatic particle levitation. In principle, the CCD camera method can be improved from current resolution levels of 200 microns through the incorporation of a higher-pixel device and more complex digital signal processor interface. Nevertheless, the one-dimensional position detectors exhibited superior, better-than-one-micron resolution.

  12. Effect of permanent-magnet irregularities in levitation force measurements.

    SciTech Connect

    Hull, J. R.

    1999-10-14

    In the measurement of the levitation force between a vertically magnetized permanent magnet (PM) and a bulk high-temperature superconductor (HTS), PM domains with horizontal components of magnetization are shown to produce a nonnegligible contribution to the levitation force in most systems. Such domains are typically found in all PMs, even in those that exhibit zero net horizontal magnetic moment. Extension of this analysis leads to an HTS analog of Earnshaw's theorem, in which at the field-cooling position the vertical stiffness is equal to the sum of the horizontal stiffnesses, independent of angular distribution of magnetic moments within the PM.

  13. Design and implementation of an efficient acoustically levitated drop reactor for in stillo measurements.

    PubMed

    Field, Christopher R; Scheeline, Alexander

    2007-12-01

    We present the details necessary for building an efficient acoustic drop levitator with reduced electrical power consumption and greater drop stability compared to previous designs. The system is optimized so that the levitated drop may be used as a chemical reactor. By introducing a temperature, pressure, and relative humidity sensor for feedback control of a linear actuator for adjusting resonator length, we have built a completely automated system capable of continuous levitation for extended periods of time. The result is a system capable of portable operation and interfacing with a variety of detection instrumentation for in stillo (in drop) measurements. PMID:18163744

  14. Nonlinear electrodynamics at Cinvestav

    NASA Astrophysics Data System (ADS)

    Bretón, Nora

    2012-02-01

    After a brief introduction to the original aims of Nonlinear electrodynamics (NLED), a review on NLED research that has been developed in the Physics Department at Cinvestav-IPN is addressed: from the seminal work by Jerzy Plebañski, which was followed by S. Hacyan and S. Alarcón, afterwards by A. García and H. Salazar; and more recently by E. Ayón-Beato and N. Bretón. We conclude by pointing to the current streams of research.

  15. Semi-classical Electrodynamics

    NASA Astrophysics Data System (ADS)

    Lestone, John

    2016-03-01

    Quantum electrodynamics is complex and its associated mathematics can appear overwhelming for those not trained in this field. We describe semi-classical approaches that can be used to obtain a more intuitive physical feel for several QED processes including electro-statics, Compton scattering, pair annihilation, the anomalous magnetic moment, and the Lamb shift, that could be taught easily to undergraduate students. Any physicist who brings their laptop to the talk will be able to build spread sheets in less than 10 minutes to calculate g/2 =1.001160 and a Lamb shift of 1057 MHz.

  16. Electrodynamic force law controversy.

    PubMed

    Graneau, P; Graneau, N

    2001-05-01

    Cavalleri et al. [Phys. Rev. E 52, 2505 (1998); Eur. J. Phys. 17, 205 (1996)] have attempted to resolve the electrodynamic force law controversy. This attempt to prove the validity of either the Ampère or Lorentz force law by theory and experiment has revealed only that the two are equivalent when predicting the force on part of a circuit due to the current in the complete circuit. However, in our analysis of internal stresses, only Ampère's force law agrees with experiment. PMID:11415053

  17. Large gap magnetic suspension system

    NASA Technical Reports Server (NTRS)

    Abdelsalam, Moustafa K.; Eyssa, Y. M.

    1991-01-01

    The design of a large gap magnetic suspension system is discussed. Some of the topics covered include: the system configuration, permanent magnet material, levitation magnet system, superconducting magnets, resistive magnets, superconducting levitation coils, resistive levitation coils, levitation magnet system, and the nitrogen cooled magnet system.

  18. Diamagnetically stabilized levitation control of an intraluminal magnetic capsule.

    PubMed

    Lam, Michael; Mintchev, Martin

    2009-08-01

    Controlled navigation promotes full utilization of capsule endoscopy for reliable real-time diagnosis in the gastrointestinal (GI) tract, but intermittent natural peristalsis can disturb the navigational control, destabilize the capsule and take it out of levitation. The focus of the present work was to develop an economical and effective real-time magnetic capsule-guiding system that can operate in the presence of naturally existing peristalsis while retaining navigational control. A real-size magnetic navigation system that can handle peristaltic forces of up to 1.5 N was designed utilizing the computer-aided design (CAD) system Maxwell 3D (Ansoft, Pittsburg, PA) and was verified using a small-size physical experimental setup. The proposed system contains a pair of 50 cm diameter, 10,000-turn copper electromagnets with a 10 cm x 10 cm ferrous core driven by currents of up to 300 A and can successfully maintain position control over the levitating capsule during peristalsis. The addition of bismuth diamagnetic casing for stabilizing the levitating capsule was also studied. A modeled magnetic field around the diamagnetically cased permanent magnet was shown to be redistributed aligning its interaction with the external electromagnets, thus stabilizing the levitating capsule. In summary, a custom-designed diamagnetically facilitated capsule navigation system can successfully steer an intraluminal magnet-carrying capsule. PMID:19550023

  19. Planar Multilayer Circuit Quantum Electrodynamics

    NASA Astrophysics Data System (ADS)

    Minev, Z. K.; Serniak, K.; Pop, I. M.; Leghtas, Z.; Sliwa, K.; Hatridge, M.; Frunzio, L.; Schoelkopf, R. J.; Devoret, M. H.

    2016-04-01

    Experimental quantum information processing with superconducting circuits is rapidly advancing, driven by innovation in two classes of devices, one involving planar microfabricated (2D) resonators, and the other involving machined three-dimensional (3D) cavities. We demonstrate that circuit quantum electrodynamics can be implemented in a multilayer superconducting structure that combines 2D and 3D advantages. We employ standard microfabrication techniques to pattern each layer, and rely on a vacuum gap between the layers to store the electromagnetic energy. Planar qubits are lithographically defined as an aperture in a conducting boundary of the resonators. We demonstrate the aperture concept by implementing an integrated, two-cavity-mode, one-transmon-qubit system.

  20. Magnetic levitation of condensed hydrogen

    NASA Technical Reports Server (NTRS)

    Paine, C. G.; Seidel, G. M.

    1991-01-01

    Liquid and solid molecular hydrogen has been levitated using a pair of small superconducting solenoids. The hydrogen samples, up to 3 mm in dimension, were trapped in a magnetic potential having either a discrete minimum or a minimum in the form of a ring 1 cm in diameter. The hydrogen could be moved about in the magnetic trap by applying an electric field.

  1. Digital Controller For Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Tarver, D. Kent

    1989-01-01

    Acoustic driver digitally controls sound fields along three axes. Allows computerized acoustic levitation and manipulation of small objects for such purposes as containerless processing and nuclear-fusion power experiments. Also used for controlling motion of vibration-testing tables in three dimensions.

  2. Microwave Levitation Of Small Objects

    NASA Technical Reports Server (NTRS)

    Watkins, John L.; Jackson, Henry W.

    1991-01-01

    Microwave radiation in resonant cavities used to levitate small objects, according to proposal. Feedback control and atmosphere not needed. Technique conceived for use in experiments on processing of materials in low gravitation of outer space, also used in normal Earth gravitation, albeit under some limitations.

  3. Levitation of liquid sodium droplets

    SciTech Connect

    Roy, S.S.; Cramb, A.W.; Hoburg, J.F.; Lally, B.

    1995-12-01

    Droplets of liquid sodium ranging from 1.2 to 2.1 g, immersed in mineral oil, were levitated in an electromagnetic field. The experimental setup was designed and constructed to levitate small metal droplets at audio frequencies. The levitated droplet was found to be very stable inside the inductor, and the equilibrium shape attained by the droplet in the electromagnetic field was measured during the experiment. A surface coupled mathematical model was used to calculate the self-consistent equilibrium droplet shape of liquid sodium under the influence of an electromagnetic field. The predicted shapes of the metal droplet and the position of the droplet inside the inductor compare well with the experimental data. The idea of casting metals and alloys without any physical contact has generated a lot of interest in the metals industry, especially in the production of metals/alloys that are highly reactive and have a very high melting point. Containerless casting can be achieved by levitating or pushing the liquid metal from the surface of the container.

  4. Vibrational Properties of High- Superconductors Levitated Above a Bipolar Permanent Magnetic Guideway

    NASA Astrophysics Data System (ADS)

    Liu, Lu; Wang, Jiasu

    2014-05-01

    A bipolar permanent magnetic guideway (PMG) has a unique magnetic field distribution profile which may introduce a better levitation performance and stability to the high- superconducting (HTS) maglev system. The dynamic vibration properties of multiple YBCO bulks arranged into different arrays positioned above a bipolar PMG and free to levitate were investigated. The acceleration and resonance frequencies were experimentally measured, and the stiffness and damping coefficients were evaluated for dynamic stability. Results indicate that the levitation stiffness is closely related to the field-cooling-height and sample positioning. The damping ratio was found to be low and nonlinear for the Halbach bipolar HTS-PMG system.

  5. Magnetic levitation and stiffness in melt-textured Y-Ba-Cu-O

    SciTech Connect

    Hull, J.R.; Mulcahy, T.M. ); Salama, K.; Selvamanickam, V. ); Weinberger, B.R.; Lynds, L. )

    1992-09-01

    Magnetic levitation and stiffness have been measured in several systems composed of a permanent magnet elastically suspended above a stationary melt-textured sample of Y-Ba-Cu-O. The levitation force and vertical stiffness have been calculated on the basis of magnetization measurements of the same system, and the calculated results showed excellent agreement with the experimental measurements. Based on the force and magnetization measurements, it is predicted that the same Y-Ba-Cu-O material configured in a geometry suitable for magnetic bearings could produce a levitation pressure of 100--400 kPa at 20 K.

  6. On the horizontal wobbling of an object levitated by near-field acoustic levitation.

    PubMed

    Kim, Cheol-Ho; Ih, Jeong-Guon

    2007-11-01

    A circular planar object can be levitated with several hundreds of microns by ultrasonic near-field acoustic levitation (NFAL). However, when both the sound source and the levitated object are circularly shaped and the center of the levitated object does not coincide with the source center, instability problem often occurs. When this happens, it becomes difficult to pick up or transport the object for the next process. In this study, when the center of the levitated object was offset from the source center, the moving direction of the levitated object was predicted by using the time averaged potential around the levitated object. The wobbling frequency of the levitated object was calculated by analyzing the nonlinear wobbling motion of the object. It was shown that the predicted wobbling frequencies agreed with measured ones well. Finally, a safe zone was suggested to avoid the unstable movement of an object. PMID:17590402

  7. Dust levitation about Itokawa's equator

    NASA Astrophysics Data System (ADS)

    Hartzell, C.; Zimmerman, M.; Takahashi, Y.

    2014-07-01

    Introduction: Electrostatic dust motion has been hypothesized to occur on the asteroids, due to the observations of the Eros dust ponds [1] and the potential presence of such a phenomenon on the Moon [2]. There are two phases of electrostatic dust motion: lofting and the subsequent trajectories. The feasibility of electrostatic dust lofting can be assessed by comparing the strength of the electrostatic force to the gravity and cohesion which hold the grain on to the surface [3--5]. The motion of the dust grains after they detach from the surface can be described as either ballistic, escaping, or levitating. We are interested in dust levitation because it could potentially redistribute grains on the surface of an asteroid (for instance, producing the Eros dust ponds) and it could also be hazardous to spacecraft. Specifically, levitating dust could obscure the observations of surface-based spacecraft or possibly trigger obstacle avoidance routines during landing. Dust Levitation: Dust levitation is defined as the altitude oscillation of grains prior to their redeposition on the surface of an asteroid. Levitation occurs about equilibria where the electrostatic and gravity forces on the grain are equal and opposite. An equilibrium state is defined as a position and charge for a specific grain size. We have previously identified equilibria using a 1D plasma model and a simple gravity model for Itokawa [6]. In this simple model, the largest grain that was capable of stable levitation above Itokawa was 3 microns (in radius) [6]. Additionally, we have shown that levitating dust grains follow the variation in the equilibria for a rotating asteroid (i.e., the grain continues to oscillate about an equilibrium state that approaches the surface) [7]. Due to the nonspherical shape of Itokawa, both the gravity and plasma environments are much more complicated than the 1D approximations made in our previous work. Thus, in order to accurately assess the feasibility of dust

  8. Diamagnetically Levitating Three Phase Motor with Optical Feedback Control

    NASA Astrophysics Data System (ADS)

    Khanna, Shrey; Nhut Ho, Joe; Irwen, Jonathan; Chih Wang, Wei

    2010-11-01

    This article describes a feasibility study of creating a low friction, low maintenance power delivering motor using a diamagnetically stabilized levitating rotor. The planar rotor described in this article uses a triangular configuration of magnets that rotates due to nine electric coils evenly spaced around the rotor. The principle behind levitation of the rotor and the dynamic forces on it are described in detail. An optical encoder feedback system is designed and fabricated that controls the frequency of the levitating rotor. The current input to the coils is given through a driving circuit that amplifies a DC pulse signal generated by a control algorithm designed in LabVIEW. The driving circuit allows current to flow through one phase at a time, which produces a magnetic field strong enough to spin the rotor. Experiments suggest that the optical encoder feedback control system can do reference tracking on the levitating rotor. The designed control algorithm can drive the rotor to specified reference frequencies up to 1.3 Hz using the optical encoder measurements.

  9. The Electrostatic Levitation Facility at NASA's Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Rogers, Jan R.; Hyers, Robert W.; Savage, Larry; Robinson, Michael B.; Rathz, Thomas J.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Containerless processing is an important area of research in materials science. Electrostatic levitation (ESL) represents an emerging technology which permits containerless processing in a vacuum environment. NASA's Marshall Space Flight Center (MSFC) established a levitation facility to provide a critical resource to the microgravity materials science research community to continue and enhance ground-based research in the support of the development of flight experiments during the transition to Space Station. During ESL processing, charged specimens are levitated in the electrostatic field produced by the system's electrodes. Three sets of positioning electrodes represent the heart of the MSFC system. Two dual-axis position sensitive detectors provide input for the PID control-loop computer. Sample position is maintained by adjusting the control voltages for the power supplies of the positioning electrodes. A UV source refreshes the charge on specimens during processing via the photoelectric effect. Lasers permit sample heating independent of positioning. The processing chamber typically operates under vacuum condition approximately = 10(exp -7) Torr. Electrostatic levitation provides a materials science research tool for investigations of refractory solids and melts. Topics of investigation include thermophysical properties, phase equilibria, metastable phase formation, undercooling and nucleation, time-temperature-transformation diagrams and other aspects of materials processing. Current capabilities and recent results of processing studies for metals, alloys and oxides will be reviewed.

  10. Magnetic levitation using high temperature superconducting pancake coils as composite bulk cylinders

    NASA Astrophysics Data System (ADS)

    Patel, A.; Hopkins, S. C.; Baskys, A.; Kalitka, V.; Molodyk, A.; Glowacki, B. A.

    2015-11-01

    Stacks of superconducting tape can be used as composite bulk superconductors for both trapped field magnets and for magnetic levitation. Little previous work has been done on quantifying the levitation force behavior between stacks of tape and permanent magnets. This paper reports the axial levitation force properties of superconducting tape wound into pancake coils to act as a composite bulk cylinder, showing that similar stable forces to those expected from a uniform bulk cylinder are possible. Force creep was also measured and simulated for the system. The geometry tested is a possible candidate for a rotary superconducting bearing. Detailed finite element modeling in COMSOL Multiphysics was also performed including a full critical state model for induced currents, with temperature and field dependent properties and 3D levitation force models. This work represents one of the most complete levitation force modeling frameworks yet reported using the H-formulation and helps explain why the coil-like stacks of tape are able to sustain levitation forces. The flexibility of geometry and consistency of superconducting properties offered by stacks of tapes, make them attractive for superconducting levitation applications.

  11. Acoustic wave levitation: Handling of components

    NASA Astrophysics Data System (ADS)

    Vandaele, Vincent; Delchambre, Alain; Lambert, Pierre

    2011-06-01

    Apart from contact micromanipulation, there exists a large variety of levitation techniques among which standing wave levitation will be proposed as a way to handle (sub)millimetric components. This paper will compare analytical formulas to calculate the order of magnitude of the levitation force. It will then describe digital simulation and experimental levitation setup. Stable levitation of various components (cardboard, steel washer, ball, ceramic capacity, water droplet) was shown along 5 degrees of freedom: The only degree of freedom that could not be mastered was the rotation about the symmetry axis of the acoustic field. More importantly, the present work will show the modification of the orientation of the radial force component in the presence of an object disturbing the acoustic field. This property can be used as a new feeding strategy as it means that levitating components are spontaneously pushed toward grippers in an acoustic plane standing wave.

  12. Photon propagator in skewon electrodynamics

    NASA Astrophysics Data System (ADS)

    Itin, Yakov

    2016-01-01

    Electrodynamics with a local and linear constitutive law is used as a framework for models violating Lorentz covariance. The constitutive tensor of such a construction is irreducibly decomposed into three independent pieces. The principal part is the anisotropic generalization of the standard electrodynamics. The two other parts, axion and skewon, represent nonclassical modifications of electrodynamics. We derive the expression for the photon propagator in the Minkowski spacetime endowed with a skewon field. For a relatively small (antisymmetric) skewon field, a modified Coulomb law is exhibited.

  13. Rapid Quench in an Electrostatic Levitator

    NASA Technical Reports Server (NTRS)

    SanSoucie, Michael P.; Rogers, Jan R.; Matson, Michael M.

    2016-01-01

    The Electrostatic Levitation (ESL) Laboratory at the NASA Marshall Space Flight Center (MSFC) is a unique facility for investigators studying high-temperature materials. The ESL laboratory’s main chamber has been upgraded with the addition of a rapid quench system. This system allows samples to be dropped into a quench vessel that can be filled with a low melting point material, such as a gallium or indium alloy, as a quench medium. Thereby allowing rapid quenching of undercooled liquid metals. Up to eight quench vessels can be loaded into a wheel inside the chamber that is indexed with control software. The system has been tested successfully with samples of zirconium, iron-cobalt alloys, iron-chromium-nickel, titanium-zirconium-nickel alloys, and a silicon-cobalt alloy. This new rapid quench system will allow materials science studies of undercooled materials and new materials development. The system is described and some initial results are presented.

  14. Rapid Quench in an Electrostatic Levitator

    NASA Technical Reports Server (NTRS)

    SanSoucie, Michael P.; Rogers, Jan R.; Matson, Douglas M.

    2016-01-01

    The Electrostatic Levitation (ESL) Laboratory at the NASA Marshall Space Flight Center (MSFC) is a unique facility for investigators studying high-temperature materials. The ESL laboratory's main chamber has been upgraded with the addition of a rapid quench system. This system allows samples to be dropped into a quench vessel that can be filled with a low melting point material, such as a gallium or indium alloy, as a quench medium. Thereby allowing rapid quenching of undercooled liquid metals. Up to eight quench vessels can be loaded into a wheel inside the chamber that is indexed with control software. The system has been tested successfully with samples of zirconium, iron-cobalt alloys, titanium-zirconium-nickel alloys, and a silicon-cobalt alloy. This new rapid quench system will allow materials science studies of undercooled materials and new materials development. In this presentation, the system is described and some initial results are presented.

  15. Theory and applications of electromagnetic levitation

    NASA Technical Reports Server (NTRS)

    Frost, R. T.; Chang, C. W.

    1982-01-01

    A simple treatment of the electromagnetic levitation problem is presented, with emphasis placed on approximate formulas useful in planning and interpreting laboratory measurements. Consideration is also given to numerical solutions for fields, eddy currents, and Lorentz forces for rapidly varying applied fields, with particular reference made to traveling wave levitation experiments. Applications of levitation processing are briefly reviewed, including thermophysical property measurements, undercooling studies, containerless crystal growth, and continuous casting of cylinders.

  16. Middle atmospheric electrodynamics

    NASA Technical Reports Server (NTRS)

    Kelley, M. C.

    1983-01-01

    A review is presented of the advances made during the last few years with respect to the study of the electrodynamics in the earth's middle atmosphere. In a report of the experimental work conducted, attention is given to large middle atmospheric electric fields, the downward coupling of high altitude processes into the middle atmosphere, and upward coupling of tropospheric processes into the middle atmosphere. It is pointed out that new developments in tethered balloons and superpressure balloons should greatly increase the measurement duration of earth-ionospheric potential measurements and of stratospheric electric field measurements in the next few years. Theoretical work considered provides an excellent starting point for study of upward coupling of transient and dc electric fields. Hays and Roble (1979) were the first to construct a model which included orographic features as well as the classical thunderstorm generator.

  17. Stability of equilibrium of a superconducting ring that levitates in the field of a fixed ring with constant current

    NASA Astrophysics Data System (ADS)

    Bishaev, A. M.; Bush, A. A.; Gavrikov, M. B.; Kamentsev, K. E.; Kozintseva, M. V.; Savel'ev, V. V.; Sigov, A. S.

    2015-11-01

    In order to develop a plasma trap with levitating superconducting magnetic coils, it is necessary to search for their stable levitating states. An analytical expression for the potential energy of a single superconducting ring that captures a fixed magnetic flux in the field of a fixed ring with constant current versus the coordinate of the free ring on the axis of the system, deviation angle of its axis from the axis of the system, and radial displacement of its plane is derived for uniform gravity field in the thin ring approximation. The calculated stable levitation states of the superconducting ring in the field of the ring with constant current are proven in experiments. The generalization of such an approach to the levitation of several rings makes it possible to search for stable levitation states of several coils that form a magnetic system of a multipole trap.

  18. Acoustic levitator for containerless measurements on low temperature liquids

    SciTech Connect

    Benmore, Chris J; Weber, Richard; Neuefeind, Joerg C; Rey, Charles A A

    2009-01-01

    A single-axis acoustic levitator was constructed and used to levitate liquid and solid drops at temperatures from -40 to +40 C. The levitator consisted of: (i) two acoustic transducers mounted on a rigid vertical support that was bolted to an optical breadboard, (ii) a acoustic power supply that controlled acoustic intensity, relative phase of the drive to the transducers, and could modulate the acoustic forces at frequencies up to 1kHz, (iii) a video camera, and (iv) a system for providing a stream of controlled temperature gas flow over the sample. The acoustic transducers were operated at their resonant frequency of ~ 22 kHz and could produce sound pressure levels up to 160 dB. The force applied by the acoustic field could be modulated using a frequency generator to excite oscillations in the sample. Sample temperature was controlled using a modified Cryostream Plus and measured using thermocouples and an infrared thermal imager. The levitator was installed at x-ray beamline 11 ID-C at the Advanced Photon Source and used to investigate the structure of supercooled liquids.

  19. Acoustic levitator for structure measurements on low temperature liquid droplets.

    PubMed

    Weber, J K R; Rey, C A; Neuefeind, J; Benmore, C J

    2009-08-01

    A single-axis acoustic levitator was constructed and used to levitate liquid and solid drops of 1-3 mm in diameter at temperatures in the range -40 to +40 degrees C. The levitator comprised (i) two acoustic transducers mounted on a rigid vertical support that was bolted to an optical breadboard, (ii) an acoustic power supply that controlled acoustic intensity, relative phase of the drive to the transducers, and could modulate the acoustic forces at frequencies up to 1 kHz, (iii) a video camera, and (iv) a system for providing a stream of controlled temperature gas flow over the sample. The acoustic transducers were operated at their resonant frequency of approximately 22 kHz and could produce sound pressure levels of up to 160 dB. The force applied by the acoustic field could be modulated to excite oscillations in the sample. Sample temperature was controlled using a modified Cryostream Plus and measured using thermocouples and an infrared thermal imager. The levitator was installed at x-ray beamline 11 ID-C at the Advanced Photon Source and used to investigate the structure of supercooled liquids. PMID:19725664

  20. Electrodynamics of planar Archimedean spiral resonator

    NASA Astrophysics Data System (ADS)

    Maleeva, N.; Averkin, A.; Abramov, N. N.; Fistul, M. V.; Karpov, A.; Zhuravel, A. P.; Ustinov, A. V.

    2015-07-01

    We present a theoretical and experimental study of electrodynamics of a planar spiral superconducting resonator of a finite length. The resonator is made in the form of a monofilar Archimedean spiral. By making use of a general model of inhomogeneous alternating current flowing along the resonator and specific boundary conditions on the surface of the strip, we obtain analytically the frequencies fn of resonances which can be excited in such system. We also calculate corresponding inhomogeneous RF current distributions ψ n ( r ) , where r is the coordinate across a spiral. We show that the resonant frequencies and current distributions are well described by simple relationships f n = f 1 n and ψ n ( r ) ≃ sin [ π n ( r / R e ) 2 ] , where n = 1 , 2... and Re is the external radius of the spiral. Our analysis of electrodynamic properties of spiral resonators' is in good agreement with direct numerical simulations and measurements made using specifically designed magnetic probe and laser scanning microscope.

  1. EMC Test Report Electrodynamic Dust Shield

    NASA Technical Reports Server (NTRS)

    Carmody, Lynne M.; Boyette, Carl B.

    2014-01-01

    This report documents the Electromagnetic Interference E M I evaluation performed on the Electrodynamic Dust Shield (EDS) which is part of the MISSE-X System under the Electrostatics and Surface Physics Laboratory at Kennedy Space Center. Measurements are performed to document the emissions environment associated with the EDS units. The purpose of this report is to collect all information needed to reproduce the testing performed on the Electrodynamic Dust Shield units, document data gathered during testing, and present the results. This document presents information unique to the measurements performed on the Bioculture Express Rack payload; using test methods prepared to meet SSP 30238 requirements. It includes the information necessary to satisfy the needs of the customer per work order number 1037104. The information presented herein should only be used to meet the requirements for which it was prepared.

  2. Cylindrical acoustic levitator/concentrator

    DOEpatents

    Kaduchak, Gregory; Sinha, Dipen N.

    2002-01-01

    A low-power, inexpensive acoustic apparatus for levitation and/or concentration of aerosols and small liquid/solid samples having particulates up to several millimeters in diameter in air or other fluids is described. It is constructed from a commercially available, hollow cylindrical piezoelectric crystal which has been modified to tune the resonance frequency of the breathing mode resonance of the crystal to that of the interior cavity of the cylinder. When the resonance frequency of the interior cylindrical cavity is matched to the breathing mode resonance of the cylindrical piezoelectric transducer, the acoustic efficiency for establishing a standing wave pattern in the cavity is high. The cylinder does not require accurate alignment of a resonant cavity. Water droplets having diameters greater than 1 mm have been levitated against the force of gravity using; less than 1 W of input electrical power. Concentration of aerosol particles in air is also demonstrated.

  3. Timelike Momenta In Quantum Electrodynamics

    DOE R&D Accomplishments Database

    Brodsky, S. J.; Ting, S. C. C.

    1965-12-01

    In this note we discuss the possibility of studying the quantum electrodynamics of timelike photon propagators in muon or electron pair production by incident high energy muon or electron beams from presently available proton or electron accelerators.

  4. Final Report: Levitated Dipole Experiment

    SciTech Connect

    Kesner, Jay; Mauel, Michael

    2013-03-10

    Since the very first experiments with the LDX, research progress was rapid and significant. Initial experiments were conducted with the high-field superconducting coil suspended by three thin rods. These experiments produced long-pulse, quasi-steady-state microwave discharges, lasting more than 10 s, having peak beta values of 20% [Garnier et al., Physics of Plasmas, 13 (2006) 056111]. High- beta, near steady-state discharges have been maintained in LDX for more than 20 seconds, and this capability made LDX the longest pulse fusion confinement experiment operating in the U.S. fusion program. A significant measure of progress in the LDX research program was the routine investigation of plasma confinement with a magnetically-levitated dipole and the resulting observations of confinement improvement. In both supported and levitated configurations, detailed measurements were made of discharge evolution, plasma dynamics and instability, and the roles of gas fueling, microwave power deposition profiles, and plasma boundary shape. High-temperature plasma was created by multi frequency electron cyclotron resonance heating at 2.45 GHz, 6.4 GHz, 10.5 GHz and 28 GHz allowing control of heating profiles. Depending upon neutral fueling rates, the LDX discharges contain a fraction of energetic electrons, with mean energies above 50 keV. Depending on whether or not the superconducting dipole was levitated or supported, the peak thermal electron temperature was estimated to exceed 500 eV and peak densities to approach 1e18 m-3. We have found that levitation causes a strong inwards density pinch [Boxer et al., Nature Physics, 6 (2010) 207] and we have observed the central plasma density increase dramatically indicating a significant improvement in the confinement of a thermal plasma species.

  5. Radial inhomogeneities in particle composition of single, levitated aerosol particles observed by Mie resonance spectroscopy (Invited)

    NASA Astrophysics Data System (ADS)

    Krieger, U. K.; Steimer, S.; Lienhard, D.; Bastelberger, S.

    2013-12-01

    Recent observations have indicated that organic aerosol particles in the atmosphere may exist in an amorphous semi-solid or even solid (i.e. glassy) state, e.g. [1]. The influence of highly viscous and glassy states on the timescale of aerosol particle equilibration with respect to water vapor have been investigated for some model systems of atmospheric aerosol, e.g. [2,3]. In particular, it has been shown that the kinetics of the water absorption/desorption process is controlled entirely by liquid-phase diffusion of water molecules for a highly viscous aerosol particle. A liquid phase diffusion model based on numerically solving the non-linear diffusion equation predicts strong internal gradients in water concentration when condensed phase diffusion impedes the water uptake from the gas phase [2]. Here we observe and quantify the internal concentration gradients in single, levitated, micron size aerosol particles of aqueous MBTCA (3-methyl-1,2,3-Butanetricarboxylic acid) and shikimic acid using elastic Mie resonance spectroscopy. A single, aqueous particle is levitated in an electro-dynamic balance (for details see [2]), dried for several days at room temperature, cooled to the target temperature and exposed to a rapid change in relative humidity. In addition to measuring the elastically backscattered light of a 'white light ' LED source and recording the full spectrum with a spectrograph as in [2], we use a tunable diode laser (TDL) to scan high resolution TE- and TM spectra. This combination allows observing various Mie resonance mode orders simultaneously. Since we perform the experiment at low temperatures and low humidities the changes in the Mie-spectra due to water uptake are sufficiently slow to resolve the kinetics. Experimental Mie resonance spectra are inverted to concentration profiles of water within the particle by applying the numerical diffusion model [2] in conjunction with Mie calculations of multilayered spheres [4]. Potential implications for

  6. Inhomogeneities in particle composition of single, levitated aerosol particles observed by Mie resonance spectroscopy

    NASA Astrophysics Data System (ADS)

    Krieger, Ulrich; Lienhard, Daniel; Bastelberger, Sandra; Steimer, Sarah

    2014-05-01

    Recent observations have indicated that organic aerosol particles in the atmosphere may exist in an amorphous semi-solid or even solid (i.e. glassy) state, e.g. [1]. The influence of highly viscous and glassy states on the timescale of aerosol particle equilibration with respect to water vapor have been investigated for some model systems of atmospheric aerosol, e.g. [2,3]. In particular, it has been shown that the kinetics of the water absorption/desorption process is controlled entirely by liquid-phase diffusion of water molecules for a highly viscous aerosol particle. A liquid phase diffusion model based on numerically solving the non-linear diffusion equation predicts strong internal gradients in water concentration when condensed phase diffusion impedes the water uptake from the gas phase [2]. Here we observe and quantify the internal concentration gradients in single, levitated, micron size aerosol particles of aqueous shikimic acid using elastic Mie resonance spectroscopy. A single, aqueous particle is levitated in an electro-dynamic balance (for details see [2]), dried for several days at room temperature, cooled to the target temperature and exposed to a rapid change in relative humidity. In addition to measuring the elastically backscattered light of a "white light" LED source and recording the full spectrum with a spectrograph as in [2], we use a tunable diode laser (TDL) to scan high resolution TE- and TM spectra. This combination allows observing various Mie resonance mode orders simultaneously. Since we perform the experiment at low temperatures and low humidities the changes in the Mie-spectra due to water uptake are sufficiently slow to resolve the kinetics. Experimental Mie resonance spectra are inverted to concentration profiles of water within the particle by applying the numerical diffusion model [2] in conjunction with Mie calculations of multilayered spheres [4]. [1] A. Virtanen et al. (2010): An amorphous solid state of biogenic secondary

  7. Two applications of axion electrodynamics

    NASA Technical Reports Server (NTRS)

    Wilczek, Frank

    1987-01-01

    The equations of axion electrodynamics are studied. Variations in the axion field can give rise to peculiar distributions of charge and current. These effects provide a simple understanding of the fractional electric charge on dyons and of some recently discovered oddities in the electrodynamics of antiphase boundaries in PbTe. Some speculations regarding the possible occurrence of related phenomena in other solids are presented.

  8. Properties of noncommutative axionic electrodynamics

    NASA Astrophysics Data System (ADS)

    Gaete, Patricio; Schmidt, Iván

    2007-07-01

    Using the gauge-invariant but path-dependent variables formalism, we compute the static quantum potential for noncommutative axionic electrodynamics, and find a radically different result than the corresponding commutative case. We explicitly show that the static potential profile is analogous to that encountered in both non-Abelian axionic electrodynamics and in Yang-Mills theory with spontaneous symmetry breaking of scale symmetry.

  9. Electrodynamic Arrays Having Nanomaterial Electrodes

    NASA Technical Reports Server (NTRS)

    Trigwell, Steven (Inventor); Biris, Alexandru S. (Inventor); Calle, Carlos I. (Inventor)

    2013-01-01

    An electrodynamic array of conductive nanomaterial electrodes and a method of making such an electrodynamic array. In one embodiment, a liquid solution containing nanomaterials is deposited as an array of conductive electrodes on a substrate, including rigid or flexible substrates such as fabrics, and opaque or transparent substrates. The nanomaterial electrodes may also be grown in situ. The nanomaterials may include carbon nanomaterials, other organic or inorganic nanomaterials or mixtures.

  10. Application of an ultrasonic focusing radiator for acoustic levitation of submillimeter samples

    NASA Technical Reports Server (NTRS)

    Lee, M. C.

    1981-01-01

    An acoustic apparatus has been specifically developed to handle samples of submillimeter size in a gaseous medium. This apparatus consists of an acoustic levitation device, deployment devices for small liquid and solid samples, heat sources for sample heat treatment, acoustic alignment devices, a cooling system and data-acquisition instrumentation. The levitation device includes a spherical aluminum dish of 12 in. diameter and 0.6 in. thickness, 130 pieces of PZT transducers attached to the back side of the dish and a spherical concave reflector situated in the vicinity of the center of curvature of the dish. The three lowest operating frequencies for the focusing-radiator levitation device are 75, 105 and 163 kHz, respectively. In comparison with other levitation apparatus, it possesses a large radiation pressure and a high lateral positional stability. This apparatus can be used most advantageously in the study of droplets and spherical shell systems, for instance, for fusion target applications.

  11. Anisotropy Effect on Levitation Performance of Bulk High-Tc Superconductors Above a Permanent Magnet Guideway

    NASA Astrophysics Data System (ADS)

    Zheng, Jun; Liao, Xinglin; Jing, Hailian; Lin, Qunxu; Ma, Guangtong; Yen, Fei; Wang, Suyu; Wang, Jiasu

    The anisotropy properties of bulk high-temperature superconductors (HTSCs) are taken into consideration for the application of high-temperature superconducting (HTS) Maglev systems, which are especially based on the different flux-trapping capabilities as well as critical current density, Jc, values between the growth section boundary (GSB) and the growth sections (GS) in bulk superconductors. By adjusting the angle between the GSB of bulk HTSCs and the strongest magnetic field position of a permanent magnet guideway (PMG), the levitation force and its relaxation processes are compared at different field-cooling conditions. Experimental results show that the levitation capability and the suppression of levitation force decay can be enhanced by optimizing the GS/GSB alignment of every bulk HTSC above the PMG. Meanwhile, our conclusions may provide references to other HTS maglev systems with small levitation gaps, i.e., superconducting magnetic bearings.

  12. The ElectroDynamic Delivery Experiment (EDDE)

    NASA Astrophysics Data System (ADS)

    Pearson, Jerome; Levin, Eugene; Oldson, John; Carroll, Joseph

    2001-02-01

    The ElectroDynamic Delivery Experiment (EDDE) is proposed for a space demonstration. EDDE consists of an autonomous space vehicle powered by lightweight solar arrays, a bi-directional electrodynamic tether, and batteries for power leveling. The EDDE vehicle can modify its orbit repeatedly without rocket fuel, and can change all six orbital parameters by modulating and reversing the current flow in the conducting tether. The base spacecraft is connected to the service module by a 6-km-long electrodynamic tether, and is designed for 2 kW of power and a total mass of 180 kg. Tether lifetime of several years is achieved with a two-strand caduceus, with the strands connected every few meters. Tether libration is minimized by mass distribution and by active current control. The vehicle and tether system concepts are developed, the operational envelopes are examined, and potential applications are evaluated. The EDDE vehicle is about twice as fast as ion rockets for high-inclination orbital plane changes, and has much higher maximum delta-V capability. A proof-of-concept experiment is proposed for a low-cost space demonstration. This on-orbit experiment could include additional secondary payloads; for example, EDDE could place low-ΔV, free-flying inspectors into arbitrary orbits from which they could approach selected objects without concern for tether dynamics or interference. .

  13. Active Control of Magnetically Levitated Bearings

    SciTech Connect

    BARNEY, PATRICK S.; LAUFFER, JAMES P.; REDMOND, JAMES M.; SULLIVAN, WILLIAM N.

    2001-03-01

    This report summarizes experimental and test results from a two year LDRD project entitled Real Time Error Correction Using Electromagnetic Bearing Spindles. This project was designed to explore various control schemes for levitating magnetic bearings with the goal of obtaining high precision location of the spindle and exceptionally high rotational speeds. As part of this work, several adaptive control schemes were devised, analyzed, and implemented on an experimental magnetic bearing system. Measured results, which indicated precision positional control of the spindle was possible, agreed reasonably well with simulations. Testing also indicated that the magnetic bearing systems were capable of very high rotational speeds but were still not immune to traditional structural dynamic limitations caused by spindle flexibility effects.

  14. Passive levitation in alternating magnetic fields

    DOEpatents

    Romero, Louis; Christenson, Todd; Aronson, Eugene A.

    2009-06-16

    Stable levitation of an object in an alternating magnetic field can be achieved by eliminating coupling between the rotational and translational forces acting on the object. Stable levitation can also be achieved by varying the coupling between the rotational and translational forces acting on the object, while maintaining one or more of the rotational and translational forces steady in time.

  15. Passive levitation in alternating magnetic fields

    DOEpatents

    Romero, Louis; Christenson, Todd; Aronson, Eugene A.

    2010-09-14

    Stable levitation of an object in an alternating magnetic field can be achieved by eliminating coupling between the rotational and translational forces acting on the object. Stable levitation can also be achieved by varying the coupling between the rotational and translational forces acting on the object, while maintaining one or more of the rotational and translational forces steady in time.

  16. Superconducting, Magnetically Levitated Merry-Go-Round

    ERIC Educational Resources Information Center

    Byer, R. L.; And Others

    1974-01-01

    Reviews the basic theory underlying the lift and drag forces of a magnetically levitated vehicle riding over a continuous sheet guideway. Included are descriptions of the future vehicle characteristics and the students' construction of a superconducting magnetically levitated merry-go-round demonstration apparatus in a laboratory experiment. (CC)

  17. Acoustical-Levitation Chamber for Metallurgy

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Trinh, E.; Wang, T. G.; Elleman, D. D.; Jacobi, N.

    1983-01-01

    Sample moved to different positions for heating and quenching. Acoustical levitation chamber selectively excited in fundamental and second-harmonic longitudinal modes to hold sample at one of three stable postions: A, B, or C. Levitated object quickly moved from one of these positions to another by changing modes. Object rapidly quenched at A or C after heating in furnace region at B.

  18. Design, Fabrication and Levitation Experiments of a Micromachined Electrostatically Suspended Six-Axis Accelerometer

    PubMed Central

    Cui, Feng; Liu, Wu; Chen, Wenyuan; Zhang, Weiping; Wu, Xiaosheng

    2011-01-01

    A micromachined electrostatically suspended six-axis accelerometer, with a square plate as proof mass housed by a top stator and bottom stator, is presented. The device structure and related techniques concerning its operating principles, such as calculation of capacitances and electrostatic forces/moments, detection and levitation control of the proof mass, acceleration measurement, and structural parameters design, are described. Hybrid MEMS manufacturing techniques, including surface micromachining fabrication of thin film electrodes and interconnections, integration fabrication of thick nickel structures about 500 μm using UV-LIGA by successful removal of SU-8 photoresist mold, DRIE of silicon proof mass in thickness of 450 μm, microassembly and solder bonding, were employed to fabricate this prototype microdevice. A levitation experiment system for the fabricated microaccelerometer chip is introduced, and levitation results show that fast initial levitation within 10 ms and stable full suspension of the proof mass have been successfully demonstrated. PMID:22247662

  19. Droplet Vaporization In A Levitating Acoustic Field

    NASA Technical Reports Server (NTRS)

    Ruff, G. A.; Liu, S.; Ciobanescu, I.

    2003-01-01

    Combustion experiments using arrays of droplets seek to provide a link between single droplet combustion phenomena and the behavior of complex spray combustion systems. Both single droplet and droplet array studies have been conducted in microgravity to better isolate the droplet interaction phenomena and eliminate or reduce the effects of buoyancy-induced convection. In most experiments involving droplet arrays, the droplets are supported on fibers to keep them stationary and close together before the combustion event. The presence of the fiber, however, disturbs the combustion process by introducing a source of heat transfer and asymmetry into the configuration. As the number of drops in a droplet array increases, supporting the drops on fibers becomes less practical because of the cumulative effect of the fibers on the combustion process. To eliminate the effect of the fiber, several researchers have conducted microgravity experiments using unsupported droplets. Jackson and Avedisian investigated single, unsupported drops while Nomura et al. studied droplet clouds formed by a condensation technique. The overall objective of this research is to extend the study of unsupported drops by investigating the combustion of well-characterized drop clusters in a microgravity environment. Direct experimental observations and measurements of the combustion of droplet clusters would provide unique experimental data for the verification and improvement of spray combustion models. In this work, the formation of drop clusters is precisely controlled using an acoustic levitation system so that dilute, as well as dense clusters can be created and stabilized before combustion in microgravity is begun. While the low-gravity test facility is being completed, tests have been conducted in 1-g to characterize the effect of the acoustic field on the vaporization of single and multiple droplets. This is important because in the combustion experiment, the droplets will be formed and

  20. Acoustic levitation methods for density measurements

    NASA Astrophysics Data System (ADS)

    Trinh, E. H.; Hsu, C. J.

    1986-12-01

    The capability of ultrasonic levitators operating in air to perform density measurements has been demonstrated. The remote determination of the density of ordinary liquids as well as low density solid metals can be carried out using levitated samples with size on the order of a few millimeters and at a frequency of 20 kHz. Two basic methods may be used. The first one is derived from a previously known technique developed for acoustic levitation in liquid media, and is based on the static equilibrium position of levitated samples in the earth's gravitational field. The second approach relies on the dynamic interaction between a levitated sample and the acoustic field. The first technique appears more accurate (1 percent uncertainty), but the latter method is directly applicable to a near gravity-free environment such as that found in space.

  1. Containerless processing of materials by acoustic levitation

    NASA Astrophysics Data System (ADS)

    Gao, J. R.; Cao, C. D.; Wei, B.

    1999-01-01

    A single-axis ultrasonic levitator which can be applied to containerless processing of materials was described. Analytical expressions of acoustic pressure, acoustic radiation potential and force were derived from the velocity potential function of the applied acoustic field. The levitation region and the levitation stability were then discussed. A sphere of liquid crystal, 4-pentylphenyl-4‧-methylbenzoate, was also selected for containerless melting and solidification using the levitator. The results showed that rapid heating of the sample is necessary so as to avoid its escape from the levitation region. However, the measured bulk undercooling of the melt is smaller than that obtained using a container. It was supposed that ultrasonic cavitation produce a local undercooling large enough to initiate solidification of the melt, thus leading to a limited bulk undercooling.

  2. Acoustic levitation methods for density measurements

    NASA Technical Reports Server (NTRS)

    Trinh, E. H.; Hsu, C. J.

    1986-01-01

    The capability of ultrasonic levitators operating in air to perform density measurements has been demonstrated. The remote determination of the density of ordinary liquids as well as low density solid metals can be carried out using levitated samples with size on the order of a few millimeters and at a frequency of 20 kHz. Two basic methods may be used. The first one is derived from a previously known technique developed for acoustic levitation in liquid media, and is based on the static equilibrium position of levitated samples in the earth's gravitational field. The second approach relies on the dynamic interaction between a levitated sample and the acoustic field. The first technique appears more accurate (1 percent uncertainty), but the latter method is directly applicable to a near gravity-free environment such as that found in space.

  3. Dielectrophoretic levitation of droplets and bubbles

    NASA Technical Reports Server (NTRS)

    Jones, T. B.

    1982-01-01

    Uncharged droplets and bubbles can be levitated dielectrophoretically in liquids using strong, nonuniform electric fields. The general equations of motion for a droplet or bubble in an axisymmetric, divergence-free electrostatic field allow determination of the conditions necessary and sufficient for stable levitation. The design of dielectrophoretic (DEP) levitation electrode structures is simplified by a Taylor-series expansion of cusped axisymmetric electrostatic fields. Extensive experimental measurements on bubbles in insulating liquids verify the simple dielectrophoretic model. Other have extended dielectrophoretic levitation to very small particles in aqueous media. Applications of DEP levitation to the study of gas bubbles, liquid droplets, and solid particles are discussed. Some of these applications are of special interest in the reduced gravitational field of a spacecraft.

  4. Low Frequency Vibration Energy Harvesting using Diamagnetically Stabilized Magnet Levitation

    NASA Astrophysics Data System (ADS)

    Palagummi, Sri Vikram

    Over the last decade, vibration-based energy harvesting has provided a technology push on the feasibility of self-powered portable small electronic devices and wireless sensor nodes. Vibration energy harvesters in general transduce energy by damping out the environmentally induced relative emotion through either a cantilever beam or an equivalent suspension mechanism with one of the transduction mechanisms, like, piezoelectric, electrostatic, electromagnetic or magnetostrictive. Two major challenges face the present harvesters in literature, one, they suffer from the unavoidable mechanical damping due to internal friction present in the systems, second, they cannot operate efficiently in the low frequency range (< 10 Hz), when most of the ambient vibrational energy is in this low frequency broadband range. Passive and friction free diamagnetically stabilized magnet levitation mechanisms which can work efficiently as a vibration energy harvester in the low frequency range are discussed in this work. First, a mono-stable vertical diamagnetic levitation (VDL) based vibration energy harvester (VEH) is discussed. The harvester consists of a lifting magnet (LM), a floating magnet (FM) and two diamagnetic plates (DPs). The LM balances out the weight of the FM and stability is brought about by the repulsive effect of the DPs, made of pyrolytic graphite. Two thick cylindrical coils, placed in grooves which are engraved in the DPs, are used to convert the mechanical energy into electrical energy. Experimental frequency response of the system is validated by the theoretical analysis which showed that the VEH works in a low frequency range but sufficient levitation gap was not achieved and the frequency response characteristic of the system was effectively linear. To overcome these challenges, the influence of the geometry of the FM, the LM, and the DP were parametrically studied to assess their effects on the levitation gap, size of the system and the natural frequency. For

  5. Capillary solitons on a levitated medium.

    PubMed

    Perrard, S; Deike, L; Duchêne, C; Pham, C-T

    2015-07-01

    A water cylinder deposited on a heated channel levitates on its own generated vapor film owing to the Leidenfrost effect. This experimental setup permits the study of the one-dimensional propagation of surface waves in a free-to-move liquid system. We report the observation of gravity-capillary waves under a dramatic reduction of gravity (up to a factor 30), leading to capillary waves at the centimeter scale. The generated nonlinear structures propagate without deformation and undergo mutual collisions and reflections at the boundaries of the domain. They are identified as Korteweg-de Vries solitons with negative amplitude and subsonic velocity. The typical width and amplitude-dependent velocities are in excellent agreement with theoretical predictions based on a generalized Korteweg-de Vries equation adapted to any substrate geometry. When multiple solitons are present, they interact and form a soliton turbulencelike spectrum. PMID:26274114

  6. Study of a new passive magnetic levitation concept

    SciTech Connect

    Post, R.F.

    1995-03-01

    As a bonus from an existing LDRD-supported project (Electromechanical Battery Research and Development) a new concept for the magnetic levitation of a moving object evolved. To initiate a study of the merits of the concept mid-year ``seed money`` LDRD funding was provided. The FY94 activities resulted in a preliminary evaluation of the merits of this concept through calculations, laboratory measurements, and the design of a simple test model. There is now considerable international interest in the ``Maglev`` concept for highspeed trains. Wear, rolling friction, and speed limitations of conventional rail technology make this technology unsuitable for such trains, whence the use of magnetic levitation. In present Maglev trains, however, such as those constructed in Germany and Japan, servo-controlled magnetic systems are required, involving sensor and control circuitry and non-trivial on-board power requirements. In such systems the failure of a control system can have serious consequences, so that redundant systems may be required, thus adding to the cost and complexity. It would be highly desirable to replace the present ``active``, servo-controlled magnetic levitation systems with a totally passive one, one for which neither control circuits nor on-board power would be required. Failure of such a system could be made to be much more benign in its consequences than for servo-controlled ones, and the cost, particularly of the on-board equipment, might be greatly reduced.

  7. Summary Presentation of the Electrodynamics Interactions Panel

    NASA Technical Reports Server (NTRS)

    Stone, N. H.

    1985-01-01

    Technological and scientific uses of electrodynamic tethers in space are considered. Areas of concern for such applications of electrodynamic tethers are enumerated. Thrust and power generation using tethers are discussed.

  8. Electrodynamics of superconducting pnictide superlattices

    SciTech Connect

    Perucchi, A.; Pietro, P. Di; Capitani, F.; Lupi, S.; Lee, S.; Kang, J. H.; Eom, C. B.; Jiang, J.; Weiss, J. D.; Hellstrom, E. E.; Dore, P.

    2014-06-02

    It was recently shown that superlattices where layers of the 8% Co-doped BaFe{sub 2}As{sub 2} superconducting pnictide are intercalated with non superconducting ultrathin layers of either SrTiO{sub 3} or of oxygen-rich BaFe{sub 2}As{sub 2}, can be used to control flux pinning, thereby increasing critical fields and currents, without significantly affecting the critical temperature of the pristine superconducting material. However, little is known about the electron properties of these systems. Here, we investigate the electrodynamics of these superconducting pnictide superlattices in the normal and superconducting state by using infrared reflectivity, from THz to visible range. We find that multigap structure of these superlattices is preserved, whereas some significant changes are observed in their electronic structure with respect to those of the original pnictide. Our results suggest that possible attempts to further increase the flux pinning may lead to a breakdown of the pnictide superconducting properties.

  9. Contactless Calorimetry for Levitated Samples

    NASA Technical Reports Server (NTRS)

    Lee, M. C.; Dokko, W.

    1986-01-01

    Temperature and specific heat of hot sample measured with pyrometer in proposed experimental technique. Technique intended expecially for contactless calorimetry of such materials as undercooled molten alloys, samples of which must be levitated to prevent contamination and premature crystallization. Contactless calorimetry technique enables data to be taken over entire undercooling temperature range with only one sample. Technique proves valuable in study of undercooling because difference in specific heat between undercooled-liquid and crystalline phases at same temperature provides driving force to convert metastable undercooled phase to stable crystalline phase.

  10. Safety of high-speed magnetic-levitation transportation systems. Magnetic-field testing of the TR07 maglev vehicle and system. Volume 2. Appendices. Final report Jun 91-Mar 92

    SciTech Connect

    Dietrich, F.; Robertson, D.; Steiner, G.

    1992-04-01

    The safety of various magnetically levitated (maglev) and high speed rail (HSR) trains proposed for application in the United States is of direct concern to the Federal Railroad Administration (FRA). The characterization of electric and magnetic fields (EMF) emissions, both steady (dc) and produced by alternating currents (ac) at power frequency (50 Hz in Europe and 60 Hz in the U.S.) and other frequencies in the Extreme Low Frequency (ELF) range (3-3000 Hz), and associated public and worker exposures to EMF, are a growing health and safety concern worldwide. As part of a comprehensive safety assessment of the German TransRapid (TR-07) maglev system undertaken by the FRA, with technical support from the DOT/RSPA Volpe National Transportation System Center (VNTSC), magnetic field measurements were performed by Electric Research and Management, Inc. (ERM) at the Transrapid Test Facility (TVE) in Emsland, Germany in August, 1990. Volume II-Appendices catalogs and documents detailed magnetic field data files and their specifics (static fields, spectral waveforms, temporal and spatial information) by location.

  11. Safety of high-speed magnetic-levitation transportation systems. Magnetic-field testing of the TR07 maglev vehicle and system. Volume 1. Analysis. Final report Jun 91-Mar 92

    SciTech Connect

    Dietrich, F.; Feero, W.E.

    1992-04-01

    The safety of various magnetically levitated (maglev) and high speed rail (HSR) trains proposed for application in the United States is of direct concern to the Federal Railroad Administration (FRA). The characterization of electric and magnetic fields (EMF) emissions, both steady (dc) and produced by alternating currents (ac) at power frequency (50 Hz in Europe and 60 Hz in the U.S.) and other frequencies in the Extreme Low Frequency (ELF) range (3-3000 Hz), and associated public and worker exposures to EMF, are a growing health and safety concern worldwide. As part of a comprehensive safety assessment of the German TransRapid (TR-07) maglev system undertaken by the FRA, with technical support from the DOT/RSPA Volpe National Transportation System Center (VNTSC), magnetic field measurements were performed by Electric Research and Management, Inc. (ERM) at the Transrapid Test Facility (TVE) in Emsland, Germany in August, 1990. Volume I-Analysis summarizes the experimental findings and compares results to common home, work, and power lines emissions for selected spectral bands.

  12. Covariant Electrodynamics in Vacuum

    NASA Astrophysics Data System (ADS)

    Wilhelm, H. E.

    1990-05-01

    The generalized Galilei covariant Maxwell equations and their EM field transformations are applied to the vacuum electrodynamics of a charged particle moving with an arbitrary velocity v in an inertial frame with EM carrier (ether) of velocity w. In accordance with the Galilean relativity principle, all velocities have absolute meaning (relative to the ether frame with isotropic light propagation), and the relative velocity of two bodies is defined by the linear relation uG = v1 - v2. It is shown that the electric equipotential surfaces of a charged particle are compressed in the direction parallel to its relative velocity v - w (mechanism for physical length contraction of bodies). The magnetic field H(r, t) excited in the ether by a charge e moving uniformly with velocity v is related to its electric field E(r, t) by the equation H=ɛ0(v - w)xE/[ 1 +w • (t>- w)/c20], which shows that (i) a magnetic field is excited only if the charge moves relative to the ether, and (ii) the magnetic field is weak if v - w is not comparable to the velocity of light c0 . It is remarkable that a charged particle can excite EM shock waves in the ether if |i> - w > c0. This condition is realizable for anti-parallel charge and ether velocities if |v-w| > c0- | w|, i.e., even if |v| is subluminal. The possibility of this Cerenkov effect in the ether is discussed for terrestrial and galactic situations

  13. International Space Station Electrodynamic Tether Reboost Study

    NASA Technical Reports Server (NTRS)

    Johnson, L.; Herrmann, M.

    1998-01-01

    The International Space Station (ISS) will require periodic reboost due to atmospheric aerodynamic drag. This is nominally achieved through the use of thruster firings by the attached Progress M spacecraft. Many Progress flights to the ISS are required annually. Electrodynamic tethers provide an attractive alternative in that they can provide periodic reboost or continuous drag cancellation using no consumables, propellant, nor conventional propulsion elements. The system could also serve as an emergency backup reboost system used only in the event resupply and reboost are delayed for some reason.

  14. Electrodynamics payloads for small rockets

    NASA Technical Reports Server (NTRS)

    Croskey, C. L.; Hale, L. C.; Mitchell, J. D.; Mccarthy, S. P.; Goodnow, K. J.; Li, C.; Goldberg, R. A.

    1992-01-01

    Totally integrated design facilitates electrical cleanliness and light weight, which are necessary in subsonic parachute-borne payloads for electrodynamics investigations. 'Blunt' probes measure ion conductivity, as do Gerdien condensers. Recent finite-element computer analyses combining flow and electrodynamics have resolved problems in determining ion densities and mobilities from Gerdien data. Three-axis electric fields are measured with deployable boom-mounted electrodes from dc through VLF. Splitting the cylindrical payload with an insulator and measuring the current between halves has provided a vertical Maxwell current detector mechanically rigid enough to measure, at ELF, energy related to coupling. A nose tip 'Smith' probe turbulence measurement is usually performed on ascent. Other instrumentation, such as photo-ionization sources and X-ray detectors, can also be included. These electrodynamic measurement payloads are about one meter in length and have a mass of about 9 kg. They can be launched with an Orion-class or smaller vehicle.

  15. Feasibility of Air Levitated Surface Stage for Lithography Tool

    NASA Astrophysics Data System (ADS)

    Tanaka, Keiichi

    The application of light-weight drive technology into the lithography stage has been the current state of art because of minimization of power loss. The purpose of this article is to point out the so-called, "surface stage" which is composed of Lorentz forced 3 DOF (Degree Of Freedom) planar motor (x, y and theta z), air levitation (bearing) system and motor cooling system, is the most balanced concept for the next generation lithography through the verification of each component by manufacturing simple parts and test stand. This paper presents the design method and procedure, and experimental results of the air levitated surface stage which was conducted several years ago, however the author is convinced that the results are enough to adapt various developments of precision machining tool.

  16. Quantum Magnetomechanics: Ultrahigh-Q-Levitated Mechanical Oscillators

    NASA Astrophysics Data System (ADS)

    Cirio, M.; Brennen, G. K.; Twamley, J.

    2012-10-01

    Engineering nanomechanical quantum systems possessing ultralong motional coherence times allows for applications in precision quantum sensing and quantum interfaces, but to achieve ultrahigh motional Q one must work hard to remove all forms of motional noise and heating. We examine a magneto-meso-mechanical quantum system that consists of a 3D arrangement of miniature superconducting loops which is stably levitated in a static inhomogeneous magnetic field. The motional decoherence is predominantly due to loss from induced eddy currents in the magnetized sphere which provides the trapping field ultimately yielding Q˜109 with motional oscillation frequencies of several hundreds of kilohertz. By inductively coupling this levitating object to a nearby driven flux qubit one can cool its motion very close to the ground state and this may permit the generation of macroscopic entangled motional states of multiple clusters.

  17. Quantum electrodynamics effects on NMR magnetic shielding constants of He-like and Be-like atomic systems

    NASA Astrophysics Data System (ADS)

    Gimenez, Carlos A.; Kozioł, Karol; Aucar, Gustavo A.

    2016-03-01

    NMR shielding constants for He- and Be-like atomic systems of Ne, Ar, Kr, Xe, and Rn have been calculated at the random-phase-approximation level of approach, including an estimation of QED corrections within the polarization propagator formalism. We show that QED effects enhance electron correlation when Z becomes heavier, which happens with relativistic effects, and also that QED effects become smaller when going from more to less ionized systems. We studied two- and four-electron systems. Then such studies could easily be generalized to other many-electron systems. Results of calculations with our relatively simple model, which includes QED and electron correlation effects on the same theoretical grounds, have a summarized error in the range from 10% (for Ne) up to 24% (for Rn), so that our accuracy is a little lower than for calculations on H-like systems. Our findings should stimulate the development and/or the application of more rigorous formalisms to get more accurate QED corrections to response properties in many-electron systems.

  18. Cavity cooling of an optically levitated submicron particle

    PubMed Central

    Kiesel, Nikolai; Blaser, Florian; Delić, Uroš; Grass, David; Kaltenbaek, Rainer; Aspelmeyer, Markus

    2013-01-01

    The coupling of a levitated submicron particle and an optical cavity field promises access to a unique parameter regime both for macroscopic quantum experiments and for high-precision force sensing. We report a demonstration of such controlled interactions by cavity cooling the center-of-mass motion of an optically trapped submicron particle. This paves the way for a light–matter interface that can enable room-temperature quantum experiments with mesoscopic mechanical systems. PMID:23940352

  19. Time-dependent Kohn-Sham approach to quantum electrodynamics

    SciTech Connect

    Ruggenthaler, M.; Mackenroth, F.; Bauer, D.

    2011-10-15

    We prove a generalization of the van Leeuwen theorem toward quantum electrodynamics, providing the formal foundations of a time-dependent Kohn-Sham construction for coupled quantized matter and electromagnetic fields. We circumvent the symmetry-causality problems associated with the action-functional approach to Kohn-Sham systems. We show that the effective external four-potential and four-current of the Kohn-Sham system are uniquely defined and that the effective four-current takes a very simple form. Further we rederive the Runge-Gross theorem for quantum electrodynamics.

  20. Space Station Reboost with Electrodynamic Tethers

    NASA Technical Reports Server (NTRS)

    Vas, Irwin E.; Kelly, Thomas J.; Scarl, Ethan A.

    1999-01-01

    This paper presents the results of a study of an electrodynamic tether system to reboost the International Space Station (ISS). One recommendation is to use a partially bare tether for electron collection. Locations are suggested as to where the tether system is to be attached at the space station. The effects of the tether system on the microgravity environment may actually be beneficial, because the system can neutralize aerodrag during quiescent periods and, if deployed from a movable boom, can permit optimization of laboratory positioning with respect to acceleration contours. Alternative approaches to tether deployment and retrieval are discussed. It is shown that a relatively short tether system, 7 km long, operating at a power level of 5 kW could provide cumulative savings or over a billion dollars during a 10-year period ending in 2012. This savings is the direct result of a reduction in the number or nights that would otherwise be required to deliver propellant for reboost, with larger cost savings for higher tether usage. In addition to economic considerations, an electrodynamic tether promises a practical backup system that could ensure ISS survival in the event of an (otherwise) catastrophic delay in propellant delivery.

  1. Time-optimal control of the magnetically levitated photolithography platen

    SciTech Connect

    Redmond, J.; Tucker, S.

    1995-01-01

    This report summarizes two approaches to time-optimal control of a nonlinear magnetically levitated platen. The system of interest is a candidate technology for next-generation photolithography machines used in the manufacture of integrated circuits. The dynamics and the variable peak control force of the electro-magnetic actuators preclude the direct application of classical time-optimal control methodologies for determining optimal rest-to-rest maneuver strategies. Therefore, this study explores alternate approaches using a previously developed computer simulation. In the first approach, conservative estimates of the available control forces are used to generate suboptimal switching curves. In the second approach, exact solutions are determined iteratively and used as a training set for an artificial neural network. The trained network provides optimal actuator switching times that incorporate the full nonlinearities of the magnetic levitation actuators. Sample problems illustrate the effectiveness of these techniques as compared to traditional proportional-derivative control.

  2. Analysis of SPAR 8 single-axis levitation experiment

    NASA Technical Reports Server (NTRS)

    Rush, J. E.; Schafer, C. F.; Holland, R. L.

    1981-01-01

    The melting and resolidification of SPAR 8 payload melting and resolidification of a glass specimen from the in a containerless condition and the retrieval and examination of the specimen from the. The absence of container contact was assured by use of a single-axis acoustic levitation system. However, the sample contacted a wire cage after being held without container contact by the acoustic field for only approximately 87 seconds. At this time, the sample was still molten and, therefore, flowed aroung the wire and continued to adhere to it. An analysis of why the sample did not remain levitated free of container contact is presented. The experiment is described, and experimental observations are discussed and analyzed.

  3. A novel ultrasonic clutch using near-field acoustic levitation.

    PubMed

    Chang, Kuo-Tsi

    2004-10-01

    This paper investigates design, fabrication and drive of an ultrasonic clutch with two transducers. For the two transducers, one serving as a driving element of the clutch is connected to a driving shaft via a coupling, and the other serving as a slave element of the clutch is connected to a slave shaft via another coupling. The principle of ultrasonic levitation is first expressed. Then, a series-resonant inverter is used to generate AC voltages at input terminals of each transducer, and a speed measuring system with optic sensors is used to find the relationship between rotational speed of the slave shaft and applied voltage of each transducer. Moreover, contact surfaces of the two transducers are coupled by the frictional force when both the two transducers are not energized, and separated using the ultrasonic levitation when at least one of the two transducers is energized at high voltages at resonance. PMID:15358528

  4. Path integral quantization of generalized quantum electrodynamics

    SciTech Connect

    Bufalo, R.; Pimentel, B. M.; Zambrano, G. E. R.

    2011-02-15

    In this paper, a complete covariant quantization of generalized electrodynamics is shown through the path integral approach. To this goal, we first studied the Hamiltonian structure of the system following Dirac's methodology and, then, we followed the Faddeev-Senjanovic procedure to obtain the transition amplitude. The complete propagators (Schwinger-Dyson-Fradkin equations) of the correct gauge fixation and the generalized Ward-Fradkin-Takahashi identities are also obtained. Afterwards, an explicit calculation of one-loop approximations of all Green's functions and a discussion about the obtained results are presented.

  5. Subclassical fields and polarization in electrodynamics

    SciTech Connect

    Planat, Mathieu; Polonyi, Janos

    2010-08-15

    Expectation values of the electromagnetic field and the electric current are introduced at space-time resolution which belongs to the quantum domain. These allow us to approach some key features of classical electrodynamics from the underlying QED. One is the emergence of the radiation field in the retarded solution of the Maxwell equation, derived from an action principle. Another question discussed is the systematic derivation of the polarizability of a charge system. Furthermore, the decoherence and the consistency of the photon field are established by a perturbative calculation of the reduced density matrix for the electromagnetic field within the closed time path formalism.

  6. A diamagnetically stabilized horizontally levitated electromagnetic vibration energy harvester

    NASA Astrophysics Data System (ADS)

    Palagummi, S.; Zou, J.; Yuan, F. G.

    2015-04-01

    This article investigates a horizontal diamagnetic levitation (HDL) system for vibration energy harvesting. In this configuration, two large magnets, alias lifting magnets, are arranged co-axially at a distance such that in between them a magnet, alias floating magnet, is passively levitated at a laterally offset equilibrium position. The levitation is stabilized in the horizontal direction by two diamagnetic plates made of pyrolytic graphite placed on each side of the floating magnet. This HDL configuration permits large amplitude vibration of the floating magnet and exploits the ability to tailor the geometry to meet specific applications due to its frequency tuning capability. Theoretical modeling techniques are discussed followed by an experimental setup to validate it. At an input root mean square (RMS) acceleration of 0.0434 m/s2 (0.0044 grms) and at a resonant frequency of 1.2 Hz, the prototype generated a RMS power of 3.6 μW with an average system efficiency of 1.93%. Followed by the validation, parametric studies on the geometry of the components are undertaken to show that with the optimized parameters the efficiency can be further enhanced.

  7. Topological vortices in generalized Born-Infeld-Higgs electrodynamics

    NASA Astrophysics Data System (ADS)

    Casana, R.; Hora, E. da; Rubiera-Garcia, D.; Santos, C. dos

    2015-08-01

    A consistent BPS formalism to study the existence of topological axially symmetric vortices in generalized versions of the Born-Infeld-Higgs electrodynamics is implemented. Such a generalization modifies the field dynamics via the introduction of three nonnegative functions depending only in the Higgs field, namely, , , and . A set of first-order differential equations is attained when these functions satisfy a constraint related to the Ampère law. Such a constraint allows one to minimize the system's energy in such way that it becomes proportional to the magnetic flux. Our results provides an enhancement of the role of topological vortex solutions in Born-Infeld-Higgs electrodynamics. Finally, we analyze a set of models entailing the recovery of a generalized version of Maxwell-Higgs electrodynamics in a certain limit of the theory.

  8. Electrostatic Levitation Technique for Investigations of Physical Properties of Liquid States

    NASA Astrophysics Data System (ADS)

    Okada, Junpei; Ishikawa, Takehiko; Paradis, Paul-Francois; Yoda, Shinichi

    Electrostatic levitator (ESL) levitates a charged sample in a high vacuum using computer con-trolled electrostatic fields [1]. It can levitate materials such as metals, semiconductors, and some insulators. Sample temperature can be varied over a wide range, and samples can be deeply undercooled. We have been engaged in the research and development of the electro-static levitation technique with the aim of performing levitation dissolution experiments in the International Space Station (ISS). Our device for the electrostatic levitation dissolution test has been developed for experiments on the ISS. To this end, the system is designed to be compact and portable so that it can be launched by rocket and used for experiments in the limited space on the ISS. Accordingly, the device can be installed not just on the ISS or our research laboratory, but also in various external sites. We devised a plan to install the electrostatic levitation system in a site other than the ISS to study atomic structure and electron structure of ultra-high-temperature liquids. We mounted our system on third generation synchrotron radiation facility "SPring-8" in Japan, to investigate the atomic and electron structures of high-temperature liquids. The SPring-8 is an experimental facility that allows use of the most powerful X-rays in the world. We conducted a variety of experiments on ultra-high-temperature liquids using SPring-8. The X-ray is ideal for exploring atomic structure and electron structure. Since the X-ray is an electromagnetic wave, it interacts with electrons. In addition, most electrons gather around the atomic nucleus. By close analysis of the scattered x-rays, we can determine its atomic structure and electron structure in detail. In this talk, we introduce an x-ray Compton scattering and x-ray Raman scattering measurements on liquid aluminum and silicon. [1] W. -K. Rhim, et al, Rev. Sci. Instrum. (1985) 56 307.

  9. Engineering squeezed states of microwave radiation with circuit quantum electrodynamics

    SciTech Connect

    Li Pengbo; Li Fuli

    2011-03-15

    We introduce a squeezed state source for microwave radiation with tunable parameters in circuit quantum electrodynamics. We show that when a superconducting artificial multilevel atom interacting with a transmission line resonator is suitably driven by external classical fields, two-mode squeezed states of the cavity modes can be engineered in a controllable fashion from the vacuum state via adiabatic following of the ground state of the system. This scheme appears to be robust against decoherence and is realizable with present techniques in circuit quantum electrodynamics.

  10. Acoustic levitation in the presence of gravity

    NASA Technical Reports Server (NTRS)

    Collas, P.; Barmatz, M.; Shipley, C.

    1989-01-01

    The method of Gor'kov (1961) has been applied to derive general expressions for the total potential and force on a small spherical object in a resonant chamber in the presence of both acoustic and gravitational force fields. The levitation position is also determined in rectangular resonators for the simultaneous excitation of up to three acoustic modes, and the results are applied to the triple-axis acoustic levitator. The analysis is applied to rectangular, spherical, and cylindrical single-mode levitators that are arbitrarily oriented relative to the gravitational force field. Criteria are determined for isotropic force fields in rectangular and cylindrical resonators. It is demonstrated that an object will be situated within a volume of possible levitation positions at a point determined by the relative strength of the acoustic and gravitational fields and the orientation of the chamber relative to gravity.

  11. Eutectic growth under acoustic levitation conditions

    NASA Astrophysics Data System (ADS)

    Xie, W. J.; Cao, C. D.; Lü, Y. J.; Wei, B.

    2002-12-01

    Samples of Pb-Sn eutectic alloy with a high density of 8.5×103 kg/m3 are levitated with a single-axis acoustic levitator, and containerlessly melted and then solidified in argon atmosphere. High undercoolings up to 38 K are obtained, which results in a microstructural transition of ``lamellas-broken lamellas-dendrites.'' This transition is further investigated in the light of the coupled zone for eutectic growth and the effects of ultrasound. The breaking of regular eutectic lamellas and suppression of gravity-induced macrosegregation of (Pb) and (Sn) dendrites are explained by the complicated internal flow inside the levitated drop, which is jointly induced by the shape oscillation, bulk vibration and rotation of the levitated drop. The ultrasonic field is also found to drive forced surface vibration, which subsequently excites capillary ripples and catalyzes nucleation on the sample surface.

  12. Thermophysical property measurements in electromagnetic levitators

    NASA Technical Reports Server (NTRS)

    Hauge, Robert H.; Lee, P.; Norem, Nathan; Baykara, Tarik; Margrave, John L.

    1990-01-01

    Proper measurements of thermophysical properties of hot levitated liquid drops require the following: accurate temperature measurement (brightness measurement, emissivity measurement); precise drop shape measurements with submillisecond time resolution (density determination, rotational and vibrational shape information); precise control of drop shape (high symmetry variable gap levitators); accurate energy transfer measurements (direct measurements of energy transfer rates for defined gas flows over samples with quantitative measurements of energy transfer rates for defined flows over samples with known shapes); and precise measurements of repetitive sample motions (rapid repetitive shape measurements, frequency measurements with reflected laser light, measurements in the levitator and as a freely falling drop). Recent advances in coil design and control of sample rotation in an electromagnetic levitator are discussed with respect to the above requirements.

  13. Eutectic growth under acoustic levitation conditions.

    PubMed

    Xie, W J; Cao, C D; Lü, Y J; Wei, B

    2002-12-01

    Samples of Pb-Sn eutectic alloy with a high density of 8.5 x 10(3) kg/m(3) are levitated with a single-axis acoustic levitator, and containerlessly melted and then solidified in argon atmosphere. High undercoolings up to 38 K are obtained, which results in a microstructural transition of "lamellas-broken lamellas-dendrites." This transition is further investigated in the light of the coupled zone for eutectic growth and the effects of ultrasound. The breaking of regular eutectic lamellas and suppression of gravity-induced macrosegregation of (Pb) and (Sn) dendrites are explained by the complicated internal flow inside the levitated drop, which is jointly induced by the shape oscillation, bulk vibration and rotation of the levitated drop. The ultrasonic field is also found to drive forced surface vibration, which subsequently excites capillary ripples and catalyzes nucleation on the sample surface. PMID:12513291

  14. Equilibrium shapes of acoustically levitated drops

    NASA Astrophysics Data System (ADS)

    Trinh, E. H.; Hsu, C.-J.

    1986-05-01

    The quantitative determination of the shape of liquid drops levitated in an ultrasonic standing wave has provided experimental data on the radiation pressure-induced deformations of freely suspended liquids. Within the limits of small deviations from the spherical shape and small drop diameter relative to the acoustic wavelength, an existing approximate theory yields a good agreement with experimental evidence. The data were obtained for millimeter and submillimeter drops levitated in air under 1 g, where g is the sea level gravitational acceleration.

  15. Levitation of Iridium and Liquid Mercury by Ultrasound

    NASA Astrophysics Data System (ADS)

    Xie, W. J.; Cao, C. D.; Lü, Y. J.; Wei, B.

    2002-08-01

    Single-axis acoustic levitation of the heaviest solid (iridium, ρ=22.6 g cm-3) and liquid (mercury, ρ=13.6 g cm-3 on the Earth is achieved by greatly enhancing both the levitation force and stability through optimizing the geometric parameters of the levitator. The acoustically levitated Pb-Sn eutectic alloy melt (ρ=8.5 g cm-3) is highly undercooled by up to 38K, which results in a microstructural transition of ``lamellae-broken lamellae-dendrites.'' The drastic enhancement of levitation capability indicates a broader application range of single-axis acoustic levitation.

  16. Levitation of iridium and liquid mercury by ultrasound.

    PubMed

    Xie, W J; Cao, C D; Lü, Y J; Wei, B

    2002-09-01

    Single-axis acoustic levitation of the heaviest solid (iridium, rho=22.6 g cm(-3)) and liquid (mercury, rho=13.6 g cm(-3) on the Earth is achieved by greatly enhancing both the levitation force and stability through optimizing the geometric parameters of the levitator. The acoustically levitated Pb-Sn eutectic alloy melt (rho=8.5 g cm(-3)) is highly undercooled by up to 38 K, which results in a microstructural transition of "lamellae-broken lamellae-dendrites." The drastic enhancement of levitation capability indicates a broader application range of single-axis acoustic levitation. PMID:12225198

  17. Velocity and rotation measurements in acoustically levitated droplets

    NASA Astrophysics Data System (ADS)

    Saha, Abhishek; Basu, Saptarshi; Kumar, Ranganathan

    2012-10-01

    The velocity scale inside an acoustically levitated droplet depends on the levitator and liquid properties. Using Particle Imaging Velocimetry (PIV), detailed velocity measurements have been made in a levitated droplet of different diameters and viscosity. The maximum velocity and rotation are normalized using frequency and amplitude of acoustic levitator, and droplet viscosity. The non-dimensional data are fitted for micrometer- and millimeter-sized droplets levitated in different levitators for different viscosity fluids. It is also shown that the rotational speed of nanosilica droplets at an advanced stage of vaporization compares well with that predicted by exponentially fitted parameters.

  18. Electrostatic Levitation for Studies of Additive Manufactured Materials

    NASA Technical Reports Server (NTRS)

    SanSoucie, Michael P.; Rogers, Jan R.; Tramel, Terri

    2014-01-01

    The electrostatic levitation (ESL) laboratory at NASA's Marshall Space Flight Center is a unique facility for investigators studying high temperature materials. The laboratory boasts two levitators in which samples can be levitated, heated, melted, undercooled, and resolidified. Electrostatic levitation minimizes gravitational effects and allows materials to be studied without contact with a container or instrumentation. The lab also has a high temperature emissivity measurement system, which provides normal spectral and normal total emissivity measurements at use temperature. The ESL lab has been instrumental in many pioneering materials investigations of thermophysical properties, e.g., creep measurements, solidification, triggered nucleation, and emissivity at high temperatures. Research in the ESL lab has already led to the development of advanced high temperature materials for aerospace applications, coatings for rocket nozzles, improved medical and industrial optics, metallic glasses, ablatives for reentry vehicles, and materials with memory. Modeling of additive manufacturing materials processing is necessary for the study of their resulting materials properties. In addition, the modeling of the selective laser melting processes and its materials property predictions are also underway. Unfortunately, there is very little data for the properties of these materials, especially of the materials in the liquid state. Some method to measure thermophysical properties of additive manufacturing materials is necessary. The ESL lab is ideal for these studies. The lab can provide surface tension and viscosity of molten materials, density measurements, emissivity measurements, and even creep strength measurements. The ESL lab can also determine melting temperature, surface temperatures, and phase transition temperatures of additive manufactured materials. This presentation will provide background on the ESL lab and its capabilities, provide an approach to using the ESL

  19. Improved Plasma Properties in RT-1 with a Levitated Coil

    NASA Astrophysics Data System (ADS)

    Saitoh, Haruhiko; Yoshida, Zensho; Ogawa, Yuichi; Morikawa, Junji; Watanabe, Sho; Yano, Yoshihisa; Suzuki, Junko

    2007-11-01

    Ring Trap-1 (RT-1) is a novel device to confine plasmas in a magnetosphere-like configuration generated by a superconducting internal conductor. The ring coil is excited with a permanent current of Ic=250kAT that is magnetically levitated in the chamber to minimize disturbances to the plasmas. The main scientific objective of RT-1 is to realize self-organized states of flowing plasmas with a very high beta value, where the thermal pressure of plasmas is balanced by the hydrodynamic pressure of a fast flow (S. M. Mahajan & Z. Yoshida, PRL 81, 4863 (1998), Z. Yoshida & S. M. Mahajan, PRL 88, 095001 (2002)). We have started a series of initial plasma experiments since 2006, and in this study, we focused on the improvements of plasma properties by the coil levitation. Hydrogen plasmas were generated by an 8.2GHz ECH system. When the coil was levitated, a line integrated electron density increased to ne=4x10^17m-2 and the peak density was close to the O-mode cut off density of the microwave. The beta value of the plasma was ˜3% and the pressure was mainly sustained by a high energy component of electrons. The magnetic surface configuration of RT-1 is also suitable for the confinement of non-neutral plasmas. Experiments on electron plasmas were conducted in RT-1 expanding the previous work in a normal conducting device.

  20. Electrochemistry in an acoustically levitated drop.

    PubMed

    Chainani, Edward T; Ngo, Khanh T; Scheeline, Alexander

    2013-02-19

    Levitated drops show potential as microreactors, especially when radicals are present as reactants or products. Solid/liquid interfaces are absent or minimized, avoiding adsorption and interfacial reaction of conventional microfluidics. We report amperometric detection in an acoustically levitated drop with simultaneous ballistic addition of reactant. A gold microelectrode sensor was fabricated with a lithographic process; active electrode area was defined by a photosensitive polyimide mask. The microdisk gold working electrode of radius 19 μm was characterized using ferrocenemethanol in aqueous buffer. Using cyclic voltammetry, the electrochemically active surface area was estimated by combining a recessed microdisk electrode model with the Randles-Sevcik equation. Computer-controlled ballistic introduction of reactant droplets into the levitated drop was developed. Chronoamperometric measurements of ferrocyanide added ballistically demonstrate electrochemical monitoring using the microfabricated electrode in a levitated drop. Although concentration increases with time due to drop evaporation, the extent of concentration is predictable with a linear evaporation model. Comparison of diffusion-limited currents in pendant and levitated drops show that convection arising from acoustic levitation causes an enhancement of diffusion-limited current on the order of 16%. PMID:23351154

  1. Levitation and lateral forces between a point magnetic dipole and a superconducting sphere

    NASA Astrophysics Data System (ADS)

    H, M. Al-Khateeb; M, K. Alqadi; F, Y. Alzoubi; B, Albiss; M, K. Hasan (Qaseer; N, Y. Ayoub

    2016-05-01

    The dipole–dipole interaction model is employed to investigate the angular dependence of the levitation and lateral forces acting on a small magnet in an anti-symmetric magnet/superconducting sphere system. Breaking the symmetry of the system enables us to study the lateral force which is important in the stability of the magnet above a superconducting sphere in the Meissner state. Under the assumption that the lateral displacement of the magnet is small compared to the physical dimensions of our proposed system, analytical expressions are obtained for the levitation and lateral forces as a function of the geometrical parameters of the superconductor as well as the height, the lateral displacement, and the orientation of the magnetic moment of the magnet. The dependence of the levitation force on the height of the levitating magnet is similar to that in the symmetric magnet/superconducting sphere system within the range of proposed lateral displacements. It is found that the levitation force is linearly dependent on the lateral displacement whereas the lateral force is independent of this displacement. A sinusoidal variation of both forces as a function of the polar and azimuthal angles specifying the orientation of the magnetic moment is observed. The relationship between the stability and the orientation of the magnetic moment is discussed for different orientations.

  2. Apparent Paradoxes in Classical Electrodynamics: Relativistic Transformation of Force

    ERIC Educational Resources Information Center

    Kholmetskii, A. L.; Yarman, T.

    2007-01-01

    In this paper, we analyse a number of paradoxical teaching problems of classical electrodynamics, dealing with the relativistic transformation of force for complex macro systems, consisting of a number of subsystems with nonzero relative velocities such as electric circuits that change their shape in the course of time. (Contains 7 figures.)

  3. Aspects of passive magnetic levitation based on high-T(sub c) superconducting YBCO thin films

    NASA Technical Reports Server (NTRS)

    Schoenhuber, P.; Moon, F. C.

    1995-01-01

    Passive magnetic levitation systems reported in the past were mostly confined to bulk superconducting materials. Here we present fundamental studies on magnetic levitation employing cylindrical permanent magnets floating above high-T(sub c) superconducting YBCO thin films (thickness about 0.3 mu m). Experiments included free floating rotating magnets as well as well-established flexible beam methods. By means of the latter, we investigated levitation and drag force hysteresis as well as magnetic stiffness properties of the superconductor-magnet arrangement. In the case of vertical motion of the magnet, characteristic high symmetry of repulsive (approaching) and attractive (withdrawing) branches of the pronounced force-displacement hysteresis could be detected. Achievable force levels were low as expected but sufficient for levitation of permanent magnets. With regard to magnetic stiffness, thin films proved to show stiffness-force ratios about one order of magnitude higher than bulk materials. Phenomenological models support the measurements. Regarding the magnetic hysteresis of the superconductor, the Irie-Yamafuji model was used for solving the equation of force balance in cylindrical coordinates allowing for a macroscopic description of the superconductor magnetization. This procedure provided good agreement with experimental levitation force and stiffness data during vertical motion. For the case of (lateral) drag force basic qualitative characteristics could be recovered, too. It is shown that models, based on simple asymmetric magnetization of the superconductor, describe well asymptotic transition of drag forces after the change of the magnet motion direction. Virgin curves (starting from equilibrium, i.e. symmetric magnetization) are approximated by a linear approach already reported in literature only. This paper shows that basic properties of superconducting thin films allow for their application to magnetic levitation or - without need of levitation

  4. Carl Neumann's Contributions to Electrodynamics

    NASA Astrophysics Data System (ADS)

    Schlote, Karl-Heinz

    2004-09-01

    I examine the publications of Carl Neumann (1832 1925) on electrodynamics, which constitute a major part of his work and which illuminate his approach to mathematical physics. I show how Neumann contributed to physics at an important stage in its development and how his work led to a polemic with Hermann Helmholtz (1821 1894). Neumann advanced and extended the ideas of the Königsberg school of mathematical physics. His investigations were aimed at founding a mathematically exact physical theory of electrodynamics, following the approach of Carl G.J. Jacobi (1804 1851) on the foundation of a physical theory as outlined in Jacobi’s lectures on analytical mechanics. Neumann’s work also shows how he clung to principles that impeded him in appreciating and developing new ideas such as those on field theory that were proposed by Michael Faraday (1791 1867) and James Clerk Maxwell (1831 1879).

  5. Pyroshock testing-electrodynamic shakers

    NASA Astrophysics Data System (ADS)

    Smallwood, David O.

    2002-05-01

    Far field pyroshock (accelerations less than a few hundred grams, and bandwidths less than a few kHz) can be simulated on electrodynamic shakers. Typically, the specification is in terms of the shock response spectrum (SRS). Wave forms are synthesized which will match the required SRS. The process is not unique, as many wave forms can have essentially the same SRS. Sometimes additional restrictions are placed on the synthesized wave form. Most common are restrictions on the duration of the wave form. The process of synthesizing wave forms, which will match an SRS and conform to the limitations of electrodynamic shakers, will be described. The methods used to reproduce these wave forms on the shaker will then be discussed.

  6. How to Simply Demonstrate Diamagnetic Levitation with Pencil Lead

    ERIC Educational Resources Information Center

    Koudelkova, Vera

    2016-01-01

    A new simple arrangement how to demonstrate diamagnetic levitation is presented. It uses pencil lead levitating in a track built from neodymium magnets. This arrangement can also be used as a classroom experiment.

  7. How to simply demonstrate diamagnetic levitation with pencil lead

    NASA Astrophysics Data System (ADS)

    Koudelkova, Vera

    2016-01-01

    A new simple arrangement how to demonstrate diamagnetic levitation is presented. It uses pencil lead levitating in a track built from neodymium magnets. This arrangement can also be used as a classroom experiment.

  8. Accelerator and electrodynamics capability review

    SciTech Connect

    Jones, Kevin W

    2010-01-01

    Los Alamos National Laboratory (LANL) uses capability reviews to assess the science, technology and engineering (STE) quality and institutional integration and to advise Laboratory Management on the current and future health of the STE. Capability reviews address the STE integration that LANL uses to meet mission requirements. The Capability Review Committees serve a dual role of providing assessment of the Laboratory's technical contributions and integration towards its missions and providing advice to Laboratory Management. The assessments and advice are documented in reports prepared by the Capability Review Committees that are delivered to the Director and to the Principal Associate Director for Science, Technology and Engineering (PADSTE). Laboratory Management will use this report for STE assessment and planning. LANL has defined fifteen STE capabilities. Electrodynamics and Accelerators is one of the seven STE capabilities that LANL Management (Director, PADSTE, technical Associate Directors) has identified for review in Fiscal Year (FY) 2010. Accelerators and electrodynamics at LANL comprise a blend of large-scale facilities and innovative small-scale research with a growing focus on national security applications. This review is organized into five topical areas: (1) Free Electron Lasers; (2) Linear Accelerator Science and Technology; (3) Advanced Electromagnetics; (4) Next Generation Accelerator Concepts; and (5) National Security Accelerator Applications. The focus is on innovative technology with an emphasis on applications relevant to Laboratory mission. The role of Laboratory Directed Research and Development (LDRD) in support of accelerators/electrodynamics will be discussed. The review provides an opportunity for interaction with early career staff. Program sponsors and customers will provide their input on the value of the accelerator and electrodynamics capability to the Laboratory mission.

  9. Instantaneous fields in classical electrodynamics

    NASA Astrophysics Data System (ADS)

    Heras, J. A.

    2005-01-01

    In this paper we express the retarded fields of Maxwell's theory in terms of the instantaneous fields of a Galilei-invariant electromagnetic and we find the vector function χL whose spatial and temporal derivatives transform the Euclidean fields into the retarded ones. We conclude that the instantaneous fields can formally be introduced as unphysical objects into classical electrodynamics which can be used to find the physical retarded fields.

  10. Spacecraft Solar Sails Containing Electrodynamic Tethers

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Matloff, Greg

    2005-01-01

    A report discusses a proposal to use large, lightweight solar sails embedded with electrodynamic tethers (essentially, networks of wires) to (1) propel robotic spacecraft to distant planets, then (2) exploit the planetary magnetic fields to capture the spacecraft into orbits around the planets. The purpose of the proposal is, of course, to make it possible to undertake long interplanetary missions without incurring the large cost and weight penalties of conventional rocket-type propulsion systems. Through transfer of momentum from reflected solar photons, a sail would generate thrust outward from the Sun. Upon arrival in the vicinity of a planet, the electrodynamic tethers would be put to use: Motion of the spacecraft across the planetary magnetic field would induce electric currents in the tether wires, giving rise to an electromagnetic drag force that would be exploited to brake the spacecraft for capture into orbit. The sail with embedded tethers would be made to spin to provide stability during capture. Depending upon the requirements of a particular application, it could be necessary to extend the tether to a diameter greater than that of the sail.

  11. Polymeric Coatings for Electrodynamic Tethers

    NASA Technical Reports Server (NTRS)

    Vaughn, Jason A.; Kamenetzky, Rachel R.; Finckenor, Miria M.; Schuler, Peter

    2000-01-01

    Two polymeric coatings have been developed for the Propulsive Small Expendable Deployer System (ProSEDS) mission. ProSEDS is designed to provide an on-orbit demonstration of the electrodynamic propulsion capabilities of tethers in space. The ProSEDS experiment will be a secondary payload on a Delta II unmanned expendable booster scheduled for launch in August 2000. A 5-km conductive tether is attached to the Delta 11 second stage and collects current from the low Earth orbit (LEO) plasma to facilitate de-orbit of the spent stage. The conductive tether is attached to a 10-km non-conductive tether, the other end of which is attached to an endmass containing several scientific instruments. A bare metal tether would have the best conductivity but thermal concerns preclude this design. A conductive polymer developed by Triton Systems has been optimized for conductivity and thermo-optical properties. The current design for the ProSEDS conductive tether is seven strands of 28 AWG aluminum wire individually coated with 8.7 micrometers (0.35 mil) of an atomic oxygen-resistant conductive polymer composed of a mixture of 87% Clear Oxygen-Resistant polymer (COR) and 13% polyanaline (PANi), wrapped around a braided Kevlar (TM) 49 core. Extensive testing has been performed at the Marshall Space Flight Center (MSFC) to qualify this material for flight on ProSEDS. Atomic oxygen exposure was performed, with solar absorptance and infrared emittance measured before and after exposure. Conductivity was measured before and after atomic oxygen exposure. High voltage tests, up to 1500 V, of the current collecting ability of the COR/PANi have been completed. Approximately 160 meters of the conductive tether closest to the Delta 11 second stage is insulated to prevent any electron reconnection to the tether from the plasma contactor. The insulation is composed of polyimide overcoated with TOR-BP, another polymeric coating developed by Triton for this mission. TOR-BP acts as both insulator

  12. Studies on the levitation height decay of the high temperature superconducting Maglev vehicle

    NASA Astrophysics Data System (ADS)

    Deng, Z. G.; Zheng, J.; Zhang, J.; Wang, J. S.; Wang, S. Y.; Zhang, Y.; Liu, L.

    2007-10-01

    The levitation height decay was found in the high temperature superconducting (HTS) Maglev test vehicle system during man-loading running. Experimental results show that the no-load levitating system would drift to a new equilibrium position by the external loaded history, but the new equilibrium position will almost not drift by the second-round same loaded history. A new method is proposed to improve the stability of the HTS Maglev vehicle, that is, a pre-load was applied to the HTS Maglev vehicle before running. The impulse responses are performed on the HTS Maglev vehicle before the pre-load and after the pre-load. The results show that the pre-load method is considerably effective to improve the stiffness and damping coefficient of the HTS Maglev vehicle. Moreover, it helps to suppress the levitation height decay and enhance the stability of the HTS Maglev vehicle in practical operation.

  13. Laser Induced Rotation of a Levitated Sample in Vacuum

    NASA Technical Reports Server (NTRS)

    Rhim, W. K.; Paradis, P. F.

    1999-01-01

    A method of systematically controlling the rotational state of a sample levitated in a high vacuum using the photon pressure is described. A zirconium sphere was levitated in the high-temperature electrostatic levitator and it was rotated by irradiating it with a narrow beam of a high power laser on a spot off the center of mass.

  14. Levitation performance of the magnetized bulk high- Tc superconducting magnet with different trapped fields

    NASA Astrophysics Data System (ADS)

    Liu, W.; Wang, J. S.; Liao, X. L.; Zheng, S. J.; Ma, G. T.; Zheng, J.; Wang, S. Y.

    2011-03-01

    To a high- Tc superconducting (HTS) maglev system which needs large levitation force density, the magnetized bulk high- Tc superconductor (HTSC) magnet is a good candidate because it can supply additional repulsive or attractive force above a permanent magnet guideway (PMG). Because the induced supercurrent within a magnetized bulk HTSC is the key parameter for the levitation performance, and it is sensitive to the magnetizing process and field, so the magnetized bulk HTSC magnets with different magnetizing processes had various levitation performances, not only the force magnitude, but also its force relaxation characteristics. Furthermore, the distribution and configuration of the induced supercurrent are also important factor to decide the levitation performance, especially the force relaxation characteristics. This article experimentally investigates the influences of different magnetizing processes and trapped fields on the levitation performance of a magnetized bulk HTSC magnet with smaller size than the magnetic inter-pole distance of PMG, and the obtained results are qualitatively analyzed by the Critical State Model. The test results and analyses of this article are useful for the suitable choice and optimal design of magnetized bulk HTSC magnets.

  15. Design of electrostatically levitated micromachined rotational gyroscope based on UV-LIGA technology

    NASA Astrophysics Data System (ADS)

    Cui, Feng; Chen, Wenyuan; Su, Yufeng; Zhang, Weiping; Zhao, Xiaolin

    2004-12-01

    The prevailing micromachined vibratory gyroscope typically has a proof mass connected to the substrate by a mechanical suspension system, which makes it face a tough challenge to achieve tactical or inertial grade performance levels. With a levitated rotor as the proof mass, a micromachined rotational gyroscope will potentially have higher performance than vibratory gyroscope. Besides working as a moment rebalance dual-axis gyroscope, the micromachined rotational gyroscope based on a levitated rotor can simultaneously work as a force balance tri-axis accelerometer. Micromachined rotational gyroscope based on an electrostatically levitated silicon micromachined rotor has been notably developed. In this paper, factors in designing a rotational gyro/accelerometer based on an electrostatically levitated disc-like rotor, including gyroscopic action of micro rotor, methods of stable levitation, micro displacement detection and control, rotation drive and speed control, vacuum packaging and microfabrication, are comprehensively considered. Hence a design of rotational gyro/accelerometer with an electroforming nickel rotor employing low cost UV-LIGA technology is presented. In this design, a wheel-like flat rotor is proposed and its basic dimensions, diameter and thickness, are estimated according to the required loading capability. Finally, its micromachining methods based on UV-LIGA technology and assembly technology are discussed.

  16. Self-arraying of charged levitating droplets.

    PubMed

    Kauffmann, Paul; Nussbaumer, Jérémie; Masse, Alain; Jeandey, Christian; Grateau, Henri; Pham, Pascale; Reyne, Gilbert; Haguet, Vincent

    2011-06-01

    Diamagnetic levitation of water droplets in air is a promising phenomenon to achieve contactless manipulation of chemical or biochemical samples. This noncontact handling technique prevents contaminations of samples as well as provides measurements of interaction forces between levitating reactors. Under a nonuniform magnetic field, diamagnetic bodies such as water droplets experience a repulsive force which may lead to diamagnetic levitation of a single or few micro-objects. The levitation of several repulsively charged picoliter droplets was successfully performed in a ~1 mm(2) adjustable flat magnetic well provided by a centimeter-sized cylindrical permanent magnet structure. Each droplet position results from the balance between the centripetal diamagnetic force and the repulsive Coulombian forces. Levitating water droplets self-organize into satellite patterns or thin clouds, according to their charge and size. Small triangular lattices of identical droplets reproduce magneto-Wigner crystals. Repulsive forces and inner charges can be measured in the piconewton and the femtocoulomb ranges, respectively. Evolution of interaction forces is accurately followed up over time during droplet evaporation. PMID:21500859

  17. Dynamics of acoustically levitated disk samples.

    PubMed

    Xie, W J; Wei, B

    2004-10-01

    The acoustic levitation force on disk samples and the dynamics of large water drops in a planar standing wave are studied by solving the acoustic scattering problem through incorporating the boundary element method. The dependence of levitation force amplitude on the equivalent radius R of disks deviates seriously from the R3 law predicted by King's theory, and a larger force can be obtained for thin disks. When the disk aspect ratio gamma is larger than a critical value gamma(*) ( approximately 1.9 ) and the disk radius a is smaller than the critical value a(*) (gamma) , the levitation force per unit volume of the sample will increase with the enlargement of the disk. The acoustic levitation force on thin-disk samples ( gammalevitation of a large water drop is to adjust the reflector-emitter interval H slightly above the resonant interval H(n) . The simulation shows that the drop is flattened and the central parts of its top and bottom surface become concave with the increase of sound pressure level, which agrees with the experimental observation. The main frequencies of the shape oscillation under different sound pressures are slightly larger than the Rayleigh frequency because of the large shape deformation. The simulated translational frequencies of the vertical vibration under normal gravity condition agree with the theoretical analysis. PMID:15600551

  18. Study on Transient Properties of Levitated Object in Near-Field Acoustic Levitation

    NASA Astrophysics Data System (ADS)

    Jia, Bing; Chen, Chao; Zhao, Chun-Sheng

    2011-12-01

    A new approach to the study on the transient properties of the levitated object in near-field acoustic levitation (NFAL) is presented. In this article, the transient response characteristics, including the levitated height of an object with radius of 24 mm and thickness of 5 mm, the radial velocity and pressure difference of gas at the boundary of clearance between the levitated object and radiating surface (squeeze film), is calculated according to several velocity amplitudes of radiating surface. First, the basic equations in fluid areas on Arbitrary Lagrange—Euler (ALE) form are numerically solved by using streamline upwind petrov galerkin (SUPG) finite elements method. Second, the formed algebraic equations and solid control equations are solved by using synchronous alternating method to gain the transient messages of the levitated object and gas in the squeeze film. Through theoretical and numerical analyses, it is found that there is a oscillation time in the transient process and that the response time does not simply increase with the increasing of velocity amplitudes of radiating surface. More investigations in this paper are helpful for the understanding of the transient properties of levitated object in NFAL, which are in favor of enhancing stabilities and responsiveness of levitated object.

  19. Superconducting pipes and levitating magnets

    NASA Astrophysics Data System (ADS)

    Levin, Yan; Rizzato, Felipe B.

    2006-12-01

    Motivated by a beautiful demonstration of the Faraday and the Lenz laws in which a small neodymium magnet falls slowly through a conducting nonferromagnetic tube, we consider the dynamics of a magnet falling coaxially through a superconducting pipe. Unlike the case of normal conducting pipes, in which the magnet quickly reaches the terminal velocity, inside a superconducting tube the magnet falls freely. On the other hand, to enter the pipe the magnet must overcome a large electromagnetic energy barrier. For sufficiently strong magnets, the barrier is so large that the magnet will not be able to penetrate it and will be levitated over the mouth of the pipe. We calculate the work that must done to force the magnet to enter a superconducting tube. The calculations show that superconducting pipes are very efficient at screening magnetic fields. For example, the magnetic field of a dipole at the center of a short pipe of radius a and length L≳a decays, in the axial direction, with a characteristic length ξ≈0.26a . The efficient screening of the magnetic field might be useful for shielding highly sensitive superconducting quantum interference devices. Finally, the motion of the magnet through a superconducting pipe is compared and contrasted to the flow of ions through a trans-membrane channel.

  20. Superconducting pipes and levitating magnets.

    PubMed

    Levin, Yan; Rizzato, Felipe B

    2006-12-01

    Motivated by a beautiful demonstration of the Faraday and the Lenz laws in which a small neodymium magnet falls slowly through a conducting nonferromagnetic tube, we consider the dynamics of a magnet falling coaxially through a superconducting pipe. Unlike the case of normal conducting pipes, in which the magnet quickly reaches the terminal velocity, inside a superconducting tube the magnet falls freely. On the other hand, to enter the pipe the magnet must overcome a large electromagnetic energy barrier. For sufficiently strong magnets, the barrier is so large that the magnet will not be able to penetrate it and will be levitated over the mouth of the pipe. We calculate the work that must done to force the magnet to enter a superconducting tube. The calculations show that superconducting pipes are very efficient at screening magnetic fields. For example, the magnetic field of a dipole at the center of a short pipe of radius a and length L approximately > a decays, in the axial direction, with a characteristic length xi approximately 0.26a. The efficient screening of the magnetic field might be useful for shielding highly sensitive superconducting quantum interference devices. Finally, the motion of the magnet through a superconducting pipe is compared and contrasted to the flow of ions through a trans-membrane channel. PMID:17280160

  1. Materials science investigations using electromagnetic levitation

    NASA Astrophysics Data System (ADS)

    Seidel, A.; Soellner, W.; Stenzel, C.

    2011-12-01

    EML on ISS allows levitating liquid samples both above and below their melting points for extended periods under ultra-high vacuum or ultra clean noble gas atmosphere. Various stimuli can be applied to the samples for dedicated experiment objectives. The heat input into the sample can be modulated to induce a thermal response of the sample, short heater pulses can be used to induce surface shape oscillations of the liquid sample, a custom made trigger needle can be driven into the undercooled sample to induce heterogeneous nucleation at a predefined temperature, touching of the sample by a dedicated chill cool plate or application of a forced gas flow can be used to increase the cooling rate of the sample or to simulate convection for reference experiments. Dedicated diagnostics elements are available to measure the physical properties of the sample. Sample temperature is measured by a pyrometer; two video units in orthogonal views provide both high spatial (up to 1 Megapixel and relative size resolution 2 * 10-4) and temporal (up to 30 kHz) resolution. Additional capabilities are under discussion which would allow to measure the electrical conductivity of the sample from electrical data of the rf coil system, and to determine the residual oxygen content of the process atmosphere.

  2. Double row loop-coil configuration for high-speed electrodynamic maglev suspension, guidance, propulsion and guideway directional switching

    SciTech Connect

    He, J.; Rote, D.M.

    1994-12-31

    A stabilization and propulsion system comprising a series of loop-coils arranged in parallel rows wherein two rows form a magnetic rail. Levitation and lateral stability is provided when the induced field in the magnetic rails interacts with the superconducting magnets (SCM) mounted on the magnetic levitation vehicle. A multiphase propulsion system interconnects specific coils in a given magnetic rail and interacts with the SCM to produce a propulsion force to the vehicle.

  3. Acoustic levitation of a large solid sphere

    NASA Astrophysics Data System (ADS)

    Andrade, Marco A. B.; Bernassau, Anne L.; Adamowski, Julio C.

    2016-07-01

    We demonstrate that acoustic levitation can levitate spherical objects much larger than the acoustic wavelength in air. The acoustic levitation of an expanded polystyrene sphere of 50 mm in diameter, corresponding to 3.6 times the wavelength, is achieved by using three 25 kHz ultrasonic transducers arranged in a tripod fashion. In this configuration, a standing wave is created between the transducers and the sphere. The axial acoustic radiation force generated by each transducer on the sphere was modeled numerically as a function of the distance between the sphere and the transducer. The theoretical acoustic radiation force was verified experimentally in a setup consisting of an electronic scale and an ultrasonic transducer mounted on a motorized linear stage. The comparison between the numerical and experimental acoustic radiation forces presents a good agreement.

  4. Overview of the Levitated Dipole Experiment

    NASA Astrophysics Data System (ADS)

    Mauel, M. E.; Garnier, D. T.; Hansen, A.; Pedersen, T. Sunn; Kesner, J.; Jones, C. M.; Karim, I.; Liptac, J.; Minervini, J.; Michael, P.; Radovinsky, A.; Schultz, J. H.; Smith, B. A.; Zhukovsky, A.

    2001-10-01

    The Levitated Dipole Experiment (LDX) [http://www.psfc.mit.edu/ldx/] will be the first experiment able to study high-beta plasma confined by a magnetic dipole with near classical energy confinement. LDX consists of three superconducting magnets and illustrates the role of innovative magnetic technology that makes possible explorations of entirely new confinement concepts. We describe the LDX machine design and detail the fabrication status of the superconducting floating-coil, charging-coil, and levitation-coil. In addition, we summarize (1) our procedure to cool, to inductively charge, and to levitate the 1.3 MA floating coil, (2) our initial diagnostic set, and (3) our experimental and physics plans that answer the key questions of high-beta stability and confinement in the dipole fusion concept.

  5. Levitation Performance of Two Opposed Permanent Magnet Pole-Pair Separated Conical Bearingless Motors

    NASA Technical Reports Server (NTRS)

    Kascak, Peter; Jansen, Ralph; Dever, Timothy; Nagorny, Aleksandr; Loparo, Kenneth

    2013-01-01

    In standard motor applications, rotor suspension with traditional mechanical bearings represents the most economical solution. However, in certain high performance applications, rotor suspension without contacting bearings is either required or highly beneficial. Examples include applications requiring very high speed or extreme environment operation, or with limited access for maintenance. This paper expands upon a novel bearingless motor concept, in which two motors with opposing conical air-gaps are used to achieve full five-axis levitation and rotation of the rotor. Force in this motor is created by deliberately leaving the motor s pole-pairs unconnected, which allows the creation of different d-axis flux in each pole pair. This flux imbalance is used to create lateral force. This approach is different than previous bearingless motor designs, which require separate windings for levitation and rotation. This paper examines the predicted and achieved suspension performance of a fully levitated prototype bearingless system.

  6. A Low-Profile Design for the Noncontact Ultrasonically Levitated Stage

    NASA Astrophysics Data System (ADS)

    Ide, Takeshi; Friend, James Robert; Nakamura, Kentaro; Ueha, Sadayuki

    2005-06-01

    In this paper, we propose a new low-profile design for a linear bearing based on Near-Field Acoustic Levitation (NFAL). Two flat beams at a 45° angle are used as a guide rail, and a slider is levitated by ultrasonic bending vibrations excited along the beams. The beams are excited by a pair of Langevin transducers with “+”-shaped vibration direction converters (L-L converters) to install the transducers in the same plane of the beam and to lower the total height of the setup. First, the design of the vibration converter is described. Then, a two-phase driving system to excite a traveling wave is investigated theoretically and experimentally. The levitation characteristics and the sliding performance of the prototype stage are measured and discussed.

  7. Raman acoustic levitation spectroscopy of red blood cells and Plasmodium falciparum trophozoites.

    PubMed

    Puskar, Ljiljana; Tuckermann, Rudolf; Frosch, Torsten; Popp, Jürgen; Ly, Vanalysa; McNaughton, Don; Wood, Bayden R

    2007-09-01

    Methods to probe the molecular structure of living cells are of paramount importance in understanding drug interactions and environmental influences in these complex dynamical systems. The coupling of an acoustic levitation device with a micro-Raman spectrometer provides a direct molecular probe of cellular chemistry in a containerless environment minimizing signal attenuation and eliminating the affects of adhesion to walls and interfaces. We show that the Raman acoustic levitation spectroscopic (RALS) approach can be used to monitor the heme dynamics of a levitated 5 microL suspension of red blood cells and to detect hemozoin in malaria infected cells. The spectra obtained have an excellent signal-to-noise ratio and demonstrate for the first time the utility of the technique as a diagnostic and monitoring tool for minute sample volumes of living animal cells. PMID:17713610

  8. Electrostatic Levitation of Plant Seeds and Flower Buds

    NASA Astrophysics Data System (ADS)

    Hu, Liang; Wang, Hai-Peng; Li, Liu-Hui; Wei, Bing-Bo

    2012-06-01

    We report the electrostatic levitation of various kinds of seeds and flower buds. Coral berry and pepper near a spherical shape show a stable levitation state. The prolate ellipsoid soybean and flower buds are always “standing" in the free space with satisfactory levitation stability. For the irregular mushroom and wheat grain, the levitation state is characterized as a “top-heavy" posture. These special stable equilibrium states are proved by the analysis of surface charge distribution. The obtained saturation polarization charge of samples presents a good accordance with experimental data. The levitation ability is weighed by the factor m(inr+2)/(inrD2).

  9. Particle manipulation by a non-resonant acoustic levitator

    SciTech Connect

    Andrade, Marco A. B.; Pérez, Nicolás; Adamowski, Julio C.

    2015-01-05

    We present the analysis of a non-resonant acoustic levitator, formed by an ultrasonic transducer and a concave reflector. In contrast to traditional levitators, the geometry presented herein does not require the separation distance between the transducer and the reflector to be a multiple of half wavelength. The levitator behavior is numerically predicted by applying a numerical model to calculate the acoustic pressure distribution and the Gor'kov theory to obtain the potential of the acoustic radiation force that acts on a levitated particle. We also demonstrate that levitating particles can be manipulated by controlling the reflector position while maintaining the transducer in a fixed position.

  10. Particle manipulation by a non-resonant acoustic levitator

    NASA Astrophysics Data System (ADS)

    Andrade, Marco A. B.; Pérez, Nicolás; Adamowski, Julio C.

    2015-01-01

    We present the analysis of a non-resonant acoustic levitator, formed by an ultrasonic transducer and a concave reflector. In contrast to traditional levitators, the geometry presented herein does not require the separation distance between the transducer and the reflector to be a multiple of half wavelength. The levitator behavior is numerically predicted by applying a numerical model to calculate the acoustic pressure distribution and the Gor'kov theory to obtain the potential of the acoustic radiation force that acts on a levitated particle. We also demonstrate that levitating particles can be manipulated by controlling the reflector position while maintaining the transducer in a fixed position.

  11. Electrodynamic vibration supression

    NASA Astrophysics Data System (ADS)

    Behrens, Sam; Fleming, Andrew J.; Moheimani, S. O. R.

    2003-07-01

    This paper introduces electromagnetic shunt damping (EMSD) which is similar to piezoelectric shunt damping. EMSD has four major advantages over piezoelectric shunt damping; simple transducer manufacturing, smaller shunt voltages, long stroke and larger control forces. A novel single mode shunt control strategy is validated through experimentation on a simple electromagnetic mass spring damper system. Theoretical results are also presented.

  12. Determining Equilibrium Position For Acoustical Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Aveni, G.; Putterman, S.; Rudnick, J.

    1989-01-01

    Equilibrium position and orientation of acoustically-levitated weightless object determined by calibration technique on Earth. From calibration data, possible to calculate equilibrium position and orientation in presence of Earth gravitation. Sample not levitated acoustically during calibration. Technique relies on Boltzmann-Ehrenfest adiabatic-invariance principle. One converts resonant-frequency-shift data into data on normalized acoustical potential energy. Minimum of energy occurs at equilibrium point. From gradients of acoustical potential energy, one calculates acoustical restoring force or torque on objects as function of deviation from equilibrium position or orientation.

  13. Acoustic levitating apparatus for submillimeter samples

    NASA Astrophysics Data System (ADS)

    Lee, M. C.; Feng, I.-A.

    1982-06-01

    A hemispherical focusing radiator has been employed to generate ultrahigh intensity sound waves in a gaseous medium at the center of curvature of the radiator (focal point) at 75, 107, and 163 kHz. A volumetric force is produced by optimally placing a reflector in the vicinity of the focal point to levitate samples of submillimeter sizes. It has been demonstrated that a sample with a specific gravity of 19.3 can be levitated with this apparatus. The lateral positional wandering of the sample in the force well is estimated at less than 5% of the dimension of the sample size used.

  14. Oscillational instabilities in single mode acoustics levitators

    NASA Technical Reports Server (NTRS)

    Rudnick, J.; Barmatz, Martin

    1990-01-01

    An extention of standard results for the acoustic force on an object in a single-mode resonant chamber yields predictions for the onset of oscillational instabilities when objects are levitated or positioned in these chambers. The authors' results are consistent with those of experimental investigators. The present approach accounts for the effects of time delays in the response of a cavity to the motion of an object inside of it. Quantitative features of the instabilities are investigated. The experimental conditions required for sample stability, saturation of sample oscillations, hysteretic effects, and the loss of ability to levitate are discussed.

  15. Acoustic levitating apparatus for submillimeter samples

    NASA Technical Reports Server (NTRS)

    Lee, M. C.; Feng, I.-A.

    1982-01-01

    A hemispherical focusing radiator has been employed to generate ultrahigh intensity sound waves in a gaseous medium at the center of curvature of the radiator (focal point) at 75, 107, and 163 kHz. A volumetric force is produced by optimally placing a reflector in the vicinity of the focal point to levitate samples of submillimeter sizes. It has been demonstrated that a sample with a specific gravity of 19.3 can be levitated with this apparatus. The lateral positional wandering of the sample in the force well is estimated at less than 5% of the dimension of the sample size used.

  16. High T sub c superconducting levitation motor with a laser commutator

    SciTech Connect

    Weeks, D.E. )

    1990-01-01

    A high {ital T}{sub {ital c}} superconducting levitation bearing driven by an optically switched solenoid is described. The bearing uses flux pinning in the new high {ital T}{sub {ital c}} superconductors for stability. A simple liquid nitrogen supply system is described that greatly improves the ease with which high {ital T}{sub {ital c}} superconductors can be maintained at 77 K for extended periods of time in small styrofoam dishes. A force versus height curve is given and is used to determine the design limits of the levitation bearing. Alternate motor designs are discussed.

  17. Some Considerations about Podolsky-Axionic Electrodynamics

    NASA Astrophysics Data System (ADS)

    Gaete, Patricio

    For a Podolsky-axionic electrodynamics, we compute the interaction potential within the structure of the gauge-invariant but path-dependent variables formalism. The result is equivalent to that of axionic electrodynamics from a new noncommutative approach, up to first-order in θ.

  18. Electrodynamics at the highest energies

    SciTech Connect

    Klein, Spencer R.

    2002-06-17

    At very high energies, the bremsstrahlung and pair production cross sections exhibit complex behavior due to the material in which the interactions occur. The cross sections in dense media can be dramatically different than for isolated atoms. This writeup discusses these in-medium effects, emphasizing how the cross section has different energy and target density dependencies in different regimes. Data from SLAC experiment E-146 will be presented to confirm the energy and density scaling. Finally, QCD analogs of the electrodynamics effects will be discussed.

  19. Quantum Electrodynamics for Vector Mesons

    SciTech Connect

    Djukanovic, Dalibor; Schindler, Matthias R.; Scherer, Stefan; Gegelia, Jambul

    2005-07-01

    Quantum electrodynamics for {rho} mesons is considered. It is shown that, at the tree level, the value of the gyromagnetic ratio of the {rho}{sup +} is fixed to 2 in a self-consistent effective quantum field theory. Further, the mixing parameter of the photon and the neutral vector meson is equal to the ratio of electromagnetic and strong couplings, leading to the mass difference M{sub {rho}}{sub {sup 0}}-M{sub {rho}}{sub {sup {+-}}}{approx}1 MeV at tree order.

  20. A model of nonlinear electrodynamics

    SciTech Connect

    Kruglov, S.I.

    2015-02-15

    A new model of nonlinear electrodynamics with two parameters is investigated. We also consider a model with one dimensional parameter. It was shown that the electric field of a point-like charge is not singular at the origin and there is the finiteness of the static electric energy of point-like charged particle. We obtain the canonical and symmetrical Belinfante energy–momentum tensors and dilatation currents. It is demonstrated that the dilatation symmetry and dual symmetry are broken in the models suggested. We have calculated the static electric energy of point-like particles.

  1. Ultrathin metallic coatings can induce quantum levitation between nanosurfaces

    NASA Astrophysics Data System (ADS)

    Boström, Mathias; Ninham, Barry W.; Brevik, Iver; Persson, Clas; Parsons, Drew F.; Sernelius, Bo E.

    2012-06-01

    There is an attractive Casimir-Lifshitz force between two silica surfaces in a liquid (bromobenze or toluene). We demonstrate that adding an ultrathin (5-50 Å) metallic nanocoating to one of the surfaces results in repulsive Casimir-Lifshitz forces above a critical separation. The onset of such quantum levitation comes at decreasing separations as the film thickness decreases. Remarkably, the effect of retardation can turn attraction into repulsion. From that we explain how an ultrathin metallic coating may prevent nanoelectromechanical systems from crashing together.

  2. Electrodynamic convection in silicon floating zones

    NASA Astrophysics Data System (ADS)

    Mühlbauer, A.; Erdmann, W.; Keller, W.

    1983-12-01

    Using a simplified Navier-Stokes equation it has been possible to compute the electrodynamic convection generated by a radio frequency coil field for the modern needle-eye float-zone growth of silicon. The calculated electrodynamic force in such a zone shows maximum values up to 11.7 N/cm 3 and generates flow velocities between 25 and 100 cm/s. As only superficial convection can be brought about by electrodynamic forces, the axial and radial dopant incorporation will not be influenced strongly. A comparison of electrodynamic forces with the other forces possibly causing flow in silicon floating zones shows that the electrodynamic forces exceed all other forces by several orders of magnitude.

  3. A numerical simulation of auroral ionospheric electrodynamics

    NASA Technical Reports Server (NTRS)

    Mallinckrodt, A. J.

    1985-01-01

    A computer simulation of auroral ionospheric electrodynamics in the altitude range 80 to 250 km has been developed. The routine will either simulate typical electron precipitation profiles or accept observed data. Using a model background ionosphere, ion production rates are calculated from which equilibrium electron densities and the Hall and Pedersen conductivities may be determined. With the specification of suitable boundary conditions, the entire three-dimensional current system and electric field may be calculated within the simulation region. The results of the application of the routine to a typical inverted-V precipitation profile are demonstrated. The routine is used to explore the observed anticorrelation between electric field magnitude and peak energy in the precipitating electron spectrum of an auroral arc.

  4. Electrodynamics of the Getaway Tether Experiment

    NASA Technical Reports Server (NTRS)

    Greene, Michael; Baginski, Michael; Wheelock, Douglas

    1989-01-01

    An electrodynamic circuit model of the interaction of a pair of small tethered satellites and the ionosphere is developed and analyzed. The system under study, the Getaway Tether Experiment (GATE), is composed of two small satellites and 1 km of insulated conducting tether. The nonlinear model has elements representing the emission, collection, and resistive flow of charge through an electrically conductive tether, plasma contactors, and the ionosphere. The circuit model is incorporated into a dynamic orbital simulation to predict mission performance. Simulation results show the feasibility to bilaterally transfer energy between stored electrical energy and orbital momentum. A transient model is also developed using the circuit model and a string of N lumped-parameter modules, each consisting of resistance, capacitance, and induced potential for the tether. Transients are shown via simulation to occur over millisecond intervals.

  5. Research on Orbital Plasma Electrodynamics (ROPE)

    NASA Technical Reports Server (NTRS)

    Intriligator, Devrie S.

    1998-01-01

    This final report summarizes some of the important scientific contributions to the Research on Orbital Plasma Electrodynamics (ROPE) investigation, to the Tethered Satellite System (TSS) mission, and to NASA that resulted from the work carried out under this contract at Carmel Research Center. These include Dr. Intriligator's participation in the PIT for the TSS-1R simulations and flight, her participation in ROPE team meetings and IWG meetings, her scientific analyses, and her writing and submitting technical papers to scientific journals. The scientific analyses concentrated on the characterization of energetic ions and their possible relation to pickup ion effects, correlation of particle and other effects (e.g., magnetic field, satellite surface), and collaboration with theorists including with ROPE co-investigators. In addition, scientific analyses were carried out of the effects due to satellite gas releases.

  6. Thickness dependence of the levitation performance of double-layer high-temperature superconductor bulks above a magnetic rail

    NASA Astrophysics Data System (ADS)

    Sun, R. X.; Zheng, J.; Liao, X. L.; Che, T.; Gou, Y. F.; He, D. B.; Deng, Z. G.

    2014-10-01

    A double-layer high-temperature superconductor (HTSC) arrangement was proposed and proved to be able to bring improvements to both levitation force and guidance force compared with present single-layer HTSC arrangement. To fully exploit the applied magnetic field by a magnetic rail, the thickness dependence of a double-layer HTSC arrangement on the levitation performance was further investigated in the paper. In this study, the lower-layer bulk was polished step by step to different thicknesses, and the upper-layer bulk with constant thickness was directly superimposed on the lower-layer one. The levitation force and the force relaxation of the double-layer HTSC arrangement were measured above a Halbach magnetic rail. Experimental result shows that a bigger levitation force and a less levitation force decay could be achieved by optimizing the thickness of the lower-layer bulk HTSC. This thickness optimization method could be applied together with former reported double-layer HTSC arrangement method with aligned growth sector boundaries pattern. This series of study on the optimized combination method do bring a significant improvement on the levitation performance of present HTS maglev systems.

  7. Aspects of passive magnetic levitation based on high-T{sub c} superconducting YBCO thin films

    SciTech Connect

    Schoenhuber, P.; Moon, F.C.

    1995-04-01

    Passive magnetic levitation systems reported in the past were mostly confined to bulk superconducting materials. Here the authors present fundamental studies on magnetic levitation employing cylindrical permanent magnets floating above high-T{sub c} superconducting YBCO thin films (thickness about 0.3 mu m). Experiments included free floating rotating magnets as well as well-established flexible beam methods. By means of the latter, the authors investigated levitation and drag force hysteresis as well as magnetic stiffness properties of the superconductor-magnet arrangement. In the case of vertical motion of the magnet, characteristic high symmetry of repulsive (approaching) and attractive (withdrawing) branches of the pronounced force-displacement hysteresis could be detected. Achievable force levels were low as expected but sufficient for levitation of permanent magnets. With regard to magnetic stiffness, thin films proved to show stiffness-force ratios about one order of magnitude higher than bulk materials. Phenomenological models support the measurements. Regarding the magnetic hysteresis of the superconductor, the Irie-Yamafuji model was used for solving the equation of force balance in cylindrical coordinates allowing for a macroscopic description of the superconductor magnetization. This procedure provided good agreement with experimental levitation force and stiffness data during vertical motion. For the case of (lateral) drag force basic qualitative characteristics could be recovered, too. It is shown that models, based on simple asymmetric magnetization of the superconductor, describe well asymptotic transition of drag forces after the change of the magnet motion direction. Virgin curves (starting from equilibrium, i.e. symmetric magnetization) are approximated by a linear approach already reported in literature only. This paper shows that basic properties of superconducting thin films allow for their application to magnetic levitation.

  8. Electrodynamic radioactivity detector for microparticles

    NASA Astrophysics Data System (ADS)

    Ward, T. L.; Davis, E. J.; Jenkins, R. W., Jr.; McRae, D. D.

    1989-03-01

    A new technique for the measurement of the radioactive decay of single microparticles has been demonstrated. Although the experiments were made with droplets of order 20 μm in diameter, microparticles in the range 0.1-100 μm can be accommodated. An electrodynamic balance and combination light-scattering photometer were used to measure the charge-loss rate and size of a charged microsphere suspended in a laser beam by superposed ac and dc electrical fields. The charged particle undergoes charge loss in the partially ionized gas atmosphere which results from radioactive decay of 14C-tagged compounds, and the rate of charge loss is proportional to the rate of decay here. The charge on a particle was determined by measuring the dc voltage necessary to stably suspend the particle against gravity while simultaneously determining the droplet size by light-scattering techniques. The parameters which affect the operation of the electrodynamic balance as a radioactivity detector are examined, and the limits of its sensitivity are explored. Radioactivity levels as low as 120 pCi have been measured, and it appears that by reducing the background contamination inside our balance activity levels on the order of 10 pCi can be detected. This new technique has application in the measurement of activity levels and source discrimination of natural and man-made aerosols and smokes and is also useful for studies involving specifically labeled radio-chemical probes.

  9. Architecture dependence of photon antibunching in cavity quantum electrodynamics

    NASA Astrophysics Data System (ADS)

    Bradford, Matthew; Shen, Jung-Tsung

    2015-08-01

    We investigate numerically the architecture dependence of the characteristics of antibunched photons generated in cavity quantum electrodynamic systems. We show that the quality of antibunching [the smallness of the second-order intensity correlation function at zero time g(2 )(0 ) ] and the generation efficiency significantly depend on the configurations: the arrangements of single-mode optical cavities and waveguides. We found that for certain class of architecture, when the Jaynes-Cummings system (the atom-cavity system) couples to two terminated waveguides, there exists a fundamental tradeoff between high transmission and low g(2 )(0 ) , and is sensitive to dissipation. We further show that optimal antibunching can be achieved in two alternative cavity quantum electrodynamic configurations operating in the dissipatively weak coupling regime such that the two-photon transmission can be two orders of magnitude higher for the same g(2 )(0 ) .

  10. Apparatus and method for aerodynamic levitation

    NASA Technical Reports Server (NTRS)

    Williamson, John W. (Inventor); al-Darwish, Mohamad M. (Inventor); Cashen, Grant E. (Inventor)

    1993-01-01

    An apparatus for the levitation of a liquid drop by a fluid flow comprising a profile generator, a fluid flow supply means operatively connected to the profile generator. The profile generator includes an elongate cylindrical shell in which is contained a profiling means for configuring the velocity profile of the fluid flow exiting the profile generator.

  11. Levitating a Magnet Using a Superconductive Material.

    ERIC Educational Resources Information Center

    Juergens, Frederick H.; And Others

    1987-01-01

    Presented are the materials and a procedure for demonstrating the levitation of a magnet above a superconducting material. The demonstration can be projected with an overhead projector for a large group of students. Kits to simplify the demonstration can be purchased from the Institute for Chemical Education of the University of Wisconsin-Madison.…

  12. Precise Fabrication of Electromagnetic-Levitation Coils

    NASA Technical Reports Server (NTRS)

    Ethridge, E.; Curreri, P.; Theiss, J.; Abbaschian, G.

    1985-01-01

    Winding copper tubing on jig ensures reproducible performance. Sequence of steps insures consistent fabrication of levitation-and-melting coils. New method enables technician to produce eight coils per day, 95 percent of them acceptable. Method employs precise step-by-step procedure on specially designed wrapping and winding jig.

  13. Reducing Thermal Conduction In Acoustic Levitators

    NASA Technical Reports Server (NTRS)

    Lierke, Ernst G.; Leung, Emily W.; Bhat, Balakrishna T.

    1991-01-01

    Acoustic transducers containing piezoelectric driving elements made more resistant to heat by reduction of effective thermal-conductance cross sections of metal vibration-transmitting rods in them, according to proposal. Used to levitate small objects acoustically for noncontact processing in furnaces. Reductions in cross sections increase amplitudes of transmitted vibrations and reduce loss of heat from furnaces.

  14. Blowing Polymer Bubbles in an Acoustic Levitator

    NASA Technical Reports Server (NTRS)

    Lee, M. C.

    1985-01-01

    In new manufacturing process, small gas-filled polymer shells made by injecting gas directly into acoustically levitated prepolymer drops. New process allows sufficient time for precise control of shell geometry. Applications foreseen in fabrication of deuterium/tritium-filled fusion targets and in pharmaceutical coatings. New process also useful in glass blowing and blow molding.

  15. Magnetic Levitational Assembly for Living Material Fabrication.

    PubMed

    Tasoglu, Savas; Yu, Chu Hsiang; Liaudanskaya, Volha; Guven, Sinan; Migliaresi, Claudio; Demirci, Utkan

    2015-07-15

    Functional living materials with microscale compositional topographies are prevalent in nature. However, the creation of biomaterials composed of living micro building blocks, each programmed by composition, functionality, and shape, is still a challenge. A powerful yet simple approach to create living materials using a levitation-based magnetic method is presented. PMID:25872008

  16. Levitated crystals and quasicrystals of metamaterials

    SciTech Connect

    Wang, Zhehui; Morris, Christopher; Goree, John A

    2012-07-25

    New scientific and technological opportunities exist by marrying dusty plasma research with metamaterials. Specifically, by balancing control and self-assembly, certain laboratory plasmas can become a generic levitation platform for novel structure formation and nanomaterial synthesis. We propose to experimentally investigate two dimensional (2D) and three dimensional (3D) levitated structures of metamaterials and their properties. Such structures can self assemble in laboratory plasmas, similar to levitated dust crystals which were discovered in the mid 1990's. Laboratory plasma platform for metamaterial formation eliminates substrates upon which most metamaterials have to be supported. Three types of experiments, with similar setups, are discussed here. Levitated crystal structures of metamaterials using anisotropic microparticles are the most basic of the three. The second experiment examines whether quasicrystals of metamaterials are possible. Quasicrystals, discovered in the 1980's, possess so-called forbidden symmetries according to the conventional crystallography. The proposed experiment could answer many fundamental questions about structural, thermal and dynamical properties of quasicrystals. And finally, how to use nanoparticle coated microparticles to synthesize very long carbon nanotubes is also described. All of the experiments can fit inside a standard International Space Station locker with dimensions of 8-inch x 17-inch X 18-inch. Microgravity environment is deemed essential in particular for large 3D structures and very long carbon nanotube synthesis.

  17. Dynamic performance of a magnetic levitation haptic device

    NASA Astrophysics Data System (ADS)

    Berkelman, Peter; Hollis, Ralph L.

    1997-12-01

    A new haptic interface device has been developed which uses Lorentz force magnetic levitation for actuation. With this device, the user grasps a floating rigid body to interact with the system. The levitated moving part grasped by the user contains curved oval wound coils and LEDs embedded in a hemispherical shell with a handle fixed at its center. The stationary base contains magnet assemblies facing the flotor coils and optical position sensors facing the flotor LEDs. The device is mounted in the top cover of a desk-side cabinet enclosure containing all the amplifiers, control hardware, microprocessing, and power supplies needed for operation. A network connection provides communication with a workstation to allow interaction with simulated 3D environments in real time. Ideally, the haptic interface device should reproduce the dynamics of the modelled or remote environment with such high fidelity that the user cannot distinguish interaction with the device from interaction with a real object in a real environment. In practice, this ideal can only be approached with a fidelity that depends on its dynamic properties such as position and force bandwidths, maximum forces and accelerations, position resolution, and realizable impedance range. The motion range of the moving part is approximately 25 mm and 15 - 20 degrees in all directions. A current of 0.75 A is required in three of the six coils to generate the vertical force to lift the 850 g levitated mass, dissipating only 13.5 W. Peak forces of over 50 N and torques of over 6 Nm are achievable with the present amplifiers without overheating the actuator coils. Other measured performance results include stiffness ranges from 0.005 N/mm to 25.0 N/mm and a position control bandwidth of approximately 75 Hz.

  18. Atmospheric electrodynamics in the U.S. - 1987-1990

    NASA Technical Reports Server (NTRS)

    Holzworth, R. H.

    1991-01-01

    Atmospheric electrodynamics research is summarized, focusing on three general areas: the ionosphere as a source for middle atmospheric electrodynamics, regional and global scale electrodynamics, and thunderstorms and lightning. New or improved instrumentation techniques which have furthered atmospheric electrodynamics research are also discussed.

  19. Electrodynamic studies of upper and lower atmospheric coupling

    NASA Technical Reports Server (NTRS)

    Chiu, Y. T.; Cornwall, J. M.; Edgar, B. C.; Schulz, M.; Sharp, L. R.

    1981-01-01

    Theoretical interprotations and data interpretations of electrodynamical studies in upper and lower atmosphere coupling are reported. The following topics are discussed: (1) magnetosphere/ionosphere/atmosphere coupling in auroral electrodynamics; (2) middle atmosphere electrodynamics; (3) thermosphere troposphere coupling; and (4) tropospheric electrodynamics. Understanding of the near Earth space environment shows the interrelationships between various components of the Earth's atmosphere.

  20. Atmospheric electrodynamics in the U. S. - 1987-1990

    SciTech Connect

    Holzworth, R.H. )

    1991-01-01

    Atmospheric electrodynamics research is summarized, focusing on three general areas: the ionosphere as a source for middle atmospheric electrodynamics, regional and global scale electrodynamics, and thunderstorms and lightning. New or improved instrumentation techniques which have furthered atmospheric electrodynamics research are also discussed. 93 refs.

  1. Electrodynamics of ionospheric weather over low latitudes

    NASA Astrophysics Data System (ADS)

    Abdu, Mangalathayil Ali

    2016-12-01

    The dynamic state of the ionosphere at low latitudes is largely controlled by electric fields originating from dynamo actions by atmospheric waves propagating from below and the solar wind-magnetosphere interaction from above. These electric fields cause structuring of the ionosphere in wide ranging spatial and temporal scales that impact on space-based communication and navigation systems constituting an important segment of our technology-based day-to-day lives. The largest of the ionosphere structures, the equatorial ionization anomaly, with global maximum of plasma densities can cause propagation delays on the GNSS signals. The sunset electrodynamics is responsible for the generation of plasma bubble wide spectrum irregularities that can cause scintillation or even disruptions of satellite communication/navigation signals. Driven basically by upward propagating tides, these electric fields can suffer significant modulations from perturbation winds due to gravity waves, planetary/Kelvin waves, and non-migrating tides, as recent observational and modeling results have demonstrated. The changing state of the plasma distribution arising from these highly variable electric fields constitutes an important component of the ionospheric weather disturbances. Another, often dominating, component arises from solar disturbances when coronal mass ejection (CME) interaction with the earth's magnetosphere results in energy transport to low latitudes in the form of storm time prompt penetration electric fields and thermospheric disturbance winds. As a result, drastic modifications can occur in the form of layer restructuring (Es-, F3 layers etc.), large total electron content (TEC) enhancements, equatorial ionization anomaly (EIA) latitudinal expansion/contraction, anomalous polarization electric fields/vertical drifts, enhanced growth/suppression of plasma structuring, etc. A brief review of our current understanding of the ionospheric weather variations and the

  2. The power of magnetic levitation-Part 2; Is magnetic transportation in the future

    SciTech Connect

    Moon, F.C. . Sibley School of Mechanical and Aerospace Engineering)

    1990-01-01

    This article discusses how new magnetic-levitation (MAGLEV) transportation technologies can be used to relieve airport congestion. New superconducting materials may improve the cost/benefits ratio for some MAGLEV systems. According to the author, postponement of research in MAGLEV technology in the United States will mean the loss of jobs and worsening trade balances near the end of the decade.

  3. Radiative Levitation in Hot White Dwarfs

    NASA Astrophysics Data System (ADS)

    Chayer, P.; Fontaine, G.; Wesemael, F.

    1994-12-01

    We present the results of detailed calculations of radiative levitation in hot white dwarfs using the extensive and homogeneous atomic data given in TOPBASE. Radiative accelerations and equilibrium abundances have been computed for C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, and Fe on grids of pure hydrogen and pure helium stellar envelope models. The DA model grid has log g = 7.0, 7.5, 8.0, and 8.5, and spans the range of effective temperature 100,000 >= Teff >= 20,000 K in steps of 2,500 K. The DO/DB grid is similar but extends to Teff = 130,000 K. We discuss at some length the input physics used in order to provide a good physical understanding of radiative levitation under white dwarf conditions. We also discuss the depth dependence and the morphology of the reservoirs of levitating elements created by an equilibrium between the radiative acceleration and the local effective gravity in various stellar envelopes. The important role played in the morphology of the reservoirs by dominant ionization states in closed-shell electronic configurations is emphasized. Our central results are presented in the form of figures showing the behavior of the expected photospheric abundance of each element as a function of effective temperature and surface gravity. While only a handful of abundances are available from the few analyses of observations that have been carried out, we are nevertheless able to infer through a detailed comparison that equilibrium radiative levitation theory fails to explain the observed abundance patterns of heavy elements in hot white dwarfs. At least one other mechanism must be competing with radiative levitation and gravitational settling in the atmospheres/envelopes of hot white dwarfs. Finally, we indicate promising avenues for further progress in spectral evolution theory for white dwarfs. This work has been supported by NASA contract NAS5-30180.

  4. Electrodynamic Tether as a Thruster for LEO Mission Applications

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V; Krivorutsky, E. N.; Johnson, L.

    2006-01-01

    Electrodynamic tether propulsion has a number of attractive features and has been widely discussed for different low earth orbit applications. Despite the commonality of application, the choice of the proper design for any particular mission is a unique problem. The flight trajectory, duration, available power and voltage, and drag force should be taken into consideration with other mission requirements. Characteristics of tether performance such as system acceleration and electrical efficiency should be calculated and assessed based on the system's capability to collect electrical current. We discuss the choice of parameters for circular, tape, and grid-sphere tether anodes and their applicability to International Space Station (ISS) reboost and Momentum Exchange Electrodynamic Reboost (MXER) applications.

  5. Electrodynamic Tether Propulsion and Power Generation at Jupiter

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Johnson, L.; Moore, J.; Bagenal, F.

    1998-01-01

    The results of a study performed to evaluate the feasibility and merits of using an electrodynamic tether for propulsion and power generation for a spacecraft in the Jovian system are presented. The environment of the Jovian system has properties which are particularly favorable for utilization of an electrodynamic tether. Specifically, the planet has a strong magnetic field and the mass of the planet dictates high orbital velocities which, when combined with the planet's rapid rotation rate, can produce very large relative velocities between the magnetic field and the spacecraft. In a circular orbit close to the planet, tether propulsive forces are found to be as high as 50 N and power levels as high as 1 MW.

  6. Primordial magnetic fields and nonlinear electrodynamics

    SciTech Connect

    Kunze, Kerstin E.

    2008-01-15

    The creation of large scale magnetic fields is studied in an inflationary universe where electrodynamics is assumed to be nonlinear. After inflation ends electrodynamics becomes linear and thus the description of reheating and the subsequent radiation dominated stage are unaltered. The nonlinear regime of electrodynamics is described by Lagrangians having a power-law dependence on one of the invariants of the electromagnetic field. It is found that there is a range of parameters for which primordial magnetic fields of cosmologically interesting strengths can be created.

  7. Axion electrodynamics and nonrelativistic photons in nuclear and quark matter

    NASA Astrophysics Data System (ADS)

    Yamamoto, Naoki

    2016-04-01

    We argue that the effective theory for electromagnetic fields in spatially varying meson condensations in dense nuclear and quark matter is given by the axion electrodynamics. We show that one of the helicity states of photons there has the nonrelativistic gapless dispersion relation ω ˜k2 at small momentum, while the other is gapped. This "nonrelativistic photon" may also be realized at the interface between topological and trivial insulators in condensed matter systems.

  8. Fluctuational electrodynamics of hyperbolic metamaterials

    SciTech Connect

    Guo, Yu; Jacob, Zubin

    2014-06-21

    We give a detailed account of equilibrium and non-equilibrium fluctuational electrodynamics of hyperbolic metamaterials. We show the unifying aspects of two different approaches; one utilizes the second kind of fluctuation dissipation theorem and the other makes use of the scattering method. We analyze the near-field of hyperbolic media at finite temperatures and show that the lack of spatial coherence can be attributed to the multi-modal nature of super-Planckian thermal emission. We also adopt the analysis to phonon-polaritonic super-lattice metamaterials and describe the regimes suitable for experimental verification of our predicted effects. The results reveal that far-field thermal emission spectra are dominated by epsilon-near-zero and epsilon-near-pole responses as expected from Kirchoff's laws. Our work should aid both theorists and experimentalists to study complex media and engineer equilibrium and non-equilibrium fluctuations for applications in thermal photonics.

  9. Observations on the Freezing of Supercooled Pollen Washing Water by a New Electrodynamic Balance

    NASA Astrophysics Data System (ADS)

    Tong, Haijie; Pope, Francis D.; Kalberer, Markus

    2014-05-01

    Primary biological particles can act as efficient ice nuclei (IN) by initiating freezing events at temperatures warmer than the homogenous freezing temperature [1, 2]. For example, pollen grain particles can trigger freezing events at temperatures as warm as -5 °C in the contact freezing mode [3]. More recently pollen residues, which are released by washing pollen grains in water, were also observed to act as efficient IN in the immersion mode [4, 5]. In this study we developed a new cold electrodynamic balance (CEDB) system and investigated the freezing properties of single particles of supercooled pollen washing water (SPWW). The EDB technique allows for a contact free measurement of freezing events. The phase of the particle (liquid or frozen solid) can be distinguished via measuring the Mie scattering signal from the particle. Furthermore the size of liquid (spherical) particles can be determined. The freezing events are characterized through the loss of the regular Mie scattering signal from the levitated droplet as it changes state from liquid to a frozen solid. The statistical freezing probabilities of SPWW were obtained in the temperature range: -15 to -40 °C. Each temperature measurement point consists of the analysis of 30-100 droplets. Preliminary conclusions are that SPWW is IN active in the immersion mode. Further discussion will focus on the temperature range of the IN activity, the important variables (other than temperature) for IN activity, other likely modes of IN activity, and the implications of these results in terms of the atmospheric relevance of SPWW. This study was supported by the NERC. We acknowledge Professor Jonathan Reid and James Davis from the University of Bristol for providing information of the design of the warm EDB system. References: [1] Möhler, O., et al. (2007) Biogeosciences, 4, 1059-1071. [2] Prenni, A. J., et al. (2009) Nat. Geosci., 2, 401-404. [3] Diehl, K., et al. (2002) Atmos. Res., 61, 125-133. [4] Pummer, B. G

  10. On the slow dynamics of near-field acoustically levitated objects under High excitation frequencies

    NASA Astrophysics Data System (ADS)

    Ilssar, Dotan; Bucher, Izhak

    2015-10-01

    This paper introduces a simplified analytical model describing the governing dynamics of near-field acoustically levitated objects. The simplification converts the equation of motion coupled with the partial differential equation of a compressible fluid, into a compact, second order ordinary differential equation, where the local stiffness and damping are transparent. The simplified model allows one to more easily analyse and design near-field acoustic levitation based systems, and it also helps to devise closed-loop controller algorithms for such systems. Near-field acoustic levitation employs fast ultrasonic vibrations of a driving surface and exploits the viscosity and the compressibility of a gaseous medium to achieve average, load carrying pressure. It is demonstrated that the slow dynamics dominates the transient behaviour, while the time-scale associated with the fast, ultrasonic excitation has a small presence in the oscillations of the levitated object. Indeed, the present paper formulates the slow dynamics under an ultrasonic excitation without the need to explicitly consider the latter. The simplified model is compared with a numerical scheme based on Reynolds equation and with experiments, both showing reasonably good results.

  11. Thermal levitation of 10 um size particles in low vacuum

    NASA Astrophysics Data System (ADS)

    Fung, Long Fung Frankie; Kowalski, Nicholas; Parker, Colin; Chin, Cheng

    2016-05-01

    We report on experimental methods for trapping 10 micron-sized ice, glass, ceramic and polyethylene particles with thermophoresis in medium vacuum, at pressures between 5 Torr and 25 Torr. Under appropriate conditions particles can launch and levitate robustly for up to an hour. We describe the experimental setup used to produce the temperature gradient necessary for the levitation, as well as our procedure for generating and introducing ice into the experimental setup. In addition to analyzing the conditions necessary for levitation, and the dependence of levitation on the experimental parameters, we report on the behavior of particles during levitation and ejection, including position and stability, under different pressures and temperatures. We also note a significant discrepancy between theory and data, suggesting the presence of other levitating forces.

  12. Containerless Processing Studies in the MSFC Electrostatic Levitator

    NASA Technical Reports Server (NTRS)

    Rogers, J. R.; SanSoucie, M. P.

    2012-01-01

    Levitation or containerless processing represents an important tool in materials research. Levitated specimens are free from contact with a container, which permits studies of deeply undercooled melts, and high-temperature, highly reactive materials. Containerless processing provides data for studies of thermophysical properties, phase equilibria, metastable state formation, microstructure formation, undercooling, and nucleation. Levitation techniques include: acoustic, aero-acoustic, electromagnetic, and electrostatic. In microgravity, levitation can be achieved with greatly reduced positioning forces. Microgravity also reduces the effects of buoyancy and sedimentation in melts. The European Space Agency (ESA) and the German Aerospace Center (DLR) jointly developed an electromagnetic levitator facility (MSL-EML) for containerless materials processing in space. The MSL-EML will be accommodated in the European Columbus Facility on the International Space Station (ISS). The electrostatic levitator (ESL) facility at the Marshall Space Flight Center provides support for the development of containerless processing studies for the ISS. The capabilities of the facility and recent results will be discussed.

  13. Theoretical and experimental examination of near-field acoustic levitation.

    PubMed

    Nomura, Hideyuki; Kamakura, Tomoo; Matsuda, Kazuhisa

    2002-04-01

    A planar object can be levitated stably close to a piston sound source by making use of acoustic radiation pressure. This phenomenon is called near-field acoustic levitation [Y. Hashimoto et al., J. Acoust. Soc. Am. 100, 2057-2061 (1996)]. In the present article, the levitation distance is predicted theoretically by numerically solving basic equations in a compressible viscous fluid subject to the appropriate initial and boundary conditions. Additionally, experiments are carried out using a 19.5-kHz piston source with a 40-mm aperture and various aluminum disks of different sizes. The measured levitation distance agrees well with the theory, which is different from a conventional theory, and the levitation distance is not inversely proportional to the square root of the surface density of the levitated disk in a strict sense. PMID:12002842

  14. Analysis of a Non-resonant Ultrasonic Levitation Device

    NASA Astrophysics Data System (ADS)

    Andrade, Marco A. B.; Pérez, Nicolás; Adamowski, Julio C.

    In this study, a non-resonant configuration of ultrasonic levitation device is presented, which is formed by a small diameter ultrasonic transducer and a concave reflector. The influence of different levitator parameters on the levitation performance is investigated by using a numerical model that combines the Gor'kov theory with a matrix method based on the Rayleigh integral. In contrast with traditional acoustic levitators, the non-resonant ultrasonic levitation device allows the separation distance between the transducer and the reflector to be adjusted continually, without requiring the separation distance to be set to a multiple of half-wavelength. It is also demonstrated, both numerically and experimentally, that the levitating particle can be manipulated by maintaining the transducer in a fixed position in space and moving the reflector in respect to the transducer.

  15. Promotion of alpha-cyano-4-hydroxycinnamic acid and peptide cocrystallization within levitated droplets with net charge.

    PubMed

    Bogan, Michael J; Bakhoum, Samuel F W; Agnes, George R

    2005-02-01

    Many reactions occur as a result of charge imbalance within or between reactive species in reaction vessels that have zero net charge. Here, chemical processes taking place within reaction vessels having net excess charge were studied. For mass spectroscopists, a familiar example of vessels that defy electroneutrality are the charged droplets produced by an electrospray ion source. Evidence is presented that control of the magnitude of the net charge contained in a reaction vessel, in this case a levitated droplet, can be used to promote nucleation and crystal growth of a mixture of an organic acid, alpha-cyano-4-hydroxycinnamic acid (CHCA), with one or more peptides. This phenomenon was first observed during our ongoing development of wall-less sample preparation (WaSP), electrodynamic charged droplet processing methodology capable of creating micrometer-sized sample spots for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) from subnanoliter volumes of sample material. Peptide ion signal-to-noise (S/N) ratios obtained by MALDI-TOF-MS from sample spots created from droplets that had high relative magnitude of net charge were consistently greater than those detected from sample spots created from droplets that had lower net charge. To study this unexpected phenomenon further, WaSP methodology was developed to process different mass-to-charge (m/z) droplets levitated in an electrodynamic balance (EDB), facilitating their deposition onto different positions of a target to create arrays of droplet residues ordered from highest to lowest m/z. This capability allowed simultaneous levitation with subsequent separation of a population of droplets created from a single starting solution, but the droplets had varied magnitudes of net charge. After the droplets were ejected from the EDB and collected on a glass slide or MALDI plate, the solids contained in the deposited droplets were characterized using microscopy and MALDI

  16. The unconventional electrodynamics of high {Tc} and organic superconductors

    SciTech Connect

    Timusk, T.; Cao, N.; Basov, D.N.; Homes, C.C.

    1996-12-31

    The combination of lowered dimensionality and electron-electron correlations are responsible for the unusual temperature and frequency dependence of the electrical conductivity of the new superconductors. The authors first review the electrodynamics of two systems, U{sub 2}Ru{sub 2}Si{sub 2} and Sr{sub 2}RuO{sub 4} where conventional Fermi liquid ideas seem to work. Here transport is by free carriers with strongly renormalized masses. On the other hand the electrodynamics of the high {Tc} cuprates and the organic charge transfer salts is unconventional. The high {Tc}`s show a Drude peak with an anomalous temperature and frequency dependent scattering rate for the in-plane conductivity, while normal to the planes they are almost insulating. In the organics, the transport currents are carried by a narrow collective mode coupled to phonons. 44 refs., 7 figs.

  17. Electrodynamic Maglev coil design and analysis

    SciTech Connect

    Davey, K.R.

    1997-09-01

    Electrodynamic Maglev systems are distinguished from electromagnetic systems in that the currents yielding lift and guidance forces are induced by the movement of the vehicle. Above a threshold speed, such a system is inherently stable, and has the additional benefit of having greater flexibility to system construction tolerances in that the magnet vertical position can change by as much as 5 cm. A stacked magnet design is considered which couples into a set of interleave coils which are interconnected in such a way as to yield both lift and guidance forces. A mutual coupling analysis is embraced wherein the mutual inductance between the permanent magnets on board the vehicle and the coils are computed using closed form analytical expressions for filaments. The derivatives of these expressions are then averaged to compute both the induced current and the forces on the coils as a function of the system geometry and speed. A full transient analysis must be performed to accurately account for entry and exit effects. The results are compared to those experimentally measured on a test track and extrapolations are offered to suggest future design considerations.

  18. Optical levitation of a microdroplet containing a single quantum dot.

    PubMed

    Minowa, Yosuke; Kawai, Ryoichi; Ashida, Masaaki

    2015-03-15

    We demonstrate the optical levitation or trapping in helium gas of a single quantum dot (QD) within a liquid droplet. Bright single photon emission from the levitated QD in the droplet was observed for more than 200 s. The observed photon count rates are consistent with the value theoretically estimated from the two-photon-action cross section. This Letter presents the realization of an optically levitated solid-state quantum emitter. PMID:25768143

  19. Electromagnetic levitation coil fabrication technique for MSFC containerless processing facilities

    NASA Technical Reports Server (NTRS)

    Ethridge, E. C.; Theiss, J.; Curreri, P. A.; Abbaschian, G. J.

    1983-01-01

    A technique is described for more reproducible fabrication of electromagnetic levitation coils. A split mandrel was developed upon which the coil is wound. After fabrication the mandrel can be disassembled to remove it from the coil. Previously, a full day was required to fabricate a levitation coil and the success rate for a functional coil was only 50 percent. About eight coils may be completed in one day using the technique developed and 95 percent of them are good levitation coils.

  20. Non-contact transportation using near-field acoustic levitation

    PubMed

    Ueha; Hashimoto; Koike

    2000-03-01

    Near-field acoustic levitation, where planar objects 10 kg in weight can levitate stably near the vibrating plate, is successfully applied both to non-contact transportation of objects and to a non-contact ultrasonic motor. Transporting apparatuses and an ultrasonic motor have been fabricated and their characteristics measured. The theory of near-field acoustic levitation both for a piston-like sound source and a flexural vibration source is also briefly described. PMID:10829622

  1. Levitation of a magnet by an alternating magnetic field

    NASA Astrophysics Data System (ADS)

    Gough, W.; Hunt, M. O.; Summerskill, W. S. H.

    2013-01-01

    An experiment is described in which a small strong cylindrical magnet is levitated by a vertical non-uniform alternating magnetic field. Surprisingly, no superimposed constant field is necessary, but the levitation can be explained when the vertical motion of the magnet is taken into account. The theoretical mean levitation force is (0.26 ± 0.06) N, which is in good agreement with the levitated weight of (0.239 ± 0.001) N. This experiment is suitable for an undergraduate laboratory, particularly as a final year project. Students have found it interesting, and it sharpens up knowledge of basic magnetism.

  2. Dependence of acoustic levitation capabilities on geometric parameters.

    PubMed

    Xie, W J; Wei, B

    2002-08-01

    A two-cylinder model incorporating boundary element method simulations is developed, which builds up the relationship between the levitation capabilities and the geometric parameters of a single-axis acoustic levitator with reference to wavelength. This model proves to be successful in predicting resonant modes of the acoustic field and explaining axial symmetry deviation of the levitated samples near the reflector and emitter. Concave reflecting surfaces of a spherical cap, a paraboloid, and a hyperboloid of revolution are investigated systematically with regard to the dependence of the levitation force on the section radius R(b) and curvature radius R (or depth D) of the reflector. It is found that the levitation force can be remarkably enhanced by choosing an optimum value of R or D, and the possible degree of this enhancement for spherically curved reflectors is the largest. The degree of levitation force enhancement by this means can also be facilitated by enlarging R(b) and employing a lower resonant mode. The deviation of the sample near the reflector is found likely to occur in case of smaller R(b), larger D, and a higher resonant mode. The calculated dependence of levitation force on R, R(b), and the resonant mode is also verified by experiment and finally demonstrated to be in good agreement with experimental results, in which considerably a strong levitation force is achieved to levitate an iridium sphere which has the largest density of 22.6 g/cm(3). PMID:12241309

  3. Aerodynamics of magnetic levitation (MAGLEV) trains

    NASA Technical Reports Server (NTRS)

    Schetz, Joseph A.; Marchman, James F., III

    1996-01-01

    High-speed (500 kph) trains using magnetic forces for levitation, propulsion and control offer many advantages for the nation and a good opportunity for the aerospace community to apply 'high tech' methods to the domestic sector. One area of many that will need advanced research is the aerodynamics of such MAGLEV (Magnetic Levitation) vehicles. There are important issues with regard to wind tunnel testing and the application of CFD to these devices. This talk will deal with the aerodynamic design of MAGLEV vehicles with emphasis on wind tunnel testing. The moving track facility designed and constructed in the 6 ft. Stability Wind Tunnel at Virginia Tech will be described. Test results for a variety of MAGLEV vehicle configurations will be presented. The last topic to be discussed is a Multi-disciplinary Design approach that is being applied to MAGLEV vehicle configuration design including aerodynamics, structures, manufacturability and life-cycle cost.

  4. Sputter coating of microspherical substrates by levitation

    DOEpatents

    Lowe, A.T.; Hosford, C.D.

    Microspheres are substantially uniformly coated with metals or nonmetals by simltaneously levitating them and sputter coating them at total chamber pressures less than 1 torr. A collimated hole structure comprising a parallel array of upwardly projecting individual gas outlets is machined out to form a dimple. Glass microballoons,, which are particularly useful in laser fusion applications, can be substantially uniformly coated using the coating method and apparatus.

  5. Electrostatic Levitation Furnace for the ISS

    NASA Technical Reports Server (NTRS)

    Murakami, Keiji; Koshikawa, Naokiyo; Shibasaki, Kohichi; Ishikawa, Takehiko; Okada, Junpei; Takada, Tetsuya; Arai, Tatsuya; Fujino, Naoki; Yamaura, Yukiko

    2012-01-01

    JAXA (Japan Aerospace Exploration Agency) has just started the development of Electrostatic Levitation Furnace to be launched in 2014 for the ISS. This furnace can control the sample position with electrostatic force and heat it above 2000 degree Celsius using semiconductor laser from four different directions. The announcement of Opportunity will be issued soon for this furnace. In this paper, we will show the specifications of this furnace and also the development schedule

  6. Experimenting with a Superconducting Levitation Train

    ERIC Educational Resources Information Center

    Miryala, Santosh; Koblischka, M. R.

    2014-01-01

    The construction and operation of a prototype high-"Tc" superconducting train model is presented. The train is levitated by a melt-processed GdBa[subscript 2]Cu[subscript 3]O[subscript x] (Gd-123) superconducting material over a magnetic rail (track). The oval shaped track is constructed in S-N-S or PM3N configuration arranged on an iron…

  7. Spin stabilized magnetic levitation of horizontal rotors.

    SciTech Connect

    Romero, Louis Anthony

    2004-10-01

    In this paper we present an analysis of a new configuration for achieving spin stabilized magnetic levitation. In the classical configuration, the rotor spins about a vertical axis; and the spin stabilizes the lateral instability of the top in the magnetic field. In this new configuration the rotor spins about a horizontal axis; and the spin stabilizes the axial instability of the top in the magnetic field.

  8. Sputter coating of microspherical substrates by levitation

    DOEpatents

    Lowe, Arthur T.; Hosford, Charles D.

    1981-01-01

    Microspheres are substantially uniformly coated with metals or nonmetals by simultaneously levitating them and sputter coating them at total chamber pressures less than 1 torr. A collimated hole structure 12 comprising a parallel array of upwardly projecting individual gas outlets 16 is machined out to form a dimple 11. Glass microballoons, which are particularly useful in laser fusion applications, can be substantially uniformly coated using the coating method and apparatus.

  9. Levitational Image Cytometry with Temporal Resolution.

    PubMed

    Tasoglu, Savas; Khoory, Joseph A; Tekin, Huseyin C; Thomas, Clemence; Karnoub, Antoine E; Ghiran, Ionita C; Demirci, Utkan

    2015-07-01

    A simple, yet powerful magnetic-levitation-based device is reported for real-time, label-free separation, as well as high-resolution monitoring of cell populations based on their unique magnetic and density signatures. This method allows a wide variety of cellular processes to be studied, accompanied by transient or permanent changes in cells' fundamental characteristics as a biological material. PMID:26058598

  10. Middle Atmosphere Electrodynamics (MAE). Middle atmospheric electrodynamics during MAP

    NASA Technical Reports Server (NTRS)

    Goldberg, R. A.

    1989-01-01

    The recent revival and strong motivation for research in middle atmospheric electrodynamics can be attributed, in large part, to the discovery of large (V/m) electric fields within the lower mesosphere during the decade prior to MAP. Subsequent rocket soundings appeared to verify the preliminary findings. During the MAP era, more sophisticated techniques have been employed to obtain measurements which respond positively to criticisms of earlier results, and which provide more insight regarding the character of the fields. The occurrence of mesospheric V/m electric fields now seems to require the presence of aerosols, of local winds and related dynamics, and of an atmospheric electrical conductivity less than 10(-10)S/m. Furthermore, new theoretical ideas describing the origin of the V/m fields are consistent with the measurements. The current status of results regarding V/m fields in the middle atmosphere is reviewed in light of the more widely accepted electric field structure for this region from rocket, balloon and modeling results.

  11. Experiments for electromagnetic levitation in microgravity

    NASA Technical Reports Server (NTRS)

    Willnecker, R.; Egry, I.

    1990-01-01

    Containerless processing is a promising research tool for investigating the properties of undercooled melts and their solidification. For conducting samples RF-electromagnetic levitation offers the possibility to obtain large undercoolings by avoiding heterogeneous nucleation at container walls. On earth, however, strong magnetic fields are needed to compensate the gravitational force which imposes a lower limit on the available temperatures and on the accessible undercooling range. Under microgravity conditions the magnetic positioning fields can be minimized and hence, undercooling becomes feasible under ultra-high vacuum conditions and lower temperatures become accessible. In contrast to other undercooling and solidification techniques, electromagnetic levitation allows for diagnostic measurements during the early steps of nucleation and phase selection. Experiments cover a wide field of research topics: nucleation, directional solidification at high velocities, generation of metastable phases, evolution of microstructures, properties of undercooled liquids. Examples from these classes including experiments selected for the IML-2 mission are discussed with emphasis on technical requirements. An overview is given on the German TEMPUS (electromagnetic levitation facility) program.

  12. Non-US electrodynamic launchers research and development

    SciTech Connect

    Parker, J.V.; Batteh, J.H.; Greig, J.R.; Keefer, D.; McNab, I.R.; Zabar, Z.

    1994-11-01

    Electrodynamic launcher research and development work of scientists outside the United States is analyzed and assessed by six internationally recognized US experts in the field of electromagnetic and electrothermal launchers. The assessment covers five broad technology areas: (1) Experimental railguns; (2) Railgun theory and design; (3) Induction launchers; (4) Electrothermal guns; (5) Energy storage and power supplies. The overall conclusion is that non-US work on electrodynamic launchers is maturing rapidly after a relatively late start in many countries. No foreign program challenges the US efforts in scope, but it is evident that the United States may be surpassed in some technologies within the next few years. Until recently, published Russian work focused on hypervelocity for research purposes. Within the last two years, large facilities have been described where military-oriented development has been underway since the mid-1980s. Financial support for these large facilities appears to have collapsed, leaving no effective effort to develop practical launchers for military or civilian applications. Electrodynamic launcher research in Europe is making rapid progress by focusing on a single application, tactical launchers for the military. Four major laboratories, in Britain, France, Germany, and the Netherlands, are working on this problem. Though narrower in scope than the US effort, the European work enjoys a continuity of support that has accelerated its progress. The next decade will see the deployment of electrodynamic launcher technology, probably in the form of an electrothermal-chemical upgrade for an existing gun system. The time scale for deployment of electromagnetic launchers is entirely dependent on the level of research-and-development effort. If resources remain limited, the advantage will lie with cooperative efforts that have reasonably stable funding such as the present French-German program.

  13. Global ionospheric dynamics and electrodynamics during geomagnetic storms (Invited)

    NASA Astrophysics Data System (ADS)

    Mannucci, A. J.; Tsurutani, B.; Verkhoglyadova, O. P.; Komjathy, A.; Butala, M. D.

    2013-12-01

    Globally distributed total electron content (TEC) data has become an important tool for exploring the consequences of storm-time electrodynamics. Magnetosphere-ionosphere coupling during the main phase is responsible for the largest ionospheric effects observed during geomagnetic storms, mediated by global scale electrodynamics. Recent research using case studies reveals a complex picture of M-I coupling and its relationship to interplanetary drivers such as the solar wind electric field. Periods of direct coupling exist where the solar wind electric field is strongly correlated with prompt penetration electric fields, observed as enhanced vertical plasma drifts or an enhanced electrojet in the daytime equatorial ionosphere. Periods of decoupling between low latitude electric fields and the solar wind electric field are also observed, but the factors distinguishing these two types of response have not been clearly identified. Recent studies during superstorms suggest a role for the transverse (y-component) of the interplanetary magnetic field, which affects magnetospheric current systems and therefore may affect M-I coupling, with significant ionospheric consequences. Observations of the global ionospheric response to a range of geomagnetic storm intensities are presented. Scientific understanding of the different factors that affect electrodynamic aspects of M-I coupling are discussed.

  14. Electrodynamic Approach for Visualization of Sound Propagation in Solids

    NASA Astrophysics Data System (ADS)

    Völz, U.; Mrasek, H.; Matthies, K.; Wü; stenberg, H.; Kreutzbruck, M.

    2009-03-01

    The visualization of sound propagation in solids is vital for transducer adaptation and better understanding of complex test samples and their wave propagation modeling. In this work we present an electrodynamic technique detecting the grazing sound beam with a 10 mm-sized electrodynamic probe. The particle displacement along the sample's surface was then measured as a function of time and position. Adapting the electrodynamic probe and its coil alignment allows for measuring the displacement components in all three dimensions. Thus horizontal and vertical particle displacement with respect to the surface can be detected. A SNR of up to 40 dB could be achieved within ferromagnetic and high conductive chrome steel when using a shear wave generated by an angle beam probe. When dealing with nonconductive materials such as PMMA we obtained a reduced SNR of 12 dB. We report on measurements of the sound field in complex weld joints. One example shows a narrow gap weld joining a nickel alloy with a chrome steel. The weld of the 80 mm-thick test block shows a distinct anisotropic texture. The system enables us to visualize the wave propagation within the weld and indicates the reflection and scattering scenario and the energy losses due to both the anisotropic structure and material defects.

  15. Covariant hyperbolization of force-free electrodynamics

    NASA Astrophysics Data System (ADS)

    Carrasco, F. L.; Reula, O. A.

    2016-04-01

    Force-free electrodynamics (FFE) is a nonlinear system of equations modeling the evolution of the electromagnetic field, in the presence of a magnetically dominated relativistic plasma. This configuration arises on several astrophysical scenarios which represent exciting laboratories to understand physics in extreme regimes. We show that this system, when restricted to the correct constraint submanifold, is symmetric hyperbolic. In numerical applications, it is not feasible to keep the system in that submanifold, and so it is necessary to analyze its structure first in the tangent space of that submanifold and then in a whole neighborhood of it. As has been shown [1], a direct (or naive) formulation of this system (in the whole tangent space) results in a weakly hyperbolic system of evolution equations for which well-posedness for the initial value formulation does not follow. Using the generalized symmetric hyperbolic formalism of Geroch [2], we introduce here a covariant hyperbolization for the FFE system. In fact, in analogy to the usual Maxwell case, a complete family of hyperbolizers is found, both for the restricted system on the constraint submanifold as well as for a suitably extended system defined in a whole neighborhood of it. A particular symmetrizer among the family is then used to write down the pertaining evolution equations, in a generic (3 +1 ) decomposition on a background spacetime. Interestingly, it turns out that for a particular choice of the lapse and shift functions of the foliation, our symmetrized system reduces to the one found in [1]. Finally, we analyze the characteristic structure of the resulting evolution system.

  16. Conjunctions and Collision Avoidance with Electrodynamic Tethers

    NASA Astrophysics Data System (ADS)

    Levin, E.

    2013-09-01

    Electrodynamic propulsion technology is currently in development by NASA, ESA, and JAXA for the purpose of affordable removal of large debris objects from LEO. At the same time, the Naval Research Laboratory is preparing a 3U CubeSat with a 1-km electrodynamic tether for a flight demonstration of electrodynamic propulsion. This type of propulsion does not require fuel. The electrodynamic thrust is the Lorentz force acting on the electric current in a long conductor (tether) in the geomagnetic field. Electrons are collected from the ambient plasma on one end and emitted back into the plasma from the other end. The electric current loop is closed through the ionosphere, as demonstrated in two previous flights. The vehicle is solar powered. To support safe navigation of electrodynamic tethers, proper conjunction analysis and collision avoidance strategies are needed. The typical lengths of electrodynamic tethers for near-term applications are measured in kilometers, and the conjunction geometry is very different from the geometry of conjunctions between compact objects. It is commonly thought that the collision cross-section in a conjunction between a tether and a compact object is represented by the product of the tether length and the size of the object. However, rigorous analysis shows that this is not the case, and that the above assumption leads to grossly overestimated collision probabilities. The paper will present the results of a detailed mathematical analysis of the conjunction geometry and collision probabilities in close approaches between electrodynamic tethers and compact objects, such as satellites, rocket bodies, and debris fragments. Electrodynamic spacecraft will not require fuel, and therefore, can thrust constantly. Their orbit transfers can take many days, but can result in major orbit changes, including large rotations of the orbital plane, both in the inclination and the node. During these orbit transfers, the electrodynamic spacecraft will

  17. Regolith Levitation on Small Fast Rotating Asteroids

    NASA Astrophysics Data System (ADS)

    Campo Bagatin, Adriano; Moreno, Fernando; Molina, Antonio

    2014-11-01

    A number of NEAs larger than few hundred meters are found with relatively high spin rates (from ~2.2 to less than 4 hr, depending on composition). On those bodies, local acceleration near their equator may be directed outwards, as in the case of the primaries of binary asteroids Didymos and 1996 FG3. They both are potential targets of future space missions. What are the effects of high spin states on regolith material at low asteroidal latitudes?NEAs come from the asteroid belt and are believed to be mostly gravitational aggregates at D > 0.5 - 1 km due to their former collisional evolution history (Campo Bagatin et al, 2001). Once in the inner Solar System, NEAs may undergo spin up evolution through YORP causing their components to disperse, shed mass or fission and eventually form binary, multiple systems or asteroid pairs (Walsh et al, 2008, Jacobson and Scheers, 2010, Pravec et al, 2009 and 2010). The end state of those events is often an object spinning above any Chandrasekhar stability limit, kept together by friction (Holsapple, 2007) and sometimes characterized by an equatorial “bulge”, as shown by radar images (Ostro et al, 2006).The centrifugal force acting on surface particles at equatorial latitudes may overcome the gravitational pull of the asteroid itself, and particles may leave its suface. Centrifugal is an apparent contact force, and as soon as particles lift off they mainly move under the gravitational field of the asteroid and the satellite, they may levitate for some time, land on the surface and repeat this cycle over and over. We are studying the motion of particles in the 1 μm to 10 cm range in the non-inertial reference frame of the rotating primary, accounting for centrifugal and Coriolis apparent forces as well as the gravitational fields of the primary, the secondary, the Sun and the radiation forces by the Sun itself. The main features of this effect are presented in the case of Didymos and 1996 FG3.

  18. Conductive Tether Coating for Electrodynamic Tethers

    NASA Technical Reports Server (NTRS)

    Vaughn, Jason A.; Schuler, Pete

    2000-01-01

    The Propulsive Small Expendable Deployer System (ProSEDS), which is an on-orbit demonstration of the propulsion capabilities of electrodynamic tethers in space, is a secondary payload on a Delta 11 unmanned expendable booster. The ProSEDS tether consists of a 5 km bare electrodynamic tether and a 1 0-km non-conductive leader tether. Near the Delta 11, 160 m of the conductive tether is insulated to prevent plasma electron collection from the plasma contactor and for other science requirements. The remainder of the 5-km conductive tether is coated with a new conductive coating to collect plasma electrons. A bare metal tether easily collects electrons from the plasma, but thermal concerns preclude this design. A highly emissive conductive polymer developed by Triton Systems, Inc. has been optimized for both conductivity and thermo-optical properties. The current design for the ProSEDS conductive tether is seven individually coated strands of 28 AWG aluminum wire, coated with an atomic oxygen-resistant conductive polymer composed of a mixture of COR (Colorless Oxygen Resistant) and polyanaline (PANI) known as C-COR (Conductive-Colorless Oxygen Resistant). The conductive-coated wire strands are cold-welded to individually coated strands of the insulated tether. The insulated tether is coated with 1 mil of polyimide and an atomic oxygen resistant polymer TOR-BP. The insulated tether must stand off the entire voltage of the tether (1 200 V) at various times during the mission. All seven wires are twisted around a Kevlar-29 core using the Hi-wire design. Extensive testing has been performed at the Marshall Space Flight Center to qualify both the conductive coating and insulating coating for use on the ProSEDS tether. The conductive coating has been exposed to a plasma to verify the coatings ability to collect electrons from the space plasma from 0 to 1500 V, and to verify the coatings ability to collect electrons after atomic oxygen exposure. The insulated coating has been

  19. Global electrodynamics from superpressure balloons

    NASA Technical Reports Server (NTRS)

    Holzworth, R. H.; Hu, H.

    1995-01-01

    Electric field and conductivity measurements in the stratosphere between November 1992 and March 1993 have been made using superpressure balloons in the southern hemisphere. Over 400 payload-days of data have been made during a record setting experiment called ELBBO (Extended Life Balloon Borne Observatories). This experiment resulted in 4 flights aloft simultaneously for over 2 months including one flight which lasted over 4 months. Electrodynamical coupling between the atmosphere and ionosphere is studied using the measured electric fields, and a simple empirical model of the stratospheric conductivity. Altitude profiles of conductivity have been obtained from several superpressure balloon flights using the large end-of-flight altitude swings on the last few days of each flight (as the balloon begins to loose superpressure). Coupling between the fields and atmospheric inertial waves has been observed. Effects and dynamics of the global circuit suggest that standard models are missing significant phenomena. Large scale ionospheric convection activity has been studied from the polar cap to the middle latitudes. Cusp latitude fields have been continuously measured for many days in a row.

  20. Electrodynamics of the Duskside Aurora

    NASA Astrophysics Data System (ADS)

    Shue, J.; Newell, P. T.; Liou, K.; Meng, C.; Germany, G. A.; Hairston, M. R.; Rich, F. J.

    2002-12-01

    Shue et al. [2002] reported that an auroral feature, which is called the two-cell aurora, was identified from Polar Ultraviolet Imager auroral images. The characteristics of the two-cell aurora are azimuthal elongation over extended local times with gaps at noon and midnight. Its electrodynamic association with the convection, particle precipitation, and field-aligned currents has not been fully understood. In conjunctions with DMSP F12 spacecraft on the duskside branch of the aurora, we are able to investigate the association of auroral emissions with convection reversals, upward field-aligned currents, and energy fluxes and average energy of particles. It is found that the location of the convection reversal is colocated with the upward field-aligned currents. The maximum auroral emissions occur at or poleward of the convection reversals. The energy flux and average energy derived from auroral images are consistent with observations from DMSP in a region mapped to the plasma sheet. However, inconsistency occurs in a region mapped to the plasma sheet boundary layer. Shue, J.-H., P. T. Newell, K. Liou, C.-I. Meng, Y. Kamide, and R. P. Lepping, Two-component auroras, Geophys. Res. Lett., 29(10), 10.1029/2002GL14657, 2002.

  1. Nonlinear electrodynamics and CMB polarization

    SciTech Connect

    Cuesta, Herman J. Mosquera; Lambiase, G. E-mail: lambiase@sa.infn.it

    2011-03-01

    Recently WMAP and BOOMERanG experiments have set stringent constraints on the polarization angle of photons propagating in an expanding universe: Δα = (−2.4±1.9)°. The polarization of the Cosmic Microwave Background radiation (CMB) is reviewed in the context of nonlinear electrodynamics (NLED). We compute the polarization angle of photons propagating in a cosmological background with planar symmetry. For this purpose, we use the Pagels-Tomboulis (PT) Lagrangian density describing NLED, which has the form L ∼ (X/Λ{sup 4}){sup δ−1} X, where X = ¼F{sub αβ}F{sup αβ}, and δ the parameter featuring the non-Maxwellian character of the PT nonlinear description of the electromagnetic interaction. After looking at the polarization components in the plane orthogonal to the (x)-direction of propagation of the CMB photons, the polarization angle is defined in terms of the eccentricity of the universe, a geometrical property whose evolution on cosmic time (from the last scattering surface to the present) is constrained by the strength of magnetic fields over extragalactic distances.

  2. Optimal Electrodynamic Tether Phasing Maneuvers

    NASA Technical Reports Server (NTRS)

    Bitzer, Matthew S.; Hall, Christopher D.

    2007-01-01

    We study the minimum-time orbit phasing maneuver problem for a constant-current electrodynamic tether (EDT). The EDT is assumed to be a point mass and the electromagnetic forces acting on the tether are always perpendicular to the local magnetic field. After deriving and non-dimensionalizing the equations of motion, the only input parameters become current and the phase angle. Solution examples, including initial Lagrange costates, time of flight, thrust plots, and thrust angle profiles, are given for a wide range of current magnitudes and phase angles. The two-dimensional cases presented use a non-tilted magnetic dipole model, and the solutions are compared to existing literature. We are able to compare similar trajectories for a constant thrust phasing maneuver and we find that the time of flight is longer for the constant thrust case with similar initial thrust values and phase angles. Full three-dimensional solutions, which use a titled magnetic dipole model, are also analyzed for orbits with small inclinations.

  3. Orbital applications of electrodynamic propulsion

    NASA Astrophysics Data System (ADS)

    Irwin, Troy

    1993-12-01

    Electrodynamic propulsion (EDP) uses forces resulting from electric currents in conductors as a spacecraft travels through a magnetic field. A vehicle-independent expression for the specific power required for any maneuver is derived and used to assess EDP feasibility. Analytical expressions for the accelerations and combined current-conductor vector required to change the orbital plane or the argument of perigee are developed based on Lagrange's planetary equations. Solutions to the forced Clohessy-Wiltshire equations are developed to study iii-plane rendezvous. Results show EDP can change inclination or right ascension of the ascending mode at approximately 0.4 degrees/day with current spacecraft specific power technology. The effects of the Earth's oblateness on a 24 hour, 90 degree inclination Molniya orbit can be negated. Rendezvous is possible with EDP, and approaches along the target velocity vector with no attitude change are possible with current spacecraft specific power. Approaches involving altitude changes will be possible when modest spacecraft power improvements are made. EDP allows a soft dock - velocities and accelerations decay to zero as the chase vehicle the target - and there is no thruster plume to impart momentum or contaminate the target.

  4. Nanofriction in Cavity Quantum Electrodynamics.

    PubMed

    Fogarty, T; Cormick, C; Landa, H; Stojanović, Vladimir M; Demler, E; Morigi, Giovanna

    2015-12-01

    The dynamics of cold trapped ions in a high-finesse resonator results from the interplay between the long-range Coulomb repulsion and the cavity-induced interactions. The latter are due to multiple scatterings of laser photons inside the cavity and become relevant when the laser pump is sufficiently strong to overcome photon decay. We study the stationary states of ions coupled with a mode of a standing-wave cavity as a function of the cavity and laser parameters, when the typical length scales of the two self-organizing processes, Coulomb crystallization and photon-mediated interactions, are incommensurate. The dynamics are frustrated and in specific limiting cases can be cast in terms of the Frenkel-Kontorova model, which reproduces features of friction in one dimension. We numerically recover the sliding and pinned phases. For strong cavity nonlinearities, they are in general separated by bistable regions where superlubric and stick-slip dynamics coexist. The cavity, moreover, acts as a thermal reservoir and can cool the chain vibrations to temperatures controlled by the cavity parameters and by the ions' phase. These features are imprinted in the radiation emitted by the cavity, which is readily measurable in state-of-the-art setups of cavity quantum electrodynamics. PMID:26684118

  5. Nanofriction in Cavity Quantum Electrodynamics

    NASA Astrophysics Data System (ADS)

    Fogarty, T.; Cormick, C.; Landa, H.; Stojanović, Vladimir M.; Demler, E.; Morigi, Giovanna

    2015-12-01

    The dynamics of cold trapped ions in a high-finesse resonator results from the interplay between the long-range Coulomb repulsion and the cavity-induced interactions. The latter are due to multiple scatterings of laser photons inside the cavity and become relevant when the laser pump is sufficiently strong to overcome photon decay. We study the stationary states of ions coupled with a mode of a standing-wave cavity as a function of the cavity and laser parameters, when the typical length scales of the two self-organizing processes, Coulomb crystallization and photon-mediated interactions, are incommensurate. The dynamics are frustrated and in specific limiting cases can be cast in terms of the Frenkel-Kontorova model, which reproduces features of friction in one dimension. We numerically recover the sliding and pinned phases. For strong cavity nonlinearities, they are in general separated by bistable regions where superlubric and stick-slip dynamics coexist. The cavity, moreover, acts as a thermal reservoir and can cool the chain vibrations to temperatures controlled by the cavity parameters and by the ions' phase. These features are imprinted in the radiation emitted by the cavity, which is readily measurable in state-of-the-art setups of cavity quantum electrodynamics.

  6. Applications of Electromagnetic Levitation and Development of Mathematical Models: A Review of the Last 15 Years (2000 to 2015)

    NASA Astrophysics Data System (ADS)

    Gao, Lei; Shi, Zhe; Li, Donghui; Zhang, Guifang; Yang, Yindong; McLean, Alexander; Chattopadhyay, Kinnor

    2016-02-01

    Electromagnetic levitation (EML) is a contact-less, high-temperature technique which has had extensive application with respect to the investigation of both thermophysical and thermochemical properties of liquid alloy systems. The varying magnetic field generates an induced current inside the metal droplet, and interactions are created which produce both the Lorentz force that provides support against gravity and the Joule heating effect that melts the levitated specimen. Since metal droplets are opaque, transport phenomena inside the droplet cannot be visualized. To address this aspect, several numerical modeling techniques have been developed. The present work reviews the applications of EML techniques as well as the contributions that have been made by the use of mathematical modeling to improve understanding of the inherent processes which are characteristic features of the levitation system.

  7. Noncontact true temperature measurement. [of levitated sample using laser pyrometer

    NASA Technical Reports Server (NTRS)

    Lee, Mark C.; Allen, James L.

    1987-01-01

    A laser pyrometer has been developed for acquiring the true temperature of a levitated sample. The laser beam is first expanded to cover the entire cross-sectional surface of the target. For calibration of such a system, the reflectivity signal of an ideal 0.95 cm diameter gold-coated sphere (reflectivity = 0.99) is used as the reference for any other real targets. The emissivity of the real target can then be calculated. The overall system constant is obtained by passively measuring the radiance of a blackbody furnace (emissivity = 1.0) at a known, arbitrary temperature. Since the photo sensor used is highly linear over the entire operating temperature range, the true temperature of the target can then be computed. Preliminary results indicate that true temperatures thus obtained are in excellent correlation with thermocouple measured temperatures.

  8. An electromagnetically levitated two-axis gimbaless pointing mechanism

    NASA Technical Reports Server (NTRS)

    Volpe, Gerald T.

    1993-01-01

    A brief description for a proposed new pointing mechanism which requires no mechanical gimbals, is virtually friction free, and is vibration isolated from a ground support system or vehicle is presented. The device uses electromagnetic forces for support levitation and pointing, both being accomplished from a ground reference thereby leaving the payload virtually free from a remotely located command center. Solid pointing angles of almost 2(pi) steradians are achievable, limited only by structural interference. A third degree-of-freedom tilt axis can be added at will, but will not be elaborated. Although the system is primarily intended for space vehicles in a micro-gravity environment, earth-ground support is possible with superconducting electromagnets.

  9. Magnetic Vibration Simulator with Magnetic Levitation for EDS Maglev

    NASA Astrophysics Data System (ADS)

    Murai, Toshiaki; Hasegawa, Hitoshi; Kashiwagi, Takayuki

    A magnetic vibration simulator is one of the most important test tools to evaluate the basic performance of superconducting magnet (SCM) for EDS maglev. In this paper, we propose a new magnetic vibration simulator which can also suspend car and bogie mounted with the SCMs to evaluate the performance of not only SCMs but also vehicle dynamics with levitation. This system is composed of magnetic exciting coils which can simultaneously suspend and vibrate the SCMs and inverters which can simultaneously control 3-phase and zero-phase currents. This paper describes the principle, analytical method and control method of this system, and using numerical example, the vehicle dynamics and the vibration response of SCM are revealed.

  10. An electromagnetically levitated two-axis gimbaless pointing mechanism

    NASA Astrophysics Data System (ADS)

    Volpe, Gerald T.

    A brief description for a proposed new pointing mechanism which requires no mechanical gimbals, is virtually friction free, and is vibration isolated from a ground support system or vehicle is presented. The device uses electromagnetic forces for support levitation and pointing, both being accomplished from a ground reference thereby leaving the payload virtually free from a remotely located command center. Solid pointing angles of almost 2(pi) steradians are achievable, limited only by structural interference. A third degree-of-freedom tilt axis can be added at will, but will not be elaborated. Although the system is primarily intended for space vehicles in a micro-gravity environment, earth-ground support is possible with superconducting electromagnets.

  11. Middle atmosphere electrodynamics: Report of the Workshop on the Role of the Electrodynamics of the Middle Atmosphere on Solar Terrestrial Coupling

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The middle atmosphere (MA), which is defined as the region bounded below by the tropopause near 10 km and above by the mesopause near 90 to 100 km, is regarded as a passive medium through which electric fields and currents are transmitted from sources above and below. A scientific background is given for: sources of MA electric fields; MA conductivity and currents; and MA plasma characteristics. Recommendations are given for research in MA electrodynamics in the following areas: (1) MA electrodynamical parameters; (2) models and supportive laboratory measurements; and (3) investigation of specific problems in the coupled systems.

  12. Method for obtaining large levitation pressure in superconducting magnetic bearings

    DOEpatents

    Hull, J.R.

    1997-08-05

    A method and apparatus are disclosed for compressing magnetic flux to achieve high levitation pressures. Magnetic flux produced by a magnetic flux source travels through a gap between two high temperature superconducting material structures. The gap has a varying cross-sectional area to compress the magnetic flux, providing an increased magnetic field and correspondingly increased levitation force in the gap. 4 figs.

  13. Method for obtaining large levitation pressure in superconducting magnetic bearings

    DOEpatents

    Hull, John R.

    1997-01-01

    A method and apparatus for compressing magnetic flux to achieve high levitation pressures. Magnetic flux produced by a magnetic flux source travels through a gap between two high temperature superconducting material structures. The gap has a varying cross-sectional area to compress the magnetic flux, providing an increased magnetic field and correspondingly increased levitation force in the gap.

  14. Method for obtaining large levitation pressure in superconducting magnetic bearings

    DOEpatents

    Hull, John R.

    1996-01-01

    A method and apparatus for compressing magnetic flux to achieve high levitation pressures. Magnetic flux produced by a magnetic flux source travels through a gap between two high temperature superconducting material structures. The gap has a varying cross-sectional area to compress the magnetic flux, providing an increased magnetic field and correspondingly increased levitation force in the gap.

  15. Method for obtaining large levitation pressure in superconducting magnetic bearings

    DOEpatents

    Hull, J.R.

    1996-10-08

    A method and apparatus are disclosed for compressing magnetic flux to achieve high levitation pressures. Magnetic flux produced by a magnetic flux source travels through a gap between two high temperature superconducting material structures. The gap has a varying cross-sectional area to compress the magnetic flux, providing an increased magnetic field and correspondingly increased levitation force in the gap. 4 figs.

  16. Spin-stabilized magnetic levitation without vertical axis of rotation

    DOEpatents

    Romero, Louis; Christenson, Todd; Aaronson, Gene

    2009-06-09

    The symmetry properties of a magnetic levitation arrangement are exploited to produce spin-stabilized magnetic levitation without aligning the rotational axis of the rotor with the direction of the force of gravity. The rotation of the rotor stabilizes perturbations directed parallel to the rotational axis.

  17. The measurement of heats of solution of high melting metallic systems in an electromagnetic levitation field. Ph.D. Thesis - Tech. Univ. Berlin - 1979

    NASA Technical Reports Server (NTRS)

    Frohberg, M. G.; Betz, G.

    1982-01-01

    A method was tested for measuring the enthalpies of mixing of liquid metallic alloying systems, involving the combination of two samples in the electromagnetic field of an induction coil. The heat of solution is calculated from the pyrometrically measured temperature effect, the heat capacity of the alloy, and the heat content of the added sample. The usefulness of the method was tested experimentally with iron-copper and niobium-silicon systems. This method should be especially applicable to high-melting alloys, for which conventional measurements have failed.

  18. Acoustic levitation for high temperature containerless processing in space

    NASA Technical Reports Server (NTRS)

    Rey, C. A.; Sisler, R.; Merkley, D. R.; Danley, T. J.

    1990-01-01

    New facilities for high-temperature containerless processing in space are described, including the acoustic levitation furnace (ALF), the high-temperature acoustic levitator (HAL), and the high-pressure acoustic levitator (HPAL). In the current ALF development, the maximum temperature capabilities of the levitation furnaces are 1750 C, and in the HAL development with a cold wall furnace they will exceed 2000-2500 C. The HPAL demonstrated feasibility of precursor space flight experiments on the ground in a 1 g pressurized-gas environment. Testing of lower density materials up to 1300 C has also been accomplished. It is suggested that advances in acoustic levitation techniques will result in the production of new materials such as ceramics, alloys, and optical and electronic materials.

  19. Resolution of a paradox in classical electrodynamics

    SciTech Connect

    Pinto, Fabrizio

    2006-05-15

    It is an early result of electrostatics in curved space that the gravitational mass of a charge distribution changes by an amount equal to U{sub es}/c{sup 2}, where U{sub es} is the internal electrostatic potential energy and c is the speed of light, if the system is supported at rest by external forces. This fact, independently rediscovered in recent years in the case of a simple dipole, confirms a very reasonable expectation grounded in the mass-energy equivalency equation. However, it is an unsolved paradox of classical electrodynamics that the renormalized mass of an accelerated dipole calculated from the self-forces due to the distortion of the Coulomb field differs in general from that expected from the energy correction, U{sub es}/c{sup 2}, unless the acceleration is transversal to the orientation of the dipole. Here we show that this apparent paradox disappears for any dipole orientation if the self-force is evaluated by means of Whittaker's exact solution for the field of the single charge in a homogeneous gravitational field described in the Rindler metric. The discussion is supported by computer algebra results, diagrams of the electric fields distorted by gravitation, and a brief analysis of the prospects for realistic experimentation. The gravitational correction to dipole-dipole interactions is also discussed.

  20. Renormalizable Electrodynamics of Scalar and Vector Mesons. Part II

    DOE R&D Accomplishments Database

    Salam, Abdus; Delbourgo, Robert

    1964-01-01

    The "gauge" technique" for solving theories introduced in an earlier paper is applied to scalar and vector electrodynamics. It is shown that for scalar electrodynamics, there is no {lambda}φ*2φ2 infinity in the theory, while with conventional subtractions vector electrodynamics is completely finite. The essential ideas of the gauge technique are explained in section 3, and a preliminary set of rules for finite computation in vector electrodynamics is set out in Eqs. (7.28) - (7.34).

  1. Growth anisotropy effect of bulk high temperature superconductors on the levitation performance in the applied magnetic field

    NASA Astrophysics Data System (ADS)

    Zheng, J.; Liao, X. L.; Jing, H. L.; Deng, Z. G.; Yen, F.; Wang, S. Y.; Wang, J. S.

    2013-10-01

    Growth anisotropies of bulk high temperature superconductors (HTSCs) fabricated by a top-seeded melt texture growth process, that is, different pinning effect in the growth sectors (GSs) and growth sector boundaries (GSBs), possess effect on the macro flux trapping and levitation performance of bulk HTSCs. Previous work (Physics Procedia, 36 (2012) 1043) has found that the bulk HTSC array with aligned GSB pattern (AGSBP) exhibits better capability for levitation and suppression of levitation force decay above a permanent magnet guideway (PMG) compared with misaligned GSB pattern (MGSBP). In this paper, we further examine this growth anisotropy effect on the maglev performance of a double-layer bulk HTSC. In contrast to reported trapped flux cases (Supercond. Sci. Technol. 19 (2006) S466), the two superposed bulk HTSCs with same AGSBP with PMG are found to show better maglev performance. These series of results are helpful and support a new way for the performance optimization of present HTS maglev systems.

  2. Containerless processing at high temperatures using acoustic levitation

    NASA Technical Reports Server (NTRS)

    Rey, C. A.; Merkley, D. R.; Hampton, S.; Devos, J.; Mapes-Riordan, D.; Zatarski, M.

    1991-01-01

    Advanced techniques are presented which facilitate the development of inert or reducing atmospheres in excess of 2000 K in order to improve processing of containerless capabilities at higher temperatures and to provide more contamination-free environments. Recent testing, in the laboratory and aboard the NASA KC-135 aircraft, of a high-temperature acoustic positioner demonstrated the effectiveness of a specimen motion damping system and of specimen spin control. It is found that stable positioning can be achieved under ambient and heated conditions, including the transient states of heat-up and cool-down. An incorporated high-temperature levitator was found capable of processing specimens of up to 6-mm diameter in a high-purity environment without the contaminating effects of a container at high temperatures and with relative quiescence.

  3. Green chemistry and nanofabrication in a levitated Leidenfrost drop.

    PubMed

    Abdelaziz, Ramzy; Disci-Zayed, Duygu; Hedayati, Mehdi Keshavarz; Pöhls, Jan-Hendrik; Zillohu, Ahnaf Usman; Erkartal, Burak; Chakravadhanula, Venkata Sai Kiran; Duppel, Viola; Kienle, Lorenz; Elbahri, Mady

    2013-01-01

    Green nanotechnology focuses on the development of new and sustainable methods of creating nanoparticles, their localized assembly and integration into useful systems and devices in a cost-effective, simple and eco-friendly manner. Here we present our experimental findings on the use of the Leidenfrost drop as an overheated and charged green chemical reactor. Employing a droplet of aqueous solution on hot substrates, this method is capable of fabricating nanoparticles, creating nanoscale coatings on complex objects and designing porous metal in suspension and foam form, all in a levitated Leidenfrost drop. As examples of the potential applications of the Leidenfrost drop, fabrication of nanoporous black gold as a plasmonic wideband superabsorber, and synthesis of superhydrophilic and thermal resistive metal-polymer hybrid foams are demonstrated. We believe that the presented nanofabrication method may be a promising strategy towards the sustainable production of functional nanomaterials. PMID:24169567

  4. Green chemistry and nanofabrication in a levitated Leidenfrost drop

    NASA Astrophysics Data System (ADS)

    Abdelaziz, Ramzy; Disci-Zayed, Duygu; Hedayati, Mehdi Keshavarz; Pöhls, Jan-Hendrik; Zillohu, Ahnaf Usman; Erkartal, Burak; Chakravadhanula, Venkata Sai Kiran; Duppel, Viola; Kienle, Lorenz; Elbahri, Mady

    2013-10-01

    Green nanotechnology focuses on the development of new and sustainable methods of creating nanoparticles, their localized assembly and integration into useful systems and devices in a cost-effective, simple and eco-friendly manner. Here we present our experimental findings on the use of the Leidenfrost drop as an overheated and charged green chemical reactor. Employing a droplet of aqueous solution on hot substrates, this method is capable of fabricating nanoparticles, creating nanoscale coatings on complex objects and designing porous metal in suspension and foam form, all in a levitated Leidenfrost drop. As examples of the potential applications of the Leidenfrost drop, fabrication of nanoporous black gold as a plasmonic wideband superabsorber, and synthesis of superhydrophilic and thermal resistive metal-polymer hybrid foams are demonstrated. We believe that the presented nanofabrication method may be a promising strategy towards the sustainable production of functional nanomaterials.

  5. Battery cars on superconducting magnetically levitated carriers: One commuting solution

    NASA Astrophysics Data System (ADS)

    Briggs, B. Mike; Oman, Henry

    1992-05-01

    Commuting to work in an urban-suburban metropolitan environment is becoming an unpleasant time-wasting process. We applied the technology of communication management to this commuting problem. Communication management is a system-engineering tool that produced today's efficient telephone network. The resulting best commuting option is magnetically levitated carriers of two-passenger, battery-powered, personally-owned local-travel cars. A commuter drives a car to a nearby station, selects a destination, drives on a waiting carrier, and enters an accelerating ramp. A central computer selects an optimum 100 miles-per-hour trunk route, considering existing and forecast traffic; assigns the commuter a travel slot, and subsequently orders switching-station actions. The commuter uses the expensive facilities for only a few minutes during each trip. The cost of travel could be less than 6 cents per mile.

  6. Green chemistry and nanofabrication in a levitated Leidenfrost drop

    PubMed Central

    Abdelaziz, Ramzy; Disci-Zayed, Duygu; Hedayati, Mehdi Keshavarz; Pöhls, Jan-Hendrik; Zillohu, Ahnaf Usman; Erkartal, Burak; Chakravadhanula, Venkata Sai Kiran; Duppel, Viola; Kienle, Lorenz; Elbahri, Mady

    2013-01-01

    Green nanotechnology focuses on the development of new and sustainable methods of creating nanoparticles, their localized assembly and integration into useful systems and devices in a cost-effective, simple and eco-friendly manner. Here we present our experimental findings on the use of the Leidenfrost drop as an overheated and charged green chemical reactor. Employing a droplet of aqueous solution on hot substrates, this method is capable of fabricating nanoparticles, creating nanoscale coatings on complex objects and designing porous metal in suspension and foam form, all in a levitated Leidenfrost drop. As examples of the potential applications of the Leidenfrost drop, fabrication of nanoporous black gold as a plasmonic wideband superabsorber, and synthesis of superhydrophilic and thermal resistive metal–polymer hybrid foams are demonstrated. We believe that the presented nanofabrication method may be a promising strategy towards the sustainable production of functional nanomaterials. PMID:24169567

  7. Electrodynamics of the middle atmosphere: Superpressure balloon program

    NASA Technical Reports Server (NTRS)

    Holzworth, Robert H.

    1987-01-01

    In this experiment a comprehensive set of electrical parameters were measured during eight long duration flights in the southern hemisphere stratosphere. These flight resulted in the largest data set ever collected from the stratosphere. The stratosphere has never been electrodynamically sampled in the systematic manner before. New discoveries include short term variability in the planetary scale electric current system, the unexpected observation of stratospheric conductivity variations over thunderstorms and the observation of direct stratospheric conductivity variations following a relatively small solar flare. Major statistical studies were conducted of the large scale current systems, the stratospheric conductivity and the neutral gravity waves (from pressure and temperature data) using the entire data set.

  8. Emil Cohn's electrodynamics of moving bodies

    NASA Astrophysics Data System (ADS)

    Darrigol, Olivier

    1995-10-01

    A now forgotten figure, Emil Cohn was one of the leading experts in electrodynamics at the turn of the century. Unsatisfied with Lorentz's electron theory, he proposed an alternative electrodynamics of moving bodies based on a modification of Maxwell's macroscopic field equations that managed to account for all relevant electrodynamic and optical experiments, including that of Michelson and Morley. Some of his insights foreshadow aspects of Einstein's relativity theory, especially the elimination of the ether and the criticism of Lorentz's implicit distinction between true and measured coordinates of space and time. However, Cohn did not believe in the general validity of the relativity principle, and did not require a revision of the usual concepts of space and time.

  9. ELECTRODYNAMICS à la HOŘAVA

    NASA Astrophysics Data System (ADS)

    Romero, Juan M.; Santiago, José A.; González-Gaxiola, O.; Zamora, Adolfo

    We study an electrodynamics consistent with anisotropic transformations of spacetime with an arbitrary dynamic exponent z. The equations of motion and conserved quantities are explicitly obtained. We show that the propagator of this theory can be regarded as a quantum correction to the usual propagator. Moreover, we obtain that both the momentum and angular momentum are not modified, but their conservation laws do change. We also show that in this theory the speed of light and the electric charge are modified with z. The magnetic monopole in this electrodynamics and its duality transformations are also investigated. For that we found that there exists a dual electrodynamics, with higher derivatives in the electric field, invariant under the same anisotropic transformations.

  10. Ampere-Neumann electrodynamics of metals

    SciTech Connect

    Graneau, P.

    1985-01-01

    Maxwell described Ampere's force law as the cardinal formula of electrodynamics. This law predicts longitudinal mechanical forces along current streamlines in metallic conductors. The Ampere forces set up tension in wires and busbars and compression in liquid metal. At normal current densities they are negligible but, increasing with the square of current, they become dominant in pulse power circuits. Ampere tension and compression have been revealed by exploding wire experiments, in liquid metal jets at solid - liquid interfaces, and with an electrodynamic pendulum. Ampere stresses are already playing an important role in the development of railguns, fuses, current limiters, opening switches, pulse magnets, and a host of other pulse-power devices. This book outlines the electrodynamic action-at-a-distance theory developed by Ampere, Neumann, Weber and, to some extent, by Maxwell. One chapter describes the 20th century extensions of the theory by Graneau and others.

  11. An optimal design of a mono-stable vertical diamagnetic levitation based electromagnetic vibration energy harvester

    NASA Astrophysics Data System (ADS)

    Palagummi, S.; Yuan, F. G.

    2015-04-01

    A detailed analysis of a mono-stable vertical diamagnetic levitation (VDL) system for optimal vibration energy harvesting is presented. Initial studies showed that simple analytical techniques such as the dipole model and the image method provide useful guideline for understanding the potential of a diamagnetic levitation system, however, it is discussed here that the more accurate semi-analytical techniques such as the thin coil model and the discrete volume method are needed for quantitative optimization and design of the VDL system. With the semi-analytical techniques, the influence of the cylindrical geometry of the floating magnet, the lifting magnet and the diamagnetic plate are parametrically studied to assess their effects on the levitation gap, size of the system and the natural frequency. For efficient vibration energy harvesting using the VDL system, ways to mitigate eddy current damping and a coil geometry for transduction are critically discussed. With the optimized parameters, an experimental system is realized which showed a hardening type nonlinearity. The results show an overall efficiency of 1.54 percent, a root mean square (rms) power output of 1.72 μW when excited at a peak acceleration of 0.081 m/s2 and at a frequency of 2.1 Hz.

  12. Mass Spectrometry of Acoustically Levitated Droplets

    PubMed Central

    Westphall, Michael S.; Jorabchi, Kaveh; Smith, Lloyd M.

    2008-01-01

    Containerless sample handling techniques such as acoustic levitation offer potential advantages for mass spectrometry, by eliminating surfaces where undesired adsorption/desorption processes can occur. In addition, they provide a unique opportunity to study fundamental aspects of the ionization process as well as phenomena occurring at the air–droplet interface. Realizing these advantages is contingent, however, upon being able to effectively interface levitated droplets with a mass spectrometer, a challenging task that is addressed in this report. We have employed a newly developed charge and matrix-assisted laser desorption/ionization (CALDI) technique to obtain mass spectra from a 5-μL acoustically levitated droplet containing peptides and an ionic matrix. A four-ring electrostatic lens is used in conjunction with a corona needle to produce bursts of corona ions and to direct those ions toward the droplet, resulting in droplet charging. Analyte ions are produced from the droplet by a 337-nm laser pulse and detected by an atmospheric sampling mass spectrometer. The ion generation and extraction cycle is repeated at 20 Hz, the maximum operating frequency of the laser employed. It is shown in delayed ion extraction experiments that both positive and negative ions are produced, behavior similar to that observed for atmospheric pressure matrix-assisted laser absorption/ionization. No ion signal is observed in the absence of droplet charging. It is likely, although not yet proven, that the role of the droplet charging is to increase the strength of the electric field at the surface of the droplet, reducing chargere combination after ion desorption. PMID:18582090

  13. Mass spectrometry of acoustically levitated droplets.

    PubMed

    Westphall, Michael S; Jorabchi, Kaveh; Smith, Lloyd M

    2008-08-01

    Containerless sample handling techniques such as acoustic levitation offer potential advantages for mass spectrometry, by eliminating surfaces where undesired adsorption/desorption processes can occur. In addition, they provide a unique opportunity to study fundamental aspects of the ionization process as well as phenomena occurring at the air-droplet interface. Realizing these advantages is contingent, however, upon being able to effectively interface levitated droplets with a mass spectrometer, a challenging task that is addressed in this report. We have employed a newly developed charge and matrix-assisted laser desorption/ionization (CALDI) technique to obtain mass spectra from a 5-microL acoustically levitated droplet containing peptides and an ionic matrix. A four-ring electrostatic lens is used in conjunction with a corona needle to produce bursts of corona ions and to direct those ions toward the droplet, resulting in droplet charging. Analyte ions are produced from the droplet by a 337-nm laser pulse and detected by an atmospheric sampling mass spectrometer. The ion generation and extraction cycle is repeated at 20 Hz, the maximum operating frequency of the laser employed. It is shown in delayed ion extraction experiments that both positive and negative ions are produced, behavior similar to that observed for atmospheric pressure matrix-assisted laser absorption/ionization. No ion signal is observed in the absence of droplet charging. It is likely, although not yet proven, that the role of the droplet charging is to increase the strength of the electric field at the surface of the droplet, reducing charge recombination after ion desorption. PMID:18582090

  14. Determination of the viscous acoustic field for liquid drop positioning/forcing in an acoustic levitation chamber in microgravity

    NASA Technical Reports Server (NTRS)

    Lyell, Margaret J.

    1992-01-01

    The development of acoustic levitation systems has provided a technology with which to undertake droplet studies as well as do containerless processing experiments in a microgravity environment. Acoustic levitation chambers utilize radiation pressure forces to position/manipulate the drop. Oscillations can be induced via frequency modulation of the acoustic wave, with the modulated acoustic radiation vector acting as the driving force. To account for tangential as well as radial forcing, it is necessary that the viscous effects be included in the acoustic field. The method of composite expansions is employed in the determination of the acoustic field with viscous effects.

  15. Secondary lift for magnetically levitated vehicles

    DOEpatents

    Cooper, Richard K.

    1976-01-01

    A high-speed terrestrial vehicle that is magnetically levitated by means of magnets which are used to induce eddy currents in a continuous electrically conductive nonferromagnetic track to produce magnetic images that repel the inducing magnet to provide primary lift for the vehicle. The magnets are arranged so that adjacent ones have their fields in opposite directions and the magnets are spaced apart a distance that provides a secondary lift between each magnet and the adjacent magnet's image, the secondary lift being maximized by optimal spacing of the magnets.

  16. Undercooling of acoustically levitated molten drops

    NASA Astrophysics Data System (ADS)

    Ohsaka, K.; Trinh, E. H.; Glicksman, M. E.

    1990-11-01

    The effect of ultrasound on the undercooling of an acoustically levitated molten drop is investigated by measuring the onset temperature of solidification. The measurement indicates that ultrasound occasionally terminates undercooling by initiating the nucleation of a solid at an undercooling level which is lower than that determined for nucleation catalyzed by the impurities in the drop. The results are interpreted by thermodynamic considerations which indicate a significant increase in effective undercooling of the liquid, beyond the level set by the impurities upon the collapse of acoustically driven pre-existing gas microbubbles.

  17. Rotation of ultrasonically levitated glycerol drops

    NASA Technical Reports Server (NTRS)

    Biswas, A.; Leung, E. W.; Trinh, E. H.

    1991-01-01

    Ultrasonic levitation is used to suspend single millimeter-size glycerol drops in a rectangular chamber. Audio-frequency laterally standing waves set up in the chamber are used to torque the suspended drops. The shape evolution of the drop under the combined effect of centrifugal forces and the acoustic radiation stress, along with its angular velocity are monitored, using video imaging and light scattering techniques. The results show good qualitative agreement with the theoretically predicted shape evolution as a function of angular velocity.

  18. Superconducting bearings with levitation control configurations

    SciTech Connect

    Flom, Y.; Royston, J.D.

    1992-05-26

    This patent describes a superconducting rotating assembly. It comprises first and second bearing means comprising a material exhibiting superconducting properties; a rotatable member having two extremities aligned along a common axis; magnet means at each extremity; means for maintaining each the bearing means at a temperature where the superconducting properties are manifest; means for rotating the rotatable member; means for sensing the position of the rotatable member relative to each the bearing means; and means for controlling the levitation forces exerted on the rotatable member by each the bearing means.

  19. Electrodynamic treatment of reversed-type emulsions

    SciTech Connect

    Skachkov, A.E.; Lavrov, I.S.; Timonov, S.M.

    1985-11-01

    The authors have produced an inhomogeneous electric field in processing reversed emulsions by using the oscillations of conducting spheres in an electric field; this is known as the electrical pendulum effect. The apparatus for the electrodynamic treatment of reversed-type emulsion is shown and the physical characteristics (density, kinematic viscosity, dielectric constant) are shown for the hydrocarbons used: hexane, octane, hexadecane and diesel fuel. It is shown that there is a minimum in the dependence of the residual water content after electrodynamic treatment on the external field strength; the minimum shifts to larger external field strength as the viscosity increases.

  20. Application of Fuzzy Logic to EMS-type Magnetically Levitated Railway Vehicle

    NASA Astrophysics Data System (ADS)

    Kusagawa, Shinichi; Baba, Jumpei; Shutoh, Katsuhiko; Masada, Eisuke

    A type of the magnetically levitated railway system with the electro-magnetic suspension system (EMS), which is named HSST system, will be put into revenue service as an urban transport in Nagoya, Japan at the beginning of April 2005. To extend its operational velocity higher than 200km/h for applications in other cities, the design of its EMS system is reexamined for improvement of riding comfort and performances of a train. In order to achieve these objectives, the multipurpose optimization on the basis of the genetic algorithm is applied for the design of EMS-type magnetically levitated vehicle, control parameters of which are optimized both to follow the rail exactly in high-speed and to provide enough riding comfort to passengers. However, the ability to follow sharp irregularities of the rail and to cope with high frequency noises in the gap length control system should be coordinated with riding comfort. The fuzzy logic is introduced into the dynamic control loop and verified to solve the problem. Far better coordination is obtained between the vehicle performances and riding comfort of passengers in high-speed against such various rail conditions. The levitation control with fuzzy logic is shown to be useful for the critical design problem as the high-speed maglev railways.