WorldWideScience

Sample records for hybrid magnetically levitated

  1. Magnetic Levitation.

    Science.gov (United States)

    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…

  2. Magnetic Levitation.

    Science.gov (United States)

    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…

  3. Statics of levitated vehicle model with hybrid magnets

    Institute of Scientific and Technical Information of China (English)

    Desheng LI; Zhiyuan LU; Tianwu DONG

    2009-01-01

    By studying the special characteristics of permanent and electronic magnets, a levitated vehicle model with hybrid magnets is established. The mathematical model of the vehicle is built based on its dynamics equation by studying its machine structure and working principle. Based on the model, the basic characteristics and the effect between the excluding forces from permanent magnets in three different spatial directions are analyzed, statics characteristics of the interference forces in three different spatial directions are studied, and self-adjusting equilibrium characteristics and stabilization are analyzed. Based on the structure above, the vehicle can levitate steadily by control system adjustment.

  4. Zero Power Levitation Control of Hybrid Electro-Magnetic Levitation System by Load Observer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Youn Hyun; Lee, Ju [Hanyang University, Seoul (Korea)

    2001-06-01

    This paper introduces the scheme that improve the control performance of electromagnetic levitation system with zero power controller. Magnetic levitation is used widely, but the electromagnetic force has nonlinear characteristics because it is proportioned to a square of the magnetic flux density and it is in inverse proportion to a square of the air gap. So, it is complicate and difficult to control the electromagnetic force. Besides, it is more difficult to control if the equivalent gap is unknown in case of zero power control. Therefore, this paper proposed the hybrid electro-magnetic levitation control method in which the variable load is estimated by using a load observer and its system is controlled at a new zero power equilibrium air gap position. Also it is confirmed that the proposed control method improve the control performance through simulation and experiment. (author). 10 refs., 17 figs., 1 tab.

  5. Improvement of the Levitation Characteristics in the Magnetic Bearing System Using HTSC-Permanent Magnet Hybrid Structure

    Science.gov (United States)

    Ohashi, Shunsuke

    Magnetic bearing using pining force of a permanent magnet and a high-temperature superconductor has been developed. Additional permanent magnet is introduced to increase the levitation force of the magnetic bearing. In this hybrid magnetic bearing system, levitation force is mainly given by the repulsive force of the permanent magnets, and stability for the lateral direction is given by pining force of the superconductor. The experimental device is developed. A ring type superconductor and a bulk one are examined. Levitation characteristics of the hybrid magnetic bearing are measured. A bulk superconductor shows better characteristics both levitation and lateral stability than ring one. Levitation force of the hybrid system becomes about twice as large as that of the no-hybrid one. Although repulsive force of the permanent magnet decreases lateral stability of the system, its influence becomes small by choosing adequate position of the permanent magnets and the superconductor.

  6. Levitation and Guidance Characteristics of the Permanent magnet-HTSC Hybrid Magnetic Conveyance System

    Science.gov (United States)

    Ohashi, Shunsuke; Dodo, Daiki

    Hybrid magnetically levitated transportation system has been developed. The magnetic rail is set on the ground, and the carrier with permanent magnets and high-Tc superconductors (HTSC) levitates on the rail. In this system, pinning force of HTSC and repulsive force of permanent magnet is combined. Repulsive force of permanent magnet is introduced to support weight. Pinning force is used to support weight of the frame of the carrier and to achieve lateral stability of the carrier. To decrease influence of weight on the levitation gap of the carrier, the weight stage is fixed to the carrier frame by linear sliders, and moves freely for vertical direction. As a result, there is little influence on levitation gap of the carrier. Basic levitation and guidance characteristics of the system are shown. Repulsive force generates very large levitation force. It also generates unstable lateral force. Weight added to the carrier has some influence on lateral stability. Although lateral position recovery force by pinning effect decreases at a heavier weight, the carrier shows enough force to keep lateral stability.

  7. Study on the Levitation and Restoring Force Characteristics of the Improved HTS-permanent Magnet Hybrid Magnetic Bearing

    Science.gov (United States)

    Sugiyama, R.; Oguni, K.; Ohashi, S.

    We have developed the hybrid magnetic bearing using permanent magnets and high temperature bulk super conductor (HTS). In this system, the permanent magnet has ring type structure so that the permanent magnet and the HTS can be set to the stator. The pinning force of the HTS is used for the levitation and the guidance. Repulsive force of the permanent magnets was used in the conventional hybrid system. However the restoring force in the guidance direction of the conventional hybrid system decreases by the side slip force of the permanent magnets. In this research, attractive force of permanent magnets is used for increasing the load weight in the guidance direction. In this paper, influence of the hybrid system on the static characteristics of the rotor is studied. Three-dimensional numerical analysis of the linkage flux (in the levitation and the guidance direction) in the HTS is undertaken. The stator side permanent magnet increases the linkage flux of the levitation direction. Therefore in the hybrid system the linkage flux of the levitation direction increases. The levitation and restoring force of the rotor is measured. The levitation force of the hybrid system becomes smaller than that of the non-hybrid one by attractive force. The rotor in the hybrid system is supported by the pinning force and attractive force. The restoring force of the hybrid system becomes larger than that of the non-hybrid one because of increasing the linkage flux of the levitation direction.

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

    Energy Technology Data Exchange (ETDEWEB)

    Chu, S.Y.; Hwang, Y.J.; Choi, S.; Na, J.B.; Kim, Y.J.; Chang, K.S. [School of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Bae, D.K. [Chungju National University, Chungju 380-702 (Korea, Republic of); Lee, C.Y. [Ultra High-Speed Train Research Department, Korea Railroad Research Institute, Uiwang-Si 437-757 (Korea, Republic of); Ko, T.K., E-mail: tkko@yonsei.ac.kr [School of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2011-11-15

    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{sub 2}).

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Nishio, R.; Ikeda, M.; Sasaki, R. [Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680 (Japan); Ohashi, S., E-mail: ohashi@kansai-u.ac.jp [Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680 (Japan)

    2011-11-15

    The hybrid magnetically levitated carrying system is developed. Control method of running velocity of the carrier is studied. Running velocity is controlled by current of the propulsion coils. Propulsion characteristcs are improved. 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. Magnetic levitation of single cells

    National Research Council Canada - National Science Library

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

    2015-01-01

    .... 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...

  12. Improvement of the levitation stability of the HTSC-permanent magnet hybrid bearing by using the new arrangement of the permanent magnet

    Science.gov (United States)

    Sukedaia, M.; Emoto, K.; Sugiyama, R.; Ohashi, S.

    The hybrid magnetic bearing using permanent magnets and the high temperature superconductor (HTSC) has been developed. Repulsive force of the permanent magnet is introduced to increase the load weight of the magnetic bearing. Effect of the hybrid system has been shown. Although the previous configuration improves the load weight of the rotor, levitation and guidance stability has been decreased because of the repulsive force of the permanent magnet. Three-dimensional numerical analysis of the system has been undertaken to reduce lateral force which decreases lateral stability of the rotor. From the results, effective arrangement of the hybrid system is given. Increment of the load weight is confirmed. Influence of the hybrid system on the pinning force between the HTSC and the permanent magnet is shown to be smaller than previous one.

  13. Improvement of levitation force characteristics in magnetic levitation type seismic isolation device composed of HTS bulk and permanent magnet

    Science.gov (United States)

    Tsuda, M.; Kawasaki, T.; Yagai, T.; Hamajima, T.

    2008-02-01

    Magnetic levitation type seismic isolation device composed of HTS bulks and permanent magnets can theoretically remove horizontal vibration completely. It is, however, not easy to generate the large levitation force by using only the levitation system composed of HTS bulk and permanent magnet (HTS-PM system). We focused on a hybrid levitation system composed of the HTS-PM system and the PM-PM system composed of only permanent magnets and investigated the suitable arranging method of the hybrid system for improving levitation force and obtaining stable levitation. In order to clarify the most suitable permanent magnet arrangement in the PM-PM system for the levitation force improvement, repulsive force between permanent magnets was measured in various kinds of the PM-PM system. The maximum repulsive force per unit area in the PM-PM system was at least three times larger than the levitation force per unit area in the HTS-PM system, so that the levitation force in the hybrid system was larger than that of the HTS-PM system. Stable levitation was also achieved in the hybrid system. This is because repulsive force in the PM-PM system against horizontal displacement was much smaller than restoring force in the HTS-PM system.

  14. Magnetic levitation of single cells.

    Science.gov (United States)

    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.

  15. Attractors of hybrid magnetic levitation ball system and stability research%混合磁悬浮球系统吸引子及稳定性研究

    Institute of Scientific and Technical Information of China (English)

    马凤莲; 江东; 张翔; 杨嘉祥

    2012-01-01

    为了避免磁悬浮球混沌运动,设计了永磁和电磁混合型磁悬浮球模型,推导了磁悬浮球的动力学方程,并建立了磁悬浮球系统的仿真模型.通过改变初始状态,得到不同初始条件下的磁悬浮球系统吸引子.混合型磁悬浮球系统具有单、双两类吸引子,双吸引子表现出较强的混沌特性,磁悬浮球围绕平衡点附近的波动较大,磁悬浮球由混沌运动状态向非混沌运动状态转变时,由双吸引子逐渐向单吸引子过渡,系统演变为具有周期特性的运动状态,再演变为相轨迹收敛于一个点,磁悬浮球处于较稳定的运动状态.仿真和实验结果表明,通过磁悬浮球吸引子的研究可了解混沌产生的初始区间,进而为设计中避开混沌区实现磁悬浮球的稳定运动提供了参考依据.%In order to avoid magnetic levitation ball in the chaotic region, the model of permanent magnet and electromagnet hybrid magnetic levitation ball system was designed,the dynamic equation of magnetic levitation ball was deduced, and the magnetic levitation system simulation mode] was set up. The different attractors were obtained by changing the initial states. The simulation results show that the hybrid magnetic levitation ball system designed has single and double two types of attractors. The double attractors have stronger chaotic performance and the magnetic levitation ball has greater fluctuation around the equilibrium point. The attractor is gradually from double attractors to single attractor in magnetic levitation ball from chaotic station transition to non-chaotic state, the magnetic levitation ball becomes a cyclical nature of the motion state and it gradually evolves to a point of phase trajectories when the system presents a stable state. Simulation and test show that the chaos generated by the initial region can be understood by studying the magnetic levitation ball attractors, which provides a reference design basis to a

  16. Magnet levitation at your fingertips

    Science.gov (United States)

    Geim, A. K.; Simon, M. D.; Boamfa, M. I.; Heflinger, L. O.

    1999-07-01

    The stable levitation of magnets is forbidden by Earnshaw's theorem, which states that no stationary object made of magnets in a fixed configuration can be held in stable equilibrium by any combination of static magnetic or gravitational forces. Earnshaw's theorem can be viewed as a consequence of the Maxwell equations, which do not allow the magnitude of a magnetic field in a free space to possess a maximum, as required for stable equilibrium. Diamagnets (which respond to magnetic fields with mild repulsion) are known to flout the theorem, as their negative susceptibility results in the requirement of a minimum rather than a maximum in the field's magnitude. Nevertheless, levitation of a magnet without using superconductors is widely thought to be impossible. We find that the stable levitation of a magnet can be achieved using the feeble diamagnetism of materials that are normally perceived as being non-magnetic, so that even human fingers can keep a magnet hovering in mid-air without touching it.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  19. Repulsive Magnetic Levitation Systems Using Motion Control of Magnets

    OpenAIRE

    水野, 毅; 石野, 裕二; 荒木, 獻次; 大内, 泰平

    1995-01-01

    Repulsive magnetic levitation systems with magnets driven by actuators were studied in this paper. In one system, a levitation magnet was driven in the direction of repulsive force to control the position and vibration of the levitated object. In another, a levitation magnet was moved in the lateral directions to stabilize the system in the manner of an inverted pendulum. The first type was studied experimentally with an experimental setup using a magnetostrictive actuator. The damping charac...

  20. Passive levitation in alternating magnetic fields

    Science.gov (United States)

    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.

  1. An ionization chamber with magnetic levitated electrodes

    CERN Document Server

    Kawaguchi, T

    1999-01-01

    A new type of ionization chamber which has magnetically levitated electrodes has been developed. The electrodes are supplied voltages for the repelling of ions by a battery which is also levitated with the electrodes. The characteristics of this ionization chamber are investigated in this paper.

  2. Magnetic levitation and MHD propulsion

    Science.gov (United States)

    Tixador, P.

    1994-04-01

    Magnetic levitation and MHD propulsion are now attracting attention in several countries. Different superconducting MagLev and MHD systems will be described concentrating on, above all, the electromagnetic aspect. Some programmes occurring throughout the world will be described. Magnetic levitated trains could be the new high speed transportation system for the 21st century. Intensive studies involving MagLev trains using superconductivity have been carried out in Japan since 1970. The construction of a 43 km long track is to be the next step. In 1991 a six year programme was launched in the United States to evaluate the performances of MagLev systems for transportation. The MHD (MagnetoHydroDynamic) offers some interesting advantages (efficiency, stealth characteristics, ...) for naval propulsion and increasing attention is being paid towards it nowadays. Japan is also up at the top with the tests of Yamato I, a 260 ton MHD propulsed ship. Depuis quelques années nous assistons à un redémarrage de programmes concernant la lévitation et la propulsion supraconductrices. Différents systèmes supraconducteurs de lévitation et de propulsion seront décrits en examinant plus particulièrement l'aspect électromagnétique. Quelques programmes à travers le monde seront abordés. Les trains à sustentation magnétique pourraient constituer un nouveau mode de transport terrestre à vitesse élevée (500 km/h) pour le 21^e siècle. Les japonais n'ont cessé de s'intéresser à ce système avec bobine supraconductrice. Ils envisagent un stade préindustriel avec la construction d'une ligne de 43 km. En 1991 un programme américain pour une durée de six ans a été lancé pour évaluer les performances des systèmes à lévitation pour le transport aux Etats Unis. La MHD (Magnéto- Hydro-Dynamique) présente des avantages intéressants pour la propulsion navale et un regain d'intérêt apparaît à l'heure actuelle. Le japon se situe là encore à la pointe des d

  3. Effects of Magnet Size and Geometry on Magnetic Levitation Force

    Institute of Scientific and Technical Information of China (English)

    M. K. Alqadi; H. M. Al-khateeb; F. Y. Alzoubi; N. Y. Ayoub

    2007-01-01

    We obtain analytical relations for the levitation force as a function of dimensions of the superconductor-magnet system. The force has been calculated on the basis of the dipole-dipole interaction model.The effect of thickness of the superconductor on the levitation force is investigated. The results show that the influence of geometry and thickness of the magnet becomes significantly large at small levitation distances. Furthermore, approximating the permanent magnet as a point dipole results in an inaccurate estimation of the levitation force.

  4. Vibrations in Magnet/Superconductor Levitation Systems

    Institute of Scientific and Technical Information of China (English)

    F. Y. Alzoubi; H. M. Al-khateeb; M. K. Alqadi; N. Y. Ayoub

    2006-01-01

    The problem of a small magnet levitating above a very thin superconducting disc in the Meissner state is analysed. The dipole-dipole interaction model is employed to derive analytical expressions for the interaction energy, levitation force, magnetic stiffness and frequency of small vibrations about the equilibrium position in two different configurations, i.e. with the magnetic moment parallel and perpendicular to the superconductor. The results show that the frequency of small vibrations decreases with the increasing levitation height for a particular radius of the superconducting disc, which is in good agreement with the experimental results. However, the frequency increases monotomcally up to saturation by increasing the radius of the disc for a particular height of the magnet. In addition, the frequency of vibrations is higher when the system is in the vertical configuration than that when the system is in the horizontal configuration.

  5. The Inductrack Approach to Magnetic Levitation

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Magnetic Levitation Experiments with the Electrodynamic Wheel

    Science.gov (United States)

    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.

  7. Magnetic levitation system for moving objects

    Science.gov (United States)

    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.

  8. Stop of magnetic flux movement in levitating superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Smolyak, B.M., E-mail: b-smolyak@yandex.ru; Zakharov, M.S., E-mail: maksim.s.zakharov@gmail.com

    2017-01-15

    Highlights: • A direct experimental study of magnetic flux creep in the levitating superconductor. • When a levitating object is in a fixed position, magnetic flux movement is observed. • Levitation stops flux creep process. - Abstract: A phenomenon of magnetic relaxation stopping in a levitating superconductor was studied. It was experimentally shown that magnetic flux creep (diffusion of flux lines to regions with lower vortex density) is absent in magnetic suspension of the superconductor. Magnetic relaxation arises, when a rigid constraint that fixes a position of the superconductor relative to a magnet is imposed on a levitating object. It is assumed that oscillations of magnetic structure, which is due to free oscillations of the levitating superconductor, stop magnetic relaxation.

  9. Method for obtaining large levitation pressure in superconducting magnetic bearings

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL)

    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.

  10. Method for obtaining large levitation pressure in superconducting magnetic bearings

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL)

    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.

  11. Trial Application of Pulse-Field Magnetization to Magnetically Levitated Conveyor System

    Directory of Open Access Journals (Sweden)

    Yoshihito Miyatake

    2012-01-01

    Full Text Available Magnetically levitated conveyor system using superconductors is discussed. The system is composed of a levitated conveyor, magnetic rails, a linear induction motor, and some power supplies. In the paper, pulse-field magnetization is applied to the system. Then, the levitation height and the dynamics of the conveyor are controlled. The static and dynamic characteristics of the levitated conveyor are discussed.

  12. Aerodynamics of magnetic levitation (MAGLEV) trains

    Science.gov (United States)

    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.

  13. Magnetic levitation from negative permeability materials

    Energy Technology Data Exchange (ETDEWEB)

    Coffey, Mark W., E-mail: mcoffey@mines.edu [Department of Physics, Colorado School of Mines, Golden, CO 80401 (United States)

    2012-09-03

    As left-handed materials and metamaterials are becoming more prevalent, we examine the effect of negative permeability upon levitation force. We first consider two half spaces of differing permeability and a point magnetic source, so that the method of images may be employed. We determine that the resulting force may be larger than for conventional magnetic materials. We then illustrate the inclusion of a finite sample thickness. -- Highlights: ► The effect of negative permeability upon levitation force is considered. ► Such an effect could be realized with metamaterials. ► The resulting force may be larger than with conventional materials. ► The analysis is extended to allow for a finite sample thickness. ► Representative numerical values are given.

  14. Knolle Magnetrans: A magnetically levitated train system

    Science.gov (United States)

    Knolle, Ernst G.

    1992-05-01

    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.

  15. Spin-stabilized magnetic levitation without vertical axis of rotation

    Science.gov (United States)

    Romero, Louis [Albuquerque, NM; Christenson, Todd [Albuquerque, NM; Aaronson, Gene [Albuquerque, NM

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Development and Control of a Non Linear Magnetic Levitation System

    Directory of Open Access Journals (Sweden)

    A Sanjeevi Gandhi

    2013-06-01

    Full Text Available Nowadays, studies to develop and control non linear systems is of great significance. Magnetic Levitation System has gained considerable interests due to its great practical importance in different engineering fields In this paper an electromagnetic levitation system was developed and mathematical model for the system was derived. The developed system was controlled manually.

  18. Potential Development of Vehicle Traction Levitation Systems with Magnetic Suspension

    Directory of Open Access Journals (Sweden)

    A.V. Kireev

    2015-03-01

    Full Text Available Below is given the brief analysis of development trend for vehicle traction levitation systems with magnetic suspension. It is presented the assessment of potential development of traction levitation systems in terms of their simplicity. The examples are considered of technical solutions focused on reducing the complexity of transport systems. It is proposed the forecast of their further development.

  19. Smart-Phone Based Magnetic Levitation for Measuring Densities.

    Science.gov (United States)

    Knowlton, Stephanie; Yu, Chu Hsiang; Jain, Nupur; Ghiran, Ionita Calin; Tasoglu, Savas

    2015-01-01

    Magnetic levitation, which uses a magnetic field to suspend objects in a fluid, is a powerful and versatile technology. We develop a compact magnetic levitation platform compatible with a smart-phone to separate micro-objects and estimate the density of the sample based on its levitation height. A 3D printed attachment is mechanically installed over the existing camera unit of a smart-phone. Micro-objects, which may be either spherical or irregular in shape, are suspended in a paramagnetic medium and loaded in a microcapillary tube which is then inserted between two permanent magnets. The micro-objects are levitated and confined in the microcapillary at an equilibrium height dependent on their volumetric mass densities (causing a buoyancy force toward the edge of the microcapillary) and magnetic susceptibilities (causing a magnetic force toward the center of the microcapillary) relative to the suspending medium. The smart-phone camera captures magnified images of the levitating micro-objects through an additional lens positioned between the sample and the camera lens cover. A custom-developed Android application then analyzes these images to determine the levitation height and estimate the density. Using this platform, we were able to separate microspheres with varying densities and calibrate their levitation heights to known densities to develop a technique for precise and accurate density estimation. We have also characterized the magnetic field, the optical imaging capabilities, and the thermal state over time of this platform.

  20. Smart-Phone Based Magnetic Levitation for Measuring Densities.

    Directory of Open Access Journals (Sweden)

    Stephanie Knowlton

    Full Text Available Magnetic levitation, which uses a magnetic field to suspend objects in a fluid, is a powerful and versatile technology. We develop a compact magnetic levitation platform compatible with a smart-phone to separate micro-objects and estimate the density of the sample based on its levitation height. A 3D printed attachment is mechanically installed over the existing camera unit of a smart-phone. Micro-objects, which may be either spherical or irregular in shape, are suspended in a paramagnetic medium and loaded in a microcapillary tube which is then inserted between two permanent magnets. The micro-objects are levitated and confined in the microcapillary at an equilibrium height dependent on their volumetric mass densities (causing a buoyancy force toward the edge of the microcapillary and magnetic susceptibilities (causing a magnetic force toward the center of the microcapillary relative to the suspending medium. The smart-phone camera captures magnified images of the levitating micro-objects through an additional lens positioned between the sample and the camera lens cover. A custom-developed Android application then analyzes these images to determine the levitation height and estimate the density. Using this platform, we were able to separate microspheres with varying densities and calibrate their levitation heights to known densities to develop a technique for precise and accurate density estimation. We have also characterized the magnetic field, the optical imaging capabilities, and the thermal state over time of this platform.

  1. A new magnetic bearing using Halbach magnet arrays for a magnetic levitation stage.

    Science.gov (United States)

    Choi, Young-Man; Lee, Moon G; Gweon, Dae-Gab; Jeong, Jaehwa

    2009-04-01

    Next-generation lithography requires a high precision stage, which is compatible with a high vacuum condition. A magnetic levitation stage with six degrees-of-freedom is considered state-of-the-art technology for a high vacuum condition. The noncontact characteristic of magnetic levitation enables high precision positioning as well as no particle generation. To position the stage against gravity, z-directional electromagnetic levitation mechanisms are widely used. However, if electromagnetic actuators for levitation are used, heat is inevitably generated, which deforms the structures and degrades accuracy of the stage. Thus, a gravity compensator is required. In this paper, we propose a new magnetic bearing using Halbach magnet arrays for a magnetic levitation stage. The novel Halbach magnetic bearing exerts a force four times larger than a conventional magnetic bearing with the same volume. We also discuss the complementary characteristics of the two magnetic bearings. By modifying the height of the center magnet in a Halbach magnetic bearing, a performance compromise between levitating force density and force uniformity is obtained. The Halbach linear active magnetic bearing can be a good solution for magnetic levitation stages because of its large and uniform levitation force.

  2. Magnetically levitated autoparametric broadband vibration energy harvesting

    Science.gov (United States)

    Kurmann, L.; Jia, Y.; Manoli, Y.; Woias, P.

    2016-11-01

    Some of the lingering challenges within the current paradigm of vibration energy harvesting (VEH) involve narrow operational frequency range and the inevitable non-resonant response from broadband noise excitations. Such VEHs are only suitable for limited applications with fixed sinusoidal vibration, and fail to capture a large spectrum of the real world vibration. Various arraying designs, frequency tuning schemes and nonlinear vibratory approaches have only yielded modest enhancements. To fundamentally address this, the paper proposes and explores the potentials in using highly nonlinear magnetic spring force to activate an autoparametric oscillator, in order to realize an inherently broadband resonant system. Analytical and numerical modelling illustrate that high spring nonlinearity derived from magnetic levitation helps to promote the 2:1 internal frequency matching required to activate parametric resonance. At the right internal parameters, the resulting system can intrinsically exhibit semi-resonant response regardless of the bandwidth of the input vibration, including broadband white noise excitation.

  3. Magnetic levitation Maglev technology and applications

    CERN Document Server

    Han, Hyung-Suk

    2016-01-01

    This book provides a comprehensive overview of magnetic levitation (Maglev) technologies, from fundamental principles through to the state-of-the-art, and describes applications both realised and under development. It includes a history of Maglev science and technology showing the various milestones in its advancement. The core concepts, operating principles and main challenges of Maglev applications attempted across various fields are introduced and discussed. The principle difficulties encountered when applying Maglev technology to different systems, namely air gap control and stabilization, are addressed in detail. The book describes how major advancements in linear motor and magnet technologies have enabled the development of the linear-motor-powered Maglev train, which has a high speed advantage over conventional wheeled trains and has the potential to reach speed levels achieved by aircraft. However, many expect that Maglev technology to be a green technology that is applied not only in rail transportat...

  4. Interaction between propulsion and levitation system in the HTSC-permanent magnet conveyance system

    Science.gov (United States)

    Ohashi, S.; Nishio, R.; Hashikawa, T.

    2010-11-01

    The magnetically levitated conveyance system has been developed. Pinning force of high temperature bulk superconductors (HTSC) are used for the levitation and the guidance of the carrier. The magnetic rail is set on the ground, and flux from the magnetic rail is pinned by HTSCs on the carrier body. To increase the load weight, the repulsive force of the permanent magnet is introduced. The hybrid levitation system is composed. The 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. As the load stage is connected to the carrier body by the linear sliders, the mass of the load weight does not act on the carrier body. The interaction between the electromagnet and the permanent magnet under the load stage generates the propulsion force. The electromagnet is constructed by the air core coils, and excited only when the load stage passes. The interaction between the propulsion and the levitation system is investigated. Disturbance of the propulsion system on the levitation and the guidance force is measured. The results show the influence of the propulsion electromagnet on the pinning force is little, and this propulsion system works effectively.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    Hull, John R.

    2000-06-01

    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 non-negligible 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 analogue of Earnshaw's theorem, in which the vertical stiffness is equal to the sum of the horizontal stiffness at the field-cooling position, independent of the angular distribution of magnetic moments within the PM.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. [Energy Technology Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2000-06-01

    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 non-negligible 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 analogue of Earnshaw's theorem, in which the vertical stiffness is equal to the sum of the horizontal stiffness at the field-cooling position, independent of the angular distribution of magnetic moments within the PM. (author)

  9. Position control of active magnetic levitation using sphere-shaped HTS bulk for inertial nuclear fusion

    Science.gov (United States)

    Suga, K.; Riku, K.; Agatsuma, K.; Ueda, H.; Ishiyama, A.

    2008-02-01

    We have developed an active magnetic levitation system that comprises a field-cooled disk-shaped or sphere-shaped HTS bulk and multiple ring-shaped electromagnets. In this system, the levitation height of HTS bulk can be controlled by adjusting the operating current of each electromagnet individually. Further, the application of the vertical noncontact levitation system is expected due to its levitation stability without mechanical supports. We assume that this system is applied to inertial nuclear fusion. However, one of the important issues is to achieve position control with high accuracy of the fusion fuel in order to illuminate the target evenly over the entire surface. Therefore, this system is applied to the levitation and position control of a sphere-shaped superconducting capsule containing nuclear fusion fuel. In this study, we designed and constructed a position control system for the sphere-shaped HTS bulk with a diameter of 5 mm by using numerical simulation based on hybrid finite element and boundary element analysis. We then carried out the experiment of levitation height and position control characteristics of the HTS bulk in this system. With regard to position control, accuracies within 59 ?m are obtained.

  10. Superconducting bulk magnets for magnetic levitation systems

    Science.gov (United States)

    Fujimoto, H.; Kamijo, H.

    2000-06-01

    The major applications of high-temperature superconductors have mostly been confined to products in the form of wires and thin films. However, recent developments show that rare-earth REBa 2Cu 3O 7- x and light rare-earth LREBa 2Cu 3O 7- x superconductors prepared by melt processes have a high critical-current density at 77 K and high magnetic fields. These superconductors will promote the application of bulk high-temperature superconductors in high magnetic fields; the superconducting bulk magnet for the Maglev train is one possible application. We investigated the possibility of using bulk magnets in the Maglev system, and examined flux-trapping characteristics of multi-superconducting bulks arranged in array.

  11. Two-dimensional inverted pendulum using repulsive magnetic levitation

    Energy Technology Data Exchange (ETDEWEB)

    Eirich, Max; Ishino, Yuji; Takasaki, Masaya; Mizuno, Takeshi [Saitama Univ. (Japan). Dept. of Mechanical Engineering

    2010-07-01

    The active control of two-degree-of-freedom motion of the repulsive levitated object (floator) is studied. In this system of permanent magnets, the vertical motions of the rotor are passively supported by repulsive forces between the permanent magnets. The inclination angle is actively stabilized using the motion control of additional magnets. (orig.)

  12. Three-dimensional Tissue Culture Based on Magnetic Cell Levitation

    Science.gov (United States)

    Souza, Glauco R.; Molina, Jennifer R.; Raphael, Robert M.; Ozawa, Michael G.; Stark, Daniel J.; Levin, Carly S.; Bronk, Lawrence F.; Ananta, Jeyarama S.; Mandelin, Jami; Georgescu, Maria-Magdalena; Bankson, James A.; Gelovani, Juri G.

    2015-01-01

    Cell culture is an essential tool for drug discovery, tissue engineering, and stem cell research. Conventional tissue culture produces two-dimensional (2D) cell growth with gene expression, signaling, and morphology that can differ from those in vivo and thus compromise clinical relevancy1–5. Here we report a three-dimensional (3D) culture of cells based on magnetic levitation in the presence of hydrogels containing gold and magnetic iron oxide (MIO) nanoparticles plus filamentous bacteriophage. This methodology allows for control of cell mass geometry and guided, multicellular clustering of different cell types in co-culture through spatial variance of the magnetic field. Moreover, magnetic levitation of human glioblastoma cells demonstrates similar protein expression profiles to those observed in human tumor xenografts. Taken together, these results suggest levitated 3D culture with magnetized phage-based hydrogels more closely recapitulates in vivo protein expression and allows for long-term multi-cellular studies. PMID:20228788

  13. Research on typical topologies of a tubular horizontal-gap passive magnetic levitation vibration isolator

    Directory of Open Access Journals (Sweden)

    Zhou Yiheng

    2017-01-01

    Full Text Available Magnetic levitation vibration isolators have attracted more and more attention in the field of high-precision measuring and machining equipment. In this paper, we describe a tubular horizontal-gap passive magnetic levitation vibration isolator. Four typical topologies of the tubular horizontal-gap passive magnetic levitation vibration isolator are proposed. The analytical expression of magnetic force is derived. The relationship between levitation force, force density, force ripple and major structural parameters are analysed by finite element method, which is conductive to the design and optimization of the tubular horizontal-gap passive magnetic levitation vibration isolator. The force characteristics of different topologies of the tubular horizontal-gap passive magnetic levitation vibration isolator are compared and evaluated from the aspect of force density, force ripple and manufacturability. In comparison with conventional passive magnetic levitation vibration isolators, the proposed tubular horizontal-gap passive magnetic levitation vibration isolator shows advantage in higher force density.

  14. Stable diamagnetic self-levitation of a micro-magnet by improvement of its magnetic gradients

    NARCIS (Netherlands)

    Profijt, H.B.; Pigot, C.; Reyne, G.; Grechishkin, R.M.; Cugat, O.

    2009-01-01

    A disc-shaped SmCo magnet with a diameter of 0.85 mm is levitated above a graphite diamagnetic plate at a height of about 14 μm. The magnet is magnetised into a double dipole. The levitation of multipolar magnets above a diamagnetic material was suggested in 1956 by Boerdijk and patented in 1995 by

  15. Stable diamagnetic self-levitation of a micro-magnet by improvement of its magnetic gradients

    NARCIS (Netherlands)

    Profijt, H.B.; Pigot, C.; Reyne, G.; Grechishkin, R.M.; Cugat, O.

    2009-01-01

    A disc-shaped SmCo magnet with a diameter of 0.85 mm is levitated above a graphite diamagnetic plate at a height of about 14 μm. The magnet is magnetised into a double dipole. The levitation of multipolar magnets above a diamagnetic material was suggested in 1956 by Boerdijk and patented in 1995 by

  16. FPGA Fuzzy Controller Design for Magnetic Ball Levitation

    Directory of Open Access Journals (Sweden)

    Basil Hamed

    2012-09-01

    Full Text Available this paper presents a fuzzy controller design for nonlinear system using FPGA. A magnetic levitation system is considered as a case study and the fuzzy controller is designed to keep a magnetic object suspended in the air counteracting the weight of the object. Fuzzy controller will be implemented using FPGA chip. The design will use a high-level programming language HDL for implementing the fuzzy logic controller using the Xfuzzy tools to implement the fuzzy logic controller into HDL code. This paper, advocates a novel approach to implement the fuzzy logic controller for magnetic ball levitation system by using FPGA.

  17. Design, implementation and control of a magnetic levitation device

    Science.gov (United States)

    Shameli, Ehsan

    Magnetic levitation technology has shown a great deal of promise for micromanipulation tasks. Due to the lack of mechanical contact, magnetic levitation systems are free of problems caused by friction, wear, sealing and lubrication. These advantages have made magnetic levitation systems a great candidate for clean room applications. In this thesis, a new large gap magnetic levitation system is designed, developed and successfully tested. The system is capable of levitating a 6.5(gr) permanent magnet in 3D space with an air gap of approximately 50(cm) with the traveling range of 20x20x30 mm3. The overall positioning accuracy of the system is 60mum. With the aid of finite elements method, an optimal geometry for the magnetic stator is proposed. Also, an energy optimization approach is utilized in the design of the electromagnets. In order to facilitate the design of various controllers for the system, a mathematical model of the magnetic force experienced by the levitated object is obtained. The dynamic magnetic force model is determined experimentally using frequency response system identification. The response of the system components including the power amplifiers, and position measurement system are also considered in the development of the force model. The force model is then employed in the controller design for the magnetic levitation device. Through a modular approach, the controller design for the 3D positioning system is started with the controller design for the vertical direction, i.e. z, and then followed by the controller design in the horizontal directions, i.e. x and y. For the vertical direction, several controllers such as PID, feed forward and feedback linearization are designed and their performances are compared. Also a control command conditioning method is introduced as a solution to increase the control performance and the results of the proposed controller are compared with the other designs. Experimental results showed that for the magnetic

  18. Magnetically levitated space elevator to low-earth orbit

    Science.gov (United States)

    Hull, John R.; Mulcahy, Thomas M.; Niemann, Ralph C.

    2002-05-01

    The properties of currently available NbTi superconductors 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 ≈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 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. A preliminary economic analysis estimates the cost to orbit at <30/kg when amortized over ten years with a large volume of traffic; estimated construction cost is well within the ability of many industrial nations.

  19. Cascade Control of Magnetic Levitation with Sliding Modes

    Directory of Open Access Journals (Sweden)

    Eroğlu Yakup

    2016-01-01

    Full Text Available The effectiveness and applicability of magnetic levitation systems need precise feedback control designs. A cascade control approach consisting of sliding mode control plus sliding mode control (SMC plus SMC is designed to solve position control problem and to provide a high control performance and robustness to the magnetic levitation plant. It is shown that the SMC plus SMC cascade controller is able to eliminate the effects of the inductance related uncertainties of the electromagnetic coil of the plant and achieve a robust and precise position control. Experimental and numerical results are provided to validate the effectiveness and feasibility of the method.

  20. Simulation Model of Magnetic Levitation Based on NARX Neural Networks

    Directory of Open Access Journals (Sweden)

    Dragan Antić

    2013-04-01

    Full Text Available In this paper, we present analysis of different training types for nonlinear autoregressive neural network, used for simulation of magnetic levitation system. First, the model of this highly nonlinear system is described and after that the Nonlinear Auto Regressive eXogenous (NARX of neural network model is given. Also, numerical optimization techniques for improved network training are described. It is verified that NARX neural network can be successfully used to simulate real magnetic levitation system if suitable training procedure is chosen, and the best two training types, obtained from experimental results, are described in details.

  1. Stable levitation of steel rotors using permanent magnets and high-temperature superconductors

    Science.gov (United States)

    Hull, J. R.; Passmore, J. L.; Mulcahy, T. M.; Rossing, T. D.

    1994-07-01

    Individual freely spinning magnetic steel rotors were levitated by combining the attractive force between permanent magnets and the rotor with the repulsive force between high-temperature superconductors and the steel. The levitation force and stiffness of several configurations are presented, and the application of this levitation method to high-speed bearings is discussed.

  2. Levitation performance of YBCO bulk in different applied magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W. [Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu 610031 (China)], E-mail: asclab@asclab.cn; Wang, S.Y.; Jing, H.; Zheng, J.; Jiang, M.; Wang, J.S. [Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu 610031 (China)

    2008-07-01

    The maglev performance of bulk high-T{sub c} superconductor (HTS) is investigated above three different types of permanent magnet guideways (PMGs). The main difference among these PMGs is the method used to concentrate the magnetic flux. The experimental results indicate that the levitation force depends only in part on the peak value of the magnetic field. The variation of the vertical component of the magnetic field (B{sub z}), and the structure of the magnetic field are also responsible for the levitation force. These results imply that the permanent magnet with high coercive force is better at concentrating flux th an iron. The conclusions contribute in a very helpful way to the design and optimization of PMGs for HTS maglev systems.

  3. Levitation of Superconductive Cable in Earth Magnetic Field

    Directory of Open Access Journals (Sweden)

    Bohus Ulrych

    2006-01-01

    Full Text Available The paper represents an introductory study about a superconductive cable levitating in Earth’s magnetic field. Built are two mathematical models of the problem providing both the shape of the arc of the cable and forces acting along it. The theoretical analysis is supplemented with an illustrative example.

  4. Annoyance caused by the sounds of a magnetic levitation train

    NARCIS (Netherlands)

    Vos, J.

    2004-01-01

    In a laboratory study, the annoyance caused by the passby sounds from a magnetic levitation (maglev) train was investigated. The listeners were presented with various sound fragments. The task of the listeners was to respond after each presentation to the question: "How annoying would you find the s

  5. Annoyance caused by the sounds of a magnetic levitation train

    NARCIS (Netherlands)

    Vos, J.

    2004-01-01

    In a laboratory study, the annoyance caused by the passby sounds from a magnetic levitation (maglev) train was investigated. The listeners were presented with various sound fragments. The task of the listeners was to respond after each presentation to the question: "How annoying would you find the s

  6. Annoyance caused by the sounds of a magnetic levitation train

    NARCIS (Netherlands)

    Vos, J.

    2004-01-01

    In a laboratory study, the annoyance caused by the passby sounds from a magnetic levitation (maglev) train was investigated. The listeners were presented with various sound fragments. The task of the listeners was to respond after each presentation to the question: "How annoying would you find the

  7. Dependence of levitation force on frequency of an oscillating magnetic levitation field in a bulk YBCO superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Carter, Hamilton, E-mail: hcarter3@nmsu.edu [Department of Physics, New Mexico State University, Las Cruces, NM 88003 (United States); Pate, Stephen, E-mail: pate@nmsu.edu [Department of Physics, New Mexico State University, Las Cruces, NM 88003 (United States); Goedecke, George, E-mail: ggoedeck@nmsu.edu [Department of Physics, New Mexico State University, Las Cruces, NM 88003 (United States)

    2013-02-14

    Highlights: ► AC magnetic field strength required for levitation is independent of frequency. ► RMS magnetic field strength is in good agreement with DC magnetic field strength. ► Dependence of YBCO levitation force on AC magnetic field frequency is investigated. -- Abstract: The dependence of the magnetic field strength required for levitation of a melt textured, single domain YBCO superconductor disk on the frequency of the current generating the levitating magnetic field has been investigated. The magnetic field strength is found to be independent of frequency between 10 and 300 Hz. This required field strength is found to be in good experimental and theoretical agreement with the field strength required to levitate the same superconductor with a non-oscillating magnetic field. Hysteretic losses within the superconductor predicted by Bean’s critical-state model were also calculated. The measured data rules out any significant Bean’s model effects on the required levitation field strength within the measured frequency range.

  8. Lateral restoring force on a magnet levitated above a superconductor

    Science.gov (United States)

    Davis, L. C.

    1990-01-01

    The lateral restoring force on a magnet levitated above a superconductor is calculated as a function of displacement from its original position at rest using Bean's critical-state model to describe flux pinning. The force is linear for small displacements and saturates at large displacements. In the absence of edge effects the force always attracts the magnet to its original position. Thus it is a restoring force that contributes to the stability of the levitated magnet. In the case of a thick superconductor slab, the origin of the force is a magnetic dipole layer consisting of positive and negative supercurrents induced on the trailing side of the magnet. The qualitative behavior is consistent with experiments reported to date. Effects due to the finite thickness of the superconductor slab and the granular nature of high-Tc materials are also considered.

  9. Dependence of levitation force on frequency of an oscillating magnetic levitation field in a bulk YBCO superconductor

    Science.gov (United States)

    Carter, Hamilton; Pate, Stephen; Goedecke, George

    2013-02-01

    The dependence of the magnetic field strength required for levitation of a melt textured, single domain YBCO superconductor disk on the frequency of the current generating the levitating magnetic field has been investigated. The magnetic field strength is found to be independent of frequency between 10 and 300 Hz. This required field strength is found to be in good experimental and theoretical agreement with the field strength required to levitate the same superconductor with a non-oscillating magnetic field. Hysteretic losses within the superconductor predicted by Bean’s critical-state model were also calculated. The measured data rules out any significant Bean’s model effects on the required levitation field strength within the measured frequency range.

  10. Three-dimensional cell culturing by magnetic levitation.

    Science.gov (United States)

    Haisler, William L; Timm, David M; Gage, Jacob A; Tseng, Hubert; Killian, T C; Souza, Glauco R

    2013-10-01

    Recently, biomedical research has moved toward cell culture in three dimensions to better recapitulate native cellular environments. This protocol describes one method for 3D culture, the magnetic levitation method (MLM), in which cells bind with a magnetic nanoparticle assembly overnight to render them magnetic. When resuspended in medium, an external magnetic field levitates and concentrates cells at the air-liquid interface, where they aggregate to form larger 3D cultures. The resulting cultures are dense, can synthesize extracellular matrix (ECM) and can be analyzed similarly to the other culture systems using techniques such as immunohistochemical analysis (IHC), western blotting and other biochemical assays. This protocol details the MLM and other associated techniques (cell culture, imaging and IHC) adapted for the MLM. The MLM requires 45 min of working time over 2 d to create 3D cultures that can be cultured in the long term (>7 d).

  11. Reduction of characteristic RL time for fast, efficient magnetic levitation

    Science.gov (United States)

    Li, Yuqing; Feng, Guosheng; Wang, Xiaofeng; Wu, Jizhou; Ma, Jie; Xiao, Liantuan; Jia, Suotang

    2017-09-01

    We demonstrate the reduction of characteristic time in resistor-inductor (RL) circuit for fast, efficient magnetic levitation according to Kirchhoff's circuit laws. The loading time is reduced by a factor of ˜4 when a high-power resistor is added in series with the coils. By using the controllable output voltage of power supply and voltage of feedback circuit, the loading time is further reduced by ˜ 3 times. The overshoot loading in advance of the scheduled magnetic field gradient is equivalent to continuously adding a resistor without heating. The magnetic field gradient with the reduced loading time is used to form the upward magnetic force against to the gravity of the cooled Cs atoms, and we obtain an effectively levitated loading of the Cs atoms to a crossed optical dipole trap.

  12. Reduction of characteristic RL time for fast, efficient magnetic levitation

    Directory of Open Access Journals (Sweden)

    Yuqing Li

    2017-09-01

    Full Text Available We demonstrate the reduction of characteristic time in resistor-inductor (RL circuit for fast, efficient magnetic levitation according to Kirchhoff’s circuit laws. The loading time is reduced by a factor of ∼4 when a high-power resistor is added in series with the coils. By using the controllable output voltage of power supply and voltage of feedback circuit, the loading time is further reduced by ∼ 3 times. The overshoot loading in advance of the scheduled magnetic field gradient is equivalent to continuously adding a resistor without heating. The magnetic field gradient with the reduced loading time is used to form the upward magnetic force against to the gravity of the cooled Cs atoms, and we obtain an effectively levitated loading of the Cs atoms to a crossed optical dipole trap.

  13. Influence of Brownian Diffusion on Levitation of Bodies in Magnetic Fluid

    Directory of Open Access Journals (Sweden)

    V. Bashtovoi

    2013-12-01

    Full Text Available The present work deals with experimental investigation of the levitation of magnetic and non-magnetic bodies in a magnetic fluid when essentially influenced by Brownian diffusion of magnetic particles in it. It is established that the point of levitation of bodies in a magnetic fluid varies with time.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

  16. Magnetic levitation technology and its applications in exploration projects

    Science.gov (United States)

    Shu, Quan-Sheng; Cheng, Guangfeng; Susta, Joseph T.; Hull, John R.; Fesmire, James E.; Augustanowicz, Stan D.; Demko, Jonathan A.; Werfel, Frank N.

    2006-02-01

    An energy efficient cryogenic transfer line with magnetic suspension has been prototyped and cryogenically tested. The prototype transfer line exhibits cryogen saving potential of 30-35% in its suspension state as compared to its solid support state. Key technologies developed include novel magnetic levitation using multiple-pole high temperature superconductor (HTS) and rare earth permanent-magnet (PM) elements and a smart cryogenic actuator as the warm support structure. These technologies have vast applications in extremely low thermal leak cryogenic storage/delivery containers, superconducting magnetic bearings, smart thermal switches, etc. This paper reviews the development work and discusses future applications of established technologies.

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

    Science.gov (United States)

    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.

  18. Levitation forces of a bulk YBCO superconductor in gradient varying magnetic fields

    Science.gov (United States)

    Jiang, J.; Gong, Y. M.; Wang, G.; Zhou, D. J.; Zhao, L. F.; Zhang, Y.; Zhao, Y.

    2015-09-01

    The levitation forces of a bulk YBCO superconductor in gradient varying high and low magnetic fields generated from a superconducting magnet were investigated. The magnetic field intensity of the superconducting magnet was measured when the exciting current was 90 A. The magnetic field gradient and magnetic force field were both calculated. The YBCO bulk was cooled by liquid nitrogen in field-cooling (FC) and zero-field-cooling (ZFC) condition. The results showed that the levitation forces increased with increasing the magnetic field intensity. Moreover, the levitation forces were more dependent on magnetic field gradient and magnetic force field than magnetic field intensity.

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

    Science.gov (United States)

    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 (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 efficient vibration energy harvesting using the VDL system, ways to mitigate eddy current damping and a coil geometry for transduction were critically

  20. Turbine flowmeter for liquid helium with the rotor magnetically levitated

    Science.gov (United States)

    Rivetti, A.; Martini, G.; Goria, R.; Lorefice, S.

    A turbine flowmeter with no mechanical contact between rotor and body is described, to be used as a reference standard in our liquid helium flow rate calibration facility. The absence of contact, zeroing the bearings friction factor, ensures a good measurement repeatability, even at very low liquid helium flow rate values. The rotor is magnetically suspended by the Meissner effect: at liquid helium temperatures two magnetic fields generate sustaining forces against the surface of the two rotor ends, which are made of niobium. Due to the repulsive nature of the acting forces, the rotor equilibrium is intrinsically stable and no external electronics are required for its levitation. A particular configuration of the superconducting windings and of the rotor ends allow the rotor to levitate and hold good axial and radial stability. A detailed description of the solutions adopted for the realization of the prototype and the operation conditions are reported. The first results, made with the absolute liquid helium calibration facility, are shown.

  1. Sliding mode control of a magnetic levitation system

    Directory of Open Access Journals (Sweden)

    N. F. Al-Muthairi

    2004-01-01

    Full Text Available Sliding mode control schemes of the static and dynamic types are proposed for the control of a magnetic levitation system. The proposed controllers guarantee the asymptotic regulation of the statesof the system to their desired values. Simulation results of the proposed controllers are given to illustrate the effectiveness of them. Robustness of the control schemes to changes in the parameters of the system is also investigated.

  2. Sliding mode control of a magnetic levitation system

    OpenAIRE

    Al-Muthairi N. F.; Zribi M.

    2004-01-01

    Sliding mode control schemes of the static and dynamic types are proposed for the control of a magnetic levitation system. The proposed controllers guarantee the asymptotic regulation of the statesof the system to their desired values. Simulation results of the proposed controllers are given to illustrate the effectiveness of them. Robustness of the control schemes to changes in the parameters of the system is also investigated.

  3. Efficient Fuzzy Logic Controller for Magnetic Levitation Systems

    Directory of Open Access Journals (Sweden)

    D. S. Shu’aibu

    2016-12-01

    Full Text Available Magnetic levitation is a system of suspending a body or a complete system against gravity. Suspending a system in air against gravity without using fixed structure for supporting is highly unstable and complex. In the previous research many techniques of stabilizing magnetic levitation systems were discussed. In this paper magnetic levitation controller using fuzzy logic is proposed. The proposed Fuzzy logic controller (FLC is designed, and developed using triangular membership function with 7×7 rules. The system model was implemented in MATLAB/SIMULINK and the system responses to Fuzzy controller with different input signals were investigated. Using unit step input signal, the proposed controller has a settling time of 0.35 secs, percentage overshoot of 0% and there is no oscillation. The proposed controller is validated with a model of an existing practical conventional proportional plus derivatives (PD controller. The PD controller has a settling time of 0.45 secs, percentage overshoot of 7% and with oscillation. Similarly, with sinusoidal input, the FLC has a phase shift and peak response of 0^0 and 0.9967 respectively, while PD controller has a phase shift and peak response of 24.48o and 0.9616 respectively. A disturbance signal was applied to the input of the control system. Fuzzy controller succeeded in rejecting the disturbance signal without further turning of the parameters whereby PD controller failed.

  4. Correlations Between Magnetic Flux and Levitation Force of HTS Bulk Above a Permanent Magnet Guideway

    Science.gov (United States)

    Huang, Huan; Zheng, Jun; Zheng, Botian; Qian, Nan; Li, Haitao; Li, Jipeng; Deng, Zigang

    2017-06-01

    In order to clarify the correlations between magnetic flux and levitation force of the high-temperature superconducting (HTS) bulk, we measured the magnetic flux density on bottom and top surfaces of a bulk superconductor while vertically moving above a permanent magnet guideway (PMG). The levitation force of the bulk superconductor was measured simultaneously. In this study, the HTS bulk was moved down and up for three times between field-cooling position and working position above the PMG, followed by a relaxation measurement of 300 s at the minimum height position. During the whole processes, the magnetic flux density and levitation force of the bulk superconductor were recorded and collected by a multipoint magnetic field measurement platform and a self-developed maglev measurement system, respectively. The magnetic flux density on the bottom surface reflected the induced field in the superconductor bulk, while on the top, it reveals the penetrated magnetic flux. The results show that the magnetic flux density and levitation force of the bulk superconductor are in direct correlation from the viewpoint of inner supercurrent. In general, this work is instructive for understanding the connection of the magnetic flux density, the inner current density and the levitation behavior of HTS bulk employed in a maglev system. Meanwhile, this magnetic flux density measurement method has enriched present experimental evaluation methods of maglev system.

  5. Ultrasensitive Inertial and Force Sensors with Diamagnetically Levitated Magnets

    Science.gov (United States)

    Prat-Camps, J.; Teo, C.; Rusconi, C. C.; Wieczorek, W.; Romero-Isart, O.

    2017-09-01

    We theoretically show that a magnet can be stably levitated on top of a punctured superconductor sheet in the Meissner state without applying any external field. The trapping potential created by such induced-only superconducting currents is characterized for magnetic spheres ranging from tens of nanometers to tens of millimeters. Such a diamagnetically levitated magnet is predicted to be extremely well isolated from the environment. We propose to use it as an ultrasensitive force and inertial sensor. A magnetomechanical readout of its displacement can be performed by using superconducting quantum interference devices. An analysis using current technology shows that force and acceleration sensitivities on the order of 10-23 N /√{Hz } (for a 100-nm magnet) and 10-14 g /√{Hz } (for a 10-mm magnet) might be within reach in a cryogenic environment. Such remarkable sensitivities, both in force and acceleration, can be used for a variety of purposes, from designing ultrasensitive inertial sensors for technological applications (e.g., gravimetry, avionics, and space industry), to scientific investigations on measuring Casimir forces of magnetic origin and gravitational physics.

  6. Magnetically-levitating disks around supermassive black holes

    CERN Document Server

    Gaburov, Evghenii; Levin, Yuri

    2012-01-01

    In this paper we report on the formation of magnetically-levitating accretion disks around supermassive black holes. The structure of these disks is calculated by numerically modelling tidal disruption of magnetized interstellar gas clouds. We find that the resulting disks are entirely supported by the pressure of the magnetic fields against the component of gravitational force directed perpendicular to the disks. The magnetic field shows ordered large-scale geometry that remains stable for the duration of our numerical experiments extending over 10% of the disk lifetime. Strong magnetic pressure allows high accretion and inhibits disk fragmentation. This in combination with the repeated feeding of manetized molecular clouds to a supermassive black hole yields a possible solution to the long-standing puzzle of black hole growth in the centres of galaxies.

  7. Calculating levitation forces in the magnet-high-temperature superconductor systems

    NARCIS (Netherlands)

    Ermolaev, YS; Rudnev, IA

    2005-01-01

    A new method of calculation of the magnetic levitation force in the permanent magnet-high-temperature superconductor systems is proposed based on the Maxwell equations and the Bean model. The dependences of the levitation force on the gap width calculated for various regimes of superconductor coolin

  8. Calculating levitation forces in the magnet-high-temperature superconductor systems

    NARCIS (Netherlands)

    Ermolaev, YS; Rudnev, IA

    2005-01-01

    A new method of calculation of the magnetic levitation force in the permanent magnet-high-temperature superconductor systems is proposed based on the Maxwell equations and the Bean model. The dependences of the levitation force on the gap width calculated for various regimes of superconductor coolin

  9. Paramagnetic ionic liquids for measurements of density using magnetic levitation.

    Science.gov (United States)

    Bwambok, David K; Thuo, Martin M; Atkinson, Manza B J; Mirica, Katherine A; Shapiro, Nathan D; Whitesides, George M

    2013-09-03

    Paramagnetic ionic liquids (PILs) provide new capabilities to measurements of density using magnetic levitation (MagLev). In a typical measurement, a diamagnetic object of unknown density is placed in a container containing a PIL. The container is placed between two magnets (typically NdFeB, oriented with like poles facing). The density of the diamagnetic object can be determined by measuring its position in the magnetic field along the vertical axis (levitation height, h), either as an absolute value or relative to internal standards of known density. For density measurements by MagLev, PILs have three advantages over solutions of paramagnetic salts in aqueous or organic solutions: (i) negligible vapor pressures; (ii) low melting points; (iii) high thermal stabilities. In addition, the densities, magnetic susceptibilities, glass transition temperatures, thermal decomposition temperatures, viscosities, and hydrophobicities of PILs can be tuned over broad ranges by choosing the cation-anion pair. The low melting points and high thermal stabilities of PILs provide large liquidus windows for density measurements. This paper demonstrates applications and advantages of PILs in density-based analyses using MagLev.

  10. Overview of Magnetic Levitation Systems with Emphasis on Electrodynamic Suspension

    Directory of Open Access Journals (Sweden)

    Abbas Najjar-Khodabakhsh

    2011-07-01

    Full Text Available Nowadays, the use of magnetic levitation systems has made attention in transportation. Suspension is caused by two magnetic fields in the near distance and thus the repulsion and attraction induced between them. In Iran, different types of magnetic systems and their applications, especially in the transportation system were not considered deeply and the features and specifications of each of these systems is not discussed yet. In this article we want to review past research and studies on the applications and the characteristics of these systems to fully express and we do compare them with each other. We also offer the laboratory equipment for study the behavior of magnetic suspension systems with emphasis on electrodynamic suspension.

  11. Annoyance caused by the sounds of a magnetic levitation train

    OpenAIRE

    2004-01-01

    In a laboratory study, the annoyance caused by the passby sounds from a magnetic levitation (maglev) train was investigated. The listeners were presented with various sound fragments. The task of the listeners was to respond after each presentation to the question: "How annoying would you find the sound in the preceding period if you were exposed to it at home on a regular basis?" The independent variables were (a) the driving speed of the maglev train (varying from 100 to 400 km/h), (b) the ...

  12. Nonaxisymmetric shapes of a magnetically levitated and spinning water droplet.

    Science.gov (United States)

    Hill, R J A; Eaves, L

    2008-12-05

    The shape of a weightless spinning liquid droplet is governed by the balance between the surface tension and centrifugal forces. The axisymmetric shape for slow rotation becomes unstable to a nonaxisymmetric distortion above a critical angular velocity, beyond which the droplet progresses through a series of 2-lobed shapes. Theory predicts the existence of a family of 3- and 4-lobed equilibrium shapes at higher angular velocity. We investigate the formation of a triangular-shaped magnetically levitated water droplet, driven to rotate by the Lorentz force on an ionic current within the droplet. We also study equatorial traveling waves which give the droplet threefold, fourfold, and fivefold symmetry.

  13. Nonlinear Disturbance Rejection for Magnetic Levitation Systems

    Science.gov (United States)

    2003-10-01

    B. Costic, D. Dawson and Y. Fang, "Non- linear Control of Magnetic Bearing in the Presence of Sinu- soidal Disturbance," Proceedings of the American Control Conference , pp...Unknown 61 Amplitudes and Frequencies in Linear SISO Uncertain Sys- tems," Proceedings of the American Control Conference , Anchorage, Alaska, pp. 4015

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

    Science.gov (United States)

    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.

  15. The levitation characteristics of the magnetic substances using trapped HTS bulk annuli with various magnetic field distributions

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.B., E-mail: kim@ec.okayama-u.ac.jp [Graduate School of Natural Science and Technology, Okayama University, 3-1-1, Tsushima-Naka, Kita-ku, Okayama 700-8530 (Japan); Ikegami, T.; Matsunaga, J.; Fujii, Y. [Graduate School of Natural Science and Technology, Okayama University, 3-1-1, Tsushima-Naka, Kita-ku, Okayama 700-8530 (Japan); Onodera, H. [Japan Science and Technology Agency–Core Research for Evolutional Science and Technology (JST–CREST), Tokyo 102-0076 (Japan)

    2013-11-15

    Highlights: •The spherical solenoid magnet can make a various magnetic field distributions. •We generated a large magnetic gradient at inner space of HTS bulks. •The levitation height of samples was improved by the reapplied field method. •The levitation height depends on the variation rate of magnetic field gradient. -- Abstract: We have been investigating the levitation system without any mechanical contact which is composed of a field-cooled ring-shaped high temperature superconducting (HTS) bulks [1]. In this proposed levitation system, the trapped magnetic field distributions of stacked HTS bulk are very important. In this paper, the spherical solenoid magnet composed of seven solenoid coils with different inner and outer diameters was designed and fabricated as a new magnetic source. The fabricated spherical solenoid magnet can easily make a homogeneous and various magnetic field distributions in inner space of stacked HTS bulk annuli by controlling the emerging currents of each coil. By using this spherical solenoid magnet, we tried to make a large magnetic field gradient in inner space of HTS bulk annuli, and it is very important on the levitation of magnetic substances. In order to improve the levitation properties of magnetic substances with various sizes, the external fields were reapplied to the initially trapped HTS bulk magnets. We could generate a large magnetic field gradient along the axial direction in inner space of HTS bulk annuli, and obtain the improved levitation height of samples by the proposed reapplied field method.

  16. Magnetic coupling by using levitation characteristics of YBCO superconductors

    Science.gov (United States)

    Ishigaki, H.; Ito, H.; Itoh, M.; Hida, A.; Takahata, R.

    1993-03-01

    A mechanical system which uses high lateral restoring forces of high-Tc materials as the driving force for a magnetic coupling is proposed. As the basic study of the superconducting magnetic coupling, the relationship between the lateral restoring force and levitation force, transmitted torque characteristics as a function of a twisting angle and clearance, and damping characteristics of the coupling were examined. Superiorities of the coupling such as high damping coefficients and high stability against time and twisting angle were revealed. A magnetic force sensor system was used to evaluate the superconducting characteristics of materials, and nonuniform distribution of repulsive force was observed for the YBCO pellet fabricated by the melt-powder-melt-growth process. The improvement of the homogeneity was achieved by compensating for the composition rate which had changed during the quenching process.

  17. Experiments on Inductive Magnetic Levitation with a Circular Halbach Array

    Science.gov (United States)

    Bean, Ian; Goncz, Doug; Raymer, Austin; Specht, Jason; Zalles, Ricardo; Majewski, Walerian

    2013-03-01

    Using a ring Halbach array, we are investigating a repulsive levitating force and a drag force acting on the magnet from a ring of inductors rotating below the magnet. After measuring induced currents, voltages and magnetic fields in the individual inductors (in the form of short solenoids), we investigated the dependence of lift/drag forces on the speed of relative rotation. The ratio of lift to drag increases with the angular velocity, as expected from a related theory of the induction effects in a linear motion. We are experimenting with the shape and density of inductors, and their material, in an attempt to maximize the lift at a minimal velocity of rotation. Eventually this design could have applications as frictionless bearings or as frictionless gear in a wide range of systems, especially in machinery that cannot be easily accessed.

  18. Hybrid Superconducting Magnetic Bearing (HSMB) for high load devices

    Science.gov (United States)

    McMichael, C. K.; Ma, K. B.; Lamb, M. A.; Lin, M. W.; Chow, L.; Meng, R. L.; Hor, P. H.; Chu, W. K.

    1992-05-01

    Lifting capacities greater than 41 N/cm(exp 2) (60 psi) at 77 K have been achieved with a new type of levitation (hybrid) using a combination of permanent magnets and high quality melt-mixtured YBa2Cu3O(7-delta) (YBCO). The key concept of the hybrid superconducting magnetic bearing (HSMB) is the use of strong magnetic repulsion and attraction from permanent magnets for high levitation or suspension forces in conjunction with a superconductor's flux pinning characteristics to counteract the inherent instabilities in a system consisting of magnets only. To illustrate this concept, radial and axial forces between magnet/superconductor, magnet/magnet, and magnet/superconductor/magnet, were measured and compared for the thrust bearing configuration

  19. 13th International Conference on Magnetically Levitated Systems and Linear Drives

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. The 13th International Conference on Magnetically Levitated Systems and Linear Drives MAGLEV 1993

    Science.gov (United States)

    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.

  1. Superconducting bulk magnet for maglev vehicle: Stable levitation performance above permanent magnet guideway

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Z.; Zheng, J.; Li, J.; Ma, G.; Lu, Y.; Zhang, Y.; Wang, S. [Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu 610031 (China); Wang, J. [Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu 610031 (China)], E-mail: jsywang@home.swjtu.edu.cn

    2008-06-15

    High-temperature superconducting (HTS) maglev vehicle is well known as one of the most potential applications of bulk high-temperature superconductors (HTSCs) in transported levitation system. Many efforts have promoted the practice of the HTS maglev vehicle in people's life by enhancing the load capability and stability. Besides improving the material performance of bulk HTSC and optimizing permanent magnet guideway (PMG), magnetization method of bulk HTSC is also very effective for more stable levitation. Up to now, applied onboard bulk HTSCs are directly magnetized by field cooling above the PMG for the present HTS maglev test vehicles or prototypes in China, Germany, Russia, Brazil, and Japan. By the direct-field-cooling-magnetization (DFCM) over PMG, maglev performances of the bulk HTSCs are mainly depended on the PMG's magnetic field. However, introducing HTS bulk magnet into the HTS maglev system breaks this dependence, which is magnetized by other non-PMG magnetic field. The feasibility of this HTS bulk magnet for maglev vehicle is investigated in the paper. The HTS bulk magnet is field-cooling magnetized by a Field Control Electromagnets Workbench (FCEW), which produces a constant magnetic field up to 1 T. The levitation and guidance forces of the HTS bulk magnet over PMG with different trapped flux at 15 mm working height (WH) were measured and compared with that by DFCM in the same applied PMG magnetic field at optimal field-cooling height (FCH) 30 mm, WH 15 mm. It is found that HTS bulk magnet can also realize a stable levitation above PMG. The trapped flux of HTS bulk magnet is easily controllable by the charging current of FCEW, which implies the maglev performances of HTS bulk magnet above PMG will be adjustable according to the practical requirement. The more trapped flux HTS bulk magnet will lead to bigger guidance force and smaller repulsion levitation force above PMG. In the case of saturated trapped flux for experimental HTS bulk

  2. Levitation performance of the magnetized bulk high-T{sub c} superconducting magnet with different trapped fields

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W. [Applied Superconductivity Laboratory, Southwest Jiaotong University (ASCLab), Chengdu, Sichuan 610031 (China); State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); National Laboratory of Rail Transit, Chengdu, Sichuan 610031 (China); Wang, J.S., E-mail: tonny@mars.swjtu.edu.c [Applied Superconductivity Laboratory, Southwest Jiaotong University (ASCLab), Chengdu, Sichuan 610031 (China); National Laboratory of Rail Transit, Chengdu, Sichuan 610031 (China); Liao, X.L.; Zheng, S.J.; Ma, G.T.; Zheng, J. [Applied Superconductivity Laboratory, Southwest Jiaotong University (ASCLab), Chengdu, Sichuan 610031 (China); State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); National Laboratory of Rail Transit, Chengdu, Sichuan 610031 (China); Wang, S.Y. [Applied Superconductivity Laboratory, Southwest Jiaotong University (ASCLab), Chengdu, Sichuan 610031 (China); National Laboratory of Rail Transit, Chengdu, Sichuan 610031 (China)

    2011-03-15

    Research highlights: {yields} The different trapped fields bring entirely different levitation performance. {yields} The force relaxation characters is directly bound up with the trapped field. {yields} The higher trapped field not means better levitation performance. {yields} An profitable internal induced current configuration will benefit to suppress flux motion. - Abstract: To a high-T{sub c} superconducting (HTS) maglev system which needs large levitation force density, the magnetized bulk high-T{sub c} 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.

  3. Arbitrary Finite-time Tracking Control for Magnetic Levitation Systems

    Directory of Open Access Journals (Sweden)

    Xuan-Toa Tran

    2014-10-01

    Full Text Available In this paper, an arbitrary finite-time tracking control (AFTC method is developed for magnetic levitation systems with uncertain dynamics and external disturbances. By introducing a novel augmented sliding-mode manifold function, the proposed method can eliminate the singular problem in traditional terminal sliding-mode control, as well as the reaching-phase problem. Moreover, the tracking errors can reach the reference value with faster convergence and better tracking precision in arbitrarily determined finite time. In addition, a fuzzy-arbitrary finite-time tracking control (F-AFTC scheme that combines a fuzzy technique with AFTC to enhance the robustness and sliding performance is also proposed. A fuzzy logic system is used to replace the discontinuous control term. Thus, the chattering phenomenon is resolved without degrading the tracking performance. The stability of the closed-loop system is guaranteed by the Lyapunov theory. Finally, the effectiveness of the proposed methods is illustrated by simulation and experimental study in a real magnetic levitation system.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Arbitrary Finite-time Tracking Control for Magnetic Levitation Systems

    Directory of Open Access Journals (Sweden)

    Xuan-Toa Tran

    2014-10-01

    Full Text Available In this paper, an arbitrary finite-time tracking control (AFTC method is developed for magnetic levitation systems with uncertain dynamics and external disturbances. By introducing a novel augmented sliding- mode manifold function, the proposed method can eliminate the singular problem in traditional terminal sliding-mode control, as well as the reaching-phase problem. Moreover, the tracking errors can reach the reference value with faster convergence and better tracking precision in arbitrarily determined finite time. In addition, a fuzzy-arbitrary finite-time tracking control (F- AFTC scheme that combines a fuzzy technique with AFTC to enhance the robustness and sliding performance is also proposed. A fuzzy logic system is used to replace the discontinuous control term. Thus, the chattering phenomenon is resolved without degrading the tracking performance. The stability of the closed-loop system is guaranteed by the Lyapunov theory. Finally, the effectiveness of the proposed methods is illustrated by simulation and experimental study in a real magnetic levitation system.

  6. The Japanese magnetic levitation train is on the rails; Le train a levitation magnetique japonais est sur les rails

    Energy Technology Data Exchange (ETDEWEB)

    Patrick, Henry

    2003-09-01

    In December 2002 was inaugurated in Shanghai (China) the very first magnetic levitation train. This train, named Maglev, reaches the cruise speed of 430 km/h and is the result of a Chinese-German cooperation between Transrapid International and SMTDC companies. The Maglev technology should be used for the project of very high speed train between Tokyo and Osaka (Japan). The test railways and trains of Yamanashi are today at the validation stage (technically and economically) with the aim of reducing costs and managing the noise problems due to the high number of tunnels along the line. This paper describes the specific infrastructures of the magnetic levitation train, the propulsion system (superconducting magnets) and the different kinds of switching required. (J.S.)

  7. A new Maglev. Permanent magnets to make a train levitate; Un nouveau Maglev. Des aimants permanents pour faire leviter un train

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2000-02-01

    A new, more stable and economical magnetic levitation system has been developed at the Lawrence Livermore Laboratory (USA) which uses permanent magnets instead of expensive superconducting or electro-magnets. In this new type of levitated train, the skates of the wagons are made of series of permanent magnets organized as a Hallbach net while the levitating coils are included in the rails. The construction of such a train using this 'indutrack' system would be 3 times less expensive than the German Maglev. Short paper. (J.S.)

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    Schoenhuber, P.; Moon, F. C.

    1995-04-01

    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

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

    Science.gov (United States)

    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.

  11. Control of Single Axis Magnetic Levitation System Using Fuzzy Logic Control

    Directory of Open Access Journals (Sweden)

    Tania Tariq Salim

    2013-12-01

    Full Text Available This paper presents a fuzzy logic controller design for the stabilization of magnetic levitation system (Maglev 's.Additionally, the investigation on Linear Quadratic Regulator Controller (LQRC also mentioned here. This paper presents the difference between the performance of fuzzy logic control (FLC and LQRC for the same linear model of magnetic levitation system .A magnetic levitation is a nonlinear unstable system and the fuzzy logic controller brings the magnetic levitation system to a stable region by keeping a magnetic ball suspended in the air. The modeling of the system is simulated using Matlab Simulink and connected to Hilink platform and the maglev model of Zeltom company. This paper presents a comparison for both LQRC and FLC to control a ball suspended on the air. The performance results of simulation shows that the fuzzy logic controller had better performance than the LQR control.

  12. High-Sensitivity Measurement of Density by Magnetic Levitation.

    Science.gov (United States)

    Nemiroski, Alex; Kumar, A A; Soh, Siowling; Harburg, Daniel V; Yu, Hai-Dong; Whitesides, George M

    2016-03-01

    This paper presents methods that use Magnetic Levitation (MagLev) to measure very small differences in density of solid diamagnetic objects suspended in a paramagnetic medium. Previous work in this field has shown that, while it is a convenient method, standard MagLev (i.e., where the direction of magnetization and gravitational force are parallel) cannot resolve differences in density mm) because (i) objects close in density prevent each other from reaching an equilibrium height due to hard contact and excluded volume, and (ii) using weaker magnets or reducing the magnetic susceptibility of the medium destabilizes the magnetic trap. The present work investigates the use of weak magnetic gradients parallel to the faces of the magnets as a means of increasing the sensitivity of MagLev without destabilization. Configuring the MagLev device in a rotated state (i.e., where the direction of magnetization and gravitational force are perpendicular) relative to the standard configuration enables simple measurements along the axes with the highest sensitivity to changes in density. Manipulating the distance of separation between the magnets or the lengths of the magnets (along the axis of measurement) enables the sensitivity to be tuned. These modifications enable an improvement in the resolution up to 100-fold over the standard configuration, and measurements with resolution down to 10(-6) g/cm(3). Three examples of characterizing the small differences in density among samples of materials having ostensibly indistinguishable densities-Nylon spheres, PMMA spheres, and drug spheres-demonstrate the applicability of rotated Maglev to measuring the density of small (0.1-1 mm) objects with high sensitivity. This capability will be useful in materials science, separations, and quality control of manufactured objects.

  13. Field Balancing of Magnetically Levitated Rotors without Trial Weights

    Directory of Open Access Journals (Sweden)

    Jiancheng Fang

    2013-11-01

    Full Text Available Unbalance in magnetically levitated rotor (MLR can cause undesirable synchronous vibrations and lead to the saturation of the magnetic actuator. Dynamic balancing is an important way to solve these problems. However, the traditional balancing methods, using rotor displacement to estimate a rotor’s unbalance, requiring several trial-runs, are neither precise nor efficient. This paper presents a new balancing method for an MLR without trial weights. In this method, the rotor is forced to rotate around its geometric axis. The coil currents of magnetic bearing, rather than rotor displacement, are employed to calculate the correction masses. This method provides two benefits when the MLR’s rotation axis coincides with the geometric axis: one is that unbalanced centrifugal force/torque equals the synchronous magnetic force/torque, and the other is that the magnetic force is proportional to the control current. These make calculation of the correction masses by measuring coil current with only a single start-up precise. An unbalance compensation control (UCC method, using a general band-pass filter (GPF to make the MLR spin around its geometric axis is also discussed. Experimental results show that the novel balancing method can remove more than 92.7% of the rotor unbalance and a balancing accuracy of 0.024 g mm kg−1 is achieved.

  14. 多策略粒子群算法在磁悬浮承重装置中的应用%A Multi-strategy Particle Swarm Optimization Algorithm and Its Application on Hybrid Magnetic Levitation

    Institute of Scientific and Technical Information of China (English)

    王庆燕; 马宏忠; 曹生让

    2014-01-01

    混合磁悬浮装置的各项参数相互影响,决定着整个装置的性能。在满足承重要求的条件下,有必要对该装置的各项参数进行优化研究。为此,提出一种多策略改进粒子群算法,并将其应用到混合磁悬浮承重装置的参数优化中。首先,对混合磁悬浮装置进行介绍,通过分析永磁和电磁悬浮力,以励磁损耗和资金投入最小,和在允许范围内减载程度最高为目标,建立该装置的优化模型。在算法上,通过分析传统粒子群算法的缺陷,首次提出多开端策略来提高种群的多样性,结合反向学习和参数修正等多种策略对粒子群算法进行改进(多策略改进粒子群算法),以广义Schwefel函数为验证函数,通过与其他粒子群算法的比较证明,改进算法具有更强的优势。最后,运用多策略改进粒子群算法对磁悬浮模型进行优化,将优化结果与原有参数进行比较,分析可知该结果更加符合实际情况,通过仿真验证该结果的合理性,为进一步建立实验模型奠定了理论基础。%The mutual influences among the parameters of hybrid magnetic levitation devices determine the device performances. When the load-reduction requirement is met, it is necessary to optimize structural parameters of the devices. A novel improved multi-strategy particle swarm algorithm is proposed, and is applied on the structural optimization of devices. Firstly, the principle of devices is introduced, the electromagnetic force and permanent magnetic force are analyzed. Based on the idea of minimal electromagnetic loss and investment minimum, and maximal load-reduction degree within the scope allowed, optimization objective functions of the devices are built. Then, by analyzing the defects of the traditional particle swarm algorithm, this paper proposes a multi-start strategy to improve the diversity of the swarm. The technology combines with opposition

  15. Superconducting-electromagnetic hybrid bearing using YBCO bulk locks for passive axial levitation

    Energy Technology Data Exchange (ETDEWEB)

    Nicolsky, R. [Instituto de Fisica, UFRJ, Cx. P. 68528, Rio de Janeiro 21945-970 (Brazil). E-mail: nicolsky at if.ufrj.br; Andrade, R. de Jr. [DEE/EE/UFRJ, Cx. P. 68515, Rio de Janeiro 21945-970 (Brazil); Ripper, A.; Stephan, R.M. [PEM/COPPE/UFRJ, Cx. P. 68504, Rio de Janeiro 21945-970 (Brazil); David, D.F.B.; Santisteban, J.A. [Engenharia/UFF, Rua Passo da Patria 156, Niteroi 24210-240 (Brazil); Gawalek, W.; Habisreuther, T.; Strasser, T. [Institut fuer Physikalische Hoch Technologie (IPHT), Helmhotzweg 4, D07743, Jena (Germany)

    2000-06-01

    A superconducting/electromagnetic hybrid bearing has been designed using active radial electromagnetic positioning and a superconducting passive axial levitator. This bearing has been tested for an induction machine with a vertical shaft. The prototype was conceived as a four-pole, two-phase induction machine using specially designed stator windings for delivering torque and radial positioning simultaneously. The radial bearing uses four eddy-current sensors, displaced 90 deg. from each other, for measuring the shaft position and a PID control system for feeding back the currents. The stator windings have been adapted from the ones of a standard induction motor. The superconducting axial bearing has been assembled with commercial NdFeB permanent magnets and a set of seven top-seeded-melt-textured YBCO large-grain cylindrical blocks. The bearing set-up was previously simulated by a finite element method for different permanent magnet-superconductor block configurations. The stiffness of the superconducting axial bearing has been investigated by measuring by a dynamic method the vertical and transversal elastic constants for different field cooling processes. The resulting elastic constants show a linear dependence on the air gap, i.e. the clearance between the permanent magnet assembly and the set of superconducting large-grain blocks, which is dependent on cooling distance. (author)

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

    Science.gov (United States)

    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. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  17. A new conveyor system based on a passive magnetic levitation unit having repulsive-type magnetic bearings

    Science.gov (United States)

    Ohji, T.; Ichiyama, S.; Amei, K.; Sakui, M.; Yamada, S.

    2004-05-01

    A magnetic repulsive-type conveyor system is proposed as a new application of repulsive-type magnetic bearings, which use repulsive forces between the stator and rotor permanent magnets. The proposed conveyer is composed by aligning many passive magnetic levitation units. Each unit also contains electromagnets to oscillate a levitator shaft in the radial direction. The way of generating vibration and rotation in the conveyance direction was examined by the various excitation methods.

  18. Multi-Objective PID-Controller Tuning for a Magnetic Levitation System using NSGA-II

    DEFF Research Database (Denmark)

    Pedersen, Gerulf K. M.; Yang, Zhenyu

    2006-01-01

    This paper investigates the issue of PID-controller parameter tuning for a magnetic levitation system using the non-dominated sorting genetic algorithm (NSGA-II). The magnetic levitation system is inherently unstable and the PID-controller parameters are hard to find using conventional methods....... Based on four different performance measures, derived from the step response of the levitation system, the algorithm is used to find a set of non-dominated parameters for a PID-controller that can stabilize the system and minimize the performance measures....

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

    Science.gov (United States)

    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.

  20. Experimental verification of radial magnetic levitation force on the cylindrical magnets in ferrofluid dampers

    Science.gov (United States)

    Yang, Wenming; Wang, Pengkai; Hao, Ruican; Ma, Buchuan

    2017-03-01

    Analytical and numerical calculation methods of the radial magnetic levitation force on the cylindrical magnets in cylindrical vessels filled with ferrofluid was reviewed. An experimental apparatus to measure this force was designed and tailored, which could measure the forces in a range of 0-2.0 N with an accuracy of 0.001 N. After calibrated, this apparatus was used to study the radial magnetic levitation force experimentally. The results showed that the numerical method overestimates this force, while the analytical ones underestimate it. The maximum deviation between the numerical results and the experimental ones was 18.5%, while that between the experimental results with the analytical ones attained 68.5%. The latter deviation narrowed with the lengthening of the magnets. With the aids of the experimental verification of the radial magnetic levitation force, the effect of eccentric distance of magnets on the viscous energy dissipation in ferrofluid dampers could be assessed. It was shown that ignorance of the eccentricity of magnets during the estimation could overestimate the viscous dissipation in ferrofluid dampers.

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

    Science.gov (United States)

    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.

  2. Analyzing forensic evidence based on density with magnetic levitation.

    Science.gov (United States)

    Lockett, Matthew R; Mirica, Katherine A; Mace, Charles R; Blackledge, Robert D; Whitesides, George M

    2013-01-01

    This paper describes a method for determining the density of contact trace objects with magnetic levitation (MagLev). MagLev measurements accurately determine the density (± 0.0002 g/cm(3) ) of a diamagnetic object and are compatible with objects that are nonuniform in shape and size. The MagLev device (composed of two permanent magnets with like poles facing) and the method described provide a means of accurately determining the density of trace objects. This method is inexpensive, rapid, and verifiable and provides numerical values--independent of the specific apparatus or analyst--that correspond to the absolute density of the sample that may be entered into a searchable database. We discuss the feasibility of MagLev as a possible means of characterizing forensic-related evidence and demonstrate the ability of MagLev to (i) determine the density of samples of glitter and gunpowder, (ii) separate glitter particles of different densities, and (iii) determine the density of a glitter sample that was removed from a complex sample matrix. © 2012 American Academy of Forensic Sciences.

  3. Comprehensive comparison of the levitation performance of bulk YBaCuO arrays above two different types of magnetic guideways

    Science.gov (United States)

    Deng, Zigang; Qian, Nan; Che, Tong; Jin, Liwei; Si, Shuaishuai; Zhang, Ya; Zheng, Jun

    2016-12-01

    The permanent magnet guideway (PMG) is an important part of high temperature superconducting (HTS) maglev systems. So far, two types of PMG, the normal PMG and Halbach-type PMG, are widely applied in present maglev transportation systems. In this paper, the levitation performance of high temperature superconductor bulks above the two PMGs was synthetically compared. Both static levitation performance and dynamic response characteristics were investigated. Benefiting from the reasonable magnetic field distribution, the Halbach-type PMG is able to gain larger levitation force, greater levitation force decay during the same relaxation time, bigger resonance frequency and dynamic stiffness for the bulk superconductor levitation unit compared with the normal PMG. Another finding is that the Halbach-type PMG is not sensitive to the levitation performance of the bulk levitation unit with different arrays. These results are helpful for the practical application of HTS maglev systems.

  4. The size effect on the magnetic levitation force of MgB2 bulk superconductors

    Science.gov (United States)

    Savaskan, B.; Koparan, E. T.; Güner, S. B.; Celik, S.; Yanmaz, E.

    2016-12-01

    In this study, the size effect on the magnetic levitation performance of disk-shaped MgB2 bulk superconductors and permanent magnets was investigated. MgB2 samples with varying diameters of 13 mm, 15 mm and 18 mm, each of which were 2 g in mass, were prepared by two-step solid state reaction method. Vertical levitation force measurements under both zero-field-cooled (ZFC) and field-cooled (FC) regimes were carried out at different temperatures of 20, 24 and 28 K. It was determined that the levitation force of the MgB2 strongly depends on both the diameters of the sample and the permanent magnet. In ZFC regime, the maximum levitation force value for the permanent magnet and the sample 18 mm in diameters reached to the 8.41 N at 20 K. In addition, in FC regime, attractive and repulsive force increased with increasing diameters of the sample and the permanent magnet. In that, the sample with 18 mm in diameter showed the highest attractive force value -3.46 N at 20 K and FC regime. The results obtained in this study are very useful in magnetic levitation devices as there is no detailed study on the size of superconductors and permanent magnets.

  5. Transient Response of a Novel Displacement Transducer for Magnetic Levitation System

    Directory of Open Access Journals (Sweden)

    Mrunal Deshpande

    2011-01-01

    Full Text Available Problem statement: In magnetic levitation system, position sensors are used to obtain a voltage proportional to the position of the suspended object. This is an essential feedback signal for stabilizing the system. These sensors make the system clumsy and prone to failures. To eliminate any physical attachment on the levitated object for the purpose of measuring its displacement, a novel magnetic displacement transducer has been designed. Approach: Variation in inductance of the transducer with the position of the levitated object is used to detect the position of the object. Coil of the transducer is excited by a 5 kHz voltage and variation in phase angle of its current is measured by synchronous demodulation method. Transient response of this system is also obtained for step change in the position of the levitated object. Results: By simulation as well as by experiments it is observed that a minimum delay equal to one and a half times the cycle time of the exciting frequency is always present. The delay further increases with increase in order of the filter. In magnetic levitation applications, mechanical frequency of the levitated object is generally below 10 Hz and therefore a delay of around 300 micro seconds with an exciting frequency of 5 kHz is acceptable. Steady state characteristic of the transducer is nearly linear and it is further linearized by using a look up table and cubic interpolation. Signal output from synchronous demodulation circuit has been digitally processed for application to magnetically levitated system. Conclusion: A novel yet simple circuit for sensing the position of the moving object for electromagnetic levitation system is developed. The transient response of the developed system is also obtained and the simulation results are verified experimentally.

  6. Effect of the repulsive force in the HTSC-permanent magnet hybrid bearing system

    Energy Technology Data Exchange (ETDEWEB)

    Ohashi, S., E-mail: ohashi@ipcku.kansai-u.ac.j [Kansai University, 3-3-35, Yamate-cho, Suita, Osaka 564-8680 (Japan); Kobayashi, S. [Kansai University, 3-3-35, Yamate-cho, Suita, Osaka 564-8680 (Japan)

    2009-10-15

    Magnetic levitation using the pinning force of the YBaCuO high-T{sub c} bulk superconductor (HTSC) materials has an advantage to achieve stable levitation without control. To increase levitation force, the HTSC-permanent magnet hybrid magnetic bearing system is introduced. A circular shaped three phase Nd-Fe-B permanent magnet is installed on the rotor, and HTSC bulk superconductor is set on the stator. The additional permanent magnet is installed under the HTSC. Repulsive force of the permanent magnet is used for levitation, and pinning force between the HTSC and permanent magnet is used for guidance force of the bearing. In this system, relationship between permanent magnet and the HTSC is important. When repulsive force of the permanent magnet is large, pinning force of superconductor is used to keep the rotor position. As a result, stability for the lateral direction is decreased with hybrid system. For levitation force, effect of the hybrid system is not observed with column HTSC. Compared with the ring HTSC results, the following thing is considered. Because there is no space that flux of one permanent magnet acts on the other one with the column HTSC configuration, interaction between two permanent magnets becomes small.

  7. Effect of the repulsive force in the HTSC-permanent magnet hybrid bearing system

    Science.gov (United States)

    Ohashi, S.; Kobayashi, S.

    2009-10-01

    Magnetic levitation using the pinning force of the YBaCuO high- Tc bulk superconductor (HTSC) materials has an advantage to achieve stable levitation without control. To increase levitation force, the HTSC-permanent magnet hybrid magnetic bearing system is introduced. A circular shaped three phase Nd-Fe-B permanent magnet is installed on the rotor, and HTSC bulk superconductor is set on the stator. The additional permanent magnet is installed under the HTSC. Repulsive force of the permanent magnet is used for levitation, and pinning force between the HTSC and permanent magnet is used for guidance force of the bearing. In this system, relationship between permanent magnet and the HTSC is important. When repulsive force of the permanent magnet is large, pinning force of superconductor is used to keep the rotor position. As a result, stability for the lateral direction is decreased with hybrid system. For levitation force, effect of the hybrid system is not observed with column HTSC. Compared with the ring HTSC results, the following thing is considered. Because there is no space that flux of one permanent magnet acts on the other one with the column HTSC configuration, interaction between two permanent magnets becomes small.

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

    Science.gov (United States)

    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.

  9. Angular Dependence of Lateral and Levitation Forces in Asymmetric Small Magnet/Superconducting Systems

    Institute of Scientific and Technical Information of China (English)

    H. M. Al-Khateeb; M. K. Alqadi; F. Y. Alzoubi; N. Y. Ayoub

    2007-01-01

    The dipole-dipole interaction model is used to calculate the angular dependence of lateral and levitation forces on a small permanent magnet and a cylindrical superconductor in the Meissner state lying laterally offthe symmetric axis of the cylinder. Under the assumption that the lateral displacement of the magnet is small compared with the physical dimensions of the system, we obtain analytical expressions for the lateral and levitation forces as functions of geometrical parameters of the superconductor as well as the height, the lateral displacement and the orientation of magnetic moment of the magnet. The effect of thickness and radius of the superconductor on the levitation force is similar to that for a symmetric magnet/superconducting cylinder system, but within the range of lateral displacement. The splitting in the levitation force increases with the increasing angle of orientation of the magnetic moment of the magnet. For a given lateral displacement of the magnet, the lateral force vanishes when the magnetic moment is perpendicular to the surface of the superconductor and has a maximum value when the moment is parallel to the surface. For a given orientation of the magnetic moment, the lateral force has a linear relationship with the lateral displacement. The stability of the magnet above the superconducting cylinder is discussed in detail.

  10. Noise annoyance caused by magnetic levitation train passbys

    Science.gov (United States)

    Vos, Joos

    2001-05-01

    In a laboratory study, the annoyance caused by the passby sounds from a magnetic levitation (maglev) train was investigated. The outdoor A-weighted sound exposure level (ASEL) of the maglev sounds varied from 65 to 90 dB. The driving speed of the maglev train varied from 100 to 400 km/h. Four important results were obtained. Provided that the outdoor ASELs were the same, (1) the annoyance was independent of the driving speed of the maglev train, (2) the annoyance caused by the maglev train was considerably higher than that caused by intercity trains, (3) the annoyance caused by the maglev train was hardly different from that caused by road traffic (passenger cars and trucks), and (4) the results (1)-(3) held true both for open or closed windows. On the basis of the present results, it might be expected that the sounds are equally annoying if the ASELs of the maglev-train passbys are at least 5 dB lower than those of the intercity train passbys. Consequently, the results of the present experiment do not support application of a railway bonus to the maglev-train sounds. Issues for future research, such as exploring further contributions of nonacoustic factors, will be discussed.

  11. Effect of Suspension Winding Pole Pair and Permanent Magnet Thickness on Magnetic Levitation Force in Bearingless {PMSM

    Directory of Open Access Journals (Sweden)

    H. Ebrahimpoor Hendoo

    2014-11-01

    Full Text Available One maintenance task that still exist with conventional motors, are bearing lubrication and renewal. Bearingless motors are replaced with conventional motor that uses a magnetic levitation force to suspend a rotor without any mechanical contact. In bearingless motors, additional windings are wound together with motor windings in stator slots. In this paper, a bearingless permanent magnet-type synchronous motor (BPMSM Has been studied. First, the generation of radial levitation forces is discussed and then the optimum permanent magnet thickness is determined to produce maximum levitation force. After that the effect of additional winding pole-pair in the amount of levitation force is investigated. The simulation is done in Maxwell software

  12. A practical nonlinear controller for levitation system with magnetic flux feedback

    Institute of Scientific and Technical Information of China (English)

    李金辉; 李杰

    2016-01-01

    This work proposes a practical nonlinear controller for the MIMO levitation system. Firstly, the mathematical model of levitation modules is developed and the advantages of the control scheme with magnetic flux feedback are analyzed when compared with the current feedback. Then, a backstepping controller with magnetic flux feedback based on the mathematical model of levitation module is developed. To obtain magnetic flux signals for full-size maglev system, a physical method with induction coils installed to winding of the electromagnet is developed. Furthermore, to avoid its hardware addition, a novel conception of virtual magnetic flux feedback is proposed. To demonstrate the feasibility of the proposed controller, the nonlinear dynamic model of full-size maglev train with quintessential details is developed. Based on the nonlinear model, the numerical comparisons and related experimental validations are carried out. Finally, results illustrating closed-loop performance are provided.

  13. Magnetic Signals of High-Temperature Superconductor Bulk During the Levitation Force Measurement Process

    Science.gov (United States)

    Huang, Huan; Zheng, Jun; Qian, Nan; Che, Tong; Zheng, Botian; Jin, Liwei; Deng, Zigang

    2017-05-01

    In order to study the commonly neglected magnetic field information in the course of levitation force measurement process in a superconducting maglev system, a multipoint magnetic field measurement platform was employed to acquire magnetic signals of a bulk high-Tc superconductor on both the top and the bottom surface. Working conditions including field cooling (FC) and zero field cooling were investigated for these vertical down and up motions above a permanent magnet guideway performed on a HTS maglev measurement system. We have discussed the magnetic flux variation process based on the Bean model. A magnetic hysteresis effect similar to the levitation force hysteresis loop of the bulk superconductor was displayed and analyzed in this paper. What is more valuable, there exists some available magnetic flux on the top surface of the bulk superconductor, and the proportion is as high as 62.42% in the FC condition, which provides an experimental hint to design the superconductor bulk and the applied field for practical use in a more efficient way. In particular, this work reveals real-time magnetic flux variation of the bulk superconductor in the levitation application, which is the other important information in contrast to the macroscopic levitation and guidance force investigations in previous studies, and it enriches the existing research methods. The results are significant for understanding the magnetic characteristic of superconductors, and they can contribute to optimize the present HTS maglev system design.

  14. Magnetic Signals of High-Temperature Superconductor Bulk During the Levitation Force Measurement Process

    Science.gov (United States)

    Huang, Huan; Zheng, Jun; Qian, Nan; Che, Tong; Zheng, Botian; Jin, Liwei; Deng, Zigang

    2017-02-01

    In order to study the commonly neglected magnetic field information in the course of levitation force measurement process in a superconducting maglev system, a multipoint magnetic field measurement platform was employed to acquire magnetic signals of a bulk high-Tc superconductor on both the top and the bottom surface. Working conditions including field cooling (FC) and zero field cooling were investigated for these vertical down and up motions above a permanent magnet guideway performed on a HTS maglev measurement system. We have discussed the magnetic flux variation process based on the Bean model. A magnetic hysteresis effect similar to the levitation force hysteresis loop of the bulk superconductor was displayed and analyzed in this paper. What is more valuable, there exists some available magnetic flux on the top surface of the bulk superconductor, and the proportion is as high as 62.42% in the FC condition, which provides an experimental hint to design the superconductor bulk and the applied field for practical use in a more efficient way. In particular, this work reveals real-time magnetic flux variation of the bulk superconductor in the levitation application, which is the other important information in contrast to the macroscopic levitation and guidance force investigations in previous studies, and it enriches the existing research methods. The results are significant for understanding the magnetic characteristic of superconductors, and they can contribute to optimize the present HTS maglev system design.

  15. Study on the characteristics of magnetic levitation for permanent magnets and ferromagnetic materials with various sizes using stacked HTS bulk annuli

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.B., E-mail: kim@elec.okayama-u.ac.jp [Graduate School of Natural Science and Technology, Okayama University, 3-1-1, Tsushima-Naka, Kita-ku, Okayama 700-8530 (Japan); Matsunaga, J.; Doi, A.; Ikegami, T. [Graduate School of Natural Science and Technology, Okayama University, 3-1-1, Tsushima-Naka, Kita-ku, Okayama 700-8530 (Japan); Onodera, H. [JST-CREST, K’s Gobancho 6F, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076 (Japan)

    2013-01-15

    Highlights: ► We achieved the stable levitation of irons by magnetized HTS bulk annuli. ► The relationship between magnetized field and sample size was cleared. ► The iron samples smaller than 1 mm diameter could not levitate stably. ► The spherical solenoid magnet was fabricated to levitate small iron samples. -- Abstract: We achieved stable levitation of cylindrical permanent magnets and irons using stacked ring-shaped high temperature superconducting (HTS) bulks with 20 mm ID, 60 mm OD and 50 mm height, and those were magnetized by field cooling method. The levitation characteristics of permanent magnets and iron samples located in the inner space of that levitation system were investigated experimentally. Iron samples with needle-shape and smaller than 1 mm diameter could not levitate stably. However, we found that the high strength of magnetized field was not necessary to levitate small needle-shaped irons. In order to levitate them, we need a uniform magnetic field in radial direction, so, a spherical solenoid magnet that can easily make a homogeneous magnetic field in inner space of HTS bulk annuli was developed. The spherical solenoid magnet, composed of seven solenoid coils with different inner and outer diameters, was designed by an electromagnetic analysis and fabricated.

  16. A magnetic levitation rotating plate model based on high-Tc superconducting technology

    Science.gov (United States)

    Zheng, Jun; Li, Jipeng; Sun, Ruixue; Qian, Nan; Deng, Zigang

    2017-09-01

    With the wide requirements of the training aids and display models of science, technology and even industrial products for the public like schools, museums and pleasure grounds, a simple-structure and long-term stable-levitation technology is needed for these exhibitions. Opportunely, high temperature superconducting (HTS) technology using bulk superconductors indeed has prominent advantages on magnetic levitation and suspension for its self-stable characteristic in an applied magnetic field without any external power or control. This paper explores the feasibility of designing a rotatable magnetic levitation (maglev) plate model with HTS bulks placed beneath a permanent magnet (PM) plate. The model is featured with HTS bulks together with their essential cryogenic equipment above and PMs below, therefore it eliminates the unclear visual effects by spray due to the low temperature coolant such as liquid nitrogen (LN2) and additional levitation weight of the cryogenic equipment. Besides that, a matched LN2 automation filling system is adopted to help achieving a long-term working state of the rotatable maglev plate. The key low-temperature working condition for HTS bulks is maintained by repeatedly opening a solenoid valve and automatically filling LN2 under the monitoring of a temperature sensor inside the cryostat. With the support of the cryogenic devices, the HTS maglev system can meet all requirements of the levitating display model for exhibitions, and may enlighten the research work on HTS maglev applications.

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

    Science.gov (United States)

    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.

  18. Employing Magnetic Levitation to Monitor Reaction Kinetics and Measure Activation Energy

    Science.gov (United States)

    Benz, Lauren; Cesafsky, Karen E.; Le, Tran; Park, Aileen; Malicky, David

    2012-01-01

    This article describes a simple and inexpensive undergraduate-level kinetics experiment that uses magnetic levitation to monitor the progress and determine the activation energy of a condensation reaction on a polymeric solid support. The method employs a cuvette filled with a paramagnetic solution positioned between two strong magnets. The…

  19. Employing Magnetic Levitation to Monitor Reaction Kinetics and Measure Activation Energy

    Science.gov (United States)

    Benz, Lauren; Cesafsky, Karen E.; Le, Tran; Park, Aileen; Malicky, David

    2012-01-01

    This article describes a simple and inexpensive undergraduate-level kinetics experiment that uses magnetic levitation to monitor the progress and determine the activation energy of a condensation reaction on a polymeric solid support. The method employs a cuvette filled with a paramagnetic solution positioned between two strong magnets. The…

  20. Modeling of a compliant joint in a Magnetic Levitation System for an endoscopic camera

    NARCIS (Netherlands)

    Simi, M.; Tolou, N.; Valdastri, P.; Herder, J.L.; Menciassi, A.; Dario, P.

    2012-01-01

    A novel compliant Magnetic Levitation System (MLS) for a wired miniature surgical camera robot was designed, modeled and fabricated. The robot is composed of two main parts, head and tail, linked by a compliant beam. The tail module embeds two magnets for anchoring and manual rough translation. The

  1. Modeling of a compliant joint in a Magnetic Levitation System for an endoscopic camera

    NARCIS (Netherlands)

    Simi, M.; Tolou, N.; Valdastri, P.; Herder, J.L.; Menciassi, A.; Dario, P.

    2012-01-01

    A novel compliant Magnetic Levitation System (MLS) for a wired miniature surgical camera robot was designed, modeled and fabricated. The robot is composed of two main parts, head and tail, linked by a compliant beam. The tail module embeds two magnets for anchoring and manual rough translation. The

  2. Levitation force of small clearance superconductor-magnet system under non-coaxial condition

    Science.gov (United States)

    Xu, Jimin; Jin, Yingze; Yuan, Xiaoyang; Miao, Xusheng

    2017-03-01

    A novel superconducting tilting-pad bearing was proposed for the advanced research of reusable liquid hydrogen turbopump in liquid rocket. The bearing is a combination of superconducting magnetic bearing and hydrodynamic fluid-film bearing. Since the viscosity of cryogenic fuel to activate superconducting state and form hydrodynamic fluid-film is very low, bearing clearance will be very small. This study focuses on the investigation of superconducting levitation force in this kind of small clearance superconductor-magnet system. Based on Bean critical state model and three-dimensional finite element method, an analysis method is presented to obtain the levitation force under such situation. Since the complicated operational conditions and structural arrangement for application in liquid rocket, center lines of bulk superconductor and magnet rotor will usually be in non-coaxial state. Superconducting levitation forces in axial direction and radial direction under non-coaxial situation are also analyzed by the presented method.

  3. Annoyance caused by the sounds of a magnetic levitation train

    Science.gov (United States)

    Vos, Joos

    2004-04-01

    In a laboratory study, the annoyance caused by the passby sounds from a magnetic levitation (maglev) train was investigated. The listeners were presented with various sound fragments. The task of the listeners was to respond after each presentation to the question: ``How annoying would you find the sound in the preceding period if you were exposed to it at home on a regular basis?'' The independent variables were (a) the driving speed of the maglev train (varying from 100 to 400 km/h), (b) the outdoor A-weighted sound exposure level (ASEL) of the passbys (varying from 65 to 90 dB), and (c) the simulated outdoor-to-indoor reduction in sound level (windows open or windows closed). As references to the passby sounds from the maglev train (type Transrapid 08), sounds from road traffic (passenger cars and trucks) and more conventional railway (intercity trains) were included for rating also. Four important results were obtained. Provided that the outdoor ASELs were the same, (1) the annoyance was independent of the driving speed of the maglev train, (2) the annoyance caused by the maglev train was considerably higher than that caused by the intercity train, (3) the annoyance caused by the maglev train was hardly different from that caused by road traffic, and (4) the results (1)-(3) held true both for open or closed windows. On the basis of the present results, it might be expected that the sounds are equally annoying if the ASELs of the maglev-train passbys are at least 5 dB lower than those of the intercity train passbys. Consequently, the results of the present experiment do not support application of a railway bonus to the maglev-train sounds.

  4. Active Magnetic Bearing Online Levitation Recovery through μ-Synthesis Robust Control

    Directory of Open Access Journals (Sweden)

    Alexander H. Pesch

    2017-01-01

    Full Text Available A rotor supported on active magnetic bearings (AMBs is levitated inside an air gap by electromagnets controlled in feedback. In the event of momentary loss of levitation due to an acute exogenous disturbance or external fault, reestablishing levitation may be prevented by unbalanced forces, contact forces, and the rotor’s dynamics. A novel robust control strategy is proposed for ensuring levitation recovery. The proposed strategy utilizes model-based μ-synthesis to find the requisite AMB control law with unique provisions to account for the contact forces and to prevent control effort saturation at the large deflections that occur during levitation failure. The proposed strategy is demonstrated experimentally with an AMB test rig. First, rotor drop tests are performed to tune a simple touchdown-bearing model. That model is then used to identify a performance weight, which bounds the contact forces during controller synthesis. Then, levitation recovery trials are conducted at 1000 and 2000 RPM, in which current to the AMB coils is momentarily stopped, representing an external fault. The motor is allowed to drive the rotor on the touchdown bearings until coil current is restored. For both cases, the proposed control strategy shows a marked improvement in relevitation transients.

  5. Mass determination with the magnetic levitation method—proposal for a new design of electromechanical system

    Science.gov (United States)

    Kajastie, H.; Riski, K.; Satrapinski, A.

    2009-06-01

    The method for realization of the kilogram using 'superconducting magnetic levitation' was re-evaluated at MIKES. The realization of the kilogram based on the traditional levitation method is limited by the imperfections of the superconducting materials and the indefinable dependence between supplied electrical energy and the gravitational potential energy of the superconducting mass. This indefiniteness is proportional to the applied magnetic field and is caused by increasing losses and trapped magnetic fluxes. A new design of an electromechanical system for the levitation method is proposed. In the proposed system the required magnetic field and the corresponding force are reduced, as the mass of the body (hanging from a mass comparator) is compensated by the reference weight on the mass comparator. The direction of the magnetic force can be upward (levitation force, when the body is over the coil) or downward (repulsive force, when the body is under the coil). The initial force to move the body from the coil is not needed and magnetic field sensitivity is increased, providing linearization of displacement versus applied current. This new construction allows a lower magnetic induction, reduces energy losses compared with previous designs of electromechanical system and reduces the corresponding systematic error.

  6. Non-contact property measurements of liquid and supercooled ceramics with a hybrid electrostatic-aerodynamic levitation furnace

    OpenAIRE

    Ishikawa, Takehiko; Yoda, Shinichi; Paradis, Paul-Francois; 石川 毅彦; 依田 真一

    2005-01-01

    The use of an hybrid pressurized electrostatic-aerodynamic levitation furnace and procedures developed by the Japan Aerospace Exploration Agency overcame the contamination problems associated with the processing of ceramics under extreme temperature conditions. This made possible property measurements over wide temperature ranges that cover the superheated as well as the supercooled states. In this study, samples of various ceramics were levitated and their densities were found as a function ...

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

    Science.gov (United States)

    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.

  8. A small scale magnetically levitated train for project-based laboratory education

    Directory of Open Access Journals (Sweden)

    Glehn Gregor

    2015-12-01

    Full Text Available The drive train of a small scale magnetically levitated train reveals the principles of a mechatronic system and offers challenges related to design, construction and control. Therefore, it is used at the Institute of electrical Machines (IEM of the RWTH Aachen University as a demonstrator for engineering solutions. Instead of being a part of a static predefined student laboratory, the small scale magnetically levitated train is part of dynamic individual student projects. This approach provides the advantage that the students are directly involved in the engineering process and gain motivation out of their personal ideas becoming reality.

  9. Estimating effects from trapped magnetic fluxes in superconducting magnetic levitation measurement

    Institute of Scientific and Technical Information of China (English)

    Masakazu Nakanishi

    2008-01-01

    Superconducting magnetic levitation measurement is one of the most promising approaches to define mass standard based on the fundamental physical constants. However, the present system has unknown factors causing error larger than 50 ppm. We examined the effects of magnetic fluxes trapped in the superconducting coil and the superconducting floating body. When fluxes were trapped in either coil or floating body, their effects were able to be cancelled by reversing polarities of current and magnetic field, as had been believed. However, fluxes trapped in both coil and body induced an attractive force between them and caused error. In order to reduce the fluxes, the coil and the floating body should be cooled in low magnetic field in magnetic and electromagnetic shields.

  10. Magnetic levitation using a stack of high temperature superconducting tape annuli

    Science.gov (United States)

    Patel, A.; Hahn, S.; Voccio, J.; Baskys, A.; Hopkins, S. C.; Glowacki, B. A.

    2017-02-01

    Stacks of large width superconducting tape can carry persistent currents over similar length scales to bulk superconductors, therefore giving them potential for trapped field magnets and magnetic levitation. 46 mm wide high temperature superconducting tape has previously been cut into square annuli to create a 3.5 T persistent mode magnet. The same tape pieces were used here to form a composite bulk hollow cylinder with an inner bore of 26 mm. Magnetic levitation was achieved by field cooling with a pair of rare-earth magnets. This paper reports the axial levitation force properties of the stack of annuli, showing that the same axial forces expected for a uniform bulk cylinder of infinite J c can be generated at 20 K. Levitation forces up to 550 N were measured between the rare-earth magnets and stack. Finite element modelling in COMSOL Multiphysics using the H-formulation was also performed including a full critical state model for induced currents, with temperature and field dependent properties as well as the influence of the ferromagnetic substrate which enhances the force. Spark erosion was used for the first time to machine the stack of tapes proving that large stacks can be easily machined to high geometric tolerance. The stack geometry tested is a possible candidate for a rotary superconducting bearing.

  11. Nonlinear resonances of three modes in a high-T{sub c} superconducting magnetic levitation system

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Masahiko, E-mail: galian@z2.keio.jp; Sakaguchi, Ryunosuke; Sugiura, Toshihiko, E-mail: sugiura@mach.keio.ac.jp

    2013-11-15

    Highlights: •We studied two nonlinear vibrations of a levitated beam supported by superconductors. •One of the vibrations is combination resonance of the 1st mode and the 3rd mode. •The other vibration is autoparametric resonance of the 2nd mode. •When the amplitude of the 2nd mode is small, the combination resonance is suppressed. •Otherwise, the two resonances can be resonated simultaneously. -- Abstract: In a high-T{sub c} superconducting magnetic levitation system, an object can levitate without control and contact. So it is expected to be applied to magnetically levitated transportation. To use it safely, lightening the levitated object is necessary. But this reduces the bending stiffness of the object. Besides, the system has nonlinearity. Therefore nonlinear elastic vibration can occur. This study focused on how plural nonlinear elastic vibrations of the 1st, 2nd and 3rd modes simultaneously occur. Our numerical calculation and experiment found out that the three modes simultaneously resonate when the amplitude of the 2nd mode is large enough whereas only the 2nd mode resonates when it is small.

  12. Dynamic Analysis of Micro-machined Diamagnetic Stable Permanent Magnet Levitation System

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel micro-machined diamagnetic stable-levitation system (MDSLS) which is composed of a free permanent magnetic rotor, a ring lifting permanent magnet and two diamagnetic stabilizers was presented. The static and dynamic stable characters of MDSLS were analyzed. The coupled non-linear differential equations were used to describe six-degree-of-freedom motion of the levitated rotor, and the equivalent surface current and combined diamagnetic image current method were utilized to model the interaction forces and torques between the lifting permanent magnet and rotor permanent magnet and also between the rotor permanent magnet and diamagnetic substrates. Because of difficulty to get analytical solution, the numerical calculation based on Runge-Kutta method was used to solve the dynamic model. The vibration frequencies were identified by fast Fourier transform (FFT) analysis. According to their resonance characteristics and parameters, the translational and angular dynamic stiffness were also calculated. The results show that the levitation of the rotor in MDSLS is stable, and the MDSLS is potential for the application in levitation inertial sensor.

  13. Basic Characteristics of the Propulsion System in the Permanent Magnet-HTSC Hybrid Magnetic Conveyance System

    Science.gov (United States)

    Ohashi, Shunsuke; Kumano, Daiki; Goto, Yasuyuki

    The Hybrid magnetically levitated transportation system has been developed. The magnetic rail is set on the ground, and the carrier with permanent magnets and high-Tc superconductors (HTSC) levitates on the rail. Repulsive force of permanent magnet is introduced to support load weight. Pinning force of the HTSC is used to support weight of the frame of the carrier and to achieve lateral stability of the carrier. In this paper, propulsion system of the conveyance system is studied. Propulsion function is installed on the carrier body. Magnetic gradient is used to get propulsion force. Propulsion force of the system is little. So propulsion rail system is introduced. 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. Enough propulsion force is given. Influence of the propulsion system on the levitation and guidance system is measured. Stability of levitation and guidance system is enough even when propulsion system is operated.

  14. Design and Analysis of the AlNiCo Hybrid Magnet in EMS Maglev Vehicles

    Directory of Open Access Journals (Sweden)

    Lv Chao

    2017-01-01

    Full Text Available In order to solve the problem of hybrid electromagnet lock orbit, we design a new type of AlNiCo-NdFeB hybrid levitation electromagnet. The theoretical analysis has be carried on and mathematical model is established for AlNiCo-NdFeB hybrid levitation electromagnet. Through two dimensional simulation, the electromagnetic characteristics of the suspended electromagnet are analyzed in the 3 typical operating conditions , which are in heavy load at gap 8mm, in full load at gap 16mm and in no-load at gap 3mm. And it’s compared with the traditional electromagnetic magnet and NdFeB hybrid electromagnet. Calculation and analysis show that the new hybrid levitation electromagnet can effectively solve the problems of the electromagnet lock orbit, at the same time, have a good dynamic performance and suspension regulation performance.

  15. Repulsive magnetic levitation-based ocean wave energy harvester with variable resonance: Modeling, simulation and experiment

    Science.gov (United States)

    Masoumi, Masoud; Wang, Ya

    2016-10-01

    This paper investigates a magnetic levitation characteristic used in a vibration based energy harvester, called repulsive magnetic scavenger (RMS). The RMS is capable of harvesting ocean wave energy with a unique repelling permanent magnet array, which provides a stronger and more uniform magnetic field, compared to its attracting magnetic counterparts. The levitating magnets are stacked together around a threaded rod so that the same pole is facing each other. Two fixed magnets placed with one at each end of the RMS provides a collocated harvesting and braking mechanism in the face of high amplitude vibrations. Magnets in the levitated magnet stack are separated by pole pieces which are made of metals to intensify the magnetic field strength. The effect of the thickness and the use of different materials with different permeability for pole pieces is also studied to obtain an optimal energy harvesting efficiency. Moreover, the procedure to find the restoring force applied to the levitating magnet stack is demonstrated. Then, the Duffing vibration equation of the harvester is solved and the frequency response function is calculated for various force amplitudes and electrical damping so as to investigate the effect of these parameters on the response of the system. Furthermore, the effect of the maximum displacement of the moving magnet stack on the natural frequency of the device is studied. And finally, Faraday's law is employed to estimate the output voltage and power of the system under the specified input excitation force. Experiments show that the output emf voltage of the manufactured prototype reaches up to 42 V for an excitation force with the frequency of 9 Hz and the maximum amplitude of 3.4 g.

  16. Thickness dependence of the levitation performance of double-layer high-temperature superconductor bulks above a magnetic rail

    Energy Technology Data Exchange (ETDEWEB)

    Sun, R.X.; Zheng, J.; Liao, X.L.; Che, T.; Gou, Y.F.; He, D.B.; Deng, Z.G., E-mail: zgdeng@gmail.com

    2014-10-15

    Highlights: • Thickness optimization of double-layer bulk HTSC arrangement is studied. • The new bulk HTSC arrangement makes better use of the flux distribution of the magnetic rails. • Levitation performance can be enhanced with the optimization. • The optimization can meet large levitation force requirements for HTS Maglev system. - Abstract: 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.

  17. Magnetic field is the dominant factor to induce the response of Streptomyces avermitilis in altered gravity simulated by diamagnetic levitation.

    Science.gov (United States)

    Liu, Mei; Gao, Hong; Shang, Peng; Zhou, Xianlong; Ashforth, Elizabeth; Zhuo, Ying; Chen, Difei; Ren, Biao; Liu, Zhiheng; Zhang, Lixin

    2011-01-01

    Diamagnetic levitation is a technique that uses a strong, spatially varying magnetic field to simulate an altered gravity environment, as in space. In this study, using Streptomyces avermitilis as the test organism, we investigate whether changes in magnetic field and altered gravity induce changes in morphology and secondary metabolism. We find that a strong magnetic field (12T) inhibit the morphological development of S. avermitilis in solid culture, and increase the production of secondary metabolites. S. avermitilis on solid medium was levitated at 0 g*, 1 g* and 2 g* in an altered gravity environment simulated by diamagnetic levitation and under a strong magnetic field, denoted by the asterix. The morphology was obtained by electromicroscopy. The production of the secondary metabolite, avermectin, was determined by OD(245 nm). The results showed that diamagnetic levitation could induce a physiological response in S. avermitilis. The difference between 1 g* and the control group grown without the strong magnetic field (1 g), showed that the magnetic field was a more dominant factor influencing changes in morphology and secondary metabolite production, than altered gravity. We have discovered that magnetic field, rather than altered gravity, is the dominant factor in altered gravity simulated by diamagnetic levitation, therefore care should to be taken in the interpretation of results when using diamagnetic levitation as a technique to simulate altered gravity. Hence, these results are significant, and timely to researchers considering the use of diamagnetic levitation to explore effects of weightlessness on living organisms and on physical phenomena.

  18. Robust stabilization via computer-generated Lyapunov functions: An application to a magnetic levitation system

    Energy Technology Data Exchange (ETDEWEB)

    Blanchini, F. [Universita di Udine (Italy); Carabelli, S. [Politecnico di Torino (Italy)

    1994-12-31

    We apply a technique recently proposed in literature for the robust stabilization of linear systems with time-varying uncertain parameters to a magnetic levitation system. This technique allows the construction of a polyhedral Lyapunov function and a linear variable-structure stabilizing controller.

  19. Noncontact orientation of objects in three-dimensional space using magnetic levitation.

    Science.gov (United States)

    Subramaniam, Anand Bala; Yang, Dian; Yu, Hai-Dong; Nemiroski, Alex; Tricard, Simon; Ellerbee, Audrey K; Soh, Siowling; Whitesides, George M

    2014-09-09

    This paper describes several noncontact methods of orienting objects in 3D space using Magnetic Levitation (MagLev). The methods use two permanent magnets arranged coaxially with like poles facing and a container containing a paramagnetic liquid in which the objects are suspended. Absent external forcing, objects levitating in the device adopt predictable static orientations; the orientation depends on the shape and distribution of mass within the objects. The orientation of objects of uniform density in the MagLev device shows a sharp geometry-dependent transition: an analytical theory rationalizes this transition and predicts the orientation of objects in the MagLev device. Manipulation of the orientation of the levitating objects in space is achieved in two ways: (i) by rotating and/or translating the MagLev device while the objects are suspended in the paramagnetic solution between the magnets; (ii) by moving a small external magnet close to the levitating objects while keeping the device stationary. Unlike mechanical agitation or robotic selection, orienting using MagLev is possible for objects having a range of different physical characteristics (e.g., different shapes, sizes, and mechanical properties from hard polymers to gels and fluids). MagLev thus has the potential to be useful for sorting and positioning components in 3D space, orienting objects for assembly, constructing noncontact devices, and assembling objects composed of soft materials such as hydrogels, elastomers, and jammed granular media.

  20. Separation and enrichment of enantiopure from racemic compounds using magnetic levitation.

    Science.gov (United States)

    Yang, Xiaochuan; Wong, Shin Yee; Bwambok, David K; Atkinson, Manza B J; Zhang, Xi; Whitesides, George M; Myerson, Allan S

    2014-07-18

    Crystallization of a solution with high enantiomeric excess can generate a mixture of crystals of the desired enantiomer and the racemic compound. Using a mixture of S-/RS-ibuprofen crystals as a model, we demonstrated that magnetic levitation (MagLev) is a useful technique for analysis, separation and enantioenrichment of chiral/racemic products.

  1. Magnetic levitation performance of high-temperature superconductor over three magnetic hills of permanent magnet guideway with iron shims of different thicknesses

    Institute of Scientific and Technical Information of China (English)

    Yuming Gong; Gang Liang; Lifeng Zhao; Yong Zhang; Yong Zhao; Xuyong Chen

    2014-01-01

    Superconducting magnetic levitation perfor-mance, including levitation force and guidance force, is important for the application of high-temperature super-conducting maglev. Both of them are not only affected by different arrays of superconductors and magnets, but also by the thickness of the iron shim between permanent magnets. In order to obtain the best levitation performance, the magnetic field distribution, levitation force, and guid-ance force of a new type of three magnetic hills of per-manent magnet guideway with iron shim of different thicknesses (4, 6, and 8 mm) are discussed in this paper. Simulation analysis and experiment results show that the guideway with iron shim of 8 mm thickness possesses the strongest magnetic field and levitation performance when the suspension gap is larger than 10 mm. However, with the decreasing of suspension gap, the guideway with iron shim of 4 mm thickness possesses the best levitation per-formance. The phenomena can be attributed to the density distribution of flux and magnetization of iron shim.

  2. Simulation of magnetization and levitation properties of arrays of ring-shaped type-II superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jun, E-mail: linxj8686@163.com; Huang, Chenguang; Yong, Huadong; Zhou, Youhe, E-mail: zhouyh@lzu.edu.cn

    2017-03-15

    Highlights: • A strong magnetic coupling appears if the gap between the superconducting rings is small. • The saturation magnetization of superconducting rings is related to the radial gap but independent of the vertical gap. • The array of rings in a non-uniform field experiences a levitation force, which increases with increasing height or thickness of the rings. - Abstract: This paper presents an analysis of the magnetic and mechanical properties of arrays of superconducting rings arranged in axial, radial, and matrix configurations under different magnetic fields. In terms of the Bean's critical state model and the minimum magnetic energy method, the dependences of the magnetization and levitation behaviors on the geometry, number, and gap of the superconducting rings are obtained. The results show that when the applied field is spatially uniform, the magnetic property of the superconducting array is associated with the gaps between the rings. For the case of small gaps, the entire array becomes not easy to be fully penetrated by the induced currents, and the magnetic field profiles of which are almost the same as ones in a single large ring. If the superconducting array is fully penetrated, its saturation magnetization value is affected by the radial interval and, however, is almost independent of the vertical separation. When the applied field produced by a cylindrical permanent magnet is nonuniform, the superconducting array will be subjected to a levitation force. The levitation force increases monotonically and finally reaches a saturation value with increasing height or thickness of the rings, and such saturation value is closely related to the inner radius of the array.

  3. Simulation of magnetization and levitation properties of arrays of ring-shaped type-II superconductors

    Science.gov (United States)

    Liu, Jun; Huang, Chenguang; Yong, Huadong; Zhou, Youhe

    2017-03-01

    This paper presents an analysis of the magnetic and mechanical properties of arrays of superconducting rings arranged in axial, radial, and matrix configurations under different magnetic fields. In terms of the Bean's critical state model and the minimum magnetic energy method, the dependences of the magnetization and levitation behaviors on the geometry, number, and gap of the superconducting rings are obtained. The results show that when the applied field is spatially uniform, the magnetic property of the superconducting array is associated with the gaps between the rings. For the case of small gaps, the entire array becomes not easy to be fully penetrated by the induced currents, and the magnetic field profiles of which are almost the same as ones in a single large ring. If the superconducting array is fully penetrated, its saturation magnetization value is affected by the radial interval and, however, is almost independent of the vertical separation. When the applied field produced by a cylindrical permanent magnet is nonuniform, the superconducting array will be subjected to a levitation force. The levitation force increases monotonically and finally reaches a saturation value with increasing height or thickness of the rings, and such saturation value is closely related to the inner radius of the array.

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

    Science.gov (United States)

    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.

  5. Influence of lateral displacement on the levitation performance of a magnetized bulk high-T{sub c} superconductor magnet

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W., E-mail: tonny-violet@163.com [College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059 (China) and Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu 610031 (China); Wang, J.S.; Ma, G.T.; Zheng, J. [Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu 610031 (China); State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031 (China); National Laboratory of Rail Transit, Chengdu, 610031 (China); Tuo, X.G.; Li, L.L. [College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059 (China); Ye, C.Q.; Liao, X.L. [Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu 610031 (China); National Laboratory of Rail Transit, Chengdu, 610031 (China); Wang, S.Y. [Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu 610031 (China); State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031 (China); National Laboratory of Rail Transit, Chengdu, 610031 (China)

    2012-03-15

    Compared with the permanent magnet, the magnetized bulk high-T{sub c} superconductor magnet (MBSCM) can trap higher magnetic field due to its strong flux pinning ability, so it is a good candidate to improve the levitation performance of high-T{sub c} superconductive (HTS) maglev system. The trapped magnetic flux of a MBSCM is sustained by the inductive superconducting current produced by the magnetizing process and is susceptible to the current intensity as well as configuration. In the HTS maglev system, the lateral displacement is an important process to change the superconducting current within a MBSCM and then affects its levitation performance, which is essential for the traffic ability in curve-way, the loading capacity of lateral impact and so on. The research about influence of lateral displacement on the levitation performance of MBSCM is necessary when MBSCM is applied on the HTS maglev vehicle. The experimental investigations about the influence of lateral displacement on the levitation performance of a MBSCM with different trapped fluxes and applied fields are processed in this article. The analyses and conclusions of this article are useful for the practical application of MBSCM in HTS maglev system.

  6. Magnetic levitation for effective loading of cold cesium atoms in a crossed dipole trap

    Science.gov (United States)

    Li, Yuqing; Feng, Guosheng; Xu, Rundong; Wang, Xiaofeng; Wu, Jizhou; Chen, Gang; Dai, Xingcan; Ma, Jie; Xiao, Liantuan; Jia, Suotang

    2015-05-01

    We report a detailed study of effective magnetically levitated loading of cold atoms in a crossed dipole trap: an appropriate magnetic field gradient precisely compensates for the destructive gravitational force of the atoms and an additional bias field simultaneously eliminates the antitrapping potential induced by the magnetic field gradient. The magnetic levitation is required for a large-volume crossed dipole trap to form a shallow but very effective loading potential, making it a promising method for loading and trapping more cold atoms. For cold cesium atoms in the F =3 , m F =3 state prepared by three-dimensional degenerated Raman sideband cooling, a large number of atoms ˜3.2 ×106 have been loaded into a large-volume crossed dipole trap with the help of the magnetic levitation technique. The dependence of the number of atoms loaded and trapped in the dipole trap on the magnetic field gradient and bias field, respectively, is in good agreement with the theoretical analysis. The optimum magnetic field gradient of 31.13 G/cm matches the theoretical value of 31.3 G/cm well. This method can be used to obtain more cold atoms or a large number of Bose-Einstein condensation atoms for many atomic species in high-field seeking states.

  7. Facile fabrication of tissue-engineered constructs using nanopatterned cell sheets and magnetic levitation

    Science.gov (United States)

    Penland, Nisa; Choi, Eunpyo; Perla, Mikael; Park, Jungyul; Kim, Deok-Ho

    2017-02-01

    We report a simple and versatile method for in vitro fabrication of scaffold-free tissue-engineered constructs with predetermined cellular alignment, by combining magnetic cell levitation with thermoresponsive nanofabricated substratum (TNFS) based cell sheet engineering technique. The TNFS based nanotopography provides contact guidance cues for regulation of cellular alignment and enables cell sheet transfer, while magnetic nanoparticles facilitate the magnetic levitation of the cell sheet. The temperature-mediated change in surface wettability of the thermoresponsive poly(N-isopropylacrylamide), substratum enables the spontaneous detachment of cell monolayers, which can then be easily manipulated through use of a ring or disk shaped magnet. Our developed platform could be readily applicable to production of tissue-engineered constructs containing complex physiological structures for the study of tissue structure-function relationships, drug screening, and regenerative medicine.

  8. Facile fabrication of tissue-engineered constructs using nanopatterned cell sheets and magnetic levitation.

    Science.gov (United States)

    Penland, Nisa; Choi, Eunpyo; Perla, Mikael; Park, Jungyul; Kim, Deok-Ho

    2017-02-17

    We report a simple and versatile method for in vitro fabrication of scaffold-free tissue-engineered constructs with predetermined cellular alignment, by combining magnetic cell levitation with thermoresponsive nanofabricated substratum (TNFS) based cell sheet engineering technique. The TNFS based nanotopography provides contact guidance cues for regulation of cellular alignment and enables cell sheet transfer, while magnetic nanoparticles facilitate the magnetic levitation of the cell sheet. The temperature-mediated change in surface wettability of the thermoresponsive poly(N-isopropylacrylamide), substratum enables the spontaneous detachment of cell monolayers, which can then be easily manipulated through use of a ring or disk shaped magnet. Our developed platform could be readily applicable to production of tissue-engineered constructs containing complex physiological structures for the study of tissue structure-function relationships, drug screening, and regenerative medicine.

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

    Science.gov (United States)

    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.

  10. Position feedback control of a nonmagnetic body levitated in magnetic fluid

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J H; Nam, Y J; Park, M K [Graduate School, Pusan National University, Busan 609-735 (Korea, Republic of); Yamane, R [Kokushikan University, Tokyo 154-8515 (Japan)], E-mail: magooro@pusan.ac.kr

    2009-02-01

    This paper is concerned with the position feedback control of a magnetic fluid actuator which is characterized by the passive levitation of a nonmagnetic body immersed in a magnetic fluid under magnetic fields. First of all, the magnetic fluid actuator is designed based on the ferrohydrostatic relation. After manufacturing the actuator, its static and dynamic characteristics are investigated experimentally. With the aid of the dynamic governing relation obtained experimentally and the proportional-derivative controller, the position tracking control of the actuator is carried out both theoretically and experimentally. As a result, the applicability of the proposed magnetic fluid actuator to various engineering devices is verified.

  11. VERTICAL NONCONTACT POSITIONING H∞ ROBUST CONTROL FOR MAGNETICALLY LEVITATED SURFACE MOTOR

    Institute of Scientific and Technical Information of China (English)

    TAO Tao; HAO Xiaohong; MEI Xuesong; JIANG Gedong; ZHANG Dongsheng

    2008-01-01

    To fulfill the stringent requirement, super-precision positioning and ultra cleanness, a surface motor with the integrated chip fabrication equipment is constructed by using permanent magnets and electromagnet coils as primary actuating components. It consists of stator and mover, and the mover is isolated from the stator by the magnetic bearing. The magnetic bearing in the stator is composed of eight air core electromagnet coils, the propulsion in the stator is composed of iron core and electromagnetic coils, and the mover is composed of NdFeB permanent magnets and levitated stage. Based on Lorentz law, some parameters, including permanent magnets dimensions, currents and levitation height, which may affect the stability, are analyzed and optimized. To improve the positioning accuracy in the vertical direction of the magnetic levitation surface motor, a robust controller is proposed using H∞ mixed sensitivity control theory. The simulation results show that by choosing appropriate weight functions, the controller can ensure the robustness of the closed loop system under the presence of uncertainties, and the H∞ robust controller is excellent for reducing steady error and increasing response speed.

  12. Preliminary research of magnetic levitation accelerometer%磁悬浮式加速度计前期研究

    Institute of Scientific and Technical Information of China (English)

    练斌; 叶凌云; 黄添添

    2012-01-01

    为设计新型的小型高精度磁悬浮式加速度计,利用仿真软件对自制超顺磁性加速度计悬浮体在外磁场中所受的磁力进行仿真,并通过悬浮实验测试超顺磁性加速度计悬浮体在常温常压下的悬浮性能.仿真结果表明:超顺磁性加速度计悬浮体在外磁场中所受的磁力完全受外磁场控制.悬浮实验表明:当外磁场强度合适时,超顺磁性加速度计悬浮体可在常温常压下实现悬浮.实验表明:新型超顺磁性加速度计悬浮体适用于设计小型高精度磁悬浮式加速度计.%To design new type of small size high precision magnetic levitation accelerometer, the magnetic force of self-made superparamagnetic levitalion object of accelerometer in external magnetic field is simulated by software, and the levitation properties of superparamagnetic levitation object by accelerometer is test by levitation experiments. Simulation results demonstrate that the superparamagnetic leritation object of accelerometer is fully controlled by external magnetic field. Levitation experiments indicate that the superparamagnetic levitation object of accelerometer can be levitated under normal temperature and pressure. Experimental results show that this superparamagnetic levitation object of accelerometer is suitable for designing small size high precision magnetic levitation accelerometer.

  13. Cryogenic Hybrid Magnetic Bearing

    Science.gov (United States)

    Meeks, Crawford R.; Dirusso, Eliseo; Brown, Gerald V.

    1994-01-01

    Cryogenic hybrid magnetic bearing is example of class of magnetic bearings in which permanent magnets and electromagnets used to suspend shafts. Electromagnets provide active control of position of shaft. Bearing operates at temperatures from -320 degrees F (-196 degrees C) to 650 degrees F (343 degrees C); designed for possible use in rocket-engine turbopumps, where effects of cryogenic environment and fluid severely limit lubrication of conventional ball bearings. This and similar bearings also suitable for terrestrial rotating machinery; for example, gas-turbine engines, high-vacuum pumps, canned pumps, precise gimbals that suspend sensors, and pumps that handle corrosive or gritty fluids.

  14. Topology optimization of magnetic source distributions for diamagnetic and superconducting levitation

    Science.gov (United States)

    Kuznetsov, Sergey; Guest, James K.

    2017-09-01

    Topology optimization is used to obtain a magnetic source distribution providing levitation of a diamagnetic body or type I superconductor with maximized thrust force. We show that this technique identifies non-trivial source distributions and may be useful to design devices based on non-contact magnetic suspension and other magnetic devices, such as micro-magneto-mechanical devices, high field magnets etc. Diamagnetic and superconducting suspensions are often used in physical experiments and thus we believe this approach will be interesting to physics community as it may generate non-trivial and often unexpected topologies and may be useful to create new experiments and devices.

  15. Design of a 2-DOF Control and Disturbance Estimator for a Magnetic Levitation System

    Directory of Open Access Journals (Sweden)

    A. Pati

    2017-02-01

    Full Text Available This work proposes a systematic two-degree freedom control scheme to improve the reference input tracking and load disturbance rejection for an unstable magnetic levitation system. The proposed control strategy is a two-step design process. Firstly, a proportional derivative controller is introduced purposely to get the desired set-point response of the magnetic levitation system and then, an integral square error (ISE performance specification is used for designing a set-point tracking controller. Secondly, a disturbance estimator is designed using the desired closed loop complimentary sensitivity function for the rejection of load disturbances. This leads to the decoupling of the nominal set-point response from the load disturbance response similar to an open loop control manner. Thus, it is convenient to optimize both controllers simultaneously as well as separately. The effectiveness of the proposed control strategy is validated through simulation.

  16. Measurement and calculation of levitation forces between magnets and granular superconductors

    Science.gov (United States)

    Johansen, T. H.; Bratsberg, H.; Baziljevich, M.; Hetland, P. O.; Riise, A. B.

    1995-01-01

    Recent developments indicate that exploitation of the phenomenon of magnetic levitation may become one of the most important near-term applications of high-T(sub c) superconductivity. Because of this, the interaction between a strong permanent magnet(PM) and bulk high-T(sub c) superconductor (HTSC) is currently a subject of much interest. We have studied central features of the mechanics of PM-HTSC systems of simple geometries. Here we report experimental results for the components of the levitation force, their associated stiffness and mechanical ac-loss. To analyze the observed behavior a theoretical framework based on critical-state considerations is developed. It will be shown that all the mechanical properties can be explained consistently at a quantitative level wing a minimum of model parameters.

  17. Microgravity simulation by diamagnetic levitation: effects of a strong gradient magnetic field on the transcriptional profile of Drosophila melanogaster.

    Science.gov (United States)

    Herranz, Raul; Larkin, Oliver J; Dijkstra, Camelia E; Hill, Richard J A; Anthony, Paul; Davey, Michael R; Eaves, Laurence; van Loon, Jack J W A; Medina, F Javier; Marco, Roberto

    2012-02-01

    Many biological systems respond to the presence or absence of gravity. Since experiments performed in space are expensive and can only be undertaken infrequently, Earth-based simulation techniques are used to investigate the biological response to weightlessness. A high gradient magnetic field can be used to levitate a biological organism so that its net weight is zero. We have used a superconducting magnet to assess the effect of diamagnetic levitation on the fruit fly D. melanogaster in levitation experiments that proceeded for up to 22 consecutive days. We have compared the results with those of similar experiments performed in another paradigm for microgravity simulation, the Random Positioning Machine (RPM). We observed a delay in the development of the fruit flies from embryo to adult. Microarray analysis indicated changes in overall gene expression of imagoes that developed from larvae under diamagnetic levitation, and also under simulated hypergravity conditions. Significant changes were observed in the expression of immune-, stress-, and temperature-response genes. For example, several heat shock proteins were affected. We also found that a strong magnetic field, of 16.5 Tesla, had a significant effect on the expression of these genes, independent of the effects associated with magnetically-induced levitation and hypergravity. Diamagnetic levitation can be used to simulate an altered effective gravity environment in which gene expression is tuned differentially in diverse Drosophila melanogaster populations including those of different age and gender. Exposure to the magnetic field per se induced similar, but weaker, changes in gene expression.

  18. Using magnetic levitation for non-destructive quality control of plastic parts.

    Science.gov (United States)

    Hennek, Jonathan W; Nemiroski, Alex; Subramaniam, Anand Bala; Bwambok, David K; Yang, Dian; Harburg, Daniel V; Tricard, Simon; Ellerbee, Audrey K; Whitesides, George M

    2015-03-04

    Magnetic levitation (MagLev) enables rapid and non-destructive quality control of plastic parts. The feasibility of MagLev as a method to: i) rapidly assess injection-molded plastic parts for defects during process optimization, ii) monitor the degradation of plastics after exposure to harsh environmental conditions, and iii) detect counterfeit polymers by density is demonstrated. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Design of a Discrete Tracking Controller for a Magnetic Levitation System: A Nonlinear Rational Model Approach

    Directory of Open Access Journals (Sweden)

    Fernando Gómez-Salas

    2015-01-01

    Full Text Available This work proposes a discrete-time nonlinear rational approximate model for the unstable magnetic levitation system. Based on this model and as an application of the input-output linearization technique, a discrete-time tracking control design will be derived using the corresponding classical state space representation of the model. A simulation example illustrates the efficiency of the proposed methodology.

  20. Levitation force and magnetization in bulk and thin film high T{sub c} superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Riise, A.B

    1998-04-01

    The authors present high-resolution measurements of the repulsive vertical force and its associated stiffness between a Nd-B-Fe magnet and a YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} superconductor in cylindrical geometry. The results are compared with theoretical predictions. The calculations are based on a model in which the superconductor is assumed to be either a sintered granular material or consisting of grains embedded in a nonactive matrix so that only intragranular currents are important. The critical state model is applied to each grain individually and closed form expressions for both vertical force F{sub z} and stiffness are obtained in a configuration with cylindrical symmetry. The model explains all features of the experimental results in a consistent way. A good quantitative agreement has been obtained using only three adjustable parameters. Several central aspects of the phenomenon of magnetic levitation with high-T{sub c} superconductors are presented. High-resolution measurements are made of the repulsive vertical force and its associated stiffness as well as the horizontal stabilizing force and the stiffness governing lateral vibrations. The results obtained at 77 K using a granular YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} sample and Nd-Fe-B magnet in a rectangular levitation configuration are compared with theoretical predictions. The calculations, which are based on the critical state model with the assumption that it applies to the grins individually, give closed-form expressions for all the measured quantities. It is concluded that the present model explains all features of the observations in a consistent way. Using only three adjustable parameters a good agreement exists also at a quantitative level. Experimental studies and theoretical modelling of the levitation force on a permanent magnet placed above a superconducting thin film are offered. It is shown that measurements of the levitation force is a simple and precise method to determine the

  1. Magnetically levitated nano-robots: an application to visualization of nerve cells injuries.

    Science.gov (United States)

    Lou, Mingji; Jonckheere, Edmond

    2007-01-01

    This paper proposes a swarm of magnetically levitated nano-robots with high sensitivity nano-sensors as a mean to detect chemical sources, specifically the chemical signals released by injured nervous cells. In the aftermath of the process, further observation by these nano-robots would be used to monitor the healing process and assess the amount of regeneration, if any, or even the repair, of the injured nervous cells.

  2. Stable magnetic levitation with adjustable ratio of levitation force to restoring force using rings of zero-field cooled YBa{sub 2}Cu{sub 3}O{sub y} samples

    Energy Technology Data Exchange (ETDEWEB)

    Hennig, W.; Parks, D.; Weinstein, R.; Sawh, R.-P.; Ren, Y. [Beam Particles Dynamics Laboratories and TCSUH, University of Houston, Houston, TX 77204-5506 (United States)

    2000-10-01

    Both high levitation pressures (up to 22 N cm{sup -2}) and high restoring pressures (up to 11 N cm{sup -2}) are obtained for a superconducting trapped field magnet of 1.5 T levitating above the centre of a ring of zero-field cooled high-temperature superconductors. The ratio of levitation force to restoring force can be varied between 2.9 and 0.3 by changing the quality of the superconductors. This significantly improves the stability of levitation compared to commonly used single sample configurations. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Hazi, A

    2005-09-20

    the 1960s, transportation industry planners have sought an energy-efficient design for a train that can glide through air at speeds up to 500 kilometers per hour. This type of train, called a magnetically levitated (maglev) train, is thought to be a viable solution to meet the nation's growing need for intercity and urban transportation networks. However, despite some promising developments, unresolved concerns with the operation and safety of maglev trains has prevented the transition from demonstration model to commercial development. Inductrack, a maglev system originally conceived by Livermore physicist Richard Post, is designed to address these issues. Post's work on Inductrack began with funding from Livermore's Laboratory Directed Research and Development Program, and in 2003, the technology was licensed to General Atomics (GA) in San Diego for train and transit system applications. This year, members of the Livermore-GA team received an R&D 100 Award for Inductrack's development. Inductrack uses permanent magnets to produce the magnetic fields that levitate the train and provides economic and operational advantages over other maglev systems. It can be adapted to both high-speed and urban-speed environments. In the event of a power failure, the train slows gradually until it comes to rest on its auxiliary wheels. The maintenance requirements for Inductrack are also lower than they are for other systems, plus it has a short turning radius and is designed for quiet operation. Previous designs for maglev systems did not offer the energy efficiency or safety protections that are in the Inductrack design. Electromagnetic systems (EMS) use powered electromagnets to levitate the train. However, these systems are based on magnetic attraction rather than repulsion and thus are inherently unstable. In EMS trains, the levitation gap--the separation between the magnet pole faces and the iron rail--is only about 10 millimeters and, during operation

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

    Science.gov (United States)

    Rohacs, Daniel; Rohacs, Jozsef

    2016-08-01

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

  5. Application of Fuzzy Logic to EMS-type Magnetically Levitated Railway Vehicle

    Science.gov (United States)

    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.

  6. Relaxation properties of magnetic force between a magnet and superconductor in an unsymmetrical levitation system

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xingyi; Zhou Jun; Zhou Youhe [Key Laboratory of Mechanics on Western Disaster and Environment, Ministry of Education (China); Liang Xinwen [Department of Finance, School of Economics of Sichuan University, Sichuan University, Chengdu, Sichuan 610064 (China)

    2009-02-15

    We present an experimental study of the relaxation of vertical and horizontal force components in an unsymmetrical high-temperature superconducting levitation system, with different initial cooling processes, after fixing the levitated body statically in a given position. It was found that the values of the relaxation measurements of the levitation force and lateral force remained constant or increased with time after vertical and horizontal traverses. The phenomenon has been theoretically described based on the Bean model and the thermally activated flux creep theory. The criterion developed in the present work is considered to be suitable for providing qualitative predictions of the relaxation properties in the levitation force and lateral force.

  7. Relaxation properties of magnetic force between a magnet and superconductor in an unsymmetrical levitation system

    Science.gov (United States)

    Zhang, Xing-Yi; Zhou, Jun; Zhou, You-He; Liang, Xin-Wen

    2009-02-01

    We present an experimental study of the relaxation of vertical and horizontal force components in an unsymmetrical high-temperature superconducting levitation system, with different initial cooling processes, after fixing the levitated body statically in a given position. It was found that the values of the relaxation measurements of the levitation force and lateral force remained constant or increased with time after vertical and horizontal traverses. The phenomenon has been theoretically described based on the Bean model and the thermally activated flux creep theory. The criterion developed in the present work is considered to be suitable for providing qualitative predictions of the relaxation properties in the levitation force and lateral force.

  8. Rotational characteristics in the resonance state of the HTSC-permanent magnet hybrid magnetic bearing

    Energy Technology Data Exchange (ETDEWEB)

    Morii, Y.; Sukedai, M. [Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680 (Japan); Ohashi, S., E-mail: ohashi@kansai-u.ac.jp [Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680 (Japan)

    2011-11-15

    The hybrid magnetic bearing has been developed. In the hybrid system, effect of the pinning force becomes smaller. Influence of the vibration and the gradient angle in the resonance state is large. The resonance frequency becomes small in the hybrid bearing system. The hybrid magnetic bearing using permanent magnets and the high-Tc bulk superconductor (HTSC) has been developed. Repulsive force of the permanent magnet is introduced to increase the load weight of the magnetic bearing. Effect of the hybrid system has been shown. In this paper, influence of the hybrid system on the dynamic characteristics of the rotor is studied. The rotational characteristics in the mechanical resonance state are studied, and the equivalent magnetic spring coefficient is estimated from the experimental results of the load weight. The resonance frequency is measured by the rotation experiments. The rotor achieves stable levitation even in the resonance state. In the hybrid system, effect of the pinning force becomes smaller than that of the lateral force generated by the repulsive force between the two permanent magnets at the smaller air gap. Thus influence of the lateral vibration and the gradient angle in the resonance state becomes larger at a smaller air gap. The equivalent magnetic spring coefficient becomes also small, and the resonance frequency becomes small in the hybrid bearing system.

  9. Comparison of simulation and experiment on levitation force between GdBCO bulk superconductor and superconducting magnet

    Energy Technology Data Exchange (ETDEWEB)

    Araki, S., E-mail: satoshi@sum.sd.keio.ac.j [Department of System Design Engineering, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Nagashima, K.; Seino, H. [Railway Technical Research Institute, 2-8-38 Hikari-cho, Kokubunji, Tokyo 185-8540 (Japan); Murakami, T.; Sawa, K. [Department of System Design Engineering, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan)

    2009-10-15

    High temperature bulk superconductors have significant potential for various engineering applications such as a flywheel energy storage system. This system is expected to decrease the energy loss by using bulk superconductors for the bearing. Recently, the authors have developed a new superconducting magnet to realize large levitation force. In this system, the axial component of magnetic field is canceled each other but the radial component of magnetic field expects to be enhanced. Thus, it was expected that the large levitation force can be realized and its time relaxation will be decreased. And in the previous paper, the levitation force and its time relaxation were measured under the various conditions by using this new magnet. But it is difficult to consider what phenomenon has happened in the bulk from only experimental results. In addition the quantitative evaluation cannot be done only by the experimental results, for example, the influence of the magnetic field penetration and magnetic distribution around a bulk superconductor on the maximum force and so on. Thus, in this paper, the authors simulated the levitation force of bulk superconductor by using ELF/MAGIC, which is a three-dimensional electromagnetic analytical software. In the simulation the bulk was considered as a rigid body and the simulation was executed under the same conditions and model with the experiment. The distribution of magnetic field and the levitation force were obtained and discussed.

  10. Magnetic field is the dominant factor to induce the response of Streptomyces avermitilis in altered gravity simulated by diamagnetic levitation.

    Directory of Open Access Journals (Sweden)

    Mei Liu

    Full Text Available BACKGROUND: Diamagnetic levitation is a technique that uses a strong, spatially varying magnetic field to simulate an altered gravity environment, as in space. In this study, using Streptomyces avermitilis as the test organism, we investigate whether changes in magnetic field and altered gravity induce changes in morphology and secondary metabolism. We find that a strong magnetic field (12T inhibit the morphological development of S. avermitilis in solid culture, and increase the production of secondary metabolites. METHODOLOGY/PRINCIPAL FINDINGS: S. avermitilis on solid medium was levitated at 0 g*, 1 g* and 2 g* in an altered gravity environment simulated by diamagnetic levitation and under a strong magnetic field, denoted by the asterix. The morphology was obtained by electromicroscopy. The production of the secondary metabolite, avermectin, was determined by OD(245 nm. The results showed that diamagnetic levitation could induce a physiological response in S. avermitilis. The difference between 1 g* and the control group grown without the strong magnetic field (1 g, showed that the magnetic field was a more dominant factor influencing changes in morphology and secondary metabolite production, than altered gravity. CONCLUSION/SIGNIFICANCE: We have discovered that magnetic field, rather than altered gravity, is the dominant factor in altered gravity simulated by diamagnetic levitation, therefore care should to be taken in the interpretation of results when using diamagnetic levitation as a technique to simulate altered gravity. Hence, these results are significant, and timely to researchers considering the use of diamagnetic levitation to explore effects of weightlessness on living organisms and on physical phenomena.

  11. Magnetic levitation and its application for education devices based on YBCO bulk superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Yang, W.M., E-mail: yangwm@snnu.edu.cn; Chao, X.X.; Guo, F.X.; Li, J.W.; Chen, S.L.

    2013-10-15

    Highlights: • A small superconducting maglev propeller system has been designed and constructed based on YBCO bulk superconductors. • Several small maglev vehicle models have been designed and constructed based on YBCO bulk superconductors. • The models can be used as experimental or demonstration devices for the magnetic levitation applications. -- Abstract: A small superconducting maglev propeller system, a small spacecraft model suspending and moving around a terrestrial globe, several small maglev vehicle models and a magnetic circuit converter have been designed and constructed. The track was paved by NdFeB magnets, the arrangement of the magnets made us easy to get a uniform distribution of magnetic field along the length direction of the track and a high magnetic field gradient in the lateral direction. When the YBCO bulks mounted inside the vehicle models or spacecraft model was field cooled to LN{sub 2} temperature at a certain distance away from the track, they could be automatically floating over and moving along the track without any obvious friction. The models can be used as experimental or demonstration devices for the magnetic levitation applications.

  12. Tilted Magnetic Levitation Enables Measurement of the Complete Range of Densities of Materials with Low Magnetic Permeability.

    Science.gov (United States)

    Nemiroski, Alex; Soh, Siowling; Kwok, Sen Wai; Yu, Hai-Dong; Whitesides, George M

    2016-02-03

    Magnetic levitation (MagLev) of diamagnetic or weakly paramagnetic materials suspended in a paramagnetic solution in a magnetic field gradient provides a simple method to measure the density of small samples of solids or liquids. One major limitation of this method, thus far, has been an inability to measure or manipulate materials outside of a narrow range of densities (0.8 g/cm(3) levitated magnetically. Tilting the MagLev device relative to the gravitational vector enables the magnetic force to be decreased (relative to the magnetic force) along the axis of measurement. This approach enables many practical measurements over the entire range of densities observed in matter at ambient conditions-from air bubbles (ρ ≈ 0) to osmium and iridium (ρ ≈ 23 g/cm(3)). The ability to levitate, simultaneously, objects with a broad range of different densities provides an operationally simple method that may find application to forensic science (e.g., for identifying the composition of miscellaneous objects or powders), industrial manufacturing (e.g., for quality control of parts), or resource-limited settings (e.g., for identifying and separating small particles of metals and alloys).

  13. Thickness dependence of the levitation performance of double-layer high-temperature superconductor bulks above a magnetic rail

    Science.gov (United States)

    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.

  14. Magnetic levitation and its application for education devices based on YBCO bulk superconductors

    Science.gov (United States)

    Yang, W. M.; Chao, X. X.; Guo, F. X.; Li, J. W.; Chen, S. L.

    2013-10-01

    A small superconducting maglev propeller system, a small spacecraft model suspending and moving around a terrestrial globe, several small maglev vehicle models and a magnetic circuit converter have been designed and constructed. The track was paved by NdFeB magnets, the arrangement of the magnets made us easy to get a uniform distribution of magnetic field along the length direction of the track and a high magnetic field gradient in the lateral direction. When the YBCO bulks mounted inside the vehicle models or spacecraft model was field cooled to LN2 temperature at a certain distance away from the track, they could be automatically floating over and moving along the track without any obvious friction. The models can be used as experimental or demonstration devices for the magnetic levitation applications.

  15. Characterization and adaptive fuzzy model reference control for a magnetic levitation system

    Directory of Open Access Journals (Sweden)

    J.J. Hernández-Casañas

    2016-09-01

    Full Text Available This paper shows the implementation of a fuzzy controller applied for magnetic levitation, to make this, the characterization of the magnetic actuator was computed by using ANSYS® analysis. The control law was a Mamdani PD implemented with two microcontrollers, to get a smooth control signal, it was used a model reference. A learning scheme was used to update the consequents of the fuzzy rules. Different reference signals and disturbances were applied to the system to show the robustness of the controller. Finally, LabVIEW® was used to plot the results.

  16. Dynamic circuit and Fourier series methods for moment calculation in electrodynamic repulsive magnetic levitation systems

    Science.gov (United States)

    Knowles, R.

    1982-07-01

    A general theory of moments for electrodynamic magnetic levitation systems has been developed using double Fourier series and dynamic circuit principles. Both employ Parseval's theorem using either wave constant derivatives or the polar waveconstant principle of the Fourier-Bessel/double Fourier series equivalence. A method for calculating angular derivatives of moments and forces is explained, and for all of these methods comparisons are made with experimental results obtained for single and split rail configurations. Extensions of dynamic circuit theory for tilted nonflat and circular magnets are also explained.

  17. Assembly of a three-dimensional multitype bronchiole coculture model using magnetic levitation.

    Science.gov (United States)

    Tseng, Hubert; Gage, Jacob A; Raphael, Robert M; Moore, Robert H; Killian, Thomas C; Grande-Allen, K Jane; Souza, Glauco R

    2013-09-01

    A longstanding goal in biomedical research has been to create organotypic cocultures that faithfully represent native tissue environments. There is presently great interest in representative culture models of the lung, which is a particularly challenging tissue to recreate in vitro. This study used magnetic levitation in conjunction with magnetic nanoparticles as a means of creating an organized three-dimensional (3D) coculture of the bronchiole that sequentially layers cells in a manner similar to native tissue architecture. The 3D coculture model was assembled from four human cell types in the bronchiole: endothelial cells, smooth muscle cells (SMCs), fibroblasts, and epithelial cells (EpiCs). This study represents the first effort to combine these particular cell types into an organized bronchiole coculture. These cell layers were first cultured in 3D by magnetic levitation, and then manipulated into contact with a custom-made magnetic pen, and again cultured for 48 h. Hematoxylin and eosin staining of the resulting coculture showed four distinct layers within the 3D coculture. Immunohistochemistry confirmed the phenotype of each of the four cell types and showed organized extracellular matrix formation, particularly, with collagen type I. Positive stains for CD31, von Willebrand factor, smooth muscle α-actin, vimentin, and fibronectin demonstrate the maintenance of the phenotype for endothelial cells, SMCs, and fibroblasts. Positive stains for mucin-5AC, cytokeratin, and E-cadherin after 7 days with and without 1% fetal bovine serum showed that EpiCs maintained the phenotype and function. This study validates magnetic levitation as a method for the rapid creation of organized 3D cocultures that maintain the phenotype and induce extracellular matrix formation.

  18. Magnetic Levitation Coupled with Portable Imaging and Analysis for Disease Diagnostics.

    Science.gov (United States)

    Knowlton, Stephanie M; Yenilmez, Bekir; Amin, Reza; Tasoglu, Savas

    2017-02-19

    Currently, many clinical diagnostic procedures are complex, costly, inefficient, and inaccessible to a large population in the world. The requirements for specialized equipment and trained personnel require that many diagnostic tests be performed at remote, centralized clinical laboratories. Magnetic levitation is a simple yet powerful technique and can be applied to levitate cells, which are suspended in a paramagnetic solution and placed in a magnetic field, at a position determined by equilibrium between a magnetic force and a buoyancy force. Here, we present a versatile platform technology designed for point-of-care diagnostics which uses magnetic levitation coupled to microscopic imaging and automated analysis to determine the density distribution of a patient's cells as a useful diagnostic indicator. We present two platforms operating on this principle: (i) a smartphone-compatible version of the technology, where the built-in smartphone camera is used to image cells in the magnetic field and a smartphone application processes the images and to measures the density distribution of the cells and (ii) a self-contained version where a camera board is used to capture images and an embedded processing unit with attached thin-film-transistor (TFT) screen measures and displays the results. Demonstrated applications include: (i) measuring the altered distribution of a cell population with a disease phenotype compared to a healthy phenotype, which is applied to sickle cell disease diagnosis, and (ii) separation of different cell types based on their characteristic densities, which is applied to separate white blood cells from red blood cells for white blood cell cytometry. These applications, as well as future extensions of the essential density-based measurements enabled by this portable, user-friendly platform technology, will significantly enhance disease diagnostic capabilities at the point of care.

  19. Improvement of the rotational characteristics in the HTSC-permanent magnet hybrid bearing using ring shaped magnet

    Energy Technology Data Exchange (ETDEWEB)

    Emoto, Kozo; Sugiyama, Ryo; Takagi, Shogo; Ohashi, Shunsuke, E-mail: k145676@kansai-u.ac.jp

    2013-11-15

    Highlights: •We have developed the HTS-permanent magnet hybrid bearing system. •Three dimensional numerical analysis is undertaken to get the effective hybrid configuration. •Repulsive force and pinning force are combined effectively. •The hybrid system shows better levitation characteristics than the non-hybrid one. •In the mechanical resonance state, vibration of the rotor in the hybrid system is small. -- Abstract: We have developed the hybrid magnetic bearing using permanent magnets and the high-T{sub c} bulk superconductor (HTSC). Pinning force of the HTSC is used for the levitation and the guidance. Repulsive force of the permanent magnets is introduced to increase the load weight of the magnetic bearing. In this system, the stator side permanent magnet has the ring type structure so that both pinning force and repulsive force are used effectively. In this paper, influence of the hybrid system on dynamic characteristics of the rotor is studied. The rotor which is supported by the hybrid magnetic bearing is rotated. Then, vibration and the gradient angle of the rotor are measured until the rotor reaches to the end of the resonance state. Three dimensional numerical analysis of the flux which penetrates on the surface of the HTSC is undertaken. The relation between the dynamic characteristics and the flux is considered, and that of the hybrid system is compared with the non-hybrid one. In the hybrid system, the flux is changed by the influences of the stator side permanent magnet. Vibration and the gradient angle of the hybrid system are shown to be smaller than that of the non-hybrid one.

  20. Stability of magnetic tip/superconductor levitation systems

    Institute of Scientific and Technical Information of China (English)

    M. K. Alqadi

    2015-01-01

    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.

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

    NARCIS (Netherlands)

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

    2007-01-01

    The results of the experimental and theoretical investigations of the magnetic levitation force appearing at the interaction of the multilayer superconducting block of the YBa2Cu3O7-x melted textured ceramic and a permanent magnet are presented. The maximum repulsive force and maximum attractive for

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

    NARCIS (Netherlands)

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

    2007-01-01

    The results of the experimental and theoretical investigations of the magnetic levitation force appearing at the interaction of the multilayer superconducting block of the YBa2Cu3O7-x melted textured ceramic and a permanent magnet are presented. The maximum repulsive force and maximum attractive for

  3. Hybrid Magnetics and Power Applications

    DEFF Research Database (Denmark)

    Mo, Wai Keung; Paasch, Kasper

    A hybrid magnetic approach, merging two different magnetic core properites such as ferrite and iron powder cores, is an effective solution for power converter applications. It can offer similar magnetic properties to that of magnetic powder cores but showing less copper loss than powder cores...

  4. Multi-modal vibration energy harvesting approach based on nonlinear oscillator arrays under magnetic levitation

    Science.gov (United States)

    Abed, I.; Kacem, N.; Bouhaddi, N.; Bouazizi, M. L.

    2016-02-01

    We propose a multi-modal vibration energy harvesting approach based on arrays of coupled levitated magnets. The equations of motion which include the magnetic nonlinearity and the electromagnetic damping are solved using the harmonic balance method coupled with the asymptotic numerical method. A multi-objective optimization procedure is introduced and performed using a non-dominated sorting genetic algorithm for the cases of small magnet arrays in order to select the optimal solutions in term of performances by bringing the eigenmodes close to each other in terms of frequencies and amplitudes. Thanks to the nonlinear coupling and the modal interactions even for only three coupled magnets, the proposed method enable harvesting the vibration energy in the operating frequency range of 4.6-14.5 Hz, with a bandwidth of 190% and a normalized power of 20.2 {mW} {{cm}}-3 {{{g}}}-2.

  5. Magnetically levitated mesenchymal stem cell spheroids cultured with a collagen gel maintain phenotype and quiescence

    Directory of Open Access Journals (Sweden)

    Natasha S Lewis

    2017-04-01

    Full Text Available Multicellular spheroids are an established system for three-dimensional cell culture. Spheroids are typically generated using hanging drop or non-adherent culture; however, an emerging technique is to use magnetic levitation. Herein, mesenchymal stem cell spheroids were generated using magnetic nanoparticles and subsequently cultured within a type I collagen gel, with a view towards developing a bone marrow niche environment. Cells were loaded with magnetic nanoparticles, and suspended beneath an external magnet, inducing self-assembly of multicellular spheroids. Cells in spheroids were viable and compared to corresponding monolayer controls, maintained stem cell phenotype and were quiescent. Interestingly, core spheroid necrosis was not observed, even with increasing spheroid size, in contrast to other commonly used spheroid systems. This mesenchymal stem cell spheroid culture presents a potential platform for modelling in vitro bone marrow stem cell niches, elucidating interactions between cells, as well as a useful model for drug delivery studies.

  6. Flux line depinning in a magnet-superconductor levitation system

    Science.gov (United States)

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

    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 ≈2 Oe, 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.

  7. Magnetic Levitation of MC3T3 Osteoblast Cells as a Ground-Based Simulation of Microgravity

    Science.gov (United States)

    Kidder, Louis S.; Williams, Philip C.; Xu, Wayne Wenzhong

    2009-01-01

    Diamagnetic samples placed in a strong magnetic field and a magnetic field gradient experience a magnetic force. Stable magnetic levitation occurs when the magnetic force exactly counter balances the gravitational force. Under this condition, a diamagnetic sample is in a simulated microgravity environment. The purpose of this study is to explore if MC3T3-E1 osteoblastic cells can be grown in magnetically simulated hypo-g and hyper-g environments and determine if gene expression is differentially expressed under these conditions. The murine calvarial osteoblastic cell line, MC3T3-E1, grown on Cytodex-3 beads, were subjected to a net gravitational force of 0, 1 and 2 g in a 17 T superconducting magnet for 2 days. Microarray analysis of these cells indicated that gravitational stress leads to up and down regulation of hundreds of genes. The methodology of sustaining long-term magnetic levitation of biological systems are discussed. PMID:20052306

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    Paden, Brad; Antaki, James; Groom, Nelson

    2000-01-01

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

  10. Vibration Analysis of Continuous Maglev Guideway Considering the Magnetic Levitation System

    Institute of Scientific and Technical Information of China (English)

    TENG Yan-feng; TENG Nian-guan; KOU Xin-jian

    2008-01-01

    The dynamic interaction between moving vehicles and two-span continuous guideway was discussed. With the consideration of the magnetic levitation system, the maglev vehicle/guideway dynamic interaction model was developed. Numerical simulation was performed to understand dynamic characteristics of the guide- way used in practice. The results show that vehicle speed, span length and primary frequency of the guideway have an important influence on the dynamic responses of the guideway and there is no distinct trend towards resonance vibration when f1 equals 1.0. The definite way is to control the impact coefficient and acceleration of the guideway. The conclusions can serve the design of high speed maglev guideway.

  11. Analysis of Vertical Oscillations of a Permanent Magnet Freely Levitated above an YBCO Bulk in an AC External Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    Yong Zhang; Ya-Li Zhang; Cui-Hua Cheng; Yong Zhao

    2008-01-01

    The effect of the moving speed of perma- nent magnet (PM) on levitation force between PM and high temperature superconducting (HTS) bulk is analyzed and described in the PM-HTS levitation system. The PM vibration characteristic in the PM-HTS system is investigated. The PM may collide with the HTS in vibration if the amplitude and frequency of driving force satisfy the relationship Pmin = A f n. When the load of the system is below a threshold, the minimal collision amplitude of the driving force increases with the load increasing, however, it sharply drops to zero when the load exceeds the threshold. With the increase of the initial height of the PM, the threshold load increases, but the minimal driving force which causes a collision between PM and HTS decreases.

  12. All Aboard! For a Lesson on Magnetic Levitated Trains.

    Science.gov (United States)

    Moore, Virginia S.; Kaszas, William J.

    1995-01-01

    Presents an activity that explores the operation of Maglev trains. Demonstrates that elementary students can master cutting-edge technology through creating and racing magnetic vehicles on a specially designed track, researching the history of rail transportation, and exploring a current science issue. (NB)

  13. Neural Networks Control of a Magnetic Levitation System

    Science.gov (United States)

    2001-04-17

    investigation of the use of artificial neural networks (ANN) in conjunction of proportional-integral-derivative ( PID ) controllers in control of non...neural networks in controlling closed-loop active magnetic bearing and comparison with the use of PID controllers . The obtained results should create a

  14. Bulk synthesis of monodisperse magnetic FeNi3 nanopowders by flow levitation method.

    Science.gov (United States)

    Chen, Shanjun; Chen, Yan; Kang, Xiaoli; Li, Song; Tian, Yonghong; Wu, Weidong; Tang, Yongjian

    2013-10-01

    In this work, a novel bulk synthesis method for monodisperse FeNi3 nanoparticles was developed by flow levitation method (FL). The Fe and Ni vapours ascending from the high temperature levitated droplet was condensed by cryogenic Ar gas under atmospheric pressure. X-ray diffraction was used to identify and characterize the crystal phase of prepared powders exhibiting a FeNi3 phase. The morphology and size of nanopowders were observed by transmission electron microscopy (TEM). The chemical composition of the nanoparticles was determined with energy dispersive spectrometer (EDS). The results indicated that the FeNi3 permalloy powders are nearly spherical-shaped with diameter about 50-200 nm. Measurement of the magnetic property of nanopowders by a superconducting quantum interference device (SQUID, Quantum Design MPMS-7) showed a symmetric hysteresis loop of ferromagnetic behavior with coercivity of 220 Oe and saturation magnetization of 107.17 emu/g, at 293 K. At 5 K, the obtained saturation magnetization of the sample was 102.16 emu/g. The production rate of FeNi3 nanoparticles was estimated to be about 6 g/h. This method has great potential in mass production of FeNi3 nannoparticles.

  15. Microgravity simulation by diamagnetic levitation: effects of a strong gradient magnetic field on the transcriptional profile of Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Herranz Raul

    2012-02-01

    Full Text Available Abstract Background Many biological systems respond to the presence or absence of gravity. Since experiments performed in space are expensive and can only be undertaken infrequently, Earth-based simulation techniques are used to investigate the biological response to weightlessness. A high gradient magnetic field can be used to levitate a biological organism so that its net weight is zero. Results We have used a superconducting magnet to assess the effect of diamagnetic levitation on the fruit fly D. melanogaster in levitation experiments that proceeded for up to 22 consecutive days. We have compared the results with those of similar experiments performed in another paradigm for microgravity simulation, the Random Positioning Machine (RPM. We observed a delay in the development of the fruit flies from embryo to adult. Microarray analysis indicated changes in overall gene expression of imagoes that developed from larvae under diamagnetic levitation, and also under simulated hypergravity conditions. Significant changes were observed in the expression of immune-, stress-, and temperature-response genes. For example, several heat shock proteins were affected. We also found that a strong magnetic field, of 16.5 Tesla, had a significant effect on the expression of these genes, independent of the effects associated with magnetically-induced levitation and hypergravity. Conclusions Diamagnetic levitation can be used to simulate an altered effective gravity environment in which gene expression is tuned differentially in diverse Drosophila melanogaster populations including those of different age and gender. Exposure to the magnetic field per se induced similar, but weaker, changes in gene expression.

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

    Science.gov (United States)

    Gering, James A.

    2002-01-01

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

  17. Does Magnetic Levitation or Suspension Define the Masses of Forming Stars?

    CERN Document Server

    Shu, F H; Allen, A; Shu, Frank H.; Li, Zhi-Yun; Allen, Anthony

    2004-01-01

    We investigate whether magnetic tension can define the masses of forming stars by holding up the subcritical envelope of a molecular cloud that suffers gravitational collapse of its supercritical core. We perform an equilibrium analysis of the initial and final states assuming perfect field freezing, no rotation, isothermality, and a completely flattened configuration. The sheet geometry allows us to separate the magnetic tension into a levitation associated with the split monopole formed by the trapped flux of the central star and a suspension associated with curved field lines that thread the static pseudodisk and envelope of material external to the star. We find solutions where the eigenvalue for the stellar mass is a fixed multiple of the initial core mass of the cloud. We verify the analytically derived result by an explicit numerical simulation of a closely related 3-D axisymmetric system. However, with field freezing, the implied surface magnetic fields much exceed measured values for young stars. If ...

  18. Levitation of Extended States in a Random Magnetic Field with a Finite Mean

    Institute of Scientific and Technical Information of China (English)

    LIU Wen-Sheng; LEI Xiao-Lin

    2004-01-01

    We study the localization properties of electrons in a two-dimensional system in a random magnetic field B(r) = Bo + δB(r) with the average Bo and the amplitude of the magnetic field fluctuations δB. The localization length of the system is calculated by using the finite-size scaling method combined with the transfer-matrix technique.Inthe case of weak δB, we find that the random magnetic field system is equivalent to the integer quantum Hall effect system, namely, the energy band splits into a series of disorder broadened Landau bands, at the centers of which states are extended with the localization length exponent v = 2.34 ± 0.02. With increasing δB, the extended states float up in energy, which is similar to the levitation scenario proposed for the integer quantum Hall effect.

  19. Hybrid superconductor magnet bearings

    Science.gov (United States)

    Chu, Wei-Kan

    1995-01-01

    Hybrid superconductor magnet bearings (HSMB's) utilize high temperature superconductors (HTS's) together with permanent magnets to form a frictionless interface between relatively rotating parts. They are low mass, stable, and do not incur expenditure of energy during normal operation. There is no direct physical contact between rotor and stator, and hence there is no wear and tear. However, just as any other applications of HTS's, it requires a very cold temperature to function. Whereas this might be perceived as a disadvantage on earth, it is of no great concern in space or on the moon. To astronomers, the moon is an excellent site for an observatory, but the cold and dusty vacuum environment on the moon precludes the use of mechanical bearings on the telescope mounts. Furthermore, drive mechanisms with very fine steps, and hence bearings with extremely low friction are needed to track a star from the moon, because the moon rotates very slowly. All aspects considered, the HSMB is about the only candidate that fits in naturally. Here, we present a design for one such bearing, capable of supporting a telescope that weighs about 3 lbs on Earth.

  20. Thermal instability in a magnetically levitated doubly overhung rotor

    Science.gov (United States)

    Takahashi, Naohiko; Kaneko, Shigehiko

    2013-03-01

    This paper deals with a synchronous vibration instability that occurred in a two-stage overhung centrifugal compressor supported by magnetic bearings. The authors encountered an unbalance vibration that increased spirally in a polar plot at/near the first bending critical speed. The concentration of iron loss and thermal bending due to heat have been identified as the causes of the phenomenon, because the vibration stopped increasing when unbalance force rejection control (UFRC) was applied. In this paper, prior to an in-depth discussion of experiments on the above phenomenon, the compressor and magnetic bearing system are described. To provide a theoretical perspective, a model of the thermally induced vibration is presented and the stability is discussed. In the experiments, to exceed the first bending critical speed stably, balancing of the rotor under UFRC was carried out and rapid acceleration/deceleration was applied to the variable-speed drive system. The vibration behaviors around the critical speed were measured and the results verified the theoretical model. To evaluate the stability limit of the thermal bending, a method of measuring the model parameter that determines the stability is proposed and the measured data are compared with calculated results. Finally, methods for improving the stability are discussed.

  1. Vibration isolation using six degree-of-freedom quasi-zero stiffness magnetic levitation

    Science.gov (United States)

    Zhu, Tao; Cazzolato, Benjamin; Robertson, William S. P.; Zander, Anthony

    2015-12-01

    In laboratories and high-tech manufacturing applications, passive vibration isolators are often used to isolate vibration sensitive equipment from ground-borne vibrations. However, in traditional passive isolation devices, where the payload weight is supported by elastic structures with finite stiffness, a design trade-off between the load capacity and the vibration isolation performance is unavoidable. Low stiffness springs are often required to achieve vibration isolation, whilst high stiffness is desired for supporting payload weight. In this paper, a novel design of a six degree of freedom (six-dof) vibration isolator is presented, as well as the control algorithms necessary for stabilising the passively unstable maglev system. The system applies magnetic levitation as the payload support mechanism, which realises inherent quasi-zero stiffness levitation in the vertical direction, and zero stiffness in the other five dofs. While providing near zero stiffness in multiple dofs, the design is also able to generate static magnetic forces to support the payload weight. This negates the trade-off between load capacity and vibration isolation that often exists in traditional isolator designs. The paper firstly presents the novel design concept of the isolator and associated theories, followed by the mechanical and control system designs. Experimental results are then presented to demonstrate the vibration isolation performance of the proposed system in all six directions.

  2. Three-dimensional in vitro co-culture model of breast tumor using magnetic levitation.

    Science.gov (United States)

    Jaganathan, Hamsa; Gage, Jacob; Leonard, Fransisca; Srinivasan, Srimeenakshi; Souza, Glauco R; Dave, Bhuvanesh; Godin, Biana

    2014-10-01

    In this study, we investigate a novel in vitro model to mimic heterogeneous breast tumors without the use of a scaffold while allowing for cell-cell and tumor-fibroblast interactions. Previous studies have shown that magnetic levitation system under conventional culturing conditions results in the formation of three-dimensional (3D) structures, closely resembling in vivo tissues (fat tissue, vasculature, etc.). Three-dimensional heterogeneous tumor models for breast cancer were designed to effectively model the influences of the tumor microenvironment on drug efficiency. Various breast cancer cells were co-cultured with fibroblasts and then magnetically levitated. Size and cell density of the resulting tumors were measured. The model was phenotypically compared to in vivo tumors and examined for the presence of ECM proteins. Lastly, the effects of tumor stroma in the 3D in vitro model on drug transport and efficiency were assessed. Our data suggest that the proposed 3D in vitro breast tumor is advantageous due to the ability to: (1) form large-sized (millimeter in diameter) breast tumor models within 24 h; (2) control tumor cell composition and density; (3) accurately mimic the in vivo tumor microenvironment; and (4) test drug efficiency in an in vitro model that is comparable to in vivo tumors.

  3. Designing Flexible Neuro-Fuzzy System Based on Sliding Mode Controller for Magnetic Levitation Systems

    Directory of Open Access Journals (Sweden)

    Zahra Mohammadi

    2011-07-01

    Full Text Available This study presents a novel controller of magnetic levitation system by using new neuro-fuzzy structures which called flexible neuro-fuzzy systems. In this type of controller we use sliding mode control with neuro-fuzzy to eliminate the Jacobian of plant. At first, we control magnetic levitation system with Mamdanitype neuro-fuzzy systems and logical-type neuro-fuzzy systems separately and then we use two types of flexible neuro-fuzzy systems as controllers. Basic flexible OR-type neuro-fuzzy inference system and basic compromise AND-type neuro-fuzzy inference system are two new flexible neuro-fuzzy controllers which structure of fuzzy inference system (Mamdani or logical is determined in the learning process. We can investigate with these two types of controllers which of the Mamdani or logical type systems has better performance for control of this plant. Finally we compare performance of these controllers with sliding mode controller and RBF sliding mode controller.

  4. 32 tesla hybrid magnet system

    Energy Technology Data Exchange (ETDEWEB)

    Leupold, M.J.; Iwasa, Y.; Weggel, R.J. (MIT Cambridge (U.S.A.))

    1984-01-01

    The paper describes the design and construction of a hybrid magnet system to generate 32T with 9MW of electrical power. The system consist of an 11T niobium-titanium superconducting magnet, a 1.8K/4.2K cryostat, and a high-performance, water-cooled Bitter magnet, all of which are discussed in the paper.

  5. Relationship of the Levitation Force Between Single and Multiple YBCO Bulks Above a Permanent Magnet Guideway Operating Dive-Lift Movement with Different Angles

    Science.gov (United States)

    Zeng, R.; Wang, S. Y.; Liao, X. L.; Deng, Z. G.; Wang, J. S.

    2013-04-01

    In practical applications, the acceleration and deceleration motions inevitably happen in the operation of high temperature superconducting (HTS) maglev trains. For further research of the maglev properties of YBaCuO bulk above a permanent magnet guideway (PMG), by moving a fixed vertical distance, this paper studies the relationship of the levitation force between single and multiple YBCO bulks above a PMG operating dive-lift movement with different angles. Experimental results show that the maximal levitation force increment of two bulks than one bulk is smaller than the maximal levitation force increment of three bulks than two bulks. With the degree decreasing, the maximal levitation force increment of three bulks is bigger than the maximal levitation force increment of two bulks and one bulk, and the hysteresis loop of the levitation force of the three-bulk arrangement is getting smaller.

  6. Rotational characteristics in the resonance state of the HTSC-permanent magnet hybrid magnetic bearing

    Science.gov (United States)

    Morii, Y.; Sukedai, M.; Ohashi, S.

    2011-11-01

    The hybrid magnetic bearing using permanent magnets and the high-Tc bulk superconductor (HTSC) has been developed. Repulsive force of the permanent magnet is introduced to increase the load weight of the magnetic bearing. Effect of the hybrid system has been shown. In this paper, influence of the hybrid system on the dynamic characteristics of the rotor is studied. The rotational characteristics in the mechanical resonance state are studied, and the equivalent magnetic spring coefficient is estimated from the experimental results of the load weight. The resonance frequency is measured by the rotation experiments. The rotor achieves stable levitation even in the resonance state. In the hybrid system, effect of the pinning force becomes smaller than that of the lateral force generated by the repulsive force between the two permanent magnets at the smaller air gap. Thus influence of the lateral vibration and the gradient angle in the resonance state becomes larger at a smaller air gap. The equivalent magnetic spring coefficient becomes also small, and the resonance frequency becomes small in the hybrid bearing system.

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

    Science.gov (United States)

    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…

  8. Deep cooling of optically trapped atoms implemented by magnetic levitation without transverse confinement

    Science.gov (United States)

    Li, Chen; Zhou, Tianwei; Zhai, Yueyang; Xiang, Jinggang; Luan, Tian; Huang, Qi; Yang, Shifeng; Xiong, Wei; Chen, Xuzong

    2017-05-01

    We report a setup for the deep cooling of atoms in an optical trap. The deep cooling is implemented by eliminating the influence of gravity using specially constructed magnetic coils. Compared to the conventional method of generating a magnetic levitating force, the lower trap frequency achieved in our setup provides a lower limit of temperature and more freedoms to Bose gases with a simpler solution. A final temperature as low as ˜ 6 nK is achieved in the optical trap, and the atomic density is decreased by nearly two orders of magnitude during the second stage of evaporative cooling. This deep cooling of optically trapped atoms holds promise for many applications, such as atomic interferometers, atomic gyroscopes, and magnetometers, as well as many basic scientific research directions, such as quantum simulations and atom optics.

  9. Optical and magnetic measurements of gyroscopically stabilized graphene nanoplatelets levitated in an ion trap

    Science.gov (United States)

    Nagornykh, Pavel; Coppock, Joyce E.; Murphy, Jacob P. J.; Kane, B. E.

    2017-07-01

    Using optical measurements, we demonstrate that the rotation of micron-scale graphene nanoplatelets levitated in a quadrupole ion trap in high vacuum can be frequency-locked to an applied radiofrequency electric field Erf. Over time, frequency-locking stabilizes the nanoplatelet so that its axis of rotation is normal to the nanoplatelet and perpendicular to Erf. We observe that residual slow dynamics of the direction of the axis of rotation in the plane normal to Erf is determined by an applied magnetic field. We present a simple model that accurately describes our observations. From our data and model, we can infer both a diamagnetic polarizability and a magnetic moment proportional to the frequency of rotation, which we compare to theoretical values. Our results establish that trapping technologies have applications for materials measurements at the nanoscale.

  10. A magnetic levitation robotic camera for minimally invasive surgery: Useful for NOTES?

    Science.gov (United States)

    Di Lorenzo, Nicola; Cenci, Livia; Simi, Massimiliano; Arcudi, Claudio; Tognoni, Valeria; Gaspari, Achille Lucio; Valdastri, Pietro

    2017-06-01

    Minimally invasive surgery (MIS) is rising in popularity generating a revolution in operative medicine during the past few decades. Although laparoscopic techniques have not significantly changed in the last 10 years, several advances have been made in visualization devices and instrumentation. Our team, composed of surgeons and biomedical engineers, developed a magnetic levitation camera (MLC) with a magnetic internal mechanism dedicated to MIS. Three animal trials were performed. Porcine acute model has been chosen after animal ethical committee approval, and laparoscopic cholecystectomy, nephrectomy and hernioplastic repair have been performed. MLC permits to complete efficiently several two-port laparoscopy surgeries reducing patients' invasiveness and at the same time saving surgeon's dexterity. We strongly believe that insertable and softly tethered devices like MLS camera will be an integral part of future surgical systems, thus improving procedures efficiency, minimizing invasiveness and enhancing surgeon dexterity and versatility of visions angles.

  11. Modeling of hysteretic behavior of the levitation force between superconductor and permanent magnet

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Xing-da, E-mail: shuxdw@gmail.com [School of Information Engineering, Guangdong Medical College, No. 2, Eastern Wenming Road, Zhanjiang 524023 (China); Xu, Ke-Xi, E-mail: kxxu@staff.shu.edu.cn [Department of Physics, Shanghai University, Shanghai 200444 (China); Cao, Yue; Hu, Shun-bo; Zuo, Peng-xiang; Li, Guan-dong [Department of Physics, Shanghai University, Shanghai 200444 (China)

    2013-03-15

    Highlights: ► Experimental results on hysteretic behavior of the levitaion force are presented. ► Hysteresis loop for the first descent/ascent cycle of magnet is largest. ► Hysteresis loop for the second and subsequent cycles almost overlap each other. ► Yang’s frozen-image model cannot describe this characteristic of levitation force. ► An updated frozen-image model is developed to describe these experimental results. -- Abstract: The hysteretic behavior of the levitation force between a permanent magnet and a melt-textured-growth YBCO bulk has been investigated under both zero-field cooling (ZFC) and field cooling (FC) processes. It is found that both in ZFC and FC measurements, the hysteresis loop for the first descent/ascent cycle of magnet is relatively larger than that for the second or third cycle, and the hysteresis loops for Cycle 2–4 have the same area. These results can be qualitatively understood in terms of the critical state model. To describe these experimental results, we develop an updated frozen-image model, which is obtained by modifying the change rules of the vertical movement image in the advanced frozen-image model proposed by Yang et al. Comparing with the advanced frozen-image model proposed by Yang et al., our model cannot only give the hysteretic characteristic in the first descent–ascent cycle of magnet, but also show the hysteresis loops with the same area for the second and subsequent cycles.

  12. Thermal properties of a large-bore cryocooled 10 T superconducting magnet for a hybrid magnet

    Energy Technology Data Exchange (ETDEWEB)

    Ishizuka, M., E-mail: Mas_Ishizuka@shi.co.j [Graduate School of Engineering, Tohoku University, 6-6 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8579 (Japan); Research and Development Center, Sumitomo Heavy Industries, Ltd., 19 Natsushima-chou, Yokosuka, Kanagawa 237-8555 (Japan); Hamajima, T. [Graduate School of Engineering, Tohoku University, 6-6 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8579 (Japan); Itou, T. [Ehime Works, Sumitomo Heavy Industries, Ltd., 5-2 Soubiraki-cho, Niihama, Ehime 792-8588 (Japan); Sakuraba, J. [Research and Development Center, Sumitomo Heavy Industries, Ltd., 19 Natsushima-chou, Yokosuka, Kanagawa 237-8555 (Japan); Nishijima, G.; Awaji, S.; Watanabe, K. [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

    2010-11-01

    A cryocooled 10 T superconducting magnet with a 360 mm room temperature bore has been developed for a hybrid magnet. The superconducting magnet cooled by four Gifford-McMahon cryocoolers has been designed to generate a magnetic field of 10 T. Since superconducting wires composed of coils were subjected to large hoop stress over 150 MPa and Nb{sub 3}Sn superconducting wires particularly showed a low mechanical strength due to those brittle property, Nb{sub 3}Sn wires strengthened by NbTi-filaments were developed for the cryocooled superconducting magnet. We have already reported that the hybrid magnet could generate the resultant magnetic field of 27.5 T by adding 8.5 T from the superconducting magnet and 19 T from a water-cooled Bitter resistive magnet, after the water-cooled resistive magnet was inserted into the 360 mm room temperature bore of the cryocooled superconducting magnet. When the hybrid magnet generated the field of 27.5 T, it achieved the high magnetic-force field (B x {partial_derivative}Bz/{partial_derivative}z) of 4500 T{sup 2}/m, which was useful for magneto-science in high fields such as materials levitation research. In this paper, we particularly focus on the cause that the cryocooled superconducting magnet was limited to generate the designed magnetic field of 10 T in the hybrid magnet operation. As a result, it was found that there existed mainly two causes as the limitation of the magnetic field generation. One was a decrease of thermal conductive passes due to exfoliation from the coil bobbin of the cooling flange. The other was large AC loss due to both a thick Nb{sub 3}Sn layer and its large diameter formed on Nb-barrier component in Nb{sub 3}Sn wires.

  13. Growth anisotropy effect of bulk high temperature superconductors on the levitation performance in the applied magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, J., E-mail: jzheng@swjtu.edu.cn; Liao, X.L.; Jing, H.L.; Deng, Z.G.; Yen, F.; Wang, S.Y.; Wang, J.S.

    2013-10-15

    Highlights: • The single-layer bulk HTSC with AGSBP obtains better levitation performance than that of MGSBP. • The double-layer bulk with AGSBP obtains better levitation performance than that of MGSBP too. • The double-layer bulk finding is contrast to MGSBP if pursuing high trapped field. • The optimization is highlighted by simple and easy operation, thus economical in the practice. -- Abstract: 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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Ki-Chang Lee

    2010-07-01

    Full Text Available 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.

  16. Assembly of a functional 3D primary cardiac construct using magnetic levitation

    Directory of Open Access Journals (Sweden)

    Glauco Souza

    2016-07-01

    Full Text Available Easily assembled organotypic co-cultures have long been sought in medical research. In vitro tissue constructs with faithful representation of in vivo tissue characteristics are highly desirable for screening and characteristic assessment of a variety of tissue types. Cardiac tissue analogs are particularly sought after due to the phenotypic degradation and difficulty of culture of primary cardiac myocytes. This study utilized magnetic nanoparticles and primary cardiac myocytes in order to levitate and culture multicellular cardiac aggregates (MCAs. Cells were isolated from 2 day old Sprague Dawley rat hearts and subsequently two groups were incubated with either C1: 33 µL nanoshell/million cells or C2: 50 µL nanoshell/million cells. Varying numbers of cells for each concentration were cultured in a magnetic field in a 24 well plate and observed over a period of 12 days. Constructs generally formed spherical structures. Masson’s trichrome staining of a construct shows the presence of extracellular matrix protein, indicating the presence of functional fibroblasts. Many constructs exhibited noticeable contraction after 4 days of culture and continued contracting noticeably past day 9 of culture. Noticeable contractility indicates the presence of functional primary cardiac myocytes in culture. Phenotypic conservation of cardiac cells was ascertained using IHC staining by α-actinin and collagen. CD31 and fibrinogen were probed in order to assess localization of fibroblasts and endothelial cells. The study verifies a protocol for the use of magnetic levitation in order to rapidly assemble 3D cardiac like tissue with phenotypic and functional stability.

  17. Decay Characteristics of Levitation Force of YBCO Bulk Exposed to AC Magnetic Field above NdFeB Guideway

    Science.gov (United States)

    Liu, Minxian; Lu, Yiyun; Wang, Suyu; Ma, Guangtong

    2011-04-01

    The superconducting maglev vehicle is one of the most promising applications of HTS bulks. In such a system, the nonuniformity of the magnetic field along the movement direction above the NdFeB guideway is inevitable due to the assembly error and inhomogeneity of the material property of the NdFeB magnet. So it is required to study the characteristics of levitation force of the bulks affected by the non-uniform applied magnetic fields along the moving direction. In this paper, we will study the characteristics of the levitation force relaxation between the HTS bulk and the NdFeB guideway by an experiment in which AC external magnetic field generated by an electromagnet is used to simulate the time-varying external magnetic field caused by the inhomogeneity of the guideway. From the experimental results, it has found that the levitation force is decreasing with the application of the AC external magnetic field, and the decay increasing with the amplitude of the applied magnetic field and is almost independent of the frequency.

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

    Science.gov (United States)

    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. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  19. Design of Magnetic Levitation System Based on Inverse Control Techniqueusing Adaptive Neuro-Fuzzy Inference System

    Directory of Open Access Journals (Sweden)

    Mithaq Nama Raheema

    2017-07-01

    Full Text Available The design of ANFIS network based inverse control technique is proposed in this paperfor this system. Simulation is implemented in MATLAB after the ANFIS is trained and it is shown that results are applicable in process industry and acceptable for reference control applications. The effectiveness of the proposed ANFIS in inverse controller it has been tested by entering random selected points which represent the values of input voltage from the system under control as a reference input to inverse modelling, after that entering the results of inverse modelling to the modelling of magnet levitation system to form the desired output. The result is acceptable with small errors about 0.0011

  20. Measuring binding of protein to gel-bound ligands using magnetic levitation.

    Science.gov (United States)

    Shapiro, Nathan D; Mirica, Katherine A; Soh, Siowling; Phillips, Scott T; Taran, Olga; Mace, Charles R; Shevkoplyas, Sergey S; Whitesides, George M

    2012-03-28

    This paper describes the use of magnetic levitation (MagLev) to measure the association of proteins and ligands. The method starts with diamagnetic gel beads that are functionalized covalently with small molecules (putative ligands). Binding of protein to the ligands within the bead causes a change in the density of the bead. When these beads are suspended in a paramagnetic aqueous buffer and placed between the poles of two NbFeB magnets with like poles facing, the changes in the density of the bead on binding of protein result in changes in the levitation height of the bead that can be used to quantify the amount of protein bound. This paper uses a reaction-diffusion model to examine the physical principles that determine the values of rate and equilibrium constants measured by this system, using the well-defined model system of carbonic anhydrase and aryl sulfonamides. By tuning the experimental protocol, the method is capable of quantifying either the concentration of protein in a solution, or the binding affinities of a protein to several resin-bound small molecules simultaneously. Since this method requires no electricity and only a single piece of inexpensive equipment, it may find use in situations where portability and low cost are important, such as in bioanalysis in resource-limited settings, point-of-care diagnosis, veterinary medicine, and plant pathology. It still has several practical disadvantages. Most notably, the method requires relatively long assay times and cannot be applied to large proteins (>70 kDa), including antibodies. The design and synthesis of beads with improved characteristics (e.g., larger pore size) has the potential to resolve these problems.

  1. Hybrid Processing Combining Electrostatic Levitation and Laser Heating: Application to Terrestrial Analogues of Asteroid Materials

    Directory of Open Access Journals (Sweden)

    Paul-François Paradis

    2011-01-01

    Full Text Available Electrostatic levitation combined with laser heating is becoming a mature technique that has been used for several fundamental and applied studies in fluid and materials sciences (synthesis, property determination, solidification studies, atomic dynamic studies, etc.. This is attributable to the numerous processing conditions (containerless, wide heating temperature range, cooling rates, atmospheric compositions, etc. that levitation and radiative heating offer, as well as to the variety of diagnostics tools that can be used. In this paper, we describe the facility, highlighting the combined advantages of electrostatic levitation and laser processing. The various capabilities of the facility are discussed and are exemplified with the measurements of the density of selected iron-nickel alloys taken over the liquid phase.

  2. Electromagnetic and Mechanical Characteristics Analysis of a Flat-Type Vertical-Gap Passive Magnetic Levitation Vibration Isolator

    Directory of Open Access Journals (Sweden)

    Baoquan Kou

    2016-01-01

    Full Text Available In this paper, we describe a flat-type vertical-gap passive magnetic levitation vibration isolator (FVPMLVI for active vibration isolation system (AVIS. A dual-stator scheme and a special stator magnet array are adopted in the proposed FVPMLVI, which has the effect of decreasing its natural frequency, and this enhances the vibration isolation capability of the FVPMLVI. The structure, operating principle, analytical model, and electromagnetic and mechanical characteristics of the FVPMLVI are investigated. The relationship between the force characteristics (levitation force, horizontal force, force ripple, and force density and major structural parameters (width and thickness of stator and mover magnets is analyzed by finite element method. The experiment result is in good agreement with the theoretical analysis.

  3. Analytical model for the levitation force between a small magnet and a superconducting cylinder in the critical state

    Science.gov (United States)

    de la Cruz, Artorix; Badía, Antonio

    2002-08-01

    In this work a simple analytical model is presented, which allows to obtain closed-form expressions for the maximum magnetic field trapped by a cylindrical superconductor as well as the levitation force between the sample and a small magnet. Previous models of this kind could not properly account for the behaviour of the repulsion force with the variation of the sample dimensions. In particular, the so-called Js+ Jv model (J. Appl. Phys. 72 (1992) 1013) incorporates size effects by means of a surface current density ( Js) which tends to zero for disc-shaped samples. However, we show that the features encountered both in experimental works and numerical models reported in the literature can be reproduced by a suitable modification of the Js+ Jv model. Analytical expressions of the levitation force are obtained as a function of length and radius of the sample and as well the superconductor-magnet distance.

  4. Modeling of a compliant joint in a Magnetic Levitation System for an endoscopic camera

    Directory of Open Access Journals (Sweden)

    M. Simi

    2012-01-01

    Full Text Available A novel compliant Magnetic Levitation System (MLS for a wired miniature surgical camera robot was designed, modeled and fabricated. The robot is composed of two main parts, head and tail, linked by a compliant beam. The tail module embeds two magnets for anchoring and manual rough translation. The head module incorporates two motorized donut-shaped magnets and a miniaturized vision system at the tip. The compliant MLS can exploit the static external magnetic field to induce a smooth bending of the robotic head (0–80°, guaranteeing a wide span tilt motion of the point of view. A nonlinear mathematical model for compliant beam was developed and solved analytically in order to describe and predict the trajectory behaviour of the system for different structural parameters. The entire device is 95 mm long and 12.7 mm in diameter. Use of such a robot in single port or standard multiport laparoscopy could enable a reduction of the number or size of ancillary trocars, or increase the number of working devices that can be deployed, thus paving the way for multiple view point laparoscopy.

  5. Improvement of the rotational characteristics in the HTSC-permanent magnet hybrid bearing using ring shaped magnet

    Science.gov (United States)

    Emoto, Kozo; Sugiyama, Ryo; Takagi, Shogo; Ohashi, Shunsuke

    2013-11-01

    We have developed the hybrid magnetic bearing using permanent magnets and the high-Tc bulk superconductor (HTSC). Pinning force of the HTSC is used for the levitation and the guidance. Repulsive force of the permanent magnets is introduced to increase the load weight of the magnetic bearing. In this system, the stator side permanent magnet has the ring type structure so that both pinning force and repulsive force are used effectively. In this paper, influence of the hybrid system on dynamic characteristics of the rotor is studied. The rotor which is supported by the hybrid magnetic bearing is rotated. Then, vibration and the gradient angle of the rotor are measured until the rotor reaches to the end of the resonance state. Three dimensional numerical analysis of the flux which penetrates on the surface of the HTSC is undertaken. The relation between the dynamic characteristics and the flux is considered, and that of the hybrid system is compared with the non-hybrid one. In the hybrid system, the flux is changed by the influences of the stator side permanent magnet. Vibration and the gradient angle of the hybrid system are shown to be smaller than that of the non-hybrid one.

  6. Influence of electromagnetic interference on implanted cardiac arrhythmia devices in and around a magnetically levitated linear motor car.

    Science.gov (United States)

    Fukuta, Motoyuki; Mizutani, Noboru; Waseda, Katsuhisa

    2005-01-01

    This study was designed to determine the susceptibility of implanted cardiac arrhythmia devices to electromagnetic interference in and around a magnetically levitated linear motor car [High-Speed Surface Transport (HSST)]. During the study, cardiac devices were connected to a phantom model that had similar characteristics to the human body. Three pacemakers from three manufacturers and one implantable cardioverter-defibrillator (ICD) were evaluated in and around the magnetically levitated vehicle. The system is based on a normal conductive system levitated by the attractive force of magnets and propelled by a linear induction motor without wheels. The magnetic field strength at 40 cm from the vehicle in the nonlevitating state was 0.12 mT and that during levitation was 0.20 mT. The magnetic and electric field strengths on a seat close to the variable voltage/variable frequency inverter while the vehicle was moving and at rest were 0.13 mT, 2.95 V/m and 0.04 mT, 0.36 V/m, respectively. Data recorded on a seat close to the reactor while the vehicle was moving and at rest were 0.09 mT, 2.45 V/m and 0.05 mT, 1.46 V/m, respectively. Measured magnetic and electric field strengths both inside and outside the linear motor car were too low to result in device inactivation. No sensing, pacing, or arrhythmic interactions were noted with any pacemaker or ICD programmed in either bipolar and unipolar configurations. In conclusion, our data suggest that a permanent programming change or a device failure is unlikely to occur and that the linear motor car system is probably safe for patients with one of the four implanted cardiac arrhythmia devices used in this study under the conditions tested.

  7. Magnetic levitation as a platform for competitive protein-ligand binding assays.

    Science.gov (United States)

    Shapiro, Nathan D; Soh, Siowling; Mirica, Katherine A; Whitesides, George M

    2012-07-17

    This paper describes a method based on magnetic levitation (MagLev) that is capable of indirectly measuring the binding of unlabeled ligands to unlabeled protein. We demonstrate this method by measuring the affinity of unlabeled bovine carbonic anhydrase (BCA) for a variety of ligands (most of which are benzene sulfonamide derivatives). This method utilizes porous gel beads that are functionalized with a common aryl sulfonamide ligand. The beads are incubated with BCA and allowed to reach an equilibrium state in which the majority of the immobilized ligands are bound to BCA. Since the beads are less dense than the protein, protein binding to the bead increases the overall density of the bead. This change in density can be monitored using MagLev. Transferring the beads to a solution containing no protein creates a situation where net protein efflux from the bead is thermodynamically favorable. The rate at which protein leaves the bead for the solution can be calculated from the rate at which the levitation height of the bead changes. If another small molecule ligand of BCA is dissolved in the solution, the rate of protein efflux is accelerated significantly. This paper develops a reaction-diffusion (RD) model to explain both this observation, and the physical-organic chemistry that underlies it. Using this model, we calculate the dissociation constants of several unlabeled ligands from BCA, using plots of levitation height versus time. Notably, although this method requires no electricity, and only a single piece of inexpensive equipment, it can measure accurately the binding of unlabeled proteins to small molecules over a wide range of dissociation constants (K(d) values within the range from ~10 nM to 100 μM are measured easily). Assays performed using this method generally can be completed within a relatively short time period (20 min-2 h). A deficiency of this system is that it is not, in its present form, applicable to proteins with molecular weight greater

  8. Levitation force between a small magnet and a superconducting sample of finite size in the Meissner state

    Science.gov (United States)

    Lugo, Jorge; Sosa, Victor

    1999-10-01

    The repulsion force between a cylindrical superconductor in the Meissner state and a small permanent magnet was calculated under the assumption that the superconductor was formed by a continuous array of dipoles distributed in the finite volume of the sample. After summing up the dipole-dipole interactions with the magnet, we obtained analytical expressions for the levitation force as a function of the superconductor-magnet distance, radius and thickness of the sample. We analyzed two configurations, with the magnet in a horizontal or vertical orientation.

  9. Modeling of hysteretic behavior of the levitation force between superconductor and permanent magnet

    Science.gov (United States)

    Wu, Xing-da; Xu, Ke-Xi; Cao, Yue; Hu, Shun-bo; Zuo, Peng-xiang; Li, Guan-dong

    2013-03-01

    The hysteretic behavior of the levitation force between a permanent magnet and a melt-textured-growth YBCO bulk has been investigated under both zero-field cooling (ZFC) and field cooling (FC) processes. It is found that both in ZFC and FC measurements, the hysteresis loop for the first descent/ascent cycle of magnet is relatively larger than that for the second or third cycle, and the hysteresis loops for Cycle 2-4 have the same area. These results can be qualitatively understood in terms of the critical state model. To describe these experimental results, we develop an updated frozen-image model, which is obtained by modifying the change rules of the vertical movement image in the advanced frozen-image model proposed by Yang et al. Comparing with the advanced frozen-image model proposed by Yang et al., our model cannot only give the hysteretic characteristic in the first descent-ascent cycle of magnet, but also show the hysteresis loops with the same area for the second and subsequent cycles.

  10. A cost-effective extracorporeal magnetically-levitated centrifugal blood pump employing a disposable magnet-free impeller.

    Science.gov (United States)

    Hijikata, W; Mamiya, T; Shinshi, T; Takatani, S

    2011-12-01

    In the field of rotary blood pumps, contactless support of the impeller by a magnetic bearing has been identified as a promising method to reduce blood damage and enhance durability. The authors developed a two-degrees-of-freedom radial controlled magnetic bearing system without a permanent magnet in the impeller in order that a low-cost disposable pump-head for an extracorporeal centrifugal blood pump could be manufactured more easily. Stable levitation and contactless rotation of the 'magnet-free' impeller were realized for a prototype blood-pump that made use of this magnetic bearing. The run-out of the impeller position at between 1000 r/min and 3000 r/min was less than 40 microm in the radial-controlled directions. The total power consumption of the magnetic bearing was less than 1 W at the same rotational speeds. When the pump was operated, a flow rate of 5 l/min against a head pressure of 78.66 kPa was achieved at a rotational speed of 4000 r/min, which is sufficient for extracorporeal circulation support. The proposed technology offers the advantage of low-cost mass production of disposable pump heads.

  11. Design of a Mathematical Unit in FPGA for the Implementation of the Control of a Magnetic Levitation System

    Directory of Open Access Journals (Sweden)

    Juan José Raygoza-Panduro

    2008-01-01

    Full Text Available This paper presents the design and implementation of an automatically generated mathematical unit, from a program developed in Java that describes the VHDL circuit, ready to be synthesized with the Xilinx ISE tool. The core contains diverse complex operations such as mathematical functions including sine and cosine, among others. The proposed unit is used to synthesize a sliding mode controller for a magnetic levitation system. This kind of systems is used in industrial applications requiring high level of mathematical calculations in small time periods. The core is designed to calculate trigonometric and arithmetic operations in such a way that each function is performed in a clock cycle. In this paper, the results of the mathematical core are shown in terms of implementation, utilization, and application to control a magnetic levitation system.

  12. FABRICATION TECHNOLOGY OF MAGNETIC LEVITATION FUNCTIONAL SEGMENTS%磁悬浮功能件的制作技术

    Institute of Scientific and Technical Information of China (English)

    孙建都; 余团营

    2009-01-01

    It is introduced that the fabrication technology of magnetic levitation functional segments, the control key points and hard points in the fabrication process ,as well as the functions of theses functional segments.%介绍磁悬浮功能件的制造工艺,对制造工程中控制的重点及难点进行重点阐述,可供同类工程参考.

  13. A magnetically levitated centrifugal blood pump with a simple-structured disposable pump head.

    Science.gov (United States)

    Hijikata, Wataru; Shinshi, Tadahiko; Asama, Junichi; Li, Lichuan; Hoshi, Hideo; Takatani, Setsuo; Shimokohbe, Akira

    2008-07-01

    A magnetically levitated centrifugal blood pump (MedTech Dispo) has been developed for use in a disposable extracorporeal system. The design of the pump is intended to eliminate mechanical contact with the impeller, to facilitate a simple disposable mechanism, and to reduce the blood-heating effects that are caused by motors and magnetic bearings. The bearing rotor attached to the impeller is suspended by a two degrees-of-freedom controlled radial magnetic bearing stator, which is situated outside the rotor. In the space inside the ringlike rotor, a magnetic coupling disk is placed to rotate the rotor and to ensure that the pump head is thermally isolated from the motor. In this system, the rotor can exhibit high passive stiffness due to the novel design of the closed magnetic circuits. The disposable pump head, which has a priming volume of 23 mL, consists of top and bottom housings, an impeller, and a rotor with a diameter of 50 mm. The pump can provide a head pressure of more than 300 mm Hg against a flow of 5 L/min. The normalized index of hemolysis of the MedTech Dispo is 0.0025 +/- 0.0005 g/100 L at 5 L/min against 250 mm Hg. This is one-seventh of the equivalent figure for a Bio Pump BPX-80 (Medtronic, Inc., Minneapolis, MN, USA), which has a value of 0.0170 +/- 0.0096 g/100 L. These results show that the MedTech Dispo offers high pumping performance and low blood trauma.

  14. Hybrid Magnetics and Power Applications

    DEFF Research Database (Denmark)

    Mo, Wai Keung; Paasch, Kasper

    2017-01-01

    . In order to prevent ferrite core saturation, placing an effective air gap within the ferrite core is a key method to obtain optimum hybrid magnetic performance. Furthermore, a relatively large inductance at low loading current is an excellent way to minimze power loss in order to achieve high efficiency...

  15. The attenuation of the levitation force of HTS bulk exposed to AC magnetic field on the above NdFeB guideway

    Energy Technology Data Exchange (ETDEWEB)

    Liu Minxian, E-mail: liukey_sjtu@263.net [School of Computer Science and Technology, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China); Wang Yan [Luoyang Institute of Science and Technology, Luoyang, Henan 471023 (China)

    2012-01-15

    The characteristic of the levitation force relaxation was studied by experiment. The levitation force is attenuated with the application of the AC external magnetic field. The decay increases with the amplitude of the A external magnetic field. The decay is almost independent of the frequency of AC field. In the present High Temperature Superconducting (HTS) maglev vehicle system, the air gaps between the adjacent permanent magnets make the magnetic fields above the NdFeB guideway non-uniform. So it is required to study the characteristics of levitation force of the HTS bulk affected by the non-uniform applied magnetic fields along the moving direction. In this paper, we have studied the characteristics of the levitation force relaxation by an experiment in which AC magnetic field generated by an electromagnet is used to simulate the time-varying magnetic field caused by the inhomogeneity of the NdFeB guideway. From the experiment results, it is found that the levitation force is attenuated with the application of the AC field, and the attenuation is increased with the amplitude of the AC field, but the attenuation is almost independent of the frequency the AC magnetic field.

  16. The attenuation of the levitation force of HTS bulk exposed to AC magnetic field on the above NdFeB guideway

    Science.gov (United States)

    Liu, Minxian; Wang, Yan

    2012-01-01

    In the present High Temperature Superconducting (HTS) maglev vehicle system, the air gaps between the adjacent permanent magnets make the magnetic fields above the NdFeB guideway non-uniform. So it is required to study the characteristics of levitation force of the HTS bulk affected by the non-uniform applied magnetic fields along the moving direction. In this paper, we have studied the characteristics of the levitation force relaxation by an experiment in which AC magnetic field generated by an electromagnet is used to simulate the time-varying magnetic field caused by the inhomogeneity of the NdFeB guideway. From the experiment results, it is found that the levitation force is attenuated with the application of the AC field, and the attenuation is increased with the amplitude of the AC field, but the attenuation is almost independent of the frequency the AC magnetic field.

  17. Magnetic Properties and Intergranular Action in Bonded Hybrid Magnets

    Institute of Scientific and Technical Information of China (English)

    Hua Zhenghe; Li Shandong; Han Zhida; Wang Dunhui; Zhong Wei; Gu Benxi; Lu Mu; Zhang Jianrong; Du Youwei

    2007-01-01

    Magnetic properties and intergranular action in bonded hybrid magnets, based on NdFeB and strontium ferrite powders were investigated. The long-range magnetostatic interaction and short-range exchange coupling interaction existed simultaneously in bonded hybrid magnets, and neither of them could be neglected. Some magnetic property parameters of hybrid magnets could be approximately obtained by adding the hysteresis loops of two magnets pro rata.

  18. Electromagnetic Levitation of a Disc

    Science.gov (United States)

    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…

  19. Electromagnetic Levitation of a Disc

    Science.gov (United States)

    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…

  20. Magnetic properties of high-T(sub c) superconductors: Rigid levitation, flux pinning, thermal depinning, and fluctuation

    Science.gov (United States)

    Brandt, E. H.

    1990-01-01

    The levitation of high-T(sub c) superconductors is quite conspicuous: Above magnets of low symmetry a disk of these ceramics floats motionless, without vibration or rotation; it has a continuous range of stable positions and orientations as if it were stuck in sand. Some specimens may even be suspended above or below the same magnet. This fascinating stability, inherent to no other type of levitation, is caused by the pinning of magnetic flux lines by inhomogeneities inside these extreme type-2 superconductors. The talk deals with pinning of magnetic flux in these materials, with flux flow, flux creep, thermally activated depinning, and the thermal fluctuation of the vortex positions in the flux line lattice (often called flux lattice melting). Also discussed are the fluctuations of the (nearly periodic) magnetic field inside these superconductors which are caused by random pinning sites and by the finite temperature. These fluctuations broaden the van-Hove singularities observed in the density of the magnetic field by nuclear magnetic resonance and by muon spin rotation.

  1. Magnetic levitation-based electromagnetic energy harvesting: a semi-analytical non-linear model for energy transduction.

    Science.gov (United States)

    Soares Dos Santos, Marco P; Ferreira, Jorge A F; Simões, José A O; Pascoal, Ricardo; Torrão, João; Xue, Xiaozheng; Furlani, Edward P

    2016-01-04

    Magnetic levitation has been used to implement low-cost and maintenance-free electromagnetic energy harvesting. The ability of levitation-based harvesting systems to operate autonomously for long periods of time makes them well-suited for self-powering a broad range of technologies. In this paper, a combined theoretical and experimental study is presented of a harvester configuration that utilizes the motion of a levitated hard-magnetic element to generate electrical power. A semi-analytical, non-linear model is introduced that enables accurate and efficient analysis of energy transduction. The model predicts the transient and steady-state response of the harvester a function of its motion (amplitude and frequency) and load impedance. Very good agreement is obtained between simulation and experiment with energy errors lower than 14.15% (mean absolute percentage error of 6.02%) and cross-correlations higher than 86%. The model provides unique insight into fundamental mechanisms of energy transduction and enables the geometric optimization of harvesters prior to fabrication and the rational design of intelligent energy harvesters.

  2. Magnetic levitation-based electromagnetic energy harvesting: a semi-analytical non-linear model for energy transduction

    Science.gov (United States)

    Soares Dos Santos, Marco P.; Ferreira, Jorge A. F.; Simões, José A. O.; Pascoal, Ricardo; Torrão, João; Xue, Xiaozheng; Furlani, Edward P.

    2016-01-01

    Magnetic levitation has been used to implement low-cost and maintenance-free electromagnetic energy harvesting. The ability of levitation-based harvesting systems to operate autonomously for long periods of time makes them well-suited for self-powering a broad range of technologies. In this paper, a combined theoretical and experimental study is presented of a harvester configuration that utilizes the motion of a levitated hard-magnetic element to generate electrical power. A semi-analytical, non-linear model is introduced that enables accurate and efficient analysis of energy transduction. The model predicts the transient and steady-state response of the harvester a function of its motion (amplitude and frequency) and load impedance. Very good agreement is obtained between simulation and experiment with energy errors lower than 14.15% (mean absolute percentage error of 6.02%) and cross-correlations higher than 86%. The model provides unique insight into fundamental mechanisms of energy transduction and enables the geometric optimization of harvesters prior to fabrication and the rational design of intelligent energy harvesters.

  3. Normal Spectral Emissivity Measurement of Molten Cu-Co Alloy Using an Electromagnetic Levitator Superimposed with a Static Magnetic Field

    Science.gov (United States)

    Ueno, Shoya; Nakamura, Yuki; Sugioka, Ken-Ichi; Kubo, Masaki; Tsukada, Takao; Uchikoshi, Masahito; Fukuyama, Hiroyuki

    2017-02-01

    The normal spectral emissivity of molten Cu-Co alloy with different compositions was measured in the wavelength range of 780 nm to 920 nm and in the temperature range of 1430 K to 1770 K including the undercooled condition by an electromagnetic levitator superimposed with a static magnetic field. The emissivity was determined as the ratio of the radiance from a levitated molten Cu-Co droplet measured by a spectrometer to the radiance from a blackbody calculated by Planck's law at a given temperature, where a static magnetic field of 2.5 T to 4.5 T was applied to the levitated droplet to suppress the surface oscillation and translational motion of the sample. We found little temperature dependence of the normal spectral emissivity of molten Cu-Co alloy. Concerning the composition dependence, the emissivity decreased markedly above 80 at%Cu and reached that of pure Cu, although its dependence was low between 20 at%Cu and 80 at%Cu. In addition, this composition dependence of the emissivity of molten Cu-Co alloy can be explained well by the Drude free-electron model.

  4. 3D In Vitro Model for Breast Cancer Research Using Magnetic Levitation and Bioprinting Method.

    Science.gov (United States)

    Leonard, Fransisca; Godin, Biana

    2016-01-01

    Tumor microenvironment composition and architecture are known as a major factor in orchestrating the tumor growth and its response to various therapies. In this context, in vivo studies are necessary to evaluate the responses. However, while tumor cells can be of human origin, tumor microenvironment in the in vivo models is host-based. On the other hand, in vitro studies in a flat monoculture of tumor cells (the most frequently used in vitro tumor model) are unable to recapitulate the complexity of tumor microenvironment. Three-dimensional (3D) in vitro cell cultures of tumor cells have been proven to be an important experimental tool in understanding mechanisms of tumor growth, response to therapeutics, and transport of nutrients/drugs. We have recently described a novel tool to create 3D co-cultures of tumor cells and cells in the tumor microenvironment. Our method utilizes magnetic manipulation/levitation of the specific ratios of tumor cells and cells in the tumor microenvironment (from human or animal origin) aiding in the formation of tumor spheres with defined cellular composition and density, as quickly as within 24 h. This chapter describes the experimental protocols developed to model the 3D structure of the cancer environment using the above method.

  5. TID and I-TD controller design for magnetic levitation system using genetic algorithm

    Directory of Open Access Journals (Sweden)

    Debdoot Sain

    2016-09-01

    Full Text Available This article is about the design of controllers for magnetic levitation (Maglev system in both simulation and real time. Local linearization around the equilibrium point has been done for the nonlinear Maglev system to obtain a linearized model transfer function. In this study, the design of integral-tilted-derivative (I-TD controller has been proposed for the Maglev system and its performance is compared with conventional tilted-integral-derivative (TID controller. In this study, TID controller parameters have been optimized through genetic algorithm (GA and those set of values have been employed for the design of I-TD controller. A performance comparison between TID and I-TD controller is then investigated. The analysis shows the superiority of I-TD controller over TID controller in terms of maximum overshoot, gain margin and phase margin. The settling time remains almost same in both the cases. In future, a detailed study of robustness in presence of model uncertainties will be incorporated as a scope of further research.

  6. Finite-size-induced stability of a permanent magnet levitating over a superconductor in the Meissner state

    Science.gov (United States)

    Perez-Diaz, Jose Luis; Garcia-Prada, Juan Carlos

    2007-10-01

    The force between a magnetic dipole and a finite superconductor in the Meissner state (Hlevitation of a magnet over it or even the suspension of one of them under the other one. This does not contradict the existence of flux penetration. However, this makes the flux penetration not necessary to explain both stability and attractiveness, as has been assumed until now.

  7. Stationary levitation and vibration transmission characteristic in a superconducting seismic isolation device with a permanent magnet system and a copper plate

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, S., E-mail: s.sasaki@ecei.tohoku.ac.j [Electrical Engineering Department, Graduate School, Tohoku University, 6-6-05 Aoba Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Shimada, K.; Yagai, T.; Tsuda, M.; Hamajima, T. [Electrical Engineering Department, Graduate School, Tohoku University, 6-6-05 Aoba Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Kawai, N.; Yasui, K. [Okumura Corporation, 5-6-1 Shiba, Minato-ku, Tokyo 180-8381 (Japan)

    2010-11-01

    We have devised a magnetic levitation type superconducting seismic isolation device taking advantage of the specific characteristic of HTS bulk that the HTS bulk returns to its original position by restoring force against a horizontal displacement. The superconducting seismic isolation device is composed of HTS bulks and permanent magnets (PM rails). The PMs are fixed on an iron plate to realize the same polarities in the longitudinal direction and the different polarities in the transverse direction. The superconducting seismic isolation device can theoretically remove any horizontal vibrations completely. Therefore, the vibration transmissibility in the longitudinal direction of the PM rail becomes zero in theory. The zero vibration transmissibility and the stationary levitation, however, cannot be achieved in the real device because a uniform magnetic field distribution in the longitudinal direction of PM rail cannot be realized due to the individual difference of the PMs. Therefore, to achieve stationary levitation in the real device we adopted a PM-PM system that the different polarities are faced each other. The stationary levitation could be achieved by the magnetic interaction between the PMs in the PM-PM system, while the vibration transmitted to the seismic isolation object due to the magnetic interaction. We adopted a copper plate between the PMs to reduce the vibration transmissibility. The PM-PM system with the copper plate is very useful for realizing the stationary levitation and reducing the vibration transmissibility.

  8. Haptic characterization of human skin in vivo in response to shower gels using a magnetic levitation device.

    Science.gov (United States)

    Yardley, R; Fan, A; Masters, J; Mascaro, S

    2016-02-01

    Skin products such as shower gels have a direct impact on skin health and wellness. Although qualitative haptic characterization through explicit, verbal measures in consumer studies are often sufficient for general comparison on consumer perceived skin feel, a quantitative approach is desired to characterize minute changes in skin condition in response to various skin products. Prior research has sought to characterize the haptic properties of human skin in vitro and in vivo, but very few studies have compared the haptic effects of commercial skin products having relatively similar formulations. In addition, related studies have typically utilized simple, low-precision devices and fixtures. The purpose of this study was to use a precision magnetic levitation haptic device to characterize the frictional properties of human skin in vivo before, during, and after treatment with commercially available shower gels, to capture the entire cycle of consumer experience on skin feel. A hybrid force-position control algorithm was used to control a precision magnetic levitation haptic device with silicone tactor to stroke the human skin (on the volar forearm) in vivo. Position and force data were collected from 32 human subjects using eight different commercially available shower gels, while stroking the skin before, during, and after treatment. The data were analyzed to produce coefficients of friction and viscous damping constant, which were used as metrics for comparing the effects of each shower gel type. Other factors investigated include skin test location, order, and subject age and gender. Results showed significant differences between the effects of eight various shower gels, especially after accounting for variance between subjects. Most notably, Shower Gel four with high level of petrolatum, along with Shower Gels five and six with low levels of castoryl maleate (a skin lipid analog), as well as Shower Gel two with high levels of vegetable oils yielded higher skin

  9. Suppression of magnetic levitation force in melt-textured YBa{sub 2}Cu{sub 3}O{sub 7-x} superconductors by a transverse AC magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Rudnev, I A; Ermolaev, Yu S [Department of Superconductivity and Physics of Nanostructures, Moscow Engineering Physics Institute (State University), 31 Kashirskoe Shosse, Moscow 115409 (Russian Federation)], E-mail: iarudnev@mephi.ru

    2008-02-01

    We have studied experimentally the influence of transverse ac magnetic fields on the levitation force arising between a permanent NdFeB magnet and a bulk melt-textured HTSC YBCO superconducting sample. The axes of superconducting disc and cylindrical magnet were coinciding while the transverse ac magnetic field generated by resistive coil was directed parallel to surface of a disc i.e., perpendicular to the disc axis. We found that application of both impulse and alternative transverse magnetic fields results in suppression of the value of levitation force and its relaxation rate. Namely, the variable magnetic field with amplitude 12 mT, that approximately in 20 times is less than field of a constant magnet, causes suppression of force more than twice. Monotonous behavior of value of levitation force reduction with the increase in transverse magnetic field amplitude was observed. The possible origin of observed phenomenon is discussed.

  10. A three-dimensional co-culture model of the aortic valve using magnetic levitation.

    Science.gov (United States)

    Tseng, Hubert; Balaoing, Liezl R; Grigoryan, Bagrat; Raphael, Robert M; Killian, T C; Souza, Glauco R; Grande-Allen, K Jane

    2014-01-01

    The aortic valve consists of valvular interstitial cells (VICs) and endothelial cells (VECs). While these cells are understood to work synergistically to maintain leaflet structure and valvular function, few co-culture models of these cell types exist. In this study, aortic valve co-cultures (AVCCs) were assembled using magnetic levitation and cultured for 3 days. Immunohistochemistry and quantitative reverse-transcriptase polymerase chain reaction were used to assess the maintenance of cellular phenotype and function, and the formation of extracellular matrix. AVCCs stained positive for CD31 and α-smooth muscle actin (αSMA), demonstrating that the phenotype was maintained. Functional markers endothelial nitric oxide synthase (eNOS), von Willebrand factor (VWF) and prolyl-4-hydroxylase were present. Extracellular matrix components collagen type I, laminin and fibronectin also stained positive, with reduced gene expression of these proteins in three dimensions compared to two dimensions. Genes for collagen type I, lysyl oxidase and αSMA were expressed less in AVCCs than in 2-D cultures, indicating that VICs are quiescent. Co-localization of CD31 and αSMA in the AVCCs suggests that endothelial-mesenchymal transdifferentiation might be occurring. Differences in VWF and eNOS in VECs cultured in two and three dimensions also suggests that the AVCCs possibly have anti-thrombotic potential. Overall, a co-culture model of the aortic valve was designed, and serves as a basis for future experiments to understand heart valve biology. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  11. SIMULATION STUDY OF AERODYNAMIC FORCE FOR HIGH-SPEED MAGNETICALLY-LEVITATED TRAINS

    Institute of Scientific and Technical Information of China (English)

    LI Renxian; LIU Yingqing; ZHAI Wanming

    2006-01-01

    Based on Reynolds average Navier-Storkes equations of viscous incompressible fluid and k-ε two equations turbulent model, the aerodynamic forces of high-speed magnetically-levitated(maglev) trains in transverse and longitudinal wind are investigated by finite volume method. Near 80 calculation cases for 2D transverse wind fields and 20 cases for 3D longitudinal wind fields are and lyzed. The aerodynamic side force, yawing, drag, lift and pitching moment for different types of maglev trains and a wheel/rail train are compared under the different wind speeds. The types of maglev train models for 2D transverse wind analysis included electromagnetic suspension (EMS) type train,electrodynamic suspension (EDS) type train, EMS type train with shelter wind wall in one side or two sides of guideway and the walls, which are in different height or/and different distances from train body. The situation of maglev train running on viaduct is also analyzed. For 3D longitudinal wind field analysis, the model with different sizes of air clearances beneath maglev train is examined for the different speeds. Calculation result shows that: ① Different transverse effects are shown in different types of maglev trains. ② The shelter wind wall can fairly decrease the transverse effect on the maglev train. ③ When the shelter wall height is 2 m, there is minimum side force on the train.When the shelter wall height is 2.5 m, there is minimum yawing moment on the train. ④ When the distance between inside surfaces of the walls and center of guideway is 4.0 m, there is minimum transverse influence on the train. ⑤ The size of air clearance beneath train body has a small influence on aerodynamic drag of the train, but has a fairly large effect on aerodynamic lift and pitching moment of the train. ⑥ The calculating lift and pitching moment for maglev train models are minus values.

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

    Science.gov (United States)

    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.

  13. A scaffold-free surface culture of B16F10 murine melanoma cells based on magnetic levitation.

    Science.gov (United States)

    Jeong, Yun Gyu; Lee, Jin Sil; Shim, Jae Kwon; Hur, Won

    2016-12-01

    Multicellular spheroids are obtained in a variety of three-dimensional (3D) culture systems without the use of supporting scaffold. We present here a 3D culture method that resulted in a multicellular sheet under scaffold-free conditions. A floating disk-shaped 3D culture was prepared by magnetic levitation of B16F10 cells that has ingested Fe3O4-containing fibroin microspheres. The melanoma disk grew up to 19 mm in diameter and the thickness was ranged between 80 and 100 μm. The 3D culture was filled with closely packed cells that were proliferating exponentially at a specific growth rate of µ = 0.015 h(-1). Approximately half of the cells were Ki-67 positive with no detectable levels of apoptotic or autophagic cells. However, the percentage of propidium iodide-permeable cells was 8.5 ± 1.2 %, which was probably due to physical damage in the cell membrane caused by Fe3O4-containing microspheres under a strong magnetic field. Melanin production increased by a factor of 3.0-3.7 in the 3D culture, due to an increased population of pigmented cells. This study presented a surface 3D culture of B16F10 cells without the use of a scaffold based on magnetic levitation.

  14. Experimental Verification of Theoretical Magnetic Field Model of Immersed Magnet Self-levitating in Magnetic Fluid%磁流体中永磁悬浮磁场解析模型试验验证

    Institute of Scientific and Technical Information of China (English)

    徐晨; 刘桂雄; 张沛强

    2009-01-01

    Magnet can self-levitate in magnetic fluid. Exact data of self-levitation is the key of validating theoretical model and achieving controllable levitation by getparms magnetic force. The magnetic field distribution is unique existence. The levitating magnets position model Hz can derive from the field intensity model in magnetic fluid field Hf. The Hz and magnet displacement r have the relation of one-to-one correspondence,which can be adopted to locate the magnet position in magnetic fluid. The relation of levitation position and magnetic field distribution is pointwise calibrated in holl detection test to verify the theoretical model r-Hz. The results show that the test data and theoretical curve match perfectly. the self-levitation height,43.13±0.05 mm,is acquired by test equipment. Comparing to the theoretical result 43.34 mm,it can draw a conclusion that the levitating magnets position model Hz is correct and effective in levitation height prediction.%永磁体在磁流体中能够自悬浮,准确获取悬浮位置信息是验证理论模型、调节各种影响磁场力的参数以实现悬浮位置可控的关键.磁场分布具有唯一性原理,通过磁场分布模型计算推导,可以得出永磁体悬浮位置模型HZ.该模型与永磁体位移r具有唯一对应关系.利用这种对应关系即可对磁流体中的永磁体进行定位.采用霍尔检测方法逐点测量磁场与永磁体位置之间关系,验证解析模型.结果表明试验与理论曲线匹配度好.在试验中测量得到悬浮位置为43.13±0.05 mm,与根据模型计算结果43.34 mm非常吻合,证明永磁体悬浮位置模型应用于悬浮高度预测中是正确有效的.

  15. Electromagnetic Forces in a Hybrid Magnetic-Bearing Switched-Reluctance Motor

    Science.gov (United States)

    Morrison, Carlos R.; Siebert, Mark W.; Ho, Eric J.

    2008-01-01

    Analysis and experimental measurement of the electromagnetic force loads on the hybrid rotor in a novel hybrid magnetic-bearing switched-reluctance motor (MBSRM) have been performed. A MBSRM has the combined characteristics of a switched-reluctance motor and a magnetic bearing. The MBSRM discussed in this report has an eight-pole stator and a six-pole hybrid rotor, which is composed of circular and scalloped lamination segments. The hybrid rotor is levitated using only one set of four stator poles, while a second set of four stator poles imparts torque to the scalloped portion of the rotor, which is driven in a traditional switched reluctance manner by a processor. Static torque and radial force analysis were done for rotor poles that were oriented to achieve maximum and minimum radial force loads on the rotor. The objective is to assess whether simple one-dimensional magnetic circuit analysis is sufficient for preliminary evaluation of this machine, which may exhibit strong three-dimensional electromagnetic field behavior. Two magnetic circuit geometries, approximating the complex topology of the magnetic fields in and around the hybrid rotor, were employed in formulating the electromagnetic radial force equations. Reasonable agreement between the experimental and the theoretical radial force loads predictions was obtained with typical magnetic bearing derating factors applied to the predictions.

  16. Thermometry of levitated nanoparticles in a hybrid electro-optical trap

    Science.gov (United States)

    Aranas, E. B.; Fonseca, P. Z. G.; Barker, P. F.; Monteiro, T. S.

    2017-03-01

    There have been recent rapid developments in stable trapping of levitated nanoparticles in high vacuum. Cooling of nanoparticles, from phonon occupancies of 107 down to ≃ 100{--}1000 phonons, have already been achieved by several groups. Prospects for quantum ground-state cooling seem extremely promising. Cavity-cooling without added stabilisation by feedback cooling remains challenging, but trapping at high vacuum in a cavity is now possible through the addition of a Paul trap. However, the Paul trap has been found to qualitatively modify the cavity output spectrum, with the latter acquiring an atypical ‘split-sideband’ structure, of different form from the displacement spectrum, and which depends on N, the optical well at which the particle localises. In the present work we investigate the N-dependence of the dynamics, in particular with respect to thermometry: we show that in strong cooling regions N≳ 100, the temperature may still be reliably inferred from the cavity output spectra. We also explain the N-dependence of the mechanical frequencies and optomechanical coupling showing that these may be accurately estimated. We present a simple ‘fast-cavity’ model for the cavity output and test all our findings against full numerical solutions of the nonlinear stochastic equations of motion for the system.

  17. Adipose tissue engineering in three-dimensional levitation tissue culture system based on magnetic nanoparticles.

    Science.gov (United States)

    Daquinag, Alexes C; Souza, Glauco R; Kolonin, Mikhail G

    2013-05-01

    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

  18. Hybrid Shielding for Magnetic Fields

    Science.gov (United States)

    Mullins, David; Royal, Kevin

    2017-01-01

    Precision symmetry measurements such as the search for the electric dipole moment of the neutron require magnetic shielding rooms to reduce the ambient field to the pT scale. The massive mu-metal sheets and large separation between layers make these shield rooms bulky and expensive. Active field cancellation systems used to reduce the surrounding field are limited in uniformity of cancellation. A novel approach to reducing the space between shield layers and increasing the effectiveness of active cancellation is to combine the two systems into a hybrid system, with active and passive layers interspersed. We demonstrate this idea in a prototype with an active layer sandwiched between two passive layers of shielding.

  19. Evaluation of Landing Characteristics Achieved by Simulations and Flight Tests on a Small-scaled Model Related to Magnetically Levitated Advanced Take-off and Landing Operations

    NARCIS (Netherlands)

    Rohacs, D.; Voskuijl, M.; Siepenkotter, N.

    2014-01-01

    The goal of this paper is to simulate and measure on a small-scaled model the landing characteristics related to take-off and landing (TOL) operations supported by a magnetic levitation (MAGLEV) system as ground-based power supply. The technical feasibility and the potential benefits of using ground

  20. Evaluation of Landing Characteristics Achieved by Simulations and Flight Tests on a Small-scaled Model Related to Magnetically Levitated Advanced Take-off and Landing Operations

    NARCIS (Netherlands)

    Rohacs, D.; Voskuijl, M.; Siepenkotter, N.

    2014-01-01

    The goal of this paper is to simulate and measure on a small-scaled model the landing characteristics related to take-off and landing (TOL) operations supported by a magnetic levitation (MAGLEV) system as ground-based power supply. The technical feasibility and the potential benefits of using ground

  1. Mean field J{sub C} estimation for levitation device simulations in the bean model using permanent magnets and YBCO superconducting blocks

    Energy Technology Data Exchange (ETDEWEB)

    Neves, Marcelo Azevedo; Andrade Junior, Rubens de [Universidade Federal, Rio de Janeiro, RJ (Brazil). Dept. de Eletrotecnica. Lab. de Aplicacoes de Supercondutores (LASUP); Costa, Giancarlo Cordeiro da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Lab. de Metodos Computacionais em Engenharia; Pereira, Agnaldo Souza; Nicolsky, Roberto [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Fisica

    2002-09-01

    This work presents a mean field estimation of J{sub C} as a bulk characteristic of YBCO blocks. That average J{sub C} allows a good fitting of the finite-element-method simulation of the levitation forces to experimental results. That agreement is quite enough for levitation requirements of device projects, at short gaps and zero field cooling process, within the Bean model. The physical characterization for that estimation was made measuring the interaction force between the PM and one YBCO block in 1-D and mapping the trapped magnetic field in those blocks in 2-D. (author)

  2. A magnetically levitated electrode ionization chamber of the noncontact measurement type

    CERN Document Server

    Kawaguchi, T

    2002-01-01

    A new type of ionization chamber with levitated electrode has been developed. In this ionization chamber, an ion-collection electrode levitates in the air without getting any physical support from the insulator. The electrode is charged by an electrostatic charger without physical contact. The charge of the electrode is read out at a Faraday cage periodically at a given time interval without physical contact. Because its electrode levitates, the ionization chamber produces no background current caused by leaks or piezo current. In addition, as the charging of its electrode and the read-out of its charge are carried out without physical contact, no irregular charge or contact potential difference due to the chattering between electrode and contact point occurs. Through experiments, it was found that this ionization chamber was able to measure the gamma-ray dose such as the environmental radiation with a high degree of sensitivity. The minimum detectable value of ionization current when accumulated for 1 h is a...

  3. Velocity damper for electromagnetically levitated materials

    Science.gov (United States)

    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.

  4. 磁悬浮永磁电机的结构设计与分析%Structure Design and Analysis of Magnetic Levitation Motor

    Institute of Scientific and Technical Information of China (English)

    胡峰; 曾励; 张强

    2013-01-01

      介绍了磁悬浮永磁电机的工作原理,并设计了磁悬浮永磁电机的总体结构以及各部分结构,然后依据相关资料设定了磁轴承整体结构的参数,并通过相关理论公式计算得到磁轴承的相关尺寸。利用ANSYS软件对电机磁轴承部分进行计算,通过分析结果中的磁力线分布、磁感应强度和气隙磁场情况,再对结构进行优化设计。%This paper introduced the working principle of magnetic levitation motor ,and the design of the overall structure of a magnetic levitation motor . Then ,according to relevant literatures , the paper determined the parameters of the various parts of magnetic bearings by calculation and ANSYS simulation . After analyzing the distribution of magnetic lines , the magnetic flux density ,and air‐gap magnetic field situation ,it optimized the design of magnetic levitation motor .

  5. Improved Outcome of Cardiac Extracorporeal Membrane Oxygenation in Infants and Children Using Magnetic Levitation Centrifugal Pumps.

    Science.gov (United States)

    Luciani, Giovanni Battista; Hoxha, Stiljan; Torre, Salvatore; Rungatscher, Alessio; Menon, Tiziano; Barozzi, Luca; Faggian, Giuseppe

    2016-01-01

    Extracorporeal membrane oxygenation (ECMO) has traditionally been and, for the most part, still is being performed using roller pumps. Use of first-generation centrifugal pumps has yielded controversial outcomes, perhaps due to mechanical properties of the same and the ensuing risk of hemolysis and renal morbidity. Latest-generation centrifugal pumps, using magnetic levitation (ML), exhibit mechanical properties which may have overcome limitations of first-generation devices. This retrospective study aimed to assess the safety and efficacy of veno-arterial (V-A) ECMO for cardiac indications in neonates, infants, and children, using standard (SP) and latest-generation ML centrifugal pumps. Between 2002 and 2014, 33 consecutive neonates, infants, and young children were supported using V-A ECMO for cardiac indications. There were 21 males and 12 females, with median age of 29 days (4 days-5 years) and a median body weight of 3.2 kg (1.9-18 kg). Indication for V-A ECMO were acute circulatory collapse in ICU or ward after cardiac repair in 16 (49%) patients, failure to wean after repair of complex congenital heart disease in 9 (27%), fulminant myocarditis in 4 (12%), preoperative sepsis in 2 (6%), and refractory tachy-arrhythmias in 2 (6%). Central cannulation was used in 27 (81%) patients and peripheral in 6. Seven (21%) patients were supported with SP and 26 (79%) with ML centrifugal pumps. Median duration of support was 82 h (range 24-672 h), with 26 (79%) patients weaned from support. Three patients required a second ECMO run but died on support. Seventeen (51%) patients required peritoneal dialysis for acute renal failure. Overall survival to discharge was 39% (13/33 patients). All patients with fulminant myocarditis and with refractory arrhythmias were weaned, and five (83%) survived, whereas no patient supported for sepsis survived. Risk factors for hospital mortality included lower (<2.5 kg) body weight (P = 0.02) and rescue ECMO after cardiac

  6. Research Review on Magnetic Levitation Positioning Stage%磁悬浮定位平台的研究综述

    Institute of Scientific and Technical Information of China (English)

    秦新燕; 雷金

    2012-01-01

    现代制造技术正朝着高速化、精密化和模块化方向发展,这很大程度上得益于定位平台的不断发展.磁悬浮技术可以完全消除库仑摩擦,具有转速高、无磨损等突出优点,在高速、高精运动的定位平台领域具有广阔的应用前景.简述磁悬浮技术的发展与应用,介绍国内外磁悬浮定位平台的科研成果,分析各类磁悬浮定位平台的优缺点,讨论目前研究中的一些热点问题,并指出磁悬浮定位平台亟需解决的关键核心技术,为下一步深入的改进研究提供可借鉴的研究方向.%Modern manufacturing technology is developing towards high speed, high precise and modularity, which is mainly benefit from the improvement of the positioning stage. The magnetic levitation technology can completely remove coulomb friction to make high speed, no wear and so on. These advantages have been used widely in high-speed and high-precision positioning stage. The application of the magnetic levitation technology was introduced. Scientific researches of maglev positioning stage at home and abroad were summarized. Advantages and disadvantages of various types maglev positioning stages were analyzed. Some hot issues about current research were discussed. Core technologies to be solved were pointed out. These contents offer reference direction for improving design.

  7. How to Simply Demonstrate Diamagnetic Levitation with Pencil Lead

    Science.gov (United States)

    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. A six-degree-of-freedom magnetic levitation fine stage for a high-precision and high-acceleration dual-servo stage

    Science.gov (United States)

    Kim, MyeongHyeon; Jeong, Jae-heon; Kim, HyoYoung; Gweon, DaeGab

    2015-10-01

    This paper presents a novel six-degree-of-freedom magnetic levitation fine stage for a dual-servo stage. The proposed fine stage is levitated and actuated, using a voice coil motor actuator with a Halbach magnet array. For a dual-servo stage, fine stage performance is deeply intertwined with coarse stage performance. Because the fine stage is installed over the coarse stage, the overall size of the fine stage can be limited by the moving plate of the coarse stage. Therefore, magnetic flux modeling and optimization are performed to manufacture optimal fine stages. To control the fine stage, actuator kinetics and sensor kinematics are proposed. Homing control is implemented by using linear variable differential transformers, whereas fine control is implemented by capacitance sensors and laser interferometers. Finally, experimental results of in-position stability, moving range, and repeatability are presented.

  9. Estimation of the radial force using a disturbance force observer for a magnetically levitated centrifugal blood pump.

    Science.gov (United States)

    Pai, C N; Shinshi, T; Shimokohbe, A

    2010-01-01

    Evaluation of the hydraulic forces in a magnetically levitated (maglev) centrifugal blood pump is important from the point of view of the magnetic bearing design. Direct measurement is difficult due to the absence of a rotor shaft, and computational fluid dynamic analysis demands considerable computational resource and time. To solve this problem, disturbance force observers were developed, using the radial controlled magnetic bearing of a centrifugal blood pump, to estimate the radial forces on the maglev impeller. In order to design the disturbance observer, the radial dynamic characteristics of a maglev impeller were evaluated under different working conditions. It was observed that the working fluid affects the additional mass and damping, while the rotational speed affects the damping and stiffness of the maglev system. Based on these results, disturbance force observers were designed and implemented. The designed disturbance force observers present a bandwidth of 45 Hz. In non-pulsatile conditions, the magnitude of the estimated radial thrust increases in proportion to the flowrate, and the rotational speed has little effect on the force direction. At 5 l/min against 100 mmHg, the estimated radial thrust is 0.95 N. In pulsatile conditions, this method was capable of estimating the pulsatile radial thrust with good response.

  10. Levitation in an "almost" electrostatic field

    CERN Document Server

    Miranda, E N

    2012-01-01

    It is well known that a charged particle cannot be in stable equilibrium in a purely electrostatic field. The situation is different in a magnetostatic field; consequently, magnetic levitation is possible while electrostatic levitation is not. In this paper, motivated by an analogy with a mechanical system, we show that the addition of a small oscillating electrical field to an otherwise electrostatic configuration leads to the stabilisation of unstable equilibrium points. Therefore, levitation becomes possible in an "almost electrostatic" field.

  11. Design and Implementation of a Magnetic Levitation System Controller using Global Sliding Mode Control

    Directory of Open Access Journals (Sweden)

    Rudi Uswarman

    2014-07-01

    Full Text Available This paper presents global sliding mode control and conventional sliding mode control for stabilization position of a levitation object. Sliding mode control will be robusting when in sliding mode condition. However, it is not necessarily robust at attaining phase. In the global sliding mode control, the attaining motion phase was eliminated, so that the robustness of the controller can be improved. However, the value of the parameter uncertainties needs to be limited. Besides that, the common problem in sliding mode control is high chattering phenomenon. If the chattering is too large, it can make the system unstable due the limited ability of electronics component. The strategy to overcome the chattering phenomenon is needed. Based on simulation and experimental results, the global sliding mode control has better performance than conventional sliding mode control.  

  12. The performance of induction levitators

    Science.gov (United States)

    Eastham, J. F.; Rodger, D.

    1984-09-01

    The present investigation is concerned with the performance of induction levitators, which are employed in vehicles for contactless transport systems, utilizing magnetic levitation (Maglev). A small model (38 cm long) of an induction levitator is shown. The armature consists of a laminated 'u' shaped iron yoke. Around the limbs of the yoke are wound two primary excitation coils carrying single phase 50 Hz current. Eddy currents, induced in the conducting secondary, produce a force of repulsion between secondary and yoke. A lateral stabilizing force can also be obtained. A description is presented of a study of the characteristics of these forces. Attention is given of a finite element model and the application of the Galerkin weighted residual technique, experimental and calculated results, and a design study of two single phase levitators for a 50 tonne Maglev vehicle.

  13. 3D positional control of magnetic levitation system using adaptive control: improvement of positioning control in horizontal plane

    Science.gov (United States)

    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.

  14. Research on Magnetic Levitation Operation Mechanism of Permanent Magnet Linear Motor in CNC Machine Tool%数控机床永磁直线电动机磁悬浮运行机制研究

    Institute of Scientific and Technical Information of China (English)

    蓝益鹏; 张振兴

    2012-01-01

    为实现数控机床永磁直线同步电动机的磁悬浮运行,须对电动机的电磁推力和悬浮力进行实时控制.电磁推力和悬浮力的计算是数控机床磁悬浮永磁直线同步电动机设计及控制的基础.根据数控机床永磁直线同步电动机的磁悬浮运行机制,推导出电动机的电磁推力和悬浮力与电流之间关系的数学模型.并用Ansoft对电磁推力和悬浮力进行有限元分析,将解析计算结果与Ansoft的计算结果进行比较,验证了数学模型的有效性与正确性,为数控机床永磁直线同步电动机磁悬浮控制系统的分析与设计提供依据.%Real-time control to electromagnetic thrust and levitation force is necessary in order to realize magnetic levitation stable operation of the permanent magnet linear motor in CNC machine tool. The calculations of electromagnetic thrust and levitation force are the foundation of magnetic levitalion permanent magnet linear synchronous motor design and control. Mathematical models of electromagnetic thrust and magnetic levitation force were derived based on the operating principle of double winding levitation permanent magnet linear synchronous motor in CNC machine tool. Further more, finite element analyses of electromagnetic thrust and levitation force were completed by Ansoft. Trie comparison between calculation results and simulation results confirms the correctness and effectiveness of the proposed mathematical model, which provides a basis for analysis and design of permanent magnet linear motor magnetic levitation control system in CNC machine tool.

  15. Using high-temperature superconductors for levitation applications

    Science.gov (United States)

    Hull, John R.

    1999-07-01

    Melt-textured, bulk high-temperature superconductors are finding increasing uses in superconducting bearings, flywheel energy storage, and other levitational applications. This article reviews the use of these materials in magnetic-levitation applications. The behavior of levitational force, stiffness, damping, and rotational losses is discussed.

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

    Science.gov (United States)

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

    1992-06-01

    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.

  17. Orientation and thickness dependence of magnetic levitation force and trapped magnetic field of single grain YBa{sub 2}Cu{sub 3}O{sub 7-y} bulk superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Y.; Go, S. J.; Joo, H. T. [Korea Science Academy of Korea Advanced Institute of Science and Technology, Pusan (Korea, Republic of); Lee, Y. J.; Park, S. D.; Jun, B. H.; KIm, C. J. [Neutron Utilization Technology Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-03-15

    The effects of the crystallographic orientation and sample thickness on the magnetic levitation forces (F) and trapped magnetic field (B) of single grain YBCO bulk superconductors were examined. Single grain YBCO samples with a (001), (110) or (100) surface were used as the test samples. The samples used for the force-distance (F-d) measurement were cooled at 77 K without a magnetic field (zero field cooling, ZFC), whereas the samples used for the B measurement were cooled under the external magnetic field of a Nd-B-Fe permanent magnet (field cooling, FC). It was found that F and B of the (001) surface were higher than those of the (110) or (100) surface, which is attributed to the higher critical current density (J{sub c}) of the (001) surface. For the (001) samples with t=5–18 mm, the maximum magnetic levitation forces (F{sub max}s) of the ZFC samples were larger than 40 N. About 80% of the applied magnetic field was trapped in the FC samples. However, the F and B decreased rapidly as t decreased below 5 mm. There exists a critical sample thickness (t=5 mm for the experimental condition of this study) for maintaining the large levitation/trapping properties, which is dependent on the material properties and magnitude of the external magnetic fields.

  18. Properties of Magnetized Quark-Hybrid Stars

    CERN Document Server

    Orsaria, M; Vucetich, H; Weber, F

    2011-01-01

    The structure of a magnetized quark-hybrid stars (QHS) is modeled using a standard relativistic mean-field equation of state (EoS) for the description of hadronic matter. For quark matter we consider a bag model EoS which is modified perturbatively to account for the presence of a uniform magnetic field. The mass-radius (M-R) relationship, gravitational redshift and rotational Kepler periods of such stars are compared with those of standard neutron stars (NS).

  19. Absolute vibration measurement method using magnetic levitation ball as oscillator%磁悬浮振子绝对式振动测量方法

    Institute of Scientific and Technical Information of China (English)

    江东

    2013-01-01

    Abstract:The non-contact type absolute vibration measurement method using magnetic levitation ball as oscillator is proposed.The dynamic equation of magnetic levitation ball is deduced.The equation shows that the magnetic levitation ball dynamic equation is the same as that of a mass-spring system,they are both constant coefficient second order differential equation.The feasibility of using magnetic levitation ball as oscillator is proved theoretically.The sensitivity and maximum acceleration technical specifications are given.The frequency characteristics and error analysis of the magnetic levitation oscillator vibration sensor are studied.Experiment results indicate that the displacement waveforms of the magnetic levitation oscillator vibration sensor are the same as the vibration waveforms of the external exciter.Using magnetic levitation oscillator vibration sensor to test vibration belongs to non-contact absolute vibration measurement method.This method overcomes the mechanical friction and mechanical gap errors,and the displacement signal can be outputted directly.The damping is achieved with an electronic circuit,and the damping parameters can be adjusted easily.The method features high sensitivity,wide frequency response range;and multi-dimensional vibration measurement can be implemented easily.The proposed method provides a new measurement method for absolute vibration measurement.%提出了用磁悬浮球作为振子实现非接触绝对式振动测量方法,推导了磁悬浮球的动力学方程,方程表明磁悬浮球的运动方程与质量-弹簧系统一致,均为常系数二阶微分方程,从理论上证实将磁悬浮球作为振子是可行的.给出了灵敏度和最大加速度指标,研究了磁悬浮振子振动传感器的频率特性并进行了误差分析.实验结果表明,磁悬浮振子振动传感器的输出波形与外加激振器的波形一致.磁悬浮振子振动传感器属于非接触绝对式振动测量方法,克服了

  20. Safety of high speed magnetic levitation transportation systems. Magnetic field testing of the TR07 Maglev vehicle and system. Volume 2: Appendices

    Science.gov (United States)

    Dietrich, Fred; Robertson, David; Steiner, George

    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 current (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. Appendices include catalogs and documents detailing magnetic field data files and their specifics (static fields, spectral waveforms, and temporal and spatial information) by location.

  1. 永磁体在磁流体中自悬浮能力的数值计算%Numerical Simulation of Magnet Self-levitation in Vessels Filled with Magnetic Fluid

    Institute of Scientific and Technical Information of China (English)

    张大伟; 刘桂雄; 曹东; 徐晨

    2007-01-01

    Whether magnetic fluid inertia sensor works or not depends on the suspending of magnet in magnetic fluid.The paper utilizes the method of magnetic scalar potential to compute the distribution of magnetic field. By virtue of boundary integral, the magnetic force on magnet in a vessel filled with magnetic fluid is obtained, and. the possibility of levitation of magnet is analyzed. The results indicate that in absence of external magnetic field, when the parameters of magnetic fluid, magnet and vessel are properly chosen, magnet can be self-levitated in magnetic fluid.%永磁体能否在磁流体中自悬浮,是实现磁流体惯性传感器的关键.通过标量磁势法计算封闭容器里永磁体在磁流体中产生的磁场以及对磁场分布进行数值计算,借助边界积分求得永磁体在磁流体中的受力大小,分析永磁体在磁流体中的悬浮能力.结果表明,在没有外磁场作用情况下,合理选择磁流体、永磁体及容器参数,可以实现永磁体在磁流体中自悬浮.

  2. Levitated micro-accelerometer.

    Energy Technology Data Exchange (ETDEWEB)

    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. Safety of high speed magnetic levitation transportation systems. Magnetic field testing of the TR07 Maglev vehicle and system. Volume 1: Analysis

    Science.gov (United States)

    Dietrich, Fred; Feero, William 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 field (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 exposure 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. Analysis summarizes the experimental findings and compares results to common home, work, and power lines emissions for selected spectral bands.

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

    Institute of Scientific and Technical Information of China (English)

    杨芃焘; 杨万民; 王妙; 李佳伟; 郭玉霞

    2015-01-01

    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.

  5. 基于磁悬浮效应的三维振动测量%Three-dimensional vibration measurement based on magnetic levitation effect

    Institute of Scientific and Technical Information of China (English)

    江东; 杨嘉祥

    2011-01-01

    设计了磁悬浮球系统模型,测量一定电流下磁悬浮球位移与受力得到磁悬浮球的电磁力表达式,推导了磁悬浮球运动的动力学方程.实测中磁悬浮球模型壳体与被测振动体刚性连接,通过光电传感器测出磁悬浮球与壳体的相对位移得到三维被测振动信号.通过标准振动台实测验证,小于120 Hz的最大绝对误差为±0.3 Hz,相对误差为±1.5%~±0.25%,120 Hz~5 kHz的最大绝对误差为±1Hz,相对误差为±0.83%-±0.02%.由于磁悬浮球悬浮于空中,灵敏度高,具有良好的频率响应特性,磁悬浮球运动各向同性,不存在因粘贴传感元件带来的极间耦合问题,与传统多维振动测量方法相比较该方法具有独特的优势.%A magnetic levitation ball system model was designed. The magnetic force that magnetic levitation ball bears was measured under fixed current and changing displacement. The dynamic equation of magnetic levitation ball movement is deduced. The shell of magnetic levitation ball system model joins up with the vibrating object under test rigidly in the test experiment. A photo-electric sensor is used to measure the relative displacement between the shell of the system model and the magnetic levitation ball, and three-dimensional vibration signals are obtained. Standard vibrator test verifies that the maximum absolute error is ±0.3 Hz and relative error is between ±1.5% and ±0.25%for frequency below 120 Hz, the maximum absolute error is ±1 Hz and relative error is between ±0.83% and ±0.02%for frequency between 120 Hz~5 kHz. Because magnetic levitation ball suspends in the air and the system does not have any pasted sensor, the effects from other directions do not exist. The system has excellent frequency feature and the features at different directions are the same. The system sensitivity is high. This method has better characteristics than traditional vibration measurement methods.

  6. Synthesis and Magnetic Properties of Ni and Carbon Coated Ni by Levitational Gas Condensation (LGC

    Directory of Open Access Journals (Sweden)

    Young Rang Uhm

    2013-01-01

    Full Text Available The nickel (Ni, and carbon coated nickel (Ni@C nanoparticles were synthesized by levitaional gas condensation (LGC methods using a micron powder feeding (MPF system. Both metal and carbon coated metal nano powders include a magnetic ordered phase. The synthesis by LGC yields spherical particles with a large coercivity. The abnormal initial magnetization curve for Ni indicates a non-collinear magnetic structure between the core and surface layer of the particles. The carbon coated particles had a core structure diameter at and below 10 nm and were covered by 2-3 nm thin carbon layers. The hysteresis loop of the as-prepared Ni@Cs materials with unsaturated magnetization shows a superparamagnetic state at room temperature.

  7. About the Influence of the Magnetic Field Configuration on the Levitation Characteristics of the System Superconductor - Array of Magnets

    Science.gov (United States)

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

    2014-07-01

    Interaction of a superconductor with an array of magnets having different orientations of the magnetization vector is theoretically investigated. Based on a critical state model, the interaction force arising in the system superconductor - array of magnets is calculated by the method of finite elements. Optimal configurations of the magnetic system are established in which maximum values of both attractive and repulsive forces are created.

  8. High performance hybrid magnetic structure for biotechnology applications

    Science.gov (United States)

    Humphries, David E [El Cerrito, CA; Pollard, Martin J [El Cerrito, CA; Elkin, Christopher J [San Ramon, CA

    2009-02-03

    The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides means for separation and other biotechnology applications involving holding, manipulation, or separation of magnetic or magnetizable molecular structures and targets. Also disclosed are further improvements to aspects of the hybrid magnetic structure, including additional elements and for adapting the use of the hybrid magnetic structure for use in biotechnology and high throughput processes.

  9. Levitation force relaxation under reloading in a HTS Maglev system

    Science.gov (United States)

    He, Qingyong; Wang, Jiasu; Wang, Suyu; Wang, Jiansi; Dong, Hao; Wang, Yuxin; Shao, Senhao

    2009-02-01

    The loading capacity of the high-temperature superconducting (HTS) Maglev vehicle is an important parameter in the practical application. It is closely related to the levitation force of the HTS bulk. Many papers reported that the levitation force showed the relaxation characteristic. Because different loads cause different levitation gaps and different applied magnetic fields, the levitation force relaxations under the different loads are not the same. In terms of cylindrical YBCO bulk levitated over the permanent magnetic guideway, the relationship between the levitation force relaxation and the reloading is investigated experimentally in this paper. The decrement, the decrement rate and the relaxation rate of the levitation force are calculated, respectively. This work might be helpful for studying the loading capacity of the HTS Maglev vehicle.

  10. Control system of magnetic levitation permanent magnet linear motor based on field-circuit coupling%基于场路耦合的磁悬浮永磁直线电动机控制系统

    Institute of Scientific and Technical Information of China (English)

    蓝益鹏; 张振兴; 杨波; 赵辉

    2012-01-01

    为了解决数控机床进给系统的摩擦问题,采用一种磁悬浮永磁直线电动机来实现无摩擦进给.建立磁悬浮永磁直线电动机的电压、磁链、推力和运动的数学模型及控制系统的场路耦合仿真模型,运用Ansoft软件中的Maxwell和Simplorer对磁悬浮永磁直线电动机控制系统进行场路耦合的联合仿真,并研究磁悬浮永磁直线电动机加速、刹车与反向运行过程.仿真结果表明,该磁悬浮永磁直线电动机控制系统具有良好的跟踪和抗扰性能,为深入研究整个系统的相互耦合以及搭建实验平台提供了依据.%To solve the friction problem existing in the feed system of computer numerical control (CNC) machine tool, a magnetic levitation permanent magnet linear motor was adopted to realize the friction-free feed. The mathmatical models for the voltage, flux linkage, thrust force and movement of magnetic levitation permanent magnet linear motor as well as the simulation model for the field-circuit coupling of control system were established. Maxwell and Simplorer in Ansoft software were used to carry out the co-simulation of field-circuit coupling for the control system of magnetic levitation permanent magnet linear motor. In addition, the acceleration, braking and reverse operation processes of magnetic levitation permanent magnet linear motor were studied. The simulation results show that the control system of magnetic levitation permanent magnet linear motor exhibits good tracking performance and anti-disturbance capability, which provides the basis for the research on the intercoupling of whole system and the guidance for the establishment of experiment platform.

  11. Quantum levitation using metamaterials

    Science.gov (United States)

    Pappakrishnan, Venkatesh K.

    The emergence of an attractive vacuum force (Casimir force) between two purely dielectric materials can lead to an increase in the friction and the stiction effects in nanoscale devices, resulting in degradation or decreased performance. Thus, it is of high practical importance that the conditions for the reversal of the Casimir force from attractive to repulsive are identified. Although the repulsive Casimir force has been considered for high dielectric materials as an intermediate (between the plates) medium, so far no realistic system has been proposed that can demonstrate quantum levitation with air/vacuum as a host medium. Since air is the natural environment for almost all nano- and microscopic devices, it is therefore imperative to seek a better understanding of the nature of the Casimir force under such ambient conditions. In this thesis, the conditions for achieving quantum levitation at an arbitrary temperature are investigated by considering a simple configuration consisting of two parallel plates separated by air. The proposed parallel-plate designs are based on artificial nano-engineered electromagnetic materials commonly referred to as the electromagnetic metamaterials. In the case of an ideal system consisting of non-dispersive plates, we have uncovered the existence of six universal Casimir force types. We have also derived an explicit necessary condition for Casimir force reversal as a function of the non-retarded specular functions of the plates. By introducing a modification of the Lifshitz theory, we have performed an extensive investigation of the Casimir force for general dispersive magneto-dielectric plates. Simple necessary and sufficient conditions for force reversal have been derived that can serve as a useful tool in designing quantum levitation systems. Based on the sufficient condition, the complete parametric domain for the Casimir force repulsion has been identified. A strongly magnetic response for at least one of the plates is

  12. Research on Double Closed-loop Control Strategy for Magnetic Levitation Vibrator%磁悬浮减振器的双闭环控制策略研究

    Institute of Scientific and Technical Information of China (English)

    周振雄; 曲永印; 王悦刚

    2012-01-01

    A novel magnetic levitation vibrator was studied. It was a mixed magnetic levitation system which was made up of permanent magnets and electromagnets. The mutual repulsive force between the magnets was used to provide levitating force to realize flexible damp vibration. Based on the system model, aiming at the nonlinearity of magnetic levitation system of the vibrator, the existence of non-modeling dynamic and uncertainty, and the inaccurate characteristic of the model, with the auto-disturbance rejection controller as outer loop, PID controller as inner loop, the scheme that forming double-loop feedback control to achieve a stable levitation, damping and disturbance resistance was put forward. Simulation analysis and experiment research show that using this controlling scheme, the magnetic levitation vibrator has good dynamic, static characteristic and strong disturbance resistance.%研究一种新型的磁悬浮减振器,它采用永磁铁和电磁铁构成混合式磁悬浮系统,利用磁铁间相互的斥力提供悬浮力,实现柔性减振.在系统模型的基础上,针对减振器磁悬浮系统的非线性、存在未建模动态和不确定性、模型不十分精确的特点,提出采用自抗扰控制器作为外环,PID控制器作为内环,构成双闭环反馈控制方案来实现稳定的悬浮、减振和对扰动的抑制.仿真分析和实验研究表明:采用此控制方案的磁悬浮减振器具有很好的动、静态特性和强抗扰性.

  13. A hybrid transducer to magnetically and ultrasonically evaluate magnetic fluids.

    Science.gov (United States)

    Bruno, Alexandre Colello; Pavan, Théo Z; Baffa, Oswaldo; Carneiro, Antonio Adilton Oliveira

    2013-09-01

    Ultrasound, magnetic fields, and optical techniques have been explored for clinical diagnosis and therapy. However, these techniques have limitations. In this study, we constructed and characterized a transducer to magnetically and ultrasonically investigate samples labeled with magnetic particles. The transducer is a hybrid system consisting of an ac biosusceptometer (ACB) and an ultrasonic transducer. The basic operation principle consisted of measuring the magnetization and microvibrations of ferromagnetic particles (37 and 70 μm) mixed in yogurt and excited by an external alternating magnetic field generated by the ACB's excitation coils. The vibration of the ferromagnetic particles was measured in phantoms using a Doppler ultrasonic transducer; we verified the sensitivity to detecting the vibrations at low concentrations of ferromagnetic material (~1%). The responses of the susceptometer and Doppler ultrasound linearly depended on the voltage level applied to the magnetizing coils at low ferromagnetic particle concentrations (⩽ 5%). We also conducted a repeatability test on the prototype, which indicated a deviation of 0.94% and 0.25% in the Doppler and susceptometric measurements, respectively. We can conclude that the hybrid transducer technique has potential clinical applications.

  14. MedTech Mag-Lev, single-use, extracorporeal magnetically levitated centrifugal blood pump for mid-term circulatory support.

    Science.gov (United States)

    Nagaoka, Eiki; Fujiwara, Tatsuki; Kitao, Takashi; Sakota, Daisuke; Shinshi, Tadahiko; Arai, Hirokuni; Takatani, Setsuo

    2013-01-01

    Short- to mid-term extracorporeal ventricular assist devices (VADs) are recommended for critical cardiogenic shock patients. We have designed a preclinical, single-use MedTech Mag-Lev VAD for one-month extracorporeal use. The impeller-rotor of the pump was suspended by a two degree-of-freedom active magnetic bearing in a 300 μm fluid gap, where the computational fluid dynamics analysis predicted a secondary flow of about 400-500 ml/min at a pump speed of 1800-2200 rpm. Three eddy current sensors were employed to implement noise- and drift-free magnetic levitation. The pump components were injection molded using polycarbonate for smooth surfaces as well as improved reproducibility, followed by coating with a biocompatible 2-methacryloyl-oxyethyl phosphorylcholine polymer. Chronic animal experiments were performed in nine calves. Three of the nine calves were excluded from analysis for problems with the circuit. Five of the six (83.3%) completed the 60 day duration of the study, while one prematurely died of massive bleeding due to inflow port detachment. The pump did not stop due to magnetic-levitation malfunction. Neither pump thrombosis nor major organ infarction was observed at autopsy. In comparison to machined surfaces, the injection-molded pump surfaces were thrombus-free after 60 day implantation. This study demonstrates the feasibility of MedTech Mag-Lev VAD for 60 day circulatory support.

  15. Six degree of freedom fine motion positioning stage based on magnetic levitation

    Energy Technology Data Exchange (ETDEWEB)

    Arling, R.W. [Arling (R.W.), Windham, NH (United States); Kohler, S.M. [Sandia National Labs., Albuquerque, NM (United States)

    1993-07-01

    The design of a magnetically suspended six degree of freedom positioning system capable of nanometer positioning is presented. The sample holder is controlled in six degrees of freedom (DOF) over 300 micrometers of travel in X, Y and Z directions. A design and control summary, and test results indicating stability and power dissipation are included in the paper. The system is vacuum compatible, uses commercially available materials, and requires minimal assembly and setup.

  16. Thrust Reduction of Magnetic Levitation Vehicle Driven by Long Stator Linear Synchronous Motor

    OpenAIRE

    Wan-Tsun Tseng

    2013-01-01

    The propulsion technology of long stator linear synchronous motors is used to drive high-speed maglev trains. The linear synchronous motor stator is divided into sections placed on guideway. The electric power supplies to stator sections in which the train just passes in change-step mode for long-distance operation. However, a thrust drop will be caused by change-step machinery for driving magnetic vehicle. According to the train speed and vehicle data, the change-step mode has three types of...

  17. 提高YBCO块材在外磁场中悬浮力%ENHANCING OF LEVITATION FORCE OF YBCO BULK IN APPLIED MAGNETIC FIELD

    Institute of Scientific and Technical Information of China (English)

    任仲友; 王家素; 王素玉; 王晓融; 宋宏海; 王兴志; 郑珺

    2003-01-01

    本文给出了三种提高YBCO块材在外磁场中悬浮力的方法.第一种方法是增强外磁场,对于此方法,本文研究了一块直径为30mm的圆柱状YBCO块材分别在圆柱状NdFeB永磁体和NdFeB永磁导轨上的悬浮力.测量结果表明在77K温度下YBCO块在圆柱状NdFeB永磁体上的最大悬浮力为50N,在NdFeB永磁导轨上的最大悬浮力为103.0N.第二种方法是提高YBCO块材自身的性能,包括临界电流密度、俘获磁通和块材尺寸,对于此方法,本文仅研究了块材尺寸对悬浮力的影响.三块直径分别为30mm、35mm、40mm的圆柱状YBCO块材在NdFeB永磁导轨上的悬浮力被测量,77K温度下5mm悬浮间距时的悬浮力分别为103.0N、134.5N、175.0N.第三方法是将YBCO块材变成准永久磁体,此种情况下,直径为40mm的圆柱状YBCO块材在77K温度下5mm悬浮间距时的悬浮力高达218.3N.%Three methods are presented to enhance levitation force of YBCO bulk in applied magnetic field. The first one is to strengthen applied magnetic field. For this method, levitation forces of a YBCO bulk with 30mm in diameter are studied over a single NdFeB cylinder and a NdFeB guideway respectively and their maximum levitation forces are 50.0N for the NdFeB cylinder and 103.0N for the NdFeB guideway at 77K. The second one is to promote properties of YBCO bulk itself, including critical current density and trapped flux and its size. Here, levitation forces of three YBCO bulks with 30mm, 35mm, 40mm in diameter are studied over a NdFeB guideway, and levitation forces at gap 5mm are 103.0N, 134.5N and 175.0N at 77K, respectively. The last one is to change a YBCO bulk into a superconducting quasi-permanent magnet, levitation force of a YBCO bulk with 40 mm in diameter is up to 218.3N at 5mm gap over a NdFeB guideway at 77K by this method.

  18. Temperature dependence of levitation force and its relaxation in a HTS levitation system

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Jun; Zhang Xingyi [Key Laboratory of Mechanics on Western Disaster and Environment, Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000 (China); Zhou Youhe, E-mail: zhouyh@lzu.edu.c [Key Laboratory of Mechanics on Western Disaster and Environment, Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000 (China)

    2010-03-01

    Using a modified Gifford-McMahon refrigerator to cool the cylindrical bulk YBaCuO superconductor within the region of 100-10 K, and using an updated high-temperature superconductor (HTS) maglev measurement system, the levitation force and its time relaxation at different temperatures between a YBaCuO bulk superconductor and a permanent magnet (PM) have been measured under zero-field cooling. It is found that decrease the cooling temperature of HTS can decrease the hysteresis of magnetization and increase the maximum levitation force of each hysteresis loop. For the relaxation of levitation force, if the temperature is continually lowered to 10 K after the relaxation measurement at given cooling temperature is performed for 600 s, the levitation force will continue to decrease sharply with the lowering of temperature even though it will get stable if the temperature is not lowered. Our results shown in this work are a benefit to the understanding of levitation systems.

  19. 利用场路结合方法分析磁轴承悬浮力%Levitation force analysis of magnetic bearing by circuit-field combination method

    Institute of Scientific and Technical Information of China (English)

    王大朋; 王凤翔

    2011-01-01

    针对磁轴承悬浮力分析比较复杂的问题,提出利用场路结合分析磁轴承悬浮力的方法.基于磁路法推导了径向磁轴承悬浮力的线性化模型,针对具体的磁轴承系统,利用有限元法分析了磁轴承能够满足线性化模型的偏置电流选择范围和磁轴承转子偏移范围,通过最小二乘法修正了线性化模型的电流刚度系数和位移刚度系数,并对超出线性化模型范围的悬浮力进行了分析,采用多项式拟合的方法推导了悬浮力的非线性模型.对所推导的磁轴承悬浮力模型进行了实验验证.分析及实验结果表明:由于磁饱和等因素的影响,利用磁路法推导的线性悬浮力模型已不能充分描述磁轴承悬浮力特性,通过场路结合方法推导的悬浮力模型能够更准确地计算磁轴承悬浮力.%For the analysis of magnetic force of magnetic bearings is complicated, a levitation force analysis of magnetic bearing based on field-circuit coupled method was used. Firstly, the linear expressions of magnetic levitation force was deduced based on the analysis of magnetic circuit, then the ranges of bias current and operating which can satisfy linear model were analyzed by means of the finite element analysis, through least square method the current rigidity coefficient and displacement rigidity coefficient were modified, and the nonlinear expressions of magnetic levitation force was deduced by polynomial approximation for exceeding linear model range, and finally the finite element method was verified by experiment. The analysis and experimental results show that due to the magnetic saturation and other factors, and the levitation force model which was deduced by using of the magnetic circuit method can not adequately describe the magnetic bearing levitation force characteristics, and the levitation force model which was deduced by field-circuit method can more accurately calculate magnetic bearing levitation force.

  20. Expression of transcription factors after short-term exposure of Arabidopsis thaliana cell cultures to hypergravity and simulated microgravity (2-D/3-D clinorotation, magnetic levitation)

    Science.gov (United States)

    Babbick, M.; Dijkstra, C.; Larkin, O. J.; Anthony, P.; Davey, M. R.; Power, J. B.; Lowe, K. C.; Cogoli-Greuter, M.; Hampp, R.

    Gravity is an important environmental factor that controls plant growth and development. Studies have shown that the perception of gravity is not only a property of specialized cells, but can also be performed by undifferentiated cultured cells. In this investigation, callus of Arabidopsis thaliana cv. Columbia was used to investigate the initial steps of gravity-related signalling cascades, through altered expression of transcription factors (TFs). TFs are families of small proteins that regulate gene expression by binding to specific promoter sequences. Based on microarray studies, members of the gene families WRKY, MADS-box, MYB, and AP2/EREBP were selected for investigation, as well as members of signalling chains, namely IAA 19 and phosphoinositol-4-kinase. Using qRT-PCR, transcripts were quantified within a period of 30 min in response to hypergravity (8 g), clinorotation [2-D clinostat and 3-D random positioning machine (RPM)] and magnetic levitation (ML). The data indicated that (1) changes in gravity induced stress-related signalling, and (2) exposure in the RPM induced changes in gene expression which resemble those of magnetic levitation. Two dimensional clinorotation resulted in responses similar to those caused by hypergravity. It is suggested that RPM and ML are preferable to simulate microgravity than clinorotation.

  1. Algebraic Riccati equation based Q and R matrices selection algorithm for optimal LQR applied to tracking control of 3rd order magnetic levitation system

    Directory of Open Access Journals (Sweden)

    Kumare Vinodh

    2016-03-01

    Full Text Available This paper presents an analytical approach for solving the weighting matrices selection problem of a linear quadratic regulator (LQR for the trajectory tracking application of a magnetic levitation system. One of the challenging problems in the design of LQR for tracking applications is the choice of Q and R matrices. Conventionally, the weights of a LQR controller are chosen based on a trial and error approach to determine the optimum state feedback controller gains. However, it is often time consuming and tedious to tune the controller gains via a trial and error method. To address this problem, by utilizing the relation between the algebraic Riccati equation (ARE and the Lagrangian optimization principle, an analytical methodology for selecting the elements of Q and R matrices has been formulated. The novelty of the methodology is the emphasis on the synthesis of time domain design specifications for the formulation of the cost function of LQR, which directly translates the system requirement into a cost function so that the optimal performance can be obtained via a systematic approach. The efficacy of the proposed methodology is tested on the benchmark Quanser magnetic levitation system and a detailed simulation and experimental results are presented. Experimental results prove that the proposed methodology not only provides a systematic way of selecting the weighting matrices but also significantly improves the tracking performance of the system.

  2. Thrust Reduction of Magnetic Levitation Vehicle Driven by Long Stator Linear Synchronous Motor

    Directory of Open Access Journals (Sweden)

    Wan-Tsun Tseng

    2013-01-01

    Full Text Available The propulsion technology of long stator linear synchronous motors is used to drive high-speed maglev trains. The linear synchronous motor stator is divided into sections placed on guideway. The electric power supplies to stator sections in which the train just passes in change-step mode for long-distance operation. However, a thrust drop will be caused by change-step machinery for driving magnetic vehicle. According to the train speed and vehicle data, the change-step mode has three types of operation, namely premature commutation, simultaneous commutation, and late commutation. Each type of operation has a different thrust drop which can be affected by several parameters such as jerk, running speed, motor section length, and vehicle data. This paper focuses on determining the thrust drop of the change-step mode. The study results of this paper can be used to improve the operation system of high-speed maglev trains.

  3. Optically induced interaction of magnetic moments in hybrid metamaterials.

    Science.gov (United States)

    Miroshnichenko, Andrey E; Luk'yanchuk, Boris; Maier, Stefan A; Kivshar, Yuri S

    2012-01-24

    We propose a novel type of hybrid metal-dielectric structures composed of silicon nanoparticles and split-ring resonators for advanced control of optically induced magnetic response. We reveal that a hybrid "metamolecule" may exhibit a strong distance-dependent magnetic interaction that may flip the magnetization orientation and support "antiferromagnetic" ordering in a hybrid metamaterial created by a periodic lattice of such metamolecules. The propagation of magnetization waves in the hybrid structures opens new ways for manipulating artificial "antiferromagnetic" ordering at high frequencies. © 2011 American Chemical Society

  4. Parameter estimation and actuator characteristics of hybrid magnetic bearings for axial flow blood pump applications.

    Science.gov (United States)

    Lim, Tau Meng; Cheng, Shanbao; Chua, Leok Poh

    2009-07-01

    Axial flow blood pumps are generally smaller as compared to centrifugal pumps. This is very beneficial because they can provide better anatomical fit in the chest cavity, as well as lower the risk of infection. This article discusses the design, levitated responses, and parameter estimation of the dynamic characteristics of a compact hybrid magnetic bearing (HMB) system for axial flow blood pump applications. The rotor/impeller of the pump is driven by a three-phase permanent magnet brushless and sensorless motor. It is levitated by two HMBs at both ends in five degree of freedom with proportional-integral-derivative controllers, among which four radial directions are actively controlled and one axial direction is passively controlled. The frequency domain parameter estimation technique with statistical analysis is adopted to validate the stiffness and damping coefficients of the HMB system. A specially designed test rig facilitated the estimation of the bearing's coefficients in air-in both the radial and axial directions. Experimental estimation showed that the dynamic characteristics of the HMB system are dominated by the frequency-dependent stiffness coefficients. By injecting a multifrequency excitation force signal onto the rotor through the HMBs, it is noticed in the experimental results the maximum displacement linear operating range is 20% of the static eccentricity with respect to the rotor and stator gap clearance. The actuator gain was also successfully calibrated and may potentially extend the parameter estimation technique developed in the study of identification and monitoring of the pump's dynamic properties under normal operating conditions with fluid.

  5. 磁悬浮开关磁阻球体电机的数学模型及其仿真%Spherical switched reluctance motor with magnetic levitation

    Institute of Scientific and Technical Information of China (English)

    戴敏; 曾励

    2011-01-01

    针对双绕组无轴承开关磁阻电机的绕组结构复杂、绝缘程度要求高及加工成本高的缺陷,结合悬浮原理和磁阻最小原理,提出一种磁悬浮开关磁阻球体电机.分析了磁悬浮开关磁阻球体电机的基本组成和运行机理,采用磁路分割法对各部分磁路进行推导与计算,建立了球体电机的数学模型.利用Matalab/simunik软件进行仿真,结果表明电机能够实现动子快速稳定悬浮和旋转,并且具有良好的抗干扰性能.%In view of the bearingless switched reluctance motor with double windings, which has a complicated structure, an absolute insulation, and expensive manufacture cost, the paper presents a spherical switched reluctance motor with magnetic levitation on the basis of suspension theory and minimum reluctance principle. It analyses elements and machanism of the spherical switched reluctance motor with magnetic levitation, deduces and calculates the magnetic conduction of the gap by means of the magnetic segmentation. It obtaines a model building of spherical electric machines.With the Matalab/simunik model, simulation results show that the rotor realizes quick stable suspension and rotation, it has excellent anti-jamming performance as well.

  6. The Wonders of Levitation

    Science.gov (United States)

    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.)

  7. Running characteristics of the superconducting magnetically levitated train in the case of the superconducting coil quenching; Chodendo jiki fujo ressha no chodendo coil quenching ji no soko tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Ohashi, H. [Kansai University, Osaka (Japan); Osaki, H.; Masada, E. [The University of Tokyo, Tokyo (Japan)

    1998-07-01

    A superconducting (SC) magnetically levitated (Maglev) transportation system has been developed in Japan and various experiments have been done in the new test line at Yamanashi prefecture. Although the superconducting electrodynamic suspension (EDS) system has the advantage of stable levitation without active control, various electromagnetic or mechanical disturbances can cause the change of gap length and the displacement or oscillation of the bogie. In this system, the severest disturbance is SC coil quenching. Therefore it is important to show the running characteristics of the Maglev train and to increase the stability in this case. We developed three dimensional numerical simulation program for the Maglev train. Using this program, running simulation of the train for Yamanashi new test track was undertaken in the case of SC coil quenching. Because of the damping characteristics of the EDS system, influence of the coil quenching is smaller at a higher speed. In the train model, electromagnetic spring strength of the EDS system is larger than mechanical spring of the secondary suspension system connecting a bogie and cabins. Therefore influence of the quenching is only seen in the cabins connected to the quenched bogie. Demagnetization of the SC coil quenching is considered to increase the stability of the train. Although this method is useful to decrease large guidance force, lateral displacement, yaw and roll angle of the bogie, vertical displacement and pitch angle become large. 10 refs., 17 figs., 2 tabs.

  8. Levitation characteristics of HTS tape stacks

    Energy Technology Data Exchange (ETDEWEB)

    Pokrovskiy, S. V.; Ermolaev, Y. S.; Rudnev, I. A. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation)

    2015-03-15

    Due to the considerable development of the technology of second generation high-temperature superconductors and a significant improvement in their mechanical and transport properties in the last few years it is possible to use HTS tapes in the magnetic levitation systems. The advantages of tapes on a metal substrate as compared with bulk YBCO material primarily in the strength, and the possibility of optimizing the convenience of manufacturing elements of levitation systems. In the present report presents the results of the magnetic levitation force measurements between the stack of HTS tapes containing of tapes and NdFeB permanent magnet in the FC and ZFC regimes. It was found a non- linear dependence of the levitation force from the height of the array of stack in both modes: linear growth at small thickness gives way to flattening and constant at large number of tapes in the stack. Established that the levitation force of stacks comparable to that of bulk samples. The numerical calculations using finite element method showed that without the screening of the applied field the levitation force of the bulk superconductor and the layered superconductor stack with a critical current of tapes increased by the filling factor is exactly the same, and taking into account the screening force slightly different.

  9. Analysis and design of permanent magnet biased magnetic bearing based on hybrid factor

    Directory of Open Access Journals (Sweden)

    Jinji Sun

    2016-03-01

    Full Text Available In this article, hybrid factor is proposed for hybrid magnetic bearing. The hybrid factor is defined as the ratio of the force produced by the permanent magnet and the forces produced by the permanent magnet and current in hybrid magnetic bearing. It is deduced from a certain radial hybrid magnetic bearing using its important parameters such as the current stiffness and displacement stiffness at first and then the dynamic model of magnetically suspended rotor system is established. The relationship between structural parameters and control system parameters is analyzed based on the hybrid factor. Some influencing factors of hybrid factor in hybrid magnetic bearing, such as the size of the permanent magnet, length of air gap, and area of the stator poles, are analyzed in this article. It can be concluded that larger hybrid factor can be caused by the smaller power loss according to the definition of hybrid factor mentioned above. Meanwhile, the hybrid factor has a maximum value, which is related to control system parameters such as proportional factor expect for structural parameters. Finally, the design steps of parameters of hybrid magnetic bearing can be concluded.

  10. Axisymmetric Magnetic Mirror Fusion-Fission Hybrid

    Energy Technology Data Exchange (ETDEWEB)

    Moir, R. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Martovetsky, N. N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Molvik, A. W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ryutov, D. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Simonen, T. C. [Univ. of California, Berkeley, CA (United States)

    2011-05-13

    The achieved performance of the gas dynamic trap version of magnetic mirrors and today’s technology we believe are sufficient with modest further efforts for a neutron source for material testing (Q=Pfusion/Pinput~0.1). The performance needed for commercial power production requires considerable further advances to achieve the necessary high Q>>10. An early application of the mirror, requiring intermediate performance and intermediate values of Q~1 are the hybrid applications. The Axisymmetric Mirror has a number of attractive features as a driver for a fusion-fission hybrid system: geometrical simplicity, inherently steady-state operation, and the presence of the natural divertors in the form of end tanks. This level of physics performance has the virtue of low risk and only modest R&D needed and its simplicity promises economy advantages. Operation at Q~1 allows for relatively low electron temperatures, in the range of 4 keV, for the DT injection energy ~ 80 keV. A simple mirror with the plasma diameter of 1 m and mirror-to-mirror length of 35 m is discussed. Simple circular superconducting coils are based on today’s technology. The positive ion neutral beams are similar to existing units but designed for steady state. A brief qualitative discussion of three groups of physics issues is presented: axial heat loss, MHD stability in the axisymmetric geometry, microstability of sloshing ions. Burning fission reactor wastes by fissioning actinides (transuranics: Pu, Np, Am, Cm, .. or just minor actinides: Np, Am, Cm, …) in the hybrid will multiply fusion’s energy by a factor of ~10 or more and diminish the Q needed to less than 1 to overcome the cost of recirculating power for good economics. The economic value of destroying actinides by fissioning is rather low based on either the cost of long-term storage or even deep geologic disposal so most of the revenues of hybrids will come from electrical power. Hybrids that obtain revenues from

  11. Structure and magnetic properties of SiO{sub 2}/PCL novel sol–gel organic–inorganic hybrid materials

    Energy Technology Data Exchange (ETDEWEB)

    Catauro, Michelina, E-mail: michelina.catauro@unina2.it [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa (Italy); Bollino, Flavia [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa (Italy); Cristina Mozzati, Maria [Department of Physics, CNISM and INSTM, University of Pavia, Via Bassi 6, 27100 Pavia (Italy); Ferrara, Chiara; Mustarelli, Piercarlo [Department of Chemistry, Section of Physical Chemistry, University of Pavia and INSTM, Via Taramelli 16, 27100 Pavia (Italy)

    2013-07-15

    Organic–inorganic nanocomposite materials have been synthesized via sol–gel. They consist of an inorganic SiO{sub 2} matrix, in which different percentages of poly(ε-caprolactone) (PCL) have been incorporated. The formation of H-bonds among the carbonyl groups of the polymer chains and Si–OH group of the inorganic matrix has been proved by means of Fourier transform infrared spectroscopy (FT-IR) analysis and has been confirmed by solid-state nuclear magnetic resonance (NMR). X-Ray diffraction (XRD) analysis highlighted the amorphous nature of the synthesized materials. Scanning electron microscope (SEM) micrograph and atomic force microscope (AFM) topography showed their homogeneous morphology and nanostructure nature. Considering the opportunity to synthesize these hybrid materials under microgravity conditions by means of magnetic levitation, superconducting quantum interference device (SQUID) magnetometry has been used to quantify their magnetic susceptibility. This measure has shown that the SiO{sub 2}/PCL hybrid materials are diamagnetic and that their diamagnetic susceptibility is independent of temperature and increases with the PCL amount. - Graphical abstract: Characterization and magnetic properties of SiO{sub 2}/PCL organic–inorganic hybrid materials synthesized via sol–gel. FT-IR, Fourier transform infrared spectroscopy; solid-state NMR: solid-state nuclear magnetic resonance; SQUID: superconducting quantum interference device. - Highlights: • Sol–gel synthesis of SiO{sub 2}/PCL amorphous class I organic–inorganic hybrid materials. • FT-IR and NMR analyses show the hydrogen bonds formation between SiO{sub 2} and PCL. • AFM and SEM analyses confirm that the SiO{sub 2}/PCL are homogenous hybrid materials. • The SQUID measures show that the simples are diamagnetic. • Diamagnetic susceptibility of SiO{sub 2}/PCL materials increases with the PCL amount.

  12. Hybrid magnet project at Tohoku University

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Y.; Noto, K.; Hoshi, A.; Miura, S.; Watanabe, K.; Muto, Y. (Tohoku University (Japan))

    1984-01-01

    The construction of three hybrid magnets has been conceived in this project. The smallest one now in operation is composed of a non-cryostable NbTi coil weighing 270 kg and a Bitter coil with a power of 3.1 MW, producing 20 T field in a 32 mm diameter bore. The second one, 20 T in 52 mm at present, will produce 23 T when the power supply will be enlarged to 8 MW. The largest one, 31 T in 32 mm or 29 T in 52 mm, has been designed to consist of a multifilamentary Nb/sub 3/Sn + NbTi coil and a polyhelix-type water-cooled coil.

  13. An Adaptive Controller Design for Magnetic Levitation Ball System%磁悬浮球系统的自适应控制器设计

    Institute of Scientific and Technical Information of China (English)

    刘宁

    2011-01-01

    For a magnetic levitation ball system, a design method for an adaptive controller based on the linearized model and Backstepping scheme is proposed in this paper. The adaptive controller has some significant advantages such as the simple structure, easy to be realized and convenient to obtain the control input. Finally, the simulation results show the effectiveness of the proposed controller.%本文以磁悬浮球系统为研究对象,基于该系统的线性化模型,通过Backstepping设计方法设计了一类自适应控制器,所设计的控制器具有结构简单易于实现,控制输入易于得到等优点,仿真实验验证了该控制器的有效性.

  14. Mechanism of hybrid-magnetic-circuit multi-couple motor

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Discusses the interval between laminations in a permanent-magnet inductor motor which makes the air-gap magnetic field produced by the permanent magnet very uneven in the axial direction, and limits the performance of a motor. Proposes a hybrid-magnetic-circuit multi-couple motor to compensate for the uneven air-gap magnetic field, thereby improving the performance of a motor.

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

    Science.gov (United States)

    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).

  16. Design of Magnetic Flux Feedback Controller in Hybrid Suspension System

    Directory of Open Access Journals (Sweden)

    Wenqing Zhang

    2013-01-01

    Full Text Available Hybrid suspension system with permanent magnet and electromagnet consumes little power consumption and can realize larger suspension gap. But realizing stable suspension of hybrid magnet is a tricky problem in the suspension control sphere. Considering from this point, we take magnetic flux signal as a state variable and put this signal back to suspension control system. So we can get the hybrid suspension mathematical model based on magnetic flux signal feedback. By application of MIMO feedback linearization theory, we can further realize linearization of the hybrid suspension system. And then proportion, integral, differentiation, magnetic flux density B (PIDB controller is designed. Some hybrid suspension experiments have been done on CMS04 magnetic suspension bogie of National University of Defense Technology (NUDT in China. The experiments denote that the new hybrid suspension control algorithm based on magnetic flux signal feedback designed in this paper has more advantages than traditional position-current double cascade control algorithm. Obviously, the robustness and stability of hybrid suspension system have been enhanced.

  17. Design and parameter estimation of hybrid magnetic bearings for blood pump applications

    Science.gov (United States)

    Lim, Tau Meng; Zhang, Dongsheng; Yang, Juanjuan; Cheng, Shanbao; Low, Sze Hsien; Chua, Leok Poh; Wu, Xiaowei

    2009-10-01

    This paper discusses the design and parameter estimation of the dynamics characteristics of a high-speed hybrid magnetic bearings (HMBs) system for axial flow blood pump applications. The rotor/impeller of the pump is driven by a three-phase permanent magnet (PM) brushless and sensorless DC motor. It is levitated by two HMBs at both ends in five-degree-of-freedom with proportional-integral-derivative (PID) controllers; among which four radial directions are actively controlled and one axial direction is passively controlled. Test results show that the rotor can be stably supported to speeds of 14,000 rpm. The frequency domain parameter estimation technique with statistical analysis is adopted to validate the stiffness and damping coefficients of the HMBs system. A specially designed test rig facilitated the estimation of the bearing's coefficients in air—in both the radial and axial directions. The radial stiffness of the HMBs is compared to the Ansoft's Maxwell 2D/3D finite element magnetostatic results. Experimental estimation showed that the dynamics characteristics of the HMBs system are dominated by the frequency-dependent stiffness coefficients. The actuator gain was also successfully calibrated and may potentially extend the parameter estimation technique developed in the study of identification and monitoring of the pump's dynamics properties under normal operating conditions with fluid.

  18. Organic-inorganic hybrid polymer-encapsulated magnetic nanobead catalysts.

    Science.gov (United States)

    Arai, Takayoshi; Sato, Toru; Kanoh, Hirofumi; Kaneko, Katsumi; Oguma, Koichi; Yanagisawa, Akira

    2008-01-01

    A new strategy for the encapsulation of magnetic nanobeads was developed by using the in situ self-assembly of an organic-inorganic hybrid polymer. The hybrid polymer of {[Cu(bpy)(BF(4))(2)(H(2)O)(2)](bpy)}(n) (bpy=4,4'-bipyridine) was constructed on the surface of amino-functionalized magnetic beads and the resulting hybrid-polymer-encapsulated beads were utilized as catalysts for the oxidation of silyl enolates to provide the corresponding alpha-hydroxy carbonyl compounds in high yield. After the completion of the reaction, the catalyst was readily recovered by magnetic separation and the recovered catalyst could be reused several times. Because the current method did not require complicated procedures for incorporating the catalyst onto the magnetic beads, the preparation and the application of various other types of organic-inorganic hybrid-polymer-coated magnetic beads could be possible.

  19. SMES: Superconducting Magnetic Energy Storage

    Science.gov (United States)

    1993-01-01

    power to magnetically levitated trains . A very small size SMES can poten- tially be part of a hybrid propul- sion system on large transit buses...potentially lead to the increased use of urban transit, maglev and electric vehicles, thereby re- ducing air pollution. Illustration courtesy of

  20. 交替极永磁无轴承电机的直接悬浮力控制%Direct Levitation Force Control of a Consequent-Pole Permanent Magnet Bearingless Motor

    Institute of Scientific and Technical Information of China (English)

    仇志坚; 邓智泉; 章跃进

    2011-01-01

    With the reference of direct torque control of conventional permanent magnet synchronous motor,a novel direct levitation force control algorithm based on space vector pulse width modulation method is proposed in this paper.To control radial magnetic levitation forces in permanent magnet-type bearingless motors directly,a profound theoretical analysis on mechanism of direct force control is presented and a real-time levitation force and torque control system is also designed.The experimental results of a consequent-pole permanent magnet bearingless machine show good performance of static and dynamic suspension and confirm the validity and availability of this new arithmetic.%通过借鉴永磁同步电机直接转矩控制(PMSM-DTC)的思想,将直接转矩控制的理论和方法应用到永磁型无轴承电机磁悬浮力的控制上去,提出了一种新颖的基于空间矢量脉宽调制(SVPWM)方法的直接悬浮力控制算法,并在一台交替极无轴承永磁电机上进行了实验验证,结果表明该控制思想的正确性和有效性。

  1. Self-arraying of charged levitating droplets.

    Science.gov (United States)

    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.

  2. Levitation Technology in International Space Station Research

    Science.gov (United States)

    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

  3. Preparation and characterization of functional silica hybrid magnetic nanoparticles

    Science.gov (United States)

    Digigow, Reinaldo G.; Dechézelles, Jean-François; Dietsch, Hervé; Geissbühler, Isabelle; Vanhecke, Dimitri; Geers, Christoph; Hirt, Ann M.; Rothen-Rutishauser, Barbara; Petri-Fink, Alke

    2014-08-01

    We report on the synthesis and characterization of functional silica hybrid magnetic nanoparticles (SHMNPs). The co-condensation of 3-aminopropyltriethoxysilane (APTES) and tetraethyl orthosilicate (TEOS) in presence of superparamagnetic iron oxide nanoparticles (SPIONs) leads to hybrid magnetic silica particles that are surface-functionalized with primary amino groups. In this work, a comprehensive synthetic study is carried out and completed by a detailed characterization of hybrid particles' size and morphology, surface properties, and magnetic responses using different techniques. Depending on the mass ratio of SPIONs and the two silanes (TEOS and APTES), we were able to adjust the number of surface amino groups and tune the magnetic properties of the superparamagnetic hybrid particles.

  4. A Quiescent, Regeneration-Responsive Tissue Engineered Mesenchymal Stem Cell Bone Marrow Niche Model via Magnetic Levitation.

    Science.gov (United States)

    Lewis, Emily Elizabeth Louise; Wheadon, Helen; Lewis, Natasha; Yang, Jingli; Mullin, Margaret; Hursthouse, Andrew; Stirling, David; Dalby, Matthew John; Berry, Catherine Cecilia

    2016-09-27

    The bone marrow niche represents a specialized environment that regulates mesenchymal stem cell quiescence and self-renewal, yet fosters stem cell migration and differentiation upon demand. An in vitro model that embodies these features would open up the ability to perform detailed study of stem cell behavior. In this paper we present a simple bone marrow-like niche model, which comprises of nanomagnetically levitated stem cells cultured as multicellular spheroids within a type I collagen gel. The stem cells maintained are nestin positive and remain quiescent until regenerative demand is placed upon them. In response to coculture wounding, they migrate and appropriately differentiate upon engraftment. This tissue engineered regeneration-responsive bone marrow-like niche model will allow for greater understanding of stem cell response to injury and also facilitate as a testing platform for drug candidates in a multiwell plate format.

  5. Hybrid composites of xanthan and magnetic nanoparticles for cellular uptake.

    Science.gov (United States)

    Bueno, Vânia Blasques; Silva, Anielle Martins; Barbosa, Leandro Ramos Souza; Catalani, Luiz Henrique; Teixeira-Neto, Erico; Cornejo, Daniel Reinaldo; Petri, Denise Freitas Siqueira

    2013-11-04

    We describe a fast and simple method to prepare composite films of magnetite nanoparticles and xanthan networks. The particles are distributed close to hybrid film surface, generating a coercivity of 27 ± 2 Oe at 300 K. The proliferation of fibroblast cells on the hybrid composites was successful, particularly when an external magnetic field was applied.

  6. Final Report: Levitated Dipole Experiment

    Energy Technology Data Exchange (ETDEWEB)

    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, Phys. Plasmas, v13, p. 056111, 2006]. High-beta, near steady-state discharges have been maintained in LDX for more than 20 seconds, and this capability makes LDX the longest pulse fusion confinement experiment now operating in the U.S. fusion program. In both supported and levitated configurations, detailed measurements are 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 is created by multifrequency electron cyclotron resonance heating 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 is levitated or supported, the peak thermal electron temperature is estimated to exceed 500 eV and peak densities reach 1.0E18 (1/m3). Several significant discoveries resulted from the routine investigation of plasma confinement with a magnetically-levitated dipole. For the first time, toroidal plasma with pressure approaching the pressure of the confining magnetic field was well-confined in steady-state without a toroidal magnetic field. Magnetic levitation proved to be reliable and is now routine. The dipole's cryostat allows up to three hours of "float time" between re-cooling with liquid helium and providing scientists unprecedented access to the physics of magnetizd plasma. Levitation eliminates field-aligned particle sources and sinks and results in a toroidal, magnetically-confined plasma where profiles are determined by cross

  7. ZHANG Caihong. Fusion algorithm of H¥ and sliding-mode control for magnetic levitation systems%H¥与滑模融合控制算法在磁悬浮系统中的应用

    Institute of Scientific and Technical Information of China (English)

    李丹丹; 何荣卜; 张彩红

    2014-01-01

    磁悬浮系统在实际运行中会出现模型摄动和各种外界干扰,提高磁悬浮系统的鲁棒性非常重要,给出了磁悬浮系统的数学模型;结合H∞控制和滑模控制的优点,给出一种 H¥控制和滑模控制的融合算法,把该算法应用在磁悬浮系统中;通过Matlab仿真,验证了该算法能有效抑制磁悬浮系统中存在的确定性和不确定性干扰,从而使控制系统的性能得到提高。%Magnetic levitation control system has model perturbation and a variety of outside interference during operation, so, improving the robustness of magnetic levitation system is very important. This paper gives a mathematical model of magnetic levitation system;a fusion algorithm of H¥ and sliding-mode control is discussed;simulation is obtained by Matlab tool. The results show that the algorithm is robust to the uncertainty of the system on the matching and non-matching at the same time.

  8. Leidenfrost levitation: beyond droplets.

    Science.gov (United States)

    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.

  9. An Ultrasonic Levitator

    Directory of Open Access Journals (Sweden)

    R.R. Boullosa

    2013-12-01

    Full Text Available We report the development of an ultrasonic levitation system. Liquid drops or solid samples of diameter less than one half wavelength of the excitation frequency are levitated without contact just below the pressure nodes. The piezo transducer is excited by an ultrasonic signal of around 29 kHz through a voltage amplifier. The choice of the number of half-waves of the acoustic field in the space between the reflector and radiator is made by means of a micrometer. A lamp, an amplifier and a frequency generator are integrated to the levitator. The diameters of the droplets of liquid that can levitate are of the order of tenths of mm to 3 or 4 mm, depending on the liquid properties (density, surface tension, etc.. Solid objects can also be levitated. The maximum voltage of the system is 20 Vrms.

  10. Hybrid Spintronic Structures With Magnetic Oxides and Heusler Alloys

    DEFF Research Database (Denmark)

    Xu, Y. B.; Hassan, S. S. A.; Wong, P. K. J.;

    2008-01-01

    Hybrid spintronic structures, integrating half-metallic magnetic oxides and Heusler alloys with their predicted high spin polarization, are important for the development of second-generation spintronics with high-efficient spin injection. We have synthesized epitaxial magnetic oxide Fe3O4 on GaAs...

  11. Final Report: Levitated Dipole Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kesner, Jay [Massachusetts Institute of Technology, Cambridge, MA (United States); Mauel, Michael [Columbia Univ., New York, NY (United States)

    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.

  12. Hybride magnetic nanostructure based on amino acids functionalized polypyrrole

    Science.gov (United States)

    Nan, Alexandrina; Bunge, Alexander; Turcu, Rodica

    2015-12-01

    Conducting polypyrrole is especially promising for many commercial applications because of its unique optical, electric, thermal and mechanical properties. We report the synthesis and characterization of novel pyrrole functionalized monomers and core-shell hybrid nanostructures, consisting of a conjugated polymer layer (amino acids functionalized pyrrole copolymers) and a magnetic nanoparticle core. For functionalization of the pyrrole monomer we used several amino acids: tryptophan, leucine, phenylalanine, serine and tyrosine. These amino acids were linked via different types of hydrophobic linkers to the nitrogen atom of the pyrrole monomer. The magnetic core-shell hybrid nanostructures are characterized by various methods such as FTIR spectroscopy, transmission electron microscopy (TEM) and magnetic measurements.

  13. Hybride magnetic nanostructure based on amino acids functionalized polypyrrole

    Energy Technology Data Exchange (ETDEWEB)

    Nan, Alexandrina, E-mail: alexandrina.nan@itim-cj.ro; Bunge, Alexander; Turcu, Rodica [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293 Cluj-Napoca (Romania)

    2015-12-23

    Conducting polypyrrole is especially promising for many commercial applications because of its unique optical, electric, thermal and mechanical properties. We report the synthesis and characterization of novel pyrrole functionalized monomers and core-shell hybrid nanostructures, consisting of a conjugated polymer layer (amino acids functionalized pyrrole copolymers) and a magnetic nanoparticle core. For functionalization of the pyrrole monomer we used several amino acids: tryptophan, leucine, phenylalanine, serine and tyrosine. These amino acids were linked via different types of hydrophobic linkers to the nitrogen atom of the pyrrole monomer. The magnetic core-shell hybrid nanostructures are characterized by various methods such as FTIR spectroscopy, transmission electron microscopy (TEM) and magnetic measurements.

  14. Investigations of levitated helium drops

    Science.gov (United States)

    Whitaker, Dwight Lawrence

    1999-11-01

    We report on the development of two systems capable of levitating drops of liquid helium. Helium drops of ˜20 mum have been levitated with the radiation pressure from two counter-propagating Nd:YAG laser beams. Drops are produced with a submerged piezoelectric transducer, and could be held for up to three minutes in our optical trap. Calculations show that Brillouin and Raman scattering of the laser light in the liquid helium produces a negligible rate of evaporation of the drop. Evaporation caused by the enhanced vapor pressure of the curved drop surfaces appears to be a significant effect limiting the drop lifetimes. Helium drops as large as 2 cm in diameter have been suspended in the earth's gravitational field with a magnetic field. A commercial superconducting solenoid provides the necessary field, field-gradient product required to levitate the drops. Drops are cooled to 0.5 K with a helium-3 refrigerator, and can be held in the trap indefinitely. We have found that when two or more drops are levitated in the same magnetic trap, the drops often remain in a state of apparent contact without coalescing. This effect is a result of the evaporation of liquid from between the two drops, and is found to occur only for normal fluid drops. We can induce shape oscillations in charged, levitated drops with an applied ac electric field. We have measured the resonance frequencies and damping rates for the l = 2 mode of oscillation as function of temperature. We have also developed a theory to describe the small amplitude shape oscillations of a He II drop surrounded by its saturated vapor. In our theory, we have considered two sets of boundary conditions---one where the drop does not evaporate and another in which the liquid and vapor are in thermodynamic equilibrium. We have found that both solutions give a frequency that agrees well with experiment, but that the data for the damping rate agree better with the solution without evaporation.

  15. Development of a 40 T compact hybrid magnet

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, K.; Awaji, S.; Kobayashi, N. [Tohoku Univ., Sendai (Japan). Inst. for Materials Research] [and others

    1996-07-01

    A 40 T compact hybrid magnet consisting of a 16 T outer superconducting magnet and a 24 T inner resistive magnet is conceptually designed. A highly strengthened superconducting magnet with a 360 mm room temperature bore can be made using newly developed (Nb,Ti){sub 3}Sn wires with Cu-Nb or Cu-Al{sub 2}O{sub 3} reinforcing stabilizer, and as a result the coil weight is outstandingly reduced by about 70%. A poly-Bitter resistive magnet which generates 24 T in a 14 mm room temperature bore is realized consuming 8 MW power.

  16. A Double-Decker Levitation Experiment Using a Sandwich of Superconductors.

    Science.gov (United States)

    Jacob, Anthony T.; And Others

    1988-01-01

    Shows that the mutual repulsion that enables a superconductor to levitate a magnet and a magnet to levitate a superconductor can be combined into a single demonstration. Uses an overhead projector, two pellets of "1-2-3" superconductor, Nd-Fe-B magnets, liquid nitrogen, and paraffin. Offers superconductor preparation, hazards, and disposal…

  17. Levitation effects involving high Tc thallium based superconductors

    Science.gov (United States)

    Harter, William G.; Hermann, A. M.; Sheng, Z. Z.

    1988-09-01

    The thallium based superconductor Tl2Ca2Ba2Cu3O(10 + y) has been shown to exhibit very stable and unusual levitation equilibria in various arrangements involving this material and permanent magnets. Attractive and repulsive forces are evident in experiments in which samples are levitated above and below magnets. Photographs of these experiments and approximate quantitative discussions of the results are given.

  18. Electric Levitation Using Epsilon-Near-Zero Metamaterials

    OpenAIRE

    Rodríguez-Fortuño, Francisco J.; Vakil, Ashkan; Engheta, Nader

    2013-01-01

    Levitation of objects with action at a distance has always been intriguing to humans. Several ways to achieve this, such as aerodynamic, acoustic, or electromagnetic methods, including radiation pressure, stable potential wells, and quantum Casimir-Lifshitz forces, exist. A fascinating approach for levitation is that of magnets over superconductors based on the Meissner effect -the expulsion of the magnetic field by a superconductor. With the advent of metamaterials -designed structures with ...

  19. Vibrations of a diamagnetically levitated water droplet

    CERN Document Server

    Hill, R J A

    2010-01-01

    We measure the frequencies of small-amplitude shape oscillations of a magnetically-levitated water droplet. The drop levitates in a magnetogravitational potential trap. The restoring forces of the trap, acting on the droplet's surface in addition to the surface tension, increase the frequency of the oscillations. We derive the eigenfrequencies of the normal mode vibrations of a spherical droplet in the trap and compare it with our experimental measurements. We also consider the effect of the shape of the potential trap on the eigenfrequencies.

  20. Low Complex System for Levitating Ferromagnetic Materials

    Directory of Open Access Journals (Sweden)

    Dahiru Sani Shu'aibu

    2010-06-01

    Full Text Available This paper primarily presents detailed design and implementation of a low complex magnetic levitation system which can be used in laboratory for levitation experiments. The system transfer function was derived from the coenergy and the mathematical model of the state space representation was obtained. The mathematical model showed that, the system is highly non-linear and inherently unstable. Based on simulation, a low complex circuit was designed and implemented to stabilize the system, using MATLAB control tool-box. The developed controller was simple, cheap and effective, capable of controlling weights of different masses at various distances as compared to some controllers in literature.

  1. CSEM-Steel hybrid wiggler/undulator magnetic field studies

    Energy Technology Data Exchange (ETDEWEB)

    Halbach, K.; Hoyer, E.; Marks, S.; Plate, D.; Shuman, D.

    1985-06-01

    Current design of permanent magnet wiggler/undulators use either pure charge sheet equivalent material (CSEM) or the CSEM-Steel hybrid configuration. Hybrid configurations offer higher field strength at small gaps, field distributions dominated by the pole surfaces and pole tuning. Nominal performance of the hybrid is generally predicted using a 2-D magnetic design code neglecting transverse geometry. Magnetic measurements are presented showing transverse configuration influence on performance, from a combination of models using CSEMs, REC (H/sub c/ = 9.2 KOe) and NdFe (H/sub c/ = 10.7 kOe), different pole widths and end configurations. Results show peak field improvement using NdFe in place of REC in identical models, gap peak field decrease with pole width decrease (all results less than computed 2-D fields), transverse gap field distributions, and importance of CSEM material overhanging the poles in the transverse direction for highest gap fields. 3 refs., 6 figs.

  2. Design and resistive inserts for NHMFL 45-T hybrid magnet

    Energy Technology Data Exchange (ETDEWEB)

    Bird, M.D.; Bole, S.; Eyssa, Y.M.; Gao, B.J.; Zhang, H.; Schneider-Muntau, H.J. [National High Magnetic Field Lab., Tallahassee, FL (United States)

    1994-07-01

    The authors present conceptual designs for 24--27 MW hybrid magnet inserts generating more than 31 T in a warm bore of 32 mm to be installed at the new National High Magnetic Field Laboratory (NHMFL). The insert housing is designed to accommodate both axially and radially cooled magnets although here they only present axially cooled designs. The magnet coils are radially partitioned (poly-Bitter) to provide high fields at moderate stress and cooling levels. GlidCop, Cu-Be and Cu-Ag conductors are considered providing resistive fields at high as 34 T in a background field of 14 T.

  3. Research on Magnetic Levitation Permanent Magnet Linear Motor and Its Control System%磁悬浮永磁直线电动机及其控制系统研究

    Institute of Scientific and Technical Information of China (English)

    蓝益鹏; 刘宇菲

    2015-01-01

    According to the special structure and operation mechanism of the maglev permanent magnet linear motor,a mathematical model of electromagnetic thrust and levitation force of the motor was given.The finite element calculation model of maglev permanent magnet linear motor was estab-lished.The air gap flux density,magnetic thrust and levitation force were calculated by finite element method,and the air gap flux density was carried out by harmonic analysis method.A research proto-type of the maglev permanent magnet linear motor was design.The magnetic suspension subsystem and the feed servo subsystem were made.The results of the magnetic suspension subsystem and feed subsystem were obtained by experiments.Experimental results show that adopting the maglev perma-nent magnet linear motor can achieve the feasibility of direct drive and frictionless operation.%根据磁悬浮永磁直线电动机的特殊结构与运行机理,给出了电动机电磁推力和悬浮力的数学模型。建立了磁悬浮永磁直线电动机的有限元计算模型,对气隙磁密、电磁推力和悬浮力进行了有限元计算,并对气隙磁密作了谐波分析。设计了磁悬浮永磁直线电动机的研究样机,制作了磁悬浮子系统和进给伺服子系统,对系统进行实验研究,获得了磁悬浮子系统和进给子系统运行的实验结果。实验研究结果表明,该磁悬浮永磁直线电动机可实现直接驱动与无摩擦运行。

  4. Testing of a centrifugal blood pump with a high efficiency hybrid magnetic bearing.

    Science.gov (United States)

    Locke, Dennis H; Swanson, Erik S; Walton, James F; Willis, John P; Heshmat, Hooshang

    2003-01-01

    The purpose of this article is to present test results for a second generation, high efficiency, nonpulsatile centrifugal blood pump that is being developed for use as a left ventricular assist device (LVAD). The LVAD pump uses a hybrid passive-active magnetic bearing support system that exhibits extremely low power loss, low vibration, and high reliability under transient conditions and varying pump orientations. A unique feature of the second generation design configuration is the very simple and direct flow path for both main and washing blood flows. The pump was tested in both vertical and horizontal orientations using a standard flow loop to demonstrate the performance and durability of the second generation LVAD. Steady state and transient orientation pump operating characteristics including pressure, flow, speed, temperatures, vibration, and rotor orientation were measured. During the tests, pump performance was mapped at several operating conditions including points above and below the nominal design of 5 L/min at 100 mm Hg pressure rise. Flow rates from 2 to 7 L/min and pressure rises from 50 to 150 mm Hg were measured. Pump speeds were varied during these tests from 2,500 to 3,500 rpm. The nominal design flow of 5 L/min at 100 mm Hg pressure rise was successfully achieved at the design speed of 3,000 rpm. After LVAD performance testing, both 28 day continuous duty and 5 day transient orientation durability tests were completed without incident. A hydrodynamic backup bearing design feasibility study was also conducted. Results from this design study indicate that an integral hydrodynamic backup bearing may be readily incorporated into the second generation LVAD and other magnetically levitated pump rotors.

  5. High temperature superconductors for magnetic suspension applications

    Science.gov (United States)

    Mcmichael, C. K.; Cooley, R. S.; Chen, Q. Y.; Ma, K. B.; Lamb, M. A.; Meng, R. L.; Chu, C. W.; Chu, W. K.

    1994-01-01

    High temperature superconductors (HTS) hold the promise for applications in magnetic levitation bearings, vibration damping, and torque coupling. Traditional magnetic suspension systems require active feedback and vibration controls in which power consumption and low frequency vibration are among the major engineering concerns. HTS materials have been demonstrated to be an enabling approach towards such problems due to their flux trapping properties. In our laboratory at TCSUH, we have been conducting a series of experiments to explore various mechanical applications using HTS. We have constructed a 30 lb. model flywheel levitated by a hybrid superconducting magnetic bearing (HSMB). We are also developing a levitated and vibration-dampled platform for high precision instrumentation. These applications would be ideal for space usages where ambient temperature is adequate for HTS to operate properly under greatly reduced cryogenic requirements. We will give a general overview of these potential applications and discuss the operating principles of the HTS devices we have developed.

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

    Science.gov (United States)

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

    2011-05-01

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

  7. Flip effect in the orientation of a magnet levitating over a superconducting torus in the Meissner state

    Energy Technology Data Exchange (ETDEWEB)

    Diez-Jimenez, Efren, E-mail: ediez@ing.uc3m.e [Departamento de Ingenieria Mecanica, Universidad Carlos III de Madrid, Butarque, 15, E28911 Leganes (Spain); Perez-Diaz, Jose-Luis [Departamento de Ingenieria Mecanica, Universidad Carlos III de Madrid, Butarque, 15, E28911 Leganes (Spain)

    2011-01-15

    Research highlights: {yields} A torus superconductor shape has been analyzed. {yields} There is a flip effect on the stablest angular position of a magnet over the superconductor. {yields} The basis for a binary contactless proximity sensor has been presented. - Abstract: The torque between a permanent magnet and a toroidal superconductor in the Meissner state is calculated using a model previously proposed based on London's and Maxwell's equations. A flip effect on the stable orientation of the magnet as a function of position is demonstrated. At large distances the magnet tends to be perpendicular to the axis of the torus, but when you approach it, at a certain point there is a flip and it tends to be parallel to that axis while being closer than a certain limit. This effect can be easily used as a binary detector for proximity.

  8. Hybrid high gradient permanent magnet quadrupole

    Science.gov (United States)

    N'gotta, P.; Le Bec, G.; Chavanne, J.

    2016-12-01

    This paper presents an innovative compact permanent magnet quadrupole with a strong gradient for potential use in future light source lattices. Its magnetic structure includes simple mechanical parts, rectangular permanent magnet blocks and soft iron poles. It has a wide aperture in the horizontal plane to accommodate an x-ray beam port, a common constraint in storage ring-based light sources. This specificity introduces field quality deterioration because of the resulting truncation of the poles; a suitable field quality can be restored with an optimized pole shape. A 82 T /m prototype with a bore radius of 12 mm and a 10 mm vertical gap between poles has been constructed and magnetically characterized. Gradient inhomogeneities better than 10-3 in the good field region were obtained after the installation of special shims.

  9. Damping in high-temperature superconducting levitation systems

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Damping in high-temperature superconducting levitation systems

    Science.gov (United States)

    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.

  11. Superconducting and hybrid systems for magnetic field shielding

    Science.gov (United States)

    Gozzelino, L.; Gerbaldo, R.; Ghigo, G.; Laviano, F.; Truccato, M.; Agostino, A.

    2016-03-01

    In this paper we investigate and compare the shielding properties of superconducting and hybrid superconducting/ferromagnetic systems, consisting of cylindrical cups with an aspect ratio of height/radius close to unity. First, we reproduced, by finite-element calculations, the induction magnetic field values measured along the symmetry axis in a superconducting (MgB2) and in a hybrid configuration (MgB2/Fe) as a function of the applied magnetic field and of the position. The calculations are carried out using the vector potential formalism, taking into account simultaneously the non-linear properties of both the superconducting and the ferromagnetic material. On the basis of the good agreement between the experimental and the computed data we apply the same model to study the influence of the geometric parameters of the ferromagnetic cup as well as of the thickness of the lateral gap between the two cups on the shielding properties of the superconducting cup. The results show that in the considered non-ideal geometry, where the edge effect in the flux penetration cannot be disregarded, the superconducting shield is always the most efficient solution at low magnetic fields. However, a partial recovery of the shielding capability of the hybrid configuration occurs if a mismatch in the open edges of the two cups is considered. In contrast, at high magnetic fields the hybrid configurations are always the most effective. In particular, the highest shielding factor was found for solutions with the ferromagnetic cup protruding over the superconducting one.

  12. Magnetic properties of hybrid elastomers with magnetically hard fillers: rotation of particles

    Science.gov (United States)

    Stepanov, G. V.; Borin, D. Yu; Bakhtiiarov, A. V.; Storozhenko, P. A.

    2017-03-01

    Hybrid magnetic elastomers belonging to the family of magnetorheological elastomers contain magnetically hard components and are of the utmost interest for the development of semiactive and active damping devices as well as actuators and sensors. The processes of magnetizing of such elastomers are accompanied by structural rearrangements inside the material. When magnetized, the elastomer gains its own magnetic moment resulting in changes of its magneto-mechanical properties, which remain permanent, even in the absence of external magnetic fields. Influenced by the magnetic field, magnetized particles move inside the matrix forming chain-like structures. In addition, the magnetically hard particles can rotate to align their magnetic moments with the new direction of the external field. Such an elastomer cannot be demagnetized by the application of a reverse field.

  13. New generation extracorporeal membrane oxygenation with MedTech Mag-Lev, a single-use, magnetically levitated, centrifugal blood pump: preclinical evaluation in calves.

    Science.gov (United States)

    Fujiwara, Tatsuki; Nagaoka, Eiki; Watanabe, Taiju; Miyagi, Naoto; Kitao, Takashi; Sakota, Daisuke; Mamiya, Taichi; Shinshi, Tadahiko; Arai, Hirokuni; Takatani, Setsuo

    2013-05-01

    We have evaluated the feasibility of a newly developed single-use, magnetically levitated centrifugal blood pump, MedTech Mag-Lev, in a 3-week extracorporeal membrane oxygenation (ECMO) study in calves against a Medtronic Bio-Pump BPX-80. A heparin- and silicone-coated polypropylene membrane oxygenator MERA NHP Excelung NSH-R was employed as an oxygenator. Six healthy male Holstein calves with body weights of about 100 kg were divided into two groups, four in the MedTech group and two in the Bio-Pump group. Under general anesthesia, the blood pump and oxygenator were inserted extracorporeally between the main pulmonary artery and the descending aorta via a fifth left thoracotomy. Postoperatively, both the pump and oxygen flow rates were controlled at 3 L/min. Heparin was continuously infused to maintain the activated clotting time at 200-240 s. All the MedTech ECMO calves completed the study duration. However, the Bio-Pump ECMO calves were terminated on postoperative days 7 and 10 because of severe hemolysis and thrombus formation. At the start of the MedTech ECMO, the pressure drop across the oxygenator was about 25 mm Hg with the pump operated at 2800 rpm and delivering 3 L/min flow. The PO2 of the oxygenator outlet was higher than 400 mm Hg with the PCO2 below 45 mm Hg. Hemolysis and thrombus were not seen in the MedTech ECMO circuits (plasma-free hemoglobin [PFH] 20 mg/dL) and large thrombus were observed in the Bio-Pump ECMO circuits. Plasma leakage from the oxygenator did not occur in any ECMO circuits. Three-week cardiopulmonary support was performed successfully with the MedTech ECMO without circuit exchanges. The MedTech Mag-Lev could help extend the durability of ECMO circuits by the improved biocompatible performances.

  14. Development of a disposable magnetically levitated centrifugal blood pump (MedTech Dispo) intended for bridge-to-bridge applications--two-week in vivo evaluation.

    Science.gov (United States)

    Nagaoka, Eiki; Someya, Takeshi; Kitao, Takashi; Kimura, Taro; Ushiyama, Tomohiro; Hijikata, Wataru; Shinshi, Tadahiko; Arai, Hirokuni; Takatani, Setsuo

    2010-09-01

    Last year, we reported in vitro pump performance, low hemolytic characteristics, and initial in vivo evaluation of a disposable, magnetically levitated centrifugal blood pump, MedTech Dispo. As the first phase of the two-stage in vivo studies, in this study we have carried out a 2-week in vivo evaluation in calves. Male Holstein calves with body weight of 62.4–92.2 kg were used. Under general anesthesia, a left heart bypass with a MedTech Dispo pump was instituted between the left atrium and the descending aorta via left thoracotomy. Blood-contacting surface of the pump was coated with a 2-methacryloyloxyethyl phosphorylcholine polymer. Post-operatively, with activated clotting time controlled at 180–220 s using heparin and bypass flow rate maintained at 50 mL/kg/min, plasma-free hemoglobin (Hb), coagulation, and major organ functions were analyzed for evaluation of biocompatibility. The animals were electively sacrificed at the completion of the 2-week study to evaluate presence of thrombus inside the pump,together with an examination of major organs. To date, we have done 13 MedTech Dispo implantations, of which three went successfully for a 2-week duration. In these three cases, the pump produced a fairly constant flow of 50 mL/Kg/min. Neurological disorders and any symptoms of thromboembolism were not seen. Levels of plasma-free Hb were maintained very low. Major organ functions remained within normal ranges. Autopsy results revealed no thrombus formation inside the pump. In the last six cases, calves suffered from severe pneumonia and they were excluded from the analysis. The MedTech Dispo pump demonstrated sufficient pump performance and biocompatibility to meet requirements for 1-week circulatory support. The second phase (2-month in vivo study) is under way to prove the safety and efficacy of MedTech Dispo for 1-month applications.

  15. Effect of assembled bar magnet configuration on levitation force of single domain GdBCO bulk superconductor%条状永磁体的组合形式及间距对单畴GdBCO超导体磁悬浮力的影响

    Institute of Scientific and Technical Information of China (English)

    马俊; 杨万民

    2011-01-01

    By measuring the levitation forces between a single domain GdBCO bulk superconductor and assembled bar magnets (ABM) in different configurations at liquid nitrogen temperature, the effects of ABM configurations on the levitation force of single domain GdBCO bulk superconductor are investigated. The maximum levitation force is obtained at the same vertical gap distance Z = 5 mm between the superconductor and the ABM for configurations with different lateral gap distance(D)between the magnets of the ABM. It is found that 1) for the ABM consisting of 3 bar magnet, the levitation force of the GdBCO bulk decreases from 22.8N to 9.7N with the D value increasing from 0 to 30 mm, when the magnetic pole N of the middle magnet is pointed upwards and the directions of magnetic pole N of two side magnets are pointed to the middle magnet in horizontal direction; the levitation force of the GdBCO bulk increases first from 9.2N to 13.9N and then decreases tol0.4 N with D value increasing from 0 to 30ram, if the magnetic pole N of the middle magnet is pointed upwards and the directions of magnetic pole N of two side magnets are pointed downwards;2)for the ABM consisting of 2 bar magnets, the levitation force of the GdBCO bulk decreases from l 1.2N to 1.2N with D value increasing from 0 to 30mm, when the directions of magnetic pole N of two side magnets are pointed upwards ; the levitation force of the GdBCO bulk increases first from 6. ON to 6.8N and then decreases to 2.9N with D value increasing from 0 to 30mm, if the directions of magnetic pole N of two magnets are anti-parallel in horizontal direction; 3) for the ABM consisting of only 1 bar magnets, D = 0, and the levitation force of the GdBCO bulk is about 9.5N. The results indicate that the magnet configuration and its detailed parameters of ABM are very important for improving the levitation force of a superconductor and helpful for designing and application based on the superconducting magnetic levitation

  16. Electron spin control of optically levitated nanodiamonds in vacuum

    Science.gov (United States)

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

    2016-07-01

    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.

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

    Science.gov (United States)

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

    2016-07-19

    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.

  18. Magnetic equivalent circuit model for unipolar hybrid excitation synchronous machine

    Directory of Open Access Journals (Sweden)

    Kupiec Emil

    2015-03-01

    Full Text Available Lately, there has been increased interest in hybrid excitation electrical machines. Hybrid excitation is a construction that combines permanent magnet excitation with wound field excitation. Within the general classification, these machines can be classified as modified synchronous machines or inductor machines. These machines may be applied as motors and generators. The complexity of electromagnetic phenomena which occur as a result of coupling of magnetic fluxes of separate excitation systems with perpendicular magnetic axis is a motivation to formulate various mathematical models of these machines. The presented paper discusses the construction of a unipolar hybrid excitation synchronous machine. The magnetic equivalent circuit model including nonlinear magnetization curves is presented. Based on this model, it is possible to determine the multi-parameter relationships between the induced voltage and magnetomotive force in the excitation winding. Particular attention has been paid to the analysis of the impact of additional stator and rotor yokes on above relationship. Induced voltage determines the remaining operating parameters of the machine, both in the motor and generator mode of operation. The analysis of chosen correlations results in an identification of the effective control range of electromotive force of the machine.

  19. Internal resonance of an elastic body levitated above high-Tc superconducting bulks

    Energy Technology Data Exchange (ETDEWEB)

    Kokuzawa, T; Toshihiko, S; Yoshizawa, M, E-mail: sugiura@mech.keio.ac.j [Mechanical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama (Japan)

    2010-06-01

    In high-Tc superconducting magnetic levitation systems, levitated bodies can keep stable levitation with no contact and no control and thus their damping is very small. Thanks to these features, their applications to various apparatus are expected. However, on account of their small damping, the nonlinearity of electromagnetic levitation force can give notable effects upon motion of the levitated bodies. Therefore this nonlinearity must be taken into account to accurately analyze the dynamical behavior of the levitated bodies. Structures of such a levitated body can show elastic deformation if the large electromagnetic force acts on it. Therefore, we need to deal with the model as an elastic body. As mentioned above, nonlinear characteristics easily appear in this elastic vibration on account of the small damping. Especially when the ratio of the natural frequencies of the eigenmodes is integer, internal resonance can occur. This nonlinear resonance is derived from nonlinear interactions among the eigenmodes of the elastic levitated body. This kind of internal resonance of an elastic body appearing in high-Tc superconducting levitation systems has not been studied so far. This research especially deals with internal resonance of a beam supported at both its ends by electromagnetic forces acting on permanent magnets. The governing equation with the nonlinear boundary conditions for the dynamics of a levitated beam has been derived. Numerical results show internal resonance of the 1st mode and the 3rd mode. Experimental results are qualitatively in good agreement with numerical ones.

  20. A Practical Permanent Magnetic Motor Drive for Hybrid Motorcycle

    Institute of Scientific and Technical Information of China (English)

    崔巍; 江建中; 邵定国; 杨斌

    2003-01-01

    A novel embedded-type permanent magnetic motor for hybrid motorcycle, which employs asymmetric design of eccentric air-gap, is proposed in the paper. This special design of air-gap well conforms to the mono-directional operation characteristic of motorcycle and effectively suppresses the distortion of air-gap magnetic field caused by armature reaction. Hence the torque ripple is reduced. A drive system consisting of the newly-designed Nd-Fe-B permanent magnet synchronous motor and parallel-MOSFET threephase inverter for hybrid motorcycle propulsion is established. Wide-range speed operation is realized through a simple and novel control strategy. Computer simulation is described and experimental results given to verify the practicality of the proposed motor design and control strategy.

  1. 无轴承扰动补偿悬浮系统的稳定性分析与验证%Stability analysis and verification for bearingless magnetic levitation system with disturbance rejection

    Institute of Scientific and Technical Information of China (English)

    王晓琳; 贺鹏

    2012-01-01

    目前,无轴承磁悬浮系统多采用PID等经典控制策略,然而由于外界扰动、参数摄动等诸多原因,难以实现高性能的悬浮控制.本文针对上述问题,通过在传统PID悬浮控制系统中增加扩张状态观测器,对悬浮力扰动进行实时补偿,从而建立基于扩张状态观测器的无轴承悬浮控制系统.其中,根据扩张状态观测器对综合扰动进行观测的基本原理,构建了系统数学模型,并对其稳定性进行了分析.在此基础上,对观测器参数调节的选取原则和稳定域的参考范围进行了理论分析,从而提出了一套无轴承悬浮控制系统参数整定方案.此外,本文还结合模型中主要参数的物理意义,进一步完善了非线性扩张状态观测器参数的设定原则.最后,通过仿真验证了扩张状态观测器对无轴承悬浮系统扰动抑制的作用,以及所述参数整定方案的正确性.%Although the PID control strategy is widely adopted in the bearingless magnetic levitation system, it is impossible to realize high performance in the levitation control due to the influences of disturbance to the levitation forces and the parameters perturbation, etc. To deal with this problem, we develop a novel bearingless levitation system by adding an extended state observer (ESO) to obverse the comprehensive disturbances, making the system able to compensate the disturbances in real-time. The mathematical model of the ESO is built based on the operating principle, and its stability is analyzed. On this basis, the principle of the parameter selection and the stable region of the parameters for the levitation control system are considered theoretically, thus a complete control scheme for the bearingless magnetic levitation system is presented. Additionally, the principle of the parameter adjustment in the nonlinear extended state observer is improved by considering the physical meanings of those

  2. Microgravity simulation by diamagnetic levitation: effects of a strong gradient magnetic field on the transcriptional profile of Drosophila melanogaster

    NARCIS (Netherlands)

    Herranz, R.; Larkin, O.J.; Dijkstra, C.E.; Hill, R.J.A.; Anthony, P.; Davey, M.R.; Michael, R.; Eaves, L.; van Loon, J.J.W.A.; Medina, F.J.; Marco, R.

    2012-01-01

    Background Many biological systems respond to the presence or absence of gravity. Since experiments performed in space are expensive and can only be undertaken infrequently, Earth-based simulation techniques are used to investigate the biological response to weightlessness. A high gradient magnetic

  3. Microgravity simulation by diamagnetic levitation: effects of a strong gradient magnetic field on the transcriptional profile of Drosophila melanogaster

    NARCIS (Netherlands)

    Herranz, R.; Larkin, O.J.; Dijkstra, C.E.; Hill, R.J.A.; Anthony, P.; Davey, M.R.; Michael, R.; Eaves, L.; van Loon, J.J.W.A.; Medina, F.J.; Marco, R.

    2012-01-01

    Background Many biological systems respond to the presence or absence of gravity. Since experiments performed in space are expensive and can only be undertaken infrequently, Earth-based simulation techniques are used to investigate the biological response to weightlessness. A high gradient magnetic

  4. Tailoring of the flip effect in the orientation of a magnet levitating over a superconducting torus: Geometrical dependencies

    Energy Technology Data Exchange (ETDEWEB)

    Diez-Jimenez, Efren, E-mail: ediez@ing.uc3m.e [Departamento de Ingenieria Mecanica, Universidad Carlos III de Madrid, Butarque, 15, E28911 Leganes (Spain); Sander, Berit; Timm, Lauri; Perez-Diaz, Jose-Luis [Departamento de Ingenieria Mecanica, Universidad Carlos III de Madrid, Butarque, 15, E28911 Leganes (Spain)

    2011-04-15

    Research highlights: {yields} A local model is used to demonstrate a flip effect in the orientation of a magnet over a superconductor. {yields} A superconducting torus shape is studied. {yields} Increasing the inner radius of the torus elevates the flip effect point. {yields} There are linear piecewises in the geometrical dependency functions that help to fit the flip effect point. - Abstract: In a previous study, a general local model was used in order to demonstrate the apparition of a flip effect in the equilibrium orientation of a magnet when it is over a superconducting torus. This effect can be easily used in devices such as binary position detectors for magneto-microscopy, contactless sieves or magnetic levels amongst others. We present an initial study useful to design devices based on the flip effect between magnets and torus superconductors. It demonstrates that varying different geometrical parameters the flip effect point can be fixed. Also, it can be observed that increasing the inner radius of the torus elevates the flip effect point. A magneto-mechanical explanation of this phenomenon is exposed. For an increment of cross-section diameter occurs the same behavior. There are linear piecewises in the geometrical dependency functions that can be used for a more accurate fitting of the flip effect point.

  5. High levitation pressures with cage-cooled superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. [Energy Technology Division, Argonne National Laboratory, Argonne, IL (United States); Komori, Mochimitsu [Department of Mechanical Systems Engineering, Kyushu Institute of Technology, Iizuka, Fukuoka (Japan)

    2002-05-01

    We present an analysis of and experimental results from a levitational system comprising a stationary, bulk high-temperature superconductor (HTS) and a levitated component (rotor) that consists of a cylindrical permanent magnet surrounded by an annular HTS. The rotor is cooled below the critical temperature of the HTS while surrounded by a ferromagnetic cage. When the ferromagnetic cage is removed, the flux from the permanent magnet is essentially excluded from the interior of the HTS. When brought into proximity with the HTS stator, the cage-cooled rotor experiences a levitational force. The levitational force may be calculated by applying magnetic circuit theory. Such calculations indicate that for a sufficiently high critical current density, the levitational pressure may exceed that between the permanent magnet and its mirror image. We constructed a rotor from an NdFeB permanent magnet and YBCO bulk HTS with a critical current density of {approx}5 kA cm{sup -2}. A soft ferromagnetic steel cage was constructed in segments. The critical current density of the stator HTS was also {approx}5 kA cm{sup -2}. Experimental results obtained with the cage-cooled rotor and stationary HTS show a significant increase in force over that of an equivalent PM rotor and stationary HTS. (author)

  6. High levitation pressures with cage-cooled superconductors

    Science.gov (United States)

    Hull, John R.; Komori, Mochimitsu

    2002-05-01

    We present an analysis of and experimental results from a levitational system comprising a stationary, bulk high-temperature superconductor (HTS) and a levitated component (rotor) that consists of a cylindrical permanent magnet surrounded by an annular HTS. The rotor is cooled below the critical temperature of the HTS while surrounded by a ferromagnetic cage. When the ferromagnetic cage is removed, the flux from the permanent magnet is essentially excluded from the interior of the HTS. When brought into proximity with the HTS stator, the cage-cooled rotor experiences a levitational force. The levitational force may be calculated by applying magnetic circuit theory. Such calculations indicate that for a sufficiently high critical current density, the levitational pressure may exceed that between the permanent magnet and its mirror image. We constructed a rotor from an NdFeB permanent magnet and YBCO bulk HTS with a critical current density of ≈5 kA cm-2. A soft ferromagnetic steel cage was constructed in segments. The critical current density of the stator HTS was also ≈5 kA cm-2. Experimental results obtained with the cage-cooled rotor and stationary HTS show a significant increase in force over that of an equivalent PM rotor and stationary HTS.

  7. Modeling of Hybrid Permanent Magnetic-Gas Bearings

    DEFF Research Database (Denmark)

    Morosi, Stefano; Santos, Ilmar

    2009-01-01

    Modern turbomachinery applications require nowadays ever-growing rotational speeds and high degree of reliability. It then becomes natural to focus the attention of the research to contact-free bearings elements. The present alternatives focus on gas lubricated journal bearings or magnetic bearings....... In the present paper both the technologies are combined with the aim of developing a new kind of hybrid permanent magnetic - gas bearing. This new kind of machine is intended to exploit the benefits of the two technologies while minimizing their drawbacks. The poor start-up and low speed operation performance...... of the gas bearing is balanced by the properties of the passive magnetic one. At high speeds the dynamic characteristics of the gas bearing are improved by offsetting the stator ring of the permanent magnetic bearing. Furthermore this design shows a kind of redundancy, which offers soft failure properties...

  8. Modeling of Hybrid Permanent Magnetic-Gas Bearings

    DEFF Research Database (Denmark)

    Morosi, Stefano; Santos, Ilmar

    2009-01-01

    Modern turbomachinery applications require nowadays ever-growing rotational speeds and high degree of reliability. It then becomes natural to focus the attention of the research to contact-free bearings elements. The present alternatives focus on gas lubricated journal bearings or magnetic bearings...... concentric rings with radial magnetic orientation - analytical expressions for the calculation of the magnetic flux density and forces are employed, opposed to the main literature trend where finite element software is utilized at least for the calculation of the B-field. Numerical analysis shows how...... the rotor equilibrium position can be made independent on the rotational speed and applied load; it becomes function of the passive magnetic bearing offset. By adjusting the offset it is possible to significantly influence the dynamic coefficients of the hybrid bearing....

  9. Holographic acoustic elements for manipulation of levitated objects

    Science.gov (United States)

    Marzo, Asier; Seah, Sue Ann; Drinkwater, Bruce W.; Sahoo, Deepak Ranjan; Long, Benjamin; Subramanian, Sriram

    2015-10-01

    Sound can levitate objects of different sizes and materials through air, water and tissue. This allows us to manipulate cells, liquids, compounds or living things without touching or contaminating them. However, acoustic levitation has required the targets to be enclosed with acoustic elements or had limited manoeuvrability. Here we optimize the phases used to drive an ultrasonic phased array and show that acoustic levitation can be employed to translate, rotate and manipulate particles using even a single-sided emitter. Furthermore, we introduce the holographic acoustic elements framework that permits the rapid generation of traps and provides a bridge between optical and acoustical trapping. Acoustic structures shaped as tweezers, twisters or bottles emerge as the optimum mechanisms for tractor beams or containerless transportation. Single-beam levitation could manipulate particles inside our body for applications in targeted drug delivery or acoustically controlled micro-machines that do not interfere with magnetic resonance imaging.

  10. 辅助永磁体的引入方式对单畴GdBCO超导块材磁场分布及其磁悬浮力的影响%The effects of magnetization methods with additional permanent magnet on the magnetic field distribution and levitation force of single domain GdBCO bulk superconductor

    Institute of Scientific and Technical Information of China (English)

    马俊; 杨万民; 李佳伟; 王妙; 陈森林

    2012-01-01

    通过对永磁体辅助下单畴GdBCO超导体和方形永磁体在液氮温度、零场冷、轴对称情况下磁悬浮力的测量,研究了三种不同组态中辅助永磁体的引入方式对单畴GdBCO超导块材磁场分布及其磁悬浮力的影响.实验结果表明,如果处在超导体上方的测量用方形永磁体N极向下,则在轴对称情况下,当方形辅助永磁体N极向上与超导体下表面贴在一起时,超导体的最大磁悬浮力从没有引入辅助永磁体磁化的14.3 N增加到31.8 N,提高到222%;当方形辅助永磁体放置在超导体上表面、N极垂直向上且场冷后去掉辅助永磁体时,超导体的最大磁悬浮力从没有引入辅助永磁体磁化的14.3 N增加到21.6N,增加到151%;当方形辅助永磁体放置在超导体上表面、N极垂直向下且场冷后去掉方形辅助永磁体时,超导体的最大磁悬浮力从没有引入辅助永磁体磁化的14.3 N减小到8.6 N,减小为无辅助永磁体时的60%.这些结果说明,只有通过科学合理地设计超导体和永磁体的组合方式,才能获得较高的磁场强度,有效地提高超导体的磁悬浮力特性,该结果对促进超导体的应用具有重要的指导意义.%The effects of magnetization methods with additional permanent magnet on the magnetic field distribution and the levitation force of single domain GdBCO bulk superconductor are investigated with a cubic permanent magnet in their coaxial configuration in zero field cooled state at liquid nitrogen temperature in three different ways. It is found that when the N pole of the cubic permanent magnet, for the levitation force measurement, is placed above the GdBCO bulk superconductor and in the downward direction, the maximal levitation force can be improved to 31.8 N, and that when the N pole of the additional cubic permanent magnet points to upward and sticks to the bottom of the GdBCO bulk, the maximal levitation force is increased up to about 222% of the

  11. 基于MATLAB的磁悬浮球系统PID控制器设计与实现%Design and implemen tation of PID controller based on MATLAB for magnetic levitation ball system

    Institute of Scientific and Technical Information of China (English)

    陈亚栋; 高文华; 张井岗; 刘鑫

    2013-01-01

    The structure and work principle of magnetic levitation ball system was introduced in this paper . The mathematical model was got through and linearized near the equilibrium point . Then the PID controller will be made based on the mathematical model . The model of the control system was built in the Simulink environment to simulate research . At last , the control system model conducted the real-time control experiment on the googol GML1001 series of magnetic levitation device . The experimental results showed that the proposed PID controller guaranteed the suspension ball to achieve the expectation fast and had excellent anti-in-terference performance .%介绍了磁悬浮球系统的结构和工作原理,建立了磁悬浮系统的数学模型并进行线性化处理;设计 PID 控制器,在 Simulink 环境下搭建控制系统的模型进行仿真研究,并在固高 GML1001系列磁悬浮装置上进行实时控制实验。实验结果表明,采用 PID 控制,能使钢球快速地悬浮在期望位置,并且有一定的抗干扰能力。

  12. Photovoltaic-wind hybrid system for permanent magnet DC motor

    Science.gov (United States)

    Nasir, M. N. M.; Lada, M. Y.; Baharom, M. F.; Jaafar, H. I.; Ramani, A. N.; Sulaima, M. F.

    2015-05-01

    Hybrid system of Photovoltaic (PV) - Wind turbine (WT) generation has more advantages and reliable compared to PV or wind turbine system alone. The aim of this paper is to model and design hybrid system of PV-WT supplying 100W permanent-magnet dc motor. To achieve the objective, both of PV and WT are connected to converter in order to get the same source of DC supply. Then both sources were combined and straightly connected to 100W permanent magnet dc motor. All the works in this paper is only applied in circuit simulator by using Matlab Simulink. The output produced from each converter is expected to be suit to the motor specification. The output produced from each renewable energy system is as expected to be high as it can support the motor if one of them is breakdown

  13. Analysis and Design of Hybrid Excitation Permanent Magnet Synchronous Generators

    Institute of Scientific and Technical Information of China (English)

    JIN Wan-bing; ZHANG Dong; AN Zhong-liang; TAN Ren-yuan

    2006-01-01

    On the basis of a conventional permanent magnet (PM) synchronous generator's construction,a novel kind of Hybrid Excitation Permanent Magnet Synchronous Generator (HEPMSG) is introduced by inserting exciting winding in the stator or rotor.Firstly,the construction of HEPMSG is improved with the addition of PM excitation on the ferromagnetic pole,and its working principle and design method are studied in detail.Then,an appropriate exciting current control system is presented considering the characteristics of HEPMSG.Finally,a prototype is made,and test results confirm the analysis and design.

  14. Experimenting with a Superconducting Levitation Train

    Science.gov (United States)

    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…

  15. Hybrid material as contrast agent in magnetic resonance images

    OpenAIRE

    Botella Asunción, Pablo; Cabrera García, Alejandro

    2015-01-01

    [EN] The invention relates to a contrast agent of magnetic resonance based on a hybrid material formed by an organo-metallic core derived from Prussian blue and a silica cover, and optionally, molecules of a poly(ethylene glycol), a fluorescent agent, a radio nucleus and/or a substance that directs to specific receptors, cells or tissues, joined by covalent bonding to the surface of the inorganic cover.

  16. Hybrid material as contrast agent in magnetic resonance images

    OpenAIRE

    Botella Asunción, Pablo; Cabrera García, Alejandro

    2015-01-01

    [EN] The invention relates to a contrast agent of magnetic resonance based on a hybrid material formed by an organo-metallic core derived from Prussian blue and a silica cover, and optionally, molecules of a poly(ethylene glycol), a fluorescent agent, a radio nucleus and/or a substance that directs to specific receptors, cells or tissues, joined by covalent bonding to the surface of the inorganic cover.

  17. Levitation Kits Demonstrate Superconductivity.

    Science.gov (United States)

    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)

  18. Levitation Kits Demonstrate Superconductivity.

    Science.gov (United States)

    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)

  19. Magnetic Hybrid Nanosorbents for the Uptake of Paraquat from Water.

    Science.gov (United States)

    Fernandes, Tiago; Soares, Sofia F; Trindade, Tito; Daniel-da-Silva, Ana L

    2017-03-18

    Although paraquat has been banned in European countries, this herbicide is still used all over the world, thanks to its low-cost, high-efficiency, and fast action. Because paraquat is highly toxic to humans and animals, there is interest in mitigating the consequences of its use, namely by implementing removal procedures capable of curbing its environmental and health risks. This research describes new magnetic nanosorbents composed of magnetite cores functionalized with bio-hybrid siliceous shells, that can be used to uptake paraquat from water using magnetically-assisted procedures. The biopolymers κ-carrageenan and starch were introduced into the siliceous shells, resulting in two hybrid materials, Fe₃O₄@SiO₂/SiCRG and Fe₃O₄@SiO₂/SiStarch, respectively, that exhibit a distinct surface chemistry. The Fe₃O₄@SiO₂/SiCRG biosorbents displayed a superior paraquat removal performance, with a good fitting to the Langmuir and Toth isotherm models. The maximum adsorption capacity of paraquat for Fe₃O₄@SiO₂/SiCRG biosorbents was 257 mg·g(-1), which places this sorbent among the best systems for the removal of this herbicide from water. The interesting performance of the κ-carrageenan hybrid, along with its magnetic properties and good regeneration capacity, presents a very efficient way for the remediation of water contaminated with paraquat.

  20. Magnetic Hybrid Nanosorbents for the Uptake of Paraquat from Water

    Directory of Open Access Journals (Sweden)

    Tiago Fernandes

    2017-03-01

    Full Text Available Although paraquat has been banned in European countries, this herbicide is still used all over the world, thanks to its low-cost, high-efficiency, and fast action. Because paraquat is highly toxic to humans and animals, there is interest in mitigating the consequences of its use, namely by implementing removal procedures capable of curbing its environmental and health risks. This research describes new magnetic nanosorbents composed of magnetite cores functionalized with bio-hybrid siliceous shells, that can be used to uptake paraquat from water using magnetically-assisted procedures. The biopolymers κ-carrageenan and starch were introduced into the siliceous shells, resulting in two hybrid materials, Fe3O4@SiO2/SiCRG and Fe3O4@SiO2/SiStarch, respectively, that exhibit a distinct surface chemistry. The Fe3O4@SiO2/SiCRG biosorbents displayed a superior paraquat removal performance, with a good fitting to the Langmuir and Toth isotherm models. The maximum adsorption capacity of paraquat for Fe3O4@SiO2/SiCRG biosorbents was 257 mg·g−1, which places this sorbent among the best systems for the removal of this herbicide from water. The interesting performance of the κ-carrageenan hybrid, along with its magnetic properties and good regeneration capacity, presents a very efficient way for the remediation of water contaminated with paraquat.

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

    Energy Technology Data Exchange (ETDEWEB)

    Agramunt-Puig, Sebastia; Del-Valle, Nuria; Navau, Carles, E-mail: carles.navau@uab.cat; Sanchez, Alvaro

    2013-04-15

    Highlights: ► Study of the levitation of a superconducting bar over different magnetic guideways. ► A soft ferromagnet within permanent magnets improves levitation stability. ► We study the best geometry for large levitation force with full stability. -- Abstract: 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.

  2. Magnetic properties of the magnetic hybrid membranes based on various polymer matrices and inorganic fillers

    Energy Technology Data Exchange (ETDEWEB)

    Rybak, Aleksandra, E-mail: Aleksandra.Rybak@polsl.pl [Department of Physical Chemistry and Technology of Polymers, Faculty of Chemistry, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland); Kaszuwara, Waldemar [Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warszawa (Poland)

    2015-11-05

    Magnetic hybrid membranes based on ethylcellulose (EC), poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and various magnetic praseodymium and neodymium powder microparticles as fillers were obtained. Permeability, diffusion and sorption coefficients of O{sub 2}, N{sub 2} and synthetic air components were estimated for homogeneous and heterogeneous membranes using the Time Lag method based on constant pressure permeation technique. The microstructure studies and the phase analysis of magnetic membranes were also performed using SEM and XRD. The influence of magnetic parameters, like coercivity, remanence and saturation magnetization of created membranes on the gas transport properties was studied. The results showed that their coercivity depended on composition and microstructure of the magnetic powder. On the other hand, remanence and saturation magnetization increased with the increase of the powder addition in the membrane. It was found that the magnetic membrane's gas transport properties were improved with the increase of membrane's remanence, saturation magnetization and magnetic particle filling. The decrease in powder particle size and associated increase of the membrane's coercivity also positively influenced the gas transport and separation properties of investigated membranes. It was observed that the magnetic ethylcellulose and poly(2,6-dimethyl-1,4-phenylene oxide) membranes had higher gas permeability, while their permselectivity and solubility coefficient values were rather maintained or slightly increased. The results also showed that the magnetic powder content enhanced significantly gas diffusivity in EC and PPO membranes. It was also analyzed the dependence of the drift coefficient w on the magnetic parameters of investigated membranes. The correlation between the membrane selectivity, permeability and magnetic properties with their XRD characteristics was stated. - Highlights: • Membrane's production consisting of EC or PPO

  3. Measurement of Levitation Forces of High-"T[subscript c] Superconductors

    Science.gov (United States)

    Becker, M.; Koblischka, M. R.; Hartmann, U.

    2010-01-01

    We show the construction of a so-called levitation balance which is capable of measuring the levitation forces between a permanent magnet and a superconducting high-T[subscript c] thin film sample. The underlying theoretical basis is discussed in detail. The experiment is performed as an introductory physics experiment for school students as well…

  4. Measurement of Levitation Forces of High-"T[subscript c] Superconductors

    Science.gov (United States)

    Becker, M.; Koblischka, M. R.; Hartmann, U.

    2010-01-01

    We show the construction of a so-called levitation balance which is capable of measuring the levitation forces between a permanent magnet and a superconducting high-T[subscript c] thin film sample. The underlying theoretical basis is discussed in detail. The experiment is performed as an introductory physics experiment for school students as well…

  5. 五自由度全永磁轴承系统的稳定悬浮特性分析%Stable Levitation Performance Analysis of Five Degrees of Freedom All Permanent Magnetic Bearing System

    Institute of Scientific and Technical Information of China (English)

    张钢; 孟庆涛; 钟永彦; 张坚; 张海龙; 樊曼

    2015-01-01

    为探讨永磁悬浮轴承系统的稳定悬浮特性,从轴承刚度角度对五自由度全永磁轴承系统的稳定悬浮特性进行了分析。采用等效磁荷理论建立永磁轴承的承载力、承载力矩和刚度的数学表达式,并利用蒙特卡洛法对表达式中存在的四重积分进行求解。探究转子在受迫进动情况下以及受到外力矩干扰时继续保持稳定旋转所需要的最低临界转速。基于轴向永磁轴承与径向永磁轴承的结构,提出一种六磁环五自由度全永磁轴承系统结构模型,对全永磁轴承的转子系统承受轴向和径向外载荷的承载力、力矩和承载刚度进行分析,得出轴向可以承受外载荷而径向无法承受外载荷,即静态下轴向可以稳定悬浮、径向不能稳定悬浮,符合 Earnshaw 定理。利用刚性转子的陀螺惯性力矩来承受全永磁轴承系统的不平衡力矩和外力矩,从而保持转子定轴自稳定悬浮,并对系统稳定悬浮特性进行计算,结果表明转子在超过最低临界转速后是可以实现动态稳定悬浮的,具有一定的工程应用价值。%To investigate the stable levitation performance of permanent magnetic bearings system, the stable levitation performance of the five-DOF permanent magnetic bearing (PMB) system is analyzed from the perspective of bearing stiffness. The analysis formulas of PMB’ s loading capacity, torque and stiffness are established based on the equivalent magnetic charge theory, then use Monte Carlo method to solve the quadruple integral formula to get the result of the force, moment and stiffness. The minimum critical speed for rotor in the case of forced precession and in the situation of external torque is explored. Puts forward a six circular magnetic rings and five DOF all permanent magnetic bearing structure model based on the structure of radial and axial magnetic bearings, the carrying capacity, moment and stiffness of five-DOF PMB

  6. A review of the hybrid techniques for the fabrication of hard magnetic microactuators based on bonded magnetic powders

    Science.gov (United States)

    Pallapa, M.; Yeow, J. T. W.

    2015-02-01

    Polymer composites based on permanent magnetic bonded powders exhibit immense potential for applications in microactuators and sensors with magnetic performances comparable to their fully dense counterparts. While fabrication and integration of magnetic devices based on bonded magnetic powders is challenging via conventional deposition and electrochemical growth techniques, hybrid fabrication offers a promising alternative. This paper presents the evolution of permanent magnetic materials into bonded magnetic powders, the magnetic performance figures of merit of permanent magnetic materials significant for the design and manufacture of polymer based sensors and actuators. A review of the hybrid fabrication techniques such as replica molding, squeegee coating, spin casting etc are reported. Critical factors affecting the fabrication of polymer magnetic composites such as filler particle size and effect of magnetic field during fabrication are discussed. Prior art based on polymer magnetic composites for the fabrication of hard magnetic films and hard magnetic actuators are presented.

  7. Conceptual Design of the 45 T Hybrid Magnet at the Nijmegen High Field Magnet Laboratory

    CERN Document Server

    Wiegers, SAJ; Bird, M D; Rook, J; Perenboom, J A A J; Wiegers, S A J; Bonito-Oliva, A; den Ouden, A

    2010-01-01

    A 45 T Hybrid Magnet System is being developed at the Nijmegen High Field Magnet Laboratory as part of the Nijmegen Center for Advanced Spectroscopy. The 45 T Hybrid Magnet System will be used in combination with far-infra-red light produced by a Free Electron Laser under construction directly adjacent to the High Field Magnet Laboratory. The superconducting outsert magnet will consist of three CICC coils wound on a single coil form, using Nb3Sn strands. A test program for strand and cable qualification is underway. The CICC will carry 13 kA and the coils will produce 12 T on axis field in a 600 mm warm bore. The nominal operating temperature will be 4.5 K maintained with forced-flow supercritical helium. The insert magnet will produce 33 T at 40 kA in a 32 mm bore consuming 20 MW, and will consist of four coils. The insert magnet will be galvanically and mechanically isolated from the outsert magnet. Complete system availability for users is expected in 2014. In this paper we will report on the conceptual de...

  8. New laser power sensor using diamagnetic levitation.

    Science.gov (United States)

    Pinot, P; Silvestri, Z

    2017-08-01

    This paper presents a preliminary study of an elementary device consisting of a small plate made from pyrolytic carbon levitated above a magnet array which is sensitive to any irradiating laser power. This device might provide an interesting alternative to power meters based on thermal measurement techniques via the Stefan-Boltzmann law or the photon-electron interaction. We show that the photo-response of a pyrolytic carbon plate in terms of levitation height versus irradiation power in the range of 20 mW to 1 W is sufficiently linear, sensitive, and reproducible to be used as a laser power sensor. The elevation height change as a function of irradiance time appears to be a suitable measurement parameter for establishing a relation with the irradiating laser power. The influence of some quantities affecting the measurement results has been highlighted. The study demonstrates that such a device should prove useful for applications in metrology, industry, or emerging technologies.

  9. 33. 6 T dc magnetic field produced in a hybrid magnet with Ho pole pieces

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, L.G.; Brandt, B.L.; Weggel, R.J.; Foner, S.; McNiff E.J. Jr.

    1986-07-07

    A dc magnetic field of 33.6 +- 0.3 T was produced in a hybrid magnet whose central field was enhanced by a 3.5 T contribution from holmium pole pieces. The working (sample) volume was a 2-mm gap between the 19-mm-diam x 32-mm-long pole pieces tapered to 12-mm-diam faces. The magnetic field was measured with high-field/low-temperature Hall-effect sensors whose reproducibility and linearity made practical an extrapolation technique for fields above 30 T. Three superconducting samples with previously measured upper critical fields were used as calibration check points.

  10. Pixel hybrid photon detector magnetic distortions characterization and compensation

    CERN Document Server

    Aglieri-Rinella, G; D'Ambrosio, Carmelo; Forty, Roger W; Gys, Thierry; Patel, Mitesh; Piedigrossi, Didier; Van Lysebetten, Ann

    2004-01-01

    The LHCb experiment requires positive kaon identification in the momentum range 2-100 GeV/c. This is provided by two ring imaging Cherenkov detectors. The stringent requirements on the photon detectors are fully satisfied by the novel pixel hybrid photon detector, HPD. The HPD is a vacuum tube with a quartz window, S20 photo-cathode, cross-focusing electron optics and a silicon anode encapsulated within the tube. The anode is a 32*256 pixels hybrid detector, with a silicon sensor bump-bonded onto a readout chip containing 8192 channels with analogue front-end and digital read-out circuitry. An external magnetic field influences the trajectory of the photoelectrons and could thereby degrade the inherent excellent space resolution of the HPD. The HPDs must be operational in the fringe magnetic field of the LHCb magnet. This paper reports on an extensive experimental characterization of the distortion effects. The characterization has allowed the development of parameterisations and of a compensation algorithm. ...

  11. Hybrid Method for 3D Segmentation of Magnetic Resonance Images

    Institute of Scientific and Technical Information of China (English)

    ZHANGXiang; ZHANGDazhi; TIANJinwen; LIUJian

    2003-01-01

    Segmentation of some complex images, especially in magnetic resonance brain images, is often difficult to perform satisfactory results using only single approach of image segmentation. An approach towards the integration of several techniques seems to be the best solution. In this paper a new hybrid method for 3-dimension segmentation of the whole brain is introduced, based on fuzzy region growing, edge detection and mathematical morphology, The gray-level threshold, controlling the process of region growing, is determined by fuzzy technique. The image gradient feature is obtained by the 3-dimension sobel operator considering a 3×3×3 data block with the voxel to be evaluated at the center, while the gradient magnitude threshold is defined by the gradient magnitude histogram of brain magnetic resonance volume. By the combined methods of edge detection and region growing, the white matter volume of human brain is segmented perfectly. By the post-processing using mathematical morphological techniques, the whole brain region is obtained. In order to investigate the validity of the hybrid method, two comparative experiments, the region growing method using only gray-level feature and the thresholding method by combining gray-level and gradient features, are carried out. Experimental results indicate that the proposed method provides much better results than the traditional method using a single technique in the 3-dimension segmentation of human brain magnetic resonance data sets.

  12. Sound Waves Levitate Substrates

    Science.gov (United States)

    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.

  13. 多模型切换控制方法在磁悬浮系统中的应用%Multi-model Switching Control Method of Magnetic Levitation System

    Institute of Scientific and Technical Information of China (English)

    彭辉; 高杰

    2011-01-01

    An multi-model switching based Linear quadratic regulator (LQR) is proposed for the magnetic levitation system characterized by, nonlinearity and complexity.The structure, principle, model-rank choice, identification of the ARX models are dis, cussed the stale spale model and the design of LQR is presented.With existing experimental equipment such as PC, data collector and magnetic levitation system, a real-time control system is constracted based-on Matlab/Simulink environment to implement the control strategy.The experimental curves under different algorithms are given, and the multi-modle switching control method is used to improve the proformance.The results of real-time control on the magnetic levitation system show the and satisfactory performance of model and control approach.%针对磁悬浮装置的非线性及对实时性要求高的特点,对磁悬浮装置构造线性二次型调节器(Linear Quadratic regulator-LQR)并采用多模型切换的控制方法对磁悬浮装置进行实时控制,取得了较好的控制效果.讨论了ARX模型的结构、原理、模型阶次的选择和辫识方法等问题,介绍了状态空间的创建方法和LQR控制器的构造方案,利用实验室现有的试验设备:PC、数据采集卡以及磁悬浮装置,在Matlab/Simulink中组建实时控制模块,对铁球在磁悬浮装置中的位置进行实时控制.并且对磁悬浮球系统在不同信号源给定下的控制效果进行了讨论和分析,针时磁悬浮系统的非线性强的特点提出了多模型切换的控制方法.最后比较了多模型切换的LQR控制方法和传统PID控制方法的控制效果,证明了提出的方法有更好的性能.

  14. Application of discrete sliding mode variable structure control in magnetic levitation ball system%离散滑模变结构控制在磁悬浮球系统中的应用

    Institute of Scientific and Technical Information of China (English)

    钱玉恒; 杨亚非; 张翔

    2012-01-01

    The magnetic levitation ball experiment device is a typical nonlinear system, which provides conventional PID control, but hardly achieves ideal control effect. Therefore, a discrete sliding mode variable structure control is put forward in order to study the system. Firstly, the discrete sliding mode switching surface and tendency rate are analyzed. Secondly, based on the design of discrete sliding mode controller under system disturbances and jitter, and by studying the controller's convergence, the integral compensation discrete sliding mode controller is proposed which can overcome disturbances and jitter. Finally, the proposed ' control method is verified on the magnetic levitation ball experiment device. The experiment results show that the system's response time is reduced to 5 s with the new method, while it is 15 s with the PID control, and the control error is also decreased, which prove that the control effect of the proposed method is better than that of PID control, and the method is suitable for the control of magnetic levitation ball system. It provides a set of new experiment methods for the experiment device.%磁悬浮球实验装置是典型的非线性系统,该装置提供了常规PID控制,但难以达到理想的控制效果,由此提出采用离散滑模变结构控制来研究该系统.文中首先分析了离散滑模切换面和趋近率,然后设计了存在系统干扰和抖动情况下的离散滑模控制器,并研究了其收敛性,在此基础上提出了克服干扰和抖动的积分补偿离散滑模控制器,最后将所提出的控制方法在磁悬浮球实验装置上进行验证.试验验证结果表明,系统响应时间由PID控制的15s减小到5s,控制偏差也有所减小,控制效果优于PID控制,适合磁悬浮球系统的控制,为该实验装置提供了一套新的实验方法,

  15. 模糊自适应PID算法在磁悬浮实时控制系统中的应用研究%Application Research on Fuzzy PID Algorithm in Real-time Control System of Magnetic Levitation

    Institute of Scientific and Technical Information of China (English)

    李明然; 贺建军

    2012-01-01

    针对磁悬浮系统的复杂非线性及模型不确定的特点,采用模糊PID算法对其进行控制,以满足系统对动态性能和静态性能的要求;结合PID实时控制中的经验,建立合理的模糊规则,模糊推理机构根据不同的偏差e、偏差变化率ec对PID参数Kp、Ki和Kd进行自校正;在磁悬浮实验装置中进行实时控制实验,通过与常规PID控制效果的比较来验证模糊PID控制器的性能;在系统输入存在正弦扰动时,模糊PID控制器使系统响应过程中的振荡幅度得到明显减小,干扰对控制效果的影响被减弱;实验证明,模糊PID控制器具有较强的鲁棒性和抗干扰能力,对于磁悬浮这种非线性系统具有良好的控制效果.%Aiming at the characteristics of the complex nonlinearity and uncertain model, fuzzy PID algorithm is adopted to satisfy the requirements of dynamic and static performance in the control of magnetic levitation system. Based on the experience in the real time PID control experiment, fuzzy control rules are established. According to different deviation e and deviation rate of changeec. , PID parameters Kp , K, and KdWere accomplished self tuning by fuzzy inference mechanism. The real- time control experiment is done in the magnetic levitation device in order to verify the control performance of fuzzy PIDconlroller. When system input exists sinusoidal disturbance, the oscillation amplitude cif the system in response process and the impact of interference are reduced obviously by fuzzy PID controller. The experiment proves that this fuzzy PID controller owns better robustness and stronger anti - interference and has good control performance for the nonlinear system such as magnetic levitation system.

  16. A hybrid data acquisition system for magnetic measurements of accelerator magnets

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.; Hafalia, R.; Joseph, J.; Lizarazo, J.; Martchevsky, M.; Sabbi, G. L.

    2011-06-03

    A hybrid data acquisition system was developed for magnetic measurement of superconducting accelerator magnets at LBNL. It consists of a National Instruments dynamic signal acquisition (DSA) card and two Metrolab fast digital integrator (FDI) cards. The DSA card records the induced voltage signals from the rotating probe while the FDI cards records the flux increment integrated over a certain angular step. This allows the comparison of the measurements performed with two cards. In this note, the setup and test of the system is summarized. With a probe rotating at a speed of 0.5 Hz, the multipole coefficients of two magnets were measured with the hybrid system. The coefficients from the DSA and FDI cards agree with each other, indicating that the numerical integration of the raw voltage acquired by the DSA card is comparable to the performance of the FDI card in the current measurement setup.

  17. Poisson Spot with Magnetic Levitation

    Science.gov (United States)

    Hoover, Matthew; Everhart, Michael; D'Arruda, Jose

    2010-01-01

    In this paper we describe a unique method for obtaining the famous Poisson spot without adding obstacles to the light path, which could interfere with the effect. A Poisson spot is the interference effect from parallel rays of light diffracting around a solid spherical object, creating a bright spot in the center of the shadow.

  18. Observation of vacuum-enhanced electron spin resonance of levitated nanodiamonds

    CERN Document Server

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

    2015-01-01

    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. Our results show that optical levitation of nanodiamonds in vacuum not only can improve the mechanical quality of its oscillation, but also enhance the ESR contrast, which pave the way towards a novel levitated spin-optomechanical system for studying macroscopic quantum mechanics. The results also indicate potenti...

  19. Observation of vacuum-enhanced electron spin resonance of optically levitated nanodiamonds

    Science.gov (United States)

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

    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. Our results show that optical levitation of nanodiamonds in vacuum not only can improve the mechanical quality of its oscillation, but also enhance the ESR contrast, which pave the way towards a novel levitated spin-optomechanical system for studying macroscopic quantum mechanics. The results also indicate potential applications of NV centers in gas sensing.

  20. Analysis of Geometric Accuracy of Magnetic Levitation Cylindrical Linear Motion Guide%磁悬浮圆柱形直线运动导轨副几何精度分析

    Institute of Scientific and Technical Information of China (English)

    吴强; 钱永明; 马苏扬; 俞冀; 廖萍

    2013-01-01

    提出了一种新型的加工方便、稳定性优越、更利于实现系列化和模块化并适用于高速轻载高精密加工场合的磁悬浮圆柱形直线运动导轨副。介绍了该导轨副的工作原理,利用ANSYS有限元分析软件分析了磁悬浮滑块稳定悬浮时的悬浮气隙为0.3 mm时,圆柱形支承导轨几何精度和装配精度对磁场力和加工精度的影响。分析结果表明:单个圆柱形支承导轨圆柱度误差以及两圆柱形支承导轨安装时的平行度分别不超过-0.0010~0.0005 mm/100 mm和0.024 mm时,磁悬浮圆柱形直线运动导轨副工作性能稳定,加工精度满足要求,为其几何精度的确定提供了理论依据。%A new kind of magnetic levitation (maglev)cylindrical linear motion guide with the advantages of easy fabrication, stable performance,be more conducive to the realization of serialization and modularization and be applicable to the machining occasion of high speed,light load and high precision was proposed.The working principle of the guide was introduced.The influences of the cy-lindrical bear guide's geometric and assembly precision on the magnetic force and machining accuracy were analyzed by using the Finite Element Analysis (FEA)ANSYS software,when the maglev sliding bar was stably levitated at 0.3 mm of levitation air gap.The analy-sis results show that when the cylindricity of single cylindrical bear guide and the installed parallelism between two cylindrical bear guide were not over than-0.001 0~0.000 5 mm/100 mm and 0.024 mm respectively,the working performance of the maglev cylin-drical linear motion guide was stable and the requirements of machining accuracy was met,which provides the theoretical basis for de-termining its geometric accuracy.

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

    Science.gov (United States)

    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

  2. Improvement in field uniformity of the hybrid insert magnet

    Energy Technology Data Exchange (ETDEWEB)

    Asano, T; Yoshioka, H; Matsumoto, S; Kiyoshi, T [Tsukuba Magnet Laboratory, National Institute for Materials Science, Sakura 3-13, Tsukuba, Ibaraki 305-0003 (Japan)

    2006-11-15

    The hybrid magnet (HM) at the Tsukuba Magnet Laboratory (TML) generates 35 T in a 52-mm warm bore with a field uniformity of about 6500 ppm in a 10 mm diameter sphere volume (DSV). A new resistive insert magnet with the same bore was designed to provide the higher field uniformity in the HM operation and the construction was started. This e-magnet is composed of three concentric Bitter coils. The height of the outer coil is almost equal to that of present insert, . Tand the middle coil is made of a split-paired winding; . Tthe split gap is 53 mm. The A uniformity better than 10 ppm in a 10 mm DSV will be achieved at a themagnetic field of 34.0 T in a backup field of 14 T. This eimprovement in uniformity, in conjuncllaboration with the improvements of the DC power supply already in progress at the TML, will make it possible to expand the application fields of the HM of the TML.

  3. 准直误差对磁浮寻北仪寻北精度的影响分析%Influence Analysis of Collimation Error on North-Seeking Precision About Magnetic Levitation Gyrocompass

    Institute of Scientific and Technical Information of China (English)

    谭立龙; 仲启媛; 黄先祥; 王姣; 王亮

    2013-01-01

    From the north-seeking principle of the magnetic levitation gyrocompass north-seeking instrument, the earth’s rotation angular velocity is decomposed to the gyro coordinate system. The north-seeking error is analyzed under the existing of collimation error and the relational expression between the collimation error and the north-seeking error is derived which be used for north-seeking accuracy compensation calculation. By this way, the problem of the precise collimation consume time resulting in the total north seeking time extended is avoided. The actual application shows that collimating range from 3" expand to 1', can shorten the magnetic levitation closed time about 60 s, by measuring the collimation error and compensating calculation, but the total north-seeking accuracy has not changed.%  从磁悬浮陀螺寻北仪的寻北原理出发,将地球自转角速度分解到陀螺坐标系上,分析了存在准直误差的情况下所引起的寻北误差,推导出了用于补偿运算的准直误差与寻北误差之间的关系表达式,避免了精确准直消耗时间造成总寻北时间延长的问题。实际应用结果表明:准直范围由3″扩大到1′,可缩短磁浮闭路时间约60 s,通过测量准直误差并补偿,仪器总寻北精度没有改变。

  4. Observation of the Field, Current and Force Distributions in an Optimized Superconducting Levitation with Translational Symmetry

    Science.gov (United States)

    Ye, Chang-Qing; Ma, Guang-Tong; Liu, Kun; Wang, Jia-Su

    2016-08-01

    The superconducting levitation realized by immersing the high-temperature superconductors (HTSs) into nonuniform magnetic field is deemed promising in a wide range of industrial applications such as maglev transportation and kinetic energy storage. Using a well-established electromagnetic model to mathematically describe the HTS, we have developed an efficient scheme that is capable of intelligently and globally optimizing the permanent magnet guideway (PMG) with single or multiple HTSs levitated above for the maglev transportation applications. With maximizing the levitation force as the principal objective, we optimized the dimensions of a Halbach-derived PMG to observe how the field, current and force distribute inside the HTSs when the optimized situation is achieved. Using a pristine PMG as a reference, we have analyzed the critical issues for enhancing the levitation force through comparing the field, current and force distributions between the optimized and pristine PMGs. It was also found that the optimized dimensions of the PMG are highly dependent upon the levitated HTS. Moreover, the guidance force is not always contradictory to the levitation force and may also be enhanced when the levitation force is prescribed to be the principle objective, depending on the configuration of levitation system and lateral displacement.

  5. Observation of the Field, Current and Force Distributions in an Optimized Superconducting Levitation with Translational Symmetry

    Science.gov (United States)

    Ye, Chang-Qing; Ma, Guang-Tong; Liu, Kun; Wang, Jia-Su

    2017-01-01

    The superconducting levitation realized by immersing the high-temperature superconductors (HTSs) into nonuniform magnetic field is deemed promising in a wide range of industrial applications such as maglev transportation and kinetic energy storage. Using a well-established electromagnetic model to mathematically describe the HTS, we have developed an efficient scheme that is capable of intelligently and globally optimizing the permanent magnet guideway (PMG) with single or multiple HTSs levitated above for the maglev transportation applications. With maximizing the levitation force as the principal objective, we optimized the dimensions of a Halbach-derived PMG to observe how the field, current and force distribute inside the HTSs when the optimized situation is achieved. Using a pristine PMG as a reference, we have analyzed the critical issues for enhancing the levitation force through comparing the field, current and force distributions between the optimized and pristine PMGs. It was also found that the optimized dimensions of the PMG are highly dependent upon the levitated HTS. Moreover, the guidance force is not always contradictory to the levitation force and may also be enhanced when the levitation force is prescribed to be the principle objective, depending on the configuration of levitation system and lateral displacement.

  6. Preparation of Magnetic Hybrid Microspheres with Well-Defined Yolk-Shell Structure

    Directory of Open Access Journals (Sweden)

    Yuan Zhao

    2016-01-01

    Full Text Available A facile and efficient route was reported to prepare a kind of yolk-shell magnetic hybrid microspheres by suspension polymerization and calcinations method. The morphology, structure, and composition of the magnetic microspheres were characterized by FTIR, XRD, TEM, SEM, and TGA analysis. The vibrating-sample magnetometry (VSM results clearly showed that the magnetic particles were superparamagnetic with saturation magnetization of 32.82 emu/g which makes the microcomposites easily controlled by an external magnetic field. The results revealed that the magnetic hybrid microspheres might have important applications in magnetic bioseparation and drug delivery.

  7. 3D modeling of forces between magnet and HTS in a levitation system using new approach of the control volume method based on an unstructured grid

    Energy Technology Data Exchange (ETDEWEB)

    Alloui, L., E-mail: lotfi.alloui@lgep.supelec.fr [Laboratoire de Genie Electrique de Paris - LGEP, CNRS UMR 8507, Supelec, Universite Pierre et Marie Curie-Paris 6, Universite Paris Sud-Paris 11, Plateau de Moulon, 11 rue Joliot Curie, 91192 Gif-Sur-Yvette Cedex (France); Laboratoire de modelisation des systemes energetiques (LMSE), Universite de Biskra, 07000 Biskra (Algeria); Bouillault, F., E-mail: bouillault@lgep.supelec.fr [Laboratoire de Genie Electrique de Paris - LGEP, CNRS UMR 8507, Supelec, Universite Pierre et Marie Curie-Paris 6, Universite Paris Sud-Paris 11, Plateau de Moulon, 11 rue Joliot Curie, 91192 Gif-Sur-Yvette Cedex (France); Bernard, L., E-mail: laurent.bernardl@lgep.supelc.fr [Laboratoire de Genie Electrique de Paris - LGEP, CNRS UMR 8507, Supelec, Universite Pierre et Marie Curie-Paris 6, Universite Paris Sud-Paris 11, Plateau de Moulon, 11 rue Joliot Curie, 91192 Gif-Sur-Yvette Cedex (France); Leveque, J., E-mail: jean.leveque@green.uhp-nancy.fr [Groupe de recherche en electronique et electrotechnique de Nancy, Universite Henry Poincare, BP 239, 54506 Vandoeuvre les Nancy (France)

    2012-05-15

    In this paper we present new 3D numerical model to calculate the vertical and the guidance forces in high temperature superconductors taking into account the influence of the flux creep phenomena. In the suggested numerical model, we adopt a new approach of the control volume method. This approach is based on the use of an unstructured grid which can be used to model more complex geometries. A comparison of the control volume method results with experiments verifies the validity of this approach and the proposed numerical model. Based on this model, the levitation force's relaxation at different temperatures was also studied.

  8. A tubular hybrid Halbach/axially-magnetized permanent-magnet linear machine

    Directory of Open Access Journals (Sweden)

    Yi Sui

    2017-05-01

    Full Text Available A single-phase tubular permanent-magnet linear machine (PMLM with hybrid Halbach/axially-magnetized PM arrays is proposed for free-piston Stirling power generation system. Machine topology and operating principle are elaborately illustrated. With the sinusoidal speed characteristic of the free-piston Stirling engine considered, the proposed machine is designed and calculated by finite-element analysis (FEA. The main structural parameters, such as outer radius of the mover, radial length of both the axially-magnetized PMs and ferromagnetic poles, axial length of both the middle and end radially-magnetized PMs, etc., are optimized to improve both the force capability and power density. Compared with the conventional PMLMs, the proposed machine features high mass and volume power density, and has the advantages of simple control and low converter cost. The proposed machine topology is applicable to tubular PMLMs with any phases.

  9. A tubular hybrid Halbach/axially-magnetized permanent-magnet linear machine

    Science.gov (United States)

    Sui, Yi; Liu, Yong; Cheng, Luming; Liu, Jiaqi; Zheng, Ping

    2017-05-01

    A single-phase tubular permanent-magnet linear machine (PMLM) with hybrid Halbach/axially-magnetized PM arrays is proposed for free-piston Stirling power generation system. Machine topology and operating principle are elaborately illustrated. With the sinusoidal speed characteristic of the free-piston Stirling engine considered, the proposed machine is designed and calculated by finite-element analysis (FEA). The main structural parameters, such as outer radius of the mover, radial length of both the axially-magnetized PMs and ferromagnetic poles, axial length of both the middle and end radially-magnetized PMs, etc., are optimized to improve both the force capability and power density. Compared with the conventional PMLMs, the proposed machine features high mass and volume power density, and has the advantages of simple control and low converter cost. The proposed machine topology is applicable to tubular PMLMs with any phases.

  10. BUILDING A MOVEMENT OF MAGNETO AND LEVITATING TRAINS IN AN UNPREDICTABLE ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    V. A. Polyakov

    2009-07-01

    Full Text Available The method of constructing the goal-directed dynamics of magnet-levitation train is offered. The components of its motion are divided on useful and parasitic. Their situation is expected unpredictable.

  11. Hybrid magnetic – Semiconductor nanocomposites: optical, magnetic and nanosecond dynamical properties

    Energy Technology Data Exchange (ETDEWEB)

    Emam, A.N.; Girgis, E.; Mostafa, A.A. [National Research Center, Dokki, Giza (Egypt); Guirguis, O.W. [Biophysics Department, Faculty of Science, Cairo University, Giza (Egypt); Mohamed, M.B., E-mail: monabmohamed@gmail.com [National Institute of Laser Enhanced Science, Cairo University, Giza (Egypt); NanoTech Egypt for Photoelectronics, Dreamland, Giza (Egypt)

    2015-07-15

    A series of colloidal CdSe quantum dots doped with different concentration of cobalt ions has been prepared via organometallic pyrolysis of a mixture of cadmium stearate and cobalt dithiocarbazate. The conditions required for successful doping depend on the source of cobalt ions and the dopant concentration. The structure and morphology of the prepared nanocrystals have been characterized using X-Ray Diffraction (XRD), and Transmission Electron Microscope (TEM). Slight shift in the interplaner space was observed in the XRD pattern of the doped nanocrystals. Formation of separate cobalt nanoclusters has been observed in the TEM images upon increasing the cobalt concentration more than 2% of the original cadmium concentration. This was confirmed by magnetic measurements of the prepared samples. Room-temperature ferromagnetism has been observed, in which the switching field increases as the cobalt ratio increases. Increasing the cobalt ratio more than 5% increases the coercivity due to formation of Co{sup 0} nanoclusters. Moreover, the presence of localized magnetic ions in semiconductor QDs leads to strong exchange interactions between sp band electrons and the magnetic ions d electrons. This would influence the optical properties such as absorption, emission, as well as nanosecond relaxation dynamics. - Graphical abstract: Display Omitted - Highlights: • Hybrid semiconductor-magnetic nanostructure was prepared via chemical method. • Room-temperature ferromagnetism for hybrid CdSe–Co quantum dots has been observed. • Co{sup +2} ions induces slight shift in the interplaner space distance of the doped QDs. • Hybrid CdSe–Co QDs have better quantum yield than pure CdSe QDs. • Hybrid CdSe–Co nanocrystals have faster electron-hole dynamics than pure CdSe QDs.

  12. 单电磁铁悬浮系统的非线性鲁棒控制%Single electric magnetic levitation system nonlinear robust control

    Institute of Scientific and Technical Information of China (English)

    林志雄; 李全国

    2014-01-01

    Based on the state feedback precise linearization and Linear robust control theory,one methord of designing Nonlinear robust controller is proposed,which contributes to the research of nonlin-ear robust control of single electromagnet levitation system.With wide application's needs,it characters conciseness and practical applicability.Firstly,we build an corresponding linear system robust control strategy by using feedback precise linearization.And then,we can figure out the original nonlinear system control law with preliminary feedback and have deduced that the control law possesses robustness in single electromagnet levitation system at last.%结合状态反馈精确线性化和线性鲁棒控制理论研究单电磁铁悬浮系统的非线性鲁棒控制问题,给出一种简洁实用的非线性鲁棒控制器设计方法,先用反馈精确线性化构造相应的线性系统的鲁棒控制策略,然后再用预反馈求出原非线性系统的控制律,最后证明该控制律对于单电磁铁悬浮系统具有鲁棒性。

  13. A Novel Integral 5-DOFs Hybrid Magnetic Bearing with One Permanent Magnet Ring Used for Turboexpander

    Directory of Open Access Journals (Sweden)

    Bangcheng Han

    2014-01-01

    Full Text Available We propose a novel combined five-degrees-of-freedom (5-DOFs hybrid magnetic bearing (HMB with only one permanent magnet ring (PMR used for turboexpanders. It has two radial magnetic bearing (RMB units; each has four poles and one thrust magnetic bearing (TMB to control 5-DOFs. Based on one PMR, the bias flux of the two radial magnetic bearing units and the one thrust magnetic bearing unit is constructed. As a result, ultra-high-speed, lower power loss, small size, and low cost can be achieved. Furthermore, the equivalent magnetic circuit method and 3D finite element method (FEM are used to model and analyze the combined 5-DOFs HMB. The force-current, force-position, torque-coil currents, the torque-angle position, and the stiffness models of the combined 5-DOFs HMB are given. Moreover, its coupling problems between the RMB units and the AMB unit are also proposed in this paper. An example is given to clarify the mathematical models and the coupling problems, and the linearized models are proposed for the follow-up controller design.

  14. Microstructure and levitation properties of floating zone melted YBCO samples

    Energy Technology Data Exchange (ETDEWEB)

    Bashkirov, Yu.A.; Fleishman, L.S.; Vdovin, A.B.; Zubritsky, I.A.; Smirnov, V.V.; Vinogradov, A.V. [Krzhizhanovsky Power Engineering Inst., Moscow (Russian Federation)

    1994-07-01

    Radiation zone melting has been used to produce texture in sintered YBCO cylindrical samples. Microstructural analysis by electron microscopy and pole figure measurements reveals that the production process gives rise to a preferential orientation within large domains. D.C. transport measurements show that changes in alignment orientation can result in the inability to carry a transport current. Both a.c. magnetic field shielding and levitation properties are substantially improved by the floating zone melting, the levitation force being increased with the texture domain size growth.

  15. Flywheel Energy Storage System Suspended by Hybrid Magnetic Bearing

    Science.gov (United States)

    Owusu-Ansah, Prince; Hu, Yefa; Misbawu, Adam

    This work presents a prototype flywheel energy storage system (FESS) suspended by hybrid magnetic bearing (HMB) rotating at a speed of 20000rpm with a maximum storage power capacity of 30W with a maximum tip speed of 300m/s. The design presented is an improvement of most existing FESS, as the design incorporates a unique feature in that the upper and the lower rotor and stator core are tapered which enhances larger thrust and much lower radial force to be exerted on the system. Without any adverse effect being experienced by the model. The work also focuses on the description of developing a prototype FESS suspended by HMB using solid works as a basis of developing in the nearer future a more improved FESS suspended by HMB capable of injecting the ever increasing high energy demand situation in the 21st century and beyond.

  16. Cryogenic Design of the 43 T LNCMI Grenoble Hybrid Magnet

    Science.gov (United States)

    Hervieu, B.; Berriaud, Ch.; Berthier, R.; Debray, F.; Fazilleau, Ph.; Manil, P.; Massinger, M.; Pfister, R.; Pugnat, P.; Ronayette, L.; Trophime, C.

    The association of two inner resistive coils (Polyhelix and Bitter) producing 34.5 T with an outer NbTi superconducting coil producing 8.5 T to obtain a 43 T hybrid magnet is a technical challenge. Accidental failure modes leading to complex electromagnetic behaviors and large transient dynamical forces should be anticipated. These considerations lead to a reinforced design and a thermo-hydraulic strategy to limit the overpressure. The cryostat has been designed with innovative thermo-mechanical supports sustaining the coil at 1.8 K-1200 hPa and the eddy current shield at 30 K, both being possibly overloaded by high dynamic forces in the worst accidental failure case.

  17. Influence of the lateral movement on the levitation and guidance force in the high-temperature superconductor maglev system

    Science.gov (United States)

    Song, Honghai; de Haas, Oliver; Beyer, Christoph; Krabbes, Gernot; Verges, Peter; Schultz, Ludwig

    2005-05-01

    After the levitation force relaxation was studied for different field-cooling height and working-levitation height, the high-temperature superconductor (HTS) bulk was horizontally moved in the lateral direction above the permanent magnet guideway. Both levitation and guidance force were collected by the measurement system at the same time. It was found that the decay of levitation force is dependent on both the maximum lateral displacement and the movement cycle times, while the guidance force hysteresis curve does not change after the first cycle. This work provided scientific analysis for the HTS maglev system design.

  18. Hybrid Magnetic Core-Shell Nanophotocatalysts for Environmental Applications

    Energy Technology Data Exchange (ETDEWEB)

    Gaulden, Patrick [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Murph, Simona Hunyadi [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Univ. of Georgia, Athens, GA (United States). Dept. of Physics and Astronomy

    2016-07-29

    This research study describes a facile sol-gel method to creating hybrid iron (III) oxide/silica/titania nanomaterials decorated with gold nanoparticles for use in environmental applications. The multi-functional composition of the nanomaterials allows for photocatalyzed reactions to occur in both the visible and the UV range. The morphologies, elemental composition, and surface charge of the nanoparticles were determined by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and Phase Analysis Light Scattering (PALS), respectively. The photocatalytic activity of the synthesized hybrid nanoparticles for breaking down a model analyte, methyl orange (MO), was then evaluated using UV-Vis Spectroscopy. The efficiency of the photocatalyst under UV light irradiation was measured and compared to other well-studied nanophotocatalysts, namely titanium oxide and iron oxide nanoparticles. The concentration dependence of both the photocatalyst and the analyte was also investigated. By utilizing the known UV-active properties of TiO2, the magnetic properties of Fe2O3, the optical properties of gold in the visible range of the spectrum, and the high stability of silica, a novel, highly efficient photocatalyst that is active on a broad range of the spectrum (UV-Vis) can be created to destroy organic pollutants in wastewater streams.

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

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Zhao-Fei; Gou, Xiao-Fan, E-mail: xfgou@hhu.edu.cn

    2015-12-15

    Highlights: • In this article, for the eddy current damper attached to the HTSC, we • quantitatively investigated the damping coefficient c, damping ratio, Joule heating of the copper damper, and the vibration frequency of the PM as well. • presented four different arrangements of the copper damper, and comparatively studied their damping effects and Joule heating, and finally proposed the most advisable arrangement. - Abstract: 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 J{sub c} 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/V{sub Cu}, in which V{sub Cu} is the volume of the damper) and Joule heating, and finally presented the most advisable arrangement.

  20. Classification of magnetic inhomogeneities and 0 -π transitions in superconducting-magnetic hybrid structures

    Science.gov (United States)

    Baker, Thomas E.; Richie-Halford, Adam; Bill, Andreas

    2016-09-01

    We present a comparative study of pair correlations and currents through superconducting-magnetic hybrid systems with a particular emphasis on the tunable Bloch domain wall of an exchange spring. This study of the Gor'kov functions contrasts magnetic systems with domain walls that change at discrete points in the magnetic region with those that change continuously throughout. We present results for misaligned homogeneous magnetic multilayers, including spin valves, for discrete domain walls, as well as exchange springs and helical domain walls—such as Holmium—for the continuous case. Introducing a rotating basis to disentangle the role of singlet and triplet correlations, we demonstrate that substantial amounts of (so-called short-range) singlet correlations are generated throughout the magnetic system in a continuous domain wall via the cascade effect. We propose a classification of 0 -π transitions of the Josephson current into three types, according to the predominant pair correlations symmetries involved in the current. Properties of exchange springs for an experimental study of the proposed effects are discussed. The interplay between components of the Gor'kov function that are parallel and perpendicular to the local magnetization lead to a novel prediction about their role in a proximity system with a progressively twisting helix that is experimentally measurable.

  1. Oscillating Permanent Magnets.

    Science.gov (United States)

    Michaelis, M. M.; Haines, C. M.

    1989-01-01

    Describes several ways to partially levitate permanent magnets. Computes field line geometries and oscillation frequencies. Provides several diagrams illustrating the mechanism of the oscillation. (YP)

  2. Recent Advances of Graphene-based Hybrids with Magnetic Nanoparticles for Biomedical Applications.

    Science.gov (United States)

    Alegret, Nuria; Criado, Alejandro; Prato, Maurizio

    2017-01-01

    The utilization of graphene-based nanomaterials combined with magnetic nanoparticles offers key benefits in the modern biomedicine. In this minireview, we focus on the most recent advances in hybrids of magnetic graphene derivatives for biomedical applications. We initially analyze the several methodologies employed for the preparation of graphene-based composites with magnetic nanoparticles, more specifically the kind of linkage between the two components. In the last section, we focus on the biomedical applications where these magnetic-graphene hybrids are essential and pay special attention on how the addition of graphene improves the resulting devices in magnetic resonance imaging, controlled drug delivery, magnetic photothermal therapy and cellular separation and isolation. Finally, we highlight the use of these magnetic hybrids as multifunctional material that will lead to a next generation of theranostics. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. A new 3D levitation force measuring device for REBCO bulk superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S.L. [School of Physics, Shaanxi Normal University, Xi’an 710062 (China); Yang, W.M., E-mail: yangwm@snnu.edu.cn [School of Physics, Shaanxi Normal University, Xi’an 710062 (China); Li, J.W.; Yuan, X.C. [School of Physics, Shaanxi Normal University, Xi’an 710062 (China); Ma, J. [School of Physics, Shaanxi Normal University, Xi’an 710062 (China); Department of Physics, Qinghai Normal University, Xining 810008 (China); Wang, M. [School of Physics, Shaanxi Normal University, Xi’an 710062 (China)

    2014-01-15

    Highlights: •A new 3D levitation force measuring device has been designed and constructed. •It can measure the 3D real-time interaction force simultaneously and directly. •Performance, accuracy and effectiveness has been demonstrate by tests. -- Abstract: A new 3D levitation force measuring device for ReBa{sub 2}Cu{sub 3}O{sub 7−x} (REBCO) bulk superconductors has been designed and constructed. Three pull pressure load cells are orthogonally set on a fixing bracket to test the interaction force between a bulk superconductor and a magnet in three dimensions. To realize the simple, rapid and accurate measurement of the levitation force, a non-magnetic hollow cylinder flange, three pull pressure load cells, a piece of iron plate, a NbFeB permanent magnet (PM) and some steel balls are elaborately constructed with the fixing bracket, thus the magnet or REBCO bulk superconductor can be well and rigidly connected with the load cells, and the mutual interference from the three pull pressure load cells can be effectively avoided during the levitation force measuring processes. This device can be used to measure the interaction (or levitation) force between a superconductor and a magnet, that between a magnet and a magnet, or the magnetic force among magnetic materials in three dimensions.

  4. Study on Machine Tool Crossbeam Magnetic Levitation System Based on Backstepping Self-adaptive Dynamic Sliding Mode Control%机床横梁悬浮系统的反演自适应动态滑模变结构控制研究

    Institute of Scientific and Technical Information of China (English)

    王通; 迟青光

    2011-01-01

    Disturbance and the system parameters time variation have effects on magnetic levitation system when the tool was cutting. In order to achieve levitation gaps precision control, a backstepping self-adaptive dynamic sliding mode controller was designed at the moving crossbeam levitation system of the gantry NC machining center. Using this method, chatting of the system could be effectively decreased and the stability of levitation system could be kept. Due to the introduction of self-adaptive control strategy, the control ability restraining parameters uncertainty was greatly improved. The simulated result shows that this controller has powerful anti-disturbance ability and makes the system has high rigidity. It can achieve steady levitation.%在龙门数控加工中心移动横梁磁悬浮系统中,刀具切削工件过程中磁悬浮系统所受到扰动和系统自身参数的时变性对悬浮高度有影响.为了实现悬浮高度的精确控制,设计了控制悬浮高度的反演自适应动态滑模控制器,该控制器可有效削弱系统抖振并保持悬浮高度的稳定性;引入自适应控制策略,大大改进了滑模控制对不确定性系统参数的控制能力.仿真结果表明:该控制器具有很强的抗扰性,并使系统具有较高刚度,实现了稳定悬浮.

  5. Anisotropic Thermal Properties of Nanostructured Magnetic, Carbon and Hybrid Magnetic - Carbon Materials

    Science.gov (United States)

    Ramirez, Sylvester

    In this dissertation research we investigated thermal properties of three groups of nanostructured materials: (i) magnetic; (ii) reduced graphene oxide films; and (iii) hybrid magnetic -- graphite -- graphene composites. The thermal measurements were conducted using the transient "hot disk" and "laser flash" techniques. The rare-earth free nanostructured SrFe12O19 permanent magnets were produced by the current activated pressure assisted densification technique. The thermal conductivity of the nanostructured bulk magnets was found to range from 3.8 to 5.6 W/mK for the in-plane and 2.36 W/mk to 2.65 W/mK for the cross-plane directions, respectively. The heat conduction was dominated by phonons near the room temperature. The anisotropy of heat conduction was explained by the brick-like alignment of crystalline grains with the longer grain size in-plane direction. The thermal conductivity scales up with the average grain size and mass density of the material revealing weak temperature dependence. Using the nanostructured ferromagnetic Fe3O4 composites as an example system, we incorporated graphene and graphite fillers into magnetic material without changing their morphology. It was demonstrated that addition of 5 wt. % of equal mixture of graphene and graphite flakes to the composite results in a factor of x2.6 enhancement of the thermal conductivity without significant degradation of the saturation magnetization. We investigated thermal conductivity of free-standing reduced graphene oxide films subjected to a high-temperature treatment of up to 1000°C. It was found that the high-temperature annealing dramatically increased the in-plane thermal conductivity, K, of the films from ˜3 W/mK to ˜61 W/mK at room temperature. The cross-plane thermal conductivity, K⊥, revealed an interesting opposite trend of decreasing to a very small value of ˜0.09 W/mK in the reduced graphene oxide films annealed at 1000°C. The obtained films demonstrated an exceptionally strong

  6. 超导磁悬浮微飞轮系统设计与功耗分析%Power consumption analysis and design of superconducting magnetic levitation micro-flywheel system

    Institute of Scientific and Technical Information of China (English)

    程千兵; 宣明; 武俊峰; 吴一辉

    2012-01-01

    针对飞轮系统在高转速时功耗大的问题,设计了基于超导磁悬浮轴承的微飞轮系统样机,研究了超导磁悬浮轴承对飞轮系统功耗的影响.微飞轮系统采用超导磁悬浮轴承作为支撑机构,以平面直流无刷电机作为驱动装置,在保证超导轴承场冷高度和电机间隙的条件下设计真空系统,通过搭建飞轮能耗实验平台,对超导磁悬浮飞轮系统的功耗进行分析,并通过测试不同场冷高度下的飞轮系统降速曲线,研究场冷高度对超导磁悬浮轴承的摩擦损耗影响.实验结果表明,在同样功耗下飞轮转子的最高转速可达到33 000 r/min,在15 000 r/min时超导磁悬浮轴承的功耗仅为机械飞轮系统功耗的1/7,并可以通过增加场冷高度进一步减少系统功耗.超导磁悬浮技术可以满足飞轮系统高转速、低功耗的要求.%A prototype of the micro-flywheel system with the superconducting magnetic bearing has been designed concerning the problem of huge loss at a high rotating speed of flywheel systems. This micro-flywheel system adopted the superconducting magnetic bearing as the supporting mechanism, and the brushless planar DC motor as driving device. Vacuum system was designed within the restrictions of field-cooling height and motor gap, so that the flywheel could operate stably in the vacuum circumstance. The experimental platform of flywheel was build to analyze the energy consumption of the superconducting magnetic levitation flywheel system and stud-y the influence of the power consumption of the flywheel system by the superconducting magnetic levitating bearing. The influence of friction loss of the superconducting magnetic bearing by the cooling height was studied through testing the spin-down curve of the flywheel. Test result shows that the maximum speed of the flywheel rotor could reach up to 33 000 r/min at the same energy consumption, and the energy consumption of superconducting magnetic bearing is

  7. A contribution on the investigation of the dynamic behavior of rotating shafts with a Hybrid Magnetic Bearing Concept (HMBC) for blower application

    Energy Technology Data Exchange (ETDEWEB)

    Gronek, Martin, E-mail: MGronek@hs-zigr.d [HOCHSCHULE ZITTAU/GOERLITZ-University of Applied Sciences, Institute of Process Technology, Process Automation and Measuring Technology (IPM), Department Mechatronical Systems, Theodor-Koerner-Allee 16, 02763 Zittau (Germany); Rottenbach, Torsten; Worlitz, Frank [HOCHSCHULE ZITTAU/GOERLITZ-University of Applied Sciences, Institute of Process Technology, Process Automation and Measuring Technology (IPM), Department Mechatronical Systems, Theodor-Koerner-Allee 16, 02763 Zittau (Germany)

    2010-10-15

    Within a subproject of the RAPHAEL-Program, which was part of the 6th EURATOM Framework Program supervised by the European Commission, it was investigated whether the use of a Hybrid Magnetic Bearing Concept (HMBC) will be beneficial for a blower application. Within the RAPHAEL program, the subproject 'Component Development' is dealing with R and D of components of High Temperature Reactor Technology (HTR), where a major focus is on safety- and reliability-related issues. That implies special requirements for the support of high speed rotating shafts in HTR-Applications that only can be satisfied by using Active Magnetic Bearings (AMB). Regarding safety and competitiveness, AMBs are considered to be key components for the support of rotating HTR-components due to their technical features. AMBs are characterized by an electromagnetic actuator that is generating the bearing force depending on the clearance between stator and rotor, in which the rotor is levitated. Therefore an active control of the coil current is necessary. Furthermore, Touch Down Bearings (TDB) are needed to avoid damages in case of an emergency shut down or in case of energy supply losses. This contribution provides an internal insight on the advantages of a Hybrid Magnetic Bearing Concept that is characterized by a completely Active Magnetic Bearing-supported vertical arranged rotor and an additional permanent magnetic radial orientated bearing. One benefit of the HMBC is an additional radial guidance of the shaft that may reduce the loads while dropping into the Touch Down Bearings e.g. in case of energy supply losses of the AMBs. Reduced loads on the TDBs will increase their life cycle and the availability of the AMB supported component. The scope of this R and D-Project, which will be described more detailed in this contribution, includes: the analytical modeling and simulation of the dynamic behavior of the Hybrid Magnetic Bearing System; the modification of the completely AMB

  8. Diamagnetic levitation enhances growth of liquid bacterial cultures by increasing oxygen availability.

    Science.gov (United States)

    Dijkstra, Camelia E; Larkin, Oliver J; Anthony, Paul; Davey, Michael R; Eaves, Laurence; Rees, Catherine E D; Hill, Richard J A

    2011-03-06

    Diamagnetic levitation is a technique that uses a strong, spatially varying magnetic field to reproduce aspects of weightlessness, on the Earth. We used a superconducting magnet to levitate growing bacterial cultures for up to 18 h, to determine the effect of diamagnetic levitation on all phases of the bacterial growth cycle. We find that diamagnetic levitation increases the rate of population growth in a liquid culture and reduces the sedimentation rate of the cells. Further experiments and microarray gene analysis show that the increase in growth rate is owing to enhanced oxygen availability. We also demonstrate that the magnetic field that levitates the cells also induces convective stirring in the liquid. We present a simple theoretical model, showing how the paramagnetic force on dissolved oxygen can cause convection during the aerobic phases of bacterial growth. We propose that this convection enhances oxygen availability by transporting oxygen around the liquid culture. Since this process results from the strong magnetic field, it is not present in other weightless environments, e.g. in Earth orbit. Hence, these results are of significance and timely to researchers considering the use of diamagnetic levitation to explore effects of weightlessness on living organisms and on physical phenomena.

  9. 磁悬浮球系统的自适应反演滑模控制%Adaptive back-stepping sliding mode control of magnetic levitation ball system

    Institute of Scientific and Technical Information of China (English)

    郑建英; 于占东

    2016-01-01

    磁悬浮球系统是一种典型的开环不稳定系统,为了实现磁悬浮球系统的精确控制,而且使系统更具有实际意义,设计了一种自适应反演滑模控制器。在实际控制系统中,不确定性及外加干扰是未知的,本文基于实际应用,利用该系统的线性化模型,来设计此控制器。实验结果表明:所设计的自适应反演滑模控制器与普通滑模控制器相比,能减小系统的抖振,能较好的实现小球的稳定悬浮并具有良好的动态跟踪性能,与自适应滑模控制器相比,能更好的在实践中应用。%Magnetic levitation ball system is a typical open-loop and unstable system, in order to achieve precise control of the magnetic levitation ball system, and make the system more practical, we design an adaptive back-stepping sliding mode controller. In the actual control system, uncertainties and external disturbances are unknown, we base on the practical application of this system, use a linear model of the system, to design the controller. The results show that:compared with the normal mode controller, the design of adaptive back-stepping sliding mode controller can reduce chattering of the system, can better achieve a stable suspension of the ball and has good dynamic tracking performance, and compared to the adaptive sliding mode controller, the controller we design in this paper can better applied in practice.

  10. Theoretical and FEM analysis of suspension and propulsion system with HTS hybrid electromagnets in an EMS Maglev model

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Y.D., E-mail: ydchung@suwon.ac.kr [Department of Electrical Engineering, Suwon University, Bongdang Eup, Hwaseong Si 445-743 (Korea, Republic of); Lee, C.Y. [Korea Railroad Research Institute, Woram Dong, Uiwang Si 437-757 (Korea, Republic of); Jang, J.Y. [Department of Electrical Engineering, Ansan College of Technology, Choji-Dong, Ansan Si 425-792 (Korea, Republic of); Yoon, Y.S. [Department of Electrical and Electronic Engineering, Yonsei University, Sinchon-dong, Seoul 120-749 (Korea, Republic of); Ko, T.K. [Department of Electrical Engineering, Ansan College of Technology, Choji-Dong, Ansan Si 425-792 (Korea, Republic of)

    2011-11-15

    We examine levitation and propulsion forces of the proto-type maglev vehicle system based on 3D FEM. The levitation force increases over 15% due to AC current of the guideway. The levitation force by HTS electromagnet (EM) and AC current is larger over 30% than that of only HTS EM. We have been constructed a proto-type electromagnetic suspension (EMS) based maglev vehicle system. The maglev concept utilizes magnetic forces for noncontact suspension, guidance and propulsion. The suspension system with high temperature superconducting (HTS) hybrid electromagnet (EM) is composed of HTS coils and normal coils, which consume little power to keep large suspension gap. The magnetic forces realize to guide the vehicle, propel the vehicle along the guide-way and assist in braking action. The proto-type EMS-based Maglev model is designed to keep the suspension gap of 20 mm. This paper presents the theoretical analysis of the maglev vehicle based on the EMS model to obtain the designing parameters for levitation and propulsion forces. The magnetic field distributions of the electromagnetic forces with hybrid EM and propulsion stator coils are analyzed based on three dimension (3D) finite element method (FEM) analysis. From the simulation results, appropriately design parameters of the suspension, guidance and propulsion were obtained.

  11. Hybrid magnet devices for molecule manipulation and small scale high gradient-field applications

    Science.gov (United States)

    Humphries, David E.; Hong, Seok-Cheol; Cozzarelli, legal representative, Linda A.; Pollard, Martin J.; Cozzarelli, Nicholas R.

    2009-01-06

    The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides means for separation and other biotechnology applications involving holding, manipulation, or separation of magnetizable molecular structures and targets. Also disclosed are hybrid magnetic tweezers able to exert approximately 1 nN of force to 4.5 .mu.m magnetic bead. The maximum force was experimentally measured to be .about.900 pN which is in good agreement with theoretical estimations and other measurements. In addition, a new analysis scheme that permits fast real-time position measurement in typical geometry of magnetic tweezers has been developed and described in detail.

  12. Development of Axial Flow Pump with a Hydrodynamic-magnetically Levitated Impeller for Heart Assistance%磁-液悬浮轴流泵心脏辅助装置研制

    Institute of Scientific and Technical Information of China (English)

    李国荣; 朱晓东; 郝宗超; 田步升; 陈海丰

    2013-01-01

      Object: To suspend the impeller of axial flow pumps by hydrodynamic, magnetically levitating field. Methods: The newly developed axial fow pump is composed of a cylindric pump house, a impeller with magnetic rotor and a diffuser. The axial displacement of the impel er is restricted by the magnetic feld formed by the rotor and the electromagnetic stator. A tiny gap, the hydrodynamic levitating gap, is formed between the blade tip of the impl er and pump house since the diameter of impel er is slightly less than the inner-diamiter of the cylindric pump house. Hydrodynamic force wil produced inside this gap on rotating of the impel er, limiting its radial movement. Thuse the impel er wil be ful y suspended by hydrodynamic––magnetical force. A outlet diffuser is arranged behind the impel er to enhance the pump effciency, with its blades projected directly from the wal of the pump house, eliminating the center hub which is usual y for holding the diffuser blades, making a hol ow space in the diffuser center. This design al ow some blood fow through the centric passage to wash out the “dead area”behind the impel er, in favor of enhancement of antithrombotic performance. Results: Currently the prototype of the hydrodynamic, magnetical levitating axial fow pump is 23mm in diameter and 65mm in length, yielding a fow rate of 5L/min at 100 mmHg pressure with a rotating speed of 14000rpm. The normalized hemolysis index (NIH) is 0.12g/100L. Conclusion: Our newly developed axial fow pump with hydrodynamic, magnetical y levitated impel er is feasible for left ventricular assistance, just for in vivo animal test in future studies.%  目的:应用磁力和流体动压控制实现轴流泵叶轮的完全悬浮。材料和方法:磁-液悬浮轴流泵由轴流泵泵筒,轴流叶轮,尾导叶叶片等组成。采用约束磁力限制旋转叶轮的轴向位移,约束磁力由旋转叶轮轮毂中的永磁体与轴流泵电机定子铁芯之间通过磁相

  13. Bearing gap adjustment for improvement of levitation performance in a hydrodynamically levitated centrifugal blood pump.

    Science.gov (United States)

    Kosaka, Ryo; Yoshida, Fumihiko; Nishida, Masahiro; Maruyama, Osamu; Kawaguchi, Yasuo; Yamane, Takashi

    2015-01-01

    The purpose of the present study is to investigate a bearing gap adjustment for improvement of levitation performance in a hydrodynamically levitated centrifugal blood pump to realize a blood pump with a low hemolysis level. The impeller levitates axially by balancing a gravitational force, buoyancy, a magnetic force, and hydrodynamic forces on the top and bottom sides of the impeller. To adjust the levitation position of the impeller, the balance of acting forces on the impeller was adjusted by changing the shroud area on the bottom impeller. Three pumps having various shroud area were prepared as tested models: 817 mm(2) (HH-S), 875 mm(2) (HH-M) and 931 mm(2) (HH-L). First, for evaluating the bearing gap adjustment, the bearing gap was estimated by calculating a balancing position of the acting forces on the impeller. We actually measured the gravitational force, buoyancy and the magnetic force, and numerically analyzed hydrodynamic forces on the top and bottom sides of the impeller. Second, to verify accuracy of the estimated bearing gap, the measurement test of the bearing gap was performed. Finally, an in-vitro hemolysis test was performed to evaluate a hemolysis level of the pump. As a result, bottom bearing gaps were estimated as 40 μm (HH-S), 60 μm (HH-M) and 238 μm (HH-L). In the measurement test, bottom bearing gaps were measured as 63 μm (HH-S), 219 μm (HH-M), and 231 μm (HH-L). The estimated bearing gaps had positively correlated with the measured bearing gaps in relation to the shroud area on the impeller. In the hemolysis test, hemolysis level in every model was almost equivalent to that of BPX-80, when the bearing gap was adjusted greater than 60 μm. We could adjust the bearing gap by changing the shroud area on the impeller for improvement of levitation performance to realize a blood pump with a low hemolysis level.

  14. Design, fabrication and levitation experiments of a micromachined electrostatically suspended six-axis accelerometer.

    Science.gov (United States)

    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.

  15. The Mechanism Study of Alternating Arc(ACMagnetic Levitation Induction Motor

    Directory of Open Access Journals (Sweden)

    Li Zeng

    2015-01-01

    Full Text Available Magnetic levitation (no bearings motor by using magnetic force to make rotor suspend and drive realize its high or ultra-high speed rotating. The stator’s structure of traditional no bearing magnetic levitation motor is double winding which is polar logarithmic difference 1 of 2 sets of winding (torque winding and suspension winding and embedded in the stator. Using two inverter respectively for the two sets of winding to go into the same frequency current in order to realize the suspension of the rotor and motor’s driven, small carrying capacity of motor’s structure, controlling complex system. This paper based on the traditional motor technology puts forward a kind of arc principle and respectively decorates two arc motors in horizontal and vertical direction symmetric to rotor according to the electromagnetic bearing suspension technology that is constituted the arc magnetic levitation induction motor. Establishing air-gap transformation regular between rotor and stator (air-gap length motor is under the effect of interference. Based on the electromagnetic theory establishing distribution regular of the air-gap magnetic induction intensity. Virtual displacement principle is used to establish electromagnetism mathematical model and motor electromagnetism levitation. By the finite element analysis carrying on simulation research to the magnetic induction intensity, electric magnetic levitation force and distribution features of electromagnetic torque and so on.

  16. The effect of additional permanent magnet magnetizing methods on magnetic field distribution and the levitation force of single domain GdBCO bulk superconductor%辅助永磁体磁化方式对单畴GdBCO超导块材捕获磁场分布及其磁悬浮力的影响

    Institute of Scientific and Technical Information of China (English)

    马俊; 杨万民; 王妙; 陈森林; 冯忠岭

    2013-01-01

    It has been investigated that the interaction force between a cubic permanent magnet PM1 and a GdBCO bulk (HTSC) super-conducting permanent magnet (SCPM) magnetized by a cubic permanent magnet PM2 under different configurations at 77 K. Two configurations were used for the magnetization of the GdBCO bulk, one is that the North pole of the PM2 is in upward direction, the other is in downward direction, so that the North pole of the SCPM is in two states SCPM↑and SCPM↓;the vertical distance between the bottom surface of PM1 and the top surface of SCPM is kept as a constant value, but the PM2 can be fixed at any positions (x) along a diameter of the GdBCO bulk during the magnetization process. It is found that:for the PM1↓-SCPM↑configuration, the maximum levitation force is increasing from 16.7 N to 23.1 N when x increases from−15 mm to 0, and then decreases to 16.6 N when x further increases to 15 mm;but for the PM1↓-SCPM↓configuration, the maximum levitation force is decreasing from 17.7 N to 7 N when x increases from−15 mm to 0, and then increases to 17.6 N when x further increases to 15 mm. These results are not only much different in the two configurations, but also much different from the maximum levitation force 17.1 N of the sample under zero field cooled condition, which is closely related with the trapped field distribution of the SCPM at different x values. These results indicate that the levitation force of high temperature bulk superconductors can be effectively improved by introducing additional permanent magnet based on scientific and reasonable designing of the system configurations, which is very important during the practical design and applications of superconducting magnetic levitation systems.%通过对方形永磁体和方形辅助永磁体在液氮温度下对GdBCO超导体磁化后超导磁悬浮力的测量,研究了两种组态中方形辅助永磁体对超导体的磁化方式对单畴GdBCO超导块材

  17. Green synthetic, multifunctional hybrid micelles with shell embedded magnetic nanoparticles for theranostic applications.

    Science.gov (United States)

    Li, Yongyong; Ma, Junping; Zhu, Haiyan; Gao, Xiaolong; Dong, Haiqing; Shi, Donglu

    2013-08-14

    The objective of this study is to design and develop a green-synthetic, multifunctional hybrid micelles with shell embedded magnetic nanoparticles for theranostic applications. The hybrid micelles were engineered based on complex micelles self-assembled from amphiphilic block copolymers Pluronic F127 and peptide-amphiphile (PA) pal-AAAAHHHD. The reason to choose PA is due to its amphiphilic character and the coordination capability for Fe(3+) and Fe(2+). The PA incorporation allows the in situ growth of the magnetic iron oxide nanoparticles onto the complex micelles, to yield the nanostructures with shell embedded magnetic nanoparticles at an ambient condition without any organic solvents. The anticancer drug doxorubicin (DOX) can be efficiently loaded into the hybrid micelles. Interestingly, the magnetic nanoparticles anchored on the shell were found to significantly retard the DOX release behavior of the drug loaded hybrid micelles. It was proposed that a cross-linking effect of the shell by magnetic nanoparticles is a key to underlie the above intriguing phenomenon, which could enhance the stability and control the drug diffusion of the hybrid micelles. Importantly, in vitro and in vivo magnetic resonance imaging (MRI) revealed the potential of these hybrid micelles to be served as a T2-weighted MR imaging contrast enhancer for clinical diagnosis.

  18. Shape-controlled fabrication of magnetite silver hybrid nanoparticles with high performance magnetic hyperthermia.

    Science.gov (United States)

    Ding, Qi; Liu, Dongfang; Guo, Dawei; Yang, Fang; Pang, Xingyun; Che, Renchao; Zhou, Naizhen; Xie, Jun; Sun, Jianfei; Huang, Zhihai; Gu, Ning

    2017-04-01

    Superparamagnetic Fe3O4 nanoparticles (NPs)-based hyperthermia is a promising non-invasive approach for cancer therapy. However, the heat transfer efficiency of Fe3O4 NPs is relative low, which hinders their practical clinical applications. Therefore, it is promising to improve the magnetic hyperthermia efficiency by exploring the higher performance magnetic NPs-based hybrid nanostructures. In the current study, it presents a straightforward in situ reduction method for the shape-controlled preparation of magnetite (Fe3O4) silver (Ag) hybrid NPs designed as magnetic hyperthermia heat mediators. The magnetite silver hybrid NPs with core-shell (Fe3O4@Ag) or heteromer (Fe3O4-Ag) structures exhibited a higher biocompatibility with SMMC-7721 cells and L02 cells than the individual Ag NPs. Importantly, in the magnetic hyperthermia, with the exposure to alternating current magnetic field, the Fe3O4@Ag and Fe3O4-Ag hybrid NPs indicated much better tumor suppression effect against SMMC-7721 cells than the individual Fe3O4 NPs in vitro and in vivo. These results demonstrate that the hybridisation of Fe3O4 and Ag NPs could greatly enhance the magnetic hyperthermia efficiency of Fe3O4 NPs. Therefore, the Fe3O4@Ag and Fe3O4-Ag hybrid NPs can be used to be as high performance magnetic hyperthermia mediators based on a simple and effective preparation approach.

  19. Levitation decoupling control for permanent-magnet bearingless synchronous motors based on speed information observation%基于速度信息观测的无轴承永磁同步电机悬浮解耦控制

    Institute of Scientific and Technical Information of China (English)

    王晓琳; 丁强

    2011-01-01

    无轴承永磁同步电机以转子位置信息为媒介实现解耦控制,整个算法复杂且依赖速度传感器.本文研究电机无传感器运行及解耦算法简化的方法.首先将传统扩张状态观测算法简化为线性形式.然后将二、三阶线性扩张状态观测器分别加入转矩和悬浮系统电流环和位移环,并定义电角速度与转矩d-q轴电流乘积以及转矩系统q轴磁链与悬浮d-q轴电流乘积为扰动项,利用观测器辨识转速信息及悬浮扰动力.接着对转速信息进行处理、对悬浮扰动力进行补偿从而实现无速度传感器运行并简化悬浮解耦算法.最后通过仿真验证所提控制策略能够实现电机无速度传感器运行,保证额定转速下稳定悬浮.%The conventional decoupling control of permanent-magnet bearingless synchronous motors depends on the rotor-position information. This control algorithm is complex and dependent on speed-sensor. We propose a decoupling control algorithm with no speed-sensor working for the motor. First, the traditional extended state observer(ESO) algorithm is simplified to a linear form, and then, the second-order and third-order linear-ESO algorithms are added respectively to the current-loop in the torque system and the displacement-loop in the suspension system. The product of the electrical angular speed and the d-q axis current in the torque system, and the product of the q-axis flux in the torque system and the d-q axis current in the suspension system are defined as disturbances to the linear-ESO in identifying the speed information and the levitation disturbance force. Thirdly, the speed information is processed, and the levitation disturbance force is simplified, thus realizing the operation without the speed-sensor, and the simplication of the levitation decoupling algorithm. Finally, the simulation results show that the proposed control strategy can achieve the operation with no speed-sensor and guarantee the

  20. Design of a cryocooler-cooled magnet for a compact hybrid magnet; Konpakuto haiburiddo magunetto yo reitoki reikyaku chodendo magunetto no gainen sekkei

    Energy Technology Data Exchange (ETDEWEB)

    Asano, T. [National Research Inst. for Metals, Tokyo (Japan); Koyanagi, K.; Matsumoto, S.; Kiyoshi, T.; Wada, H. [National Research Inst. for Metals, Tokyo (Japan); Japan Science and Technology Corpration, Saitama (Japan)

    1999-11-10

    In Natl. Res. Inst. for Metals, we examine the possibility of the operation of the hybrid magnet which combined refrigerating machine conduction cooling style superconducting magnet of the large diameter with the water-cooling copper magnet. The examination of the stability considering the electromagnetic interaction with the water-cooling copper magnet is required so that the conduction-cooling magnet may be made to run as a superconducting magnet for the hybrid magnet. In this report, the result of making on the magnet considering thermal load and coil protection to refrigerating machine conceptual design is described. (NEDO)

  1. Electric Levitation Using Epsilon-Near-Zero Metamaterials

    CERN Document Server

    Fortuño, Francisco J Rodríguez; Engheta, Nader

    2013-01-01

    Levitation of objects with action at a distance has always been intriguing to humans. Several ways to achieve this, such as aerodynamic, acoustic, or electromagnetic methods, including radiation pressure, stable potential wells, and quantum Casimir-Lifshitz forces, exist. A fascinating approach for levitation is that of magnets over superconductors based on the Meissner effect -the expulsion of the magnetic field by a superconductor. With the advent of metamaterials -designed structures with electromagnetic properties that may not be found in nature- we ask whether a material may be conceived exhibiting similar field expulsion, but involving the electric field. We show how a special subcategory of metamaterials, called epsilon-near-zero materials, exhibits such electric classic analog to the Meissner effect, exerting a repulsion on nearby sources. Repulsive forces using anisotropic and chiral metamaterials have been investigated, but our proposal uses a different mechanism based on field expulsion, and is ver...

  2. Magnetic-field-mediated coupling and control in hybrid atomic-nanomechanical systems

    CERN Document Server

    Tretiakov, A

    2016-01-01

    Magnetically coupled hybrid quantum systems enable robust quantum state control through Landau-Zener transitions. Here, we show that an ultracold atomic sample coupled to a nanomechanical resonator via oscillating magnetic fields can be used to cool the resonator's mechanical motion, to measure the mechanical temperature, and to enable entanglement of these mesoscopic objects. We calculate the expected coupling for both permanent-magnet and current-conducting nanostring resonators and describe how this hybridization is attainable using recently developed fabrication techniques, including SiN nanostrings and atom chips.

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

    Science.gov (United States)

    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.

  4. Relaxation transition due to different cooling processes in a superconducting levitation system

    Science.gov (United States)

    Zhou, You-He; Zhang, Xing-Yi; Zhou, Jun

    2008-06-01

    We present an experimental study of relaxation of vertical and horizontal force components in a high-temperature superconducting levitation system, with different initial cooling process after fixing the levitated body in an expected position statically. In the experiment, the bulk YBaCuO cylinder superconductor and the permanent magnet disk are employed. For a selected levitation height (LH) and a lateral displacement (LD) of the system, the experimental results show that the relaxations of the vertical and horizontal forces are strongly dependent on the initial cooling height (CH). With CH decreasing, the transition of the lateral force from repulsion to attraction is found as well as the changing characteristics with time from decrease to increase. Additionally, when LH is fixed at the CH, the transition phenomenon is also observed in the levitation force behavior and their relaxation under different LDs.

  5. Dynamics and stability of rigid rotors levitated by passive cylinder-magnet bearings and driven/supported axially by pointwise contact clutch

    DEFF Research Database (Denmark)

    Andersen, Søren Bøgh; Enemark, Søren; Santos, Ilmar

    2013-01-01

    A stable rotor—supported laterally by passive magnetic bearings and longitudinally by magnetic forces and a clutch—loses suddenly its contact to the clutch and executes abruptly longitudinal movements away from its original equilibrium position as a result of small increases in angular velocity. ...

  6. Nonlinear dynamics and millikelvin cavity-cooling of levitated nanoparticles

    CERN Document Server

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

    2015-01-01

    Optomechanical systems explore and exploit the coupling between light and the mechanical motion of matter. A nonlinear coupling offers access to rich new physics, in both the quantum and classical regimes. We investigate a dynamic, as opposed to the usually studied static, nonlinear optomechanical system, comprising of a nanosphere levitated and cooled in a hybrid electro-optical trap. An optical cavity offers readout of both linear-in-position and quadratic-in-position (nonlinear) light-matter coupling, whilst simultaneously cooling the nanosphere to millikelvin temperatures for indefinite periods of time in high vacuum. We observe cooling of the linear and non-linear motion, leading to a $10^5$ fold reduction in phonon number $n_p$, attaining final occupancies of $n_p = 100-1000$. This work puts cavity cooling of a levitated object to the quantum ground-state firmly within reach.

  7. Optical Levitation of Nanodiamonds by Doughnut Beams in Vacuum

    CERN Document Server

    Zhou, Lei-Ming; Chen, Jun; Zhao, Nan

    2016-01-01

    Optically levitated nanodiamonds with nitrogen-vacancy centers promise a high-quality hybrid spin-optomechanical system. However, the trapped nanodiamond absorbs energy form laser beams and causes thermal damage in vacuum. We propose to solve the problem by trapping a composite particle (a nanodiamond core coated with a less absorptive silica shell) at the center of strongly focused doughnut-shaped laser beams. Systematical study on the trapping stability, heat absorption, and oscillation frequency concludes that the azimuthally polarized Gaussian beam and the linearly polarized Laguerre-Gaussian beam ${\\rm LG}_{03}$ are the optimal choices. With our proposal, particles with strong absorption coefficients can be trapped without obvious heating and, thus, the spin-optomechanical system based on levitated nanodiamonds are made possible in high vacuum with the present experimental techniques.

  8. Interpretation of the method of images in estimating superconducting levitation

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Diaz, Jose Luis [Departamento de Ingenieria Mecanica, Universidad Carlos III de Madrid, Butarque 15, E28911 Leganes (Spain)], E-mail: jlperez@ing.uc3m.es; Garcia-Prada, Juan Carlos [Departamento de Ingenieria Mecanica, Universidad Carlos III de Madrid, Butarque 15, E28911 Leganes (Spain)

    2007-12-01

    Among different papers devoted to superconducting levitation of a permanent magnet over a superconductor using the method of images, there is a discrepancy of a factor of two when estimating the lift force. This is not a minor matter but an interesting fundamental question that contributes to understanding the physical phenomena of 'imaging' on a superconductor surface. We solve it, make clear the physical behavior underlying it, and suggest the reinterpretation of some previous experiments.

  9. Interpretation of the method of images in estimating superconducting levitation

    Science.gov (United States)

    Perez-Diaz, Jose Luis; Garcia-Prada, Juan Carlos

    2007-12-01

    Among different papers devoted to superconducting levitation of a permanent magnet over a superconductor using the method of images, there is a discrepancy of a factor of two when estimating the lift force. This is not a minor matter but an interesting fundamental question that contributes to understanding the physical phenomena of "imaging" on a superconductor surface. We solve it, make clear the physical behavior underlying it, and suggest the reinterpretation of some previous experiments.

  10. Electromagnetic levitation system

    OpenAIRE

    Starikov, D. P.; Rybakov, E. A.

    2014-01-01

    Magnetism is a physical phenomenon produced by the motion of electric charge, resulting in attractive and repulsive forces between objects. It is widely adopted in many spheres of our routine life. By using the effect of magnetism, it has become possible to create non-frictional bearings, contact-free shock absorbers and many things, which found their appliance in industrial usage. There are many great inventions connected with magnets, such as the train on the air cushion (Maglev train). Mag...

  11. Hybrid R-Fe-B/R-Co Magnets with Improved Thermal Stability

    Science.gov (United States)

    2009-12-23

    known that Nd2Fe14B -based magnets display excellent room temperature magnetic performance with (BH)max up to 50 MGOe. However, their low Curie... Nd2Fe14B - and Sm2Co17-based permanent magnets. This temperature range covers the exact temperatures that are very critical for many important...make a hybrid Nd2Fe14B /Sm2(Co,Fe,Cu,Zr)17 magnet that may combine the high magnetic performance of Nd2Fe14B and excellent high temperature stability

  12. Two-dimensional magnetic modeling of ferromagnetic materials by using a neural networks based hybrid approach

    Energy Technology Data Exchange (ETDEWEB)

    Cardelli, E.; Faba, A. [Department of Engineering, University of Perugia, Via G. Duranti 93, 06125 Perugia (Italy); Laudani, A.; Lozito, G.M.; Riganti Fulginei, F.; Salvini, A. [Department of Engineering, Roma Tre University, Via V. Volterra 62, 00146 Rome (Italy)

    2016-04-01

    This paper presents a hybrid neural network approach to model magnetic hysteresis at macro-magnetic scale. That approach aims to be coupled together with numerical treatments of magnetic hysteresis such as FEM numerical solvers of the Maxwell's equations in time domain, as in case of the non-linear dynamic analysis of electrical machines, and other similar devices, allowing a complete computer simulation with acceptable run times. The proposed Hybrid Neural System consists of four inputs representing the magnetic induction and magnetic field components at each time step and it is trained by 2D and scalar measurements performed on the magnetic material to be modeled. The magnetic induction B is assumed as entry point and the output of the Hybrid Neural System returns the predicted value of the field H at the same time step. Within the Hybrid Neural System, a suitably trained neural network is used for predicting the hysteretic behavior of the material to be modeled. Validations with experimental tests and simulations for symmetric, non-symmetric and minor loops are presented.

  13. Antimagnets: controlling magnetic fields with superconductor-metamaterial hybrids

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Alvaro; Navau, Carles; Prat-Camps, Jordi; Chen Duxing, E-mail: alvar.sanchez@uab.cat [Grup d' Electromagnetisme, Departament de Fisica, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona, Catalonia (Spain)

    2011-09-15

    Magnetism is very important in various areas of science and technology, ranging from magnetic recording through energy generation to trapping cold atoms. Physicists have managed to master magnetism-to create and manipulate magnetic fields-almost at will. Surprisingly, there is at least one property that has been elusive until now: how to 'switch off' the magnetic interaction of a magnetic material with existing magnetic fields without modifying them. Here we introduce the antimagnet, a design that conceals the magnetic response of a given volume from its exterior, without altering the external magnetic fields, in some respects analogous to recent theoretical proposals for cloaking electromagnetic waves with metamaterials. However, unlike these devices, which require extreme material properties, our device is feasible and needs only two kinds of available materials: superconductors and isotropic magnetic materials. Antimagnets may have applications in magnetic-based medical techniques such as magnetic resonance imaging or in reducing the magnetic signature of vessels or planes.

  14. Photophoretic levitation of engineered aerosols for geoengineering

    Science.gov (United States)

    Keith, David W.

    2010-01-01

    Aerosols could be injected into the upper atmosphere to engineer the climate by scattering incident sunlight so as to produce a cooling tendency that may mitigate the risks posed by the accumulation of greenhouse gases. Analysis of climate engineering has focused on sulfate aerosols. Here I examine the possibility that engineered nanoparticles could exploit photophoretic forces, enabling more control over particle distribution and lifetime than is possible with sulfates, perhaps allowing climate engineering to be accomplished with fewer side effects. The use of electrostatic or magnetic materials enables a class of photophoretic forces not found in nature. Photophoretic levitation could loft particles above the stratosphere, reducing their capacity to interfere with ozone chemistry; and, by increasing particle lifetimes, it would reduce the need for continual replenishment of the aerosol. Moreover, particles might be engineered to drift poleward enabling albedo modification to be tailored to counter polar warming while minimizing the impact on equatorial climates. PMID:20823254

  15. Photophoretic levitation of engineered aerosols for geoengineering.

    Science.gov (United States)

    Keith, David W

    2010-09-21

    Aerosols could be injected into the upper atmosphere to engineer the climate by scattering incident sunlight so as to produce a cooling tendency that may mitigate the risks posed by the accumulation of greenhouse gases. Analysis of climate engineering has focused on sulfate aerosols. Here I examine the possibility that engineered nanoparticles could exploit photophoretic forces, enabling more control over particle distribution and lifetime than is possible with sulfates, perhaps allowing climate engineering to be accomplished with fewer side effects. The use of electrostatic or magnetic materials enables a class of photophoretic forces not found in nature. Photophoretic levitation could loft particles above the stratosphere, reducing their capacity to interfere with ozone chemistry; and, by increasing particle lifetimes, it would reduce the need for continual replenishment of the aerosol. Moreover, particles might be engineered to drift poleward enabling albedo modification to be tailored to counter polar warming while minimizing the impact on equatorial climates.

  16. A modified Rogowski coil for measurements of hybrid permanent magnets

    Energy Technology Data Exchange (ETDEWEB)

    Bertsche, K.

    1996-08-01

    For large permanent magnets, as proposed for the Fermilab Recycler Ring, it may be important to quickly verify that the magnet`s strength is correct. This may be important, for example, if a magnet is suspected of having changed due to some sort of accident. The field strength of a pure dipole can be readily measured with a Hall probe, but for indexed dipoles and for quadrupoles a Hall probe will not give very accurate results without precise positioning. We have investigated a different approach, the use of a modified Rogowski coil to measure the magnetic potential of each pole. As long as magnet geometry is fixed and known, measurement of the magnetic potential at each pole gives a good measurement of field strength even for magnets with large quadrupole components. The construction and use of such a coil and the precision of measurements made with it will be discussed. 4 refs., 5 figs.

  17. Using NV centers to probe magnetization dynamics in normal metal/magnetic insulator hybrid system at the nanoscale

    Science.gov (United States)

    Zhang, Huiliang; Ku, Mark J. H.; Han, Minyong; Casola, Francesco; van der Sar, Toeno; Yacoby, Amir; Walsworth, Ronald L.

    2016-05-01

    Understanding magnetization dynamics induced by electric current is of great interest for both fundamental and practical reasons. Great endeavor has been dedicated to spin-orbit torques (SOT) in metallic structures, while quantitative study of analogous phenomena in magnetic insulators remains challenging where transport measurements are not feasible. Recently we have developed techniques using nitrogen vacancy (NV) centers in diamond to probe few-nanometre-scale correlated-electron magnetic excitations (i.e., spin waves). Here we demonstrate how this powerful tool can be implemented to study magnetization dynamics inside ferromagnetic insulator, Yttrium iron garnet (YIG) with spin injection from electrical current through normal metal (Platinum in our case). Particularly our work will focus on NV magnetic detection, imaging, and spectroscopy of coherent auto-oscillations in Pt/YIG microdisc. Magnetic fluctuations and local temperature measurements, both with nearby NV centers, will also be interesting topics relevant to SOT physics in Pt/YIG hybrid system.

  18. Nonvolatile, reversible electric-field controlled switching of remanent magnetization in multifunctional ferromagnetic/ferroelectric hybrids

    Science.gov (United States)

    Brandlmaier, A.; Geprägs, S.; Woltersdorf, G.; Gross, R.; Goennenwein, S. T. B.

    2011-08-01

    In spin-mechanics, the magnetoelastic coupling in ferromagnetic/ferroelectric hybrid devices is exploited in order to realize an electric-voltage control of magnetization orientation. To this end, different voltage-induced elastic strain states are used to generate different magnetization orientations. In our approach, we take advantage of the hysteretic expansion and contraction of a commercial piezoelectric actuator as a function of electrical voltage to deterministically select one of two electro-remanent elastic strain states. We investigate the resulting magnetic response in a nickel thin film/piezoelectric actuator hybrid device at room temperature, using simultaneous magneto-optical Kerr effect and magnetotransport measurements. The magnetic properties of the hybrid can be consistently described in a macrospin model, i.e., in terms of a single magnetic domain. At zero external magnetic field, the magnetization orientation in the two electro-remanent strain states differs by 15°, which corresponds to a magnetoresistance change of 0.5%. These results demonstrate that the spin-mechanics scheme indeed enables a nonvolatile electrically read- and writable memory bit where the information is encoded in a magnetic property.

  19. Numerical investigation of magnetic sensor for DNA hybridization detection using planar transformer

    Directory of Open Access Journals (Sweden)

    Sayyed M. Azimi

    2007-12-01

    Full Text Available This paper introduces a sensor for detection of DNA hybridization and investigates its performance by means of computer simulation. A planar transformer with spiral windings is proposed for hybridization detection. In order to detect the occurrence of hybridization, single strand target DNA’s are tagged with magnetic beads. Target DNA’s are then exposed to known single strand probe DNA’s which are immobilized on the surface of a functionalized layer in the proximity of the sensor. The primary winding of the transformer is driven by an AC current source. The voltage at the secondary winding is used for detection. Once the hybridization is occurred, a layer of magnetic material is formed and the coupling between the windings is varied. These variations are reflected into the detecting output voltage. The magnitude of the output voltage is numerically calculated in terms of geometrical and physical parameters and the parameter values resulting in maximum response are derived.

  20. Modal Analysis of the Flexible Rotor System of Magnetic Levitation Motors Under Nonlinear Contact%非线性接触下磁悬浮电机柔性转子系统模态分析

    Institute of Scientific and Technical Information of China (English)

    黄梓嫄; 韩邦成; 周银锋

    2014-01-01

    According to the large error problem of modal analysis of the rotor system for magnetic levitation motors, the nonlinear contact behavior between rotor components was considered. The flexible rotor system modal can be analyzed accurately based on the penalty method by optimizing the contact stiffness factor. Through the establishment of the rotor-bearing system finite element analysis model, the ten order natural frequencies and variations of the rotor system under different bearing stiffness were obtained. The simulation results are in good agreement with the test values. This article also analyzed the rotor system with the dynamic balancing ring. The accuracy of results has been proved by the critical speed tests of the experimental prototype.%针对磁悬浮电机转子系统模态分析误差较大的问题,提出考虑转子组件间的非线性接触行为,基于罚函数方法通过修正优化接触刚度因子实现对电机柔性转子系统模态的精确分析。通过建立弹性支承转子-轴承系统有限元分析模型,得到了在不同的支承刚度下转子系统前10阶固有频率的仿真值及变化规律。进行模态测试实验验证,结果表明仿真分析和测试值吻合较好,并对加动平衡环后的转子系统进行固有频率的仿真,其结果的准确性在试验样机穿越临界转速时得到了验证。

  1. Dust levitation about Itokawa's equator

    Science.gov (United States)

    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

  2. Backstepping fuzzy-neural-network control design for hybrid maglev transportation system.

    Science.gov (United States)

    Wai, Rong-Jong; Yao, Jing-Xiang; Lee, Jeng-Dao

    2015-02-01

    This paper focuses on the design of a backstepping fuzzy-neural-network control (BFNNC) for the online levitated balancing and propulsive positioning of a hybrid magnetic levitation (maglev) transportation system. The dynamic model of the hybrid maglev transportation system including levitated hybrid electromagnets to reduce the suspension power loss and the friction force during linear movement and a propulsive linear induction motor based on the concepts of mechanical geometry and motion dynamics is first constructed. The ultimate goal is to design an online fuzzy neural network (FNN) control methodology to cope with the problem of the complicated control transformation and the chattering control effort in backstepping control (BSC) design, and to directly ensure the stability of the controlled system without the requirement of strict constraints, detailed system information, and auxiliary compensated controllers despite the existence of uncertainties. In the proposed BFNNC scheme, an FNN control is utilized to be the major control role by imitating the BSC strategy, and adaptation laws for network parameters are derived in the sense of projection algorithm and Lyapunov stability theorem to ensure the network convergence as well as stable control performance. The effectiveness of the proposed control strategy for the hybrid maglev transportation system is verified by experimental results, and the superiority of the BFNNC scheme is indicated in comparison with the BSC strategy and the backstepping particle-swarm-optimization control system in previous research.

  3. Deformation of Water by a Magnetic Field

    Science.gov (United States)

    Chen, Zijun; Dahlberg, E. Dan

    2011-03-01

    After the discovery that superconducting magnets could levitate diamagnetic objects,1,2 researchers became interested in measuring the repulsion of diamagnetic fluids in strong magnetic fields,3-5 which was given the name "The Moses Effect."5 Both for the levitation experiments and the quantitative studies on liquids, the large magnetic fields necessary were produced by superconducting magnets.

  4. A Magnetic Flux Leakage and Magnetostrictive Guided Wave Hybrid Transducer for Detecting Bridge Cables

    Directory of Open Access Journals (Sweden)

    Jiang Xu

    2012-01-01

    Full Text Available Condition assessment of cables has gained considerable attention for the bridge safety. A magnetic flux leakage and magnetostrictive guided wave hybrid transducer is provided to inspect bridge cables. The similarities and differences between the two methods are investigated. The hybrid transducer for bridge cables consists of an aluminum framework, climbing modules, embedded magnetizers and a ribbon coil. The static axial magnetic field provided by the magnetizers meets the needs of the magnetic flux leakage testing and the magnetostrictive guided wave testing. The magnetizers also provide the attraction for the climbing modules. In the magnetic flux leakage testing for the free length of cable, the coil induces the axial leakage magnetic field. In the magnetostrictive guided wave testing for the anchorage zone, the coil provides a pulse high power variational magnetic field for generating guided waves; the coil induces the magnetic field variation for receiving guided waves. The experimental results show that the transducer with the corresponding inspection system could be applied to detect the broken wires in the free length and in the anchorage zone of bridge cables.

  5. Hybrid nanomaterials: anchoring magnetic molecules on naked gold nanocrystals.

    Science.gov (United States)

    Holmberg, Rebecca J; Hutchings, Amy-Jayne; Habib, Fatemah; Korobkov, Ilia; Scaiano, Juan C; Murugesu, Muralee

    2013-12-16

    The pairing of molecular magnets and nanomaterials couples top-down and bottom-up approaches to nanotechnology; facilitating a unique methodology to the controlled study of interfacial magnetic properties. Attaching Single-Molecule Magnets (SMMs) to "naked" gold nanoparticles is a novel method of exploring various avenues of magnetic nanotechnology, such as drug delivery, information storage, catalysis, and assembly of magnetic-nanostructural motifs. Herein we report the successful capping of laser ablation synthesized "naked" gold nanoparticles with a dinuclear dysprosium complex, while introducing new information regarding the changes in molecular magnetic properties upon surface attachment. We anticipate that this methodology in producing these magneto-plasmonic nanostructures not only provides answers to fundamental questions but also has the potential to provide new avenues to applications including information storage, multimodal imaging, biomedicine, and optoelectronics.

  6. Adsorption mechanism of magnetically separable Fe{sub 3}O{sub 4}/graphene oxide hybrids

    Energy Technology Data Exchange (ETDEWEB)

    Ouyang, Ke [Department of Chemical and Environment Engineering, Wuyi University, Jiangmen, Guangdong 529020 (China); Zhu, Chuanhe [Department of Civil, Construction and Environmental Engineering, Department of Chemical and Biological Engineering, Iowa State University, Ames, IA 50011 (United States); Zhao, Ya; Wang, Leichao [Department of Chemical and Environment Engineering, Wuyi University, Jiangmen, Guangdong 529020 (China); Xie, Shan, E-mail: wyuchemxs@126.com [Department of Chemical and Environment Engineering, Wuyi University, Jiangmen, Guangdong 529020 (China); Wang, Qun, E-mail: qunwang@iastate.edu [Department of Civil, Construction and Environmental Engineering, Department of Chemical and Biological Engineering, Iowa State University, Ames, IA 50011 (United States)

    2015-11-15

    Graphical abstract: A recyclable Fe{sub 3}O{sub 4}/graphene oxide (GO) magnetic hybrid was successfully synthesized via a facile one-pot polylol approach and exhibited an effective adsorption of BPA in aqueous solution. - Highlights: • Magnetically separable Fe{sub 3}O{sub 4}/GO hybrids were synthesized via a facile one-pot polylol approach. • The Fe{sub 3}O{sub 4}/GO hybrid could be easily recovered and met the need of magnetic separation, exhibiting excellent reproducibility and reusability. • The hybrids showed excellent adsorption ability for bisphenol A in aqueous solution. • The effect of pH value, temperature and coexisting ions on the adsorption was studied. • π–π interactions were postulated to be the primary mechanisms of adsorption of BPA on Fe{sub 3}O{sub 4}/GO hybrids. - Abstract: A reclaimable Fe{sub 3}O{sub 4}/graphene oxide (GO) magnetic hybrid was successfully synthesized via a facile one-pot polyol approach and employed as a recyclable adsorbent for Bisphenol A (BPA) in aqueous solutions. The maximum adsorption capacity (q{sub m}) of the Fe{sub 3}O{sub 4}/GO hybrid for BPA was 72.80 mg/g at 273 K. The kinetics of the adsorption process and the adsorption isotherm data were fitted using the Freundlich equation and a pseudo-second-order kinetic model. The results of the thermodynamic parameters ΔH°, ΔS° and ΔG° showed that the adsorption process was exothermic and spontaneous. Furthermore, the reusability of the samples was investigated, and the results indicated that the samples exhibited high stability. The magnetic characterization demonstrated that hybrids were superparamagnetic and could be recovered conveniently by magnetic separation. The strong π–π interaction was determined to be the predominant driving force behind the adsorption of BPA onto the Fe{sub 3}O{sub 4}/GO hybrid. Therefore, the Fe{sub 3}O{sub 4}/GO hybrid could be regarded as a potential adsorbent for wastewater treatment and purification processes.

  7. Synthesis of Ni-Au-ZnO ternary magnetic hybrid nanocrystals with enhanced photocatalytic activity.

    Science.gov (United States)

    Zeng, Deqian; Chen, Yuanzhi; Wang, Zhichao; Wang, Junbao; Xie, Qingshui; Peng, Dong-Liang

    2015-07-14

    The functional synergy between the metal and the semiconductor in metal-semiconductor hybrid nanocrystals with specific structures and morphologies makes them suitable candidates for a wide range of applications. To date, the synthesis and the corresponding properties of ternary metal-semiconductor hetero-nanostructures, especially for hybrid nanocrystals containing magnetic metals, are seldom discussed and thus worthy of extensive research. In this study, we report a nonaqueous approach for the synthesis of Ni-Au-ZnO ternary hybrid nanocrystals with three morphologies, including nanomultipods, matchstick-like nanorods and nanopyramids. In the synthetic strategy, the Ni precursor dissolved in oleylamine was injected into a hot solution containing preformed Au-ZnO nanocrystals with specific morphologies. Then Ni prefers to grow on the unoccupied surfaces of Au, thus forming a hybrid hetero-nanostructure which retains the main morphologies of Au-ZnO nanocrystals. The ultraviolet-visible spectra not only show the band gap absorption of ZnO but also exhibit a broadened and weakened surface plasmon resonance (SPR) band of Au. The Ni-Au-ZnO nanocrystals exhibit much higher photocatalytic efficiency than pure ZnO in the degradation of Rhodamine B. Meanwhile, these hybrid nanocrystals are superparamagnetic at room temperature and can be readily recycled by a magnetic field for reuse. The as-prepared ternary Ni-Au-ZnO hybrid nanocrystals possess plasmonic, magnetic and enhanced photocatalytic properties, and thus are expected to find wide applications in the future.

  8. Diamagnetic levitation promotes osteoclast differentiation from RAW264.7 cells.

    Science.gov (United States)

    Sun, Yu-Long; Chen, Zhi-Hao; Chen, Xiao-Hu; Yin, Chong; Li, Di-Jie; Ma, Xiao-Li; Zhao, Fan; Zhang, Ge; Shang, Peng; Qian, Ai-Rong

    2015-03-01

    The superconducting magnet with a high magnetic force field can levitate diamagnetic materials. In this study, a specially designed superconducting magnet with large gradient high magnetic field (LGHMF), which provides three apparent gravity levels (μg, 1 g, and 2 g), was used to study its influence on receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation from preosteoclast cell line RAW264.7. The effects of LGHMF on the viability, nitric oxide (NO) production, morphology in RAW264.7 cells were detected by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method, the Griess method, and the immunofluorescence staining, respectively. The changes induced by LGHMF in osteoclast formation, mRNA expression, and bone resorption were determined by tartrate-resistant acid phosphatase staining, semiquantity PCR, and bone resorption test, respectively. The results showed that: 1) LGHMF had no lethal effect on osteoclast precursors but attenuated NO release in RAW264.7 cells. 2) Diamagnetic levitation (μg) enhanced both the formation and bone resorption capacity of osteoclast. Moreover, diamagnetic levitation up-regulated mRNA expression of RANK, Cathepsin K, MMP-9, and NFATc1, while down-regulated RunX2 in comparison with controls. Furthermore, diamagnetic levitation induced obvious morphological alterations in osteoclast, including active cytoplasmic peripheral pseudopodial expansion, formation of pedosome belt, and aggregation of actin ring. 3) Magnetic field produced by LGHMF attenuated osteoclast resorption activity. Collectively, LGHMF with combined effects has multiple effects on osteoclast, which attenuated osteoclast resorption with magnetic field, whereas promoted osteoclast differentiation with diamagnetic levitation. Therefore, these findings indicate that diamagnetic levitation could be used as a novel ground-based microgravity simulator, which facilitates bone cell research of weightlessness condition.

  9. Inducing transparency with large magnetic response and group indices by hybrid dielectric metamaterials.

    Science.gov (United States)

    Chen, Cheng-Kuang; Lai, Yueh-Chun; Yang, Yu-Hang; Chen, Chia-Yun; Yen, Ta-Jen

    2012-03-26

    We present metamaterial-induced transparency (MIT) phenomena with enhanced magnetic fields in hybrid dielectric metamaterials. Using two hybrid structures of identical-dielectric-constant resonators (IDRs) and distinct-dielectric-constant resonators (DDRs), we demonstrate a larger group index (ng~354), better bandwidth-delay product (BDP~0.9) than metallic-type metamaterials. The keys to enable these properties are to excite either the trapped mode or the suppressed mode resonances, which can be managed by controlling the contrast of dielectric constants between the dielectric resonators in the hybrid metamaterials.

  10. Design of magnetic akaganeite-cyanobacteria hybrid biofilms

    Energy Technology Data Exchange (ETDEWEB)

    Dahoumane, Si Amar [Universite Paris Diderot (Paris 7), CNRS, UMR 7086, Interfaces, Traitements, Organisation et Dynamique des Systemes (ITODYS), 15 rue Jean de Baif, F-75205 Paris Cedex 13 (France); Djediat, Chakib; Yepremian, Claude; Coute, Alain [Museum National d' Histoire Naturelle (MNHN), Departement RDDM, USM 505, 57 rue Cuvier, F-75005 Paris (France); Fievet, Fernand [Universite Paris Diderot (Paris 7), CNRS, UMR 7086, Interfaces, Traitements, Organisation et Dynamique des Systemes (ITODYS), 15 rue Jean de Baif, F-75205 Paris Cedex 13 (France); Brayner, Roberta, E-mail: roberta.brayner@univ-paris-diderot.f [Universite Paris Diderot (Paris 7), CNRS, UMR 7086, Interfaces, Traitements, Organisation et Dynamique des Systemes (ITODYS), 15 rue Jean de Baif, F-75205 Paris Cedex 13 (France)

    2010-07-30

    Common Anabaena cyanobacteria are shown to form intra-cellularly akaganeite {beta}-FeOOH nanorods of well-controlled size and unusual morphology at room temperature. High-resolution transmission electron microscopy showed that these nanorods present a complex arrangement of pores forming a spongelike structure. These hybrid akaganeite-cyanobacteria were used to form 'one-pot' hybrid biofilms. The hybrid biofilm presents higher coercivity (H{sub c} = 44.6 kA m{sup -1} (560 Oe)) when compared to lyophilized akaganeite-cyanobacteria powder (H{sub c} = 0.8 kA m{sup -1} (10 Oe)) due to the quasi-assembly of the cells on the glass substrate compared to the lyophilized randomly akaganeite-cyanobacteria powder.

  11. Development of an extraction type magnetometer under low temperature and high magnetic fields over 20 T by the hybrid magnet

    Energy Technology Data Exchange (ETDEWEB)

    Koyama, K; Sakakura, R; Watanabe, K [High Field Laboratory for Superconducting materials, Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)], E-mail: kkoyama@imr.tohoku.ac.jp

    2009-03-01

    An extraction-type magnetometer has been developed, which is performed under the low temperature of 0.5-0.6 K using a {sup 3}He-refrigerator and high magnetic fields up to 18 T using a superconducting magnet (SM) and 27 T using a hybrid magnet (HM). Magnetization curves can be measured with the absolute value over 0.0005 emu using SM and 0.005 emu using HM. We confirmed that the resolution is 0.001 emu for SM and 0.005 emu for HM. For demonstrating the ability of the magnetometer, high field magnetization curves of NdO{sub 4}Ag in 0.6-4.2 K are presented.

  12. Fabrication of Magnetic-Antimicrobial-Fluorescent Multifunctional Hybrid Microspheres and Their Properties

    Directory of Open Access Journals (Sweden)

    Ling-Han Xiao

    2013-04-01

    Full Text Available Novel magnetic-antimicrobial-fluorescent multifunctional hybrid microspheres with well-defined nanostructure were synthesized by the aid of a poly(glycidyl methacrylate (PGMA template. The hybrid microspheres were fully characterized by scanning electron microscopy (SEM, transmission electron microscopy (TEM, Fourier transform infrared (FTIR, X-ray diffraction (XRD and digital fluorescence microscope. The as-synthesized microspheres PGMA, amino-modified PGMA (NH2-PGMA and magnetic PGMA (M-PGMA have a spherical shape with a smooth surface and fine monodispersity. M-PGMA microspheres are super-paramagnetic, and their saturated magnetic field is 4.608 emu·g−1, which made M-PGMA efficiently separable from aqueous solution by an external magnetic field. After poly(haxemethylene guanidine hydrochloride (PHGH functionalization, the resultant microspheres exhibit excellent antibacterial performance against both Gram-positive and Gram-negative bacteria. The fluorescence feature originating from the quantum dot CdTe endowed the hybrid microspheres with biological functions, such as targeted localization and biological monitoring functions. Combination of magnetism, antibiosis and fluorescence into one single hybrid microsphere opens up the possibility of the extensive study of multifunctional materials and widens the potential applications.

  13. A low-noise, high-bandwidth magnetically-levitated momentum-wheel for 3-axis attitude control from a single wheel

    OpenAIRE

    Seddon, Jon; Pechev, Alexandre

    2009-01-01

    This paper proposes a new concept for attitude actuation for small satellites that uses active magnetic bearings to support and tilt a spinning rotor to provide 3-axis attitude control of the satellite using a single actuator. A controlled 3D motion in the spinning rotor provides a conventional torque output about the momentum axis and a gyroscopic torque output about any direction in the plane normal to the spinning axis. Therefore, a single tilting momentum-wheel can generate torque along t...

  14. Exchange coupling in hybrid anisotropy magnetic multilayers quantified by vector magnetometry

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, C., E-mail: C.Morrison.2@warwick.ac.uk; Miles, J. J.; Thomson, T. [School of Computer Science, University of Manchester, Manchester M13 9PL (United Kingdom); Anh Nguyen, T. N. [Materials Physics, School of ICT, KTH Royal Institute of Technology, Electrum 229, 164 40 Kista (Sweden); Spintronics Research Group, Laboratory for Nanotechnology (LNT), VNU-HCM, Ho Chi Minh City (Viet Nam); Fang, Y.; Dumas, R. K. [Department of Physics, University of Gothenburg, 412 96 Gothenburg (Sweden); Åkerman, J. [Materials Physics, School of ICT, KTH Royal Institute of Technology, Electrum 229, 164 40 Kista (Sweden); Department of Physics, University of Gothenburg, 412 96 Gothenburg (Sweden)

    2015-05-07

    Hybrid anisotropy thin film heterostructures, where layers with perpendicular and in-plane anisotropy are separated by a thin spacer, are novel materials for zero/low field spin torque oscillators and bit patterned media. Here, we report on magnetization reversal and exchange coupling in a archetypal Co/Pd (perpendicular)-NiFe (in-plane) hybrid anisotropy system studied using vector vibrating sample magnetometry. This technique allows us to quantify the magnetization reversal in each individual magnetic layer, and measure of the interlayer exchange as a function of non-magnetic spacer thickness. At large (>1 nm) spacer thicknesses Ruderman-Kittel-Kasuya-Yosida-like exchange dominates, with orange-peel coupling providing a significant contribution only for sub-nm spacer thickness.

  15. Hybrid bronchoscope tracking using a magnetic tracking sensor and image registration.

    Science.gov (United States)

    Mori, Kensaku; Deguchi, Daisuke; Akiyama, Kenta; Kitasaka, Takayuki; Maurer, Calvin R; Suenaga, Yasuhito; Takabatake, Hirotsugu; Mori, Masaki; Natori, Hiroshi

    2005-01-01

    In this paper, we propose a hybrid method for tracking a bronchoscope that uses a combination of magnetic sensor tracking and image registration. The position of a magnetic sensor placed in the working channel of the bronchoscope is provided by a magnetic tracking system. Because of respiratory motion, the magnetic sensor provides only the approximate position and orientation of the bronchoscope in the coordinate system of a CT image acquired before the examination. The sensor position and orientation is used as the starting point for an intensity-based registration between real bronchoscopic video images and virtual bronchoscopic images generated from the CT image. The output transformation of the image registration process is the position and orientation of the bronchoscope in the CT image. We tested the proposed method using a bronchial phantom model. Virtual breathing motion was generated to simulate respiratory motion. The proposed hybrid method successfully tracked the bronchoscope at a rate of approximately 1 Hz.

  16. 抗磁性物质磁悬浮方法在空间生物学与生物技术中的应用%Application of Magnetic Levitation of Diamagnetic Materials for Space Biology and Biotechnology

    Institute of Scientific and Technical Information of China (English)

    曹建平; 尹大川; 骞爱荣; 田宗成; 续惠云; 黄勇平; 商澎

    2011-01-01

    Weightlessness is one of the important physical characteristics of space environment. For several decades, weightless environment in space has been used for investigation and exploration in many scientific fields. Because of shortage and limit of experiments in real space environment, many kinds of ground-based simulated techniques and methods inspired by space experimental environments were developed for simulating the weightlessness of space environment and the effects of weightlessness. However, these techniques and methods have limitations not only in principle, but also in application for space biology and biotechnology. In this paper, we introduced a new technique for simulating weightlessness, magnetic levitation of diamagnetic materials produced by large gradlient high magnetic field, and summarized the research progress by using this technique in crystal growth of proteins, molecular cell biology and integrated biology.%失重是特定空间运动条件下的重要环境物理特征之一,一般以微重力环境来表示.几十年来人类利用空间失重环境进行了多学科领域的科学研究与探索.由于真实空间失重环境下科学实验机会稀少,人类为研究空间失重环境或效应,开发了多种地基的空间模拟实验技术方法.然而,对于空间生物学和空间生物技术研究而言,已有的各种模拟实验技术手段在原理上和应用上均存在一定的局限性.本文介绍了抗磁性物质在大梯度强磁场中的悬浮现象,及将其用于模拟空间失重环境的方法与原理;简述了近年来利用抗磁性物质悬浮方法进行生物大分子晶体生长、分子细胞生物学及整体生物学等方面研究与应用的进展.

  17. Directed self-assembly of mesoscopic electronic components into sparse arrays with controlled orientation using diamagnetic levitation

    Energy Technology Data Exchange (ETDEWEB)

    Tkachenko, Anton, E-mail: tkacha@rpi.edu; Lu, James J.-Q.

    2015-07-01

    This paper presents a directed self-assembly (DSA) approach for assembling small electronic components, such as semiconductor dies, into sparse 2D arrays using diamagnetic levitation. The dies attached to a diamagnetic layer can be levitated at a room temperature over a stage made of magnets arranged in a checkerboard pattern. By selecting a proper die design, levitation height, and vibration pattern of the magnetic stage we assemble the dies into a regular 2D array with a specific lateral and vertical orientation of the dies. The assembled dies are transferred to a receiving substrate using capillary force. - Highlights: • Self-assembly of semiconductor dies into arrays using diamagnetic levitation. • Control over the die orientation in vertical and lateral dimensions. • Simulation shows good scalability of assembly time with the number of dies. • Suitable for assembly of LED panels, displays and microcell photovoltaics.

  18. A Methodology for Modeling Electromagnetic Confinement Systems: Application to Levitation Melting

    Science.gov (United States)

    El-Kaddah, Nagy; Natarajan, Thinium T.

    A modeling strategy is presented for computing the electromagnetic field and the shape of the molten metal in electromagnetic confinement systems. This strategy involves the use of a hybrid finite element/integral technique to calculate the electromagnetic field and force distribution in the melt. The free surface shape is determined from minimization of electromagnetic, gravitational and surface tension energies using the Lagrange method of multipliers. This approach was applied to model the electromagnetic levitation melting process. The model was found to accurately predict the measured shape of levitated droplets.

  19. A Hybrid Nonlinear Control Scheme for Active Magnetic Bearings

    Science.gov (United States)

    Xia, F.; Albritton, N. G.; Hung, J. Y.; Nelms, R. M.

    1996-01-01

    A nonlinear control scheme for active magnetic bearings is presented in this work. Magnet winding currents are chosen as control inputs for the electromechanical dynamics, which are linearized using feedback linearization. Then, the desired magnet currents are enforced by sliding mode control design of the electromagnetic dynamics. The overall control scheme is described by a multiple loop block diagram; the approach also falls in the class of nonlinear controls that are collectively known as the 'integrator backstepping' method. Control system hardware and new switching power electronics for implementing the controller are described. Various experiments and simulation results are presented to demonstrate the concepts' potentials.

  20. 超导磁悬浮微飞轮系统设计与测试%TESTING AND DESIGN OF SUPERCONDUCTING MAGNETIC LEVITATION MICRO-FLYWHEEL SYSTEM

    Institute of Scientific and Technical Information of China (English)

    程千兵; 武俊峰; 吴一辉; 宣明

    2011-01-01

    A prototype of the micro-flywheel system with the superconducting magnetic bearing has been designed. This micro-flywheel system adopts the superconducting magnetic bearing as the supporting mechanism, and the brushless planar DC motor as driving device. The maximum speed of the flywheel rotor is 15000rpm at 14. 4V and 0. 36A. Through the test of flywheel system's free spin-down curve of speed with the mechanical bearings and the superconducting magnetic bearing, the friction loss of different bearing is obtained, and the equivalent friction coefficient of the superconducting flywheel system is 0. 001-0. 007 under different rotational speed. Equivalent friction coefficient of the superconductivity hearing is found to increase along with the speed. The analysis indicated that the superconductivity magnetic bearing eddy current loss and the hysteretic loss also increase along with the rotational speed.%设计了一种基于超导磁悬浮轴承的微飞轮系统样机.该微飞轮系统以超导磁悬浮轴承作为支撑机构,以平面直流无刷电机作为驱动装置,在输入电压14.4V电流0.36A时,飞轮转子在空气中最高转速可达到15000rpm.通过对采用机械轴承的飞轮系统和超导磁悬浮飞轮系统的自由降速曲线测试,求出不同轴承的摩擦损耗,并得到超导磁悬浮飞轮系统在不同转速下的等效摩擦系数为0.001-0.007,发现超导轴承等效摩擦系数随着速度的增加而增加,分析表明随着转速增加,超导磁悬浮轴承涡流损耗和磁滞损耗增加.