WorldWideScience

Sample records for strong pulsed electromagnetic

  1. Strong electromagnetic pulses generated in high-intensity laser-matter interactions

    Science.gov (United States)

    Rączka, P.; Dubois, J.-L.; Hulin, S.; Rosiński, M.; Zaraś-Szydłowska, A.; Badziak, J.

    2018-01-01

    Results are reported of an experiment performed at the Eclipse laser facility in CELIA, Bordeaux, on the generation of strong electromagnetic pulses. Measurements were performed of the target neutralization current, the total target charge and the tangential component of the magnetic field for the laser energies ranging from 45 mJ to 92 mJ with the pulse duration approximately 40 fs, and for the pulse durations ranging from 39 fs to 1000 fs, with the laser energy approximately 90 mJ. It was found that the values obtained for thick (mm scale) Cu targets are visibly higher than values reported in previous experiments, which is argued to be a manifestation of a strong dependence of the target electric polarization process on the laser contrast and hence on the amount of preplasma. It was also found that values obtained for thin (μm scale) Al foils were visibly higher than values for thick Cu targets, especially for pulse durations longer than 100 fs. The correlations between the total target charge versus the maximum value of the target neutralization current, and the maximum value of the tangential component of the magnetic field versus the total target charge were analysed. They were found to be in very good agreement with correlations seen in data from previous experiments, which provides a good consistency check on our experimental procedures.

  2. Dynamic Test Method Based on Strong Electromagnetic Pulse for Electromagnetic Shielding Materials with Field-Induced Insulator-Conductor Phase Transition

    Science.gov (United States)

    Wang, Yun; Zhao, Min; Wang, Qingguo

    2018-01-01

    In order to measure the pulse shielding performance of materials with the characteristic of field-induced insulator-conductor phase transition when materials are used for electromagnetic shielding, a dynamic test method was proposed based on a coaxial fixture. Experiment system was built by square pulse source, coaxial cable, coaxial fixture, attenuator, and oscilloscope and insulating components. S11 parameter of the test system was obtained, which suggested that the working frequency ranges from 300 KHz to 7.36 GHz. Insulating performance is good enough to avoid discharge between conductors when material samples is exposed in the strong electromagnetic pulse field up to 831 kV/m. This method is suitable for materials with annular shape, certain thickness and the characteristic of field-induced insulator-conductor phase transition to get their shielding performances of strong electromagnetic pulse.

  3. Strong electromagnetic pulses generated in laser-matter interactions with 10TW-class fs laser

    Science.gov (United States)

    Rączka, Piotr; Rosiński, Marcin; Zaraś-Szydłowska, Agnieszka; Wołowski, Jerzy; Badziak, Jan

    2018-01-01

    The results of an experiment on the generation of electromagnetic pulses (EMP) in the interaction of 10TW fs pulses with thick (mm scale) and thin foil (μm scale) targets are described. Such pulses, with frequencies in the GHz range, may pose a threat to safe and reliable operation of high-power, high-intensity laser facilities. The main point of the experiment is to investigate the fine temporal structure of such pulses using an oscilloscope capable of measurements at very high sampling rate. It is found that the amazing reproducibility of such pulses is confirmed at this high sampling rate. Furthermore, the differences between the EMP signals generated from thick and thin foil targets are clearly seen, which indicates that besides electric polarization of the target and the target neutralization current there may be other factors essential for the EMP emission.

  4. Strong electromagnetic pulses generated in high-intensity short-pulse laser interactions with thin foil targets

    Science.gov (United States)

    Rączka, P.; Dubois, J.-L.; Hulin, S.; Tikhonchuk, V.; Rosiński, M.; Zaraś-Szydłowska, A.; Badziak, J.

    2017-12-01

    Measurements are reported of the target neutralization current, the target charge, and the tangential component of the magnetic field generated as a result of laser-target interaction by pulses with the energy in the range of 45 mJ to 92 mJ on target and the pulse duration from 39 fs to 1000 fs. The experiment was performed at the Eclipse facility in CELIA, Bordeaux. The aim of the experiment was to extend investigations performed for the thick (mm scale) targets to the case of thin (micrometer thickness) targets in a way that would allow for a straightforward comparison of the results. We found that thin foil targets tend to generate 20 to 50 percent higher neutralization current and the target charge than the thick targets. The measurement of the tangential component of the magnetic field had shown that the initial spike is dominated by the 1 ns pulse consistent with the 1 ns pulse of the neutralization current, but there are some differences between targets of different type on sub-ns scale, which is an effect going beyond a simple picture of the target acting as an antenna. The sub-ns structure appears to be reproducible to surprising degree. We found that there is in general a linear correlation between the maximum value of the magnetic field and the maximum neutralization current, which supports the target-antenna picture, except for pulses hundreds of fs long.

  5. Theory of atoms in strong, pulsed electromagnetic fields: 2, A free electron and a harmonically bound electron

    International Nuclear Information System (INIS)

    Multiple scale methods are used to treat several ingredients of the theory of atoms in strong electromagnetic fields. First, a focused electromagnetic field is expanded. Second, a classical electron is described giving the ponderomotive potential. Third, the quantum electron is treated in the WKB approximation. Fourth, the one dimensional quantum harmonic oscillator is solved; and last the one dimensional square well, showing the low intensity limit of the theory

  6. Particle acceleration by electromagnetic pulses

    International Nuclear Information System (INIS)

    Lai, H.M.

    1982-01-01

    Particle interaction with plane electromagnetic pulses is studied. It is shown that particle acceleration by a wavy pulse, depending on the shape of the pulse, may not be small. Further, a diffusive-type particle acceleration by multiple weak pulses is described and discussed. (author)

  7. Relativistically strong electromagnetic radiation in a plasma

    Science.gov (United States)

    Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Kiriyama, H.; Kondo, K.

    2016-03-01

    Physical processes in a plasma under the action of relativistically strong electromagnetic waves generated by high-power lasers have been briefly reviewed. These processes are of interest in view of the development of new methods for acceleration of charged particles, creation of sources of bright hard electromagnetic radiation, and investigation of macroscopic quantum-electrodynamical processes. Attention is focused on nonlinear waves in a laser plasma for the creation of compact electron accelerators. The acceleration of plasma bunches by the radiation pressure of light is the most efficient regime of ion acceleration. Coherent hard electromagnetic radiation in the relativistic plasma is generated in the form of higher harmonics and/or electromagnetic pulses, which are compressed and intensified after reflection from relativistic mirrors created by nonlinear waves. In the limit of extremely strong electromagnetic waves, radiation friction, which accompanies the conversion of radiation from the optical range to the gamma range, fundamentally changes the behavior of the plasma. This process is accompanied by the production of electron-positron pairs, which is described within quantum electrodynamics theory.

  8. Electromagnetic Pulse Coupling Analysis of Electronic Equipment

    OpenAIRE

    Hong Lei; Qingying LI

    2017-01-01

    High-intensity nuclear explosion caused by high-altitude nuclear electromagnetic pulse through the antenna, metal cables, holes and other channels, coupled with very high energy into the electronic device, and cause serious threats. In this paper, the mechanism, waveform, coupling path and damage effect of nuclear electromagnetic pulse is analyzed, and the coupling mechanism of nuclear electromagnetic pulse is studied.

  9. Ultrarelativistic electromagnetic pulses in plasmas

    Science.gov (United States)

    Ashour-Abdalla, M.; Leboeuf, J. N.; Tajima, T.; Dawson, J. M.; Kennel, C. F.

    1981-01-01

    The physical processes of a linearly polarized electromagnetic pulse of highly relativistic amplitude in an underdense plasma accelerating particles to very high energies are studied through computer simulation. An electron-positron plasma is considered first. The maximum momenta achieved scale as the square of the wave amplitude. This acceleration stops when the bulk of the wave energy is converted to particle energy. The pulse leaves behind as a wake a vacuum region whose length scales as the amplitude of the wave. The results can be explained in terms of a snow plow or piston-like action of the radiation on the plasma. When a mass ratio other than unity is chosen and electrostatic effects begin to play a role, first the ion energy increases faster than the electron energy and then the electron energy catches up later, eventually reaching the same value.

  10. Electromagnetic pulses at the boundary of a nonlinear plasma

    International Nuclear Information System (INIS)

    Satorius, E.H.

    1975-01-01

    An investigation was made of the behavior of strong electromagnetic pulses at the boundary of a nonlinear, cold, collisionless, and uniform plasma. The nonlinearity considered here is due to the nonlinear terms in the fluid equation which is used to describe the plasma. Two cases are studied. First, the case where there is a voltage pulse applied across the plane boundary of a semi-infinite, nonlinear plasma. Two different voltage pulses are considered, i.e., a delta function pulse and a suddenly turned-on sinusoidal pulse. The resulting electromagnetic fields propagating in the nonlinear plasma are found in this case. In the second case, the reflection of incident E-polarized and H-polarized, electromagnetic pulses at various angles of incidence from a nonlinear, semi-infinite plasma are considered. Again, two forms of incident pulses are considered: a delta function pulse and a suddenly turned-on sinusoidal pulse. In case two, the reflected electromagnetic fields are found. In both cases, the method used for finding the fields is to first solve the fluid equation (which describes the plasma) for the nonlinear conduction current in terms of the electric field using a perturbation method (since the nonlinear effects are assumed to be small). Next, this current is substituted into Maxwell's equations, and finally the electromagnetic fields which satisfy the boundary conditions are found. (U.S.)

  11. Development of a strong electromagnet wiggler

    International Nuclear Information System (INIS)

    Burns, M.J.; Deis, G.A.; Holmes, R.H.; Van Maren, R.D.; Halbach, K.

    1987-01-01

    The Strong Electromagnet (SEM) wiggler is a permanent magnet-assisted electromagnet under development at the Lawrence Livermore National Laboratory (LLNL) as part of the Induction Linac Free-Electron-Laser (IFEL) program. This concept uses permanent magnets within the wiggler to provide a reverse bias flux in the iron and thus delay the onset of magnetic saturation. The electromagnet coils determine the wiggler field and operate at low current densities by virtue of their placement away from the midplane. We describe here the design approach used and test data from a 7-period wiggler prototype that includes curved pole tips to provide wiggle-plane focusing. 7 refs

  12. Atom collisions in a strong electromagnetic field

    International Nuclear Information System (INIS)

    Smirnov, V.S.; Chaplik, A.V.

    1976-01-01

    It is shown that the long-range part of interatomic interaction is considerably altered in a strong electromagnetic field. Instead of the van der Waals law the potential asymptote can best be described by a dipole-dipole R -3 law. Impact broadening and the line shift in a strong nonresonant field are calculated. The possibility of bound states of two atoms being formed in a strong light field is discussed

  13. Combine material against electromagnetic pulse disturbance

    International Nuclear Information System (INIS)

    Liu Yan

    2004-01-01

    A novel combined material is introduced, which is hard against electromagnetic pulse disturbance, The attenuation characteristics and the penetration probability of the combine material is discussed in detail. The penetration probability of electromagnetic wave is calculated approximately and the characteristic curve is measured for this material. (authors)

  14. Ultra-Wideband, Short Pulse Electromagnetics 9

    CERN Document Server

    Rachidi, Farhad; Kaelin, Armin; Sabath, Frank; UWB SP 9

    2010-01-01

    Ultra-wideband (UWB), short-pulse (SP) electromagnetics are now being used for an increasingly wide variety of applications, including collision avoidance radar, concealed object detection, and communications. Notable progress in UWB and SP technologies has been achieved by investigations of their theoretical bases and improvements in solid-state manufacturing, computers, and digitizers. UWB radar systems are also being used for mine clearing, oil pipeline inspections, archeology, geology, and electronic effects testing. Ultra-wideband Short-Pulse Electromagnetics 9 presents selected papers of deep technical content and high scientific quality from the UWB-SP9 Conference, which was held from July 21-25, 2008, in Lausanne, Switzerland. The wide-ranging coverage includes contributions on electromagnetic theory, time-domain computational techniques, modeling, antennas, pulsed-power, UWB interactions, radar systems, UWB communications, and broadband systems and components. This book serves as a state-of-the-art r...

  15. Electromagnetic pulses, localized and causal

    Science.gov (United States)

    Lekner, John

    2018-01-01

    We show that pulse solutions of the wave equation can be expressed as time Fourier superpositions of scalar monochromatic beam wave functions (solutions of the Helmholtz equation). This formulation is shown to be equivalent to Bateman's integral expression for solutions of the wave equation, for axially symmetric solutions. A closed-form one-parameter solution of the wave equation, containing no backward-propagating parts, is constructed from a beam which is the tight-focus limit of two families of beams. Application is made to transverse electric and transverse magnetic pulses, with evaluation of the energy, momentum and angular momentum for a pulse based on the general localized and causal form. Such pulses can be represented as superpositions of photons. Explicit total energy and total momentum values are given for the one-parameter closed-form pulse.

  16. Electromagnetic or other directed energy pulse launcher

    Science.gov (United States)

    Ziolkowski, Richard W.

    1990-01-01

    The physical realization of new solutions of wave propagation equations, such as Maxwell's equations and the scaler wave equation, produces localized pulses of wave energy such as electromagnetic or acoustic energy which propagate over long distances without divergence. The pulses are produced by driving each element of an array of radiating sources with a particular drive function so that the resultant localized packet of energy closely approximates the exact solutions and behaves the same.

  17. Electromagnetic processes in strong crystalline fields

    CERN Multimedia

    2007-01-01

    We propose a number of new investigations on aspects of radiation from high energy electron and positron beams (10-300 GeV) in single crystals and amorphous targets. The common heading is radiation emission by electrons and positrons in strong electromagnetic fields, but as the setup is quite versatile, other related phenomena in radiation emission can be studied as well. The intent is to clarify the role of a number of important aspects of radiation in strong fields as e.g. observed in crystals. We propose to measure trident 'Klein-like' production in strong crystalline fields, 'crystalline undulator' radiation, 'sandwich' target phenomena, LPM suppression of pair production as well as axial and planar effects in contributions of spin to the radiation.

  18. Electromagnetic Processes in strong Crystalline Fields

    CERN Multimedia

    2007-01-01

    We propose a number of new investigations on aspects of radiation from high energy electron and positron beams (10-300 GeV) in single crystals and amorphous targets. The common heading is radiation emission by electrons and positrons in strong electromagnetic fields, but as the setup is quite versatile, other related phenomena in radiation emission can be studied as well. The intent is to clarify the role of a number of important aspects of radiation in strong fields as e.g. observed in crystals. We propose to measure trident 'Klein-like' production in strong crystalline fields, 'crystalline undulator' radiation, 'sandwich' target phenomena, LPM suppression of pair production as well as axial and planar effects in contributions of spin to the radiation.

  19. Electromagnetic coupling of high-altitude, nuclear electromagnetic pulses

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    We have used scale models to measure the predicted coupling of electromagnetic fields simulating the effects of high-altitude nuclear electromagnetic pulses (HEMP) on the interior surfaces of electronic components. Predictive tools for exterior coupling are adequate. For interior coupling, however, such tools are in their infancy. Our methodological approach combines analytical, computational, and laboratory techniques in a complementary way to take advantage of their separate strengths. Computer models are a promising tool, as they can be used to treat complex objects with arbitrary shapes, dielectrics, and cables, and multiple apertures. Laboratory tests can expand the domain of investigation even further

  20. A two-dimensional system-generated electromagnetic pulse

    International Nuclear Information System (INIS)

    Wang Taichun; Wang Yuzhi

    1986-01-01

    The relations between IEMP (Internal Electromagnetic Pulse) and SGEMP (System-Generated Electromagnetic Pulse) are discussed. Numerical results of SGEMP are obtained under the conditions that the objects are exposed to X-rays

  1. Electromagnetic modes in cold magnetized strongly coupled plasmas

    OpenAIRE

    Tkachenko, I. M.; Ortner, J.; Rylyuk, V. M.

    1999-01-01

    The spectrum of electromagnetic waves propagating in a strongly coupled magnetized fully ionized hydrogen plasma is found. The ion motion and damping being neglected, the influence of the Coulomb coupling on the electromagnetic spectrum is analyzed.

  2. Charged particle interaction with a chirped electromagnetic pulse

    NARCIS (Netherlands)

    Khachatryan, A.G.; Boller, Klaus J.; van Goor, F.A.

    2003-01-01

    It is found that a charged particle can get a net energy gain from the interaction with an electromagnetic chirped pulse. Theoretically, the energy gain increases with the pulse amplitude and with the relative frequency variation in the pulse.

  3. Strong permanent magnet-assisted electromagnetic undulator

    Science.gov (United States)

    Halbach, Klaus

    1988-01-01

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

  4. Ultra-Wideband Electromagnetic Pulse Propagation through Causal Media

    Science.gov (United States)

    2016-03-04

    AFRL-AFOSR-VA-TR-2016-0112 Ultra-Wideband Electromagnetic Pulse Propagation through Causal Media Natalie Cartwright RESEARCH FOUNDATION OF STATE... Electromagnetic Pulse Propagation through Causal Media 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-13-1-0013 5c.  PROGRAM ELEMENT NUMBER 61102F 6...SUPPLEMENTARY NOTES 14. ABSTRACT When an electromagnetic pulse travels through a dispersive material each frequency of the transmitted pulse changes in both

  5. Strong and superstrong pulsed magnetic fields generation

    CERN Document Server

    Shneerson, German A; Krivosheev, Sergey I

    2014-01-01

    Strong pulsed magnetic fields are important for several fields in physics and engineering, such as power generation and accelerator facilities. Basic aspects of the generation of strong and superstrong pulsed magnetic fields technique are given, including the physics and hydrodynamics of the conductors interacting with the field as well as an account of the significant progress in generation of strong magnetic fields using the magnetic accumulation technique. Results of computer simulations as well as a survey of available field technology are completing the volume.

  6. Nonlinear generation of ultra-short electromagnetic pulses in plasmas

    International Nuclear Information System (INIS)

    Isanin, A.; Bulanov, S.S.; Kamenets, F.; Pegoraro, F.

    2005-01-01

    When a low-frequency relativistic soliton interacts with the electron density modulations of a wake plasma wave, part of the soliton electromagnetic energy is reflected in the form of an extremely short and ultraintense electromagnetic pulse. By computing analytically the spectra of the reflected and of the transmitted electromagnetic pulses, we show that the reflected wave has the form of a single cycle attosecond pulse

  7. Relativistic rapprochement of electromagnetic and strong interactions

    International Nuclear Information System (INIS)

    Strel'tsov, V.N.

    1995-01-01

    On the basis of the Lienard-Wiechert potential and the relativistic Yukawa potential it is shown that the corresponding interactions with velocity growth increase differently (the electromagnetic one increases faster). According to preliminary estimations they are equivalent, at distances of the 'action radius' of nuclear forces, at γ≅ 960, where γ is the Lorentz factor. 2 refs

  8. Electromagnetic sinc Schell-model pulses in dispersive media

    International Nuclear Information System (INIS)

    Tang, Miaomiao; Zhao, Daomu; Zhu, Yingbin; Ang, Lay-Kee

    2016-01-01

    A class of random electromagnetic pulsed sources with sinc Schell-model correlations is introduced. Analytical formulas for the electromagnetic pulses generated by such pulsed sources propagating in dispersive media are derived. It is shown that the temporal intensity distribution of this new type of pulse exhibits unique propagation features, such as reshaping its average intensity from the initial Gaussian profile to a double-layer flat-top distribution at far field. The effects, arising from the source temporal coherent length and the dispersion coefficient, on the profiles of the temporal intensity distribution and the temporal degree of polarization are analyzed in detail. The results presented here demonstrate the potential of coherence modulation for pulse shaping applications. - Highlights: • We introduced a new class of random electromagnetic pulsed sources. • We derived its analytical formulas for the electromagnetic pulses in dispersive media. • It is shown that its temporal intensity distribution exhibits unique propagation features.

  9. Electromagnetic field, excited by monodirected X-radiation pulse

    International Nuclear Information System (INIS)

    Zhemerov, A.V.; Metelkin, E.V.

    1994-01-01

    Parameters of electromagnetic field, generated in the atmosphere by monodirected pulse source of X radiation located at the altitude of approximately several kilometers have been estimated by the method of delayed potentials. The source radiation is directed towards the Earth surface. The conclusion was made that restricted areas of approximately 1 km with considerable pulse electromagnetic fields can be created on the Earth surface

  10. Fast Atom Ionization in Strong Electromagnetic Radiation

    Science.gov (United States)

    Apostol, M.

    2018-05-01

    The Goeppert-Mayer and Kramers-Henneberger transformations are examined for bound charges placed in electromagnetic radiation in the non-relativistic approximation. The consistent inclusion of the interaction with the radiation field provides the time evolution of the wavefunction with both structural interaction (which ensures the bound state) and electromagnetic interaction. It is shown that in a short time after switching on the high-intensity radiation the bound charges are set free. In these conditions, a statistical criterion is used to estimate the rate of atom ionization. The results correspond to a sudden application of the electromagnetic interaction, in contrast with the well-known ionization probability obtained by quasi-classical tunneling through classically unavailable non-stationary states, or other equivalent methods, where the interaction is introduced adiabatically. For low-intensity radiation the charges oscillate and emit higher-order harmonics, the charge configuration is re-arranged and the process is resumed. Tunneling ionization may appear in these circumstances. Extension of the approach to other applications involving radiation-induced charge emission from bound states is discussed, like ionization of molecules, atomic clusters or proton emission from atomic nuclei. Also, results for a static electric field are included.

  11. Characteristics of Electromagnetic Pulse Propagation in Metal

    Science.gov (United States)

    Namkung, M.; Wincheski, B.; Nath, S.; Fulton, J. P.

    2004-01-01

    It is well known that the solution of the diffusion equation for an electromagnetic field with a time harmonic term, e(sup iwt), is in the form of a traveling wave whose amplitude attenuates over distance into a conducting medium. As the attenuation is an increasing function of frequency, the high frequency components attenuate more rapidly than those of low ones upon entering a well conducting object. At the same time, the phase velocity of an individual component is also an increasing function of frequency causing a broadening of the pulse traveling inside a conductor. In the results of our previous study of numerical simulations, the problem of using a gaussian input pulse was immediately clear. First, having the dominant frequency components distributed around zero, the movement of the peak was not well defined. Second, with the amplitude of fourier components varying slowly over a wide range, the dispersion-induced blurring of the peak position was seen to be severe. For the present study, we have used a gaussian modulated single frequency sinusoidal wave, i. e., the carrier, as an input pulse in an effort to improve the issues related to the unclear movement of peak and dispersion as described above. This was based on the following two anticipated advantages: First, the packet moves in a conductor at the group velocity calculated at the carrier frequency, which means it is well controllable. Second, the amplitude of frequency components other than that of the carrier can be almost negligible, such that the effect of dispersion can be significantly reduced. A series of experiments of transmitting electromagnetic pulses through aluminum plates of various thickness was performed to test the validity of the above points. The results of numerical simulation based on wave propagation are discussed with respect to the experimental results. Finally, a simple simulation was performed based on diffusion of a continuous sine wave input and the results are compared with

  12. Biological effects of electromagnetic fields and recently updated safety guidelines for strong static magnetic fields

    International Nuclear Information System (INIS)

    Yamaguchi-Sekino, Sachiko; Sekino, Masaki; Ueno, Shoogo

    2011-01-01

    Humans are exposed daily to artificial and naturally occurring magnetic fields that originate from many different sources. We review recent studies that examine the biological effects of and medical applications involving electromagnetic fields, review the properties of static and pulsed electromagnetic fields that affect biological systems, describe the use of a pulsed electromagnetic field in combination with an anticancer agent as an example of a medical application that incorporates an electromagnetic field, and discuss the recently updated safety guidelines for static electromagnetic fields. The most notable modifications to the 2009 International Commission on Non-Ionizing Radiation Protection guidelines are the increased exposure limits, especially for those who work with or near electromagnetic fields (occupational exposure limits). The recommended increases in exposure were determined using recent scientific evidence obtained from animal and human studies. Several studies since the 1994 publication of the guidelines have examined the effects on humans after exposure to high static electromagnetic fields (up to 9.4 tesla), but additional research is needed to ascertain further the safety of strong electromagnetic fields. (author)

  13. Biological effects of electromagnetic fields and recently updated safety guidelines for strong static magnetic fields.

    Science.gov (United States)

    Yamaguchi-Sekino, Sachiko; Sekino, Masaki; Ueno, Shoogo

    2011-01-01

    Humans are exposed daily to artificial and naturally occurring magnetic fields that originate from many different sources. We review recent studies that examine the biological effects of and medical applications involving electromagnetic fields, review the properties of static and pulsed electromagnetic fields that affect biological systems, describe the use of a pulsed electromagnetic field in combination with an anticancer agent as an example of a medical application that incorporates an electromagnetic field, and discuss the recently updated safety guidelines for static electromagnetic fields. The most notable modifications to the 2009 International Commission on Non-Ionizing Radiation Protection guidelines are the increased exposure limits, especially for those who work with or near electromagnetic fields (occupational exposure limits). The recommended increases in exposure were determined using recent scientific evidence obtained from animal and human studies. Several studies since the 1994 publication of the guidelines have examined the effects on humans after exposure to high static electromagnetic fields (up to 9.4 tesla), but additional research is needed to ascertain further the safety of strong electromagnetic fields.

  14. Pulsed Electromagnetic Acceleration of Plasma: A Review

    Science.gov (United States)

    Thio, Y. C. Francis; Turchi, Peter J.; Markusic, Thomas E.; Cassibry, Jason T.; Sommer, James; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    Much have been learned in the acceleration mechanisms involved in accelerating a plasma electromagnetically in the laboratory over the last 40 years since the early review by Winston Bostik of 1963, but the accumulated understanding is very much scattered throughout the literature. This literature extends back at least to the early sixties and includes Rosenbluth's snowplow model, discussions by Ralph Lovberg, Colgate's boundary-layer model of a current sheet, many papers from the activity at Columbia by Robert Gross and his colleagues, and the relevant, 1-D unsteady descriptions developed from the U. of Maryland theta-pinch studies. Recent progress on the understanding of the pulsed penetration of magnetic fields into collisionless or nearly collisionless plasmas are also be reviewed. Somewhat more recently, we have the two-dimensional, unsteady results in the collisional regime associated with so-called wall-instability in large radius pinch discharges and also in coaxial plasma guns (e.g., Plasma Flow Switch). Among other things, for example, we have the phenomenon of a high- density plasma discharge propagating in a cooaxial gun as an apparently straight sheet (vs paraboloid) because mass re-distribution (on a microsecond timescale) compensates for the 1/r- squared variation of magnetic pressure. We will attempt to collate some of this vast material and bring some coherence tc the development of the subject.

  15. Electromagnetic pulsed thermography for natural cracks inspection

    Science.gov (United States)

    Gao, Yunlai; Tian, Gui Yun; Wang, Ping; Wang, Haitao; Gao, Bin; Woo, Wai Lok; Li, Kongjing

    2017-01-01

    Emerging integrated sensing and monitoring of material degradation and cracks are increasingly required for characterizing the structural integrity and safety of infrastructure. However, most conventional nondestructive evaluation (NDE) methods are based on single modality sensing which is not adequate to evaluate structural integrity and natural cracks. This paper proposed electromagnetic pulsed thermography for fast and comprehensive defect characterization. It hybrids multiple physical phenomena i.e. magnetic flux leakage, induced eddy current and induction heating linking to physics as well as signal processing algorithms to provide abundant information of material properties and defects. New features are proposed using 1st derivation that reflects multiphysics spatial and temporal behaviors to enhance the detection of cracks with different orientations. Promising results that robust to lift-off changes and invariant features for artificial and natural cracks detection have been demonstrated that the proposed method significantly improves defect detectability. It opens up multiphysics sensing and integrated NDE with potential impact for natural understanding and better quantitative evaluation of natural cracks including stress corrosion crack (SCC) and rolling contact fatigue (RCF). PMID:28169361

  16. Electromagnetic emission of a strongly charged oscillating droplet

    Science.gov (United States)

    Grigor'ev, A. I.; Kolbneva, N. Yu.; Shiryaeva, S. O.

    2016-08-01

    Analytical expressions for electric field in the vicinity of an oscillating strongly charged droplet of nonviscous conducting liquid and intensity of electromagnetic radiation are derived in the linear approximation with respect to perturbation amplitude of the droplet surface. Order-of-magnitude estimations of the radiation intensity are presented. The intensity of electromagnetic radiation of a ball lightning that can be simulated using a charged droplet is not related to the surface oscillations.

  17. Control of solidification microstructure using programmable electro-magnetic pulses

    International Nuclear Information System (INIS)

    Manuwong, T; Zhang, W; Kazinczi, P L; Mi, J

    2016-01-01

    A programmable electro-magnetic pulse (PEMP) apparatus has been designed and made, and used to study the effect of different pulse amplitude and frequencies on the solidification microstructure. The measured magnetic fluxes agree well with the simulated fluxes using finite element method. The solidification microstructure of a Sn-18%wtPb was studied using different pulse amplitudes and frequencies. It was found that higher pulse amplitude and frequency lead to more grain refinement. (paper)

  18. Inductive-pulsed power supplying system for a betatron electromagnet

    International Nuclear Information System (INIS)

    Otrubyannikov, Yu.A.; Safronov, A.S.

    1984-01-01

    Circuit of producing quasitriangular current pulses designed for the pulsed power supply system of betatron electromagnet is described. Introduction of additional winding into electromagnet provides circuit galvanic isolation, artificial commutation of basic circuit thyristors and inductive power input to the winding during thyristor commutation. The considered system is used for excitation of betatron electromagnet up to 18 MeV. Magnetic field energy equals 1100 Y. The maximal voltage in energy storage capacitor - 4.8 kV. Current amplitude in basic winding - 335 A. The number of loops in basic winding equals 80, in additional one - 32. Current pulse duration in electromagnet-3.8 ms. The system provides operation with controlled current pulse frequency from 0 up to 150 Hz. The maximal consumption power - 18 kW

  19. Rydberg atoms ionization by microwave field and electromagnetic pulses

    International Nuclear Information System (INIS)

    Kaulakys, B.; Vilutis, G.

    1995-01-01

    A simple theory of the Rydberg atoms ionization by electromagnetic pulses and microwave field is presented. The analysis is based on the scale transformation which reduces the number of parameters and reveals the functional dependencies of the processes. It is shown that the observed ionization of Rydberg atoms by subpicosecond electromagnetic pulses scale classically. The threshold electric field required to ionise a Rydberg state may be simply evaluated in the photonic basis approach for the quantum dynamics or from the multiphoton ionization theory

  20. On Acceptable Exposures to Short Pulses of Electromagnetic Fields

    Science.gov (United States)

    2015-09-01

    standards and other research on the safety to humans of short pulses of electromagnetic radiation . Special attention is paid to a ten nanosecond...excitation limits the Food and Drug Administration (FDA) applies to magnetic resonance imaging (MRI) machines and shows that in many cases they are...pulses of electromagnetic radiation have been considered. Considerations for implanted medical devices and implanted metal objects and the like are

  1. Interaction of free charged particles with a chirped electromagnetic pulse

    International Nuclear Information System (INIS)

    Khachatryan, A.G.; Goor, F.A. van; Boller, K.-J.

    2004-01-01

    We study the effect of chirp on electromagnetic (EM) pulse interaction with a charged particle. Both the one-dimensional (1D) and 3D cases are considered. It is found that, in contrast to the case of a nonchirped pulse, the charged particle energy can be changed after the interaction with a 1D EM chirped pulse. Different types of chirp and pulse envelopes are considered. In the case of small chirp, an analytical expression is found for arbitrary temporal profiles of the chirp and the pulse envelope. In the 3D case, the interaction with a chirped pulse results in a polarization-dependent scattering of charged particles

  2. Pulse power supply system for the betatron electromagnet

    International Nuclear Information System (INIS)

    Vasil'ev, V.V.; Furman, Eh.G.

    1977-01-01

    The power supply system for a betatron electromagnet is developed on the base of a capacitive energy storage operating in a unipolar mode. A simple and effective circuit for pulsed power input with an intermediate inductive energy storage is used. This permits lowering pulse loads on a supply network and extending the power control range. An electric circuit of a pulse power supply is given and its operation is described in detail. The proposed power supply is used to excite the electromagnet of a 15 MeV betatron with a magnetic field energy of 3.5x10 3 J in the electromagnet. The maximum voltage across the capacitive storage is 2.4x10 3 V, while the maximum pulse repetition rate is 50 Hz. The power supply is simple and reliable in operation; it permits shaping triangular and trapezoidal current pulses with a flat top duration of up to 5x10 -3

  3. Electrodynamics of a hydrogenlike atom in a strong electromagnetic field

    International Nuclear Information System (INIS)

    Kovarskij, V.A.; Perel'man, N.F.

    1974-01-01

    The quasienergy spectrum of the hydrogen atom in strong electromagnetic radiation is studied, the luminescence of the atom under these conditions is considered. It is shown that in a strong field the atom, being even in the ground state, radiates a spectrum of frequencies corresponding to transitions from the ground state into excited states, the strong field photons being involved. The intensity of such a luminescence is basically a non-linear function of the strong field. The exposure of the atom to two strong electromagnetic fields Ω and ω (Ω>>ω) is considered, the Ω coinciding with one of the natural frquencies of the atom. The effct of modulation of the resonance shift for an atomic level by the ω-field strength is predicted. The dependence of Ω-absorption in the ω-field on the statistic properties of the latter is investigated. (author)

  4. Nonlinear interaction of charged particles with strong laser pulses in a gaseous media

    Directory of Open Access Journals (Sweden)

    H. K. Avetissian

    2007-07-01

    Full Text Available The charged particles nonlinear dynamics in the field of a strong electromagnetic wave pulse of finite duration and certain form of the envelope, in the refractive medium with a constant and variable refraction indexes, is investigated by means of numerical integration of the classical relativistic equations of motion. The particle energy dependence on the pulse intensity manifests the nonlinear threshold phenomenon of a particle reflection and capture by actual laser pulses in dielectric-gaseous media that takes place for a plane electromagnetic wave in the induced Cherenkov process. Laser acceleration of the particles in the result of the reflection from the pulse envelope and in the capture regime with the variable refraction index along the pulse propagation direction is investigated.

  5. On e(+)e(-) pair production by colliding electromagnetic pulses

    NARCIS (Netherlands)

    Narozhny, NB; Bulanov, SS; Mur, VD; Popov, VS

    2004-01-01

    Electron-positron pair production from vacuum in an electromagnetic field created by two counterpropagating focused laser pulses interacting with each other is analyzed. The dependence of the number of produced pairs on the intensity of a laser pulse and the focusing parameter is studied with a

  6. Interaction of free charged particles with a chirped electromagnetic pulse

    NARCIS (Netherlands)

    Khachatryan, A.G.; van Goor, F.A.; Boller, Klaus J.

    2004-01-01

    We study the effect of chirp on electromagnetic (EM) pulse interaction with a charged particle. Both the one-dimensional (1D) and 3D cases are considered. It is found that, in contrast to the case of a nonchirped pulse, the charged particle energy can be changed after the interaction with a 1D EM

  7. Faraday tarotion: new parameter for electromagnetic pulse propagation in magnetoplasma

    International Nuclear Information System (INIS)

    Bloch, S.C.; Lyons, P.W.

    1976-01-01

    Extreme distortion and time-dependent Faraday rotation occur for propagation of short electromagnetic pulses in magnetoplasma, for some ranges of plasma parameters. In order to relate pulse and monochromatic waves for propagation-path diagnostic purposes, a new parameter is introduced for the transmitted pulse train which has properties that correspond very accurately to results that would be expected for Faraday rotation of a continuous wave having the central frequency of the incident pulse spectrum. Results for 5-ns pulses (10 GHz) are presented for varying propagating length, static magnetic field, electron density, and collisional absorption

  8. Certain relativistic effects due to strong electromagnetic fields in plasmas

    International Nuclear Information System (INIS)

    Tsintsadze, N.L.

    1974-01-01

    It is shown that the propagation of a strong electromagnetic wave in an electron plasma can lead to a generation of a constant electron current along the direction of propagation and to a large increase in the average electron density. (Auth.)

  9. Time profile of harmonics generated by a single atom in a strong electromagnetic field

    International Nuclear Information System (INIS)

    Antoine, P.; Piraux, B.; Maquet, A.

    1995-01-01

    We show that the time profile of the harmonics emitted by a single atom exposed to a strong electromagnetic field may be obtained through a wavelet or a Gabor analysis of the acceleration of the atomic dipole. This analysis is extremely sensitive to the details of the dynamics and sheds some light on the competition between the atomic excitation or ionization processes and photon emission. For illustration we study the interaction of atomic hydrogen with an intense laser pulse

  10. Spontaneous electromagnetic emission from a strongly localized plasma flow.

    Science.gov (United States)

    Tejero, E M; Amatucci, W E; Ganguli, G; Cothran, C D; Crabtree, C; Thomas, E

    2011-05-06

    Laboratory observations of electromagnetic ion-cyclotron waves generated by a localized transverse dc electric field are reported. Experiments indicate that these waves result from a strong E×B flow inhomogeneity in a mildly collisional plasma with subcritical magnetic field-aligned current. The wave amplitude scales with the magnitude of the applied radial dc electric field. The electromagnetic signatures become stronger with increasing plasma β, and the radial extent of the power is larger than that of the electrostatic counterpart. Near-Earth space weather implications of the results are discussed.

  11. Current pulse generator of an induction accelerator electromagnet

    International Nuclear Information System (INIS)

    Baginskij, B.A.; Makarevich, V.N.; Shtejn, M.M.

    1987-01-01

    Thyristor generator forming in betatron electromagnet coil sinusoidal and quasisinusoidal current unipolar pulses, the field being deforced at the beginning of acceleration cycle, and with the pulse flat top in the cycle end, is described. The current amplitude is controlled by pulse-phase method. The current pulse time shift permitted to decrease the loss rate in the accumulating capacitor. The generator is used in systems with 1-10 ms pulse duration, electromagnet magnetic field maximal energy - 45-450 J, the voltage amplitude in the coil 960-1500 V and amplitude of the current passing the coil 100-500 A, the repetition frequency being 50-200 Hz. In particular, the generator is used to supply betatrons designed for defectoscopy in nonstationary conditions, the accelerated electron energy being 4, 6, 8 and 15 MeV

  12. Electromagnetic gate for the pulsed gas supply in vacuum devices

    International Nuclear Information System (INIS)

    Strokach, A.P.; Klochkov, K.N.

    1980-01-01

    A design of an electromagnetic lock for gas flows with an intensity of 10 18 - 10 23 molecule/s at a pulse duration of 0.3-2 ms is described. The valve of gas lock is an armature with a teflon sealing bushing. The gas comes to a vacuum system when the valve is separated from the base by a pulsed magnetic field produced by an electromagnet. The adjustment of the lock and change of the operating gap (from O.1 to 0.4 mm) between the armature and the magnetic circuit are performed by displacing the base with the help of an ajusting nut. Pulse durations and gas flow values, at a fixed diameter of a dosage hole are adjusted by changing the operating gap, amplitude and duration of current in the electromagnet coil, and working gas pressure in the lock casing. The lock can operate at a frequency of up to 1 kHz

  13. [Pulsed electromagnetic fields (PEMF)--results in evidence based medicine].

    Science.gov (United States)

    Pieber, Karin; Schuhfried, Othmar; Fialka-Moser, Veronika

    2007-01-01

    Therapy with electromagnetic fields has a very old tradition in medicine. The indications are widespread, whereas little is known about the effects. Controlled randomizied studies with positive results for pulsed electromagnetic fields (PEMF) are available for osteotomies, the healing of skin wounds, and osteoarthritis. Comparison of the studies is difficult because of the different doses applied and intervals of therapy. Therefore recommendations regarding an optimal dosis and interval are, depending on the disease, quite variable.

  14. Nonlinear dynamics of electromagnetic pulses in cold relativistic plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Bonatto, A.; Pakter, R.; Rizzato, F.B. [Universidade Federal do Rio Grande do Sul, Instituto de Fisica, Rio Grande do Sul (Brazil)

    2004-07-01

    The propagation of intense electromagnetic pulses in plasmas is a subject of current interest particularly for particle acceleration and laser fusion.In the present analysis we study the self consistent propagation of nonlinear electromagnetic pulses in a one dimensional relativistic electron-ion plasma, from the perspective of nonlinear dynamics. We show how a series of Hamiltonian bifurcations give rise to the electric fields which are of relevance in the subject of particle acceleration. Connections between these bifurcated solutions and results of earlier analysis are made. (authors)

  15. High-altitude electromagnetic pulse environment over the lossy ground

    International Nuclear Information System (INIS)

    Xie Yanzhao; Wang Zanji

    2003-01-01

    The electromagnetic field above ground produced by an incident high-altitude electromagnetic pulse plane wave striking the ground plane was described in this paper in terms of the Fresnel reflection coefficients and the numerical FFT. The pulse reflected from the ground plane always cancel the incident field for the horizontal field component, but the reflected field adds to the incident for the vertical field component. The results of several cases for variations in the observation height, angle of incidence and lossy ground electrical parameters were also presented showing different e-field components above the earth

  16. Effect of electromagnetic and phonon pulses on a photon echo in LaF3: Pr3+

    International Nuclear Information System (INIS)

    Shegeda, A.M.; Khabibullin, B.M.; Lisin, V.N.

    1995-01-01

    The effect of electromagnetic-field pulses of the nanosecond duration on the inverted two-pulse, three-pulse, and long-lived three-pulse photon echoes in LaF 3 :Pr 3+ is studied. The eletromagnetic pulses were produced by a current pulse flowing through a thin metal film evaporated on the sample surface parallel to the C 3- axis. A strong decrease in echo signals is observed, even if the eletromagnetic pulses were switched on prior to laser pulses. The experimental results can be qualitatively interpreted under the assumption that during the flowing of current through the metal film, the generation of transverse acoustic and electromagnetic fields occurs that induces the pseudo-Stark splitting of energy levels of Pr 3+ ions and, as a consequence, the decrease in echo signals, if the current was switched on prior to or, correspondingly, at the instant of the action of the laser pulses. 12 refs., 5 figs

  17. Interference and protection of electromagnetic pulse to digital signal processor

    International Nuclear Information System (INIS)

    Wang Yan; Jiao Hongling; He Shanhong; Pan Chao; Feng Deren; Che Wenquan; Xiong Ying

    2013-01-01

    The effective electromagnetic pulse protection is studied in this paper, first the interference of electromagnetic pulse simulator path is analyzed, including the digital signal processor (DSP) and the discharge circuit of coupling interference and net electricity coupling interference. Using the structure optimization design, the hardware block reinforcement measurement and the setting of open software trap, and the watchdog anti-jamming measures, the interference test is completed such as the central processor core voltage of DSP, input/output (I/O) ports of DSP and the display screen. The experimental results show that the combination of hardware and software protection reinforcement technology is effective, and the interference pulse amplitude of DSP board I/O port and the kernel work voltage are reduced, and the interference duration is reduced from 2 μs to 400 ns. The interference pulse is effectively restrained. (authors)

  18. Some models of propagation of extremely short electromagnetic pulses in a nonlinear medium

    International Nuclear Information System (INIS)

    Maimistov, Andrei I

    2000-01-01

    Some cases of model media considered in this paper allow analytical solutions to nonlinear wave equations to be found and the time dependence of the electric field strength to be determined in the explicit form for arbitrarily short electromagnetic pulses. Our analysis does not employ any assumptions concerning a harmonic carrier wave or the variation rate of the field in such pulses. The class of models considered includes two-level resonance and quasi-resonance systems. Nonresonance media are analysed in terms of models of anharmonic oscillators - the Duffing and Lorentz models. In most cases, only particular solutions describing the stationary propagation of a video pulse (a unipolar transient of the electric field or a pulse including a small number of oscillations of the electric field around zero) can be found. These solutions correspond to sufficiently strong electromagnetic fields when the dispersion inherent in the medium is suppressed by nonlinear processes. (invited paper)

  19. Emission and formation of electromagnetic pulses in cylindrical systems

    International Nuclear Information System (INIS)

    Lomize, L.G.; Sveshnikova, N.N.; Kuz'min, V.A.

    1983-01-01

    During the passage of a charged particle bunch through a cylindrical resonator after the process of field formation has been over the radiation, having separated from the intrinsic field, freely propagates over the resonator volume while undergoing multiple reflections from the resonator walls. As the numerical experiments have shown not only localized reflections from the resonator walls but the distributed reflections from the near-axial region take place; they result in the formation of a short intense pulse of the accelerating field along the resonator axis. The pulse runs in the direction of the bunch motion and is responsible for the process of particle autoacceleration. Transformations of the electromagnetic pUlse shape at subsequent reflections are rather of a regular character and repeated almost periodically in a certain period of time during which the light in the vacuum covers eight radii of the resonator. Conservation of the pulse shape from a period to another proceeds the more precisely, the shorter the range of the electromagnetic pulse is as compared with the resonator radius. If the resonator is permeated by successive bunches, then at a pulse frequency, for which the wave length is equal to eight radii of the resonator, a pulse resonance should arise, while at the wave length eqUal to four resonator radii a pulse antiresonance should arise

  20. High-Altitude Electromagnetic Pulse (HEMP) Testing

    Science.gov (United States)

    2015-07-09

    all electromagnetic signals from a few seconds to several hours depending on weapon yield and height-of-burst ( HOB ). Radio communications depend on...spectrum. There are three basic mechanisms for EM coupling to a conducting structure: electrical induction , the basic mechanism for linear conductors...magnetic induction , the principal mechanism when the conducting structure forms a closed loop; and earth transfer impedance for buried conductors

  1. Cytological effects of pulsed electromagnetic fields and static ...

    African Journals Online (AJOL)

    Background: There is a trend towards the use of magnetic fields in medicine. Pulsed electromagnetic fields (PEMFs) technology was based upon 20 years of fundamental studies on the electromechanical properties of bone and other connective tissues. More recently, these magnetic fields have been used to treat several ...

  2. Three dimensional internal electromagnetic pulse calculated by particle source method

    International Nuclear Information System (INIS)

    Wang Yuzhi; Wang Taichun

    1986-01-01

    The numerical results of the primary electric current and the internal electromagnetic pulse were obtained by particle method in the rectanglar cavity. The results obtained from this method is compared with three dimensional Euler-method. It is shown that two methods are in good agreement if the conditions are the same

  3. Collision frequency shift of a short electromagnetic pulse

    International Nuclear Information System (INIS)

    Chegotov, M V

    2004-01-01

    The frequency shift of a short electromagnetic pulse interaction with a plasma-like medium is discovered and studied. The shift is caused by elastic collisions of free electrons with ions or neutral particles. (interaction of laser radiation with matter. laser plasma)

  4. Possible application of transient electromagnetic pulses to high brightness e-guns

    International Nuclear Information System (INIS)

    Kurnit, N.A.; Benicewicz, P.K.; Taylor, A.J.

    1992-01-01

    A number of groups have recently demonstrated the production of freely propagating, focusable pulses of terahertz radiation, consisting of essentially a single subpicosecond cycle of a baseband electromagnetic field. We discuss the possible application of these techniques to the production of strong fields at photocathode surfaces, in a manner analogous to radial-line switched-power concepts. Experimental status in production of these pulses in our laboratory and elsewhere is reviewed, and recent progress in development of short-pulse solid-state lasers useful for this technology is summarized

  5. Effect of pulsed electromagnetic fields on orthodontic tooth movement.

    Science.gov (United States)

    Stark, T M; Sinclair, P M

    1987-02-01

    The purpose of this study was to determine whether the application of a simple surgically noninvasive, pulsed electromagnetic field could increase both the rate and amount of orthodontic tooth movement observed in guinea pigs. In addition, the objective was to evaluate the electromagnetic field's effects on bony physiology and metabolism and to search for possible systemic side effects. Laterally directed orthodontic force was applied to the maxillary central incisors of a sample of 40 young male, Hartley guinea pigs (20 experimental, 20 control) by means of a standardized intraoral coil spring inserted under constricting pressure into holes drilled in the guinea pigs' two maxillary central incisors. During the experimental period, the guinea pigs were placed in specially constructed, plastic animal holders with their heads positioned in an area of uniform electromagnetic field. Control animals were placed in similar plastic holders that did not carry the electrical apparatus. The application of a pulsed electromagnetic field to the experimental animals significantly increased both the rate and final amount of orthodontic tooth movement observed over the 10-day experimental period. The experimental animals also demonstrated histologic evidence of significantly greater amounts of bone and matrix deposited in the area of tension between the orthodontically moved maxillary incisors. This increase in cellular activity was also reflected by the presence of significantly greater numbers of osteoclasts in the alveolar bone surrounding the maxillary incisors of the experimental animals. After a 10-day exposure to pulsed electromagnetic field, minor changes in serologic parameters relating to protein metabolism and muscle activity were noted. The results of this study suggest that it is possible to increase the rate of orthodontic tooth movement and bone deposition through the application of a noninvasive, pulsed electromagnetic field.

  6. Assessment and mitigation of electromagnetic pulse (EMP) impacts at short-pulse laser facilities

    Science.gov (United States)

    Brown, C. G., Jr.; Bond, E.; Clancy, T.; Dangi, S.; Eder, D. C.; Ferguson, W.; Kimbrough, J.; Throop, A.

    2010-08-01

    The National Ignition Facility (NIF) will be impacted by electromagnetic pulse (EMP) during normal long-pulse operation, but the largest impacts are expected during short-pulse operation utilizing the Advanced Radiographic Capability (ARC). Without mitigation these impacts could range from data corruption to hardware damage. We describe our EMP measurement systems on Titan and NIF and present some preliminary results and thoughts on mitigation.

  7. A 16 MJ compact pulsed power system for electromagnetic launch

    Science.gov (United States)

    Dai, Ling; Zhang, Qin; Zhong, Heqing; Lin, Fuchang; Li, Hua; Wang, Yan; Su, Cheng; Huang, Qinghua; Chen, Xu

    2015-07-01

    This paper has established a compact pulsed power system (PPS) of 16 MJ for electromagnetic rail gun. The PPS consists of pulsed forming network (PFN), chargers, monitoring system, and current junction. The PFN is composed of 156 pulse forming units (PFUs). Every PFU can be triggered simultaneously or sequentially in order to obtain different total current waveforms. The whole device except general control table is divided into two frameworks with size of 7.5 m × 2.2 m × 2.3 m. It is important to estimate the discharge current of PFU accurately for the design of the whole electromagnetic launch system. In this paper, the on-state characteristics of pulse thyristor have been researched to improve the estimation accuracy. The on-state characteristics of pulse thyristor are expressed as a logarithmic function based on experimental data. The circuit current waveform of the single PFU agrees with the simulating one. On the other hand, the coaxial discharge cable is a quick wear part in PFU because the discharge current will be up to dozens of kA even hundreds of kA. In this article, the electromagnetic field existing in the coaxial cable is calculated by finite element method. On basis of the calculation results, the structure of cable is optimized in order to improve the limit current value of the cable. At the end of the paper, the experiment current wave of the PPS with the load of rail gun is provided.

  8. Theoretical models for ultrashort electromagnetic pulse propagation in nonlinear metamaterials

    International Nuclear Information System (INIS)

    Wen, Shuangchun; Xiang, Yuanjiang; Dai, Xiaoyu; Tang, Zhixiang; Su, Wenhua; Fan, Dianyuan

    2007-01-01

    A metamaterial (MM) differs from an ordinary optical material mainly in that it has a dispersive magnetic permeability and offers greatly enhanced design freedom to alter the linear and nonlinear properties. This makes it possible for us to control the propagation of ultrashort electromagnetic pulses at will. Here we report on generic features of ultrashort electromagnetic pulse propagation and demonstrate the controllability of both the linear and nonlinear parameters of models for pulse propagation in MMs. First, we derive a generalized system of coupled three-dimensional nonlinear Schroedinger equations (NLSEs) suitable for few-cycle pulse propagation in a MM with both nonlinear electric polarization and nonlinear magnetization. The coupled equations recover previous models for pulse propagation in both ordinary material and a MM under the same conditions. Second, by using the coupled NLSEs in the Drude dispersive model as an example, we identify the respective roles of the dispersive electric permittivity and magnetic permeability in ultrashort pulse propagation and disclose some additional features of pulse propagation in MMs. It is shown that, for linear propagation, the sign and magnitude of space-time focusing can be controlled through adjusting the linear dispersive permittivity and permeability. For nonlinear propagation, the linear dispersive permittivity and permeability are incorporated into the nonlinear magnetization and nonlinear polarization, respectively, resulting in controllable magnetic and electric self-steepening effects and higher-order dispersively nonlinear terms in the propagation models

  9. Experimental Testing of a Van De Graaff Generator as an Electromagnetic Pulse Generator

    Science.gov (United States)

    2016-07-01

    EXPERIMENTAL TESTING OF A VAN DE GRAAFF GENERATOR AS AN ELECTROMAGNETIC PULSE GENERATOR THESIS...protection in the United States AFIT-ENP-MS-16-S-075 EXPERIMENTAL TESTING OF A VAN DE GRAAFF GENERATOR AS AN ELECTROMAGNETIC PULSE GENERATOR...RELEASE; DISTRIBUTION UNLIMITED. AFIT-ENP-MS-16-S-075 EXPERIMENTAL TESTING OF A VAN DE GRAAFF GENERATOR AS AN ELECTROMAGNETIC PULSE GENERATOR

  10. Design of Electric Field Sensors for Measurement of Electromagnetic Pulse

    Directory of Open Access Journals (Sweden)

    Hui ZHANG

    2014-01-01

    Full Text Available In this paper, a D-dot electric field sensor and a fiber-optic transmission electric field sensor are developed for measurement of electromagnetic pulse. The D-dot sensor is a differential model sensor without source and has a simple structure. The fiber-optic transmission sensor is in the type of small dipole antenna, which uses its outside shielding layer as a pair of antennas. Design of the sensor circuit and the test system are introduced in this paper. A calibration system for these pulsed field sensors is established and the test results verified the ability of the developed sensors for measurement of the standard electromagnetic pulse field (the half peak width is 25 ns and the rising time is 2.5 ns.

  11. Dynamical equations and transport coefficients for the metals at high pulse electromagnetic fields

    International Nuclear Information System (INIS)

    Volkov, N B; Chingina, E A; Yalovets, A P

    2016-01-01

    We offer a metal model suitable for the description of fast electrophysical processes in conductors under influence of powerful electronic and laser radiation of femto- and picosecond duration, and also high-voltage electromagnetic pulses with picosecond front and duration less than 1 ns. The obtained dynamic equations for metal in approximation of one quasineutral liquid are in agreement with the equations received by other authors formerly. New wide-range expressions for the electronic conduction in strong electromagnetic fields are obtained and analyzed. (paper)

  12. Pulsed Electromagnetic Field Assisted in vitro Electroporation: A Pilot Study

    Science.gov (United States)

    Novickij, Vitalij; Grainys, Audrius; Lastauskienė, Eglė; Kananavičiūtė, Rūta; Pamedytytė, Dovilė; Kalėdienė, Lilija; Novickij, Jurij; Miklavčič, Damijan

    2016-09-01

    Electroporation is a phenomenon occurring due to exposure of cells to Pulsed Electric Fields (PEF) which leads to increase of membrane permeability. Electroporation is used in medicine, biotechnology, and food processing. Recently, as an alternative to electroporation by PEF, Pulsed ElectroMagnetic Fields (PEMF) application causing similar biological effects was suggested. Since induced electric field in PEMF however is 2-3 magnitudes lower than in PEF electroporation, the membrane permeabilization mechanism remains hypothetical. We have designed pilot experiments where Saccharomyces cerevisiae and Candida lusitaniae cells were subjected to single 100-250 μs electrical pulse of 800 V with and without concomitant delivery of magnetic pulse (3, 6 and 9 T). As expected, after the PEF pulses only the number of Propidium Iodide (PI) fluorescent cells has increased, indicative of membrane permeabilization. We further show that single sub-millisecond magnetic field pulse did not cause detectable poration of yeast. Concomitant exposure of cells to pulsed electric (PEF) and magnetic field (PMF) however resulted in the increased number PI fluorescent cells and reduced viability. Our results show increased membrane permeability by PEF when combined with magnetic field pulse, which can explain electroporation at considerably lower electric field strengths induced by PEMF compared to classical electroporation.

  13. Experimental study of pulsed heating of electromagnetic cavities

    International Nuclear Information System (INIS)

    Pritzkau, D.P.; Menegat, A.; Siemann, R.H.

    1997-01-01

    An experiment to study the effects of pulsed heating in electromagnetic cavities will be performed. Pulsed heating is believed to be the limiting mechanism of high acceleration gradients at short wavelengths. A cylindrical cavity operated in the TE 011 mode at a frequency of 11.424 GHz will be used. A klystron will be used to supply a peak input power of 20 MW with a pulse length of 1.5 μs. The temperature response of the cavity will be measured by a second waveguide designed to excite a TE 012 mode in the cavity with a low-power CW signal at a frequency of 17.8 GHz. The relevant theory of pulsed heating will be discussed and the results from cold-testing the structure will be presented

  14. Principles and techniques of radiation hardening. Volume 3. Electromagnetic pulse (EMP) and system generated EMP

    International Nuclear Information System (INIS)

    Rudie, N.J.

    1976-01-01

    The three-volume book is intended to serve as a review of the effects of thermonuclear explosion induced radiation (x-rays, gamma rays, and beta particles) and the resulting electromagnetic pulse (EMP). Volume 3 deals with the following topics: selected fundamentals of electromagnetic theory; EMP induced currents on antennas and cables; the EMP response of electronics; EMP hardening; EMP testing; injection currents; internal electromagnetic pulse (IEMP); replacement currents; and system generated electromagnetic pulse (SGEMP) hardening

  15. The electromagnetic pulse (EMP) as a danger for the world of electronics

    International Nuclear Information System (INIS)

    Horak, O.

    1984-01-01

    After discussing the characteristics and formation of a nuclear electromagnetic pulse, the author considers the effects such a pulse would have on various types of electronic systems. Finally he discusses what protection there is against such pulses. (Auth.)

  16. Effects of nuclear electromagnetic pulse (EMP) on nuclear power plants

    International Nuclear Information System (INIS)

    Barnes, P.R.; Manweiler, R.W.; Davis, R.R.

    1977-09-01

    The electromagnetic pulse (EMP) from a high-altitude nuclear detonation consists of a transient pulse of high intensity electromagnetic fields. These intense fields induce current and voltage transients in electrical conductors. Although most nuclear power plant cables are not directly exposed to these fields, the attenuated EMP fields that propagate into the plant will couple some EMP energy to these cables. The report predicts the probable effects of the EMP transients that could be induced in critical circuits of safety-related systems. It was found that the most likely consequence of EMP for nuclear plants is an unscheduled shutdown. EMP could prolong the shutdown period by the unnecessary actuation of certain safety systems. In general, EMP could be a nuisance to nuclear power plants, but it is not considered a serious threat to plant safety

  17. Electromagnetic pulses generated by high-power laser experiments

    International Nuclear Information System (INIS)

    Lubrano-Lavaderci, F.; Dubois, J.L.; Gazave, J.; Raffestin, D.; Bazzoli, S.

    2013-01-01

    During high-power laser experiments, intense electromagnetic fields are produced. For future facilities, the field level is extrapolated from measurements performed on current experimental rooms. In the LMJ (Laser Mega Joule) target chamber with the high-power PETAL beam (Petawatt Aquitaine Laser), the expected field is about 1 MW/m for high laser intensity shots (higher than 10 19 W/cm 2 ). This is a harsh environment for electric equipments. For these short-pulse laser experiments, simulations show that electromagnetic pulses are due to charged particles emission during the shot, more exactly they are due to the resulting replacement currents that appear in the target chamber. This paper shows a simulation (with the numerical tool SOPHIE) of this phenomenon, in good agreement with experimental data from Titan and Omega-EP facilities. (authors)

  18. Effects of Pulsed Electromagnetic Fields on Osteoporosis Model

    Science.gov (United States)

    Xiaowei, Yang; Liming, Wang; Guan, Z. C.; Yaou, Zhang; Xiangpeng, Wang

    The purpose of this paper was to investigate the preventive effects and long term effects of extremely low frequency pulsed electromagnetic fields (PEMFs), generated by circular coils and pulsed electromagnetic fields stimulators, on osteoporosis in bilaterally ovariectomized rats. In preventive experiment, thirty three-month old female Sprague-Dawley rats were randomly divided into three different groups: sham (SHAM), ovariectomy (OVX), PEMFs stimulation (PEMFs). All rats were subjected to bilaterally ovariectomy except those in SHAM group. The PEMFs group was exposed to pulsed electromagnetic fields with frequency 15 Hz, peak magnetic induction density 2.2mT and exposure time 2 hours per day. The bone mineral density (BMD) of vertebra and left femur were measured by dual energy X-ray absorptiometry at eighth week, twelfth week and sixteenth week after surgery. In long term effects experiment, forty four rats were randomly divided into sham (14 rats, SHAM), ovariectomy group (10 rats, OVX), 15Hz PEMFs group(10 rats, 15Hz) and 30Hz PEMFs group(10 rats, 30Hz) at twenty-sixth week after surgery. Rats in PEMFs groups were stimulated sixteen weeks. In preventive experiment, the Corrected BMD of vertebra and femur was significantly higher than that of OVX group after 16 weeks (P<0.001, P<0.001 respectively). In long term effects experiment, the vertebral BMD of 15Hz PEMFs group and 30Hz PEMFs group was significantly higher than that of OVX groups (P<0.01, P<0.05 respectively). The experimental results demonstrated that extremely low intensity, low frequency, single pulsed electromagnetic fields significantly slowed down the loss of corrected vertebral and femoral BMD in bilaterally ovariectomized rats and suggest that PEMFs may be beneficial in the treatment of osteoporosis.

  19. Force-free electromagnetic pulses in a laboratory plasma

    Science.gov (United States)

    Stenzel, R. L.; Urrutia, J. M.

    1990-01-01

    A short, intense current pulse is drawn from an electrode immersed in a magnetized afterglow plasma. The induced magnetic field B(r,t) assumes the shape of a helical double vortex which propagates along B(0) through the uniform plasma as a whistler mode. The observations support a prediction of force-free (J x B + neE = 0) electromagnetic fields and solitary waves. Energy and helicity are approximately conserved.

  20. Mechanisms and therapeutic effectiveness of pulsed electromagnetic field therapy in oncology

    OpenAIRE

    Vadal?, Maria; Morales?Medina, Julio Cesar; Vallelunga, Annamaria; Palmieri, Beniamino; Laurino, Carmen; Iannitti, Tommaso

    2016-01-01

    Abstract Cancer is one of the most common causes of death worldwide. Available treatments are associated with numerous side effects and only a low percentage of patients achieve complete remission. Therefore, there is a strong need for new therapeutic strategies. In this regard, pulsed electromagnetic field (PEMF) therapy presents several potential advantages including non?invasiveness, safety, lack of toxicity for non?cancerous cells, and the possibility of being combined with other availabl...

  1. A Delay Line for Compression of Electromagnetic Pulses

    International Nuclear Information System (INIS)

    Pchelnikov, Yuriy N.; Nyce, David S.

    2003-01-01

    A novel method to obtain an electromagnetic signal delay is described. It is shown that the positive magnetic and electric coupling between impedance conductors produces an increase in the time delay. It is also shown that the increase in delay time is obtained without additional attenuation. This allows a reduction in electromagnetic losses, by a factor of several times, for a delay time. An approximate analysis of electromagnetic delay lines based on coupled impedance conductors with 'spiral' and 'meander' patterns allowed obtaining very simple expressions for the wave deceleration factor, wave impedance, and attenuation factor. The results of the analysis are confirmed by the results of measurements. It is shown that a delay line based on counter-wound radial spirals can be successfully used for compression of electromagnetic pulses. Although the offered delay line was designed to operate with a relatively small signal, the analysis of the 'coupling effect', taking place in this delay line, might be useful in devices for compression of high-power microwave pulses

  2. Discrimination of nuclear-explosion and lightning electromagnetic pulse

    International Nuclear Information System (INIS)

    Qi Shufeng; Li Ximei; Han Shaoqing; Niu Chao; Feng Jun; Liu Daizhi

    2012-01-01

    The discrimination of nuclear-explosion and lightning electromagnetic pulses was studied using empirical mode decomposition and the fractal analytical method. The box dimensions of nuclear-explosion and lightning electromagnetic pulses' original signals were calculated, and the box dimensions of the intrinsic mode functions (IMFs) of nuclear-explosion and lightning electromagnetic pulses' original signals after empirical mode decomposition were also obtained. The discrimination of nuclear explosion and lightning was studied using the nearest neighbor classification. The experimental results show that, the discrimination rate of the box dimension based on the first and second IMF after the original signal empirical mode decomposition is higher than that based on the third and forth IMF; the discrimination rate of the box dimension based on the original signal is higher than that based on any IMF; and the discrimination rate based on two-dimensional and three-dimensional characters is higher and more stable than that based on one-dimensional character, besides, the discrimination rate based on three-dimensional character is over 90%. (authors)

  3. Multiple Colliding Electromagnetic Pulses: A Way to Lower the Threshold of e+e- Pair Production from Vacuum

    Science.gov (United States)

    Bulanov, S. S.; Mur, V. D.; Narozhny, N. B.; Nees, J.; Popov, V. S.

    2010-06-01

    The scheme of a simultaneous multiple pulse focusing on one spot naturally arises from the structural features of projected new laser systems, such as the Extreme Light Infrastructure (ELI) and High Power laser Energy Research (HiPER). It is shown that the multiple pulse configuration is beneficial for observing e+e- pair production from a vacuum under the action of sufficiently strong electromagnetic fields. The field of focused pulses is described using a realistic three-dimensional model based on an exact solution of the Maxwell equations. The e+e- pair production threshold in terms of electromagnetic field energy can be substantially lowered if, instead of one or even two colliding pulses, multiple pulses are focused on one spot. The multiple pulse interaction geometry gives rise to subwavelength field features in the focal region. These features result in the production of extremely short e+e- bunches.

  4. Electromagnetic pulses from high-energy showers: Implications for neutrino detection

    International Nuclear Information System (INIS)

    Zas, E.; Halzen, F.; Stanev, T.

    1992-01-01

    We review the properties of electromagnetic showers in dense media and calculate in detail the associated electromagnetic pulses generated by shower electrons. We perform real-time simulations recording the charge, trajectory, and time of each cascade particle and compute the associated electromagnetic wave. Our results are relevant to experiments detecting radio pulses from showers initiated by cosmic particles interacting with the Earth

  5. Strong-field short-pulse nondipole dynamics

    DEFF Research Database (Denmark)

    Dimitrovski, Darko; Førre, Morten; Madsen, Lars Bojer

    2009-01-01

    We present a quantitative investigation of strong-field short-pulse nondipole dynamics in laser-matter interactions. We find excellent agreement between ab initio numerical and analytic results obtained using the Magnus expansion. We show that in the short-pulse limit, ultrafast transfer and cont......We present a quantitative investigation of strong-field short-pulse nondipole dynamics in laser-matter interactions. We find excellent agreement between ab initio numerical and analytic results obtained using the Magnus expansion. We show that in the short-pulse limit, ultrafast transfer...... and control of population can be achieved using nondipole effects. The relative importance of nondipole to dipole effects depends on the displacement imparted to a free classical electron....

  6. A strong permanent magnet-assisted electromagnetic undulator

    Science.gov (United States)

    Halbach, K.

    1987-01-30

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

  7. Cerenkov radio pulses from electromagnetic showers in the time domain

    International Nuclear Information System (INIS)

    Alvarez-Muniz, Jaime; Romero-Wolf, Andres; Zas, Enrique

    2010-01-01

    The electric field of the Cerenkov radio pulse produced by a single charged particle track in a dielectric medium is derived from first principles. An algorithm is developed to obtain the pulse in the time domain for numerical calculations. The algorithm is implemented in a Monte Carlo simulation of electromagnetic showers in dense media (specifically designed for coherent radio emission applications) as might be induced by interactions of ultrahigh energy neutrinos. The coherent Cerenkov radio emission produced by such showers is obtained simultaneously both in the time and frequency domains. A consistency check performed by Fourier transforming the pulse in time and comparing it to the frequency spectrum obtained directly in the simulations yields, as expected, fully consistent results. The reversal of the time structure inside the Cerenkov cone and the signs of the corresponding pulses are addressed in detail. The results, besides testing algorithms used for reference calculations in the frequency domain, shed new light into the properties of the radio pulse in the time domain. The shape of the pulse in the time domain is directly related to the depth development of the excess charge in the shower and its width to the observation angle with respect to the Cerenkov direction. This information can be of great practical importance for interpreting actual data.

  8. Photoconductive Semiconductor Switch Technology for Short Pulse Electromagnetics and Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Denison, Gary J.; Helgeson, Wesley D.; Hjalmarson, Harold P.; Loubriel, Guillermo M.; Mar, Alan; O' Malley, Martin W.; Zutavern, Fred J.

    1999-08-05

    High gain photoconductive semiconductor switches (PCSS) are being used to produce high power electromagnetic pulses foc (1) compact, repetitive accelerators, (2) ultra-wide band impulse sources, (3) precision gas switch triggers, (4) optically-activated firesets, and (5) high power optical pulse generation and control. High power, sub-nanosecond optical pulses are used for active optical sensors such as compact optical radars and range-gated hallistic imaging systems. Following a brief introduction to high gain PCSS and its general applications, this paper will focus on PCSS for optical pulse generation and control. PCSS technology can be employed in three distinct approaches to optical pulse generation and control: (1) short pulse carrier injection to induce gain-switching in semiconductor lasers, (2) electro-optical Q-switching, and (3) optically activated Q-switching. The most significant PCSS issues for these applications are switch rise time, jitter, and longevity. This paper will describe both the requirements of these applications and the most recent results from PCSS technology. Experiments to understand and expand the limitations of high gain PCSS will also be described.

  9. Analog modeling of splitting the envelope of an electromagnetic pulse reflected from a plasma layer

    International Nuclear Information System (INIS)

    Bakunov, M.I.; Rogozhin, I.Yu.

    1997-01-01

    By means of a simple radio engineering model, an experimental study is carried out of the effect of the strong deformation of the envelope of a quasimonochromatic electromagnetic pulse reflected from a thin plasma layer placed on the surface of an ideal conductor. This deformation is considered under the conditions of the plasma resonance in the plasma layer and when the thickness of the layer is less then the wavelength of the incident radiation. It is shown that the pulse whose initial profile is Gaussian, after the reflection, is separated (entirely of partially) into two pulses with amplitudes that can be controlled by means of varying the parameters of the incident pulse and plasma layer

  10. Measurement of Ultra-Short Solitary Electromagnetic Pulses

    Directory of Open Access Journals (Sweden)

    Eva Gescheidtova

    2004-01-01

    Full Text Available In connection with the events of the last few years and with the increased number of terrorist activities, the problem of identification and measurement of electromagnetic weapons or other systems impact occurred. Among these are also microwave sources, which can reach extensive peak power of up to Pmax = 100 MW. Solitary, in some cases several times repeated, impulses lasting from tp E <1, 60>ns, cause the destruction of semiconductor junctions. These days we can find scarcely no human activity, where semiconductor structures are not used. The problem of security support of the air traffic, transportation, computer nets, banks, national strategic data canter’s, and other applications crops up. Several types of system protection from the ultra-short electromagnetic pulses present itself, passive and active protection. The analysis of the possible measuring methods, convenient for the identification and measurement of the ultra-short solitary electromagnetic pulses in presented in this paper; some of the methods were chosen and used for practical measurement. This work is part of Research object MSM262200022 "Research of microelectronic systems".

  11. Generation of electromagnetic pulses from plasma channels induced by femtosecond light strings

    OpenAIRE

    Cheng, Chung-Chieh; Wright, E. M.; Moloney, J. V.

    2000-01-01

    We present a model that elucidates the physics underlying the generation of an electromagnetic pulse from a femtosecond laser induced plasma channel. The radiation pressure force from the laser pulse spatially separates the ionized electrons from the heavier ions and the induced dipole moment subsequently oscillates at the plasma frequency and radiates an electromagnetic pulse.

  12. Phenomenological Model of Current Sheet Canting in Pulsed Electromagnetic Accelerators

    Science.gov (United States)

    Markusic, Thomas; Choueiri, E. Y.

    2003-01-01

    The phenomenon of current sheet canting in pulsed electromagnetic accelerators is the departure of the plasma sheet (that carries the current) from a plane that is perpendicular to the electrodes to one that is skewed, or tipped. Review of pulsed electromagnetic accelerator literature reveals that current sheet canting is a ubiquitous phenomenon - occurring in all of the standard accelerator geometries. Developing an understanding of current sheet canting is important because it can detract from the propellant sweeping capabilities of current sheets and, hence, negatively impact the overall efficiency of pulsed electromagnetic accelerators. In the present study, it is postulated that depletion of plasma near the anode, which results from axial density gradient induced diamagnetic drift, occurs during the early stages of the discharge, creating a density gradient normal to the anode, with a characteristic length on the order of the ion skin depth. Rapid penetration of the magnetic field through this region ensues, due to the Hall effect, leading to a canted current front ahead of the initial current conduction channel. In this model, once the current sheet reaches appreciable speeds, entrainment of stationary propellant replenishes plasma in the anode region, inhibiting further Hall-convective transport of the magnetic field; however, the previously established tilted current sheet remains at a fairly constant canting angle for the remainder of the discharge cycle, exerting a transverse J x B force which drives plasma toward the cathode and accumulates it there. This proposed sequence of events has been incorporated into a phenomenological model. The model predicts that canting can be reduced by using low atomic mass propellants with high propellant loading number density; the model results are shown to give qualitative agreement with experimentally measured canting angle mass dependence trends.

  13. Characterization of stochastic spatially and spectrally partially coherent electromagnetic pulsed beams

    International Nuclear Information System (INIS)

    Ding Chaoliang; Lue Baida; Pan Liuzhan

    2009-01-01

    The unified theory of coherence and polarization proposed by Wolf is extended from stochastic stationary electromagnetic beams to stochastic spatially and spectrally partially coherent electromagnetic pulsed beams. Taking the stochastic electromagnetic Gaussian Schell-model pulsed (GSMP) beam as a typical example of stochastic spatially and spectrally partially coherent electromagnetic pulsed beams, the expressions for the spectral density, spectral degree of polarization and spectral degree of coherence of stochastic electromagnetic GSMP beams propagating in free space are derived. Some special cases are analyzed. The illustrative examples are given and the results are interpreted physically.

  14. Numerical simulation of compact intracloud discharge and generated electromagnetic pulse

    Science.gov (United States)

    Babich, L. P.; Bochkov, E. I.; Kutsyk, I. M.

    2015-06-01

    Using the concept of the relativistic runaway electron avalanche, numerical simulation of compact intracloud discharge as a generator of powerful natural electromagnetic pulses (EMPs) in the HF-UHF range was conducted. We evaluated the numbers of electrons initiating the avalanche, with which the calculated EMP characteristics are consistent with measured ones. The discharge capable of generating EMPs produces runaway electrons in numbers close to those in the source of terrestrial γ-flashes (TGF) registered in the nearest space, which may be an argument for a joint EMP and TGF source.

  15. Effects of Pulse Electromagnetic Field on Corrosion Resistance of Al-5 % Cu Alloy

    Science.gov (United States)

    Wang, B.; Tang, L. D.; Qi, J. G.; Wang, J. Z.

    2013-03-01

    It was investigated that corrosion resistance of Al-5 % Cu alloy was influenced by pulse electromagnetic field (PEMF). The morphologies were observed by scanning election microscopy (SEM). The corrosion behaviors were investigated by potentiodynamic polarization tests and immersion tests. The results indicated that corrosion resistance of samples could be increased by using pulse electromagnetic field, moreover, the optimum parameter of pulse electromagnetic field in this experiment was showed as follows: 500 V, 3 Hz, 30 s. Decreasing the quantity of eutectic in grain boundaries and refining the grains were main causations for increasing corrosion resistance of Al-5 % Cu alloy with pulse electromagnetic field.

  16. Electromagnetic pulse measurement system based on optical fiber transmission under radiated-wave test

    International Nuclear Information System (INIS)

    Liu Shunkun; Nie Xin; Chen Xiangyue; Xiang Hui

    2010-01-01

    Radiated-wave Electromagnetic Pulse Simulator is an important device used to study Electromagnetic Pulse effect of large electronic equipment in test. On the characteristic of radiated-EMP simulator test and the needs to measurement system, Electromagnetic Pulse measurement system based on optical fiber transmission and its composition are introduced in the paper. Sort of measurement system and Calibration method of its are present. The expression of uncertainty in Electromagnetic Pulse measurement system is discussed also. The measurement results are analyzed which be gained by radiated field test. (authors)

  17. Note on Inverse Bremsstrahlung in a Strong Electromagnetic Field

    Science.gov (United States)

    Bethe, H. A.

    1972-09-01

    The collisional energy loss of an electron undergoing forced oscillation in an electromagnetic field behaves quite differently in the low and high intensity limits. ... It is shown that in the case of an electromagnetic field v {sub o} >> v {sub t} the rate of transfer is much slower, and actually decreases with the strength of the field.

  18. Nonresonant interaction of ultrashort electromagnetic pulses with multilevel quantum systems

    Science.gov (United States)

    Belenov, E.; Isakov, V.; Nazarkin, A.

    1994-01-01

    Some features of the excitation of multilevel quantum systems under the action of electromagnetic pulses which are shorter than the inverse frequency of interlevel transitions are considered. It is shown that the interaction is characterized by a specific type of selectivity which is not connected with the resonant absorption of radiation. The simplest three-level model displays the inverse population of upper levels. The effect of an ultrashort laser pulse on a multilevel molecule was regarded as an instant reception of the oscillation velocity by the oscillator and this approach showed an effective excitation and dissociation of the molecule. The estimations testify to the fact that these effects can be observed using modern femtosecond lasers.

  19. Electrochemotherapy by pulsed electromagnetic field treatment (PEMF in mouse melanoma B16F10 in vivo

    Directory of Open Access Journals (Sweden)

    Kranjc Simona

    2016-03-01

    Full Text Available Pulsed electromagnetic field (PEMF induces pulsed electric field, which presumably increases membrane permeabilization of the exposed cells, similar to the conventional electroporation. Thus, contactless PEMF could represent a promising approach for drug delivery.

  20. Interaction of the electromagnetic precursor from a relativistic shock with the upstream flow - I. Synchrotron absorption of strong electromagnetic waves

    Science.gov (United States)

    Lyubarsky, Yuri

    2018-02-01

    This paper is the first in the series of papers aiming to study interaction of the electromagnetic precursor waves generated at the front of a relativistic shock with the upstream flow. It is motivated by a simple consideration showing that the absorption of such an electromagnetic precursor could yield an efficient transformation of the kinetic energy of the upstream flow to the energy of accelerated particles. Taking into account that the precursor is a strong wave, in which electrons oscillate with relativistic velocities, the standard plasma-radiation interaction processes should be reconsidered. In this paper, I calculate the synchrotron absorption of strong electromagnetic waves.

  1. Interaction of attosecond electromagnetic pulses with atoms: The exactly solvable model

    International Nuclear Information System (INIS)

    Popov, Yu. V.; Kouzakov, K. A.; Vinitsky, S. I.; Gusev, A. A.

    2007-01-01

    We consider the exactly solvable model of interaction of zero-duration electromagnetic pulses with an atom. The model has a number of peculiar properties which are outlined in the cases of a single pulse and two opposite pulses. In perspective, it can be useful in different fields of physics involving interaction of attosecond laser pulses with quantum systems

  2. Stochastic electromagnetic plane-wave pulse with non-uniform correlation distribution

    International Nuclear Information System (INIS)

    Ding, Chaoliang; Cai, Yangjian; Zhang, Yongtao; Wang, Haixia; Zhao, Zhiguo; Pan, Liuzhan

    2013-01-01

    Stochastic electromagnetic plane-wave (SEPW) pulse with non-uniform correlation distribution is introduced. The realizability condition for such pulse is derived. It is found that the evolution properties of the intensity and the degree of polarization of an SEPW pulse with non-uniform correlation distribution in dispersive media are much different from those of an SEPW pulse with uniform correlation distribution.

  3. Qubit lattice coherence induced by electromagnetic pulses in superconducting metamaterials.

    Science.gov (United States)

    Ivić, Z; Lazarides, N; Tsironis, G P

    2016-07-12

    Quantum bits (qubits) are at the heart of quantum information processing schemes. Currently, solid-state qubits, and in particular the superconducting ones, seem to satisfy the requirements for being the building blocks of viable quantum computers, since they exhibit relatively long coherence times, extremely low dissipation, and scalability. The possibility of achieving quantum coherence in macroscopic circuits comprising Josephson junctions, envisioned by Legett in the 1980's, was demonstrated for the first time in a charge qubit; since then, the exploitation of macroscopic quantum effects in low-capacitance Josephson junction circuits allowed for the realization of several kinds of superconducting qubits. Furthermore, coupling between qubits has been successfully achieved that was followed by the construction of multiple-qubit logic gates and the implementation of several algorithms. Here it is demonstrated that induced qubit lattice coherence as well as two remarkable quantum coherent optical phenomena, i.e., self-induced transparency and Dicke-type superradiance, may occur during light-pulse propagation in quantum metamaterials comprising superconducting charge qubits. The generated qubit lattice pulse forms a compound "quantum breather" that propagates in synchrony with the electromagnetic pulse. The experimental confirmation of such effects in superconducting quantum metamaterials may open a new pathway to potentially powerful quantum computing.

  4. The response of antennas on a submarine to nuclear electromagnetic pulse

    International Nuclear Information System (INIS)

    Gao Zheng; Li Junli; Fan Jiajin

    2005-01-01

    Nuclear electromagnetic pulse will do harm to the communication and navigation systems. In this paper, the response of antennas on a submarine to nuclear electromagnetic pulse is analyzed, and the induced current in antennas and energy collected by antennas are calculated, which are very important to the protection systems design. (authors)

  5. Study on irradiation effects of nucleus electromagnetic pulse on single chip computer system

    International Nuclear Information System (INIS)

    Hou Minsheng; Liu Shanghe; Wang Shuping

    2001-01-01

    Intense electromagnetic pulse, namely nucleus electromagnetic pulse (NEMP), lightning electromagnetic pulse (LEMP) and high power microwave (HPM), can disturb and destroy the single chip computer system. To study this issue, the authors made irradiation experiments by NEMPs generated by gigahertz transversal electromagnetic (GTEM) Cell. The experiments show that shutdown, restarting, communication errors of the single chip microcomputer system would occur when it was irradiated by the NEMPs. Based on the experiments, the cause on the effects on the single chip microcomputer system is discussed

  6. The Analysis of Pulse Electromagnetic Field Effect on Solution Conductivity

    OpenAIRE

    Mahardiono, Novan Agung; Fakhrurroja, Hanif; Luvita, V; Cahyaningsih, Sudaryati

    2016-01-01

    This paper presents the observation of magnetization process variables influence the conductivity of a solution of FeSO4, MnSO4, MgCl2 and CaCl2. Some of the survey results reveal that there has been a decline in the rate of particle formation FeSO4, MnSO4, MgCl2 and CaCl2 of the ions in the hard water sample magnetized. The research method in this paper is to test the conductivity of a solution of FeSO4, MnSO4, MgCl2 and CaCl2 before and after a given pulse electromagnetic field with a conc...

  7. Electromagnetic pulses produced by expanding laser-produced Au plasma

    Czech Academy of Sciences Publication Activity Database

    De Marco, Massimo; Cikhardt, J.; Krása, Josef; Velyhan, Andriy; Pfeifer, Miroslav; Krouský, Eduard; Klír, D.; Řezáč, K.; Limpouch, J.; Margarone, Daniele; Ullschmied, Jiří

    2015-01-01

    Roč. 60, č. 2 (2015), s. 239-243 ISSN 0029-5922 R&D Projects: GA MŠk EE2.3.20.0279; GA ČR GAP205/12/0454; GA MŠk(CZ) LD14089; GA MŠk LM2010014 Grant - others:LaserZdroj (OP VK 3)(XE) CZ.1.07/2.3.00/20.0279 Institutional support: RVO:68378271 ; RVO:61389021 Keywords : laser-produced plasma * electromagnetic pulse (EMP) * return target current * Moebius loop antenna * inductive target probe Subject RIV: BL - Plasma and Gas Discharge Physics; BH - Optics, Masers, Lasers (UFP-V) Impact factor: 0.546, year: 2015

  8. Multistage ionization of atoms in a very strong electromagnetic field

    International Nuclear Information System (INIS)

    Krajnov, V.P.; Manykin, Eh.A.

    1980-01-01

    Considered is a problem of multiple ionization of middle and heavy atoms as a function of the intensity of an electromagnetic field. The atom is considered in the Thomas -Fermi approximation. Presented are estimates of ionization degree for lead, tungsten and tantalum

  9. Energy-level transitions and emission of atom at interaction with ultrashort pulse of electromagnetic field

    International Nuclear Information System (INIS)

    Matveev, V.I.

    2003-01-01

    The electron transitions and atom emission by its interaction with the ultrashort pulse of the electromagnetic field are considered on the basis of the sudden perturbations approximation. The probabilities of excitation and ionization as well as the spectra and cross sections of such a pulse over-emission by the atom are obtained. The conclusion is made on the coherent character of the process of the electromagnetic field ultrashort pulses over-emission by the multielectron atoms [ru

  10. Ionization of atoms in strong low-frequency electromagnetic field

    International Nuclear Information System (INIS)

    Krainov, V. P.

    2010-01-01

    The ionization of atoms in a low-frequency linearly polarized electromagnetic field (the photon energy is much lower than the ionization potential of an atom) is considered under new conditions, in which the Coulomb interaction of an electron with the atomic core in the final state of the continuum cannot be considered in perturbation theory in the interaction of the electron with the electromagnetic field. The field is assumed to be much weaker that the atomic field. In these conditions, the classical motion of the electron in the final state of the continuum becomes chaotic (so-called dynamic chaos). Using the well-known Chirikov method of averaging over chaotic variations of the phase of motion, the problem can be reduced to non-linear diffusion on the energy scale. We calculate the classical electron energy in the final state, which is averaged over fast chaotic oscillations and takes into account both the Coulomb field and the electromagnetic field. This energy is used to calculate the probability of ionization from the ground state of the atom to a lower-lying state in the continuum using the Landau-Dykhne approximation (to exponential accuracy). This ionization probability noticeably depends on the field frequency. Upon a decrease in frequency, a transition to the well-known tunnel ionization limit with a probability independent of the field frequency is considered.

  11. Sleep EEG alterations: effects of pulsed magnetic fields versus pulse-modulated radio frequency electromagnetic fields.

    Science.gov (United States)

    Schmid, Marc R; Murbach, Manuel; Lustenberger, Caroline; Maire, Micheline; Kuster, Niels; Achermann, Peter; Loughran, Sarah P

    2012-12-01

    Studies have repeatedly shown that electroencephalographic power during sleep is enhanced in the spindle frequency range following radio frequency electromagnetic field exposures pulse-modulated with fundamental frequency components of 2, 8, 14 or 217 Hz and combinations of these. However, signals used in previous studies also had significant harmonic components above 20 Hz. The current study aimed: (i) to determine if modulation components above 20 Hz, in combination with radio frequency, are necessary to alter the electroencephalogram; and (ii) to test the demodulation hypothesis, if the same effects occur after magnetic field exposure with the same pulse sequence used in the pulse-modulated radio frequency exposure. In a randomized double-blind crossover design, 25 young healthy men were exposed at weekly intervals to three different conditions for 30 min before sleep. Cognitive tasks were also performed during exposure. The conditions were a 2-Hz pulse-modulated radio frequency field, a 2-Hz pulsed magnetic field, and sham. Radio frequency exposure increased electroencephalogram power in the spindle frequency range. Furthermore, delta and theta activity (non-rapid eye movement sleep), and alpha and delta activity (rapid eye movement sleep) were affected following both exposure conditions. No effect on sleep architecture and no clear impact of exposure on cognition was observed. These results demonstrate that both pulse-modulated radio frequency and pulsed magnetic fields affect brain physiology, and the presence of significant frequency components above 20 Hz are not fundamental for these effects to occur. Because responses were not identical for all exposures, the study does not support the hypothesis that effects of radio frequency exposure are based on demodulation of the signal only. © 2012 European Sleep Research Society.

  12. PERCEPTION LEVEL EVALUATION OF RADIO ELECTRONIC MEANS TO A PULSE OF ELECTROMAGNETIC RADIATION

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available The method for evaluating the perception level of electronic means to pulsed electromagnetic radiation is consid- ered in this article. The electromagnetic wave penetration mechanism towards the elements of electronic systems and the impact on them are determined by the intensity of the radiation field on the elements of electronic systems. The impact of electromagnetic radiation pulses to the electronic systems refers to physical and analytical parameters of the relationship between exposure to pulses of electromagnetic radiation and the sample parameters of electronic systems. A physical and mathematical model of evaluating the perception level of electronic means to pulsed electromagnetic radiation is given. The developed model was based on the physics of electronics means failure which represents the description of electro- magnetic, electric and thermal processes that lead to the degradation of the original structure of the apparatus elements. The conditions that lead to the total equation electronic systems functional destruction when exposed to electromagnetic radia- tion pulses are described. The internal characteristics of the component elements that respond to the damaging effects are considered. The ratio for the power failure is determined. A thermal breakdown temperature versus pulse duration of expo- sure at various power levels is obtained. The way of evaluation the reliability of electronic systems when exposed to pulses of electromagnetic radiation as a destructive factor is obtained.

  13. Description of meson strong and electromagnetic interactions in quantum chiral theory

    International Nuclear Information System (INIS)

    Volkov, M.K.; Pervushin, V.N.

    1978-01-01

    Strong and electromagnetic interactions of mesons in the framework of the chiral theory are considered. The pion-pion scattering phases, the pion electromagnetic form factor, the mean squared radius of a K-meson, and the electric and magnetic polarizabilities of pions are calculated using the superpropagator method. The rho-meson mass, Msub(rho)=800 MeV, is calculated too

  14. Effect of frequency variation on electromagnetic pulse interaction with charges and plasma

    NARCIS (Netherlands)

    Khachatryan, A.G.; van Goor, F.A.; Verschuur, Jeroen W.J.; Boller, Klaus J.

    2005-01-01

    The effect of frequency variation (chirp) in an electromagnetic (EM) pulse on the pulse interaction with a charged particle and plasma is studied. Various types of chirp and pulse envelopes are considered. In vacuum, a charged particle receives a kick in the polarization direction after interaction

  15. Low-intensity pulsed ultrasound (LIPUS) and pulsed electromagnetic field (PEMF) treatments affect degeneration of cultured articular cartilage explants

    NARCIS (Netherlands)

    Tan, Lijun; Ren, Yijin; van Kooten, Theo G.; Grijpma, Dirk W.; Kuijer, Roelof

    PURPOSE: Articular cartilage has some capacity for self-repair. Clinically used low-intensity pulsed ultrasound (LIPUS) and pulsed electromagnetic field (PEMF) treatments were compared in their potency to prevent degeneration using an explant model of porcine cartilage. METHODS: Explants of porcine

  16. Low-intensity pulsed ultrasound (LIPUS) and pulsed electromagnetic field (PEMF) treatments affect degeneration of cultured articular cartilage explants

    NARCIS (Netherlands)

    Tan, Lijun; Tan, Lijun; Ren, Yijin; van Kooten, Theo G.; Grijpma, Dirk W.; Kuijer, Roel

    2015-01-01

    Purpose: Articular cartilage has some capacity for self-repair. Clinically used low-intensity pulsed ultrasound (LIPUS) and pulsed electromagnetic field (PEMF) treatments were compared in their potency to prevent degeneration using an explant model of porcine cartilage. Methods: Explants of porcine

  17. A Model for Microcontroller Functionality Upset Induced by External Pulsed Electromagnetic Irradiation

    Science.gov (United States)

    2016-11-21

    AFRL-RD-PS- AFRL-RD-PS- TN-2016-0003 TN-2016-0003 A Model for Microcontroller Functionality Upset Induced by External Pulsed Electromagnetic ...External Pulsed Electromagnetic Irradiation 5a. CONTRACT NUMBER FA9451-15-C-0004 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6 . AUTHOR(S) David...microcontroller (µC) subjected to external irradiation by a narrowband electromagnetic (EM) pulse . In our model, the state of a µC is completely specified by

  18. Thyristor current-pulse generator for betatron electromagnet with independent low-voltage supply

    International Nuclear Information System (INIS)

    Baginskii, B.A.; Makarevich, V.N.; Shtein, M.M.

    1989-01-01

    A thyristor generator is described that produces unipolar current pulses in the winding of a betatron electromagnet. The voltage on the electro-magnet is increased and the shape of the current pulses is improved by use of an intermediate inductive storage device. The current pulses have a duration of 11 msec, an amplitude of 190 A, and a repetition frequency of 50 Hz. The maximum magnetic-field energy is 450 J, the voltage on the electromagnet winding is 1.5 kV, and the supply voltage is 27 V

  19. Electromagnetic excitation of a generic cavity with a variable e-beam pulse

    International Nuclear Information System (INIS)

    Fleetwood, R.; Kerris, K.; Merkel, G.; Roberts, H.; Smith, M.

    1987-01-01

    Relativistic electron-beam nose-erosion techniques have been employed to produce an electron beam with variable pulse shape and bremsstrahlung capability (''dial a pulse''). This capability has been employed to excite a large number of electromagnetic fields inside a canonical cavity. Electron-beam and bremsstrahlung pulse-shape parameters have been varied to produce changes in the electromagnetic cavity response. For example, generic cavity test parameters such as displacement currents or conduction currents can be emphasized or de-emphasized. A theoretical interpretation of these electromagnetic excitations is presented

  20. Considerations for human exposure standards for fast-rise-time high-peak-power electromagnetic pulses.

    Science.gov (United States)

    Merritt, J H; Kiel, J L; Hurt, W D

    1995-06-01

    Development of new emitter systems capable of producing high-peak-power electromagnetic pulses with very fast rise times and narrow pulse widths is continuing. Such directed energy weapons systems will be used in the future to defeat electronically vulnerable targets. Human exposures to these pulses can be expected during testing and operations. Development of these technologies for radar and communications purposes has the potential for wider environmental exposure, as well. Current IEEE C95.1-1991 human exposure guidelines do not specifically address these types of pulses, though limits are stated for pulsed emissions. The process for developing standards includes an evaluation of the relevant bioeffects data base. A recommendation has been made that human exposure to ultrashort electromagnetic pulses that engender electromagnetic transients, called precursor waves, should be avoided. Studies that purport to show the potential for tissue damage induced by such pulses were described. The studies cited in support of the recommendation were not relevant to the issues of tissue damage by propagated pulses. A number of investigations are cited in this review that directly address the biological effects of electromagnetic pulses. These studies have not shown evidence of tissue damage as a result of exposure to high-peak-power pulsed microwaves. It is our opinion that the current guidelines are sufficiently protective for human exposure to these pulses.

  1. Effects of pulsed electromagnetic fields on postmenopausal osteoporosis.

    Science.gov (United States)

    Zhu, Siyi; He, Hongchen; Zhang, Chi; Wang, Haiming; Gao, Chengfei; Yu, Xijie; He, Chengqi

    2017-09-01

    Postmenopausal osteoporosis (PMOP) is considered to be a well-defined subject that has caused high morbidity and mortality. In elderly women diagnosed with PMOP, low bone mass and fragile bone strength have been proven to significantly increase risk of fragility fractures. Currently, various anabolic and anti-resorptive therapies have been employed in an attempt to retain healthy bone mass and strength. Pulsed electromagnetic fields (PEMFs), first applied in treating patients with delayed fracture healing and nonunions, may turn out to be another potential and effective therapy for PMOP. PEMFs can enhance osteoblastogenesis and inhibit osteoclastogenesis, thus contributing to an increase in bone mass and strength. However, accurate mechanisms of the positive effects of PEMFs on PMOP remain to be further elucidated. This review attempts to summarize recent advances of PEMFs in treating PMOP based on clinical trials, and animal and cellular studies. Possible mechanisms are also introduced, and the future possibility of application of PEMFs on PMOP are further explored and discussed. Bioelectromagnetics. 38:406-424, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  2. Pulsed Electromagnetic Fields and Tissue Engineering of the Joints.

    Science.gov (United States)

    Iwasa, Kenjiro; Reddi, A Hari

    2018-04-01

    Bone and joint formation, maintenance, and regeneration are regulated by both chemical and physical signals. Among the physical signals there is an increasing realization of the role of pulsed electromagnetic fields (PEMF) in the treatment of nonunions of bone fractures. The discovery of the piezoelectric properties of bone by Fukada and Yasuda in 1953 in Japan established the foundation of this field. Pioneering research by Bassett and Brighton and their teams resulted in the approval by the Food and Drug Administration (FDA) of the use of PEMF in the treatment of fracture healing. Although PEMF has potential applications in joint regeneration in osteoarthritis (OA), this evolving field is still in its infancy and offers novel opportunities. We have systematically reviewed the literature on the influence of PEMF in joints, including articular cartilage, tendons, and ligaments, of publications from 2000 to 2016. PEMF stimulated chondrocyte proliferation, differentiation, and extracellular matrix synthesis by release of anabolic morphogens such as bone morphogenetic proteins and anti-inflammatory cytokines by adenosine receptors A2 A and A3 in both in vitro and in vivo investigations. It is noteworthy that in clinical translational investigations a beneficial effect was observed on improving function in OA knees. However, additional systematic studies on the mechanisms of action of PEMF on joints and tissues therein, articular cartilage, tendons, and ligaments are required.

  3. In vitro exposure of human chondrocytes to pulsed electromagnetic fields

    Directory of Open Access Journals (Sweden)

    V Nicolin

    2009-08-01

    Full Text Available The effect of pulsed electromagnetic fields (PEMFs on the proliferation and survival of matrix-induced autologous chondrocyte implantation (MACI®-derived cells was studied to ascertain the healing potential of PEMFs. MACI-derived cells were taken from cartilage biopsies 6 months after surgery and cultured. No dedifferentiation towards the fibroblastic phenotype occurred, indicating the success of the surgical implantation. The MACI-derived cultured chondrocytes were exposed to 12 h/day (short term or 4 h/day (long term PEMFs exposure (magnetic field intensity, 2 mT; frequency, 75 Hz and proliferation rate determined by flow cytometric analysis. The PEMFs exposure elicited a significant increase of cell number in the SG2M cell cycle phase. Moreover, cells isolated from MACI® scaffolds showed the presence of collagen type II, a typical marker of chondrocyte functionality. The results show that MACI® membranes represent an optimal bioengineering device to support chondrocyte growth and proliferation in surgical implants. The surgical implant of MACI® combined with physiotherapy is suggested as a promising approach for a faster and safer treatment of cartilage traumatic lesions.

  4. Scattering of an ultrashort electromagnetic radiation pulse by an atom in a broad spectral range

    International Nuclear Information System (INIS)

    Astapenko, V. A.

    2011-01-01

    The scattering of an ultrashort electromagnetic pulse by atomic particles is described using a consistent quantum-mechanical approach taking into account excitation of a target and nondipole electromagnetic interaction, which is valid in a broad spectral range. This approach is applied to the scattering of single- and few-cycle pulses by a multielectron atom and a hydrogen atom. Scattering spectra are obtained for ultrashort pulses of different durations. The relative contribution of “elastic” scattering of a single-cycle pulse by a hydrogen atom is studied in the high-frequency limit as a function of the carrier frequency and scattering angle.

  5. Direct space-time observation of pulse tunneling in an electromagnetic band gap

    International Nuclear Information System (INIS)

    Doiron, Serge; Hache, Alain; Winful, Herbert G.

    2007-01-01

    We present space-time-resolved measurements of electromagnetic pulses tunneling through a coaxial electromagnetic band gap structure. The results show that during the tunneling process the field distribution inside the barrier is an exponentially decaying standing wave whose amplitude increases and decreases as it slowly follows the temporal evolution of the input pulse. At no time is a pulse maximum found inside the barrier, and hence the transmitted peak is not the incident peak that has propagated to the exit. The results support the quasistatic interpretation of tunneling dynamics and confirm that the group delay is not the traversal time of the input pulse peak

  6. High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices: Threat Assessments

    National Research Council Canada - National Science Library

    Wilson, Clay

    2006-01-01

    Electromagnetic Pulse (EMP) is an instantaneous, intense energy field that can disrupt at a distance numerous electrical systems and high technology microcircuits that are especially sensitive to power surges...

  7. High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices: Threat Assessments

    National Research Council Canada - National Science Library

    Wilson, Clay

    2008-01-01

    Electromagnetic Pulse (EMP) is an instantaneous, intense energy field that can overload or disrupt at a distance numerous electrical systems and high technology microcircuits, which are especially sensitive to power surges...

  8. Use of Pulsing Electromagnetic Fields for the Treatment of Pelvic Stress Fractures Among Female Soldiers

    National Research Council Canada - National Science Library

    Jones, D

    1995-01-01

    .... Pulsing electromagnetic fields (PEMFs)have been shown to speed the healing of non-union fractures and we have used them successfully to treat stress fractures in the lower limbs. All women at Ft...

  9. THE INFLUENCE OF NANOSECOND ELECTROMAGNETIC PULSES TO OBTAIN TIN AND THE PROPERTIES OF ITS ALLOYS

    Directory of Open Access Journals (Sweden)

    V. G. Komkov

    2012-01-01

    Full Text Available Experimentally found that the effect of nanosecond electromagnetic pulses to melt the charge, while the carbon thermal recovery of the tin ore, accelerates the formation of the metallic phase.

  10. Damage assessment of long-range rocket system by electromagnetic pulse weapon

    Science.gov (United States)

    Cao, Lingyu; Liu, Guoqing; Li, Jinming

    2017-08-01

    This paper analyzes the damage mechanism and characteristics of electromagnetic pulse weapon, establishes the index system of survivability of long-range rocket launcher system, and uses AHP method to establish the combat effectiveness model of long-range rocket missile system. According to the damage mechanism and characteristics of electromagnetic pulse weapon, the damage effect of the remote rocket system is established by using the exponential method to realize the damage efficiency of the remote rocket system.

  11. High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices: Threat Assessments

    Science.gov (United States)

    2008-07-21

    against HEMP effects resulting from a nuclear exchange.40 The Limited Test Ban Treaty of 1963 prohibits nuclear explosions in the atmosphere, in space, and...Order Code RL32544 High Altitude Electromagnetic Pulse ( HEMP ) and High Power Microwave (HPM) Devices: Threat Assessments Updated July 21, 2008 Clay...2008 to 00-00-2008 4. TITLE AND SUBTITLE High Altitude Electromagnetic Pulse ( HEMP ) and High Power Microwave (HPM) Devices: Threat Assessments 5a

  12. Wake-Field Wave Resonant Excitation in Magnetized Plasmas by Electromagnetic Pulse

    International Nuclear Information System (INIS)

    Milant'ev, V.P.; Turikov, V.A.

    2006-01-01

    In this paper the space charge wave excitation process at electromagnetic pulse propagation along external magnetic field in vicinity of electron cyclotron resonance. In hydrodynamic approach it is obtained an equation for plasma density under ponderomotive force action. With help of this equation we investigated a wake-field wave amplitude dependence from resonance detuning. The numerical simulation using a PIC method electromagnetic pulse propagation process in the resonant conditions was done

  13. Simulation study of a pulsed neutron focusing using a pulsed electromagnetic lens coupled with a permanent magnet

    International Nuclear Information System (INIS)

    Iwashita, H.; Iwasa, H.; Hiraga, F.; Kamiyama, T.; Kiyanagi, Y.; Suzuki, J.; Shinohara, T.; Oku, T.; Shimizu, H.M.

    2009-01-01

    A pulsed sextupole electromagnetic lens with suitably controlled time-dependent magnetic field can in principle focus pulsed neutrons at the same focal point over a wide range of wavelength as the lens removes aberrations. However, in fact, it is difficult to focus neutrons over a wide range of wavelength because attenuation of a practical pulsed sextupole electromagnet is faster than an ideal case. We have devised a method of canceling the difference between the practical pulsed sextupole magnetic field and the ideal magnetic field with the use of a permanent sextupole magnet. We performed simulation calculations to investigate the feasibility of this method, and it was shown that focusing wavelength range spread compared with the case using a pulsed magnetic lens only. This result indicates the usefulness of the method.

  14. Estimation of the Lithospheric Component Share in the Earth Natural Pulsed Electromagnetic Field Structure

    Science.gov (United States)

    Malyshkov, S. Y.; Gordeev, V. F.; Polyvach, V. I.; Shtalin, S. G.; Pustovalov, K. N.

    2017-04-01

    Article describes the results of the atmosphere and Earth’s crust climatic and ecological parameters integrated monitoring. The estimation is made for lithospheric component share in the Earth natural pulsed electromagnetic field structure. To estimate lithospheric component we performed a round-the-clock monitoring of the Earth natural pulsed electromagnetic field background variations at the experiment location and measured the Earth natural pulsed electromagnetic field under electric shields. Natural materials in a natural environment were used for shielding, specifically lakes with varying parameters of water conductivity. Skin effect was used in the experiment - it is the tendency of electromagnetic waves amplitude to decrease with greater depths in the conductor. Atmospheric and lithospheric component the Earth natural pulsed electromagnetic field data recorded on terrain was compared against the recorded data with atmosphere component decayed by an electric shield. In summary we have demonstrated in the experiment that thunderstorm discharge originating electromagnetic field decay corresponds to the decay calculated using Maxwell equations. In the absence of close lightning strikes the ratio of field intensity recorded on terrain to shielded field intensity is inconsistent with the ratio calculated for atmospheric sources, that confirms there is a lithospheric component present to the Earth natural pulsed electromagnetic field.

  15. Pulse interactions in a quantum dot waveguide in the regime of electromagnetically Induced transparency

    DEFF Research Database (Denmark)

    Nielsen, Per; Nielsen, Henri; Mørk, Jesper

    2006-01-01

    The interaction of optical pulses in a quantum dot waveguide in the slow-light regime is investigated. Dipole oscillations lead to strong interactions between the two pulses, implying a minimum pulse separation for optical buffer applications.......The interaction of optical pulses in a quantum dot waveguide in the slow-light regime is investigated. Dipole oscillations lead to strong interactions between the two pulses, implying a minimum pulse separation for optical buffer applications....

  16. Converting Existing Copper Wire Firing System to a Fiber Optically Controlled Firing System for Electromagnetic Pulsed Power Experiments

    Science.gov (United States)

    2017-12-19

    Firing System for Electromagnetic Pulsed Power Experiments by Robert Borys Jr and Colby Adams Approved for public release...2017 4. TITLE AND SUBTITLE Converting Existing Copper Wire Firing System to a Fiber-Optically Controlled Firing System for Electromagnetic Pulsed ...US Army Research Laboratory Converting Existing Copper Wire Firing System to a Fiber-Optically Controlled Firing System for Electromagnetic

  17. Pulsed Neutron Scattering Studies of Strongly Fluctuating solids, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Collin Broholm

    2006-06-22

    The conventional description of a solid is based on a static atomic structure with small amplitude so-called harmonic fluctuations about it. This is a final technical report for a project that has explored materials where fluctuations are sufficiently strong to severely challenge this approach and lead to unexpected and potentially useful materials properties. Fluctuations are enhanced when a large number of configurations share the same energy. We used pulsed spallation source neutron scattering to obtain detailed microscopic information about structure and fluctuations in such materials. The results enhance our understanding of strongly fluctuating solids and their potential for technical applications. Because new materials require new experimental techniques, the project has also developed new techniques for probing strongly fluctuating solids. Examples of material that were studied are ZrW2O8 with large amplitude molecular motion that leads to negative thermal expansion, NiGa2S4 where competing interactions lead to an anomalous short range ordered magnet, Pr1- xBixRu2O7 where a partially filled electron shell (Pr) in a weakly disordered environment produces anomalous metallic properties, and TbMnO3 where competing interactions lead to a magneto-electric phase. The experiments on TbMnO3 exemplify the relationship between research funded by this project and future applications. Magneto-electric materials may produce a magnetic field when an electric field is applied or vise versa. Our experiments have clarified the reason why electric and magnetic polarization is coupled in TbMnO3. While this knowledge does not render TbMnO3 useful for applications it will focus the search for a practical room temperature magneto-electric for applications.

  18. Effect of pulsed electromagnetic fields on endoplasmic reticulum stress.

    Science.gov (United States)

    Keczan, E; Keri, G; Banhegyi, G; Stiller, I

    2016-10-01

    The maintenance of protein homeostasis in the endoplasmic reticulum (ER) is crucial in cell life. Disruption of proteostasis results in ER stress that activates the unfolded protein response (UPR); a signalling network assigned to manage the accumulated misfolded or unfolded proteins. Prolonged or unresolved ER stress leads to apoptotic cell death that can be the basis of many serious diseases. Our aim was to study the effect of pulsed electromagnetic fields (PEMF), an alternative, non-invasive therapeutic method on ER stressed cell lines. First, the effect of PEMF treatment on the expression of ER stress markers was tested in three different cell lines. PEMF had no remarkable effect on ER stress protein levels in human embryonic kidney (HEK293T) and human liver carcinoma (HepG2) cell lines. However, the expression of BiP, Grp94 and CHOP were increased in HeLa cells upon PEMF exposure. Therefore, HepG2 cell line was selected for further experiments. Cells were stressed by tunicamycin and exposed to PEMF. Grp94, PDI, CHOP and PARP expression as markers of stress were monitored by Western blot and cell viability was also investigated. Tunicamycin treatment, as expected, increased the expression of Grp94, PDI, CHOP and inactivated PARP. Analysis of protein expression showed that PEMF was able to decrease the elevated level of ER chaperons Grp94, PDI and the apoptosis marker CHOP. The truncated, inactive form of PARP was also decreased. Accordingly, cell viability was also improved by PEMF exposure. These results indicate that PEMF is able to moderate ER stress induced by tunicamycin in HepG2 cells. However, our results clearly draw attention to that different cell lines may vary in the response to PEMF treatment.

  19. Pulsed electromagnetic field treatments enhance the healing of fibular osteotomies.

    Science.gov (United States)

    Midura, Ronald J; Ibiwoye, Michael O; Powell, Kimerly A; Sakai, Yoshitada; Doehring, Todd; Grabiner, Mark D; Patterson, Thomas E; Zborowski, Maciej; Wolfman, Alan

    2005-09-01

    This study tested the hypothesis that pulsed electromagnetic field (PEMF) treatments augment and accelerate the healing of bone trauma. It utilized micro-computed tomography imaging of live rats that had received bilateral 0.2 mm fibular osteotomies (approximately 0.5% acute bone loss) as a means to assess the in vivo rate dynamics of hard callus formation and overall callus volume. Starting 5 days post-surgery, osteotomized right hind limbs were exposed 3 h daily to Physio-Stim PEMF, 7 days a week for up to 5 weeks of treatment. The contralateral hind limbs served as sham-treated, within-animal internal controls. Although both PEMF- and sham-treatment groups exhibited similar onset of hard callus at approximately 9 days after surgery, a 2-fold faster rate of hard callus formation was observed thereafter in PEMF-treated limbs, yielding a 2-fold increase in callus volume by 13-20 days after surgery. The quantity of the new woven bone tissue within the osteotomy sites was significantly better in PEMF-treated versus sham-treated fibulae as assessed via hard tissue histology. The apparent modulus of each callus was assessed via a cantilever bend test and indicated a 2-fold increase in callus stiffness in the PEMF-treated over sham-treated fibulae. PEMF-treated fibulae exhibited an apparent modulus at the end of 5-weeks that was approximately 80% that of unoperated fibulae. Overall, these data indicate that Physio-Stim PEMF treatment improved osteotomy repair. These beneficial effects on bone healing were not observed when a different PEMF waveform, Osteo-Stim, was used. This latter observation demonstrates the specificity in the relationship between waveform characteristics and biological outcomes.

  20. Giant elves: Lightning-generated electromagnetic pulses in giant planets.

    Science.gov (United States)

    Luque Estepa, Alejandro; Dubrovin, Daria; José Gordillo-Vázquez, Francisco; Ebert, Ute; Parra-Rojas, Francisco Carlos; Yair, Yoav; Price, Colin

    2015-04-01

    We currently have direct optical observations of atmospheric electricity in the two giant gaseous planets of our Solar System [1-5] as well as radio signatures that are possibly generated by lightning from the two icy planets Uranus and Neptune [6,7]. On Earth, the electrical activity of the troposphere is associated with secondary electrical phenomena called Transient Luminous Events (TLEs) that occur in the mesosphere and lower ionosphere. This led some researchers to ask if similar processes may also exist in other planets, focusing first on the quasi-static coupling mechanism [8], which on Earth is responsible for halos and sprites and then including also the induction field, which is negligible in our planet but dominant in Saturn [9]. However, one can show that, according to the best available estimation for lightning parameters, in giant planets such as Saturn and Jupiter the effect of the electromagnetic pulse (EMP) dominates the effect that a lightning discharge has on the lower ionosphere above it. Using a Finite-Differences, Time-Domain (FDTD) solver for the EMP we found [10] that electrically active storms may create a localized but long-lasting layer of enhanced ionization of up to 103 cm-3 free electrons below the ionosphere, thus extending the ionosphere downward. We also estimate that the electromagnetic pulse transports 107 J to 1010 J toward the ionosphere. There emissions of light of up to 108 J would create a transient luminous event analogous to a terrestrial elve. Although these emissions are about 10 times fainter than the emissions coming from the lightning itself, it may be possible to target them for detection by filtering the appropiate wavelengths. [1] Cook, A. F., II, T. C. Duxbury, and G. E. Hunt (1979), First results on Jovian lightning, Nature, 280, 794, doi:10.1038/280794a0. [2] Little, B., C. D. Anger, A. P. Ingersoll, A. R. Vasavada, D. A. Senske, H. H. Breneman, W. J. Borucki, and The Galileo SSI Team (1999), Galileo images of

  1. Uncertainty assessment of breakdown threshold values test of semiconductor components for electromagnetic pulse

    International Nuclear Information System (INIS)

    Mao Congguang; Sun Beiyun; Nie Xin; Chen Xiangyue; Zhou Hui

    2009-01-01

    According to the national military standard GJB538-88, the pulse current injection (PCI) test are conducted to measure the breakdown threshold values of solid-state relays for electromagnetic pulse. The method and procedure of measurement uncertainty assessment are provided. And the specific characteristics in the assessment of the breakdown test are discussed in details. (authors)

  2. Pulsed electromagnetic field radiation from a narrow slot antenna with a dielectric layer

    NARCIS (Netherlands)

    Štumpf, M.; De Hoop, A.T.; Lager, I.E.

    2010-01-01

    Analytic time domain expressions are derived for the pulsed electromagnetic field radiated by a narrow slot antenna with a dielectric layer in a two?dimensional model configuration. In any finite time window of observation, exact pulse shapes for the propagated, reflected, and refracted wave

  3. 7th conference on ultra-wideband, short-pulse electromagnetics

    CERN Document Server

    Schenk, Uwe; Nitsch, Daniel; Sabath, Frank; Ultra-Wideband, Short-Pulse Electromagnetics 7; UWBSP7

    2007-01-01

    Ultra-wideband (UWB), short-pulse (SP) electromagnetics are now being used for an increasingly wide variety of applications, including collision avoidance radar, concealed object detection, and communications. Notable progress in UWB and SP technologies has been achieved by investigations of their theoretical bases and improvements in solid-state manufacturing, computers, and digitizers. UWB radar systems are also being used for mine clearing, oil pipeline inspections, archeology, geology, and electronic effects testing. Ultra-Wideband Short-Pulse Electromagnetics 7 presents selected papers of deep technical content and high scientific quality from the UWB-SP7 Conference, including wide-ranging contributions on electromagnetic theory, scattering, UWB antennas, UWB systems, ground penetrating radar (GPR), UWB communications, pulsed-power generation, time-domain computational electromagnetics, UWB compatibility, target detection and discrimination, propagation through dispersive media, and wavelet and multi-res...

  4. Mechanisms and therapeutic effectiveness of pulsed electromagnetic field therapy in oncology.

    Science.gov (United States)

    Vadalà, Maria; Morales-Medina, Julio Cesar; Vallelunga, Annamaria; Palmieri, Beniamino; Laurino, Carmen; Iannitti, Tommaso

    2016-11-01

    Cancer is one of the most common causes of death worldwide. Available treatments are associated with numerous side effects and only a low percentage of patients achieve complete remission. Therefore, there is a strong need for new therapeutic strategies. In this regard, pulsed electromagnetic field (PEMF) therapy presents several potential advantages including non-invasiveness, safety, lack of toxicity for non-cancerous cells, and the possibility of being combined with other available therapies. Indeed, PEMF stimulation has already been used in the context of various cancer types including skin, breast, prostate, hepatocellular, lung, ovarian, pancreatic, bladder, thyroid, and colon cancer in vitro and in vivo. At present, only limited application of PEMF in cancer has been documented in humans. In this article, we review the experimental and clinical evidence of PEMF therapy discussing future perspectives in its use in oncology. © 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  5. Reemission spectra and inelastic processes at interaction of attosecond and shorter duration electromagnetic pulses with atoms

    Directory of Open Access Journals (Sweden)

    Makarov D.N.

    2017-01-01

    Full Text Available Inelastic processes and the reemission of attosecond and shorter electromagnetic pulses by atoms have been considered within the analytical solution of the Schrödinger equation in the sudden perturbation approximation. A method of calculations with the exact inclusion of spatial inhomogeneity of the field of an ultrashort pulse and the momenta of photons in the reemission processes has been developed. The probabilities of inelastic processes and spectra of reemission of ultrashort electromagnetic pulses by one- and many-electron atoms have been calculated. The results have been presented in the form of analytical formulas.

  6. Autler-Townes doublet and electromagnetically induced transparency resonance probed by an ultrashort pulse train

    International Nuclear Information System (INIS)

    Soares, A A; De Araujo, Luis E E

    2010-01-01

    We study theoretically the interaction between an ultrashort pulse train and a three-level atom driven by a cw laser. We show that the pulse train can be employed to observe spectra of Autler-Townes doublet and electromagnetically induced transparency resonance that are time and frequency resolved. The observation of subnatural linewidth features associated with the electromagnetically induced transparency resonance is described. The temporal evolution of electromagnetically induced transparency of the pulse train is shown to exhibit new and different features compared to that of the related phenomenon of coherent population trapping. By matching the tooth separation of the frequency comb associated with the pulse train to that of the Autler-Townes doublet, quantum beats between the doublet components can be induced. We show that coherent accumulation of excitation plays a major role in the two studied phenomena.

  7. 8th conference on Ultra-Wideband Short-Pulse Electromagnetics

    CERN Document Server

    Tyo, J. Scott; Baum, Carl E; Ultra-Wideband Short-Pulse Electromagnetics 8; UWBSP8

    2007-01-01

    The purpose of the Ultra-Wideband Short-Pulse Electromagnetics Conference series is to focus on advanced technologies for the generation, radiation and detection of ultra-wideband short pulse signals, taking into account their propagation and scattering from and coupling to targets of interest. This Conference series reports on developments in supporting mathematical and numerical methods and presents current and potential future applications of the technology. Ultra-Wideband Short-Pulse Electromagnetics 8 is based on the American Electromagnetics 2006 conference held from June 3-7 in Albuquerque, New Mexico. Topical areas covered in this volume include pulse radiation and measurement, scattering theory, target detection and identification, antennas, signal processing, and communications.

  8. Pulsed electromagnetic field radiation from a narrow slot antenna with a dielectric layer

    OpenAIRE

    Stumpf, M.; de Hoop, A. T.; Lager, I. E.

    2010-01-01

    Analytic time domain expressions are derived for the pulsed electromagnetic field radiated by a narrow slot antenna with a dielectric layer in a two?dimensional model configuration. In any finite time window of observation, exact pulse shapes for the propagated, reflected, and refracted wave constituents are constructed with the aid of the modified Cagniard method (Cagniard?DeHoop method). Numerical results are presented for vanishing slot width and field pulse shapes at the dielectric/free s...

  9. Electrochemotherapy by pulsed electromagnetic field treatment (PEMF) in mouse melanoma B16F10 in vivo

    OpenAIRE

    Kranjc Simona; Kranjc Matej; Scancar Janez; Jelenc Jure; Sersa Gregor; Miklavcic Damijan

    2016-01-01

    Introduction Pulsed electromagnetic field (PEMF) induces pulsed electric field, which presumably increases membrane permeabilization of the exposed cells, similar to the conventional electroporation. Thus, contactless PEMF could represent a promising approach for drug delivery. Materials and methods Noninvasive electroporation was performed by magnetic field pulse generator connected to an applicator consisting of round coil. Subcutaneous mouse B16F10 melanoma tumors were treated with intrave...

  10. Dynamic behavior of superconducting flux qubit excited by a series of electromagnetic pulses

    International Nuclear Information System (INIS)

    Kiyko, A.S.; Omelyanchouk, A.N.; Shevchenko, S.N.

    2007-01-01

    We study theoretically the behavior of the superconducting flux qubit subjected to a series of electromagnetic pulses. The possibility of controlling system state via changing the parameters of the pulse is studied. We calculated the phase shift in a tank circuit weakly coupled to the qubit which can be measured by the impedance measurement technique. For the flux qubit we consider the possibility of estimating the relaxation rate from the impedance measurements by varying the delay time between the pulses

  11. Sound absorption in a field of a strong electromagnetic wave in a quantizied magnetic field

    International Nuclear Information System (INIS)

    Chajkovskij, I.A.

    1974-01-01

    A coefficient of sound absorption GAMMA in a semiconductor and semi-metal in the quantized magnetic field is calculated for a system exposed to a field of strong electromagnetic radiation. The cases E parallel H and E orthogonal H are considered. Along with the already known strong oscillations of sound absorption in magnetic fields, the absorption spectrum GAMMAsub(par) and GAMMAsub(orth) shows new oscillations representing a manifestation of the quasi-energetic electron spectrum in the field of a strong electromagnetic wave. The oscillation height at E parallel H is modulated by the electromagnetic field. It is shown that the ratio GAMMAsub(par)/GAMMAsub(orth) allows the determination of the effective mass of the carriers

  12. Theoretical & Experimental Research in Weak, Electromagnetic & Strong Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Nandi, Satyanarayan [Oklahoma State Univ., Stillwater, OK (United States); Babu, Kaladi [Oklahoma State Univ., Stillwater, OK (United States); Rizatdinova, Flera [Oklahoma State Univ., Stillwater, OK (United States); Khanov, Alexander [Oklahoma State Univ., Stillwater, OK (United States); Haley, Joseph [Oklahoma State Univ., Stillwater, OK (United States)

    2015-09-17

    The conducted research spans a wide range of topics in the theoretical, experimental and phenomenological aspects of elementary particle interactions. Theory projects involve topics in both the energy frontier and the intensity frontier. The experimental research involves energy frontier with the ATLAS Collaboration at the Large Hadron Collider (LHC). In theoretical research, novel ideas going beyond the Standard Model with strong theoretical motivations were proposed, and their experimental tests at the LHC and forthcoming neutrino facilities were outlined. These efforts fall into the following broad categories: (i) TeV scale new physics models for LHC Run 2, including left-right symmetry and trinification symmetry, (ii) unification of elementary particles and forces, including the unification of gauge and Yukawa interactions, (iii) supersummetry and mechanisms of supersymmetry breaking, (iv) superworld without supersymmetry, (v) general models of extra dimensions, (vi) comparing signals of extra dimensions with those of supersymmetry, (vii) models with mirror quarks and mirror leptons at the TeV scale, (viii) models with singlet quarks and singlet Higgs and their implications for Higgs physics at the LHC, (ix) new models for the dark matter of the universe, (x) lepton flavor violation in Higgs decays, (xi) leptogenesis in radiative models of neutrino masses, (xii) light mediator models of non-standard neutrino interactions, (xiii) anomalous muon decay and short baseline neutrino anomalies, (xiv) baryogenesis linked to nucleon decay, and (xv) a new model for recently observed diboson resonance at the LHC and its other phenomenological implications. The experimental High Energy Physics group has been, and continues to be, a successful and productive contributor to the ATLAS experiment at the LHC. Members of the group performed search for gluinos decaying to stop and top quarks, new heavy gauge bosons decaying to top and bottom quarks, and vector-like quarks

  13. Attosecond electromagnetic pulse generation due to the interaction of a relativistic soliton with a breaking-wake plasma wave

    International Nuclear Information System (INIS)

    Isanin, A.V.; Kamenets, F.F.; Bulanov, S.S.; Pegoraro, F.

    2005-01-01

    During the interaction of a low-frequency relativistic soliton with the electron density modulations of a wake plasma wave, part of the electromagnetic energy of the soliton is reflected in the form of an extremely short and ultraintense electromagnetic pulse. We calculate the spectra of the reflected and of the transmitted electromagnetic pulses analytically. The reflected wave has the form of a single cycle attosecond pulse

  14. Electron-positron pair production by electromagnetic pulses

    International Nuclear Information System (INIS)

    Bulanov, S. S.; Narozhny, N. B.; Mur, V. D.; Popov, V. S.

    2006-01-01

    Electron-positron pair production in vacuum by a single focused laser pulse and by two counter-propagating colliding focused pulses is analyzed. A focused laser pulse is described using a realistic three-dimensional model based on an exact solution of Maxwell's equations. In particular, this model reproduces an important property of focused beams, namely, the existence of two types of waves with a transverse electric or magnetic vector (e-or h-polarized wave, respectively). The dependence of the number of produced pairs on the radiation intensity and focusing parameter is studied. It has been shown that the number of pairs produced in the field of a single e-polarized pulse is many orders of magnitude larger than that for an h-polarized pulse. The pulse-intensity dependence of the number of pairs produced by a single pulse is so sharp that the total energy of pairs produced by the e-polarized pulse with intensity near the intensity I S 4.65 x 10 29 W/cm 2 characteristic of QED is comparable with the energy of the pulse itself. This circumstance imposes a natural physical bound on the maximum attainable intensity of a laser pulse. For the case of two colliding circularly polarized pulses, it is shown that pair production becomes experimentally observable when the intensity of each beam is I ∼ 10 26 W/cm 2 , which is one to two orders of magnitude lower than that for a single pulse

  15. High Accuracy DOA Estimation of Electromagnetic Pulses using Analogue Signal Processing

    Science.gov (United States)

    Kumazawa, Takao; Oka, Fujio; Kashizaki, Tsutomu

    Partial discharges (PDs), which occur at coupling points of tension insulators or binding spots of insulated wire of distribution lines, might cause television interference or ground fault. A technique for location of the sources of PDs using time differences in arrival of electromagnetic pulses radiated from PDs has been investigated recently, because it is difficult to find the sources by visual inspection from the ground. However, the technique requires a large and expensive apparatus such as digital storage oscilloscope able to record waveforms of the electromagnetic pulses very fast. We investigate a new technique to estimate the direction of arrival (DOA) of the electromagnetic pulses using analogue signal processing. The experimental analogue circuits for measurement of the time (phase) differences are composed of general purpose modules, i.e., amplifiers, filters, local oscillator, dividers, mixers, etc, and the DOA of the electromagnetic pulse is indicated using a circular symbol superimposed onto the photo image taken with a CCD camera. From the results of the experiments on the DOA estimation, it was proved that the new technique is available for high accuracy DOA estimation of the electromagnetic pulses radiated from PDs in air.

  16. Three-dimensional electromagnetic strong turbulence. II. Wave packet collapse and structure of wave packets during strong turbulence

    Science.gov (United States)

    Graham, D. B.; Robinson, P. A.; Cairns, Iver H.; Skjaeraasen, O.

    2011-07-01

    Large-scale simulations of wave packet collapse are performed by numerically solving the three-dimensional (3D) electromagnetic Zakharov equations, focusing on individual wave packet collapses and on wave packets that form in continuously driven strong turbulence. The collapse threshold is shown to decrease as the electron thermal speed νe/c increases and as the temperature ratio Ti/Te of ions to electrons decreases. Energy lost during wave packet collapse and dissipation is shown to depend on νe/c. The dynamics of density perturbations after collapse are studied in 3D electromagnetic strong turbulence for a range of Ti/Te. The structures of the Langmuir, transverse, and total electric field components of wave packets during strong turbulence are investigated over a range of νe/c. For νe/c ≲0.17, strong turbulence is approximately electrostatic and wave packets have very similar structure to purely electrostatic wave packets. For νe/c ≳0.17, transverse modes become trapped in density wells and contribute significantly to the structure of the total electric field. At all νe/c, the Langmuir energy density contours of wave packets are predominantly oblate (pancake shaped). The transverse energy density contours of wave packets are predominantly prolate (sausage shaped), with the major axis being perpendicular to the major axes of the Langmuir component. This results in the wave packet becoming more nearly spherical as νe/c increases, and in turn generates more spherical density wells during collapse. The results obtained are compared with previous 3D electrostatic results and 2D electromagnetic results.

  17. 2nd International Conference on Ultra-Wideband, Short-Pulse Electromagnetics

    CERN Document Server

    Felsen, Leopold

    1995-01-01

    The papers published in this volume were presented at the Second International Conference on Ultra-WidebandiShort-Pulse (UWB/SP) Electromagnetics, ApriIS-7, 1994. To place this second international conference in proper perspective with respect to the first conference held during October 8-10, 1992, at Polytechnic University, some background information is necessary. As we had hoped, the first conference struck a responsive cord, both in timeliness and relevance, among the electromagnetic community 1. Participants at the first conference already inquired whether and when a follow-up meeting was under consideration. The first concrete proposal in this direction was made a few months after the first conference by Prof. A. Terzuoli of the Air Force Institute of Technology (AFIT), Dayton, Ohio, who has been a strong advocate of time-domain methods and technologies. He initially proposed a follow-up time-domain workshop under AFIT auspices. Realizing that interest in this subject is lodged also at other Air Force i...

  18. FDTD computation of human eye exposure to ultra-wideband electromagnetic pulses

    International Nuclear Information System (INIS)

    Simicevic, Neven

    2008-01-01

    With an increase in the application of ultra-wideband (UWB) electromagnetic pulses in the communications industry, radar, biotechnology and medicine, comes an interest in UWB exposure safety standards. Despite an increase of the scientific research on bioeffects of exposure to non-ionizing UWB pulses, characterization of those effects is far from complete. A numerical computational approach, such as a finite-difference time domain (FDTD) method, is required to visualize and understand the complexity of broadband electromagnetic interactions. The FDTD method has almost no limits in the description of the geometrical and dispersive properties of the simulated material, it is numerically robust and appropriate for current computer technology. In this paper, a complete calculation of exposure of the human eye to UWB electromagnetic pulses in the frequency range of 3.1-10.6, 22-29 and 57-64 GHz is performed. Computation in this frequency range required a geometrical resolution of the eye of 0.1 mm and an arbitrary precision in the description of its dielectric properties in terms of the Debye model. New results show that the interaction of UWB pulses with the eye tissues exhibits the same properties as the interaction of the continuous electromagnetic waves (CWs) with the frequencies from the pulse's frequency spectrum. It is also shown that under the same exposure conditions the exposure to UWB pulses is from one to many orders of magnitude safer than the exposure to CW

  19. Bow Wave from Ultraintense Electromagnetic Pulses in Plasmas

    International Nuclear Information System (INIS)

    Esirkepov, T. Zh.; Bulanov, S. V.; Kato, Y.

    2008-01-01

    We show a new effect of the bow-wave excitation by an intense short laser pulse propagating in underdense plasma. Because of spreading of the laser pulse energy in transverse direction, the bow wave causes a large-scale transverse modulation of the electron density. This can significantly increase the electric potential of the wake wave since the wake wave is generated in the region much wider than the laser pulse waist

  20. Parity violation effects in the hydrogen atom in the field of a strong electromagnetic wave

    International Nuclear Information System (INIS)

    Labzovsky, L.N.; Mitrushchenkov, A.O.

    1989-01-01

    The parity violation effects in the hydrogen atom in a strong electromagnetic laser field are considered. It is shown that there is the possibility of hyperrate measurements of different constants of the weak interaction in the hydrogen magnetic resonance experiments. (orig.)

  1. Manifestation of Symmetry Properties of Nucleon Structure in Strong and Electromagnetic Processes

    Science.gov (United States)

    Tomasi-Gustafsson, Egle; Rekalo, Michail P.

    2004-04-01

    In this contribution we present a specific application of a result obtained by Franco Iachello (in collaboration with R. Bijker and A. Leviatan), which concerns the inelastic electromagnetic form factors on the nucleons. In particular we show examples where symmetries inherent to the structure of the nucleon resonances can manifest in complicated processes of the strong interaction.

  2. 10th and 11th conference on Ultra-Wideband Short-Pulse Electromagnetics

    CERN Document Server

    Mokole, Eric; UWB SP 10; UWB SP 11

    2014-01-01

    This book presents contributions of deep technical content and high scientific quality in the areas of electromagnetic theory, scattering, UWB antennas, UWB systems, ground penetrating radar (GPR), UWB communications, pulsed-power generation, time-domain computational electromagnetics, UWB compatibility, target detection and discrimination, propagation through dispersive media, and wavelet and multi-resolution techniques. Ultra-wideband (UWB), short-pulse (SP) electromagnetics are now being used for an increasingly wide variety of applications, including collision avoidance radar, concealed object detection, and communications. Notable progress in UWB and SP technologies has been achieved by investigations of their theoretical bases and improvements in solid-state manufacturing, computers, and digitizers. UWB radar systems are also being used for mine clearing, oil pipeline inspections, archeology, geology, and electronic effects testing. Like previous books in this series, Ultra-Wideband Short-Pulse Electrom...

  3. Fractional Calculus Based FDTD Modeling of Layered Biological Media Exposure to Wideband Electromagnetic Pulses

    Directory of Open Access Journals (Sweden)

    Luciano Mescia

    2017-11-01

    Full Text Available Electromagnetic fields are involved in several therapeutic and diagnostic applications such as hyperthermia and electroporation. For these applications, pulsed electric fields (PEFs and transient phenomena are playing a key role for understanding the biological response due to the exposure to non-ionizing wideband pulses. To this end, the PEF propagation in the six-layered planar structure modeling the human head has been studied. The electromagnetic field and the specific absorption rate (SAR have been calculated through an accurate finite-difference time-domain (FDTD dispersive modeling based on the fractional derivative operator. The temperature rise inside the tissues due to the electromagnetic field exposure has been evaluated using both the non-thermoregulated and thermoregulated Gagge’s two-node models. Moreover, additional parametric studies have been carried out with the aim to investigate the thermal response by changing the amplitude and duration of the electric pulses.

  4. The Effects of Transcranial Pulsed Electromagnetic Field stimulation on quality of life in Parkinson's Disease

    DEFF Research Database (Denmark)

    Morberg, Bo Mohr; Malling, Anne Sofie; Jensen, Bente Rona

    2018-01-01

    BACKGROUND: Pulsed electromagnetic fields induce a protective and anti-inflammatory effect in the nervous system primarily due to growth factor up regulation that possibly abates neurodegeneration in Parkinson's disease. This study investigated treatment effects of transcranial pulsed...... electromagnetic fields on quality of life in Parkinson's disease and secondly the feasibility and safety of this treatment. METHODS: In this double-blinded clinical study, 97 participants with idiopathic Parkinson's disease (Hoehn & Yahr I-IV) in optimal medical anti-parkinson treatment, were block randomized 3......:3 to either active (n=49) or placebo treatment (n=48). Treatment with transcranial pulsed electromagnetic fields entailed one daily 30-minute home treatment for eight consecutive weeks. The 39-item Parkinson's Disease Questionnaire was assessed at baseline and at endpoint. Profiling adverse events a special...

  5. Nucleation and Grain Refinement of 7A04 Aluminum Alloy Under a Low-Power Electromagnetic Pulse

    Science.gov (United States)

    Bai, Qingwei; Ma, Yonglin; Xing, Shuqing; Bao, Xinyu; Feng, Yanfei; Kang, Xiaolan

    2018-02-01

    The effects of a low-power electromagnetic pulse on the grain size and cooling curve of high-strength aluminum alloy 7A04 were investigated for various pulse duty cycles. This electromagnetic pulse treatment was found to effectively produce fine grains with globular crystals and a uniform microstructure for pulse duty cycles between 20 and 40%. The key factors that affected grain refinement under the electromagnetic pulse included the electromagnetic energy and the conversion frequency between \\varvec{B} and \\varvec{E} . The nucleation rate increased as the nucleation period was extended. A new kinetic condition of magnetic nucleation was explored by decreasing the critical Gibbs free energy in the electromagnetic pulse, which was more sensitive under low undercooling. In addition, the crystal orientation was controlled in such a solidification environment.

  6. Emission and electron transitions in an atom interacting with an ultrashort electromagnetic pulse

    International Nuclear Information System (INIS)

    Matveev, V.I.

    2003-01-01

    Electron transitions and emission of an atom interacting with a spatially inhomogeneous ultrashort electromagnetic pulse are considered. The excitation and ionization probabilities are obtained as well as the spectra and cross sections of the reemission of such a pulse by atoms. By way of an example, one- and two-electron inelastic processes accompanying the interaction of ultrashort pulses with hydrogen- and helium-like atoms are considered. The developed technique makes it possible to take into account exactly the spatial nonuniformity of the ultrashort pulse field and photon momenta in the course of reemission

  7. Application of CPML to two-dimension numerical simulation of nuclear electromagnetic pulse from air explosions

    International Nuclear Information System (INIS)

    Gao Chunxia; Wang Lianghou

    2005-01-01

    The characteristics of different types of PML were analyzed and the convolutional PML was chosen to truncate the open boundaries in numerical simulation of nuclear electromagnetic pulse from air explosions. On the basis of the split-field PML and the plane-wave solution of electromagnetic field in free space, the unsplit-field PML was constructed. By applying the convolutional theorem of Fourier transform, the discrete iterative equations of electromagnetic field components were presented in the CPML media under the two-dimension prolate-spheroidal coordinate system. The numerical results indicate that the method of CPML can largely decrease calculation errors of boundary fields. (authors)

  8. Response on the earth surface due to illumination by electromagnetic pulse of nuclear explosion

    International Nuclear Information System (INIS)

    Nesic, R.

    1983-01-01

    Electromagnetic pulse is one of environment responses to extitation by nuclear explosion, its influence on the surface of the earth is most expressed in case of a nuclear explosion in ionosphere. For electromagnetic pulse of ionospheric explosion the time response, spectrum, spectral distribution and integral flux of energy on the earth surface were analysed, responses to them in shape of conductive voltage and currents were defined. Obtained shapes of responses and their range of variation are the base to define requirements for needed and justified protections. (author)

  9. Interactions of Low-Frequency, Pulsed Electromagnetic Fields with Living Tissue: Biochemical Responses and Clinical Results

    DEFF Research Database (Denmark)

    Rahbek, Ulrik L.; Tritsaris, Katerina; Dissing, Steen

    2005-01-01

    , are still lacking. Despite the apparent success of the PEMF technology very little is known regarding the coupling between pulsed electrical fields and biochemical events leading to cellular responses. Insight into this research area is therefore of great importance. In this review we describe the physical...... properties of PEMF-induced electrical fields and explain the typical set up for coils and pulse patterns. Furthermore, we discuss possible models that can account for mechanisms by which induced electric fields are able to enhance cellular signaling. We have emphasized the currently well-documented effects......In recent years many studies have demonstrated stimulatory effects of pulsed electromagnetic fields (PEMF) on biological tissue. However, controversies have also surrounded the research often due to the lack of knowledge of the different physical consequences of static versus pulsed electromagnetic...

  10. Lightning initiation: Strong pulses of VHF radiation accompany preliminary breakdown

    Czech Academy of Sciences Publication Activity Database

    Kolmašová, Ivana; Santolík, Ondřej; Defer, E.; Rison, W.; Coquillat, S.; Pedeboy, S.; Lán, Radek; Uhlíř, Luděk; Lambert, D.; Pinty, J.P.; Prieur, S.; Pont, V.

    2018-01-01

    Roč. 8, č. 1 (2018), č. článku 3650. ISSN 2045-2322 R&D Projects: GA ČR GA17-07027S Grant - others:AV ČR(CZ) AP1401 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:68378289 Keywords : controlled study * article * electromagnetic radiation * magnetic field * waveform * lightning * mapping array * discharges * ionosphere * luminosity * flashes * leaders * system Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics ) Impact factor: 4.259, year: 2016 https://www.nature.com/articles/s41598-018-21972-z

  11. [Metrology of pulse modulated electromagnetic fields with diode-type meters].

    Science.gov (United States)

    Kubacki, Roman; Kieliszek, Jarosław; Sobiech, Jaromir; Puta, Robert

    2007-01-01

    Electromagnetic field meters used for occupational and general public health protection are commonly calibrated in the continuous wave conditions, but a large number of medical devices, mobile base station antennas and radars generate pulse modulated fields. The results of an analysis of additional errors of pulse fields measurements by diode-type meters (EMR 200/300, PMM and MEH) are presented in this paper.

  12. Analysis of electromagnetic pulse (EMP measurements in the National Ignition Facility's target bay and chamber

    Directory of Open Access Journals (Sweden)

    Brown C.G.

    2013-11-01

    Full Text Available From May 2009 to the present we have recorded electromagnetic pulse (EMP strength and spectrum (100 MHz – 5 GHz in the target bay and chamber of the National Ignition Facility (NIF. The dependence of EMP strength and frequency spectrum on target type and laser energy is discussed. The largest EMP measured was for relatively low-energy, short-pulse (100 ps flat targets.

  13. Metrology of Pulse Modulated Electromagnetic Fields with Diode-Type Meters

    International Nuclear Information System (INIS)

    Kubacki, R.; Kieliszek, J.; Sobiech, J.; Puta, R.

    2007-01-01

    Electromagnetic field meters used for occupational and general public health protection are commonly calibrated in the continuous wave conditions, but a large number of medical devices, mobile base station antennas and radars generate pulse modulated fields. The results of an analysis of additional errors of pulse fields measurements by diode-type meters (EMR 200/300, PMM and MEH) are presented in this paper. (author)

  14. Atomic Interferometry with Detuned Counter-Propagating Electromagnetic Pulses

    Energy Technology Data Exchange (ETDEWEB)

    Tsang, Ming -Yee [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-09-05

    Atomic fountain interferometry uses atoms cooled with optical molasses to 1 μK, which are then launched in a fountain mode. The interferometer relies on the nonlinear Raman interaction of counter-propagating visible light pulses. We present models of these key transitions through a series of Hamiltonians. Our models, which have been verified against special cases with known solutions, allow us to incorporate the effects of non-ideal pulse shapes and realistic laser frequency or wavevector jitter.

  15. Ionization of a two-electron atom in a strong electromagnetic field

    International Nuclear Information System (INIS)

    Ovodova, O.V.; Popov, A.M.; Tikhonova, O.V.

    1997-01-01

    A one-dimensional model of a helium atom in an intense field of a femtosecond electromagnetic pulse has been constructed using the Hartree technique. 'Exact' calculations have been compared to the approximations of 'frozen' and 'passive' electrons. A nonmonotonic dependence of the single-electron ionization probability on the radiation intensity has been detected. Minima in the ionization probability are due to multiphoton resonances between different atomic states due to the dynamic Stark effect. We suggest that the ionization suppression is due to the interference stabilization in this case

  16. Electro-optic analysis of the influence of target geometry on electromagnetic pulses generated by petawatt laser-matter interactions

    Directory of Open Access Journals (Sweden)

    Robinson Timothy

    2018-01-01

    Full Text Available We present an analysis of strong laser-driven electromagnetic pulses using novel electro-optic diagnostic techniques. A range of targets were considered, including thin plastic foils (20-550 nm and mass-limited, optically-levitated micro-targets. Results from foils indicate a dependence of EMP on target thickness, with larger peak electric fields observed with thinner targets. Spectral analysis suggests high repeatability between shots, with identified spectral features consistently detected with 30 MeV energies, suggesting the discharge current contribution to EMP is dominant.

  17. Particle Production in Strong Electromagnetic Fields in Relativistic Heavy-Ion Collisions

    Directory of Open Access Journals (Sweden)

    Kirill Tuchin

    2013-01-01

    Full Text Available I review the origin and properties of electromagnetic fields produced in heavy-ion collisions. The field strength immediately after a collision is proportional to the collision energy and reaches ~mπ2 at RHIC and ~10mπ2 at LHC. I demonstrate by explicit analytical calculation that after dropping by about one-two orders of magnitude during the first fm/c of plasma expansion, it freezes out and lasts for as long as quark-gluon plasma lives as a consequence of finite electrical conductivity of the plasma. Magnetic field breaks spherical symmetry in the direction perpendicular to the reaction plane, and therefore all kinetic coefficients are anisotropic. I examine viscosity of QGP and show that magnetic field induces azimuthal anisotropy on plasma flow even in spherically symmetric geometry. Very strong electromagnetic field has an important impact on particle production. I discuss the problem of energy loss and polarization of fast fermions due to synchrotron radiation, consider photon decay induced by magnetic field, elucidate J/ψ dissociation via Lorentz ionization mechanism, and examine electromagnetic radiation by plasma. I conclude that all processes in QGP are affected by strong electromagnetic field and call for experimental investigation.

  18. Systemic treatment with pulsed electromagnetic fields do not affect bone microarchitecture in osteoporotic rats

    NARCIS (Netherlands)

    O.P. van der Jagt (Olav); J.C. van der Linden (Jacqueline); J.H. Waarsing (Jan); J.A.N. Verhaar (Jan); H.H. Weinans (Harrie)

    2012-01-01

    textabstractPurpose: Pulsed electromagnetic fields (PEMF) are currently used in the treatment of spinal fusions and non-unions. There are indications that PEMF might also be effective in the treatment of osteoporosis. In this study we examined whether whole-body PEMF treatment affects the bone

  19. Stimulation of osteogenic differentiation in human osteoprogenitor cells by pulsed electromagnetic fields: An in vitro study

    NARCIS (Netherlands)

    J.H.W. Jansen (Justus); O.P. van der Jagt (Olav); B.J. Punt (Bas); J.A.N. Verhaar (Jan); J.P.T.M. van Leeuwen (Hans); H.H. Weinans (Harrie); H. Jahr (Holger)

    2010-01-01

    textabstractBackground: Although pulsed electromagnetic field (PEMF) stimulation may be clinically beneficial during fracture healing and for a wide range of bone disorders, there is still debate on its working mechanism. Mesenchymal stem cells are likely mediators facilitating the observed clinical

  20. [Pulsed electromagnetic field therapy inhibits chondrocyte apoptosis in rabbits with osteoarthritis].

    Science.gov (United States)

    Xie, Wei; Zhou, Jun; Luo, Qing-Lua; Liu, Hui-Fang; He, Cheng-Qi

    2014-01-01

    To determine the effect of pulsed electromagnetic field (PEMF) treatment on chondrocyte morphology, chondrocyte apoptosis, and the expression of apoptosis related proteins in rabbits. 24 white New Zealand rabbits were randomly divided into three groups: normal control group (NC group), anterior cruciate ligament transection without treatment (ACLT group), and anterior cruciate ligament transection with pulsed electromagnetic field treatment (PEMF group). Six weeks after anterior cruciate ligament transection, the rabbits in the PEMF group were given 2 weeks of pulsed electromagnetic field treatment. Rabbits in the PEMF group had significantly lower Mankin scores than those in the ACLT group, although the scores were higher than that of the NC group. The rabbits in the PEMF groups also had significantly lower levels of apoptosis index of chondrocytes and expression of caspase-3 compared with those in the ACLT group. The expression of caspase-8 in the rabbits in the PEMF group was higher compared to the NC group, but no significant difference compared with that of the ACLT group. Pulsed electromagnetic field treatment has therapeutic effect on the experimental osteoarthritis, which is likely a result of inhibition of apoptosis in chondrocytes.

  1. Electromagnetic Fields, Pulsed Radiofrequency Radiation, and Epigenetics: How Wireless Technologies May Affect Childhood Development

    Science.gov (United States)

    Sage, Cindy; Burgio, Ernesto

    2018-01-01

    Mobile phones and other wireless devices that produce electromagnetic fields (EMF) and pulsed radiofrequency radiation (RFR) are widely documented to cause potentially harmful health impacts that can be detrimental to young people. New epigenetic studies are profiled in this review to account for some neurodevelopmental and neurobehavioral changes…

  2. [Effect of pulsed electromagnetic field on orthodontic tooth movement through transmission electromicroscopy].

    Science.gov (United States)

    Chen, Q

    1991-01-01

    This experiment is to observe the effect of pulsed electromagnetic field (PEMF) on orthodontic tooth movement of guinea pigs through transmission electron microscope (TEM). 14-days observations indicate that PEMF could accelerate the rate of orthodontic tooth movement as a result of the increase in quantity of active cell without changing the ultrastructures of cells and have no unfavorable effects on periodontal tissues.

  3. analysis of large electromagnetic pulse simulators using the electric field integral equation method in time domain

    International Nuclear Information System (INIS)

    Jamali, J.; Aghajafari, R.; Moini, R.; Sadeghi, H.

    2002-01-01

    A time-domain approach is presented to calculate electromagnetic fields inside a large Electromagnetic Pulse (EMP) simulator. This type of EMP simulator is used for studying the effect of electromagnetic pulses on electrical apparatus in various structures such as vehicles, a reoplanes, etc. The simulator consists of three planar transmission lines. To solve the problem, we first model the metallic structure of the simulator as a grid of conducting wires. The numerical solution of the governing electric field integral equation is then obtained using the method of moments in time domain. To demonstrate the accuracy of the model, we consider a typical EMP simulator. The comparison of our results with those obtained experimentally in the literature validates the model introduced in this paper

  4. Simulation of condensed matter dynamics in strong femtosecond laser pulses

    International Nuclear Information System (INIS)

    Wachter, G.

    2014-01-01

    Ultrashort custom-tailored laser pulses can be employed to observe and control the motion of electrons in atoms and small molecules on the (sub-) femtosecond time scale. Very recently, efforts are underway to extend these concepts to solid matter. This monograph theoretically explores first applications of electron control by ultrashort laser pulses in three paradigmatic systems of solid-state density: a metal nano-structure (nanometric metal tip), a bulk dielectric (quartz glass), and the buckminsterfullerene molecule (C60) as arguably the smallest possible nano-particle. The electron motion is resolved on the atomic length and time scale by ab-initio simulations based on time-dependent density functional theory. Our quantum simulations are complemented by classical and semi-classical models elucidating the underlying mechanisms. We compare our results to experiments where already available and find good agreement. With increasing laser intensity, we find a transition from vertical photoexcitation to tunneling-like excitation. For nanostructures, that leads to temporally confined electron photoemission and thereby to quantum interferences in the energy spectra of emitted electrons. Similarly, tunneling can be induced between neighboring atoms inside an insulator. This provides a mechanism for ultrafast light-field controlled currents and modification of the optical properties of the solid, promising to eventually realize light-field electronic devices operating on the femtosecond time scale and nanometer length scale. Electron-electron interaction leads to near field enhancement and spatial localization of the non-linear response and is investigated both classically by solving the Maxwell equations near a nanostructure as well as quantum mechanically for the fullerene molecule. For the latter, we discuss scrutiny of the molecular near-field by the attosecond streaking technique. Our results demonstrate that ultrashort laser pulses can be employed to steer the

  5. Mechanism and Simulation of Generating Pulsed Strong Magnetic Field

    Science.gov (United States)

    Yang, Xian-Jun; Wang, Shuai-Chuang; Deng, Ai-Dong; Gu, Zhuo-Wei; Luo, Hao

    2014-10-01

    A strong magnetic field (over 1000 T) was recently experimentally produced at the Academy of Engineering Physics in China. The theoretical methods, which include a simple model and MHD code, are discussed to investigate the physical mechanism and dynamics of generating the strong magnetic field. The analysis and simulation results show that nonlinear magnetic diffusion contributes less as compared to the linear magnetic diffusion. This indicates that the compressible hydrodynamic effect and solid imploding compression may have a large influence on strong magnetic field generation.

  6. Auger effect in the presence of strong x-ray pulses

    International Nuclear Information System (INIS)

    Liu Jicai; Sun Yuping; Wang Chuankui; Aagren, Hans; Gel'mukhanov, Faris

    2010-01-01

    We study the role of propagation of strong x-ray free-electron laser pulses on the Auger effect. When the system is exposed to a strong x-ray pulse the stimulated emission starts to compete with the Auger decay. As an illustration we present numerical results for Ar gas with the frequency of the incident x-ray pulse tuned in the 2p 3/2 -4s resonance. It is shown that the pulse propagation is accompanied by two channels of amplified spontaneous emission, 4s-2p 3/2 and 3s-2p 3/2 , which reshape the pulse when the system is inverted. The population inversion is quenched for longer propagation distances where lasing without inversion enhances the Stokes component. The results of simulations show that the propagation of the strong x-ray pulses affect intensively the Auger branching ratio.

  7. An Optimization of Pulsed ElectroMagnetic Fields Study

    Science.gov (United States)

    Goodwin, Thomas J.

    2006-01-01

    To date, in our research we have focused on the use of normal human neuronal progenitor (NHNP) cells because of their importance in human nervous system regeneration, development and maintenance, but we have developed 2-D and 3-D bioreactors that can accommodate any cell line. In this Project, we will include the use of tissues important for physiological regeneration: Human osteoblasts or chondrocytes, and vascular cells. Our initial results with the NHNP cells were quite startling using extremely low-level electromagnetic fields (5 microtesla at 10Hz; 6mA). The low-amplitude, rapidly time-varying electromagnetic fields exert a very potent effect on the proliferation, morphology, and gene expression of the cells in culture, both in standard 2-dimensional culture plates as well as cells organized into 3-dimensional tissue-like assemblies (TLAs) in a 3D bioreactor. We have replicated our preliminary results many, many times, have analyzed the gene expression using gene arrays (followed by Luminex analysis for protein production), and have monitored cell proliferation, orientation, morphology, and glucose metabolism, and we are confident that we have a stable and reliable model to study the control of high-level cellular processes by application of low-amplitude, time varying electromagnetic fields (TVEMF) (1, 2). In additional studies at the University of Michigan, we have been able to generate functional in vitro engineered mammalian skeletal muscle, and have employed nerve-muscle co-culture techniques to promote axonal sprouting. We believe that nearly all tissues, in particular, neural, are susceptible to the influences of low-level TVEMF.

  8. Prediction of electromagnetic pulse generation by picosecond avalanches in high-pressure air

    International Nuclear Information System (INIS)

    Mayhall, D.J.; Yee, J.H.

    1993-01-01

    The gas avalanche switch is a laser-activated, high-voltage switch, consisting of a set of pulse-charged electrodes in a high-pressure gas. Induced electrons from a picosecond-scale laser pulse initiate an avalanche discharge between high-voltage and grounded electrodes. If the voltage, pressure, and dimensions are correct, the rapid avalanche, fueled by the immense number of electrons available in the gas, collapses the applied voltage in picoseconds and generates electromagnetic pulses with widths as short as 1-10 ps and 3 dB bandwidths of 20-120 GHz. With proper voltage or pressure detuning, wider pulses and lower bandwidths occur. In addition to picosecond electromagnetic pulse generation, application of this switch should result in ultra-fast Marx bank pulsers. A number of versions of the switch are possible. The simplest is a parallel plate capacitor, consisting of a gas between two parallel plate conductors. High voltage is applied across the two plates. A parallel plate, Blumlein geometry features a center electrode between two grounded parallel plates. This geometry emits a single pulse in each direction along the parallel plates. A frozen wave geometry with multiple, oppositely charged center electrodes will emit AC pulses. Series switches consisting of gas gaps between two electrodes are also possible

  9. Transient field behavior in an electromagnetic pulse from neutral-beam reflection

    International Nuclear Information System (INIS)

    Strobel, G.L.

    1990-01-01

    A neutral beam of electrons and positrons catches up to an electromagnetic pulse moving in a medium with refractive index n. The neutral beam is reflected and deposits some of its energy in a current region in the tail of the pulse. The location, size, and shape of the transient-induced electric fields in the current region are modeled using current densities from uniform averaged fields. The electric field in the current region is predicted to rise linearly with time, with a doubling time determined by the beam parameters and the initial local electromagnetic field. A coordinate frame comoving with the pulse is used to determine the extent of and conditions within the current region. In this comoving frame the Lorentz-transformed electric field is zero, but there is an enhanced Lorentz-transformed magnetic field. The extent of the current region is found from the radius of the semicircular charged-particle orbits in the comoving frame

  10. Inelastic Processes in the Interaction of an Atom with an Ultrashort Electromagnetic Pulse

    International Nuclear Information System (INIS)

    Matveev, V.I.; Gusarevich, E.S.; Pashev, I.N.

    2005-01-01

    Electron transitions occurring during the interaction of a heavy relativistic atom with a spatially inhomogeneous ultrashort electromagnetic pulse are considered by solving the Dirac equation. The corresponding transition probabilities are expressed in terms of known inelastic atomic form factors, which are widely used in the theory of relativistic collisions between charged particles and atoms. By way of example, the inelastic processes accompanying the interaction of ultrashort pulses with hydrogen-like atoms are considered. The probabilities of ionization and production of a bound-free electron-positron pair on a bare nucleus, which are accompanied by the formation of a hydrogen-like atom in the final state and a positron in the continuum, are calculated. The developed technique makes it possible to take into account exactly not only the spatial inhomogeneity of an ultrashort electromagnetic pulse, but also the magnetic interaction

  11. Inelastic processes in interaction of an atom with ultrashort pulse of an electromagnetic field

    International Nuclear Information System (INIS)

    Matveev, V.I.; Gusarevich, E.S.; Pashev, I.N.

    2005-01-01

    Electron transitions occurring when a heavy relativistic atom interacts with a spatially inhomogeneous ultrashort electromagnetic pulse are considered. Transition probabilities are expressed in terms of the known inelastic atomic form factors. By way of example, the inelastic processes accompanying the interaction of ultrashort pulses with hydrogen-like atoms are considered. The probabilities of ionization and production of a bound-free electron-positron pair on a bare nucleus, which are accompanied by the formation of a hydrogen-like atom in the final state and a positron in the continuum, are calculated. The developed technique makes it possible to take into exact account magnetic interaction besides spatial inhomogeneity of an ultrashort electromagnetic pulse [ru

  12. XUV and x-ray elastic scattering of attosecond electromagnetic pulses on atoms

    Science.gov (United States)

    Rosmej, F. B.; Astapenko, V. A.; Lisitsa, V. S.

    2017-12-01

    Elastic scattering of electromagnetic pulses on atoms in XUV and soft x-ray ranges is considered for ultra-short pulses. The inclusion of the retardation term, non-dipole interaction and an efficient scattering tensor approximation allowed studying the scattering probability in dependence of the pulse duration for different carrier frequencies. Numerical calculations carried out for Mg, Al and Fe atoms demonstrate that the scattering probability is a highly nonlinear function of the pulse duration and has extrema for pulse carrier frequencies in the vicinity of the resonance-like features of the polarization charge spectrum. Closed expressions for the non-dipole correction and the angular dependence of the scattered radiation are obtained.

  13. SHORT-PULSE ELECTROMAGNETIC TRANSPONDER FOR HOLE-TO-HOLE USE.

    Science.gov (United States)

    Wright, David L.; Watts, Raymond D.; Bramsoe, Erik

    1983-01-01

    Hole-to-hole observations were made through nearly 20 m of granite using an electromagnetic transponder (an active reflector) in one borehole and a single-hole short-pulse radar in another. The transponder is inexpensive, operationally simple, and effective in extending the capability of a short-pulse borehole radar system to allow hole-to-hole operation without requiring timing cables. A detector in the transponder senses the arrival of each pulse from the radar. Each pulse detection triggers a kilovolt-amplitude pulse for retransmission. The transponder 'echo' may be stronger than that of a passive reflector by a factor of as much as 120 db. The result is an increase in range capability by a factor which depends on attenuation in the medium and hole-to-hole wavepath geometry.

  14. Systemic treatment with pulsed electromagnetic fields do not affect bone microarchitecture in osteoporotic rats.

    Science.gov (United States)

    van der Jagt, Olav P; van der Linden, Jacqueline C; Waarsing, Jan H; Verhaar, Jan A N; Weinans, Harrie

    2012-07-01

    Pulsed electromagnetic fields (PEMF) are currently used in the treatment of spinal fusions and non-unions. There are indications that PEMF might also be effective in the treatment of osteoporosis. In this study we examined whether whole-body PEMF treatment affects the bone microarchitecture in an osteoporotic rat model. Twenty-week-old female rats were ovariectomised (n=20). Four different PEMF treatment protocols based on previous experimental studies and based on clinically used PEMF signals were examined (2 h/day, 5 days/week). A control group did not receive PEMF. At zero, three and six weeks cancellous and cortical bone architectural changes at the proximal tibia were evaluated using in vivo microCT scanning. PEMF treatment did not induce any changes in cancellous or cortical bone compared to untreated controls. Although previous studies have shown strong effects of PEMF in osteoporosis we were unable to demonstrate this in any of the treatment protocols. Using in vivo microCT scanning we were able to identify small bone changes in time. Subtle differences in the experimental set-up might explain the differences in study outcomes in the literature. Since PEMF treatment is safe, future experimental studies on the effect of PEMF on bone can better be performed directly on humans, eliminating the potential translation issues between animals and humans. In this study we found no support for the use of PEMF in the treatment of osteoporosis.

  15. Interaction with the lower ionosphere of electromagnetic pulses from lightning: Heating, attachment, and ionization

    International Nuclear Information System (INIS)

    Taranenko, Y.N.; Inan, U.S.; Bell, T.F.

    1993-01-01

    The authors model the interaction of lightning flashes with the lower ionosphere. They use a Boltzmann formulation of the electron distribution function, and use Maxwells equations for the electromagnetic fields. Electromagnetic pulses from lightning have pulse lengths of 50 to 150 μs and produce peak fields of 50 V/m at distances of 100 km from the discharges. Fields greater than 16 V/m can cause avalanche ionization of neutrals at elevations of 100 km, where typical mean free paths for electrons are at least a meter. Modeling the lightning flash as a 100 μs pulse of 10 kHz radiation emitted at 70km altitude, they find that in nighttime skies the pulse can affect the electron density in the range of 1 to 30%. A sequence of pulses can lead to substantial impact on the electron density. The propagation characteristics of the pulses are such as to result in a steepening of the boundary of the lower ionosphere

  16. Three-dimensional electromagnetic model of the pulsed-power Z-pinch accelerator

    Directory of Open Access Journals (Sweden)

    D. V. Rose

    2010-01-01

    Full Text Available A three-dimensional, fully electromagnetic model of the principal pulsed-power components of the 26-MA ZR accelerator [D. H. McDaniel et al., in Proceedings of the 5th International Conference on Dense Z-Pinches (AIP, New York, 2002, p. 23] has been developed. This large-scale simulation model tracks the evolution of electromagnetic waves through the accelerator’s intermediate-storage capacitors, laser-triggered gas switches, pulse-forming lines, water switches, triplate transmission lines, and water convolute to the vacuum insulator stack. The insulator-stack electrodes are coupled to a transmission-line circuit model of the four-level magnetically insulated vacuum-transmission-line section and double-post-hole convolute. The vacuum-section circuit model is terminated by a one-dimensional self-consistent dynamic model of an imploding z-pinch load. The simulation results are compared with electrical measurements made throughout the ZR accelerator, and are in good agreement with the data, especially for times until peak load power. This modeling effort demonstrates that 3D electromagnetic models of large-scale, multiple-module, pulsed-power accelerators are now computationally tractable. This, in turn, presents new opportunities for simulating the operation of existing pulsed-power systems used in a variety of high-energy-density-physics and radiographic applications, as well as even higher-power next-generation accelerators before they are constructed.

  17. Engineering Design Guidelines for Electromagnetic Pulse Hardening of Naval Equipment.

    Science.gov (United States)

    1981-07-15

    Mexico , 1963-Present. 2.12 Merewether, D. E., J. A. Cooper, and R. L. Parker (editors), "Electro- magnetic Pulse Handbook for Missiles and Aircraft in...Guidelines for EMP Hardenino of Aeronautical Systems, Autonetics Report No. C72-451/201, August 1972. 4.8 Rickets , L.W., et.al., E-’P Radiation & Protective...Contract # N60921-74-C-0176. ,0.5 Rickets , L.W., et.al., "EMP Radiation and Protective Techniques," Wiley-Interscience, 1976. ,1,79 CHAPTER 11

  18. Long Wavelength Electromagnetic Light Bullets Generated by a 10.6 micron CO2 Ultrashort Pulsed Source

    Science.gov (United States)

    2016-11-29

    AFRL-AFOSR-VA-TR-2016-0365 Long Wavelength Electromagnetic Light Bullets Generated by a 10.6 micron CO2 Ultrashort Pulsed Source Jerome Moloney...SUBTITLE "Long Wavelength Electromagnetic Light Bullets Generated by a 10.6 micron CO2 Ultrashort Pulsed Source 5a. CONTRACT NUMBER FA9550-15-1-0272 5b...Wavelength Electromagnetic Light Bullets Generated by a 10 µm CO2 Ultrashort Pulsed Source Grant/Contract Number AFOSR assigned control number. It must

  19. Electromagnetic interactions

    CERN Document Server

    Bosanac, Slobodan Danko

    2016-01-01

    This book is devoted to theoretical methods used in the extreme circumstances of very strong electromagnetic fields. The development of high power lasers, ultrafast processes, manipulation of electromagnetic fields and the use of very fast charged particles interacting with other charges requires an adequate theoretical description. Because of the very strong electromagnetic field, traditional theoretical approaches, which have primarily a perturbative character, have to be replaced by descriptions going beyond them. In the book an extension of the semi-classical radiation theory and classical dynamics for particles is performed to analyze single charged atoms and dipoles submitted to electromagnetic pulses. Special attention is given to the important problem of field reaction and controlling dynamics of charges by an electromagnetic field.

  20. Impact of the strong electromagnetic field on the QCD effective potential for homogeneous Abelian gluon field configurations

    International Nuclear Information System (INIS)

    Galilo, Bogdan V.; Nedelko, Sergei N.

    2011-01-01

    The one-loop quark contribution to the QCD effective potential for the homogeneous Abelian gluon field in the presence of an external strong electromagnetic field is evaluated. The structure of extrema of the potential as a function of the angles between chromoelectric, chromomagnetic, and electromagnetic fields is analyzed. In this setup, the electromagnetic field is considered as an external one while the gluon field represents domain structured nonperturbative gluon configurations related to the QCD vacuum in the confinement phase. Two particularly interesting gluon configurations, (anti-)self-dual and crossed orthogonal chromomagnetic and chromoelectric fields, are discussed specifically. Within this simplified framework it is shown that the strong electromagnetic fields can play a catalyzing role for a deconfinement transition. At the qualitative level, the present consideration can be seen as a highly simplified study of an impact of the electromagnetic fields generated in relativistic heavy ion collisions on the strongly interacting hadronic matter.

  1. A strong ultraviolet pulse from a newborn type Ia supernova.

    Science.gov (United States)

    Cao, Yi; Kulkarni, S R; Howell, D Andrew; Gal-Yam, Avishay; Kasliwal, Mansi M; Valenti, Stefano; Johansson, J; Amanullah, R; Goobar, A; Sollerman, J; Taddia, F; Horesh, Assaf; Sagiv, Ilan; Cenko, S Bradley; Nugent, Peter E; Arcavi, Iair; Surace, Jason; Woźniak, P R; Moody, Daniela I; Rebbapragada, Umaa D; Bue, Brian D; Gehrels, Neil

    2015-05-21

    Type Ia supernovae are destructive explosions of carbon-oxygen white dwarfs. Although they are used empirically to measure cosmological distances, the nature of their progenitors remains mysterious. One of the leading progenitor models, called the single degenerate channel, hypothesizes that a white dwarf accretes matter from a companion star and the resulting increase in its central pressure and temperature ignites thermonuclear explosion. Here we report observations with the Swift Space Telescope of strong but declining ultraviolet emission from a type Ia supernova within four days of its explosion. This emission is consistent with theoretical expectations of collision between material ejected by the supernova and a companion star, and therefore provides evidence that some type Ia supernovae arise from the single degenerate channel.

  2. First physics pulses in the Barrel Electromagnetic Calorimeter with cosmics

    CERN Multimedia

    Laurent Serin

    2006-01-01

    The electromagnetic barrel calorimeter has been installed in its final position in October 2005. Since then, the calorimeter is being equipped with front-end electronics. Starting in April 2006, electronics calibration runs are taken a few times per week to debug the electronics and to study the performance in the pit (stability, noise). Today, 10 out of the 32 Front End crates are being read out, amounting to about 35000 channels. cool down, few little typos --> After a 6-week cool down, the barrel cryostat was filled with Liquid Argon in May. The presence of a few shorts (~1MΩ) at the edges of the modules was indicating the possibility of conducting dust having entered into the calorimeter with the flowing liquid. In order to try to improve this situation, the calorimeter was emptied and filled again, but this time by condensating the argon instead of flowing it in liquid phase. The new High Voltage tests are not showing any significant improvement but the situation is statisfactory for ATLAS runn...

  3. D region disturbances caused by electromagnetic pulses from lightning

    Science.gov (United States)

    Rodriguez, Juan V.; Inan, Umran S.; Bell, Timothy F.

    1992-01-01

    Attention is given to a simple formulation of the propagation and absorption in a magnetized collisional plasma of EM pulses from lightning which describes the effect of discharge orientation and radiated electric field on the structure and magnitude of heating and secondary ionization in the D region. Radiation from most lightning discharges can heat substantially, but only the most intense (not less than 20 V/m) are likely to cause ionization enhancements not less than 10 percent of the ambient in a single ionization cycle. This dependence on the radiated electric field is modified by the discharge radiation pattern: a horizontal cloud discharge tends to cause larger heating and ionizaton maxima while a vertical return stroke causes disturbances of a larger horizontal extent.

  4. Dynamic chaos in the tunnelling ionization produced by a strong low-frequency electromagnetic field

    International Nuclear Information System (INIS)

    Krainov, V P

    2014-01-01

    Ionization of atoms by a strong low-frequency linearly polarized electromagnetic field (the photon energy is small compared to the atomic ionization potential) is considered under new conditions compared to the well known Keldysh approach. The field strength is supposed to be small in comparison to the atomic field strength. But the Coulomb interaction of an electron with atomic core is assumed to be of the same order of magnitude as the interaction between an electron and the external electromagnetic field. It was shown that then classical electron motion in the continuum becomes chaotic (this is so-called dynamic chaos). Using the averaging procedure of Chirikov about the chaotic variation of the phase of motion, the considered Newton problem is transformed into the problem of nonlinear electron diffusion over energy scale. In this work we derive the classical electron energy averaged over fast chaotic oscillations of an electron in the final continuum state which takes into account both the Coulomb field and electromagnetic field. This energy is used for analytic calculation of the ionization rate of the ground atomic state into the low lying continuum state based on the Landau–Dykhne approximation (with exponential accuracy). We found that the ionization rate depends significantly on the field frequency. When field frequency decreases, the well known tunnelling limit has been obtained, and then the ionization rate does not depend on the field frequency. (paper)

  5. Description of an aircraft lightning and simulated nuclear electromagnetic pulse (NEMP) threat based on experimental data

    Science.gov (United States)

    Rustan, Pedro L., Jr.

    1987-01-01

    Lightning data obtained by measuring the surface electromagnetic fields on a CV-580 research aircraft during 48 lightning strikes between 1500 and 18,000 feet in central Florida during the summers of 1984 and 1985, and nuclear electromagnetic pulse (NEMP) data obtained by surface electromagnetic field measurements using a 1:74 CV-580 scale model, are presented. From one lightning event, maximum values of 3750 T/s for the time rate of change of the surface magnetic flux density, and 4.7 kA for the peak current, were obtained. From the simulated NEMP test, maximum values of 40,000 T/s for the time rate of change of the surface magnetic flux density, and 90 A/sq m for the total normal current density, were found. The data have application to the development of a military aircraft lightning/NEMP standard.

  6. A comparison of lightning and nuclear electromagnetic pulse response of tactical shelters

    Science.gov (United States)

    Perala, R. A.; Rudolph, T. H.; Mckenna, P. M.

    1984-01-01

    The internal response (electromagnetic fields and cable responses) of tactical shelters is addressed. Tactical shelters are usually well-shielded systems. Apart from penetrations by signal and power lines, the main leakage paths to the interior are via seams and the environment control unit (ECU) honeycomb filter. The time domain in three-dimensional finite-difference technique is employed to determine the external and internal coupling to a shelter excited by nuclear electromagnetic pulses (NEMP) and attached lightning. The responses of interest are the internal electromagnetic fields and the voltage, current, power, and energy coupled to internal cables. Leakage through the seams and ECU filter is accomplished by their transfer impedances which relate internal electric fields to external current densities. Transfer impedances which were experimentally measured are used in the analysis. The internal numerical results are favorably compared to actual shelter test data under simulated NEMP illumination.

  7. Pulsed electromagnetic fields do not reduce vesicant skin ulcers in mice

    OpenAIRE

    Dorr, RT; Soble, MJ; Meyskens, FL

    1986-01-01

    A study was conducted in mice to teat the efficacy of pulsed electromagnetic fields (PEW) as a means of reducing acute and chronic skin ulceration from two model vesicant anticancer drugs. Adult female BALB/c mice were dehaired dorsally and given 0.5 mg intradermal injections of the DNA intercalators, doxorubicin and bisantrene. The mice-re then housed in plexiglass cages and exposed to 2-Hz PEMF of repetitive pulse bursts of 250 μsec or 20 μsec duration. Skin lesions and survival were assess...

  8. Peculiarities of two-electron atom ionization in strong electromagnetic field

    International Nuclear Information System (INIS)

    Ovodova, O.V.; Popov, A.M.; Tikhonova, O.V.

    1997-01-01

    One-dimensional model of helium atom in strong field of electromagnetic wave of femtosecond activity is plotted within the Hartree method frames. Comparison of 'exact' calculations with the calculations conducted within the frames of the 'frozen' and 'passive' electrons is made. The nonmonotonous dependence of one-dimensional ionization probability on the radiation intensity is found. It is shown that the ionization minima are connected with multiphoton resonances between various atomic states, originating due to the Stark effect. It is supposed that the effect of ionization suppression in this case is related to interference stabilization

  9. On the electromagnetic pulse generated by exo-atmospheric nuclear detonations

    International Nuclear Information System (INIS)

    Leuthaeuser, K.D.

    1983-01-01

    When gamma rays produced by high altitude nuclear weapons explosions interact with the atmosphere they generate an electromagnetic pulse (EMP) propagating towards the earth's surface. The EMP covers large areas of millions of km 2 and reaches peak electric fields of more than 50 kV/m which may couple into all kinds of conducting systems. The present paper deals with a simple model to calculate EMP fields basing on Maxwell's equations. (orig.)

  10. Methodology to assess the effects of magnetohydrodynamic electromagnetic pulse (MHD-EMP) on power systems

    International Nuclear Information System (INIS)

    Legro, J.R.; Abi-Samra, N.C.; Crouse, J.C.; Tesche, F.M.

    1985-01-01

    This paper summarizes a method to evaluate the possible effects of magnetohydrodynamic-electromagnetic pulse (MHD-EMP) on power systems. This method is based on the approach adapted to study the impact of geomagnetic storms on power systems. The paper highlights the similarities and differences between the two phenomena. Also presented are areas of concern which are anticipated from MHD-EMP on the overall system operation. 12 refs., 1 fig

  11. Osteogenic differentiation of amniotic epithelial cells: synergism of pulsed electromagnetic field and biochemical stimuli

    OpenAIRE

    Wang, Qian; Wu, Wenchao; Han, Xiaoyu; Zheng, Ai; Lei, Song; Wu, Jiang; Chen, Huaiqing; He, Chengqi; Luo, Fengming; Liu, Xiaojing

    2014-01-01

    Background Pulsed electromagnetic field (PEMF) is a non-invasive physical therapy used in the treatment of fracture nonunion or delayed healing. PEMF can facilitate the osteogenic differentiation of bone marrow mesenchymal stem cells in vitro. Amniotic epithelial cells (AECs) have been proposed as a potential source of stem cells for cell therapy. However, whether PEMF could modulate the osteogenic differentiation of AECs is unknown. In the present study, the effects of PEMF on the osteogenic...

  12. Pulsed electromagnetic field improves cardiac function in response to myocardial infarction

    OpenAIRE

    Hao, Chang-Ning; Huang, Jing-Juan; Shi, Yi-Qin; Cheng, Xian-Wu; Li, Hao-Yun; Zhou, Lin; Guo, Xin-Gui; Li, Rui-Lin; Lu, Wei; Zhu, Yi-Zhun; Duan, Jun-Li

    2014-01-01

    Extracorporeal pulsed electromagnetic field (PEMF) has been shown the ability to improve regeneration in various ischemic episodes. Here, we examined whether PEMF therapy facilitate cardiac recovery in rat myocardial infarction (MI), and the cellular/molecular mechanisms underlying PEMF-related therapy was further investigated. The MI rats were exposed to active PEMF for 4 cycles per day (8 minutes/cycle, 30 ± 3 Hz, 5 mT) after MI induction. The data demonstrated that PEMF treatment significa...

  13. Novel protective effects of pulsed electromagnetic field ischemia/reperfusion injury rats

    OpenAIRE

    Ma, Fenfen; Li, Wenwen; Li, Xinghui; Tran, Ba?Hieu; Suguro, Rinkiko; Guan, Ruijuan; Hou, Cuilan; Wang, Huijuan; Zhang, Aijie; Zhu, Yichun; Zhu, YiZhun

    2016-01-01

    Extracorporeal pulsed electromagnetic field (PEMF) has shown the ability to regenerate tissue by promoting cell proliferation. In the present study, we investigated for the first time whether PEMF treatment could improve the myocardial ischaemia/reperfusion (I/R) injury and uncovered its underlying mechanisms. In our study, we demonstrated for the first time that extracorporeal PEMF has a novel effect on myocardial I/R injury. The number and function of circulating endothelial progenitor cell...

  14. Pulsed electromagnetic field improves postnatal neovascularization in response to hindlimb ischemia

    OpenAIRE

    Li, Rui-Lin; Huang, Jing-Juan; Shi, Yi-Qin; Hu, An; Lu, Zhao-Yang; Weng, Liang; Wang, Shen-Qi; Han, Yi-Peng; Zhang, Lan; Hao, Chang-Ning; Duan, Jun-Li

    2015-01-01

    Pulsed electromagnetic fields (PEMF) have been shown to promote proliferation and regeneration in the damaged tissue. Here, we examined whether PEMF therapy improved postnatal neovascularization using murine model of hindlimb ischemia, and the underlying cellular/molecular mechanisms were further investigated. Hindlimb ischemia was induced by unilateral femoral artery resection using 6-8 week-old male C57BL6 mice. Then, mice were exposed to extracorporeal PEMF therapy (4 cycles, 8min/cycle, 3...

  15. The Effects of Pulsed Electromagnetic Field Treatment in Pain Due to Diabetic Polyneuropathy

    OpenAIRE

    FEZYİOĞLU, Pervin; Özdemir, Ferda; ÖZDEMİR, Ferda; GÜLDİKEN, Sibel; BALCI, Kemal; Süt, Necdet

    2014-01-01

    Objectives: Diabetic polyneuropathy is the most common and disabled complication of diabetes mellitus. Pharmacological treatment of diabetic neuropathy is limited because of the side efects of the drugs, used in the treatment of diabetic neuropthy. Alternative treatments are also used in diabetic neuropathy. Systemic side effects of non-pharmacological treatment modalities are rare. We evaluated the value of pulsed electromagnetic field treatment in patients with pain due to diabetic polyneur...

  16. Use of Pulsing Electromagnetic Fields for the Treatment of Pelvic Stress Fractures Among Female Soldiers.

    Science.gov (United States)

    1995-08-11

    activities. Pulsing electromagnetic fields ( PEMFs )have been shown to speed the healing of non-union fractures and we have used them successfully to...and then randomized into actual PEMF and placebo PEMF groups and treated for one hour per day until they return to duty. Changes in the bone scan are...musculoskeletal groups. Results to date indicate that pelvic stress fractures are being misdiagnosed. If these results are confirmed, treatments for

  17. UTILIZATION OF PULSED ELECTROMAGNETIC FIELD AND TRADITIONAL PHYSIOTHERAPY IN KNEE OSTEOARTHRITIS MANAGEMENT

    OpenAIRE

    Kadrya H. Battecha; Elsadat Saad Soliman

    2015-01-01

    Background and Objectives: Pulsed electromagnetic field (PEMF) has been suggested as a treatment method for musculoskeletal system disorders. The present study was conducted to determine whether the addition of PEMF to traditional physiotherapy produces better clinical outcomes than traditional physiotherapy alone in the management of moderate knee osteoarthritis (OA). Design: A single-blinded, randomized controlled study Methods: Twenty subjects (5 men and 15 women) with unilateral mo...

  18. Low Intensity and Frequency Pulsed Electromagnetic Fields Selectively Impair Breast Cancer Cell Viability

    OpenAIRE

    Crocetti, Sara; Beyer, Christian; Schade, Grit; Egli, Marcel; Fr?hlich, J?rg; Franco-Obreg?n, Alfredo

    2013-01-01

    INTRODUCTION: A common drawback of many anticancer therapies is non-specificity in action of killing. We investigated the potential of ultra-low intensity and frequency pulsed electromagnetic fields (PEMFs) to kill breast cancer cells. Our criteria to accept this technology as a potentially valid therapeutic approach were: 1) cytotoxicity to breast cancer cells and; 2) that the designed fields proved innocuous to healthy cell classes that would be exposed to the PEMFs during clinical treatmen...

  19. Internal electromagnetic pulse produced by the prompt-γ photons in the rectanglar cavity

    International Nuclear Information System (INIS)

    Wang Taichun; Wang Yuzhi

    1986-01-01

    The internal electromagnetic pulses produced by the prompt-γ photons were calculated by self-consistent and non-self-consistent method respectively in the rectanglar cavity of the matel. The computational results were analyzed. Under the condition that the electric field is weak and the cavity is small, the results obtained by the self-consistent method is in agreement with the results by the non-self-consistent

  20. Electromagnetic pulse coupling through an aperture into a two-parallel-plate region

    Science.gov (United States)

    Rahmat-Samii, Y.

    1978-01-01

    Analysis of electromagnetic-pulse (EMP) penetration via apertures into cavities is an important study in designing hardened systems. In this paper, an integral equation procedure is developed for determining the frequency and consequently the time behavior of the field inside a two-parallel-plate region excited through an aperture by an EMP. Some discussion of the numerical results is also included in the paper for completeness.

  1. Report of the Commission to Assess the Threat to the United States from Electromagnetic Pulse (EMP) Attack: Critical National Infrastructures

    National Research Council Canada - National Science Library

    Foster, Jr., John S; Gjelde, Earl; Graham, William R; Hermann, Robert J; Kluepfel, Henry M; Lawson, Richard L; Soper, Gordon K; Wood, Lowell L; Woodard, Joan B

    2008-01-01

    ...) attack on our critical national infrastructures. An earlier report, Report of the Commission to Assess the Threat to the United States from Electromagnetic Pulse (EMP), Volume 1: Executive Report (2004...

  2. Basic features of electromagnetic pulse generated in a laser-target chamber at 3-TW laser facility PALS

    International Nuclear Information System (INIS)

    De Marco, M; Pfeifer, M; Krousky, E; Krasa, J; Cikhardt, J; Klir, D; Nassisi, V

    2014-01-01

    We describe the radiofrequency emission taking place when 300 ps laser pulses irradiate various solid targets with an intensity of 10 16 W/cm 2 . The emission of intense electromagnetic pulses was observed outside the laser target chamber by two loop antennas up to 1 GHz. Electromagnetic pulses can be 800 MHz transients, which decay from a peak electromagnetic field of E 0 ≊ 7 kV/m and H 0 ≊ 15 A/m. The occurrence of these electromagnetic pulses is associated with generation of hard x-rays with photon energies extending beyond 1 MeV. This contribution reports the first observation of this effect at the PALS facility.

  3. A Concept for Directly Coupled Pulsed Electromagnetic Acceleration of Plasmas

    Science.gov (United States)

    Thio, Y.C. Francis; Cassibry, Jason T.; Eskridge, Richard; Smith, James; Wu, S. T.; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    Plasma jets with high momentum flux density are required for a variety of applications in propulsion research. Methods of producing these plasma jets are being investigated at NASA Marshall Space Flight Center. The experimental goal in the immediate future is to develop plasma accelerators which are capable of producing plasma jets with momentum flux density represented by velocities up to 200 km/s and ion density up to 10(exp 24) per cu m, with sufficient precision and reproducibility in their properties, and with sufficiently high efficiency. The jets must be sufficiently focused to allow them to be transported over several meters. A plasma accelerator concept is presented that might be able to meet these requirements. It is a self-switching, shaped coaxial pulsed plasma thruster, with focusing of the plasma flow by shaping muzzle current distribution as in plasma focus devices, and by mechanical tapering of the gun walls. Some 2-D MHD modeling in support of the conceptual design will be presented.

  4. Effects of Pulsed Electromagnetic Field on Differentiation of HUES-17 Human Embryonic Stem Cell Line

    Directory of Open Access Journals (Sweden)

    Yi-Lin Wu

    2014-08-01

    Full Text Available Electromagnetic fields are considered to potentially affect embryonic development, but the mechanism is still unknown. In this study, human embryonic stem cell (hESC line HUES-17 was applied to explore the mechanism of exposure on embryonic development to pulsed electromagnetic field (PEMF for 400 pulses at different electric field intensities and the differentiation of HUES-17 cells was observed after PEMF exposure. The expression of alkaline phosphatase (AP, stage-specific embryonic antigen-3 (SSEA-3, SSEA-4 and the mRNA level and protein level of Oct4, Sox2 and Nanog in HUES-17 cells remained unchanged after PEMF exposure at the electric field intensities of 50, 100, 200 or 400 kV/m. Four hundred pulses PEMF exposure at the electric field intensities of 50, 100, 200 or 400 kV/m did not affect the differentiation of HUES-17 cells. The reason why electromagnetic fields affect embryonic development may be due to other mechanisms rather than affecting the differentiation of embryonic stem cells.

  5. The effects of samarium-cobalt magnets and pulsed electromagnetic fields on tooth movement.

    Science.gov (United States)

    Darendeliler, M A; Sinclair, P M; Kusy, R P

    1995-06-01

    The purpose of this study was to determine whether the application of either samarium cobalt magnets or pulsed electromagnetic fields could increase the rate and amount of orthodontic tooth movement observed in guinea pigs. In addition, the objective was to evaluate the effect of a magnetic field on bony physiology and metabolism and to monitor for possible systemic side effects. Fifteen grams of laterally directed orthodontic force were applied to move the maxillary central incisors of a sample of 18 young male Hartley guinea pigs divided into three groups: group 1, an orthodontic coil spring was used to move the incisors; group 2, a pair of samarium-cobalt magnets provided the tooth moving force; and group 3, a coil spring was used in combination with a pulsed electromagnetic field. The results showed that both the static magnetic field produced by the samarium-cobalt magnets and the pulsed electromagnetic field used in combination with the coil spring were successful in increasing the rate of tooth movement over that produced by the coil springs alone. The mechanism producing this effect appears to have involved a reduction in the "lag" phase often seen in orthodontic tooth movement. Both magnetically stimulated groups also showed increases in both the organization and amount of new bone deposited in the area of tension between the orthodontically moved maxillary incisors.

  6. Comparison of low-intensity pulsed ultrasound and pulsed electromagnetic field treatments on OPG and RANKL expression in human osteoblast-like cells

    NARCIS (Netherlands)

    Borsje, Manon A.; Ren, Yijin; de Haan-Visser, H. Willy; Kuijer, Roel

    OBJECTIVE: To compare two clinically applied treatments to stimulate bone healing-low-intensity pulsed ultrasound (LIPUS) and pulsed electromagnetic field (PEMF)-for their effects on RANKL and OPG expression in osteoblast-like cells in vitro. MATERIALS AND METHODS: LIPUS or PEMF was applied to

  7. A Novel Single Pulsed Electromagnetic Field Stimulates Osteogenesis of Bone Marrow Mesenchymal Stem Cells and Bone Repair

    OpenAIRE

    Fu, Yin-Chih; Lin, Chih-Chun; Chang, Je-Ken; Chen, Chung-Hwan; Tai, I-Chun; Wang, Gwo-Jaw; Ho, Mei-Ling

    2014-01-01

    Pulsed electromagnetic field (PEMF) has been successfully applied to accelerate fracture repair since 1979. Recent studies suggest that PEMF might be used as a nonoperative treatment for the early stages of osteonecrosis. However, PEMF treatment requires a minimum of ten hours per day for the duration of the treatment. In this study, we modified the protocol of the single-pulsed electromagnetic field (SPEMF) that only requires a 3-minute daily treatment. In the in vitro study, cell proliferat...

  8. Ultrashort Laser Pulses and Electromagnetic Pulse Generation in Air and on Dielectric Surfaces

    National Research Council Canada - National Science Library

    Sprangle, Phillip

    2003-01-01

    ...). The purpose of this paper is to analyze EMP generation from the interaction of ultrashort laser pulses with air and with dielectric surfaces and to determine the efficiency of conversion of laser energy to EMP energy...

  9. Interference effects at photoionization of Rydberg atoms by a strong electromagnetic field

    International Nuclear Information System (INIS)

    Movsesyan, A.M.; Fedorov, M.V.

    1989-01-01

    The photoionization of Rydberg atoms in a strong electromagnetic field is considered. Degeneration of the levels with respect to the orbital moment, their Stark splitting and the possibility of resonant interaction with levels of lower energy are taken into account. The complex quasi-energies of the system, photoelectron spectrum in the limit of an infinite duration of interaction and the time dependence of the total ionization probability are found. It is shown that a narrowing of the quasi-energy levels occurs in a strong field. Against a background of the quasi- continuum the quasi-energy spectrum consists of more or less narrow levels. In this case the photoelectron spectrum acquires a multi-peak form. With increasing field strength the height of the peaks increases, whereas their width decreases. The ionization rate decreases with increasing field strength. The presence of a quasi-continuum is the cause of the partially non-exponential nature of the atomic disintegration

  10. Fresnel formulas for the forced electromagnetic pulses and their application for optical-to-terahertz conversion in nonlinear crystals.

    Science.gov (United States)

    Bakunov, M I; Maslov, A V; Bodrov, S B

    2007-11-16

    We show that the usual Fresnel formulas for a free-propagating pulse are not applicable for a forced terahertz electromagnetic pulse supported by an optical pulse at the end of a nonlinear crystal. The correct linear reflection and transmission coefficients that we derive show that such pulses can experience a gain or loss at the boundary. This energy change depends on linear dielectric constants only. We also predict a regime where a complete disappearance of the forced pulse under oblique incidence occurs, an effect that has no counterpart for free-propagating pulses.

  11. Lagrangian formulation for a gauge theory of strong and electromagnetic interactions defined on a Cartan bundle

    International Nuclear Information System (INIS)

    Drechsler, W.

    1977-01-01

    A Lagrangian formalism invariant under the gauge group U 1 xUSpsub(2.2) is set up in terms of spinor fields defined on a fiber bundle with Cartan connexion. The fiber of the Cartan bundle over space-time associated with strong interactions is characterized by an elementary length parameter R related to the range of the strong forces, and the structural group USpsub(2.2) of the bundle (being the covering group of the SOsub(4.1) de Sitter group) implies a gauge description of strong interactions based on the noncompact gauge group USpsub(2.2). The U 1 factor in the total gauge group corresponds to the usual gauge formulation for the electromagnetic interactions. The positivity of the energy associated with stable extended one-particle states in this dualistic description of charged hadronic matter immersed in the fiber geometry (this dualism is called strong fiber dynamics (SFD)) requires hadrons to be assigned to representations of the compact subgroup SU 2 xSU 2 of the strong-interaction gauge group USpsub(2.2). A brief discussion of the point-particle limit R→O is given by linking the presented SFD formalism for extended hadrons to an idealized description in terms of operators in a local quantum field theory

  12. Modeling ultrashort electromagnetic pulses with a generalized Kadomtsev-Petviashvili equation

    Science.gov (United States)

    Hofstrand, A.; Moloney, J. V.

    2018-03-01

    In this paper we derive a properly scaled model for the nonlinear propagation of intense, ultrashort, mid-infrared electromagnetic pulses (10-100 femtoseconds) through an arbitrary dispersive medium. The derivation results in a generalized Kadomtsev-Petviashvili (gKP) equation. In contrast to envelope-based models such as the Nonlinear Schrödinger (NLS) equation, the gKP equation describes the dynamics of the field's actual carrier wave. It is important to resolve these dynamics when modeling ultrashort pulses. We proceed by giving an original proof of sufficient conditions on the initial pulse for a singularity to form in the field after a finite propagation distance. The model is then numerically simulated in 2D using a spectral-solver with initial data and physical parameters highlighting our theoretical results.

  13. A letter of intent for an experiment to study strong electromagnetic fields at RHIC via multiple electromagnetic processes

    Science.gov (United States)

    Fatyga, M.; Norbury, John W.

    1992-01-01

    An experimental program at the Relativistic Heavy Ion Collider (RHIC) which is designed to study nonperturbative aspects of electrodynamics is outlined. Additional possibilities for new studies of electrodynamics via multiple electromagnetic processes are also described.

  14. Strongly lensed gravitational waves and electromagnetic signals as powerful cosmic rulers

    Science.gov (United States)

    Wei, Jun-Jie; Wu, Xue-Feng

    2017-12-01

    In this paper, we discuss the possibility of using strongly lensed gravitational waves (GWs) and their electromagnetic (EM) counterparts as powerful cosmic rulers. In the EM domain, it has been suggested that joint observations of the time delay (Δτ) between lensed quasar images and the velocity dispersion (σ) of the lensing galaxy (i.e. the combination Δτ/σ2) are able to constrain the cosmological parameters more strongly than Δτ or σ2 separately. Here, for the first time, we propose that this Δτ/σ2 method can be applied to the strongly lensed systems observed in both GW and EM windows. Combining the redshifts, images and σ observed in the EM domain with the very precise Δτ derived from lensed GW signals, we expect that accurate multimessenger cosmology can be achieved in the era of third-generation GW detectors. Comparing with the constraints from the Δτ method, we prove that using Δτ/σ2 can improve the discrimination between cosmological models. Furthermore, we demonstrate that with ∼50 strongly lensed GW-EM systems, we can reach a constraint on the dark energy equation of state w comparable to the 580 Union2.1 Type Ia supernovae data. Much more stringent constraints on w can be obtained when combining the Δτ and Δτ/σ2 methods.

  15. Changes in some Hematological Parameters and Thyroid Hormones in Rats Exposed to Pulsed Electromagnetic Field

    International Nuclear Information System (INIS)

    EL-Abiad, N.M.; Marzook, E.A.; EI-Aragi, G.M.

    2007-01-01

    In the present study pulsed electromagnetic spectrum was used to evaluate the effect of exposure on some biochemical and hematological parameters in male albino rats. Three groups of rats (10 each) were exposed to 10, 15, 20 pulses of electromagnetic spectrum 3 times per week for 3 weeks, the unexposed group was considered as the control group. At the end of experiment, serum levels of thyroid hormones triiodothryronine and thyroxine (T 3 ,T 4 ) and some hematological parameters were estimated. The hematological studies revealed that exposure to electromagnetic spectrum induced significant reduction in red blood cell count(RBC),and also in hemoglobin concentration(Hb), while reticulocytic count(Ret.) was elevated in the three exposed groups, platelets count was increased only on the second exposed group, while leukocytic count (WBC's), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MGH), mean corpuscular hemoglobin concentration (MCHC) were not affected, lymphocytic count was decreased only on the second exposed group, the impairment of thyroid functions was noticed by elevation of T 3 and T 4 in the three exposed groups

  16. Effect of pulsed electromagnetic field on some biochemical and hematological parameters of female rats

    International Nuclear Information System (INIS)

    Marzook, E.A.

    2006-01-01

    The present study was designed to investigate the effect of exposure to pulsed electromagnetic spectrum on some biochemical and hematological parameters in female albino rats. A group of mature female rats was exposed to 10 pulses of electromagnetic spectrum (frequency 8-12 GHz) 3 times/week for 3 weeks. The untreated group was considered as the control group. At the end of the experiment, serum levels of malondialdehyde, thyroid triiodothyronine and thyroxine (T3, T4), α-feto protein, estradiol, calcium, urea, creatinine and other hematological parameters were estimated. The present data revealed that serum levels of estradiol, malondialdehyde, urea, creatinine, triiodothyronine and thyroxine were elevated in the exposed group while serum calcium was significantly decreased. Non-significant difference was found in the value of α-feto protein between the two groups. The hematological studies revealed that exposure of rats to electromagnetic spectrum induced significant reduction in red blood cells (RBCs), hemoglobin concentration (Hb) and in hematocrit percent (Hct%), while reticulocyte count (Ret %) was elevated in the treated group. Non-significant changes were observed in platelets, leukocyte (WBCs) and lymphocytic counts in the exposed group as compared to the control group

  17. DNA Riboprinting and Biochemical Studies on The Effect of Exposure to Pulsed Electromagnetic Field on Rats

    International Nuclear Information System (INIS)

    Marzook, E.A.; EL-Abiad, N.M.; Awwad, M.H.; El-Aragi, G.M.

    2006-01-01

    In the present study pulsed electromagnetic field (PEMF) was used to evaluate the effect of exposure on some molecular and biochemical aspects in male albino rats (Rattus rattus). Three groups of rats were exposed to PEMF (10, 15, 20 pulses/day three times per week for three weeks) with frequency of 8-12 GHz. An unexposed group was considered the control group. At the end of experiment, serum levels of total protein, albumin, globulin, A/G ratio, testosterone, triglycerides and cholesterol were determined. The results revealed that exposure to electromagnetic field induced significant increases in scrum total protein, globulin, triglycerides and testosterone hormone on the second exposed group only. Non significant changes were found in serum levels of albumin and cholesterol in the same group with decreased A/G ratio. All the tested parameters were not affected on the other two exposed groups. An indicative hypothesis for spotting the effect of electromagnetic spectrum on the liver of albino rats was proposed based on the examination of total DNA genome by using PacI, Sfil, Notl and SWal restriction endonucleases. The results achieved have established the value of the physical map as an additional complement to the standard biodosimetric methods

  18. Introduction to gauge theories of the strong, weak, and electromagnetic interactions

    International Nuclear Information System (INIS)

    Quigg, C.

    1980-07-01

    The plan of these notes is as follows. Chapter 1 is devoted to a brief evocative review of current beliefs and prejudices that form the context for the discussion to follow. The idea of Gauge Invariance is introduced in Chapter 2, and the connection between conservation laws and symmetries of the Lagrangian is recalled. Non-Abelian gauge field theories are constructed in Chapter 3, by analogy with the familiar case of electromagnetism. The Yang-Mills theory based upon isospin symmetry is constructed explicitly, and the generalization is made to other gauge groups. Chapter 4 is concerned with spontaneous symmetry breaking and the phenomena that occur in the presence or absence of local gauge symmetries. The existence of massless scalar fields (Goldstone particles) and their metamorphosis by means of the Higgs mechanism are illustrated by simple examples. The Weinberg-Salam model is presented in Chapter 5, and a brief resume of applications to experiment is given. Quantum Chromodynamics, the gauge theory of colored quarks and gluons, is developed in Chapter 6. Asymptotic freedom is derived schematically, and a few simple applications of perturbative QCD ae exhibited. Details of the conjectured confinement mechanism are omitted. The strategy of grand unified theories of the strong, weak, and electromagnetic interactions is laid out in Chapter 7. Some properties and consequences of the minimal unifying group SU(5) are presented, and the gauge hierarchy problem is introduced in passing. The final chapter contains an essay on the current outlook: aspirations, unanswered questions, and bold scenarios

  19. Electro-optic analysis of the influence of target geometry on electromagnetic pulses generated by petawatt laser-matter interactions

    Science.gov (United States)

    Robinson, Timothy; Giltrap, Samuel; Eardley, Samuel; Consoli, Fabrizio; De Angelis, Riccardo; Ingenito, Francesco; Stuart, Nicholas; Verona, Claudio; Smith, Roland A.

    2018-01-01

    We present an analysis of strong laser-driven electromagnetic pulses using novel electro-optic diagnostic techniques. A range of targets were considered, including thin plastic foils (20-550 nm) and mass-limited, optically-levitated micro-targets. Results from foils indicate a dependence of EMP on target thickness, with larger peak electric fields observed with thinner targets. Spectral analysis suggests high repeatability between shots, with identified spectral features consistently detected with earth following ejection of hot electrons from the plasma, in contrast to predictions for pin-mounted foils in the Poyé EMP generation model. With levitated targets, no EMP was measurable above the noise threshold of any diagnostic, despite observation of protons accelerated to >30 MeV energies, suggesting the discharge current contribution to EMP is dominant.

  20. Comparison of electric dipole and magnetic dipole models for electromagnetic pulse generated by nuclear detonation in space

    International Nuclear Information System (INIS)

    Zhu Meng; Zhou Hui; Cheng Yinhui; Li Baozhong; Wu Wei; Li Jinxi; Ma Liang; Zhao Mo

    2013-01-01

    Electromagnetic pulse can be generated by the nuclear detonation in space via two radiation mechanisms. The electric dipole and magnetic dipole models were analyzed. The electric radiation in the far field generated by two models was calculated as well. Investigations show that in the case of one hundred TNT yield detonations, when electrons are emitted according to the Gaussian shape, two radiation models can give rise to the electric field in great distances with amplitudes of kV/m and tens of V/m, independently. Because the geomagnetic field in space is not strong and the electrons' angular motion is much weaker than the motion in the original direction, radiations from the magnetic dipole model are much weaker than those from the electric dipole model. (authors)

  1. Instantaneous coherent destruction of tunneling and fast quantum state preparation for strongly pulsed spin qubits in diamond

    DEFF Research Database (Denmark)

    Wubs, Martijn

    2010-01-01

    Qubits driven by resonant strong pulses are studied and a parameter regime is explored in which the dynamics can be solved in closed form. Instantaneous coherent destruction of tunneling can be seen for longer pulses, whereas shorter pulses allow a fast preparation of the qubit state. Results...... are compared with recent experiments of pulsed nitrogen-vacancy center spin qubits in diamond....

  2. [Apoptosis of human lung carcinoma cell line GLC-82 induced by high power electromagnetic pulse].

    Science.gov (United States)

    Cao, Xiao-zhe; Zhao, Mei-lan; Wang, De-wen; Dong, Bo

    2002-09-01

    Electromagnetic pulse (EMP) could be used for sterilization of food and the efficiency is higher than 2450 MHz continuous microwave done. This study was designed to evaluate the effect of electromagnetic pulse (EMP) on apoptosis of human lung carcinoma cell line GLC-82, so that to explore and develop therapeutic means for cancer. The injury changes in GLC-82 cells after irradiated with EMP (electric field intensity was 60 kV/m, 5 pulses/2 min) were analyzed by cytometry, MTT chronometry, and flow cytometry. The immunohistochemical SP staining was used to determine the expressions of bcl-2 protein and p53 protein. The stained positive cells were analyzed by CMIAS-II image analysis system at a magnification 400. All data were analyzed by SPSS8.0 software. EMP could obviously inhibited proliferation and activity of lung carcinoma cell line GLC-82. The absorbance value (A570) of MTT decreased immediately, at 0 h, 1 h, and 6 h after the GLC-82 cells irradiated by EMP as compared with control group. The highest apoptosis rate was found to reach 13.38% by flow cytometry at 6 h after EMP irradiation. Down-regulation of bcl-2 expression and up-regulation of p53 expression were induced by EMP. EMP promotes apoptosis of GLC-82 cells. At same time, EMP can down-regulate bcl-2 expression and up-regulate p53 expression in GLC-82 cells. The bcl-2 and the p53 protein may involve the apoptotic process.

  3. Integrated field equations methods for the computation of electromagnetic fields in strongly inhomogeneous media

    NARCIS (Netherlands)

    Jorna, P.

    2005-01-01

    Electromagnetic field theory plays a very important role in present-day technology; examples of technologies based on electromagnetism that are inextricably bound up with every day life are: radar, remote sensing, geoelectromagnetics, bioelectromagnetics, antennas, wireless communication, optics,

  4. Remote detection of radioactive material using high-power pulsed electromagnetic radiation.

    Science.gov (United States)

    Kim, Dongsung; Yu, Dongho; Sawant, Ashwini; Choe, Mun Seok; Lee, Ingeun; Kim, Sung Gug; Choi, EunMi

    2017-05-09

    Remote detection of radioactive materials is impossible when the measurement location is far from the radioactive source such that the leakage of high-energy photons or electrons from the source cannot be measured. Current technologies are less effective in this respect because they only allow the detection at distances to which the high-energy photons or electrons can reach the detector. Here we demonstrate an experimental method for remote detection of radioactive materials by inducing plasma breakdown with the high-power pulsed electromagnetic waves. Measurements of the plasma formation time and its dispersion lead to enhanced detection sensitivity compared to the theoretically predicted one based only on the plasma on and off phenomena. We show that lower power of the incident electromagnetic wave is sufficient for plasma breakdown in atmospheric-pressure air and the elimination of the statistical distribution is possible in the presence of radioactive material.

  5. Remote detection of radioactive material using high-power pulsed electromagnetic radiation

    Science.gov (United States)

    Kim, Dongsung; Yu, Dongho; Sawant, Ashwini; Choe, Mun Seok; Lee, Ingeun; Kim, Sung Gug; Choi, Eunmi

    2017-05-01

    Remote detection of radioactive materials is impossible when the measurement location is far from the radioactive source such that the leakage of high-energy photons or electrons from the source cannot be measured. Current technologies are less effective in this respect because they only allow the detection at distances to which the high-energy photons or electrons can reach the detector. Here we demonstrate an experimental method for remote detection of radioactive materials by inducing plasma breakdown with the high-power pulsed electromagnetic waves. Measurements of the plasma formation time and its dispersion lead to enhanced detection sensitivity compared to the theoretically predicted one based only on the plasma on and off phenomena. We show that lower power of the incident electromagnetic wave is sufficient for plasma breakdown in atmospheric-pressure air and the elimination of the statistical distribution is possible in the presence of radioactive material.

  6. A comparison of lightning and nuclear electromagnetic pulse response of a helicopter

    Science.gov (United States)

    Easterbrook, C. C.; Perala, R. A.

    1984-01-01

    A numerical modeling technique is utilized to investigate the response of a UH-60A helicopter to both lightning and nuclear electromagnetic pulses (NEMP). The analytical approach involves the three-dimensional time domain finite-difference solutions of Maxwell's equations. Both the external currents and charges as well as the internal electromagnetic fields and cable responses are computed. Results of the analysis indicate that, in general, the short circuit current on internal cables is larger for lightning, whereas the open-circuit voltages are slightly higher for NEMP. The lightning response is highly dependent upon the rise time of the injected current as was expected. The analysis shows that a coupling levels to cables in a helicopter are 20 to 30 dB larger than those observed in fixed-wing aircraft.

  7. Spectral and temporal characteristics of target current and electromagnetic pulse induced by nanosecond laser ablation

    Czech Academy of Sciences Publication Activity Database

    Krása, Josef; De Marco, Massimo; Cikhardt, Jakub; Pfeifer, Miroslav; Velyhan, Andriy; Klír, Daniel; Řezáč, Karel; Limpouch, J.; Krouský, Eduard; Dostál, Jan; Ullschmied, Jiří; Dudžák, Roman

    2017-01-01

    Roč. 59, č. 6 (2017), 1-8, č. článku 065007. ISSN 0741-3335 R&D Projects: GA MŠk EF15_008/0000162; GA ČR GA16-07036S EU Projects: European Commission(XE) 654148 - LASERLAB-EUROPE Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 ; RVO:61389021 Keywords : laser-produced plasma * target current * electromagnetic pulse Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.392, year: 2016

  8. Field test and theoretical analysis of electromagnetic pulse propagation velocity on crossbonded cable systems

    DEFF Research Database (Denmark)

    Jensen, Christian Flytkjær; Bak, Claus Leth; Gudmundsdottir, Unnur Stella

    2014-01-01

    In this paper, the electromagnetic pulse propagation velocity on a three-phase cable system, consisting of three single core (SC) cables in flat formation with an earth continuity conductor is under study. The propagation velocity is an important parameter for most travelling wave off- and online...... fault location methods and needs to be exactly known for optimal performance of these algorithm types. Field measurements are carried out on a 6.9 km and a 31.4 km 245 kV crossbonded cable system, and the results are analysed using the modal decomposition theory. Several ways for determining...

  9. Transcranial low voltage pulsed electromagnetic fields in patients with treatment-resistant depression

    DEFF Research Database (Denmark)

    Martiny, Klaus Per Juul; Lunde, Marianne; Bech, Per

    2010-01-01

    of a new principle using low-intensity transcranially applied pulsed electromagnetic fields (T-PEMF) in combination with antidepressants in patients with treatment-resistant depression. METHODS: This was a sham-controlled double-blind study comparing 5 weeks of active or sham T-PEMF in patients...... seven separate coils located over the skull that generated an electrical field in tissue with orders of magnitude weaker than those generated by rTMS equipment. RESULTS: Patients on active T-PEMF showed a clinically and statistically significant better outcome than patients treated with sham T...

  10. The Effects of Pulsed Electromagnetic Field in the Treatment of Osteoarthritis in Dogs: Clinical Study

    OpenAIRE

    Stefania Pinna*§, Francesca Landucci§, Anna Maria Tribuiani§, Fabio Carli and Antonio Venturini

    2013-01-01

    In this study the effects of pulsed electromagnetic field (PEMF) on pain relief and functional capacity of dogs with osteoarthritis (OA) were investigated, and compared with firocoxib. Patients were randomly assigned to two groups: twenty-five client-owned dogs were treated with PEMF once a day for 20 sessions, and fifteen dogs (control group) were treated with 5 mg/kg of firocoxib once daily for 20 days. Blinded clinical examination and owner’s assessment were recorded before and after the t...

  11. Defects in regular nanosystems and interference spectra at reemission of electromagnetic field attosecond pulses

    Directory of Open Access Journals (Sweden)

    Matveev V.I.

    2017-01-01

    Full Text Available The effect of defects in nanostructured targets on interference spectra at the reemission of attosecond electromagnetic pulses has been considered. General expressions have been obtained for calculations of spectral distributions for one-, two-, and three-dimensional multiatomic nanosystems consisting of identical complex atoms with defects such as bends, vacancies, and breaks. Changes in interference spectra by a linear chain with several removed atoms (chain with breaks and by a linear chain with a bend have been calculated as examples allowing a simple analytical representation. Generalization to two- and three-dimensional nanosystems has been developed.

  12. Interaction of electromagnetic pulse with commercial nuclear-power-plant systems

    International Nuclear Information System (INIS)

    Ericson, D.M. Jr.; Strawe, D.F.; Sandberg, S.J.; Jones, V.K.; Rensner, G.D.; Shoup, R.W.; Hanson, R.J.; Williams, C.B.

    1983-02-01

    This study examines the interaction of the electromagnetic pulse from a high altitude nuclear burst with commercial nuclear power plant systems. The potential vulnerability of systems required for safe shutdown of a specific nuclear power plant are explored. EMP signal coupling, induced plant response and component damage thresholds are established using techniques developed over several decades under Defense Nuclear Agency sponsorship. A limited test program was conducted to verify the coupling analysis technique as applied to a nuclear power plant. The results are extended, insofar as possible, to other nuclear plants

  13. Observation of strongly enhanced ultrashort pulses in 3-D metallic funnel-waveguide.

    Science.gov (United States)

    Lee, Dong-Hyub; Choi, Joonhee; Kim, Seungchul; Park, In-Yong; Han, Seunghwoi; Kim, Hyunwoong; Kim, Seung-Woo

    2014-07-14

    For strong field enhancement of ultrashort light pulses, a 3-D metallic funnel-waveguide is analyzed using the finite-difference time-domain (FDTD) method. Then the maximum intensity enhancement actually developed by the funnel-waveguide upon the injection of femtosecond laser pulses is observed using two-photon luminescence (TPL) microscopy. In addition, the ultrafast dephasing profile of the localized field at the hot spot of the funnel-waveguide is verified through the interferometric autocorrelation of the TPL signal. Finally it is concluded the funnel-waveguide is an effective 3-D nanostructure that is capable of boosting the peak pulse intensity of stronger than 80 TWcm(-2) by an enhancement factor of 20 dB without significant degradation of the ultrafast spatiotemporal characteristics of the original pulses.

  14. Numerical simulation of narrow bipolar electromagnetic pulses generated by thunderstorm discharges

    Science.gov (United States)

    Bochkov, E. I.; Babich, L. P.; Kutsyk, I. M.

    2013-07-01

    Using the concept of avalanche relativistic runaway electrons (REs), we perform numerical simulations of compact intracloud discharge (CID) as a generator of powerful natural electromagnetic pulses (EMPs) in the HF-VHF range, called narrow bipolar pulses (NBPs). For several values of the field overvoltage and altitude at which the discharge develops, the numbers of seed electrons initiating the avalanche are evaluated, with which the calculated EMP characteristics are consistent with the measured NBP parameters. We note shortcomings in the hypothesis assuming participation of cosmic ray air showers in avalanche initiation. The discharge capable of generating NBPs produces REs in numbers close to those in the source of terrestrial γ-ray flashes (TGFs), which can be an argument in favor of a unified NBP and TGF source.

  15. Numerical simulation of narrow bipolar electromagnetic pulses generated by thunderstorm discharges

    International Nuclear Information System (INIS)

    Bochkov, E. I.; Babich, L. P.; Kutsyk, I. M.

    2013-01-01

    Using the concept of avalanche relativistic runaway electrons (REs), we perform numerical simulations of compact intracloud discharge (CID) as a generator of powerful natural electromagnetic pulses (EMPs) in the HF-VHF range, called narrow bipolar pulses (NBPs). For several values of the field overvoltage and altitude at which the discharge develops, the numbers of seed electrons initiating the avalanche are evaluated, with which the calculated EMP characteristics are consistent with the measured NBP parameters. We note shortcomings in the hypothesis assuming participation of cosmic ray air showers in avalanche initiation. The discharge capable of generating NBPs produces REs in numbers close to those in the source of terrestrial γ-ray flashes (TGFs), which can be an argument in favor of a unified NBP and TGF source

  16. High-latitude electromagnetic and particle energy flux during an event with sustained strongly northward IMF

    Directory of Open Access Journals (Sweden)

    H. Korth

    2005-06-01

    Full Text Available We present a case study of a prolonged interval of strongly northward orientation of the interplanetary magnetic field on 16 July 2000, 16:00-19:00 UT to characterize the energy exchange between the magnetosphere and ionosphere for conditions associated with minimum solar wind-magnetosphere coupling. With reconnection occurring tailward of the cusp under northward IMF conditions, the reconnection dynamo should be separated from the viscous dynamo, presumably driven by the Kelvin-Helmholtz (KH instability. Thus, these conditions are also ideal for evaluating the contribution of a viscous interaction to the coupling process. We derive the two-dimensional distribution of the Poynting vector radial component in the northern sunlit polar ionosphere from magnetic field observations by the constellation of Iridium satellites together with drift meter and magnetometer observations from the Defense Meteorological Satellite Program (DMSP F13 and F15 satellites. The electromagnetic energy flux is then compared with the particle energy flux obtained from auroral images taken by the far-ultraviolet (FUV instrument on the Imager for Magnetopause to Aurora Global Exploration (IMAGE spacecraft. The electromagnetic energy input to the ionosphere of 51 GW calculated from the Iridium/DMSP observations is eight times larger than the 6 GW due to particle precipitation all poleward of 78° MLAT. This result indicates that the energy transport is significant, particularly as it is concentrated in a small region near the magnetic pole, even under conditions traditionally considered to be quiet and is dominated by the electromagnetic flux. We estimate the contributions of the high and mid-latitude dynamos to both the Birkeland currents and electric potentials finding that high-latitude reconnection accounts for 0.8 MA and 45kV while we attribute <0.2MA and ~5kV to an interaction at lower latitudes having the sense of a viscous interaction. Given that these

  17. High power radiators of ultra-short electromagnetic quasi-unipolar pulses

    International Nuclear Information System (INIS)

    Fedorov, V M; Ostashev, V E; Tarakanov, V P; Ul’yanov, A V

    2017-01-01

    Results of creation, operation, and diagnostics of the high power radiators for ultra-short length electromagnetic pulses (USEMPs) with a quasi-unipolar profile, which have been developed in our laboratory, are presented. The radiating module contains: the ultra-wideband (UWB) antenna array, the exciting high voltage pulse semiconductor generator (a pulser), the power source and the control unit. The principles of antenna array with a high efficiency aperture about 0.9 were developed using joint four TEM-horns with shielding electrodes in every TEM-horn. Sizes of the antenna apertures were (16-60) cm. The pulsers produced by “FID Technology” company had the following parameters: 50 Ohm connector impedance, unipolar pulses voltages (10-100) kV, the rise-time (0.04-0.15) ns, and the width (0.2-1) ns. The modules radiate the USEMPs of (0.1-10) GHz spectrum, their repetition rate is (1-100) kHz, and the effective potential is E*R = (20-400) kV, producing the peak E-field into the far-zone of R-distance. Parameters of the USEMP waves were measured by a calibrated sensor with the following characteristics: the sensitivity 0.32V/(kV/m), the rise-time 0.03 ns, the duration up to 7 ns. The measurements were in agreement with the simulation results, which were obtained using the 3-D code “KARAT”. The USEMP waves with amplitudes (1-10) kV/m and the pulse repetition rate (0.5-100) kHz were successfully used to examine various electronic devices for an electromagnetic immunity. (paper)

  18. High power radiators of ultra-short electromagnetic quasi-unipolar pulses

    Science.gov (United States)

    Fedorov, V. M.; Ostashev, V. E.; Tarakanov, V. P.; Ul'yanov, A. V.

    2017-05-01

    Results of creation, operation, and diagnostics of the high power radiators for ultra-short length electromagnetic pulses (USEMPs) with a quasi-unipolar profile, which have been developed in our laboratory, are presented. The radiating module contains: the ultra-wideband (UWB) antenna array, the exciting high voltage pulse semiconductor generator (a pulser), the power source and the control unit. The principles of antenna array with a high efficiency aperture about 0.9 were developed using joint four TEM-horns with shielding electrodes in every TEM-horn. Sizes of the antenna apertures were (16-60) cm. The pulsers produced by “FID Technology” company had the following parameters: 50 Ohm connector impedance, unipolar pulses voltages (10-100) kV, the rise-time (0.04-0.15) ns, and the width (0.2-1) ns. The modules radiate the USEMPs of (0.1-10) GHz spectrum, their repetition rate is (1-100) kHz, and the effective potential is E*R = (20-400) kV, producing the peak E-field into the far-zone of R-distance. Parameters of the USEMP waves were measured by a calibrated sensor with the following characteristics: the sensitivity 0.32V/(kV/m), the rise-time 0.03 ns, the duration up to 7 ns. The measurements were in agreement with the simulation results, which were obtained using the 3-D code “KARAT”. The USEMP waves with amplitudes (1-10) kV/m and the pulse repetition rate (0.5-100) kHz were successfully used to examine various electronic devices for an electromagnetic immunity.

  19. Calcium homeostasis of isolated heart muscle cells exposed to pulsed high-frequency electromagnetic fields.

    Science.gov (United States)

    Wolke, S; Neibig, U; Elsner, R; Gollnick, F; Meyer, R

    1996-01-01

    The intracellular calcium concentration ([Ca(2+)]i) of isolated ventricular cardiac myocytes of the guinea pig was measured during the application of pulsed high-frequency electromagnetic fields. The high-frequency fields were applied in a transverse electromagnetic cell designed to allow microscopic observation of the myocytes during the presence of the high-frequency fields. The [Ca(2+)]i was measured as fura-2 fluorescence by means of digital image analysis. Both the carrier frequency and the square-wave pulse-modulation pattern were varied during the experiments (carrier frequencies: 900, 1,300, and 1,800 MHz pulse modulated at 217Hz with 14 percent duty cycle; pulsation pattern at 900 MHz: continuous wave, 16 Hz, and 50 Hz modulation with 50 percent duty cycle and 30 kHz modulation with 80 percent duty cycle). The mean specific absorption rate (SAR) values in the solution were within one order of magnitude of 1 mW/kg. They varied depending on the applied carrier frequency and pulse pattern. The experiments were designed in three phases: 500 s of sham exposure, followed by 500 s of field exposure, then chemical stimulation without field. The chemical stimulation (K+ -depolarization) indicated the viability of the cells. The K+ depolarization yielded a significant increase in [Ca(2+)]i. Significant differences between sham exposure and high-frequency field exposure were not found except when a very small but statistically significant difference was detected in the case of 900 MHz/50 Hz. However, this small difference was not regarded as a relevant effect of the exposure.

  20. Autler-Townes effect in a strongly driven electromagnetically induced transparency resonance

    International Nuclear Information System (INIS)

    Yang Lijun; Zhang Lianshui; Li Xiaoli; Han Li; Fu Guangsheng; Manson, Neil B.; Suter, Dieter; Wei Changjiang

    2005-01-01

    In this paper we study the nonlinear behavior of an electromagnetically induced transparency (EIT) resonance subject to a coherent driving field. The EIT is associated with a Λ three-level system where two hyperfine levels within an electronic ground state are coupled to a common excited state level by a coupling field and a probe field. In addition there is an radio-frequency (rf) field driving a hyperfine transition within the ground state. The paper contrasts two different situations. In one case the rf-driven transition shares a common level with the probed transition and in the second case it shares a common level with the coupled transition. In both cases the EIT resonance is split into a doublet and the characteristics of the EIT doublet are determined by the strength and frequency of the rf-driving field. The doublet splitting originates from the rf-field induced dynamic Stark effect and has close analogy with the Autler-Townes effect observed in three-level pump-probe spectroscopy study. The situation changes when the rf field is strong and the two cases are very different. One is analogous to two Λ three-level systems with EIT resonance associated with each. The other corresponds to a doubly driven three-level system with rf-field-induced electromagnetically induced absorption resonance. The two situations are modeled using numerical solutions of the relevant equation of motion of density matrix. In addition a physical account of their behaviors is given in terms of a dressed state picture

  1. Speed of Gravitational Waves from Strongly Lensed Gravitational Waves and Electromagnetic Signals.

    Science.gov (United States)

    Fan, Xi-Long; Liao, Kai; Biesiada, Marek; Piórkowska-Kurpas, Aleksandra; Zhu, Zong-Hong

    2017-03-03

    We propose a new model-independent measurement strategy for the propagation speed of gravitational waves (GWs) based on strongly lensed GWs and their electromagnetic (EM) counterparts. This can be done in two ways: by comparing arrival times of GWs and their EM counterparts and by comparing the time delays between images seen in GWs and their EM counterparts. The lensed GW-EM event is perhaps the best way to identify an EM counterpart. Conceptually, this method does not rely on any specific theory of massive gravitons or modified gravity. Its differential setting (i.e., measuring the difference between time delays in GW and EM domains) makes it robust against lens modeling details (photons and GWs travel in the same lensing potential) and against internal time delays between GW and EM emission acts. It requires, however, that the theory of gravity is metric and predicts gravitational lensing similar to general relativity. We expect that such a test will become possible in the era of third-generation gravitational-wave detectors, when about 10 lensed GW events would be observed each year. The power of this method is mainly limited by the timing accuracy of the EM counterpart, which for kilonovae is around 10^{4}  s. This uncertainty can be suppressed by a factor of ∼10^{10}, if strongly lensed transients of much shorter duration associated with the GW event can be identified. Candidates for such short transients include short γ-ray bursts and fast radio bursts.

  2. Strong-field QED processes in short laser pulses. One- and two-photon Compton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Seipt, Daniel

    2012-12-20

    The purpose of this thesis is to advance the understanding of strong-field QED processes in short laser pulses. The processes of non-linear one-photon and two-photon Compton scattering are studied, that is the scattering of photons in the interaction of relativistic electrons with ultra-short high-intensity laser pulses. These investigations are done in view of the present and next generation of ultra-high intensity optical lasers which are supposed to achieve unprecedented intensities of the order of 10{sup 24} W/cm{sup 2} and beyond, with pulse lengths in the order of some femtoseconds. The ultra-high laser intensity requires a non-perturbative description of the interaction of charged particles with the laser field to allow for multi-photon interactions, which is beyond the usual perturbative expansion of QED organized in powers of the fine structure constant. This is achieved in strong-field QED by employing the Furry picture and non-perturbative solutions of the Dirac equation in the presence of a background laser field as initial and final state wave functions, as well as the laser dressed Dirac-Volkov propagator. The primary objective is a realistic description of scattering processes with regard to the finite laser pulse duration beyond the common approximation of infinite plane waves, which is made necessary by the ultra-short pulse length of modern high-intensity lasers. Non-linear finite size effects are identified, which are a result of the interplay between the ultra-high intensity and the ultra-short pulse length. In particular, the frequency spectra and azimuthal photon emission spectra are studied emphasizing the differences between pulsed and infinite laser fields. The proper description of the finite temporal duration of the laser pulse leads to a regularization of unphysical infinities (due to the infinite plane-wave description) of the laser-dressed Dirac-Volkov propagator and in the second-order strong-field process of two-photon Compton

  3. Strong-field QED processes in short laser pulses. One- and two-photon Compton scattering

    International Nuclear Information System (INIS)

    Seipt, Daniel

    2012-01-01

    The purpose of this thesis is to advance the understanding of strong-field QED processes in short laser pulses. The processes of non-linear one-photon and two-photon Compton scattering are studied, that is the scattering of photons in the interaction of relativistic electrons with ultra-short high-intensity laser pulses. These investigations are done in view of the present and next generation of ultra-high intensity optical lasers which are supposed to achieve unprecedented intensities of the order of 10 24 W/cm 2 and beyond, with pulse lengths in the order of some femtoseconds. The ultra-high laser intensity requires a non-perturbative description of the interaction of charged particles with the laser field to allow for multi-photon interactions, which is beyond the usual perturbative expansion of QED organized in powers of the fine structure constant. This is achieved in strong-field QED by employing the Furry picture and non-perturbative solutions of the Dirac equation in the presence of a background laser field as initial and final state wave functions, as well as the laser dressed Dirac-Volkov propagator. The primary objective is a realistic description of scattering processes with regard to the finite laser pulse duration beyond the common approximation of infinite plane waves, which is made necessary by the ultra-short pulse length of modern high-intensity lasers. Non-linear finite size effects are identified, which are a result of the interplay between the ultra-high intensity and the ultra-short pulse length. In particular, the frequency spectra and azimuthal photon emission spectra are studied emphasizing the differences between pulsed and infinite laser fields. The proper description of the finite temporal duration of the laser pulse leads to a regularization of unphysical infinities (due to the infinite plane-wave description) of the laser-dressed Dirac-Volkov propagator and in the second-order strong-field process of two-photon Compton scattering. An

  4. Low-intensity pulsed ultrasound (LIPUS) and pulsed electromagnetic field (PEMF) treatments affect degeneration of cultured articular cartilage explants.

    Science.gov (United States)

    Tan, Lijun; Ren, Yijin; van Kooten, Theo G; Grijpma, Dirk W; Kuijer, Roel

    2015-03-01

    Articular cartilage has some capacity for self-repair. Clinically used low-intensity pulsed ultrasound (LIPUS) and pulsed electromagnetic field (PEMF) treatments were compared in their potency to prevent degeneration using an explant model of porcine cartilage. Explants of porcine cartilage and human osteoarthritic cartilage were cultured for four weeks and subjected to daily LIPUS or PEMF treatments. At one, two, three and four weeks follow-up explants were prepared for histological assessment or gene expression (porcine only). Non-treated porcine explants showed signs of atrophy of the superficial zone starting at one week. Treated explants did not. In LIPUS-treated explants cell clusters were observed. In PEMF-treated explants more hypertrophic-like changes were observed at later follow up. Newly synthesized tissue was present in treated explants. Gene expression profiles did indicate differences between the two methods. Both methods reduced expression of the aggrecan and collagen type II gene compared to the control. LIPUS treatment of human cartilage samples resulted in a reduction of degeneration according to Mankin scoring. PEMF treatment did not. LIPUS or PEMF prevented degenerative changes in pig knee cartilage explants. LIPUS reduced degeneration in human cartilage samples. LIPUS treatment seems to have more potency in the treatment of osteoarthritis than PEMF treatment.

  5. Overcoming Antimicrobial Resistance in Bacteria Using Bioactive Magnetic Nanoparticles and Pulsed Electromagnetic Fields

    Directory of Open Access Journals (Sweden)

    Vitalij Novickij

    2018-01-01

    Full Text Available Nisin is a known bacteriocin, which exhibits a wide spectrum of antimicrobial activity, while commonly being inefficient against Gram-negative bacteria. In this work, we present a proof of concept of novel antimicrobial methodology using targeted magnetic nisin-loaded nano-carriers [iron oxide nanoparticles (NPs (11–13 nm capped with citric, ascorbic, and gallic acids], which are activated by high pulsed electric and electromagnetic fields allowing to overcome the nisin-resistance of bacteria. As a cell model the Gram-positive bacteria Bacillus subtilis and Gram-negative Escherichia coli were used. We have applied 10 and 30 kV cm-1 electric field pulses (100 μs × 8 separately and in combination with two pulsed magnetic field protocols: (1 high dB/dt 3.3 T × 50 and (2 10 mT, 100 kHz, 2 min protocol to induce additional permeabilization and local magnetic hyperthermia. We have shown that the high dB/dt pulsed magnetic fields increase the antimicrobial efficiency of nisin NPs similar to electroporation or magnetic hyperthermia methods and a synergistic treatment is also possible. The results of our work are promising for the development of new methods for treatment of the drug-resistant foodborne pathogens to minimize the risks of invasive infections.

  6. Mechanisms of amplification of ultrashort electromagnetic pulses in gyrotron traveling wave tube with helically corrugated waveguide

    International Nuclear Information System (INIS)

    Ginzburg, N. S.; Zaslavsky, V. Yu.; Zotova, I. V.; Sergeev, A. S.; Zheleznov, I. V.; Samsonov, S. V.; Mishakin, S. V.

    2015-01-01

    A time-domain self consistent theory of a gyrotron traveling wave tube with a helically corrugated operating waveguide has been developed. Based on this model, the process of short pulse amplification was studied in regimes of grazing and intersection of the dispersion curves of the electromagnetic wave and the electron beam. In the first case, the possibility of amplification without pulse form distortion was demonstrated for the pulse spectrum width of the order of the gain bandwidth. In the second case, when the electrons' axial velocity was smaller than the wave's group velocity, it was shown that the slippage of the incident signal with respect to the electron beam provides feeding of the signal by “fresh” electrons without initial modulation. As a result, the amplitude of the output pulse can exceed the amplitude of its saturated value for the case of the grazing regime, and, for optimal parameters, the peak output power can be even larger than the kinetic power of the electron beam

  7. Detection and Characterization of Flaws in Sprayed on Foam Insulation with Pulsed Terahertz Frequency Electromagnetic Waves

    Science.gov (United States)

    Winfree, William P.; Madaras, Eric I.

    2005-01-01

    The detection and repair of flaws such as voids and delaminations in the sprayed on foam insulation of the external tank reduces the probability of foam debris during shuttle ascent. The low density of sprayed on foam insulation along with it other physical properties makes detection of flaws difficult with conventional techniques. An emerging technology that has application for quantitative evaluation of flaws in the foam is pulsed electromagnetic waves at terahertz frequencies. The short wavelengths of these terahertz pulses make them ideal for imaging flaws in the foam. This paper examines the application of terahertz pulses for flaw detection in foam characteristic of the foam insulation of the external tank. Of particular interest is the detection of voids and delaminations, encapsulated in the foam or at the interface between the foam and a metal backing. The technique is shown to be capable of imaging small voids and delaminations through as much as 20 cm of foam. Methods for reducing the temporal responses of the terahertz pulses to improve flaw detection and yield quantitative characterizations of the size and location of the flaws are discussed.

  8. Electromagnetic pulse from supernovae. [model for old low-mass stars

    Science.gov (United States)

    Colgate, S. A.

    1975-01-01

    Upper and lower limits to the radiated electromagnetic pulse from a supernova are calculated assuming that the mass fraction of the matter expanding inside the dipole magnetic field shares energy and maintains the pressure balance in the process. A supernova model is described in which the explosion occurs in old low-mass stars containing less than 10% hydrogen in their ejecta and a remnant neutron star is produced. The analysis indicates that although the surface layer of a star of 1 g/cu thickness may be shock-accelerated to an energy factor of about 100 and may expand into the vacuum with an energy factor approaching 10,000, the equatorial magnetic field will retard this expansion so that the inner, more massive ejecta layers will effectively accelerate the presumed canonical dipole magnetic field to greater velocities than would the surface layer alone. A pulse of 10 to the 46th power ergs in a width of about 150 cm will result which will not be affected by circumstellar matter or electron self-radiation effects. It is shown that interstellar matter will attenuate the pulse, but that charge separation may reduce the attenuation and allow a larger pulse to escape.

  9. Sleep EEG alterations: effects of different pulse-modulated radio frequency electromagnetic fields.

    Science.gov (United States)

    Schmid, Marc R; Loughran, Sarah P; Regel, Sabine J; Murbach, Manuel; Bratic Grunauer, Aleksandra; Rusterholz, Thomas; Bersagliere, Alessia; Kuster, Niels; Achermann, Peter

    2012-02-01

    Previous studies have observed increases in electroencephalographic power during sleep in the spindle frequency range (approximately 11-15 Hz) after exposure to mobile phone-like radio frequency electromagnetic fields (RF EMF). Results also suggest that pulse modulation of the signal is crucial to induce these effects. Nevertheless, it remains unclear which specific elements of the field are responsible for the observed changes. We investigated whether pulse-modulation frequency components in the range of sleep spindles may be involved in mediating these effects. Thirty young healthy men were exposed, at weekly intervals, to three different conditions for 30 min directly prior to an 8-h sleep period. Exposure consisted of a 900-MHz RF EMF, pulse modulated at 14 Hz or 217 Hz, and a sham control condition. Both active conditions had a peak spatial specific absorption rate of 2 W kg(-1) . During exposure subjects performed three different cognitive tasks (measuring attention, reaction speed and working memory), which were presented in a fixed order. Electroencephalographic power in the spindle frequency range was increased during non-rapid eye movement sleep (2nd episode) following the 14-Hz pulse-modulated condition. A similar but non-significant increase was also observed following the 217-Hz pulse-modulated condition. Importantly, this exposure-induced effect showed considerable individual variability. Regarding cognitive performance, no clear exposure-related effects were seen. Consistent with previous findings, our results provide further evidence that pulse-modulated RF EMF alter brain physiology, although the time-course of the effect remains variable across studies. Additionally, we demonstrated that modulation frequency components within a physiological range may be sufficient to induce these effects. © 2011 European Sleep Research Society.

  10. An Approach for Effect Analysis of Electromagnetic Pulse in Operating NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Ho Sun; Ye, Song Hae; Kim, Minyi; Lee, Euijong [KHNP CRI, Daejeon (Korea, Republic of)

    2016-10-15

    Recently, there is a growing Electromagnetic Pulse (EMP) threat caused by North Korea’s nuclear weapons and unmanned aerial vehicles (UAVs). KHNP CRI is currently conducting a research project that will evaluate the safety of domestic nuclear power plants (NPPs) against EMP effects and prepare safety measures to counter vulnerable points. We will instead use simulation tools to evaluate the electromagnetic shielding ability and the conductivity of cables through vulnerable points in NPPs. Through a study of electromagnetic simulation techniques and tools, this paper suggests a simulation method for analysis of EMP effects in operating NPPs. Although 3D tools are relatively accurate, is difficult to use only 3D tools to simulate EMP effects for huge and complex structures such as NPPs. It is more efficient in terms of cost and time to use a 3D tool and an EMT tool for the simulation of such structures. We have compared the advantages and disadvantages of various methods and have selected the most appropriate tools; we will proceed in our next paper with the simulation of EMP effects.

  11. Effects of Presowing Pulsed Electromagnetic Treatment of Tomato Seed on Growth, Yield, and Lycopene Content

    Science.gov (United States)

    Efthimiadou, Aspasia; Katsenios, Nikolaos; Papastylianou, Panayiota; Triantafyllidis, Vassilios; Travlos, Ilias; Bilalis, Dimitrios J.

    2014-01-01

    The use of magnetic field as a presowing treatment has been adopted by researchers as a new environmental friendly technique. The aim of this study was to determine the effect of magnetic field exposure on tomato seeds covering a range of parameters such as transplanting percentage, plant height, shoot diameter, number of leaves per plant, fresh weight, dry weight, number of flowers, yield, and lycopene content. Pulsed electromagnetic field was used for 0, 5, 10, and 15 minutes as a presowing treatment of tomato seeds in a field experiment for two years. Papimi device (amplitude on the order of 12.5 mT) has been used. The use of pulsed electromagnetic field as a presowing treatment was found to enhance plant growth in tomato plants at certain duration of exposure. Magnetic field treatments and especially the exposure of 10 and 15 minutes gave the best results in all measurements, except plant height and lycopene content. Yield per plant was higher in magnetic field treatments, compared to control. MF-15 treatment yield was 80.93% higher than control treatment. Lycopene content was higher in magnetic field treatments, although values showed no statistically significant differences. PMID:25097875

  12. Pulsed electromagnetic field stimulation may improve fusion rates in cervical arthrodesis in high-risk populations.

    Science.gov (United States)

    Coric, D; Bullard, D E; Patel, V V; Ryaby, J T; Atkinson, B L; He, D; Guyer, R D

    2018-02-01

    Pulsed electromagnetic field (PEMF) stimulation was evaluated after anterior cervical discectomy and fusion (ACDF) procedures in a randomized, controlled clinical study performed for United States Food and Drug Administration (FDA) approval. PEMF significantly increased fusion rates at six months, but 12-month fusion outcomes for subjects at elevated risk for pseudoarthrosis were not thoroughly reported. The objective of the current study was to evaluate the effect of PEMF treatment on subjects at increased risk for pseudoarthrosis after ACDF procedures. Two evaluations were performed that compared fusion rates between PEMF stimulation and a historical control (160 subjects) from the FDA investigational device exemption (IDE) study: a post hoc (PH) analysis of high-risk subjects from the FDA study (PH PEMF); and a multicentre, open-label (OL) study consisting of 274 subjects treated with PEMF (OL PEMF). Fisher's exact test and multivariate logistic regression was used to compare fusion rates between PEMF-treated subjects and historical controls. In separate comparisons of PH PEMF and OL PEMF groups to the historical control group, PEMF treatment significantly (p PEMF treatment can be recommended for patients who are at high risk for pseudoarthrosis. Cite this article : D. Coric, D. E. Bullard, V. V. Patel, J. T. Ryaby, B. L. Atkinson, D. He, R. D. Guyer. Pulsed electromagnetic field stimulation may improve fusion rates in cervical arthrodesis in high-risk populations. Bone Joint Res 2018;7:124-130. DOI: 10.1302/2046-3758.72.BJR-2017-0221.R1. © 2018 Coric et al.

  13. Development of Design Information Template for Nuclear Power Plants for Electromagnetic Pulse (EMP) Effect Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Minyi; Ryu, Hosan; Ye, Songhae; Lee, Euijong [KNHP CRI, Daejeon (Korea, Republic of)

    2016-10-15

    An electromagnetic pulse (EMP) is a transient electromagnetic shock wave that has powerful electric and magnetic fields that can destroy electronic equipment. It is generally well-known that EMPs can cause the malfunction and disorder of electronic equipment and serious damages to electric power systems and communication networks. Research is being carried out to protect nuclear power plants (NPPs) from EMP threats. Penetration routes of EMPs can be roughly categorized into two groups, radioactivity and conductivity. The radioactive effect refers to an impact transmitted to the ground from high-altitude electromagnetic pulses (HEMP). Such an impact may affect target equipment through the point of entry (POE) of the concrete structure of an NPP. The conductive effect refers to induced voltage or current coupled to the NPPs cable structure. The induced voltage and current affect the target equipment via connected cables. All these factors must be considered when taking into account EMP effect analysis for NPPs. To examine all factors, it is necessary to fully understand the schemes of NPPs. This paper presents a four type design information template that can be used to analyze the EMP effect in operating nuclear power plants. In order to analyze of the effects of EMPs on operating NPPs, we must consider both the conductive and radioactive effects on the target (system, equipment, structure). For these reasons, not only the equipment information, but also the information about the structure and the external penetration will be required. We are developing a design information template for robust nuclear design information acquisition. We expect to develop a block diagram on the basis of the template.

  14. Electromagnetics

    CERN Document Server

    Rothwell, Edward J

    2009-01-01

    Introductory concepts Notation, conventions, and symbology The field concept of electromagneticsThe sources of the electromagnetic field Problems Maxwell's theory of electromagnetism The postulate Maxwell's equations in moving frames The Maxwell-Boffi equations Large-scale form of Maxwell's equationsThe nature of the four field quantities Maxwell's equations with magnetic sources Boundary (jump) conditions Fundamental theorems The wave nature of the electromagnetic field ProblemsThe static electromagnetic field Static fields and steady currents ElectrostaticsMagnetostatics Static field theorem

  15. Increases in microvascular perfusion and tissue oxygenation via pulsed electromagnetic fields in the healthy rat brain.

    Science.gov (United States)

    Bragin, Denis E; Statom, Gloria L; Hagberg, Sean; Nemoto, Edwin M

    2015-05-01

    High-frequency pulsed electromagnetic field stimulation is an emerging noninvasive therapy being used clinically to facilitate bone and cutaneous wound healing. Although the mechanisms of action of pulsed electromagnetic fields (PEMF) are unknown, some studies suggest that its effects are mediated by increased nitric oxide (NO), a well-known vasodilator. The authors hypothesized that in the brain, PEMF increase NO, which induces vasodilation, enhances microvascular perfusion and tissue oxygenation, and may be a useful adjunct therapy in stroke and traumatic brain injury. To test this hypothesis, they studied the effect of PEMF on a healthy rat brain with and without NO synthase (NOS) inhibition. In vivo two-photon laser scanning microscopy (2PLSM) was used on the parietal cortex of rat brains to measure microvascular tone and red blood cell (RBC) flow velocity in microvessels with diameters ranging from 3 to 50 μm, which includes capillaries, arterioles, and venules. Tissue oxygenation (reduced nicotinamide adenine dinucleotide [NADH] fluorescence) was also measured before and for 3 hours after PEMF treatment using the FDA-cleared SofPulse device (Ivivi Health Sciences, LLC). To test NO involvement, the NOS inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME) was intravenously injected (10 mg/kg). In a time control group, PEMF were not used. Doppler flux (0.8-mm probe diameter), brain and rectal temperatures, arterial blood pressure, blood gases, hematocrit, and electrolytes were monitored. Pulsed electromagnetic field stimulation significantly dilated cerebral arterioles from a baseline average diameter of 26.4 ± 0.84 μm to 29.1 ± 0.91 μm (11 rats, p PEMF-induced changes in arteriolar diameter, microvascular perfusion, and tissue oxygenation (7 rats). No changes in measured parameters were observed throughout the study in the untreated time controls (5 rats). This is the first demonstration of the acute effects of PEMF on cerebral cortical microvascular

  16. Pulse electromagnetic fields enhance extracellular electron transfer in magnetic bioelectrochemical systems.

    Science.gov (United States)

    Zhou, Huihui; Liu, Bingfeng; Wang, Qisong; Sun, Jianmin; Xie, Guojun; Ren, Nanqi; Ren, Zhiyong Jason; Xing, Defeng

    2017-01-01

    Microbial extracellular electron transfer (EET) is essential in driving the microbial interspecies interaction and redox reactions in bioelectrochemical systems (BESs). Magnetite (Fe 3 O 4 ) and magnetic fields (MFs) were recently reported to promote microbial EET, but the mechanisms of MFs stimulation of EET and current generation in BESs are not known. This study investigates the behavior of current generation and EET in a state-of-the-art pulse electromagnetic field (PEMF)-assisted magnetic BES (PEMF-MBES), which was equipped with magnetic carbon particle (Fe 3 O 4 @N-mC)-coated electrodes. Illumina Miseq sequencing of 16S rRNA gene amplicons was also conducted to reveal the changes of microbial communities and interactions on the anode in response to magnetic field. PEMF had significant influences on current generation. When reactors were operated in microbial fuel cell (MFC) mode with pulse electromagnetic field (PEMF-MMFCs), power densities increased by 25.3-36.0% compared with no PEMF control MFCs (PEMF-OFF-MMFCs). More interestingly, when PEMF was removed, the power density dropped by 25.7%, while when PEMF was reintroduced, the value was restored to the previous level. Illumina sequencing of 16S rRNA gene amplicon and principal component analysis (PCA) based on operational taxonomic units (OTUs) indicate that PEMFs led to the shifts in microbial community and changes in species evenness that decreased biofilm microbial diversity. Geobacter spp. were found dominant in all anode biofilms, but the relative abundance in PEMF-MMFCs (86.1-90.0%) was higher than in PEMF-OFF-MMFCs (82.5-82.7%), indicating that the magnetic field enriched Geobacter on the anode. The current generation of Geobacter -inoculated microbial electrolysis cells (MECs) presented the same change regularity, the accordingly increase or decrease corresponding with switch of PEMF, which confirmed the reversible stimulation of PEMFs on microbial electron transfer. The pulse electromagnetic

  17. Counteracting radio frequency inhomogeneity in the human brain at 7 Tesla using strongly modulating pulses.

    Science.gov (United States)

    Boulant, N; Mangin, J-F; Amadon, A

    2009-05-01

    We report flip angle and spoiled gradient echo measurements at 7 Tesla on human brains in three-dimensional imaging, using strongly modulating pulses to counteract the transmitted radiofrequency inhomogeneity problem. Compared with the standard square pulse results, three points of improvement are demonstrated, namely: (i) the removal of the bright center (typical at high fields when using a quadrature head coil), (ii) the substantial gain of signal in the regions of low B(1) intensity, and (iii) an increased 35% signal uniformity over the whole brain at the flip angle where maximum contrast between white and gray matter occurs. We also find by means of simulations that standard BIR-4 adiabatic pulses need several times more energy to reach a similar performance at the same field strength. (c) 2009 Wiley-Liss, Inc.

  18. Electrochemotherapy by pulsed electromagnetic field treatment (PEMF) in mouse melanoma B16F10 in vivo.

    Science.gov (United States)

    Kranjc, Simona; Kranjc, Matej; Scancar, Janez; Jelenc, Jure; Sersa, Gregor; Miklavcic, Damijan

    2016-03-01

    Pulsed electromagnetic field (PEMF) induces pulsed electric field, which presumably increases membrane permeabilization of the exposed cells, similar to the conventional electroporation. Thus, contactless PEMF could represent a promising approach for drug delivery. Noninvasive electroporation was performed by magnetic field pulse generator connected to an applicator consisting of round coil. Subcutaneous mouse B16F10 melanoma tumors were treated with intravenously injection of cisplatin (CDDP) (4 mg/kg), PEMF (480 bipolar pulses, at frequency of 80 Hz, pulse duration of 340 μs) or with the combination of both therapies (electrochemotherapy - PEMF + CDDP). Antitumor effectiveness of treatments was evaluated by tumor growth delay assay. In addition, the platinum (Pt) uptake in tumors and serum, as well as Pt bound to the DNA in the cells and Pt in the extracellular fraction were measured by inductively coupled plasma mass spectrometry. The antitumor effectiveness of electrochemotherapy with CDDP mediated by PEMF was comparable to the conventional electrochemotherapy with CDDP, with the induction of 2.3 days and 3.0 days tumor growth delay, respectively. The exposure of tumors to PEMF only, had no effect on tumor growth, as well as the injection of CDDP only. The antitumor effect in combined treatment was related to increased drug uptake into the electroporated tumor cells, demonstrated by increased amount of Pt bound to the DNA. Approximately 2-fold increase in cellular uptake of Pt was measured. The obtained results in mouse melanoma model in vivo demonstrate the possible use of PEMF induced electroporation for biomedical applications, such as electrochemotherapy. The main advantages of electroporation mediated by PEMF are contactless and painless application, as well as effective electroporation compared to conventional electroporation.

  19. Electrochemotherapy by pulsed electromagnetic field treatment (PEMF) in mouse melanoma B16F10 in vivo

    International Nuclear Information System (INIS)

    Kranjc, Simona; Kranjc, Matej; Scancar, Janez; Jelenc, Jure; Sersa, Gregor; Miklavcic, Damijan

    2016-01-01

    Pulsed electromagnetic field (PEMF) induces pulsed electric field, which presumably increases membrane permeabilization of the exposed cells, similar to the conventional electroporation. Thus, contactless PEMF could represent a promising approach for drug delivery. Noninvasive electroporation was performed by magnetic field pulse generator connected to an applicator consisting of round coil. Subcutaneous mouse B16F10 melanoma tumors were treated with intravenously injection of cisplatin (CDDP) (4 mg/kg), PEMF (480 bipolar pulses, at frequency of 80 Hz, pulse duration of 340 μs) or with the combination of both therapies (electrochemotherapy − PEMF + CDDP). Antitumor effectiveness of treatments was evaluated by tumor growth delay assay. In addition, the platinum (Pt) uptake in tumors and serum, as well as Pt bound to the DNA in the cells and Pt in the extracellular fraction were measured by inductively coupled plasma mass spectrometry. The antitumor effectiveness of electrochemotherapy with CDDP mediated by PEMF was comparable to the conventional electrochemotherapy with CDDP, with the induction of 2.3 days and 3.0 days tumor growth delay, respectively. The exposure of tumors to PEMF only, had no effect on tumor growth, as well as the injection of CDDP only. The antitumor effect in combined treatment was related to increased drug uptake into the electroporated tumor cells, demonstrated by increased amount of Pt bound to the DNA. Approximately 2-fold increase in cellular uptake of Pt was measured. The obtained results in mouse melanoma model in vivo demonstrate the possible use of PEMF induced electroporation for biomedical applications, such as electrochemotherapy. The main advantages of electroporation mediated by PEMF are contactless and painless application, as well as effective electroporation compared to conventional electroporation

  20. Electromagnetic cascade in high-energy electron, positron, and photon interactions with intense laser pulses

    Science.gov (United States)

    Bulanov, S. S.; Schroeder, C. B.; Esarey, E.; Leemans, W. P.

    2013-06-01

    The interaction of high-energy electrons, positrons, and photons with intense laser pulses is studied in head-on collision geometry. It is shown that electrons and/or positrons undergo a cascade-type process involving multiple emissions of photons. These photons can consequently convert into electron-positron pairs. As a result charged particles quickly lose their energy developing an exponentially decaying energy distribution, which suppresses the emission of high-energy photons, thus reducing the number of electron-positron pairs being generated. Therefore, this type of interaction suppresses the development of the electromagnetic avalanche-type discharge, i.e., the exponential growth of the number of electrons, positrons, and photons does not occur in the course of interaction. The suppression will occur when three-dimensional effects can be neglected in the transverse particle orbits, i.e., for sufficiently broad laser pulses with intensities that are not too extreme. The final distributions of electrons, positrons, and photons are calculated for the case of a high-energy e-beam interacting with a counterstreaming, short intense laser pulse. The energy loss of the e-beam, which requires a self-consistent quantum description, plays an important role in this process, as well as provides a clear experimental observable for the transition from the classical to quantum regime of interaction.

  1. Exposure to pulse-modulated radio frequency electromagnetic fields affects regional cerebral blood flow.

    Science.gov (United States)

    Huber, R; Treyer, V; Schuderer, J; Berthold, T; Buck, A; Kuster, N; Landolt, H P; Achermann, P

    2005-02-01

    We investigated the effects of radio frequency electromagnetic fields (RF EMF) similar to those emitted by mobile phones on waking regional cerebral blood flow (rCBF) in 12 healthy young men. Two types of RF EMF exposure were applied: a 'base-station-like' and a 'handset-like' signal. Positron emission tomography scans were taken after 30 min unilateral head exposure to pulse-modulated 900 MHz RF EMF (10 g tissue-averaged spatial peak-specific absorption rate of 1 W/kg for both conditions) and sham control. We observed an increase in relative rCBF in the dorsolateral prefrontal cortex on the side of exposure. The effect depended on the spectral power in the amplitude modulation of the RF carrier such that only 'handset-like' RF EMF exposure with its stronger low-frequency components but not the 'base-station-like' RF EMF exposure affected rCBF. This finding supports our previous observation that pulse modulation of RF EMF is necessary to induce changes in the waking and sleep EEG, and substantiates the notion that pulse modulation is crucial for RF EMF-induced alterations in brain physiology.

  2. Strategies, Protections and Mitigations for Electric Grid from Electromagnetic Pulse Effects

    Energy Technology Data Exchange (ETDEWEB)

    Foster, Rita Ann [Idaho National Lab. (INL), Idaho Falls, ID (United States); Frickey, Steven Jay [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-01-01

    The mission of DOE’s Office of Electricity Delivery and Energy Reliability (OE) is to lead national efforts to modernize the electricity delivery system, enhance the security and reliability of America’s energy infrastructure and facilitate recovery from disruptions to the energy supply. One of the threats OE is concerned about is a high-altitude electro-magnetic pulse (HEMP) from a nuclear explosion and eletro-magnetic pulse (EMP) or E1 pulse can be generated by EMP weapons. DOE-OE provides federal leadership and technical guidance in addressing electric grid issues. The Idaho National Laboratory (INL) was chosen to conduct the EMP study for DOE-OE due to its capabilities and experience in setting up EMP experiments on the electric grid and conducting vulnerability assessments and developing innovative technology to increase infrastructure resiliency. This report identifies known impacts to EMP threats, known mitigations and effectiveness of mitigations, potential cost of mitigation, areas for government and private partnerships in protecting the electric grid to EMP, and identifying gaps in our knowledge and protection strategies.

  3. On the application of a new principle and new class of materials for protection of the IC systems against high power electromagnetic pulses (HPEMP)

    International Nuclear Information System (INIS)

    Vuchkov, L.

    2008-01-01

    The aim of the present work is to make a survey of a new principle and the possibilities for scientific investigations, testing and industrial incorporation of a new shielding material and technology for protection of the IC systems against high energy electromagnetic pulses and ion irradiation. The main result of the implementation of the new- principle, material and technology is to increase the safety of the critical military and civilian infrastructures, land-based and space techniques, apparatuses, devices and their components against high energy electromagnetic pulses and ion irradiation, including electromagnetic weapon arsenal of the international terrorist groups. Key words: electromagnetic pulses, ion irradiation, IC electronic equipment degradation, shielding protection

  4. Interaction with the lower ionosphere of electromagnetic pulses from lightning - Heating, attachment, and ionization

    Science.gov (United States)

    Taranenko, Y. N.; Inan, U. S.; Bell, T. F.

    1993-01-01

    A Boltzmann formulation of the electron distribution function and Maxwell's equations for the EM fields are used to simulate the interaction of lightning radiated EM pulses with the lower ionosphere. Ionization and dissociative attachment induced by the heated electrons cause significant changes in the local electron density, N(e). Due to 'slow' field changes of typical lightning EM pulses over time scales of tens of microsec, the distribution function follows the quasi-equilibrium solution of the Boltzmann equation in the altitude range of interest (70 to 100 km). The EM pulse is simulated as a planar 100 microsec long single period oscillation of a 10 kHz wave injected at 70 km. Under nighttime conditions, individual pulses of intensity 10-20 V/m (normalized to 100 km horizontal distance) produce changes in N(e) of 1-30 percent while a sequence of pulses leads to strong modification of N(e) at altitudes less than 95 km. The N(e) changes produce a 'sharpening' of the lower ionospheric boundary by causing a reduction in electron density at 75-85 km (due to attachment) and a substantial increase at 85-95 km (due to ionization) (e.g., the scale height decreases by a factor of about 2 at about 85 km for a single 20 V/m EM pulse). No substantial N(e) changes occur during daytime.

  5. Problems related to stimulated electromagnetic emissions, strong turbulence and ionospheric modification

    International Nuclear Information System (INIS)

    Goodman, S.

    1993-05-01

    Optical pumping of the ionospheric plasma by high-frequency radio waves produces a state of turbulence. Several consequences of the pumping are considered in this thesis. At reflection altitude the plasma is thought to be dominated by parametric instabilities and strong turbulence; these are both encapsulated in the so called Zakharov equations. The Zakharov equations are derived and generalised from kinetic theory. Limits of validity, corrections to the ion sound speed,effective ponderomotive force, nonlinear damping and other generalisation are included. As an example of the difference a kinetic approach makes, the threshold for parametric instabilities is seen to be lowered in a kinetic plasma. Mostly relevant to the upper hybrid layer is the recent discovery in the pumping experiments of stimulated electromagnetic emissions (SEE). In particular one feature of SEE which occurs around the cyclotron harmonics and depends on density striations is investigated. The observed frequency of emission, dependency on striations, time evolution and cutoff frequency below which the feature does not occur, are explained. Two theoretical approaches are taken. The first is a parametric three wave decay instability followed by a nonlinear mixing to produce SEE. Thresholds for the instability are well within experimental capacity. The second, less orthodox, approach, is a finite amplitude model. The finite amplitude model goes beyond the traditional parametric approach by being able to predict radiated power output. Miscellaneous aspects of a turbulent ionosphere are also examined. The dependency of the scattering cross section of a turbulent plasma upon higher order perturbations is considered. In a turbulent plasma, density gradients steeper than characteristic plasma scales may develop. The case of calculating the dielectric permittivity for a linear gradient of arbitrary steepness is considered

  6. Electromagnetic Fields, Pulsed Radiofrequency Radiation, and Epigenetics: How Wireless Technologies May Affect Childhood Development.

    Science.gov (United States)

    Sage, Cindy; Burgio, Ernesto

    2018-01-01

    Mobile phones and other wireless devices that produce electromagnetic fields (EMF) and pulsed radiofrequency radiation (RFR) are widely documented to cause potentially harmful health impacts that can be detrimental to young people. New epigenetic studies are profiled in this review to account for some neurodevelopmental and neurobehavioral changes due to exposure to wireless technologies. Symptoms of retarded memory, learning, cognition, attention, and behavioral problems have been reported in numerous studies and are similarly manifested in autism and attention deficit hyperactivity disorders, as a result of EMF and RFR exposures where both epigenetic drivers and genetic (DNA) damage are likely contributors. Technology benefits can be realized by adopting wired devices for education to avoid health risk and promote academic achievement. © 2017 The Authors. Child Development © 2017 Society for Research in Child Development, Inc.

  7. Electromagnetic pulse (EMP) radiation by laser interaction with a solid H.sub.2./sub. ribbon

    Czech Academy of Sciences Publication Activity Database

    De Marco, Massimo; Krása, Josef; Cikhardt, J.; Velyhan, Andriy; Pfeifer, Miroslav; Dudžák, Roman; Dostál, Jan; Krouský, Eduard; Limpouch, J.; Pisarczyk, T.; Kalinowska, Z.; Chodukowski, T.; Ullschmied, Jiří; Giuffrida, Lorenzo; Chatain, D.; Perin, J.P.; Margarone, Daniele

    2017-01-01

    Roč. 24, č. 8 (2017), s. 1-6, č. článku 083103. ISSN 1070-664X R&D Projects: GA MŠk EF15_008/0000162; GA ČR GA16-07036S; GA MŠk(CZ) LD14089; GA MŠk LQ1606 EU Projects: European Commission(XE) 654148 - LASERLAB-EUROPE Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 ; RVO:61389021 Keywords : laser-produced plasma * electromagnetic pulse * solid hydrogen ribbon Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.115, year: 2016

  8. Stimulation of experimental endochondral ossification by low-energy pulsing electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Aaron, R.K.; Ciombor, D.M.; Jolly, G.

    1989-04-01

    Pulsed electromagnetic fields (PEMFs) of certain configuration have been shown to be effective clinically in promoting the healing of fracture nonunions and are believed to enhance calcification of extracellular matrix. In vitro studies have suggested that PEMFs may also have the effect of modifying the extracellular matrix by promoting the synthesis of matrix molecules. This study examines the effect of one PEMF upon the extracellular matrix and calcification of endochondral ossification in vivo. The synthesis of cartilage molecules is enhanced by PEMF, and subsequent endochondral calcification is stimulated. Histomorphometric studies indicate that the maturation of bone trabeculae is also promoted by PEMF stimulation. These results indicate that a specific PEMF can change the composition of cartilage extracellular matrix in vivo and raises the possibility that the effects on other processes of endochondral ossification (e.g., fracture healing and growth plates) may occur through a similar mechanism.

  9. Extremely low frequency pulsed electromagnetic fields increase cell proliferation in lymphocytes from young and aged subjects

    Energy Technology Data Exchange (ETDEWEB)

    Cossarizza, A.; Monti, D.; Bersani, F.; Cantini, M.; Cadossi, R.; Sacchi, A.; Franceschi, C.

    1989-04-28

    The effect of the in vitro exposure to extremely low frequency pulsed electromagnetic fields (PEMFs) on the proliferation of human lymphocytes from 24 young and 24 old subjects was studied. The exposure to PEMFs during a 3-days culture period or during the first 24 hours was able to increase phytohaemagglutinin-induced lymphocyte proliferation in both groups. Such effect was greater in lymphocytes from old people which showed a markedly reduced proliferative capability and, after PEMF exposure, reached values of /sup 3/H-TdR incorporation similar to those of young subjects. The relevance of these data for the understanding and the reversibility of the proliferative defects in cells from aged subjects and for the assessment of risk related to the environmental exposure to PEMFs has to be considered.

  10. Extremely low frequency pulsed electromagnetic fields increase cell proliferation in lymphocytes from young and aged subjects

    International Nuclear Information System (INIS)

    Cossarizza, A.; Monti, D.; Bersani, F.; Cantini, M.; Cadossi, R.; Sacchi, A.; Franceschi, C.

    1989-01-01

    The effect of the in vitro exposure to extremely low frequency pulsed electromagnetic fields (PEMFs) on the proliferation of human lymphocytes from 24 young and 24 old subjects was studied. The exposure to PEMFs during a 3-days culture period or during the first 24 hours was able to increase phytohaemagglutinin-induced lymphocyte proliferation in both groups. Such effect was greater in lymphocytes from old people which showed a markedly reduced proliferative capability and, after PEMF exposure, reached values of 3 H-TdR incorporation similar to those of young subjects. The relevance of these data for the understanding and the reversibility of the proliferative defects in cells from aged subjects and for the assessment of risk related to the environmental exposure to PEMFs has to be considered

  11. Biological effects of PEMF (Pulsing Electromagnetic Field): An attempt to modify cell resistance to anticancer agents

    Energy Technology Data Exchange (ETDEWEB)

    Pasquinelli, P. (C.R.E.S.A.M., Pisa (Italy)); Petrini, M.; Mattii, L.; Saviozzi, M.; Malvaldi, G. (Univ. of Pisa (Italy)); Galimberti, S. (Scuola di Perfezionamento S. Anna, Pisa (Italy))

    Pulsing Electromagnetic Field (PEMF) effects lead to a modification of the multidrug resistance (MDR) of cells in vitro and in vivo. The murine leukemic doxorubicin-resistant cell line, P388/Dx, subjected to PEMF irradiation in vitro, showed a significant difference in thymidine incorporation when the concentration of doxorubicin reached a level of 1 [mu]g/mL, which corresponds to the inhibition dose 50 (ID[sub 50]). The human lymphoblastic leukemia vinblastine-resistant cell line, CEM/VLB[sub 100], also showed a significant modification under the same experimental conditions at the in vitro ID[sub 50] corresponding to a vinblastine concentration of 100 ng/mL. BDF1 mice transplanted with P388/Dx cells also had an increase in their life span when Doxorubicin was injected intraperitoneally in fractionated doses, while being subjected to PEMF irradiation. 7 refs., 5 figs., 1 tab.

  12. Spectral and temporal characteristics of target current and electromagnetic pulse induced by nanosecond laser ablation

    Science.gov (United States)

    Krása, J.; De Marco, M.; Cikhardt, J.; Pfeifer, M.; Velyhan, A.; Klír, D.; Řezáč, K.; Limpouch, J.; Krouský, E.; Dostál, J.; Ullschmied, J.; Dudžák, R.

    2017-06-01

    The current balancing the target charging and the emission of transient electromagnetic pulses (EMP) driven by the interaction of a focused 1.315 μm iodine 300 ps PALS laser with metallic and plastic targets were measured with the use of inductive probes. It is experimentally proven that the duration of return target currents and EMPs is much longer than the duration of laser-target interaction. The laser-produced plasma is active after the laser-target interaction. During this phase, the target acts as a virtual cathode and the plasma-target interface expands. A double exponential function is used in order to obtain the temporal characteristics of EMP. The rise time of EMPs fluctuates in the range up to a few tens of nanoseconds. Frequency spectra of EMP and target currents are modified by resonant frequencies of the interaction chamber.

  13. The interaction with the lower ionosphere of electromagnetic pulses from lightning: Excitation of optical emissions

    Science.gov (United States)

    Taranenko, Y. N.; Inan, U. S.; Bell, T. F.

    1993-01-01

    A self consistent and fully kinetic simulation of the interaction of lightning radiated electromagnetic (EM) pulses with the nighttime lower ionosphere indicates that optical emissions observable with conventional instruments would be excited. For example, emissions of the 1st and 2nd positive bands of N2 occur at rates reaching 7 x 10(exp 7) and 10(exp 7) cu cm/s respectively at 92 km altitude for a lightning discharge with an electric field E(sub 100) = 20 V/m (normalized to a 100 km distance). The maximum height integrated intensities of these emissions are 4 x 10(exp 7) and 6 x 10(exp 6) R respectively, lasting for approx. 50 micrometers.

  14. The therapeutic effect of a pulsed electromagnetic field on the reproductive patterns of male Wistar rats exposed to a 2.45-GHz microwave field

    Directory of Open Access Journals (Sweden)

    Sanjay Kumar

    2011-01-01

    Full Text Available INTRODUCTION: Environmental exposure to man-made electromagnetic fields has been steadily increasing with the growing demand for electronic items that are operational at various frequencies. Testicular function is particularly susceptible to radiation emitted by electromagnetic fields. OBJECTIVES: This study aimed to examine the therapeutic effects of a pulsed electromagnetic field (100 Hz on the reproductive systems of male Wistar rats (70 days old. METHODS: The experiments were divided into five groups: microwave sham, microwave exposure (2.45 GHz, pulsed electromagnetic field sham, pulsed electromagnetic field (100 Hz exposure, and microwave/pulsed electromagnetic field exposure. The animals were exposed for 2 hours/day for 60 days. After exposure, the animals were sacrificed, their sperm was used for creatine and caspase assays, and their serum was used for melatonin and testosterone assays. RESULTS: The results showed significant increases in caspase and creatine kinase and significant decreases in testosterone and melatonin in the exposed groups. This finding emphasizes that reactive oxygen species (a potential inducer of cancer are the primary cause of DNA damage. However, pulsed electromagnetic field exposure relieves the effect of microwave exposure by inducing Faraday currents. CONCLUSIONS: Electromagnetic fields are recognized as hazards that affect testicular function by generating reactive oxygen species and reduce the bioavailability of androgen to maturing spermatozoa. Thus, microwave exposure adversely affects male fertility, whereas pulsed electromagnetic field therapy is a non-invasive, simple technique that can be used as a scavenger agent to combat oxidative stress.

  15. The therapeutic effect of a pulsed electromagnetic field on the reproductive patterns of male Wistar rats exposed to a 2.45-GHz microwave field.

    Science.gov (United States)

    Kumar, Sanjay; Kesari, Kavindra Kumar; Behari, Jitendra

    2011-01-01

    Environmental exposure to man-made electromagnetic fields has been steadily increasing with the growing demand for electronic items that are operational at various frequencies. Testicular function is particularly susceptible to radiation emitted by electromagnetic fields. This study aimed to examine the therapeutic effects of a pulsed electromagnetic field (100 Hz) on the reproductive systems of male Wistar rats (70 days old). The experiments were divided into five groups: microwave sham, microwave exposure (2.45 GHz), pulsed electromagnetic field sham, pulsed electromagnetic field (100 Hz) exposure, and microwave/pulsed electromagnetic field exposure. The animals were exposed for 2 hours/day for 60 days. After exposure, the animals were sacrificed, their sperm was used for creatine and caspase assays, and their serum was used for melatonin and testosterone assays. The results showed significant increases in caspase and creatine kinase and significant decreases in testosterone and melatonin in the exposed groups. This finding emphasizes that reactive oxygen species (a potential inducer of cancer) are the primary cause of DNA damage. However, pulsed electromagnetic field exposure relieves the effect of microwave exposure by inducing Faraday currents. Electromagnetic fields are recognized as hazards that affect testicular function by generating reactive oxygen species and reduce the bioavailability of androgen to maturing spermatozoa. Thus, microwave exposure adversely affects male fertility, whereas pulsed electromagnetic field therapy is a non-invasive, simple technique that can be used as a scavenger agent to combat oxidative stress.

  16. Transcranial pulsed electromagnetic fields for multiple chemical sensitivity: Study protocol for a randomized, double-blind, placebo-controlled trial

    DEFF Research Database (Denmark)

    Tran, Marie Thi Dao; Skovbjerg, Sine; Arendt-Nielsen, Lars

    2013-01-01

    . The symptoms may have severe impact on patients' lives, but an evidence-based treatment for the condition is nonexisting. The pathophysiology is unclarified, but several indicators point towards abnormal processing of sensory signals in the central nervous system. Pulsed electromagnetic fields (PEMF) offer...

  17. Treatment of knee osteoarthritis with pulsed electromagnetic fields: a randomized, double-blind, placebo-controlled study

    DEFF Research Database (Denmark)

    Thamsborg, G; Florescu, A; Oturai, P

    2005-01-01

    OBJECTIVE: The investigation aimed at determining the effectiveness of pulsed electromagnetic fields (PEMF) in the treatment of osteoarthritis (OA) of the knee by conducting a randomized, double-blind, placebo-controlled clinical trial. DESIGN: The trial consisted of 2h daily treatment 5 days per...

  18. Generalized Sturmian approach to extracting transition amplitudes for two-photon ionization of atoms by electromagnetic pulses

    International Nuclear Information System (INIS)

    Gómez, A I; Gasaneo, G; Mitnik, D M

    2015-01-01

    In this work we present the application of the Generalized Sturmian basis to the process of photonionization by an electromagnetic pulse in the framework of a perturbation theory. The Generalized Sturmian basis have the proper asymptotic behavior allowing us to extract the transition amplitudes directly from the coefficients of expansion. (paper)

  19. Pulsed electromagnetic fields stimulation affects BMD and local factor production of rats with disuse osteoporosis.

    Science.gov (United States)

    Shen, Wei-Wei; Zhao, Jian-Hua

    2010-02-01

    Pulsed electromagnetic fields (PEMF) have been used widely to treat nonunion fractures and related problems in bone healing, as a biological and physical method. With the use of Helmholtz coils and PEMF stimulators to generate uniform time-varying electromagnetic fields, the effects of extremely low frequency electromagnetic fields on bone mineral density (BMD) and local factor production in disuse osteoporosis (DOP) rats were investigated. Eighty 4-month-old female Sprague Dawley (SD) rats were randomly divided into intact (INT) group, DOP group, calcitonin-treated (CT) group, and PEMF stimulation group. The right hindlimbs of all the rats were immobilized by tibia-tail fixation except for those rats in the INT group. Rats in the CT group were injected with calcitonin (2 IU/kg, i.p., once a day) and rats in the PEMF group were irradiated with PEMF immediately postoperative. The BMD, serum transforming growth factor-beta 1 (TGF-beta1), and interleukin-6 (IL-6) concentration of the proximal femur were measured 1, 2, 4, and 8 weeks after treatment. Compared with the CT and DOP groups, the BMD and serum TGF-beta1 concentration in the PEMF group increased significantly after 8 weeks. The IL-6 concentration in the DOP group was elevated significantly after operation. The PEMF group showed significantly lower IL-6 level than the DOP group. The results found demonstrate that PEMF stimulation can efficiently suppress bone mass loss. We, therefore, conclude that PEMF may affect bone remodeling process through promoting TGF-beta1 secretion and inhibiting IL-6 expression. (c) 2009 Wiley-Liss, Inc.

  20. Effects of the pulsed electromagnetic field PST® on human tendon stem cells: a controlled laboratory study.

    Science.gov (United States)

    Randelli, Pietro; Menon, Alessandra; Ragone, Vincenza; Creo, Pasquale; Alfieri Montrasio, Umberto; Perucca Orfei, Carlotta; Banfi, Giuseppe; Cabitza, Paolo; Tettamanti, Guido; Anastasia, Luigi

    2016-08-18

    Current clinical procedures for rotator cuff tears need to be improved, as a high rate of failure is still observed. Therefore, new approaches have been attempted to stimulate self-regeneration, including biophysical stimulation modalities, such as low-frequency pulsed electromagnetic fields, which are alternative and non-invasive methods that seem to produce satisfying therapeutic effects. While little is known about their mechanism of action, it has been speculated that they may act on resident stem cells. Thus, the purpose of this study was to evaluate the effects of a pulsed electromagnetic field (PST®) on human tendon stem cells (hTSCs) in order to elucidate the possible mechanism of the observed therapeutic effects. hTSCs from the rotator cuff were isolated from tendon biopsies and cultured in vitro. Then, cells were exposed to a 1-h PST® treatment and compared to control untreated cells in terms of cell morphology, proliferation, viability, migration, and stem cell marker expression. Exposure of hTSCs to PST® did not cause any significant changes in proliferation, viability, migration, and morphology. Instead, while stem cell marker expression significantly decreased in control cells during cell culturing, PST®-treated cells did not have a significant reduction of the same markers. While PST® did not have significant effects on hTSCs proliferation, the treatment had beneficial effects on stem cell marker expression, as treated cells maintained a higher expression of these markers during culturing. These results support the notion that PST® treatment may increase the patient stem cell regenerative potential.

  1. Influence of Pulsed Electromagnetic Field on Plant Growth, Nutrient Absorption and Yield of Durum Wheat

    Directory of Open Access Journals (Sweden)

    Nikolaos KATSENIOS

    2015-12-01

    Full Text Available Researchers have adopted the use of magnetic field as a new pre-sowing, environmental friendly technique. Enhancements on plant characteristics with economic impact on producer’s income could be the future of a modern, organic and sustainable agriculture. A field experiment was established at Soil Science Institute of Athens, Lycovrissi, Greece, in the winter of 2014. Two durum wheat cultivars were used. It was a pot experiment with 6 treatments (2 cultivars with 3 magnetic field time exposure. The seeds were treated using a PAPIMI electromagnetic field generator for 0, 30 and 45 minutes one day before planting. The experiment followed a completely randomized design with six treatments and 30 replications. The aim of this study was to evaluate the positive effect of magnetic field pre-sowing treatment in a wide range of plant measurements, including yield. The influence of pulsed electromagnetic field on two varieties of durum wheat seeds showed some statistically significant differences at the 0.05 level in growth measurements, physiological measurements and root growth measurements. Plant tissue analysis showed that magnetic field treatments had higher values than control in total nitrogen, phosphorus, potassium, magnesium, copper (only MF-45, zinc (only MF-30 and boron content, although values showed statistically significant differences only in total nitrogen. The results indicate that this innovative technique can increase the yield of durum wheat, through enhanced absorption of nutrients. Pre-sowing treatment of the seeds leads to vigorous plant growth that are more productive.

  2. Effect of pulsed electromagnetic field (PEMF) on infarct size and inflammation after cerebral ischemia in mice.

    Science.gov (United States)

    Pena-Philippides, Juan Carlos; Yang, Yirong; Bragina, Olga; Hagberg, Sean; Nemoto, Edwin; Roitbak, Tamara

    2014-08-01

    Pulsed electromagnetic fields (PEMF) have been demonstrated to have anti-inflammatory and pro-regenerative effects in animals and humans. We used the FDA-approved Sofpulse (Ivivi Health Sciences, LLC) to study effect of PEMF on infarct size and poststroke inflammation following distal middle cerebral artery occlusion (dMCAO) in mice. Electromagnetic field was applied within 30-45 min after ischemic brain damage and utilized twice a day for 21 consecutive days. Ischemic infarct size was assessed using MRI and histological analysis. At 21 days after dMCAO, the infarct size was significantly (by 26%) smaller in PEMF-treated animals as compared to controls. Neuroinflammation in these animals was evaluated using specialized cytokine/chemokine PCR array. We demonstrate that PEMF significantly influenced expression profile of pro- and anti-inflammatory factors in the hemisphere ipsilateral to ischemic damage. Importantly, expression of gene encoding major pro-inflammatory cytokine IL-1α was significantly reduced, while expression of major anti-inflammatory IL-10 was significantly increased. PEMF application significantly downregulated genes encoding members of the major pro-apoptotic tumor necrosis factor (TNF) superfamily indicating that the treatment could have both anti-inflammatory and anti-apoptotic effects. Both reduction of infarct size and influence on neuroinflammation could have a potentially important positive impact on the poststroke recovery process, implicating PEMF as a possible adjunctive therapy for stroke patients.

  3. Influence of electromagnetic pulse on the offspring sex ratio of male BALB/c mice.

    Science.gov (United States)

    Li, Jin-Hui; Jiang, Da-Peng; Wang, Ya-Feng; Yan, Jia-Jia; Guo, Qi-Yan; Miao, Xia; Lang, Hai-Yang; Xu, Sheng-Long; Liu, Jun-Ye; Guo, Guo-Zhen

    2017-09-01

    Public concern is growing about the exposure to electromagnetic fields (EMF) and its effect on male reproductive health. Detrimental effect of EMF exposure on sex hormones, reproductive performance and sex-ratio was reported. The present study was designed to clarify whether paternal exposure to electromagnetic pulse (EMP) affects offspring sex ratio in mice. 50 male BALB/c mice aged 5-6 weeks were exposed to EMP daily for 2 weeks before mated with non-exposed females at 0d, 7d, 14d, 21d and 28d after exposure. Sex hormones including total testosterone, LH, FSH, and GnRH were detected using radioimmunoassay. The sex ratio was examined by PCR and agarose gel electrophoresis. The results of D0, D21 and D28 showed significant increases compared with sham-exposed groups. The serum testosterone increased significantly in D0, D14, D21, and D28 compared with sham-exposed groups (p<0.05). Overall, this study suggested that EMP exposure may lead to the disturbance of reproductive hormone levels and affect the offspring sex ratio. Copyright © 2017. Published by Elsevier B.V.

  4. Direct time integration of Maxwell's equations in linear dispersive media with absorption for scattering and propagation of femtosecond electromagnetic pulses

    Science.gov (United States)

    Joseph, Rose M.; Hagness, Susan C.; Taflove, Allen

    1991-01-01

    The initial results for femtosecond pulse propagation and scattering interactions for a Lorentz medium obtained by a direct time integration of Maxwell's equations are reported. The computational approach provides reflection coefficients accurate to better than 6 parts in 10,000 over the frequency range of dc to 3 x 10 to the 16th Hz for a single 0.2-fs Gaussian pulse incident upon a Lorentz-medium half-space. New results for Sommerfeld and Brillouin precursors are shown and compared with previous analyses. The present approach is robust and permits 2D and 3D electromagnetic pulse propagation directly from the full-vector Maxwell's equations.

  5. Pulsed or continuous electromagnetic field induce p53/p21-mediated apoptotic signaling pathway in mouse spermatogenic cells in vitro and thus may affect male fertility.

    Science.gov (United States)

    Solek, Przemyslaw; Majchrowicz, Lena; Bloniarz, Dominika; Krotoszynska, Ewelina; Koziorowski, Marek

    2017-05-01

    The impact of electromagnetic field (EMF) on the human health and surrounding environment is a common topic investigated over the years. A significant increase in the electromagnetic field concentration arouses public concern about the long-term effects of EMF on living organisms associated with many aspects. In the present study, we investigated the effects of pulsed and continuous electromagnetic field (PEMF/CEMF) on mouse spermatogenic cell lines (GC-1 spg and GC-2 spd) in terms of cellular and biochemical features in vitro. We evaluated the effect of EMF on mitochondrial metabolism, morphology, proliferation rate, viability, cell cycle progression, oxidative stress balance and regulatory proteins. Our results strongly suggest that EMF induces oxidative and nitrosative stress-mediated DNA damage, resulting in p53/p21-dependent cell cycle arrest and apoptosis. Therefore, spermatogenic cells due to the lack of antioxidant enzymes undergo oxidative and nitrosative stress-mediated cytotoxic and genotoxic events, which contribute to infertility by reduction in healthy sperm cells pool. In conclusion, electromagnetic field present in surrounding environment impairs male fertility by inducing p53/p21-mediated cell cycle arrest and apoptosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. STRONG SOLAR WIND DYNAMIC PRESSURE PULSES: INTERPLANETARY SOURCES AND THEIR IMPACTS ON GEOSYNCHRONOUS MAGNETIC FIELDS

    International Nuclear Information System (INIS)

    Zuo, Pingbing; Feng, Xueshang; Wang, Yi; Xie, Yanqiong; Xu, Xiaojun

    2015-01-01

    In this investigation, we first present a statistical result of the interplanetary sources of very strong solar wind dynamic pressure pulses (DPPs) detected by WIND during solar cycle 23. It is found that the vast majority of strong DPPs reside within solar wind disturbances. Although the variabilities of geosynchronous magnetic fields (GMFs) due to the impact of positive DPPs have been well established, there appears to be no systematic investigations on the response of GMFs to negative DPPs. Here, we study both the decompression effects of very strong negative DPPs and the compression from strong positive DPPs on GMFs at different magnetic local time sectors. In response to the decompression of strong negative DPPs, GMFs on the dayside near dawn and near dusk on the nightside, are generally depressed. But near the midnight region, the responses of GMF are very diverse, being either positive or negative. For part of the events when GOES is located at the midnight sector, the GMF is found to abnormally increase as the result of magnetospheric decompression caused by negative DPPs. It is known that under certain conditions magnetic depression of nightside GMFs can be caused by the impact of positive DPPs. Here, we find that a stronger pressure enhancement may have a higher probability of producing the exceptional depression of GMF at the midnight region. Statistically, both the decompression effect of strong negative DPPs and the compression effect of strong positive DPPs depend on the magnetic local time, which are stronger at the noon sector

  7. Analysis of the damage threshold of the GaAs pseudomorphic high electron mobility transistor induced by the electromagnetic pulse

    Science.gov (United States)

    Xi, Xiao-Wen; Chai, Chang-Chun; Liu, Yang; Yang, Yin-Tang; Fan, Qing-Yang; Shi, Chun-Lei

    2016-08-01

    An electromagnetic pulse (EMP)-induced damage model based on the internal damage mechanism of the GaAs pseudomorphic high electron mobility transistor (PHEMT) is established in this paper. With this model, the relationships among the damage power, damage energy, pulse width and signal amplitude are investigated. Simulation results show that the pulse width index from the damage power formula obtained here is higher than that from the empirical formula due to the hotspot transferring in the damage process of the device. It is observed that the damage energy is not a constant, which decreases with the signal amplitude increasing, and then changes little when the signal amplitude reaches up to a certain level. Project supported by the National Basic Research Program of China (Grant No. 2014CB339900) and the Open Fund of Key Laboratory of Complex Electromagnetic Environment Science and Technology, China Academy of Engineering Physics (CAEP) (Grant No. 2015-0214.XY.K).

  8. Emission of ultrashort electromagnetic pulses from electron bunches formed and accelerated by laser beams with tilted amplitude fronts

    International Nuclear Information System (INIS)

    Galkin, A.L.; Korobkin, V.V.; Romanovsky, M.Yu.; Shiryaev, O.B.; Trofimov, V.A.

    2013-01-01

    The dynamics of an electron in a standing wave generated by a pair of counterpropagating linearly polarized relativistically intense laser pulses and the emission of electromagnetic radiation by the electron are analyzed. The pulses are assumed to have tilted amplitude fronts and asymmetric focal spots. The analysis of the dynamics is performed by solving numerically the Newton equation with the corresponding Lorentz force, and the emission of radiation is simulated based on the Lienard-Wiechert potentials. The electrons are accelerated by the direct action of the standing wave field and are shown to form a small short bunch. For relativistic intensities, the energies gained by the electrons reach several GeV. It is demonstrated that the radiation emitted by the electrons in the bunch is a single electromagnetic pulse confined to a narrow solid angle and having an attosecond duration. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Self-consistent evolution of plasma discharge and electromagnetic fields in a microwave pulse compressor

    International Nuclear Information System (INIS)

    Shlapakovski, A. S.; Beilin, L.; Krasik, Ya. E.; Hadas, Y.; Schamiloglu, E.

    2015-01-01

    Nanosecond-scale evolution of plasma and RF electromagnetic fields during the release of energy from a microwave pulse compressor with a plasma interference switch was investigated numerically using the code MAGIC. The plasma was simulated in the scope of the gas conductivity model in MAGIC. The compressor embodied an S-band cavity and H-plane waveguide tee with a shorted side arm filled with pressurized gas. In a simplified approach, the gas discharge was initiated by setting an external ionization rate in a layer crossing the side arm waveguide in the location of the electric field antinode. It was found that with increasing ionization rate, the microwave energy absorbed by the plasma in the first few nanoseconds increases, but the absorption for the whole duration of energy release, on the contrary, decreases. In a hybrid approach modeling laser ignition of the discharge, seed electrons were set around the electric field antinode. In this case, the plasma extends along the field forming a filament and the plasma density increases up to the level at which the electric field within the plasma decreases due to the skin effect. Then, the avalanche rate decreases but the density still rises until the microwave energy release begins and the electric field becomes insufficient to support the avalanche process. The extraction of the microwave pulse limits its own power by terminating the rise of the plasma density and filament length. For efficient extraction, a sufficiently long filament of dense plasma must have sufficient time to be formed

  10. Self-consistent evolution of plasma discharge and electromagnetic fields in a microwave pulse compressor

    Science.gov (United States)

    Shlapakovski, A. S.; Beilin, L.; Hadas, Y.; Schamiloglu, E.; Krasik, Ya. E.

    2015-07-01

    Nanosecond-scale evolution of plasma and RF electromagnetic fields during the release of energy from a microwave pulse compressor with a plasma interference switch was investigated numerically using the code MAGIC. The plasma was simulated in the scope of the gas conductivity model in MAGIC. The compressor embodied an S-band cavity and H-plane waveguide tee with a shorted side arm filled with pressurized gas. In a simplified approach, the gas discharge was initiated by setting an external ionization rate in a layer crossing the side arm waveguide in the location of the electric field antinode. It was found that with increasing ionization rate, the microwave energy absorbed by the plasma in the first few nanoseconds increases, but the absorption for the whole duration of energy release, on the contrary, decreases. In a hybrid approach modeling laser ignition of the discharge, seed electrons were set around the electric field antinode. In this case, the plasma extends along the field forming a filament and the plasma density increases up to the level at which the electric field within the plasma decreases due to the skin effect. Then, the avalanche rate decreases but the density still rises until the microwave energy release begins and the electric field becomes insufficient to support the avalanche process. The extraction of the microwave pulse limits its own power by terminating the rise of the plasma density and filament length. For efficient extraction, a sufficiently long filament of dense plasma must have sufficient time to be formed.

  11. Study on ultrastructural changes in thyroid gland of rats exposed to pulsed electromagnetic wave

    International Nuclear Information System (INIS)

    Zhou Xiaoguang; Zeng Guiying; Ren Dongqing; Fang Henghu; Su Xiaoming; Huang Xiaofeng

    2006-01-01

    The work is to observe effects of PEMW (pulse electromagnetic wave) exposure on function and morphology of thyroid gland of rats. At different time points (24, 48, 96 and 192 h) after exposure to PEMW (E=115 kV m -1 , 12000 pulses), radioimmunoassay was performed to observe the levels of thyroid-stimulating hormone (TSH), thyroxine (T 4 ) and triiodo- thyronine (T 3 ) in sera of the male Sparague-Dawley rats. Optic microscopy and transmission electron microscopy (TEM) were used to observe structural changes of the thyroid gland at the time points. The T 3 , T 4 and TSH in sera increased significantly, reaching a peak at 24 h and decreasing gradually then. Although no obvious changes in the thyroid gland were observed under the optic microscope, some ultrastructural changes in the thyroid gland were found under the TEM. The ultrastructures were obviously changed at 12 h and aggravated until 48 h. In the experimented rats, dilatated endoplasmic reticulum gathered with lots of protein excretion, lipid droplet and heterochromatin gathered under the nucleus membranes were observed in follicular epithelial cells. These changes were palliated at 96 h but not recovered. PEMW can affect levels of hormones in sera and the hazard ultrastructural changes of thyroid gland. Endoplasmic reticulum is the main injured organelle. (authors)

  12. Modulation of Osteogenesis in Human Mesenchymal Stem Cells by Specific Pulsed Electromagnetic Field Stimulation

    Science.gov (United States)

    Tsai, Ming-Tzu; Li, Wan-Ju; Tuan, Rocky S.; Chang, Walter H.

    2009-01-01

    Human mesenchymal stem cells (hMSCs) are a promising candidate cell type for regenerative medicine and tissue engineering applications by virtue of their capacity for self-renewal and multipotent differentiation. Our intent was to characterize the effect of pulsed electromagnetic fields (PEMFs) on the proliferation and osteogenic differentiation of hMSCs in vitro. hMSCs isolated from the bone marrow of adult patients were cultured with osteogenic medium for up to 28 days and exposed to daily PEMF stimulation with single, narrow 300 μs quasi-rectangular pulses with a repetition rate of 7.5 Hz. Relatively greater cell numbers were observed at late stages of osteogenic culture with PEMF exposure. The production of alkaline phosphatase (ALP), an early marker of osteogenesis, was significantly enhanced at day 7 with PEMF treatment in both basal and osteogenic cultures as compared to untreated controls. Furthermore, the expressions of other early osteogenic genes, including Runx2/Cbfa1 and ALP, were also partially modulated by PEMF exposure, indicating that osteogenesis in hMSCs was associated with the specific PEMF stimulation. Based on ALP and alizarin red S staining, the accumulation of ALP protein produced by the hMSCs as well as calcium deposits reached their highest levels at day 28. Our results indicate that extremely low frequency PEMF stimulation may play a modulating role in hMSC osteogenesis. Taken together, these findings provide insights on the development of PEMF as an effective technology for regenerative medicine. PMID:19274753

  13. 3D modeling of lightning-induced electromagnetic pulses on Venus, Jupiter and Saturn

    Science.gov (United States)

    Pérez-Invernón, Francisco J.; Luque, Alejandro; Gordillo-Vázquez, Francisco J.

    2017-04-01

    Atmospheric electricity is a common phenomenon in some planets of The Solar System. We know that atmospheric discharges exist on Earth and gaseous planets; however, some characteristics of lightning on Saturn and Jupiter as well as their relevance on the effects of lightning in the atmospheres of these planets are still unknown. In the case of Venus, there exist some radio evidences of lightning, but the lack of optical observations suggests exploring indirect methods of detection, such as searching for lightning-induced transient optical emissions from the upper atmosphere. The Akatsuki probe, currently orbiting Venus, is equipped with a camera whose temporal resolution is high enough to detect optical emissions from lightning discharges and to measure nightglow enhancements. In this work, we extend previous models [1,2] to investigate the chemical impact and transient optical emissions produced by possible lightning-emitted electromagnetic pulses (EMP) in Venus, Saturn and Jupiter. Using a 3D FDTD ("Finite Differences Time Domain") model we solve the Maxwell equations coupled with the Langevin equation for electrons [3] and with a kinetic scheme, different for each planetary atmosphere. This method is useful to investigate the temporal and spatial impact of lightning-induced electromagnetic fields in the atmosphere of each planet for different lightning characteristics (e.g. energy released, orientation). This 3D FDTD model allows us to include the saturnian and jovian background magnetic field inclination and magnitude at different latitudes, and to determine the effects of different lightning channel inclinations. Results provide useful information to interpret lightning observations on giant gaseous planets and in the search for indirect optical signals from atmospheric discharge on Venus such as fast nightglow transient enhancements related to lightning as seen on Earth. Furthermore, we underline the observation of electrical discharges characteristics as a

  14. Curious Consequences of Strong Coupling in NMR Experiments Involving Selective Pulses

    Science.gov (United States)

    Huth, Johannes; Fu, Riqiang; Bodenhausen, Geoffrey

    This study is concerned with the effects of applying selective pulses to systems with strong second-order scalar couplings in isotropic phase, where different transitions ( rs) are associated with different transition matrix elements F+( rs) . Two unusual features can be distinguished: the nutation angle ("flip angle") depends on the matrix element of the irradiated transition ( rs), and, in contrast to the behavior of an isolated spin- {1}/{2} system, the norm of the three single-transition operators [ I( rs) x, I( rs) y, I( rs) z] associated with the fictitious spin- {1}/{2} space of the irradiated transition ( rs) is generally not conserved. It is necessary to consider the single-transition operators [ I( rp) x, I( rp) y, I( rp) z] and [ I( sq) x, I( sq) y, I( sq) z] associated with all connected transitions ( rp) and ( sq) that share a common energy level ror swith the irradiated transition ( rs). If the pulse applied to the ( rs) transition is sufficiently selective, the transverse components I( rp) x, I( rp) y, I( sq) x, and I( sq) y, can be neglected, since their expectation values remain equal to zero after application of a selective pulse to the ( rs) transition, but the longitudinal components I( rp) zand I( sq) zacquire nonvanishing expectation values. When the selective pulse affects several transitions simultaneously, the response varies from one transition to another, depending on the matrix elements and the connectivities. These effects manifest themselves in unusual amplitudes and phases of signals excited by selective pulses, in particular in selective two-dimensional correlation spectra.

  15. The effects of lightning and high altitude electromagnetic pulse on power distribution lines

    Energy Technology Data Exchange (ETDEWEB)

    Uman, M.A.; Rubinstein, M.; Yacoub, Z. [Florida Univ., Gainesville, FL (United States)

    1995-01-01

    We simultaneously recorded the voltages induced by lightning on both ends of an unenergized 448-meter long unenergized electric power line and the lightning vertical electric and horizontal magnetic fields at ground level near the line. The lightning data studied and presented here were due both to cloud lightning and to very close (about 20 m from the line) artificially initiated lightning. For cloud sources, a frequency-domain computer program called EMPLIN was used to calculate induced line voltages as a function of source elevation, angle of incidence, and wave polarization of the radiated cloud discharge pulses in order to compare with the measurements. For very-close lightning, the measured line voltages could be grouped into two categories, those in which multiple, similarly shaped, evenly spaced pulses were observed, which we call oscillatory, and those dominated by a principal pulse with subsidiary oscillations of much smaller amplitude, which we call impulsive. The amplitude of the induced voltage ranged from tens of kilovolts for oscillatory voltages to hundreds of kilovolts for impulsive voltages. A new technique is derived for the calculation of the electromagnetic fields from nearby lightning to ground above an imperfectly conducting ground. This technique was used in conjunction with an existing time domain coupling theory and lightning return stroke model to calculate voltages at either end of the line. The results show fair agreement with the measured oscillatory voltage waveforms if corona is ignored and improved results when corona effects are modeled. The modeling of the impulsive voltage, for which local flashover probably successful. In an attempt to understand better the sources of the line voltages for very close lightning, measurements of the horizontal and vertical electric fields 30 m from triggered lightning were obtained.

  16. First Electromagnetic Pulse Associated with a Gravitational-wave Event: Profile, Duration, and Delay

    Science.gov (United States)

    Lin, Da-Bin; Liu, Tong; Lin, Jie; Wang, Xiang-Gao; Gu, Wei-Min; Liang, En-Wei

    2018-04-01

    We study the first electromagnetic (EM) pulse after the gravitational-wave (GW) chirp signal, focusing on its profile and duration. It is found that the light curve, especially the steep decay (SD) phase, can be very different by adopting different viewing angles θ view of the jet shell. For an on-axis jet with a power-law radiation spectrum, the observed flux in the SD is proportional to {t}obs}-2-β with β being the spectral index and t obs being the observer time. Here, t obs = 0 is set at the time we observe the jet being ejected from the central engine. The SD may become steep by increasing θ view. We also study the bolometric luminosity L from a jet shell with a non-power-law radiation spectrum. For an on-axis jet, L ∝ t obs ‑3 is found in the SD. However, the SD is steeper than L\\propto {t}obs}-3 for radiation from an off-axis jet. The higher value of the θ view is, the steeper SD would be. Then, we suggest that the SD phase can be used to discriminate an off-axis jet from an on-axis jet. The reason for the above behaviors is discussed. In addition, we find that the duration of first EM pulse is close to its peak time, especially for θ view ∼ 20°. This result is consistent with that found in GW 170817/GRB 170817A. Thus, the jet corresponding to the prompt emission of GRB 170817A should be ejected immediately after the merger. Our results also reveal that the duration of the first EM pulse can provide information on the time to search for GWs.

  17. A pulse programmable parahydrogen polarizer using a tunable electromagnet and dual channel NMR spectrometer.

    Science.gov (United States)

    Coffey, Aaron M; Shchepin, Roman V; Feng, Bibo; Colon, Raul D; Wilkens, Ken; Waddell, Kevin W; Chekmenev, Eduard Y

    2017-11-01

    Applications of parahydrogen induced polarization (PHIP) often warrant conversion of the chemically-synthesized singlet-state spin order into net heteronuclear magnetization. In order to obtain optimal yields from the overall hyperpolarization process, catalytic hydrogenation must be tightly synchronized to subsequent radiofrequency (RF) transformations of spin order. Commercial NMR consoles are designed to synchronize applied waves on multiple channels and consequently are well-suited as controllers for these types of hyperpolarization experiments that require tight coordination of RF and non-RF events. Described here is a PHIP instrument interfaced to a portable NMR console operating with a static field electromagnet in the milliTesla regime. In addition to providing comprehensive control over chemistry and RF events, this setup condenses the PHIP protocol into a pulse-program that in turn can be readily shared in the manner of traditional pulse sequences. In this device, a TTL multiplexer was constructed to convert spectrometer TTL outputs into 24 VDC signals. These signals then activated solenoid valves to control chemical shuttling and reactivity in PHIP experiments. Consolidating these steps in a pulse-programming environment speeded calibration and improved quality assurance by enabling the B 0 /B 1 fields to be tuned based on the direct acquisition of thermally polarized and hyperpolarized NMR signals. Performance was tested on the parahydrogen addition product of 2-hydroxyethyl propionate-1- 13 C-d 3 , where the 13 C polarization was estimated to be P 13C =20±2.5% corresponding to 13 C signal enhancement approximately 25 million-fold at 9.1 mT or approximately 77,000-fold 13 C enhancement at 3 T with respect to thermally induced polarization at room temperature. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Effects of electromagnetic pulse exposure on gelatinase of blood-brain barrier in vitro.

    Science.gov (United States)

    Zhou, Yan; Qiu, Lian-Bo; An, Guang-Zhou; Zhou, Jia-Xing; Du, Le; Ma, Ya-Hong; Guo, Guo-Zhen; Ding, Gui-Rong

    2017-01-01

    The biological effects of electromagnetic pulse (EMP) on the brain have been focused on for years. It was reported that gelatinase played an important role in maintaining brain function through regulating permeability in the blood-brain barrier (BBB). To investigate the effects of EMP on gelatinase of BBB, an in vitro BBB model was established using primary cultured rat brain microvascular endothelial cells (BMVEC), astrocytes and half-contact culture of these cells in a transwell chamber. Cultured supernatant and cells were collected at different time points after exposure to EMP (peak intensity 400 kV/m, rise time 10 ns, pulse width 350 ns, 0.5 pps and 200 pulses). Protein levels of cellular gelatinase MMP-2 and MMP-9, and endogenous inhibitor TIMP-1 and TIMP-2 were detected by Western blot. The activity of gelatinase in culture supernatant was detected by gelatin zymography. It was found that compared with the sham-exposed group, the protein level of MMP-2 was significantly increased at 6 h (p < 0.05), and the protein level of its endogenous inhibitor TIMP-2 did not change after EMP exposure. In addition, the protein levels of MMP-9 and its endogenous inhibitor TIMP-1 did not change after EMP exposure. Gelatin zymography results showed that the activity of MMP-2 in the inner pool and the outer pool of the transwell chamber was significantly increased at 6 h after EMP exposure compared with that of the sham group. These results suggested that EMP exposure could affect the expression and activity of MMP-2 in the BBB model.

  19. Density Determination of Liquid Copper and Liquid Nickel by Means of Fast Resistive Pulse Heating and Electromagnetic Levitation

    Science.gov (United States)

    Schmon, Alexander; Aziz, Kirmanj; Pottlacher, Gernot

    2015-06-01

    Fast resistive pulse-heating techniques and electromagnetic levitation techniques are capable of determining thermophysical properties of metals in the liquid phase. These properties have become increasingly important as input data for modern numerical simulations. Among others, density is a very relevant parameter for e.g., casting modeling. Density determinations of copper and nickel in their liquid states are performed using a fast resistive pulse-heating setup and a recently build up electromagnetic levitation apparatus. Both methods use optical imaging techniques to determine thermal expansion of the specimen under investigation, but are operating at very different experimental durations. The pulse-heating setup provides a heating of the sample using it as part of an electrical discharge circuit. Heating rates of 108 K/s lead to experimental durations of about 60 µs. Temperature is determined by measuring surface radiance emitted from the sample by a pyrometer. The sample's thermal expansion is monitored by an adapted CCD camera system. The electromagnetic levitation apparatus enables noncontact investigations of samples by levitating and heating them by an induction coil generating inhomogeneous electromagnetic fields. Temperature again is determined by a pyrometer. For thermal expansion determination, shadowgraph images are recorded with a high-speed CCD camera and evaluated with an edge detection algorithm. Thermal expansion then is calculated by averaging several 1000 frames for each temperature point. Investigations of copper and nickel in the liquid state were performed with both techniques and are compared to each other and to literature values.

  20. Investigation of energy spectrum structure in a system atom + strong external electromagnetic field

    International Nuclear Information System (INIS)

    Volkova, E.A.; Popov, A.M.; Tikhonova, O.V.

    1996-01-01

    Method of direct numerical integration of nonstationary Schroedinger equation is used for investigation into dynamics of quantum system with short-range potential under the cooperative effect of high-frequency electromagnetic field with super atomic value of intensity and low-frequency field with low radiation intensity

  1. Effects of BMP-2 and pulsed electromagnetic field (PEMF) on rat primary osteoblastic cell proliferation and gene expression.

    Science.gov (United States)

    Selvamurugan, Nagarajan; Kwok, Sukyee; Vasilov, Anatoliy; Jefcoat, Stephen C; Partridge, Nicola C

    2007-09-01

    Bone morphogenetic proteins (BMPs) strongly promote osteoblast differentiation. Pulsed electromagnetic fields (PEMFs) promote fracture healing in non-union fractures. In this study, we hypothesized that a combined BMP-2 and PEMF stimulation would augment bone formation to a greater degree than treatment with either single stimulus. BMP-2 maximally increased the proliferative activity of rat primary osteoblastic cells at 25 ng/ml concentration. Real-time reverse transcription-polymerase chain reaction (RT-PCR) showed that BMP-2 stimulated mRNA levels of alkaline phosphatase (ALP), alpha(1) (I) procollagen, and osteocalcin (OC) in the differentiation phase and only OC mRNA expression in the mineralization phase after 24-h treatment. Both BMP-2 and PEMF (Spinal-Stim) increased cell proliferation, which was additive when both agents were combined. PEMF alone or together with BMP-2 increased only ALP mRNA expression and only during the differentiation phase 24 h after one 4-h treatment. This effect was additive when both agents were combined. Continuous daily 4-h treatment with PEMF alone or together with BMP-2 increased expression of all three osteoblast marker genes during the differentiation phase and increased the mineralized matrix. This effect was additive when both agents were combined, suggesting that the two interventions may be working on different cellular pathways. Thus, a combined effect of BMP-2 and PEMF in vitro could be considered as groundwork for in vivo bone development that may support skeletal therapy.

  2. Induction of neuritogenesis in PC12 cells by a pulsed electromagnetic field via MEK-ERK1/2 signaling.

    Science.gov (United States)

    Kudo, Tada-aki; Kanetaka, Hiroyasu; Shimizu, Yoshinaka; Abe, Toshihiko; Mori, Hitoshi; Mori, Kazumi; Suzuki, Eizaburo; Takagi, Toshiyuki; Izumi, Shin-ichi

    2013-01-01

    We examined the regulation of neuritogenesis by a pulsed electromagnetic field (PEMF) in rat PC12 pheochromocytoma cells, which can be induced to differentiate into neuron-like cells with elongated neurites by inducers such as nerve growth factor (NGF). Plated PC12 cells were exposed to a single PEMF (central magnetic flux density, 700 mT; frequency, 0.172 Hz) for up to 12 h per day and were then evaluated for extent of neuritogenesis or acetylcholine esterase (AChE) activity. To analyze the mechanism underlying the effect of the PEMF on the cells, its effects on intracellular signaling were examined using the ERK kinase (MEK) inhibitors PD098059 and U0126 (U0124 was used as a negative control for U0126). The number of neurite-bearing PC12 cells and AChE activity increased after PEMF exposure without the addition of other inducers of neuritogenesis. Additionally, PEMF exposure induced sustained activation of ERK1/2 in PC12 cells, but not in NR8383 rat alveolar macrophages. Furthermore, U0126 strongly inhibited PEMF-dependent ERK1/2 activation and neuritogenesis. The PEMF-dependent neuritogenesis was also suppressed by PD098059, but not U0124. These results suggest that PEMF stimulation independently induced neuritogenesis and that activation of MEK-ERK1/2 signaling was induced by a cell-type-dependent mechanism required for PEMF-dependent neuritogenesis in PC12 cells.

  3. Nonlinear propagation of strong-field THz pulses in doped semiconductors

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Hvam, Jørn Märcher; Hoffmann, Matthias C.

    2012-01-01

    We report on nonlinear propagation of single-cycle THz pulses with peak electric fields reaching 300 kV/cm in n-type semiconductors at room temperature. Dramatic THz saturable absorption effects are observed in GaAs, GaP, and Ge, which are caused by the nonlinear electron transport in THz fields......-effective-mass states in the energy-momentum space of the conduction band. Further, we observe the typical accompanying effects of saturable absorption on the THz pulses, such as an increase of the group delay, as the peak electric field of the pulse increases. In this paper we present the results of nonlinear THz time....... The semiconductor conductivity, and hence the THz absorption, is modulated due to the acceleration of carriers in strong THz fields, leading to an increase of the effective mass of the electron population, as the electrons are redistributed from the low-momentum, low-effective-mass states to the high-momentum, high...

  4. Preventing Electromagnetic Pulse Irradiation Damage on Testis Using Selenium-rich Cordyceps Fungi. A Preclinical Study in Young Male Mice.

    Science.gov (United States)

    Miao, Xia; Wang, Yafeng; Lang, Haiyang; Lin, Yanyun; Guo, Qiyan; Yang, Mingjuan; Guo, Juan; Zhang, Yanjun; Zhang, Jie; Liu, Junye; Liu, Yaning; Zeng, Lihua; Guo, Guozhen

    2017-02-01

    Networked 21st century society, globalization, and communications technologies are paralleled by the rise of electromagnetic energy intensity in our environments and the growing pressure of the environtome on human biology and health. The latter is the entire complement of environmental factors, including the electromagnetic energy and the technologies that generate them, enacting on the digital citizen in the new century. Electromagnetic pulse (EMP) irradiation might have serious damaging effects not only on electronic equipment but also in the whole organism and reproductive health, through nonthermal effects and oxidative stress. We sought to determine whether EMP exposure (1) induces biological damage on reproductive health and (2) the extent to which selenium-rich Cordyceps fungi (daily coadministration) offer protection on the testicles and spermatozoa. In a preclinical randomized study, 3-week-old male BALB/c mice were repeatedly exposed to EMP (peak intensity 200 kV/m, pulse edge 3.5 ns, pulse width 15 ns, 0.1 Hz, and 400 pulses/day) 5 days per week for four consecutive weeks, with or without coadministration of daily selenium-rich Cordyceps fungi (100 mg/kg). Testicular index and spermatozoa formation were measured at baseline and 1, 7, 14, 28, and 60 day time points after EMP exposure. The group without Cordyceps cotreatment displayed decreased spermatozoa formation, shrunk seminiferous tubule diameters, and diminished antioxidative capacity at 28 and 60 days after exposure (p digital citizenship.

  5. Effects of pulsed electromagnetic field on knee osteoarthritis: a systematic review.

    Science.gov (United States)

    Ryang We, Seo; Koog, Yun Hyung; Jeong, Kwang-Il; Wi, Hyungsun

    2013-05-01

    Many reviews have been previously published on the efficacy of pulsed electromagnetic field (PEMF) in the management of knee OA. However, their results regarding pain and function yielded conflicting conclusions. Therefore this study was conducted to determine the efficacy of PEMF as compared with a placebo. We reviewed randomized, placebo-controlled trials using electronic databases. We also manually reviewed sources to identify additional relevant studies. Fourteen trials were analysed, comprising 482 patients in the treatment group and 448 patients in the placebo group. When the efficacy of PEMF in treating pain was investigated, no significant effects were observed at any of the time points considered. However, when trials employing high-quality methodology were analysed, PEMF was significantly more effective at 4 and 8 weeks than the placebo. When the efficacy of PEMF was evaluated for function, a significant improvement was observed 8 weeks after the treatment initiation, with a standardized mean difference of 0.30 (95% CI 0.07, 0.53). No significant association was found between the use of PEMF and the occurrence of adverse events, as indicated by a relative risk of 1.47 (95% CI 0.67, 3.20). However, three (21.4%) trials applied electromagnetic field intensity over the levels recommended by the International Commission on Non-Ionizing Radiation Protection. The present study provided suggestive evidence supporting PEMF efficacy in the management of knee OA. Our results further raise the need for more well-controlled trials, employing adequate methodology, to conclusively evaluate the efficacy of PEMF.

  6. A comparison of lightning electromagnetic fields with the nuclear electromagnetic pulse in the frequency range 10 to the 4th to 10 to the 7th Hz

    International Nuclear Information System (INIS)

    Uman, M.A.; Master, M.J.; Krider, E.P.

    1982-01-01

    The electromagnetic fields produced by both direct lightning strikes and nearby lightning are compared with the nuclear electromagnetic pulse (NEMP) from an exoatmospheric burst. Model calculations indicate that, in the frequency range from 10 kHz to near 10 MHz, the Fourier amplitude spectra of the return stroke magnetic fields near ground 1 m from an average lightning strike will exceed that of the NEMP. Nearby first return strokes at a range of about 50 m, if they are severe, produce electric field spectra near ground which exceed that of the NEMP below about 1 MHz, while the spectra of average nearby first return strokes exceed that of the NEMP below about 300 kHz. Implications of these results for aircraft in flight are discussed

  7. Pulsed electromagnetic fields potentiate neurite outgrowth in the dopaminergic MN9D cell line.

    Science.gov (United States)

    Lekhraj, Rukmani; Cynamon, Deborah E; DeLuca, Stephanie E; Taub, Eric S; Pilla, Arthur A; Casper, Diana

    2014-06-01

    Pulsed electromagnetic fields (PEMF) exert biological effects and are in clinical use to facilitate bone repair and wound healing. Research has demonstrated that PEMF can induce signaling molecules and growth factors, molecules that play important roles in neuronal differentiation. Here, we tested the effects of a low-amplitude, nonthermal, pulsed radiofrequency signal on morphological neuronal differentiation in MN9D, a dopaminergic cell line. Cells were plated in medium with 10% fetal calf serum. After 1 day, medium was replaced with serum-containing medium, serum-free medium, or medium supplemented with dibutyryl cyclic adenosine monophosphate (Bt2 cAMP), a cAMP analog known to induce neurite outgrowth. Cultures were divided into groups and treated with PEMF signals for either 30 min per day or continuously for 15 min every hour for 3 days. Both serum withdrawal and Bt2 cAMP significantly increased neurite length. PEMF treatment similarly increased neurite length under both serum-free and serum-supplemented conditions, although to a lesser degree in the presence of serum, when continuous treatments had greater effects. PEMF signals also increased cell body width, indicating neuronal maturation, and decreased protein content, suggesting that this treatment was antimitotic, an effect reversed by the inhibitor of cAMP formation dideoxyadenosine. Bt2 cAMP and PEMF effects were not additive, suggesting that neurite elongation was achieved through a common pathway. PEMF signals increased cAMP levels from 3 to 5 hr after treatment, supporting this mechanism of action. Although neuritogenesis is considered a developmental process, it may also represent the plasticity required to form and maintain synaptic connections throughout life. Copyright © 2014 Wiley Periodicals, Inc.

  8. Effect of intervention initiation timing of pulsed electromagnetic field on ovariectomy-induced osteoporosis in rats.

    Science.gov (United States)

    Zhou, Jun; Liao, Yuan; Zeng, Yahua; Xie, Haitao; Fu, Chengxiao; Li, Neng

    2017-09-01

    The aim of this study is to explore the effect of timing of initiation of pulsed electromagnetic field (PEMF) therapy on bone mass, microarchitecture, and biomechanical properties, and to investigate receptor activator of NF-kB (RANK) expression in ovariectomized (OVX) rats. Sixty female Sprague-Dawley rats were randomly divided into two equal batches of three groups each (10 rats in each group). The first batch comprised of sham-operated (Sham-0 group), ovariectomized (OVX-0 group), and ovariectomized plus treated with PEMF starting from the day of OVX (Early PEMF group). The second batch comprised of sham-operated (Sham-12 group), ovariectomized (OVX-12 group), and ovariectomized plus treated with PEMF starting 12 weeks after OVX (Late PEMF group). Rats (whole body) in the early and late PEMF groups were exposed to PEMF (3.8 mT peak, 8 Hz pulse burst repetition rate). After 12 weeks of PEMF therapy, Early PEMF prevented OVX-induced deterioration in bone mineral density (BMD) and mechanical properties in lumbar vertebral body and femur, and deterioration in bone microarchitecture in lumbar vertebral body and proximal tibia. Late PEMF intervention only inhibited deterioration of BMD, bone microarchitecture, and mechanical properties in lumbar vertebral body. Both early and late PEMF therapy suppressed RANK protein expression in OVX rats without a concomitant effect on RANK mRNA expression. These results demonstrate that timing of initiation of PEMF therapy plays an important role in achieving optimal beneficial effects. The specific PEMF parameters may exert these favorable biological responses, at least partially, via inhibition of protein expression of RANK. Bioelectromagnetics. 38:456-465, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  9. Design and test of a simple fast electromagnetic inductive gas valve for planar pulsed inductive plasma thruster

    Science.gov (United States)

    Guo, Dawei; Cheng, Mousen; Li, Xiaokang

    2017-10-01

    In support of our planar pulsed inductive plasma thruster research, a fast electromagnetic inductive valve for a gas propellant injection system has been built and tested. A new and important design feature is the use of a conical diaphragm as the action part, which greatly contributes to the virtue of simplicity for adopting the resultant force of the diaphragm deformation as the closing force. An optical transmission technique is adopted to measure the opening and closing characters of the valve while the gas throughput is determined by measuring the pressure change per pulse in a test chamber with a capacitance manometer. The experimental results revealed that the delay time before the valve reaction is less than 40 μs, and the valve pulse width is no longer than 160 μs full width at half maximum. The valve delivers 0-2.5 mg of argon gas per pulse varied by adjusting the drive voltage and gas pressure.

  10. Influence of lateral target size on hot electron production and electromagnetic pulse emission from laser-irradiated metallic targets

    International Nuclear Information System (INIS)

    Chen Ziyu; Li Jianfeng; Yu Yong; Li Xiaoya; Peng Qixian; Zhu Wenjun; Wang Jiaxiang

    2012-01-01

    The influences of lateral target size on hot electron production and electromagnetic pulse emission from laser interaction with metallic targets have been investigated. Particle-in-cell simulations at high laser intensities show that the yield of hot electrons tends to increase with lateral target size, because the larger surface area reduces the electrostatic field on the target, owing to its expansion along the target surface. At lower laser intensities and longer time scales, experimental data characterizing electromagnetic pulse emission as a function of lateral target size also show target-size effects. Charge separation and a larger target tending to have a lower target potential have both been observed. The increase in radiation strength and downshift in radiation frequency with increasing lateral target size can be interpreted using a simple model of the electrical capacity of the target.

  11. Influence of lateral target size on hot electron production and electromagnetic pulse emission from laser-irradiated metallic targets

    Energy Technology Data Exchange (ETDEWEB)

    Chen Ziyu; Li Jianfeng; Yu Yong; Li Xiaoya; Peng Qixian; Zhu Wenjun [National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Wang Jiaxiang [State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China)

    2012-11-15

    The influences of lateral target size on hot electron production and electromagnetic pulse emission from laser interaction with metallic targets have been investigated. Particle-in-cell simulations at high laser intensities show that the yield of hot electrons tends to increase with lateral target size, because the larger surface area reduces the electrostatic field on the target, owing to its expansion along the target surface. At lower laser intensities and longer time scales, experimental data characterizing electromagnetic pulse emission as a function of lateral target size also show target-size effects. Charge separation and a larger target tending to have a lower target potential have both been observed. The increase in radiation strength and downshift in radiation frequency with increasing lateral target size can be interpreted using a simple model of the electrical capacity of the target.

  12. [Pulse-modulated Electromagnetic Radiation of Extremely High Frequencies Protects Cellular DNA against Damaging Effect of Physico-Chemical Factors in vitro].

    Science.gov (United States)

    Gapeyev, A B; Lukyanova, N A

    2015-01-01

    Using a comet assay technique, we investigated protective effects of. extremely high frequency electromagnetic radiation in combination with the damaging effect of X-ray irradiation, the effect of damaging agents hydrogen peroxide and methyl methanesulfonate on DNA in mouse whole blood leukocytes. It was shown that the preliminary exposure of the cells to low intensity pulse-modulated electromagnetic radiation (42.2 GHz, 0.1 mW/cm2, 20-min exposure, modulation frequencies of 1 and 16 Hz) caused protective effects decreasing the DNA damage by 20-45%. The efficacy of pulse-modulated electromagnetic radiation depended on the type of genotoxic agent and increased in a row methyl methanesulfonate--X-rays--hydrogen peroxide. Continuous electromagnetic radiation was ineffective. The mechanisms of protective effects may be connected with an induction of the adaptive response by nanomolar concentrations of reactive oxygen species formed by pulse-modulated electromagnetic radiation.

  13. The Effects of Pulsed Electromagnetic Field in the Treatment of Osteoarthritis in Dogs: Clinical Study

    Directory of Open Access Journals (Sweden)

    Stefania Pinna*§, Francesca Landucci§, Anna Maria Tribuiani§, Fabio Carli and Antonio Venturini

    2013-01-01

    Full Text Available In this study the effects of pulsed electromagnetic field (PEMF on pain relief and functional capacity of dogs with osteoarthritis (OA were investigated, and compared with firocoxib. Patients were randomly assigned to two groups: twenty-five client-owned dogs were treated with PEMF once a day for 20 sessions, and fifteen dogs (control group were treated with 5 mg/kg of firocoxib once daily for 20 days. Blinded clinical examination and owner’s assessment were recorded before and after the therapy, as well as 4 and 12 months later. Data collections were statistically compared before and after treatments and between groups. Both groups showed decreased clinical signs of OA during the treatment. Compared with baseline, these improvements were statistically significant (P<0.01 during the therapies. Differences were recorded during observation time spans following the end of treatments. In the PEMF group the effects were sustained until the end of the study, whereas in the control group the progress tended to return to baseline values after the end of therapy. The beneficial effects of PEMF on pain relief and functional capacity make it a potential treatment modality for canine osteoarthritis compared to traditional pharmacological therapy, in absence of adverse effects and in favour of the quality of life.

  14. Study on the Shielding Effectiveness of an Arc Thermal Metal Spraying Method against an Electromagnetic Pulse

    Directory of Open Access Journals (Sweden)

    Han-Seung Lee

    2017-10-01

    Full Text Available An electromagnetic pulse (EMP explodes in real-time and causes critical damage within a short period to not only electric devices, but also to national infrastructures. In terms of EMP shielding rooms, metal plate has been used due to its excellent shielding effectiveness (SE. However, it has difficulties in manufacturing, as the fabrication of welded parts of metal plates and the cost of construction are non-economical. The objective of this study is to examine the applicability of the arc thermal metal spraying (ATMS method as a new EMP shielding method to replace metal plate. The experimental parameters, metal types (Cu, Zn-Al, and coating thickness (100–700 μm used for the ATMS method were considered. As an experiment, a SE test against an EMP in the range of 103 to 1010 Hz was conducted. Results showed that the ATMS coating with Zn-Al had similar shielding performance in comparison with metal plate. In conclusion, the ATMS method is judged to have a high possibility of actual application as a new EMP shielding material.

  15. Can Pulsed Electromagnetic Fields Trigger On-Demand Drug Release from High-Tm Magnetoliposomes?

    Science.gov (United States)

    Nardoni, Martina; Della Valle, Elena; Liberti, Micaela; Relucenti, Michela; Casadei, Maria Antonietta; Paolicelli, Patrizia; Apollonio, Francesca; Petralito, Stefania

    2018-03-27

    Recently, magnetic nanoparticles (MNPs) have been used to trigger drug release from magnetoliposomes through a magneto-nanomechanical approach, where the mechanical actuation of the MNPs is used to enhance the membrane permeability. This result can be effectively achieved with low intensity non-thermal alternating magnetic field (AMF), which, however, found rare clinic application. Therefore, a different modality of generating non-thermal magnetic fields has now been investigated. Specifically, the ability of the intermittent signals generated by non-thermal pulsed electromagnetic fields (PEMFS) were used to verify if, once applied to high-transition temperature magnetoliposomes (high-Tm MLs), they could be able to efficiently trigger the release of a hydrophilic model drug. To this end, hydrophilic MNPs were combined with hydrogenated soybean phosphatidylcholine and cholesterol to design high-Tm MLs. The release of a dye was evaluated under the effect of PEMFs for different times. The MNPs motions produced by PEMF could effectively increase the bilayer permeability, without affecting the liposomes integrity and resulted in nearly 20% of release after 3 h exposure. Therefore, the current contribution provides an exciting proof-of-concept for the ability of PEMFS to trigger drug release, considering that PEMFS find already application in therapy due to their anti-inflammatory effects.

  16. Effects of local vibration and pulsed electromagnetic field on bone fracture: A comparative study.

    Science.gov (United States)

    Bilgin, Hakkı Murat; Çelik, Ferhat; Gem, Mehmet; Akpolat, Veysi; Yıldız, İsmail; Ekinci, Aysun; Özerdem, Mehmet Siraç; Tunik, Selçuk

    2017-07-01

    The effectiveness of various therapeutic methods on bone fracture has been demonstrated in several studies. In the present study, we tried to evaluate the effect of local low-magnitude, high-frequency vibration (LMHFV) on rat tibia fracture in comparison with pulsed electromagnetic fields (PEMF) during the healing process. Mid-diaphysis tibiae fractures were induced in 30 Sprague-Dawley rats. The rats were assigned into groups such as control (CONT), LMHFV (15 min/day, 7 days/week), and PEMF (3.5 h/day, 7 days/week) for a three-week treatment. Nothing was applied to control group. Radiographs, serum osteocalcin levels, and stereological bone analyses of the three groups were compared. The X-rays of tibiae were taken 21 days after the end of the healing process. PEMF and LMHFV groups had more callus formation when compared to CONT group; however, the difference was not statistically significant (P = 0.375). Serum osteocalcin levels were elevated in the experimental groups compared to CONT (P ≤ 0.001). Stereological tests also showed higher osteogenic results in experimental groups, especially in LMHFV group. The results of the present study suggest that application of direct local LMHFV on fracture has promoted bone formation, showing great potential in improving fracture outcome. Bioelectromagnetics. 38:339-348, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  17. Pulsed electromagnetic field improves postnatal neovascularization in response to hindlimb ischemia.

    Science.gov (United States)

    Li, Rui-Lin; Huang, Jing-Juan; Shi, Yi-Qin; Hu, An; Lu, Zhao-Yang; Weng, Liang; Wang, Shen-Qi; Han, Yi-Peng; Zhang, Lan; Hao, Chang-Ning; Duan, Jun-Li

    2015-01-01

    Pulsed electromagnetic fields (PEMF) have been shown to promote proliferation and regeneration in the damaged tissue. Here, we examined whether PEMF therapy improved postnatal neovascularization using murine model of hindlimb ischemia, and the underlying cellular/molecular mechanisms were further investigated. Hindlimb ischemia was induced by unilateral femoral artery resection using 6-8 week-old male C57BL6 mice. Then, mice were exposed to extracorporeal PEMF therapy (4 cycles, 8min/cycle, 30 ± 3 Hz, 5 mT) every day until day 14. Our data demonstrated that PEMF therapy significantly accelerated wound healing, decreased prevalence of gangrene and increased postnatal neovascularization. Moreover, the levels of vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS) and Akt phosphorylation in ischemic muscles were markedly enhanced following PEMF therapy. In vitro, PEMF inhibited the process of hypoxia-induced apoptosis and augmented tube formation, migration and proliferative capacities of human umbilical vein endothelial cells (HUVECs). Additionally, PEMF exposure increased VEGF secretion, as well as the eNOS and Akt phosphorylation, and these benefits could be blocked by either phosphoinositide 3-kinase (PI3K) or eNOS inhibitor. In conclusion, our data indicated that PEMF therapy enhanced ischemia-mediated angiogenesis, through up-regulating VEGF expression and activating the PI3K-Akt-eNOS pathway. Therefore, PEMF should be a valuable treatment for the patients with critical limb ischemia.

  18. Pulsed electromagnetic fields promote the proliferation and differentiation of osteoblasts by reinforcing intracellular calcium transients.

    Science.gov (United States)

    Tong, Jie; Sun, Lijun; Zhu, Bin; Fan, Yun; Ma, Xingfeng; Yu, Liyin; Zhang, Jianbao

    2017-10-01

    Pulsed electromagnetic fields (PEMF) can be used to treat bone-related diseases, but the underlying mechanism remains unclear, especially the process by which PEMFs initiate biological effects. In this study, we demonstrated the effects of PEMF on proliferation and differentiation of osteoblasts using the model of calcium transients induced by high extracellular calcium. Our results showed that PEMF can increase both the percentage of responding cells and amplitude of intracellular calcium transients induced by high extracellular calcium stimulation. Compared with corresponding extracellular calcium levels, PEMF stimulation increased proliferation and differentiation of osteoblasts and related gene expressions, such as insulin-like growth factor 1 (IGF-1), alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2), and osteocalcin (OCN), which can be completely abolished by BAPTA-AM. Moreover, PEMF did not affect proliferation and differentiation of osteoblasts if no intracellular calcium transient was present in osteoblasts during PEMF exposure. Our results revealed that PEMF affects osteoblast proliferation and differentiation through enhanced intracellular calcium transients, which provided a cue to treat bone-related diseases with PEMF. Bioelectromagnetics. 38:541-549, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  19. Pulsed electromagnetic field during cast immobilization in postmenopausal women with Colles’ fracture

    Directory of Open Access Journals (Sweden)

    Lazović Milica

    2012-01-01

    Full Text Available Introduction. Although Colles’ fracture i.e. a dorsally displaced distal radius fracture (DRF is one of the most common fractures, there is no enough evidence to determine the best form of rehabilitation. Objective. To assess whether the use of pulsed electromagnetic field (PEMF therapy during cast immobilization of DRF provides beneficial effects on pain, edema, wrist range of motion and function, as well as on the frequency of complications immediately after cast removal. Methods. The prospective randomized controlled study included 60 women over the age of 55 years with extra-articular displaced DRF treated with reduction and cast immobilization. The patients were alternately allocated to either a PEMF group (n=30, received 10 days of PEMF therapy during immobilization, or a control group (n=30, without PEMF therapy. Pain, function, hand circumference, wrist and forearm range of motion and frequency of complications for each patient was evaluated within two to three days of cast removal. Results. Better mean values for the majority of examined parameters were recorded in the PEMF group than in the control group, but the difference was statistically significant just for edema (p<0.001, flexion, extension and supination range (p<0.01. Conclusion. During immobilization PEMF therapy in DRF patients gave better results immediately after cast removal in terms of edema and wrist range of motion (ROM.

  20. Pulsed electromagnetic fields (PEMF) promote early wound healing and myofibroblast proliferation in diabetic rats.

    Science.gov (United States)

    Cheing, Gladys Lai-Ying; Li, Xiaohui; Huang, Lin; Kwan, Rachel Lai-Chu; Cheung, Kwok-Kuen

    2014-04-01

    Reduced collagen deposition possibly leads to slow recovery of tensile strength in the healing process of diabetic cutaneous wounds. Myofibroblasts are transiently present during wound healing and play a key role in wound closure and collagen synthesis. Pulsed electromagnetic fields (PEMF) have been shown to enhance the tensile strength of diabetic wounds. In this study, we examined the effect of PEMF on wound closure and the presence of myofibroblasts in Sprague-Dawley rats after diabetic induction using streptozotocin. A full-thickness square-shaped dermal wound (2 cm × 2 cm) was excised aseptically on the shaved dorsum. The rats were randomly divided into PEMF-treated (5 mT, 25 Hz, 1 h daily) and control groups. The results indicated that there were no significant differences between the groups in blood glucose level and body weight. However, PEMF treatment significantly enhanced wound closure (days 10 and 14 post-wounding) and re-epithelialization (day 10 post-wounding), although these improvements were no longer observed at later stages of the wound healing process. Using immunohistochemistry against α-smooth muscle actin (α-SMA), we demonstrated that significantly more myofibroblasts were detected on days 7 and 10 post-wounding in the PEMF group when compared to the control group. We hypothesized that PEMF would increase the myofibroblast population, contributing to wound closure during diabetic wound healing. © 2014 Wiley Periodicals, Inc.

  1. An Investigation on the Effect of Extremely Low Frequency Pulsed Electromagnetic Fields on Human Electrocardiograms (ECGs)

    Science.gov (United States)

    Fang, Qiang; Mahmoud, Seedahmed S.; Yan, Jiayong; Li, Hui

    2016-01-01

    For this investigation, we studied the effects of extremely low frequency pulse electromagnetic fields (ELF-PEMF) on the human cardiac signal. Electrocardiograms (ECGs) of 22 healthy volunteers before and after a short duration of ELF-PEMF exposure were recorded. The experiment was conducted under single-blind conditions. The root mean square (RMS) value of the recorded data was considered as comparison criteria. We also measured and analysed four important ECG time intervals before and after ELF-PEMF exposure. Results revealed that the RMS value of the ECG recordings from 18 participants (81.8% of the total participants) increased with a mean value of 3.72%. The increase in ECG voltage levels was then verified by a second experimental protocol with a control exposure. In addition to this, we used hyperbolic T-distributions (HTD) in the analysis of ECG signals to verify the change in the RR interval. It was found that there were small shifts in the frequency-domain signal before and after EMF exposure. This shift has an influence on all frequency components of the ECG signals, as all spectrums were shifted. It is shown from this investigation that a short time exposure to ELF-PEMF can affect the properties of ECG signals. Further study is needed to consolidate this finding and discover more on the biological effects of ELF-PEMF on human physiological processes. PMID:27886102

  2. Can Pulsed Electromagnetic Fields Trigger On-Demand Drug Release from High-Tm Magnetoliposomes?

    Directory of Open Access Journals (Sweden)

    Martina Nardoni

    2018-03-01

    Full Text Available Recently, magnetic nanoparticles (MNPs have been used to trigger drug release from magnetoliposomes through a magneto-nanomechanical approach, where the mechanical actuation of the MNPs is used to enhance the membrane permeability. This result can be effectively achieved with low intensity non-thermal alternating magnetic field (AMF, which, however, found rare clinic application. Therefore, a different modality of generating non-thermal magnetic fields has now been investigated. Specifically, the ability of the intermittent signals generated by non-thermal pulsed electromagnetic fields (PEMFS were used to verify if, once applied to high-transition temperature magnetoliposomes (high-Tm MLs, they could be able to efficiently trigger the release of a hydrophilic model drug. To this end, hydrophilic MNPs were combined with hydrogenated soybean phosphatidylcholine and cholesterol to design high-Tm MLs. The release of a dye was evaluated under the effect of PEMFs for different times. The MNPs motions produced by PEMF could effectively increase the bilayer permeability, without affecting the liposomes integrity and resulted in nearly 20% of release after 3 h exposure. Therefore, the current contribution provides an exciting proof-of-concept for the ability of PEMFS to trigger drug release, considering that PEMFS find already application in therapy due to their anti-inflammatory effects.

  3. Pulsed electromagnetic fields dosing impacts postoperative pain in breast reduction patients.

    Science.gov (United States)

    Taylor, Erin M; Hardy, Krista L; Alonso, Amanda; Pilla, Arthur A; Rohde, Christine H

    2015-01-01

    Pulsed electromagnetic fields (PEMF) reduce postoperative pain and narcotic requirements in breast augmentation, reduction, and reconstruction patients. PEMF enhances both calmodulin-dependent nitric oxide and/or cyclic guanosine monophosphate signaling and phosphodiesterase activity, which blocks cyclic guanosine monophosphate. The clinical effect of these competing responses on PEMF dosing is not known. Two prospective, nonrandomized, active cohorts of breast reduction patients, with 15 min PEMF per 2 h; "Q2 (active)", and 5 min PEMF per 20 min; "5/20 (active)", dosing regimens were added to a previously reported double-blind clinical study wherein 20 min PEMF per 4 h, "Q4 (active)", dosing significantly accelerated postoperative pain reduction compared with Q4 shams. Postoperative visual analog scale pain scores and narcotic use were compared with results from the previous study. Visual analog scale scores at 24 h were 43% and 35% of pain at 1 h in the Q4 (active) and Q2 (active) cohorts, respectively (P PEMF dosing, accelerated postoperative pain reduction compared with historical shams. The 5/20 (active) regimen increases NO 4-fold faster than the Q4 (active) regimen, possibly accelerating phosphodiesterase inhibition of cyclic guanosine monophosphate sufficiently to block the PEMF effect. This study helps define the dosing limits of clinically useful PEMF signals. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Osteogenic differentiation of amniotic epithelial cells: synergism of pulsed electromagnetic field and biochemical stimuli.

    Science.gov (United States)

    Wang, Qian; Wu, Wenchao; Han, Xiaoyu; Zheng, Ai; Lei, Song; Wu, Jiang; Chen, Huaiqing; He, Chengqi; Luo, Fengming; Liu, Xiaojing

    2014-08-11

    Pulsed electromagnetic field (PEMF) is a non-invasive physical therapy used in the treatment of fracture nonunion or delayed healing. PEMF can facilitate the osteogenic differentiation of bone marrow mesenchymal stem cells in vitro. Amniotic epithelial cells (AECs) have been proposed as a potential source of stem cells for cell therapy. However, whether PEMF could modulate the osteogenic differentiation of AECs is unknown. In the present study, the effects of PEMF on the osteogenic differentiation of AECs were investigated. AECs were isolated from amniotic membrane of human placenta by trypsin digestion and were induced by PEMF and/or osteo-induction medium. After 21 days we used real time RT-PCR and immunocytochemistry to study the expression of osteoblast markers. The signal transduction of osteogenesis was further investigated. The PEMF stimulation, or osteo-induction medium alone could induce osteogenic differentiation of AECs, as shown by expression of osteoblast specific genes and proteins including alkaline phosphatase and osteocalcin. Furthermore, a combination of PEMF and osteo-induction medium had synergy effects on osteogenic differentiation. In our study, the gene expression of BMP-2, Runx2, β-catenin, Nrf2, Keap1 and integrinβ1 were up-regulated in the osteogenic differentiation of AECs induced by PEMF and/or osteo-induction medium. Combined application of PEMF and osteo-induction medium is synergistic for the osteogenic differentiation of AECs. It might be a novel approach in the bone regenerative medicine.

  5. Effects of low-frequency pulsed electromagnetic fields on plateau frostbite healing in rats.

    Science.gov (United States)

    Jiao, Mingke; Lou, Lin; Jiao, Lin; Hu, Jie; Zhang, Peng; Wang, Zhongming; Xu, Wenjuan; Geng, Xiliang; Song, Hongping

    2016-11-01

    Plateau frostbite (PF) treatments have remained a clinical challenge because this condition injures tissues in deep layers and affected tissues exhibit unique pathological characteristics. For instance, low-frequency pulsed electromagnetic field (PEMF) can affect tissue restoration and penetrate tissues. Therefore, the effect of PEMF on PF healing should be investigated. This study aimed to evaluate the effects of low-frequency PEMF on PF healing systematically. Ninety-six Sprague-Dawley rats were randomly and equally divided into three groups: normal control, partial thickness plateau frostbite (PTPF), and PTPF with low-frequency PEMF exposure (PTPF + PEMF). PTPF wounds were induced in the dorsum of the rats. The PTPF + PEMF group was exposed to low-frequency PEMF daily. During PF healing, wound microcirculation in each group was monitored through contrast ultrasonography. Wound appearance, histological observation, and wound tensile strength were also evaluated. Results showed that the rate of the microcirculation restoration of the PTPF + PEMF group was nearly 25% faster than that of the PTPF group, and wound appearance suggested that the healing of the PTPF group was slower than that of the PTPF + PEMF group. Histological observation revealed that PEMF accelerated the growth of different deep tissues, as confirmed by tensile strength examination. Low-frequency PEMF could penetrate PF tissues, promote their restoration, and provide a beneficial effect on PF healing. Therefore, this technique may be a potential alternative to treat PF. © 2016 by the Wound Healing Society.

  6. Pulsed Electromagnetic Field (PEMF) Mitigates High Intracranial Pressure (ICP) Induced Microvascular Shunting (MVS) in Rats.

    Science.gov (United States)

    Bragin, Denis E; Bragina, Olga A; Hagberg, Sean; Nemoto, Edwin M

    2018-01-01

    High-frequency pulsed electromagnetic field (PEMF) stimulation is an emerging noninvasive therapy that we have shown increases cerebral blood flow (CBF) and tissue oxygenation in the healthy rat brain. In this work, we tested the effect of PEMF on the brain at high intracranial pressure (ICP). We previously showed that high ICP in rats caused a transition from capillary (CAP) to non-nutritive microvascular shunt (MVS) flow, tissue hypoxia and increased blood brain barrier (BBB) permeability. Using in vivo two-photon laser scanning microscopy (2PLSM) over the rat parietal cortex, and studied the effects of PEMF on microvascular blood flow velocity, tissue oxygenation (NADH autofluorescence), BBB permeability and neuronal necrosis during 4 h of elevated ICP to 30 mmHg. PEMF significantly dilated arterioles, increased capillary blood flow velocity and reduced MVS/capillary ratio compared to sham-treated animals. These effects led to a significant decrease in tissue hypoxia, BBB degradation and neuronal necrosis. PEMF attenuates high ICP-induced pathological microcirculatory changes, tissue hypoxia, BBB degradation and neuronal necrosis.

  7. Novel protective effects of pulsed electromagnetic field ischemia/reperfusion injury rats.

    Science.gov (United States)

    Ma, Fenfen; Li, Wenwen; Li, Xinghui; Tran, Ba Hieu; Suguro, Rinkiko; Guan, Ruijuan; Hou, Cuilan; Wang, Huijuan; Zhang, Aijie; Zhu, Yichun; Zhu, YiZhun

    2016-12-01

    Extracorporeal pulsed electromagnetic field (PEMF) has shown the ability to regenerate tissue by promoting cell proliferation. In the present study, we investigated for the first time whether PEMF treatment could improve the myocardial ischaemia/reperfusion (I/R) injury and uncovered its underlying mechanisms.In our study, we demonstrated for the first time that extracorporeal PEMF has a novel effect on myocardial I/R injury. The number and function of circulating endothelial progenitor cells (EPCs) were increased in PEMF treating rats. The in vivo results showed that per-treatment of PEMF could significantly improve the cardiac function in I/R injury group. In addition, PEMF treatment also reduced the apoptosis of myocardial cells by up-regulating the expression of anti-apoptosis protein B-cell lymphoma 2 (Bcl-2) and down-regulating the expression of pro-apoptosis protein (Bax). In vitro, the results showed that PEMF treatment could significantly reduce the apoptosis and reactive oxygen species (ROS) levels in primary neonatal rat cardiac ventricular myocytes (NRCMs) induced by hypoxia/reoxygenation (H/R). In particular, PEMF increased the phosphorylation of protein kinase B (Akt) and endothelial nitric oxide synthase (eNOS), which might be closely related to attenuated cell apoptosis by increasing the releasing of nitric oxide (NO). Therefore, our data indicated that PEMF could be a potential candidate for I/R injury. © 2016 The Author(s).

  8. Pulsed electromagnetic field improves cardiac function in response to myocardial infarction.

    Science.gov (United States)

    Hao, Chang-Ning; Huang, Jing-Juan; Shi, Yi-Qin; Cheng, Xian-Wu; Li, Hao-Yun; Zhou, Lin; Guo, Xin-Gui; Li, Rui-Lin; Lu, Wei; Zhu, Yi-Zhun; Duan, Jun-Li

    2014-01-01

    Extracorporeal pulsed electromagnetic field (PEMF) has been shown the ability to improve regeneration in various ischemic episodes. Here, we examined whether PEMF therapy facilitate cardiac recovery in rat myocardial infarction (MI), and the cellular/molecular mechanisms underlying PEMF-related therapy was further investigated. The MI rats were exposed to active PEMF for 4 cycles per day (8 minutes/cycle, 30 ± 3 Hz, 5 mT) after MI induction. The data demonstrated that PEMF treatment significantly inhibited cardiac apoptosis and improved cardiac systolic function. Moreover, PEMF treatment increased capillary density, the levels of vascular endothelial growth factor (VEGF) and hypoxic inducible factor-1α in infarct border zone. Furthermore, the number and function of circulating endothelial progenitor cells were advanced in PEMF treating rats. In vitro, PEMF induced the degree of human umbilical venous endothelial cells tubulization and increased soluble pro-angiogenic factor secretion (VEGF and nitric oxide). In conclusion, PEMF therapy preserves cardiac systolic function, inhibits apoptosis and trigger postnatal neovascularization in ischemic myocardium.

  9. Pulsed electromagnetic fields promote survival and neuronal differentiation of human BM-MSCs.

    Science.gov (United States)

    Urnukhsaikhan, Enerelt; Cho, Hyunjin; Mishig-Ochir, Tsogbadrakh; Seo, Young-Kwon; Park, Jung-Kueg

    2016-04-15

    Pulsed electromagnetic fields (PEMF) are known to affect biological properties such as differentiation, regulation of transcription factor and cell proliferation. However, the cell-protective effect of PEMF exposure is largely unknown. The aim of this study is to understand the mechanisms underlying PEMF-mediated suppression of apoptosis and promotion of survival, including PEMF-induced neuronal differentiation. Treatment of induced human BM-MSCs with PEMF increased the expression of neural markers such as NF-L, NeuroD1 and Tau. Moreover, treatment of induced human BM-MSCs with PEMF greatly decreased cell death in a dose- and time-dependent manner. There is evidence that Akt and Ras are involved in neuronal survival and protection. Activation of Akt and Ras results in the regulation of survival proteins such as Bad and Bcl-xL. Thus, the Akt/Ras signaling pathway may be a desirable target for enhancing cell survival and treatment of neurological disease. Our analyses indicated that PEMF exposure dramatically increased the activity of Akt, Rsk, Creb, Erk, Bcl-xL and Bad via phosphorylation. PEMF-dependent cell protection was reversed by pretreatment with LY294002, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K). Our data suggest that the PI3K/Akt/Bad signaling pathway may be a possible mechanism for the cell-protective effects of PEMF. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Circadian Rhythm Influences the Promoting Role of Pulsed Electromagnetic Fields on Sciatic Nerve Regeneration in Rats

    Science.gov (United States)

    Zhu, Shu; Ge, Jun; Liu, Zhongyang; Liu, Liang; Jing, Da; Ran, Mingzi; Wang, Meng; Huang, Liangliang; Yang, Yafeng; Huang, Jinghui; Luo, Zhuojing

    2017-01-01

    Circadian rhythm (CR) plays a critical role in the treatment of several diseases. However, the role of CR in the treatment of peripheral nerve defects has not been studied. It is also known that the pulsed electromagnetic fields (PEMF) can provide a beneficial microenvironment to quicken the process of nerve regeneration and to enhance the quality of reconstruction. In this study, we evaluate the impact of CR on the promoting effect of PEMF on peripheral nerve regeneration in rats. We used the self-made “collagen-chitosan” nerve conduits to bridge the 15-mm nerve gaps in Sprague-Dawley rats. Our results show that PEMF stimulation at daytime (DPEMF) has most effective outcome on nerve regeneration and rats with DPEMF treatment achieve quickly functional recovery after 12 weeks. These findings indicate that CR is an important factor that determines the promoting effect of PEMF on peripheral nerve regeneration. PEMF exposure in the daytime enhances the functional recovery of rats. Our study provides a helpful guideline for the effective use of PEMF mediations experimentally and clinically. PMID:28360885

  11. Novel protective effects of pulsed electromagnetic field ischemia/reperfusion injury rats

    Science.gov (United States)

    Ma, Fenfen; Li, Wenwen; Li, Xinghui; Tran, Ba Hieu; Suguro, Rinkiko; Guan, Ruijuan; Hou, Cuilan; Wang, Huijuan; Zhang, Aijie; Zhu, Yichun; Zhu, YiZhun

    2016-01-01

    Extracorporeal pulsed electromagnetic field (PEMF) has shown the ability to regenerate tissue by promoting cell proliferation. In the present study, we investigated for the first time whether PEMF treatment could improve the myocardial ischaemia/reperfusion (I/R) injury and uncovered its underlying mechanisms. In our study, we demonstrated for the first time that extracorporeal PEMF has a novel effect on myocardial I/R injury. The number and function of circulating endothelial progenitor cells (EPCs) were increased in PEMF treating rats. The in vivo results showed that per-treatment of PEMF could significantly improve the cardiac function in I/R injury group. In addition, PEMF treatment also reduced the apoptosis of myocardial cells by up-regulating the expression of anti-apoptosis protein B-cell lymphoma 2 (Bcl-2) and down-regulating the expression of pro-apoptosis protein (Bax). In vitro, the results showed that PEMF treatment could significantly reduce the apoptosis and reactive oxygen species (ROS) levels in primary neonatal rat cardiac ventricular myocytes (NRCMs) induced by hypoxia/reoxygenation (H/R). In particular, PEMF increased the phosphorylation of protein kinase B (Akt) and endothelial nitric oxide synthase (eNOS), which might be closely related to attenuated cell apoptosis by increasing the releasing of nitric oxide (NO). Therefore, our data indicated that PEMF could be a potential candidate for I/R injury. PMID:27780890

  12. Pulsed electromagnetic field therapy promotes healing and microcirculation of chronic diabetic foot ulcers: a pilot study.

    Science.gov (United States)

    Kwan, Rachel Lai-Chu; Wong, Wing-Cheung; Yip, Siu-Leung; Chan, Ka-Lun; Zheng, Yong-Ping; Cheing, Gladys Lai-Ying

    2015-05-01

    To examine the effects of pulsed electromagnetic field (PEMF) therapy on promoting the healing and microcirculation of chronic diabetic foot ulcers. A randomized, double-blind, placebo-controlled clinical trial on a homogenous subset of chronic diabetic foot ulcers. Hospital and university. Thirteen subjects (7 in the PEMF group and 6 in the control group) diagnosed with type 2 diabetes and had unsatisfactory healing of ulcer(s) in the preceding 4 weeks were recruited. Subjects were randomly allocated to receive either active PEMF therapy (duration: 60 minutes; frequency: 12 Hz; intensity: 12 Gauss) or nonactive PEMF for 14 sessions within 3 weeks. Assessment on wound closure, wound depth, and microcirculation were performed at the baseline, end of the treatment period, and 1-month follow-up. By the end of the treatment period, there was an 18% decrease in wound size in the active PEMF group as compared with a 10% decrease in the control group. The PEMF group demonstrated significant cumulative increase in cutaneous capillary blood velocity (by 28%) and 14% increase in capillary diameter. In contrast, the control group showed a decrease in both capillary blood velocity and diameter. In this study, PEMF therapy seemed to accelerate wound healing and improve microcirculation.

  13. Therapeutic ultrasound plus pulsed electromagnetic field improves recovery from peripheral arterial disease in hypertension

    Science.gov (United States)

    Lu, Zhao-Yang; Zhou, Hong-Sheng; Su, Zhi-Xiao; Qi, Jia; Zhang, Jian; Xue, Guan-Hua; Li, Yue; Hao, Chang-Ning; Shi, Yi-Qin; Duan, Jun-Li

    2017-01-01

    The objective of this investigation was to evaluate the therapy effect of combined therapeutic ultrasound (TUS) treatment and pulsed electromagnetic field (PEMF) therapy on angiogenesis in hypertension-related hindlimb ischemia. After subjecting excision of the left femoral artery, spontaneously hypertensive rats (SHRs) were randomly distributed to one of four groups: SHR; TUS treated SHR (SHR-TUS); PEMF treated SHR (PEMF-TUS); and TUS plus PEMF treated SHR (SHR-TUS-PEMF). Wistar-Kyoto rats (WKYs) with femoral artery excision were regarded as a control group. At day 14 after surgery, the TUS plus PEMF united administration had the greatest blood perfusion accompanied by elevated capillary density and the lowest TUNEL index. Interestingly, the united administration up-regulated the angiogenic factors expression of phosphorylated Akt (p-Akt), phosphorylated endothelial nitric oxide synthase (p-eNOS), vascular endothelial growth factor (VEGF), anti-apoptotic protein of Bcl-2 and down-regulated pro-apoptotic protein levels of Bax and Cleaved caspase-3 in vivo. Our results demonstrated that the united administration could significantly rescue hypertension-related inhibition of ischemia-induced neovascularization partly by promoting angiogenesis and inhibiting apoptosis. PMID:28979692

  14. Effects of pulsed electromagnetic field therapy on delayed-onset muscle soreness in biceps brachii.

    Science.gov (United States)

    Jeon, Hye-Seon; Kang, Sun-Young; Park, Joo-Hee; Lee, Hyun-Sook

    2015-02-01

    to compare the effects of pulsed electromagnetic field (PEMF) therapy and sham treatment on DOMS-related variables in elbow flexors at 24, 48 and 72 h after delayed onset muscle soreness (DOMS) induction exercise. randomized, double-blind, placebo-controlled study. Yonsei University laboratory. In total, 30 healthy male college students. Muscle soreness, peak torque, median frequency (MDF) and electromechanical delay (EMD) during isometric contraction at 24, 48 and 72 h after DOMS induction exercise. Overall, the application of the PEMF was found to be effective in reducing the physiological deficits associated with DOMS, including improved recovery of perceived muscle soreness, MDF, and EMD during isometric contraction. Our results did not show that PEMF treatment was mechanically more effective for isometric peak torque generation compared to the sham group. this study indicates that PEMF may be useful as a modality to reduce DOMS symptoms. However, further well-designed experiments are required to determine optimal treatment dosage and duration, and to investigate the physiological and clinical mechanisms of PEMF on DOMS. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Pulsed electromagnetic field treatment enhances healing callus biomechanical properties in an animal model of osteoporotic fracture.

    Science.gov (United States)

    Androjna, Caroline; Fort, Brian; Zborowski, Maciej; Midura, Ronald J

    2014-09-01

    Delayed bone healing has been noted in osteoporosis patients and in the ovariectomized (OVX) rat model of estrogen-depletion osteopenia. Pulsed electromagnetic field (PEMF) devices are clinically approved as an adjunct to cervical fusion surgery in patients at high risk for non-fusion and for the treatment of fracture non-unions. These bone growth stimulating devices also accelerate the healing of fresh fracture repair in skeletally mature normal rats but have not been tested for efficacy to accelerate and/or enhance the delayed bone repair process in OVX rats. The current study tested the hypothesis that daily PEMF treatments would improve the fracture healing response in skeletally mature OVX rats. By 6 weeks of healing, PEMF treatments resulted in improved hard callus elastic modulus across fibula fractures normalizing the healing process in OVX rats with respect to this mechanical property. Radiographic evidence showed an improved hard callus bridging across fibula fractures in OVX rats treated with PEMF as compared to sham treatments. These findings provide a scientific rationale for investigating whether PEMF might improve bone-healing responses in at-risk osteoporotic patients. © 2014 Wiley Periodicals, Inc.

  16. Evaluation of pulsed electromagnetic field therapy in the management of patients with discogenic lumbar radiculopathy.

    Science.gov (United States)

    Omar, Aziza Sayed; Awadalla, Magdy Ahmed; El-Latif, Maii Abd

    2012-10-01

    This randomized clinical trial was designed to evaluate the effect of pulsed electromagnetic field therapy (PEMF) in the management of patients with discogenic lumbar radiculopathy. Forty patients suffering from lumbar radiculopathy due to lumbar disc prolapse were randomly assigned to one of two groups: a study group that included 20 patients who received PEMF therapy and a control group that included 20 patients who received placebo treatment. Both groups were evaluated at bases line and after 3 weeks by using a visual analogue scale (VAS) (0-10), somatosensory evoked potentials (SSEPs) for selected dermatomes and Modified Oswestry Low Back Pain Disability Questionnaire (OSW), and findings were compared before and after treatment. Significant differences were observed between both groups before and after application of PEMF therapy relative to VAS (P=0.024), total OSW (PPEMF therapy is an effective method for the conservative treatment of lumbar radiculopathy caused by lumbar disc prolapse. In addition to improvement of clinically observed radicular symptoms, PEMF also seems effective in reducing nerve root compression as evidenced by improvement of SSEP parameters after treatment. © 2012 The Authors International Journal of Rheumatic Diseases © 2012 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  17. Evidence-based use of pulsed electromagnetic field therapy in clinical plastic surgery.

    Science.gov (United States)

    Strauch, Berish; Herman, Charles; Dabb, Richard; Ignarro, Louis J; Pilla, Arthur A

    2009-01-01

    The initial development of pulsed electromagnetic field (PEMF) therapy and its evolution over the last century for use in clinical surgery has been slow, primarily because of lack of scientifically-derived, evidence-based knowledge of the mechanism of action. Our objective was to review the major scientific breakthroughs and current understanding of the mechanism of action of PEMF therapy, providing clinicians with a sound basis for optimal use. A literature review was conducted, including mechanism of action and biologic and clinical studies of PEMF. Using case illustrations, a holistic exposition on the clinical use of PEMF in plastic surgery was performed. PEMF therapy has been used successfully in the management of postsurgical pain and edema, the treatment of chronic wounds, and in facilitating vasodilatation and angiogenesis. Using scientific support, the authors present the currently accepted mechanism of action of PEMF therapy. This review shows that plastic surgeons have at hand a powerful tool with no known side effects for the adjunctive, noninvasive, nonpharmacologic management of postoperative pain and edema. Given the recent rapid advances in development of portable and economical PEMF devices, what has been of most significance to the plastic surgeon is the laboratory and clinical confirmation of decreased pain and swelling following injury or surgery.

  18. Attenuation of interleukin-1beta by pulsed electromagnetic fields after traumatic brain injury.

    Science.gov (United States)

    Rasouli, Jonathan; Lekhraj, Rukmani; White, Nicholas M; Flamm, Eugene S; Pilla, Arthur A; Strauch, Berish; Casper, Diana

    2012-06-21

    Traumatic Brain Injury (TBI) is a major cause of morbidity and mortality in civilian and military populations. Interleukin-1beta (IL-1β) is a pro-inflammatory cytokine with a key role in the inflammatory response following TBI and studies indicate that attenuation of this cytokine improves behavioral outcomes. Pulsed electromagnetic fields (PEMF) can reduce inflammation after soft tissue injuries in animals and humans. Therefore, we explored whether PEMF signals could alter the course of IL-1β production in rats subjected to closed-head contusive weight-drop injuries (Marmarou method) and penetrating needle-stick brain injuries. Protein levels, measured by the Biorad assay, were not altered by injuries or PEMF treatment. In addition, we verified that IL-1β levels in cerebrospinal fluid (CSF) were proportional to injury severity in the contusion model. Results demonstrate that PEMF treatment attenuated IL-1β levels up to 10-fold in CSF within 6h after contusive injury and also significantly suppressed IL-1β within 17-24h after penetrating injury. In contrast, no differences in IL-1β were seen between PEMF-treated and control groups in brain homogenates. To the authors' knowledge, this is the first report of the use of PEMF to modulate an inflammatory cytokine after TBI. These results warrant further studies to assess the effects of PEMF on other inflammatory markers and functional outcomes. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  19. Did high-altitude EMP (electromagnetic pulse) cause the Hawaiian streetlight incident

    Energy Technology Data Exchange (ETDEWEB)

    Vittitoe, C N

    1989-04-01

    Studies of electromagnetic pulse (EMP) effects on civilian and military systems predict results ranging from severe destruction to no damage. Convincing analyses that support either extreme are rare. The Hawaiian streetlight incident associated with the Starfish nuclear burst is the most widely quoted observed damage. We review the streetlight characteristics and estimate the coupling between the Starfish EMP and a particular streetlight circuit identified as one of the few that failed. Evidence indicates that the damage was EMP-generated. The main contributing factors were the azimuthal angle of the circuit relative to the direction of EMP propagation, and the rapid rise of the EMP signal. The azimuthal angle provided coherent buildup of voltage as the EMP swept across the transmission line. The rapid rise allowed substantial excitation before the canceling effects of ground reflections limited the signals. Resulting voltages were at the threshold for causing the observed fuse damage and are consistent with this damage occurring in only some of the strings in the systems. 15 refs., 16 figs., 4 tabs.

  20. The effect of pulsed electromagnetic fields on the acceleration of tooth movement.

    Science.gov (United States)

    Showkatbakhsh, Rahman; Jamilian, Abdolreza; Showkatbakhsh, Mehrdad

    2010-01-01

    Accelerating the speed of orthodontic tooth movement should contribute to the shortening of the treatment period. This study was designed to determine whether a pulsed electromagnetic field (PEMF) affects orthodontic tooth movement. The canines of one side of 10 patients (mean age 23.0 ± 3.3 years) who needed canine retraction were exposed to a PEMF; the canines on the contralateral sides of the same patients were not similarly exposed. After extraction of the maxillary first premolars, both canines were retracted with coil springs. A circuit and a watch battery were used to generate a PEMF (1 Hz). The generator was embedded in a removable appliance. Foil was used to obstruct the contol group from PEMF exposure. Patients were instructed to use the device from the commencement of canine retraction, and it was removed when Class I canine relationship was achieved in either of the canines after 5.0 ± 0.6 months. The changes in the space between the maxillary canine and first molar were measured to indicate the amount of tooth movement. The canine retraction distances were compared by paired t test. Afterward, the treatment plan was continued. With exposure to a PEMF, canine retraction was 1.57 ± 0.83 mm more than the control group (Porthodontic tooth movement. © 2011 BY QUINTESSENCE PUBLISHING CO, INC.

  1. Effects of nuclear electromagnetic pulse (EMP) on synchronous stability of the electric power system

    International Nuclear Information System (INIS)

    Manweiler, R.W.

    1975-11-01

    The effects of a nuclear electromagnetic pulse (EMP) on the synchronous stability of the electric power transmission and distribution systems are evaluated. The various modes of coupling of EMP to the power system are briefly discussed, with particular emphasis on those perturbations affecting the synchronous stability of the transmission system. A brief review of the fundamental concepts of the stability problem is given, with a discussion of the general characteristics of transient analysis. A model is developed to represent single sets as well as repetitive sets of multiple faults on the distribution systems, as might be produced by EMP. The results of many numerical stability calculations are presented to illustrate the transmission system's response from different types of perturbations. The important parameters of both multiple and repetitive faults are studied, including the dependence of the response on the size of the perturbed area, the fault density, and the effective impedance between the fault location and the transmission system. Both major load reduction and the effect of the opening of tie lines at the time of perturbation are also studied. We conclude that there is a high probability that EMP can induce perturbations on the distribution networks causing a large portion of the transmission network in the perturbed area to lose synchronism. The result would be an immediate and massive power failure

  2. Enhanced skin permeation of naltrexone by pulsed electromagnetic fields in human skin in vitro.

    Science.gov (United States)

    Krishnan, Gayathri; Edwards, Jeffrey; Chen, Yan; Benson, Heather A E

    2010-06-01

    The aim of the present study was to evaluate the skin permeation of naltrexone (NTX) under the influence of a pulsed electromagnetic field (PEMF). The permeation of NTX across human epidermis and a silicone membrane in vitro was monitored during and after application of the PEMF and compared to passive application. Enhancement ratios of NTX human epidermis permeation by PEMF over passive diffusion, calculated based on the AUC of cumulative NTX permeation to the receptor compartment verses time for 0-4 h, 4-8 h, and over the entire experiment (0-8 h) were 6.52, 5.25, and 5.66, respectively. Observation of the curve indicated an initial enhancement of NTX permeation compared to passive delivery whilst the PEMF was active (0-4 h). This was followed by a secondary phase after termination of PEMF energy (4-8 h) in which there was a steady increase in NTX permeation. No significant enhancement of NTX penetration across silicone membrane occurred with PEMF application in comparison to passively applied NTX. In a preliminary experiment PEMF enhanced the penetration of 10 nm gold nanoparticles through the stratum corneum as visualized by multiphoton microscopy. This suggests that the channels through which the nanoparticles move must be larger than the 10 nm diameter of these rigid particles. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association

  3. [The effects of electromagnetic pulse on fluidity and lipid peroxidation of mitochondrial membrane].

    Science.gov (United States)

    Wang, Changzhen; Cong, Jianbo; Xian, Hong; Cao, Xiaozhe; Sun, Cunpu; Wu, Ke

    2002-08-01

    To study the effects of intense electromagnetic pulse(EMP) on the biological effects of mitochondrial membrane. Rat liver mitochondrial suspension was exposed to EMP at 60 kV/m level. The changes of membrane lipid fluidity and membrane protein mobility were detected by ESR and spin label technique. Malondialdehyde(MDA) was detected by spectrophotometer. The mobility of membrane protein decreased significantly(P < 0.05). Correlation time (tau c) of control group was (0.501 +/- 0.077) x 10(-9)s, and tau c of EMP group was (0.594 +/- 0.049) x 10(-9)s, indicating that the mobility of protein was restricted. The fluidity of mitochondrial membrane increased significantly(P < 0.05) at the same time. Order parameter(S) of mitochondrial membrane lipid in control group was 0.63 +/- 0.01, while S of EMP group was 0.61 +/- 0.01(P < 0.05). MDA decreased significantly. The mobility and lipid peroxidation of mitochondrial membrane may be disturbed after EMP exposure.

  4. An Investigation on the Effect of Extremely Low Frequency Pulsed Electromagnetic Fields on Human Electrocardiograms (ECGs).

    Science.gov (United States)

    Fang, Qiang; Mahmoud, Seedahmed S; Yan, Jiayong; Li, Hui

    2016-11-23

    For this investigation, we studied the effects of extremely low frequency pulse electromagnetic fields (ELF-PEMF) on the human cardiac signal. Electrocardiograms (ECGs) of 22 healthy volunteers before and after a short duration of ELF-PEMF exposure were recorded. The experiment was conducted under single-blind conditions. The root mean square (RMS) value of the recorded data was considered as comparison criteria. We also measured and analysed four important ECG time intervals before and after ELF-PEMF exposure. Results revealed that the RMS value of the ECG recordings from 18 participants (81.8% of the total participants) increased with a mean value of 3.72%. The increase in ECG voltage levels was then verified by a second experimental protocol with a control exposure. In addition to this, we used hyperbolic T-distributions (HTD) in the analysis of ECG signals to verify the change in the RR interval. It was found that there were small shifts in the frequency-domain signal before and after EMF exposure. This shift has an influence on all frequency components of the ECG signals, as all spectrums were shifted. It is shown from this investigation that a short time exposure to ELF-PEMF can affect the properties of ECG signals. Further study is needed to consolidate this finding and discover more on the biological effects of ELF-PEMF on human physiological processes.

  5. Effects of pulsed electromagnetic field (PEMF) on the tensile biomechanical properties of diabetic wounds at different phases of healing

    OpenAIRE

    Choi, Harry M. C.; Cheing, Alex K. K.; Ng, Gabriel Y. F.; Cheing, Gladys L. Y.

    2018-01-01

    The present study investigated the effects of pulsed electromagnetic field (PEMF) on the tensile biomechanical properties of diabetic wounds at different phases of healing. Two intensities of PEMF were adopted for comparison. We randomly assigned 111 10-week-old male streptozotocin-induced diabetic Sprague-Dawley rats to two PEMF groups and a sham control group. Six-millimetre biopsy punched full thickness wounds were made on the lateral side of their hindlimbs. The PEMF groups received activ...

  6. Generation and propagation of an electromagnetic pulse in the Trigger experiment and its possible role in electron acceleration

    Science.gov (United States)

    Kelley, M. C.; Kintner, P. M.; Kudeki, E.; Holmgren, G.; Bostrom, R.; Fahleson, U. V.

    1980-01-01

    Instruments onboard the Trigger payload detected a large-amplitude, low-frequency, electric field pulse which was observed with a time delay consistent only with an electromagnetic wave. A model for this perturbation is constructed, and the associated field-aligned current is calculated as a function of altitude. This experiment may simulate the acceleration mechanism which results in the formation of auroral arcs, and possibly even other events in cosmic plasmas.

  7. Pulsed electromagnetic field: an organic compatible method to promote plant growth and yield in two corn types.

    Science.gov (United States)

    Bilalis, Dimitrios J; Katsenios, Nikolaos; Efthimiadou, Aspasia; Karkanis, Anestis

    2012-12-01

    Pre-sowing treatment of pulsed electromagnetic fields was used in corn seeds, in both indoor and outdoor conditions, in order to investigate the effect on plant growth and yield. The results of this research showed that pulsed electromagnetic fields can enhance plant characteristics, both under controlled environmental conditions and uncontrolled field conditions. The two varieties responded differently in the duration of magnetic field. Seeds were treated for 0, 15, 30, and 45 min with pulsed electromagnetic field (MF-0, MF-15, MF-30, and MF-45). Common corn variety performed better results in MF-30 treatment, while sweet corn variety performed better in MF-45 treatment. Magnetic field improved germination percentage, vigor, chlorophyll content, leaf area, plant fresh and dry weight, and finally yields. In the very interesting measurement of yield, seeds that have been exposed to magnetic field for 30 and 45 min have been found to perform the best results with no statistical differences among them. Another interesting finding was in root dry weight measurements, where magnetic field has a negative impact in MF-30 treatment in both hybrids, however without affecting other measurements. Enhancements on plant characteristics with economic impact on producer's income could be the future of a modern, organic, and sustainable agriculture.

  8. Unprecedentedly strong and narrow electromagnetic emissions stimulated by high-frequency radio waves in the ionosphere.

    Science.gov (United States)

    Norin, L; Leyser, T B; Nordblad, E; Thidé, B; McCarrick, M

    2009-02-13

    Experimental results of secondary electromagnetic radiation, stimulated by high-frequency radio waves irradiating the ionosphere, are reported. We have observed emission peaks, shifted in frequency up to a few tens of Hertz from radio waves transmitted at several megahertz. These emission peaks are by far the strongest spectral features of secondary radiation that have been reported. The emissions are attributed to stimulated Brillouin scattering, long predicted but hitherto never unambiguously identified in high-frequency ionospheric interaction experiments. The experiments were performed at the High-Frequency Active Auroral Research Program (HAARP), Alaska, USA.

  9. The significance of a new correspondence principle for electromagnetic interaction in strong optical field ionisation

    International Nuclear Information System (INIS)

    Boreham, B. W.; Hora, H.

    1997-01-01

    We have recently developed a correspondence principle for electromagnetic interaction. When applied to laser interactions with electrons this correspondence principle identifies a critical laser intensity I*. This critical intensity is a transition intensity separating classical mechanical and quantum mechanical interaction regimes. In this paper we discuss the further application of I* to the interaction of bound electrons in atoms. By comparing I* with the ionisation threshold intensities as calculated from a cycle-averaged simple-atom model we conclude that I* can be usefully interpreted as a lower bound to the classical regime in studies of ionisation of gas atoms by intense laser beams

  10. Double atom ionization by multicharged ions and strong electromagnetic field: correlation effects in a continuous spectrum

    International Nuclear Information System (INIS)

    Presnyakov, L.P.; Uskov, D.B.

    1997-01-01

    The nonstationary theory of double ionization of two-electron atoms in collisions with multicharged ions or under the impact of intensive electromagnetic field is developed. The approach, making it possible to study both problems by uniform method, is formulated. The two-electron wave function of continuous spectrum, accounting for interaction of electrons with atomic nucleus, external ionizer and between themselves is obtained. The calculation results on the helium atoms double ionization by multicharged ions is a good quantitative agreement with available experimental data

  11. Compression of TW class laser pulses in a planar hollow waveguide for applications in strong-field physics

    Science.gov (United States)

    Jarnac, Amélie; Brizuela, Fernando; Heyl, Christoph M.; Rudawski, Piotr; Campi, Filippo; Kim, Byunghoon; Rading, Linnea; Johnsson, Per; Mysyrowicz, André; L'Huillier, Anne; Houard, Aurélien; Arnold, Cord L.

    2014-12-01

    We demonstrate pulse post-compression of a TW class chirped pulse amplification laser employing a gas-filled planar hollow waveguide. A waveguide throughput of 80% is achieved for 50 mJ input pulse energy. Good focusability is found and after compression with chirped mirrors a pulse duration of sub-15 fs is measured in the beam center. Whereas a total energy efficiency of ≈70% should be achievable, our post-compressor currently delivers 20 mJ output pulse energy (≈40% efficiency), mostly limited by apertures of chirped mirrors and vacuum windows. The viability of the planar hollow waveguide compression scheme for applications in strong-field physics is demonstrated by generating high-order harmonics in a pulsed Ar gas cell. Contribution to the Topical Issue "X-ray Generation from Ultrafast Lasers", edited by Germán J. de Valcárcel, Luis Roso and Amelle Zaïr.

  12. Influence of strong magnetic fields on laser pulse propagation in underdense plasma

    Science.gov (United States)

    Wilson, T. C.; Li, F. Y.; Weikum, M.; Sheng, Z. M.

    2017-06-01

    We examine the interaction between intense laser pulses and strongly magnetised plasmas in the weakly relativistic regime. An expression for the electron Lorentz factor coupling both relativistic and cyclotron motion nonlinearities is derived for static magnetic fields along the laser propagation axis. This is applied to predict modifications to the refractive index, critical density, group velocity dispersion and power threshold for relativistic self-focusing. It is found that electron quiver response is enhanced under right circularly-polarised light, decreasing the power threshold for various instabilities, while a dampening effect occurs under left circularly-polarised light, increasing the power thresholds. Derived theoretical predictions are tested by one- and three-dimensional particle-in-cell simulations.

  13. Dependence the Integrated Energy of the Electromagnetic Response from Excitation Pulse Duration for Epoxy Samples With Sand Filler

    Science.gov (United States)

    Surzhikov, V. P.; Demikhova, A. A.

    2017-01-01

    Results of research of influence of the excitation pulse duration on the parameters of the electromagnetic response of epoxy samples with filler the quartz sand presented in the paper. The electric component of a response was registered by the capacitive sensors using a differential amplifier. Measurements were carried out at two frequencies of the master generator of 65 kHz and 74 kHz. The pulse duration was changing from 10 to 100 microseconds. The stepped sort of dependence of the integrated oscillations energy in the response from duration of the excitation pulse was discovered. The conclusion was made about the determining role of the normal oscillations in formation of such dependence.

  14. Stimulation of osteogenic differentiation in human osteoprogenitor cells by pulsed electromagnetic fields: an in vitro study

    Directory of Open Access Journals (Sweden)

    Jansen Justus HW

    2010-08-01

    Full Text Available Abstract Background Although pulsed electromagnetic field (PEMF stimulation may be clinically beneficial during fracture healing and for a wide range of bone disorders, there is still debate on its working mechanism. Mesenchymal stem cells are likely mediators facilitating the observed clinical effects of PEMF. Here, we performed in vitro experiments to investigate the effect of PEMF stimulation on human bone marrow-derived stromal cell (BMSC metabolism and, specifically, whether PEMF can stimulate their osteogenic differentiation. Methods BMSCs derived from four different donors were cultured in osteogenic medium, with the PEMF treated group being continuously exposed to a 15 Hz, 1 Gauss EM field, consisting of 5-millisecond bursts with 5-microsecond pulses. On culture day 1, 5, 9, and 14, cells were collected for biochemical analysis (DNA amount, alkaline phosphatase activity, calcium deposition, expression of various osteoblast-relevant genes and activation of extracellular signal-regulated kinase (ERK signaling. Differences between treated and control groups were analyzed using the Wilcoxon signed rank test, and considered significant when p Results Biochemical analysis revealed significant, differentiation stage-dependent, PEMF-induced differences: PEMF increased mineralization at day 9 and 14, without altering alkaline phosphatase activity. Cell proliferation, as measured by DNA amounts, was not affected by PEMF until day 14. Here, DNA content stagnated in PEMF treated group, resulting in less DNA compared to control. Quantitative RT-PCR revealed that during early culture, up to day 9, PEMF treatment increased mRNA levels of bone morphogenetic protein 2, transforming growth factor-beta 1, osteoprotegerin, matrix metalloproteinase-1 and -3, osteocalcin, and bone sialoprotein. In contrast, receptor activator of NF-κB ligand expression was primarily stimulated on day 14. ERK1/2 phosphorylation was not affected by PEMF stimulation

  15. Pulsed Electromagnetic Fields Enhance Bone Morphogenetic Protein-2 Dependent-Bone Regeneration.

    Science.gov (United States)

    Yang, Hoon Joo; Kim, Ri Youn; Hwang, Soon Jung

    2015-10-01

    The use of recombinant human bone morphogenetic protein-2 (rhBMP-2) for the purpose of promoting bone regeneration is emerging; however, the high dose of rhBMP-2 required in humans is accompanied by several limitations, including bone resorption and swelling. To reduce the dose of rhBMP-2 required, the applicability of pulsed electromagnetic fields (PEMF) was evaluated using a rat calvarial defect model. After creating an 8-mm-diameter calvarial bone defect, a collagen sponge soaked in different concentrations (0, 2.5, 5, 10 μg) of rhBMP-2 was implanted at the defect area. One week after surgery, PEMF was applied for 8 h/day over 5 days in an experimental group of animals (n = 28) using a width of 12 μs, a pulse frequency of 60 Hz, and a magnetic intensity of 10 G. Animals were sacrificed 4 weeks after surgery and assessed by microcomputed tomography and histological and immunohistochemical analyses. In the absence of application of PEMF, bone volume, bone mineral density, trabecular thickness, trabecular number, and trabecular separation, all showed statistically significant differences, depending on the concentration of rhBMP-2 utilized (p PEMF accelerated bone regeneration in the groups that received 0, 2.5, and 5 μg rhBMP-2 (p PEMF. Groups receiving no rhBMP-2 showed distinct bone regeneration in the central zone of the bone defect when treated with PEMF, whereas they failed to bridge the defect space without PEMF. Among the groups without PEMF, soft tissue infiltrations from the outer surface on the skin side were common. Among groups with PEMF, the groups receiving 5 and 10 μg rhBMP-2 displayed denser bone with significantly reduced dead spaces. The application of PEMF did not result in an accelerated effect on bone regeneration in groups treated with 10 μg rhBMP-2. Therefore, our data demonstrate that PEMF can promote bone regeneration in animals treated with a low concentration of rhBMP-2.

  16. Acceleration of neutral atoms in strong short-pulse laser fields.

    Science.gov (United States)

    Eichmann, U; Nubbemeyer, T; Rottke, H; Sandner, W

    2009-10-29

    A charged particle exposed to an oscillating electric field experiences a force proportional to the cycle-averaged intensity gradient. This so-called ponderomotive force plays a major part in a variety of physical situations such as Paul traps for charged particles, electron diffraction in strong (standing) laser fields (the Kapitza-Dirac effect) and laser-based particle acceleration. Comparably weak forces on neutral atoms in inhomogeneous light fields may arise from the dynamical polarization of an atom; these are physically similar to the cycle-averaged forces. Here we observe previously unconsidered extremely strong kinematic forces on neutral atoms in short-pulse laser fields. We identify the ponderomotive force on electrons as the driving mechanism, leading to ultrastrong acceleration of neutral atoms with a magnitude as high as approximately 10(14) times the Earth's gravitational acceleration, g. To our knowledge, this is by far the highest observed acceleration on neutral atoms in external fields and may lead to new applications in both fundamental and applied physics.

  17. The CO/NOx emissions of swirled, strongly pulsed jet diffusion flames

    KAUST Repository

    Liao, Ying-Hao

    2014-05-28

    The CO and NOx exhaust emissions of swirled, strongly pulsed, turbulent jet diffusion flames were studied experimentally in a coflow swirl combustor. Measurements of emissions were performed on the combustor centerline using standard emission analyzers combined with an aspirated sampling probe located downstream of the visible flame tip. The highest levels of CO emissions are generally found for compact, isolated flame puffs, which is consistent with the quenching due to rapid dilution with excess air. The imposition of swirl generally results in a decrease in CO levels by up to a factor of 2.5, suggesting more rapid and compete fuel/air mixing by imposing swirl in the coflow stream. The levels of NO emissions for most cases are generally below the steady-flame value. The NO levels become comparable to the steady-flame value for sufficiently short jet-off times. The swirled coflow air can, in some cases, increase the NO emissions due to a longer combustion residence time due to the flow recirculation within the swirl-induced recirculation zone. Scaling relations, when taking into account the impact of air dilution over an injection cycle on the flame length, reveal a strong correlation between the CO emissions and the global residence time. However, the NO emissions do not successfully correlate with the global residence time. For some specific cases, a compact flame with a simultaneous decrease in both CO and NO emissions compared to the steady flames was observed. © Copyright © Taylor & Francis Group, LLC.

  18. Effects of pulsed electromagnetic field on intervertebral disc cell apoptosis in rats.

    Science.gov (United States)

    Reihani Kermani, Hamed; Pourghazi, Mehdi; Mahani, Saeed Esmaeili

    2014-09-01

    Despite numerous studies on pulsed electromagnetic field (PEMF) application, its effects of PEMF on intervertebral disc (IVD) have not yet been investigated in vivo. Accordingly, the effects of PEMF upon IVD in rats were evaluated through molecular surveys. Rats were divided into six groups: Group I and II were exposed to low and high frequency of PEMF (LF and HF, respectively). Group III and IV underwent induced disc degeneration and were exposed to low and high frequency of PEMF (LF/IDD and HF/IDD, respectively). Group V underwent induced disc degeneration (IDD), and group VI was control. The values of caspase 3, Bax, Bcl-2 and β-actin band density, as cell apoptotic markers, were obtained from band densitometry. Our results showed that the value of cleaved caspase-3 of cells and Bax/Bcl-2 ratio in IDD group increased significantly compared to the control group (p < 0.001). The value of cleaved caspase-3 and Bax/Bcl-2 ratio decreased significantly in LF/IDD and HF/IDD groups compared to IDD group (p < 0.05). No significant increase was seen in the cell apoptotic markers in the groups just exposed to PEMF compared to the control group. There was also no significant decrease in the Bax/Bcl-2 ratio in HF/IDD and LF/IDD groups compared to the control group. These data suggest that PEMF attenuates degenerative processes in rat's intervertebral discs and has no effect on normal discs. Regulations of the expression of apoptotic proteins may be one of the mechanisms by which PEMF is effective in reduce disc degeneration.

  19. Low intensity and frequency pulsed electromagnetic fields selectively impair breast cancer cell viability.

    Directory of Open Access Journals (Sweden)

    Sara Crocetti

    Full Text Available INTRODUCTION: A common drawback of many anticancer therapies is non-specificity in action of killing. We investigated the potential of ultra-low intensity and frequency pulsed electromagnetic fields (PEMFs to kill breast cancer cells. Our criteria to accept this technology as a potentially valid therapeutic approach were: 1 cytotoxicity to breast cancer cells and; 2 that the designed fields proved innocuous to healthy cell classes that would be exposed to the PEMFs during clinical treatment. METHODS: MCF7 breast cancer cells and their normal counterparts, MCF10 cells, were exposed to PEMFs and cytotoxic indices measured in order to design PEMF paradigms that best kill breast cancer cells. The PEMF parameters tested were: 1 frequencies ranging from 20 to 50 Hz; 2 intensities ranging from 2 mT to 5 mT and; 3 exposure durations ranging from 30 to 90 minutes per day for up to three days to determine the optimum parameters for selective cancer cell killing. RESULTS: We observed a discrete window of vulnerability of MCF7 cells to PEMFs of 20 Hz frequency, 3 mT magnitude and exposure duration of 60 minutes per day. The cell damage accrued in response to PEMFs increased with time and gained significance after three days of consecutive daily exposure. By contrast, the PEMFs parameters determined to be most cytotoxic to breast cancer MCF-7 cells were not damaging to normal MCF-10 cells. CONCLUSION: Based on our data it appears that PEMF-based anticancer strategies may represent a new therapeutic approach to treat breast cancer without affecting normal tissues in a manner that is non-invasive and can be potentially combined with existing anti-cancer treatments.

  20. Low Intensity and Frequency Pulsed Electromagnetic Fields Selectively Impair Breast Cancer Cell Viability

    Science.gov (United States)

    Crocetti, Sara; Beyer, Christian; Schade, Grit; Egli, Marcel; Fröhlich, Jürg; Franco-Obregón, Alfredo

    2013-01-01

    Introduction A common drawback of many anticancer therapies is non-specificity in action of killing. We investigated the potential of ultra-low intensity and frequency pulsed electromagnetic fields (PEMFs) to kill breast cancer cells. Our criteria to accept this technology as a potentially valid therapeutic approach were: 1) cytotoxicity to breast cancer cells and; 2) that the designed fields proved innocuous to healthy cell classes that would be exposed to the PEMFs during clinical treatment. Methods MCF7 breast cancer cells and their normal counterparts, MCF10 cells, were exposed to PEMFs and cytotoxic indices measured in order to design PEMF paradigms that best kill breast cancer cells. The PEMF parameters tested were: 1) frequencies ranging from 20 to 50 Hz; 2) intensities ranging from 2 mT to 5 mT and; 3) exposure durations ranging from 30 to 90 minutes per day for up to three days to determine the optimum parameters for selective cancer cell killing. Results We observed a discrete window of vulnerability of MCF7 cells to PEMFs of 20 Hz frequency, 3 mT magnitude and exposure duration of 60 minutes per day. The cell damage accrued in response to PEMFs increased with time and gained significance after three days of consecutive daily exposure. By contrast, the PEMFs parameters determined to be most cytotoxic to breast cancer MCF-7 cells were not damaging to normal MCF-10 cells. Conclusion Based on our data it appears that PEMF-based anticancer strategies may represent a new therapeutic approach to treat breast cancer without affecting normal tissues in a manner that is non-invasive and can be potentially combined with existing anti-cancer treatments. PMID:24039828

  1. Therapeutic effects of whole-body devices applying pulsed electromagnetic fields (PEMF): a systematic literature review.

    Science.gov (United States)

    Hug, Kerstin; Röösli, Martin

    2012-02-01

    Pulsed electromagnetic fields (PEMF) delivered by whole-body mats are promoted in many countries for a wide range of therapeutic applications and for enhanced well-being. However, neither the therapeutic efficacy nor the potential health hazards caused by these mats have been systematically evaluated. We conducted a systematic review of trials investigating the therapeutic effects of low-frequency PEMF devices. We were interested in all health outcomes addressed so far in randomized, sham-controlled, double-blind trials. In total, 11 trials were identified. They were focused on osteoarthritis of the knee (3 trials) or the cervical spine (1), fibromyalgia (1), pain perception (2), skin ulcer healing (1), multiple sclerosis-related fatigue (2), or heart rate variability and well-being (1). The sample sizes of the trials ranged from 12 to 71 individuals. The observation period lasted 12 weeks at maximum, and the applied magnetic flux densities ranged from 3.4 to 200 µT. In some trials sporadic positive effects on health were observed. However, independent confirmation of such singular findings was lacking. We conclude that the scientific evidence for therapeutic effects of whole-body PEMF devices is insufficient. Acute adverse effects have not been reported. However, adverse effects occurring after long-term application have not been studied so far. In summary, the therapeutic use of low-frequency whole-body PEMF devices cannot be recommended without more scientific evidence from high-quality, double-blind trials. Copyright © 2011 Wiley Periodicals, Inc.

  2. Pulsed electromagnetic fields in knee osteoarthritis: a double blind, placebo-controlled, randomized clinical trial.

    Science.gov (United States)

    Bagnato, Gian Luca; Miceli, Giovanni; Marino, Natale; Sciortino, Davide; Bagnato, Gian Filippo

    2016-04-01

    This trial aimed to test the effectiveness of a wearable pulsed electromagnetic fields (PEMF) device in the management of pain in knee OA patients. In this randomized [with equal randomization (1:1)], double-blind, placebo-controlled clinical trial, patients with radiographic evidence of knee OA and persistent pain higher than 40 mm on the visual analog scale (VAS) were recruited. The trial consisted of 12 h daily treatment for 1 month in 60 knee OA patients. The primary outcome measure was the reduction in pain intensity, assessed through VAS and WOMAC scores. Secondary outcomes included quality of life assessment through the 36-item Medical Outcomes Study Short-Form version 2 (SF-36 v2), pressure pain threshold (PPT) and changes in intake of NSAIDs/analgesics. Sixty-six patients were included, and 60 completed the study. After 1 month, PEMF induced a significant reduction in VAS pain and WOMAC scores compared with placebo. Additionally, pain tolerance, as expressed by PPT changes, and physical health improved in PEMF-treated patients. A mean treatment effect of -0.73 (95% CI - 1.24 to - 0.19) was seen in VAS score, while the effect size was -0.34 (95% CI - 0.85 to 0.17) for WOMAC score. Twenty-six per cent of patients in the PEMF group stopped NSAID/analgesic therapy. No adverse events were detected. These results suggest that PEMF therapy is effective for pain management in knee OA patients and also affects pain threshold and physical functioning. Future larger studies, including head-to-head studies comparing PEMF therapy with standard pharmacological approaches in OA, are warranted. ClinicalTrials.gov, http://www.clinicaltrials.gov, NCT01877278. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Rheumatology.

  3. Transcranial low voltage pulsed electromagnetic fields in patients with treatment-resistant depression.

    Science.gov (United States)

    Martiny, Klaus; Lunde, Marianne; Bech, Per

    2010-07-15

    Approximately 30% of patients with depression are resistant to antidepressant drugs. Repetitive transcranial magnetic stimulation (rTMS) has been found effective in combination with antidepressants in this patient group. The aim of this study was to evaluate the antidepressant effect of a new principle using low-intensity transcranially applied pulsed electromagnetic fields (T-PEMF) in combination with antidepressants in patients with treatment-resistant depression. This was a sham-controlled double-blind study comparing 5 weeks of active or sham T-PEMF in patients with treatment-resistant major depression. The antidepressant treatment, to which patients had been resistant, was unchanged 4 weeks before and during the study period. Weekly assessments were performed using both clinician-rated and patient-rated scales. The T-PEMF equipment was designed as a helmet containing seven separate coils located over the skull that generated an electrical field in tissue with orders of magnitude weaker than those generated by rTMS equipment. Patients on active T-PEMF showed a clinically and statistically significant better outcome than patients treated with sham T-PEMF, with an onset of action within the first weeks of therapy. Effect size on the Hamilton 17-item Depression Rating Scale was .62 (95% confidence interval .21-1.02). Treatment-emergent side effects were few and mild. The T-PEMF treatment was superior to sham treatment in patients with treatment-resistant depression. Few side effects were observed. Mechanism of the antidepressant action, in light of the known effects of PEMF stimulation to the brain, is discussed. Copyright 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  4. [Effect of electromagnetic pulse irradiation on structure and function of Leydig cells in mice].

    Science.gov (United States)

    Wang, Shui-Ming; Wang, De-Wen; Peng, Rui-Yun; Gao, Ya-Bing; Yang, Yi; Hu, Wen-Hua; Chen, Hao-Yu; Zhang, You-Ren; Gao, Yan

    2003-08-01

    To explore the effect of electromagnetic pulse (EMP) irradiation on structure and function of Leydig cells in mice. One hundred and fourteen male Kunming mice were randomly divided into irradiated and control group, the former radiated generally by 8 x 10(3) V/m, 2 x 10(4) V/m and 6 x 10(4) V/m EMP respectively five times within two minutes. Pathological changes of Leydig cells were observed by light and electron microscope. Serum testosterone (T), luteinizing hormone (LH) and estradiol (E2) were measured dynamically by radioimmunoassay at 6 h, 1 d, 3 d, 7 d, 14 d and 28 d after irradiation. Main pathological changes were edema and vacuolation, swelling of cytoplasmic mitochondria, reduce of lipid droplets, pale staining of most of lipid droplets, and partial or complete cavitation of lipid droplets in Leydig cells within 28 days after EMP radiation. Compared with normal controls, serum T decreased in all in different degrees within 28 days, and dropped significantly at 6 h-14 d, 6 h-7 d and 1 d-28 d after 8 x 10(3) V/m, 2 x 10(4) V/m and 6 x 10(4) V/m EMP irradiation(P < 0.05 or P < 0.01). EMP irradiation caused no significant changes in serum LH and E2. Leydig cells are among those that are the most susceptible to EMP irradiation. EMP irradiation may cause significant injury in structure and function of Leydig cells in mice, whose earlier and continuous effect is bound to affect sexual function and sperm production.

  5. Electromagnetism

    CERN Document Server

    Grant, Ian S

    1990-01-01

    The Manchester Physics Series General Editors: D. J. Sandiford; F. Mandl; A. C. Phillips Department of Physics and Astronomy, University of Manchester Properties of Matter B. H. Flowers and E. Mendoza Optics Second Edition F. G. Smith and J. H. Thomson Statistical Physics Second Edition F. Mandl Electromagnetism Second Edition I. S. Grant and W. R. Phillips Statistics R. J. Barlow Solid State Physics Second Edition J. R. Hook and H. E. Hall Quantum Mechanics F. Mandl Particle Physics Second Edition B. R. Martin and G. Shaw the Physics of Stars Second Edition A. C. Phillips Computing for Scient

  6. Instability of collective strong-interaction phenomena in hadron production as a possible origin of the weak and electromagnetic interactions

    International Nuclear Information System (INIS)

    Arnold, R.C.

    1975-12-01

    A systematic calculus of long-range Regge cut effects in multiparticle production is constructed in the form of an infrared-divergent stochastic field theory. Total cross sections and two-body overlap integrals in such a theory may depend very sensitively upon internal quantum-numbers of incident particles, resulting in a strong symmetry breaking at ultra-high energies. Such symmetry violations will influence low energy processes through dispersion relations, and a bootstrap of weak interactions becomes possible. A rough analytic estimate of the scale of thresholds for such effects yields a BCS-type gap equation, which expresses the scale of weak and electromagnetic couplings in terms of purely strong-interaction parameters

  7. Strong-field Breit–Wheeler pair production in two consecutive laser pulses with variable time delay

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, Martin J.A.; Müller, Carsten, E-mail: c.mueller@tp1.uni-duesseldorf.de

    2017-03-10

    Photoproduction of electron–positron pairs by the strong-field Breit–Wheeler process in an intense laser field is studied. The laser field is assumed to consist of two consecutive short pulses, with a variable time delay in between. By numerical calculations within the framework of scalar quantum electrodynamics, we demonstrate that the time delay exerts a strong impact on the pair-creation probability. For the case when both pulses are identical, the effect is traced back to the relative quantum phase of the interfering S-matrix amplitudes and explained within a simplified analytical model. Conversely, when the two laser pulses differ from each other, the pair-creation probability depends not only on the time delay but, in general, also on the temporal order of the pulses.

  8. The electromagnetic radiation fields of a relativistic electron avalanche with special attention to the origin of narrow bipolar pulses

    Science.gov (United States)

    Cooray, G. V.; Cooray, G. K.

    2011-12-01

    Gurevich et al. [1] postulated that the source of narrow bipolar pulses, a class of high energy pulses that occur during thunderstorms, could be a runaway electron avalanche driven by the intense electric fields of a thunderstorm. Recently, Watson and Marshall [2] used the modified transmission line model to test the mechanism of the source of narrow bipolar pulses. In a recent paper, Cooray and Cooray [3] demonstrated that the electromagnetic fields of accelerating charges could be used to evaluate the electromagnetic fields from electrical discharges if the temporal and spatial variation of the charges in the discharge is known. In the present study, those equations were utilized to evaluate the electromagnetic fields generated by a relativistic electron avalanche. In the analysis it is assumed that all the electrons in the avalanche are moving with the same speed. In other words, the growth or the decay of the number of electrons takes place only at the head of the avalanche. It is shown that the radiation is emanating only from the head of the avalanche where electrons are being accelerated. It is also shown that an analytical expression for the radiation field of the avalanche at any distance can be written directly in terms of the e-folding length of the avalanche. This makes it possible to extract directly the spatial variation of the e-folding length of the avalanche from the measured radiation fields. In the study this model avalanche was used to investigate whether it can be used to describe the measured electromagnetic fields of narrow bipolar pulses. The results obtained are in reasonable agreement with the two station data of Eack [4] for speeds of propagation around (2 - 2.5) x 10^8 m/s and when the propagation effects on the electric fields measured at the distant station is taken into account. [1] Gurevich et al. (2004), Phys. Lett. A., 329, pp. 348 -361. [2] Watson, S. S. and T. C. Marshall (2007), Geophys. Res. Lett., Vol. 34, L04816, doi: 10

  9. Electrons in a relativistic-intensity laser field: generation of zeptosecond electromagnetic pulses and energy spectrum of the accelerated electrons

    International Nuclear Information System (INIS)

    Andreev, A A; Galkin, A L; Kalashnikov, M P; Korobkin, V V; Romanovsky, Mikhail Yu; Shiryaev, O B

    2011-01-01

    We study the motion of an electron and emission of electromagnetic waves by an electron in the field of a relativistically intense laser pulse. The dynamics of the electron is described by the Newton equation with the Lorentz force in the right-hand side. It is shown that the electrons may be ejected from the interaction region with high energy. The energy spectrum of these electrons and the technique of using the spectrum to assess the maximal intensity in the focus are analysed. It is found that electromagnetic radiation of an electron moving in an intense laser field occurs within a small angle around the direction of the electron trajectory tangent. The tangent quickly changes its direction in space; therefore, electromagnetic radiation of the electron in the far-field zone in a certain direction in the vicinity of the tangent is a short pulse with a duration as short as zeptoseconds. The calculation of the temporary and spectral distribution of the radiation field is carried out. (superintense laser fields)

  10. Janus magneto-electric nanosphere dimers exhibiting unidirectional visible light scattering and strong electromagnetic field enhancement.

    Science.gov (United States)

    Wang, Hao; Liu, Pu; Ke, Yanlin; Su, Yunkun; Zhang, Lei; Xu, Ningsheng; Deng, Shaozhi; Chen, Huanjun

    2015-01-27

    Steering incident light into specific directions at the nanoscale is very important for future nanophotonics applications of signal transmission and detection. A prerequisite for such a purpose is the development of nanostructures with high-efficiency unidirectional light scattering properties. Here, from both theoretical and experimental sides, we conceived and demonstrated the unidirectional visible light scattering behaviors of a heterostructure, Janus dimer composed of gold and silicon nanospheres. By carefully adjusting the sizes and spacings of the two nanospheres, the Janus dimer can support both electric and magnetic dipole modes with spectral overlaps and comparable strengths. The interference of these two modes gives rise to the narrow-band unidirectional scattering behaviors with enhanced forward scattering and suppressed backward scattering. The directionality can further be improved by arranging the dimers into one-dimensional chain structures. In addition, the dimers also show remarkable electromagnetic field enhancements. These results will be important not only for applications of light emitting devices, solar cells, optical filters, and various surface enhanced spectroscopies but also for furthering our understanding on the light-matter interactions at the nanoscale.

  11. Propagation of a strong x-ray pulse: Pulse compression, stimulated Raman scattering, amplified spontaneous emission, lasing without inversion, and four-wave mixing

    International Nuclear Information System (INIS)

    Sun Yuping; Wang Chuankui; Liu Jicai; Gel'mukhanov, Faris

    2010-01-01

    We study the compression of strong x-ray pulses from x-ray free-electron lasers (XFELs) propagating through the resonant medium of atomic argon. The simulations are based on the three-level model with the frequency of the incident x-ray pulse tuned in the 2p 3/2 -4s resonance. The pulse propagation is accompanied by the self-seeded stimulated resonant Raman scattering (SRRS). The SRRS starts from two channels of amplified spontaneous emission (ASE), 4s-2p 3/2 and 3s-2p 3/2 , which form the extensive ringing pattern and widen the power spectrum. The produced seed field triggers the Stokes ASE channel 3s-2p 3/2 . The population inversion is quenched for longer propagation distances where the ASE is followed by the lasing without inversion (LWI), which amplifies the Stokes component. Both ASE and LWI reshape the input pulse: The compressed front part of the pulse (up to 100 as) is followed by the long tail of the ringing and beating between the pump and Stokes frequencies. The pump pulse also generates weaker Stokes and anti-Stokes fields caused by four-wave mixing. These four spectral bands have fine structures caused by the dynamical Stark effect. A slowdown of the XFEL pulse up to 78% of the speed of light in vacuum is found because of a large nonlinear refractive index.

  12. The propagation of a strong x-ray pulse followed by pulse slowdown and compression, amplified spontaneous emission and lasing without inversion

    Energy Technology Data Exchange (ETDEWEB)

    Sun Yuping; Liu Jicai; Gel' mukhanov, Faris, E-mail: jicai@theochem.kth.s [Department of Theoretical Chemistry, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm (Sweden)

    2009-10-28

    We study self-seeded stimulated resonant x-ray Raman scattering and show a 20-fold compression of the strong XFEL pulse propagating through the resonant medium of atomic argon with the frequency (244.3 eV) tuned to the 2p{sub 3/2}-4s resonance. The strong x-ray pulse inverts the medium and produces an extensive ringing tail which widens the power spectrum. Newly created seed field triggers the Stokes channel 3s-2p{sub 3/2} of amplified spontaneous emission. The population inversions are quenched for longer propagation distances where lasing without inversion enhances the Stokes component. The pump pulse also generates weaker Stokes and anti-Stokes fields caused by four-wave mixing. The group velocity is decreased up to 78% of the speed of light in vacuum. (fast track communication)

  13. The propagation of a strong x-ray pulse followed by pulse slowdown and compression, amplified spontaneous emission and lasing without inversion

    International Nuclear Information System (INIS)

    Sun Yuping; Liu Jicai; Gel'mukhanov, Faris

    2009-01-01

    We study self-seeded stimulated resonant x-ray Raman scattering and show a 20-fold compression of the strong XFEL pulse propagating through the resonant medium of atomic argon with the frequency (244.3 eV) tuned to the 2p 3/2 -4s resonance. The strong x-ray pulse inverts the medium and produces an extensive ringing tail which widens the power spectrum. Newly created seed field triggers the Stokes channel 3s-2p 3/2 of amplified spontaneous emission. The population inversions are quenched for longer propagation distances where lasing without inversion enhances the Stokes component. The pump pulse also generates weaker Stokes and anti-Stokes fields caused by four-wave mixing. The group velocity is decreased up to 78% of the speed of light in vacuum. (fast track communication)

  14. Damage effect and mechanism of the GaAs pseudomorphic high electron mobility transistor induced by the electromagnetic pulse

    Science.gov (United States)

    Xiao-Wen, Xi; Chang-Chun, Chai; Gang, Zhao; Yin-Tang, Yang; Xin-Hai, Yu; Yang, Liu

    2016-04-01

    The damage effect and mechanism of the electromagnetic pulse (EMP) on the GaAs pseudomorphic high electron mobility transistor (PHEMT) are investigated in this paper. By using the device simulation software, the distributions and variations of the electric field, the current density and the temperature are analyzed. The simulation results show that there are three physical effects, i.e., the forward-biased effect of the gate Schottky junction, the avalanche breakdown, and the thermal breakdown of the barrier layer, which influence the device current in the damage process. It is found that the damage position of the device changes with the amplitude of the step voltage pulse. The damage appears under the gate near the drain when the amplitude of the pulse is low, and it also occurs under the gate near the source when the amplitude is sufficiently high, which is consistent with the experimental results. Project supported by the National Basic Research Program of China (Grant No. 2014CB339900), and the Open Fund of Key Laboratory of Complex Electromagnetic Environment Science and Technology, China Academy of Engineering Physics (CAEP) (Grant No. 2015-0214.XY.K).

  15. Effect of Higher Order Axial Electron Temperature on Self-Focusing of Electromagnetic Pulsed Beam in Collisional Plasma

    International Nuclear Information System (INIS)

    Xia Xiongping; Yi Lin

    2012-01-01

    Effect of higher order axial electron temperature on self-focusing of electromagnetic pulsed beam in collisional plasma is investigated. It is shown that higher order axial electron temperature T p4 is not trivial than T p0 and T p2 , which can modify slightly radial redistribution of electron density and increases effective dielectric constant. As a result, on one hand, slightly reduce electromagnetic beam self-focusing in the course of oscillatory convergence, on the other hand, quicken beam divergence in the course of steady divergence, i.e., higher order axial electron temperature T p4 can decrease the influence of collisional nonlinearity in collisional plasma. (physics of gases, plasmas, and electric discharges)

  16. Turbulent structure and dynamics of swirled, strongly pulsed jet diffusion flames

    KAUST Repository

    Liao, Ying-Hao

    2013-11-02

    The structure and dynamics of swirled, strongly pulsed, turbulent jet diffusion flames were examined experimentally in a co-flow swirl combustor. The dynamics of the large-scale flame structures, including variations in flame dimensions, the degree of turbulent flame puff interaction, and the turbulent flame puff celerity were determined from high-speed imaging of the luminous flame. All of the tests presented here were conducted with a fixed fuel injection velocity at a Reynolds number of 5000. The flame dimensions were generally found to be more impacted by swirl for the cases of longer injection time and faster co-flow flow rate. Flames with swirl exhibited a flame length up to 34% shorter compared to nonswirled flames. Both the turbulent flame puff separation and the flame puff celerity generally decreased when swirl was imposed. The decreased flame length, flame puff separation, and flame puff celerity are consistent with a greater momentum exchange between the flame and the surrounding co-flow, resulting from an increased rate of air entrainment due to swirl. Three scaling relations were developed to account for the impact of the injection time, the volumetric fuel-to-air flow rate ratio, and the jet-on fraction on the visible flame length. © 2013 Copyright Taylor and Francis Group, LLC.

  17. Pulse low-intensity electromagnetic field as prophylaxis of heterotopic ossification in patients with traumatic spinal cord injury

    Directory of Open Access Journals (Sweden)

    Đurović Aleksandar

    2009-01-01

    Full Text Available Background/Aim. Heterotopic ossification (HO is an important complication of head and spinal cord injuries (SCI. Pulse low-intensity electromagnetic field (PLIMF therapy increases blood flow to an area of pain or inflammation, bringing more oxygen to that area and helps to remove toxic substances. The aim of this study was to determine the effect of PLIMF as prophylaxis of HO in patients with SCI. Methods. This prospective random control clinical study included 29 patients with traumatic SCI. The patients were randomly divided into experimental (n = 14 and control group (n = 15. The patients in the experimental group, besides exercise and range of motion therapy, were treated by PLIMF of the following characteristics: induction of 10 mT, frequency of 25 Hz and duration of 30 min. Pulse low-intensity electromagnetic field therapy started in the 7th week after the injury and lasted 4 weeks. The presence or absence of HO around the patients hips we checked by a plane radiography and Brookers classification. Functional capabilities and motor impairment were checked by Functional Independent Measure (FIM, Barthel index and American Spinal Injury Association (ASIA impairment class. Statistic analysis included Kolmogorov-Smirnov test, Shapiro-Wilk test, Mann Whitney Exact test, Exact Wilcoxon signed rank test and Fischer Exact test. Statistical significance was set up to p < 0.05. Results. At the end of the treatment no patient from the experimental group had HO. In the control group, five patients (33.3% had HO. At the end of the treatment the majority of the patients from the experimental group (57.14% moved from ASIA-A to ASIA-B class. Conclusion. Pulse low-intensity electromagnetic field therapy could help as prophylaxis of HO in patients with traumatic SCI.

  18. Biochemical study of human periodontal ligament: preparation of cell attachment materials induced by pulsed electromagnetic fields.

    Science.gov (United States)

    Kim, K T

    1990-09-01

    The periodontium, especially the periodontal ligament and alveolar bone, are tissues constantly subjected to physical stress such as occlusion and mastication. This study was designed to explore the effect of the pulsed electromagnetic fields (PEMF) on the cell attachment and the spread of human periodontal ligament fibroblasts (HPLF) and rat osteoblasts (ROB). PEMF are categorized as one type of mechanical stress. HPLF were obtained by the explantation method described by Saito et al. They were then subcultured in Dulbecco's modified Eagle's medium (D-MEM) and supplemented with 2 mg/ml dialyzed fetal calf serum protein (FCSP), 50 micrograms/ml ascorbic acid and penicillin/streptomycin after trypsinization. ROB were isolated from a two-day-old rat calvaria by the sequential bacterial collagenase digestion method described by Dziak and Brand and were subcultured in D-MEM supplemented with FCSP, ascorbic acid and penicillin/streptomycin. After the confluent HPLF were cultured with serum-free MCDB 107 medium, the quiescent HPLF were exposed with or without PEMF for 24 hr. This was followed by the collection of the control conditioned medium (C-CM) and PEMF exposed conditioned medium (PEMF-CM). The cell attachment assay was performed so that the hydrophobic 24 multiwells were coated with the whole conditioned medium or fractionated conditioned medium by a PO-60K column. After coating, heat inactivated BSA blocked nonspecific sites for cell adhesion, and 3H-TdR labeled HPLF or ROB were cultured on the precoated wells. The activity of cell attachment and spreading was determined by the radioactivity of 3H-TdR using a scintillation counter. The characters of cell attachment factors derived from HPLF were hydrophobic, heat labile and proteolytic enzyme digestible. In addition, the fractionated PEMF-CM enhanced the spreading activity of ROB. PEMF induced the 10 KDa which can enhance the HPLF and ROB spreading. Therefore, the cell attachment and spreading factors secreted by

  19. Effect of low frequency low energy pulsing electromagnetic field (PEMF) on X-ray-irradiated mice

    International Nuclear Information System (INIS)

    Cadossi, R.; Hentz, V.R.; Kipp, J.

    1989-01-01

    C3H/Km flora-defined mice were used to investigate the effect of exposure to pulsing electromagnetic field (PEMF) after total body x-ray irradiation. Prolonged exposure to PEMF had no effect on normal nonirradiated mice. When mice irradiated with different doses of x-ray (8.5 Gy, 6.8 Gy, and 6.3 Gy) were exposed to PEMF 24 h a day, we observed a more rapid decline in white blood cells (WBC) in the peripheral blood of mice exposed to PEMF at all the x-ray dosages used. No effect of exposure to PEMF was observed on the survival of the mice irradiated with 6.3 Gy and 8.5 Gy; in mice irradiated with 6.8 Gy, 2 out of 12 survived when exposed to PEMF as compared to 10 out of 12 control mice that were irradiated only. At day 4 after irradiation autoradiographic studies performed on bone marrow and spleen of 8.5-Gy-irradiated mice showed no difference between controls and mice exposed to PEMF, whereas on 6.8-Gy mice the bone marrow labeling index was lower in mice exposed to PEMF. In mice irradiated to 6.3 Gy we observed that the recovery of WBC in the peripheral blood was slowed in mice exposed to PEMF and their body weight was significantly lower than in control mice that were irradiated only. The spleen and bone marrow of the mice irradiated to 6.3 Gy and sacrificed at days 4, 14, 20, and 25 after irradiation were analyzed by autoradiography to evaluate the labeling index. Half of the spleens from mice sacrificed at day 25 after irradiation were used to evaluate the RNA content. Autoradiography showed that in the spleen and bone marrow of control mice, there were more cells labeled with [3H]thymidine at days 4 and 14 and less at days 20 and 25 after irradiation in comparison with mice irradiated and exposed to PEMF

  20. Effect of low frequency low energy pulsing electromagnetic field (PEMF) on X-ray-irradiated mice

    Energy Technology Data Exchange (ETDEWEB)

    Cadossi, R.; Hentz, V.R.; Kipp, J.; Eiverson, R.; Ceccherelli, G.; Zucchini, P.; Emilia, G.; Torelli, G.; Franceschi, C.; Cossarizza, A.

    1989-02-01

    C3H/Km flora-defined mice were used to investigate the effect of exposure to pulsing electromagnetic field (PEMF) after total body x-ray irradiation. Prolonged exposure to PEMF had no effect on normal nonirradiated mice. When mice irradiated with different doses of x-ray (8.5 Gy, 6.8 Gy, and 6.3 Gy) were exposed to PEMF 24 h a day, we observed a more rapid decline in white blood cells (WBC) in the peripheral blood of mice exposed to PEMF at all the x-ray dosages used. No effect of exposure to PEMF was observed on the survival of the mice irradiated with 6.3 Gy and 8.5 Gy; in mice irradiated with 6.8 Gy, 2 out of 12 survived when exposed to PEMF as compared to 10 out of 12 control mice that were irradiated only. At day 4 after irradiation autoradiographic studies performed on bone marrow and spleen of 8.5-Gy-irradiated mice showed no difference between controls and mice exposed to PEMF, whereas on 6.8-Gy mice the bone marrow labeling index was lower in mice exposed to PEMF. In mice irradiated to 6.3 Gy we observed that the recovery of WBC in the peripheral blood was slowed in mice exposed to PEMF and their body weight was significantly lower than in control mice that were irradiated only. The spleen and bone marrow of the mice irradiated to 6.3 Gy and sacrificed at days 4, 14, 20, and 25 after irradiation were analyzed by autoradiography to evaluate the labeling index. Half of the spleens from mice sacrificed at day 25 after irradiation were used to evaluate the RNA content. Autoradiography showed that in the spleen and bone marrow of control mice, there were more cells labeled with (3H)thymidine at days 4 and 14 and less at days 20 and 25 after irradiation in comparison with mice irradiated and exposed to PEMF.

  1. Pulsed electromagnetic fields stimulation prevents steroid-induced osteonecrosis in rats

    Directory of Open Access Journals (Sweden)

    Zhou Jian-Lin

    2011-09-01

    Full Text Available Abstract Background Pulsed electromagnetic fields (PEMF stimulation has been used successfully to treat nonunion fractures and femoral head osteonecrosis, but relatively little is known about its effects on preventing steroid-induced osteonecrosis. The purpose of the study was to investigate the effects of PEMF stimulation on the prevention of steroid-induced osteonecrosis in rats and explore the underlying mechanisms. Methods Seventy-two male adult Wistar rats were divided into three groups and treated as follows. (1 PEMF stimulation group (PEMF group, n = 24: intravenously injected with lipopolysaccharide (LPS, 10 μg/kg on day 0 and intramuscularly injected with methylprednisolone acetate (MPSL, 20 mg/kg on days 1, 2 and 3, then subjected to PEMF stimulation 4 h per day for 1 to 8 weeks. (2 Methylprednisolone-treated group (MPSL group, n = 24: injected the same dose of LPS and MPSL as the PEMF group but without exposure to PEMF. (3 Control group (PS group, n = 24: injected 0.9% saline in the same mode at the same time points. The incidence of osteonecrosis, serum lipid levels and the mRNA and protein expression of transforming growth factor β1 (TGF-β1 in the proximal femur were measured 1, 2, 4 and 8 weeks after the last MPSL (or saline injection. Results The incidence of osteonecrosis in the PEMF group (29% was significantly lower than that observed in the MPSL group (75%, while no osteonecrosis was observed in the PS group. The serum lipid levels were significantly lower in the PEMF and PS groups than in the MPSL group. Compared with the MPSL and PS groups, the mRNA expression of TGF-β1 increased, reaching a peak 1 week after PEMF treatment, and remained high for 4 weeks, then declined at 8 weeks, whereas the protein expression of TGF-β1 increased, reaching a peak at 2 weeks after PEMF treatment, and remained high for 8 weeks. Conclusions PEMF stimulation can prevent steroid-induced osteonecrosis in rats, and the underlying mechanisms

  2. Pulsed electromagnetic fields stimulation prevents steroid-induced osteonecrosis in rats.

    Science.gov (United States)

    Ding, Shuai; Peng, Hao; Fang, Hong-Song; Zhou, Jian-Lin; Wang, Zhe

    2011-09-29

    Pulsed electromagnetic fields (PEMF) stimulation has been used successfully to treat nonunion fractures and femoral head osteonecrosis, but relatively little is known about its effects on preventing steroid-induced osteonecrosis. The purpose of the study was to investigate the effects of PEMF stimulation on the prevention of steroid-induced osteonecrosis in rats and explore the underlying mechanisms. Seventy-two male adult Wistar rats were divided into three groups and treated as follows. (1) PEMF stimulation group (PEMF group, n = 24): intravenously injected with lipopolysaccharide (LPS, 10 μg/kg) on day 0 and intramuscularly injected with methylprednisolone acetate (MPSL, 20 mg/kg) on days 1, 2 and 3, then subjected to PEMF stimulation 4 h per day for 1 to 8 weeks. (2) Methylprednisolone-treated group (MPSL group, n = 24): injected the same dose of LPS and MPSL as the PEMF group but without exposure to PEMF. (3) Control group (PS group, n = 24): injected 0.9% saline in the same mode at the same time points. The incidence of osteonecrosis, serum lipid levels and the mRNA and protein expression of transforming growth factor β1 (TGF-β1) in the proximal femur were measured 1, 2, 4 and 8 weeks after the last MPSL (or saline) injection. The incidence of osteonecrosis in the PEMF group (29%) was significantly lower than that observed in the MPSL group (75%), while no osteonecrosis was observed in the PS group. The serum lipid levels were significantly lower in the PEMF and PS groups than in the MPSL group. Compared with the MPSL and PS groups, the mRNA expression of TGF-β1 increased, reaching a peak 1 week after PEMF treatment, and remained high for 4 weeks, then declined at 8 weeks, whereas the protein expression of TGF-β1 increased, reaching a peak at 2 weeks after PEMF treatment, and remained high for 8 weeks. PEMF stimulation can prevent steroid-induced osteonecrosis in rats, and the underlying mechanisms involve decreased serum lipid levels and increased

  3. Pulsed electromagnetic fields stimulation prevents steroid-induced osteonecrosis in rats

    Science.gov (United States)

    2011-01-01

    Background Pulsed electromagnetic fields (PEMF) stimulation has been used successfully to treat nonunion fractures and femoral head osteonecrosis, but relatively little is known about its effects on preventing steroid-induced osteonecrosis. The purpose of the study was to investigate the effects of PEMF stimulation on the prevention of steroid-induced osteonecrosis in rats and explore the underlying mechanisms. Methods Seventy-two male adult Wistar rats were divided into three groups and treated as follows. (1) PEMF stimulation group (PEMF group, n = 24): intravenously injected with lipopolysaccharide (LPS, 10 μg/kg) on day 0 and intramuscularly injected with methylprednisolone acetate (MPSL, 20 mg/kg) on days 1, 2 and 3, then subjected to PEMF stimulation 4 h per day for 1 to 8 weeks. (2) Methylprednisolone-treated group (MPSL group, n = 24): injected the same dose of LPS and MPSL as the PEMF group but without exposure to PEMF. (3) Control group (PS group, n = 24): injected 0.9% saline in the same mode at the same time points. The incidence of osteonecrosis, serum lipid levels and the mRNA and protein expression of transforming growth factor β1 (TGF-β1) in the proximal femur were measured 1, 2, 4 and 8 weeks after the last MPSL (or saline) injection. Results The incidence of osteonecrosis in the PEMF group (29%) was significantly lower than that observed in the MPSL group (75%), while no osteonecrosis was observed in the PS group. The serum lipid levels were significantly lower in the PEMF and PS groups than in the MPSL group. Compared with the MPSL and PS groups, the mRNA expression of TGF-β1 increased, reaching a peak 1 week after PEMF treatment, and remained high for 4 weeks, then declined at 8 weeks, whereas the protein expression of TGF-β1 increased, reaching a peak at 2 weeks after PEMF treatment, and remained high for 8 weeks. Conclusions PEMF stimulation can prevent steroid-induced osteonecrosis in rats, and the underlying mechanisms involve decreased

  4. Analytical model for electromagnetic radiation from a wakefield excited by intense short laser pulses in an unmagnetized plasma

    Energy Technology Data Exchange (ETDEWEB)

    Chen Ziyu; Chen Shi; Dan Jiakun; Li Jianfeng; Peng Qixian, E-mail: ziyuch@gmail.com [Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China)

    2011-10-15

    A simple one-dimensional analytical model for electromagnetic emission from an unmagnetized wakefield excited by an intense short-pulse laser in the nonlinear regime has been developed in this paper. The expressions for the spectral and angular distributions of the radiation have been derived. The model suggests that the origin of the radiation can be attributed to the violent sudden acceleration of plasma electrons experiencing the accelerating potential of the laser wakefield. The radiation process could help to provide a qualitative interpretation of existing experimental results, and offers useful information for future laser wakefield experiments.

  5. Analytical model for electromagnetic radiation from a wakefield excited by intense short laser pulses in an unmagnetized plasma

    International Nuclear Information System (INIS)

    Chen Ziyu; Chen Shi; Dan Jiakun; Li Jianfeng; Peng Qixian

    2011-01-01

    A simple one-dimensional analytical model for electromagnetic emission from an unmagnetized wakefield excited by an intense short-pulse laser in the nonlinear regime has been developed in this paper. The expressions for the spectral and angular distributions of the radiation have been derived. The model suggests that the origin of the radiation can be attributed to the violent sudden acceleration of plasma electrons experiencing the accelerating potential of the laser wakefield. The radiation process could help to provide a qualitative interpretation of existing experimental results, and offers useful information for future laser wakefield experiments.

  6. Application of chaotic pulse width modulation control for suppressing electromagnetic interference in a half-bridge converter

    Directory of Open Access Journals (Sweden)

    Yuhong Song

    2014-08-01

    Full Text Available It was proposed in the former research that chaos control can be used to suppress electromagnetic interference (EMI in DC–DC converters. Analysis on a half-bridge converter is detailed in this study. Here, the practical example of the power supply of personal computers is given to show that, with an external chaotic signal to a pulse width modulation control circuit, the proposed approach can reduce EMI by reducing the amplitudes of power signals such as transformer current and output inductor currents at multiples of fundamental frequency.

  7. Probes and Tests of Strong-Field Gravity with Observations in the Electromagnetic Spectrum

    Directory of Open Access Journals (Sweden)

    Psaltis Dimitrios

    2008-11-01

    Full Text Available Neutron stars and black holes are the astrophysical systems with the strongest gravitational fields in the universe. In this article, I review the prospect of using observations of such compact objects to probe some of the most intriguing general relativistic predictions in the strong-field regime: the absence of stable circular orbits near a compact object and the presence of event horizons around black-hole singularities. I discuss the need for a theoretical framework, within which future experiments will provide detailed, quantitative tests of gravity theories. Finally, I summarize the constraints imposed by current observations of neutron stars on potential deviations from general relativity.

  8. Role of pulsed electromagnetic therapy in the management of backache: a study conducted at armed forces institute of rehabilitation medicine, rawalpindi

    International Nuclear Information System (INIS)

    Mumtaz, N.; Ahmad, K.; Shah, S.H.

    2014-01-01

    To determine the role of pulsed electromagnetic therapy in providing pain relief for backache. Study Design: This was a quasi experimental study. Place and Duration: This study was conducted at Armed Forces Institute of Rehabilitation Medicine, Rawalpindi, Pakistan from Jan 2012 to June 2012. Material and Methods: This study included 65 consecutive patients with backache. The pain was assessed on 11 points (0-10) Numeric Rating Scale (NRS) and patients with score = 1 were included in the study. Detailed history was obtained and examination was performed. All patients were subjected to pulsed electromagnetic therapy. The pain was assessed at first week, 2nd week, third week and six week after start of the pulsed electromagnetic therapy. Data was compiled and analysed using SPSS version 17. A p-value < 0.05 was considered as significant. Results: There was marked reduction in pain of patients with backache after treatment with pulsed electromagnetic therapy. Reduction in pain as calculated by the NRS (numeric rating scale) value after 1st week was 25.35% (p=0.002), after 2nd week was 43.66% (p=0.001), after 3rd week was 50.7% (p=0.001) and after 6 weeks was 71.83% (p=0.001). Conclusion: Pulsed electromagnetic therapy is very effective in relieving pain in patients with backache. (author)

  9. Electromagnetically induced transparency and nonlinear pulse propagation in a combined tripod and Λ atom-light coupling scheme

    International Nuclear Information System (INIS)

    Hamedi, H R; Ruseckas, J; Juzeliūnas, G

    2017-01-01

    We consider propagation of a probe pulse in an atomic medium characterized by a combined tripod and Lambda (Λ) atom-light coupling scheme. The scheme involves three atomic ground states coupled to two excited states by five light fields. It is demonstrated that dark states can be formed for such an atom-light coupling. This is essential for formation of the electromagnetically induced transparency (EIT) and slow light. In the limiting cases the scheme reduces to conventional Λ- or N -type atom-light couplings providing the EIT or absorption, respectively. Thus, the atomic system can experience a transition from the EIT to the absorption by changing the amplitudes or phases of control lasers. Subsequently the scheme is employed to analyze the nonlinear pulse propagation using the coupled Maxwell–Bloch equations. It is shown that a generation of stable slow light optical solitons is possible in such a five-level combined tripod and Λ atomic system. (paper)

  10. DIFFUSION OF THE PULSED ELECTROMAGNETIC FIELD INTO THE MULTI-LAYER CORE OF INDUCTOR AT PULSED DEVICES

    Directory of Open Access Journals (Sweden)

    Volodymyr T. Chemerys

    2008-02-01

    Full Text Available  The problem of the pulsed magnetic field distribution in the cross section of the inductor core at the induction accelerator of electron beam is under consideration in this paper. Owing to multi-layer structure of the core package it has the magnetic and electric anisotropy with different speed of the field diffusion along the sheets of magnetic and across the sheets. At the pulse duration less than one microsecond the essential non-uniformity of the field along both axes of the core cross section can be found. This effect reduces the efficiency of the ferromagnetic material using with corresponding loss of the accelerator efficiency. The main conclusion of the paper consists of the necessity to check the field diffusion characteristics in the process of inductor design to be sure that the pulsed field is able to fill the cross section of the core during the pulse switching. The magnetic characteristics of the anisotropic core have been investigated in the paper by one-dimensional and two-dimensional simulation in the quasi-stationary approximation using the traditional equation of the field diffusion.

  11. Description of meson strong weak and electromagnetic interactions in quantum chiral theory

    International Nuclear Information System (INIS)

    Volkov, M.K.; Ehbert, D.

    1979-01-01

    The picture of all the principal meson decays of the basic octet has been obtained in the framework of the SU(3)xSU(3) symmetric chiral model of the field theory. An attempt is made to generalize the nonlinear chiral model for the case of charmed hadrons, i.e., a transition from the SU(3)xSU(3) group to the SU(4)xSU(4) group. The authors have succeeded in elucidating unambiguously the role of the Kabibbo angle both in weak and strong interactions (it defines the structure of weak hadron currents and hadron mass splitting in isotopic multiplets). Proceeding from decays of the basic octet mesons it has been shown that the nonlinear chiral SU(3)xSU(3) symmetric theory may be considered as the quantum field theory, which satisfactorily describes the low-energy meson physics in two first orders of the perturbation theory (tree and single-loop approximations)

  12. Resonant excitation and the decay of autoionization states in a strong electromagnetic field

    International Nuclear Information System (INIS)

    Andryushin, A.I.; Kazakov, A.E.; Fedorov, M.V.

    1985-01-01

    Photoionization of atoms involving resonant excitation of the auto-ionization state is studied. The evolution of the total ionization probability, its dependence on the frequency of the resonance radiation and also the photoelectron energy spectrum are investigated. It is shown that the energy of the final state of the system may be localized either in the vicinity of E approximately Esub(α), where Esub(α) is the auto-ionization energy, or in the vicinity of E approximately Esub(α)+h/2πω where h/2πω is the quantum energy of the resonance radiation. The photoelectron specturum in the region E approximately Esub(α)+h/2πω as a whole is similar to the electron spectrum on photoionization of atoms involving resonance excitation of the bound state. A strong effect on the photoelectron spectrum in the region E approximately Esub(α) is exerted by interference of various decay channels of the ground state in the resonance field which leads to the appearance in the spectrum of a characteristic structure of the Fano type. Interence also affects the widths of the two spectral curves, the relatve amount of electrons in the two energy ranges and also other characteristics of the ionization process. It is shown that the presence of a noninterfering photoionization channel of the autoionization state ensures the finiteness of the swidths and heights of the spectral curves and the absence of complete ''coherency merging''

  13. Hot electromagnetic outflows. III. Displaced fireball in a strong magnetic field

    International Nuclear Information System (INIS)

    Thompson, Christopher; Gill, Ramandeep

    2014-01-01

    The evolution of a dilute electron-positron fireball is calculated in the regime of strong magnetization and high compactness (ℓ ∼ 10 3 -10 8 ). Heating is applied at a low effective temperature (<25 keV), appropriate to breakout from a confining medium, so that relaxation to a blackbody is inhibited by pair annihilation. The diffusion equation for Compton scattering by thermal pairs is coupled to a trans-relativistic cyclo-synchrotron source. We find that the photon spectrum develops a quasi-thermal peak at energy ∼0.1 m e c 2 in the comoving frame, with a power-law slope below it that is characteristic of gamma-ray bursts (GRBs; F ω ∼ const). The formation of a thermal high-energy spectrum is checked using the full kinetic equations. Calculations for a baryon-dominated photosphere reveal a lower spectral peak energy, and a harder low-energy spectrum, unless ion rest mass carries ≲ 10 –5 of the energy flux. We infer that (1) the GRB spectrum is inconsistent with the neutron-rich wind emitted by a young magnetar or neutron torus, and points to an event horizon in the engine; (2) neutrons play a negligible role in prompt gamma-ray emission; (3) the relation between observed peak frequency and burst energy is bounded below by the observed Amati relation if the Lorentz factor ∼(opening angle) –1 at breakout, and the jet is surrounded by a broader sheath that interacts with a collapsing stellar core; (4) X-ray flashes are consistent with magnetized jets with ion-dominated photospheres; (5) high-frequency Alfvén waves may become charge starved in the dilute pair gas; (6) limitations on magnetic reconnection from plasma collisionality have been overestimated.

  14. Investigation of thin manganite films at strong pulsed electric and magnetic fields

    OpenAIRE

    Cimmperman, Piotras

    2006-01-01

    The main aim of this work was to investigate electrical conductivity of La-Ca(Sr)-MnO thin films at high pulsed electric and magnetic fields and to clear up the possibilities to use these materials for high pulsed magnetic field sensor and fault current limiter applications. The dissertation consists of the preface, six chapters, summary and main conclusions, references, list of publications and abstract (in Lithuanian). The main objectives of the work, scientific novelty, goals, valida...

  15. Laser and Plasma Parameters for Laser Pulse Amplification by Stimulated Brillouin Backscattering in the Strong Coupling Regime

    Science.gov (United States)

    Gangolf, Thomas; Blecher, Marius; Bolanos, Simon; Lancia, Livia; Marques, Jean-Raphael; Cerchez, Mirela; Prasad, Rajendra; Aurand, Bastian; Loiseau, Pascal; Fuchs, Julien; Willi, Oswald

    2017-10-01

    In the ongoing quest for novel techniques to obtain ever higher laser powers, plasma amplification has drawn much attention, benefiting from the fact that a plasma can sustain much higher energy densities than a solid state amplifier. As a plasma process, Stimulated Brillouin Backscattering in the strong coupling regime (sc-SBS) can be used to transfer energy from one laser pulse (pump) to another (seed), by a nonlinear ion oscillation forced by the pump laser. Here, we report on experimental results on amplification by sc-SBS using the ARCTURUS Ti:Sapphire multi-beam laser system at the University of Duesseldorf, Germany. Counter-propagating in a supersonic Hydrogen gas jet target, an ultrashort seed pulse with a pulse duration between 30 and 160 fs and an energy between 1 and 12 mJ was amplified by a high-energy pump pulse (1.7 ps, 700 mJ). For some of the measurements, the gas was pre-ionized with a separate laser pulse (780 fs, 460 mJ). Preliminary analysis shows that the amplification was larger for the longer seed pulses, consistent with theoretical predictions.

  16. Pulsed electromagnetic fields (PEMF) attenuate changes in vertebral bone mass, architecture and strength in ovariectomized mice.

    Science.gov (United States)

    Lei, Tao; Liang, Zhuowen; Li, Feijiang; Tang, Chi; Xie, Kangning; Wang, Pan; Dong, Xu; Shan, Shuai; Jiang, Maogang; Xu, Qiaoling; Luo, Erping; Shen, Guanghao

    2018-03-01

    Pulsed electromagnetic fields (PEMF) has been investigated as a noninvasive alternative method to prevent bone loss for postmenopausal osteoporosis (OP), and the bone tissue involved in these studies are usually long bones such as femur and tibia in OP patients or rat models. However, few studies have investigated the effects of PEMF on the vertebral bone in mice with OP. This study aimed to investigate whether PEMF preserve lumbar vertebral bone mass, microarchitecture and strength in ovariectomized (OVX) mouse model of OP and its associated mechanisms. Thirty 3-month-old female BALB/c mice were randomly divided into three groups (n=10): sham-operated control (Sham), ovariectomy (OVX), and ovariectomy with PEMF treatment (OVX+PEMF). The OVX+PEMF group was exposed to 15Hz, 1.6 mT PEMF for 8h/day, 7days/week. After 8weeks, the mice were sacrificed. The OVX+PEMF group showed lower body weight gain of mice induced by estrogen deficiency compared with OVX group. Biochemical analysis of serum demonstrated that serum bone formation markers including bone specific alkaline phosphatase (BALP), serum osteocalcin (OCN), osteoprotegerin (OPG) and N-terminal propeptide of type I procollagen (P1NP) were markedly higher in OVX+PEMF group compared with OVX group. Besides, serum bone resorption markers including tartrate-resistant acid phosphatase 5b (TRAP-5b) and C-terminal crosslinked telopeptides of type I collagen (CTX-I) were markedly lower in OVX+PEMF group compared with OVX group. Biomechanical test observed that OVX+PEMF group showed higher compressive maximum load and stiffness of the lumbar vertebrae compared with OVX group. Micro-computed tomography (μCT) and histological analysis of lumbar vertebrae revealed that PEMF partially prevented OVX-induced decrease of trabecular bone mass and deterioration of trabecular bone microarchitecture in lumbar vertebrae. Real-time PCR showed that the canonical Wnt signaling pathway of the lumbar vertebrae, including Wnt3a, LRP5 and

  17. Randomized, prospective, and controlled clinical trial of pulsed electromagnetic field stimulation for cervical fusion.

    Science.gov (United States)

    Foley, Kevin T; Mroz, Thomas E; Arnold, Paul M; Chandler, Howard C; Dixon, Robert A; Girasole, Gerard J; Renkens, Kenneth L; Riew, K Daniel; Sasso, Rick C; Smith, Richard C; Tung, Howard; Wecht, Daniel A; Whiting, Donald M

    2008-01-01

    Multilevel fusions, the use of allograft bone, and smoking have been associated with an increased risk of nonunion after anterior cervical discectomy and fusion (ACDF) procedures. Pulsed electromagnetic field (PEMF) stimulation has been shown to increase arthrodesis rates after lumbar spine fusion surgery, but there are minimal data concerning the effect of PEMF stimulation on cervical spine fusion. To determine the efficacy and safety of PEMF stimulation as an adjunct to arthrodesis after ACDF in patients with potential risk factors for nonunion. A randomized, controlled, prospective multicenter clinical trial. Three hundred and twenty-three patients with radiographic evidence (computed tomography-myelogram [CT-myelo] or magnetic resonance imaging [MRI]) of a compressed cervical nerve root and symptomatic radiculopathy appropriate to the compressed root that had failed to respond to nonoperative management were enrolled in the study. The patients were either smokers (more than one pack per day) and/or were undergoing multilevel fusions. All patients underwent ACDF using the Smith-Robinson technique. Allograft bone and an anterior cervical plate were used in all cases. Measurements were obtained preoperatively and at each postoperative interval and included neurologic assessment, visual analog scale (VAS) scores for shoulder/arm pain at rest and with activity, SF-12 scores, the neck disability index (NDI), and radiographs (anteroposterior, lateral, and flexion-extension views). Two orthopedic surgeons not otherwise affiliated with the study and blinded to treatment group evaluated the radiographs, as did a blinded radiologist. Adverse events were reported by all patients throughout the study to determine device safety. Patients were randomly assigned to one of two groups: those receiving PEMF stimulation after surgery (PEMF group, 163 patients) and those not receiving PEMF stimulation (control group, 160 patients). Postoperative care was otherwise identical. Follow

  18. Hadronic vs. electromagnetic pulse shape discrimination in CsI(Tl) for high energy physics experiments

    Science.gov (United States)

    Longo, S.; Roney, J. M.

    2018-03-01

    Pulse shape discrimination using CsI(Tl) scintillators to perform neutral hadron particle identification is explored with emphasis towards application at high energy electron-positron collider experiments. Through the analysis of the pulse shape differences between scintillation pulses from photon and hadronic energy deposits using neutron and proton data collected at TRIUMF, it is shown that the pulse shape variations observed for hadrons can be modelled using a third scintillation component for CsI(Tl), in addition to the standard fast and slow components. Techniques for computing the hadronic pulse amplitudes and shape variations are developed and it is shown that the intensity of the additional scintillation component can be computed from the ionization energy loss of the interacting particles. These pulse modelling and simulation methods are integrated with GEANT4 simulation libraries and the predicted pulse shape for CsI(Tl) crystals in a 5 × 5 array of 5 × 5 × 30 cm3 crystals is studied for hadronic showers from 0.5 and 1 GeV/c KL0 and neutron particles. Using a crystal level and cluster level approach for photon vs. hadron cluster separation we demonstrate proof-of-concept for neutral hadron detection using CsI(Tl) pulse shape discrimination in high energy electron-positron collider experiments.

  19. A novel single pulsed electromagnetic field stimulates osteogenesis of bone marrow mesenchymal stem cells and bone repair.

    Science.gov (United States)

    Fu, Yin-Chih; Lin, Chih-Chun; Chang, Je-Ken; Chen, Chung-Hwan; Tai, I-Chun; Wang, Gwo-Jaw; Ho, Mei-Ling

    2014-01-01

    Pulsed electromagnetic field (PEMF) has been successfully applied to accelerate fracture repair since 1979. Recent studies suggest that PEMF might be used as a nonoperative treatment for the early stages of osteonecrosis. However, PEMF treatment requires a minimum of ten hours per day for the duration of the treatment. In this study, we modified the protocol of the single-pulsed electromagnetic field (SPEMF) that only requires a 3-minute daily treatment. In the in vitro study, cell proliferation and osteogenic differentiation was evaluated in the hBMSCs. In the in vivo study, new bone formation and revascularization were evaluated in the necrotic bone graft. Results from the in vitro study showed no significant cytotoxic effects on the hBMSCs after 5 days of SPEMF treatment (1 Tesla, 30 pulses per day). hBMSC proliferation was enhanced in the SPEMF-treated groups after 2 and 4 days of treatment. The osteogenic differentiation of hBMSCs was significantly increased in the SPEMF-treated groups after 3-7 days of treatment. Mineralization also increased after 10, 15, 20, and 25 days of treatment in SPEMF-treated groups compared to the control group. The 7-day short-course treatment achieved similar effects on proliferation and osteogenesis as the 25-day treatment. Results from the in vivo study also demonstrated that both the 7-day and 25-day treatments of SPEMF increased callus formation around the necrotic bone and also increased new vessel formation and osteocyte numbers in the grafted necrotic bone at the 2nd and 4th weeks after surgery. In conclusion, the newly developed SPEMF accelerates osteogenic differentiation of cultured hBMSCs and enhances bone repair, neo-vascularization, and cell growth in necrotic bone in mice. The potential clinical advantage of the SPEMF is the short daily application and the shorter treatment course. We suggest that SPEMF may be used to treat fractures and the early stages of osteonecrosis.

  20. A novel single pulsed electromagnetic field stimulates osteogenesis of bone marrow mesenchymal stem cells and bone repair.

    Directory of Open Access Journals (Sweden)

    Yin-Chih Fu

    Full Text Available Pulsed electromagnetic field (PEMF has been successfully applied to accelerate fracture repair since 1979. Recent studies suggest that PEMF might be used as a nonoperative treatment for the early stages of osteonecrosis. However, PEMF treatment requires a minimum of ten hours per day for the duration of the treatment. In this study, we modified the protocol of the single-pulsed electromagnetic field (SPEMF that only requires a 3-minute daily treatment. In the in vitro study, cell proliferation and osteogenic differentiation was evaluated in the hBMSCs. In the in vivo study, new bone formation and revascularization were evaluated in the necrotic bone graft. Results from the in vitro study showed no significant cytotoxic effects on the hBMSCs after 5 days of SPEMF treatment (1 Tesla, 30 pulses per day. hBMSC proliferation was enhanced in the SPEMF-treated groups after 2 and 4 days of treatment. The osteogenic differentiation of hBMSCs was significantly increased in the SPEMF-treated groups after 3-7 days of treatment. Mineralization also increased after 10, 15, 20, and 25 days of treatment in SPEMF-treated groups compared to the control group. The 7-day short-course treatment achieved similar effects on proliferation and osteogenesis as the 25-day treatment. Results from the in vivo study also demonstrated that both the 7-day and 25-day treatments of SPEMF increased callus formation around the necrotic bone and also increased new vessel formation and osteocyte numbers in the grafted necrotic bone at the 2nd and 4th weeks after surgery. In conclusion, the newly developed SPEMF accelerates osteogenic differentiation of cultured hBMSCs and enhances bone repair, neo-vascularization, and cell growth in necrotic bone in mice. The potential clinical advantage of the SPEMF is the short daily application and the shorter treatment course. We suggest that SPEMF may be used to treat fractures and the early stages of osteonecrosis.

  1. Trigger-less readout system with pulse pile-up recovery for the PANDA electromagnetic calorimeter

    NARCIS (Netherlands)

    Kavatsyuk, M.; Tambave, G.; Hevinga, M.; Lemmens, P. J. J.; Schakel, P.; Schreuder, F.; Speelman, R.; Löhner, H.

    2013-01-01

    A simple, efficient, and robust on-line data-processing scheme was developed for the digital front-end electronics of the electromagnetic calorimeter of the PANDA spectrometer at FAIR, Darmstadt. The implementation of the processing algorithm in FPGA enables the construction of an almost dead-time

  2. Computational and experimental progress on laser-activated gas avalanche switches for broadband, high-power electromagnetic pulse generation

    International Nuclear Information System (INIS)

    Mayhall, D.J.; Yee, J.H.; Villa, F.

    1991-01-01

    This paper discusses the gas avalanche switch, a high-voltage, picosecond-speed switch, which has been proposed. The basic switch consists of pulse-charged electrodes, immersed in a high-pressure gas. An avalanche discharge is induced in the gas between the electrodes by ionization from a picosecond-scale laser pulse. The avalanching electrons move toward the anode, causing the applied voltage to collapse in picoseconds. This voltage collapse, if rapid enough, generates electromagnetic waves. A two-dimensional (2D), finite difference computer code solves Maxwell's equations for transverse magnetic modes for rectilinear electrodes between parallel plate conductors, along with electron conservation equations for continuity, momentum, and energy. Collision frequencies for ionization and momentum and energy transfer to neutral molecules are assumed to scale linearly with neutral pressure. Electrode charging and laser-driven electron deposition are assumed to be instantaneous. Code calculations are done for a pulse generator geometry, consisting of an 0.7 mm wide by 0.8 mm high, beveled, rectangular center electrode between grounded parallel plates at 2 mm spacing in air

  3. Microsecond pulsed DC matching measurements on MOSFETs in strong and weak inversion

    NARCIS (Netherlands)

    Andricciola, Pietro; Andricciola, P.; Tuinhout, Hans; Wils, Nicole; Schmitz, Jurriaan

    2011-01-01

    We present a first successful attempt to use microsecond DC pulses for matching measurements on 65-nm MOS transistors down to low current levels. We demonstrate that the interface states that contribute to the mismatch (if they indeed do so) in the weak and moderate inversion region must have

  4. Comparison of low-intensity pulsed ultrasound and pulsed electromagnetic field treatments on OPG and RANKL expression in human osteoblast-like cells.

    Science.gov (United States)

    Borsje, Manon A; Ren, Yijin; de Haan-Visser, H Willy; Kuijer, Roel

    2010-05-01

    To compare two clinically applied treatments to stimulate bone healing-low-intensity pulsed ultrasound (LIPUS) and pulsed electromagnetic field (PEMF)-for their effects on RANKL and OPG expression in osteoblast-like cells in vitro. LIPUS or PEMF was applied to Saos-2 cells for 10 minutes or 3 hours. RANKL and OPG expressions were analyzed at 0, 4, 8, or 12 hours after treatment with real-time PCR. Secreted protein levels in culture supernatant were analyzed at the same posttreatment time points using specific ELISA assays. Neither LIPUS nor PEMF had an effect on RANKL protein expression. OPG protein was significantly increased by LIPUS after 0 and 4 hours (brief short-term effect) and was increased almost 2.5-fold by PEMF after 8 hours. The mRNA levels of OPG and RANKL were hardly affected by LIPUS treatment at any time point. PEMF induced a fivefold increase in RANKL mRNA expression at t = 0. A brief PEMF treatment of 10 minutes resulted in downregulation of RANKL expression after 0 and 4 hours and upregulation at 12 hours. OPG mRNA was downregulated after 8 hours. The effects of LIPUS or PEMF expression on OPG and RANKL are limited. From our experiments, it seems that LIPUS treatment resulted in a quick protein response, while the response of cells to PEMF (3 hours) was delayed. The increase in OPG protein at 8 hours post PEMF treatment is indicative of reduction of osteolysis.

  5. Electromagnetic fields of an ultra-short tightly-focused radially-polarized laser pulse

    Science.gov (United States)

    Salamin, Yousef I.; Li, Jian-Xing

    2017-12-01

    Fully analytic expressions, for the electric and magnetic fields of an ultrashort and tightly focused laser pulse of the radially polarized category, are presented to lowest order of approximation. The fields are derived from scalar and vector potentials, along the lines of our earlier work for a similar pulse of the linearly polarized variety. A systematic program is also described from which the fields may be obtained to any desired accuracy, analytically or numerically.

  6. BLANKET REPRESENTATION AND EXPEDIENT OF DISINFECTING WATER USING PULSING ELECTROMAGNETIC FIELD

    Directory of Open Access Journals (Sweden)

    Ibragimova Ozoda

    2013-11-01

    Full Text Available ABSTRACT:  The paper deals with comparative analysis of existing expedients and devices of disinfecting water, spots ways of the solution and a new method of  water purification using electromagnetic field applied in a cross wise direction. ABSTRAK: Dalam operasi, analisis perbandingan dijalankan bagi menentukan  kesesuaian yang sedia ada dan alatan untuk menyahjangkit air. Dengan mengaplikasikan medan magnet lintang, penyelesaian masalah dikenal pasti dengan meningkatkan kemagnetan terhadap medan elektromagnet ke atas air.

  7. Electromagnetic Pulse (EMP) Handbook for Air Force Communications Service Communications-Electronics-Meteorological Engineers

    Science.gov (United States)

    1976-11-01

    5.10.13.4 Thyrites . . . . . . . . . . . . . . . . . . . 63 5.10.14 Fast Relays. . . . . . . .............. 6 3 5.10.15 Crowbar Circuits...2 Energy Floiaga .’ ; .; g ; a . .. 4 3 Surface Burst.... . . . . . . . . . . . S 4 Illustration of the Basic Geometry of the Hgh Altitude Burst...nanoseconds). It can be assumed that these very fast rise times can also occur for’nuclear-created electromagnetic environments, although wide

  8. Influence of the external component on the damage of the bipolar transistor induced by the electromagnetic pulse

    Energy Technology Data Exchange (ETDEWEB)

    Xi Xiaowen; Chai Changchun; Ren Xingrong; Yang Yintang; Ma Zhenyang; Wang Jing, E-mail: xixiaowen523103@163.co [Key Laboratory of Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi' an 710071 (China)

    2010-07-15

    A study on the influence of the external resistor and the external voltage source during the injection of the electromagnetic pulse (EMP) into the bipolar transistor (BJT) is carried out. Research shows that the increase of the external resistor R{sub b} at base makes the burnout time of the device decrease slightly, the increase of the external voltage source V{sub be} at base can aid the damage of the device when the magnitude of the injecting voltage is relatively low and has little influence when the magnitude is sufficiently high causing the device appearing the PIN structure damage, and the increase of the external resistor R{sub e} can remarkably reduce the voltage drops added to the device and improve the durability of the device. In the final analysis, the effect of the external circuit component on the BJT damage is the influence on the condition which makes the device appear current-mode second breakdown.

  9. Influence of the external component on the damage of the bipolar transistor induced by the electromagnetic pulse

    Science.gov (United States)

    Xiaowen, Xi; Changchun, Chai; Xingrong, Ren; Yintang, Yang; Zhenyang, Ma; Jing, Wang

    2010-07-01

    A study on the influence of the external resistor and the external voltage source during the injection of the electromagnetic pulse (EMP) into the bipolar transistor (BJT) is carried out. Research shows that the increase of the external resistor Rb at base makes the burnout time of the device decrease slightly, the increase of the external voltage source Vbe at base can aid the damage of the device when the magnitude of the injecting voltage is relatively low and has little influence when the magnitude is sufficiently high causing the device appearing the PIN structure damage, and the increase of the external resistor Re can remarkably reduce the voltage drops added to the device and improve the durability of the device. In the final analysis, the effect of the external circuit component on the BJT damage is the influence on the condition which makes the device appear current-mode second breakdown.

  10. Onset of Coulomb explosion in small silicon clusters exposed to strong-field laser pulses

    Science.gov (United States)

    Sayres, S. G.; Ross, M. W.; Castleman, A. W., Jr.

    2012-05-01

    It is now well established that, under intense laser illumination, clusters undergo enhanced ionization compared to their isolated atomic and molecular counterparts being subjected to the same pulses. This leads to extremely high charge states and concomitant Coulomb explosion. Until now, the cluster size necessary for ionization enhancement has not been quantified. Here, we demonstrate that through the comparison of ion signal from small covalently bound silicon clusters exposed to low intensity laser pulses with semi-classical theory, their ionization potentials (IPs) can be determined. At moderate laser intensities the clusters are not only atomized, but all valence electrons are removed from the cluster, thereby producing up to Si4+. The effective IPs for the production of the high charge states are shown to be ˜40% lower than the expected values for atomic silicon. Finally, the minimum cluster size responsible for the onset of the enhanced ionization is determined utilizing the magnitude of the kinetic energy released from the Coulomb explosion.

  11. Revisiting the Balazs thought experiment in the case of a left-handed material: electromagnetic-pulse-induced displacement of a dispersive, dissipative negative-index slab.

    Science.gov (United States)

    Chau, Kenneth J; Lezec, Henri J

    2012-04-23

    We propose a set of postulates to describe the mechanical interaction between a plane-wave electromagnetic pulse and a dispersive, dissipative slab having a refractive index of arbitrary sign. The postulates include the Abraham electromagnetic momentum density, a generalized Lorentz force law, and a model for absorption-driven mass transfer from the pulse to the medium. These opto-mechanical mechanisms are incorporated into a one-dimensional finite-difference time-domain algorithm that solves Maxwell's equations and calculates the instantaneous force densities exerted by the pulse onto the slab, the momentum-per-unit-area of the pulse and slab, and the trajectories of the slab and system center-of-mass. We show that the postulates are consistent with conservation of global energy, momentum, and center-of-mass velocity at all times, even for cases in which the refractive index of the slab is negative or zero. Consistency between the set of postulates and well-established conservation laws reinforces the Abraham momentum density as the one true electromagnetic momentum density and enables, for the first time, identification of the correct form of the electromagnetic mass density distribution and development of an explicit model for mass transfer due to absorption, for the most general case of a ponderable medium that is both dispersive and dissipative. © 2012 Optical Society of America

  12. The clinical and radiological outcome of pulsed electromagnetic field treatment for acute scaphoid fractures: a randomised double-blind placebo-controlled multicentre trial

    NARCIS (Netherlands)

    Hannemann, P.F.; Gottgens, K.W.; van Wely, B.J.; Kolkman, K.A.; Werre, A.J.; Poeze, M.; Brink, P.R.

    2012-01-01

    The use of pulsed electromagnetic fields (PEMF) to stimulate bone growth has been recommended as an alternative to the surgical treatment of ununited scaphoid fractures, but has never been examined in acute fractures. We hypothesised that the use of PEMF in acute scaphoid fractures would accelerate

  13. CT scan-evaluated outcome of pulsed electromagnetic fields in the treatment of acute scaphoid fractures: a randomised, multicentre, double-blind, placebo-controlled trial

    NARCIS (Netherlands)

    Hannemann, P.F.; van Wezenbeek, M.R.; Kolkman, K.A.; Twiss, E.L.; Berghmans, C.H.; Dirven, P.A.; Brink, P.R.; Poeze, M.

    2014-01-01

    We hypothesised that the use of pulsed electromagnetic field (PEMF) bone growth stimulation in acute scaphoid fractures would significantly shorten the time to union and reduce the number of nonunions in a randomised, double-blind, placebo-controlled multicentre trial. A total of 102 patients (78

  14. Effects of Pulsed Electromagnetic Field with Predatory Stress on Functional and Histological Index of Injured-Sciatic Nerve in Rat.

    Science.gov (United States)

    Tasbih-Forosh, Maryam; Zarei, Leila; Saboory, Ehsan; Bahrami-Bukani, Mehran

    2017-04-01

    To assess the effect of combination of pulsed electromagnetic fields (PEMF) with predatory stress on transected sciatic nerve regeneration in rats. In sham- operated group (SOG) the nerve was manipulated and left intact. The 10-mm rat sciatic nerve gap was created in rats. In transected group (Transected) nerve stumps were sutured to adjacent muscle and in vein graft group (VG) the gap was bridged using an inside-out vein graft. In VG/PEMF group the transected nerve was bridged using vein graft, phosphate buffered saline was administered into the graft and the whole body was exposed to PEMF. In VG/PS group the transected nerve was bridged using vein graft, phosphate buffered saline was administered into the graft and the rats underwent predatory stress (PS).  In VG/PEMF/PS group the transected nerve was bridged using vein graft, phosphate buffered saline was administered into the graft, the whole body was exposed to PEMF and the rats underwent predatory stress. The regenerated nerve fibers were studied within 12 weeks after surgery. Functional, gastrocnemius muscle mass findings and morphometric indices confirmed faster recovery of regenerated axons in VG/PEMF and VG/PEMF/PS groups compared to those in the other groups ( p =0.001). The whole body exposure to PEMF improved functional recovery. Predatory stress did not affect nerve regeneration in the animals undergone predatory stress ( p =0.343). Pulsed electromagnetic fields could be considered as an effective, safe and tolerable treatment for peripheral nerve repair in clinical practice.

  15. Effects of Pulsed Electromagnetic Field with Predatory Stress on Functional and Histological Index of Injured-Sciatic Nerve in Rat

    Science.gov (United States)

    Tasbih -Forosh, Maryam; Zarei, Leila; Saboory, Ehsan; Bahrami-Bukani, Mehran

    2017-01-01

    Objective: To assess the effect of combination of pulsed electromagnetic fields (PEMF) with predatory stress on transected sciatic nerve regeneration in rats.  Methods: In sham- operated group (SOG) the nerve was manipulated and left intact. The 10-mm rat sciatic nerve gap was created in rats. In transected group (Transected) nerve stumps were sutured to adjacent muscle and in vein graft group (VG) the gap was bridged using an inside-out vein graft. In VG/PEMF group the transected nerve was bridged using vein graft, phosphate buffered saline was administered into the graft and the whole body was exposed to PEMF. In VG/PS group the transected nerve was bridged using vein graft, phosphate buffered saline was administered into the graft and the rats underwent predatory stress (PS).  In VG/PEMF/PS group the transected nerve was bridged using vein graft, phosphate buffered saline was administered into the graft, the whole body was exposed to PEMF and the rats underwent predatory stress. The regenerated nerve fibers were studied within 12 weeks after surgery. Results: Functional, gastrocnemius muscle mass findings and morphometric indices confirmed faster recovery of regenerated axons in VG/PEMF and VG/PEMF/PS groups compared to those in the other groups (p=0.001). The whole body exposure to PEMF improved functional recovery. Predatory stress did not affect nerve regeneration in the animals undergone predatory stress (p=0.343).  Conclusion: Pulsed electromagnetic fields could be considered as an effective, safe and tolerable treatment for peripheral nerve repair in clinical practice. PMID:28507996

  16. Size-based cell sorting with a resistive pulse sensor and an electromagnetic pump in a microfluidic chip.

    Science.gov (United States)

    Song, Yongxin; Li, Mengqi; Pan, Xinxiang; Wang, Qi; Li, Dongqing

    2015-02-01

    An electrokinetic microfluidic chip is developed to detect and sort target cells by size from human blood samples. Target-cell detection is achieved by a differential resistive pulse sensor (RPS) based on the size difference between the target cell and other cells. Once a target cell is detected, the detected RPS signal will automatically actuate an electromagnetic pump built in a microchannel to push the target cell into a collecting channel. This method was applied to automatically detect and sort A549 cells and T-lymphocytes from a peripheral fingertip blood sample. The viability of A549 cells sorted in the collecting well was verified by Hoechst33342 and propidium iodide staining. The results show that as many as 100 target cells per minute can be sorted out from the sample solution and thus is particularly suitable for sorting very rare target cells, such as circulating tumor cells. The actuation of the electromagnetic valve has no influence on RPS cell detection and the consequent cell-sorting process. The viability of the collected A549 cell is not impacted by the applied electric field when the cell passes the RPS detection area. The device described in this article is simple, automatic, and label-free and has wide applications in size-based rare target cell sorting for medical diagnostics. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Atomic structure dependence of nonsequential double ionization of He, Ne and Ar in strong laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, V L B de; Feuerstein, B; Zrost, K; Fischer, D; Rudenko, A; Afaneh, F; Schroeter, C D; Moshammer, R; Ullrich, J [Max-Planck-Institut fuer Kernphysik, D-69029 Heidelberg (Germany)

    2004-04-28

    The ion momentum spectra for nonsequential double ionization of rare gases (He, Ne and Ar) in 23 fs 795 nm laser pulses were measured in the intensity range 0.075-1.25 PW cm{sup -2}. In the studies published, confusing differences in the shape of momentum distributions among different targets are consistently explained within a recollision scenario: excitation during recollision plus subsequent field ionization, not implemented in most theoretical approaches, evidently plays a decisive role for He and Ar nonsequential double ionization whereas it plays only a minor role for Ne. (letter to the editor)

  18. Magnetic study of a few antiferromagnets in very-strong pulsed fields (450 kOE)

    International Nuclear Information System (INIS)

    Krebs, J.

    1968-01-01

    In this thesis we describe a pulsed field device with which we obtain magnetization curves up to 450 kOE at all temperatures between 1. 6 and 300. We have studied the 'spin-flopping'(and therefore the anisotropy) in MnF 2 versus temperature, below the Neel point. We have also studied the antiferromagnets MnSO 4 . and MnSO 4 .H 2 O which have revealed saturation fields respectively of 250 kOE and 320 kOE. (author) [fr

  19. The Sterilization Effect of Cooperative Treatment of High Voltage Electrostatic Field and Variable Frequency Pulsed Electromagnetic Field on Heterotrophic Bacteria in Circulating Cooling Water

    Science.gov (United States)

    Gao, Xuetong; Liu, Zhian; Zhao, Judong

    2018-01-01

    Compared to other treatment of industrial circulating cooling water in the field of industrial water treatment, high-voltage electrostatic field and variable frequency pulsed electromagnetic field co-sterilization technology, an advanced technology, is widely used because of its special characteristics--low energy consumption, nonpoisonous and environmentally friendly. In order to get a better cooling water sterilization effect under the premise of not polluting the environment, some experiments about sterilization of heterotrophic bacteria in industrial circulating cooling water by cooperative treatment of high voltage electrostatic field and variable frequency pulsed electromagnetic field were carried out. The comparison experiment on the sterilization effect of high-voltage electrostatic field and variable frequency pulsed electromagnetic field co-sterilization on heterotrophic bacteria in industrial circulating cooling water was carried out by change electric field strength and pulse frequency. The results show that the bactericidal rate is selective to the frequency and output voltage, and the heterotrophic bacterium can only kill under the condition of sweep frequency range and output voltage. When the voltage of the high voltage power supply is 4000V, the pulse frequency is 1000Hz and the water temperature is 30°C, the sterilization rate is 48.7%, the sterilization rate is over 90%. Results of this study have important guiding significance for future application of magnetic field sterilization.

  20. Primary human osteoblasts with reduced alkaline phosphatase and matrix mineralization baseline capacity are responsive to extremely low frequency pulsed electromagnetic field exposure - Clinical implication possible.

    Science.gov (United States)

    Ehnert, Sabrina; Falldorf, Karsten; Fentz, Anne-Kristin; Ziegler, Patrick; Schröter, Steffen; Freude, Thomas; Ochs, Björn G; Stacke, Christina; Ronniger, Michael; Sachtleben, Jens; Nussler, Andreas K

    2015-12-01

    For many years electromagnetic fields (EMFs) have been used clinically with various settings as an exogenous stimulation method to promote fracture healing. However, underlying mechanisms of action and EMF parameters responsible for certain effects remain unclear. Our aim was to investigate the influence of defined EMFs on human osteoblasts' and osteoclasts' viability and function. Primary human osteoblasts and osteoclasts were treated 3 times weekly for 21 days during their maturation process using the Somagen® device (Sachtleben GmbH, Hamburg, Germany), generating defined extremely low-frequency pulsed electromagnetic fields (ELF-PEMFs). Certain ELF-PEMF treatment significantly increased the total protein content (up to 66%), mitochondrial activity (up to 91.1%) and alkaline phosphatase (AP) activity (up to 129.9%) of human osteoblasts during the entire differentiation process. Furthermore, ELF-PEMF treatment enhanced formation of mineralized matrix (up to 276%). Interestingly, ELF-PEMF dependent induction of AP activity and matrix mineralization was strongly donor dependent - only osteoblasts with a poor initial osteoblast function responded to the ELF-PEMF treatment. As a possible regulatory mechanism, activation of the ERK1/2 signaling pathway was identified. Maturation of osteoclasts from human monocytes was not affected by the ELF-PEMF treatment. In summary the results indicate that a specific ELF-PEMF treatment with the Somagen® device improves viability and maturation of osteoblasts, while osteoclast viability and maturation was not affected. Hence, ELF-PEMF might represent an interesting adjunct to conventional therapy supporting bone formation during fracture healing or even for the treatment of osteoporosis.

  1. Primary human osteoblasts with reduced alkaline phosphatase and matrix mineralization baseline capacity are responsive to extremely low frequency pulsed electromagnetic field exposure — Clinical implication possible

    Directory of Open Access Journals (Sweden)

    Sabrina Ehnert

    2015-12-01

    Full Text Available For many years electromagnetic fields (EMFs have been used clinically with various settings as an exogenous stimulation method to promote fracture healing. However, underlying mechanisms of action and EMF parameters responsible for certain effects remain unclear. Our aim was to investigate the influence of defined EMFs on human osteoblasts' and osteoclasts' viability and function. Primary human osteoblasts and osteoclasts were treated 3 times weekly for 21 days during their maturation process using the Somagen® device (Sachtleben GmbH, Hamburg, Germany, generating defined extremely low-frequency pulsed electromagnetic fields (ELF-PEMFs. Certain ELF-PEMF treatment significantly increased the total protein content (up to 66%, mitochondrial activity (up to 91.1% and alkaline phosphatase (AP activity (up to 129.9% of human osteoblasts during the entire differentiation process. Furthermore, ELF-PEMF treatment enhanced formation of mineralized matrix (up to 276%. Interestingly, ELF-PEMF dependent induction of AP activity and matrix mineralization was strongly donor dependent — only osteoblasts with a poor initial osteoblast function responded to the ELF-PEMF treatment. As a possible regulatory mechanism, activation of the ERK1/2 signaling pathway was identified. Maturation of osteoclasts from human monocytes was not affected by the ELF-PEMF treatment. In summary the results indicate that a specific ELF-PEMF treatment with the Somagen® device improves viability and maturation of osteoblasts, while osteoclast viability and maturation was not affected. Hence, ELF-PEMF might represent an interesting adjunct to conventional therapy supporting bone formation during fracture healing or even for the treatment of osteoporosis.

  2. Electromagnetic radiation emitted by a plasma produced in air by laser pulses with lambda = 10.6 μm

    International Nuclear Information System (INIS)

    Danilychev, V.A.; Zvorykin, V.D.; Kholin, I.V.; Chugunov, A.Y.

    1981-01-01

    The spectrum, brightness, and energy have been measured for the electromagnetic radiation emitted by a plasma produced in air near a solid surface by pulses from a high-power CO 2 laser. The air pressure was varied over the range p 0 = 0.1--760 torr, and the laser power density was varied over the range q = 5 x 10 6 --10 8 W/cm 2 . At p 0 > or approx. =2--5 torr the radiation properties of the plasma are determined by a laser-beam absorption wave which arises in the gas. The maximum brightness temperature, T/sub b/approx. =50 000 K (lambda = 400 +- 20 nm), is reached at p 0 = 25 torr. The emission spectrum is quite different from an equilibrium spectrum, consisting primarily of NII, OII, and NIII lines. The total energy radiation by the plasma in the wavelength interval 360--2600 nm into a solid angle of 4π sr reaches 2.3% of the laser pulse energy

  3. Transient interaction model of electromagnetic field generated by lightning current pulses and human body

    International Nuclear Information System (INIS)

    Iváncsy, T; Kiss, I; Tamus, Z Á; Szücs, L

    2015-01-01

    The lightning current generates time-varying magnetic field near the down-conductor and the down-conductors are mounted on the wall of the buildings where residential places might be situated. It is well known that the rapidly changing magnetic fields can generate dangerous eddy currents in the human body.The higher duration and gradient of the magnetic field can cause potentially life threatening cardiac stimulation. The coupling mechanism between the electromagnetic field and the human body is based on a well-known physical phenomena (e.g. Faradays law of induction). However, the calculation of the induced current is very complicated because the shape of the organs is complex and the determination of the material properties of living tissues is difficult, as well. Our previous study revealed that the cardiac stimulation is independent of the rising time of the lightning current and only the peak of the current counts.In this study, the authors introduce an improved model of the interaction of electromagnetic fields of lighting current near down-conductor and human body. Our previous models are based on the quasi stationer field calculations, the new improved model is a transient model. This is because the magnetic field around the down-conductor and in the human body can be determined more precisely, therefore the dangerous currents in the body can be estimated. (paper)

  4. Asymmetric Ultrasonic Pulse Radiation Using Electromagnetic-Induction Transducer and PZT(Pb(Zr-Ti)O3) Transducer with Wave Synthesis Method

    Science.gov (United States)

    Endoh, Nobuyuki; Yamamoto, Koji

    1993-05-01

    In medical applications, especially in urology, we use a fragmentation calculus technique with shock waves. This technique is very profitable because of no abdominal surgery for a human being. Large negative sound amplitude pulses, however, can cause problems such as internal hemorrhage or pain in the human body. The final goal of this study is to develop a means to project an intense positive unipolar pulse without negative sound pressure. We improved a composite transducer consisting of an electromagnetic-induction-type (EMI) transducer and PZT (Pb(Zr-Ti)O3) transducers. An EMI transducer consisting of a metal coil and vibration membrane can project intense sound pulses into water. In order to suppress its negative sound pressure, we project a compensation pulse with PZT transducers using an inverse filtering method. An asymmetric pulse whose P+ to P- amplitude ratio was very high was projected in water.

  5. Interactions of Low-Frequency, Pulsed Electromagnetic Fields with Living Tissue: Biochemical Responses and Clinical Results

    DEFF Research Database (Denmark)

    Rahbek, Ulrik L.; Tritsaris, Katerina; Dissing, Steen

    2005-01-01

    fields. PEMF is widely used for treating fractures and non-unions as well as for treating diseases of the joints. Furthermore, new research has suggested that the technology can be used for nerve regeneration and wound healing although conclusive clinical trials, besides those for fracture healing......, are still lacking. Despite the apparent success of the PEMF technology very little is known regarding the coupling between pulsed electrical fields and biochemical events leading to cellular responses. Insight into this research area is therefore of great importance. In this review we describe the physical...... properties of PEMF-induced electrical fields and explain the typical set up for coils and pulse patterns. Furthermore, we discuss possible models that can account for mechanisms by which induced electric fields are able to enhance cellular signaling. We have emphasized the currently well-documented effects...

  6. Method and split cavity oscillator/modulator to generate pulsed particle beams and electromagnetic fields

    Science.gov (United States)

    Clark, M. Collins; Coleman, P. Dale; Marder, Barry M.

    1993-01-01

    A compact device called the split cavity modulator whose self-generated oscillating electromagnetic field converts a steady particle beam into a modulated particle beam. The particle beam experiences both signs of the oscillating electric field during the transit through the split cavity modulator. The modulated particle beam can then be used to generate microwaves at that frequency and through the use of extractors, high efficiency extraction of microwave power is enabled. The modulated beam and the microwave frequency can be varied by the placement of resistive wires at nodes of oscillation within the cavity. The short beam travel length through the cavity permit higher currents because both space charge and pinching limitations are reduced. The need for an applied magnetic field to control the beam has been eliminated.

  7. Electromagnetic fields from pulsed electron beam experiments in space - Spacelab-2 results

    Science.gov (United States)

    Bush, R. I.; Reeves, G. D.; Banks, P. M.; Neubert, T.; Williamson, P. R.

    1987-01-01

    During the Spacelab-2 mission a small satellite carrying various plasma diagnostic instruments was released from the Shuttle to coorbit at distances up to 300 m. During a magnetic conjunction of the Shuttle and the satellite an electron beam modulated at 1.22 kHz was emitted from the Shuttle during a 7 min period. The spatial structure of the electromagnetic fields generated by the beam was observed from the satellite out to a distance of 153 m perpendicular to the beam. The magnetic field amplitude of the strongest harmonics were comparable to the amplitude of simultaneously observed whistlers, while the electric field amplitudes were estimated to 1-10 mV/m.

  8. Influence of pulse electromagnetic fields on electronic equipment and systems in smart buildings

    Directory of Open Access Journals (Sweden)

    Jacek Paś

    2016-07-01

    Full Text Available The article presents information about the impact of electromagnetic fields’ impulses on technical infrastructure of electronic equipment and systems in intelligent buildings. The use of modern technical solutions in intelligent building management, i.e., human resources control and automation systems, efficient building space management, requires a large number of integrated electronic systems. Impulse interference, lightning or electricity as natural phenomena are among the most responsible for the occurrence of interference in buses, transmission lines systems, electrical installations, equipment and electronic systems used in intelligent buildings. To a large extent, it is associated with catastrophic damages that may occur in electronic devices or in completed systems such as intelligent building, e.g. ICT, security, etc. under the influence of induced voltages and interfering signals’ currents. Keywords: noise, static electricity, lightning

  9. Emission of strong Terahertz pulses from laser wakefields in weakly coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Divya, E-mail: dsingh@rajdhani.du.ac.in [PWAPA Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110 016 (India); Department of Physics & Electronics, Rajdhani College, University of Delhi, Raja Garden, Ring Road, New Delhi 110015 (India); Malik, Hitendra K. [PWAPA Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110 016 (India)

    2016-09-01

    The present paper discusses the laser plasma interaction for the wakefield excitation and the role of external magnetic field for the emission of Terahertz radiation in a collisional plasma. Flat top lasers are shown to be more appropriate than the conventional Gaussian lasers for the effective excitation of wakefields and hence, the generation of strong Terahertz radiation through the transverse component of wakefield.

  10. Flight test techniques for validating simulated nuclear electromagnetic pulse aircraft responses

    Science.gov (United States)

    Winebarger, R. M.; Neely, W. R., Jr.

    1984-01-01

    An attempt has been made to determine the effects of nuclear EM pulses (NEMPs) on aircraft systems, using a highly instrumented NASA F-106B to document the simulated NEMP environment at the Kirtland Air Force Base's Vertically Polarized Dipole test facility. Several test positions were selected so that aircraft orientation relative to the test facility would be the same in flight as when on the stationary dielectric stand, in order to validate the dielectric stand's use in flight configuration simulations. Attention is given to the flight test portions of the documentation program.

  11. Effects of short-term resistance training and pulsed electromagnetic fields on bone metabolism and joint function in severe haemophilia A patients with osteoporosis: a randomized controlled trial.

    Science.gov (United States)

    Parhampour, Behrouz; Torkaman, Giti; Hoorfar, Hamid; Hedayati, Mehdi; Ravanbod, Roya

    2014-05-01

    To assess the effects of short-term resistance training and pulsed electromagnetic fields on bone metabolism and joint function in patients with haemophilia with osteoporosis. A randomized, controlled, patient and blood sample assessor-blinded, six-week trial, three times weekly. Hospital outpatients with severe haemophilia A and osteoporosis. Forty-eight patients were randomly assigned to resistance training (RT, n = 13), combined resistance training with pulsed electromagnetic fields (RTPEMF, n = 12), pulsed electromagnetic fields (PEMF, n = 11) and control (n = 12) groups. The RT group received 30-40 minutes of resistance exercises and placebo pulsed electromagnetic fields. The RTPEMF group received the same exercises with lower repetition and 30 minutes of pulsed electromagnetic fields. The PEMF group was exposed to 60 minutes of pulsed electromagnetic fields (30 Hz and 40 Gauss). Bone-specific alkaline phosphatase, N-terminal telopeptide of type 1 collagen, and joint function, using the modified Colorado Questionnaire, were measured before and after the programme. The absolute change of bone-specific alkaline phosphatase was significant in the RT and RTPEMF groups compared with the control group (25.41 ± 14.40, 15.09 ± 5.51, and -4.73 ± 2.93 U/L, respectively). The absolute changes in the total score for joint function were significant for knees, ankles, and elbows in the RT group (9.2 ± 1.38, 5.1 ± 0.5, and 3.2 ± 0.8, respectively) and the RTPEMF group (7.7 ± 1.0, 3.3 ± 0.6, and 2.5 ± 0.7, respectively) compared to the PEMF and control groups. This value was significant for knee joints in the PEMF group compared to the control group (3.4 ± 0.5 and 0.66 ± 0.4, respectively). Resistance training is effective for improving bone formation and joint function in severe haemophilia A patients with osteoporosis.

  12. Strong coupling effects during X-pulse CPMG experiments recorded on heteronuclear ABX spin systems: artifacts and a simple solution

    International Nuclear Information System (INIS)

    Vallurupalli, Pramodh; Scott, Lincoln; Williamson, James R.; Kay, Lewis E.

    2007-01-01

    Simulation and experiment have been used to establish that significant artifacts can be generated in X-pulse CPMG relaxation dispersion experiments recorded on heteronuclear ABX spin-systems, such as 13 C i - 13 C j - 1 H, where 13 C i and 13 C j are strongly coupled. A qualitative explanation of the origin of these artifacts is presented along with a simple method to significantly reduce them. An application to the measurement of 1 H CPMG relaxation dispersion profiles in an HIV-2 TAR RNA molecule where all ribose sugars are protonated at the 2' position, deuterated at all other sugar positions and 13 C labeled at all sugar carbons is presented to illustrate the problems that strong 13 C- 13 C coupling introduces and a simple solution is proposed

  13. Writing of 3D optical integrated circuits with ultrashort laser pulses in the presence of strong spherical aberration

    Science.gov (United States)

    Bukharin, M. A.; Skryabin, N. N.; Khudyakov, D. V.; Vartapetov, S. K.

    2016-09-01

    A novel technique was proposed for 3D femtosecond writing of waveguides and optical integrated circuits in the presence of strong spherical aberration, caused by inscription at significantly different depth under the surface of optical glasses and crystals. Strong negative effect of spherical aberration and related asymmetry of created structures was reduced due to transition to the cumulative thermal regime of femtosecond interaction with the material. The differences in the influence of spherical aberration effect in a broad depth range (larger than 200 µm) was compensated by dynamic adjustment of laser pulse energy during the process of waveguides recording. The presented approach has been experimentally implemented in fused silica. Obtained results can be used in production of a broad class of femtosecond written three-dimensional integrated optical systems, inscripted at non-optimal (for focusing lens) optical depth or in significantly extended range of depths.

  14. Pulsed Electromagnetic Fields in the treatment of fresh scaphoid fractures. A multicenter, prospective, double blind, placebo controlled, randomized trial.

    Science.gov (United States)

    Hannemann, Pascal; Göttgens, Kevin W A; van Wely, Bob J; Kolkman, Karel A; Werre, Andries J; Poeze, Martijn; Brink, Peter R G

    2011-05-06

    The scaphoid bone is the most commonly fractured of the carpal bones. In the Netherlands 90% of all carpal fractures is a fracture of the scaphoid bone. The scaphoid has an essential role in functionality of the wrist, acting as a pivot. Complications in healing can result in poor functional outcome. The scaphoid fracture is a troublesome fracture and failure of treatment can result in avascular necrosis (up to 40%), non-union (5-21%) and early osteo-arthritis (up to 32%) which may seriously impair wrist function. Impaired consolidation of scaphoid fractures results in longer immobilization and more days lost at work with significant psychosocial and financial consequences.Initially Pulsed Electromagnetic Fields was used in the treatment of tibial pseudoarthrosis and non-union. More recently there is evidence that physical forces can also be used in the treatment of fresh fractures, showing accelerated healing by 30% and 71% reduction in nonunion within 12 weeks after initiation of therapy. Until now no double blind randomized, placebo controlled trial has been conducted to investigate the effect of this treatment on the healing of fresh fractures of the scaphoid. This is a multi center, prospective, double blind, placebo controlled, randomized trial. Study population consists of all patients with unilateral acute scaphoid fracture. Pregnant women, patients having a life supporting implanted electronic device, patients with additional fractures of wrist, carpal or metacarpal bones and pre-existing impairment in wrist function are excluded. The scaphoid fracture is diagnosed by a combination of physical and radiographic examination (CT-scanning).Proven scaphoid fractures are treated with cast immobilization and a small Pulsed Electromagnetic Fields bone growth stimulating device placed on the cast. Half of the devices will be disabled at random in the factory.Study parameters are clinical consolidation, radiological consolidation evaluated by CT-scanning, functional

  15. An open-label pilot study of pulsed electromagnetic field therapy in the treatment of failed back surgery syndrome pain

    Directory of Open Access Journals (Sweden)

    Harper WL

    2014-12-01

    Full Text Available Wayne L Harper,1 William K Schmidt,2 Nicole J Kubat,3 Richard A Isenberg41Tarheel Clinical Research, LLC, Raleigh, NC, USA; 2NorthStar Consulting, LLC, Davis, CA, USA; 3Nicole Kubat Consulting, Pasadena, CA, USA; 4Regenesis Biomedical, Inc., Scottsdale, AZ, USAAbstract: Persistent pain following back surgery remains a major treatment challenge. The primary objective of this open-label exploratory study was to investigate the analgesic effectiveness of pulsed electromagnetic field therapy administered twice daily over a 45-day period in 34 subjects (68% female with persistent or recurrent pain following back surgery. A secondary goal was to guide the design of future randomized controlled trials that could target responsive subpopulations. All predefined primary and secondary outcomes, including change in pain intensity (PI, physical function (Oswestry Disability Index, analgesic consumption, and overall well-being (Patient Global Impression of Change, are reported. A responder analysis (≥30% reduction in PI versus baseline was added as a post hoc evaluation. Safety outcomes, as well as results of a cost-avoidance survey, are also summarized. Of the 30 per-protocol subjects who completed the study, 33% reported a clinically meaningful (≥30% reduction in PI. A higher response rate (60% was reported for subjects who had undergone discectomy prior to the trial compared to subjects who had undergone other types of surgical interventions (decompression or fusion without discectomy. Improvements in PI were paralleled by improvements in secondary outcomes. Relative to baseline, responders reported an average 44% and 55% reduction in back PI and leg PI (respectively, and an average 13% improvement in Oswestry Disability Index scores. In the per-protocol population, 50% of responders and 12% of nonresponders reported less analgesia consumption at the end of treatment versus baseline. Sixty-seven percent of per-protocol responders and 0% of

  16. Pulsed Electromagnetic Fields in the treatment of fresh scaphoid fractures. A multicenter, prospective, double blind, placebo controlled, randomized trial

    Directory of Open Access Journals (Sweden)

    Poeze Martijn

    2011-05-01

    Full Text Available Abstract Background The scaphoid bone is the most commonly fractured of the carpal bones. In the Netherlands 90% of all carpal fractures is a fracture of the scaphoid bone. The scaphoid has an essential role in functionality of the wrist, acting as a pivot. Complications in healing can result in poor functional outcome. The scaphoid fracture is a troublesome fracture and failure of treatment can result in avascular necrosis (up to 40%, non-union (5-21% and early osteo-arthritis (up to 32% which may seriously impair wrist function. Impaired consolidation of scaphoid fractures results in longer immobilization and more days lost at work with significant psychosocial and financial consequences. Initially Pulsed Electromagnetic Fields was used in the treatment of tibial pseudoarthrosis and non-union. More recently there is evidence that physical forces can also be used in the treatment of fresh fractures, showing accelerated healing by 30% and 71% reduction in nonunion within 12 weeks after initiation of therapy. Until now no double blind randomized, placebo controlled trial has been conducted to investigate the effect of this treatment on the healing of fresh fractures of the scaphoid. Methods/Design This is a multi center, prospective, double blind, placebo controlled, randomized trial. Study population consists of all patients with unilateral acute scaphoid fracture. Pregnant women, patients having a life supporting implanted electronic device, patients with additional fractures of wrist, carpal or metacarpal bones and pre-existing impairment in wrist function are excluded. The scaphoid fracture is diagnosed by a combination of physical and radiographic examination (CT-scanning. Proven scaphoid fractures are treated with cast immobilization and a small Pulsed Electromagnetic Fields bone growth stimulating device placed on the cast. Half of the devices will be disabled at random in the factory. Study parameters are clinical consolidation

  17. Pulsed electromagnetic field therapy for management of osteoarthritis-related pain, stiffness and physical function: clinical experience in the elderly

    Directory of Open Access Journals (Sweden)

    Iannitti T

    2013-09-01

    Full Text Available Tommaso Iannitti,1,2 Gregorio Fistetto,2 Anna Esposito,2 Valentina Rottigni,2,3 Beniamino Palmieri2,3 1Department of Physiology, University of Kentucky Medical Center, Lexington, KY, USA; 2Poliambulatorio del Secondo Parere, Modena, Italy; 3Department of General Surgery and Surgical Specialties, University of Modena and Reggio Emilia Medical School, Surgical Clinic, Modena, Italy Background: Pulsed electromagnetic field (PEMF therapy has shown promising therapeutic effectiveness on bone- and cartilage-related pathologies, being also safe for management of knee osteoarthritis. Aim: The aim of this study was to investigate the clinical efficacy of a PEMF device for management of knee osteoarthritis in elderly patients. Materials and methods: A total of 33 patients were screened, and 28 patients, aged between 60 and 83 and affected by bilateral knee osteoarthritis, were enrolled in this study. They received PEMF therapy on the right leg for a total of three 30-minute sessions per week for a period of 6 weeks, while the left leg did not receive any treatment and served as control. An intravenous drip containing ketoprofen, sodium clodronate, glucosamine sulfate, calcitonin, and ascorbic acid, for a total volume of 500 mL, was administered during PEMF therapy. At baseline and 3 months post-PEMF therapy, Visual Analog Scale (VAS was used to assess knee pain and Western Ontario McMaster Universities Osteoarthritis Index (WOMAC was used to measure knee pain, stiffness and physical function. Results: Changes in VAS and WOMAC scores were calculated for both knees as baseline minus post-treatment. A two sample Student’s t-test, comparing change in knee-related VAS pain for PEMF-treated leg (49.8 ± 2.03 vs control leg (11 ± 1.1, showed a significant difference in favor of PEMF therapy (P < 0.001. A two sample Student’s t-test comparing change in knee-related WOMAC pain, stiffness, and physical function for PEMF-treated leg (8.5 ± 0.4, 3.5 ± 0.2, 38

  18. The application of a high pulse repetition rate CO2 laser with high average power for isotope separation by molecular dissociation in a strong IR field

    International Nuclear Information System (INIS)

    Bagratashvili, V.N.; Kolomisky, Y.R.; Letokhov, V.S.; Ryabov, E.A.; Baranov, V.Y.; Kazakov, S.A.; Nizjev, V.G.; Pismenny, V.D.; Starodubtsev, A.I.; Velikhov, E.P.

    1977-01-01

    Considering a SF 6 molecule we demonstrate feasibility of using high pulse repetition rate CO 2 laser for isotope separation by selective molecular dissociation in a strong IR field. Dependences of dissociation efficiency as well as separation selectivity on pulse repetition rate up to 150 Hz are investigated. The inherent thermal effects are discussed. (orig.) [de

  19. Responses of human normal osteoblast cells and osteoblast-like cell line, MG-63 cells, to pulse electromagnetic field (PEMF

    Directory of Open Access Journals (Sweden)

    Suttatip Kamolmatyakul

    2008-01-01

    Full Text Available The objective of this in vitro study is to investigate the effect of pulsed electromagnetic field (PEMF on cellular proliferation and osteocalcin production of osteoblast-like cell line, MG-63 cells, and human normal osteoblast cells (NHOC obtained from surgical bone specimens. The cells were placed in 24-well culture plates in the amount of 3x104 cell/wells with 2 ml αMEM media supplemented with 10% FBS. The experimental plates were placed between a pair of Helmoltz coils powered by a pulse generator (PEMF, 50 Hz, 1.5 mV/cm in the upper compartment of a dual incubator (Forma. The control plates were placed in the lower compartment of the incubator without Helmotz coils. After three days, the cell proliferation was measured by the method modified from Mossman (J. Immunol Methods 1983; 65: 55-63. Other sets of plates were used for osteocalcin production assessment. Media from these sets were collected after 6 days and assessed for osteocalcin production using ELISA kits. The data were analyzed using a one-way analysis of variance (ANOVA. The results showed that MG-63 cells from the experimental group proliferated significantly more than those from the control group (20% increase, p<0.05. No significant difference in osteocalcin production was detected between the two groups. On the other hand, NHOC from the experimental group produced larger amount of osteocalcin (25% increase, p<0.05 and proliferated significantly more than those from the control group (100% increase, p<0.05. In conclusion, PEMF effect on osteoblasts might depend on their cell type of origin. For osteoblast-like cell line, MG-63 cells, PEMF increased proliferation rate but not osteocalcin production of the cells. However, PEMF stimulation effect on human normal osteoblast cells was most likely associated with enhancement of both osteocalcin production and cell proliferation.

  20. Comment on ''Generation of Electromagnetic Pulses from Plasma Channels Induced by Femtosecond Light Strings''

    International Nuclear Information System (INIS)

    Shvets, Gennady; Kaganovich, Igor; Startsev, Edward

    2002-01-01

    In a recent Letter, Cheng et al. calculated/predicted several new effects: that (a) fraction of the short laser pulse momentum can be imparted to plasma electrons via collisional damping of the laser, thereby exciting a long-lived (longer than an oscillation period) plasma wave, which (b) gives rise to a spatially uniform dipole moment of a plasma, which (c) emits far-field narrow-band radiation at the plasma frequency omega subscript ''p'' over the recombination time of the plasma. We claim that the calculation of the effect (a) is in error and the predicted effects (b,c) do not occur as described. In fact, predicted narrow-band emission at omega subscript ''p'' would not occur even if the momentum transfer and the dipole excitation were calculated correctly

  1. Measurement of electromagnetic pulses generated during interactions of high power lasers with solid targets

    Czech Academy of Sciences Publication Activity Database

    De Marco, Massimo; Krása, Josef; Cikhardt, Jakub; Pfeifer, Miroslav; Krouský, Eduard; Margarone, Daniele; Ahmed, H.; Borghesi, M.; Kar, S.; Giuffrida, Lorenzo; Vrána, Roman; Velyhan, Andriy; Limpouch, J.; Korn, Georg; Weber, Stefan A.; Velardi, L.; Delle Side, D.; Nassisi, V.; Ullschmied, Jiří

    2016-01-01

    Roč. 11, Jun (2016), 1-8, č. článku C06004. ISSN 1748-0221 R&D Projects: GA MŠk LQ1606; GA MŠk EF15_008/0000162; GA ČR(CZ) GA15-02964S; GA MŠk(CZ) LD14089; GA MŠk ED1.1.00/02.0061 Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162; ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061 Institutional support: RVO:68378271 ; RVO:61389021 Keywords : lasers * pulsed power Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.220, year: 2016

  2. Construction of three-dimensional graphene interfaces into carbon fiber textiles for increasing deposition of nickel nanoparticles: flexible hierarchical magnetic textile composites for strong electromagnetic shielding

    Science.gov (United States)

    Bian, Xing-Ming; Liu, Lin; Li, Hai-Bing; Wang, Chan-Yuan; Xie, Qing; Zhao, Quan-Liang; Bi, Song; Hou, Zhi-Ling

    2017-01-01

    Since manipulating electromagnetic waves with electromagnetic active materials for environmental and electric engineering is a significant task, here a novel prototype is reported by introducing reduced graphene oxide (RGO) interfaces in carbon fiber (CF) networks for a hierarchical carbon fiber/reduced graphene oxide/nickel (CF-RGO-Ni) composite textile. Upon charaterizations of the microscopic morphologies, electrical and magnetic properties, the presence of three-dimensional RGO interfaces and bifunctional nickel nanoparticles substantially influences the related physical properties in the resulting hierarchical composite textiles. Eletromagnetic interference (EMI) shielding performance suggests that the hierarchical composite textiles hold a strong shielding effectiveness greater than 61 dB, showing greater advantages than conventional polymeric and foamy shielding composites. As a polymer-free lightweight structure, flexible CF-RGO-Ni composites of all electromagnetic active components offer unique understanding of the multi-scale and multiple mechanisms in electromagnetic energy consumption. Such a novel prototype of shielding structures along with convenient technology highlight a strategy to achieve high-performance EMI shielding, coupled with a universal approach for preparing advanced lightweight composites with graphene interfaces.

  3. Strong-field photoelectron holography of atoms by bicircular two-color laser pulses

    Science.gov (United States)

    Li, Min; Jiang, Wei-Chao; Xie, Hui; Luo, Siqiang; Zhou, Yueming; Lu, Peixiang

    2018-02-01

    We study photoelectron holography in strong bicircular two-color laser fields by solving the time-dependent Schrödinger equation (TDSE) and a semiclassical rescattering model with implementing interference effect. The holographic patterns observed in the TDSE are well recaptured by the semiclassical rescattering model. Four types of photoelectron holographic interferences between the forward scattered and nonscattered trajectories are predicted by the semiclassical rescattering model in the bicircular two-color laser field. We find that those holographic patterns are spatially separated from each other in the electron momentum distribution. We further show that the dependence of the initial transverse momentum at the tunnel exit on the ionization time for the rescattering electron is recorded by the holographic patterns.

  4. Effect of low frequency low energy pulsing electromagnetic fields on mice injected with cyclophosphamide

    International Nuclear Information System (INIS)

    Cadossi, R.; Zucchini, P.; Emilia, G.; Franceschi, C.; Cossarizza, A.; Santantonio, M.; Mandolini, G.; Torelli, G.

    1991-01-01

    C3H mice have been used to investigate the effect of a combination of cyclophosphamide (CY) and electromagnetic fields (PEMF). Mice were injected i.p. with a single dose of 200 mg/kg body weight of CY and then exposed to PEMF 24 h per day. In an initial series of experiments immediately after CY injection mice were exposed to PEMF until sacrifice. WBC counts in the peripheral blood demonstrated a quicker decline in WBC at days 1 and 2 in mice exposed to PEMF. Groups of mice were sacrificed at days 1, 4, 6, 8, and 10 after CY injection. In mice exposed to PEMF the spleen weight was less than in controls at days 6, 8, and 10. Autoradiographic studies demonstrated that the labeling index of bone marrow smears did not significantly differ between controls and experimental mice exposed to PEMF, whereas the spleen labeling index proved to be higher among control mice versus mice exposed to PEMF at day 6, and higher among mice exposed to PEMF versus controls at day 8. In a second series of experiments mice were exposed to PEMF only over the 24 h following CY injection. We found that the spleens of mice exposed to PEMF weighed less than those of controls at days 6 and 8. The labeling index of bone marrow did evidence a slight decrease among mice exposed to PEMF at days 8 and 10 after CY injection versus control mice. The spleen labeling index proved to be lower in experimental mice exposed to PEMF than in controls at days 4, 6, and 8. Mice were then injected with CY, half were exposed to PEMF, and 24 h later bone marrow was recovered from both groups of animals. The same number of bone marrow cells was injected via the tail vein into recipient mice irradiated to 8.5 Gy

  5. Effect of low frequency low energy pulsing electromagnetic fields on mice injected with cyclophosphamide

    Energy Technology Data Exchange (ETDEWEB)

    Cadossi, R.; Zucchini, P.; Emilia, G.; Franceschi, C.; Cossarizza, A.; Santantonio, M.; Mandolini, G.; Torelli, G. (Univ. of Modena (Italy))

    1991-03-01

    C3H mice have been used to investigate the effect of a combination of cyclophosphamide (CY) and electromagnetic fields (PEMF). Mice were injected i.p. with a single dose of 200 mg/kg body weight of CY and then exposed to PEMF 24 h per day. In an initial series of experiments immediately after CY injection mice were exposed to PEMF until sacrifice. WBC counts in the peripheral blood demonstrated a quicker decline in WBC at days 1 and 2 in mice exposed to PEMF. Groups of mice were sacrificed at days 1, 4, 6, 8, and 10 after CY injection. In mice exposed to PEMF the spleen weight was less than in controls at days 6, 8, and 10. Autoradiographic studies demonstrated that the labeling index of bone marrow smears did not significantly differ between controls and experimental mice exposed to PEMF, whereas the spleen labeling index proved to be higher among control mice versus mice exposed to PEMF at day 6, and higher among mice exposed to PEMF versus controls at day 8. In a second series of experiments mice were exposed to PEMF only over the 24 h following CY injection. We found that the spleens of mice exposed to PEMF weighed less than those of controls at days 6 and 8. The labeling index of bone marrow did evidence a slight decrease among mice exposed to PEMF at days 8 and 10 after CY injection versus control mice. The spleen labeling index proved to be lower in experimental mice exposed to PEMF than in controls at days 4, 6, and 8. Mice were then injected with CY, half were exposed to PEMF, and 24 h later bone marrow was recovered from both groups of animals. The same number of bone marrow cells was injected via the tail vein into recipient mice irradiated to 8.5 Gy.

  6. Role of pulsed electromagnetic fields (PEMF) on tenocytes and myoblasts-potential application for treating rotator cuff tears.

    Science.gov (United States)

    Liu, Mengyao; Lee, Carlin; Laron, Dominique; Zhang, Nianli; Waldorff, Erik I; Ryaby, James T; Feeley, Brian; Liu, Xuhui

    2017-05-01

    The post-surgery integrity of the tendons and muscle quality are the two major factors in success of rotator cuff (RC) repair. Though surgical techniques for rotator cuff repair have significantly improved in the past two decades, there are no effective treatments to improve tendon-to-bone healing and muscle quality after repair at this point in time. Pulsed electromagnetic fields (PEMF) have previously been used for promoting fracture healing. Previous studies have shown that PEMF has a positive role in promoting osteoblast precursors proliferation and differentiation. However, PEMFs effect on tenocytes and muscle cells has not been determined fully yet. The purpose of this study is to define the role of a commercially available PEMF on tenocytes and myoblasts growth and differentiation in vitro. Human rotator cuff tenocytes and C2C12 murine myoblasts were cultured and treated with PEMF for 2 weeks under regular and inflammatory conditions. Our results showed that 2 weeks treatment of PEMF enhanced gene expressions of growth factors in human rotator cuff tenocytes under inflammatory conditions. PEMF significantly enhanced C2C12 myotube formation under normal and inflammatory conditions. Results from this study suggest that PEMF has a positive role in promoting tenocyte gene expression and myoblast differentiation. Therefore, PEMF may potentially serve as a non-operative treatment to improve clinical incomes rotator cuff tendon repairs. Results © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:956-964, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  7. Effect of pulsed electromagnetic field therapy on experimental pain: A double-blind, randomized study in healthy young adults.

    Science.gov (United States)

    Beaulieu, Karen; Beland, Patricia; Pinard, Marilee; Handfield, Guilène; Handfield, Nicole; Goffaux, Philippe; Corriveau, Hélène; Léonard, Guillaume

    2016-01-01

    Previous studies suggested that pulsed electromagnetic field (PEMF) therapy can decrease pain. To date, however, it remains difficult to determine whether the analgesic effect observed in patients are attributable to a direct effect of PEMF on pain or to an indirect effect of PEMF on inflammation and healing. In the present study, we used an experimental pain paradigm to evaluate the direct effect of PEMF on pain intensity, pain unpleasantness, and temporal summation of pain. Twenty-four healthy subjects (mean age 22 ± 2 years; 9 males) participated in the experiment. Both real and sham PEMF were administered to every participant using a randomized, double-blind, cross-over design. For each visit, PEMF was applied for 10 minutes on the right forearm using a portable device. Experimental pain was evoked before (baseline) and after PEMF with a 9 cm(2) Pelletier-type thermode, applied on the right forearm (120 s stimulation; temperature individually adjusted to produce moderate baseline pain). Pain intensity and unpleasantness were evaluated using a 0-100 numerical pain rating scale. Temporal summation was evaluated by comparing pain intensity ratings obtained at the end of tonic nociceptive stimulation (120 s) with pain intensity ratings obtained after 60 s of stimulation. When compared to baseline, there was no change in pain intensity and unpleasantness following the application of real or sham PEMF. PEMF did not affect temporal summation. The present observations suggest that PEMF does not directly influence heat pain perception in healthy individuals.

  8. Effects of pulsed electromagnetic fields on swelling and pain after implant surgery: a double-blind, randomized study.

    Science.gov (United States)

    Menini, M; Bevilacqua, M; Setti, P; Tealdo, T; Pesce, P; Pera, P

    2016-03-01

    The aim of this split-mouth, double-blind, randomized study was to determine whether pulsed electromagnetic field therapy (PEMF) can improve swelling and the management of pain after full-arch immediate loading implant surgery. Eleven patients were selected for the study. Each patient received four distal tilted implants in the upper or lower jaw and underwent full-arch immediate loading rehabilitation. After surgery, two PEMF devices were applied to each patient, one on each cheek. In a random manner, one of these PEMF devices was switched on (test side); the other served as a placebo (control side). Forty-eight hours after surgery clinicians estimated postoperative swelling through photographic documentation, comparing the condition before and after surgery, while pain was assessed using a verbal rating scale. The patient's degree of comfort in relation to the PEMF devices was analyzed by questionnaire using a numerical rating scale. No statistically significant difference was observed between the test and control sides for swelling or pain (P>0.05). Most of the patients did not present swelling or pain at 48h after surgery, regardless of whether the PEMF device was activated or not. Various outcomes were found in the comfort evaluation. Within the limitations of this study, PEMF does not reduce postoperative swelling or pain after implant surgery. Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  9. Pulsed electromagnetic fields accelerate functional recovery of transected sciatic nerve bridged by chitosan conduit: an animal model study.

    Science.gov (United States)

    Mohammadi, Rahim; Faraji, Darab; Alemi, Hanieh; Mokarizadeh, Aram

    2014-12-01

    Effect of whole body exposure to pulsed electromagnetic fields (PEMF) on nerve regeneration in a rat sciatic nerve transection model was assessed. Sixty male white Wistar rats were divided into four experimental groups (n = 15), randomly: In transected group (TC) left sciatic nerve was transected and stumps were fixed in adjacent muscle. In chitosan group (CHIT) the defect was bridged using a chitosan conduit filled with phosphate-buffered saline. In treatment group (CHIT/PEMF) the whole body was exposed to PEMF (0.3 mT, 2 Hz) for 4 h/day within 1-5 days. In normal control group (NC) sciatic nerve was only dissected and manipulated. Each group was subdivided into three subgroups of five animals each and nerve fibers were studied 4, 8 and 12 weeks after surgery. Behavioral, functional, electrophysiological, biomechanical, gastrocnemius muscle mass findings and morphometric indices confirmed faster recovery of regenerated axons in CHIT/PEMF than in CHIT group (p PEMF were more positive than that in CHIT group. Whole body exposure to PEMF improved functional recovery and morphometric indices of sciatic nerve. Detailed mechanism of neuroprotective action remains to be investigated. PEMF combine with chitosan grafting could be considered as an effective, safe and tolerable treatment for peripheral nerve repair in clinical practice. Copyright © 2014 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

  10. Pulsed Electromagnetic Field Stimulation Promotes Anti-cell Proliferative Activity in Doxorubicin-treated Mouse Osteosarcoma Cells.

    Science.gov (United States)

    Muramatsu, Yoshitaka; Matsui, Takuya; Deie, Masataka; Sato, Keiji

    2017-01-02

    We aimed to investigate the synergistic effects of pulsed electromagnetic field (PEMF) and doxorubicin therapy in a mouse osteosarcoma cell line (LM8 cells) in vitro. The effects of PEMF (5 mT, 200 Hz) of different durations and doxorubicin on the proliferative activity of LM8 cells were measured by the MTT assay. Apoptotic-related factors such as cell-cycle phase, mitochondrial membrane potential, and caspase 3/7 activity were investigated using 4',6-diamidino-2-phenylindole staining and apoptosis kits. Identification of intracellular signaling molecules induced by the combination was comprehensively explored using a stress and apoptosis-related protein array kit. PEMF enhanced the inhibition of cell proliferation mediated by doxorubicin but did not affect the cell cycle, mitochondrial membrane potential, or doxorubicin-induced G 2 /M arrest. The combination of PEMF and doxorubicin altered a few signaling molecules. PEMF tended to reduce the doxorubicin-induced decrease of phosphorylated BAD, while reducing the increased expression of total IĸB and phosphorylated-CHK1 induced by doxorubicin. Our results indicate that combination of PEMF and doxorubicin could be a novel chemotherapeutic strategy. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  11. A randomised, placebo-controlled trial of transcranial pulsed electromagnetic fields in patients with multiple chemical sensitivity.

    Science.gov (United States)

    Tran, Marie Thi Dao; Skovbjerg, Sine; Arendt-Nielsen, Lars; Christensen, Karl Bang; Elberling, Jesper

    2017-10-01

    To evaluate the efficacy of transcranially applied pulsed electromagnetic fields (PEMF) on functional impairments and symptom severity in multiple chemical sensitivity (MCS) patients. The study was conducted as a nationwide trial in Denmark using a randomised, parallel-group, double-blind and placebo-controlled design. Sample size was estimated at 40 participants. Eligibility criteria were age 18-75 years and fulfilment of the MCS case criteria. Participants received either PEMF or placebo PEMF (no stimulation) applied transcranially for 6 weeks. The primary outcome was the Life Impact Scale (LIS) of the Quick Environmental Exposure and Sensitivity Inventory (QEESI). Secondary outcomes were the Symptom Severity Scale (SSS) and the Chemical Intolerance Scale of QEESI. A total of 39 participants were randomised to PEMF or placebo treatment. No significant difference was observed on QEESI LIS between groups with a mean change score of -5.9 in the PEMF group compared with -1.5 in the placebo group (p=0.35, effect size=-0.31). However, a significant decrease was detected on QEESI SSS within and between groups with a mean change score of -11.3 in the PEMF group compared with -3.2 in the placebo group (p=0.03, effect size=-0.60). PEMF treatment of 6 weeks showed no effect on functional impairments in MCS. However, a significant decrease in symptom severity was observed.

  12. Effect of pulsed electromagnetic fields (PEMF) on late-phase osteotomy gap healing in a canine tibial model.

    Science.gov (United States)

    Inoue, Nozomu; Ohnishi, Isao; Chen, Dongan; Deitz, Luke W; Schwardt, Jeffrey D; Chao, Edmund Y S

    2002-09-01

    The effects of a pulsed electromagnetic field (PEMF) on late bone healing phases using an osteotomy gap model in the canine mid-tibia were investigated. A transverse mid-diaphyseal tibial osteotomy with a 2-mm gap was performed unilaterally in 12 adult mixed-breed dogs and stabilized with external fixation. Animals in the variable group (n = 6) were treated with PEMF for 1 h daily starting 4 weeks after surgery for a total of 8 weeks, whereas no stimulation signal was generated in the control group (n = 6). Functional load-bearing and radiographic assessments were conducted time-sequentially until euthanasia 12 weeks after surgery. Torsional tests and an analysis of undecalcified histology were performed on the retrieved mid-tibial diaphysis containing the osteotomy site. In the PEMF group, load-bearing of the operated limb recovered earlier when compared to the control group (p PEMF group at 8 weeks was greater than in the control group (p PEMF group, while a significant increase was observed at 8 and 10 weeks after surgery (p PEMF group were significantly greater than those of the control group (p PEMF group. PEMF stimulation of 1 h per day for 8 weeks provided faster recovery of load-bearing, a significant increase in new bone formation, and a higher mechanical strength of the healing mid-tibial osteotomy. This study revealed enhancing effects of PEMF on callus formation and maturation in the late-phase of bone healing.

  13. A Pulsed Electromagnetic Field Protects against Glutamate-Induced Excitotoxicity by Modulating the Endocannabinoid System in HT22 Cells.

    Science.gov (United States)

    Li, Xin; Xu, Haoxiang; Lei, Tao; Yang, Yuefan; Jing, Da; Dai, Shuhui; Luo, Peng; Xu, Qiaoling

    2017-01-01

    Glutamate-induced excitotoxicity is common in the pathogenesis of many neurological diseases. A pulsed electromagnetic field (PEMF) exerts therapeutic effects on the nervous system, but its specific mechanism associated with excitotoxicity is still unknown. We investigated the role of PEMF exposure in regulating glutamate-induced excitotoxicity through the endocannabinoid (eCB) system. PEMF exposure improved viability of HT22 cells after excitotoxicity and reduced lactate dehydrogenase release and cell death. An eCB receptor 1 (CB1R) specific inhibitor suppressed the protective effects of PEMF exposure, even though changes in CB1R expression were not observed. Elevation of N-arachidonylethanolamide (AEA) and 2-arachidonylglycerol (2-AG) following PEMF exposure indicated that the neuroprotective effects of PEMF were related to modulation of the eCB metabolic system. Furthermore, CB1R/ERK signaling was shown to be an important downstream pathway of PEMF in regulating excitotoxicity. These results suggest that PEMF exposure leads to neuroprotective effects against excitotoxicity by facilitating the eCB/CB1R/ERK signaling pathway. Therefore, PEMF may be a potential physical therapeutic technique for preventing and treating neurological diseases.

  14. Mechanical Stimulation (Pulsed Electromagnetic Fields "PEMF" and Extracorporeal Shock Wave Therapy "ESWT") and Tendon Regeneration: A Possible Alternative.

    Science.gov (United States)

    Rosso, Federica; Bonasia, Davide E; Marmotti, Antonio; Cottino, Umberto; Rossi, Roberto

    2015-01-01

    The pathogenesis of tendon degeneration and tendinopathy is still partially unclear. However, an active role of metalloproteinases (MMP), growth factors, such as vascular endothelial growth factor (VEGF) and a crucial role of inflammatory elements and cytokines was demonstrated. Mechanical stimulation may play a role in regulation of inflammation. In vitro studies demonstrated that both pulsed electromagnetic fields (PEMF) and extracorporeal shock wave therapy (ESWT) increased the expression of pro-inflammatory cytokine such as interleukin (IL-6 and IL-10). Moreover, ESWT increases the expression of growth factors, such as transforming growth factor β(TGF-β), (VEGF), and insulin-like growth factor 1 (IGF1), as well as the synthesis of collagen I fibers. These pre-clinical results, in association with several clinical studies, suggest a potential effectiveness of ESWT for tendinopathy treatment. Recently PEMF gained popularity as adjuvant for fracture healing and bone regeneration. Similarly to ESWT, the mechanical stimulation obtained using PEMFs may play a role for treatment of tendinopathy and for tendon regeneration, increasing in vitro TGF-β production, as well as scleraxis and collagen I gene expression. In this manuscript the rational of mechanical stimulations and the clinical studies on the efficacy of extracorporeal shock wave (ESW) and PEMF will be discussed. However, no clear evidence of a clinical value of ESW and PEMF has been found in literature with regards to the treatment of tendinopathy in human, so further clinical trials are needed to confirm the promising hypotheses concerning the effectiveness of ESWT and PEMF mechanical stimulation.

  15. Pulsed electromagnetic energy treatment offers no clinical benefit in reducing the pain of knee osteoarthritis: a systematic review

    Directory of Open Access Journals (Sweden)

    Callaghan Michael

    2006-06-01

    Full Text Available Abstract Background The rehabilitation of knee osteoarthritis often includes electrotherapeutic modalities as well as advice and exercise. One commonly used modality is pulsed electromagnetic field therapy (PEMF. PEMF uses electro magnetically generated fields to promote tissue repair and healing rates. Its equivocal benefit over placebo treatment has been previously suggested however recently a number of randomised controlled trials have been published that have allowed a systematic review to be conducted. Methods A systematic review of the literature from 1966 to 2005 was undertaken. Relevant computerised bibliographic databases were searched and papers reviewed independently by two reviewers for quality using validated criteria for assessment. The key outcomes of pain and functional disability were analysed with weighted and standardised mean differences being calculated. Results Five randomised controlled trials comparing PEMF with placebo were identified. The weighted mean differences of the five papers for improvement in pain and function, were small and their 95% confidence intervals included the null. Conclusion This systematic review provides further evidence that PEMF has little value in the management of knee osteoarthritis. There appears to be clear evidence for the recommendation that PEMF does not significantly reduce the pain of knee osteoarthritis.

  16. Pulsed electromagnetic fields rapidly modulate intracellular signaling events in osteoblastic cells: comparison to parathyroid hormone and insulin.

    Science.gov (United States)

    Schnoke, Matthew; Midura, Ronald J

    2007-07-01

    Pulsed electromagnetic field (PEMF) devices are approved for the healing of bone nonunions, but there is a lack of understanding as to their mechanism of action at the cell and molecular level. Intermittent parathyroid hormone (PTH) therapy is currently utilized for treatment of osteoporosis, and is also being investigated for the purpose of augmenting fracture healing. Insulin and IGF-1 are also thought to play important anabolic roles in osteogenesis. In this report, signaling pathways activated by acute PTH or insulin treatments were compared to those activated by PEMF treatment in osteoblast-like cells. Some signaling molecules like the extracellular response kinases 1/2 (Erk1/2) and the cAMP response element binding protein (CREB) were activated by insulin and PTH, respectively, but not by PEMF treatment. Other signaling molecules like the insulin receptor substrate-1 (IRS-1), the S6 ribosomal subunit kinase, and the endothelial nitric oxide synthase (eNOS) were phosphorylated by PTH, insulin, and PEMF to the same relative extent and within the same time frame. IRS-1, eNOS, and S6 have been implicated in bone anabolism, and our results suggest that the anabolic effects of PEMF may be mediated, in part, through the activation of these proteins. Copyright (c) 2007 Orthopaedic Research Society.

  17. Pulsed electromagnetic field therapy improves tendon-to-bone healing in a rat rotator cuff repair model

    Science.gov (United States)

    Tucker, Jennica J; Cirone, James M.; Morris, Tyler R.; Nuss, Courtney A.; Huegel, Julianne; Waldorff, Erik I.; Zhang, Nianli; Ryaby, James T.; Soslowsky, Louis J.

    2017-01-01

    Rotator cuff tears are common musculoskeletal injuries often requiring surgical intervention with high failure rates. Currently, pulsed electromagnetic fields (PEMFs) are used for treatment of long-bone fracture and lumbar and cervical spine fusion surgery. No studies have investigated PEMF in healing soft tissue. Therefore, we investigated the effect of PEMF on rotator cuff healing using a rat rotator cuff repair model. We hypothesized that PEMF exposure following rotator cuff repair would improve tendon mechanical properties, tissue morphology, and alter in vivo joint function. 70 adult male Sprague-Dawley rats were assigned to three groups: bilateral repair with PEMF (n=30), bilateral repair followed by cage activity (n=30), uninjured control with cage activity (n=10). Rats in the surgical groups were sacrificed at 4, 8, and 16 weeks. Control group was sacrificed at 8 weeks. Passive joint mechanics and gait analysis were assessed over time. Biomechanical analysis and µCT was performed on left shoulders; histological analysis on right shoulders. Results indicate no differences in passive joint mechanics and ambulation. At 4 weeks the PEMF group had decreased cross-sectional area and increased modulus and maximum stress. At 8 weeks the PEMF group had increased modulus and more rounded cells in the midsubstance. At 16 weeks the PEMF group had improved bone quality. Therefore, results indicate that PEMF improves early tendon healing and does not alter joint function in a rat rotator cuff repair model. Statement of Clinical Significance PEMF exposure following rotator cuff repair improves early tendon healing. PMID:27282093

  18. Assessment of pulsed electromagnetic field therapy with Serum YKL-40 and ultrasonography in patients with knee osteoarthritis.

    Science.gov (United States)

    Dündar, Ümit; Aşık, Gülşah; Ulaşlı, Alper Murat; Sınıcı, Şükrü; Yaman, Fatima; Solak, Özlem; Toktaş, Hasan; Eroğlu, Selma

    2016-03-01

    The use of biomarkers of osteoarthritis (OA) have potential for early diagnosis, evaluation of disease severity and monitoring treatment. Serum and synovial fluid YKL-40 levels are increased in severe knee OA. Pulsed electromagnetic field (PEMF) therapy is a novel treatment method for OA. However, studies evaluating the PEMF therapy in treatment of knee OA revealed conflicting results. This study was conducted to objectively assess the effect of PEMF therapy in patients with knee OA, by using ultrasonographic measurements and a novel biomarker, YKL-40. Forty patients were randomized into two treatment groups. Both groups received conventional physical therapy, while Group 1 received additional PEMF therapy. The patients were asked to rate their pain on a visual analogue scale (VAS) and complete a Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire. Serum YKL-40 levels were measured, and knee effusion and cartilage degeneration level were evaluated with ultrasonography before and after treatment. Pre-treatment YKL-40 level was correlated with WOMAC pain subscale (P = 0.032, r = 0.339). VAS and WOMAC scores significantly improved in both treatment groups (P PEMF therapy has no additional effect on pain in patients with knee OA. Serum YKL-40 level seems to be unuseful for monitoring the treatment in knee OA. © 2015 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  19. Effects of pulsed electromagnetic field vibration on tooth movement induced by magnetic and mechanical forces: a preliminary study.

    Science.gov (United States)

    Darendeliler, M Ali; Zea, A; Shen, G; Zoellner, H

    2007-12-01

    This study was designed to determine whether or not high-frequency and low-magnitude vibration affects orthodontic tooth movement caused by magnetic or/and mechanical forces. Forty-four 7-week-old Wistar rats were randomly divided into four groups, with each group further divided into experimental and control subgroups. Neodymium-Iron-Boron (Nd-Fe-B) magnets and Sentalloy closed coil springs were placed between maxillary or mandibular first molars and incisors to activate tooth movement. The animals of experimental subgroups were exposed to the vibration induced by pulsed electromagnetic fields (PEMF) whilst the control subgroups were under normal atmosphere. The experiment lasted for 14 days and all of the animals were sacrificed for examination. The changes in the space between the molar and incisor were measured to indicate the amount of tooth movement. The coil springs, either with sham or active magnets, move molar much more than magnets alone, regardless of absence or presence of PEMF (p < 0.001). Under PEMF, the coil spring moved significantly more amount of tooth movement than that of coil-magnet combination (p < 0.01), as did the magnets compared to sham magnets (p < 0.019). Under a non-PEMF scenario, there was no significant difference in tooth movement between coil spring and coil-magnets combination, nor was there difference between magnets and sham magnets. It is suggested that the PEMF-induced vibration may enhance the effect of mechanical and magnetic forces on tooth movement.

  20. Effects of combined pulse electromagnetic field stimulation plus glutamine on the healing of colonic anastomosis in rats.

    Science.gov (United States)

    Girgin, Sadullah; Gedik, Ercan; Ozturk, Hayrettin; Akpolat, Veysi; Akbulut, Veysi; Kale, Ebru; Buyukbayram, Huseyin; Celik, Salih

    2009-04-01

    An experimental study was designed to investigate the effect of combined pulse electromagnetic field (PEMF) stimulation plus glutamine administration on colonic anastomosis. Anastomosis of the left colon was performed in 28 rats, which were divided into four groups; Group 1: normal resection anastomosis plus oral 50 mg/kg/day glutamine; Group 2: normal resection anastomosis plus PEMF stimulation plus oral 50 mg/kg/day glutamine; Group 3: normal resection anastomosis plus PEMF stimulation; Group 4: normal resection anastomosis. On the seventh postoperative day, the animals were killed and the bursting pressure and tissue hydroxyproline concentration of the anastomosis were analyzed and compared. The mean anastomotic bursting pressure in Group 2 was significantly higher than in Groups 1 and 4. On the other hand, the mean anastomotic bursting pressure in Group 1 was significantly higher than in Group 4. The collagen deposition and the fibroblast infiltration were significantly increased on the seventh day in Group 3 compared the other groups. On the other hand, Groups 1 and 2 had higher scores for collagen deposition and fibroblast infiltration than Group 4. In conclusion, burst pressures, hydroxyproline, and histologic features (fibroblast infiltration and collagen deposition) were improved in the PEMF group, and both PEMF and glutamine-enriched nutrition provide a significant gain in the strength of colonic anastomoses in rats.

  1. Limitations of the strong field approximation in ionization of the hydrogen atom by ultrashort pulses

    International Nuclear Information System (INIS)

    Arbo, D.G.; Toekesi, K.; Miraglia, J.E.; FCEN, University of Buenos Aires

    2008-01-01

    Complete text of publication follows. We presented a theoretical study of the ionization of hydrogen atoms as a result of the interaction with an ultrashort external electric field. Doubly-differential momentum distributions and angular momentum distributions of ejected electrons calculated in the framework of the Coulomb-Volkov and strong field approximations, as well as classical calculations are compared with the exact solution of the time dependent Schroedinger equation. We have shown that the Coulomb-Volkov approximation (CVA) describes the quantum atomic ionization probabilities exactly when the external field is described by a sudden momentum transfer [1]. The velocity distribution of emitted electrons right after ionization by a sudden momentum transfer is given through the strong field approximation (SFA) within both the CVA and CTMC methods. In this case, the classical and quantum time dependent evolutions of an atom subject to a sudden momentum transfer are identical. The difference between the classical and quantum final momentum distributions resides in the time evolution of the escaping electron under the subsequent action of the Coulomb field. Furthermore, classical mechanics is incapable of reproducing the quantum angular momentum distribution due to the improper initial radial distribution used in the CTMC calculations, i.e., the microcanonical ensemble. We find that in the limit of high momentum transfer, based on the SFA, there is a direct relation between the cylindrical radial distribution dP/dρ and the final angular momentum distribution dP/dL. This leads to a close analytical expression for the partial wave populations (dP/dL) SFA-Q given by dP SFA-Q / dL = 4Z 3 L 2 / (Δp) 3 K 1 (2ZL/Δp) which, together with the prescription L = l + 1/2, reproduces quite accurately the quantum (CVA) results. Considering the inverse problem, knowing the final angular momentum distribution can lead to the inference of the initial probability distribution

  2. Short-term effects of extremely low-frequency pulsed electromagnetic field and pulsed low-level laser therapy on rabbit model of corneal alkali burn.

    Science.gov (United States)

    Rezaei Kanavi, Mozhgan; Tabeie, Faraj; Sahebjam, Farzin; Poursani, Nima; Jahanbakhsh, Nazanin; Paymanpour, Pouya; AfsarAski, Sasha

    2016-04-01

    This study was conducted to investigate the effect of combining extremely low frequency-pulsed electromagnetic field (ELF-PEMF) and low-level laser therapy (LLLT) on alkali-burned rabbit corneas. Fifty alkali-burned corneas of 50 rabbits were categorized into five groups: ELF-PEMF therapy with 2 mT intensity (ELF 2) for 2 h daily; LLLT for 30 min twice daily; combined ELF-PEMF and LLLT (ELF + LLLT); medical therapy (MT); and control (i.e., no treatment). Clinical examination and digital photography of the corneas were performed on days 0, 2, 7, and 14. After euthanizing the rabbits, the affected eyes were evaluated by histopathology. The clinical and histopathologic results were compared between the groups. On days 7 and 14, no significant difference in the corneal defect area was evident between the ELF, LLLT, ELF + LLLT, and MT groups. Excluding the controls, none of the study groups demonstrated a significant corneal neovascularization in both routine histopathology and immunohistochemistry for CD31. Keratocyte loss was significantly higher in the MT group than in the ELF, LLLT, and ELF + LLLT groups. Moderate to severe stromal inflammation in the LLLT group was comparable with that in the MT group and was significantly lower than that in the other groups. In conclusion, combining LLLT and ELF was not superior to ELF alone or LLLT alone in healing corneal alkali burns. However, given the lower intensity of corneal inflammation and the lower rate of keratocytes loss with LLLT, this treatment may be superior to other proposed treatment modalities for healing alkali-burned corneas. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Corrigendum to “Influence of Pulsed Electromagnetic Field on Plant Growth, Nutrient Absorption and Yield of Durum Wheat” [Notulae Scientia Biologicae, 2015, 7(4:505-509

    Directory of Open Access Journals (Sweden)

    Nikolaos KATSENIOS

    2016-03-01

    Full Text Available Corrigendum to the article: “Influence of Pulsed Electromagnetic Field on Plant Growth, Nutrient Absorption and Yield of Durum Wheat”, Notulae Scientia Biologicae 7(4:505-509, 2015. In the printed version of this article, a figure (page 508, Fig. 5 that was published in Acta Agriculturae Scandinavica Section B 62(1:94-99 (2012 was accidentally used. The figure was replaced with an original one (Fig. 5 PAPIMI device.

  4. Pulsed Electromagnetic Fields Improve Bone Microstructure and Strength in Ovariectomized Rats through a Wnt/Lrp5/?-Catenin Signaling-Associated Mechanism

    OpenAIRE

    Jing, Da; Li, Feijiang; Jiang, Maogang; Cai, Jing; Wu, Yan; Xie, Kangning; Wu, Xiaoming; Tang, Chi; Liu, Juan; Guo, Wei; Shen, Guanghao; Luo, Erping

    2013-01-01

    Growing evidence has demonstrated that pulsed electromagnetic field (PEMF), as an alternative noninvasive method, could promote remarkable in vivo and in vitro osteogenesis. However, the exact mechanism of PEMF on osteopenia/osteoporosis is still poorly understood, which further limits the extensive clinical application of PEMF. In the present study, the efficiency of PEMF on osteoporotic bone microarchitecture and bone quality together with its associated signaling pathway mechanisms was sys...

  5. Effects of low-intensity pulsed electromagnetic fields on bone microarchitecture, mechanical strength and bone turnover in type 2 diabetic db/db mice

    OpenAIRE

    Li, Jianjun; Zeng, Zhaobin; Zhao, Yantao; Jing, Da; Tang, Chuhua; Ding, Yin; Feng, Xue

    2017-01-01

    Type 2 diabetic patients have impaired bone quality, leading to increased fracture risk. Substantial evidence demonstrates that pulsed electromagnetic fields (PEMF) could resist osteopenia/osteoporosis induced by estrogen deficiency and disuse. However, the effects of PEMF on osteopenia/osteoporosis associated with diabetes, especially for more prevalent type 2 diabetes, remain poorly understood. We herein investigated the skeletal effects and mechanisms of PEMF (15?Hz, 20 Gs) on leptin recep...

  6. Comparison of ATLOG and Xyce for Bell Labs Electromagnetic Pulse Excitation of Finite-Long Dissipative Conductors over a Ground Plane.

    Energy Technology Data Exchange (ETDEWEB)

    campione, Salvatore [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Warne, Larry K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schiek, Richard [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Basilio, Lorena I. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    This report details the modeling results for the response of a finite-length dissipative conductor interacting with a conducting ground to the Bell Labs electromagnetic pulse excitation. We use both a frequency-domain and a time-domain method based on transmission line theory through a code we call ATLOG - Analytic Transmission Line Over Ground. Results are compared to the circuit simulator Xyce for selected cases. Intentionally Left Blank

  7. Design and Fabrication of Helmholtz Coils to Study the Effects of Pulsed Electromagnetic Fields on the Healing Process in Periodontitis: Preliminary Animal Results

    Directory of Open Access Journals (Sweden)

    Haghnegahdar A

    2014-09-01

    Full Text Available Background: Effects of electromagnetic fields on healing have been investigated for centuries. Substantial data indicate that exposure to electromagnetic field can lead to enhanced healing in both soft and hard tissues. Helmholtz coils are devices that generate pulsed electromagnetic fields (PEMF. Objective: In this work, a pair of Helmholtz coils for enhancing the healing process in periodontitis was designed and fabricated. Method: An identical pair of square Helmholtz coils generated the 50 Hz magnetic field. This device was made up of two parallel coaxial circular coils (100 turns in each loop, wound in series which were separated from each other by a distance equal to the radius of one coil (12.5 cm. The windings of our Helmholtz coil was made of standard 0.95mm wire to provide the maximum possible current. The coil was powered by a function generator. Results: The Helmholtz Coils generated a uniform magnetic field between its coils. The magnetic field strength at the center of the space between two coils was 97.6 μT. Preliminary biological studies performed on rats show that exposure of laboratory animals to pulsed electromagnetic fields enhanced the healing of periodontitis. Conclusion: Exposure to PEMFs can lead to stimulatory physiological effects on cells and tissues such as enhanced healing of periodontitis.

  8. Measurement and analysis of electromagnetic fields of pulsed magnetic field therapy systems for private use

    International Nuclear Information System (INIS)

    Jaermann, Thomas; Suter, Fabian; Osterwalder, Diego; Luechinger, Roger

    2011-01-01

    Recently, pulsed magnetic field therapy (PMFT) systems have become available for private use. Although they may be applied without medical supervision, only a little is known about their field quantities. In this study, the spatial distribution and the temporal characteristics of the magnetic flux densities of three PMFT systems, available in Europe, were analysed. In close proximity to the surface, the maxima of the peak magnetic flux densities were 461 μT, 170 μT and 133 μT, respectively. At a distance of 30 cm above the whole body mat, the peak magnetic flux density was 77 μT. The excitation patterns consisted of repeating bursts with carrier frequencies between 210 and 1667 Hz. In conclusion, magnetic flux densities were far above International Commission on Non-Ionizing Radiation Protection reference levels. Since these systems are supposed to be medical devices as well as wellness devices, risk analysis of PMFT systems and the effectiveness of these devices need to be investigated in future studies.

  9. Carpal scaphoid non-union treatment: a retrospective trial comparing simple retrograde percutaneous screw fixation versus percutaneous screw fixation plus pulsed electromagnetic fields (Physiostim®).

    Science.gov (United States)

    Pereira, Alexis; Hidalgo Díaz, Juan José; Saur, Maurise; Salazar Botero, Santiago; Facca, Sybille; Liverneaux, Philippe

    2017-05-01

    The purpose of this retrospective comparative study was to assess whether a complementary treatment by pulsed electromagnetic field could increase the bone-healing rate of scaphoid non-union without SNAC (scaphoid non-union advanced collapse) treated by retrograde percutaneous screw fixation. Eighteen patients with scaphoid non-union were included in this retrospective study. The group 1 was made of nine cases (seven stage IIA and two stage IIB) of scaphoid non-union treated by retrograde percutaneous screw fixation and pulsed electromagnetic fields (Physiostim ® ). The group 2 was made of nine cases (six stage IIA and three stage IIB) treated by simple retrograde percutaneous screw fixation. With a 10-month follow-up in group 1 and a 9.5-month follow-up in group 2, there were three cases of non-union in group 1 and two cases in group 2. Regarding the type of non-union, there was one case among the stage IIB and four cases among the stage IIA. The results of the study did not show any interest in the use of pulsed electromagnetic field for the treatment of carpal scaphoid non-union. They should be dropped. III.

  10. THE GENERATION OF THERMOELASTIC STRESS WAVES BY IMPULSIVE ELECTROMAGNETIC RADIATION.

    Science.gov (United States)

    ELECTROMAGNETIC RADIATION , ABSORPTION), (*STRESSES, ELECTROMAGNETIC RADIATION ), SURFACE PROPERTIES, INTERACTIONS, HEAT TRANSFER, ELASTIC PROPERTIES, ELECTROMAGNETIC PULSES, LASERS, MATHEMATICAL ANALYSIS, BOUNDARY VALUE PROBLEMS, SOLIDS

  11. Electromagnetic Pulse in the Magnetosphere Generated by Impulsive Current near the Lower Boundary of the Ionosphere

    Science.gov (United States)

    Surkov, V. V.; Galperin, Yu. I.

    2000-11-01

    A solution to the problem of current spreading is constructed in the case of relaxation of electric charges, which have arisen in the mesosphere for one reason or other. These currents penetrate into the conductive region with anisotropic conductivity of the D- and E-layers of the ionosphere, being transformed to a MHD-wave that propagates into the magnetosphere. Based on this solution, the form and spectrum of the generated MHD signal are calculated for Alfvenic and magnetosonic modes coming out to the ionosphere and magnetosphere. Electric charges and currents can arise, for example, in the space between a thunderstorm cloud and the ionosphere, or between the shock wave from a ground explosion and the ionosphere. Some signal parameters accepted in the model are close to those expected for high-altitude electric discharges of the Red Sprite type. The conditions are determined under which the Alfven impulse with an amplitude of up to 100 nT propagates in the magnetosphere above high-altitude discharge of this type. Such an impulse was recorded by the AUREOL-3 satellite after the ground explosion MASSA-1. Recently, this impulse was hypothesized to originate as a result of a high-altitude electric discharge. The hypothesis on a similar MHD pulse allows one to explain in a semiquantitative way the short burst of electron field-aligned acceleration observed by the DE-2 satellite over the Debbie hurricane. The high-altitude atmospheric discharge of this type can be a powerful, though short-time and local, source of electrons with kiloelectronvolt energies at low and middle latitudes. One could expect that such an effect causes a modified character of the so-called Trimpi-effect (a short-term disturbance of propagation of VLF waves in the ionosphere), and thus, it can be observable.

  12. Hydroxytyrosol contributes to cell proliferation and inhibits apoptosis in pulsed electromagnetic fields treated human umbilical vein endothelial cells in vitro

    Science.gov (United States)

    Cheng, Yong; Qu, Zhiwei; Fu, Ximeng; Jiang, Qi; Fei, Jianfeng

    2017-01-01

    A variety of pulsed electromagnetic fields (PEMFs) have been experimentally and clinically used in an effort to promote wound healing, although the mechanisms involved remain unknown. The aim of the present study was to investigate the action of a novel protocol of co-treatment with PEMFs and hydroxytyrosol (HTY) on the proliferation and differentiation potential of human umbilical vein endothelial cells (HUVECs). The HUVECs were assigned randomly into three groups: Control, PEMF-treated and PEMF + HT-treated. The intensity of the electromagnetic field used in this protocol was 2.25 mT, the frequency of the bursts was 50 Hz and the application time was 15 min. A Cell Counting kit-8 (CCK-8) assay was used to assess cell proliferation, and cell apoptosis was analyzed by TUNEL apoptosis assay kit and calcein-acetoxymethyl/propidium iodide dual-staining assay. In addition, protein and mRNA expression levels of protein kinase B (Akt), mechanistic target of rapamycin (mTOR), transforming growth factor (TGF)-β1 and p53 were determined by western blotting and reverse transcription-quantitative polymerase chain reaction assays, respectively. The CCK-8 assay demonstrated that HTY contributed to HUVEC proliferation mediated by PEMFs in a time-dependent manner. The Transwell assay and scratch wound results demonstrated that co-treatment of HTY and PEMFs could increase HUVEC migration. Furthermore, the levels of apoptotic cells were reversed by pre-incubation with HTY in the PEMF treatment group, while PEMF treatment alone had no such effect. The proteins and mRNA expression levels of Akt, mTOR, TGF-β1 were elevated in co-treatment of HTY and PEMFs, whereas there was no effect on levels of p53. Therefore, the results indicated that combined exposure of HUVECs to PEMFs and HTY exerted protective effects in HUVECs by promoting cell proliferation and inhibiting apoptosis. In conclusion, to the best of our knowledge, the present study was the first to demonstrate the beneficial

  13. Therapeutic effects of 15 Hz pulsed electromagnetic field on diabetic peripheral neuropathy in streptozotocin-treated rats.

    Science.gov (United States)

    Lei, Tao; Jing, Da; Xie, Kangning; Jiang, Maogang; Li, Feijiang; Cai, Jing; Wu, Xiaoming; Tang, Chi; Xu, Qiaoling; Liu, Juan; Guo, Wei; Shen, Guanghao; Luo, Erping

    2013-01-01

    Although numerous clinical studies have reported that pulsed electromagnetic fields (PEMF) have a neuroprotective role in patients with diabetic peripheral neuropathy (DPN), the application of PEMF for clinic is still controversial. The present study was designed to investigate whether PEMF has therapeutic potential in relieving peripheral neuropathic symptoms in streptozotocin (STZ)-induced diabetic rats. Adult male Sprague-Dawley rats were randomly divided into three weight-matched groups (eight in each group): the non-diabetic control group (Control), diabetes mellitus with 15 Hz PEMF exposure group (DM+PEMF) which were subjected to daily 8-h PEMF exposure for 7 weeks and diabetes mellitus with sham PEMF exposure group (DM). Signs and symptoms of DPN in STZ-treated rats were investigated by using behavioral assays. Meanwhile, ultrastructural examination and immunohistochemical study for vascular endothelial growth factor (VEGF) of sciatic nerve were also performed. During a 7-week experimental observation, we found that PEMF stimulation did not alter hyperglycemia and weight loss in STZ-treated rats with DPN. However, PEMF stimulation attenuated the development of the abnormalities observed in STZ-treated rats with DPN, which were demonstrated by increased hind paw withdrawal threshold to mechanical and thermal stimuli, slighter demyelination and axon enlargement and less VEGF immunostaining of sciatic nerve compared to those of the DM group. The current study demonstrates that treatment with PEMF might prevent the development of abnormalities observed in animal models for DPN. It is suggested that PEMF might have direct corrective effects on injured nerves and would be a potentially promising non-invasive therapeutic tool for the treatment of DPN.

  14. Pulsed electromagnetic field (PEMF) treatment reduces expression of genes associated with disc degeneration in human intervertebral disc cells.

    Science.gov (United States)

    Miller, Stephanie L; Coughlin, Dezba G; Waldorff, Erik I; Ryaby, James T; Lotz, Jeffrey C

    2016-06-01

    Pulsed electromagnetic field (PEMF) therapies have been applied to stimulate bone healing and to reduce the symptoms of arthritis, but the effects of PEMF on intervertebral disc (IVD) biology is unknown. The purpose of this study was to determine how PEMF affects gene expression of IVD cells in normal and inflammatory environments. This was an in vitro human cell culture and microarray gene expression study. Human annulus fibrosus (AF) and nucleus pulposus (NP) cells were separately encapsulated in alginate beads and exposed to interleukin 1α (IL-1α) (10 ng/mL) to stimulate the inflammatory environment associated with IVD degeneration and/or stimulated by PEMF for 4 hours daily for up to 7 days. RNA was isolated from each treatment group and analyzed via microarray to assess IL-1α- and PEMF-induced changes in gene expression. Although PEMF treatment did not completely inhibit the effects of IL-1α, PEMF treatment lessened the IL-1α-induced upregulation of genes expressed in degenerated IVDs. Consistent with our previous results, after 4 days, PEMF tended to reduce IL-1α-associated gene expression of IL-6 (25%, p=.07) in NP cells and MMP13 (26%, p=.10) in AF cells. Additionally, PEMF treatment significantly diminished IL-1α-induced gene expression of IL-17A (33%, p=.01) and MMP2 (24%, p=.006) in NP cells and NFκB (11%, p=.04) in AF cells. These results demonstrate that IVD cells are responsive to PEMF and motivate future studies to determine whether PEMF may be helpful for patients with IVD degeneration. Copyright © 2016. Published by Elsevier Inc.

  15. Effect of pulsed electromagnetic field treatment on programmed resolution of inflammation pathway markers in human cells in culture.

    Science.gov (United States)

    Kubat, Nicole J; Moffett, John; Fray, Linley M

    2015-01-01

    Inflammation is a complex process involving distinct but overlapping biochemical and molecular events that are highly regulated. Pulsed electromagnetic field (PEMF) therapy is increasingly used to treat pain and edema associated with inflammation following surgery involving soft tissue. However, the molecular and cellular effects of PEMF therapy on pathways involved in the resolution of inflammation are poorly understood. Using cell culture lines relevant to trauma-induced inflammation of the skin (human dermal fibroblasts, human epidermal keratinocytes, and human mononuclear cells), we investigated the effect of PEMF on gene expression involved in the acute and resolution phases of inflammation. We found that PEMF treatment was followed by changes in the relative amount of messenger (m)RNAs encoding enzymes involved in heme catabolism and removal of reactive oxygen species, including an increase in heme oxygenase 1 and superoxide dismutase 3 mRNAs, in all cell types examined 2 hours after PEMF treatment. A relative increase in mRNAs encoding enzymes involved in lipid mediator biosynthesis was also observed, including an increase in arachidonate 12- and 15-lipoxygenase mRNAs in dermal fibroblasts and epidermal keratinocytes, respectively. The relative amount of both of these lipoxygenase mRNAs was elevated in mononuclear cells following PEMF treatment relative to nontreated cells. PEMF treatment was also followed by changes in the mRNA levels of several cytokines. A decrease in the relative amount of interleukin 1 beta mRNA was observed in mononuclear cells, similar to that previously reported for epidermal keratinocytes and dermal fibroblasts. Based on our results, we propose a model in which PEMF therapy may promote chronic inflammation resolution by mediating gene expression changes important for inhibiting and resolving inflammation.

  16. Pulsed electromagnetic field therapy for management of osteoarthritis-related pain, stiffness and physical function: clinical experience in the elderly.

    Science.gov (United States)

    Iannitti, Tommaso; Fistetto, Gregorio; Esposito, Anna; Rottigni, Valentina; Palmieri, Beniamino

    2013-01-01

    Pulsed electromagnetic field (PEMF) therapy has shown promising therapeutic effectiveness on bone- and cartilage-related pathologies, being also safe for management of knee osteoarthritis. The aim of this study was to investigate the clinical efficacy of a PEMF device for management of knee osteoarthritis in elderly patients. A total of 33 patients were screened, and 28 patients, aged between 60 and 83 and affected by bilateral knee osteoarthritis, were enrolled in this study. They received PEMF therapy on the right leg for a total of three 30-minute sessions per week for a period of 6 weeks, while the left leg did not receive any treatment and served as control. An intravenous drip containing ketoprofen, sodium clodronate, glucosamine sulfate, calcitonin, and ascorbic acid, for a total volume of 500 mL, was administered during PEMF therapy. At baseline and 3 months post-PEMF therapy, Visual Analog Scale (VAS) was used to assess knee pain and Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) was used to measure knee pain, stiffness and physical function. Changes in VAS and WOMAC scores were calculated for both knees as baseline minus post-treatment. A two sample Student's t-test, comparing change in knee-related VAS pain for PEMF-treated leg (49.8 ± 2.03) vs control leg (11 ± 1.1), showed a significant difference in favor of PEMF therapy (P PEMF-treated leg (8.5 ± 0.4, 3.5 ± 0.2, 38.5 ± 2.08, respectively) vs control leg (2.6 ± 0.2; 1.6 ± 0.1; 4.5 ± 0.5 respectively), also showed a significant difference in favor of PEMF therapy (P PEMF therapy improves pain, stiffness and physical function in elderly patients affected by knee osteoarthritis.

  17. β-Adrenergic response is counteracted by extremely-low-frequency pulsed electromagnetic fields in beating cardiomyocytes.

    Science.gov (United States)

    Cornacchione, Marisa; Pellegrini, Manuela; Fassina, Lorenzo; Mognaschi, Maria Evelina; Di Siena, Sara; Gimmelli, Roberto; Ambrosino, Paolo; Soldovieri, Maria Virginia; Taglialatela, Maurizio; Gianfrilli, Daniele; Isidori, Andrea M; Lenzi, Andrea; Naro, Fabio

    2016-09-01

    Proper β-adrenergic signaling is indispensable for modulating heart frequency. Studies on extremely-low-frequency pulsed electromagnetic field (ELF-PEMF) effects in the heart beat function are contradictory and no definitive conclusions were obtained so far. To investigate the interplay between ELF-PEMF exposure and β-adrenergic signaling, cultures of primary murine neonatal cardiomyocytes and of sinoatrial node were exposed to ELF-PEMF and short and long-term effects were evaluated. The ELF-PEMF generated a variable magnetic induction field of 0-6mT at a frequency of 75Hz. Exposure to 3mT ELF-PEMF induced a decrease of contraction rate, Ca(2+) transients, contraction force, and energy consumption both under basal conditions and after β-adrenergic stimulation in neonatal cardiomyocytes. ELF-PEMF exposure inhibited β-adrenergic response in sinoatrial node (SAN) region. ELF-PEMF specifically modulated β2 adrenergic receptor response and the exposure did not modify the increase of contraction rate after adenylate cyclase stimulation by forskolin. In HEK293T cells transfected with β1 or β2 adrenergic receptors, ELF-PEMF exposure induced a rapid and selective internalization of β2 adrenergic receptor. The β-adrenergic signaling, was reduced trough Gi protein by ELF-PEMF exposure since the phosphorylation level of phospholamban and the PI3K pathway were impaired after isoproterenol stimulation in neonatal cardiomyocytes. Long term effects of ELF-PEMF exposure were assessed in cultures of isolated cardiomyocytes. ELF-PEMF counteracts cell size increase, the generation of binucleated of cardiomyocytes and prevents the up-regulation of hypertrophic markers after β-adrenergic stimulation, indicating an inhibition of cell growth and maturation. These data show that short and long term exposure to ELF-PEMF induces a reduction of cardiac β-adrenergic response at molecular, functional and adaptative levels. Published by Elsevier Ltd.

  18. Dynamic imaging demonstrates that pulsed electromagnetic fields (PEMF) suppress IL‐6 transcription in bovine nucleus pulposus cells

    Science.gov (United States)

    Tang, Xinyan; Alliston, Tamara; Coughlin, Dezba; Miller, Stephanie; Zhang, Nianli; Waldorff, Erik I.; Ryaby, James T.

    2017-01-01

    ABSTRACT Inflammatory cytokines play a dominant role in the pathogenesis of disc degeneration. Pulsed electromagnetic fields (PEMF) are noninvasive biophysical stimulus that has been used extensively in the orthopaedic field for many years. However, the specific cellular responses and mechanisms involved are still unclear. The objective of this study was to assess the time‐dependent PEMF effects on pro‐inflammatory factor IL‐6 expression in disc nucleus pulposus cells using a novel green fluorescence protein (GFP) reporter system. An MS2‐tagged GFP reporter system driven by IL‐6 promoter was constructed to visualize PEMF treatment effect on IL‐6 transcription in single living cells. IL‐6‐MS2 reporter‐labeled cells were treated with IL‐1α to mimic the in situ inflammatory environment of degenerative disc while simultaneously exposed to PEMF continuously for 4 h. Time‐lapse imaging was recorded using a confocal microscope to track dynamic IL‐6 transcription activity that was demonstrated by GFP. Finally, real‐time RT‐PCR was performed to confirm the imaging data. Live cell imaging demonstrated that pro‐inflammatory factor IL‐1α significantly promoted IL‐6 transcription over time as compared with DMEM basal medium condition. Imaging and PCR data demonstrated that the inductive effect of IL‐1α on IL‐6 expression could be significantly inhibited by PEMF treatment in a time‐dependent manner (early as 2 h of stimulus initiation). Our data suggest that PEMF may have a role in the clinical management of patients with chronic low back pain. Furthermore, this study shows that the MS2‐tagged GFP reporter system is a useful tool for visualizing the dynamic events of mechanobiology in musculoskeletal research. © 2017 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 35:778–787, 2018. PMID:28851112

  19. Mechanical stimulation (pulsed electromagnetic fields "PEMF" and extracorporeal shock wave therapy "ESWT" and tendon regeneration: a possible alternative.

    Directory of Open Access Journals (Sweden)

    Federica eRosso

    2015-11-01

    Full Text Available The pathogenesis of tendon degeneration and tendinopathy is still partially unclear. However, an active role of metalloproteinases (MMP, growth factors, such as vascular endothelial growth factor (VEGF and a crucial role of inflammatory elements and cytokines was demonstrated. Mechanical stimulation may play a role in regulation of inflammation. In vitro studies demonstrated that both pulsed electromagnetic fields (PEMF and extracorporeal shock wave therapy (ESWT increased the expression of pro-inflammatory cytokine such as interleukin (IL-6 and IL-10. Moreover ESWT increases the expression of growth factors, such as transforming growth factor beta (TGF-beta, Vascular Endothelial Growth Factor (VEGF, and insulin-like growth factor 1 (IGF1, as well as the synthesis of collagen I fibers. These pre-clinical results, in association with several clinical studies, suggest a potential effectiveness of ESWT for tendinopathy treatment. Recently PEMF gained popularity as adjuvant for fracture healing and bone regeneration. Similarly to ESWT, the mechanical stimulation obtained using PEMFs may play a role for treatment of tendinopathy and for tendon regeneration, increasing in-vitro TGF-beta production, as well as scleraxis and collagen I gene expression. In this manuscript the rational of mechanical stimulations and the clinical studies on the efficacy of extracorporeal shock wave (ESW and PEMF will be discussed. However, no clear evidence of a clinical value of ESW and PEMF has been found in literature with regards to the treatment of tendinopathy in human, so further clinical trials are needed to confirm the promising hypotheses concerning the effectiveness of ESWT and PEMF mechanical stimulation.

  20. Low-level laser therapy vs. pulsed electromagnetic field on neonatal rat calvarial osteoblast-like cells.

    Science.gov (United States)

    Emes, Yusuf; Akça, Kivanç; Aybar, Buket; Yalçın, Serhat; Çavuşoğlu, Yeliz; Baysal, Uğur; Işsever, Halim; Atalay, Belir; Vural, Pervin; Ergüven, Mine; Çehreli, Murat Cavit; Bilir, Ayhan

    2013-05-01

    To compare the effects of pulsed electromagnetic field (PEMF) and low-level laser therapy (LLLT) on osteoblast cells in a cell culture model. Fifty thousand neonatal rat calvarial osteoblast-like cells per milliliter were seeded and 0.06 mT PEMF, 0.2 mT PEMF, and LLLT at 808 nm were applied for 24 and 96 h on the cells. To evaluate cellular proliferation and differentiation, specimens were examined for DNA synthesis, alkaline phosphatase (ALP) activity, cell numbers, and viability of the cells. Morphological appearances of the cells were observed using scanning electron microcopy after 24 and 96 h of incubation. At 24 and 96 h, the control group had a higher cell proliferation than 0.06 and 0.2 mT PEMF groups (p=0.001). At 96 h, 0.2 mT PEMF group had higher cell proliferation rate than 0.06 mT PEMF and LLLT groups (p=0.001). The cell count and cell viability in 0.2 mT PEMF group were higher than the 0.06-mT PEMF and LLLT groups, although these differences were not statistically significant at 96 h (p>0.05). At 24 and 96 h, cell viability in the control group was higher than the test groups. Alkaline phosphatase levels of the groups were comparable in both time intervals (p>0.05). 0.2 mT PEMF application on osteoblast-like cells led to cell proliferation and differentiation better than 0.06 mT PEMF and LLLT at 808 nm, although a remarkable effect of both PEMF and LLLT could not be detected. The ALP activity of 0.2 and 0.06 mT PEMF and LLLT were comparable.