Science.gov

Sample records for fast plasma shutdowns

  1. The behavior of runaway current in massive gas injection fast shutdown plasmas in J-TEXT

    NASA Astrophysics Data System (ADS)

    Chen, Z. Y.; Huang, D. W.; Luo, Y. H.; Tang, Y.; Dong, Y. B.; Zeng, L.; Tong, R. H.; Wang, S. Y.; Wei, Y. N.; Wang, X. H.; Jian, X.; Li, J. C.; Zhang, X. Q.; Rao, B.; Yan, W.; Ma, T. K.; Hu, Q. M.; Yang, Z. J.; Gao, L.; Ding, Y. H.; Wang, Z. J.; Zhang, M.; Zhuang, G.; Pan, Y.; Jiang, Z. H.; J-TEXT Team

    2016-11-01

    Runaway currents following disruptions have an important effect on the first wall in current tokamaks and will be more severe in next generation tokamaks. The behavior of runaway currents in massive gas injection (MGI) induced disruptions have been investigated in the J-TEXT tokamak. The cold front induced by the gas jet penetrates helically along field lines, preferentially toward the high field side and stops at a location near the q  =  2 surface before the disruption. When the cold front reaches the q  =  2 surface it initiates magnetohydrodynamic activities and results in disruption. It is found that the MGI of He or Ne results in runaway free shutdown in a large range of gas injections. Mixture injection of He and Ar (90% He and 10%Ar) consistently results in runaway free shutdown. A moderate amount of Ar injection could produce significant runaway current. The maximum runaway energy in the runaway plateau is estimated using a simplified model which neglects the drag forces and other energy loss mechanisms. The maximum runaway energy increases with decreasing runaway current. Imaging of the runaway beam using a soft x-ray array during the runaway current plateau indicates that the runaway beam is located in the center of the plasma. Resonant magnetic perturbation (RMP) is applied to reduce the runaway current successfully during the disruption phase in a small scale tokamak, J-TEXT. When the runaway current builds up, the application of RMP cannot decouple the runaway beam due to the lower sensitivity of the energetic runaway electrons to the magnetic perturbation.

  2. A fast shutdown system for SRS (Savannah River Site) reactors

    SciTech Connect

    Baumann, N.P.

    1990-01-01

    Power has been sharply reduced at Savannah River Site (SRS) reactors in large part to ensure that no bulk boiling occurs during hypothesized loss of coolant accidents. A fast shutdown system is essential to regain much of this lost power. Computations and experiments indicate that a He-3 injection system will serve this function. Instrumented tests of a full system are planned for early 1991 for one of the SRS reactors. 4 refs., 7 figs., 1 tab.

  3. DIII-D Studies of Massive Gas Injection Fast Shutdowns for Disruption Mitigation

    SciTech Connect

    Hollmann, E; Jernigan, T; Antar, G; Bakhtiari, M; Boedo, J; Combs, S; Evans, T; Gray, D; Groth, M; Huymphreys, D; Lasnier, C; Moyer, R; Parks, P; Rudakov, D; Strait, E; Wesley, J; West, W; Whyte, D; Yu, J

    2006-06-19

    Injection of massive quantities of gas is a promising technique for fast shutdown of ITER for the purpose of avoiding divertor and first wall damage from disruptions. Previous experiments using massive gas injection (MGI) to terminate discharges in the DIII-D tokamak have demonstrated rapid shutdown with reduced wall heating and halo currents (relative to natural disruptions) and with very small runaway electron (RE) generation [1]. Figure 1 shows time traces which give an overview of shutdown time scales. Typically, of order 5 x 10{sup 22} Ar neutrals are fired over a pulse of 25 ms duration into stationary (non-disrupting) discharges. The observed results are consistent with the following scenario: within several ms of the jet trigger, sufficient Ar neutrals are delivered to the plasma to cause the edge temperature to collapse, initiating the inward propagation of a cold front. The exit flow of the jet [Fig. 1(a)] has a {approx} 9 ms rise time; so the quantity of neutrals which initiates the edge collapse is small (<10{sup 20}). When the cold front reaches q {approx} 2 surface, global magnetohydrodynamic (MHD) modes are destabilized [2], mixing hot core plasma with edge impurities. Here, q is the safety factor. Most (>90%) of the plasma thermal energy is lost via impurity radiation during this thermal quench (TQ) phase. Conducted heat loads to the wall are low because of the cold edge temperature. After the TQ, the plasma is very cold (of order several eV), so conducted wall (halo) currents are low, even if the current channel contacts the wall. The plasma current profile broadens and begins decaying resistively. The decaying current generates a toroidal electric field which can accelerate REs; however, RE beam formation appears to be limited in MGI shutdowns. Presently, it is thought that the conducted heat flux and halo current mitigation qualities of the MGI shutdown technique will scale well to a reactor-sized tokamak. However, because of the larger RE gain

  4. FFTF (Fast Flux Test Facility) reactor shutdown system reliability reevaluation

    SciTech Connect

    Pierce, B.F.

    1986-07-01

    The reliability analysis of the Fast Flux Test Facility reactor shutdown system was reevaluated. Failure information based on five years of plant operating experience was used to verify original reliability numbers or to establish new ones. Also, system modifications made subsequent to performance of the original analysis were incorporated into the reevaluation. Reliability calculations and sensitivity analyses were performed using a commercially available spreadsheet on a personal computer. The spreadsheet was configured so that future failures could be tracked and compared with expected failures. A number of recommendations resulted from the reevaluation including both increased and decreased surveillance intervals. All recommendations were based on meeting or exceeding existing reliability goals. Considerable cost savings will be incurred upon implementation of the recommendations.

  5. DIII-D Studies of Massive Gas Injection Fast Shutdowns for Disruption Mitigation

    SciTech Connect

    Hollmann, E; Jernigan, T; Antar, G; Bakhtiari, M; Boedo, J; Combs, S; Evans, T; Gray, D; Groth, M; Humphreys, D; Lasnier, C; Moyer, R; Parks, P; Rudakov, D; Strait, E; Wesley, J; West, W; Whyte, D; Yu, J

    2006-09-29

    Injection of massive quantities of gas is a promising technique for fast shutdown of ITER for the purpose of avoiding divertor and first wall damage from disruptions. Previous experiments using massive gas injection (MGI) to terminate discharges in the DIII-D tokamak have demonstrated rapid shutdown with reduced wall heating and halo currents (relative to natural disruptions) and with very small runaway electron (RE) generation [1]. Figure 1 shows time traces which give an overview of shutdown time scales. Typically, of order 5 x 10{sup 22} Ar neutrals are fired over a pulse of 25 ms duration into stationary (non-disrupting) discharges. The observed results are consistent with the following scenario: within several ms of the jet trigger, sufficient Ar neutrals are delivered to the plasma to cause the edge temperature to collapse, initiating the inward propagation of a cold front. The exit flow of the jet [Fig. 1(a)] has a {approx} 9 ms rise time; so the quantity of neutrals which initiates the edge collapse is small (<10{sup 20}). When the cold front reaches q {approx} 2 surface, global magnetohydrodynamic (MHD) modes are destabilized [2], mixing hot core plasma with edge impurities. Here, q is the safety factor. Most (>90%) of the plasma thermal energy is lost via impurity radiation during this thermal quench (TQ) phase. Conducted heat loads to the wall are low because of the cold edge temperature. After the TQ, the plasma is very cold (of order several eV), so conducted wall (halo) currents are low, even if the current channel contacts the wall. The plasma current profile broadens and begins decaying resistively. The decaying current generates a toroidal electric field which can accelerate REs; however, RE beam formation appears to be limited in MGI shutdowns. Presently, it is thought that the conducted heat flux and halo current mitigation qualities of the MGI shutdown technique will scale well to a reactor-sized tokamak. However, because of the larger RE gain

  6. Plasma-surface interactions during tokamak disruptions and rapid shutdowns

    SciTech Connect

    Hollmann, E. M.; Arnoux, G.; Commaux, Nicolas JC; Eidietis, N. W.; Evans, T.E.; Granetz, R. S.; Huber, A.; Humphreys, D A; Izzo, V. A.; James, A. N.; Jernigan, Thomas C; Lehnen, M.; Maddaluno, G.; Paccagnella, R.; Parks, P. B.; Phillipps, V.; Reinke, M. L.; Rudakov, D. L.; Saint-Laurent, F.; Strait, E. J.; Wesley, J. C.; Wong, C. P. C.; Yu, J.H.

    2011-01-01

    Recent progress in understanding of disruptions and in developing methods to avoid disruption damage is presented. Nearly complete mitigation of conducted heat loads has been achieved with high-Z gas jet shutdown. The resulting local radiation heat flash melting in the main chamber might be a concern in ITER, especially with beryllium walls. During the current quench, significant vessel forces can occur due to halo currents I-halo; however, these are found to fall reliably below a boundary of (halo current fraction times halo current peaking factor) <0.7 both experimentally and numerically. Numerical simulations indicate that runaway electrons (REs) could cause serious damage to hard-to reach components in ITER, making their suppression a high priority. During the current quench, less than 20% of the density required for collisional suppression of REs appears to have been achieved. Collisional suppression of REs may have been achieved, however, in full-current RE beams with gas injection. (C) 2010 Elsevier B.V. All rights reserved.

  7. Fast pulse nonthermal plasma reactor

    DOEpatents

    Rosocha, Louis A.

    2005-06-14

    A fast pulsed nonthermal plasma reactor includes a discharge cell and a charging assembly electrically connected thereto. The charging assembly provides plural high voltage pulses to the discharge cell. Each pulse has a rise time between one and ten nanoseconds and a duration of three to twenty nanoseconds. The pulses create nonthermal plasma discharge within the discharge cell. Accordingly, the nonthermal plasma discharge can be used to remove pollutants from gases or break the gases into smaller molecules so that they can be more efficiently combusted.

  8. Fast shut-down protection system for radio frequency breakdown and multipactor testing.

    PubMed

    Graves, T P; Hanson, P; Michaelson, J M; Farkas, A D; Hubble, A A

    2014-02-01

    Radio frequency (RF) breakdown such as multipactor or ionization breakdown is a device-limiting phenomenon for on-orbit spacecraft used for communication, navigation, or other RF payloads. Ground testing is therefore part of the qualification process for all high power components used in these space systems. This paper illustrates a shut-down protection system to be incorporated into multipactor/ionization breakdown ground testing for susceptible RF devices. This 8 channel system allows simultaneous use of different diagnostic classes and different noise floors. With initiation of a breakdown event, diagnostic signals increase above a user-specified level, which then opens an RF switch to eliminate RF power from the high power amplifier. Examples of this system in use are shown for a typical setup, illustrating the reproducibility of breakdown threshold voltages and the lack of multipactor conditioning. This system can also be utilized to prevent excessive damage to RF components in tests with sensitive or flight hardware. PMID:24593380

  9. Fast wave evanescence in filamentary boundary plasmas

    SciTech Connect

    Myra, J. R.

    2014-02-15

    Radio frequency waves for heating and current drive of plasmas in tokamaks and other magnetic confinement devices must first traverse the scrape-off-layer (SOL) before they can be put to their intended use. The SOL plasma is strongly turbulent and intermittent in space and time. These turbulent properties of the SOL, which are not routinely taken into account in wave propagation codes, can have an important effect on the coupling of waves through an evanescent SOL or edge plasma region. The effective scale length for fast wave (FW) evanescence in the presence of short-scale field-aligned filamentary plasma turbulence is addressed in this paper. It is shown that although the FW wavelength or evanescent scale length is long compared with the dimensions of the turbulence, the FW does not simply average over the turbulent density; rather, the average is over the exponentiation rate. Implications for practical situations are discussed.

  10. Laser–plasma interactions for fast ignition

    DOE PAGESBeta

    Kemp, A. J.; Fiuza, F.; Debayle, A.; Johzaki, T.; Mori, W. B.; Patel, P. K.; Sentoku, Y.; Silva, L. O.

    2014-04-17

    In the electron-driven fast-ignition approach to inertial confinement fusion, petawatt laser pulses are required to generate MeV electrons that deposit several tens of kilojoules in the compressed core of an imploded DT shell. We review recent progress in the understanding of intense laser- plasma interactions (LPI) relevant to fast ignition. Increases in computational and modeling capabilities, as well as algorithmic developments have led to enhancement in our ability to perform multidimensional particle-in-cell (PIC) simulations of LPI at relevant scales. We discuss the physics of the interaction in terms of laser absorption fraction, the laser-generated electron spectra, divergence, and their temporalmore » evolution. Scaling with irradiation conditions such as laser intensity, f-number and wavelength are considered, as well as the dependence on plasma parameters. Different numerical modeling approaches and configurations are addressed, providing an overview of the modeling capabilities and limitations. In addition, we discuss the comparison of simulation results with experimental observables. In particular, we address the question of surrogacy of today's experiments for the full-scale fast ignition problem.« less

  11. Laser–plasma interactions for fast ignition

    SciTech Connect

    Kemp, A. J.; Fiuza, F.; Debayle, A.; Johzaki, T.; Mori, W. B.; Patel, P. K.; Sentoku, Y.; Silva, L. O.

    2014-04-17

    In the electron-driven fast-ignition approach to inertial confinement fusion, petawatt laser pulses are required to generate MeV electrons that deposit several tens of kilojoules in the compressed core of an imploded DT shell. We review recent progress in the understanding of intense laser- plasma interactions (LPI) relevant to fast ignition. Increases in computational and modeling capabilities, as well as algorithmic developments have led to enhancement in our ability to perform multidimensional particle-in-cell (PIC) simulations of LPI at relevant scales. We discuss the physics of the interaction in terms of laser absorption fraction, the laser-generated electron spectra, divergence, and their temporal evolution. Scaling with irradiation conditions such as laser intensity, f-number and wavelength are considered, as well as the dependence on plasma parameters. Different numerical modeling approaches and configurations are addressed, providing an overview of the modeling capabilities and limitations. In addition, we discuss the comparison of simulation results with experimental observables. In particular, we address the question of surrogacy of today's experiments for the full-scale fast ignition problem.

  12. Investigations on natural circulation in reactor models and shutdown heat removal systems for LMFBRs (liquid metal fast breeder reactors)

    SciTech Connect

    Hoffmann, H.; Weinberg, D.; Marten, K. ); Ieda, Yoshiaki )

    1989-11-01

    For sodium-cooled pool-type reactors, studies have been undertaken to remove the decay heat by natural convection alone, as in the case of failure of all power supplies. For this purpose, four immersion coolers (ICs), two each installed at a 180-deg circumferential position with respect to the others, are arranged within the reactor tank. They are connected with natural-drift air coolers through independent intermediate circuits. The primary sodium in the tank as well as the secondary sodium in the intermediate loop circulate by natural convection. The general functioning of this passive shutdown decay heat removal (DHR) system is demonstrated in 1:20 and 1:5 scale test models using water as a simulant fluid for sodium. The model design is based on the thermohydraulics similarity criteria. In the RAMONA three-dimensional 1:20 scale model, experiments were carried out to clarify the steady-state in-vessel thermohydraulics for different parameter combinations (core power, radial power distribution across the core, DHR by 2 or 4 ICs in operation, above-core structure geometry and position, different IC designs). For all mentioned parameters, temperatures and their fluctuations were measured and used to indicate isotherms and lines of identical temperature fluctuations. The flow patterns were observed visually. The experiments were recalculated by an updated version of the single-phase three-dimensional thermohydraulics code COMMIX.

  13. Optical properties of fast-diffusing solid-state plasmas

    SciTech Connect

    Forchel, A.; Schweizer, H.; Mahler, G.

    1983-08-08

    Transmission and emission spectra of fast-diffusing nonequilibrium electron-hole plasmas in semiconductors are calculated with use of displaced Fermi distributions. The carrier drift significantly alters the plasma spectra and removes previously reported incomprehensible discrepancies between experimental and theoretical plasma parameters, indicating the necessity to reinterpret entirely the spectroscopic data from nonequilibrium plasmas.

  14. Misled by the Morning "Fasting" Plasma Glucose.

    PubMed

    King, Allen B

    2015-11-01

    Because of its ease and simplicity of its measurement, the morning fasting plasma glucose (FPG), has been as used a surrogate marker for the entire basal day when titrating once-nightly basal insulin. Common in obese insulin-treated patients with type 2 diabetes, late and large evening meals elevate the FPG. This has led to dosing of basal insulin well beyond the basal requirements and contributes to hypoglycemia and weight gain seen with this therapy. It is recommended that during basal insulin titration, the evening meal be limited and hypoglycemia be monitored early in the morning, that bewitching time when the "peakless" basal insulin's action is peaking and the predawn phenomenon insulin sensitivity is higher. PMID:25972281

  15. Fast Plasma Investigation for Magnetospheric Multiscale

    NASA Astrophysics Data System (ADS)

    Pollock, C.; Moore, T.; Jacques, A.; Burch, J.; Gliese, U.; Saito, Y.; Omoto, T.; Avanov, L.; Barrie, A.; Coffey, V.; Dorelli, J.; Gershman, D.; Giles, B.; Rosnack, T.; Salo, C.; Yokota, S.; Adrian, M.; Aoustin, C.; Auletti, C.; Aung, S.; Bigio, V.; Cao, N.; Chandler, M.; Chornay, D.; Christian, K.; Clark, G.; Collinson, G.; Corris, T.; De Los Santos, A.; Devlin, R.; Diaz, T.; Dickerson, T.; Dickson, C.; Diekmann, A.; Diggs, F.; Duncan, C.; Figueroa-Vinas, A.; Firman, C.; Freeman, M.; Galassi, N.; Garcia, K.; Goodhart, G.; Guererro, D.; Hageman, J.; Hanley, J.; Hemminger, E.; Holland, M.; Hutchins, M.; James, T.; Jones, W.; Kreisler, S.; Kujawski, J.; Lavu, V.; Lobell, J.; LeCompte, E.; Lukemire, A.; MacDonald, E.; Mariano, A.; Mukai, T.; Narayanan, K.; Nguyan, Q.; Onizuka, M.; Paterson, W.; Persyn, S.; Piepgrass, B.; Cheney, F.; Rager, A.; Raghuram, T.; Ramil, A.; Reichenthal, L.; Rodriguez, H.; Rouzaud, J.; Rucker, A.; Saito, Y.; Samara, M.; Sauvaud, J.-A.; Schuster, D.; Shappirio, M.; Shelton, K.; Sher, D.; Smith, D.; Smith, K.; Smith, S.; Steinfeld, D.; Szymkiewicz, R.; Tanimoto, K.; Taylor, J.; Tucker, C.; Tull, K.; Uhl, A.; Vloet, J.; Walpole, P.; Weidner, S.; White, D.; Winkert, G.; Yeh, P.-S.; Zeuch, M.

    2016-03-01

    The Fast Plasma Investigation (FPI) was developed for flight on the Magnetospheric Multiscale (MMS) mission to measure the differential directional flux of magnetospheric electrons and ions with unprecedented time resolution to resolve kinetic-scale plasma dynamics. This increased resolution has been accomplished by placing four dual 180-degree top hat spectrometers for electrons and four dual 180-degree top hat spectrometers for ions around the periphery of each of four MMS spacecraft. Using electrostatic field-of-view deflection, the eight spectrometers for each species together provide 4pi-sr field-of-view with, at worst, 11.25-degree sample spacing. Energy/charge sampling is provided by swept electrostatic energy/charge selection over the range from 10 eV/q to 30000 eV/q. The eight dual spectrometers on each spacecraft are controlled and interrogated by a single block redundant Instrument Data Processing Unit, which in turn interfaces to the observatory's Instrument Suite Central Instrument Data Processor. This paper describes the design of FPI, its ground and in-flight calibration, its operational concept, and its data products.

  16. Fast Camera Movies of NSTX Plasmas

    DOE Data Explorer

    Maqueda, Ricky; Wurden, Glenn

    The National Spherical Torus Experiment (NSTX) is an innovative magnetic fusion device that is being used to study the physics principles of spherically shaped plasmas -- hot ionized gases in which nuclear fusion will occur under the appropriate conditions of temperature, density, and confinement in a magnetic field. Fusion is the energy source of the Sun and all the stars. Scientists believe it can provide an inexhaustible, safe, and environmentally attractive source. NSTX was constructed by the Princeton Plasma Physics Laboratory (PPPL) in conjunction with Oak Ridge National Laboratory, Columbia University, and the University of Washington Seattle. The original TIF images recorded by the KODAK digital camera (i.e., "raw data") are available, using the contact information given on the same web page that provides access to these fast camera movies. MPEG clips are organized under the following headings: • Gas Puff Imaging (GPI) diagnostic • GPI experiments • H-modes (longer) • H-modes (short) • Coaxial Helicity Injection experiments More than 100 MPEGS dating back to 1999 are available for public access.

  17. Laser-plasma interactions for fast ignition

    NASA Astrophysics Data System (ADS)

    Kemp, A. J.; Fiuza, F.; Debayle, A.; Johzaki, T.; Mori, W. B.; Patel, P. K.; Sentoku, Y.; Silva, L. O.

    2014-05-01

    In the electron-driven fast-ignition (FI) approach to inertial confinement fusion, petawatt laser pulses are required to generate MeV electrons that deposit several tens of kilojoules in the compressed core of an imploded DT shell. We review recent progress in the understanding of intense laser-plasma interactions (LPI) relevant to FI. Increases in computational and modelling capabilities, as well as algorithmic developments have led to enhancement in our ability to perform multi-dimensional particle-in-cell simulations of LPI at relevant scales. We discuss the physics of the interaction in terms of laser absorption fraction, the laser-generated electron spectra, divergence, and their temporal evolution. Scaling with irradiation conditions such as laser intensity are considered, as well as the dependence on plasma parameters. Different numerical modelling approaches and configurations are addressed, providing an overview of the modelling capabilities and limitations. In addition, we discuss the comparison of simulation results with experimental observables. In particular, we address the question of surrogacy of today's experiments for the full-scale FI problem.

  18. Fast Plasma Instrument for MMS: Simulation Results

    NASA Technical Reports Server (NTRS)

    Figueroa-Vinas, Adolfo; Adrian, Mark L.; Lobell, James V.; Simpson, David G.; Barrie, Alex; Winkert, George E.; Yeh, Pen-Shu; Moore, Thomas E.

    2008-01-01

    Magnetospheric Multiscale (MMS) mission will study small-scale reconnection structures and their rapid motions from closely spaced platforms using instruments capable of high angular, energy, and time resolution measurements. The Dual Electron Spectrometer (DES) of the Fast Plasma Instrument (FPI) for MMS meets these demanding requirements by acquiring the electron velocity distribution functions (VDFs) for the full sky with high-resolution angular measurements every 30 ms. This will provide unprecedented access to electron scale dynamics within the reconnection diffusion region. The DES consists of eight half-top-hat energy analyzers. Each analyzer has a 6 deg. x 11.25 deg. Full-sky coverage is achieved by electrostatically stepping the FOV of each of the eight sensors through four discrete deflection look directions. Data compression and burst memory management will provide approximately 30 minutes of high time resolution data during each orbit of the four MMS spacecraft. Each spacecraft will intelligently downlink the data sequences that contain the greatest amount of temporal structure. Here we present the results of a simulation of the DES analyzer measurements, data compression and decompression, as well as ground-based analysis using as a seed re-processed Cluster/PEACE electron measurements. The Cluster/PEACE electron measurements have been reprocessed through virtual DES analyzers with their proper geometrical, energy, and timing scale factors and re-mapped via interpolation to the DES angular and energy phase-space sampling measurements. The results of the simulated DES measurements are analyzed and the full moments of the simulated VDFs are compared with those obtained from the Cluster/PEACE spectrometer using a standard quadrature moment, a newly implemented spectral spherical harmonic method, and a singular value decomposition method. Our preliminary moment calculations show a remarkable agreement within the uncertainties of the measurements, with the

  19. Fast Plasma Instrument for MMS: Simulation Results

    NASA Astrophysics Data System (ADS)

    Viñas, A. F.; Adrian, M. L.; Lobell, J. V.; Simpson, D. G.; Barrie, A.; Winkert, G. E.; Yeh, P.; Moore, T. E.

    2008-12-01

    Magnetospheric Multiscale (MMS) mission will study small-scale reconnection structures and their rapid motions from closely spaced platforms using instruments capable of high angular, energy, and time resolution measurements. The Dual Electron Spectrometer (DES) of the Fast Plasma Instrument (FPI) for MMS meets these demanding requirements by acquiring the electron velocity distribution functions (VDF's) for the full sky with high-resolution angular measurements every 30 ms. This will provide unprecedented access to electron scale dynamics within the reconnection diffusion region. The DES consists of eight half-top-hat energy analyzers. Each analyzer has a 6° × 180° field of view (FOV) with a single pixel resolution of 6° × 11.25°. Full-sky coverage is achieved by electrostatically stepping the FOV of each of the eight sensors through four discrete deflection look directions. Data compression and burst memory management will provide approximately 30 minutes of high time resolution data during each orbit of the four MMS spacecraft. Each spacecraft will intelligently downlink the data sequences that contain the greatest amount of temporal structure. Here we present the results of a simulation of the DES analyzer measurements, data compression and decompression, as well as ground- based analysis using as a seed re-processed Cluster/PEACE electron measurements. The Cluster/PEACE electron measurements have been re-processed through virtual DES analyzers with their proper geometrical, energy, and timing scale factors and re-mapped via interpolation to the DES angular and energy phase- space sampling measurements. The results of the simulated DES measurements are analyzed and the full moments of the simulated VDF's are compared with those obtained from the Cluster/PEACE spectrometer using a standard quadrature moment, a newly implemented spectral spherical harmonic method, and a singular value decomposition method. Our preliminary moment calculations show a

  20. Turbulent transport of fast ions in the Large Plasma Device

    SciTech Connect

    Zhou Shu; Heidbrink, W. W.; Boehmer, H.; McWilliams, R.; Carter, T.; Vincena, S.; Tripathi, S. K. P.; Popovich, P.; Friedman, B.; Jenko, F.

    2010-09-15

    Strong drift wave turbulence is observed in the Large Plasma Device [H. Gekelman et al., Rev. Sci. Instrum. 62, 2875 (1991)] on density gradients produced by a plate limiter. Energetic lithium ions orbit through the turbulent region. Scans with a collimated ion analyzer and with Langmuir probes give detailed profiles of the fast ion spatial distribution and the fluctuating fields. The fast ion transport decreases rapidly with increasing fast ion gyroradius. Unlike the diffusive transport caused by Coulomb collisions, in this case the turbulent transport is nondiffusive. Analysis and simulation suggest that such nondiffusive transport is due to the interaction of the fast ions with stationary two-dimensional electrostatic turbulence.

  1. Predictive models for fast ion profiles relaxation in burning plasmas

    NASA Astrophysics Data System (ADS)

    Gorelenkov, Nikolai; Heidbrink, W. W.; Lestz, J.; Podesta, M.; van Zeeland, M.; White, R. B.

    2014-10-01

    The performance of the burning plasmas is limited by the confinement of superalfvenic fusion products, alpha particles, which are capable to resonate with the Alfvénic eigenmodes (AEs). Two techniques based on linear AE stability theory are developed to evaluate the AE induced fast ion relaxation. The first is the reduced quasilinear technique or critical gradient model (CGM) where marginally unstable (or critical) gradient of fast ion pressure is due to unstable AEs. It allows the reconstruction of fast ion pressure profile and compute their losses. The second technique is called hybrid that is also based on NOVA-K linear stability computations of TAE (or RSAE) mode structures and growth rates. AE amplitudes are computed from the nonlinear theory perturbatively and used in numerical runs. With the help of the guiding center code ORBIT the hybrid model predicts the relaxation of the fast particle profiles. We apply these models for NSTX and DIII-D plasmas with the neutral beam injections in order to validate the models. Both methods are relatively fast ways to predict the fast ion profiles in burning plasmas and can be used for plasma modeling prior to building experimental devices such as ITER. Partially supported by US DOE Contract DE-AC02-09CH11466.

  2. EVOLUTION OF FAST MAGNETOACOUSTIC PULSES IN RANDOMLY STRUCTURED CORONAL PLASMAS

    SciTech Connect

    Yuan, D.; Li, B.; Pascoe, D. J.; Nakariakov, V. M.; Keppens, R. E-mail: bbl@sdu.edu.cn

    2015-02-01

    We investigate the evolution of fast magnetoacoustic pulses in randomly structured plasmas, in the context of large-scale propagating waves in the solar atmosphere. We perform one-dimensional numerical simulations of fast wave pulses propagating perpendicular to a constant magnetic field in a low-β plasma with a random density profile across the field. Both linear and nonlinear regimes are considered. We study how the evolution of the pulse amplitude and width depends on their initial values and the parameters of the random structuring. Acting as a dispersive medium, a randomly structured plasma causes amplitude attenuation and width broadening of the fast wave pulses. After the passage of the main pulse, secondary propagating and standing fast waves appear. Width evolution of both linear and nonlinear pulses can be well approximated by linear functions; however, narrow pulses may have zero or negative broadening. This arises because narrow pulses are prone to splitting, while broad pulses usually deviate less from their initial Gaussian shape and form ripple structures on top of the main pulse. Linear pulses decay at an almost constant rate, while nonlinear pulses decay exponentially. A pulse interacts most efficiently with a random medium with a correlation length of about half of the initial pulse width. This detailed model of fast wave pulses propagating in highly structured media substantiates the interpretation of EIT waves as fast magnetoacoustic waves. Evolution of a fast pulse provides us with a novel method to diagnose the sub-resolution filamentation of the solar atmosphere.

  3. Fast Magnetic Reconnection: Bridging Laboratory and Space Plasma Physics

    SciTech Connect

    Bhattacharjee, Amitava

    2012-02-16

    Recent developments in experimental and theoretical studies of magnetic reconnection hold promise for providing solutions to outstanding problems in laboratory and space plasma physics. Examples include sawtooth crashes in tokamaks, substorms in the Earth’s Magnetosphere, eruptive solar flares, and more recently, fast reconnection in laser-produced high energy density plasmas. In each of these examples, a common and long-standing challenge has been to explain why fast reconnection proceeds rapidly from a relatively quiescent state. In this talk, we demonstrate the advantages of viewing these problems and their solutions from a common perspective. We focus on some recent, surprising discoveries regarding the role of secondary plasmoid instabilities of thin current sheets. Nonlinearly, these instabilities lead to fast reconnection rates that are very weakly dependent on the Lundquist number of the plasma.

  4. Interaction of fast magnetoacoustic solitons in dense plasmas

    SciTech Connect

    Jahangir, R.; Saleem, Khalid; Masood, W.; Siddiq, M.; Batool, Nazia

    2015-09-15

    One dimensional propagation of fast magnetoacoustic solitary waves in dense plasmas with degenerate electrons is investigated in this paper in the small amplitude limit. In this regard, Korteweg deVries equation is derived and discussed using the plasma parameters that are typically found in white dwarf stars. The interaction of fast magnetoacoustic solitons is explored by using the Hirota bilinear formalism, which admits multi soliton solutions. It is observed that the values of the propagation vectors determine the interaction of solitary waves. It is further noted that the amplitude of the respective solitary waves remain unchanged after the interaction; however, they do experience a phase shift.

  5. Interaction of fast magnetoacoustic solitons in dense plasmas

    NASA Astrophysics Data System (ADS)

    Jahangir, R.; Masood, W.; Siddiq, M.; Batool, Nazia; Saleem, Khalid

    2015-09-01

    One dimensional propagation of fast magnetoacoustic solitary waves in dense plasmas with degenerate electrons is investigated in this paper in the small amplitude limit. In this regard, Korteweg deVries equation is derived and discussed using the plasma parameters that are typically found in white dwarf stars. The interaction of fast magnetoacoustic solitons is explored by using the Hirota bilinear formalism, which admits multi soliton solutions. It is observed that the values of the propagation vectors determine the interaction of solitary waves. It is further noted that the amplitude of the respective solitary waves remain unchanged after the interaction; however, they do experience a phase shift.

  6. A Midsize Tokamak As Fast Track To Burning Plasmas

    SciTech Connect

    E. Mazzucato

    2010-07-14

    This paper presents a midsize tokamak as a fast track to the investigation of burning plasmas. It is shown that it could reach large values of energy gain (≥10) with only a modest improvement in confinement over the scaling that was used for designing the International Thermonuclear Experimental Reactor (ITER). This could be achieved by operating in a low plasma recycling regime that experiments indicate can lead to improved plasma confinement. The possibility of reaching the necessary conditions of low recycling using a more efficient magnetic divertor than those of present tokamaks is discussed.

  7. Thermal plasma and fast ion transport in electrostatic turbulence in the large plasma device

    SciTech Connect

    Zhou Shu; Heidbrink, W. W.; Boehmer, H.; McWilliams, R.; Carter, T. A.; Vincena, S.; Tripathi, S. K. P.; Van Compernolle, B.

    2012-05-15

    The transport of thermal plasma and fast ions in electrostatic microturbulence is studied. Strong density and potential fluctuations ({delta}n/n{approx}{delta}{phi}/kT{sub e}{approx} 0.5, f {approx} 5-50 kHz) are observed in the large plasma device (LAPD) [W. Gekelman, H. Pfister, Z. Lucky et al., Rev. Sci. Instrum. 62, 2875 (1991)] in density gradient regions produced by obstacles with slab or cylindrical geometry. Wave characteristics and the associated plasma transport are modified by driving sheared E Multiplication-Sign B drift through biasing the obstacle and by modification of the axial magnetic fields (B{sub z}) and the plasma species. Cross-field plasma transport is suppressed with small bias and large B{sub z} and is enhanced with large bias and small B{sub z}. The transition in thermal plasma confinement is well explained by the cross-phase between density and potential fluctuations. Large gyroradius lithium fast ion beam ({rho}{sub fast}/{rho}{sub s} {approx} 10) orbits through the turbulent region. Scans with a collimated analyzer give detailed profiles of the fast ion spatial-temporal distribution. Fast-ion transport decreases rapidly with increasing fast-ion energy and gyroradius. Background waves with different scale lengths also alter the fast ion transport. Experimental results agree well with gyro-averaging theory. When the fast ion interacts with the wave for most of a wave period, a transition from super-diffusive to sub-diffusive transport is observed, as predicted by diffusion theory. Besides turbulent-wave-induced fast-ion transport, the static radial electric field (E{sub r}) from biasing the obstacle leads to drift of the fast-ion beam centroid. The drift and broadening of the beam due to static E{sub r} are evaluated both analytically and numerically. Simulation results indicate that the E{sub r} induced transport is predominately convective.

  8. Measuring Fast Ion Losses in a Reversed Field Pinch Plasma

    NASA Astrophysics Data System (ADS)

    Bonofiglo, P. J.; Anderson, J. K.; Almagri, A. F.; Kim, J.; Clark, J.; Capecchi, W.; Sears, S. H.

    2015-11-01

    The reversed field pinch (RFP) provides a unique environment to study fast ion confinement and transport. The RFP's weak toroidal field, strong magnetic shear, and ability to enter a 3D state provide a wide range of dynamics to study fast ions. Core-localized, 25 keV fast ions are sourced into MST by a tangentially injected hydrogen/deuterium neutral beam. Neutral particle analysis and measured fusion neutron flux indicate enhanced fast ion transport in the plasma core. Past experiments point to a dynamic loss of fast ions associated with the RFP's transition to a 3D state and with beam-driven, bursting magnetic modes. Consequently, fast ion transport and losses in the RFP have garnered recent attention. Valuable information on fast-ion loss, such as energy and pitch distributions, are sought to provide a better understanding of the transport mechanisms at hand. We have constructed and implemented two fast ion loss detectors (FILDs) for use on MST. The FILDs have two, independent, design concepts: collecting particles as a function of v⊥ or with pitch greater than 0.8. In this work, we present our preliminary findings and results from our FILDs on MST. This research is supported by US DOE.

  9. Plasma instability in fast spherical discharge induced by a preionization

    SciTech Connect

    Antsiferov, P. S.; Dorokhin, L. A.

    2015-04-07

    As it was shown earlier, fast discharge (dI/dt ∼ 10{sup 12 }A/s and I{sub max} ≈ 40 kA) in a spherical cavity (Al{sub 2}O{sub 3}, inner diameter 11 mm, 4 mm apertures for the current supply) filled with working gas (Ar and Xe, pressure 80 Pa), results in the formation of a plasma with the form close to spherical. The physical mechanism can be the cumulation of a convergent shock wave, which was originated near the inner surface of the discharge cavity. It was also shown for the cylindrical fast discharge that the preionization influences the dynamics of the cylindrical convergent shock wave, its evolutions becomes faster. The present work is devoted to the study of the influence of the preionization on the plasma formation in the fast discharge with spherical geometry (Ar, 80 Pa). The inductive storage with plasma erosion opening switch was used as a current driver. The spatial structure of the discharge plasma was studied by means of a pin-hole camera with the microchannel plate (MCP) detector with time gate of 5 ns. The extreme ultra violet spectra were studied by means of the grazing incidence spectrometer with the same MCP detector with time gate of 20 ns. Beside the expected effects (reduction of the spherical plasma formation time and some increase of the electron temperature), the preionization of the discharge by the current 500 A results also in the development of the plasma instabilities and destruction of the compact plasma ball in several tens of nanoseconds. Possible mechanism of the instability is discussed.

  10. Study of plasma heating induced by fast electrons

    NASA Astrophysics Data System (ADS)

    Morace, A.; Magunov, A.; Batani, D.; Redaelli, R.; Fourment, C.; Santos, J. J.; Malka, G.; Boscheron, A.; Casner, A.; Nazarov, W.; Vinci, T.; Okano, Y.; Inubushi, Y.; Nishimura, H.; Flacco, A.; Spindloe, C.; Tolley, M.

    2009-12-01

    We studied the induced plasma heating in three different kinds of targets: mass limited, foam targets, and large mass targets. The experiment was performed at Alisé Laser Facility of CEA/CESTA. The laser system emitted a ˜1 ps pulse with ˜10 J energy at a wavelength of ˜1 μm. Mass limited targets had three layers with thicknesses of 10 μm C8H8, 1 μm C8H7Cl, and 10 μm C8H8 with size of 100×100 μm2. Detailed spectroscopic analysis of x rays emitted from the Cl tracer showed that it was possible to heat up the plasma from mass limited targets to a temperature of ˜250 eV with density of ˜1021 cm-3. The plasma heating is only produced by fast electron transport in the target, being the 10 μm C8H8 overcoating thick enough to prevent any possible direct irradiation of the tracer layer even taking into account mass-ablation due to the prepulse. These results demonstrate that with mass limited targets, it is possible to generate a plasma heated up to several hundreds eV. It is also very important for research concerning high energy density phenomena and for fast ignition (in particular for the study of fast electrons transport and induced heating).

  11. Resonance absorption of propagating fast waves in a cold plasma

    NASA Technical Reports Server (NTRS)

    Hollweg, Joseph V.

    1990-01-01

    Absorption of propagating waves impinging on a surface in which the plasma and magnetic field may change is investigated by examining in depth the problem of a combination of cold plasma, uniform magnetic field and a surface density which varies linearly from zero at the left end to some finite value at the right end, beyond which the density is constant. Two cases are considered: one in which the plasma is a vacuum everywhere to the left of the surface (which may correspond to coronal conditions) and one in which the plasma density jumps to a very large value to the left of the surface (which may mimic the magnetosphere with the dense region at the left corresponding to the plasmasphere). A complete discussion of the resonance absorption of propagating fast waves for the case considered by Kiveloson and Southwood (1986) is presented, emphasizing approximate analytical results whenever possible; these results are then compared with exact numerical solutions.

  12. Safety shutdown separators

    SciTech Connect

    Carlson, Steven Allen; Anakor, Ifenna Kingsley; Farrell, Greg Robert

    2015-06-30

    The present invention pertains to electrochemical cells which comprise (a) an anode; (b) a cathode; (c) a solid porous separator, such as a polyolefin, xerogel, or inorganic oxide separator; and (d) a nonaqueous electrolyte, wherein the separator comprises a porous membrane having a microporous coating comprising polymer particles which have not coalesced to form a continuous film. This microporous coating on the separator acts as a safety shutdown layer that rapidly increases the internal resistivity and shuts the cell down upon heating to an elevated temperature, such as 110.degree. C. Also provided are methods for increasing the safety of an electrochemical cell by utilizing such separators with a safety shutdown layer.

  13. Fast plasma heating by anomalous and inertial resistivity effects

    NASA Technical Reports Server (NTRS)

    Duijveman, A.; Hoyng, P.; Ionson, J. A.

    1981-01-01

    Fast plasma heating by anomalous and inertial resistivity effects is described. A small fraction of the plasma contains strong currents that run parallel to the magnetic field and are driven by an exponentiating electric field. The anomalous character of the current dissipation is caused by the excitation of electrostatic ion cyclotron and/or ion acoustic waves. The role of resistivity due to geometrical effects is considered. Through the use of a marginal stability analysis, equations for the average electron and ion temperatures are derived and numerically solved. The evolution of the plasma is described as a path in the drift velocity diagram, in which the drift velocity is plotted as a function of the electron to ion temperature ratio.

  14. Fast discharge in a plasma gun with hemispherical insulator

    SciTech Connect

    Antsiferov, P. S.; Dorokhin, L. A.; Sidelnikov, Yu. V.; Koshelev, K. N.

    2009-05-15

    A method of creation of hot dense plasma is proposed. It is based on cumulation of a shockwave, which originates on a hemispherical surface of insulator of plasma gun. The results of first experiments are presented. The shock wave is driven by fast electrical discharge (dI/dt>10{sup 12} A/s). The inductive storage with semiconductor opening switch is used as a current driver. Time resolved pin-hole images and vacuum ultraviolet (vuv) spectra are studied. Shockwaves from hemispherical insulator with 4 mm radius create plasma with a form of column about 1 mm diameter and 3-4 mm length. vuv spectra contain the lines of Ar ions that corresponds to the electron temperature about 20 eV. Possible practical application is discussed.

  15. Normal fasting plasma glucose levels in some birds of prey.

    PubMed

    O'Donnell, J A; Garbett, R; Morzenti, A

    1978-10-01

    Blood samples taken from five great horned owls (Bubo virginianus), eight red-tailed hawks (Buteo jamaicensis), four marsh hawks (Circus cyaneus), two prairie falcons (Falco mexicanus), five golden eagles (Aquila chrysaetos), and five white leghorn chickens (Gallus domesticus) that had been fasted for 24 h were used to determine plasma levels of glucose by the glucose oxidase method. The mean plasma glucose levels were: great horned owls 374.6 mg/100 ml, red-tailed hawks 346.5 mg/00 ml, marsh hawks 369.3 mg/100 ml, prairie falcons 414.5 mg/100 ml, golden eagles 368.4 mg/100 ml, and white Leghorn chickens 218.2 mg/100 ml. The plasma glucose levels obtained for the raptorial birds in this study were considerably higher than those found for the chickens. These values are discussed in relation to the carnivorous food habits of raptors. PMID:739587

  16. Study of plasma heating induced by fast electrons

    SciTech Connect

    Morace, A.; Batani, D.; Redaelli, R.; Magunov, A.; Fourment, C.; Santos, J. J.; Malka, G.; Boscheron, A.; Nazarov, W.; Vinci, T.; Okano, Y.; Inubushi, Y.; Nishimura, H.; Flacco, A.; Spindloe, C.; Tolley, M.

    2009-12-15

    We studied the induced plasma heating in three different kinds of targets: mass limited, foam targets, and large mass targets. The experiment was performed at Alise Laser Facility of CEA/CESTA. The laser system emitted a approx1 ps pulse with approx10 J energy at a wavelength of approx1 {mu}m. Mass limited targets had three layers with thicknesses of 10 {mu}m C{sub 8}H{sub 8}, 1 {mu}m C{sub 8}H{sub 7}Cl, and 10 {mu}m C{sub 8}H{sub 8} with size of 100x100 {mu}m{sup 2}. Detailed spectroscopic analysis of x rays emitted from the Cl tracer showed that it was possible to heat up the plasma from mass limited targets to a temperature of approx250 eV with density of approx10{sup 21} cm{sup -3}. The plasma heating is only produced by fast electron transport in the target, being the 10 {mu}m C{sub 8}H{sub 8} overcoating thick enough to prevent any possible direct irradiation of the tracer layer even taking into account mass-ablation due to the prepulse. These results demonstrate that with mass limited targets, it is possible to generate a plasma heated up to several hundreds eV. It is also very important for research concerning high energy density phenomena and for fast ignition (in particular for the study of fast electrons transport and induced heating).

  17. On Plasma Rotation Induced by Traveling Fast Alfvin Waves

    SciTech Connect

    F.W. Perkins; R.B. White; and V.S. Chan

    2001-08-09

    Absorption of fast Alfven waves by the minority fundamental ion-cyclotron resonance, coupled with finite banana width physics, generates torque distributions and ultimately rotational shear layers in the bulk plasma, even when the toroidal wavenumber k(subscript ''phi'') = n/R of the fast wave vanishes (n=0) and cyclotron absorption introduces no angular momentum nor canonical angular momentum [F.W. Perkins, R.B. White, P.T. Bonoli, and V.S. Chan, Phys. Plasmas 8 (2001) 2181]. The present work extends these results to travelling waves with non-zero n where heating directly introduces angular momentum. Since tokamak fast-wave antennas have approximately one wavelength per toroidal field coil, the toroidal mode number n lies in the range n = 10-20, independent of machine size. A zero-dimensional analysis shows that the rotation rate arising from direct torque is comparable to that of the rotational shear layer and has the same scaling. Nondimensional rotation profiles for n = (-10, 10) show modest changes from the n = 0 case in the expected direction. For a balanced antenna spectrum, the nondimensional rotational profile (averaged over n = -10, 10) lies quite close to the n = 0 profile.

  18. Plasma distribution in Mercury's magnetosphere derived from MESSENGER Magnetometer and Fast Imaging Plasma Spectrometer observations

    NASA Astrophysics Data System (ADS)

    Korth, Haje; Anderson, Brian J.; Gershman, Daniel J.; Raines, Jim M.; Slavin, James A.; Zurbuchen, Thomas H.; Solomon, Sean C.; McNutt, Ralph L.

    2014-04-01

    We assess the statistical spatial distribution of plasma in Mercury's magnetosphere from observations of magnetic pressure deficits and plasma characteristics by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. The statistical distributions of proton flux and pressure were derived from 10 months of Fast Imaging Plasma Spectrometer (FIPS) observations obtained during the orbital phase of the MESSENGER mission. The Magnetometer-derived pressure distributions compare favorably with those deduced from the FIPS observations at locations where depressions in the magnetic field associated with the presence of enhanced plasma pressures are discernible in the Magnetometer data. The magnitudes of the magnetic pressure deficit and the plasma pressure agree on average, although the two measures of plasma pressure may deviate for individual events by as much as a factor of ~3. The FIPS distributions provide better statistics in regions where the plasma is more tenuous and reveal an enhanced plasma population near the magnetopause flanks resulting from direct entry of magnetosheath plasma into the low-latitude boundary layer of the magnetosphere. The plasma observations also exhibit a pronounced north-south asymmetry on the nightside, with markedly lower fluxes at low altitudes in the northern hemisphere than at higher altitudes in the south on the same field line. This asymmetry is consistent with particle loss to the southern hemisphere surface during bounce motion in Mercury's offset dipole magnetic field.

  19. Plasma Distribution in Mercury's Magnetosphere Derived from MESSENGER Magnetometer and Fast Imaging Plasma Spectrometer Observations

    NASA Technical Reports Server (NTRS)

    Korth, Haje; Anderson, Brian J.; Gershman, Daniel J.; Raines, Jim M.; Slavin, James A.; Zurbuchen, Thomas H.; Solomon, Sean C.; McNutt, Ralph L.

    2014-01-01

    We assess the statistical spatial distribution of plasma in Mercury's magnetosphere from observations of magnetic pressure deficits and plasma characteristics by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. The statistical distributions of proton flux and pressure were derived from 10months of Fast Imaging Plasma Spectrometer (FIPS) observations obtained during the orbital phase of the MESSENGER mission. The Magnetometer-derived pressure distributions compare favorably with those deduced from the FIPS observations at locations where depressions in the magnetic field associated with the presence of enhanced plasma pressures are discernible in the Magnetometer data. The magnitudes of the magnetic pressure deficit and the plasma pressure agree on average, although the two measures of plasma pressure may deviate for individual events by as much as a factor of approximately 3. The FIPS distributions provide better statistics in regions where the plasma is more tenuous and reveal an enhanced plasma population near the magnetopause flanks resulting from direct entry of magnetosheath plasma into the low-latitude boundary layer of the magnetosphere. The plasma observations also exhibit a pronounced north-south asymmetry on the nightside, with markedly lower fluxes at low altitudes in the northern hemisphere than at higher altitudes in the south on the same field line. This asymmetry is consistent with particle loss to the southern hemisphere surface during bounce motion in Mercury's offset dipole magnetic field.

  20. Fasting and 2-Hour Plasma Glucose and Insulin

    PubMed Central

    Libman, Ingrid M.; Barinas-Mitchell, Emma; Bartucci, Andrea; Chaves-Gnecco, Diego; Robertson, Robert; Arslanian, Silva

    2010-01-01

    OBJECTIVE To determine whether elevated fasting or 2-h plasma glucose and/or insulin better reflects the presence of cardiovascular disease (CVD) risk markers in an overweight pediatric population with normal glucose tolerance. RESEARCH DESIGN AND METHODS A total of 151 overweight youths (8–17 years old) were evaluated with oral glucose tolerance tests and measurement of CVD risk factors. The study population was categorized according to quartiles of fasting and 2-h glucose and insulin levels. ANCOVA, adjusted for age, sex, race, Tanner stage, and percent body fat (measured by dual-energy X-ray absorptiometry), was used to compare metabolic variables between the quartiles of glucose and insulin groups. RESULTS Increasing quartiles of fasting and 2-h insulin were associated with increasing CVD risk factors. Glucose quartiles on the other hand, either fasting or at 2 h, were not. CONCLUSIONS These data suggest that hyperinsulinemia may be the earliest and/or primary metabolic alteration in childhood associated with risk markers for CVD. Prospective studies are needed. PMID:21115769

  1. Gestational diabetes mellitus: Screening with fasting plasma glucose.

    PubMed

    Agarwal, Mukesh M

    2016-07-25

    Fasting plasma glucose (FPG) as a screening test for gestational diabetes mellitus (GDM) has had a checkered history. During the last three decades, a few initial anecdotal reports have given way to the recent well-conducted studies. This review: (1) traces the history; (2) weighs the advantages and disadvantages; (3) addresses the significance in early pregnancy; (4) underscores the benefits after delivery; and (5) emphasizes the cost savings of using the FPG in the screening of GDM. It also highlights the utility of fasting capillary glucose and stresses the value of the FPG in circumventing the cumbersome oral glucose tolerance test. An understanding of all the caveats is crucial to be able to use the FPG for investigating glucose intolerance in pregnancy. Thus, all health professionals can use the patient-friendly FPG to simplify the onerous algorithms available for the screening and diagnosis of GDM - thereby helping each and every pregnant woman. PMID:27525055

  2. Gestational diabetes mellitus: Screening with fasting plasma glucose

    PubMed Central

    Agarwal, Mukesh M

    2016-01-01

    Fasting plasma glucose (FPG) as a screening test for gestational diabetes mellitus (GDM) has had a checkered history. During the last three decades, a few initial anecdotal reports have given way to the recent well-conducted studies. This review: (1) traces the history; (2) weighs the advantages and disadvantages; (3) addresses the significance in early pregnancy; (4) underscores the benefits after delivery; and (5) emphasizes the cost savings of using the FPG in the screening of GDM. It also highlights the utility of fasting capillary glucose and stresses the value of the FPG in circumventing the cumbersome oral glucose tolerance test. An understanding of all the caveats is crucial to be able to use the FPG for investigating glucose intolerance in pregnancy. Thus, all health professionals can use the patient-friendly FPG to simplify the onerous algorithms available for the screening and diagnosis of GDM - thereby helping each and every pregnant woman. PMID:27525055

  3. Secondary Fast Magnetoacoustic Waves Trapped in Randomly Structured Plasmas

    NASA Astrophysics Data System (ADS)

    Yuan, Ding; Li, Bo; Walsh, Robert W.

    2016-09-01

    Fast magnetoacoustic waves are an important tool for inferring parameters of the solar atmosphere. We numerically simulate the propagation of fast wave pulses in randomly structured plasmas that mimic the highly inhomogeneous solar corona. A network of secondary waves is formed by a series of partial reflections and transmissions. These secondary waves exhibit quasi-periodicities in both time and space. Since the temporal and spatial periods are related simply through the speed of the fast wave, we quantify the properties of secondary waves by examining the dependence of the average temporal period (\\bar{p}) on the initial pulse width (w 0) and studying the density contrast ({δ }ρ ) and correlation length (L c ) that characterize the randomness of the equilibrium density profiles. For small-amplitude pulses, {δ }ρ does not alter \\bar{p} significantly. Large-amplitude pulses, on the other hand, enhance the density contrast when {δ }ρ is small but have a smoothing effect when {δ }ρ is sufficiently large. We found that \\bar{p} scales linearly with L c and that the scaling factor is larger for a narrower pulse. However, in terms of the absolute values of \\bar{p}, broader pulses generate secondary waves with longer periods, and this effect is stronger in random plasmas with shorter correlation lengths. Secondary waves carry the signatures of both the leading wave pulse and the background plasma. Our study may find applications in magnetohydrodynamic seismology by exploiting the secondary waves detected in the dimming regions after coronal mass ejections or extreme ultraviolet waves.

  4. Fast moving plasma structures in the distant magnetotail

    NASA Technical Reports Server (NTRS)

    Scholer, M.; Klecker, B.; Hovestadt, D.; Gloeckler, G.; Ipavich, F. M.; Smith, E. J.

    1984-01-01

    The paper reports for the first time the detailed time behavior of the intensities and the angular distributions of energetic protons and electrons in the distant magnetotail of the earth at 220 earth radii and 110 earth radii. The data have been obtained by the Max-Planck-Institut/University of Maryland sensor system on ISEE 3 during the spacecraft's first deep tail passage. Three energetic particle bursts are studied in detail. It is suggested that the satellite encounters detached plasma structures evidenced by the isotropic electrons. These structures, probably plasmoids, move with high velocities (about 800 km/s) down the tail. The energetic electrons and protons stream ahead of these fast tailward moving plasma structures, which leads to the various time dispersion effects. This allows, in principle, a determination of the source distance from the satellite.

  5. Collimated fast electron beam generation in critical density plasma

    SciTech Connect

    Iwawaki, T. Habara, H.; Morita, K.; Tanaka, K. A.; Baton, S.; Fuchs, J.; Chen, S.; Nakatsutsumi, M.; Rousseaux, C.; Filippi, F.; Nazarov, W.

    2014-11-15

    Significantly collimated fast electron beam with a divergence angle 10° (FWHM) is observed when an ultra-intense laser pulse (I = 10{sup 14 }W/cm{sup 2}, 300 fs) irradiates a uniform critical density plasma. The uniform plasma is created through the ionization of an ultra-low density (5 mg/c.c.) plastic foam by X-ray burst from the interaction of intense laser (I = 10{sup 14 }W/cm{sup 2}, 600 ps) with a thin Cu foil. 2D Particle-In-Cell (PIC) simulation well reproduces the collimated electron beam with a strong magnetic field in the region of the laser pulse propagation. To understand the physical mechanism of the collimation, we calculate energetic electron motion in the magnetic field obtained from the 2D PIC simulation. As the results, the strong magnetic field (300 MG) collimates electrons with energy over a few MeV. This collimation mechanism may attract attention in many applications such as electron acceleration, electron microscope and fast ignition of laser fusion.

  6. Jump conditions at fast shocks in an anisotropic magnetized plasma

    NASA Astrophysics Data System (ADS)

    Vogl, D. F.; Erkaev, N. V.; Biernat, H. K.; Mühlbachler, S.; Farrugia, C. J.

    2001-01-01

    In this paper we report on the variations of the magnetic field strength and the plasma parameters across a fast shock as functions of upstream Alfvén Mach numbers and pressure anisotropy downstream of the shock. In our study we consider an oblique shock where the angle between the magnetic field vector and the normal vector upstream of the shock is chosen to be 45°. We further use two threshold conditions of plasma instabilities as additional equations to bound the range of the pressure anisotropy, p⊥/ p|, i.e., the criterion of the mirror instability and that of the fire—hose instability. We found that the variations of the parallel pressure, the parallel temperature, as well as the tangential component of the velocity are most sensitive to the pressure anisotropy downstream of the shock, whereas the variations of the plasma density, the normal velocity, the magnetic field strength, and perpendicular pressure and temperature with respect to the magnetic field show much less pronounced dependence on the anisotropy.

  7. High Resolution Plasma Measurements From The Fast Plasma Investigation On Magnetospheric Multiscale

    NASA Astrophysics Data System (ADS)

    Pollock, C. J.

    2015-12-01

    NASA's Magnetospheric Multiscale (MMS) mission, launched in March 2015, targets understanding of the fundamental physics of magnetic reconnection using Earth's magnetosphere as a laboratory within which to study this naturally occurring process. The first mission phase, currently in progress, focuses on reconnection occurring at Earth's dayside magnetopause. The relevant electron and ion scale processes have never before been fully resolved and differentiated, owing to limitations in the time (thus spatial) resolution available. The Fast Plasma Investigation (FPI) was developed for flight on MMS in order to fully resolve 3D plasma distribution functions on both the ion scale and the substantially smaller electron scale. MMS is designed to provide multi-point measurements of fast plasma, electric and magnetic fields, ion composition and energetic particles at the four points of a variably sized tetrahedron. Thus, MMS enables specification of all relevant plasma parameters and their spatial derivatives in order to understand the roles of the various terms in the Generalized Ohm's Law that governs the plasma behavior at reconnection sites. In this talk, we provide a brief description of FPI and show a sampling of early results, including MMS crossings of the magnetopause.

  8. Simulation of laser-plasma interactions and fast-electron transport in inhomogeneous plasma

    SciTech Connect

    Cohen, B.I. Kemp, A.J.; Divol, L.

    2010-06-20

    A new framework is introduced for kinetic simulation of laser-plasma interactions in an inhomogeneous plasma motivated by the goal of performing integrated kinetic simulations of fast-ignition laser fusion. The algorithm addresses the propagation and absorption of an intense electromagnetic wave in an ionized plasma leading to the generation and transport of an energetic electron component. The energetic electrons propagate farther into the plasma to much higher densities where Coulomb collisions become important. The high-density plasma supports an energetic electron current, return currents, self-consistent electric fields associated with maintaining quasi-neutrality, and self-consistent magnetic fields due to the currents. Collisions of the electrons and ions are calculated accurately to track the energetic electrons and model their interactions with the background plasma. Up to a density well above critical density, where the laser electromagnetic field is evanescent, Maxwell's equations are solved with a conventional particle-based, finite-difference scheme. In the higher-density plasma, Maxwell's equations are solved using an Ohm's law neglecting the inertia of the background electrons with the option of omitting the displacement current in Ampere's law. Particle equations of motion with binary collisions are solved for all electrons and ions throughout the system using weighted particles to resolve the density gradient efficiently. The algorithm is analyzed and demonstrated in simulation examples. The simulation scheme introduced here achieves significantly improved efficiencies.

  9. Hybrid Simulation of Laser-Plasma Interactions and Fast Electron Transport in Inhomogeneous Plasma

    SciTech Connect

    Cohen, B I; Kemp, A; Divol, L

    2009-05-27

    A new framework is introduced for kinetic simulation of laser-plasma interactions in an inhomogenous plasma motivated by the goal of performing integrated kinetic simulations of fast-ignition laser fusion. The algorithm addresses the propagation and absorption of an intense electromagnetic wave in an ionized plasma leading to the generation and transport of an energetic electron component. The energetic electrons propagate farther into the plasma to much higher densities where Coulomb collisions become important. The high-density plasma supports an energetic electron current, return currents, self-consistent electric fields associated with maintaining quasi-neutrality, and self-consistent magnetic fields due to the currents. Collisions of the electrons and ions are calculated accurately to track the energetic electrons and model their interactions with the background plasma. Up to a density well above critical density, where the laser electromagnetic field is evanescent, Maxwell's equations are solved with a conventional particle-based, finite-difference scheme. In the higher-density plasma, Maxwell's equations are solved using an Ohm's law neglecting the inertia of the background electrons with the option of omitting the displacement current in Ampere's law. Particle equations of motion with binary collisions are solved for all electrons and ions throughout the system using weighted particles to resolve the density gradient efficiently. The algorithm is analyzed and demonstrated in simulation examples. The simulation scheme introduced here achieves significantly improved efficiencies.

  10. Dense magnetized plasma associated with a fast radio burst

    NASA Astrophysics Data System (ADS)

    Masui, Kiyoshi; Lin, Hsiu-Hsien; Sievers, Jonathan; Anderson, Christopher J.; Chang, Tzu-Ching; Chen, Xuelei; Ganguly, Apratim; Jarvis, Miranda; Kuo, Cheng-Yu; Li, Yi-Chao; Liao, Yu-Wei; McLaughlin, Maura; Pen, Ue-Li; Peterson, Jeffrey B.; Roman, Alexander; Timbie, Peter T.; Voytek, Tabitha; Yadav, Jaswant K.

    2015-12-01

    Fast radio bursts are bright, unresolved, non-repeating, broadband, millisecond flashes, found primarily at high Galactic latitudes, with dispersion measures much larger than expected for a Galactic source. The inferred all-sky burst rate is comparable to the core-collapse supernova rate out to redshift 0.5. If the observed dispersion measures are assumed to be dominated by the intergalactic medium, the sources are at cosmological distances with redshifts of 0.2 to 1 (refs 10 and 11). These parameters are consistent with a wide range of source models. One fast burst revealed circular polarization of the radio emission, but no linear polarization was detected, and hence no Faraday rotation measure could be determined. Here we report the examination of archival data revealing Faraday rotation in the fast radio burst FRB 110523. Its radio flux and dispersion measure are consistent with values from previously reported bursts and, accounting for a Galactic contribution to the dispersion and using a model of intergalactic electron density, we place the source at a maximum redshift of 0.5. The burst has a much higher rotation measure than expected for this line of sight through the Milky Way and the intergalactic medium, indicating magnetization in the vicinity of the source itself or within a host galaxy. The pulse was scattered by two distinct plasma screens during propagation, which requires either a dense nebula associated with the source or a location within the central region of its host galaxy. The detection in this instance of magnetization and scattering that are both local to the source favours models involving young stellar populations such as magnetars over models involving the mergers of older neutron stars, which are more likely to be located in low-density regions of the host galaxy.

  11. Dense magnetized plasma associated with a fast radio burst.

    PubMed

    Masui, Kiyoshi; Lin, Hsiu-Hsien; Sievers, Jonathan; Anderson, Christopher J; Chang, Tzu-Ching; Chen, Xuelei; Ganguly, Apratim; Jarvis, Miranda; Kuo, Cheng-Yu; Li, Yi-Chao; Liao, Yu-Wei; McLaughlin, Maura; Pen, Ue-Li; Peterson, Jeffrey B; Roman, Alexander; Timbie, Peter T; Voytek, Tabitha; Yadav, Jaswant K

    2015-12-24

    Fast radio bursts are bright, unresolved, non-repeating, broadband, millisecond flashes, found primarily at high Galactic latitudes, with dispersion measures much larger than expected for a Galactic source. The inferred all-sky burst rate is comparable to the core-collapse supernova rate out to redshift 0.5. If the observed dispersion measures are assumed to be dominated by the intergalactic medium, the sources are at cosmological distances with redshifts of 0.2 to 1 (refs 10 and 11). These parameters are consistent with a wide range of source models. One fast burst revealed circular polarization of the radio emission, but no linear polarization was detected, and hence no Faraday rotation measure could be determined. Here we report the examination of archival data revealing Faraday rotation in the fast radio burst FRB 110523. Its radio flux and dispersion measure are consistent with values from previously reported bursts and, accounting for a Galactic contribution to the dispersion and using a model of intergalactic electron density, we place the source at a maximum redshift of 0.5. The burst has a much higher rotation measure than expected for this line of sight through the Milky Way and the intergalactic medium, indicating magnetization in the vicinity of the source itself or within a host galaxy. The pulse was scattered by two distinct plasma screens during propagation, which requires either a dense nebula associated with the source or a location within the central region of its host galaxy. The detection in this instance of magnetization and scattering that are both local to the source favours models involving young stellar populations such as magnetars over models involving the mergers of older neutron stars, which are more likely to be located in low-density regions of the host galaxy. PMID:26633633

  12. Dense magnetized plasma associated with a fast radio burst.

    PubMed

    Masui, Kiyoshi; Lin, Hsiu-Hsien; Sievers, Jonathan; Anderson, Christopher J; Chang, Tzu-Ching; Chen, Xuelei; Ganguly, Apratim; Jarvis, Miranda; Kuo, Cheng-Yu; Li, Yi-Chao; Liao, Yu-Wei; McLaughlin, Maura; Pen, Ue-Li; Peterson, Jeffrey B; Roman, Alexander; Timbie, Peter T; Voytek, Tabitha; Yadav, Jaswant K

    2015-12-24

    Fast radio bursts are bright, unresolved, non-repeating, broadband, millisecond flashes, found primarily at high Galactic latitudes, with dispersion measures much larger than expected for a Galactic source. The inferred all-sky burst rate is comparable to the core-collapse supernova rate out to redshift 0.5. If the observed dispersion measures are assumed to be dominated by the intergalactic medium, the sources are at cosmological distances with redshifts of 0.2 to 1 (refs 10 and 11). These parameters are consistent with a wide range of source models. One fast burst revealed circular polarization of the radio emission, but no linear polarization was detected, and hence no Faraday rotation measure could be determined. Here we report the examination of archival data revealing Faraday rotation in the fast radio burst FRB 110523. Its radio flux and dispersion measure are consistent with values from previously reported bursts and, accounting for a Galactic contribution to the dispersion and using a model of intergalactic electron density, we place the source at a maximum redshift of 0.5. The burst has a much higher rotation measure than expected for this line of sight through the Milky Way and the intergalactic medium, indicating magnetization in the vicinity of the source itself or within a host galaxy. The pulse was scattered by two distinct plasma screens during propagation, which requires either a dense nebula associated with the source or a location within the central region of its host galaxy. The detection in this instance of magnetization and scattering that are both local to the source favours models involving young stellar populations such as magnetars over models involving the mergers of older neutron stars, which are more likely to be located in low-density regions of the host galaxy.

  13. Fast reconnection in relativistic plasmas: the magnetohydrodynamics tearing instability revisited

    NASA Astrophysics Data System (ADS)

    Del Zanna, L.; Papini, E.; Landi, S.; Bugli, M.; Bucciantini, N.

    2016-08-01

    Fast reconnection operating in magnetically dominated plasmas is often invoked in models for magnetar giant flares, for magnetic dissipation in pulsar winds, or to explain the gamma-ray flares observed in the Crab nebula; hence, its investigation is of paramount importance in high-energy astrophysics. Here we study, by means of two-dimensional numerical simulations, the linear phase and the subsequent non-linear evolution of the tearing instability within the framework of relativistic resistive magnetohydrodynamics (MHD), as appropriate in situations where the Alfvén velocity approaches the speed of light. It is found that the linear phase of the instability closely matches the analysis in classical MHD, where the growth rate scales with the Lundquist number S as S-1/2, with the only exception of an enhanced inertial term due to the thermal and magnetic energy contributions. In addition, when thin current sheets of inverse aspect ratio scaling as S-1/3 are considered, the so-called ideal tearing regime is retrieved, with modes growing independently of S and extremely fast, on only a few light crossing times of the sheet length. The overall growth of fluctuations is seen to solely depend on the value of the background Alfvén velocity. In the fully non-linear stage, we observe an inverse cascade towards the fundamental mode, with Petschek-type supersonic jets propagating at the external Alfvén speed from the X-point, and a fast reconnection rate at the predicted value {R}˜ (ln S)^{-1}.

  14. Nuclear reactor shutdown system

    DOEpatents

    Bhate, Suresh K.; Cooper, Martin H.; Riffe, Delmar R.; Kinney, Calvin L.

    1981-01-01

    An inherent shutdown system for a nuclear reactor having neutron absorbing rods affixed to an armature which is held in an upper position by a magnetic flux flowing through a Curie temperature material. The Curie temperature material is fixedly positioned about the exterior of an inner duct in an annular region through which reactor coolant flows. Elongated fuel rods extending from within the core upwardly toward the Curie temperature material are preferably disposed within the annular region. Upon abnormal conditions which result in high neutron flux and coolant temperature, the Curie material loses its magnetic permeability, breaking the magnetic flux path and allowing the armature and absorber rods to drop into the core, thus shutting down the fissioning reaction. The armature and absorber rods are retrieved by lowering the housing for the electromagnet forming coils which create a magnetic flux path which includes the inner duct wall. The coil housing then is raised, resetting the armature.

  15. Fast molecular tracking maps nanoscale dynamics of plasma membrane lipids

    PubMed Central

    Sahl, Steffen J.; Leutenegger, Marcel; Hilbert, Michael; Hell, Stefan W.; Eggeling, Christian

    2010-01-01

    We describe an optical method capable of tracking a single fluorescent molecule with a flexible choice of high spatial accuracy (∼10–20 nm standard deviation or ∼20–40 nm full-width-at-half-maximum) and temporal resolution (< 1 ms). The fluorescence signal during individual passages of fluorescent molecules through a spot of excitation light allows the sequential localization and thus spatio-temporal tracking of the molecule if its fluorescence is collected on at least three separate point detectors arranged in close proximity. We show two-dimensional trajectories of individual, small organic dye labeled lipids diffusing in the plasma membrane of living cells and directly observe transient events of trapping on < 20 nm spatial scales. The trapping is cholesterol-assisted and much more pronounced for a sphingo- than for a phosphoglycero-lipid, with average trapping times of ∼15 ms and < 4 ms, respectively. The results support previous STED nanoscopy measurements and suggest that, at least for nontreated cells, the transient interaction of a single lipid is confined to macromolecular dimensions. Our experimental approach demonstrates that fast molecular movements can be tracked with minimal invasion, which can reveal new important details of cellular nano-organization. PMID:20351247

  16. Effects of prolonged physical exercise and fasting upon plasma testosterone level in rats.

    PubMed

    Guezennec, C Y; Ferre, P; Serrurier, B; Merino, D; Pesquies, P C

    1982-01-01

    Prolonged physical exercise and fasting in male rats were studied to determine the effect of these two treatments on plasma testosterone level. Blood and tissue samples were drawn after 1 h, 3 h, 5 h, and 7 h treadmill running, and after 24 h, 48 h, and 72 h of fasting. Both treatments resulted in a significant fall in plasma testosterone, plasma luteinizing hormone (LH), plasma Insulin (IRI) and in liver and muscle glycogen stores. In the course of these two treatments the injection of a supra maximal dose of Human Chorionic Gonadotropin (HCG) produced a rise in plasma testosterone similar to that in control rats. This indicates that the decrease of plasma LH may be responsible for the decrease in plasma testosterone, which is time-related with the decrease in glycogen stores. The possible metabolic role of the decrease in plasma testosterone is discussed. PMID:6889494

  17. Fast Plasma Instrument for MMS: Data Compression Simulation Results

    NASA Astrophysics Data System (ADS)

    Barrie, A.; Adrian, M. L.; Yeh, P.; Winkert, G.; Lobell, J.; Vinas, A. F.; Simpson, D. G.

    2009-12-01

    Magnetospheric Multiscale (MMS) mission will study small-scale reconnection structures and their rapid motions from closely spaced platforms using instruments capable of high angular, energy, and time resolution measurements. To meet these requirements, the Fast Plasma Instrument (FPI) consists of eight (8) identical half top-hat electron sensors and eight (8) identical ion sensors and an Instrument Data Processing Unit (IDPU). The sensors (electron or ion) are grouped into pairs whose 6° x 180° fields-of-view (FOV) are set 90° apart. Each sensor is equipped with electrostatic aperture steering to allow the sensor to scan a 45° x 180° fan about the its nominal viewing (0° deflection) direction. Each pair of sensors, known as the Dual Electron Spectrometer (DES) and the Dual Ion Spectrometer (DIS), occupies a quadrant on the MMS spacecraft and the combination of the eight electron/ion sensors, employing aperture steering, image the full-sky every 30-ms (electrons) and 150-ms (ions), respectively. To probe the diffusion regions of reconnection, the highest temporal/spatial resolution mode of FPI results in the DES complement of a given spacecraft generating 6.5-Mb s-1 of electron data while the DIS generates 1.1-Mb s-1 of ion data yielding an FPI total data rate of 6.6-Mb s-1. The FPI electron/ion data is collected by the IDPU then transmitted to the Central Data Instrument Processor (CIDP) on the spacecraft for science interest ranking. Only data sequences that contain the greatest amount of temporal/spatial structure will be intelligently down-linked by the spacecraft. Currently, the FPI data rate allocation to the CIDP is 1.5-Mb s-1. Consequently, the FPI-IDPU must employ data/image compression to meet this CIDP telemetry allocation. Here, we present updated simulations of the CCSDS 122.0-B-1 algorithm-based compression of the FPI-DES electron data as well as the FPI-DIS ion data. Compression analysis is based upon a seed of re-processed Cluster

  18. Control rod drive for reactor shutdown

    DOEpatents

    McKeehan, Ernest R.; Shawver, Bruce M.; Schiro, Donald J.; Taft, William E.

    1976-01-20

    A means for rapidly shutting down or scramming a nuclear reactor, such as a liquid metal-cooled fast breeder reactor, and serves as a backup to the primary shutdown system. The control rod drive consists basically of an in-core assembly, a drive shaft and seal assembly, and a control drive mechanism. The control rod is driven into the core region of the reactor by gravity and hydraulic pressure forces supplied by the reactor coolant, thus assuring that common mode failures will not interfere with or prohibit scramming the reactor when necessary.

  19. Spectroscopic interpretation and velocimetry analysis of fluctuations in a cylindrical plasma recorded by a fast camera

    SciTech Connect

    Oldenbuerger, S.; Brandt, C.; Brochard, F.; Lemoine, N.; Bonhomme, G.

    2010-06-15

    Fast visible imaging is used on a cylindrical magnetized argon plasma produced by thermionic discharge in the Mirabelle device. To link the information collected with the camera to a physical quantity, fast camera movies of plasma structures are compared to Langmuir probe measurements. High correlation is found between light fluctuations and plasma density fluctuations. Contributions from neutral argon and ionized argon to the overall light intensity are separated by using interference filters and a light intensifier. Light emitting transitions are shown to involve a metastable neutral argon state that can be excited by thermal plasma electrons, thus explaining the good correlation between light and density fluctuations. The propagation velocity of plasma structures is calculated by adapting velocimetry methods to the fast camera movies. The resulting estimates of instantaneous propagation velocity are in agreement with former experiments. The computation of mean velocities is discussed.

  20. Spectroscopic interpretation and velocimetry analysis of fluctuations in a cylindrical plasma recorded by a fast camera.

    PubMed

    Oldenbürger, S; Brandt, C; Brochard, F; Lemoine, N; Bonhomme, G

    2010-06-01

    Fast visible imaging is used on a cylindrical magnetized argon plasma produced by thermionic discharge in the Mirabelle device. To link the information collected with the camera to a physical quantity, fast camera movies of plasma structures are compared to Langmuir probe measurements. High correlation is found between light fluctuations and plasma density fluctuations. Contributions from neutral argon and ionized argon to the overall light intensity are separated by using interference filters and a light intensifier. Light emitting transitions are shown to involve a metastable neutral argon state that can be excited by thermal plasma electrons, thus explaining the good correlation between light and density fluctuations. The propagation velocity of plasma structures is calculated by adapting velocimetry methods to the fast camera movies. The resulting estimates of instantaneous propagation velocity are in agreement with former experiments. The computation of mean velocities is discussed.

  1. Fast Plasma Instrument for MMS: Data Compression Simulation Results

    NASA Astrophysics Data System (ADS)

    Barrie, A. C.; Adrian, M. L.; Yeh, P.; Winkert, G. E.; Lobell, J. V.; Viňas, A. F.; Simpson, D. G.; Moore, T. E.

    2008-12-01

    Magnetospheric Multiscale (MMS) mission will study small-scale reconnection structures and their rapid motions from closely spaced platforms using instruments capable of high angular, energy, and time resolution measurements. To meet these requirements, the Fast Plasma Instrument (FPI) consists of eight (8) identical half top-hat electron sensors and eight (8) identical ion sensors and an Instrument Data Processing Unit (IDPU). The sensors (electron or ion) are grouped into pairs whose 6° × 180° fields-of-view (FOV) are set 90° apart. Each sensor is equipped with electrostatic aperture steering to allow the sensor to scan a 45° × 180° fan about the its nominal viewing (0° deflection) direction. Each pair of sensors, known as the Dual Electron Spectrometer (DES) and the Dual Ion Spectrometer (DIS), occupies a quadrant on the MMS spacecraft and the combination of the eight electron/ion sensors, employing aperture steering, image the full-sky every 30-ms (electrons) and 150-ms (ions), respectively. To probe the diffusion regions of reconnection, the highest temporal/spatial resolution mode of FPI results in the DES complement of a given spacecraft generating 6.5-Mb s-1 of electron data while the DIS generates 1.1-Mb s-1 of ion data yielding an FPI total data rate of 7.6-Mb s-1. The FPI electron/ion data is collected by the IDPU then transmitted to the Central Data Instrument Processor (CIDP) on the spacecraft for science interest ranking. Only data sequences that contain the greatest amount of temporal/spatial structure will be intelligently down-linked by the spacecraft. Currently, the FPI data rate allocation to the CIDP is 1.5-Mb s-1. Consequently, the FPI-IDPU must employ data/image compression to meet this CIDP telemetry allocation. Here, we present simulations of the CCSDS 122.0-B-1 algorithm- based compression of the FPI-DES electron data. Compression analysis is based upon a seed of re- processed Cluster/PEACE electron measurements. Topics to be

  2. Fast Plasma Instrument for MMS: Data Compression Simulation Results

    NASA Technical Reports Server (NTRS)

    Barrie, A.; Adrian, Mark L.; Yeh, P.-S.; Winkert, G. E.; Lobell, J. V.; Vinas, A.F.; Simpson, D. J.; Moore, T. E.

    2008-01-01

    Magnetospheric Multiscale (MMS) mission will study small-scale reconnection structures and their rapid motions from closely spaced platforms using instruments capable of high angular, energy, and time resolution measurements. To meet these requirements, the Fast Plasma Instrument (FPI) consists of eight (8) identical half top-hat electron sensors and eights (8) identical ion sensors and an Instrument Data Processing Unit (IDPU). The sensors (electron or ion) are grouped into pairs whose 6 deg x 180 deg fields-of-view (FOV) are set 90 deg apart. Each sensor is equipped with electrostatic aperture steering to allow the sensor to scan a 45 deg x 180 deg fan about its nominal viewing (0 deg deflection) direction. Each pair of sensors, known as the Dual Electron Spectrometer (DES) and the Dual Ion Spectrometer (DIS), occupies a quadrant on the MMS spacecraft and the combination of the eight electron/ion sensors, employing aperture steering, image the full-sky every 30-ms (electrons) and 150-ms (ions), respectively. To probe the results in the DES complement of a given spacecraft generating 6.5-Mbs(exp -1) of electron data while the DIS generates 1.1-Mbs(exp -1) of ion data yielding an FPI total data rate of 6.6-MBs(exp -1). The FPI electron/ion data is collected by the IDPU then transmitted to the Central Data Instrument Processor (CIDP) on the spacecraft for science interest ranking. Only data sequences that contain the greatest amount of temporal/spatial structure will be intelligently down-linked by the spacecraft. Currently, the FPI data rate allocation to the CIDP is 1.5-Mbs(exp -1). Consequently, the FPI-IDPU must employ data/image compression to meet this CIDP telemetry allocation. Here, we present simulations of the CCSDS 122.0-B-1 algorithm-based compression of the FPI-DES electron data. Compression analysis is based upon a seed of re-processed Cluster/PEACE electron measurements. Topics to be discussed include: review of compression algorithm; data quality

  3. Measurements of Prompt and MHD-Induced Fast Ion Loss from National Spherical Torus Experiment Plasmas

    SciTech Connect

    D.S. Darrow; S.S. Medley; A.L. Roquemore; W.W. Heidbrink; A. Alekseyev; F.E. Cecil; J. Egedal; V.Ya. Goloborod'ko; N.N. Gorelenkov; M. Isobe; S. Kaye; M. Miah; F. Paoletti; M.H. Redi; S.N. Reznik; A. Rosenberg; R. White; D. Wyatt; V.A. Yavorskij

    2002-10-15

    A range of effects may make fast ion confinement in spherical tokamaks worse than in conventional aspect ratio tokamaks. Data from neutron detectors, a neutral particle analyzer, and a fast ion loss diagnostic on the National Spherical Torus Experiment (NSTX) indicate that neutral beam ion confinement is consistent with classical expectations in quiescent plasmas, within the {approx}25% errors of measurement. However, fast ion confinement in NSTX is frequently affected by magnetohydrodynamic (MHD) activity, and the effect of MHD can be quite strong.

  4. Fast ion beta limit measurements by collimated neutron detection in MST plasmas

    NASA Astrophysics Data System (ADS)

    Capecchi, William; Anderson, Jay; Bonofiglo, Phillip; Kim, Jungha; Sears, Stephanie

    2015-11-01

    Fast ion orbits in the reversed field pinch (RFP) are well ordered and classically confined despite magnetic field stochasticity generated by multiple tearing modes. Classical TRANSP modeling of a 1MW tangentially injected hydrogen neutral beam in MST deuterium plasmas predicts a core-localized fast ion density that can be up to 25% of the electron density and a fast ion beta of many times the local thermal beta. However, neutral particle analysis of an NBI-driven mode (presumably driven by a fast ion pressure gradient) shows mode-induced transport of core-localized fast ions and a saturated fast ion density. The TRANSP modeling is presumed valid until the onset of the beam-driven mode and gives an initial estimate of the volume-averaged fast ion beta of 1-2% (local core value up to 10%). A collimated neutron detector for fusion product profile measurements will be used to determine the spatial distribution of fast ions, allowing for a first measurement of the critical fast-ion pressure gradient required for mode destabilization. Testing/calibration data and initial fast-ion profiles will be presented. Characterization of both the local and global fast ion beta will be done for deuterium beam injection into deuterium plasmas for comparison to TRANSP predictions. Work supported by US DOE.

  5. Heating a plasma by a broadband stream of fast electrons: Fast ignition, shock ignition, and Gbar shock wave applications

    SciTech Connect

    Gus’kov, S. Yu.; Nicolai, Ph.; Ribeyre, X.; Tikhonchuk, V. T.

    2015-09-15

    An exact analytic solution is found for the steady-state distribution function of fast electrons with an arbitrary initial spectrum irradiating a planar low-Z plasma with an arbitrary density distribution. The solution is applied to study the heating of a material by fast electrons of different spectra such as a monoenergetic spectrum, a step-like distribution in a given energy range, and a Maxwellian spectrum, which is inherent in laser-produced fast electrons. The heating of shock- and fast-ignited precompressed inertial confinement fusion (ICF) targets as well as the heating of a target designed to generate a Gbar shock wave for equation of state (EOS) experiments by laser-produced fast electrons with a Maxwellian spectrum is investigated. A relation is established between the energies of two groups of Maxwellian fast electrons, which are responsible for generation of a shock wave and heating the upstream material (preheating). The minimum energy of the fast and shock igniting beams as well as of the beam for a Gbar shock wave generation increases with the spectral width of the electron distribution.

  6. Interaction of Fast Ions with Global Plasma Modes in the C-2 Field Reversed Configuration Experiment

    NASA Astrophysics Data System (ADS)

    Smirnov, Artem; Dettrick, Sean; Clary, Ryan; Korepanov, Sergey; Thompson, Matthew; Trask, Erik; Tuszewski, Michel

    2012-10-01

    A high-confinement operating regime [1] with plasma lifetimes significantly exceeding past empirical scaling laws was recently obtained by combining plasma gun edge biasing and tangential Neutral Beam Injection (NBI) in the C-2 field-reversed configuration (FRC) experiment [2, 3]. We present experimental and computational results on the interaction of fast ions with the n=2 rotational and n=1 wobble modes in the C-2 FRC. It is found that the n=2 mode is similar to quadrupole magnetic fields in its detrimental effect on the fast ion transport due to symmetry breaking. The plasma gun generates an inward radial electric field, thus stabilizing the n=2 rotational instability without applying the quadrupole magnetic fields. The resultant FRCs are nearly axisymmetric, which enables fast ion confinement. The NBI further suppresses the n=2 mode, improves the plasma confinement characteristics, and increases the plasma configuration lifetime [4]. The n=1 wobble mode has relatively little effect on the fast ion transport, likely due to the approximate axisymmetry about the displaced plasma column. [4pt] [1] M. Tuszewski et al., Phys. Rev. Lett. 108, 255008 (2012).[0pt] [2] M. Binderbauer et al., Phys. Rev. Lett. 105, 045003 (2010).[0pt] [3] H.Y. Guo et al., Phys. Plasmas 18, 056110 (2011).[0pt] [4] M. Tuszewski et al., Phys. Plasmas 19, 056108 (2012)

  7. Accelerated ions from pulsed-power-driven fast plasma flow in perpendicular magnetic field

    NASA Astrophysics Data System (ADS)

    Takezaki, Taichi; Takahashi, Kazumasa; Sasaki, Toru; Kikuchi, Takashi; Harada, Nob.

    2016-06-01

    To understand the interaction between fast plasma flow and perpendicular magnetic field, we have investigated the behavior of a one-dimensional fast plasma flow in a perpendicular magnetic field by a laboratory-scale experiment using a pulsed-power discharge. The velocity of the plasma flow generated by a tapered cone plasma focus device is about 30 km/s, and the magnetic Reynolds number is estimated to be 8.8. After flow through the perpendicular magnetic field, the accelerated ions are measured by an ion collector. To clarify the behavior of the accelerated ions and the electromagnetic fields, numerical simulations based on an electromagnetic hybrid particle-in-cell method have been carried out. The results show that the behavior of the accelerated ions corresponds qualitatively to the experimental results. Faster ions in the plasma flow are accelerated by the induced electromagnetic fields modulated with the plasma flow.

  8. Determining diabetes prevalence: a rational basis for the use of fasting plasma glucose concentrations?

    PubMed

    Finch, C F; Zimmet, P Z; Alberti, K G

    1990-08-01

    The World Health Organization and the National Diabetes Data Group each recommend a diagnostic cut-off point for diabetes of 7.8 mmol l-1 for fasting plasma glucose concentrations as part of the diagnostic criteria for epidemiological studies. However, this cut-off has been shown to be insensitive compared with a screening test based on 2-h plasma glucose levels. In thirteen Pacific populations, from four ethnic groups (Asian Indian, Melanesian, Micronesian, and Polynesian), we have examined whether a different cut-off point for fasting plasma glucose would be more accurate for obtaining an estimate of the prevalence of diabetes when compared with 2-h levels. A fasting plasma glucose diagnostic cut-off of 7.0 mmol l-1 gave an estimate of prevalence not significantly different from that based on the 2-h plasma glucose in 12 of the 13 populations (mean difference 0.27, range -1.51 to +2.44,%). On the other hand, when a cut-off of 7.8 mmol l-1 for fasting plasma glucose was used, the resulting prevalence over-estimated the 2-h glucose prevalence in all populations (mean difference 1.91, range 0.14-5.80,%). Thus for Pacific populations, a fasting plasma glucose cut-off of 7.0 mmol l-1 provides estimates of prevalence that are equivalent to those based on 2-h plasma glucose levels. In epidemiological studies designed to estimate diabetes prevalence, we recommend use of a fasting plasma glucose cut-off of 7.0 mmol l-1 in preference to a detection level of 7.8 mmol l-1, if glucose loading is not possible.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Confirmation of shutdown cooling effects

    NASA Astrophysics Data System (ADS)

    Sato, Kotaro; Tabuchi, Masato; Sugimura, Naoki; Tatsumi, Masahiro

    2015-12-01

    After the Fukushima accidents, all nuclear power plants in Japan have gradually stopped their operations and have long periods of shutdown. During those periods, reactivity of fuels continues to change significantly especially for high-burnup UO2 fuels and MOX fuels due to radioactive decays. It is necessary to consider these isotopic changes precisely, to predict neutronics characteristics accurately. In this paper, shutdown cooling (SDC) effects of UO2 and MOX fuels that have unusual operation histories are confirmed by the advanced lattice code, AEGIS. The calculation results show that the effects need to be considered even after nuclear power plants come back to normal operation.

  10. Confirmation of shutdown cooling effects

    SciTech Connect

    Sato, Kotaro Tabuchi, Masato; Sugimura, Naoki; Tatsumi, Masahiro

    2015-12-31

    After the Fukushima accidents, all nuclear power plants in Japan have gradually stopped their operations and have long periods of shutdown. During those periods, reactivity of fuels continues to change significantly especially for high-burnup UO{sub 2} fuels and MOX fuels due to radioactive decays. It is necessary to consider these isotopic changes precisely, to predict neutronics characteristics accurately. In this paper, shutdown cooling (SDC) effects of UO{sub 2} and MOX fuels that have unusual operation histories are confirmed by the advanced lattice code, AEGIS. The calculation results show that the effects need to be considered even after nuclear power plants come back to normal operation.

  11. Measurements of Fast Ion Distribution in ICRF Heated Plasmas

    SciTech Connect

    Bader, A.; Sears, J.; Bonoli, P.; Granetz, R.; Parker, R.; Wukitch, S.

    2009-11-26

    Alcator C-Mod uses ICRF for the bulk auxiliary heating and relies primarily on hydrogen minority heating scenarios. Measuring the resulting hydrogen ion distribution provides an opportunity to validate upgraded ICRF simulation capability that includes non-Maxwellian ions. The Compact Neutral Particle Analyzer (CNPA) is a diagnostic employed on Alcator C-Mod to measure this fast ion distribution function. The diagnostic can measure the energy distribution of the fast ion tail, serving as a benchmark for simulation results and allowing for an assessment of the simulation algorithm and physics kernel. In this poster, we will present results from the detector in the most recent campaigns. We will discuss the calculation of the fast ion distribution from the measured CNPA distribution and the resulting effective temperature from applying a Stix fit to this distribution.

  12. Fast and slow magnetosonic waves in two-dimensional spin-1/2 quantum plasma

    SciTech Connect

    Mushtaq, A.; Vladimirov, S. V.

    2010-10-15

    Using the spin-1/2 resistive quantum magnetohydrodynamics model, linear and nonlinear relations for slow and fast magnetosonic modes are derived. Spin effects are incorporated via spin force and macroscopic spin magnetization current. The plasma resistivity is shown to play a role of dissipation in the system. With the aid of tanh method the traveling wave solution of Kadomstev-Petviashvili-Burgers is obtained. The solution shows a general shock wave profile superposed by a perturbative solitary-wave contribution. The dynamics of fast and slow magnetosonic shock and soliton, respectively, in the presence and absence of dissipation is investigated with respect to electron spin magnetization, quantum diffraction, and plasma statistic. It is found that results obtained from the spin quantum plasmas differ significantly from the nonspin quantum plasmas. The relevance of the present work to dense astrophysical plasmas such as pulsar magnetosphere is pointed out.

  13. EMERGENCY SHUTDOWN FOR NUCLEAR REACTORS

    DOEpatents

    Paget, J.A.; Koutz, S.L.; Stone, R.S.; Stewart, H.B.

    1963-12-24

    An emergency shutdown or scram apparatus for use in a nuclear reactor that includes a neutron absorber suspended from a temperature responsive substance that is selected to fail at a preselected temperature in excess of the normal reactor operating temperature, whereby the neutron absorber is released and allowed to fall under gravity to a preselected position within the reactor core is presented. (AEC)

  14. Fast electron generation and transport in a turbulent, magnetized plasma

    SciTech Connect

    Stoneking, W.R.

    1994-05-01

    The nature of fast electron generation and transport in the Madison Symmetric Torus (MST) reversed field pinch (RFP) is investigated using two electron energy analyzer (EEA) probes and a thermocouple calorimeter. The parallel velocity distribution of the fast electron population is well fit by a drifted Maxwellian distribution with temperature of about 100 eV and drift velocity of about 2 {times} 10{sup 6} m/s. Cross-calibration of the EEA with the calorimeter provides a measurement of the fast electron perpendicular temperature of 30 eV, much lower than the parallel temperature, and is evidence that the kinetic dynamo mechanism (KDT) is not operative in MST. The fast electron current is found to match to the parallel current at the edge, and the fast electron density is about 4 {times} 10{sup 11} cm{sup {minus}3} independent of the ratio of the applied toroidal electric field to the critical electric field for runaways. First time measurements of magnetic fluctuation induced particle transport are reported. By correlating electron current fluctuations with radial magnetic fluctuations the transported flux of electrons is found to be negligible outside r/a{approximately}0.9, but rises the level of the expected total particle losses inside r/a{approximately}0.85. A comparison of the measured diffusion coefficient is made with the ausilinear stochastic diffusion coefficient. Evidence exists that the reduction of the transport is due to the presence of a radial ambipolar electric field of magnitude 500 V/m, that acts to equilibrate the ion and electron transport rates. The convective energy transport associated with the measured particle transport is large enough to account for the observed magnetic fluctuation induced energy transport in MST.

  15. Fast-ion D{sub {alpha}} measurements and simulations in quiet plasmas

    SciTech Connect

    Luo, Y.; Heidbrink, W. W.; Burrell, K. H.; Ruskov, E.; Solomon, W. M.

    2007-11-15

    The D{sub {alpha}} light emitted by neutralized deuterium fast ions is measured in magnetohydrodynamics (MHD)-quiescent, magnetically confined plasmas during neutral beam injection. A weighted Monte Carlo simulation code models the fast-ion D{sub {alpha}} spectra based on the fast-ion distribution function calculated classically by TRANSP [R. V. Budny, Nucl. Fusion 34, 1247 (1994)]. The spectral shape is in excellent agreement and the magnitude also has reasonable agreement. The fast-ion D{sub {alpha}} signal has the expected dependencies on various parameters including injection energy, injection angle, viewing angle, beam power, electron temperature, and electron density. The neutral particle diagnostic and measured neutron rate corroborate the fast-ion D{sub {alpha}} measurements. The relative spatial profile agrees with TRANSP and is corroborated by the fast-ion pressure profile inferred from the equilibrium.

  16. Communication through a plasma sheet around a fast moving vehicle

    NASA Astrophysics Data System (ADS)

    Sotnikov, V. I.; Mudaliar, S.; Genoni, T.; Rose, D.; Oliver, B. V.; Mehlhorn, T. A.

    2011-10-01

    Investigation of the complicated problem of scattering of electromagnetic waves on turbulent pulsations induced by a sheared flow inside a plasma sheath is important for many applications including communication with hypersonic and re-entry vehicles. Theoretical and computational work aimed at improving the understanding of electromagnetic wave scattering processes in such turbulent plasmas is presented. We analyze excitation of low frequency ion-acoustic type oscillations in a compressible plasma flow with flow velocity shear and influence of such turbulent pulsations on scattering of high frequency electromagnetic waves used for communication purposes. We have appropriately included in our analysis the presence of electron and ion collisions with neutrals as well as electron - ion collisions. Results of numerical solutions for plasma density and electric field perturbations for different velocity profiles have been used in the derived expressions for scattered wave energy and scattering cross section. Work supported by the Air Force Research Laboratory and Air Force Office Of Scientific Research Sandia is a multiprogram laboratory operated by Sandia Corporation, A Lockheed Martin Company, under contract DE-AC04-94AL85000.

  17. 33 CFR 127.205 - Emergency shutdown.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Emergency shutdown. 127.205... Waterfront Facilities Handling Liquefied Natural Gas Equipment § 127.205 Emergency shutdown. Each transfer system must have an emergency shutdown system that— (a) Can be activated manually; and (b) Is...

  18. Fast figuring of large optics by reactive atom plasma

    NASA Astrophysics Data System (ADS)

    Castelli, Marco; Jourdain, Renaud; Morantz, Paul; Shore, Paul

    2012-09-01

    The next generation of ground-based astronomical observatories will require fabrication and maintenance of extremely large segmented mirrors tens of meters in diameter. At present, the large production of segments required by projects like E-ELT and TMT poses time frames and costs feasibility questions. This is principally due to a bottleneck stage in the optical fabrication chain: the final figuring step. State-of-the-art figure correction techniques, so far, have failed to meet the needs of the astronomical community for mass production of large, ultra-precise optical surfaces. In this context, Reactive Atom Plasma (RAP) is proposed as a candidate figuring process that combines nanometer level accuracy with high material removal rates. RAP is a form of plasma enhanced chemical etching at atmospheric pressure based on Inductively Coupled Plasma technology. The rapid figuring capability of the RAP process has already been proven on medium sized optical surfaces made of silicon based materials. In this paper, the figure correction of a 3 meters radius of curvature, 400 mm diameter spherical ULE mirror is presented. This work demonstrates the large scale figuring capability of the Reactive Atom Plasma process. The figuring is carried out by applying an in-house developed procedure that promotes rapid convergence. A 2.3 μm p-v initial figure error is removed within three iterations, for a total processing time of 2.5 hours. The same surface is then re-polished and the residual error corrected again down to λ/20 nm rms. These results highlight the possibility of figuring a metre-class mirror in about ten hours.

  19. Arbitrary amplitude fast electron-acoustic solitons in three-electron component space plasmas

    NASA Astrophysics Data System (ADS)

    Mbuli, L. N.; Maharaj, S. K.; Bharuthram, R.; Singh, S. V.; Lakhina, G. S.

    2016-06-01

    We examine the characteristics of fast electron-acoustic solitons in a four-component unmagnetised plasma model consisting of cool, warm, and hot electrons, and cool ions. We retain the inertia and pressure for all the plasma species by assuming adiabatic fluid behaviour for all the species. By using the Sagdeev pseudo-potential technique, the allowable Mach number ranges for fast electron-acoustic solitary waves are explored and discussed. It is found that the cool and warm electron number densities determine the polarity switch of the fast electron-acoustic solitons which are limited by either the occurrence of fast electron-acoustic double layers or warm and hot electron number density becoming unreal. For the first time in the study of solitons, we report on the coexistence of fast electron-acoustic solitons, in addition to the regular fast electron-acoustic solitons and double layers in our multi-species plasma model. Our results are applied to the generation of broadband electrostatic noise in the dayside auroral region.

  20. A fluctuation-induced plasma transport diagnostic based upon fast-Fourier transform spectral analysis

    NASA Technical Reports Server (NTRS)

    Powers, E. J.; Kim, Y. C.; Hong, J. Y.; Roth, J. R.; Krawczonek, W. M.

    1978-01-01

    A diagnostic, based on fast Fourier-transform spectral analysis techniques, that provides experimental insight into the relationship between the experimentally observable spectral characteristics of the fluctuations and the fluctuation-induced plasma transport is described. The model upon which the diagnostic technique is based and its experimental implementation is discussed. Some characteristic results obtained during the course of an experimental study of fluctuation-induced transport in the electric field dominated NASA Lewis bumpy torus plasma are presented.

  1. Fast Ion Confinement in High Beta, Steady-State Scenario Plasmas

    NASA Astrophysics Data System (ADS)

    Heidbrink, W. W.; Chen, X.; Ferron, J. R.; van Zeeland, M. A.; Grierson, B. A.; Holcomb, C. T.

    2013-10-01

    Fast-ion confinement is studied for qmin between 1.2-2.8 in plasmas with normalized β > 2 . 6 . Fast-ion D-alpha (FIDA), neutron, and neutral-particle diagnostics measure the confined fast ions. Tearing modes and a ``sea'' of unstable Alfvén eigenmodes (AE) are observed. In preliminary analysis, the degradation in fast-ion confinement increases with qmin ; increased AE activity appears responsible. Predictions of a model that assumes that AE-induced fast-ion transport is stiff are compared with the data. Work supported by the US Department of Energy under SC-G903402, DE-FC-02-04ER54698, DE-AC02-09CH11466, and DE-AC52-07NA27344.

  2. Electromagnetic Fluctuations during Fast Reconnection in a Laboratory Plasma

    SciTech Connect

    Hantao Ji; Stephen Terry; Masaaki Yamada; Russell Kulsrud; Aleksey Kuritsyn; Yang Ren

    2003-02-11

    Clear evidence for a positive correlation is established between the magnitude of magnetic fluctuations in the lower-hybrid frequency range and enhancement of reconnection rates in a well-controlled laboratory plasma. The fluctuations belong to the right-hand polarized whistler wave branch, propagating obliquely to the reconnecting magnetic field, with a phase velocity comparable to the relative drift velocity between electrons and ions. The short coherence length and large variation along the propagation direction indicate their strongly nonlinear nature in three dimensions.

  3. Effect of bremsstrahlung radiation emission on fast electrons in plasmas

    NASA Astrophysics Data System (ADS)

    Embréus, O.; Stahl, A.; Fülöp, T.

    2016-09-01

    Bremsstrahlung radiation emission is an important energy loss mechanism for energetic electrons in plasmas. In this paper we investigate the effect of spontaneous bremsstrahlung emission on the momentum‑space structure of the electron distribution, fully accounting for the emission of finite‑energy photons by modeling the bremsstrahlung interactions with a Boltzmann collision operator. We find that electrons accelerated by electric fields can reach significantly higher energies than predicted by the commonly used radiative stopping‑power model. Furthermore, we show that the emission of soft photons can contribute significantly to the dynamics of electrons with an anisotropic distribution by causing pitch‑angle scattering at a rate that increases with energy.

  4. Effect of bremsstrahlung radiation emission on fast electrons in plasmas

    NASA Astrophysics Data System (ADS)

    Embréus, O.; Stahl, A.; Fülöp, T.

    2016-09-01

    Bremsstrahlung radiation emission is an important energy loss mechanism for energetic electrons in plasmas. In this paper we investigate the effect of spontaneous bremsstrahlung emission on the momentum-space structure of the electron distribution, fully accounting for the emission of finite-energy photons by modeling the bremsstrahlung interactions with a Boltzmann collision operator. We find that electrons accelerated by electric fields can reach significantly higher energies than predicted by the commonly used radiative stopping-power model. Furthermore, we show that the emission of soft photons can contribute significantly to the dynamics of electrons with an anisotropic distribution by causing pitch-angle scattering at a rate that increases with energy.

  5. Integrated kinetic simulation of laser-plasma interactions, fast-electron generation, and transport in fast ignition

    SciTech Connect

    Kemp, A. J.; Cohen, B. I.; Divol, L.

    2010-05-15

    We present new results on the physics of short-pulse laser-matter interaction of kilojoule-picosecond pulses at full spatial and temporal scale using a new approach that combines a three-dimensional collisional electromagnetic particle-in-cell code with a magnetohydrodynamic-hybrid model of high-density plasma. In the latter, collisions damp out plasma waves, and an Ohm's law with electron inertia effects neglected determines the electric field. In addition to yielding orders of magnitude in speed-up while avoiding numerical instabilities, this allows us to model the whole problem in a single unified framework: the laser-plasma interaction at subcritical densities, energy deposition at relativistic critical densities, and fast- electron transport in solid densities. Key questions such as the multipicosecond temporal evolution of the laser energy conversion into hot electrons, the impact of return currents on the laser-plasma interaction, and the effect of self-generated electric and magnetic fields on electron transport will be addressed. We will report applications to current experiments.

  6. Integrated Kinetic Simulation of Laser-Plasma Interactions, Fast-Electron Generation and Transport in Fast Ignition

    SciTech Connect

    Kemp, A; Cohen, B; Divol, L

    2009-11-16

    We present new results on the physics of short-pulse laser-matter interaction of kilojoule-picosecond pulses at full spatial and temporal scale, using a new approach that combines a 3D collisional electromagnetic Particle-in-Cell code with an MHD-hybrid model of high-density plasma. In the latter, collisions damp out plasma waves, and an Ohm's law with electron inertia effects neglected determines the electric field. In addition to yielding orders of magnitude in speed-up while avoiding numerical instabilities, this allows us to model the whole problem in a single unified framework: the laser-plasma interaction at sub-critical densities, energy deposition at relativistic critical densities, and fast-electron transport in solid densities. Key questions such as the multi-picosecond temporal evolution of the laser energy conversion into hot electrons, the impact of return currents on the laser-plasma interaction, and the effect of self-generated electric and magnetic fields on electron transport will be addressed. We will report applications to current experiments.

  7. Fast-acting calorimeter measures heat output of plasma gun accelerator

    NASA Technical Reports Server (NTRS)

    Dethlefson, R.; Larson, A. V.; Liebing, L.

    1967-01-01

    Calorimeter measures the exhaust energy from a shot of a pulsed plasma gun accelerator. It has a fast response time and requires only one measurement to determine the total energy. It uses a long ribbon of copper foil wound around a glass frame to form a reentrant cavity.

  8. The role of curvature and stretching on the existence of fast dynamo plasma in Riemannian space

    SciTech Connect

    Garcia de Andrade, L. C.

    2008-12-15

    Vishik's anti-dynamo theorem is applied to a nonstretched twisted magnetic flux tube in Riemannian space. Marginal or slow dynamos along curved (folded), torsioned (twisted), and nonstretching flux tubes plasma flows are obtained. Riemannian curvature of the twisted magnetic flux tube is computed in terms of the Frenet curvature in the thin tube limit. It is shown that, for nonstretched filaments, fast dynamo action in the diffusive case cannot be obtained, in agreement with Vishik's argument that fast dynamos cannot be obtained in nonstretched flows. Instead of a fast dynamo, a nonuniform stretching slow dynamo is obtained. An example is given, which generalizes plasma dynamo laminar flows, recently presented by Wang et al. [Phys Plasmas 9, 1491 (2002)], in the case of low magnetic Reynolds number Re{sub m}{>=}210. Curved and twisting Riemannian heliotrons, where nondynamo modes are found even when stretching is present, shows that the simple presence of stretching is not enough for the existence of dynamo action. In this paper, folding plays the role of Riemannian curvature and can be used to cancel magnetic fields, not enhancing the dynamo action. Nondynamo modes are found for certain values of torsion, or Frenet curvature (folding) in the spirit of the anti-dynamo theorem. It is also shown that curvature and stretching are fundamental for the existence of fast dynamos in plasmas.

  9. Effects of fast monoenergetic electrons on the generalized Bohm criterion for electronegative dusty plasma

    SciTech Connect

    Chekour, S.; Tahraoui, A.; Zaham, B.

    2012-05-15

    In this work, we have generalized the computation of Bohm criterion for electronegative complex plasma in the presence of fast monoenergetic electrons coming from a plane electrode. For this, we have established a 1D, collisionless, stationary, and unmagnetized electronegative plasma sheath model. The electrons and negative ions are considered in thermodynamic equilibrium; however, the positive ions, the dust grains, and the fast monoenergetic electrons are described by cold fluid equations. The generalized Bohm criterion has been calculated by using Sagdeev's pseudo potential method and the dust grain charge equation. The self-consistent relation between the dust grain surface potential at the edge and dust grains density is also derived. The numerical results reveal that the presence of the fast monoenergetic electrons increases the positive ion Mach number. On the other hand, the raise of electronegativity decreases this positive Mach number. The evolution of dust grain surface potential at the sheath edge is also illustrated and discussed.

  10. Heating efficiency evaluation with mimicking plasma conditions of integrated fast-ignition experiment.

    PubMed

    Fujioka, Shinsuke; Johzaki, Tomoyuki; Arikawa, Yasunobu; Zhang, Zhe; Morace, Alessio; Ikenouchi, Takahito; Ozaki, Tetsuo; Nagai, Takahiro; Abe, Yuki; Kojima, Sadaoki; Sakata, Shohei; Inoue, Hiroaki; Utsugi, Masaru; Hattori, Shoji; Hosoda, Tatsuya; Lee, Seung Ho; Shigemori, Keisuke; Hironaka, Youichiro; Sunahara, Atsushi; Sakagami, Hitoshi; Mima, Kunioki; Fujimoto, Yasushi; Yamanoi, Kohei; Norimatsu, Takayoshi; Tokita, Shigeki; Nakata, Yoshiki; Kawanaka, Junji; Jitsuno, Takahisa; Miyanaga, Noriaki; Nakai, Mitsuo; Nishimura, Hiroaki; Shiraga, Hiroyuki; Nagatomo, Hideo; Azechi, Hiroshi

    2015-06-01

    A series of experiments were carried out to evaluate the energy-coupling efficiency from heating laser to a fuel core in the fast-ignition scheme of laser-driven inertial confinement fusion. Although the efficiency is determined by a wide variety of complex physics, from intense laser plasma interactions to the properties of high-energy density plasmas and the transport of relativistic electron beams (REB), here we simplify the physics by breaking down the efficiency into three measurable parameters: (i) energy conversion ratio from laser to REB, (ii) probability of collision between the REB and the fusion fuel core, and (iii) fraction of energy deposited in the fuel core from the REB. These three parameters were measured with the newly developed experimental platform designed for mimicking the plasma conditions of a realistic integrated fast-ignition experiment. The experimental results indicate that the high-energy tail of REB must be suppressed to heat the fuel core efficiently. PMID:26172803

  11. Heating efficiency evaluation with mimicking plasma conditions of integrated fast-ignition experiment.

    PubMed

    Fujioka, Shinsuke; Johzaki, Tomoyuki; Arikawa, Yasunobu; Zhang, Zhe; Morace, Alessio; Ikenouchi, Takahito; Ozaki, Tetsuo; Nagai, Takahiro; Abe, Yuki; Kojima, Sadaoki; Sakata, Shohei; Inoue, Hiroaki; Utsugi, Masaru; Hattori, Shoji; Hosoda, Tatsuya; Lee, Seung Ho; Shigemori, Keisuke; Hironaka, Youichiro; Sunahara, Atsushi; Sakagami, Hitoshi; Mima, Kunioki; Fujimoto, Yasushi; Yamanoi, Kohei; Norimatsu, Takayoshi; Tokita, Shigeki; Nakata, Yoshiki; Kawanaka, Junji; Jitsuno, Takahisa; Miyanaga, Noriaki; Nakai, Mitsuo; Nishimura, Hiroaki; Shiraga, Hiroyuki; Nagatomo, Hideo; Azechi, Hiroshi

    2015-06-01

    A series of experiments were carried out to evaluate the energy-coupling efficiency from heating laser to a fuel core in the fast-ignition scheme of laser-driven inertial confinement fusion. Although the efficiency is determined by a wide variety of complex physics, from intense laser plasma interactions to the properties of high-energy density plasmas and the transport of relativistic electron beams (REB), here we simplify the physics by breaking down the efficiency into three measurable parameters: (i) energy conversion ratio from laser to REB, (ii) probability of collision between the REB and the fusion fuel core, and (iii) fraction of energy deposited in the fuel core from the REB. These three parameters were measured with the newly developed experimental platform designed for mimicking the plasma conditions of a realistic integrated fast-ignition experiment. The experimental results indicate that the high-energy tail of REB must be suppressed to heat the fuel core efficiently.

  12. Influence of circulating fast ions on nonlinear kink-tearing modes in tokamak plasmas

    NASA Astrophysics Data System (ADS)

    Wang, Xian-Qu

    2016-08-01

    Nonlinear radial displacement modified by the kinetic effect of circulating fast ions is derived. It is found that circulating fast ions play a crucial role in the nonlinear dynamics of m = 1 kink-tearing modes. For a large fraction of fast ions, resonant fast ions can destabilize the mode by wave-particle interaction and enhance the mode saturation level significantly, meanwhile, fast-ion current has a modification on the mode amplitude depending on the plasma pressure gradient. A relation of mode amplitude to linear growth rate is explored by this model, which is valid to study the effects of circulating or trapped fast particles on the mode. The calculation results for the ITER-like parameters suggest that the kink-tearing mode with a global structure is dominated by the wave-particle interaction rather than the fast-ion current, particularly for the small island in which the fraction of fast ions is ignorable in comparison with the ideal region. The dependence of radial displacement on the mode frequency is discussed for different stabilities of the MHD modes.

  13. Fast and Slow Mode Solitary Waves in a Five Component Plasma

    NASA Astrophysics Data System (ADS)

    Sebastian, Sijo; Michael, Manesh; Varghese, Anu; Sreekala, G.; Venugopal, Chandu

    2016-07-01

    We have investigated fast and slow mode solitary profiles in a five component plasma consisting of positively and negatively charged pair ions, hydrogen ions and hotter and colder electrons. Of these, the heavier ions and colder photo-electrons are of cometary origin while the other components are of solar origin; the electrons being described by kappa distributions. The Zakharov-Kuznetzov (ZK) equation is derived and solutions for fast and slow mode solitary structures are plotted for parameters relevant to that of comet Halley. From the figures, it is seen that the presence of hydrogen ion determines the polarity of fast and slow mode solitary structures. Also different pair ions like He, C and O have significant effect on the width of the fast and slow mode solitary structures.

  14. Reactor shutdown delays medical procedures

    NASA Astrophysics Data System (ADS)

    Gwynne, Peter

    2008-01-01

    A longer-than-expected maintenance shutdown of the Canadian nuclear reactor that produces North America's entire supply of molybdenum-99 - from which the radioactive isotopes technetium-99 and iodine-131 are made - caused delays to the diagnosis and treatment of thousands of seriously ill patients last month. Technetium-99 is a key component of nuclear-medicine scans, while iodine-131 is used to treat cancer and other diseases of the thyroid. Production eventually resumed, but only after the Canadian government had overruled the Canadian Nuclear Safety Commission (CNSC), which was still concerned about the reactor's safety.

  15. Fast camera studies at an electron cyclotron resonance table plasma generator

    SciTech Connect

    Rácz, R.; Biri, S.

    2014-02-15

    A simple table-size ECR plasma generator operates in the ATOMKI without axial magnetic trap and without any particle extraction tool. Radial plasma confinement is ensured by a NdFeB hexapole. The table-top ECR is a simplified version of the 14 GHz ATOMKI-ECRIS. Plasma diagnostics experiments are planned to be performed at this device before installing the measurement setting at the “big” ECRIS. Recently, the plasma generator has been operated in pulsed RF mode in order to investigate the time evolution of the ECR plasma in two different ways. (1) The visible light radiation emitted by the plasma was investigated by the frames of a fast camera images with 1 ms temporal resolution. Since the visible light photographs are in strong correlation with the two-dimensional spatial distribution of the cold electron components of the plasma it can be important to understand better the transient processes just after the breakdown and just after the glow. (2) The time-resolved ion current on a specially shaped electrode was measured simultaneously in order to compare it with the visible light photographs. The response of the plasma was detected by changing some external setting parameters (gas pressure and microwave power) and was described in this paper.

  16. Fast camera studies at an electron cyclotron resonance table plasma generator.

    PubMed

    Rácz, R; Biri, S; Hajdu, P; Pálinkás, J

    2014-02-01

    A simple table-size ECR plasma generator operates in the ATOMKI without axial magnetic trap and without any particle extraction tool. Radial plasma confinement is ensured by a NdFeB hexapole. The table-top ECR is a simplified version of the 14 GHz ATOMKI-ECRIS. Plasma diagnostics experiments are planned to be performed at this device before installing the measurement setting at the "big" ECRIS. Recently, the plasma generator has been operated in pulsed RF mode in order to investigate the time evolution of the ECR plasma in two different ways. (1) The visible light radiation emitted by the plasma was investigated by the frames of a fast camera images with 1 ms temporal resolution. Since the visible light photographs are in strong correlation with the two-dimensional spatial distribution of the cold electron components of the plasma it can be important to understand better the transient processes just after the breakdown and just after the glow. (2) The time-resolved ion current on a specially shaped electrode was measured simultaneously in order to compare it with the visible light photographs. The response of the plasma was detected by changing some external setting parameters (gas pressure and microwave power) and was described in this paper.

  17. Development and Benchmarking of a Hybrid PIC Code For Dense Plasmas and Fast Ignition

    SciTech Connect

    Witherspoon, F. Douglas; Welch, Dale R.; Thompson, John R.; MacFarlane, Joeseph J.; Phillips, Michael W.; Bruner, Nicki; Mostrom, Chris; Thoma, Carsten; Clark, R. E.; Bogatu, Nick; Kim, Jin-Soo; Galkin, Sergei; Golovkin, Igor E.; Woodruff, P. R.; Wu, Linchun; Messer, Sarah J.

    2014-05-20

    Radiation processes play an important role in the study of both fast ignition and other inertial confinement schemes, such as plasma jet driven magneto-inertial fusion, both in their effect on energy balance, and in generating diagnostic signals. In the latter case, warm and hot dense matter may be produced by the convergence of a plasma shell formed by the merging of an assembly of high Mach number plasma jets. This innovative approach has the potential advantage of creating matter of high energy densities in voluminous amount compared with high power lasers or particle beams. An important application of this technology is as a plasma liner for the flux compression of magnetized plasma to create ultra-high magnetic fields and burning plasmas. HyperV Technologies Corp. has been developing plasma jet accelerator technology in both coaxial and linear railgun geometries to produce plasma jets of sufficient mass, density, and velocity to create such imploding plasma liners. An enabling tool for the development of this technology is the ability to model the plasma dynamics, not only in the accelerators themselves, but also in the resulting magnetized target plasma and within the merging/interacting plasma jets during transport to the target. Welch pioneered numerical modeling of such plasmas (including for fast ignition) using the LSP simulation code. Lsp is an electromagnetic, parallelized, plasma simulation code under development since 1995. It has a number of innovative features making it uniquely suitable for modeling high energy density plasmas including a hybrid fluid model for electrons that allows electrons in dense plasmas to be modeled with a kinetic or fluid treatment as appropriate. In addition to in-house use at Voss Scientific, several groups carrying out research in Fast Ignition (LLNL, SNL, UCSD, AWE (UK), and Imperial College (UK)) also use LSP. A collaborative team consisting of HyperV Technologies Corp., Voss Scientific LLC, FAR-TECH, Inc., Prism

  18. Momentum broadening of a fast parton in a perturbative quark-gluon plasma

    SciTech Connect

    Majumder, Abhijit; Mueller, Berndt; Mrowczynski, Stanislaw

    2009-12-15

    The average transverse momentum transfer per unit path length to a fast parton scattering elastically in a perturbative quark-gluon plasma is related to the radiative energy loss of the parton. We first calculate the momentum transfer coefficient q-circumflex in terms of a classical Langevin problem and then define it quantum mechanically through a scattering matrix element. After treating the well-known case of a quark-gluon plasma in equilibrium, we consider an off-equilibrium unstable plasma. As a specific example, we treat the two-stream plasma with unstable modes of longitudinal chromoelectric field. In the presence of the instabilities, q-circumflex is shown to exponentially grow in time.

  19. High-Harmonic Fast Wave Driven H-mode Plasmas on NSTX

    SciTech Connect

    B.P. LeBlanc; R.E. Bell; S.I. Bernabei; K. Indireshkumar; S.M. Kaye; R. Maingi; T.K. Mau; D.W. Swain; G. Taylor; P.M. Ryan; J.B Wilgen; J.R. Wilson

    2003-05-01

    The launch of High-Harmonic Fast Waves (HHFW) routinely provides auxiliary power to NSTX plasmas, where it is used to heat electrons and pursue drive current. H-mode transitions have been observed in deuterium discharges, where only HHFW and ohmic heating, and no neutral beam injection (NBI), were applied to the plasma. The usual H-mode signatures are observed. A drop of the Da light marks the start of a stored energy increase, which can double the energy content. These H-mode plasmas also have the expected kinetic profile signatures with steep edge density and electron temperature pedestal. Similar to its NBI driven counterpart--also observed on NSTX-- the HHFW H mode have density profiles that features ''ears'' in the peripheral region. These plasmas are likely candidates for long pulse operation because of the combination of bootstrap current, associated with H-mode kinetic profiles, and active current drive, which can be generated with HHFW power.

  20. An arbitrary amplitude fast magnetosonic soliton in quantum electron-positron-ion plasmas

    NASA Astrophysics Data System (ADS)

    Hussain, S.; Mushtaq, A.; Mahmood, S.

    2013-02-01

    Nonlinear fast magnetosonic waves are studied in a collisionless homogenous, magnetized electron-positron-ion (e-p-i) plasma. The multi-component quantum magneto-hydrodynamic model is used in which ions are assumed to be dynamic whereas electron and positron quantum fluids are taken to be inertialess. The Sagdeev potential approach is used to obtain arbitrary amplitude magnetosonic structures in dense e-p-i plasmas. It is found that the wave amplitude as well as the width of the magnetosonic structure depends on different plasma parameters such as the electron to positron density ratio, plasma beta, quantum parameter and the Alfvénic Mach number. The numerical results have also been obtained for illustration.

  1. Advances in High Harmonic Fast Wave Heating of NSTX H-mode Plasmas

    SciTech Connect

    Ryan, Philip Michael; Ahn, Joonwook; Bell, R. E.; Bonoli, P.; Chen, Guangye; Green, David L; Harvey, R. W.; Hosea, J.; Jaeger, Erwin Frederick; Kaye, S.; LeBlanc, B; Maingi, Rajesh; Phillips, Cynthia; Podesta, M.; Taylor, G.; Wilgen, John B; Wilson, J. R.

    2010-01-01

    High-harmonic fast wave (HHFW) heating and current drive is being developed in NSTX to provide bulk electron heating and q(0) control during non-inductively sustained Hmode plasmas fuelled by deuterium neutral-beam injection (NBI). In addition, it is used to assist the plasma current ramp-up. A major modification to increase the RF power limit was made in 2009; the original end-grounded, single end-powered current straps of the 12- element array were replaced with center-grounded, double end-powered straps. Greater than 3 MW have been coupled into NBI-driven, ELMy H-mode plasmas with this upgraded antenna. Improved core HHFW heating, particularly at longer wavelengths and during low-density start-up and plasma current ramp-up, has been obtained by lowering the edge density with lithium wall conditioning, thereby moving the critical density for fast-wave propagation away from the vessel wall [1]. Significant core electron heating of NBI-fuelled H-modes has been observed for the first time over a range of launched wavelengths and H-modes can be accessed by HHFW alone. Visible and IR camera images of the antenna and divertor indicate that fast wave interactions can deposit considerable RF energy on the outboard divertor plate, especially at longer wavelengths that begin to propagate closer to the vessel walls. Edge power loss can also arise from HHFWgenerated parametric decay instabilities; edge ion heating is observed that is wavelength dependent. During plasmas where HHFW is combined with NBI, there is a significant enhancement in neutron rate, and fast-ion D-alpha (FIDA) emission measurements clearly show broadening of the fast-ion profile in the plasma core. Large edge localized modes (ELMs) have been observed immediately following the termination of RF power, whether the power turn off is programmed or due to antenna arcing. Causality has not been established but new experiments are planned and will be reported. Fast digitization of the reflected power signal

  2. 33 CFR 127.205 - Emergency shutdown.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) WATERFRONT FACILITIES WATERFRONT FACILITIES HANDLING LIQUEFIED NATURAL GAS AND LIQUEFIED HAZARDOUS GAS Waterfront Facilities Handling Liquefied Natural Gas Equipment § 127.205 Emergency shutdown. Each...

  3. 33 CFR 127.205 - Emergency shutdown.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) WATERFRONT FACILITIES WATERFRONT FACILITIES HANDLING LIQUEFIED NATURAL GAS AND LIQUEFIED HAZARDOUS GAS Waterfront Facilities Handling Liquefied Natural Gas Equipment § 127.205 Emergency shutdown. Each...

  4. 33 CFR 127.205 - Emergency shutdown.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) WATERFRONT FACILITIES WATERFRONT FACILITIES HANDLING LIQUEFIED NATURAL GAS AND LIQUEFIED HAZARDOUS GAS Waterfront Facilities Handling Liquefied Natural Gas Equipment § 127.205 Emergency shutdown. Each...

  5. 33 CFR 127.205 - Emergency shutdown.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) WATERFRONT FACILITIES WATERFRONT FACILITIES HANDLING LIQUEFIED NATURAL GAS AND LIQUEFIED HAZARDOUS GAS Waterfront Facilities Handling Liquefied Natural Gas Equipment § 127.205 Emergency shutdown. Each...

  6. Development of fast steering mirror control system for plasma heating and diagnostics

    SciTech Connect

    Okada, K. Kubo, S.; Shimozuma, T.; Yoshimura, Y.; Igami, H.; Takahashi, H.; Tanaka, K.; Kobayashi, S.; Ito, S.; Mizuno, Y.; Ogasawara, S.; Nishiura, M.

    2014-11-15

    A control system for a fast steering mirror has been newly developed for the electron cyclotron heating (ECH) launchers in the large helical device. This system enables two-dimensional scan during a plasma discharge and provides a simple feedback control function. A board mounted with a field programmable gate array chip has been designed to realize feedback control of the ECH beam position to maintain higher electron temperature by ECH. The heating position is determined by a plasma diagnostic signal related to the electron temperature such as electron cyclotron emission and Thomson scattering.

  7. Development of fast steering mirror control system for plasma heating and diagnostics

    NASA Astrophysics Data System (ADS)

    Okada, K.; Nishiura, M.; Kubo, S.; Shimozuma, T.; Yoshimura, Y.; Igami, H.; Takahashi, H.; Tanaka, K.; Kobayashi, S.; Ito, S.; Mizuno, Y.; Ogasawara, S.

    2014-11-01

    A control system for a fast steering mirror has been newly developed for the electron cyclotron heating (ECH) launchers in the large helical device. This system enables two-dimensional scan during a plasma discharge and provides a simple feedback control function. A board mounted with a field programmable gate array chip has been designed to realize feedback control of the ECH beam position to maintain higher electron temperature by ECH. The heating position is determined by a plasma diagnostic signal related to the electron temperature such as electron cyclotron emission and Thomson scattering.

  8. Development of fast steering mirror control system for plasma heating and diagnostics.

    PubMed

    Okada, K; Nishiura, M; Kubo, S; Shimozuma, T; Yoshimura, Y; Igami, H; Takahashi, H; Tanaka, K; Kobayashi, S; Ito, S; Mizuno, Y; Ogasawara, S

    2014-11-01

    A control system for a fast steering mirror has been newly developed for the electron cyclotron heating (ECH) launchers in the large helical device. This system enables two-dimensional scan during a plasma discharge and provides a simple feedback control function. A board mounted with a field programmable gate array chip has been designed to realize feedback control of the ECH beam position to maintain higher electron temperature by ECH. The heating position is determined by a plasma diagnostic signal related to the electron temperature such as electron cyclotron emission and Thomson scattering.

  9. Fast magnetic field annihilation driven by two laser pulses in underdense plasma

    SciTech Connect

    Gu, Y. J.; Kumar, D.; Weber, S.; Korn, G.; Klimo, O.; Bulanov, S. V.; Esirkepov, T. Zh.

    2015-10-15

    Fast magnetic annihilation is investigated by using 2.5-dimensional particle-in-cell simulations of two parallel ultra-short petawatt laser pulses co-propagating in underdense plasma. The magnetic field generated by the laser pulses annihilates in a current sheet formed between the pulses. Magnetic field energy is converted to an inductive longitudinal electric field, which efficiently accelerates the electrons of the current sheet. This new regime of collisionless relativistic magnetic field annihilation with a timescale of tens of femtoseconds can be extended to near-critical and overdense plasma with the ultra-high intensity femtosecond laser pulses.

  10. Asymmetric double Langmuir probe for fast and automatic measurements of plasma temperature

    SciTech Connect

    Uckan, T.

    1987-11-01

    We present a fast technique for determining the plasma electron temperature T/sub e/ automatically from the small signal application of the asymmetric double Langmuir probe when it is operated in the region where -1 < eV/sub a/T/sub e/ < 1. The method described here is based on simple time and rms averages of the probe current that results from a sinusoidally varying applied voltage V/sub a/. 4 refs., 2 figs.

  11. Relationship between natriuresis and changes in plasma atrial natriuretic factor, renin activity and aldosterone levels in fasting obese subjects.

    PubMed

    Donckier, J E; Kolanowski, J; Berbinschi, A; Gerard, G; Ketelslegers, J M

    1990-01-01

    This study was conducted to assess whether changes in atrial natriuretic factor (ANF) secretion could account for the natriuresis of the early phase of fasting. To this end, 8 AM (supine) and 10 AM (standing) plasma ANF concentrations were determined daily and compared with plasma renin activity and aldosterone levels in 8 obese subjects submitted to a 7-day total fast. Depiste constant daily sodium intake (51 mmol), urinary sodium excretion increased from 35 +/- 7 to 109 +/- 8 mmol/day after 4 days of fast (p less than 0.001) and declined thereafter. Urinary ketone excretion progressively increased over the whole period of fasting (p less than 0.001). Interestingly, fasting induced a decrease in plasma ANF concentrations (p less than 0.05). A contrast analysis revealed no significant change in ANF during the initial natriuretic phase of fasting but a decrease at the end of fasting averaging 36% (p less than 0.05) and 18% (p less than 0.05) at 8 and 10 AM respectively. In contrast, plasma aldosterone rose during fasting (p less than 0.05), the difference being significant at the end of fasting (p less than 0.01). Plasma renin activity and cortisol did not change significantly over the fasting period. Postural and/or diurnal changes of ANF, aldosterone, renin and cortisol were preserved during fasting (p less than 0.01). Postural changes of ANF were, however, attenuated at the end of fasting (p less than 0.05). These data indicate that the fasting natriuresis cannot be explained by changes in ANF levels but that the loss of sodium may contribute to a decline of basal ANF levels, with an attenuation of their physiological postural changes, and to a stimulation of the aldosterone secretion.

  12. LSP simulations of fast ions slowing down in cool magnetized plasma

    NASA Astrophysics Data System (ADS)

    Evans, Eugene S.; Cohen, Samuel A.

    2015-11-01

    In MFE devices, rapid transport of fusion products, e.g., tritons and alpha particles, from the plasma core into the scrape-off layer (SOL) could perform the dual roles of energy and ash removal. Through these two processes in the SOL, the fast particle slowing-down time will have a major effect on the energy balance of a fusion reactor and its neutron emissions, topics of great importance. In small field-reversed configuration (FRC) devices, the first-orbit trajectories of most fusion products will traverse the SOL, potentially allowing those particles to deposit their energy in the SOL and eventually be exhausted along the open field lines. However, the dynamics of the fast-ion energy loss processes under conditions expected in the FRC SOL, where the Debye length is greater than the electron gyroradius, are not fully understood. What modifications to the classical slowing down rate are necessary? Will instabilities accelerate the energy loss? We use LSP, a 3D PIC code, to examine the effects of SOL plasma parameters (density, temperature and background magnetic field strength) on the slowing down time of fast ions in a cool plasma with parameters similar to those expected in the SOL of small FRC reactors. This work supported by DOE contract DE-AC02-09CH11466.

  13. Existence domains of slow and fast ion-acoustic solitons in two-ion space plasmas

    SciTech Connect

    Maharaj, S. K.; Bharuthram, R.; Singh, S. V. Lakhina, G. S.

    2015-03-15

    A study of large amplitude ion-acoustic solitons is conducted for a model composed of cool and hot ions and cool and hot electrons. Using the Sagdeev pseudo-potential formalism, the scope of earlier studies is extended to consider why upper Mach number limitations arise for slow and fast ion-acoustic solitons. Treating all plasma constituents as adiabatic fluids, slow ion-acoustic solitons are limited in the order of increasing cool ion concentrations by the number densities of the cool, and then the hot ions becoming complex valued, followed by positive and then negative potential double layer regions. Only positive potentials are found for fast ion-acoustic solitons which are limited only by the hot ion number density having to remain real valued. The effect of neglecting as opposed to including inertial effects of the hot electrons is found to induce only minor quantitative changes in the existence regions of slow and fast ion-acoustic solitons.

  14. Stability properties and fast ion confinement of hybrid tokamak plasma configurations

    NASA Astrophysics Data System (ADS)

    Graves, J. P.; Brunetti, D.; Pfefferle, D.; Faustin, J. M. P.; Cooper, W. A.; Kleiner, A.; Lanthaler, S.; Patten, H. W.; Raghunathan, M.

    2015-11-01

    In hybrid scenarios with flat q just above unity, extremely fast growing tearing modes are born from toroidal sidebands of the near resonant ideal internal kink mode. New scalings of the growth rate with the magnetic Reynolds number arise from two fluid effects and sheared toroidal flow. Non-linear saturated 1/1 dominant modes obtained from initial value stability calculation agree with the amplitude of the 1/1 component of a 3D VMEC equilibrium calculation. Viable and realistic equilibrium representation of such internal kink modes allow fast ion studies to be accurately established. Calculations of MAST neutral beam ion distributions using the VENUS-LEVIS code show very good agreement of observed impaired core fast ion confinement when long lived modes occur. The 3D ICRH code SCENIC also enables the establishment of minority RF distributions in hybrid plasmas susceptible to saturated near resonant internal kink modes.

  15. Hollow Cathode and Keeper-region Plasma Measurements Using Ultra-fast Miniature Scanning Probes

    NASA Technical Reports Server (NTRS)

    Goebel, Dan M.; Jameson, Kristina K.; Watkins, Ron M.; Katz, Ira

    2004-01-01

    In order to support the development of comprehensive performance and life models for future deep space missions that will utilize ion thrusters, we have undertaken a study of the plasma structure in hollow cathodes using an new pneumatic scanning probe diagnostic. This device is designed to insert a miniature probe directly into the hollow cathode orifice from either the upstream insert region in the interior of the hollow cathode, or from the downstream keeper-plasma region at the exit of the hollow cathode, to provide complete axial profiles of the discharge plasma parameters. Previous attempts to diagnose this region with probes was Limited by the melting of small probes in the intense discharge near the orifice, or caused significant perturbation of the plasma by probes large enough to survive. Our new probe is extremely compact, and when configured as a single Langmuir probe, the ceramic tube insulator is only 0.5mm in diameter and the current collecting conductor has a total area of 0.002 cm2. A series of current-voltage characteristics are obtained by applying a rapid sawtooth voltage waveform to the probe as it is scanned by the pneumatic actuator into and out of the plasma region, The bellow-sealed pneumatic drive scans the probe 4 cm in the cathode insert region and 10 cm in the anode/keeper plasmas region at average speeds of about 1 mm/msec, and the residence time at the end of the insertion stroke in the densest part of the plasma near the orifice is measured to be only 10 msec. Since the voltage sweep time is fast compared to the motion of the probe, axial profiles of the plasma density, temperature and potential with reasonable spatial resolution are obtained. Measurements of the internal cathode pressures and the axial plasma-parameter profiles for a hollow cathode operating at discharge currents of up to 35 A in xenon will be presented.

  16. 33 CFR 155.780 - Emergency shutdown.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Emergency shutdown. 155.780...) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS FOR VESSELS Transfer Personnel, Procedures, Equipment, and Records § 155.780 Emergency shutdown. (a) A tank vessel with a capacity of 250...

  17. 33 CFR 155.780 - Emergency shutdown.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Emergency shutdown. 155.780...) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS FOR VESSELS Transfer Personnel, Procedures, Equipment, and Records § 155.780 Emergency shutdown. (a) A tank vessel with a capacity of 250...

  18. 33 CFR 155.780 - Emergency shutdown.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Emergency shutdown. 155.780 Section 155.780 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED..., Procedures, Equipment, and Records § 155.780 Emergency shutdown. (a) A tank vessel with a capacity of 250...

  19. 33 CFR 127.1205 - Emergency shutdown.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Emergency shutdown. 127.1205 Section 127.1205 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Waterfront Facilities Handling Liquefied Hazardous Gas Equipment § 127.1205 Emergency shutdown. (a)...

  20. 33 CFR 127.1205 - Emergency shutdown.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Emergency shutdown. 127.1205 Section 127.1205 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Waterfront Facilities Handling Liquefied Hazardous Gas Equipment § 127.1205 Emergency shutdown. (a)...

  1. EFFECTS OF LASER RADIATION ON MATTER: Fast holographic cinematography of a laser plasma

    NASA Astrophysics Data System (ADS)

    Barikhin, B. A.; Ivanov, A. Yu; Nedolugov, V. I.

    1990-11-01

    A fast holographic cinematography method was used in an investigation of a laser plasma initiated at the surfaces of metal samples by pulses from a rhodamine laser. The time evolution of the electron densities and heavy-particle concentrations was determined and a study was made of the nature of motion of a shock wave front. A weak dependence of the evolution of the shock wave velocity on the target materials (aluminum, copper, zinc) was observed in the average power density range 10-25 MW/cm2. A faster increase in the dimensions of a refracting plasma region, compared with a luminous region, and strong expulsion of cold air by an erosion plasma were recorded.

  2. Higher fasting plasma glucose is associated with striatal and hippocampal shape differences: the 2sweet project

    PubMed Central

    Zhang, Tianqi; Shaw, Marnie; Humphries, Jacob; Sachdev, Perminder; Anstey, Kaarin J; Cherbuin, Nicolas

    2016-01-01

    Objective Previous studies have demonstrated associations between higher normal fasting plasma glucose levels (NFG) (<6.1 mmol/L), type 2 diabetes (T2D) and hippocampal atrophy and other cerebral abnormalities. Little is known about the association between plasma glucose and the striatum despite sensorimotor deficits being implicated in T2D. This study aimed to investigate the relationship between plasma glucose levels and striatal and hippocampal morphology using vertex-based shape analysis. Design A population-based, cross-sectional study. Setting Canberra and Queanbeyan, Australia. Participants 287 cognitively healthy individuals (mean age 63 years, 132 female, 273 Caucasian) with (n=261) or without T2D (n=26), selected from 2551 participants taking part in the Personality & Total Health (PATH) Through Life study by availability of glucose data, MRI scan, and absence of gross brain abnormalities and cognitive impairment. Outcome measures Fasting plasma glucose was measured at first assessment, and MRI images were collected 8 years later. Shape differences indicating outward and inward deformation at the hippocampus and the striatum were examined with FMRIB Software Library-Integrated Registration and Segmentation Toolbox (FSL-FIRST) after controlling for sociodemographic and health variables. Results Higher plasma glucose was associated with shape differences indicating inward deformation, particularly at the caudate and putamen, among participants with NFG after controlling for age, sex, body mass index (BMI), hypertension, smoking and depressive symptoms. Those with T2D showed shape differences indicating inward deformation at the right hippocampus and bilateral striatum, but outward deformation at the left hippocampus, compared with participants with NFG. Conclusions These findings further emphasize the importance of early monitoring and management of plasma glucose levels, even within the normal range, as a risk factor for cerebral atrophy. PMID

  3. Electron Generation and Transport in Intense Relativistic Laser-Plasma Interactions Relevant to Fast Ignition ICF

    SciTech Connect

    Ma, Tammy Yee Wing

    2010-01-01

    The reentrant cone approach to Fast Ignition, an advanced Inertial Confinement Fusion scheme, remains one of the most attractive because of the potential to efficiently collect and guide the laser light into the cone tip and direct energetic electrons into the high density core of the fuel. However, in the presence of a preformed plasma, the laser energy is largely absorbed before it can reach the cone tip. Full scale fast ignition laser systems are envisioned to have prepulses ranging between 100 mJ to 1 J. A few of the imperative issues facing fast ignition, then, are the conversion efficiency with which the laser light is converted to hot electrons, the subsequent transport characteristics of those electrons, and requirements for maximum allowable prepulse this may put on the laser system. This dissertation examines the laser-to-fast electron conversion efficiency scaling with prepulse for cone-guided fast ignition. Work in developing an extreme ultraviolet imager diagnostic for the temperature measurements of electron-heated targets, as well as the validation of the use of a thin wire for simultaneous determination of electron number density and electron temperature will be discussed.

  4. Demonstration of rapid shutdown using large shattered deuterium pellet injection in DIII-D

    SciTech Connect

    Commaux, Nicolas JC; Baylor, Larry R; Jernigan, Thomas C; Hollmann, E. M.; Parks, P. B.; Humphreys, D A; Wesley, J. C.; Yu, J.H.

    2010-11-01

    A severe consequence of a disruption on large tokamaks such as ITER could be the generation of multi-megaelectronvolt electron beams that could damage the vacuum vessel and the structures of the machine if they hit the wall unmitigated. The mitigation of runaway electron beams is thus a key requirement for reliable operation of ITER. In order to achieve reliable disruption mitigation, a new fast shutdown technique has been developed: the injection of a large shattered cryogenic pellet in the plasma, which is expected to increase the electron density up to levels where the beam generation processes are mitigated by collisional losses. This technique has been implemented and tested for the first time ever on DIII-D. The first tests show evidence of an almost instantaneous deposition of more than 260 Pa m(3) of deuterium deep in the core. Record local densities during the thermal quench were observed for each injection with a very high reliability. Pellet mass and plasma energy content scans show an improvement of the assimilation of the particles for higher plasma energy and larger pellet mass.

  5. Demonstration of Rapid Shutdown Using Large Shattered Deuterium Pellet Injection in DIII-D

    SciTech Connect

    Commaux, Nicolas JC; Baylor, Larry R; Jernigan, Thomas C; Hollmann, E. M.; Parks, P. B.; Humphrey, D. A.; Wesley, J. C.; Yu, J.H.

    2010-01-01

    A severe consequence of a disruption on large tokamaks such as ITER could be the generation of multi-megaelectronvolt electron beams that could damage the vacuum vessel and the structures of the machine if they hit the wall unmitigated. The mitigation of runaway electron beams is thus a key requirement for reliable operation of ITER. In order to achieve reliable disruption mitigation, a new fast shutdown technique has been developed: the injection of a large shattered cryogenic pellet in the plasma, which is expected to increase the electron density up to levels where the beam generation processes are mitigated by collisional losses. This technique has been implemented and tested for the first time ever on DIII-D. The first tests show evidence of an almost instantaneous deposition of more than 260 Pa m3 of deuterium deep in the core. Record local densities during the thermal quench were observed for each injection with a very high reliability. Pellet mass and plasma energy content scans show an improvement of the assimilation of the particles for higher plasma energy and larger pellet mass.

  6. Effects of fasting on plasma glucose and prolonged tracer measurement of hepatic glucose output in NIDDM

    SciTech Connect

    Glauber, H.; Wallace, P.; Brechtel, G.

    1987-10-01

    We studied the measurement of hepatic glucose output (HGO) with prolonged (3-/sup 3/H)glucose infusion in 14 patients with non-insulin-dependent diabetes mellitus (NIDDM). Over the course of 10.5 h, plasma glucose concentration fell with fasting by one-third, from 234 +/- 21 to 152 +/- 12 mg/dl, and HGO fell from 2.35 +/- 0.18 to 1.36 +/- 0.07 mg . kg-1 . min-1 (P less than .001). In the basal state, HGO and glucose were significantly correlated (r = 0.68, P = .03), and in individual patients, HGO and glucose were closely correlated as both fell with fasting (mean r = 0.79, P less than .01). Plasma (3-/sup 3/H)glucose radioactivity approached a steady state only 5-6 h after initiation of the primed continuous infusion, and a 20% overestimate of HGO was demonstrated by not allowing sufficient time for tracer labeling of the glucose pool. Assumption of steady-state instead of non-steady-state kinetics in using Steele's equations to calculate glucose turnover resulted in a 9-24% overestimate of HGO. Stimulation of glycogenolysis by glucagon injection demonstrated no incorporation of (3-/sup 3/H)glucose in hepatic glycogen during the prolonged tracer infusion. In a separate study, plasma glucose was maintained at fasting levels (207 +/- 17 mg/dl) for 8 h with the glucose-clamp technique. Total glucose turnover rates remained constant during this prolonged tracer infusion. However, HGO fell to 30% of the basal value simply by maintaining fasting hyperglycemia in the presence of basal insulin levels.

  7. EFFECTS OF LASER RADIATION ON MATTER. LASER PLASMA: Conversion of the energy of fast electrons to thermal plasma radiation

    NASA Astrophysics Data System (ADS)

    Vergunova, G. A.; Rozanov, Vladislav B.

    1992-01-01

    An analysis is made of the conversion of the energy of highly energetic fast electrons, generated by the action of CO2 laser radiation on a target, into characteristic radiation emitted by a plasma formed from shell targets which, for instance, may be present inside targets irradiated by the CO2 laser. Analytical formulas are obtained for the temperature of the converted radiation. The results show that it is possible to control this radiation by choosing the parameters of the target and of the fast electron flux. The efficiency of conversion into characteristic thermal radiation is found numerically to be 95%. This method of conversion is more favorable than direct interaction of CO2 laser radiation with a target since the emitting region is localized in the target mass. When a laser interacts with a target the mass of this region increases with time and so the temperature of the emitted radiation is lower than in the case when fast electrons act on the target.

  8. Magnetic field measurements for study of fast electron transport in magnetized HED plasma

    NASA Astrophysics Data System (ADS)

    Sawada, Hiroshi; Griffin, Brandon; Presura, Radu; Haque, Showera; Sentoku, Yasuhiko

    2014-10-01

    Interaction of megagauss magnetic fields with high energy density (HED) plasma is of great interest in the field of magnetized plasma. The field changes fundamental properties of the HED plasma such as thermal and magnetic diffusion. A coupled capability utilizing the 1.0 MA Zebra pulsed power generator and the 50 TW Leopard laser at Nevada Terawatt Facility enables to create such a condition for studies of magnetized plasma properties. We have conducted an experiment to measure magnetic fields generated by a 1.0 MA, 100 ns Zebra pulsed current in stainless steel coils. Using a 532 nm continuous laser from a single longitudinal mode laser system, the temporal change in the magnetic field was measured with the Faraday rotation in F2 glass. The probe laser passing through the 1.5 mm in radius and 1.75 mm thick glass placed in the vicinity of the inductive coils was split with a Glan-Taylor prism to measure vertical and horizontal polarization components with photodiodes. We will present the analysis of the experimental result and a design of a coupled experiment for study of fast electron transport in the magnetized plasma.

  9. Neutron Production and Fast Deuteron Characteristics at the Plasma Focus Discharge

    SciTech Connect

    Kubes, P.; Kravarik, J.; Klir, D.; Rezac, K.; Scholz, M.; Paduch, M.; Ivanova-Stanik, I.; Karpinski, L.; Tomaszewski, K.

    2009-01-21

    This paper summarized the results of interferometry, X-ray and neutron diagnostics performed at the plasma focus facility filled with deuterium. The fusion processes are produced mainly in the dense and hot spherical structure of 2 cm diameter 5-8 cm in front of the anode. The electron temperature of this structure is about 750 eV and the density 5x10{sup 24}-5x10{sup 25}. The neutron energy distribution was calculated using time of flight analysis and showed the dominant direction of the fast deuteron velocity downstream. The deuteron energy distribution was estimated supposing isotropy distribution of the sum of opposite orientation. The total number of fast deuterons in the energy range of 10-400 keV is about 10{sup 18} with total energy of 20 kJ. Plasma in the spherical structure is heated dominantly with ion-ion Coulomb collisions of fast deuterons in the energy range below 10 keV.

  10. CHARACTERISTICS OF A FAST RISE TIME POWER SUPPLY FOR A PULSED PLASMA REACTOR FOR CHEMICAL VAPOR DESTRUCTION

    EPA Science Inventory

    Rotating spark gap devices for switching high-voltage direct current (dc) into a corona plasma reactor can achieve pulse rise times in the range of tens of nanoseconds. The fast rise times lead to vigorous plasma generation without sparking at instantaneous applied voltages highe...

  11. Solvent changeouts without plant shutdown

    SciTech Connect

    Vickery, D.J.; Campbell, S.W. )

    1988-01-01

    For reasons of greater selectivity, lower regeneration energy requirements, reduced corrosivity and possible greater amine stability, MDEA continues to replace DEA in numerous selective H/sub 2/S removal applications. Solvent changeouts from DEA to MDEA often require no equipment modification, yet they are generally achieved by shutting down the plant, draining the old solvent, cleaning, and finally recharging with MDEA. However, in at least one plant, solvent changeout was done on the fly simply by periodically making up normal DEA losses with MDEA until the plant was finally operating on MDEA alone. Gradual solvent changeouts have the advantages of no lost production, no disposal problems with the environmentally-hazardous old solvent, no use and subsequent disposal of cleaning agents, and no additional manpower requirements. An advanced flowsheet simulation capability can suggest when such a procedure is feasible and, when it is, plant simulation can help to ensure that the solvent changeout is done reliably and with no production or cost penalties. GASPLANT-PLUS(TM) is currently the only commercial simulator having formulated solvent (mixed amine) capabilities within a fully flexible flowsheeting environment. After highlighting its technical foundations, they will compare GASPLANT-PLUS predictions with some commercial plant data and, through examples, they will show how solvent changeouts can be done gradually, without plant shutdown.

  12. Effects of prolonged fasting on plasma cortisol and TH in postweaned northern elephant seal pups

    NASA Technical Reports Server (NTRS)

    Ortiz, R. M.; Wade, C. E.; Ortiz, C. L.

    2001-01-01

    Northern elephant seal (Mirounga angustirostris) pups rely on the oxidation of fat stores as their primary source of energy during their 8- to 12-wk postweaning fast; however, potential endocrine mechanisms involved with this increased fat metabolism have yet to be examined. Therefore, 15 pups were serially blood sampled in the field during the first 7 wk of their postweaning fast to examine the changes in plasma concentrations of cortisol and thyroid hormones (TH), which are involved in fat metabolism in other mammals. Cortisol increased, indicating that it contributed to an increase in lipolysis. Increased total triiodothyronine (tT(3)) and thyroxine (tT(4)) may not reflect increased thyroid gland activity, but rather alterations in hormone metabolism. tT(3)-to-tT(4) ratio decreased, suggesting a decrease in thyroxine (T(4)) deiodination, whereas the negative correlation between total proteins and free T(4) suggests that the increase in free hormone is attributed to a decrease in binding globulins. Changes in TH are most similar to those observed during hibernation than starvation in mammals, suggesting that the metabolic adaptations to natural fasting are more similar to hibernation despite the fact these animals remain active throughout the fasting period.

  13. The sound generated by a fast parton in the quark-gluon plasma is a crescendo

    NASA Astrophysics Data System (ADS)

    Neufeld, R. B.; Müller, B.

    2009-11-01

    The total energy deposited into the medium per unit length by a fast parton traversing a quarkgluon plasma is calculated. We take the medium excitation due to collisions to be given by the well known expression for the collisional drag force. The parton's radiative energy loss contributes to the energy deposition because each radiated gluon acts as an additional source of collisional energy loss in the medium. In our model, this leads to a length dependence on the differential energy loss due to the interactions of radiated gluons with the medium. The final result, which is a sum of the primary and the secondary contributions, is then treated as the coefficient of a local hydrodynamic source term. Results are presented for energy density wave induced by two fast, back-to-back partons created in an initial hard interaction.

  14. Fast, Deep-Record-Length, Fiber-Coupled Photodiode Imaging Array for Plasma Diagnostics

    NASA Astrophysics Data System (ADS)

    Brockington, Samuel; Case, Andrew; Witherspoon, F. Douglas

    2015-11-01

    HyperV Technologies has been developing an imaging diagnostic comprised of an array of fast, low-cost, long-record-length, fiber-optically-coupled photodiode channels to investigate plasma dynamics and other fast, bright events. By coupling an imaging fiber bundle to a bank of amplified photodiode channels, imagers and streak imagers can be constructed. By interfacing analog photodiode systems directly to commercial analog-to-digital converters and modern memory chips, a scalable solution for 100 to 1000 pixel systems with 14 bit resolution and record-lengths of 128k frames has been developed. HyperV is applying these techniques to construct a prototype 1000 Pixel framing camera with up to 100 Msamples/sec rate and 10 to 14 bit depth. Preliminary experimental results as well as future plans will be discussed. Work supported by USDOE Phase 2 SBIR Grant DE-SC0009492.

  15. Fast, Deep-Record-Length, Fiber-Coupled Photodiode Imaging Array for Plasma Diagnostics

    NASA Astrophysics Data System (ADS)

    Brockington, Samuel; Case, Andrew; Witherspoon, F. Douglas

    2014-10-01

    HyperV Technologies has been developing an imaging diagnostic comprised of an array of fast, low-cost, long-record-length, fiber-optically-coupled photodiode channels to investigate plasma dynamics and other fast, bright events. By coupling an imaging fiber bundle to a bank of amplified photodiode channels, imagers and streak imagers of 100 to 1000 pixels can be constructed. By interfacing analog photodiode systems directly to commercial analog-to-digital converters and modern memory chips, a prototype 100 pixel array with an extremely deep record length (128 k points at 20 Msamples/s) and 10 bit pixel resolution has already been achieved. HyperV now seeks to extend these techniques to construct a prototype 1000 Pixel framing camera with up to 100 Msamples/sec rate and 10 to 12 bit depth. Preliminary experimental results as well as Phase 2 plans will be discussed. Work supported by USDOE Phase 2 SBIR Grant DE-SC0009492.

  16. Imploded Plasma Heating by Irradiation of Heating Laser through a Cone with a Hole for Fast Ignition

    NASA Astrophysics Data System (ADS)

    Taga, M.; Shiraga, H.; Fujioka, S.; Azechi, H.

    2016-03-01

    It is of great importance for the fast ignition research to investigate the heating properties of the imploded core plasma by injection of the heating laser. The open-end cone was introduced recently. An expanding self-emission of x-ray from the core plasma near the cone tip was observed after the heating laser irradiation through the cone. It indicates that the core plasma was heated by the heating laser.

  17. Electromagnetic ELF wave intensification associated with fast earthward flows in mid-tail plasma sheet

    NASA Astrophysics Data System (ADS)

    Liang, J.; Ni, B.; Cully, C. M.; Donovan, E. F.; Thorne, R. M.; Angelopoulos, V.

    2012-03-01

    In this study we perform a statistical survey of the extremely-low-frequency wave activities associated with fast earthward flows in the mid-tail central plasma sheet (CPS) based upon THEMIS measurements. We reveal clear trends of increasing wave intensity with flow enhancement over a broad frequency range, from below fLH (lower-hybrid resonant frequency) to above fce (electron gyrofrequency). We mainly investigate two electromagnetic wave modes, the lower-hybrid waves at frequencies below fLH, and the whistler-mode waves in the frequency range fLH < f < fce. The waves at f < fLH dramatically intensify during fast flow intervals, and tend to contain strong electromagnetic components in the high-plasma-beta CPS region, consistent with the theoretical expectation of the lower-hybrid drift instability in the center region of the tail current sheet. ULF waves with very large perpendicular wavenumber might be Doppler-shifted by the flows and also partly contribute to the observed waves in the lower-hybrid frequency range. The fast flow activity substantially increases the occurrence rate and peak magnitude of the electromagnetic waves in the frequency range fLH < f < fce, though they still tend to be short-lived and sporadic in occurrence. We also find that the electron pitch-angle distribution in the mid-tail CPS undergoes a variation from negative anisotropy (perpendicular temperature smaller than parallel temperature) during weak flow intervals, to more or less positive anisotropy (perpendicular temperature larger than parallel temperature) during fast flow intervals. The flow-related electromagnetic whistler-mode wave tends to occur in conjunction with positive electron anisotropy.

  18. Dynamics of dust-free cavities behind fast projectiles in a dusty plasma under microgravity conditions

    SciTech Connect

    Caliebe, D.; Arp, O.; Piel, A.

    2011-07-15

    The penetration of a dusty plasma by fast charged projectiles is studied under microgravity conditions. The mass and charge of the projectiles are larger than those of the target particles. A projectile generates a dust-free cavity in its wake, whose shape strongly depends on the projectile velocity. The faster the projectile the more elongated becomes the cavity while its cross-section decreases. The opening time of the cavity is found independent of the projectile velocity. For supersonic projectiles, the dynamics of the cavity can be decomposed into an initial impulse and a subsequent elastic response that can be modeled by a damped harmonic oscillator.

  19. Fast electron energy deposition in a magnetized plasma: Kinetic theory and particle-in-cell simulation

    SciTech Connect

    Robiche, J.; Rax, J.-M.; Bonnaud, G.; Gremillet, L.

    2010-03-15

    The collisional dynamics of a relativistic electron jet in a magnetized plasma are investigated within the framework of kinetic theory. The relativistic Fokker-Planck equation describing slowing down, pitch angle scattering, and cyclotron rotation is derived and solved. Based on the solution of this Fokker-Planck equation, an analytical formula for the root mean square spot size transverse to the magnetic field is derived and this result predicts a reduction in radial transport. Some comparisons with particle-in-cell simulation are made and confirm striking agreement between the theory and the simulation. For fast electron with 1 MeV typical kinetic energy interacting with a solid density hydrogen plasma, the energy deposition density in the transverse direction increases by a factor 2 for magnetic field of the order of 1 T. Along the magnetic field, the energy deposition profile is unaltered compared with the field-free case.

  20. Fast ion generation and bulk plasma heating with three-ion ICRF scenarios

    SciTech Connect

    Kazakov, Ye. O. Van Eester, D.; Ongena, J.; Lerche, E.; Messiaen, A.

    2015-12-10

    Launching electromagnetic waves in the ion cyclotron range of frequencies (ICRF) is an efficient method of plasma heating, actively employed in most of fusion machines. ICRF has a number of important supplementary applications, including the generation of high-energy ions. In this paper, we discuss a new set of three-ion ICRF scenarios and the prospect of their use as a dedicated tool for fast ion generation in tokamaks and stellarators. A distinct feature of these scenarios is a strong absorption efficiency possible at very low concentrations of resonant minority ions (∼ 1% or even below). Such concentration levels are typical for impurities contaminating fusion plasmas. An alternative ICRF scenario for maximizing the efficiency of bulk D-T ion heating is suggested for JET and ITER tokamaks, which is based on three-ion ICRF heating of intrinsic Beryllium impurities.

  1. Plasma radiometry with 30 chord resolution for fast transients in the DIII-D tokamak

    SciTech Connect

    Gray, D.S.; Hollmann, E.M.; Luckhardt, S.C.; Chalfant, J.; Chousal, L.; Hernandez, R.; Jones, E.; Kellman, A.G.

    2004-10-01

    A diagnostic capable of providing time resolved measurements of plasma radiated power during disruptions and other fast transients, e.g., edge localized modes has been employed in the DIII-D tokamak. The radiation is detected with absolute extreme ultraviolet (AXUV) photodiode arrays. Thirty chords from a single port provide measurements from a full slice of the plasma at one toroidal location. The analog bandwidth is up to 1 MHz for the brightest events, i.e., disruptions. Active cooling of the diode arrays prevents damage during high temperature vessel baking. Effective responsivity values of 0.12-0.18 A/W are taken from previous work on the application of AXUV diodes in DIII-D. The total radiated energy in disruptions typically agrees with bolometer measurements within about 12%.

  2. Shear flow instability in a partially-ionized plasma sheath around a fast-moving vehicle

    SciTech Connect

    Sotnikov, V. I.; Mudaliar, S.; Genoni, T. C.; Rose, D. V.; Oliver, B. V.; Mehlhorn, T. A.

    2011-06-15

    The stability of ion acoustic waves in a sheared-flow, partially-ionized compressible plasma sheath around a fast-moving vehicle in the upper atmosphere, is described and evaluated for different flow profiles. In a compressible plasma with shear flow, instability occurs for any velocity profile, not just for profiles with an inflection point. A second-order differential equation for the electrostatic potential of excited ion acoustic waves in the presence of electron and ion collisions with neutrals is derived and solved numerically using a shooting method with boundary conditions appropriate for a finite thickness sheath in contact with the vehicle. We consider three different velocity flow profiles and find that in all cases that neutral collisions can completely suppress the instability.

  3. Be Foil "Filter Knee Imaging" NSTX Plasma with Fast Soft X-ray Camera

    SciTech Connect

    B.C. Stratton; S. von Goeler; D. Stutman; K. Tritz; L.E. Zakharov

    2005-08-08

    A fast soft x-ray (SXR) pinhole camera has been implemented on the National Spherical Torus Experiment (NSTX). This paper presents observations and describes the Be foil Filter Knee Imaging (FKI) technique for reconstructions of a m/n=1/1 mode on NSTX. The SXR camera has a wide-angle (28{sup o}) field of view of the plasma. The camera images nearly the entire diameter of the plasma and a comparable region in the vertical direction. SXR photons pass through a beryllium foil and are imaged by a pinhole onto a P47 scintillator deposited on a fiber optic faceplate. An electrostatic image intensifier demagnifies the visible image by 6:1 to match it to the size of the charge-coupled device (CCD) chip. A pair of lenses couples the image to the CCD chip.

  4. Plasma flow and fast particles in a hypervelocity accelerator - A color presentation. [micrometeoroid simulation

    NASA Technical Reports Server (NTRS)

    Igenbergs, E. B.; Cour-Palais, B.; Fisher, E.; Stehle, O.

    1975-01-01

    A new concept for particle acceleration for micrometeoroid simulation was developed at NASA Marshall Space Flight Center, using a high-density self-luminescent fast plasma flow to accelerate glass beads (with a diameter up to 1.0 mm) to velocities between 15-20 km/sec. After a short introduction to the operation of the hypervelocity range, the eight-converter-camera unit used for the photographs of the plasma flow and the accelerated particles is described. These photographs are obtained with an eight-segment reflecting pyramidal beam splitter. Wratten filters were mounted between the beam splitter and the converter tubes of the cameras. The photographs, which were recorded on black and white film, were used to make the matrices for the dye-color process, which produced the prints shown.

  5. Fast ion generation and bulk plasma heating with three-ion ICRF scenarios

    NASA Astrophysics Data System (ADS)

    Kazakov, Ye. O.; Van Eester, D.; Dumont, R.; Ongena, J.; Lerche, E.; Messiaen, A.

    2015-12-01

    Launching electromagnetic waves in the ion cyclotron range of frequencies (ICRF) is an efficient method of plasma heating, actively employed in most of fusion machines. ICRF has a number of important supplementary applications, including the generation of high-energy ions. In this paper, we discuss a new set of three-ion ICRF scenarios and the prospect of their use as a dedicated tool for fast ion generation in tokamaks and stellarators. A distinct feature of these scenarios is a strong absorption efficiency possible at very low concentrations of resonant minority ions (˜ 1% or even below). Such concentration levels are typical for impurities contaminating fusion plasmas. An alternative ICRF scenario for maximizing the efficiency of bulk D-T ion heating is suggested for JET and ITER tokamaks, which is based on three-ion ICRF heating of intrinsic Beryllium impurities.

  6. Measurement and Processing of Fast Pulsed Discharge Current in Plasma Focus Machines

    NASA Astrophysics Data System (ADS)

    Lee, S.; Saw, S. H.; Rawat, R. S.; Lee, P.; Verma, R.; Talebitaher, A.; Hassan, S. M.; Abdou, A. E.; Ismail, Mohamed; Mohamed, Amgad; Torreblanca, H.; Al Hawat, Sh.; Akel, M.; Chong, P. L.; Roy, F.; Singh, A.; Wong, D.; Devi, K.

    2012-04-01

    The fast pulsed electric discharge current drives all physical processes in the plasma focus device; in turn all physical processes in the focus affect the current waveform. Thus the discharge current waveform is the most important indicator of plasma focus performance. This underlies the importance of properly measuring, processing and interpreting the discharge current waveform. This paper reports the measurement of fast pulsed discharge current by the Rogowski coil, in two different modes: the current transformer, "I" mode, and current derivative, "Idot" mode. The processing and interpretation of recorded current waveform to obtain useful information about the physical processes in the plasma focus device are discussed. The current transformer with a large number of turns and a sub-1 Ohm terminator has good high frequency response, necessary for the sharp current dip region when dI/ dt exceeds 2 × 1011 A/s. However the signal is "noisy" in the current dip region. Several methods to extract the current dip from the noise are discussed and examples of how low pass filters affect the signals are shown. The dI/ dt coil, the Rogowski coil in "Idot" mode, with a few turns terminated by 50-Ohm is also described. Integrating the 1 GSa/s digital waveform does remove the high frequency noise components, yet the extracted waveform shows sharp angular features indicative of the retention of short-time features. This makes the dI/ dt coil superior to the current transformer. A 7-turn coil is tested against the Lee Model code and found to be suitable to measure the plasma focus discharge current.

  7. Generation of plasma rotation in a tokamak by ion-cyclotron absorption of fast Alfven waves

    SciTech Connect

    F.W. Perkins; R.B. White; P. Bonoli

    2000-06-13

    Control of rotation in tokamak plasmas provides a method for suppressing fine-scale turbulent transport by velocity shear and for stabilizing large-scale magnetohydrodynamic instabilities via a close-fitting conducting shell. The experimental discovery of rotation in a plasma heated by the fast-wave minority ion cyclotron process is important both as a potential control method for a fusion reactor and as a fundamental issue, because rotation arises even though this heating process introduces negligible angular momentum. This paper proposes and evaluates a mechanism which resolves this apparent conflict. First, it is assumed that angular momentum transport in a tokamak is governed by a diffusion equation with a no-slip boundary condition at the plasma surface and with a torque-density source that is a function of radius. When the torque density source consists of two separated regions of positive and negative torque density, a non-zero central rotation velocity results, even when the total angular momentum input vanishes. Secondly, the authors show that localized ion-cyclotron heating can generate regions of positive and negative torque density and consequently central plasma rotation.

  8. A comparison of fasting plasma insulin and growth hormone concentrations in marasmic, kwashiorkor, marasmic-kwashiorkor and underweight children.

    PubMed

    Robinson, H; Picou, D

    1977-05-01

    Fasting plasma insulin and growth hormone concentrations were measured in 24 marasmic, 11 kwashiorkor, 16 marasmic-kwashiorkor, and 4 underweight children. Hormone measurements were made by a special modification of the Hales and Randle double antibody immunoassay with increased sensitivity in the concentration range 0-25 micronU/ml. Fasting plasma insulin was low in marasmus, kwashiorkor, and marasmic-kwashiorkor children, and increased to normal levels after recovery. Fasting plasma growth hormone was elevated in all groups during malnutrition and was significantly decreased to normal levels after recovery. There were no significant differences in plasma insulin or growth hormone levels between the different clinical types of severe protein energy malnutrition. These hormonal changes in severe protein energy malnutrition are of complex and not fully understood etiology. However, recovered children appear to have a hormonal pattern similar to that described in normal control infants and children.

  9. ACS SBC Recovery from Anomalous Shutdown

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2012-10-01

    This proposal is designed to permit recovery of the SBC {FUV MAMA} detector after an anomalous shutdown. Anomalous shutdowns can occur as a result of bright object violations which trigger the Bright Scene Detection or Software Global Monitor. Anomalous shutdowns can also occur as a result of SBC hardware problems. The recovery from anomalous shutdown procedure consists of four tests: 1} a signal processing electronics check, 2} a slow high voltage ramp-up to an intermediate voltage, 3} a slow high-voltage ramp-up to the full operating voltage, and 4} a Fold Test. During the two high-voltage ramp-ups, dark ACCUM exposures are taken. At high voltage, dark ACCUM exposures and diagnostics are taken. This proposal is based on Proposal 12738 from Cycle 19.

  10. ACS SBC Recovery from Anomalous Shutdown

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2010-09-01

    This proposal is designed to permit recovery of the SBC {FUV MAMA} detector after an anomalous shutdown. Anomalous shutdowns can occur as a result of bright object violations which trigger the Bright Scene Detection or Software Global Monitor. Anomalous shutdowns can also occur as a result of SBC hardware problems. The recovery from anomalous shutdown procedure consists of four tests: a signal processing electronics check, a slow high voltage ramp-up to an intermediate voltage, a slow high-voltage ramp-up to the full operating voltage, and lastly, a Fold Test. During the two high-voltage ramp-ups, dark ACCUM exposures are taken. At high voltage, dark ACCUM exposures and diagnostics are taken. This proposal is based on proposal 11884, visits 1 to 4.

  11. A Fast Pulse, High Intensity Neutron Source Based Upon The Dense Plasma Focus

    SciTech Connect

    Krishnan, M.; Bures, B.; Madden, R.; Blobner, F.; Elliott, K. Wilson

    2009-12-02

    Alameda Applied Sciences Corporation (AASC) has built a bench-top source of fast neutrons (approx10-30 ns, 2.45 MeV), that is portable and can be scaled to operate at approx100 Hz. The source is a Dense Plasma Focus driven by three different capacitor banks: a 40 J/30 kA/100 Hz driver; a 500 J/130 kA/2 Hz driver and a 3 kJ/350 kA/0.5 Hz driver. At currents of approx130 kA, this source produces approx1x10{sup 7} (DD) n/pulse. The neutron pulse widths are approx10-30 ns and may be controlled by adjusting the DPF electrode geometry and operating parameters. This paper describes the scaling of the fast neutron output with current from such a Dense Plasma Focus source. For each current and driver, different DPF head designs are required to match to the current rise-time, as the operating pressure and anode radius/shape are varied. Doping of the pure D{sub 2} gas fill with Ar or Kr was shown earlier to increase the neutron output. Results are discussed in the light of scaling laws suggested by prior literature.

  12. Renal responses to plasma volume expansion and hyperosmolality in fasting seal pups

    NASA Technical Reports Server (NTRS)

    Ortiz, Rudy M.; Wade, Charles E.; Costa, Daniel P.; Ortiz, C. Leo

    2002-01-01

    Renal responses were quantified in northern elephant seal (Mirounga angustirostris) pups during their postweaning fast to examine their excretory capabilities. Pups were infused with either isotonic (0.9%; n = 8; Iso) or hypertonic (16.7%; n = 7; Hyper) saline via an indwelling catheter such that each pup received 3 mmol NaCl/kg. Diuresis after the infusions was similar in magnitude between the two treatments. Osmotic clearance increased by 37% in Iso and 252% in Hyper. Free water clearance was reduced 3.4-fold in Hyper but was not significantly altered in Iso. Glomerular filtration rate increased 71% in the 24-h period after Hyper, but no net change occurred during the same time after Iso. Natriuresis increased 3.6-fold in Iso and 5.3-fold in Hyper. Iso decreased plasma arginine vasopressin (AVP) and cortisol acutely, whereas Hyper increased plasma and excreted AVP and cortisol. Iso was accompanied by the retention of water and electrolytes, whereas the Hyper load was excreted within 24 h. Natriuresis is attributed to increased filtration and is independent of an increase in atrial natriuretic peptide and decreases in ANG II and aldosterone. Fasting pups appear to have well-developed kidneys capable of both extreme conservation and excretion of Na(+).

  13. Hollow cathode theory and experiment. I. Plasma characterization using fast miniature scanning probes

    SciTech Connect

    Goebel, Dan M.; Jameson, Kristina K.; Watkins, Ron M.; Katz, Ira; Mikellides, Ioannis G.

    2005-12-01

    A detailed study of the spatial variation of plasma density, temperature, and potential in hollow cathodes using miniature fast scanning probes has been undertaken in order to better understand the cathode operation and to provide benchmark data for the modeling of the cathode performance and life described in a companion paper. Profiles are obtained throughout the discharge and in the very high-density orifice region by pneumatically driven Langmuir probes, which are inserted directly into the hollow cathode orifice from either the upstream insert region inside the hollow cathode or from the downstream anode-plasma region. A fast transverse-scanning probe is also used to provide radial profiles of the cathode plume as a function of position from the cathode exit. The probes are extremely small to avoid perturbing the plasma; the ceramic tube insulator is 0.05 cm in diameter with a probe tip area of 0.002 cm{sup 2}. A series of current-voltage characteristics are obtained by applying a rapid sawtooth voltage wave form to the probe as it is scanned through the plasma at speeds of up to 2 m/s to produce the profiles with a spatial resolution of about 0.05 cm. At discharge currents of 10-25 A from the 1.5-cm-diameter hollow cathode, the plasma density inside the cathode is found to exceed 10{sup 14} cm{sup -3}, with the peak density occurring upstream of the orifice. The plasma potentials on axis inside the cathode are found to be in the 10-20 V range with electron temperatures of 2-5 eV, depending on the discharge current and gas flow rate. A potential discontinuity or double layer of less than 10 V is observed in the orifice region, and under certain conditions appears in the bright 'plasma ball' in front of the cathode. This structure tends to change location and magnitude with discharge current, gas flow, and orifice size. A potential maximum proposed in the literature to exist in or near the cathode orifice is not observed. Instead, the plasma potential increases

  14. ATF edge plasma turbulence studies using a fast reciprocating Langmuir probe

    SciTech Connect

    Uckan, T.; Hidalgo, C.; Bell, J.D.; Harris, J.H.; Dunlap, J.L.; Dyer, G.R.; Mioduszewski, P.K.; Wilgen, J.B. ); Ritz, C.P.; Wootton, A.J.; Rhodes, T.L.; Carter, K. . Fusion Research Center)

    1991-01-01

    Electrostatic turbulence on the edge of the Advanced Toroidal Facility (ATF) torsatron is investigated experimentally with a fast reciprocating Langmuir probe (FRLP) array. Initial measurements of plasma electron density n{sub e} and temperature T{sub e} and fluctuations in density ({tilde n}{sub e}) and plasma floating potential ({tilde {phi}}{sub f}) are made in electron cyclotron heated plasmas at 1 T. At the last closed flux surface (LCFS, r{radical}a {approximately} 1), T{sub e} {approx} 20--40 eV and n{sub e} {approx} 10{sup 12} cm{sup {minus}3} for a line-averaged electron density {bar n}{sub e} = (3--6) {times} 10{sup 12} cm{sup {minus}3}. Relative fluctuation levels, as the FRLP is moved into core plasma where T{sub e} > 20 eV, are {tilde n}{sub e}/n{sub e} {approx} 5% and e{tilde {phi}}{sub f}/T{sub e} {approx} 2{tilde n}{sub e}/n{sub e} about 2 cm inside the LCFS. The observed fluctuation spectra are broadband (40--300 kHz) with {bar k}{rho}{sub s} {le} 0.1, where {bar k} is the wavenumber of the fluctuations and {rho}{sub s} is the ion Larmor radius at the sound speed. The propagation direction of the fluctuations reverses to the electron diamagnetic direction around r{radical}a < 1. The phase velocity and the electron drift velocity are comparable (v{sub ph} {approximately} v{sub de}). The fluctuation-induced particle flux is comparable to fluxes estimated from the particle balance using the H{sub {alpha}} spectroscopic measurements. Many of the features seen in these experiments resemble the features of ohmically heated plasmas in the Texas Experimental Tokamak (TEXT). 18 refs., 10 figs.

  15. ATF (Advanced Toroidal Facility) edge plasma turbulence studies using a fast reciprocating Langmuir probe

    SciTech Connect

    Uckan, T.; Hidalgo, C.; Bell, J.D.; Harris, J.H.; Dunlap, J.L.; Dyer, G.R.; Mioduszewski, P.K.; Wilgen, J.B. ); Ritz, C.P.; Wootton, A.J.; Rhodes, T.L.; Carter, K. . Fusion Research Center)

    1990-01-01

    Electrostatic turbulence on the edge of the Advanced Torodial Facility (ATF) torsatron is investigated experimentally with a fast reciprocating Langmuir probe (FRLP) array. Initial measurements of plasma electron density n{sub e} and temperature T{sub e} and fluctuations in density ({tilde n}{sub e}) and plasma floating potential ({tilde {phi}}{sub f}) are made in ECH plasmas at 1 T. At the last closed flux surface (LCFS, r/{bar a} {approximately}1), T{sub e} {approx} 20--40 eV and n{sub e} {approx} 10{sup 12} cm{sup {minus}3} for a line-averaged electron density {bar n}{sub e} = (3--6) {times} 10{sup 12} cm{sup {minus}3}. Relative fluctuation levels, as the FRLP is moved into core plasma where T{sub e} > 20 eV, are {tilde n}{sub e}/n{sub e} {approx} 5%, and e {tilde {phi}}{sub f}/T{sub e} {approx} 2{tilde n}{sub e}/n{sub e} about 2 cm inside the LCFS. The observed fluctuation spectra are broadband (40--300 kHz) with {bar k}{rho}{sub s} {le} 0.1, where {bar k} is the wavenumber of the fluctuations and {rho}{sub s} is the ion Larmor radius at the sound speed. The propagation direction of the fluctuations reverses to the electron diamagnetic direction around r/{bar a} < 1. The phase velocity and the electron drift velocity are comparable (v{sub ph} {approximately} v{sub de}). The fluctuation-induced particle flux is comparable to fluxes estimated from the particle balance using the H{sub {alpha}} spectroscopic measurements. Many of the features seen in these experiments resemble the features of ohmically heated plasmas in the Texas Experimental Tokamak (TEXT). 17 refs., 10 figs.

  16. Diagnostics of fast formation of distributed plasma discharges using X-band microwaves

    SciTech Connect

    Xiang, X. Kupczyk, B.; Booske, J.; Scharer, J.

    2014-02-14

    We present measurements of high power (25.7 kW), pulsed (800 ns), X-band (9.382 GHz) microwave breakdown plasmas, including reflected power measurements, mixer reflected amplitude and phase measurements, optical emission spectroscopy (OES) measurements, and an analysis that estimates the average electron density and electron temperature. In addition, a six-region, 1-D model was used to determine plasma parameters and compare with the experimental results. The experimental results show that using a 43 Hz repetition rate with an 800 ns pulse, fast (<300 ns) breakdown occurs in neon measured between 50 Torr and 250 Torr, producing plasma that lasts for over 7 μs. It also leads to large microwave reflections (70%) and an on-axis transmission attenuation of −15 dB. Moreover, a comparison between a 1-D model and mixer measurements shows that at 100 Torr, the neon plasma electron density peaked at 2 × 10{sup 12} cm{sup −3}, and the electron temperature peaked at 2.5 eV assuming a Maxwellian distribution. The addition of 2% Ar in Ne reduced the breakdown time and allowed OES measurements to determine the effective electron temperature. OES measurements of mixed (Ne/Ar: 98/2) argon line ratios (420.1 nm/419.8 nm) were used to determine the average effective electron temperature T{sub e(eff)} = 1.2 eV, averaged over the entire 7μs plasma lifetime. They indicate that the electron energy distribution was not Maxwellian but, instead, tended towards a Druyvesteyn character.

  17. Study on the Fast Nitriding Process of Active Screen Plasma Nitriding

    NASA Astrophysics Data System (ADS)

    Han, L.; Dai, J. T.; Huang, X. R.; Zhao, C.

    A new nitriding technology using active screen plasma nitriding (ASPN) was carried out in order to increase the nitriding speed of AISI 5140 steel. The fast nitriding process is based upon the different solubility and diffuse rate of nitrogen atoms in austenite and in ferrite of steel respectively. First, the nitriding samples were heated above the eutectoid temperature for a few minutes to dissolve a large amount of nitrogen and form a nitrogen-rich layer on the surface of the nitrided samples. Then, the nitriding temperature was decreased below the eutectoid temperature and kept the temperature for a long time to make the dissolved nitrogen in the nitrogen-rich layer diffuse into ferrite. The two different nitriding processes were carried on alternately. Experimental results indicate that the fast nitriding process not only enhances the nitriding speed remarkably, but also keeps the high hardness of the nitrided layer. The new fast nitriding technology with nitrogen-rich layer can be explained with "absorption- diffusion" model.

  18. Analytical and Numerical Studies of the Complex Interaction of a Fast Ion Beam Pulse with a Background Plasma

    SciTech Connect

    Igor D. Kaganovich; Edward A. Startsev; Ronald C. Davidson

    2003-11-25

    Plasma neutralization of an intense ion beam pulse is of interest for many applications, including plasma lenses, heavy ion fusion, high energy physics, etc. Comprehensive analytical, numerical, and experimental studies are underway to investigate the complex interaction of a fast ion beam with a background plasma. The positively charged ion beam attracts plasma electrons, and as a result the plasma electrons have a tendency to neutralize the beam charge and current. A suite of particle-in-cell codes has been developed to study the propagation of an ion beam pulse through the background plasma. For quasi-steady-state propagation of the ion beam pulse, an analytical theory has been developed using the assumption of long charge bunches and conservation of generalized vorticity. The analytical results agree well with the results of the numerical simulations. The visualization of the data obtained in the numerical simulations shows complex collective phenomena during beam entry into and ex it from the plasma.

  19. Plasma facing components: a conceptual design strategy for the first wall in FAST tokamak

    NASA Astrophysics Data System (ADS)

    Labate, C.; Di Gironimo, G.; Renno, F.

    2015-09-01

    Satellite tokamaks are conceived with the main purpose of developing new or alternative ITER- and DEMO-relevant technologies, able to contribute in resolving the pending issues about plasma operation. In particular, a high criticality needs to be associated to the design of plasma facing components, i.e. first wall (FW) and divertor, due to physical, topological and thermo-structural reasons. In such a context, the design of the FW in FAST fusion plant, whose operational range is close to ITER’s one, takes place. According to the mission of experimental satellites, the FW design strategy, which is presented in this paper relies on a series of innovative design choices and proposals with a particular attention to the typical key points of plasma facing components design. Such an approach, taking into account a series of involved physical constraints and functional requirements to be fulfilled, marks a clear borderline with the FW solution adopted in ITER, in terms of basic ideas, manufacturing aspects, remote maintenance procedure, manifolds management, cooling cycle and support system configuration.

  20. Hot-electron generation from laser–pre-plasma interactions in cone-guided fast ignition

    SciTech Connect

    Li, J.; Davies, J. R.; Ma, T.; Mori, W. B.; Tonge, J.; Ren, C.; Solodov, A. A.; Theobald, W.

    2013-05-15

    Two-dimensional particle-in-cell (PIC) simulations were performed for the cone-in-shell integrated fast-ignition experiments at the Omega Laser Facility [W. Theobald et al., Phys. Plasmas 18, 056305 (2011)]. The initial plasma density profile in the PIC simulations was taken from hydrodynamic simulations of the prepulse interaction with the gold cone. Hot-electron generation from laser–pre-plasma interactions and transport up to 100× the critical density (n{sub c}) was studied. The simulation showed a mean divergence half-angle of 68° and 50% absorption for the hot electrons. The simulation results show that the generated hot electrons were dominated in number by low-energy electrons but in energy by multi-MeV electrons. Electron transport between 5 and 100 n{sub c} was ballistic. In the late stage of the simulation, all the results were largely independent of polarization, indicating a stochastic hot-electron–generation mechanism.

  1. Fast magnetic twister and plasma perturbations in a three-dimensional coronal arcade

    SciTech Connect

    Murawski, K.; Srivastava, A. K.; Musielak, Z. E. E-mail: asrivastava.app@iitbhu.ac.in E-mail: musielak@kis.uni-freiburg.de

    2014-06-10

    We present results of three-dimensional (3D) numerical simulations of a fast magnetic twister excited above a foot-point of the potential solar coronal arcade that is embedded in the solar atmosphere with the initial VAL-IIIC temperature profile, which is smoothly extended into the solar corona. With the use of the FLASH code, we solve 3D ideal magnetohydrodynamic equations by specifying a twist in the azimuthal component of magnetic field in the solar chromosphere. The imposed perturbation generates torsional Alfvén waves as well as plasma swirls that reach the other foot-point of the arcade and partially reflect back from the transition region. The two vortex channels are evident in the generated twisted flux-tube with a fragmentation near its apex which results from the initial twist as well as from the morphology of the tube. The numerical results are compared to observational data of plasma motions in a solar prominence. The comparison shows that the numerical results and the data qualitatively agree even though the observed plasma motions occur over comparatively large spatio-temporal scales in the prominence.

  2. Fast plasma sintering delivers functional graded materials components with macroporous structures and osseointegration properties.

    PubMed

    Godoy, R F; Coathup, M J; Blunn, G W; Alves, A L; Robotti, P; Goodship, A E

    2016-04-13

    We explored the osseointegration potential of two macroporous titanium surfaces obtained using fast plasma sintering (FPS): Ti macroporous structures with 400-600 µmØ pores (TiMac400) and 850-1000 µmØ pores (TiMac850). They were compared against two surfaces currently in clinical use: Ti-Growth® and air plasma spray (Ti-Y367). Each surface was tested, once placed over a Ti-alloy and once onto a CoCr bulk substrate. Implants were placed in medial femoral condyles in 24 sheep. Samples were explanted at four and eight weeks after surgery. Push-out loads were measured using a material-testing system. Bone contact and ingrowth were assessed by histomorphometry and SEM and EDX analyses. Histology showed early osseointegration for all the surfaces tested. At 8 weeks, TiMac400, TiMac850 and Ti-Growth® showed deep bone ingrowth and extended colonisation with newly formed bone. The mechanical push-out force was equal in all tested surfaces. Plasma spray surfaces showed greater bone-implant contact and higher level of pores colonisation with new bone than FPS produced surfaces. However, the void pore area in FPS specimens was significantly higher, yet the FPS porous surfaces allowed a deeper osseointegration of bone to implant. FPS manufactured specimens showed similar osseointegration potential to the plasma spray surfaces for orthopaedic implants. FPS is a useful technology for manufacturing macroporous titanium surfaces. Furthermore, its capability to combine two implantable materials, using bulk CoCr with macroporous titanium surfaces, could be of interest as it enables designers to conceive and manufacture innovative components. FPS delivers functional graded materials components with macroporous structures optimised for osseointegration.

  3. STIS MAMA Recovery from Anomalous Shutdown

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2012-10-01

    This proposal is designed to permit a safe and orderly recovery of the STIS FUV MAMA or NUV MAMA detector after an anomalous shutdown. This is accomplished by using slower-than-normal MCP high-voltage ramp-ups and diagnostics. Anomalous shutdowns can occur because of bright object violations, which trigger the Global Hardware Monitor or the Global Software Monitor. Anomalous shutdowns can also occur because of MAMA hardware anomalies or failures. The cause of the shutdown should be thoroughly investigated and understood prior to recovery. Twenty-four hour wait intervals are required after each test for MCP gas desorption and data analysis. Event flags are used to prevent inadvertent MAMA usage.The recovery procedure consists of three separate tests {i.e. visits} to check the MAMAâ_Ts health after an anomalous shutdown: 1} signal processing electronics check, 2} slow, intermediate voltage high voltage ramp-up, and 3} ramp-up to full operating voltage followed by a fold analysis test {See STIS ISR 98-02R}. Each must be successfully completed before proceeding onto the next. This proposal executes the same steps as Cycle 19 proposal 12779.

  4. COS NUV Detector Recovery After Anomalous Shutdown

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2011-10-01

    This proposal is designed to permit a safe and orderly recovery of the NUV-MAMA detector after an anomalous shutdown. This is accomplished by using slower-than-normal MCP high-voltage ramp-ups and diagnostics. Anomalous shutdowns can occur because of bright object violations, which trigger the Global Hardware Monitor or the Global Software Monitor. Anomalous shutdowns can also occur because of MAMA hardware anomalies or failures. The cause of the shutdown should be thoroughly investigated and understood prior to recovery. Twenty-four hour wait intervals are required after each test for MCP gas desorption and data analysis. Event flag 2 is used to prevent inadvertent MAMA usage.The recovery procedure consists of four separate tests {i.e. visits} to check the MAMAâ??s health after an anomalous shutdown: signal processing electronics check, slow, intermediate voltage high-voltage ramp-up, ramp-up to full operating voltage, and fold analysis test {See COS TIR 2010-01}. Each must be successfully completed before proceeding onto the next. This proposal executes the same steps as Cycle 18 proposal 12430.

  5. STIS MAMA Recovery from Anomalous Shutdown

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2013-10-01

    This proposal is designed to permit a safe and orderly recovery of the STIS FUV MAMA or NUV MAMA detector after an anomalous shutdown. This is accomplished by using slower-than-normal MCP high-voltage ramp-ups and diagnostics. Anomalous shutdowns can occur because of bright object violations which trigger the Global Hardware Monitor or the Global Software Monitor. Anomalous shutdowns can also occur because of MAMA hardware anomalies or failures. The cause of the shutdown should be thoroughly investigated and understood prior to recovery. Twenty-four hour wait intervals are required after each test for MCP gas desorption and data analysis. Event flags are used to prevent inadvertent MAMA usage.The recovery procedure consists of three separate tests {i.e. visits} to check the MAMA's health after an anomalous shutdown: 1} signal processing electronics check, 2} slow, intermediate voltage high voltage ramp-up, and 3} ramp-up to full operating voltage followed by a fold analysis test {See STIS ISR 98-02R}. Each must be successfully completed before proceeding onto the next. This proposal executes the same steps as Cycle 20 proposal 13150.

  6. COS NUV Detector Recovery after Anomalous Shutdown

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2013-10-01

    This proposal is designed to permit a safe and orderly recovery of the NUV-MAMA detector after an anomalous shutdown. This is accomplished by using slower-than-normal MCP high-voltage ramp-ups and diagnostics. Anomalous shutdowns can occur because of bright object violations which trigger the Global Hardware Monitor or the Global Software Monitor. Anomalous shutdowns can also occur because of MAMA hardware anomalies or failures. The cause of the shutdown should be thoroughly investigated and understood prior to recovery. Twenty-four hour wait intervals are required after each test for MCP gas desorption and data analysis. Event flag 2 is used to prevent inadvertent MAMA usage.The recovery procedure consists of four separate tests {i.e. visits} to check the MAMA's health after an anomalous shutdown: 1} signal processing electronics check, 2} slow, intermediate voltage high-voltage ramp-up, 3} ramp-up to full operating voltage, and 4} fold analysis test {See COS TIR 2010-01}. Each must be successfully completed before proceeding onto the next. This proposal executes the same steps as Cycle 20 proposal 13129. Adjustments were made the the Software Global Monitor {SGM} to account for an increase in the dark counts due to window glow and to align the SGM to previously obtained Fold Analysis event data.

  7. ACS SBC Recovery from Anomalous Shutdown

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2013-10-01

    This proposal is designed to permit a safe and orderly recovery of the SBC {FUV MAMA} detector after an anomalous shutdown. This is accomplished by using slower-than-normal MCP high-voltage ramp-ups and diagnostics. Anomalous shutdowns can occur because of bright object violations, which trigger the Global Hardware Monitor or the Global Software Monitor. Anomalous shutdowns can also occur because of MAMA hardware anomalies or failures. The cause of the shutdown should be thoroughly investigated and understood prior to recovery. Twenty-four hour wait intervals are required after each test for MCP gas desorption and data analysis. Event flag 2 is used to prevent inadvertent MAMA usage. The recovery procedure consists of four separate tests {i.e. visits} to check the MAMA's health after an anomalous shutdown: 1} signal processing electronics check, 2} slow, high-voltage ramp-up to an intermediate voltage, 3} a slow high-voltage ramp-up to the nominal operating HV, and 4} fold analysis test. Each must be completed successfully before proceeding onto the next. During the two high-voltage ramp-ups, dark ACCUM exposures are taken. At high voltage, dark ACCUM exposures and diagnostics are taken. This proposal is based on Proposal 13163 from Cycle 20. For additional MAMA recovery information, see STIS ISR 98-02R.

  8. COS NUV Detector Recovery After Anomalous Shutdown

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2012-10-01

    This proposal is designed to permit a safe and orderly recovery of the NUV-MAMA detector after an anomalous shutdown. This is accomplished by using slower-than-normal MCP high-voltage ramp-ups and diagnostics. Anomalous shutdowns can occur because of bright object violations, which trigger the Global Hardware Monitor or the Global Software Monitor. Anomalous shutdowns can also occur because of MAMA hardware anomalies or failures. The cause of the shutdown should be thoroughly investigated and understood prior to recovery. Twenty-four hour wait intervals are required after each test for MCP gas desorption and data analysis. Event flag 2 is used to prevent inadvertent MAMA usage.The recovery procedure consists of four separate tests {i.e. visits} to check the MAMAâ_Ts health after an anomalous shutdown: 1} signal processing electronics check, 2} slow, intermediate voltage high-voltage ramp-up, 3} ramp-up to full operating voltage, and 4} fold analysis test {See COS TIR 2010-01}. Each must be successfully completed before proceeding onto the next. This proposal executes almost the same steps as Cycle 19 proposal 12723. Adjustments were made the the Software Global Monitor {SGM} to account for an increase in the dark counts due to window glow and to align the SGM to previously obtained Fold Analysis event data.

  9. MHD study of three-dimensional spontaneous fast magnetic reconnection for cross-tail plasma inflows in magnetotail

    NASA Astrophysics Data System (ADS)

    Shimizu, Tohru; Torii, Hiroyuki; Kondoh, Koji

    2016-05-01

    The 3D instability of spontaneous fast magnetic reconnection process is studied with magnetohydrodynamic simulations, where 2D model of the spontaneous fast magnetic reconnection process is destabilized in three dimensions. In this 3D instability, the spontaneous fast magnetic reconnection process is intermittently and randomly caused in 3D. In this paper, as a typical event study, a single 3D fast magnetic reconnection process often observed in the 3D instability is studied in detail. As a remarkable feature, it is reported that, when the 3D fast magnetic reconnection process starts, plasma inflows along the magnetic neutral line are observed, which are driven by plasma static pressure gradient along the neutral line. The plasma inflow speed reaches about 15 in the upstream field region. The unmagnetized inflow tends to prevent the 3D reconnection process; nevertheless, the 3D reconnection process is intermittently maintained. Such high-speed plasma inflows along the neutral line may be observed as dawn-dusk flows in space satellite observations of magnetotail's bursty bulk flows.

  10. Investigating plasma viscosity with fast framing photography in the ZaP-HD Flow Z-Pinch experiment

    NASA Astrophysics Data System (ADS)

    Weed, Jonathan Robert

    The ZaP-HD Flow Z-Pinch experiment investigates the stabilizing effect of sheared axial flows while scaling toward a high-energy-density laboratory plasma (HEDLP > 100 GPa). Stabilizing flows may persist until viscous forces dissipate a sheared flow profile. Plasma viscosity is investigated by measuring scale lengths in turbulence intentionally introduced in the plasma flow. A boron nitride turbulence-tripping probe excites small scale length turbulence in the plasma, and fast framing optical cameras are used to study time-evolved turbulent structures and viscous dissipation. A Hadland Imacon 790 fast framing camera is modified for digital image capture, but features insufficient resolution to study turbulent structures. A Shimadzu HPV-X camera captures the evolution of turbulent structures with great spatial and temporal resolution, but is unable to resolve the anticipated Kolmogorov scale in ZaP-HD as predicted by a simplified pinch model.

  11. Ultra Intense Laser Pulse Interactions with Planer and Spherical Plasmas for Fast Ignitor

    NASA Astrophysics Data System (ADS)

    Tanaka, Kazuo A.

    1999-11-01

    The fast ignitor concept requires the guiding or penetration of an ultra-intense laser close to a highly compressed (1000 times solid density) core and the generation of energetic electrons (MeV). Ultra-intense laser plasma interactions have been intensively studied using the Peta Watt Module (PWM) laser system synchronized with the GEKKO XII laser system. The ultra-intense laser pulse of 50J energy, 0.5-1 psec pulse width and 1053 nm laser wavelength could be focused onto a preformed plasma created on a solid target at an intensity of 1e19 W/cm2. The preformed plasma had a cut-off density surface at around 100 micron from the surface. Changing the focus position of this 100 TW laser pulse relative to the preformed plasma, we found an anomalous mode. Side view of x-ray pinhole camera showed that there was a local tiny spot almost at the surface of the solid target which indicates the propagation of the pulse in the long scale-length plasma into an over-dense region for over 100 micorn distance. The erergy spectrum and angular distribution of more than MeV electrons were measured. Its energy transport was studied with K-a spectroscopy. The backscattered light of the ultra-intense laser light was spectrally and spatially resolved. The backscattered light image showed several hot spots within the focused region. The spatilally resolved spectra of the backscattered light were totally different at the hot spots and surrounding regions. The details of neutron spectra were measured using ``MANDALA" neutron spectormeters with a total of 841 channel photo-multiplier detectors. The data indicates that deuterium ions were accelerated by the hot electrons up to 100 keV and created beam fusion reactions within solid CD targets. Guiding channels were created utilizing a ponderomotive self-focusing in preformed plasmas created on a solid target. The self-focus channel was measured by both UV and x-ray laser probes. The details of the experiment as well as the theoretical

  12. Stable isotope models of sugar intake using hair, red blood cells, and plasma, but not fasting plasma glucose, predict sugar intake in a Yup'ik study population.

    PubMed

    Nash, Sarah H; Kristal, Alan R; Hopkins, Scarlett E; Boyer, Bert B; O'Brien, Diane M

    2014-01-01

    Objectively measured biomarkers will help to resolve the controversial role of sugar intake in the etiology of obesity and related chronic diseases. We recently validated a dual-isotope model based on RBC carbon (δ(13)C) and nitrogen (δ(15)N) isotope ratios that explained a large percentage of the variation in self-reported sugar intake in a Yup'ik study population. Stable isotope ratios can easily be measured from many tissues, including RBCs, plasma, and hair; however, it is not known how isotopic models of sugar intake compare among these tissues. Here, we compared self-reported sugar intake with models based on RBCs, plasma, and hair δ(13)C and δ(15)N in Yup'ik people. We also evaluated associations of sugar intake with fasting plasma glucose δ(13)C. Finally, we evaluated relations between δ(13)C and δ(15)N values in hair, plasma, RBCs, and fasting plasma glucose to allow comparison of isotope ratios across tissue types. Models using RBCs, plasma, or hair isotope ratios explained similar amounts of variance in total sugar, added sugar, and sugar-sweetened beverage intake (∼53%, 48%, and 34%, respectively); however, the association with δ(13)C was strongest for models based on RBCs and hair. There were no associations with fasting plasma glucose δ(13)C (R(2) = 0.03). The δ(13)C and δ(15)N values of RBCs, plasma, and hair showed strong, positive correlations; the slopes of these relations did not differ from 1. This study demonstrates that RBC, plasma, and hair isotope ratios predict sugar intake and provides data that will allow comparison of studies using different sample types.

  13. Sound Produced by a Fast Parton in the Quark-Gluon Plasma is a ``Crescendo''

    NASA Astrophysics Data System (ADS)

    Neufeld, R. B.; Müller, B.

    2009-07-01

    We calculate the total energy deposited into the medium per unit length by fast partons traversing a quark-gluon plasma. The medium excitation due to collisions is taken to be given by the well-known expression for the collisional drag force. The radiative energy loss of the parton contributes to the energy deposition because each radiated gluon acts as an additional source of collisional energy loss in the medium. We derive a differential equation which governs how the spectrum of radiated gluons is modified when this energy loss is taken into account. This modified spectrum is then used to calculate the additional energy deposition due to the interactions of radiated gluons with the medium. Numerical results are presented for the medium response for the case of two energetic back-to-back partons created in a hard interaction.

  14. Sound produced by a fast parton in the quark-gluon plasma is a "crescendo".

    PubMed

    Neufeld, R B; Müller, B

    2009-07-24

    We calculate the total energy deposited into the medium per unit length by fast partons traversing a quark-gluon plasma. The medium excitation due to collisions is taken to be given by the well-known expression for the collisional drag force. The radiative energy loss of the parton contributes to the energy deposition because each radiated gluon acts as an additional source of collisional energy loss in the medium. We derive a differential equation which governs how the spectrum of radiated gluons is modified when this energy loss is taken into account. This modified spectrum is then used to calculate the additional energy deposition due to the interactions of radiated gluons with the medium. Numerical results are presented for the medium response for the case of two energetic back-to-back partons created in a hard interaction.

  15. Fast and accurate quantum molecular dynamics of dense plasmas across temperature regimes

    DOE PAGESBeta

    Sjostrom, Travis; Daligault, Jerome

    2014-10-10

    Here, we develop and implement a new quantum molecular dynamics approximation that allows fast and accurate simulations of dense plasmas from cold to hot conditions. The method is based on a carefully designed orbital-free implementation of density functional theory. The results for hydrogen and aluminum are in very good agreement with Kohn-Sham (orbital-based) density functional theory and path integral Monte Carlo calculations for microscopic features such as the electron density as well as the equation of state. The present approach does not scale with temperature and hence extends to higher temperatures than is accessible in the Kohn-Sham method and lowermore » temperatures than is accessible by path integral Monte Carlo calculations, while being significantly less computationally expensive than either of those two methods.« less

  16. Fast and accurate quantum molecular dynamics of dense plasmas across temperature regimes

    SciTech Connect

    Sjostrom, Travis; Daligault, Jerome

    2014-10-10

    Here, we develop and implement a new quantum molecular dynamics approximation that allows fast and accurate simulations of dense plasmas from cold to hot conditions. The method is based on a carefully designed orbital-free implementation of density functional theory. The results for hydrogen and aluminum are in very good agreement with Kohn-Sham (orbital-based) density functional theory and path integral Monte Carlo calculations for microscopic features such as the electron density as well as the equation of state. The present approach does not scale with temperature and hence extends to higher temperatures than is accessible in the Kohn-Sham method and lower temperatures than is accessible by path integral Monte Carlo calculations, while being significantly less computationally expensive than either of those two methods.

  17. Time dependence of fast electron beam divergence in ultraintense laser-plasma interactions.

    PubMed

    Akli, K U; Storm, M J; McMahon, M; Jiang, S; Ovchinnikov, V; Schumacher, D W; Freeman, R R; Dyer, G; Ditmire, T

    2012-08-01

    We report on the measurement and computer simulation of the divergence of fast electrons generated in an ultraintense laser-plasma interaction (LPI) and the subsequent propagation in a nonrefluxing target. We show that, at Iλ(2) of 10(20) Wcm(-2)μm(2), the time-integrated electron beam full divergence angle is (60±5)°. However, our time-resolved 2D particle-in-cell simulations show the initial beam divergence to be much smaller (≤30°). Our simulations show the divergence to monotonically increase with time, reaching a final value of (68±7)° after the passage of the laser pulse, consistent with the experimental time-integrated measurements. By revealing the time-dependent nature of the LPI, we find that a substantial fraction of the laser energy (~7%) is transported up to 100 μm with a divergence of 32°.

  18. A comparison of fasting plasma glucose and glucose challenge test for screening of gestational diabetes mellitus.

    PubMed

    Poomalar, G K; Rangaswamy, V

    2013-07-01

    Glucose challenge test (GCT) has been used as an effective screening test for gestational diabetes mellitus (GDM), though it has its own limitations. Hence, we assessed the effectiveness of fasting plasma glucose (FPG) as a simpler alternative procedure. A prospective study was done in 500 pregnant women with gestational age between 22 and 37 weeks. FPG, GCT and GTT were performed in all patients using the glucose oxidase/peroxidase method. The overall sensitivity and specificity of GCT were 75.0% and 92.0%, respectively and the corresponding values for FPG were 88.8% and 95.2%. The positive predictive value and negative predictive value were 42.2% and 97.9% for GCT and 59.2% and 99.1% for FPG, respectively. We conclude that FPG can be used as an effective screening tool for gestational diabetes mellitus.

  19. Method for determining fast-alpha-particle confinement in tokamak plasmas using resonant nuclear reactors

    SciTech Connect

    Cecil, F.E.; Zweben, S.J.; Medley, S.S.

    1986-03-01

    The resonant nuclear reactions D(..cap alpha..,..gamma..)/sup 6/Li, /sup 6/Li(..cap alpha..,..gamma..)/sup 10/B, and /sup 7/Li(..cap alpha..,..gamma..)/sup 11/B are examined as diagnostics of fast-alpha-particle confinement in tokamak plasmas. Gamma rays from these resonant reactions with energies from 2.1 MeV to 9.2 MeV may be used to infer the alpha-particle population between energies of 0.4 MeV and 2.6 MeV. The ratio of these alpha-burnup reactions to the reactions T(D,..gamma..)/sup 5/He and /sup 3/He(D,..gamma..)/sup 5/Li provides a technique for the measurement of alpha confinement.

  20. The geometric factor of electrostatic plasma analyzers: A case study from the Fast Plasma Investigation for the Magnetospheric Multiscale mission

    SciTech Connect

    Collinson, Glyn A.; Dorelli, John C.; Moore, Thomas E.; Pollock, Craig; Mariano, Al; Shappirio, Mark D.; Adrian, Mark L.; Avanov, Levon A.; Lewis, Gethyn R.; Kataria, Dhiren O.; Bedington, Robert; Owen, Christopher J.; Walsh, Andrew P.; Arridge, Chris S.; Gliese, Ulrik; Barrie, Alexander C.; Tucker, Corey

    2012-03-15

    We report our findings comparing the geometric factor (GF) as determined from simulations and laboratory measurements of the new Dual Electron Spectrometer (DES) being developed at NASA Goddard Space Flight Center as part of the Fast Plasma Investigation on NASA's Magnetospheric Multiscale mission. Particle simulations are increasingly playing an essential role in the design and calibration of electrostatic analyzers, facilitating the identification and mitigation of the many sources of systematic error present in laboratory calibration. While equations for laboratory measurement of the GF have been described in the literature, these are not directly applicable to simulation since the two are carried out under substantially different assumptions and conditions, making direct comparison very challenging. Starting from first principles, we derive generalized expressions for the determination of the GF in simulation and laboratory, and discuss how we have estimated errors in both cases. Finally, we apply these equations to the new DES instrument and show that the results agree within errors. Thus we show that the techniques presented here will produce consistent results between laboratory and simulation, and present the first description of the performance of the new DES instrument in the literature.

  1. The Geometric Factor of Electrostatic Plasma Analyzers: A Case Study from the Fast Plasma Investigation for the Magnetospheric Multiscale mission

    NASA Technical Reports Server (NTRS)

    Collinson, Glyn A.; Dorelli, John Charles; Avanov, Leon A.; Lewis, Gethyn R.; Moore, Thomas E.; Pollock, Craig; Kataria, Dhiren O.; Bedington, Robert; Arridge, Chris S.; Chornay, Dennis J.; Gliese,Ulrik; Mariano, Al.; Barrie, Alexander C; Tucker, Corey; Owen, Christopher J.; Walsh, Andrew P.; Shappirio, Mark D.; Adrian, Mark L.

    2012-01-01

    We report our findings comparing the geometric factor (GF) as determined from simulations and laboratory measurements of the new Dual Electron Spectrometer (DES) being developed at NASA Goddard Space Flight Center as part of the Fast Plasma Investigation on NASA's Magnetospheric Multiscale mission. Particle simulations are increasingly playing an essential role in the design and calibration of electrostatic analyzers, facilitating the identification and mitigation of the many sources of systematic error present in laboratory calibration. While equations for laboratory measurement of the Geometric Factpr (GF) have been described in the literature, these are not directly applicable to simulation since the two are carried out under substantially different assumptions and conditions, making direct comparison very challenging. Starting from first principles, we derive generalized expressions for the determination of the GF in simulation and laboratory, and discuss how we have estimated errors in both cases. Finally, we apply these equations to the new DES instrument and show that the results agree within errors. Thus we show that the techniques presented here will produce consistent results between laboratory and simulation, and present the first description of the performance of the new DES instrument in the literature.

  2. Inversion methods for fast-ion velocity-space tomography in fusion plasmas

    NASA Astrophysics Data System (ADS)

    Jacobsen, A. S.; Stagner, L.; Salewski, M.; Geiger, B.; Heidbrink, W. W.; Korsholm, S. B.; Leipold, F.; Nielsen, S. K.; Rasmussen, J.; Stejner, M.; Thomsen, H.; Weiland, M.; the ASDEX Upgrade Team

    2016-04-01

    Velocity-space tomography has been used to infer 2D fast-ion velocity distribution functions. Here we compare the performance of five different tomographic inversion methods: truncated singular value decomposition, maximum entropy, minimum Fisher information and zeroth- and first-order Tikhonov regularization. The inversion methods are applied to fast-ion {{\\text{D}}α} measurements taken just before and just after a sawtooth crash in the ASDEX Upgrade tokamak as well as to synthetic measurements from different test distributions. We find that the methods regularizing by penalizing steep gradients or maximizing entropy perform best. We assess the uncertainty of the calculated inversions taking into account photon noise, uncertainties in the forward model as well as uncertainties introduced by the regularization which allows us to distinguish regions of high and low confidence in the tomographies. In high confidence regions, all methods agree that ions with pitch values close to zero, as well as ions with large pitch values, are ejected from the plasma center by the sawtooth crash, and that this ejection depletes the ion population with large pitch values more strongly.

  3. Pinching evidences in a miniature plasma focus with fast pseudospark switch

    NASA Astrophysics Data System (ADS)

    Hassan, S. M.; Zhang, T.; Patran, A.; Rawat, R. S.; Springham, S. V.; Tan, T. L.; Wong, D.; Wang, W.; Lee, S.; Gribkov, V. A.; Mohanty, S. R.; Lee, P.

    2006-11-01

    We report the observations of pinching in a miniature plasma focus (PF) (58—160 J) operated in repetitive mode using fast pseudospark switch (PSS). The size of the device, which includes the capacitor bank, PSS and the focus chamber, is of the order of 22 cm × 22 cm × 38 cm. Several diagnostic tools, the gated imager, streak camera, current and voltage probe, are employed simultaneously to confirm the occurrence of pinching in this fast miniature PF device. The device is optimized for operation in neon and hydrogen as the working gas. The best focus formation was obtained at pressures between 0.5 to 8.0 mbar for neon and between 7.0 to 15.0 mbar for hydrogen. When the system was operated at 100 J with hydrogen as the filling gas, the typical dip in the current derivative signal and the typical peak in the voltage signal associated with pinch compression, are observed to be most intense indicating efficient pinching in the miniature PF device.

  4. Understanding ion cyclotron harmonic fast wave heating losses in the scrape off layer of tokamak plasmas

    SciTech Connect

    Bertelli, N; Jaeger, E F; Hosea, J C; Phillips, C K; Berry, L; Bonoli, P T; Gerhardt, S P; Green, D; LeBlanc, B; Perkins, R J; Ryan, P M; Taylor, G; Valeo, E J; Wilso, J R; Wright, J C

    2014-07-01

    Fast waves at harmonics of the ion cyclotron frequency, which have been used successfully on National Spherical Torus Experiment (NSTX), will also play an important role in ITER and are a promising candidate for the Fusion Nuclear Science Facility (FNSF) designs based on spherical torus (ST). Experimental studies of high harmonic fast waves (HHFW) heating on the NSTX have demonstrated that substantial HHFW power loss occurs along the open field lines in the scrape-off layer (SOL), but the mechanism behind the loss is not yet understood. The full wave RF code AORSA, in which the edge plasma beyond the last closed flux surface (LCFS) is included in the solution domain, is applied to specific NSTX discharges in order to predict the effects and possible causes of this power loss. In the studies discussed here, a collisional damping parameter has been implemented in AORSA as a proxy to represent the real, and most likely nonlinear, damping processes. A prediction for the NSTX Upgrade (NSTX-U) experiment, that will begin operation next year, is also presented, indicating a favorable condition for the experiment due to a wider evanescent region in edge density.*Research supported by the U.S. DOE under Contract No. DE-AC02-09CH11466 with Princeton University.

  5. Investigation of interaction between fast ions and tearing modes in MST plasmas using full orbit tracing

    NASA Astrophysics Data System (ADS)

    Kim, Jungha; Anderson, Jay; Capecchi, William; Bonofiglo, Phillip; Sears, Stephanie; Tsidulko, Yuri

    2015-11-01

    Under proper conditions, global reconnection events generate an anisotropic runaway ion distribution in MST plasmas. Full orbit tracing with time-dependent fluctuating fields, calculated by the nonlinear resistive MHD code DEBS, is used to inform a refined model of ion heating to explain this phenomenon, where tearing modes and ions interact on two distinct scales. There is anisotropic heating of thermal ions (T⊥>T∥), likely through a stochastic heating mechanism that requires high diffusivity and a tearing mode induced radial electric field with correlation length of a few cm. This process does not, however, continuously energize ions into the runaway regime. At sufficient energy, the ion guiding center deviates from the background magnetic field, which reduces the effective diffusivity to classical levels even in a stochastic magnetic field. These ``fast'' ions are accelerated by a parallel electric field (length scale of meters) induced by the equilibrium change accompanying tearing modes. This process relies on multiple global tearing modes; here we focus on a single tearing mode. This is compared to an experimental state where a transition to a single, dominant tearing mode is observed to accelerate fast ions and alter their confinement properties. Work supported by US DOE.

  6. Fast XUV 16 × 16 Array Hybrid Module for Plasma Imaging Applications

    NASA Astrophysics Data System (ADS)

    Alekseyev, Andrey G.; Belov, Alexandr M.; Zabrodsky, Vladimir V.; Sukhanov, Vladislav L.; Sorokin, Andrey A.; Peterson, Byron J.

    A hybrid matrix array detector is developed for ultra-fast plasma imaging applications with the use of XUV Si photodiodes (SPD diodes) manufactured according to Ioffe Institute original technology. A basic 16 × 16 hybrid module is comprised of eight stacked sub-modules with 2 × 16 linear SPD diode arrays combined with a circuit board with a 32-channel preamplifier and four 8-channel fast multiplexers. Array front size is 31 × 31 mm2 with ˜25 % sensitive area. The module has a “zero-edge” design providing an option of stacking into the larger arrays, if necessary. The data acquisition system (DAS) consists of eight 4-channel synchronous 12-bit ADC modules with 40 MS/s upper sampling rate, thus providing less than 1 μs minimum time for the complete read-out of the array. Each channel has a 64 MB on-board memory limiting the duration of the acquired period to 0.8 sec at the maximum sampling rate. A common TCP/IP Ethernet protocol is used for the data transmission into the main PC operating as a DAS control console, data preview and storage computer.

  7. Shutdown system for a nuclear reactor

    DOEpatents

    Groh, E.F.; Olson, A.P.; Wade, D.C.; Robinson, B.W.

    1984-06-05

    An ultimate shutdown system is provided for termination of neutronic activity in a nuclear reactor. The shutdown system includes bead chains comprising spherical containers suspended on a flexible cable. The containers are comprised of mating hemispherical shells which provide a ruggedized enclosure for reactor poison material. The bead chains, normally suspended above the reactor core on storage spools, are released for downward travel upon command from an external reactor monitor. The chains are capable of horizontal movement, so as to flow around obstructions in the reactor during their downward motion. 8 figs.

  8. Shutdown system for a nuclear reactor

    DOEpatents

    Groh, Edward F.; Olson, Arne P.; Wade, David C.; Robinson, Bryan W.

    1984-01-01

    An ultimate shutdown system is provided for termination of neutronic activity in a nuclear reactor. The shutdown system includes bead chains comprising spherical containers suspended on a flexible cable. The containers are comprised of mating hemispherical shells which provide a ruggedized enclosure for reactor poison material. The bead chains, normally suspended above the reactor core on storage spools, are released for downward travel upon command from an external reactor monitor. The chains are capable of horizontal movement, so as to flow around obstructions in the reactor during their downward motion.

  9. Fast valve and nozzle for gas-puff operation of dense plasma focus

    SciTech Connect

    Milanese, Maria M.; Pouzo, Jorge O.; Cortazar, Osvaldo D.; Moroso, Roberto L.

    2006-03-15

    A simple and reliable valve and nozzle system for a very fast injection of gas has been designed and constructed for its use in gas-puff mode of dense plasma focus experiments. It delivers a very quick rise time: 55 {mu}s. The pressure measured in our setup at a distance of 15 mm from the nozzle output is about 0.285 mbar, with a plenum pressure of 3 bars (absolute). The time between the valve aperture and pressure front arrival is 360 {mu}s. This result comes up as an average of about a hundred measurements. The energy input is 95 J (270 V on a 3000 {mu}F capacitor bank). The typical dimensions of the valve are 52 mm in diameter and 80 mm in length. The entire volume of the valve is, then, very small. The relative low pressure and voltage operation are significant advantages of this development. The performance of the valve satisfactorily fulfills the objectives of gas-puff plasma focus operation.

  10. Fast valve and nozzle for gas-puff operation of dense plasma focus

    NASA Astrophysics Data System (ADS)

    Milanese, María M.; Pouzo, Jorge O.; Cortázar, Osvaldo D.; Moroso, Roberto L.

    2006-03-01

    A simple and reliable valve and nozzle system for a very fast injection of gas has been designed and constructed for its use in gas-puff mode of dense plasma focus experiments. It delivers a very quick rise time: 55μs. The pressure measured in our setup at a distance of 15 mm from the nozzle output is about 0.285 mbar, with a plenum pressure of 3 bars (absolute). The time between the valve aperture and pressure front arrival is 360μs. This result comes up as an average of about a hundred measurements. The energy input is 95 J (270 V on a 3000μF capacitor bank). The typical dimensions of the valve are 52 mm in diameter and 80 mm in length. The entire volume of the valve is, then, very small. The relative low pressure and voltage operation are significant advantages of this development. The performance of the valve satisfactorily fulfills the objectives of gas-puff plasma focus operation.

  11. Gaussian energy distribution of fast ions emitted by laser-produced plasmas

    NASA Astrophysics Data System (ADS)

    Krása, J.

    2013-05-01

    The analysis of ion collector signals with the use of a time-of-fight signal function derived from a shifted Maxwell-Boltzmann velocity distribution is used to quantify the ion characteristics as the ion temperature and velocity of centre-of-mass motion of groups of ionized species constituting the ablated plasma. The analysis is also focused on velocity and energy distributions derived from the signal of a time-of-flight detector taking into account the underlying principle of sensor operation. The energy Maxwell spectra of ions are compared with the Gauss distribution with respect to the ratio of the centre-of-mass energy of ions to their temperature. The difference threshold between the Gauss and energy Maxwell spectra is determined via the limited validity of the basic relationship between spreads in energy and time-of-flight spectra ½ΔE/E = Δt/t. The analysis of velocity spectrum of fast ions emitted by Ti plasma produced with 300 ps, kJ-class iodine laser operating at PALS facility shows that ion bursts consist of almost monoenergetic ion beams.

  12. Fasting plasma carotenoids concentrations in Crohn's and pancreatic cancer patients compared to control subjects.

    PubMed

    Drai, J; Borel, P; Faure, H; Galabert, C; Le Moël, G; Laromiguière, M; Fayol, V

    2009-03-01

    Carotenoids are colored molecules that are widespread in the plant kingdom, but animals cannot synthesize them. Carotenes are long, apolar molecules which require fully functioning digestive processes to be absorbed properly. Hence they could be interesting markers of intestinal absorption and digestion. Indeed, only few tests are available to assess these processes and only the D-xylose tolerance test is routinely used. However D-xylose is a sugar that tests only the absorption of water-soluble compounds and it only tests duodenal absorption. In this study, we have evaluated carotenoids as markers of digestion and absorption. We compared fasting plasma carotenoids concentrations in 21 control subjects, 20 patients with Crohn's disease, and 18 patients with pancreatic cancer. Crohn's disease alters intestinal absorption while pancreatic cancer decreases pancreatic enzyme secretion thus impairing digestion. Results show that all carotenoids are significantly lower in Crohn's and cancer patients as compared to control subjects and the multifactorial analysis shows that this decrease is mostly independent of dietary intake. Interestingly, maldigestion as seen in pancreatic cancer more strongly influences plasma lutein and lycopene concentrations while malabsorption in Crohn's disease acts on other carotenoids. Thus carotenoids could be interesting alternatives for testing and following patients that are suspected of having malabsorption or maldigestion syndromes. PMID:20108210

  13. NBI fast ion confinement in the helical core of MAST hybrid-like plasmas

    NASA Astrophysics Data System (ADS)

    Pfefferlé, D.; Graves, J. P.; Cooper, W. A.; Misev, C.; Chapman, I. T.; Turnyanskiy, M.; Sangaroon, S.

    2014-06-01

    Energetic ions are found to be transported strongly from the core of MAST hybrid-like plasmas during long-lived mode (LLM) magnetohydrodynamic activity. The resulting impact on the neutral beam ion deposition and concurrent current drive is modelled using the guiding-centre approximation in the internal kinked magnetic topology. General coordinate guiding-centre equations are extended for this purpose. It is found that the kinked core spirals around the position of strongest ionization, which remains geometrically centred, so that a large fraction of the population is deposited in the high shear external region where the plasma is almost axisymmetric. Those particles ionized in the low shear region exhibit exotic drift motion due to the strongly non-axisymmetric equilibrium, periodically passing near the magnetic axis and then reflected by the boundary of the kinked equilibrium, which in this respect acts as a confining pinch. Broad agreement is found against experimental measurement of fast ion particle confinement degradation as the MAST LLM amplitude varies.

  14. Device and method for relativistic electron beam heating of a high-density plasma to drive fast liners

    DOEpatents

    Thode, Lester E.

    1981-01-01

    A device and method for relativistic electron beam heating of a high-density plasma in a small localized region. A relativistic electron beam generator or accelerator produces a high-voltage electron beam which propagates along a vacuum drift tube and is modulated to initiate electron bunching within the beam. The beam is then directed through a low-density gas chamber which provides isolation between the vacuum modulator and the relativistic electron beam target. The relativistic beam is then applied to a high-density target plasma which typically comprises DT, DD, hydrogen boron or similar thermonuclear gas at a density of 10.sup.17 to 10.sup.20 electrons per cubic centimeter. The target gas is ionized prior to application of the electron beam by means of a laser or other preionization source to form a plasma. Utilizing a relativistic electron beam with an individual particle energy exceeding 3 MeV, classical scattering by relativistic electrons passing through isolation foils is negligible. As a result, relativistic streaming instabilities are initiated within the high-density target plasma causing the relativistic electron beam to efficiently deposit its energy and momentum into a small localized region of the high-density plasma target. Fast liners disposed in the high-density target plasma are explosively or ablatively driven to implosion by a heated annular plasma surrounding the fast liner which is generated by an annular relativistic electron beam. An azimuthal magnetic field produced by axial current flow in the annular plasma, causes the energy in the heated annular plasma to converge on the fast liner.

  15. The 2013 US Government Shutdown (#Shutdown) and health: an emerging role for social media.

    PubMed

    Merchant, Raina M; Ha, Yoonhee P; Wong, Charlene A; Schwartz, H Andrew; Sap, Maarten; Ungar, Lyle H; Asch, David A

    2014-12-01

    In October 2013, multiple United States (US) federal health departments and agencies posted on Twitter, "We're sorry, but we will not be tweeting or responding to @replies during the shutdown. We'll be back as soon as possible!" These "last tweets" and the millions of responses they generated revealed social media's role as a forum for sharing and discussing information rapidly. Social media are now among the few dominant communication channels used today. We used social media to characterize the public discourse and sentiment about the shutdown. The 2013 shutdown represented an opportunity to explore the role social media might play in events that could affect health.

  16. 33 CFR 154.550 - Emergency shutdown.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... point in the transfer system at which the emergency means stops the flow of oil or hazardous material on... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Emergency shutdown. 154.550 Section 154.550 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY...

  17. 33 CFR 154.550 - Emergency shutdown.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... point in the transfer system at which the emergency means stops the flow of oil or hazardous material on... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Emergency shutdown. 154.550 Section 154.550 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY...

  18. 33 CFR 154.550 - Emergency shutdown.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... point in the transfer system at which the emergency means stops the flow of oil or hazardous material on... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Emergency shutdown. 154.550 Section 154.550 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY...

  19. Dependence of fast-ion transport on the nature of the turbulence in the Large Plasma Device

    SciTech Connect

    Zhou Shu; Heidbrink, W. W.; Boehmer, H.; McWilliams, R.; Carter, T. A.; Vincena, S.; Tripathi, S. K. P.

    2011-08-15

    Strong turbulent waves ({delta}n/n {approx}0.5, f {approx}5-40 kHz) are observed in the upgraded Large Plasma Device [W. Gekelman, H. Pfister, Z. Lucky, J. Bamber, D. Leneman, and J. Maggs, Rev. Sci. Instrum. 62, 2875 (1991)] on density gradients produced by an annular obstacle. Energetic lithium ions (E{sub fast}/T{sub i}{>=}300, {rho}{sub fast}/{rho}{sub s}{approx}10) orbit through the turbulent region. Scans with a collimated analyzer and with probes give detailed profiles of the fast ion spatial distribution and of the fluctuating wave fields. The characteristics of the fluctuations are modified by changing the plasma species from helium to neon and by modifying the bias on the obstacle. Different spatial structure sizes (L{sub s}) and correlation lengths (L{sub corr}) of the wave potential fields alter the fast ion transport. The effects of electrostatic fluctuations are reduced due to gyro-averaging, which explains the difference in the fast-ion transport. A transition from super-diffusive to sub-diffusive transport is observed when the fast ion interacts with the waves for most of a wave period, which agrees with theoretical predictions.

  20. COS FUV Recovery after Anomalous Shutdown

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2012-10-01

    This proposal consists of the steps for turning on and ramping up the COS FUV high voltage in a conservative manner after a HV anomalous shutdown by executing a "reduced set" of visits from Cycle 19 Proposal 12810. The nature of the shutdown, i.e., over-light, HV current transient {"crackle"}, ion feedback {induced by a high energy particle}, or field emission {possibly caused by dust or other particulate on the QE grid or other close-by structure or hardware}, and the value of the commanded HV at the time of the shutdown will determine what visits are executed. Because of gain sag, commanded HV settings updates may be required. First, prior to execution of this proposal or selected visits from this proposal, all preliminary steps should be exercised to gather the necessary diagnostic data, e.g., science data evaluation {if a science exposure was in progress and the science data is available}, memory dumps {DCE, EXEC RAM, and possibly the CS BUFFER}, engineering telemetry, or other information that might provide insight as to the nature of the shutdown and estimated count rate. The complete step-by-step procedure is detailed in the Observing Description, but in summary, the following is done:Day 01 activities, visits 01-07, contain both QE grid off and on HV ramping to HVLow {100/100} with diagnostics {DCE dumps} and darks to exclude QE grid involvement in the shutdown. Subsequent to day 01, all HV ramping will be with the QE grid on with the same diagnostics and exposures. All days end with the setting of COS event flag 3 to prevent any FUV HV commanding.Time is allotted for cognizant detector and COS instrument scientist and engineers to examine data dumps, science exposures, and engineering telemetry. If all is well, the go-ahead will be given to clear flag 3 for the next day's visits.This proposal is modeled after the Cycle 19 Proposal 12718.

  1. 40 CFR 63.1111 - Startup, shutdown, and malfunction.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Occupational Safety and Health Administration (OSHA) or other plan, provided the alternative plans meet all the... Control Technology Standards § 63.1111 Startup, shutdown, and malfunction. (a) Startup, shutdown,...

  2. 40 CFR 63.1111 - Startup, shutdown, and malfunction.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Occupational Safety and Health Administration (OSHA) or other plan, provided the alternative plans meet all the... Control Technology Standards § 63.1111 Startup, shutdown, and malfunction. (a) Startup, shutdown,...

  3. The Prevalence and Associated Factors of Periodontitis According to Fasting Plasma Glucose in the Korean Adults

    PubMed Central

    Hong, Jae Won; Noh, Jung Hyun; Kim, Dong-Jun

    2016-01-01

    Abstract Although the relationship between diabetes and periodontitis is well established, the association between periodontitis and prediabetes has been investigated less extensively. Furthermore, there has been little research on the prevalence of periodontitis among individuals with prediabetes and diabetes as well as in the overall population using nationally representative data. Among 12,406 adults (≥19 years’ old) who participated in the 2012–2013 Korea National Health and Nutrition Examination Survey, a total of 9977 subjects completed oral and laboratory examinations and were included in this analysis. Periodontitis was defined as a community periodontal index score of ≥3 according to the World Health Organization criteria. The fasting plasma glucose level was categorized into the following 5 groups: normal fasting glucose (NFG) 1 (<90 mg/dL), NFG 2 (90–99 mg/dL), impaired fasting glucose (IFG) 1 (100–110 mg/dL), IFG 2 (111–125 mg/dL), and diabetes (≥126 mg/dL). Overall, the weighted prevalence of periodontitis among the Korean adult population was 24.8% (23.3–26.4%) (weight n = 8,455,952/34,086,014). The unadjusted weighted prevalences of periodontitis were 16.7%, 22.8%, 29.6%, 40.7%, and 46.7% in the NFG 1, NFG 2, IFG 1, IFG 2, and diabetes groups, respectively (P < 0.001). After adjusting for age, sex, smoking history, heavy alcohol drinking, college graduation, household income, waist circumference, serum triglyceride level, serum high-density lipoprotein cholesterol level, and the presence of hypertension, the adjusted weighted prevalence of periodontitis increased to 29.7% in the IFG 2 group (P = 0.045) and 32.5% in the diabetes group (P < 0.001), compared with the NFG 1 group (24%). The odds ratios for periodontitis with the above-mentioned variables as covariates were 1.42 (95% confidence interval [CI] 1.14–1.77, P = 0.002) in the diabetes group and 1.33 (95% CI 1.01–1.75, P = 0.044) in the IFG

  4. 40 CFR 63.762 - Startups, shutdowns, and malfunctions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... apply at all times except during startups or shutdowns, during malfunctions, and during periods of non... which this subpart applies. However, during the startup, shutdown, malfunction, or period of non... provisions to which they are subject must do so during the startup, shutdown, malfunction, or period of...

  5. 40 CFR 63.762 - Startups, shutdowns, and malfunctions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... apply at all times except during startups or shutdowns, during malfunctions, and during periods of non... which this subpart applies. However, during the startup, shutdown, malfunction, or period of non... provisions to which they are subject must do so during the startup, shutdown, malfunction, or period of...

  6. 40 CFR 63.762 - Startups, shutdowns, and malfunctions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... apply at all times except during startups or shutdowns, during malfunctions, and during periods of non... which this subpart applies. However, during the startup, shutdown, malfunction, or period of non... provisions to which they are subject must do so during the startup, shutdown, malfunction, or period of...

  7. 40 CFR 1037.660 - Automatic engine shutdown systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Automatic engine shutdown systems... § 1037.660 Automatic engine shutdown systems. This section specifies requirements that apply for certified automatic engine shutdown systems (AES) that are modeled under § 1037.520. It does not apply...

  8. 40 CFR 1037.660 - Automatic engine shutdown systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Automatic engine shutdown systems... § 1037.660 Automatic engine shutdown systems. This section specifies requirements that apply for certified automatic engine shutdown (AES) systems modeled under § 1037.520. It does not apply for...

  9. The Magnetospheric Multiscale Missions Fast Plasma Investigations Dual Electron Spectrometer Development

    NASA Technical Reports Server (NTRS)

    Shappirio, M.; Adrian, M.; Aulleti, C.; Avanov, L.; Barrie, A.; Chornay, D.; Moore, T.; Rosnack, T.; Tucker, C.

    2009-01-01

    The Magnetospheric Multiscale mission (MMS) is designed to examine magnetic reconnection that occurs on both the Earths dayside magnetopause and in the magnetotail region on Earths night side. In order to resolve fine structures of the three dimensional electron distributions in both regions, the Fast Plasma Investigation's (FPI) Dual Electron Spectrometer (DES) is designed to measure electron distributions with a time resolution of 30 ms. In order to achieve this unprecedented sampling rate, the DES will have eight individual spectrometers each sampling 180 x 45 degree sections of the sky. Because of the field of view limitations of top hat analyzers, each spectrometer will use electro-static deflectors to change its look direction. The engineering model of the DES has been fabricated and tested. We will present the results of measurements for fields of view, angular FVVHM responses, dE/E, analyzer constant, and geometric factors for all deflection states. We will compare these results to simulation results and discuss causes of the response variations.

  10. Elemental Bioimaging by Means of Fast Scanning Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry.

    PubMed

    Wehe, Christoph A; Thyssen, Georgina M; Herdering, Christina; Raj, Indra; Ciarimboli, Giuliano; Sperling, Michael; Karst, Uwe

    2015-08-01

    One of the most common setups for elemental bioimaging, the hyphenation of a laser ablation (LA) system and an inductively coupled plasma mass spectrometer (ICP-MS), was expanded by adding full scan mass spectrometric information as another dimension of information. While most studies deal with the analysis of typically not more than up to 10 isotopes per scan cycle, a fast scanning quadrupole mass analyzer was utilized to record the full mass spectrum of interest in this work. Mass-to-charge ratios from 6 to 250 were observed within one cycle. Besides the x- and y-position on the ablated sample and the intensity, the m/z-ratio served as fourth variable for each pixel of the obtained data, closing thereby the gap between "inorganic" and "organic" mass spectrometric imaging techniques. The benefits of this approach include an improved control of interferences, the discovery of unexpected elemental distributions, the possibility to plot isotopic ratios, and to integrate the intensities of a certain number of mass channels recorded for each isotope, thus virtually increasing sensitivity. The respective data are presented for dried droplets as well as embedded animal and human tissue slices. Limits of detection were calculated and found to be in accordance with counting statistics. A dedicated software macro was developed for data manipulation prior to common evaluation and image creation. PMID:25947196

  11. Elemental Bioimaging by Means of Fast Scanning Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Wehe, Christoph A.; Thyssen, Georgina M.; Herdering, Christina; Raj, Indra; Ciarimboli, Giuliano; Sperling, Michael; Karst, Uwe

    2015-08-01

    One of the most common setups for elemental bioimaging, the hyphenation of a laser ablation (LA) system and an inductively coupled plasma mass spectrometer (ICP-MS), was expanded by adding full scan mass spectrometric information as another dimension of information. While most studies deal with the analysis of typically not more than up to 10 isotopes per scan cycle, a fast scanning quadrupole mass analyzer was utilized to record the full mass spectrum of interest in this work. Mass-to-charge ratios from 6 to 250 were observed within one cycle. Besides the x- and y-position on the ablated sample and the intensity, the m/z-ratio served as fourth variable for each pixel of the obtained data, closing thereby the gap between "inorganic" and "organic" mass spectrometric imaging techniques. The benefits of this approach include an improved control of interferences, the discovery of unexpected elemental distributions, the possibility to plot isotopic ratios, and to integrate the intensities of a certain number of mass channels recorded for each isotope, thus virtually increasing sensitivity. The respective data are presented for dried droplets as well as embedded animal and human tissue slices. Limits of detection were calculated and found to be in accordance with counting statistics. A dedicated software macro was developed for data manipulation prior to common evaluation and image creation.

  12. Fast particle-driven ion cyclotron emission (ICE) in tokamak plasmas and the case for an ICE diagnostic in ITER

    NASA Astrophysics Data System (ADS)

    McClements, K. G.; D'Inca, R.; Dendy, R. O.; Carbajal, L.; Chapman, S. C.; Cook, J. W. S.; Harvey, R. W.; Heidbrink, W. W.; Pinches, S. D.

    2015-04-01

    The detection of fast particle-driven waves in the ion cyclotron frequency range (ion cyclotron emission or ICE) could provide a passive, non-invasive diagnostic of confined and escaping fast particles (fusion α-particles and beam ions) in ITER, and would be compatible with the high radiation environment of deuterium-tritium plasmas in that device. Recent experimental results from ASDEX Upgrade and DIII-D demonstrate the efficacy of ICE as a diagnostic of different fast ion species and of fast ion losses, while recent particle-in-cell (PIC) and hybrid simulations provide a more exact comparison with measured ICE spectra and open the prospect of exploiting ICE more fully as a fast ion diagnostic in future experiments. In particular the PIC/hybrid approach should soon make it possible to simulate the nonlinear physics of ICE in full toroidal geometry. Emission has been observed previously at a wide range of poloidal angles, so there is flexibility in the location of ICE detectors. Such a detector could be implemented in ITER by installing a small toroidally orientated loop near the plasma edge or by adding a detection capability to the ion cyclotron resonance heating (ICRH) antennae. In the latter case, the antenna could be used simultaneously to heat the plasma and detect ICE, provided that frequencies close to those of the ICRH source are strongly attenuated in the detection system using a suitable filter. Wavenumber information, providing additional constraints on the fast ion distribution exciting the emission, could be obtained by measuring ICE using a toroidally distributed array of detectors or different straps of the ICRH antenna.

  13. 0.2 Hz Plasma-Focus-based source of fast neutrons and hard x rays for applications

    SciTech Connect

    Moreno, C.; Raspa, V.; Di Lorenzo, F.; Lazarte, A.; Knoblauch, P.; Clausse, A.

    2006-12-04

    A small chamber Plasma Focus that operates at 0.2 Hz for several minutes is used as a source of hard x rays and fast neutrons. The device is powered by a microprocessor controlled capacitor charging power supply. The x rays are used for introspective imaging of metallic pieces, static and in motion, that allows for the detection of internal defects as small as 1 mm. The x ray radiation is able to produce clear images of objects placed behind several millimeters of iron and steel. The fast neutrons allow for the detection of hydrogenated substances and can discriminate between different concentrations of water located near the device.

  14. Consumption of wheat aleurone-rich foods increases fasting plasma betaine and modestly decreases fasting homocysteine and LDL-cholesterol in adults.

    PubMed

    Price, Ruth K; Keaveney, Edel M; Hamill, Lesley L; Wallace, Julie M W; Ward, Mary; Ueland, Per M; McNulty, Helene; Strain, J J; Parker, Michael J; Welch, Robert W

    2010-12-01

    There is strong evidence that whole-grain foods protect against heart disease. Although underlying mechanisms and components are unclear, betaine, found at high levels in wheat aleurone, may play a role. We evaluated the effects of a diet high in wheat aleurone on plasma betaine and related measures. In a parallel, single-blinded intervention study, 79 healthy participants (aged 45-65 y, BMI ≥ 25 kg/m(2)) incorporated either aleurone-rich cereal products (27 g/d aleurone) or control products balanced for fiber and macronutrients into their habitual diets for 4 wk. Fasting blood samples were taken at baseline and postintervention (4 wk) from participants. Compared with the control, the aleurone products provided an additional 279 mg/d betaine and resulted in higher plasma betaine (P < 0.001; intervention effect size: 5.2 μmol/L) and lower plasma total homocysteine (tHcy) (P = 0.010; -0.7 μmol/L). Plasma dimethylglycine and methionine, which are products of betaine-mediated homocysteine remethylation, were also higher (P < 0.001; P = 0.027) relative to control. There were no significant effects on plasma choline or B vitamins (folate, riboflavin, and vitamin B-6). However, LDL cholesterol was lower than in the control group (P = 0.037). We conclude that incorporating aleurone-rich products into the habitual diet for 4 wk significantly increases plasma betaine concentrations and lowers tHcy, which is attributable to enhanced betaine-homocysteine methyltransferase-mediated remethylation of homocysteine. Although this supports a role for betaine in the protective effects of whole grains, concomitant decreases in LDL suggest more than one component or mechanism may be responsible.

  15. Controlled shutdown of a fuel cell

    DOEpatents

    Clingerman, Bruce J.; Keskula, Donald H.

    2002-01-01

    A method is provided for the shutdown of a fuel cell system to relieve system overpressure while maintaining air compressor operation, and corresponding vent valving and control arrangement. The method and venting arrangement are employed in a fuel cell system, for instance a vehicle propulsion system, comprising, in fluid communication, an air compressor having an outlet for providing air to the system, a combustor operative to provide combustor exhaust to the fuel processor.

  16. Fast oscillatory behavior of the excited xenon density in the discharge cells of a plasma display panel

    SciTech Connect

    Uhm, Han S.; Choi, Eun H.

    2009-03-15

    Fast oscillation of the excited xenon density occurs universally after an electrical discharge in the cells of a plasma display panel. A theoretical model based on ion plasma oscillation simulates this oscillatory behavior of the excited xenon density reasonably well. The magnitude and lifetime of the excited xenon density in a metastable state depend highly on the electrode configuration. Particularly, T-type electrodes provide better generation and confinement of excited xenon atoms for an abundant emission of 173 nm ultraviolet light at a high level of efficiency.

  17. Large-amplitude hydromagnetic waves in collisionless relativistic plasma - Exact solution for the fast-mode magnetoacoustic wave

    NASA Technical Reports Server (NTRS)

    Barnes, A.

    1983-01-01

    An exact nonlinear solution is found to the relativistic kinetic and electrodynamic equations (in their hydromagnetic limit) that describes the large-amplitude fast-mode magnetoacoustic wave propagating normal to the magnetic field in a collisionless, previously uniform plasma. It is pointed out that a wave of this kind will be generated by transverse compression of any collisionless plasma. The solution is in essence independent of the detailed form of the particle momentum distribution functions. The solution is obtained, in part, through the method of characteristics; the wave exhibits the familiar properties of steepening and shock formation. A detailed analysis is given of the ultrarelativistic limit of this wave.

  18. Positive-column plasma studied by fast-flow glow discharge mass spectrometry: Could it be a ``Rydberg gas?''

    NASA Astrophysics Data System (ADS)

    Mason, Rod; Miller, Pat; Mortimer, Ifor; Mitchell, David; Dash, Neil

    2003-07-01

    Ions created from the fast-flowing positive column plasma of a glow discharge were monitored using a high voltage magnetic sector mass spectrometer. Since the field gradient and sheath potentials created by the plasma inside the source opposed cation transfer, it is inferred that the ions detected were the field-ionized Rydberg species. This is supported by the mass spectral changes which occurred when a negative bias was applied to the sampling aperture and by the contrasting behavior when attached to a quadrupole analyzer. Reaction with H2 (titrated into the flowing plasma) quenched not only the ionization of discharge gas Rydberg atoms but also the passage of electric current through the plasma, without significant changes to the field and sheath potentials. Few “free” ions were present and the lifetimes of the Rydberg atoms detected were much longer than seen in lower pressure experiments, indicating additional stabilization in the plasma environment. The observations support the model of the flowing plasma, given previously [R. S. Mason, P. D. Miller, and I. P. Mortimer, Phys. Rev. E 55, 7462 (1997)] as mainly a neutral Rydberg atom gas, rather than a conventional ion-electron plasma.

  19. Performance of a Discrete Wavelet Transform for Compressing Plasma Count Data and its Application to the Fast Plasma Investigation on NASA's Magnetospheric Multiscale Mission

    NASA Technical Reports Server (NTRS)

    Barrie, Alexander C.; Yeh, Penshu; Dorelli, John C.; Clark, George B.; Paterson, William R.; Adrian, Mark L.; Holland, Matthew P.; Lobell, James V.; Simpson, David G.; Pollock, Craig J.; Moore, Thomas E.

    2015-01-01

    Plasma measurements in space are becoming increasingly faster, higher resolution, and distributed over multiple instruments. As raw data generation rates can exceed available data transfer bandwidth, data compression is becoming a critical design component. Data compression has been a staple of imaging instruments for years, but only recently have plasma measurement designers become interested in high performance data compression. Missions will often use a simple lossless compression technique yielding compression ratios of approximately 2:1, however future missions may require compression ratios upwards of 10:1. This study aims to explore how a Discrete Wavelet Transform combined with a Bit Plane Encoder (DWT/BPE), implemented via a CCSDS standard, can be used effectively to compress count information common to plasma measurements to high compression ratios while maintaining little or no compression error. The compression ASIC used for the Fast Plasma Investigation (FPI) on board the Magnetospheric Multiscale mission (MMS) is used for this study. Plasma count data from multiple sources is examined: resampled data from previous missions, randomly generated data from distribution functions, and simulations of expected regimes. These are run through the compression routines with various parameters to yield the greatest possible compression ratio while maintaining little or no error, the latter indicates that fully lossless compression is obtained. Finally, recommendations are made for future missions as to what can be achieved when compressing plasma count data and how best to do so.

  20. COS FUV Recovery after Anomalous Shutdown

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2013-10-01

    This proposal consists of the steps for turning on and ramping up the COS FUV high voltage in a safe and conservative manner after a HV anomalous shutdown by executing a "reduced set" of visits from Cycle 19 Proposal 12810. The nature of the shutdown, i.e., over-light, HV current transient {"crackle"}, ion feedback {induced by a high energy particle}, or field emission {possibly caused by dust or other particulate on the QE grid or other close-by structure or hardware}, and the value of the commanded HV at the time of the shutdown will determine what visits are executed. Because of gain sag, commanded HV settings updates may be required. First, prior to execution of this proposal or selected visits from this proposal, all preliminary steps should be exercised to gather the necessary diagnostic data, e.g., science data evaluation {if a science exposure was in progress and the science data is available}, memory dumps {DCE, EXEC RAM, and possibly the CS BUFFER}, engineering telemetry, or other information that might provide insight as to the nature of the shutdown and estimated count rate. The complete step-by-step procedure is detailed in the Observing Description, but in summary, the following is done:Day 01 activities, visits 01-07, contain both QE grid off and on HV ramping to HVLow {100/100} with diagnostics {DCE dumps} and darks to exclude QE grid involvement in the shutdown. Subsequent to day 01, all HV ramping will be with the QE grid on with the same diagnostics and exposures. All days end with the setting of COS event flag 3 to prevent any FUV HV commanding.Time is allotted for cognizant detector and COS instrument scientist and engineers to examine data dumps, science exposures, and engineering telemetry. If all is well, the go-ahead will be given to clear flag 3 for the next day's visits.This proposal is modeled after the Cycle 20 Proposal 13129.

  1. Alfven eigenmode stability and fast ion loss in DIII-D and ITER reversed magnetic shear plasmas

    SciTech Connect

    Van Zeeland, Michael; Gorelenkov, Nikolai; Heidbrink, W.; Kramer, G.; Spong, Donald A; Austin, M. E.; Fisher, R K; Munoz, M G; Gorelenkova, M.; Luhmann, N.C.; Murakami, Masanori; Nazikian, Raffi; Park, J. M.; Tobias, Ben; White, R.

    2012-01-01

    Neutral beam injection into reversed-magnetic shear DIII-D plasmas produces a variety of Alfvenic activity including toroidicity-induced Alfven eigenmodes (TAEs) and reversed shear Alfven eigenmodes (RSAEs). With measured equilibrium profiles as inputs, the ideal MHD code NOVA is used to calculate eigenmodes of these plasmas. The postprocessor code NOVA-K is then used to perturbatively calculate the actual stability of the modes, including finite orbit width and finite Larmor radius effects, and reasonable agreement with the spectrum of observed modes is found. Using experimentally measured mode amplitudes, fast ion orbit following simulations have been carried out in the presence of the NOVA calculated eigenmodes and are found to reproduce the dominant energy, pitch and temporal evolution of the losses measured using a large bandwidth scintillator diagnostic. The same analysis techniques applied to a DT 8 MA ITER steady-state plasma scenario with reversed-magnetic shear and both beam ion and alpha populations show Alfven eigenmode instability. Both RSAEs and TAEs are found to be unstable with maximum growth rates occurring for toroidal mode number n = 6 and the majority of the drive coming from fast ions injected by the 1MeV negative ion beams. AE instability due to beam ion drive is confirmed by the non-perturbative code TAEFL. Initial fast ion orbit following simulations using the unstable modes with a range of amplitudes (delta B/B = 10(-5)-10(-3)) have been carried out and show negligible fast ion loss. The lack of fast ion loss is a result of loss boundaries being limited to large radii and significantly removed from the actual modes themselves.

  2. Modeling of plasma propulsion using an inflated magnetic field and its interaction with a fast plasma stream

    NASA Astrophysics Data System (ADS)

    Saha, Saikat

    It has been proposed to extract momentum from the solar wind for spacecraft propulsion in deep space. For this purpose, a magnetic bubble is inflated from the spacecraft. The magnetic bubble inflation is affected by the expansion of a dense warm plasma in the magnetic field created by a solenoid aboard the spacecraft. The interaction between the inflated magnetic field and solar wind is likely to affect the transfer of momentum for the purpose of propulsion. The aim of our research here is to study the feasibility of this propulsion scheme by means of numerical simulations. For this purpose, we developed a 3-D hybrid particle code to model (i) the expansion of plasma in an ambient magnetic field created by a solenoid and (ii) the interaction of a plasma stream with the inflated magnetic field. The code is hybrid in the sense that ions are treated as particles and electrons as an isothermal fluid. We solve the coupled set of Maxwell's equations and the electron momentum equation for the electromagnetic fields using a predictor-corrector method. Using the 3-D simulations, we have demonstrated that when a warm and high-density plasma is injected in solenoidal magnetic fields, the trapping of the plasma in a magnetic mirror creates a dense plasma. When the trapped plasma energy densities (thermal and dynamic) exceed the magnetic energy density, the expanding plasma inflates the magnetic field lines. The extent of field inflation is seen to be greatly dependent on the injection velocity of the thermal plasma. The higher the injection velocity, the larger is the size of the inflated magnetic bubble. It is seen that the original magnetic field, which decreases as R-3, is stretched to the extent where it falls as R-alpha, where R is the distance from the center of the solenoid and alpha is found in the range 1 ≤ alpha ≤ 2. We have also demonstrated that when a plasma stream resembling the solar wind interacts with the expanding magnetic bubble, a magnetopause or bow

  3. Fast-electron refluxing effects on anisotropic hard-x-ray emission from intense laser-plasma interactions.

    PubMed

    McKeever, K; Makita, M; Nersisyan, G; Dzelzainis, T; White, S; Kettle, B; Dromey, B; Zepf, M; Sarri, G; Doria, D; Ahmed, H; Lewis, C L S; Riley, D; Robinson, A P L

    2015-03-01

    Fast-electron generation and dynamics, including electron refluxing, is at the core of understanding high-intensity laser-plasma interactions. This field is itself of strong relevance to fast ignition fusion and the development of new short-pulse, intense, x-ray, γ-ray, and particle sources. In this paper, we describe experiments that explicitly link fast-electron refluxing and anisotropy in hard-x-ray emission. We find the anisotropy in x-ray emission to be strongly correlated to the suppression of refluxing. In contrast to some previous work, the peak of emission is directly along the rear normal to the target rather than along either the incident laser direction or the specular reflection direction. PMID:25871224

  4. In Flight Calibration of the Magnetospheric Multiscale Mission Fast Plasma Investigation

    NASA Technical Reports Server (NTRS)

    Barrie, Alexander C.; Gershman, Daniel J.; Gliese, Ulrik; Dorelli, John C.; Avanov, Levon A.; Salo, Chad L.; Tucker, Corey J.; Holland, Mathew P.; Pollock, Craig J.

    2015-01-01

    The Fast Plasma Investigation (FPI) on the Magnetospheric Multiscale mission (MMS) combines data from eight spectrometers, each with four deflection states, into a single map of the sky. Any systematic discontinuity, artifact, noise source, etc. present in this map may be incorrectly interpreted as legitimate data and incorrect conclusions reached. For this reason it is desirable to have all spectrometers return the same output for a given input, and for this output to be low in noise sources or other errors. While many missions use statistical analyses of data to calibrate instruments in flight, this process is difficult with FPI for two reasons: 1. Only a small fraction of high resolution data is downloaded to the ground due to bandwidth limitations and 2: The data that is downloaded is, by definition, scientifically interesting and therefore not ideal for calibration. FPI uses a suite of new tools to calibrate in flight. A new method for detection system ground calibration has been developed involving sweeping the detection threshold to fully define the pulse height distribution. This method has now been extended for use in flight as a means to calibrate MCP voltage and threshold (together forming the operating point) of the Dual Electron Spectrometers (DES) and Dual Ion Spectrometers (DIS). A method of comparing higher energy data (which has low fractional voltage error) to lower energy data (which has a higher fractional voltage error) will be used to calibrate the high voltage outputs. Finally, a comparison of pitch angle distributions will be used to find remaining discrepancies among sensors.

  5. Fast Magnetic Field Amplification in the Early Universe: Growth of Collisionless Plasma Instabilities in Turbulent Media

    NASA Astrophysics Data System (ADS)

    Falceta-Gonçalves, D.; Kowal, G.

    2015-07-01

    In this work we report on a numerical study of the cosmic magnetic field amplification due to collisionless plasma instabilities. The collisionless magnetohydrodynamic equations derived account for the pressure anisotropy that leads, in specific conditions, to the firehose and mirror instabilities. We study the time evolution of seed fields in turbulence under the influence of such instabilities. An approximate analytical time evolution of the magnetic field is provided. The numerical simulations and the analytical predictions are compared. We found that (i) amplification of the magnetic field was efficient in firehose-unstable turbulent regimes, but not in the mirror-unstable models (ii) the growth rate of the magnetic energy density is much faster than the turbulent dynamo and (iii) the efficient amplification occurs at small scales. The analytical prediction for the correlation between the growth timescales and pressure anisotropy is confirmed by the numerical simulations. These results reinforce the idea that pressure anisotropies—driven naturally in a turbulent collisionless medium, e.g., the intergalactic medium, could efficiently amplify the magnetic field in the early universe (post-recombination era), previous to the collapse of the first large-scale gravitational structures. This mechanism, though fast for the small-scale fields (∼kpc scales), is unable to provide relatively strong magnetic fields at large scales. Other mechanisms that were not accounted for here (e.g., collisional turbulence once instabilities are quenched, velocity shear, or gravitationally induced inflows of gas into galaxies and clusters) could operate afterward to build up large-scale coherent field structures in the long time evolution.

  6. In Flight Calibration of the Magnetospheric Multiscale Mission Fast Plasma Investigation

    NASA Technical Reports Server (NTRS)

    Barrie, Alexander C.; Gershman, Daniel J.; Gliese, Ulrik; Dorelli, John C.; Avanov, Levon A.; Rager, Amy C.; Schiff, Conrad; Pollock, Craig J.

    2015-01-01

    The Fast Plasma Investigation (FPI) on the Magnetospheric Multiscale mission (MMS) combines data from eight spectrometers, each with four deflection states, into a single map of the sky. Any systematic discontinuity, artifact, noise source, etc. present in this map may be incorrectly interpreted as legitimate data and incorrect conclusions reached. For this reason it is desirable to have all spectrometers return the same output for a given input, and for this output to be low in noise sources or other errors. While many missions use statistical analyses of data to calibrate instruments in flight, this process is insufficient with FPI for two reasons: 1. Only a small fraction of high resolution data is downloaded to the ground due to bandwidth limitations and 2: The data that is downloaded is, by definition, scientifically interesting and therefore not ideal for calibration. FPI uses a suite of new tools to calibrate in flight. A new method for detection system ground calibration has been developed involving sweeping the detection threshold to fully define the pulse height distribution. This method has now been extended for use in flight as a means to calibrate MCP voltage and threshold (together forming the operating point) of the Dual Electron Spectrometers (DES) and Dual Ion Spectrometers (DIS). A method of comparing higher energy data (which has low fractional voltage error) to lower energy data (which has a higher fractional voltage error) will be used to calibrate the high voltage outputs. Finally, a comparison of pitch angle distributions will be used to find remaining discrepancies among sensors.

  7. The 2013 US Government Shutdown (#Shutdown) and Health: An Emerging Role for Social Media

    PubMed Central

    Merchant, Raina M.; Ha, Yoonhee P.; Wong, Charlene A.; Schwartz, H. Andrew; Sap, Maarten; Ungar, Lyle H.; Asch, David A.

    2015-01-01

    In October 2013, multiple United States (US) federal health departments and agencies posted on Twitter, “We’re sorry, but we will not be tweeting or responding to @replies during the shutdown. We’ll be back as soon as possible!” These “last tweets” and the millions of responses they generated revealed social media’s role as a forum for sharing and discussing information rapidly. Social media are now among the few dominant communication channels used today. We used social media to characterize the public discourse and sentiment about the shutdown. The 2013 shutdown represented an opportunity to explore the role social media might play in events that could affect health. PMID:25322303

  8. Plasma levels of sex hormone-binding globulin, corticosteroid-binding globulin and cortisol in overweight subjects who develop impaired fasting glucose: a 3-year prospective study.

    PubMed

    Lewis, J G; Shand, B I; Frampton, C M; Elder, P A; Scott, R S

    2009-03-01

    Circulating sex hormone-binding globulin (SHBG), corticosteroid-binding globulin (CBG), and total and calculated free cortisol were measured in 206 overweight subjects to investigate whether or not they were markers of insulin resistance. Measurements were carried out on two occasions 36 months apart and subjects were grouped according to fasting plasma glucose. Fifty-one subjects, with a normal basal fasting glucose (<5.6 mmol/l) developed impaired fasting glucose 3 years later (> or = 5.6 mmol/l). Analysis either in toto or based on gender showed a highly significant increase in fasting insulin and insulin resistance, a modest increase in body mass index (BMI), but importantly no change in plasma SHBG, CBG, or cortisol concentrations. Subjects (n=101) with a normal fasting glucose both at baseline (<5.6 mmol/l) and at 36 months showed no significant change in fasting insulin, insulin resistance, SHBG, CBG, cortisol, or BMI. Cross-sectional analysis of the study population showed that plasma SHBG correlated negatively with insulin resistance both in men and women. Overall SHBG at baseline was not predictive of changes in fasting glucose. In females, plasma CBG correlated negatively with BMI. The major finding is that overweight subjects who developed impaired fasting glucose showed no significant change in plasma SHBG, CBG or cortisol, and therefore these indices are probably not early markers of insulin resistance in overweight subjects.

  9. Signal enhancement of neutral He emission lines by fast electron bombardment of laser-induced He plasma

    NASA Astrophysics Data System (ADS)

    Suyanto, Hery; Pardede, Marincan; Hedwig, Rinda; Marpaung, Alion Mangasi; Ramli, Muliadi; Lie, Tjung Jie; Abdulmadjid, Syahrun Nur; Kurniawan, Koo Hendrik; Tjia, May On; Kagawa, Kiichiro

    2016-08-01

    A time-resolved spectroscopic study is performed on the enhancement signals of He gas plasma emission using nanosecond (ns) and picosecond (ps) lasers in an orthogonal configuration. The ns laser is used for the He gas plasma generation and the ps laser is employed for the ejection of fast electrons from a metal target, which serves to excite subsequently the He atoms in the plasma. The study is focused on the most dominant He I 587.6 nm and He I 667.8 nm emission lines suggested to be responsible for the He-assisted excitation (HAE) mechanism. The time-dependent intensity enhancements induced by the fast electrons generated with a series of delayed ps laser ablations are deduced from the intensity time profiles of both He emission lines. The results clearly lead to the conclusion that the metastable excited triplet He atoms are actually the species overwhelmingly produced during the recombination process in the ns laser-induced He gas plasma. These metastable He atoms are believed to serve as the major energy source for the delayed excitation of analyte atoms in ns laser-induced breakdown spectroscopy (LIBS) using He ambient gas.

  10. Fast quantification of endogenous carbohydrates in plasma using hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry.

    PubMed

    Zhu, Bangjie; Liu, Feng; Li, Xituo; Wang, Yan; Gu, Xue; Dai, Jieyu; Wang, Guiming; Cheng, Yu; Yan, Chao

    2015-01-01

    Endogenous carbohydrates in biosamples are frequently highlighted as the most differential metabolites in many metabolomics studies. A simple, fast, simultaneous quantitative method for 16 endogenous carbohydrates in plasma has been developed using hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry. In order to quantify 16 endogenous carbohydrates in plasma, various conditions, including columns, chromatographic conditions, mass spectrometry conditions, and plasma preparation methods, were investigated. Different conditions in this quantified analysis were performed and optimized. The reproducibility, precision, recovery, matrix effect, and stability of the method were verified. The results indicated that a methanol/acetonitrile (50:50, v/v) mixture could effectively and reproducibly precipitate rat plasma proteins. Cold organic solvents coupled with vortex for 1 min and incubated at -20°C for 20 min were the most optimal conditions for protein precipitation and extraction. The results, according to the linearity, recovery, precision, matrix effect, and stability, showed that the method was satisfactory in the quantification of endogenous carbohydrates in rat plasma. The quantified analysis of endogenous carbohydrates in rat plasma performed excellently in terms of sensitivity, high throughput, and simple sample preparation, which met the requirement of quantification in specific expanded metabolomic studies after the global metabolic profiling research.

  11. Anticorrelated Emission of High Harmonics and Fast Electron Beams From Plasma Mirrors.

    PubMed

    Bocoum, Maïmouna; Thévenet, Maxence; Böhle, Frederik; Beaurepaire, Benoît; Vernier, Aline; Jullien, Aurélie; Faure, Jérôme; Lopez-Martens, Rodrigo

    2016-05-01

    We report for the first time on the anticorrelated emission of high-order harmonics and energetic electron beams from a solid-density plasma with a sharp vacuum interface-plasma mirror-driven by an intense ultrashort laser pulse. We highlight the key role played by the nanoscale structure of the plasma surface during the interaction by measuring the spatial and spectral properties of harmonics and electron beams emitted by a plasma mirror. We show that the nanoscale behavior of the plasma mirror can be controlled by tuning the scale length of the electron density gradient, which is measured in situ using spatial-domain interferometry. PMID:27203328

  12. Anticorrelated Emission of High Harmonics and Fast Electron Beams From Plasma Mirrors.

    PubMed

    Bocoum, Maïmouna; Thévenet, Maxence; Böhle, Frederik; Beaurepaire, Benoît; Vernier, Aline; Jullien, Aurélie; Faure, Jérôme; Lopez-Martens, Rodrigo

    2016-05-01

    We report for the first time on the anticorrelated emission of high-order harmonics and energetic electron beams from a solid-density plasma with a sharp vacuum interface-plasma mirror-driven by an intense ultrashort laser pulse. We highlight the key role played by the nanoscale structure of the plasma surface during the interaction by measuring the spatial and spectral properties of harmonics and electron beams emitted by a plasma mirror. We show that the nanoscale behavior of the plasma mirror can be controlled by tuning the scale length of the electron density gradient, which is measured in situ using spatial-domain interferometry.

  13. Rodded shutdown system for a nuclear reactor

    DOEpatents

    Golden, Martin P.; Govi, Aldo R.

    1978-01-01

    A top mounted nuclear reactor diverse rodded shutdown system utilizing gas fed into a pressure bearing bellows region sealed at the upper extremity to an armature. The armature is attached to a neutron absorber assembly by a series of shafts and connecting means. The armature is held in an uppermost position by an electromagnet assembly or by pressurized gas in a second embodiment. Deenergizing the electromagnet assembly, or venting the pressurized gas, causes the armature to fall by the force of gravity, thereby lowering the attached absorber assembly into the reactor core.

  14. Hazard Classification for Fuel Supply Shutdown Facility

    SciTech Connect

    BENECKE, M.W.

    2000-09-07

    Final hazard classification for the 300 Area N Reactor fuel storage facility resulted in the assignment of Nuclear Facility Hazard Category 3 for the uranium metal fuel and feed material storage buildings (303-A, 303-B, 303-G, 3712, and 3716). Radiological for the residual uranium and thorium oxide storage building and an empty former fuel storage building that may be used for limited radioactive material storage in the future (303-K/3707-G, and 303-E), and Industrial for the remainder of the Fuel Supply Shutdown buildings (303-F/311 Tank Farm, 303-M, 313-S, 333, 334 and Tank Farm, 334-A, and MO-052).

  15. Technical Assessment: WRAP 1 HVAC Passive Shutdown

    SciTech Connect

    Ball, D.E.; Nash, C.R.; Stroup, J.L.

    1993-08-12

    As the result of careful interpretation of DOE Order 6430.lA and other DOE Orders, the HVAC system for WRAP 1 has been greatly simplified. The HVAC system is now designed to safely shut down to Passive State if power fails for any reason. The fans cease functioning, allowing the Zone 1 and Zone 2 HVAC Confinement Systems to breathe with respect to atmospheric pressure changes. Simplifying the HVAC system avoided overdesign. Construction costs were reduced by eliminating unnecessary equipment. This report summarizes work that was done to define the criteria, physical concepts, and operational experiences that lead to the passive shutdown design for WRAP 1 confinement HVAC systems.

  16. Effects of laser polarization on jet emission of fast electrons in femtosecond-laser plasmas.

    PubMed

    Chen, L M; Zhang, J; Li, Y T; Teng, H; Liang, T J; Sheng, Z M; Dong, Q L; Zhao, L Z; Wei, Z Y; Tang, X W

    2001-11-26

    Effects of laser polarization on fast electron emission are studied from an aluminum target irradiated by ultrashort laser pulses at 2 x 10(16) W/cm(2). Jet emission of outgoing fast electrons collimated in the polarization direction is observed for s-polarized laser irradiation, whereas for p-polarized irradiation highly directional emission of outgoing fast electrons is found in the direction close to the normal of the target. The behavior of ingoing fast electrons into the target for s- and p-polarized irradiation is also investigated by observing x-ray bremsstrahlung radiation at the backside of the target.

  17. Ultra-fast pulsed microwave plasma breakdown: evidence of various ignition modes

    NASA Astrophysics Data System (ADS)

    Carbone, Emile; Nijdam, Sander

    2014-02-01

    In this communication, we investigate the ignition of pulsed microwave plasmas in a narrow dielectric tube with an electrodeless configuration. The plasma is generated using a surfatron cavity. The power is modulated as a square wave with a rise-time of 30 ns at variable frequencies from 100 Hz up to 5 MHz. The ignition and plasma propagation inside the 3 mm radius quartz tube are imaged spatially and resolved with nanosecond time resolution using an iCCD camera. The plasma is found to propagate in the form of a front moving from the launcher to the end of the plasma column with the microwave power being gradually absorbed behind it. The velocity of the plasma front decreases while the plasma goes towards a steady state. The ionization front is found to be strongly non-uniform and various structures as a function of the pulse repetition frequency (i.e. power-off time) are shown in the axial and radial directions. At low frequencies, finger-like structures are found. The plasma becomes more hollow at smaller power-off times. At higher repetition frequencies (kHz regime), a critical repetition frequency is found for which the plasma light intensity sharply increases at the head of the propagation front, taking a shape resembling a plasma bullet. This critical frequency depends on the pressure and power. For even higher frequencies, the bullet shape disappears and plasma volume ignition from the launcher to the end of the plasma column is observed. These results bring a new insight into the ignition mechanisms of pulsed microwave plasmas inside dielectric tubes. A wide variety of effects are found which seem to mostly depend on the background ionization degree. Moreover, the results show that only a 3D time-dependent model can, in general, correctly describe the ignition of a pulsed microwave discharge.

  18. Fast ion motion in the plasma part of a stellarator-mirror fission-fusion hybrid

    NASA Astrophysics Data System (ADS)

    Moiseenko, V. E.; Nemov, V. V.; Ågren, O.; Kasilov, S. V.; Garkusha, I. E.

    2016-06-01

    Recent developments of a stellarator-mirror (SM) fission-fusion hybrid concept are reviewed. The hybrid consists of a fusion neutron source and a powerful sub-critical fast fission reactor core. The aim is transmutation of spent nuclear fuel and safe fission energy production. In its fusion part, a stellarator-type system with an embedded magnetic mirror is used. The stellarator confines deuterium plasma with moderate temperature, 1-2 keV. In the magnetic mirror, a hot component of sloshing tritium ions is trapped. There, the fusion neutrons are generated. A candidate for a combined SM system is a DRACON magnetic trap. A basic idea behind an SM device is to maintain local neutron production in a mirror part, but at the same time eliminate the end losses by using a toroidal device. A possible drawback is that the stellarator part can introduce collision-free radial drift losses, which is the main topic for this study. For high energy ions of tritium with an energy of 70 keV, comparative computations of collisionless losses in the rectilinear part of a specific design of the DRACON type trap are carried out. Two versions of the trap are considered with different lengths of the rectilinear sections. Also the total number of current-carrying rings in the magnetic system is varied. The results predict that high energy ions from neutral beam injection can be satisfactorily confined in the mirror part during 0.1-1 s. The Uragan-2M experimental device is used to check key points of the SM concept. The magnetic configuration of a stellarator with an embedded magnetic mirror is arranged in this device by switching off one toroidal coil. The motion of particles magnetically trapped in the embedded mirror is analyzed numerically with use of motional invariants. It is found that without radial electric field particles quickly drift out of the SM, even if the particles initially are located on a nested magnetic surface. We will show that a weak radial electric field, which

  19. Fast ion motion in the plasma part of a stellarator-mirror fission–fusion hybrid

    NASA Astrophysics Data System (ADS)

    Moiseenko, V. E.; Nemov, V. V.; Ågren, O.; Kasilov, S. V.; Garkusha, I. E.

    2016-06-01

    Recent developments of a stellarator-mirror (SM) fission–fusion hybrid concept are reviewed. The hybrid consists of a fusion neutron source and a powerful sub-critical fast fission reactor core. The aim is transmutation of spent nuclear fuel and safe fission energy production. In its fusion part, a stellarator-type system with an embedded magnetic mirror is used. The stellarator confines deuterium plasma with moderate temperature, 1–2 keV. In the magnetic mirror, a hot component of sloshing tritium ions is trapped. There, the fusion neutrons are generated. A candidate for a combined SM system is a DRACON magnetic trap. A basic idea behind an SM device is to maintain local neutron production in a mirror part, but at the same time eliminate the end losses by using a toroidal device. A possible drawback is that the stellarator part can introduce collision-free radial drift losses, which is the main topic for this study. For high energy ions of tritium with an energy of 70 keV, comparative computations of collisionless losses in the rectilinear part of a specific design of the DRACON type trap are carried out. Two versions of the trap are considered with different lengths of the rectilinear sections. Also the total number of current-carrying rings in the magnetic system is varied. The results predict that high energy ions from neutral beam injection can be satisfactorily confined in the mirror part during 0.1–1 s. The Uragan-2M experimental device is used to check key points of the SM concept. The magnetic configuration of a stellarator with an embedded magnetic mirror is arranged in this device by switching off one toroidal coil. The motion of particles magnetically trapped in the embedded mirror is analyzed numerically with use of motional invariants. It is found that without radial electric field particles quickly drift out of the SM, even if the particles initially are located on a nested magnetic surface. We will show that a weak radial electric field

  20. Fast Plasma Investigation for MMS: Simulation of the Burst Triggering System

    NASA Astrophysics Data System (ADS)

    Barrie, A.; Dorelli, J.; Adrian, M. L.; Paterson, W. R.; Pollock, C. J.

    2011-12-01

    The Magnetospheric MultiScale (MMS) mission will enable the study of small-scale magnetic reconnection structures and their rapid motions from closely spaced platforms using instruments capable of high angular, energy, and time resolution measurements. To meet these requirements, the Fast Plasma Instrument (FPI) consists of eight (8) identical half top-hat electron sensors, eight (8) identical half top-hat ion sensors, and an Instrument Data Processing Unit (IDPU) on each of the four (4) MMS spacecraft. The sensors are packaged into pairs (DES & DIS) whose 90° x 180° (with electostatic deflection) fields-of-view (FOV) are placed at 90° intervals around the spacecraft periphery. Each sensor is equipped with electrostatic aperture steering to allow the sensor to scan a 45° x 180° fan about the its nominal viewing (0° deflection) direction. The combination of the eight electron/ion sensors, employing aperture steering, image the full-sky every 30ms (electrons) and 150ms (ions), respectively. To probe the diffusion regions of reconnection events, the highest temporal/spatial resolution mode of FPI results in the DES complement of each spacecraft generating 6.5-Mb s-1 of electron data while the DIS generates 1.1-Mb s-1 of ion data yielding an FPI total data rate of 7.6-Mb s-1 for each of the 4 MMS spacecraft. The FPI electron and ion data is collected by the IDPU and transmitted to the Central Data Instrument Processor (CIDP) on the spacecraft for science interest ranking. Owing to limitations in downlink band width, only data sequences that contain the greatest potential for reconnection science may be down-linked by the spacecraft. This requires a data ranking process implemented as part of a burst trigger system. The FPI burst trigger system uses count rate sums representing pseudo physical quantities to approximate the local plasma environments. As each pseudo quantity will have a different value, a set of two scaling factors is employed for each pseudo term

  1. Fast Plasma Investigation for MMS: Simulation of the Burst Triggering System

    NASA Technical Reports Server (NTRS)

    Barrie, A. C.; Dorelli, J. C.; Winkert, G. E.; Lobell, J. V.; Holland, M. P.; Adrian, M. L.; Pollock, C. J.

    2011-01-01

    The Magnetospheric Multiscale (MMS) mission will study small-scale reconnection structures and their rapid motions from closely spaced platforms using instruments capable of high angular, energy, and time resolution measurements. To meet these requirements, the Fast Plasma Instrument (FPI) consists of eight (8) identical half top-hat electron sensors and eight (8) identical ion sensors and an Instrument Data Processing Unit (IDPU). The sensors (electron or ion) are grouped into pairs whose 6 degree x 180 degree fields-of-view (FOV) are set 90 degrees apart. Each sensor is equipped with electrostatic aperture steering to allow the sensor to scan a 45 degree x 180 degree fan about the its nominal viewing (0 deflection) direction. Each pair of sensors, known as the Dual Electron Spectrometer (DES) and the Dual Ion Spectrometer (DIS), occupies a quadrant on the MMS spacecraft and the combination of the eight electron/ion sensors, employing aperture steering, image the full-sky every 30-ms (electrons) and 150-ms (ions), respectively. To probe the diffusion regions of reconnection, the highest temporal/spatial resolution mode of FPI results in the DES complement of a given spacecraft generating 6.5-Mb (raised dot) per second of electron data while the DIS generates 1.1-Mb (raised dot) per second of ion data yielding an FPI total data rate of 6.6-Mb (raised dot) per second. The FPI electron/ion data is collected by the IDPU then transmitted to the Central Data Instrument Processor (CIDP) on the spacecraft for science interest ranking. Only data sequences that contain the greatest amount of temporal/spatial structure will be intelligently down-linked by the spacecraft. This requires a data ranking process known as the burst trigger system. The burst trigger system uses pseudo physical quantities to approximate the local plasma environments. As each pseudo quantity will have a different value, a set of two scaling factors is employed for each pseudo term. These pseudo

  2. Decreased expression of adipose CD36 and FATP1 are associated with increased plasma nonesterified fatty acids during prolonged fasting in northern elephant seal pups (Mirounga angustirostris)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The northern elephant seal undergoes a 2-3 month post-weaning fast during which it depends primarily on the oxidation of fatty acids to meet its energetic demands. The concentration of plasma free fatty acids (FFA) increases and is associated with the development of insulin resistance in late-fasted...

  3. CELLULOSE SYNTHASE INTERACTIVE1 Is Required for Fast Recycling of Cellulose Synthase Complexes to the Plasma Membrane in Arabidopsis

    PubMed Central

    Lei, Lei; Bashline, Logan; Li, Shundai

    2015-01-01

    Plants are constantly subjected to various biotic and abiotic stresses and have evolved complex strategies to cope with these stresses. For example, plant cells endocytose plasma membrane material under stress and subsequently recycle it back when the stress conditions are relieved. Cellulose biosynthesis is a tightly regulated process that is performed by plasma membrane-localized cellulose synthase (CESA) complexes (CSCs). However, the regulatory mechanism of cellulose biosynthesis under abiotic stress has not been well explored. In this study, we show that small CESA compartments (SmaCCs) or microtubule-associated cellulose synthase compartments (MASCs) are critical for fast recovery of CSCs to the plasma membrane after stress is relieved in Arabidopsis thaliana. This SmaCC/MASC-mediated fast recovery of CSCs is dependent on CELLULOSE SYNTHASE INTERACTIVE1 (CSI1), a protein previously known to represent the link between CSCs and cortical microtubules. Independently, AP2M, a core component in clathrin-mediated endocytosis, plays a role in the formation of SmaCCs/MASCs. Together, our study establishes a model in which CSI1-dependent SmaCCs/MASCs are formed through a process that involves endocytosis, which represents an important mechanism for plants to quickly regulate cellulose synthesis under abiotic stress. PMID:26443667

  4. Fast tomographic measurements of temperature in an air plasma cutting torch

    NASA Astrophysics Data System (ADS)

    Hlína, J.; Šonský, J.; Gruber, J.; Cressault, Y.

    2016-03-01

    Temperatures in an air plasma jet were measured using a tomographic experimental arrangement providing time-resolved scans of plasma optical radiation in the spectral band 559-601 nm from two directions. The acquired data and subsequent processing yielded time-resolved temperature distributions in measurement planes perpendicular to the plasma jet axis with a temporal resolution of 1 μs. The measurement system and evaluation methods afforded detailed information about the influence of high-frequency ripple modulation of the arc current on plasma temperature.

  5. Temporal Changes in Plasma Concentration of Leptin, IGF-1, Insulin and Metabolites Under Extended Fasting and Re-Feeding Conditions in Growing Lambs

    PubMed Central

    Kiani, Ali

    2012-01-01

    Background A fall in plasma concentration of energy status related hormones (leptin, insulin-like growth factor-1 (IGF-1) and insulin) and body energy expenditure occurs in response to short term fasting. Nevertheless, the relations of the fasting-induced changes in energy related hormones and metabolites with fasting energy expenditure (FEE) under extended fasting condition have received little attention so far. Objectives It is not clear how energy status related hormones coordinate to cope with feed deprivation under extended fasting time conditions and how quickly these hormones re-bound to fed-state values in response to re-feeding. Thus the objectives of this study were: 1) to determine the effects of extended fasting on plasma concentration of leptin, IGF-1, insulin, glucose, NEFA, 3-β-hydroxybutyrate (BOHB) and urea; and 2) to study the relations of energy status related hormones with FEE and substrate oxidations under extended fasting conditions. Materials and Methods Eighteen six-month-old growing lambs (9 females and 9 males) were fasted for three days. Blood samples were taken one hour before (-1H) and 48 and 72 hours after fasting (48H and 72H) and two hours after re-feeding (+2H) from jugular vein. During the last 22 hours of fasting, gas exchange (CO2 production and O2 consumption) were measured using an open-circuit indirect calorimeter. Respiratory quotient (RQ), FEE and relative proportions of oxidized protein, fat and carbohydrate were calculated. Results Plasma levels of leptin, insulin, IGF-1 and glucose decreased but NEFA and urea levels increased within 48H of fasting. Concentration of insulin significantly increased with extended fasting while leptin and IGF-1 levels remained constant. Glucose was the only blood variable that showed a quick re-bound within two hours after re-feeding. Leptin and IGF-1 showed significant positive relations with glucose and BOHB but negative relations with NEFA and Urea. Carbohydrate, fat and proteins

  6. Spectrum response and analysis of 77 GHz band collective Thomson scattering diagnostic for bulk and fast ions in LHD plasmas

    NASA Astrophysics Data System (ADS)

    Nishiura, M.; Kubo, S.; Tanaka, K.; Seki, R.; Ogasawara, S.; Shimozuma, T.; Okada, K.; Kobayashi, S.; Mutoh, T.; Kawahata, K.; Watari, T.; LHD Experiment Group; Saito, T.; Tatematsu, Y.; Korsholm, S. B.; Salewski, M.

    2014-02-01

    A collective Thomson scattering (CTS) diagnostic was developed and used to measure the bulk and fast ions originating from 180 keV neutral beams in the Large Helical Device (LHD). Electromagnetic waves from a gyrotron at 77 GHz with 1 MW power output function as both the probe and electron cyclotron heating beam. To clarify the diagnostic applicability of the gyrotron in the 77 GHz frequency band, we investigated the dependence of the probe and receiver beam trajectories in plasmas with high electron densities of (4-5) × 1019 m-3 and low electron densities of (1-2) × 1019 m-3. At high density, a stray radiation component was observed in the CTS spectrum whereas it was negligibly small at low density. The CTS spectrum was measured and analysed after the in situ beam alignment using a beam scan. Qualitatively, the CTS spectrogram shows consistent response to ion temperatures of 1-2 keV for electron densities of (1-2) × 1019 m-3 and electron temperatures of 2-4 keV. The measured CTS spectrum shows an asymmetric shape at the foot of the bulk-ion region during the injection of 180 keV fast ions. This shape is explained by the fast-ion distribution in the velocity space (v‖, v⊥) based on Monte Carlo simulation results. The analysis method of the CTS spectra is used to evaluate the ion temperature and fast-ion velocity distribution from the measured CTS data.

  7. Physical processes taking place in dense plasma focus devices at the interaction of hot plasma and fast ion streams with materials under test

    NASA Astrophysics Data System (ADS)

    Gribkov, V. A.

    2015-06-01

    The dense plasma focus (DPF) device represents a source of powerful streams of penetrating radiations (hot plasma, fast electron and ion beams, x-rays and neutrons) of ns-scale pulse durations. Power flux densities of the radiation types may reach in certain cases the values up to 1013 W cm  -  2. They are widely used at present time in more than 30 labs in the world in the field of radiation material science. Areas of their implementations are testing of the materials perspective for use in modern fusion reactors (FR) of both types, modification of surface layers with an aim of improvements their properties, production of some nanostructures on their surface, and so on. To use a DPF correctly in these applications it is important to understand the mechanisms of generation of the above-mentioned radiations, their dynamics inside and outside of the pinch and processes of interaction of these streams with targets. In this paper, the most important issues on the above matter we discuss in relation to the cumulative hot plasma stream and the beam of fast ions with illustration of experimental results obtained at four DPF devices ranged in the limits of bank energies from 1 kJ to 1 MJ. Among them mechanisms of a jet formation, a current abruption phenomenon, a super-Alfven ion beam propagation inside and outside of DPF plasma, generation of secondary plasma and formation of shock waves in plasma and inside a solid-state target, etc. Nanosecond time-resolved techniques (electric probes, laser interferometry, frame self-luminescent imaging, x-ray/neutron probes, etc) give an opportunity to investigate the above-mentioned events and to observe the process of interaction of the radiation types with targets. After irradiation, we analyzed the specimens by contemporary instrumentation: optical and scanning electron microscopy, local x-ray spectral and structure analysis, atomic force microscopy, the portable x-ray diffractometer that combines x-ray single

  8. Two Dual Ion Spectrometer Flight Units of the Fast Plasma Instrument Suite (FPI) for the Magnetospheric Multiscale Mission (MMS)

    NASA Technical Reports Server (NTRS)

    Adams, Mitzi

    2014-01-01

    Two Dual Ion Spectrometer flight units of the Fast Plasma Instrument Suite (FPI) for the Magnetospheric Multiscale Mission (MMS) have returned to MSFC for flight testing. Anticipated to begin on June 30, tests will ensue in the Low Energy Electron and Ion Facility of the Heliophysics and Planetary Science Office (ZP13), managed by Dr. Victoria Coffey of the Natural Environments Branch of the Engineering Directorate (EV44). The MMS mission consists of four identical spacecraft, whose purpose is to study magnetic reconnection in the boundary regions of Earth's magnetosphere.

  9. Slow-time-scale magnetic fields driven by fast-time-scale waves in an underdense relativistic Vlasov plasma

    NASA Astrophysics Data System (ADS)

    Zhu, Shao-ping; He, X. T.; Zheng, C. Y.

    2001-01-01

    Slow-time-scale magnetic fields driven by fast-time-scale electromagnetic waves or plasma waves are examined from the perspective of the Vlasov-Maxwell equations for a relativistic Vlasov plasma. An equation for slow-time-scale magnetic field is obtained. The field proposed in the present paper is a result of wave-wave beating which drives a solenoidal current. The magnitude of the slow-time-scale magnetic field proposed here can be as high as 20 MG at the critical surface for a laser intensity I=1018W/cm2 at wavelength λ0=1.05 μm. The predicted magnetic field is observed in two-dimensional particle simulations presented here.

  10. ITER Plasma at Ion Cyclotron Frequency Domain: The Fusion Alpha Particles Diagnostics Based on the Stimulated Raman Scattering of Fast Magnetosonic Wave off High Harmonic Ion Bernstein Modes

    NASA Astrophysics Data System (ADS)

    Stefan, V. Alexander

    2014-10-01

    A novel method for alpha particle diagnostics is proposed. The theory of stimulated Raman scattering, SRS, of the fast wave and ion Bernstein mode, IBM, turbulence in multi-ion species plasmas, (Stefan University Press, La Jolla, CA, 2008). is utilized for the diagnostics of fast ions, (4)He (+2), in ITER plasmas. Nonlinear Landau damping of the IBM on fast ions near the plasma edge leads to the space-time changes in the turbulence level, (inverse alpha particle channeling). The space-time monitoring of the IBM turbulence via the SRS techniques may prove efficient for the real time study of the fast ion velocity distribution function, spatial distribution, and transport. Supported by Nikola Tesla Labs., La Jolla, CA 92037.

  11. A rotating directional probe for the measurements of fast ion losses and plasma rotation at Tokamak Experiment for Technology Oriented Research.

    PubMed

    Rack, M; Liang, Y; Jaegers, H; Assmann, J; Satheeswaran, G; Xu, Y; Pearson, J; Yang, Y; Denner, P; Zeng, L

    2013-08-01

    This work discusses a new directional probe designed for measurements of fast ion losses and the plasma rotation with a high angular resolution in magnetically confined plasmas. Directional and especially Mach probes are commonly used diagnostics for plasma flow measurements, and their applicability for the fast ion losses detection has been demonstrated. A limitation of static Mach probes is their low angular resolution. At the Tokamak Experiment for Technology Oriented Research, the angular resolution is strongly restricted by the finite number of available measurement channels. In a dynamic plasma, where instabilities can lead to local changes of the field line pitch-angle, plasma flow, or fast ion losses, a low angular resolution makes a precise data analysis difficult and reduces the quality of the measured data. The new probe design, the rotating directional probe, combines the features of early directional probes and Mach probes. It consists of two radially aligned arrays of nine Langmuir probe pins with each array facing opposite directions. During the measurement the probe head rotates along its axis to measure the ion saturation current from all directions. As a result, the rotating directional probe simultaneously provides an angular dependent plasma flow and fast ion losses measurement at different radial positions. Based on the angular dependent data, a precise determination of the current density is made. In addition, the simultaneous measurement of the ion saturation current at different radial positions allows for resolving radially varying field line pitch-angles and identifying the radial dynamic of processes like fast ion losses.

  12. A fast and sensitive method for the determination of nitrite in human plasma by capillary electrophoresis with fluorescence detection.

    PubMed

    Wang, Xu; Adams, Erwin; Van Schepdael, Ann

    2012-08-15

    Analysis of nitrite, the indicator of nitric oxide (NO) generation in vivo, provides a useful tool to study NO synthesis in vivo. A fast and sensitive fluorometric CE method was developed for determination of nitrite in human plasma through its derivatization with 2,3-diaminonaphthalene (DAN). Nitrite in human plasma was easily reacted with DAN under acid conditions to yield the highly fluorescent 2,3-naphthotriazole (NAT). Fluorescence detection was optimized to achieve subnanomolar detection which allows a direct analysis of plasma samples unlike most CE-UV methods using sample stacking. Acetonitrile was used to remove the protein. Short-end injection and a high voltage (-30 kV) were used to shorten the analysis time. The good separation was achieved with 20 mM borate buffer at pH 9.23. The separation of NAT was obtained within 1.4 min. The deproteinized plasma sample was injected hydrodynamically for 5s at -50 mbar into a 60 cm × 75 μm internal diameter uncoated fused-silica capillary. Excitation wavelength was selected with a broad-band filter (240-400 nm), and the emitted light was measured at 418 nm by the use of a cutoff filter. A good linearity (R(2)=0.9975) was obtained in the range from 2 to 500 nM. The detection limit of nitrite was 0.6 nM in original plasma samples, which is 750 times lower than our previous CE-UV method. The developed fluorometric CE method offers the advantages of more simple system and lower cost compared with the current fluorometric HPLC methods without losing sensitivity. The detected mean nitrite concentration in human plasma by this method was consistent with the most frequently reported values. PMID:22841058

  13. On resonant ICRF absorption in three-ion component plasmas: a new promising tool for fast ion generation

    NASA Astrophysics Data System (ADS)

    Kazakov, Ye. O.; Van Eester, D.; Dumont, R.; Ongena, J.

    2015-03-01

    We report on a very efficient ion-cyclotron-resonance-frequency (ICRF) absorption scheme (Z)-Y-X, which hinges on the presence of three ion species residing in the plasma. A mode conversion (cutoff-resonance) layer is well known to appear in two-ion species plasmas. If the location of the L-cutoff in Y-X plasmas, which can be controlled by varying the Y : X density ratio, almost coincides with the fundamental cyclotron resonance of the third ion species Z (resonant absorber), the latter—albeit present only in trace quantities—is shown to absorb almost all the incoming RF power. A quantitative criterion for the resonant Y : X plasma composition is derived and a few numerical examples are given. Since the absorbed power per resonant particle is much larger than for any other ICRF scheme, the here discussed scenarios are particularly promising for fast particle generation. Their possible application as a source of high-energy ions for the stellarator W7-X and to mimic alpha particles during the non-activated phase of ITER tokamak is briefly discussed.

  14. Nuclear reactor shutdown control rod assembly

    DOEpatents

    Bilibin, Konstantin

    1988-01-01

    A temperature responsive, self-actuated nuclear reactor shutdown control rod assembly 10. The upper end 18 of a lower drive line 17 fits within the lower end of an upper drive line 12. The lower end (not shown) of the lower drive line 17 is connected to a neutron absorber. During normal temperature conditions the lower drive line 17 is supported by detent means 22,26. When an overtemperature condition occurs thermal actuation means 34 urges ring 26 upwardly sufficiently to allow balls 22 to move radially outwardly thereby allowing lower drive line 17 to move downwardly toward the core of the nuclear reactor resulting in automatic reduction of the reactor powder.

  15. Self-actuating reactor shutdown system

    DOEpatents

    Barrus, Donald M.; Brummond, Willian A; Peterson, Leslie F.

    1988-01-01

    A control system for the automatic or self-actuated shutdown or "scram" of a nuclear reactor. The system is capable of initiating scram insertion by a signal from the plant protection system or by independent action directly sensing reactor conditions of low-flow or over-power. Self-actuation due to a loss of reactor coolant flow results from a decrease of pressure differential between the upper and lower ends of an absorber element. When the force due to this differential falls below the weight of the element, the element will fall by gravitational force to scram the reactor. Self-actuation due to high neutron flux is accomplished via a valve controlled by an electromagnet and a thermionic diode. In a reactor over-power, the diode will be heated to a change of state causing the electromagnet to be shorted thereby actuating the valve which provides the changed flow and pressure conditions required for scramming the absorber element.

  16. Magnetic latch trigger for inherent shutdown assembly

    DOEpatents

    Sowa, Edmund S.

    1976-01-01

    An inherent shutdown assembly for a nuclear reactor is provided. A neutron absorber is held ready to be inserted into the reactor core by a magnetic latch. The latch includes a magnet whose lines of force are linked by a yoke of material whose Curie point is at the critical temperature of the reactor at which the neutron absorber is to be inserted into the reactor core. The yoke is in contact with the core coolant or fissionable material so that when the coolant or the fissionable material increase in temperature above the Curie point the yoke loses its magnetic susceptibility and the magnetic link is broken, thereby causing the absorber to be released into the reactor core.

  17. The Shutdown Dissociation Scale (Shut-D)

    PubMed Central

    Schalinski, Inga; Schauer, Maggie; Elbert, Thomas

    2015-01-01

    The evolutionary model of the defense cascade by Schauer and Elbert (2010) provides a theoretical frame for a short interview to assess problems underlying and leading to the dissociative subtype of posttraumatic stress disorder. Based on known characteristics of the defense stages “fright,” “flag,” and “faint,” we designed a structured interview to assess the vulnerability for the respective types of dissociation. Most of the scales that assess dissociative phenomena are designed as self-report questionnaires. Their items are usually selected based on more heuristic considerations rather than a theoretical model and thus include anything from minor dissociative experiences to major pathological dissociation. The shutdown dissociation scale (Shut-D) was applied in several studies in patients with a history of multiple traumatic events and different disorders that have been shown previously to be prone to symptoms of dissociation. The goal of the present investigation was to obtain psychometric characteristics of the Shut-D (including factor structure, internal consistency, retest reliability, predictive, convergent and criterion-related concurrent validity). A total population of 225 patients and 68 healthy controls were accessed. Shut-D appears to have sufficient internal reliability, excellent retest reliability, high convergent validity, and satisfactory predictive validity, while the summed score of the scale reliably separates patients with exposure to trauma (in different diagnostic groups) from healthy controls. The Shut-D is a brief structured interview for assessing the vulnerability to dissociate as a consequence of exposure to traumatic stressors. The scale demonstrates high-quality psychometric properties and may be useful for researchers and clinicians in assessing shutdown dissociation as well as in predicting the risk of dissociative responding. PMID:25976478

  18. Letter report seismic shutdown system failure mode and effect analysis

    SciTech Connect

    KECK, R.D.

    1999-09-01

    The Supply Ventilation System Seismic Shutdown ensures that the 234-52 building supply fans, the dry air process fans and vertical development calciner are shutdown following a seismic event. This evaluates the failure modes and determines the effects of the failure modes.

  19. 30 CFR 250.603 - Emergency shutdown system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Emergency shutdown system. 250.603 Section 250.603 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR... Operations § 250.603 Emergency shutdown system. When well-workover operations are conducted on a well...

  20. 30 CFR 250.503 - Emergency shutdown system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... where there are other hydrocarbon-producing wells or other hydrocarbon flow, an emergency shutdown... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Emergency shutdown system. 250.503 Section 250.503 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE...

  1. 30 CFR 250.603 - Emergency shutdown system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Emergency shutdown system. 250.603 Section 250.603 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR... Operations § 250.603 Emergency shutdown system. When well-workover operations are conducted on a well...

  2. 30 CFR 250.503 - Emergency shutdown system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... hydrocarbon-producing wells or other hydrocarbon flow, an emergency shutdown system (ESD) manually controlled... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Emergency shutdown system. 250.503 Section 250.503 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS...

  3. 30 CFR 250.603 - Emergency shutdown system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Emergency shutdown system. 250.603 Section 250.603 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR... Operations § 250.603 Emergency shutdown system. When well-workover operations are conducted on a well...

  4. 30 CFR 250.603 - Emergency shutdown system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Emergency shutdown system. 250.603 Section 250.603 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF... Well-Workover Operations § 250.603 Emergency shutdown system. When well-workover operations...

  5. 30 CFR 250.503 - Emergency shutdown system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... where there are other hydrocarbon-producing wells or other hydrocarbon flow, an emergency shutdown... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Emergency shutdown system. 250.503 Section 250.503 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE...

  6. 30 CFR 250.503 - Emergency shutdown system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... where there are other hydrocarbon-producing wells or other hydrocarbon flow, an emergency shutdown... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Emergency shutdown system. 250.503 Section 250.503 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE...

  7. 30 CFR 250.503 - Emergency shutdown system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Emergency shutdown system. 250.503 Section 250.503 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF... Well-Completion Operations § 250.503 Emergency shutdown system. When well-completion operations...

  8. 46 CFR 111.33-7 - Alarms and shutdowns.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Alarms and shutdowns. 111.33-7 Section 111.33-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Semiconductor Rectifier Systems § 111.33-7 Alarms and shutdowns. Each power...

  9. 46 CFR 111.33-7 - Alarms and shutdowns.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Alarms and shutdowns. 111.33-7 Section 111.33-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Semiconductor Rectifier Systems § 111.33-7 Alarms and shutdowns. Each power...

  10. 46 CFR 111.33-7 - Alarms and shutdowns.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Alarms and shutdowns. 111.33-7 Section 111.33-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Semiconductor Rectifier Systems § 111.33-7 Alarms and shutdowns. Each power...

  11. 46 CFR 111.33-7 - Alarms and shutdowns.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Alarms and shutdowns. 111.33-7 Section 111.33-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Semiconductor Rectifier Systems § 111.33-7 Alarms and shutdowns. Each power...

  12. 46 CFR 111.33-7 - Alarms and shutdowns.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Alarms and shutdowns. 111.33-7 Section 111.33-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Semiconductor Rectifier Systems § 111.33-7 Alarms and shutdowns. Each power...

  13. Lithium ion sources for investigations of fast ion transport in magnetized plasmas

    SciTech Connect

    Zhang, Y.; Boehmer, H.; Heidbrink, W. W.; McWilliams, R.; Leneman, D.; Vincena, S.

    2007-01-15

    In order to study the interaction of ions of intermediate energies with plasma fluctuations, two plasma immersible lithium ion sources, based on solid-state thermionic emitters (Li aluminosilicate) were developed. Compared to discharge based ion sources, they are compact, have zero gas load, small energy dispersion, and can be operated at any angle with respect to an ambient magnetic field of up to 4.0 kG. Beam energies range from 400 eV to 2.0 keV with typical beam current densities in the 1 mA/cm{sup 2} range. Because of the low ion mass, beam velocities of 100-300 km/s are in the range of Alfven speeds in typical helium plasmas in the large plasma device.

  14. Lithium ion sources for investigations of fast ion transport in magnetized plasmas.

    PubMed

    Zhang, Y; Boehmer, H; Heidbrink, W W; McWilliams, R; Leneman, D; Vincena, S

    2007-01-01

    In order to study the interaction of ions of intermediate energies with plasma fluctuations, two plasma immersible lithium ion sources, based on solid-state thermionic emitters (Li aluminosilicate) were developed. Compared to discharge based ion sources, they are compact, have zero gas load, small energy dispersion, and can be operated at any angle with respect to an ambient magnetic field of up to 4.0 kG. Beam energies range from 400 eV to 2.0 keV with typical beam current densities in the 1 mAcm(2) range. Because of the low ion mass, beam velocities of 100-300 kms are in the range of Alfven speeds in typical helium plasmas in the large plasma device.

  15. LIF and fast imaging plasma jet characterization relevant for NTP biomedical applications

    NASA Astrophysics Data System (ADS)

    Riès, D.; Dilecce, G.; Robert, E.; Ambrico, P. F.; Dozias, S.; Pouvesle, J.-M.

    2014-07-01

    In the field of biomedical application, many publications report on non-thermal plasma jet potentialities for cell behaviour modifications in cancer treatment, wound healing or sterilization. However most previous plasma jet characterizations were performed when jets expend freely in air. Only recently has the influence of the targeted surface been properly considered. In this work, modifications induced by various types of targets, mimicking the biological samples, in the plasma propagation and production of hydroxyl radicals are evidenced through time-resolved intensified charge-coupled device imaging and laser-induced fluorescence (LIF) measurements. A LIF model, also specifically dedicated to estimate air and water penetration inside the jet, is used and proves to be well adapted to characterize the plasma jet under biomedical application conditions. It is shown that the plasma produced by the plasma gun counter-propagates after impinging the surface which, for the same operating parameters, leads to an increase of almost one order of magnitude in the maximum OH density (from ˜2 × 1013 cm-3 for open-air propagation to ˜1 × 1014 cm-3 for a grounded metal target). The nature of the target, especially its electrical conductivity, as well as gas flow rate and voltage amplitude are playing a key role in the production of hydroxyl radicals. The strong interplay between gas flow dynamics and plasma propagation is here confirmed by air and water distribution measurements. The need for a multi-diagnostic approach, as well as great care in setting up the in situ characterization of plasma jets, is here emphasized. Special attention must not only be paid to voltage amplitude and gas flow rate but also to the nature, humidity and conductivity of the target.

  16. Plasma FGF21 concentrations, adipose fibroblast growth factor receptor-1 and β-klotho expression decrease with fasting in northern elephant seals.

    PubMed

    Suzuki, Miwa; Lee, Andrew Y; Vázquez-Medina, José Pablo; Viscarra, Jose A; Crocker, Daniel E; Ortiz, Rudy M

    2015-05-15

    Fibroblast growth factor (FGF)-21 is secreted from the liver, pancreas, and adipose in response to prolonged fasting/starvation to facilitate lipid and glucose metabolism. Northern elephant seals naturally fast for several months, maintaining a relatively elevated metabolic rate to satisfy their energetic requirements. Thus, to better understand the impact of prolonged food deprivation on FGF21-associated changes, we analyzed the expression of FGF21, FGF receptor-1 (FGFR1), β-klotho (KLB; a co-activator of FGFR) in adipose, and plasma FGF21, glucose and 3-hydroxybutyrate in fasted elephant seal pups. Expression of FGFR1 and KLB mRNA decreased 98% and 43%, respectively, with fasting duration. While the 80% decrease in mean adipose FGF21 mRNA expression with fasting did not reach statistical significance, it paralleled the 39% decrease in plasma FGF21 concentrations suggesting that FGF21 is suppressed with fasting in elephant seals. Data demonstrate an atypical response of FGF21 to prolonged fasting in a mammal suggesting that FGF21-mediated mechanisms have evolved differentially in elephant seals. Furthermore, the typical fasting-induced, FGF21-mediated actions such as the inhibition of lipolysis in adipose may not be required in elephant seals as part of a naturally adapted mechanism to support their unique metabolic demands during prolonged fasting.

  17. Plasma FGF21 Concentrations, Adipose Fibroblast Growth Factor Receptor-1 and β-Klotho Expression Decrease with Fasting in Northern Elephant Seals

    PubMed Central

    Suzuki, Miwa; Lee, Andrew; Vázquez-Medina, Jose Pablo; Viscarra, Jose A.; Crocker, Daniel E.; Ortiz, Rudy M.

    2015-01-01

    Fibroblast growth factor (FGF)-21 is secreted from the liver, pancreas, and adipose in response to prolonged fasting/starvation to facilitate lipid and glucose metabolism. Northern elephant seals naturally fast for several months, maintaining a relatively elevated metabolic rate to satisfy their energetic requirements. Thus, to better understand the impact of prolonged food deprivation on FGF21-associated changes, we analyzed the expression of FGF21, FGF receptor-1 (FGFR1), β-klotho (KLB; a co-activator of FGFR) in adipose, and plasma FGF21, glucose and 3-hydroxybutyrate in fasted elephant seal pups. Expression of FGFR1 and KLB mRNA decreased 98% and 43%, respectively, with fasting duration. While the 80% decrease in mean adipose FGF21 mRNA expression with fasting did not reach statistical significance, it paralleled the 39% decrease in plasma FGF21 concentrations suggesting that FGF21 is suppressed with fasting in elephant seals. Data demonstrate an atypical response of FGF21 to prolonged fasting in a mammal suggesting that FGF21-mediated mechanisms have evolved differentially in elephant seals. Furthermore, the typical fasting-induced, FGF21-mediated actions such as the inhibition of lipolysis in adipose may not be required in elephant seals as part of a naturally adapted mechanism to support their unique metabolic demands during prolonged fasting. PMID:25857751

  18. Plasma FGF21 concentrations, adipose fibroblast growth factor receptor-1 and β-klotho expression decrease with fasting in northern elephant seals.

    PubMed

    Suzuki, Miwa; Lee, Andrew Y; Vázquez-Medina, José Pablo; Viscarra, Jose A; Crocker, Daniel E; Ortiz, Rudy M

    2015-05-15

    Fibroblast growth factor (FGF)-21 is secreted from the liver, pancreas, and adipose in response to prolonged fasting/starvation to facilitate lipid and glucose metabolism. Northern elephant seals naturally fast for several months, maintaining a relatively elevated metabolic rate to satisfy their energetic requirements. Thus, to better understand the impact of prolonged food deprivation on FGF21-associated changes, we analyzed the expression of FGF21, FGF receptor-1 (FGFR1), β-klotho (KLB; a co-activator of FGFR) in adipose, and plasma FGF21, glucose and 3-hydroxybutyrate in fasted elephant seal pups. Expression of FGFR1 and KLB mRNA decreased 98% and 43%, respectively, with fasting duration. While the 80% decrease in mean adipose FGF21 mRNA expression with fasting did not reach statistical significance, it paralleled the 39% decrease in plasma FGF21 concentrations suggesting that FGF21 is suppressed with fasting in elephant seals. Data demonstrate an atypical response of FGF21 to prolonged fasting in a mammal suggesting that FGF21-mediated mechanisms have evolved differentially in elephant seals. Furthermore, the typical fasting-induced, FGF21-mediated actions such as the inhibition of lipolysis in adipose may not be required in elephant seals as part of a naturally adapted mechanism to support their unique metabolic demands during prolonged fasting. PMID:25857751

  19. The Effect of LC-MS Data Preprocessing Methods on the Selection of Plasma Biomarkers in Fed vs. Fasted Rats.

    PubMed

    Gürdeniz, Gözde; Kristensen, Mette; Skov, Thomas; Dragsted, Lars O

    2012-01-18

    The metabolic composition of plasma is affected by time passed since the last meal and by individual variation in metabolite clearance rates. Rat plasma in fed and fasted states was analyzed with liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QTOF) for an untargeted investigation of these metabolite patterns. The dataset was used to investigate the effect of data preprocessing on biomarker selection using three different softwares, MarkerLynxTM, MZmine, XCMS along with a customized preprocessing method that performs binning of m/z channels followed by summation through retention time. Direct comparison of selected features representing the fed or fasted state showed large differences between the softwares. Many false positive markers were obtained from custom data preprocessing compared with dedicated softwares while MarkerLynxTM provided better coverage of markers. However, marker selection was more reliable with the gap filling (or peak finding) algorithms present in MZmine and XCMS. Further identification of the putative markers revealed that many of the differences between the markers selected were due to variations in features representing adducts or daughter ions of the same metabolites or of compounds from the same chemical subclasses, e.g., lyso-phosphatidylcholines (LPCs) and lyso-phosphatidylethanolamines (LPEs). We conclude that despite considerable differences in the performance of the preprocessing tools we could extract the same biological information by any of them. Carnitine, branched-chain amino acids, LPCs and LPEs were identified by all methods as markers of the fed state whereas acetylcarnitine was abundant during fasting in rats.

  20. BENCHMARKING FAST-TO-ALFVEN MODE CONVERSION IN A COLD MAGNETOHYDRODYNAMIC PLASMA

    SciTech Connect

    Cally, Paul S.; Hansen, Shelley C. E-mail: shelley.hansen@monash.edu

    2011-09-10

    Alfven waves may be generated via mode conversion from fast magnetoacoustic waves near their reflection level in the solar atmosphere, with implications both for coronal oscillations and for active region helioseismology. In active regions this reflection typically occurs high enough that the Alfven speed a greatly exceeds the sound speed c, well above the a = c level where the fast and slow modes interact. In order to focus on the fundamental characteristics of fast/Alfven conversion, stripped of unnecessary detail, it is therefore useful to freeze out the slow mode by adopting the gravitationally stratified cold magnetohydrodynamic model c {yields} 0. This provides a benchmark for fast-to-Alfven mode conversion in more complex atmospheres. Assuming a uniform inclined magnetic field and an exponential Alfven speed profile with density scale height h, the Alfven conversion coefficient depends on three variables only: the dimensionless transverse-to-the-stratification wavenumber {kappa} = kh, the magnetic field inclination from the stratification direction {theta}, and the polarization angle {phi} of the wavevector relative to the plane containing the stratification and magnetic field directions. We present an extensive exploration of mode conversion in this parameter space and conclude that near-total conversion to outward-propagating Alfven waves typically occurs for small {theta} and large {phi} (80{sup 0}-90{sup 0}), though it is absent entirely when {theta} is exactly zero (vertical field). For wavenumbers of helioseismic interest, the conversion region is broad enough to encompass the whole chromosphere.

  1. Fasting modifies Aroclor 1254 impact on plasma cortisol, glucose and lactate responses to a handling disturbance in Arctic charr

    USGS Publications Warehouse

    Jorgensen, E.H.; Vijayan, M.M.; Aluru, N.; Maule, A.G.

    2002-01-01

    Integrated effects of polychlorinated biphenyl (PCB) and nutritional status on responses to handling disturbance were investigated in the Arctic charr (Salvelinus alpinus). The fish were orally contaminated with Aroclor 1254 and held either with or without food for 5 months before they were subjected to a 10-min handling disturbance. Food-deprived fish were given 0, 1, 10 or 100 mg PCB kg-1 and the fed fish 0 or 100 mg PCB kg-1. Plasma cortisol, glucose and lactate levels were measured at 0 (pre-handling), 1, 3, 6 and 23 h after the handling disturbance. Food-deprived control fish had elevated plasma cortisol levels compared with fed fish before handling. These basal cortisol levels were suppressed by PCB in food-deprived fish, and elevated by PCB in fed fish. The immediate cortisol and glucose responses to handling disturbance were suppressed by PCB in a dose-dependent way in food-deprived fish. Although these responses were also lowered by PCB in the fed fish, the effect was much less pronounced than in food-deprived fish. There were only minor effects on plasma lactate responses. Our findings suggest that the stress responses of the Arctic charr are compromised by PCB and that the long-term fasting, typical of high-latitude fish, makes these species particularly sensitive to organochlorines such as PCB. ?? 2002 Elsevier Science Inc. All rights reserved.

  2. Impact of Pre-Plasma on Fast Electron Generation and Transport from Short Pulse High Intensity Lasers

    NASA Astrophysics Data System (ADS)

    Peebles, J.; McGuffey, C.; Krauland, C.; Jarrott, L. C.; Sorokovikova, A.; Qiao, B.; Krasheninnikov, S.; Beg, F. N.; Wei, M. S.; Park, J.; Link, A.; Chen, H.; McLean, H. S.; Wagner, C.; Minello, V.; McCary, E.; Meadows, A.; Spinks, M.; Gaul, E.; Dyer, G.; Hegelich, B. M.; Martinez, M.; Donovan, M.; Ditmire, T.

    2014-10-01

    We present the results and analysis from recent short pulse laser matter experiments using the Texas Petawatt Laser to study the impact of pre-plasma on fast electron generation and transport. The experimental setup consisted of 3 separate beam elements: a main, high intensity, short pulse beam for the interaction, a secondary pulse of equal intensity interacting with a separate thin foil target to generate protons for side-on proton imaging and a third, low intensity, wider beam to generate a varied scale length pre-plasma. The main target consisted of a multilayer planar Al foil with a buried Cu fluor layer. The electron beam was characterized with multiple diagnostics, including several bremsstrahlung spectrometers, magnetic electron spectrometers and Cu-K α imaging. The protons from the secondary target were used to image the fields on the front of the target in the region of laser plasma interaction. Features seen in the interaction region by these protons will be presented along with characteristics of the generated electron beam. This work performed under the auspices of the US DOE under Contracts DE-FOA-0000583 (FES, NNSA).

  3. Fast, simple, and sensitive high-performance liquid chromatography method for measuring vitamins A and E in human blood plasma.

    PubMed

    Yuan, Chao; Burgyan, Maria; Bunch, Dustin R; Reineks, Edmunds; Jackson, Raymond; Steinle, Roxanne; Wang, Sihe

    2014-09-01

    Vitamins A and E are fat-soluble vitamins that play important roles in several physiological processes. Monitoring their concentrations is needed to detect deficiency and guide therapy. In this study, we developed a high-performance liquid chromatography method to measure the major forms of vitamin A (retinol) and vitamin E (α-tocopherol and γ-tocopherol) in human blood plasma. Vitamins A and E were extracted with hexane and separated on a reversed-phase column using methanol as the mobile phase. Retinol was detected by ultraviolet absorption, whereas tocopherols were detected by fluorescence emission. The chromatographic cycle time was 4.0 min per sample. The analytical measurement range was 0.03-5.14, 0.32-36.02, and 0.10-9.99 mg/L for retinol, α-tocopherol, and γ-tocopherol, respectively. Intr-aassay and total coefficient of variation were <6.0% for all compounds. This method was traceable to standard reference materials offered by the National Institute of Standards and Technology. Reference intervals were established using plasma samples collected from 51 healthy adult donors and were found to be 0.30-1.20, 6.0-23.0, and 0.3-3.2 mg/L for retinol, α-tocopherol, and γ-tocopherol, respectively. In conclusion, we developed and validated a fast, simple, and sensitive high-performance liquid chromatography method for measuring the major forms of vitamins A and E in human plasma.

  4. Fuel cell system logic for differentiating between rapid and normal shutdown commands

    DOEpatents

    Keskula, Donald H.; Doan, Tien M.; Clingerman, Bruce J.

    2000-01-01

    A method of controlling the operation of a fuel cell system wherein each shutdown command for the system is subjected to decision logic which determines whether the command should be a normal shutdown command or rapid shutdown command. If the logic determines that the shutdown command should be a normal shutdown command, then the system is shutdown in a normal step-by-step process in which the hydrogen stream is consumed within the system. If the logic determines that the shutdown command should be a rapid shutdown command, the hydrogen stream is removed from the system either by dumping to atmosphere or routing to storage.

  5. Plasma produced by impacts of fast dust particles on a thin film

    NASA Technical Reports Server (NTRS)

    Auer, Siegfried

    1994-01-01

    The thin-film impact plasma detector was pioneered by Berg for detecting small cosmic dust particles and measuring their approximate velocities in a time-of-flight configuration. While Berg's device was highly successful in establishing the flux of interplanetary dust, the accuracy of measuring the velocities of individual particles was a moderate 18 percent in magnitude and 27 degrees in angle. A much greater accuracy of less than or equal to 1 percent in determining the velocity components appears desirable in order to associate a particle with its parent body. In order to meet that need, research was initiated to determine if a thin-film detector can be designed to provide such accurate velocity measurements. Previous laboratory investigations of the impact plasma uncovered two difficulties: (1) solid or liquid spray is ejected from a primary impact crater and strikes neighboring walls where it produces secondary impact craters and plasma clouds; as a result, both quantity and time of detection of the plasma can vary significantly with the experiment configuration. Particles from an accelerator rarely have speeds v greater than or equal to 10-15 km/s, while cosmic dust particles typically impact at v = 10-72 km/s. The purpose of the tests discussed in this paper was to resolve the two difficulties mentioned. That is, the experiment configuration was designed to reduce the contribution of plasma from secondary impacts. In addition, most particles with v less than or equal to 25 km/s and all particles with v less than or equal to 10 km/s were eliminated from the beam.

  6. Ion-induced gamma-ray detection of fast ions escaping from fusion plasmas

    SciTech Connect

    Nishiura, M. Mushiake, T.; Doi, K.; Wada, M.; Taniike, A.; Matsuki, T.; Shimazoe, K.; Yoshino, M.; Nagasaka, T.; Tanaka, T.; Kisaki, M.; Fujimoto, Y.; Fujioka, K.; Yamaoka, H.; Matsumoto, Y.

    2014-11-15

    A 12 × 12 pixel detector has been developed and used in a laboratory experiment for lost fast-ion diagnostics. With gamma rays in the MeV range originating from nuclear reactions {sup 9}Be(α, nγ){sup 12}C, {sup 9}Be(d, nγ){sup 12}C, and {sup 12}C(d, pγ){sup 13}C, a high purity germanium (HPGe) detector measured a fine-energy-resolved spectrum of gamma rays. The HPGe detector enables the survey of background-gamma rays and Doppler-shifted photo peak shapes. In the experiments, the pixel detector produces a gamma-ray image reconstructed from the energy spectrum obtained from total photon counts of irradiation passing through the detector's lead collimator. From gamma-ray image, diagnostics are able to produce an analysis of the fast ion loss onto the first wall in principle.

  7. Effect of fast positive ions incident on caesiated plasma grid of negative ion source

    SciTech Connect

    Bacal, M.

    2012-02-15

    This paper describes the effect on negative ion formation on a caesiated surface of the backscattering of positive ions approaching it with energy of a few tens of eV. For a positive ion energy of 45 eV, the surface produced negative ion current density due to these fast positive ions is 12 times larger than that due to thermal atoms, thus dominating the negative ion surface production instead of the thermal atoms, as considered until now.

  8. Excitation mechanism of hydrogen Balmer lines in a fast plasma-mixing device

    NASA Astrophysics Data System (ADS)

    Kirkici, Hulya

    1995-06-01

    The emission of hydrogen Balmer series and the laser oscillation of Hβ at 486.12 nm and Hγ at 434.06 nm in hydrogen-neon discharge operated in a pulsed mode have been reported by Dezenber and Willett [IEEE J. Quantum Electron. QE-7, 491 (1971)]. In their work, a ``two step'' excitation of molecular hydrogen to molecular ionic states, followed by dissociation of hydrogen to excited atomic species, was proposed as the main excitation mechanism. The present work was conducted to study the excitation mechanism of the hydrogen Hα line at 656.28 nm in a flowing, afterglow plasma, by using a crossed-beam plasma-mixing device. It was found that the excitation of the Hα line in this device is due to a direct dissociative energy transfer from neon metastables to molecular hydrogen.

  9. SiC detectors for radiation sources characterization and fast plasma diagnostic

    NASA Astrophysics Data System (ADS)

    Cannavò, A.; Torrisi, L.

    2016-09-01

    Semiconductor detectors based on SiC have been investigated to characterize the radiations (photons and particles) emitted from different sources, such as radioactive sources, electron guns, X-ray tubes and laser-generated plasmas. Detectors show high response velocity, low leakage current, high energy gap and high radiation hardness. Their high detection efficiency permits to use the detectors in spectroscopic mode and in time-of-flight (TOF) approach, generally employed to monitor low and high radiation fluxes, respectively. Using the laser start signal, they permit to study the properties of the generated plasma in vacuum by measuring accurately the particle velocity and energy using pulsed lasers at low and high intensities. Possible applications will be reported and discussed.

  10. Ultra-intense, short pulse laser-plasma interactions with applications to the fast ignitor

    SciTech Connect

    Wilks, S.C.; Kruer, W.L.; Young, P.E.; Hammer, J.; Tabak, M.

    1995-04-01

    Due to the advent of chirped pulse amplification (CPA) as an efficient means of creating ultra-high intensity laser light (I > 5{times}10{sup 17} W/cm{sup 2}) in pulses less than a few picoseconds, new ideas for achieving ignition and gain in DT targets with less than 1 megajoule of input energy are currently being pursued. Two types of powerful lasers are employed in this scheme: (1) channeling beams and (2) ignition beams. The current state of laser-plasma interactions relating to this fusion scheme will be discussed. In particular, plasma physics issues in the ultra-intense regime are crucial to the success of this scheme. We compare simulation and experimental results in this highly nonlinear regime.

  11. Acoustic mode driven by fast electrons in TJ-II Electron Cyclotron Resonance plasmas

    NASA Astrophysics Data System (ADS)

    Sun, B. J.; Ochando, M. A.; López-Bruna, D.

    2016-08-01

    Intense harmonic oscillations in radiation signals (δ I/I∼ 5{%}) are commonly observed during Electron Cyclotron Resonance (ECR) heating in TJ-II stellarator plasmas at low line-averaged electron density, 0.15 < \\bar{n}e < 0.6 ×1019 \\text{m}-3 . The frequency agrees with acoustic modes. The poloidal modal structure is compatible with Geodesic Acoustic Modes (GAM) but an n \

  12. FAST TRACK COMMUNICATION: Isolated unstable Weibel modes in unmagnetized plasmas with tunable asymmetry

    NASA Astrophysics Data System (ADS)

    Tautz, R. C.; Lerche, I.

    2007-07-01

    In this paper, an initially unmagnetized pair plasma with asymmetric velocity distributions is investigated where any unstable Weibel mode must be isolated, with discrete values for the growth rates and the unstable wavenumbers. For both a non-relativistic distribution with thermal spread and a high-relativistic two-stream distribution it is shown that isolated modes are excited and that, as the asymmetry tends to zero, the growth rate remains finite, as long as the distribution function is not precisely symmetric.

  13. Fast, hot electron production and ion acceleration in a helicon inductive plasma

    NASA Astrophysics Data System (ADS)

    Sung, Yung-Ta; Li, Yan; Scharer, John E.

    2016-09-01

    A large, time-averaged, double layer-like plasma potential drop of 80 V over several hundred Debye lengths has been observed in the magnetic expansion region on the Madison Helicon eXperiment. It is operated in an inductive mode at 900 W and low argon operating pressures (0.12-0.20 mTorr) in the collisionless regime. The plasma space potential drop is due to the formation of a double layer-like structure in the magnetic expansion region and is much higher than the potential drop caused by a Boltzmann expansion. With the plasma potential drop, a locally negative potential ion hole region at lower pressures with a higher electron density than ion density has been observed just the downstream of the potential drop region. Two-temperature Maxwellian electron distributions with a warm ( T e ≈ 15 eV) and bulk ( T e ≈ 5 eV) components are observed just upstream of the double layer validated through a RF compensated Langmuir probe and an optical emission spectroscopy (OES) diagnostics. In the expansion chamber downstream of the double layer-like potential drop, a single warm ( T e ≈ 15 eV) Maxwellian electron distribution is observed via both the Langmuir probe and OES diagnostics. Ion beam energies of 65 eV are also observed downstream of the potential drop.

  14. A fast rise-rate, adjustable-mass-bit gas puff valve for energetic pulsed plasma experiments.

    PubMed

    Loebner, Keith T K; Underwood, Thomas C; Cappelli, Mark A

    2015-06-01

    A fast rise-rate, variable mass-bit gas puff valve based on the diamagnetic repulsion principle was designed, built, and experimentally characterized. The ability to hold the pressure rise-rate nearly constant while varying the total overall mass bit was achieved via a movable mechanical restrictor that is accessible while the valve is assembled and pressurized. The rise-rates and mass-bits were measured via piezoelectric pressure transducers for plenum pressures between 10 and 40 psig and restrictor positions of 0.02-1.33 cm from the bottom of the linear restrictor travel. The mass-bits were found to vary linearly with the restrictor position at a given plenum pressure, while rise-rates varied linearly with plenum pressure but exhibited low variation over the range of possible restrictor positions. The ability to change the operating regime of a pulsed coaxial plasma deflagration accelerator by means of altering the valve parameters is demonstrated. PMID:26133835

  15. A fast rise-rate, adjustable-mass-bit gas puff valve for energetic pulsed plasma experiments.

    PubMed

    Loebner, Keith T K; Underwood, Thomas C; Cappelli, Mark A

    2015-06-01

    A fast rise-rate, variable mass-bit gas puff valve based on the diamagnetic repulsion principle was designed, built, and experimentally characterized. The ability to hold the pressure rise-rate nearly constant while varying the total overall mass bit was achieved via a movable mechanical restrictor that is accessible while the valve is assembled and pressurized. The rise-rates and mass-bits were measured via piezoelectric pressure transducers for plenum pressures between 10 and 40 psig and restrictor positions of 0.02-1.33 cm from the bottom of the linear restrictor travel. The mass-bits were found to vary linearly with the restrictor position at a given plenum pressure, while rise-rates varied linearly with plenum pressure but exhibited low variation over the range of possible restrictor positions. The ability to change the operating regime of a pulsed coaxial plasma deflagration accelerator by means of altering the valve parameters is demonstrated.

  16. A fast rise-rate, adjustable-mass-bit gas puff valve for energetic pulsed plasma experiments

    NASA Astrophysics Data System (ADS)

    Loebner, Keith T. K.; Underwood, Thomas C.; Cappelli, Mark A.

    2015-06-01

    A fast rise-rate, variable mass-bit gas puff valve based on the diamagnetic repulsion principle was designed, built, and experimentally characterized. The ability to hold the pressure rise-rate nearly constant while varying the total overall mass bit was achieved via a movable mechanical restrictor that is accessible while the valve is assembled and pressurized. The rise-rates and mass-bits were measured via piezoelectric pressure transducers for plenum pressures between 10 and 40 psig and restrictor positions of 0.02-1.33 cm from the bottom of the linear restrictor travel. The mass-bits were found to vary linearly with the restrictor position at a given plenum pressure, while rise-rates varied linearly with plenum pressure but exhibited low variation over the range of possible restrictor positions. The ability to change the operating regime of a pulsed coaxial plasma deflagration accelerator by means of altering the valve parameters is demonstrated.

  17. A fast rise-rate, adjustable-mass-bit gas puff valve for energetic pulsed plasma experiments

    SciTech Connect

    Loebner, Keith T. K. Underwood, Thomas C.; Cappelli, Mark A.

    2015-06-15

    A fast rise-rate, variable mass-bit gas puff valve based on the diamagnetic repulsion principle was designed, built, and experimentally characterized. The ability to hold the pressure rise-rate nearly constant while varying the total overall mass bit was achieved via a movable mechanical restrictor that is accessible while the valve is assembled and pressurized. The rise-rates and mass-bits were measured via piezoelectric pressure transducers for plenum pressures between 10 and 40 psig and restrictor positions of 0.02-1.33 cm from the bottom of the linear restrictor travel. The mass-bits were found to vary linearly with the restrictor position at a given plenum pressure, while rise-rates varied linearly with plenum pressure but exhibited low variation over the range of possible restrictor positions. The ability to change the operating regime of a pulsed coaxial plasma deflagration accelerator by means of altering the valve parameters is demonstrated.

  18. Modeling of fast neutral-beam-generated ion effects on MHD-spectroscopic observations of resistive wall mode stability in DIII-D plasmas

    SciTech Connect

    Turco, F. Hanson, J. M.; Navratil, G. A.; Turnbull, A. D.

    2015-02-15

    Experiments conducted at DIII-D investigate the role of drift kinetic damping and fast neutral beam injection (NBI)-ions in the approach to the no-wall β{sub N} limit. Modelling results show that the drift kinetic effects are significant and necessary to reproduce the measured plasma response at the ideal no-wall limit. Fast neutral-beam ions and rotation play important roles and are crucial to quantitatively match the experiment. In this paper, we report on the model validation of a series of plasmas with increasing β{sub N}, where the plasma stability is probed by active magnetohydrodynamic (MHD) spectroscopy. The response of the plasma to an externally applied field is used to probe the stable side of the resistive wall mode and obtain an indication of the proximity of the equilibrium to an instability limit. We describe the comparison between the measured plasma response and that calculated by means of the drift kinetic MARS-K code [Liu et al., Phys. Plasmas 15, 112503 (2008)], which includes the toroidal rotation, the electron and ion drift-kinetic resonances, and the presence of fast particles for the modelled plasmas. The inclusion of kinetic effects allows the code to reproduce the experimental results within ∼13% for both the amplitude and phase of the plasma response, which is a significant improvement with respect to the undamped MHD-only model. The presence of fast NBI-generated ions is necessary to obtain the low response at the highest β{sub N} levels (∼90% of the ideal no-wall limit). The toroidal rotation has an impact on the results, and a sensitivity study shows that a large variation in the predicted response is caused by the details of the rotation profiles at high β{sub N}.

  19. Fuel cell system shutdown with anode pressure control

    DOEpatents

    Clingerman, Bruce J.; Doan, Tien M.; Keskula, Donald H.

    2002-01-01

    A venting methodology and pressure sensing and vent valving arrangement for monitoring anode bypass valve operating during the normal shutdown of a fuel cell apparatus of the type used in vehicle propulsion systems. During a normal shutdown routine, the pressure differential between the anode inlet and anode outlet is monitored in real time in a period corresponding to the normal closing speed of the anode bypass valve and the pressure differential at the end of the closing cycle of the anode bypass valve is compared to the pressure differential at the beginning of the closing cycle. If the difference in pressure differential at the beginning and end of the anode bypass closing cycle indicates that the anode bypass valve has not properly closed, a system controller switches from a normal shutdown mode to a rapid shutdown mode in which the anode inlet is instantaneously vented by rapid vents.

  20. Fuel Supply Shutdown Facility Interim Operational Safety Requirements

    SciTech Connect

    BENECKE, M.W.

    2000-09-06

    The Interim Operational Safety Requirements for the Fuel Supply Shutdown (FSS) Facility define acceptable conditions, safe boundaries, bases thereof, and management of administrative controls to ensure safe operation of the facility.

  1. 46 CFR 153.296 - Emergency shutdown stations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... shutdown station must contain a single remote actuator for all quick closing shutoff valves required by..., a cargo pump, or a water spray system, must be of a type that will not defeat the operation of...

  2. 46 CFR 153.296 - Emergency shutdown stations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... shutdown station must contain a single remote actuator for all quick closing shutoff valves required by..., a cargo pump, or a water spray system, must be of a type that will not defeat the operation of...

  3. 46 CFR 153.296 - Emergency shutdown stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... shutdown station must contain a single remote actuator for all quick closing shutoff valves required by..., a cargo pump, or a water spray system, must be of a type that will not defeat the operation of...

  4. 46 CFR 153.296 - Emergency shutdown stations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... shutdown station must contain a single remote actuator for all quick closing shutoff valves required by..., a cargo pump, or a water spray system, must be of a type that will not defeat the operation of...

  5. 46 CFR 153.296 - Emergency shutdown stations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... shutdown station must contain a single remote actuator for all quick closing shutoff valves required by..., a cargo pump, or a water spray system, must be of a type that will not defeat the operation of...

  6. Detecting Prediabetes and Diabetes: Agreement between Fasting Plasma Glucose and Oral Glucose Tolerance Test in Thai Adults

    PubMed Central

    Aekplakorn, Wichai; Tantayotai, Valla; Numsangkul, Sakawduan; Sripho, Wilarwan; Tatsato, Nutchanat; Burapasiriwat, Tuanjai; Pipatsart, Rachada; Sansom, Premsuree; Luckanajantachote, Pranee; Chawarokorn, Pongpat; Thanonghan, Anek; Lakhamkaew, Watchira; Mungkung, Aungsumalin; Boonkean, Rungnapa; Chantapoon, Chanidsa; Kungsri, Mayuree; Luanseng, Kasetsak; Chaiyajit, Kornsinun

    2015-01-01

    Aim. To evaluate an agreement in identifying dysglycemia between fasting plasma glucose (FPG) and the 2 hr postprandial glucose tolerance test (OGTT) in a population with high risk of diabetes. Methods. A total of 6,884 individuals aged 35–65 years recruited for a community-based diabetes prevention program were tested for prediabetes including impaired fasting glucose (IFG) or impaired glucose tolerance (IGT), and diabetes. The agreement was assessed by Kappa statistics. Logistic regression was used to examine factors associated with missed prediabetes and diabetes by FPG. Results. A total of 2671 (38.8%) individuals with prediabetes were identified. The prevalence of prediabetes identified by FPG and OGTT was 32.2% and 22.3%, respectively. The proportions of diabetes classified by OGTT were two times higher than those identified by FPG (11.0% versus 5.4%, resp.). The Kappa statistics for agreement of both tests was 0.55. Overall, FPG missed 46.3% of all prediabetes and 54.7% of all diabetes cases. Prediabetes was more likely to be missed by FPG among female, people aged <45 yrs, and those without family history of diabetes. Conclusion. The detection of prediabetes and diabetes using FPG only may miss half of the cases. Benefit of adding OGTT to FPG in some specific groups should be confirmed. PMID:26347060

  7. Passive shut-down heat removal system

    DOEpatents

    Hundal, Rolv; Sharbaugh, John E.

    1988-01-01

    An improved shut-down heat removal system for a liquid metal nuclear reactor of the type having a vessel for holding hot and cold pools of liquid sodium is disclosed herein. Generally, the improved system comprises a redan or barrier within the reactor vessel which allows an auxiliary heat exchanger to become immersed in liquid sodium from the hot pool whenever the reactor pump fails to generate a metal-circulating pressure differential between the hot and cold pools of sodium. This redan also defines an alternative circulation path between the hot and cold pools of sodium in order to equilibrate the distribution of the decay heat from the reactor core. The invention may take the form of a redan or barrier that circumscribes the inner wall of the reactor vessel, thereby defining an annular space therebetween. In this embodiment, the bottom of the annular space communicates with the cold pool of sodium, and the auxiliary heat exchanger is placed in this annular space just above the drawn-down level that the liquid sodium assumes during normal operating conditions. Alternatively, the redan of the invention may include a pair of vertically oriented, concentrically disposed standpipes having a piston member disposed between them that operates somewhat like a pressure-sensitive valve. In both embodiments, the cessation of the pressure differential that is normally created by the reactor pump causes the auxiliary heat exchanger to be immersed in liquid sodium from the hot pool. Additionally, the redan in both embodiments forms a circulation flow path between the hot and cold pools so that the decay heat from the nuclear core is uniformly distributed within the vessel.

  8. Validating predictive models for fast ion profile relaxation in burning plasmas

    NASA Astrophysics Data System (ADS)

    Gorelenkov, N. N.; Heidbrink, W. W.; Kramer, G. J.; Lestz, J. B.; Podesta, M.; Van Zeeland, M. A.; White, R. B.

    2016-11-01

    The redistribution and potential loss of energetic particles due to MHD modes can limit the performance of fusion plasmas by reducing the plasma heating rate. In this work, we present validation studies of the 1.5D critical gradient model (CGM) for Alfvén eigenmode (AE) induced EP transport in NSTX and DIII-D neutral beam heated plasmas. In previous comparisons with a single DIII-D L-mode case, the CGM model was found to be responsible for 75% of measured AE induced neutron deficit [1]. A fully kinetic HINST is used to compute mode stability for the non-perturbative version of CGM (or nCGM). We have found that AEs show strong local instability drive up to γ /ω ∼ 20% violating assumptions of perturbative approaches used in NOVA-K code. We demonstrate that both models agree with each other and both underestimate the neutron deficit measured in DIII-D shot by approximately a factor of 2. On the other hand in NSTX the application of CGM shows good agreement for the measured flux deficit predictions. We attempt to understand these results with the help of the so-called kick model which is based on the guiding center code ORBIT. The kick model comparison gives important insight into the underlying velocity space dependence of the AE induced EP transport as well as it allows the estimate of the neutron deficit in the presence of the low frequency Alfvénic modes. Within the limitations of used models we infer that there are missing modes in the analysis which could improve the agreement with the experiments.

  9. Fasting plasma triglycerides predict the glycaemic response to treatment of Type 2 diabetes by gastric electrical stimulation. A novel lipotoxicity paradigm

    PubMed Central

    Lebovitz, H E; Ludvik, B; Yaniv, I; Haddad, W; Schwartz, T; Aviv, R

    2013-01-01

    Background Non-stimulatory, meal-mediated electrical stimulation of the stomach (TANTALUS-DIAMOND) improves glycaemic control and causes modest weight loss in patients with Type 2 diabetes who are inadequately controlled on oral anti-diabetic medications. The magnitude of the glycaemic response in clinical studies has been variable. A preliminary analysis of data from patients who had completed 6 months of treatment indicated that the glycaemic response to the electrical stimulation was inversely related to the baseline fasting plasma triglyceride level. Method An analysis of 40 patients who had had detailed longitudinal studies for 12 months. Results Twenty-two patients with fasting plasma triglycerides ≤ 1.7 mmol/l had mean decreases in HbA1c after 3, 6 and 12 months of gastric contraction modulation treatment of −15 ± 2.1 mmol/mol (−1.39 ± 0.20%), −16 ± 2.2 mmol/mol (−1.48 ± 0.20%) and −14 ± 3.0 mmol/mol (−1.31 ± 0.26%), respectively. In contrast, 18 patients with fasting plasma triglyceride > 1.7 mmol/l had mean decreases in HbA1c of −7 ± 1.7 mmol/mol (−0.66 ± 0.16%), −5 ± 1.6 mmol/mol (−0.44 ± 0.18%) and −5 ± 1.7 mmol/mol (−0.42 ± 0.16%), respectively. Pearson's correlation coefficient between fasting plasma triglyceride and decreases in HbA1c at 12 months of treatment was 0.34 (P < 0.05). Homeostasis model assessment of insulin resistance was unchanged during 12 months of treatment in patients with high baseline fasting triglycerides, while it progressively improved in patients with low fasting plasma triglycerides. Patients with low fasting plasma triglycerides had a tendency to lose more weight than those with high fasting plasma triglycerides, but this did not achieve statistical significance. Conclusions The data presented suggest the existance of a triglyceride lipotoxic mechanism that interferes with gastric/neural mediated pathways that can regulate glycaemic control in patients with type 2 diabetes. The data

  10. Deuterium retention after deuterium plasma implantation in tungsten pre-damaged by fast C+ ions

    NASA Astrophysics Data System (ADS)

    Efimov, V. S.; Gasparyan, Yu M.; Pisarev, A. A.; Khripunov, B. I.; Koidan, V. S.; Ryazanov, A. I.; Semenov, E. V.

    2016-09-01

    Thermal desorption of deuterium from W was investigated. Virgin samples and samples damaged by 10 MeV C 3+ ions were implanted from plasma in the LENTA facility at 370 K and 773 K. In comparison with the undamaged sample, deuterium retention in the damaged sample slightly increased in the case of deuterium implantation at RT, but decreased in the case of deuterium implantation at 773 K. At 773 K, deuterium was concluded to diffuse far behind the D ion range in the virgin sample, while C implantation region was concluded to be a barrier for D diffusion in the damaged sample.

  11. Extremely Nonsinusoidal Emissions and Fast Electron Phenomena from Strong Laser Pulses Obliquely P-Incident on Sharp-Edged Plasmas

    NASA Astrophysics Data System (ADS)

    Johnston, T. W.; Nikolic, L.; Tyshetskiy, Y.; Vidal, F.

    2007-11-01

    High laser harmonic light [1] emerges when the Vulcan petawatt laser's sub-ps laser pulses are obliquely incident on slab targets with extremely low pre-pulse energy. Similar work is in progress with the ALLS 200 TW Ti-Saph laser at INRS EMT. (Pulses are 24 fs at 10 Hz with 10-10 contrast, even without plasma mirrors). 2-D PIC (OSIRIS code at INRS) results on basic mechanism(s) resemble those of Gibbon [2], Naumova et al. [3] and Thaury et al. [4]. The very large and asymmetric electromagnetic ``spikes'' which account for the high harmonic content are produced by extremely concentrated 2D plasma surface currents. The connection between our 2D PIC results (also those in [3] and 1D PIC results [2,4] using the Gibbon-Bourdier moving 1D formalism[2] is also discussed, as are the fast electrons, including some related quasi-steady magnetic fields. [1] B. Dromey et al Nature Phys. Lett., 2, 456-459 (2006) [2] Paul Gibbon, Phys. Rev. Lett. 76, 50 (1996) [3] N. Naumova, et al., Phys. Rev. Lett. 93, 195003 (2004). [4] C. Thaury, et al., Nature Phys. 3, 424 (2007)

  12. Preliminary Evaluation of Removing Used Nuclear Fuel from Shutdown Sites

    SciTech Connect

    Maheras, Steven J.; Best, Ralph E.; Ross, Steven B.; Buxton, Kenneth A.; England, Jeffery L.; McConnell, Paul E.

    2013-09-30

    This report fulfills the M2 milestone M2FT-13PN0912022, “Stranded Sites De-Inventorying Report.” In January 2013, the U.S. Department of Energy (DOE) issued the Strategy for the Management and Disposal of Used Nuclear Fuel and High-Level Radioactive Waste (DOE 2013). Among the elements contained in this strategy is an initial focus on accepting used nuclear fuel from shutdown reactor sites. This focus is consistent with the recommendations of the Blue Ribbon Commission on America’s Nuclear Future, which identified removal of stranded used nuclear fuel at shutdown sites as a priority so that these sites may be completely decommissioned and put to other beneficial uses (BRC 2012). Shutdown sites are defined as those commercial nuclear power reactor sites where the nuclear power reactors have been shut down and the site has been decommissioned or is undergoing decommissioning. In this report, a preliminary evaluation of removing used nuclear fuel from 12 shutdown sites was conducted. The shutdown sites were Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, Zion, Crystal River, Kewaunee, and San Onofre. These sites have no other operating nuclear power reactors at their sites and have also notified the U.S. Nuclear Regulatory Commission that their reactors have permanently ceased power operations and that nuclear fuel has been permanently removed from their reactor vessels. Shutdown reactors at sites having other operating reactors are not included in this evaluation.

  13. Fast plasma measurements in the solar wind: Lessons from Spektr-R and implications for THOR

    NASA Astrophysics Data System (ADS)

    Prech, Lubomir; Safrankova, Jana; Nemecek, Zdenek; Nemec, Frantisek; Chen, Christopher H. K.; Zastenker, Georgy N.

    2016-04-01

    The paper discusses achievements of rapid measurements of solar wind parameters by the BMSW instrument onboard the Spektr-R spacecraft. The main advantage of these measurements is their speed that can reach 32 Hz. We present the examples of significant results concentrated on (1) the IP shock ramp thickness that is observed to be comparable with the ion gyroradius even for low-Mach number shocks; (2) wave trains connected with the IP shock and an evolution of the ion velocity distribution within these wave trains; (3) plasma turbulence around the ion spectral break, and (4) a study of variations of the He abundance on short timescales (3-30 s) and their relations to in-transit turbulence. Based on BMSW experience, we present further progress in development of a new variant of BMSW that includes simultaneous measurements of a full energy distribution function (with 2-s time resolution) and plasma moments with the time resolution of 32 Hz or better under a Maxwellian approximation. A new configuration of the set of Faraday cups allows us a perfect in-flight calibration, a special regime for helium abundance determination and quick onboard information about the solar wind bulk speed.

  14. Intensive lifestyle intervention including high-intensity interval training program improves insulin resistance and fasting plasma glucose in obese patients☆

    PubMed Central

    Marquis-Gravel, Guillaume; Hayami, Douglas; Juneau, Martin; Nigam, Anil; Guilbeault, Valérie; Latour, Élise; Gayda, Mathieu

    2015-01-01

    Objectives To analyze the effects of a long-term intensive lifestyle intervention including high-intensity interval training (HIIT) and Mediterranean diet (MedD) counseling on glycemic control parameters, insulin resistance and β-cell function in obese subjects. Methods The glycemic control parameters (fasting plasma glucose, glycated hemoglobin), insulin resistance, and β-cell function of 72 obese subjects (54 women; mean age = 53 ± 9 years) were assessed at baseline and upon completion of a 9-month intensive lifestyle intervention program conducted at the cardiovascular prevention and rehabilitation center of the Montreal Heart Institute, from 2009 to 2012. The program included 2–3 weekly supervised exercise training sessions (HIIT and resistance exercise), combined to MedD counseling. Results Fasting plasma glucose (FPG) (mmol/L) (before: 5.5 ± 0.9; after: 5.2 ± 0.6; P < 0.0001), fasting insulin (pmol/L) (before: 98 ± 57; after: 82 ± 43; P = 0.003), and insulin resistance, as assessed by the HOMA-IR score (before: 3.6 ± 2.5; after: 2.8 ± 1.6; P = 0.0008) significantly improved, but not HbA1c (%) (before: 5.72 ± 0.55; after: 5.69 ± 0.39; P = 0.448), nor β-cell function (HOMA-β, %) (before: 149 ± 78; after: 144 ± 75; P = 0.58). Conclusion Following a 9-month intensive lifestyle intervention combining HIIT and MedD counseling, obese subjects experienced significant improvements of FPG and insulin resistance. This is the first study to expose the effects of a long-term program combining HIIT and MedD on glycemic control parameters among obese subjects. PMID:26844086

  15. Experimental Studies of Fast Protons Originated from Fusion Reactions in Plasma-Focus Discharges

    SciTech Connect

    Malinowska, A.; Malinowski, K.; Sadowski, M. J.; Zebrowski, J.; Szydlowski, A.

    2008-03-19

    The paper describes results of the recent measurements of fusion-reaction protons, which were performed within the PF-360 facility operated at the IPJ in Swierk, Poland. The main aim of those studies was to perform time-integrated measurements of fast protons (of energy of about 3 MeV) by means of ion-pinhole cameras, which were equipped with solid state nuclear track detectors (SSNTD) of the PM-355 type and absorption filters made of thin metal foils. In order to determine the spatial distribution of fusion-produced protons the use was made of several miniature pinhole cameras placed at different angles to the PF-360 axis. The irradiated and etched detectors were analyzed with an optical microscope coupled with a CCD camera and a PC unit.

  16. Fast Flux Test Facility project plan. Revision 2

    SciTech Connect

    Hulvey, R.K.

    1995-11-01

    The Fast Flux Test Facility (FFTF) Transition Project Plan, Revision 2, provides changes to the major elements and project baseline for the deactivation activities necessary to transition the FFTF to a radiologically and industrially safe shutdown condition.

  17. Comparison of the clinical characteristics of diabetes mellitus diagnosed using fasting plasma glucose and haemoglobin A1c: The 2011 Korea National Health and Nutrition Examination Survey.

    PubMed

    Hong, Sangmo; Kang, Jun Goo; Kim, Chul Sik; Lee, Seong Jin; Lee, Chang Beom; Ihm, Sung-Hee

    2016-03-01

    We compared the characteristics of a Korean adult population diagnosed with diabetes using only a fasting plasma glucose criterion or an HbA1c criterion. The single difference between these two groups was age. Further studies should be undertaken to clarify whether age-specific diagnostic criteria would be appropriate in Korean populations.

  18. Use of fast scopes to enable Thomson scattering measurement in presence of fluctuating plasma light.

    SciTech Connect

    McLean, H; Moller, J; Hill, D

    2004-04-19

    The addition of inexpensive high-speed oscilloscopes has enabled higher Te Thomson scattering measurements on the SSPX spheromak. Along with signal correlation techniques, the scopes allow new analyses based on the shape of the scattered laser pulse to discriminate against fluctuating background plasma light that often make gated-integrator measurements unreliable. A 1.4 J Nd:YAG laser at 1064 nm is the scattering source. Spatial locations are coupled by viewing optics and fibers to 4-wavelength-channel filter polychrometers. Ratios between the channels determine Te while summations of the channels determine density. Typically, the channel that provides scattered signal at higher Te is contaminated by fluctuating background light. Individual channels are correlated with either a modeled representation of the laser pulse or a noise-free stray light signal to extract channel amplitudes.

  19. Implementation of moire-schlieren deflectometry on a small scale fast capillary plasma discharge

    SciTech Connect

    Valenzuela, J. C.; Wyndham, E. S.; Chuaqui, H.; Cortes, D. S.; Favre, M.; Bhuyan, H.

    2012-05-15

    We present the results of an implementation of a refractive diagnostic to study fast dynamics in capillary discharges. It consists of a moire-schlieren deflectometry technique that provides a quantitative analysis of the refractive index gradients. The technique is composed of an angular deflection mapping system (moire deflectometry) and a spatial Fourier filter (schlieren). Temporal resolution of 12 ps, 50 {mu}m of spatial resolution and minimum detectable gradient of ({nabla}n{sub e}){sub min}=6x10{sup 18}cm{sup -4} were obtained. With these parameters, a large aspect ratio capillary discharge of 15 ns half period current was studied; the diagnostic was implemented axially along the alumina tube of 1.6 mm inner diameter and 21 mm length. The detectable electron density for these conditions was 1x10{sup 17}cm{sup -3}. From the interpretation of the fringe displacement, we are able to measure the velocity of the radial compression wave and the compression ratio due to the Lorentz force. On axis, electron densities of the order of 5x10{sup 17}cm{sup -3} were obtained at the time of maximum soft x-ray emission.

  20. On The Anomalous Fast Ion Energy Diffusion in Toroidal Plasmas Due to Cavity Modes

    SciTech Connect

    N.N. Gorelenkov, N.J. Fisch and E. Fredrickson

    2010-03-09

    An enormous wave-particle diffusion coefficient along paths suitable for alpha channeling had been deduced in mode converted ion Bernstein wave experiments on Tokamak Fusion Test Reactor (TFTR) the only plausible explanation advanced for such a large diffusion coefficient was the excitation of internal cavity modes which induce particle diffusion along identical diffusion paths, but at much higher rates. Although such a mode was conjectured, it was never observed. However, recent detailed observations of high frequency compressional Alfven eigenmodes (CAEs) on the National Spherical torus Experiment (NSTX) indirectly support the existence of the related conjectured modes on TFTR. The eigenmodes responsible for the high frequency magnetic activity can be identified as CAEs through the polarization of the observed magnetic field oscillations in NSTX and through a comparison with the theoretically derived freuency dispersion relation. Here, we show how these recent observations of high frequency CAEs lend support to this explanation of the long-standing puzzle of anomalous fast ion energy diffusion on TFTR. The support of the conjecure that these internal modes could have caused the remarkable ion energy diffusion on TFTR carries significant and favorable implications for the possibilities in achieving the alpha channeling effect with small injected power in a tokamak reactor.

  1. Effects of 2-, 4- and 12-hour fasting intervals on preoperative gastric fluid pH and volume, and plasma glucose and lipid homeostasis in children.

    PubMed

    Maekawa, N; Mikawa, K; Yaku, H; Nishina, K; Obara, H

    1993-11-01

    We evaluated 105 randomly-selected unpremedicated children aged 1-14 years to determine the effects of a 2-, 4- and 12-h preoperative fasting interval on the preoperative gastric fluid pH and volume, and plasma glucose and lipid homeostasis. Each child undergoing elective surgery ingested a large volume (approximately 10 ml/kg b.w.) of apple juice and then fasted for 2, 4 or 12 h before the estimated induction of anaesthesia. After induction of anaesthesia, gastric fluid was aspirated through a large-bore, multiorifice orogastric tube. Plasma concentrations of glucose, total ketone bodies, non-esterified fatty acid (NEFA), triglycerides, and cortisol were measured at the time of induction to evaluate the fasting interval effects on preoperative plasma glucose and lipid homeostasis. There were no significant differences between the three groups in either gastric fluid volume or pH. In addition, there were no significant differences between the groups with respect to the proportion with a pH < 2.5 and volume > 0.4 ml/kg b.w. Neither plasma concentrations of glucose, triglycerides, nor cortisol at the time of anaesthetic induction differed between the three groups. Both 4 and 12 h nil per os (NPO) caused an increase in lipolysis, which was presumably a compensatory mechanism to maintain normoglycaemia. The plasma NEFA and total ketone bodies concentrations were therefore significantly higher in these two fasting intervals than in 2 h NPO. These data suggest that a 2-h NPO, after a large volume of ingested apple juice, may offer additional benefits by preventing an increase in lipolysis during the fasting interval without either increasing the volume of gastric fluid or decreasing the gastric pH.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Kilohertz sources of hard x rays and fast ions with femtosecond laser plasmas

    NASA Astrophysics Data System (ADS)

    Thoss, A.; Richardson, M.; Korn, G.; Faubel, M.; Stiel, H.; Vogt, U.; Elsaesser, T.

    2003-01-01

    We demonstrate a new, stable, kilohertz femtosecond laser plasma source of hard-x-ray continuum and Kα emission that uses a microscopic liquid jet target that is continuous and debris free. Plasmas produced by ultrashort (50-fs) intense laser pulses from a fine (10-30-μm diameter) liquid Ga jet emit bright 9.3- and 10.3-keV Kα and Kβ lines superimposed on a multikilovolt bremmstrahlung continuum. Kilohertz femtosecond x-ray sources will find many applications in time-resolved x-ray diffraction and microscopy studies. As high-intensity lasers become more compact and operate at increasingly high repetition-rates, they require a target configuration that is both repeatable from shot to shot and debris free. Our target provides a pristine, unperturbed filament surface at rates >100 kHz. A number of liquid metal targets are considered. We show the hard-x-ray spectrum described above. The source was generated by a 50-fs-duration, 1-kHz, 2-W, high-intensity Ti:sapphire laser. Using the same technology, we also generate forward-going sub-mega-electron-volt (sub-MeV) protons from a 10-μm liquid water target at 1-kHz repetition rates. Kilohertz sources of high-energy ions will find many applications in time-resolved particle interaction studies and will lead to efficient generation of short-lived isotopes for use in nuclear medicine and other applications. The protons were detected with CR-39 track detectors in both the forward and the backward directions up to energies of ~500 keV. As the intensity of compact high-repetition-rate lasers sources increases, we can expect improvements in the energy, conversion efficiency, and directionality to occur. The effect of these developments is discussed. As compact, high-repetition-rate femtosecond laser technology reaches focused intensities of ~1019 W/cm2, many new applications of high-repetition-rate hard-x-ray and MeV ion sources will become practical.

  3. Fast, kinetically self-consistent simulation of RF modulated plasma boundary sheaths

    NASA Astrophysics Data System (ADS)

    Shihab, Mohammed; Ziegler, Dennis; Brinkmann, Ralf Peter

    2012-05-01

    A mathematical model is presented which enables the efficient, kinetically self-consistent simulation of RF modulated plasma boundary sheaths in all technically relevant discharge regimes. It is defined on a one-dimensional geometry where a Cartesian x-axis points from the electrode or wall at xE ≡ 0 towards the plasma bulk. An arbitrary endpoint xB is chosen ‘deep in the bulk’. The model consists of a set of kinetic equations for the ions, Boltzmann's relation for the electrons and Poisson's equation for the electrical field. Boundary conditions specify the ion flux at xB and a periodically—not necessarily harmonically—modulated sheath voltage V(t) or sheath charge Q(t). The equations are solved in a statistical sense. However, it is not the well-known particle-in-cell (PIC) scheme that is employed, but an alternative iterative algorithm termed ensemble-in-spacetime (EST). The basis of the scheme is a discretization of the spacetime, the product of the domain [xE, xB] and the RF period [0, T]. Three modules are called in a sequence. A Monte Carlo module calculates the trajectories of a large set of ions from their start at xB until they reach the electrode at xE, utilizing the potential values on the nodes of the spatio-temporal grid. A harmonic analysis module reconstructs the Fourier modes nim(x) of the ion density ni(x, t) from the calculated trajectories. A field module finally solves the Boltzmann-Poisson equation with the calculated ion densities to generate an updated set of potential values for the spatio-temporal grid. The iteration is started with the potential values of a self-consistent fluid model and terminates when the updates become sufficiently small, i.e. when self-consistency is achieved. A subsequent post-processing determines important quantities, in particular the phase-resolved and phase-averaged values of the ion energy and angular distributions and the total energy flux at the electrode. A drastic reduction of the computational

  4. Fast magnetic reconnection in low-density electron-positron plasmas

    SciTech Connect

    Bessho, Naoki; Bhattacharjee, A.

    2010-10-15

    Two-dimensional particle-in-cell simulations have been performed to study magnetic reconnection in low-density electron-positron plasmas without a guide magnetic field. Impulsive reconnection rates become of the order of unity when the background density is much smaller than 10% of the density in the initial current layer. It is demonstrated that the outflow speed is less than the upstream Alfven speed, and that the time derivative of the density must be taken into account in the definition of the reconnection rate. The reconnection electric fields in the low-density regime become much larger than the ones in the high-density regime, and it is possible to accelerate the particles to high energies more efficiently. The inertial term in the generalized Ohm's law is the most dominant term that supports a large reconnection electric field. An effective collisionless resistivity is produced and tracks the extension of the diffusion region in the late stage of the reconnection dynamics, and significant broadening of the diffusion region is observed. Because of the broadening of the diffusion region, no secondary islands, which have been considered to play a role to limit the diffusion region, are generated during the extension of the diffusion region in the outflow direction.

  5. Method and apparatus for fast laser pulse detection using gaseous plasmas

    DOEpatents

    McLellan, Edward J.; Webb, John A.

    1984-01-01

    The method and device of the instant invention is a detector of pulsed laser radiation which utilizes the electromotive force generated by the plasma formed when such radiation is focused onto a surface (1). Measurements are made with a 10.6 .mu.m CO.sub.2 laser capable of producing peak intensities of 10.sup.13 W/cm.sup.2 when directed through a converging lens (2). Evacuated detector response to such laser intensity is 1 kV signal peak amplitude and subnanosecond risetimes into a 50.OMEGA. load (3). Detector performance is found to be greatly altered with the introduction of a background gas (4). For example, with one atmosphere of air, the detector produces prompt signals of the order of 1 V with subnanosecond response for pulse trains lasting 100 ns. With argon, krypton, or zenon at pressures of the order of 10 torr, the detector generates "trigger pulses" of about 250 V amplitude and 0.2 ns risetimes. Such detectors are quite robust when irradiated with high intensity laser radiation and are useful for qualitative laser beam monitoring.

  6. Method and apparatus for fast laser-pulse detection using gaseous plasmas

    DOEpatents

    McLellan, E.J.; Webb, J.A.

    1981-06-18

    The method and device of the instant invention is a detector of pulsed laser radiation which utilizes the electromotive force generated by the plasma formed when such radiation is focused onto a surface. Measurements are made with a 10.6 ..mu..m CO/sub 2/ laser capable of producing peak intensities of 10/sup 13/ W/cm/sup 2/ when directed through a converging lens. Evacuated detector response to such laser intensity if 1 kV signal peak amplitude and subnanosecond risetimes into a 50 ..cap omega.. load. Detector performance is found to be greatly altered with the introduction of a background gas. For example, with one atmosphere of air, the detector produces prompt signals of the order of 1 V with subnanosecond response for pulse trains lasting 100 ns. With argon, krypton, or zenon at pressures of the order of 10 torr, the detector generates trigger pulses of about 250 V amplitude and 0.2 ns risetimes. Such detectors are quite robust when irradiated with high intensity laser radiation and are useful for qualitative laser beam monitoring.

  7. Fast data transmission in dynamic data acquisition system for plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Byszuk, Adrian; Poźniak, Krzysztof; Zabołotny, Wojciech M.; Kasprowicz, Grzegorz; Wojeński, Andrzej; Cieszewski, Radosław; Juszczyk, Bartłomiej; Kolasiński, Piotr; Zienkiewicz, Paweł; Chernyshova, Maryna; Czarski, Tomasz

    2014-11-01

    This paper describes architecture of a new data acquisition system (DAQ) targeted mainly at plasma diagnostic experiments. Modular architecture, in combination with selected hardware components, allows for straightforward reconfiguration of the whole system, both offline and online. Main emphasis will be put into the implementation of data transmission subsystem in said system. One of the biggest advantages of described system is modular architecture with well defined boundaries between main components: analog frontend (AFE), digital backplane and acquisition/control software. Usage of a FPGA chips allows for a high flexibility in design of analog frontends, including ADC <--> FPGA interface. Data transmission between backplane boards and user software was accomplished with the use of industry-standard PCI Express (PCIe) technology. PCIe implementation includes both FPGA firmware and Linux device driver. High flexibility of PCIe connections was accomplished due to use of configurable PCIe switch. Whenever it's possible, described DAQ system tries to make use of standard off-the-shelf (OTF) components, including typical x86 CPU & motherboard (acting as PCIe controller) and cabling.

  8. Fast, Kinetically self-consistent simulation of RF modulated plasma boundary sheaths

    NASA Astrophysics Data System (ADS)

    Shihab, Mohammed; Brinkmann, Ralf Peter

    2012-10-01

    A mathematical model is presented which enables the efficent, kinetically self-consistent simulation of RF modulated plasma boundary sheaths in all technically relevant discharge regimes. The model consists of a set of kinetic equations for the ions, Boltzmann's relation for the electrons and Poisson's equation for the electrical field. Boundary conditions specify the ion flux at a point deep in the bulk and a periodically modulated sheath voltage or sheath charge. The equations are solved in a statistical sense. However, it is not the well-known particle-in-cell (PIC) scheme that is employed, but an alternative iterative algorithm termed ensemble-in-spacetime (EST). Three modules are called in a sequence: a Monte Carlo module, a harmonic analysis module, and a field module. The iteration is started with the potential values of a self-consistent fluid model and terminates when the updates become sufficiently small, i.e. when self-consistency is achieved. A drastic reduction of the computational effort compared with PIC calculations is achieved. As a first application of the new model, the influence of ion inertia on the dynamics of a collisionless sheath is studied and a comparison of the simulated ion energy distribution with published analytical solutions is performed.

  9. Determinants of fasting plasma glucose and glycosylated hemoglobin among low income Latinos with poorly controlled type 2 diabetes.

    PubMed

    Kollannoor-Samuel, Grace; Chhabra, Jyoti; Fernandez, Maria Luz; Vega-López, Sonia; Pérez, Sofia Segura; Damio, Grace; Calle, Mariana C; D'Agostino, Darrin; Pérez-Escamilla, Rafael

    2011-10-01

    The objective of this study was to identify demographic, socio-economic, acculturation, lifestyle, sleeping pattern, and biomedical determinants of fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA1c), among Latinos with type 2 diabetes (T2D). Latino adults (N = 211) with T2D enrolled in the DIALBEST trial were interviewed in their homes. Fasting blood samples were also collected in the participants' homes. Because all participants had poor glucose control, above-median values for FPG (173 mg/dl) and HbA1c (9.2%) were considered to be indicative of poorer glycemic control. Multivariate analyses showed that receiving heating assistance (OR: 2.20; 95% CI: 0.96-4.96), and having a radio (3.11, 1.16-8.35), were risk factors for higher FPG levels, and lower income (10.4, 1.54-69.30) was a risk factor for higher HbA1c levels. Lower carbohydrate intake during the previous day (0.04; 0.005-0.37), as well as regular physical activity (0.30; 0.13-0.69), breakfast (2.78; 1.10-6.99) and dinner skipping (3.9; 1.03-14.9) during previous week were significantly associated with FPG concentrations. Being middle aged (2.24, 1.12-4.47), 30-60 min of sleep during the day time (0.07, 0.01-0.74) and having medical insurance (0.31, 0.10-0.96) were predictors of HbA1c. Results suggest that contemporaneous lifestyle behaviors were associated with FPG and contextual biomedical factors such as health care access with HbA1c. Lower socio-economic status indicators were associated with poorer FPG and HbA1c glycemic control.

  10. Change in fasting plasma glucose and incident type 2 diabetes mellitus: results from a prospective cohort study

    PubMed Central

    Mozaffary, Amirhossein; Asgari, Samaneh; Tohidi, Maryam; Kazempour-Ardebili, Sara; Azizi, Fereidoun; Hadaegh, Farzad

    2016-01-01

    Objective To investigate the association between changes in fasting plasma glucose (FPG) values and incident type 2 diabetes (T2D) in a cohort of the Iranian population. Design Prospective cohort study. Setting This study was conducted within the framework of the Tehran Lipid and Glucose Study (TLGS) to investigate the association between change in FPG between baseline examination (1999–2001) and the second visit (2002–2005) with incident T2D. Participants A total of 3981 non-diabetic participants aged ≥20 years. Outcome measure T2D was defined if the participant was using antidiabetic drugs or if FPG was ≥7 mmol/L or if the 2 h post-challenge plasma glucose (2-hPCG) was ≥11.1 mmol/L. Results During a median follow-up of 6.17 years, after the second examination, 288 new cases of T2D were identified. In a multivariate Cox proportional hazard analysis using age as timescale, we presented a simple model including FPG change (HR 1.19, 95% CI 1.07 to 1.33) and baseline waist circumference (WC) (HR 1.004, 95% CI 1.001 to 1.008) with a discriminative power (C-index) of 72%. Furthermore, we showed that the highest quartile of FPG change enhanced the T2D risk to 1.65 (95% CI 1.2 to 2.27) compared with the lowest quartile (p for trend=0.004).The independent risk of FPG change resisted further adjustment with 2-hPCG change. Adding the 2-hPCG change only slightly increased the discriminative power of the model including FPG change and baseline value of WC (0.73% vs 0.72%). After the study population had been limited to those with normal fasting glucose/normal glucose tolerance, FPG change remained an independent predictor (HR 1.57, 95% CI 1.31 to 1.88). Conclusions Two measurements of FPG obtained about 3 years apart can help to identify populations at risk of incident T2D independently of important traditional risk factors and their changes, including 2-hPCG change. PMID:27217283

  11. Runaway electron generation as possible trigger for enhancement of magnetohydrodynamic plasma activity and fast changes in runaway beam behavior

    SciTech Connect

    Pankratov, I. M. E-mail: rjzhou@ipp.ac.cn; Zhou, R. J. E-mail: rjzhou@ipp.ac.cn; Hu, L. Q.

    2015-07-15

    Peculiar phenomena were observed during experiments with runaway electrons: rapid changes in the synchrotron spot and its intensity that coincided with stepwise increases in the electron cyclotron emission (ECE) signal (cyclotron radiation of suprathermal electrons). These phenomena were initially observed in TEXTOR (Tokamak Experiment for Technology Oriented Research), where these events only occurred in the current decay phase or in discharges with thin stable runaway beams at a q = 1 drift surface. These rapid changes in the synchrotron spot were interpreted by the TEXTOR team as a fast pitch angle scattering event. Recently, similar rapid changes in the synchrotron spot and its intensity that coincided with stepwise increases in the non-thermal ECE signal were observed in the EAST (Experimental Advanced Superconducting Tokamak) runaway discharge. Runaway electrons were located around the q = 2 rational magnetic surface (ring-like runaway electron beam). During the EAST runaway discharge, stepwise ECE signal increases coincided with enhanced magnetohydrodynamic (MHD) activity. This behavior was peculiar to this shot. In this paper, we show that these non-thermal ECE step-like jumps were related to the abrupt growth of suprathermal electrons induced by bursting electric fields at reconnection events during this MHD plasma activity. Enhancement of the secondary runaway electron generation also occurred simultaneously. Local changes in the current-density gradient appeared because of local enhancement of the runaway electron generation process. These current-density gradient changes are considered to be a possible trigger for enhancement of the MHD plasma activity and the rapid changes in runaway beam behavior.

  12. Fast-to-Alfvén Mode Conversion Mediated by the Hall Current. I. Cold Plasma Model

    NASA Astrophysics Data System (ADS)

    Cally, Paul S.; Khomenko, Elena

    2015-12-01

    The photospheric temperature minimum in the Sun and solar-like stars is very weakly ionized, with an ionization fraction f as low as 10-4. In galactic star-forming regions, f can be 10-10 or lower. Under these circumstances, the Hall current can couple low-frequency Alfvén and magnetoacoustic waves via the dimensionless Hall parameter ɛ =ω /{{{Ω }}}{{i}}f, where ω is the wave frequency and {{{Ω }}}{{i}} is the mean ion gyrofrequency. This is analyzed in the context of a cold (zero-β) plasma and in less detail for a warm plasma. It is found that Hall coupling preferentially occurs where the wavevector is nearly field-aligned. In these circumstances, Hall coupling in theory produces a continual oscillation between fast and Alfvén modes as the wave passes through the weakly ionized region. At low frequencies (mHz), characteristic of solar and stellar normal modes, ɛ is probably too small for more than a fraction of one oscillation to occur. On the other hand, the effect may be significant at the far higher frequencies (Hz) associated with magnetic reconnection events. In another context, characteristic parameters for star-forming gas clouds suggest that {O}(1) or more full oscillations may occur in one cloud crossing. This mechanism is not expected to be effective in sunspots, due to their high ion gyrofrequencies and Alfvén speeds, since the net effect depends inversely on both and therefore inverse quadratically on field strength.

  13. kHz femtosecond laser-plasma hard X-ray and fast ion source

    NASA Astrophysics Data System (ADS)

    Thoss, A.; Korn, G.; Richardson, M. C.; Faubel, M.; Stiel, H.; Voigt, U.; Siders, C. W.; Elsaesser, T.

    2002-04-01

    We describe the first demonstration of a new stable, kHz femtosecond laser-plasma source of hard x-ray continuum and Kα emission using a thin liquid metallic jet target. kHz femtosecond x-ray sources will find many applications in time-resolved x-ray diffraction and microscopy studies. As high intensity lasers become more compact and operate at increasingly high repetition-rates, they require a target configuration that is both repeatable from shot-to-shot and is debris-free. We have solved this requirement with the use of a fine (10-30 μm diameter) liquid metal jet target that provides a pristine, unperturbed filament surface at rates >100 kHz. A number of liquid metal targets are considered. We will show hard x-ray spectra recorded from liquid Ga targets that show the generation of the 9.3 keV and 10.3 keV, Kα and Kβ lines superimposed on a multi-keV Bremsstrahlung continuum. This source was generated by a 50fs duration, 1 kHz, 2W, high intensity Ti:Sapphire laser. We will discuss the extension of this source to higher powers and higher repetition rates, providing harder x-ray emission, with the incorporation of pulse-shaping and other techniques to enhance the x-ray conversion efficiency. Using the same liquid target technology, we have also demonstrated the generation of forward-going sub-MeV protons from a 10 μm liquid water target at 1 kHz repetition rates. kHz sources of high energy ions will find many applications in time-resolved particle interaction studies, as well as lead to the efficient generation of short-lived isotopes for use in nuclear medicine and other applications. The protons were detected with CR-39 track detectors both in the forward and backward directions up to energies of ~500 keV. As the intensity of compact high repetition-rate lasers sources increase, we can expect improvements in the energy, conversion efficiency and directionality to occur. The impact of these developments on a number of fields will be discussed. As compact

  14. Numerical Simulation of Pre-formed Plasma Generated by Low Intensity Pre-Pulse Before Main Heating Laser in Fast-Ignition

    NASA Astrophysics Data System (ADS)

    Sunahara, Atsushi; Hongbo, Cai; Johzaki, Tomoyuki; Nagatomo, Hideo; Mima, Kunioki

    2009-11-01

    We investigated the plasma expansion of the inner surface of the cone used for the fast-ignition scheme of the inertial confinement fusion (ICF). LFEX laser [1] in Osaka University is high intense and short pulse laser system, which has 10^19W/cm^2 to 10^20W/cm^2, and ps pulse duration. However, it has also low intense pre-pulse with the contrast ranging from 10^5 to 10^8. It is high enough to ablate the inner surface of the cone wall used for fast ignition target. We developed the two-dimensional simulation code (Star-2D) [2], and simulate plasma expansion of the inner surface of the cone. We will discuss our simulation results, and also effects of the pre-plasma expansion on fast electron production. On the other hand, our code has been applied to simulate the laser-produced plasmas for Extreme-Ultraviolet research, and its accuracy has been tested with various experiments. We will also discuss the accuracy of our simulations. [4pt] [1] H. Azechi et at., in EPS. [0pt] [2] A. Sunahara et al., Journal of Physics: Conference Series 112(2008) 042048-1-4.

  15. High Fasting Plasma Glucose Mortality Effect: A Comparative Risk Assessment in 25–64 Years Old Iranian Population

    PubMed Central

    Peykari, Niloofar; Saeedi, Moghaddam Sahar; Djalalinia, Shirin; Kasaeian, Amir; Sheidaei, Ali; Mansouri, Anita; Mohammadi, Younes; Parsaeian, Mahboubeh; Mehdipour, Parinaz; Larijani, Bagher; Farzadfar, Farshad

    2016-01-01

    Background: High fasting plasma glucose (FPG) is one of the main leading risk factors of ischemic heart disease (IHD), stroke, and chronic kidney diseases (CKDs). We estimated population attributable fraction (PAF) and attributed death of these fatal outcomes of high FPG at national and subnational levels in 25–64 years old Iranian adult. Methods: We used national and subnational data of the Non-Communicable Disease Surveillance Survey for exposure to risk factors in 2005 and 2011 among Iranian adults of 25–64 years old. For estimating the attributed death, using the death registration system data of Iran, we multiply the cause-specific PAFs by the number of outcome-specific deaths. Results: In Iran, high FPG was responsible for about 31% of attributed total deaths of IHD, stroke, and CKD in 2011. The related attributed deaths had increased from 2005 to 2011. In females, the PAFs for the effect of high FPG on IHD, stroke, and CKD were higher in 2011 than 2005 in all age groups. In males, this increase has occurred in over 45 years old. The highest PAFs of high FPG outcomes mostly related to central provinces of Iran. The central region of Iran had the highest and the southeast of the country had the lowest levels of attributed deaths. Conclusions: Considering the global 25 × 25 targets for noncommunicable disease mortality reduction, high FPG as a leading risk factor of fatal outcomes should be more targeted through the dietary, behavioral, and pharmacological interventions in Iran. PMID:27280011

  16. Evaluating the transferability of 15 European-derived fasting plasma glucose SNPs in Mexican children and adolescents

    PubMed Central

    Langlois, Christine; Abadi, Arkan; Peralta-Romero, Jesus; Alyass, Akram; Suarez, Fernando; Gomez-Zamudio, Jaime; Burguete-Garcia, Ana I.; Yazdi, Fereshteh T.; Cruz, Miguel; Meyre, David

    2016-01-01

    Genome wide association studies (GWAS) have identified single-nucleotide polymorphisms (SNPs) that are associated with fasting plasma glucose (FPG) in adult European populations. The contribution of these SNPs to FPG in non-Europeans and children is unclear. We studied the association of 15 GWAS SNPs and a genotype score (GS) with FPG and 7 metabolic traits in 1,421 Mexican children and adolescents from Mexico City. Genotyping of the 15 SNPs was performed using TaqMan Open Array. We used multivariate linear regression models adjusted for age, sex, body mass index standard deviation score, and recruitment center. We identified significant associations between 3 SNPs (G6PC2 (rs560887), GCKR (rs1260326), MTNR1B (rs10830963)), the GS and FPG level. The FPG risk alleles of 11 out of the 15 SNPs (73.3%) displayed significant or non-significant beta values for FPG directionally consistent with those reported in adult European GWAS. The risk allele frequencies for 11 of 15 (73.3%) SNPs differed significantly in Mexican children and adolescents compared to European adults from the 1000G Project, but no significant enrichment in FPG risk alleles was observed in the Mexican population. Our data support a partial transferability of European GWAS FPG association signals in children and adolescents from the admixed Mexican population. PMID:27782183

  17. Staged venting of fuel cell system during rapid shutdown

    DOEpatents

    Keskula, Donald H.; Doan, Tien M.; Clingerman, Bruce J.

    2004-09-14

    A venting methodology and system for rapid shutdown of a fuel cell apparatus of the type used in a vehicle propulsion system. H.sub.2 and air flows to the fuel cell stack are slowly bypassed to the combustor upon receipt of a rapid shutdown command. The bypass occurs over a period of time (for example one to five seconds) using conveniently-sized bypass valves. Upon receipt of the rapid shutdown command, the anode inlet of the fuel cell stack is instantaneously vented to a remote vent to remove all H.sub.2 from the stack. Airflow to the cathode inlet of the fuel cell stack gradually diminishes over the bypass period, and when the airflow bypass is complete the cathode inlet is also instantaneously vented to a remote vent to eliminate pressure differentials across the stack.

  18. Staged venting of fuel cell system during rapid shutdown

    DOEpatents

    Clingerman, Bruce J.; Doan, Tien M.; Keskula, Donald H.

    2002-01-01

    A venting methodology and system for rapid shutdown of a fuel cell apparatus of the type used in a vehicle propulsion system. H.sub.2 and air flows to the fuel cell stack are slowly bypassed to the combustor upon receipt of a rapid shutdown command. The bypass occurs over a period of time (for example one to five seconds) using conveniently-sized bypass valves. Upon receipt of the rapid shutdown command, the anode inlet of the fuel cell stack is instantaneously vented to a remote vent to remove all H.sub.2 from the stack. Airflow to the cathode inlet of the fuel cell stack gradually diminishes over the bypass period, and when the airflow bypass is complete the cathode inlet is also instantaneously vented to a remote vent to eliminate pressure differentials across the stack.

  19. Evaluation of observable phase space by fast ion loss detector by calculating particle orbits in consideration of plasma facing components and three dimensional magnetic field

    NASA Astrophysics Data System (ADS)

    Shinohara, Kouji; Kim, Junghee; Kim, Jun Young; Rhee, Tongnyeol

    2016-11-01

    The orbits of lost ions can be calculated from the information obtained by a fast ion loss detector (FILD). The orbits suggest a source of the lost fast ions in a phase space. However, it is not obvious whether an observable set of orbits, or phase space, of a FILD appropriately covers the region of interest to be investigated since the observable phase space can be affected by plasma facing components (PFCs) and a magnetic configuration. A tool has been developed to evaluate the observable phase space of FILD diagnostic by calculating particle orbits by taking the PFCs and 3D magnetic field into account.

  20. Fast-ion radial diffusivity evaluated from vertical neutral particle measurements following short pulse beam injection into a TFTR ohmic plasma

    SciTech Connect

    Kusama, Y. . Naka Fusion Research Establishment); Heidbrink, W.W. ); Barnes, C.W. ); Beer, M.; Hammett, G.W.; McCune, D.C.; Medley, S.S.; Scott, S.D.; Zarnstorff, M.C. . Plasma Physics Lab.)

    1992-01-01

    The radial diffusivity of fast ions was evaluated from vertical neutral particle measurements in experiments where a short pulse of neutral deuterium beams was injected into a TFTR ohmic deuterium plasma. A comparison between the temporal evolution of the measured neutral particle flux and theoretical calculations showed that the spatially-averaged diffusion coefficient of fast ions is {le} 0.1 m{sup 2}/sec. This value is approximately an order of magnitude less than the diffusion coefficient for thermal ions and is consistent with results obtained previously on TFTR from other diagnostics.

  1. Oak Ridge National Laboratory Isotopes Facilities Shutdown Program Management Plan

    SciTech Connect

    Hill, L.G.; Eversole, R.E.; Kibbe, R.K.

    1992-05-01

    The goal of the Isotopes Facilities Shutdown Program (IFSP) is to place the isotopes facilities at ORNL in a radiologically and industrially safe condition for routine maintenance and surveillance prior to eventual decommissioning. Implementation and completion of the shutdown program will significantly reduce the risks to the environment and public safety and health. Furthermore, it should result in reduced surveillance and maintenance costs for future years. The IFSP Management Plan has been prepared to document the objectives, define or organizational relationships and responsibilities, and outline the management control systems to be employed in the management of the program.

  2. Puget Sound acidity levels drop after ASARCO shutdown

    SciTech Connect

    Not Available

    1987-07-01

    The levels of acidity in Puget Sound region rainfall have decreased significantly since the shutdown of the ASARCO copper smelter in Tacoma, Washington, according to a study funded by the US Environmental Protection Agency. Results indicate that sulfate and hydrogen ion concentrations obtained from samples taken before the closure were significantly different than those collected after the shutdown. Rainwater samples collected downwind during smelter operation were also significantly different from those collected upwind. Sulfur dioxide is considered to be one of the principal contributors to acid rain. The smelter was a major source of sulfur dioxide emissions in the Puget Sound region before it shut down in March 1985.

  3. Use of soft x-ray diagnostic on the COMPASS tokamak for investigations of sawteeth crash neighborhood and of plasma position using fast inversion methods

    SciTech Connect

    Imrisek, M.; Weinzettl, V.; Mlynar, J.; Panek, R.; Hron, M.; Odstrcil, T.; Odstrcil, M.; Ficker, O.; Pinzon, J. R.; Ehrlacher, C.

    2014-11-15

    The soft x-ray diagnostic is suitable for monitoring plasma activity in the tokamak core, e.g., sawtooth instability. Moreover, spatially resolved measurements can provide information about plasma position and shape, which can supplement magnetic measurements. In this contribution, fast algorithms with the potential for a real-time use are tested on the data from the COMPASS tokamak. In addition, the soft x-ray data are compared with data from other diagnostics in order to discuss possible connection between sawtooth instability on one side and the transition to higher confinement mode, edge localized modes and productions of runaway electrons on the other side.

  4. Use of soft x-ray diagnostic on the COMPASS tokamak for investigations of sawteeth crash neighborhood and of plasma position using fast inversion methodsa)

    NASA Astrophysics Data System (ADS)

    Imrisek, M.; Weinzettl, V.; Mlynar, J.; Odstrcil, T.; Odstrcil, M.; Ficker, O.; Pinzon, J. R.; Ehrlacher, C.; Panek, R.; Hron, M.

    2014-11-01

    The soft x-ray diagnostic is suitable for monitoring plasma activity in the tokamak core, e.g., sawtooth instability. Moreover, spatially resolved measurements can provide information about plasma position and shape, which can supplement magnetic measurements. In this contribution, fast algorithms with the potential for a real-time use are tested on the data from the COMPASS tokamak. In addition, the soft x-ray data are compared with data from other diagnostics in order to discuss possible connection between sawtooth instability on one side and the transition to higher confinement mode, edge localized modes and productions of runaway electrons on the other side.

  5. Use of soft x-ray diagnostic on the COMPASS tokamak for investigations of sawteeth crash neighborhood and of plasma position using fast inversion methods.

    PubMed

    Imrisek, M; Weinzettl, V; Mlynar, J; Odstrcil, T; Odstrcil, M; Ficker, O; Pinzon, J R; Ehrlacher, C; Panek, R; Hron, M

    2014-11-01

    The soft x-ray diagnostic is suitable for monitoring plasma activity in the tokamak core, e.g., sawtooth instability. Moreover, spatially resolved measurements can provide information about plasma position and shape, which can supplement magnetic measurements. In this contribution, fast algorithms with the potential for a real-time use are tested on the data from the COMPASS tokamak. In addition, the soft x-ray data are compared with data from other diagnostics in order to discuss possible connection between sawtooth instability on one side and the transition to higher confinement mode, edge localized modes and productions of runaway electrons on the other side. PMID:25430340

  6. Use of soft x-ray diagnostic on the COMPASS tokamak for investigations of sawteeth crash neighborhood and of plasma position using fast inversion methods.

    PubMed

    Imrisek, M; Weinzettl, V; Mlynar, J; Odstrcil, T; Odstrcil, M; Ficker, O; Pinzon, J R; Ehrlacher, C; Panek, R; Hron, M

    2014-11-01

    The soft x-ray diagnostic is suitable for monitoring plasma activity in the tokamak core, e.g., sawtooth instability. Moreover, spatially resolved measurements can provide information about plasma position and shape, which can supplement magnetic measurements. In this contribution, fast algorithms with the potential for a real-time use are tested on the data from the COMPASS tokamak. In addition, the soft x-ray data are compared with data from other diagnostics in order to discuss possible connection between sawtooth instability on one side and the transition to higher confinement mode, edge localized modes and productions of runaway electrons on the other side.

  7. Influence of the physiological variability of fasted gastric pH and tablet retention time on the variability of in vitro dissolution and simulated plasma profiles.

    PubMed

    Kovačič, Nataša Nagelj; Pišlar, Mitja; Ilić, Ilija; Mrhar, Aleš; Bogataj, Marija

    2014-10-01

    The aim of the present study was to show that the physiological variability of fasted gastric pH and tablet gastric retention time contributes to the overall variability of simulated plasma profiles of diclofenac. Those two parameters were implemented into dissolution study and plasma profiles were simulated under assumptions that in vitro dissolution well represents that occurring in vivo, and that absorption profiles are identical to dissolution profiles, as diclofenac is a highly permeable drug. Dissolution experiments were performed using USP 2 apparatus and two consecutive dissolution media, namely, an acidic medium of various pH (ranging from 1-3), where tablets were kept for a certain time (10-200 min), and phosphate buffer (pH 6.8). It was shown that the acid pH value and acid retention time of tablets affect in vitro drug release, and consequently also influence the simulated plasma profiles. Lower acid pH resulted in lower plasma peaks at each studied acid retention time. Longer acid retention time caused lower plasma concentrations at lower acid pH values, whereas at pH 3 higher plasma concentrations were noted. Additionally, it was demonstrated that the variability of both parameters represents an important contribution to the overall variability of plasma profiles.

  8. Determinants of Fasting Plasma Glucose and Glycosylated Hemoglobin Among Low Income Latinos with Poorly Controlled Type 2 Diabetes

    PubMed Central

    Kollannoor-Samuel, Grace; Chhabra, Jyoti; Fernandez, Maria Luz; Vega-LÓpez, Sonia; Pérez, Sofia Segura; Damio, Grace; Calle, Mariana C.; D’Agostino, Darrin; Pérez-Escamilla, Rafael

    2011-01-01

    The objective of this study was to identify demographic, socio-economic, acculturation, lifestyle, sleeping pattern, and biomedical determinants of fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA1c), among Latinos with type 2 diabetes (T2D). Latino adults (N = 211) with T2D enrolled in the DIALBEST trial were interviewed in their homes. Fasting blood samples were also collected in the participants’ homes. Because all participants had poor glucose control, above-median values for FPG (173 mg/dl) and HbA1c (9.2%) were considered to be indicative of poorer glycemic control. Multivariate analyses showed that receiving heating assistance (OR: 2.20; 95% CI: 0.96–4.96), and having a radio (3.11, 1.16–8.35), were risk factors for higher FPG levels, and lower income (10.4, 1.54–69.30) was a risk factor for higher HbA1c levels. Lower carbohydrate intake during the previous day (0.04; 0.005–0.37), as well as regular physical activity (0.30; 0.13–0.69), breakfast (2.78; 1.10–6.99) and dinner skipping (3.9; 1.03–14.9) during previous week were significantly associated with FPG concentrations. Being middle aged (2.24, 1.12–4.47), 30–60 min of sleep during the day time (0.07, 0.01–0.74) and having medical insurance (0.31, 0.10–0.96) were predictors of HbA1c. Results suggest that contemporaneous lifestyle behaviors were associated with FPG and contextual biomedical factors such as health care access with HbA1c. Lower socio-economic status indicators were associated with poorer FPG and HbA1c glycemic control. PMID:21181446

  9. Comparison of the Current Diagnostic Criterion of HbA1c with Fasting and 2-Hour Plasma Glucose Concentration

    PubMed Central

    Karnchanasorn, Rudruidee; Huang, Jean; Feng, Wei; Chuang, Lee-Ming

    2016-01-01

    To determine the effectiveness of hemoglobin A1c (HbA1c) ≥ 6.5% in diagnosing diabetes compared to fasting plasma glucose (FPG) ≥ 126 mg/dL and 2-hour plasma glucose (2hPG) ≥ 200 mg/dL in a previously undiagnosed diabetic cohort, we included 5,764 adult subjects without established diabetes for whom HbA1c, FPG, 2hPG, and BMI measurements were collected. Compared to the FPG criterion, the sensitivity of HbA1c ≥ 6.5% was only 43.3% (106 subjects). Compared to the 2hPG criterion, the sensitivity of HbA1c ≥ 6.5% was only 28.1% (110 subjects). Patients who were diabetic using 2hPG criterion but had HbA1c < 6.5% were more likely to be older (64 ± 15 versus 60 ± 15 years old, P = 0.01, mean ± STD), female (53.2% versus 38.2%, P = 0.008), leaner (29.7 ± 6.1 versus 33.0 ± 6.6 kg/m2, P = 0.000005), and less likely to be current smokers (18.1% versus 29.1%, P = 0.02) as compared to those with HbA1c ≥ 6.5%. The diagnostic agreement in the clinical setting revealed the current HbA1c ≥ 6.5% is less likely to detect diabetes than those defined by FPG and 2hPG. HbA1c ≥ 6.5% detects less than 50% of diabetic patients defined by FPG and less than 30% of diabetic patients defined by 2hPG. When the diagnosis of diabetes is in doubt by HbA1c, FPG and/or 2hPG should be obtained.

  10. Comparison of the Current Diagnostic Criterion of HbA1c with Fasting and 2-Hour Plasma Glucose Concentration.

    PubMed

    Karnchanasorn, Rudruidee; Huang, Jean; Ou, Horng-Yih; Feng, Wei; Chuang, Lee-Ming; Chiu, Ken C; Samoa, Raynald

    2016-01-01

    To determine the effectiveness of hemoglobin A1c (HbA1c) ≥ 6.5% in diagnosing diabetes compared to fasting plasma glucose (FPG) ≥ 126 mg/dL and 2-hour plasma glucose (2hPG) ≥ 200 mg/dL in a previously undiagnosed diabetic cohort, we included 5,764 adult subjects without established diabetes for whom HbA1c, FPG, 2hPG, and BMI measurements were collected. Compared to the FPG criterion, the sensitivity of HbA1c ≥ 6.5% was only 43.3% (106 subjects). Compared to the 2hPG criterion, the sensitivity of HbA1c ≥ 6.5% was only 28.1% (110 subjects). Patients who were diabetic using 2hPG criterion but had HbA1c < 6.5% were more likely to be older (64 ± 15 versus 60 ± 15 years old, P = 0.01, mean ± STD), female (53.2% versus 38.2%, P = 0.008), leaner (29.7 ± 6.1 versus 33.0 ± 6.6 kg/m(2), P = 0.000005), and less likely to be current smokers (18.1% versus 29.1%, P = 0.02) as compared to those with HbA1c ≥ 6.5%. The diagnostic agreement in the clinical setting revealed the current HbA1c ≥ 6.5% is less likely to detect diabetes than those defined by FPG and 2hPG. HbA1c ≥ 6.5% detects less than 50% of diabetic patients defined by FPG and less than 30% of diabetic patients defined by 2hPG. When the diagnosis of diabetes is in doubt by HbA1c, FPG and/or 2hPG should be obtained. PMID:27597979

  11. Comparison of the Current Diagnostic Criterion of HbA1c with Fasting and 2-Hour Plasma Glucose Concentration

    PubMed Central

    Karnchanasorn, Rudruidee; Huang, Jean; Feng, Wei; Chuang, Lee-Ming

    2016-01-01

    To determine the effectiveness of hemoglobin A1c (HbA1c) ≥ 6.5% in diagnosing diabetes compared to fasting plasma glucose (FPG) ≥ 126 mg/dL and 2-hour plasma glucose (2hPG) ≥ 200 mg/dL in a previously undiagnosed diabetic cohort, we included 5,764 adult subjects without established diabetes for whom HbA1c, FPG, 2hPG, and BMI measurements were collected. Compared to the FPG criterion, the sensitivity of HbA1c ≥ 6.5% was only 43.3% (106 subjects). Compared to the 2hPG criterion, the sensitivity of HbA1c ≥ 6.5% was only 28.1% (110 subjects). Patients who were diabetic using 2hPG criterion but had HbA1c < 6.5% were more likely to be older (64 ± 15 versus 60 ± 15 years old, P = 0.01, mean ± STD), female (53.2% versus 38.2%, P = 0.008), leaner (29.7 ± 6.1 versus 33.0 ± 6.6 kg/m2, P = 0.000005), and less likely to be current smokers (18.1% versus 29.1%, P = 0.02) as compared to those with HbA1c ≥ 6.5%. The diagnostic agreement in the clinical setting revealed the current HbA1c ≥ 6.5% is less likely to detect diabetes than those defined by FPG and 2hPG. HbA1c ≥ 6.5% detects less than 50% of diabetic patients defined by FPG and less than 30% of diabetic patients defined by 2hPG. When the diagnosis of diabetes is in doubt by HbA1c, FPG and/or 2hPG should be obtained. PMID:27597979

  12. 40 CFR 1037.660 - Automatic engine shutdown systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Automatic engine shutdown systems. 1037.660 Section 1037.660 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR VEHICLES Special Compliance...

  13. 49 CFR 192.167 - Compressor stations: Emergency shutdown.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... events: (1) In the case of an unattended compressor station: (i) When the gas pressure equals the maximum... (2) In the case of a compressor station in a building: (i) When an uncontrolled fire occurs in the... 49 Transportation 3 2012-10-01 2012-10-01 false Compressor stations: Emergency shutdown....

  14. 49 CFR 192.167 - Compressor stations: Emergency shutdown.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... events: (1) In the case of an unattended compressor station: (i) When the gas pressure equals the maximum... (2) In the case of a compressor station in a building: (i) When an uncontrolled fire occurs in the... 49 Transportation 3 2011-10-01 2011-10-01 false Compressor stations: Emergency shutdown....

  15. 49 CFR 192.167 - Compressor stations: Emergency shutdown.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... events: (1) In the case of an unattended compressor station: (i) When the gas pressure equals the maximum... (2) In the case of a compressor station in a building: (i) When an uncontrolled fire occurs in the... 49 Transportation 3 2014-10-01 2014-10-01 false Compressor stations: Emergency shutdown....

  16. 49 CFR 192.167 - Compressor stations: Emergency shutdown.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... events: (1) In the case of an unattended compressor station: (i) When the gas pressure equals the maximum... (2) In the case of a compressor station in a building: (i) When an uncontrolled fire occurs in the... 49 Transportation 3 2013-10-01 2013-10-01 false Compressor stations: Emergency shutdown....

  17. 49 CFR 192.167 - Compressor stations: Emergency shutdown.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... events: (1) In the case of an unattended compressor station: (i) When the gas pressure equals the maximum... (2) In the case of a compressor station in a building: (i) When an uncontrolled fire occurs in the... 49 Transportation 3 2010-10-01 2010-10-01 false Compressor stations: Emergency shutdown....

  18. Avoiding compressor surge during emergency shutdown hybridturbine systems

    SciTech Connect

    Pezzini, Paolo; Tucker, David; Traverso, Alberto

    2013-01-01

    A new emergency shutdown procedure for a direct-fired fuel cell turbine hybrid power system was evaluated using a hardware-based simulation of an integrated gasifier/fuel cell/turbine hybrid cycle (IGFC), implemented through the Hybrid Performance (Hyper) project at the National Energy Technology Laboratory, U.S. Department of Energy (NETL). The Hyper facility is designed to explore dynamic operation of hybrid systems and quantitatively characterize such transient behavior. It is possible to model, test, and evaluate the effects of different parameters on the design and operation of a gasifier/fuel cell/gas turbine hybrid system and provide a means of quantifying risk mitigation strategies. An open-loop system analysis regarding the dynamic effect of bleed air, cold air bypass, and load bank is presented in order to evaluate the combination of these three main actuators during emergency shutdown. In the previous Hybrid control system architecture, catastrophic compressor failures were observed when the fuel and load bank were cut off during emergency shutdown strategy. Improvements were achieved using a nonlinear fuel valve ramp down when the load bank was not operating. Experiments in load bank operation show compressor surge and stall after emergency shutdown activation. The difficulties in finding an optimal compressor and cathode mass flow for mitigation of surge and stall using these actuators are illustrated.

  19. 30 CFR 250.603 - Emergency shutdown system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Emergency shutdown system. 250.603 Section 250.603 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Workover Operations § 250.603...

  20. 2004 Fermilab fall shutdown p-bar water issues

    SciTech Connect

    Dyer, Albert; Schneider, Frank; /Fermilab

    2004-11-01

    I was assigned to Frank Schneider, who works within the Accelerator Division Water Group. Frank would educate me with issues pertaining to water flow cooling at the P-Bar facility. Also during the shutdown period, water issues in the Pre-Vault Stub Room would be addressed.

  1. Multiple Functional Polymorphisms in the G6PC2 Gene Contribute to the Association with Higher Fasting Plasma Glucose Levels

    PubMed Central

    Baerenwald, D. A.; Bonnefond, A.; Bouatia-Naji, N.; Flemming, B. P.; Umunakwe, O. C.; Oeser, J. K.; Pound, L. D.; Conley, N. L.; Cauchi, S.; Lobbens, S.; Eury, E.; Balkau, B.; Lantieri, O.; Dadi, P. K.; Jacobson, D. A.; Froguel, P.; O’Brien, R. M.

    2014-01-01

    Aims We previously identified the G6PC2 locus as a strong determinant of fasting plasma glucose (FPG) and showed that a common G6PC2 intronic single nucleotide polymorphism (SNP) (rs560887) and two common G6PC2 promoter SNPs (rs573225 and rs13431652) are highly associated with FPG. However, these promoter SNPs have complex effects on G6PC2 fusion gene expression, and our data suggested that only rs13431652 is a potentially causative SNP. Here we examine the effect of rs560887 on G6PC2 pre-mRNA splicing and the contribution of an additional common G6PC2 promoter SNP, rs2232316, to the association signal. Methods Mini-gene analyzes characterized the effect of rs560887 on G6PC2 pre-mRNA splicing. Fusion gene and gel retardation analyses characterized the effect of rs2232316 on G6PC2 promoter activity and transcription factor binding. The genetic association of rs2232316 with FPG variation was assessed using regression adjusted for age, gender and body mass index in 4,220 Europeans with normal FPG. Results & Conclusions The rs560887-G allele was shown to enhance G6PC2 pre-mRNA splicing while the rs2232316-A allele enhanced G6PC2 transcription by promoting Foxa2 binding. Genetic analyses provide evidence for association of the rs2232316-A allele with increased FPG (β=0.04 mmol/l; P=4.3×10−3) as part of the same signal as rs560887, rs573225 and rs13431652. As with rs13431652 the in situ functional data with rs560887 and rs2232316 are in accord with the putative function of G6PC2 in pancreatic islets and suggest that all three are potentially causative SNPs that contribute to the association between G6PC2 and FPG. PMID:23508304

  2. High-harmonic Fast Wave Heating and Current Drive Results for Deuterium H-mode Plasmas in the National Spherical Torus Experiment

    SciTech Connect

    G. Taylor, P.T. Bonoli, R.W. Harvey, J.C. hosea, E.F. Jaeger, B.P. LeBlanc, C.K. Phillisp, P.M. Ryan, E.J. Valeo, J.R. Wilson, J.C. Wright, and the NSTX Team

    2012-07-25

    A critical research goal for the spherical torus (ST) program is to initiate, ramp-up, and sustain a discharge without using the central solenoid. Simulations of non-solenoidal plasma scenarios in the National Spherical Torus Experiment (NSTX) [1] predict that high-harmonic fast wave (HHFW) heating and current drive (CD) [2] can play an important roll in enabling fully non-inductive (fNI {approx} 1) ST operation. The NSTX fNI {approx} 1 strategy requires 5-6 MW of HHFW power (PRF) to be coupled into a non-inductively generated discharge [3] with a plasma current, Ip {approx} 250-350 kA, driving the plasma into an HHFW H-mode with Ip {approx} 500 kA, a level where 90 keV deuterium neutral beam injection (NBI) can heat the plasma and provide additional CD. The initial approach on NSTX has been to heat Ip {approx} 300 kA, inductively heated, deuterium plasmas with CD phased HHFW power [2], in order to drive the plasma into an H-mode with fNI {approx} 1.

  3. Rotation dependence of a phase delay between plasma edge electron density and temperature fields due to a fast rotating, resonant magnetic perturbation field

    SciTech Connect

    Stoschus, H.; Schmitz, O.; Frerichs, H.; Unterberg, B.; Abdullaev, S. S.; Clever, M.; Coenen, J. W.; Kruezi, U.; Schega, D.; Samm, U.; Jakubowski, M. W.

    2010-06-15

    Measurements of the plasma edge electron density n{sub e} and temperature T{sub e} fields during application of a fast rotating, resonant magnetic perturbation (RMP) field show a characteristic modulation of both, n{sub e} and T{sub e} coherent to the rotation frequency of the RMP field. A phase delay PHI between the n{sub e}(t) and T{sub e}(t) waveforms is observed and it is demonstrated that this phase delay PHI is a function of the radius with PHI(r) depending on the relative rotation of the RMP field and the toroidal plasma rotation. This provides for the first time direct experimental evidence for a rotation dependent damping of the external RMP field in the edge layer of a resistive high-temperature plasma which breaks down at low rotation and high resonant field amplitudes.

  4. 77 FR 75198 - Standard Format and Content for Post-Shutdown Decommissioning Activities Report

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-19

    ... COMMISSION Standard Format and Content for Post-Shutdown Decommissioning Activities Report AGENCY: Nuclear... Format and Content for Post-shutdown Decommissioning Activities Report.'' This guide describes a method...) 1.185, ``Standard Format and Content for Post-shutdown Decommissioning Activities Report,''...

  5. Association of consecutive Pi2-Ps6 band pulsations with earthward fast flows in the plasma sheet in response to IMF variations

    NASA Astrophysics Data System (ADS)

    Cheng, Ching-Chang; Mann, Ian R.; Baumjohann, Wolfgang

    2014-05-01

    On 11 March 2009, the H component had four consecutive bay-like variations accompanied by positive and negative deflections in the D component across the Atlantic like those affected by the substorm current wedge formation. A train of pulsations with a frequency range 2-10 mHz (referred to as Pi2-Ps6 band), sensed by Time History of Events and Macroscale Interactions during Substorms (THEMIS)/Canadian Array for Real-time Investigations of Magnetic Activity (CARISMA) magnetometers, had clearly three consecutive Pi2s followed by a Ps6 at low latitudes, but first Pi2 and then Ps6 at high latitudes mixed with large-amplitude Ps6 at midlatitudes. The geostationary orbit magnetometers sensed similar magnetic perturbations. THEMIS probes first observed earthward fast flows, magnetic dipolarizations, and modulated energetic particle fluxes at ~ XGSM -9.2 RE, then at ~ XGSM -7.5 RE for Pi2 and at ~ XGSM -18.0 RE only for Ps6. They appeared during a very quiet period for northward interplanetary magnetic field (IMF) with a clock angle variation of low to high and then low. The H spectrum shows two harmonic frequencies ~2-4 mHz and ~8-10 mHz but the D spectrum one dominant frequency ~2-4 mHz. Pi2 can result from a combination of fast magnetospheric and plasmaspheric cavity resonances and Ps6 from a fast magnetospheric cavity resonance. The surface waves at the interface separating braking earthward fast flows from the ambient plasma convection region could lead to large-amplitude Ps6 at midlatitudes. Hence, consecutive Pi2-Ps6 band pulsations can be associated with earthward fast flows in the plasma sheet, expectedly driven by magnetotail reconnection, respectively, in the near-Earth region and the distant Earth one in response to IMF variations as in the two-neutral-point model.

  6. Effect of intake on fasting heat production, respiratory quotient and plasma metabolites measured using the washed rumen technique

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective was to investigate the effect of intake prior to fasting on concentrations of metabolites and hormones, respiratory quotient (RQ) and fasting heat production (HP) using the washed rumen technique and to compare these values with those from the fed state. Six Holstein steers (360 ± 22 k...

  7. Fasting Plasma Insulin Concentrations Are Associated With Changes in Hepatic Fatty Acid Synthesis and Partitioning Prior to Changes in Liver Fat Content in Healthy Adults.

    PubMed

    Pramfalk, Camilla; Pavlides, Michael; Banerjee, Rajarshi; McNeil, Catriona A; Neubauer, Stefan; Karpe, Fredrik; Hodson, Leanne

    2016-07-01

    Resistance to the action of insulin affects fatty acid delivery to the liver, fatty acid synthesis and oxidation within the liver, and triglyceride export from the liver. To understand the metabolic consequences of hepatic fatty acid synthesis, partitioning, oxidation, and net liver fat content in the fasted and postprandial states, we used stable-isotope tracer methodologies to study healthy men and women with varying degrees of insulin resistance before and after consumption of a mixed meal. Subjects were classified as being normoinsulinemic (NI) (fasting plasma insulin <11.2 mU/L, n = 18) or hyperinsulinemic (HI) (fasting plasma insulin >11.2 mU/L, n = 19). Liver fat content was similar between HI and NI individuals, despite HI subjects having marginally more visceral fat. However, de novo lipogenesis was higher and fatty acid oxidation was lower in HI individuals compared with NI subjects. These data suggest that metabolic pathways promoting fat accumulation are enhanced in HI but, paradoxically, without any significant effect on liver fat content when observed in healthy people. This is likely to be explained by increased triglyceride secretion as observed by hypertriglyceridemia. PMID:27207513

  8. Validation of fast-ion D-alpha spectrum measurements during EAST neutral-beam heated plasmas

    NASA Astrophysics Data System (ADS)

    Huang, J.; Heidbrink, W. W.; von Hellermann, M. G.; Stagner, L.; Wu, C. R.; Hou, Y. M.; Chang, J. F.; Ding, S. Y.; Chen, Y. J.; Zhu, Y. B.; Jin, Z.; Xu, Z.; Gao, W.; Wang, J. F.; Lyu, B.; Zang, Q.; Zhong, G. Q.; Hu, L.; Wan, B.

    2016-11-01

    To investigate the fast ion behavior, a fast ion D-alpha (FIDA) diagnostic system has been installed on EAST. Fast ion features can be inferred from the Doppler shifted spectrum of Balmer-alpha light from energetic hydrogenic atoms. This paper will focus on the validation of FIDA measurements performed using MHD-quiescent discharges in 2015 campaign. Two codes have been applied to calculate the Dα spectrum: one is a Monte Carlo code, Fortran 90 version FIDASIM, and the other is an analytical code, Simulation of Spectra (SOS). The predicted SOS fast-ion spectrum agrees well with the measurement; however, the level of fast-ion part from FIDASIM is lower. The discrepancy is possibly due to the difference between FIDASIM and SOS velocity distribution function. The details will be presented in the paper to primarily address comparisons of predicted and observed spectrum shapes/amplitudes.

  9. Preliminary Evaluation of Removing Used Nuclear Fuel from Shutdown Sites

    SciTech Connect

    Maheras, Steven J.; Best, Ralph E.; Ross, Steven B.; Buxton, Kenneth A.; England, Jeffery L.; McConnell, Paul E.; Massaro, Lawrence M.; Jensen, Philip J.

    2014-10-01

    This report presents a preliminary evaluation of removing used nuclear fuel (UNF) from 12 shutdown nuclear power plant sites. At these shutdown sites the nuclear power reactors have been permanently shut down and the sites have been decommissioned or are undergoing decommissioning. The shutdown sites are Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, Zion, Crystal River, Kewaunee, and San Onofre. The evaluation was divided into four components: characterization of the UNF and greater-than-Class C low-level radioactive waste (GTCC waste) inventory; a description of the on-site infrastructure and conditions relevant to transportation of UNF and GTCC waste; an evaluation of the near-site transportation infrastructure and experience relevant to shipping transportation casks containing UNF and GTCC waste, including identification of gaps in information; and, an evaluation of the actions necessary to prepare for and remove UNF and GTCC waste. The primary sources for the inventory of UNF and GTCC waste are the U.S. Department of Energy (DOE) RW-859 used nuclear fuel inventory database, industry sources such as StoreFUEL and SpentFUEL, and government sources such as the U.S. Nuclear Regulatory Commission. The primary sources for information on the conditions of site and near-site transportation infrastructure and experience included observations and information collected during visits to the Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, and Zion sites; information provided by managers at the shutdown sites; Facility Interface Data Sheets compiled for DOE in 2005; Services Planning Documents prepared for DOE in 1993 and 1994; industry publications such as Radwaste Solutions; and Google Earth. State and Regional Group representatives, a Tribal representative, and a Federal Railroad Administration representative participated in six of the shutdown site

  10. Emergency shutdown systems: Improved understanding of design requirements

    SciTech Connect

    Bratland, O.

    1995-12-01

    Wellhead- and process emergency shutdown systems are complex in the sense that their design has to rely on knowledge from many different disciplines. This paper discusses the most common weaknesses in traditional ESD system design and proposes some modifications with emphasis on the hydraulic part of topside ESD systems. The information is based on inspections carried out on most installations in the Norwegian sector of the North Sea, countless interviews of offshore personnel and design experience from some of the largest platforms in the world. It also outlines possible simplifications and cost savings during upgrading of old systems. A newly developed valve that has the potential to reduce complexity and save costs in ESD systems is presented. In subsea control systems, the new technology can reduce installation costs considerably by reducing the need for electrical cables. The paper is relevant to designers of wellhead and process emergency shutdown systems, hydraulic power units, and accumulator banks.

  11. Dynamic responses of a semi-type offshore floating wind turbine during normal state and emergency shutdown

    NASA Astrophysics Data System (ADS)

    Hu, Zhi-qiang; Li, Liang; Wang, Jin; Hu, Qiu-hao; Shen, Ma-cheng

    2016-03-01

    This paper addresses joint wind-wave induced dynamic responses of a semi-type offshore floating wind turbine (OFWT) under normal states and fault event conditions. The analysis in this paper is conducted in time domain, using an aero-hydro-servo-elastic simulation code-FAST. Owing to the unique viscous features of the reference system, the original viscous damping model implemented in FAST is replaced with a quadratic one to gain an accurate capture of viscous effects. Simulation cases involve free-decay motion in still water, steady motions in the presence of regular waves and wind as well as dynamic response in operational sea states with and without wind. Simulations also include the cases for transient responses induced by fast blade pitching after emergency shutdown. The features of platform motions, local structural loads and a typical mooring line tension force under a variety of excitations are obtained and investigated.

  12. Gender, but not CYP7A1 or SLCO1B1 polymorphism, affects the fasting plasma concentrations of bile acids in human beings.

    PubMed

    Xiang, Xiaoqiang; Backman, Janne T; Neuvonen, Pertti J; Niemi, Mikko

    2012-03-01

    Cholesterol 7α-hydroxylase (CYP7A1) is the rate-limiting enzyme of bile acid production in human beings, and organic anion-transporting polypeptide 1B1 (OATP1B1) may influence bile acid hepatic uptake and cholesterol and bile acid synthesis rate. Our purpose was to investigate the effects of gender and CYP7A1 and SLCO1B1 polymorphisms on the fasting plasma concentrations of bile acids, bile acid synthesis marker and total cholesterol in a Finnish population. Fasting plasma concentrations of 16 endogenous bile acids, their synthesis marker (7α-hydroxy-4-cholesten-3-one) and total cholesterol were measured in 243 samples from 143 healthy volunteers. The volunteers were genotyped for 6 haplotype-tagging single-nucleotide polymorphisms (SNPs) of CYP7A1 and two functionally relevant SNPs in SLCO1B1. The mean plasma concentrations of chenodeoxycholic acid, glycochenodeoxycholic acid, ursodeoxycholic acid and glycoursodeoxycholic acid were 61-111% higher in men than in women (P ≤ 0.001). Accordingly, the mean concentration of total bile acids was 51% higher in men than in women (P = 0.001). The CYP7A1 rs8192879 and rs1023652 SNPs were associated with deoxycholic acid and hyodeoxycholic acid concentrations, respectively, but the associations were not significant after correction for multiple testing. None of the six CYP7A1 SNPs was associated with the plasma concentrations of cholesterol or 7α-hydroxy-4-cholesten-3-one. SLCO1B1 genotype was associated with total plasma cholesterol concentration only, but the association was not significant after correction for multiple testing. In general, the gender contributes substantially more to variation in fasting plasma bile acid concentrations than CYP7A1 or SLCO1B1 polymorphism do. Common genetic variability in CYP7A1 is unlikely to play a significant role in cholesterol metabolism and bile acid homeostasis under normal physiological conditions.

  13. Precluding forced plant shutdown; Long-term management effectiveness

    SciTech Connect

    Hildebrandt, P.C.; Piccolo, S.F. )

    1989-01-01

    Several operating nuclear plants have been forced to shut down for extended periods because of transient events, equipment failures or information pointing to degradation in programmatic elements such as overall corporate and plant management, material condition, maintenance and design control. The consequent management and programmatic overhauls, and demonstration of plant operational readiness takes a substantial toll on the financial and management health of the owner utility. The accompanying regulatory and political attention makes it difficult, at best, for the utility to be master of its own destiny regarding recovery of the troubled plant. How best can a utility control its own destiny in these circumstances The preferred approach,of course, is to preclude an unrecognized problem in any of the above-mentioned areas from causing the forced shutdown of a plant. Based on experience at a formerly troubled plant,this paper suggests how to preclude forced shutdown, or if forced into an extended shutdown, how the utility can manage and control its own actions for recovery.

  14. Establishment of a time-resolved fluoroimmunoassay for measuring plasma insulin-like growth factor I (IGF-I) in fish: effect of fasting on plasma concentrations and tissue mRNA expression of IGF-I and growth hormone (GH) in channel catfish (Ictalurus punctatus).

    PubMed

    Small, Brian C; Peterson, Brian C

    2005-02-01

    A time-resolved fluoroimmunoassay (TR-FIA) was established and validated that allows for the determination of plasma concentrations of insulin-like growth factor I (IGF-I) in three domestically cultured fishes: channel catfish (Ictalurus punctatus), hybrid striped bass (Morone chrysopsxM. saxatilis), and rainbow trout (Oncorhynchus mykiss). Sensitivity of the assay was 0.20 ng/ml. Intra- and inter-assay coefficients of variation (CV) were <7 and <12%, respectively. Serial dilutions of plasma from each species were parallel to the standard curve. Recovery of IGF-I from spiked plasma samples was >90% for all three species of fishes. The IGF-I TR-FIA was biologically validated via its use to determine the effect of fasting on circulating IGF-I levels in channel catfish. Fasting-induced changes in plasma growth hormone (GH), hepatic IGF-I mRNA expression, and pituitary GH mRNA expression were also determined. Fasted channel catfish lost 5.6 and 15.6% body mass after 2 and 4 weeks of fasting, respectively. Plasma IGF-I concentrations were depressed (P<0.05) relative to fed controls following 2 and 4 weeks of fasting. Plasma GH concentrations were not different (P>0.05) in fasted fish after 2 weeks, but significantly increased (P<0.05) by 4 weeks of fasting. Hepatic IGF-I mRNA expression after 2 and 4 weeks of fasting was reduced (P<0.05) relative to fed controls. Pituitary GH mRNA expression was similar (P>0.05) between 2-week-fasted catfish and fed controls, but was increased (P<0.05) in 4-week-fasted catfish. The IGF-I TR-FIA was sensitive, accurate, and precise for all three species of fishes, and provided a low-cost, and non-radioisotopic method for quantifying plasma IGF-I levels in fed and fasted channel catfish.

  15. Parametric excitation of coupled fast and slow upper hybrid waves by counter-propagating circularly polarized lasers in a magnetized plasma

    NASA Astrophysics Data System (ADS)

    Verma, Kanika; Baliyan, Sweta; Sajal, Vivek; Kumar, Ravindra; Sharma, Navneet K.

    2016-07-01

    The parametric decay of large amplitude non-resonant beating mode of counter-propagating lasers (having a frequency difference ≥ 2 ω p ) into a pair of upper hybrid waves is studied in magnetized plasma. One of the excited upper hybrid waves (known as fast wave) having phase velocity close to c , can be utilized for electron acceleration. The coupled mode equations of fast and slow upper hybrid waves are modelled by solving equation of motion and continuity equation simultaneously (using the density perturbation technique) to derive the dispersion relation for two plasmon decay process. The growth rate of the present excitation process using right circularly polarized beating lasers is higher as compared with the growth rates of the excitation processes using ordinary and extraordinary beating lasers. However, the growth rate is not significant in the case of left circularly polarized beating lasers. The growth rate ˜ 0.15 ω p s - 1 is achieved for right circularly polarized beating lasers having v 1 , 2 / c = 0.1 for scattering angle θ s ˜ 160 ° and applied magnetic field ˜ 90 T. The growth rate of fast upper hybrid wave was reduced with the applied axial magnetic field in the present case. The present work is not only significant for the electron acceleration by fast upper hybrid wave but also for diagnostic purpose.

  16. Fast growth of ultrananocrystalline diamond films by bias-enhanced nucleation and growth process in CH{sub 4}/Ar plasma

    SciTech Connect

    Saravanan, A.; Huang, B. R.; Sankaran, K. J.; Tai, N. H.; Dong, C. L.; Lin, I. N.

    2014-05-05

    This letter describes the fast growth of ultrananocrystalline diamond (UNCD) films by bias-enhanced nucleation and growth process in CH{sub 4}/Ar plasma. The UNCD grains were formed at the beginning of the film's growth without the necessity of forming the amorphous carbon interlayer, reaching a thickness of ∼380 nm in 10 min. Transmission electron microscopic investigations revealed that the application of bias voltage induced the formation of graphitic phase both in the interior and at the interface regions of UNCD films that formed interconnected paths, facilitating the transport of electrons and resulting in enhanced electron field emission properties.

  17. Comparative study of amplified spontaneous emission and short pre-pulse impacts onto fast electron generation at sub-relativistic femtosecond laser-plasma interaction

    NASA Astrophysics Data System (ADS)

    Ivanov, K. A.; Shulyapov, S. A.; Ksenofontov, P. A.; Tsymbalov, I. N.; Volkov, R. V.; Savel'ev, A. B.; Brantov, A. V.; Bychenkov, V. Yu.; Turinge, A. A.; Lapik, A. M.; Rusakov, A. V.; Djilkibaev, R. M.; Nedorezov, V. G.

    2014-09-01

    This paper describes the study of hot electron generation under the action of intense (˜1018 W/cm2) femtosecond pulses onto the surface of a solid target, in the presence of a long pre-plasma, which varied with different spatial extents and densities. The corona was formed by pre-pulses with varied intensities and temporal profiles (amplified spontaneous emission (ASE) and short pre-pulses). The most efficient fast electron acceleration, to energies well beyond the ponderomotive potential, was observed if the ASE was able to form to the extent of ˜100 μm a slightly undercritical plasma. Energy of accelerated electrons underwent further growth if the laser pulse duration increased from ˜45 to ˜350 fs at constant energy fluence. The experimental results were supported by numerical simulations using 3D3V Mandor PIC code.

  18. Transient effects in beam-plasma interactions in a space simulation chamber stimulated by a fast pulse electron gun

    NASA Technical Reports Server (NTRS)

    Raitt, W. J.; Banks, P. M.; Denig, W. F.; Anderson, H. R.

    1982-01-01

    Interest in the interaction of electron beams with plasma generated by ionization caused by the primary electron beam was stimulated by the need to develop special vacuum tubes to operate in the kMHz frequency region. The experiments of Getty and Smullin (1963) indicated that the interaction of an energetic electron beam with its self-produced plasma resulted in the emission of wave energy over a wide range of frequencies associated with cyclotron and longitudinal plasma instabilities. This enhanced the thermal plasma density in the vicinity of the beam, and the term Beam-Plasma Discharge (BPD) was employed to described this phenomenon. The present investigation is concerned with some of the transient phenomena associated with wave emission during the beam switch-on and switch-off periods. Results are presented on the changes in electron energy spectra on a time scale of tens of milliseconds following beam switch-on. The results are discussed in terms of the beam plasma discharge phenomenon.

  19. Study of Pre-Plasma Effects on Fast Electron Generation and Transport using the Split Pulse Titan Laser

    NASA Astrophysics Data System (ADS)

    Peebles, J.; Krauland, C. M.; McGuffey, C.; Sorokovikova, A.; Hua, R.; Wei, M. S.; Kerr, S.; Curry, C.; Sio, H.; Forestier-Colleoni, P.; Santos, J.; McLean, H. S.; Krasheninnikov, S.; Beg, F. N.

    2015-11-01

    Relativistic laser plasma interactions (LPI) could facilitate interesting and useful applications, such as table top particle acceleration and high energy K-alpha and gamma ray sources. In recent experiments it has been shown that the presence of an underdense, pre-formed plasma at the target surface has a significant heating effect. PIC simulations have shown that an electrostatic potential well forms on the target surface in this pre-plasma, which traps electrons and allows them to be excited to very high energy. Here we present results from an experiment conducted on the high intensity Titan laser at the Jupiter Laser Facility to further examine the role of pre-plasma in electron heating. We utilized the split beam, short pulse capability of the Titan system to generate and diagnose an interaction via proton radiography. The region was altered with a controlled pre-plasma generated by a wide focus, long pulse beam with variable energy. These experiments show that in the presence of pre-plasma, a hotter secondary population of electrons was generated. This work performed under the auspices of the US DOE Office of Sciences Program under contracts DE-NA0001858.

  20. Spectroscopic analysis of H2/CH4 microwave plasma and fast growth rate of diamond single crystal

    NASA Astrophysics Data System (ADS)

    Derkaoui, N.; Rond, C.; Hassouni, K.; Gicquel, A.

    2014-06-01

    One of the best ways to increase the diamond growth rate is to couple high microwave power to the plasma. Indeed, increasing the power density leads to increase gas temperature the atomic hydrogen density in the plasma bulk, and to produce more hydrogen and methyl at the diamond surface. Experimental and numerical approaches were used to study the microwave plasma under high power densities conditions. Gas temperature was measured by optical emission spectroscopy and H-atom density using actinometry. CH3-radical density was obtained using a 1D model that describes temperatures and plasma composition from the substrate to the top of the reactor. The results show that gas temperature in the plasma bulk, atomic hydrogen, and methyl densities at the diamond surface highly increase with the power density. As a consequence, measurements have shown that diamond growth rate also increases. At very high power density, we measured a growth rate of 40 μm/h with an H-atom density of 5 × 1017 cm-3 which corresponds to a H2 dissociation rate higher than 50%. Finally, we have shown that the growth rate can be framed between a lower and an upper limit as a function depending only on the maximum of H-atom density measured or calculated in the plasma bulk. The results also demonstrated that increasing fresh CH4 by an appropriate injection into the boundary layer is a potential way to increase the diamond growth rates.

  1. Association of adult height and leg length with fasting plasma cortisol concentrations: evidence for an effect of normal variation in adrenocortical activity on growth.

    PubMed

    Phillips, D I W; Syddall, Holly E; Cooper, Cyrus; Hanson, Mark A

    2008-01-01

    We have evaluated the relationship between activity of the hypothalamic-pituitary-adrenal (HPA) axis and adult height in adults recruited from the UK Hertfordshire Cohort Study. In a sample of 1,354 individuals, we found that height fell by 0.67 cm (95% CI 0.34-1.0) per SD (114 nmol/l) increase in fasting plasma cortisol concentrations. The association was continuous across the range of cortisol concentrations and was independent of the levels of corticosteroid binding globulin. It was of similar magnitude in men and women. In a subsample of the study available data on standing and sitting height was used to estimate trunk and leg length. Fasting plasma cortisol concentrations were found to have a much greater impact on leg length than trunk length. These findings suggest that physiological variations in adrenocortical glucocorticoid secretion in humans affect adult height. They also raise the possibility that the HPA axis may be involved in mediating resource allocation decisions and trade-offs during development perhaps by limiting physical growth to enable other competing processes.

  2. Preliminary Evaluation of Removing Used Nuclear Fuel from Shutdown Sites

    SciTech Connect

    Maheras, Steven J.; Best, Ralph E.; Ross, Steven B.; Buxton, Kenneth A.; England, Jeffery L.; McConnell, Paul E.; Massaro, Lawrence M.; Jensen, Philip J.

    2015-09-30

    A preliminary evaluation of removing spent nuclear fuel (SNF) from 13 shutdown nuclear power reactor sites was conducted. At these shutdown sites the nuclear power reactors have been permanently shut down and the sites have been decommissioned or are undergoing decommissioning. The shutdown sites were Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, Zion, Crystal River, Kewaunee, San Onofre, and Vermont Yankee. The evaluation was divided into four components: (1) characterization of the SNF and greater-than-Class C low-level radioactive waste (GTCC waste) inventory, (2) a description of the on-site infrastructure and conditions relevant to transportation of SNF and GTCC waste, (3) an evaluation of the near-site transportation infrastructure and experience relevant to shipping transportation casks containing SNF and GTCC waste, including identification of gaps in information, and (4) an evaluation of the actions necessary to prepare for and remove SNF and GTCC waste. Every site was found to have at least one off-site transportation mode option for removing its SNF and GTCC waste; some have multiple options. Experience removing large components during reactor decommissioning provided an important source of information used to identify the transportation mode options for the sites. Especially important in conducting the evaluation were site visits, through which information was obtained that would not have been available otherwise. Extensive photographs taken during the site visits proved to be particularly useful in documenting the current conditions at or near the sites. It is expected that additional site visits will be conducted to add to the information presented in the evaluation.

  3. Description of the plasma diagnostics package (PDP) for the OSS-1 Shuttle mission and JSC plasma chamber test in conjunction with the fast pulse electron gun (FPEG)

    NASA Technical Reports Server (NTRS)

    Shawhan, S. D.

    1982-01-01

    The objectives, equipment, and techniques for the plasma diagnostics package (PDP) carried by the OSS-1 instrument payload of the STS-4 and scheduled for the Spacelab-2 mission are described. The goals of the first flight were to examine the Orbiter-magnetoplasma interactions by measuring the electric and magnetic field strengths, the ionized particle wakes, and the generated waves. The RMS was employed to lift the unit out of the bay in order to allow characterization of the fields, EM interference, and plasma contamination within 15 m of the Orbiter. The PDP will also be used to examine plasma depletion, chemical reaction rates, waves, and energized plasma produced by firing of the Orbiter thrusters. Operation of the PDP was carried out in the NASA Space Environment Simulation Laboratory test chamber, where the PDP was used to assay the fields, fluxes, wave amplitudes, and particle energy spectra. The PDP instrumentation is also capable of detecting thermal ions, thermal electrons suprathermal particles, VHF/UHF EMI levels, and the S-band field strength.

  4. Common variants in the LAMA5 gene associate with fasting plasma glucose and serum triglyceride levels in a cohort of pre- and early pubertal children.

    PubMed

    De Luca, Maria; Chandler-Laney, Paula C; Wiener, Howard; Fernandez, Jose R

    2012-12-01

    Laminins are glycoproteins found in basement membranes where they play a vital role in tissue architecture and cell behavior. Previously, we reported the association of two polymorphisms (rs659822 and rs944895) in the laminin alpha5 (LAMA5) gene with anthropometric traits, fasting lipid profile, and glucose levels in pre-menopausal women and elderly subjects. Furthermore, studies in mice showed that Lama5 is involved in organogenesis and placental function during pregnancy. The objective of this study was to investigate whether rs659822 and/or rs944895 are associated with inter-individual variability in birth weight as well as anthropometric traits and metabolic phenotypes in children. Two hundred and eighty nine healthy children aged 7-12 yr of European, Hispanic, and African-American ancestry were studied. Co-dominant models adjusted for genetic admixture, age, gender, and stages of puberty were used to test for the association of the polymorphisms with each trait. Our analysis showed significant associations of rs659822 with fasting plasma glucose levels (P = 0.0004) and of rs944895 with fasting serum triglycerides (P = 0.004) after Bonferroni correction for multiple testing. Our results corroborate our previous findings that genetic variants in LAMA5 contribute to variation in metabolic phenotypes and provide evidence that this may occur early in life. PMID:27625828

  5. Common variants in the LAMA5 gene associate with fasting plasma glucose and serum triglyceride levels in a cohort of pre- and early pubertal children

    PubMed Central

    De Luca, Maria; Chandler-Laney, Paula C.; Wiener, Howard; Fernandez, Jose R.

    2012-01-01

    Laminins are glycoproteins found in basement membranes where they play a vital role in tissue architecture and cell behavior. Previously, we reported the association of two polymorphisms (rs659822 and rs944895) in the laminin alpha5 (LAMA5) gene with anthropometric traits, fasting lipid profile, and glucose levels in pre-menopausal women and elderly subjects. Furthermore, studies in mice showed that Lama5 is involved in organogenesis and placental function during pregnancy. The objective of this study was to investigate whether rs659822 and/or rs944895 are associated with inter-individual variability in birth weight as well as anthropometric traits and metabolic phenotypes in children. Two hundred and eighty nine healthy children aged 7–12 yr of European, Hispanic, and African-American ancestry were studied. Co-dominant models adjusted for genetic admixture, age, gender, and stages of puberty were used to test for the association of the polymorphisms with each trait. Our analysis showed significant associations of rs659822 with fasting plasma glucose levels (P = 0.0004) and of rs944895 with fasting serum triglycerides (P = 0.004) after Bonferroni correction for multiple testing. Our results corroborate our previous findings that genetic variants in LAMA5 contribute to variation in metabolic phenotypes and provide evidence that this may occur early in life.

  6. ADP-induced platelet aggregation after addition of tramadol in vitro in fed and fasted horses plasma.

    PubMed

    Casella, S; Giannetto, C; Giudice, E; Marafioti, S; Fazio, F; Assenza, A; Piccione, G

    2013-04-01

    Adenosine diphosphate (ADP)-induced platelet aggregation in fed and fasted horses after addition of tramadol hydrochloride was evaluated in vitro. On 10 horses citrated blood samples were collected 2h after feeding (fed animals) and 21 h after feeding (fasted animals). Final concentrations of ADP 1 and 0.5 μM, and tramadol hydrochloride (1, 15, 30, 45 and 60 min after the addition of tramadol) were used to determine the maximum degree and initial velocity of platelet aggregation. Repeated measures multifactor analysis of variance (MANOVA) was used to evaluate the effect of feeding/fasting condition, ADP concentration and addition of tramadol. Findings showed statistical differences (P≤0.05) on studied parameters after addition of tramadol to different ADP concentrations in fed and fasted horses. The clinical relevance of these results is that tramadol provides many advantages as a therapeutic option; in fact, it is an inexpensive and a relatively new analgesic in equine veterinary medicine. Further investigations would be appropriate to compare the effects of different opioids but also using different concentrations of tramadol associated with other drugs in order to have substances which can regulate the functional activity of the platelets and to extend the knowledges on equine platelet aggregation. PMID:23031839

  7. Effect of intake on fasting heat production, respiratory quotient and plasma metabolites measured using the washed rumen technique.

    PubMed

    Kim, D H; McLeod, K R; Koontz, A F; Foote, A P; Klotz, J L; Harmon, D L

    2015-01-01

    The objective was to investigate the effect of intake before fasting on concentrations of metabolites and hormones, respiratory quotient (RQ) and fasting heat production (HP) using the washed rumen technique and to compare these values with those from the fed state. Six Holstein steers (360±22 kg) were maintained at 21°C and fed three different energy intakes within a replicated 3×3 Latin square design with 21-day periods. Steers were fed alfalfa cubes to provide 1.0, 1.5 and 2.0×NEm during 19 days of each experimental period. Steers were placed in individual metabolism stalls fitted with indirect calorimetry head-boxes on day 20 of each experimental period (FED steers) and fed their normal meal. On day 21 of each period the reticulorumen was emptied, washed and refilled with ruminal buffer (NaCl=96; NaHCO3=24; KHCO3=30; K2HPO4=2; CaCl2=1.5; MgCl2=1.5 mmol/kg of buffer) aerated with 75% N2 and 25% CO2 before introduction to the rumen (steers were not fed; WASHED steers). Each gas exchange was measured over 24 h. HP for 1.0, 1.5 and 2.0×NEm were 479, 597 and 714 kJ/daykg0.75 (s.e.m. =16), respectively. The plateau RQ was 0.756, 0.824 and 0.860 for the 1.0, 1.5 and 2.0×NEm intakes for the FED steers, respectively. After rumen washing, fasting HP was 331, 359 and 400 kJ/daykg0.75 (s.e.m.=13) for 1.0, 1.5, and 2.0×NEm intakes before fasting, respectively. The RQ for WASHED rumen steers was 0.717, 0.710 and 0.719, respectively. Cortisol and β-hydroxybutyrate concentrations in WASHED rumen steers did not exceed threshold levels for severe energy deficit and stress as can be induced from prolonged fasting. This study demonstrates that a fasting state can be emulated using the washed rumen technique, minimizing the time required as opposed to traditional fasting methodologies, without causing a severe energy deficit and stress.

  8. Plasma effect on fast-electron-impact-ionization from 2p state of hydrogen-like ions

    SciTech Connect

    Qi, Y. Y.; Ning, L. N.; Wang, J. G.; Qu, Y. Z.

    2013-12-15

    Plasma effects on the high-energy electron-impact ionization process from 2p orbital of Hydrogen-like ions embedded in weakly coupled plasmas are investigated in the first Born approximation. The plasma screening of the Coulomb interaction between charged particles is represented by the Debye Hückel model. The screening of Coulomb interactions decreases the ionization energies and varies the wave functions for not only the bound orbital but also the continuum; the number of the summation for the angular-momentum states in the generalized oscillator strength densities is reduced with the plasma screening stronger when the ratio of ε/I{sub 2p} (I{sub 2p} is the ionization energy of 2p state and ε is the energy of the continuum electron) is kept, and then the contribution from the lower-angular-momentum states dominates the generalized oscillator strength densities, so the threshold phenomenon in the generalized oscillator strength densities and the double differential cross sections are remarkable: The accessional minima, the outstanding enhancement, and the resonance peaks emerge a certain energy region, whose energy position and width are related to the vicinity between δ and the critical value δ{sub nl}{sup c}, corresponding to the special plasma condition when the bound state |nl just enters the continuum; the multiple virtual-state enhancement and the multiple shape resonances in a certain energy domain also appear in the single differential cross section whenever the plasma screening parameter passes through a critical value δ{sub nl}{sup c}, which is similar to the photo-ionization process but different from it, where the dipole transition only happens, but multi-pole transition will occur in the electron-impact ionization process, so its multiple virtual-state enhancements and the multiple shape resonances appear more frequently than the photo-ionization process.

  9. Quantification of sofosbuvir and ledipasvir in human plasma by UPLC-MS/MS method: Application to fasting and fed bioequivalence studies.

    PubMed

    Rezk, Mamdouh R; Bendas, Ehab R; Basalious, Emad B; Karim, Iman A

    2016-08-15

    A rapid and sensitive LC-MS/MS method was developed, optimized and validated for quantification of sofosbuvir (SF) and ledipasvir (LD) in human plasma using eplerenone as an internal standard (IS). Analytes and IS were extracted from plasma by simple liquid-liquid extraction technique using methyl tertiary butyl ether. The prepared samples were chromatographed on Acquity UPLC BEH C18 column. Separation was done using a mobile phase formed of 0.1% formic acid and acetonitrile (50:50, v/v) in an isocratic mode at a flow rate of 0.4ml/min. The Xevo TQD LC-MS/MS was operated under the multiple-reaction monitoring mode using electrospray ionization. A full validation of the method was performed according to the FDA guidelines. Linearity was found to be in the range of 0.25-3500ng/ml for SF and 5-2000ng/ml for LD. The intra-day and inter-day precision and accuracy results were within the acceptable limits. A short run time of 2min allows analysis of more than 400 plasma samples per day. The developed method was successfully applied to both fasting and fed bioequivalence studies in healthy human volunteers. PMID:27322631

  10. A fast and simple assay for busulfan in serum or plasma by liquid chromatography-tandem mass spectrometry using turbulent flow online extraction technology.

    PubMed

    Bunch, Dustin R; Heideloff, Courtney; Ritchie, James C; Wang, Sihe

    2010-12-01

    Busulfan is used in myeloablative preparation regimens for hematopoietic bone marrow transplantation. Due to its narrow therapeutic range therapeutic drug monitoring of busulfan is recommended. In this study a fast and simple method for measuring busulfan in serum or plasma by liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed utilizing turbulent flow online extraction technology. Serum or plasma was mixed with acetonitrile containing d(8)-busulfan. After centrifugation the supernatant was injected onto a turbulent flow preparatory column then transferred to a C18 analytical column monitored by a tandem mass spectrometer set at positive electrospray ionization. The analytical cycle time was 4.0min. The method was linear from 0.15 to 41.90μmol/L with an accuracy of 87.9-103.0%. Inter- and intra-assay CVs across four concentration levels were 2.1-7.8%. No significant carryover or ion suppression was observed. No interference was observed from commercial control materials containing more than 100 compounds. Comparison with a well established LC-MS/MS method using patient specimens (n=45) showed a mean bias 1.3% with Deming regression of slope 1.02, intercept -0.02μmol/L, and a linear correlation coefficient 0.9883. The LC-MS/MS method coupled with turbulent flow online sample cleaning technology described here offers reliable busulfan quantitation in serum or plasma with minimum manual sample preparation and was fully validated for clinical use.

  11. Climatic and biotic thresholds of coral-reef shutdown

    NASA Astrophysics Data System (ADS)

    Toth, Lauren T.; Aronson, Richard B.; Cobb, Kim M.; Cheng, Hai; Edwards, R. Lawrence; Grothe, Pamela R.; Sayani, Hussein R.

    2015-04-01

    Climate change is now the leading cause of coral-reef degradation and is altering the adaptive landscape of coral populations. Increasing sea temperatures and declining carbonate saturation states are inhibiting short-term rates of coral calcification, carbonate precipitation and submarine cementation. A critical challenge to coral-reef conservation is understanding the mechanisms by which environmental perturbations scale up to influence long-term rates of reef-framework construction and ecosystem function. Here we reconstruct climatic and oceanographic variability using corals sampled from a 6,750-year core from Pacific Panamá. Simultaneous reconstructions of coral palaeophysiology and reef accretion allowed us to identify the climatic and biotic thresholds associated with a 2,500-year hiatus in vertical accretion beginning ~4,100 years ago. Stronger upwelling, cooler sea temperatures and greater precipitation--indicators of La Niña-like conditions--were closely associated with abrupt reef shutdown. The physiological condition of the corals deteriorated at the onset of the hiatus, corroborating theoretical predictions that the tipping points of radical ecosystem transitions should be manifested sublethally in the biotic constituents. Future climate change could cause similar threshold behaviours, leading to another shutdown in reef development in the tropical eastern Pacific.

  12. Development of an x-ray Talbot-Lau moire deflectometer for fast density profile measurements of dense plasmas generated by beam-target interactions

    SciTech Connect

    Clayton, Dan; Berninger, M; Meidinger, A; Stutman, Dan; Valdivia, Maria Pia

    2015-05-01

    For the first time an x-ray Talbot-Lau moire deflectometer is being developed that will use a flash tube source and fast detector for dynamic density gradient measurements. In Talbot-Lau moire deflectometry, an x-ray grating makes an image of itself on a second grating (the Talbot effect) to produce a moire pattern on a detector. The test object is placed between these gratings, with variations in index of refraction changing the pattern. A third grating in front of an incoherent x-ray source produces an array of coherent sources. With a 150 kV x-ray flash tube as the source, the gratings are placed in a glancing angle setup for performance at ~60 keV. The detector is a gated CCD with a fast scintillator for x-ray conversion. This diagnostic, designed for the Dual-Axis Radiographic Hydrodynamic Test facility (DARHT) at Los Alamos National Laboratory, measures the density profile of dense plasma plumes ejected from beam-target interactions. DARHT has two high-current, pulsed, inductive linear electron accelerators with bremsstrahlung targets at the end of each beam line to create 2-D radiographic images of hydrodynamic tests. One multi-pulse accelerator has up to four beam pulses striking the same target within 2 μs. Computer simulations that model target evolution and ejected material between pulses are used to design these targets for optimal radiographic performance; the x-ray deflectometer will directly measure density gradients in the ejected plumes and provide the first experimental constraints to these models. During the first year, currently underway, the diagnostic systems are being designed. In year two, the flash tube and fast detector will be deployed at DARHT for radiographic imaging while the deflectometer is built and tested on the bench with a continuous source. Finally, in year three, the fast deflectometer will be installed on DARHT and density measurements will be performed.

  13. Fast, downstream removal of photoresist using reactive oxygen species from the effluent of an atmospheric pressure plasma Jet

    NASA Astrophysics Data System (ADS)

    West, A.; van der Schans, M.; Xu, C.; Cooke, M.; Wagenaars, E.

    2016-04-01

    In the semiconductor industry the plasma removal of photoresist (PR) between processing steps (so-called plasma ashing) is a critical issue in enabling the creation of advanced wafer architectures associated with the next generation of devices. We investigated the feasibility of a novel atmospheric-pressure plasma jet (APPJ) to remove PR. Our device operates at atmospheric pressure, eliminating the need for low-pressure operation used in conventional plasma ashing. Also, our method uses the downstream effluent of the source, avoiding issues relating to ion bombardment, a known hinderance to atomic precision manufacturing. Two-photon absorption laser induced fluorescence (TALIF) measurements of the system has shown that the PR removal rate is directly correlated with the atomic oxygen flux to the surface. The maximum removal rates achieved were 10 μm min-1, a factor of 100 improvement over typical low-pressure methods, while the quality of the etch, as assessed by attenuated total reflection fourier transform infrared spectroscopy, was found to be equal to low-pressure standards.

  14. Bipolar square-wave current source for transient electromagnetic systems based on constant shutdown time

    NASA Astrophysics Data System (ADS)

    Wang, Shilong; Yin, Changchun; Lin, Jun; Yang, Yu; Hu, Xueyan

    2016-03-01

    Cooperative work of multiple magnetic transmitting sources is a new trend in the development of transient electromagnetic system. The key is the bipolar current waves shutdown, concurrently in the inductive load. In the past, it was difficult to use the constant clamping voltage technique to realize the synchronized shutdown of currents with different peak values. Based on clamping voltage technique, we introduce a new controlling method with constant shutdown time. We use the rising time to control shutdown time and use low voltage power source to control peak current. From the viewpoint of the circuit energy loss, by taking the high-voltage capacitor bypass resistance and the capacitor of the passive snubber circuit into account, we establish the relationship between the rising time and the shutdown time. Since the switch is not ideal, we propose a new method to test the shutdown time by the low voltage, the high voltage and the peak current. Experimental results show that adjustment of the current rising time can precisely control the value of the clamp voltage. When the rising time is fixed, the shutdown time is unchanged. The error for shutdown time deduced from the energy consumption is less than 6%. The new controlling method on current shutdown proposed in this paper can be used in the cooperative work of borehole and ground transmitting system.

  15. Association of Roadway Proximity with Fasting Plasma Glucose and Metabolic Risk Factors for Cardiovascular Disease in a Cross-Sectional Study of Cardiac Catheterization Patients

    PubMed Central

    Kraus, William E.; Blach, Colette; Haynes, Carol S.; Dowdy, Elaine; Miranda, Marie Lynn; Devlin, Robert B.; Diaz-Sanchez, David; Cascio, Wayne E.; Mukerjee, Shaibal; Stallings, Casson; Smith, Luther A.; Gregory, Simon G.; Shah, Svati H.; Hauser, Elizabeth R.; Neas, Lucas M.

    2015-01-01

    Background The relationship between traffic-related air pollution (TRAP) and risk factors for cardiovascular disease needs to be better understood in order to address the adverse impact of air pollution on human health. Objective We examined associations between roadway proximity and traffic exposure zones, as markers of TRAP exposure, and metabolic biomarkers for cardiovascular disease risk in a cohort of patients undergoing cardiac catheterization. Methods We performed a cross-sectional study of 2,124 individuals residing in North Carolina (USA). Roadway proximity was assessed via distance to primary and secondary roadways, and we used residence in traffic exposure zones (TEZs) as a proxy for TRAP. Two categories of metabolic outcomes were studied: measures associated with glucose control, and measures associated with lipid metabolism. Statistical models were adjusted for race, sex, smoking, body mass index, and socioeconomic status (SES). Results An interquartile-range (990 m) decrease in distance to roadways was associated with higher fasting plasma glucose (β = 2.17 mg/dL; 95% CI: –0.24, 4.59), and the association appeared to be limited to women (β = 5.16 mg/dL; 95% CI: 1.48, 8.84 compared with β = 0.14 mg/dL; 95% CI: –3.04, 3.33 in men). Residence in TEZ 5 (high-speed traffic) and TEZ 6 (stop-and-go traffic), the two traffic zones assumed to have the highest levels of TRAP, was positively associated with high-density lipoprotein cholesterol (HDL-C; β = 8.36; 95% CI: –0.15, 16.9 and β = 5.98; 95% CI: –3.96, 15.9, for TEZ 5 and 6, respectively). Conclusion Proxy measures of TRAP exposure were associated with intermediate metabolic traits associated with cardiovascular disease, including fasting plasma glucose and possibly HDL-C. Citation Ward-Caviness CK, Kraus WE, Blach C, Haynes CS, Dowdy E, Miranda ML, Devlin RB, Diaz-Sanchez D, Cascio WE, Mukerjee S, Stallings C, Smith LA, Gregory SG, Shah SH, Hauser ER, Neas LM. 2015. Association of roadway

  16. A fast, sensitive, and high-throughput method for the simultaneous quantitation of three ellagitannins from Euphorbiae pekinensis Radix in rat plasma by ultra-HPLC-MS/MS.

    PubMed

    Hou, Pengyi; Zeng, Yan; Ma, Bingjie; Wang, Xiaofan; Liu, Zhenzhen; Li, Lu; Qu, Kankan; Bi, Kaishun; Chen, Xiaohui

    2013-08-01

    A fast, sensitive, and high-throughput ultra-HPLC-MS/MS method has been developed and validated for the simultaneous determination of three main active constituents of Euphorbiae pekinensis Radix in rat plasma. After addition of the internal standard, plasma samples were extracted by liquid-liquid extraction with ethyl acetate/isopropanol (1:1, v/v) and separated on a CAPCELL PAK C18 column (100 × 2.0 mm, 2 μm, Shiseido, Japan), using a gradient mobile phase system of methanol/water. The detection of the analytes was performed on a 4000Q UHPLC-MS/MS system with turbo ion spray source in the negative ion and multiple reaction-monitoring mode. The linear range was 1.0-1000 ng/mL for 3,3'-di-O-methyl ellagic acid-4'-O-β-D-glucopyranoside (i), 1.5-1500 ng/mL for 3,3'-di-O-methyl ellagic acid-4'-O-β-D-xylopyranoside (ii), and 5.0-5000 ng/mL for 3,3'-di-O-methyl ellagic acid (iii). The intra- and interday precision and accuracy of all the analytes were within 15%. The extraction recoveries of the three analytes and internal standard from plasma were all more than 80%. The validated method was first successfully applied to the evaluation of pharmacokinetic parameters of compounds 1, 2, and 3 in rat plasma after intragastric administration of the Euphorbiae pekinensis Radix extract.

  17. Fast ion source and detector for investigating the interaction of turbulence with suprathermal ions in a low temperature toroidal plasma

    SciTech Connect

    Plyushchev, G.; Diallo, A.; Fasoli, A.; Furno, I.; Labit, B.; Mueller, S. H.; Podesta, M.; Poli, F. M.; Boehmer, H.; Heidbrink, W. W.; Zhang, Y.

    2006-10-15

    A specific experimental apparatus consisting of an ion source and a detector for the investigation of the interaction between suprathermal ions and drift-wave turbulence is developed on the toroidal plasma experiment. Due to the low plasma temperature ({approx}5 eV), a spatially localized, small-size ion source ({approx}4 cm) mounted inside the vacuum vessel with relatively low ion energy ({approx}100 eV-1 keV) can be used. The source consists of an aluminosilicate Li-6 ion emitter (6 mm diameter, 10-30 {mu}A current) installed on a two-dimensional (2D) poloidally moving system. The location, energy, and current density profile of the ion beam will be measured using a 2D movable gridded energy analyzer.

  18. Time-resolved study of the extreme-ultraviolet emission and plasma dynamics of a sub-Joule, fast capillary discharge

    NASA Astrophysics Data System (ADS)

    Valenzuela, J. C.; Wyndham, E. S.; Favre, M.

    2015-08-01

    In this work, we discuss experimental observations on the dynamics of a fast, low energy capillary discharge when operated in argon and its properties as an intense source of extreme-ultraviolet (EUV) radiation. The discharge pre-ionization and self-triggering were accomplished by the use of the hollow cathode effect. This allowed a compact size and low inductance discharge with multi-kA current level and a quarter-period of ˜10 ns at sub-Joule energy level. We used the novel moiré and schlieren diagnostics with a 12 ps laser to obtain the time evolution of the line electron density and to study the plasma dynamics. EUV spectroscopy and filtered diodes were also implemented to estimate the plasma temperature and density throughout the evolution of the discharge. EUV source size was measured by using a filtered slit-wire camera. We observed that EUV emission starts from a compressed plasma on axis during the second quarter-period of the current and continues until the fifth quarter-period. Ionization levels from Ar VII to X were observed. By comparing the EUV emission spectra with synthetic spectra, we found that at the onset of emission (˜7 ns), the plasma is well fitted by a single Maxwellian electron distribution function with Te ˜ 12 eV and ne ˜ 1017 cm-3. Close to peak emission (˜13 ns), plasma temperature and density increase to ˜20 eV and ne ˜ 1018 cm-3, respectively. However, in order to successfully match the experimental data, a two component electron distribution function was necessary. Later in time, a smaller fraction in the high energy component and higher temperature suggests homogenization of the plasma. The moiré and schlieren diagnostics showed multiple radial compression-waves merging on axis throughout the discharge; they are an important heating mechanism that leads to a period of severe turbulence at peak EUV emission. It was also observed that emission ceases when the axial maximum of the electron density collapses.

  19. Time-resolved study of the extreme-ultraviolet emission and plasma dynamics of a sub-Joule, fast capillary discharge

    SciTech Connect

    Valenzuela, J. C.; Wyndham, E. S.; Favre, M.

    2015-08-15

    In this work, we discuss experimental observations on the dynamics of a fast, low energy capillary discharge when operated in argon and its properties as an intense source of extreme-ultraviolet (EUV) radiation. The discharge pre-ionization and self-triggering were accomplished by the use of the hollow cathode effect. This allowed a compact size and low inductance discharge with multi-kA current level and a quarter-period of ∼10 ns at sub-Joule energy level. We used the novel moiré and schlieren diagnostics with a 12 ps laser to obtain the time evolution of the line electron density and to study the plasma dynamics. EUV spectroscopy and filtered diodes were also implemented to estimate the plasma temperature and density throughout the evolution of the discharge. EUV source size was measured by using a filtered slit-wire camera. We observed that EUV emission starts from a compressed plasma on axis during the second quarter-period of the current and continues until the fifth quarter-period. Ionization levels from Ar VII to X were observed. By comparing the EUV emission spectra with synthetic spectra, we found that at the onset of emission (∼7 ns), the plasma is well fitted by a single Maxwellian electron distribution function with T{sub e} ∼ 12 eV and n{sub e} ∼ 10{sup 17 }cm{sup −3}. Close to peak emission (∼13 ns), plasma temperature and density increase to ∼20 eV and n{sub e} ∼ 10{sup 18 }cm{sup −3}, respectively. However, in order to successfully match the experimental data, a two component electron distribution function was necessary. Later in time, a smaller fraction in the high energy component and higher temperature suggests homogenization of the plasma. The moiré and schlieren diagnostics showed multiple radial compression-waves merging on axis throughout the discharge; they are an important heating mechanism that leads to a period of severe turbulence at peak EUV emission. It was also observed that emission

  20. Generation of ultra-high-pressure shocks by collision of a fast plasma projectile driven in the laser-induced cavity pressure acceleration scheme with a solid target

    SciTech Connect

    Badziak, J.; Rosiński, M.; Krousky, E.; Kucharik, M.; Liska, R.; Ullschmied, J.

    2015-03-15

    A novel, efficient method of generating ultra-high-pressure shocks is proposed and investigated. In this method, the shock is generated by collision of a fast plasma projectile (a macro-particle) driven by laser-induced cavity pressure acceleration (LICPA) with a solid target placed at the LICPA accelerator channel exit. Using the measurements performed at the kilojoule PALS laser facility and two-dimensional hydrodynamic simulations, it is shown that the shock pressure ∼ Gbar can be produced with this method at the laser driver energy of only a few hundred joules, by an order of magnitude lower than the energy needed for production of such pressure with other laser-based methods known so far.

  1. A novel fast and flexible technique of radical kinetic behaviour investigation based on pallet for plasma evaluation structure and numerical analysis

    NASA Astrophysics Data System (ADS)

    Malinowski, Arkadiusz; Takeuchi, Takuya; Chen, Shang; Suzuki, Toshiya; Ishikawa, Kenji; Sekine, Makoto; Hori, Masaru; Lukasiak, Lidia; Jakubowski, Andrzej

    2013-07-01

    This paper describes a new, fast, and case-independent technique for sticking coefficient (SC) estimation based on pallet for plasma evaluation (PAPE) structure and numerical analysis. Our approach does not require complicated structure, apparatus, or time-consuming measurements but offers high reliability of data and high flexibility. Thermal analysis is also possible. This technique has been successfully applied to estimation of very low value of SC of hydrogen radicals on chemically amplified ArF 193 nm photoresist (the main goal of this study). Upper bound of our technique has been determined by investigation of SC of fluorine radical on polysilicon (in elevated temperature). Sources of estimation error and ways of its reduction have been also discussed. Results of this study give an insight into the process kinetics, and not only they are helpful in better process understanding but additionally they may serve as parameters in a phenomenological model development for predictive modelling of etching for ultimate CMOS topography simulation.

  2. Calculation of the energy distribution of a fast electron in a helium beam plasma by numerical methods with substantiation of the multigroup approximation

    NASA Astrophysics Data System (ADS)

    Punkevich, B. S.; Stal, N. L.; Stepanov, B. M.; Khokhlov, V. D.

    The possibility of using the multigroup method to determine the physical properties of a beam plasma is substantiated, and the effectiveness of the application of this method is analyzed. The results obtained are compared with solutions of rigorous steady-state kinetic equations and approximate equations corresponding to a model of continuous slowdown and its variants. It is shown that, in the case of the complete slowdown of a fast electron and all the secondary electrons produced by it in He, 51 percent of the primary-electron energy is expended on the ionization of helium atoms, 16 percent is converted into atom thermal energy, and 33 percent is expended on atom excitation. Of this latter 33 percent, 21 percent is expended on the excitation of energy levels corresponding to optically allowed transitions.

  3. [Determination of cefuroxime in liver-injured rat plasma by ultra fast liquid chromatography-tandem mass spectrometry via acidified protein precipitation].

    PubMed

    Zhao, Longshan; Li, Qing; Yang, Wei; He, Bosai; Wei, Binbin; Liu, Ran; Liu, Jingjing; Chen, Xiaohui; Bi, Kaishun

    2012-07-01

    In order to investigate the pharmacokinetic profiles of cefuroxime lysine, a new second generation cephalosporins, in liver-injured rat model, an ultra fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) method for the determination of cefuroxime in liver-injured rat plasma was developed and validated. The plasma sample was pretreated by protein precipitation with acidified acetonitrile. The analytes were separated on a Shim-pack XR-ODS column (75 mm x 3.0 mm, 2.2 microm) with acetonitrile-0. 1% formic acid aqueous solution (40:60, v/v) as the mobile phase at a flow rate of 400 microL/min. The mass spectrometer was operated in multiple reaction monitoring (MRM) mode with a negative electrospray ionization (ESI) interface. The precursor to product ion transitions of m/z 423.2 --> 206.8 and m/z 454.1 --> 238.4 were selected to determine cefuroxime and cefotaxime (internal standard, IS), respectively. The linearities ranged from 0.01 to 1 mg/L and 1 to 400 mg/L (r > 0.99), and the limit of quantification of cefuroxime was 0.01 mg/L. The relative standard deviations (RSDs) of intra- and inter-day precisions were both less than 11.5%, and the accuracy (relative error) was between -7.1% and 2.2%. The mean extraction recovery was more than 83.5%. The total run time was 3.0 min per sample. The method is simple and fast for the preliminary pharmacokinetic study of cefuroxime lysine in liver-injured rats.

  4. Proceedings: PWR Primary Startup/Shutdown Chemistry Workshop

    SciTech Connect

    2000-08-01

    This workshop summary outlines the proceedings of the EPRI-sponsored PWR Primary Startup/Shutdown Workshop held in San Antonio, Texas on April 25-27, 2000 to support the next revision of current EPRI PWR Chemistry Guidelines. Information was exchanged to assess the effectiveness of the guidelines. The workshop also helped identify issues needing further study before the next revision. Approximately 50 utility and industry representatives attended the workshop with utility personnel chairing four sessions. The workshop provided an opportunity for utility representatives to express an opinion as to the effectiveness of the existing PWR Primary Water Chemistry Guidelines: Volume 2, Revision 4. Potential improvements and additions to the Guidelines are outlined in this report.

  5. Long-lived plasma and fast quenching of N2(C3Π u ) by electrons in the afterglow of a nanosecond capillary discharge in nitrogen

    NASA Astrophysics Data System (ADS)

    Lepikhin, N. D.; Klochko, A. V.; Popov, N. A.; Starikovskaia, S. M.

    2016-08-01

    Quenching of electronically excited nitrogen state, {{\\text{N}}2}≤ft({{\\text{C}}3}{{\\Pi}u},{{v}\\prime}=0\\right) , in the afterglow of nanosecond capillary discharge in pure nitrogen is studied. It is found experimentally that an additional collisional mechanism appears and dominates at high specific deposited energies leading to the anomalously fast quenching of the {{\\text{N}}2}≤ft({{\\text{C}}3}{{\\Pi}u}\\right) in the afterglow. On the basis of obtained experimental data and of the analysis of possible quenching agents, it is concluded that the anomalously fast deactivation of the {{\\text{N}}2}≤ft({{\\text{C}}3}{{\\Pi}u}\\right) can be explained by quenching by electrons. Long-lived plasma at time scale of hundreds nanoseconds after the end of the pulse is observed. High electron densities, about 1014 cm‑3 at 27 mbar, are sustained by reactions of associative ionization. Kinetic 1D numerical modeling and comparison of calculated results with experimentally measured electric fields in the second high-voltage pulse 250 ns after the initial pulse, and electron density measurements in the afterglow confirm the validity of the suggested mechanism.

  6. Full wave simulations of fast wave efficiency and power losses in the scrape-off layer of tokamak plasmas in mid/high harmonic and minority heating regimes

    NASA Astrophysics Data System (ADS)

    Bertelli, N.; Jaeger, E. F.; Hosea, J. C.; Phillips, C. K.; Berry, L.; Bonoli, P. T.; Gerhardt, S. P.; Green, D.; LeBlanc, B.; Perkins, R. J.; Qin, C. M.; Pinsker, R. I.; Prater, R.; Ryan, P. M.; Taylor, G.; Valeo, E. J.; Wilson, J. R.; Wright, J. C.; Zhang, X. J.

    2016-01-01

    Several experiments on different machines and in different fast wave (FW) heating regimes, such as hydrogen minority heating and high harmonic fast waves (HHFW), have found strong interaction between radio-frequency (RF) waves and the scrape-off layer (SOL) region. This paper examines the propagation and the power loss in the SOL by using the full wave code AORSA, in which the edge plasma beyond the last closed flux surface (LCFS) is included in the solution domain and a collisional damping parameter is used as a proxy to represent the real, and most likely nonlinear, damping processes. 2D and 3D AORSA results for the National Spherical Torus eXperiment (NSTX) have shown a strong transition to higher SOL power losses (driven by the RF field) when the FW cut-off is removed from in front of the antenna by increasing the edge density. Here, full wave simulations have been extended for ‘conventional’ tokamaks with higher aspect ratios, such as the DIII-D, Alcator C-Mod, and EAST devices. DIII-D results in HHFW regime show similar behavior found in NSTX and NSTX-U, consistent with previous DIII-D experimental observations. In contrast, a different behavior has been found for C-Mod and EAST, which operate in the minority heating regime. This article is dedicated to the memory of Cynthia K. Phillips

  7. Long-lived plasma and fast quenching of N2(C3Π u ) by electrons in the afterglow of a nanosecond capillary discharge in nitrogen

    NASA Astrophysics Data System (ADS)

    Lepikhin, N. D.; Klochko, A. V.; Popov, N. A.; Starikovskaia, S. M.

    2016-08-01

    Quenching of electronically excited nitrogen state, {{\\text{N}}2}≤ft({{\\text{C}}3}{{\\Pi}u},{{v}\\prime}=0\\right) , in the afterglow of nanosecond capillary discharge in pure nitrogen is studied. It is found experimentally that an additional collisional mechanism appears and dominates at high specific deposited energies leading to the anomalously fast quenching of the {{\\text{N}}2}≤ft({{\\text{C}}3}{{\\Pi}u}\\right) in the afterglow. On the basis of obtained experimental data and of the analysis of possible quenching agents, it is concluded that the anomalously fast deactivation of the {{\\text{N}}2}≤ft({{\\text{C}}3}{{\\Pi}u}\\right) can be explained by quenching by electrons. Long-lived plasma at time scale of hundreds nanoseconds after the end of the pulse is observed. High electron densities, about 1014 cm-3 at 27 mbar, are sustained by reactions of associative ionization. Kinetic 1D numerical modeling and comparison of calculated results with experimentally measured electric fields in the second high-voltage pulse 250 ns after the initial pulse, and electron density measurements in the afterglow confirm the validity of the suggested mechanism.

  8. Full wave simulations of fast wave efficiency and power losses in the scrape-off layer of tokamak plasmas in mid/high harmonic and minority heating regimes

    DOE PAGESBeta

    Bertelli, N.; Jaeger, E. F.; Hosea, J. C.; Phillips, C. K.; Berry, L.; Bonoli, P. T.; Gerhardt, S. P.; Green, D.; LeBlanc, B.; Perkins, R. J.; et al

    2015-12-17

    Here, several experiments on different machines and in different fast wave (FW) heating regimes, such as hydrogen minority heating and high harmonic fast waves (HHFW), have found strong interaction between radio-frequency (RF) waves and the scrape-off layer (SOL) region. This paper examines the propagation and the power loss in the SOL by using the full wave code AORSA, in which the edge plasma beyond the last closed flux surface (LCFS) is included in the solution domain and a collisional damping parameter is used as a proxy to represent the real, and most likely nonlinear, damping processes. 2D and 3D AORSAmore » results for the National Spherical Torus eXperiment (NSTX) have shown a strong transition to higher SOL power losses (driven by the RF field) when the FW cut-off is removed from in front of the antenna by increasing the edge density. Here, full wave simulations have been extended for 'conventional' tokamaks with higher aspect ratios, such as the DIII-D, Alcator C-Mod, and EAST devices. DIII-D results in HHFW regime show similar behavior found in NSTX and NSTX-U, consistent with previous DIII-D experimental observations. In contrast, a different behavior has been found for C-Mod and EAST, which operate in the minority heating regime.« less

  9. Full wave simulations of fast wave efficiency and power losses in the scrape-off layer of tokamak plasmas in mid/high harmonic and minority heating regimes

    SciTech Connect

    Bertelli, N.; Jaeger, E. F.; Hosea, J. C.; Phillips, C. K.; Berry, L.; Bonoli, P. T.; Gerhardt, S. P.; Green, D.; LeBlanc, B.; Perkins, R. J.; Qin, C. M.; Pinsker, R. I.; Prater, R.; Ryan, P. M.; Taylor, G.; Valeo, E. J.; Wilson, J. R.; Wright, J. C.; Zhang, X. J.

    2015-12-17

    Here, several experiments on different machines and in different fast wave (FW) heating regimes, such as hydrogen minority heating and high harmonic fast waves (HHFW), have found strong interaction between radio-frequency (RF) waves and the scrape-off layer (SOL) region. This paper examines the propagation and the power loss in the SOL by using the full wave code AORSA, in which the edge plasma beyond the last closed flux surface (LCFS) is included in the solution domain and a collisional damping parameter is used as a proxy to represent the real, and most likely nonlinear, damping processes. 2D and 3D AORSA results for the National Spherical Torus eXperiment (NSTX) have shown a strong transition to higher SOL power losses (driven by the RF field) when the FW cut-off is removed from in front of the antenna by increasing the edge density. Here, full wave simulations have been extended for 'conventional' tokamaks with higher aspect ratios, such as the DIII-D, Alcator C-Mod, and EAST devices. DIII-D results in HHFW regime show similar behavior found in NSTX and NSTX-U, consistent with previous DIII-D experimental observations. In contrast, a different behavior has been found for C-Mod and EAST, which operate in the minority heating regime.

  10. Parametric excitation of fast upper hybrid waves by non-resonant beating of counter-propagating X-mode lasers in a magnetized plasma

    SciTech Connect

    Verma, Kanika; Sajal, Vivek Varshney, Prateek; Kumar, Ravindra; Sharma, Navneet K.

    2014-12-15

    Generation of fast and slow upper hybrid waves by two plasmon decay of non-resonant beating mode of two counter-propagating X-mode lasers is modelled in magnetized plasma. Two counter-propagating lasers having frequencies and wave-vectors (ω{sub 1},k{sub 1}) and (ω{sub 2},k{sub 2}), respectively, generate a non resonant beat wave at frequency difference ω{sub 0}≈ω{sub 1}∼ω{sub 2} and wave number k{sup →}{sub 0}≈k{sup →}{sub 1}+k{sup →}{sub 2} which parametrically excites a pair of copropagating fast and slow upper hybrid waves at ω{sub 0}≈2ω{sub h}+(3k{sub 1}{sup 2}v{sub th}{sup 2}/ω{sub h})  (1−ω{sub h}/ω{sub 1}) where ω{sub h} and v{sub th} are the upper hybrid frequency and electron thermal speed, respectively. The fast upper hybrid wave can be utilized for electron acceleration because its phase velocity is close to c. The growth rate of decay process is Γ∼ω{sub p}/10 at scattering angle θ{sub s}∼5π/6 and magnetic field ∼90  T, which is one order higher as compared to the growth rate of Raman process. The growth rate can be further enhanced (∼20%) by increasing the magnetic field ∼450 T.

  11. Autocrine Signaling Underlies Fast Repetitive Plasma Membrane Translocation of Conventional and Novel Protein Kinase C Isoforms in β Cells.

    PubMed

    Wuttke, Anne; Yu, Qian; Tengholm, Anders

    2016-07-15

    PKC signaling has been implicated in the regulation of many cell functions, including metabolism, cell death, proliferation, and secretion. Activation of conventional and novel PKC isoforms is associated with their Ca(2+)- and/or diacylglycerol (DAG)-dependent translocation to the plasma membrane. In β cells, exocytosis of insulin granules evokes brief (<10 s) local DAG elevations ("spiking") at the plasma membrane because of autocrine activation of P2Y1 purinoceptors by ATP co-released with insulin. Using total internal reflection microscopy, fluorescent protein-tagged PKCs, and signaling biosensors, we investigated whether DAG spiking causes membrane recruitment of PKCs and whether different classes of PKCs show characteristic responses. Glucose stimulation of MIN6 cells triggered DAG spiking with concomitant repetitive translocation of the novel isoforms PKCδ, PKCϵ, and PKCη. The conventional PKCα, PKCβI, and PKCβII isoforms showed a more complex pattern with both rapid and slow translocation. K(+) depolarization-induced PKCϵ translocation entirely mirrored DAG spiking, whereas PKCβI translocation showed a sustained component, reflecting the subplasma membrane Ca(2+) concentration ([Ca(2+)]pm), with additional effect during DAG spikes. Interference with DAG spiking by purinoceptor inhibition prevented intermittent translocation of PKCs and reduced insulin secretion but did not affect [Ca(2+)]pm elevation or sustained PKCβI translocation. The muscarinic agonist carbachol induced pronounced transient PKCβI translocation and sustained recruitment of PKCϵ. When rise of [Ca(2+)]pm was prevented, the carbachol-induced DAG and PKCϵ responses were somewhat reduced, but PKCβI translocation was completely abolished. We conclude that exocytosis-induced DAG spikes efficiently recruit both conventional and novel PKCs to the β cell plasma membrane. PKC signaling is thus implicated in autocrine regulation of β cell function.

  12. Reduced Fokker-Planck models for fast particle distribution across a transition layer of disparate plasma temperatures

    NASA Astrophysics Data System (ADS)

    Tang, Xian-Zhu; Berk, H. L.; Guo, Zehua; McDevitt, C. J.

    2014-03-01

    Across a transition layer of disparate plasma temperatures, the high energy tail of the plasma distribution can have appreciable deviations from the local Maxwellian distribution due to the Knudson layer effect. The Fokker-Planck equation for the tail particle population can be simplified in a series of practically useful limiting cases. The first is the approximation of background Maxwellian distribution for linearizing the collision operator. The second is the supra-thermal particle speed ordering of vTi ≪ v ≪ vTe for the tail ions and vTi ≪ vTe ≪ v for the tail electrons. Keeping both the collisional drag and energy scattering is essential for the collision operator to produce a Maxwellian tail distribution. The Fokker-Planck model for following the tail ion distribution for a given background plasma profile is explicitly worked out for systems of one spatial dimension, in both slab and spherical geometry. A third simplification is an expansion of the tail particle distribution using the spherical harmonics, which are eigenfunctions of the pitch angle scattering operator. This produces a set of coupled Fokker-Planck equations that contain energy-dependent spatial diffusion terms in two coordinates (position and energy), which originate from pitch angle scattering in the original Fokker-Planck equation. It is shown that the well-known diffusive Fokker-Planck model is a poor approximation of the two-mode truncation model, which itself has fundamental deficiency compared with the three-mode truncation model. The cause is the lack of even-symmetry representation in pitch dependence in the two-mode truncation model.

  13. FAST MAGNETIC RECONNECTION AND PARTICLE ACCELERATION IN RELATIVISTIC LOW-DENSITY ELECTRON-POSITRON PLASMAS WITHOUT GUIDE FIELD

    SciTech Connect

    Bessho, Naoki; Bhattacharjee, A.

    2012-05-10

    Magnetic reconnection and particle acceleration in relativistic Harris sheets in low-density electron-positron plasmas with no guide field have been studied by means of two-dimensional particle-in-cell simulations. Reconnection rates are of the order of one when the background density in a Harris sheet is of the order of 1% of the density in the current sheet, which is consistent with previous results in the non-relativistic regime. It has been demonstrated that the increase of the Lorentz factors of accelerated particles significantly enhances the collisionless resistivity needed to sustain a large reconnection electric field. It is shown analytically and numerically that the energy spectrum of accelerated particles near the X-line is the product of a power law and an exponential function of energy, {gamma}{sup -1/4}exp (- a{gamma}{sup 1/2}), where {gamma} is the Lorentz factor and a is a constant. However, in the low-density regime, while the most energetic particles are produced near X-lines, many more particles are energized within magnetic islands. Particles are energized in contracting islands by multiple reflection, but the mechanism is different from Fermi acceleration in magnetic islands for magnetized particles in the presence of a guide field. In magnetic islands, strong core fields are generated and plasma beta values are reduced. As a consequence, the fire-hose instability condition is not satisfied in most of the island region, and island contraction and particle acceleration can continue. In island coalescence, reconnection between two islands can accelerate some particles, however, many particles are decelerated and cooled, which is contrary to what has been discussed in the literature on particle acceleration due to reconnection in non-relativistic hydrogen plasmas.

  14. Autocrine Signaling Underlies Fast Repetitive Plasma Membrane Translocation of Conventional and Novel Protein Kinase C Isoforms in β Cells*

    PubMed Central

    Wuttke, Anne; Yu, Qian; Tengholm, Anders

    2016-01-01

    PKC signaling has been implicated in the regulation of many cell functions, including metabolism, cell death, proliferation, and secretion. Activation of conventional and novel PKC isoforms is associated with their Ca2+- and/or diacylglycerol (DAG)-dependent translocation to the plasma membrane. In β cells, exocytosis of insulin granules evokes brief (<10 s) local DAG elevations (“spiking”) at the plasma membrane because of autocrine activation of P2Y1 purinoceptors by ATP co-released with insulin. Using total internal reflection microscopy, fluorescent protein-tagged PKCs, and signaling biosensors, we investigated whether DAG spiking causes membrane recruitment of PKCs and whether different classes of PKCs show characteristic responses. Glucose stimulation of MIN6 cells triggered DAG spiking with concomitant repetitive translocation of the novel isoforms PKCδ, PKCϵ, and PKCη. The conventional PKCα, PKCβI, and PKCβII isoforms showed a more complex pattern with both rapid and slow translocation. K+ depolarization-induced PKCϵ translocation entirely mirrored DAG spiking, whereas PKCβI translocation showed a sustained component, reflecting the subplasma membrane Ca2+ concentration ([Ca2+]pm), with additional effect during DAG spikes. Interference with DAG spiking by purinoceptor inhibition prevented intermittent translocation of PKCs and reduced insulin secretion but did not affect [Ca2+]pm elevation or sustained PKCβI translocation. The muscarinic agonist carbachol induced pronounced transient PKCβI translocation and sustained recruitment of PKCϵ. When rise of [Ca2+]pm was prevented, the carbachol-induced DAG and PKCϵ responses were somewhat reduced, but PKCβI translocation was completely abolished. We conclude that exocytosis-induced DAG spikes efficiently recruit both conventional and novel PKCs to the β cell plasma membrane. PKC signaling is thus implicated in autocrine regulation of β cell function. PMID:27226533

  15. Magnetohydrodynamic structure of a plasmoid in fast reconnection in low-beta plasmas: Shock-shock interactions

    NASA Astrophysics Data System (ADS)

    Zenitani, Seiji

    2015-03-01

    The shock structure of a plasmoid in magnetic reconnection in low-beta plasmas is investigated by two-dimensional magnetohydrodynamic simulations. Using a high-accuracy code with unprecedented resolution, shocks, discontinuities, and their intersections are resolved and clarified. Contact discontinuities emanate from triple-shock intersection points, separating fluids of different origins. Shock-diamonds inside the plasmoid appear to decelerate a supersonic flow. New shock-diamonds and a slow expansion fan are found inside the Petschek outflow. A sufficient condition for the new shock-diamonds and the relevance to astrophysical jets are discussed.

  16. Magnetohydrodynamic structure of a plasmoid in fast reconnection in low-beta plasmas: Shock-shock interactions

    SciTech Connect

    Zenitani, Seiji

    2015-03-15

    The shock structure of a plasmoid in magnetic reconnection in low-beta plasmas is investigated by two-dimensional magnetohydrodynamic simulations. Using a high-accuracy code with unprecedented resolution, shocks, discontinuities, and their intersections are resolved and clarified. Contact discontinuities emanate from triple-shock intersection points, separating fluids of different origins. Shock-diamonds inside the plasmoid appear to decelerate a supersonic flow. New shock-diamonds and a slow expansion fan are found inside the Petschek outflow. A sufficient condition for the new shock-diamonds and the relevance to astrophysical jets are discussed.

  17. 76 FR 81998 - Methodology for Low Power/Shutdown Fire PRA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-29

    ... COMMISSION Methodology for Low Power/Shutdown Fire PRA AGENCY: Nuclear Regulatory Commission. ACTION: Draft... public comment a draft NUREG/CR, NUREG/CR-7114, Revision 0, ``Methodology for Low Power/Shutdown Fire PRA... quantitatively analyzing fire risk in commercial nuclear power plants during low power operation and...

  18. 77 FR 10576 - Methodology for Low Power/Shutdown Fire PRA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-22

    ... COMMISSION Methodology for Low Power/Shutdown Fire PRA AGENCY: Nuclear Regulatory Commission. ACTION: Draft NUREG/CR; extension for public comment period. SUMMARY: On December 29, 2011 (76 FR 81998), the U.S... Draft NUREG/CR-7114, Revision 0, ``Methodology for Low Power/Shutdown Fire PRA.'' In response to...

  19. 25 CFR 226.28 - Shutdown, abandonment, and plugging of wells.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Shutdown, abandonment, and plugging of wells. 226.28... OSAGE RESERVATION LANDS FOR OIL AND GAS MINING Cessation of Operations § 226.28 Shutdown, abandonment...) Prior to permanent abandonment of any well, the oil lessee or the gas lessee, as the case may be,...

  20. 25 CFR 226.28 - Shutdown, abandonment, and plugging of wells.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Shutdown, abandonment, and plugging of wells. 226.28... OSAGE RESERVATION LANDS FOR OIL AND GAS MINING Cessation of Operations § 226.28 Shutdown, abandonment...) Prior to permanent abandonment of any well, the oil lessee or the gas lessee, as the case may be,...

  1. 25 CFR 226.28 - Shutdown, abandonment, and plugging of wells.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Shutdown, abandonment, and plugging of wells. 226.28... OSAGE RESERVATION LANDS FOR OIL AND GAS MINING Cessation of Operations § 226.28 Shutdown, abandonment...) Prior to permanent abandonment of any well, the oil lessee or the gas lessee, as the case may be,...

  2. 25 CFR 226.28 - Shutdown, abandonment, and plugging of wells.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Shutdown, abandonment, and plugging of wells. 226.28... OSAGE RESERVATION LANDS FOR OIL AND GAS MINING Cessation of Operations § 226.28 Shutdown, abandonment...) Prior to permanent abandonment of any well, the oil lessee or the gas lessee, as the case may be,...

  3. 25 CFR 226.28 - Shutdown, abandonment, and plugging of wells.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Shutdown, abandonment, and plugging of wells. 226.28... OSAGE RESERVATION LANDS FOR OIL AND GAS MINING Cessation of Operations § 226.28 Shutdown, abandonment...) Prior to permanent abandonment of any well, the oil lessee or the gas lessee, as the case may be,...

  4. 30 CFR 57.8534 - Shutdown or failure of auxiliary fans.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Shutdown or failure of auxiliary fans. 57.8534... Ventilation Underground Only § 57.8534 Shutdown or failure of auxiliary fans. (a) Auxiliary fans installed and... fan maintenance or fan adjustments where air quality is maintained in compliance with the...

  5. 30 CFR 57.8534 - Shutdown or failure of auxiliary fans.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Shutdown or failure of auxiliary fans. 57.8534... Ventilation Underground Only § 57.8534 Shutdown or failure of auxiliary fans. (a) Auxiliary fans installed and... fan maintenance or fan adjustments where air quality is maintained in compliance with the...

  6. 30 CFR 57.8534 - Shutdown or failure of auxiliary fans.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Shutdown or failure of auxiliary fans. 57.8534... Ventilation Underground Only § 57.8534 Shutdown or failure of auxiliary fans. (a) Auxiliary fans installed and... fan maintenance or fan adjustments where air quality is maintained in compliance with the...

  7. 30 CFR 57.8534 - Shutdown or failure of auxiliary fans.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Shutdown or failure of auxiliary fans. 57.8534... Ventilation Underground Only § 57.8534 Shutdown or failure of auxiliary fans. (a) Auxiliary fans installed and... fan maintenance or fan adjustments where air quality is maintained in compliance with the...

  8. 30 CFR 57.8534 - Shutdown or failure of auxiliary fans.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Shutdown or failure of auxiliary fans. 57.8534... Ventilation Underground Only § 57.8534 Shutdown or failure of auxiliary fans. (a) Auxiliary fans installed and... fan maintenance or fan adjustments where air quality is maintained in compliance with the...

  9. CHARGE STATE EVOLUTION IN THE SOLAR WIND. II. PLASMA CHARGE STATE COMPOSITION IN THE INNER CORONA AND ACCELERATING FAST SOLAR WIND

    SciTech Connect

    Landi, E.; Gruesbeck, J. R.; Lepri, S. T.; Zurbuchen, T. H.; Fisk, L. A.

    2012-12-10

    In the present work, we calculate the evolution of the charge state distribution within the fast solar wind. We use the temperature, density, and velocity profiles predicted by Cranmer et al. to calculate the ionization history of the most important heavy elements in the solar corona and solar wind: C, N, O, Ne, Mg, Si, S, and Fe. The evolution of each charge state is calculated from the source region in the lower chromosphere to the final freeze-in point. We show that the solar wind velocity causes the plasma to experience significant departures from equilibrium at very low heights, well inside the field of view (within 0.6 R{sub sun} from the solar limb) of nearly all the available remote-sensing instrumentation, significantly affecting observed spectral line intensities. We also study the evolution of charge state ratios with distance from the source region, and the temperature they indicate if ionization equilibrium is assumed. We find that virtually every charge state from every element freezes in at a different height, so that the definition of freeze-in height is ambiguous. We also find that calculated freeze-in temperatures indicated by charge state ratios from in situ measurements have little relation to the local coronal temperature of the wind source region, and stop evolving much earlier than their correspondent charge state ratio. We discuss the implication of our results on plasma diagnostics of coronal holes from spectroscopic measurements as well as on theoretical solar wind models relying on coronal temperatures.

  10. A fast, sensitive, and high throughput method for the determination of cefuroxime lysine in dog plasma by UPLC-MS/MS.

    PubMed

    Zhao, Longshan; Zhao, Yunli; Li, Qing; Chen, Xiaohui; Xiao, Feng; He, Bosai; Wang, Jie; Bi, Kaishun

    2012-01-30

    In order to investigate the preclinical pharmacokinetics of cefuroxime lysine, a fast, sensitive and high throughput UPLC-ESI-MS/MS method has been developed and validated for the quantitative determination of cefuroxime in dog plasma. Cefuroxime and IS phenacetin were extracted from plasma samples by PPT or LLE procedure, and then separated on an ACQUITY UPLC™ BEH C(18) column with an isocratic elution of acetonitrile-0.1% formic acid in 10mM ammonium acetate (40:60, v/v). MRM using the fragmentation transitions of m/z 442 → 364 and 180 → 110 in positive ESI mode was performed to quantify cefuroxime and IS, respectively. The calibration curves were linear over the concentration range of 2-400 μg/ml for PPT and 0.01-5 μg/ml for LLE. The LLOQ was 0.01 μg/ml. The intra- and inter-day precisions in all samples were no more than 8.1%, while the accuracy was within ± 6.2% of nominal values. The method was successfully applied to the evaluation of pharmacokinetic parameters of cefuroxime lysine in beagle dogs.

  11. Fast combustion waves and chemi-ionization processes in a flame initiated by a powerful local plasma source in a closed reactor.

    PubMed

    Artem'ev, K V; Berezhetskaya, N K; Kazantsev, S Yu; Kononov, N G; Kossyi, I A; Popov, N A; Tarasova, N M; Filimonova, E A; Firsov, K N

    2015-08-13

    Results are presented from experimental studies of the initiation of combustion in a stoichiometric methane-oxygen mixture by a freely localized laser spark and by a high-current multispark discharge in a closed chamber. It is shown that, preceding the stage of 'explosive' inflammation of a gas mixture, there appear two luminous objects moving away from the initiator along an axis: a relatively fast and uniform wave of 'incomplete combustion' under laser spark ignition and a wave with a brightly glowing plasmoid behind under ignition from high-current slipping surface discharge. The gas mixtures in both the 'preflame' and developed-flame states are characterized by a high degree of ionization as the result of chemical ionization (plasma density n(e)≈10(12) cm(-3)) and a high frequency of electron-neutral collisions (ν(en)≈10(12) s(-1)). The role of chemical ionization in constructing an adequate theory for the ignition of a gas mixture is discussed. The feasibility of the microwave heating of both the preflame and developed-flame plasma, supplementary to a chemical energy source, is also discussed.

  12. Fast combustion waves and chemi-ionization processes in a flame initiated by a powerful local plasma source in a closed reactor

    PubMed Central

    Artem'ev, K. V.; Berezhetskaya, N. K.; Kazantsev, S. Yu.; Kononov, N. G.; Kossyi, I. A.; Popov, N. A.; Tarasova, N. M.; Filimonova, E. A.; Firsov, K. N.

    2015-01-01

    Results are presented from experimental studies of the initiation of combustion in a stoichiometric methane–oxygen mixture by a freely localized laser spark and by a high-current multispark discharge in a closed chamber. It is shown that, preceding the stage of ‘explosive’ inflammation of a gas mixture, there appear two luminous objects moving away from the initiator along an axis: a relatively fast and uniform wave of ‘incomplete combustion’ under laser spark ignition and a wave with a brightly glowing plasmoid behind under ignition from high-current slipping surface discharge. The gas mixtures in both the ‘preflame’ and developed-flame states are characterized by a high degree of ionization as the result of chemical ionization (plasma density ne≈1012 cm−3) and a high frequency of electron–neutral collisions (νen≈1012 s−1). The role of chemical ionization in constructing an adequate theory for the ignition of a gas mixture is discussed. The feasibility of the microwave heating of both the preflame and developed-flame plasma, supplementary to a chemical energy source, is also discussed. PMID:26170426

  13. Fast fabrication of nano-structured anti-reflection layers for enhancement of solar cells performance using plasma sputtering and infrared assisted roller embossing techniques.

    PubMed

    Liu, Shih-Jung; Liao, Che-Ting

    2012-02-27

    This paper reports the continuous fabrication of dual-side nano-structured anti-reflection protective layer for performance enhancement of solar cells using plasma sputtering and infrared assisted roller embossing techniques. Nano-structures were first deposited onto the surface of glass substrates using the plasma sputtering technique. After electroforming, a nickel master mold containing nano-array of 30 nm was obtained. The mold was then attached to the surfaces of the two metallic rollers in an infrared assisted roll-to-roll embossing facility. The embossing facility was used to replicate the nano-structures onto 60 μm thick polyethylene terephthalate (PET) films in the experiments. The embossed films were characterized using UV-vis spectrophotometer, atomic force microscope (AFM), and scanning electron microscope (SEM); its total conversion efficiency for solar cells was also measured by a solar simulator. The experimental results showed that the fabricated films could effectively reduce the reflectance and increase the conversion efficiency of solar cells. The proposed method shows great potential for fast fabrication of the anti-reflection protective layer of solar cells due to its simplicity and versatility.

  14. Effects of recombinant monokines on hepatic pyruvate dehydrogenase, pyruvate dehydrogenase kinase, lipogenesis de novo and plasma triacylglycerols. Abolition by prior fasting.

    PubMed Central

    Blackham, M; Cesar, D; Park, O J; Vary, T C; Wu, K; Kaempfer, S; Shackleton, C H; Hellerstein, M K

    1992-01-01

    1. The effects of recombinant human tumour necrosis factor alpha (TNF) and murine interleukin-1 alpha (IL-1) on the activation state of the hepatic pyruvate dehydrogenase complex (PDHa), the activity of mitochondrial PDH kinase, hepatic lipogenesis de novo and plasma triacylglycerol (TG) concentrations were studied. 2. Monokine effects depended upon prior nutritional state. In rats fasted for 20 h or 45 h before monokine administration and refeeding (orally or with intravenous glucose), PDHa, TG and hepatic lipogenesis were not increased. In rats fed ad libitum, treatment with TNF plus IL-1 increased the contribution of hepatic lipogenesis to circulating TG to 550% of control values (P = 0.03) and plasma TG concentrations to 159% (P = 0.02), whereas PDHa increased slightly to 120% (P = 0.02) and liver glycogen content fell to 45.8% (P = 0.05) of control values. 3. Intrinsic hepatic PDH kinase activity was not changed by monokine treatment in rats fed ad libitum. 4. The increased lipogenesis de novo showed no correlation (r2 = 0.05, not significant) with hepatic PDHa in individual animals fed ad libitum. 5. In conclusion, these results suggest that monokines increase pyruvate flux through hepatic PDH in vivo in rats fed ad libitum primarily by mechanisms other than covalent modification of PDH. Prior nutritional status exerts a permissive effect for monokine stimulation of PDHa and lipogenesis, consistent with a substrate-mediated action, but the mechanism of this permissive effect remains uncertain. PMID:1599392

  15. Fast combustion waves and chemi-ionization processes in a flame initiated by a powerful local plasma source in a closed reactor.

    PubMed

    Artem'ev, K V; Berezhetskaya, N K; Kazantsev, S Yu; Kononov, N G; Kossyi, I A; Popov, N A; Tarasova, N M; Filimonova, E A; Firsov, K N

    2015-08-13

    Results are presented from experimental studies of the initiation of combustion in a stoichiometric methane-oxygen mixture by a freely localized laser spark and by a high-current multispark discharge in a closed chamber. It is shown that, preceding the stage of 'explosive' inflammation of a gas mixture, there appear two luminous objects moving away from the initiator along an axis: a relatively fast and uniform wave of 'incomplete combustion' under laser spark ignition and a wave with a brightly glowing plasmoid behind under ignition from high-current slipping surface discharge. The gas mixtures in both the 'preflame' and developed-flame states are characterized by a high degree of ionization as the result of chemical ionization (plasma density n(e)≈10(12) cm(-3)) and a high frequency of electron-neutral collisions (ν(en)≈10(12) s(-1)). The role of chemical ionization in constructing an adequate theory for the ignition of a gas mixture is discussed. The feasibility of the microwave heating of both the preflame and developed-flame plasma, supplementary to a chemical energy source, is also discussed. PMID:26170426

  16. Fast Determination of Toxic Arsenic Species in Food Samples Using Narrow-bore High-Performance Liquid-Chromatography Inductively Coupled Plasma Mass Spectrometry.

    PubMed

    Terol, Amanda; Marcinkowska, Monika; Ardini, Francisco; Grotti, Marco

    2016-01-01

    A new method for the speciation analysis of arsenic in food using narrow-bore high-performance liquid-chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS) has been developed. Fast separation of arsenite, arsenate, monomethylarsonic acid and dimethylarsinic acid was carried out in 7 min using an anion-exchange narrow-bore Nucleosil 100 SB column and 12 mM ammonium dihydrogen phosphate of pH 5.2 as the mobile phase, at a flow rate of 0.3 mL min(-1). A PFA-ST micronebulizer jointed to a cyclonic spray chamber was used for HPLC-ICP-MS coupling. Compared with standard-bore HPLC-ICP-MS, the new method has provided higher sensitivity, reduced mobile-phase consumption, a lower matrix plasma load and a shorter analysis time. The achieved instrumental limits of detection were in the 0.3 - 0.4 ng As mL(-1) range, and the precision was better than 3%. The arsenic compounds were efficiently (>80%) extracted from various food samples using a 1:5 methanol/water solution, with additional ultrasonic treatment for rice products. The applicability of this method was demonstrated by the analysis of several samples, such as seafood (fish, mussels, shrimps, edible algae) and rice-based products (Jasmine and Arborio rice, spaghetti, flour, crackers), including three certified reference materials. PMID:27506720

  17. Comparison of the performance of HbA1c and fasting plasma glucose in identifying dysglycaemic status in Chinese high-risk subjects.

    PubMed

    Du, Ting-Ting; Yin, Ping; Zhang, Jian-Hua; Zhang, Dan; Shi, Wei; Yu, Xue-Feng

    2013-02-01

    The aim of the present study was to compare the performance of HbA1c and fasting plasma glucose (FPG) in identifying dysglycaemic status among Chinese participants. Fasting plasma glucose and HbA1c were measured in 2318 subjects with at least one risk factor for diabetes but without being previously diagnosed with diabetes. Using HbA1c to diagnose diabetes resulted in the same classification as FPG for 90.5% of the study participants, with 21.0% (n = 487) classified as having diabetes by both FPG and HbA1c and 69.5% (n = 1610) classified as not having diabetes by both FPG and HbA1c. The kappa (κ) coefficient of the FPG criterion with the HbA1c criterion for diabetes was 0.75 (95% confidence interval (CI) 0.72-0.78). The overlap index regarding diabetes diagnosed by FPG or HbA1c was 68.8%. Of 1610 subjects with FPG < 126 mg/dL and HbA1c < 6.5%, 220 (13.7%) had FPG ≥ 100 mg/dL and HbA1c < 5.7%, whereas 277 (17.2%) had FPG < 100 mg/dL and HbA1c ≥ 5.7%. The κ coefficient of the FPG criterion with the HbA1c criterion for prediabetes was 0.30 (95% CI 0.25-0.35). The overlap index between subjects diagnosed as having prediabetes by FPG of 100-125 mg/dL (impaired fasting glucose (IFG)) or HbA1c of 5.7-6.4% (increased HbA1c (IGH)) was 35.9%. The HbA1c criterion demonstrates reasonable concordance with the FPG criterion for diabetes. Hence, HbA1c and FPG can be used for the diagnosis of diabetes. However, the IGH shows limited overlap with IFG for prediabetes. Introduction of the IGH criterion in addition to IFG for the screening of prediabetes could lead to the identification of more people with this condition.

  18. Investigation on "saw-tooth" behavior of PEM fuel cell performance during shutdown and restart cycles

    NASA Astrophysics Data System (ADS)

    Qi, Zhigang; Tang, Hao; Guo, Qunhui; Du, Bin

    It was sometimes observed that the performance of a proton-exchange membrane fuel cell improved after the cell went through shutdown and restart cycles. Such a performance recovery led to a "saw-tooth" performance pattern when multiple shutdowns and restarts occurred during the endurance test of a fuel cell. The shutdowns included both planned shutdowns and unintended ones due to station trips or emergency stops (E-stops). The length of the shutdown periods ranged from a few minutes to several weeks. Although such a "saw-tooth" behavior could be attributed to multiple reasons such as: (1) catalyst surface oxidation state change; (2) catalyst surface cleansing; or (3) water management, we found that it was mainly related to water management in our cases after a systematic investigation employing both single cells and stacks.

  19. Fast ion mass spectrometry and charged particle spectrography investigations of transverse ion acceleration and beam-plasma interactions

    NASA Technical Reports Server (NTRS)

    Gibson, W. C.; Tomlinson, W. M.; Marshall, J. A.

    1987-01-01

    Ion acceleration transverse to the magnetic field in the topside ionosphere was investigated. Transverse acceleration is believed to be responsible for the upward-moving conical ion distributions commonly observed along auroral field lines at altitudes from several hundred to several thousand kilometers. Of primary concern in this investigation is the extent of these conic events in space and time. Theoretical predictions indicate very rapid initial heating rates, depending on the ion species. These same theories predict that the events will occur within a narrow vertical region of only a few hundred kilometers. Thus an instrument with very high spatial and temporal resolution was required; further, since different heating rates were predicted for different ions, it was necessary to obtain composition as well as velocity space distributions. The fast ion mass spectrometer (FIMS) was designed to meet these criteria. This instrument and its operation is discussed.

  20. Preliminary Evaluation of Removing Used Nuclear Fuel From Nine Shutdown Sites

    SciTech Connect

    Maheras, Steven J.; Best, Ralph; Ross, Steven B.; Buxton, Kenneth A.; England, Jeffery L.; McConnell, Paul

    2013-04-30

    The Blue Ribbon Commission on America’s Nuclear Future identified removal of stranded used nuclear fuel at shutdown sites as a priority so that these sites may be completely decommissioned and put to other beneficial uses. In this report, a preliminary evaluation of removing used nuclear fuel from nine shutdown sites was conducted. The shutdown sites included Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, and Zion. At these sites a total of 7649 used nuclear fuel assemblies and a total of 2813.2 metric tons heavy metal (MTHM) of used nuclear fuel are contained in 248 storage canisters. In addition, 11 canisters containing greater-than-Class C (GTCC) low-level radioactive waste are stored at these sites. The evaluation was divided in four components: • characterization of the used nuclear fuel and GTCC low-level radioactive waste inventory at the shutdown sites • an evaluation of the onsite transportation conditions at the shutdown sites • an evaluation of the near-site transportation infrastructure and experience relevant to the shipping of transportation casks containing used nuclear fuel from the shutdown sites • an evaluation of the actions necessary to prepare for and remove used nuclear fuel and GTCC low-level radioactive waste from the shutdown sites. Using these evaluations the authors developed time sequences of activities and time durations for removing the used nuclear fuel and GTCC low-level radioactive waste from a single shutdown site, from three shutdown sites located close to each other, and from all nine shutdown sites.

  1. Fast and smooth etching of indium tin oxides in BCl{sub 3}/Cl{sub 2} inductively coupled plasmas

    SciTech Connect

    Andagana, H. B.; Cao, X. A.

    2010-03-15

    The etching characteristics of evaporation-deposited indium tin oxide (ITO) films in BCl{sub 3}/Cl{sub 2} inductively coupled plasmas have been studied. High etch rates >200 nm/min were obtained at large BCl{sub 3}/Cl{sub 2} gas flow ratios and high rf chuck powers, suggesting that the etching process is limited by sputter desorption of InCl{sub x} and SnCl{sub x} compounds. The addition of a small amount of CF{sub 4}, which acts as reducing agent, increased the etch rate by 30% and resulted in very smooth etched surfaces. It has also been found that the material crystallinity has a pronounced influence on ITO etch rate. ITO films annealed at 500 deg. C exhibited the maximum etch resistance.

  2. Fasting plasma levels of nesfatin-1 in patients with type 1 and type 2 diabetes mellitus and the nutrient-related fluctuation of nesfatin-1 level in normal humans.

    PubMed

    Li, Qing-Chun; Wang, Hai-Yan; Chen, Xi; Guan, Hong-Zai; Jiang, Zheng-Yao

    2010-01-01

    The novel satiety factor nesfatin-1 has been shown to decrease food intake and body weight in rodents after i.c.v. injection. However, no further developments regarding the true patho-physiological relevance of nesfatin-1 in obesity and type 1 diabetes mellitus (T1 DM) and type 2 diabetes mellitus (T2 DM) have been reported. A recent study by Stengel et al. demonstrated that a down-regulation of NUCB2 mRNA in gastric endocrine cells was observed after 24-h fasting. They raised the possibility that nesfatin/NUCB2 gene expression may be regulated by nutritional status, suggesting that nesfatin-1 in the stomach might play a role in satiety. In the present study, fasting levels in plasma nesfatin-1, insulin and glucose were measured and analyzed in healthy subjects and in patients with T1 DM and T2 DM. Plasma nesfatin-1 levels were measured 6 times before and after oral glucose ingestion in healthy subjects. No sex differences in plasma nesfatin-1 were found. The mean fasting plasma nesfatin-1 levels were slightly but not significantly higher in T1 DM patients compared to healthy subjects. However, fasting plasma nesfatin-1 levels were significantly lower in T2 DM patients compared to healthy subjects and T1 DM patients. Plasma nesfatin-1 did not change acutely, although a small rise in circulating nesfatin-1 occurred within 30 min after the beginning of an oral glucose ingestion (from a mean basal value of 0.99+/-0.23 ng/ml to a maximum of 1.08+/-0.24 ng/ml). No significant difference in plasma nesfatin-1 before and after an oral glucose was observed. In conclusion, we showed that fasting nesfatin-1 was significantly lower in T2 DM patients compared to healthy subjects and T1 DM patients. The significance of this result is unclear but the reduction in fasting nesfatin-1 may be one of the appetite-related hormones involved in diabetic hyperphagia. In addition, neither glucose nor saline ingestions affected plasma nesfatin-1, suggesting that gastric chemosensation is

  3. Dust survey following the final shutdown of TEXTOR: metal particles and fuel retention

    NASA Astrophysics Data System (ADS)

    Fortuna-Zaleśna, E.; Weckmann, A.; Grzonka, J.; Rubel, M.; Esser, H. G.; Freisinger, M.; Kreter, A.; Sergienko, G.; Ström, P.

    2016-02-01

    The work presents results of a broad TEXTOR dust survey in terms of its composition, structure, distribution and fuel content. The dust particles were collected after final shutdown of TEXTOR in December 2013. Fuel retention, as determined by thermal desorption, varied significantly, even by two orders of magnitude, dependent on the dust location in the machine. Dust structure was examined by means of scanning electron microscopy combined with energy-dispersive x-ray spectroscopy, focused ion beam and scanning transmission electron microscopy. Several categories of dust have been identified. Carbon-based stratified and granular deposits were dominating, but the emphasis in studies was on metal dust. They were found in the form of small particles, small spheres, flakes and splashes which formed ‘comet’-like structures, clearly indicating directional effects in the impact on surfaces of plasma-facing components. Nickel-rich alloys from the Inconel liner and iron-based ones from various diagnostic holders were the main components of metal-containing dust, but also molybdenum and tungsten debris were detected. Their origin is discussed.

  4. Six weeks' sebacic acid supplementation improves fasting plasma glucose, HbA1c and glucose tolerance in db/db mice

    PubMed Central

    Membrez, M; Chou, C J; Raymond, F; Mansourian, R; Moser, M; Monnard, I; Ammon-Zufferey, C; Mace, K; Mingrone, G; Binnert, C

    2010-01-01

    Aim: To investigate the impact of chronic ingestion of sebacic acid (SA), a 10-carbon medium-chain dicarboxylic acid, on glycaemic control in a mouse model of type 2 diabetes (T2D). Methods: Three groups of 15 db/db mice were fed for 6 weeks either a chow diet (Ctrl) or a chow diet supplemented with 1.5 or 15% (SA1.5% and SA15%, respectively) energy from SA. Fasting glycaemia was measured once a week and HbA1c before and after supplementation. An oral glucose tolerance test (OGTT) was performed at the end of the supplementation. Gene expression was determined by transcriptomic analysis on the liver of the Ctrl and SA15% groups. Results: After 42 days of supplementation, fasting glycaemia and HbA1c were ∼70 and 25% lower in the SA15% group compared with the other groups showing a beneficial effect of SA on hyperglycaemia. During OGTT, plasma glucose area under the curve was reduced after SA15% compared with the other groups. This effect was associated with a tendency for an improved insulin response. In the liver, Pck1 and FBP mRNA were statistically decreased in the SA15% compared with Ctrl suggesting a reduced hepatic glucose output induced by SA. Conclusion: Dietary supplementation of SA largely improves glycaemic control in a mouse model of T2D. This beneficial effect may be due to (i) an improved glucose-induced insulin secretion and (ii) a reduced hepatic glucose output. PMID:20977585

  5. Excited Oxidized-Carbon Nanodots Induced by Ozone from Low-Temperature Plasma to Initiate Strong Chemiluminescence for Fast Discrimination of Metal Ions.

    PubMed

    Long, Zi; Fang, De-Cai; Ren, Hong; Ouyang, Jin; He, Lixin; Na, Na

    2016-08-01

    Carbon nanodots (C-dots) are recently well examined due to the emissions with color-tuning and nonblinking properties, while more studies are still needed for the appropriate understanding and application of distinct emissions. In this work, we found the emission of chemiluminescence (CL) by introducing low-temperature plasma (LTP) into C-dots solutions without any reagent added, whose intensity was affected by the presence of different metal ions. Based on both experimental data and theoretical calculations, we found with the ozonation by ozone from LTP, excited oxidized-C-dots would be generated with the addition of ozone onto the conjugated double bonds of C-dots, and these excited species could directly initiate strong CL combining with the deactivation of excited species to the ground state. Significantly, the cross-reactive CL signals were obtained from different kinds of C-dots with the presence of different metal ions. Therefore, a new sensor array (electronic tongue) composed of five different C-dots was designed for fast discrimination of metal ions, which achieved the accurate discrimination of 13 kinds of metal ions in pure water and real samples. It exhibited good reproducibility and sensitivity, which can be used for the quantitative analysis of metal ions such as showing a linear range from 4 × 10(-7) to 6 × 10(-5) mol·L(-1) (R(2) > 0.99) for Fe(3+) with a detection limit of 2.5 × 10(-7) mol·L(-1). This work not only provides a novel finding of CL from C-dots revealing explicit relationship between structures and CL properties, but also realizes the fast discrimination of metal ions, showing potentials in environmental monitoring and quality identifications. PMID:27376407

  6. High Frequency Design Considerations for the Large Detector Number and Small Form Factor Dual Electron Spectrometer of the Fast Plasma Investigation on NASA's Magnetospheric Multiscale Mission

    NASA Technical Reports Server (NTRS)

    Kujawski, Joseph T.; Gliese, Ulrik B.; Cao, N. T.; Zeuch, M. A.; White, D.; Chornay, D. J; Lobell, J. V.; Avanov, L. A.; Barrie, A. C.; Mariano, A. J.; Tucker, C. J.; Piepgrass, B.; Auletti, C.; Weidner, S.; Jacques, A. D.; Pollock, C. J.

    2015-01-01

    Each half of the Dual Electron Spectrometer (DES) of the Fast Plasma Investigation (FPI) on NASA's Magnetospheric MultiScale (MMS) mission utilizes a microchannel plate Chevron stack feeding 16 separate detection channels each with a dedicated anode and amplifier/discriminator chip. The desire to detect events on a single channel with a temporal spacing of 100 ns and a fixed dead-time drove our decision to use an amplifier/discriminator with a very fast (GHz class) front end. Since the inherent frequency response of each pulse in the output of the DES microchannel plate system also has frequency components above a GHz, this produced a number of design constraints not normally expected in electronic systems operating at peak speeds of 10 MHz. Additional constraints are imposed by the geometry of the instrument requiring all 16 channels along with each anode and amplifier/discriminator to be packaged in a relatively small space. We developed an electrical model for board level interactions between the detector channels to allow us to design a board topology which gave us the best detection sensitivity and lowest channel to channel crosstalk. The amplifier/discriminator output was designed to prevent the outputs from one channel from producing triggers on the inputs of other channels. A number of Radio Frequency design techniques were then applied to prevent signals from other subsystems (e.g. the high voltage power supply, command and data handling board, and Ultraviolet stimulation for the MCP) from generating false events. These techniques enabled us to operate the board at its highest sensitivity when operated in isolation and at very high sensitivity when placed into the overall system.

  7. Effect of treatment with a hydroxymethylglutaryl coenzyme A reductase inhibitor on fasting and postprandial plasma lipoproteins and cholesteryl ester transfer activity in patients with NIDDM.

    PubMed

    Bhatnagar, D; Durrington, P N; Kumar, S; Mackness, M I; Dean, J; Boulton, A J

    1995-04-01

    Patients with non-insulin-dependent diabetes mellitus (NIDDM) have a greater risk of developing coronary heart disease than would be expected from a similar degree of hyperlipidemia in nondiabetic populations. Accelerated transfer of cholesteryl esters (CET) from high-density lipoprotein (HDL) to low-density lipoprotein (LDL) and very-low-density lipoprotein (VLDL), a process that is associated with atherosclerosis, may be a possible explanation for this. CET, plasma lipoprotein concentration, and mass in the fasting and postprandial state have been examined in 31 hyperlipidemic patients with NIDDM before and after 8 weeks of treatment with the hydroxymethylglutaryl (HMG)-coenzyme A (CoA) reductase inhibitor pravastatin in a double-blind, placebo-controlled, parallel group study. Body mass index, glycemic control, and blood pressure remained unaltered during the study period. Compared with placebo, pravastatin decreased fasting serum cholesterol (P < 0.001) and LDL cholesterol (P < 0.002) levels. The high basal CET (34.4 +/- 13.1 nmol.ml-1.h-1) was decreased significantly by pravastatin treatment (27.5 +/- 13.7 nmol.ml-1.h-1, P = 0.013). There was a fall in the total cholesterol, free cholesterol, and phospholipid content of the Sf 0-12, 20-60, and 60-400 lipoproteins (all P = 0.001). Lecithin: cholesterol acyl transferase activity was not altered. The postprandial increase in VLDL cholesterol 5 h after a standardized mixed meal was attenuated after pravastatin treatment (P = 0.011). Inhibition of hepatic cholesterol synthesis with an HMG-CoA reductase inhibitor in hyperlipidemic patients with NIDDM decreased serum cholesterol content of triglyceride-rich lipoprotein, thereby decreasing the transfer of cholesteryl ester from HDL to LDL and VLDL. PMID:7698516

  8. Transient shutdown analysis of low-temperature thermal diodes

    NASA Technical Reports Server (NTRS)

    Williams, R. J.

    1979-01-01

    The various thermal diodes available for use in cryogenic systems are described. Two diode types, liquid-trap and liquid-blockage diodes, were considered to be the most attractive, and thermal models were constructed to predict their behavior in the reverse mode. The diodes, which are of similar size and throughput, were also examined experimentally in a parallel test setup under nominally identical conditions. Their characteristics were ascertained in terms of forward-mode and reverse-mode conductances, shutdown times and energies, and recovery to forward-mode operation with ethane as the working fluid in the temperature range 170 K to 220 K. Results show that the liquid-blockage diode is the quicker of the two diodes to shut down from the forward mode (8 min as opposed to 10 min). However, the liquid-blockage diode has a larger reverse-mode conductance which results in a greater overall evaporator temperature rise. The importance of the relative size and heat inputs to the condenser/reservoir configuration of the liquid-blockage diode and the evaporator trap configuration for the liquid-trap diode are demonstrated. Also included are data which show the susceptibility of the diodes to recovery to forward-mode operation. Guidelines for the choice of a particular diode for an actual application are given.

  9. Thermionic switched self-actuating reactor shutdown system

    DOEpatents

    Barrus, Donald M.; Shires, Charles D.; Brummond, William A.

    1989-01-01

    A self-actuating reactor shutdown system incorporating a thermionic switched electromagnetic latch arrangement which is responsive to reactor neutron flux changes and to reactor coolant temperature changes. The system is self-actuating in that the sensing thermionic device acts directly to release (scram) the control rod (absorber) without reference or signal from the main reactor plant protective and control systems. To be responsive to both temperature and neutron flux effects, two detectors are used, one responsive to reactor coolant temperatures, and the other responsive to reactor neutron flux increase. The detectors are incorporated into a thermionic diode connected electrically with an electromagnetic mechanism which under normal reactor operating conditions holds the the control rod in its ready position (exterior of the reactor core). Upon reaching either a specified temperature or neutron flux, the thermionic diode functions to short-circuit the electromagnetic mechanism causing same to lose its holding power and release the control rod, which drops into the reactor core region under gravitational force.

  10. Startup, shutdown and malfunction plans coming for large industrial boilers

    SciTech Connect

    Kasarabada, A.N.

    2007-08-15

    The US Boiler MACT (maximum achievable control technology) regulations (codified under 40 CFR Part 63) in its current form requires existing large coal-fired industrial and utility boilers (under 25 MW) to meet emission limits for particulate matter or total selected metals, mercury and hydrogen chloride, as well as other operational limits. The MACT provision also requires affected facilities to develop startup, shutdown and malfunction plans (SSMP). The original date for Boiler MACT compliance for existing units had been 13 September 2007. However, on 8 June the US Court of Appeals for the District of Columbia issued an order effectively killing all existing MACT rules for industrial boilers. The Court instructed the US EPA to rewrite two sets of regulations. (Prior to April 2006 the MACT general provisions said the SSMPs needed to be 'developed and implemented'.) It seems unlikely that any new revision of the Boiler MACT by the EPA will take effect before mid-2008. Regardless of which direction the MACT rule is headed, now is the time to be prepared to comply with the SSMP requirements. The article sets out recommended steps for developing an effective SSMP.

  11. Advanced wind turbine with lift cancelling aileron for shutdown

    DOEpatents

    Coleman, Clint; Juengst, Theresa M.; Zuteck, Michael D.

    1996-06-18

    An advanced aileron configuration for wind turbine rotors featuring an independent, lift generating aileron connected to the rotor blade. The aileron has an airfoil profile which is inverted relative to the airfoil profile of the main section of the rotor blade. The inverted airfoil profile of the aileron allows the aileron to be used for strong positive control of the rotation of the rotor while deflected to angles within a control range of angles. The aileron functions as a separate, lift generating body when deflected to angles within a shutdown range of angles, generating lift with a component acting in the direction opposite the direction of rotation of the rotor. Thus, the aileron can be used to shut down rotation of the rotor. The profile of the aileron further allows the center of rotation to be located within the envelope of the aileron, at or near the centers of pressure and mass of the aileron. The location of the center of rotation optimizes aerodynamically and gyroscopically induced hinge moments and provides a fail safe configuration.

  12. Advanced wind turbine with lift-destroying aileron for shutdown

    DOEpatents

    Coleman, Clint; Juengst, Theresa M.; Zuteck, Michael D.

    1996-06-18

    An advanced aileron configuration for wind turbine rotors featuring an aileron with a bottom surface that slopes upwardly at an angle toward the nose region of the aileron. The aileron rotates about a center of rotation which is located within the envelope of the aileron, but does not protrude substantially into the air flowing past the aileron while the aileron is deflected to angles within a control range of angles. This allows for strong positive control of the rotation of the rotor. When the aileron is rotated to angles within a shutdown range of deflection angles, lift-destroying, turbulence-producing cross-flow of air through a flow gap, and turbulence created by the aileron, create sufficient drag to stop rotation of the rotor assembly. The profile of the aileron further allows the center of rotation to be located within the envelope of the aileron, at or near the centers of pressure and mass of the aileron. The location of the center of rotation optimizes aerodynamically and gyroscopically induced hinge moments and provides a fail safe configuration.

  13. Study of Static Microchannel Plate Saturation Effects for the Fast Plasma Investigation Dual Electron Spectrometers on NASA's Magnetospheric MultiScale Mission

    NASA Technical Reports Server (NTRS)

    Avanov, L. A.; Gliese, U.; Pollock, C. J.; Moore, T. E.; Chornay, D. J.; Barrie, A. C.; Kujawski, J. T.; Gershman, D. J.; Tucker, C. J.; Mariano, A.; Smith, D. L.; Jacques, A. D.

    2015-01-01

    Imaging detecting systems based on microchannel plates (MCPs) are the most common for low energy plasma measurements for both space borne and ground applications. One of the key parameters of these detection systems is the dynamic range of the MCP's response to the input fluxes of charged particles. For most applications the dynamic range of the linear response should be as wide as possible. This is especially true for the Dual Electron Spectrometers (DESs) of the Fast Plasma Investigation (FPI) on NASA's Magnetospheric MultiScale (MMS) mission because a wide range of input fluxes are expected. To make use of the full available dynamic range, it is important to understand the MCP response behavior beyond the linear regime where the MCPs start to saturate. We have performed extensive studies of this during the characterization and calibration of the DES instruments and have identified several saturation effects of the detection system. The MCP itself exhibits saturation when the channels lack the ability to replenish charge sufficiently rapidly. It is found and will be shown that the ground system can significantly impact the correct measurement of this effect. As the MCP starts to saturate, the resulting pulse height distribution (PHD) changes shape and location (with less pulse height values), which leads to truncation of the PHD by the threshold set on the detection system discriminator. Finally, the detection system pulse amplifier exhibits saturation as the input flux drives pulse rates greater than its linear response speed. All of these effects effectively change the dead time of the overall detection system and as a result can affect the quality and interpretation of the flight data. We present results of detection system saturation effects and their interaction with special emphasis on the MCP related effects.

  14. The Prevalence and Associated Factors of Periodontitis According to Fasting Plasma Glucose in the Korean Adults: The 2012-2013 Korea National Health and Nutrition Examination Survey.

    PubMed

    Hong, Jae Won; Noh, Jung Hyun; Kim, Dong-Jun

    2016-04-01

    Although the relationship between diabetes and periodontitis is well established, the association between periodontitis and prediabetes has been investigated less extensively. Furthermore, there has been little research on the prevalence of periodontitis among individuals with prediabetes and diabetes as well as in the overall population using nationally representative data.Among 12,406 adults (≥19 years' old) who participated in the 2012-2013 Korea National Health and Nutrition Examination Survey, a total of 9977 subjects completed oral and laboratory examinations and were included in this analysis. Periodontitis was defined as a community periodontal index score of ≥ 3 according to the World Health Organization criteria. The fasting plasma glucose level was categorized into the following 5 groups: normal fasting glucose (NFG) 1 (<90  mg/dL), NFG 2 (90-99  mg/dL), impaired fasting glucose (IFG) 1 (100-110  mg/dL), IFG 2 (111-125  mg/dL), and diabetes (≥126  mg/dL).Overall, the weighted prevalence of periodontitis among the Korean adult population was 24.8% (23.3-26.4%) (weight n = 8,455,952/34,086,014). The unadjusted weighted prevalences of periodontitis were 16.7%, 22.8%, 29.6%, 40.7%, and 46.7% in the NFG 1, NFG 2, IFG 1, IFG 2, and diabetes groups, respectively (P < 0.001). After adjusting for age, sex, smoking history, heavy alcohol drinking, college graduation, household income, waist circumference, serum triglyceride level, serum high-density lipoprotein cholesterol level, and the presence of hypertension, the adjusted weighted prevalence of periodontitis increased to 29.7% in the IFG 2 group (P = 0.045) and 32.5% in the diabetes group (P < 0.001), compared with the NFG 1 group (24%). The odds ratios for periodontitis with the above-mentioned variables as covariates were 1.42 (95% confidence interval [CI] 1.14-1.77, P = 0.002) in the diabetes group and 1.33 (95% CI 1.01-1.75, P = 0.044) in the IFG 2 group

  15. Benchmark specifications for EBR-II shutdown heat removal tests

    SciTech Connect

    Sofu, T.; Briggs, L. L.

    2012-07-01

    Argonne National Laboratory (ANL) is hosting an IAEA-coordinated research project on benchmark analyses of sodium-cooled fast reactor passive safety tests performed at the Experimental Breeder Reactor-II (EBR-II). The benchmark project involves analysis of a protected and an unprotected loss of flow tests conducted during an extensive testing program within the framework of the U.S. Integral Fast Reactor program to demonstrate the inherently safety features of EBR-II as a pool-type, sodium-cooled fast reactor prototype. The project is intended to improve the participants' design and safety analysis capabilities for sodium-cooled fast reactors through validation and qualification of safety analysis codes and methods. This paper provides a description of the EBR-II tests included in the program, and outlines the benchmark specifications being prepared to support the IAEA-coordinated research project. (authors)

  16. C-Peptide Level in Fasting Plasma and Pooled Urine Predicts HbA1c after Hospitalization in Patients with Type 2 Diabetes Mellitus.

    PubMed

    Sonoda, Remi; Tanaka, Kentaro; Kikuchi, Takako; Onishi, Yukiko; Takao, Toshiko; Tahara, Tazu; Yoshida, Yoko; Suzawa, Naoki; Kawazu, Shoji; Iwamoto, Yasuhiko; Kushiyama, Akifumi

    2016-01-01

    In this study, we investigate how measures of insulin secretion and other clinical information affect long-term glycemic control in patients with type 2 diabetes mellitus. Between October 2012 and June 2014, we monitored 202 diabetes patients who were admitted to the hospital of Asahi Life Foundation for glycemic control, as well as for training and education in diabetes management. We measured glycated hemoglobin (HbA1c) six months after discharge to assess disease management. In univariate analysis, fasting plasma C-peptide immunoreactivity (F-CPR) and pooled urine CPR (U-CPR) were significantly associated with HbA1c, in contrast to ΔCPR and C-peptide index (CPI). This association was strongly independent of most other patient variables. In exploratory factor analysis, five underlying factors, namely insulin resistance, aging, sex differences, insulin secretion, and glycemic control, represented patient characteristics. In particular, insulin secretion and resistance strongly influenced F-CPR, while insulin secretion affected U-CPR. In conclusion, the data indicate that among patients with type 2 diabetes mellitus, F-CPR and U-CPR may predict improved glycemic control six months after hospitalization.

  17. Axial magnetic field and toroidally streaming fast ions in the dense plasma focus are natural consequences of conservation laws in the curved axisymmetric geometry of the current sheath

    SciTech Connect

    Auluck, S. K. H.

    2014-10-15

    Direct measurement of axial magnetic field in the PF-1000 dense plasma focus (DPF), and its reported correlation with neutron emission, call for a fresh look at previous reports of existence of axial magnetic field component in the DPF from other laboratories, and associated data suggesting toroidal directionality of fast ions participating in fusion reactions, with a view to understand the underlying physics. In this context, recent work dealing with application of the hyperbolic conservation law formalism to the DPF is extended in this paper to a curvilinear coordinate system, which reflects the shape of the DPF current sheath. Locally unidirectional shock propagation in this coordinate system enables construction of a system of 7 one-dimensional hyperbolic conservation law equations with geometric source terms, taking into account all the components of magnetic field and flow velocity. Rankine-Hugoniot jump conditions for this system lead to expressions for the axial magnetic field and three components of fluid velocity having high ion kinetic energy.

  18. Axial magnetic field and toroidally streaming fast ions in the dense plasma focus are natural consequences of conservation laws in the curved axisymmetric geometry of the current sheath

    NASA Astrophysics Data System (ADS)

    Auluck, S. K. H.

    2014-10-01

    Direct measurement of axial magnetic field in the PF-1000 dense plasma focus (DPF), and its reported correlation with neutron emission, call for a fresh look at previous reports of existence of axial magnetic field component in the DPF from other laboratories, and associated data suggesting toroidal directionality of fast ions participating in fusion reactions, with a view to understand the underlying physics. In this context, recent work dealing with application of the hyperbolic conservation law formalism to the DPF is extended in this paper to a curvilinear coordinate system, which reflects the shape of the DPF current sheath. Locally unidirectional shock propagation in this coordinate system enables construction of a system of 7 one-dimensional hyperbolic conservation law equations with geometric source terms, taking into account all the components of magnetic field and flow velocity. Rankine-Hugoniot jump conditions for this system lead to expressions for the axial magnetic field and three components of fluid velocity having high ion kinetic energy.

  19. C-Peptide Level in Fasting Plasma and Pooled Urine Predicts HbA1c after Hospitalization in Patients with Type 2 Diabetes Mellitus

    PubMed Central

    Sonoda, Remi; Tanaka, Kentaro; Kikuchi, Takako; Onishi, Yukiko; Takao, Toshiko; Tahara, Tazu; Yoshida, Yoko; Suzawa, Naoki; Kawazu, Shoji; Iwamoto, Yasuhiko; Kushiyama, Akifumi

    2016-01-01

    In this study, we investigate how measures of insulin secretion and other clinical information affect long-term glycemic control in patients with type 2 diabetes mellitus. Between October 2012 and June 2014, we monitored 202 diabetes patients who were admitted to the hospital of Asahi Life Foundation for glycemic control, as well as for training and education in diabetes management. We measured glycated hemoglobin (HbA1c) six months after discharge to assess disease management. In univariate analysis, fasting plasma C-peptide immunoreactivity (F-CPR) and pooled urine CPR (U-CPR) were significantly associated with HbA1c, in contrast to ΔCPR and C-peptide index (CPI). This association was strongly independent of most other patient variables. In exploratory factor analysis, five underlying factors, namely insulin resistance, aging, sex differences, insulin secretion, and glycemic control, represented patient characteristics. In particular, insulin secretion and resistance strongly influenced F-CPR, while insulin secretion affected U-CPR. In conclusion, the data indicate that among patients with type 2 diabetes mellitus, F-CPR and U-CPR may predict improved glycemic control six months after hospitalization. PMID:26849676

  20. Charge steering of laser plasma accelerated fast ions in a liquid spray — creation of MeV negative ion and neutral atom beams

    SciTech Connect

    Schnürer, M.; Abicht, F.; Priebe, G.; Braenzel, J.; Prasad, R.; Borghesi, M.; Andreev, A.; Nickles, P. V.; Jequier, S.; Tikhonchuk, V.; Ter-Avetisyan, S.

    2013-11-15

    The scenario of “electron capture and loss” has been recently proposed for the formation of negative ion and neutral atom beams with up to MeV kinetic energy [S. Ter-Avetisyan, et al., Appl. Phys. Lett. 99, 051501 (2011)]. Validation of these processes and of their generic nature is here provided in experiments where the ion source and the interaction medium have been spatially separated. Fast positive ions accelerated from a laser plasma source are sent through a cold spray where their charge is changed. Such formed neutral atom or negative ion has nearly the same momentum as the original positive ion. Experiments are released for protons, carbon, and oxygen ions and corresponding beams of negative ions and neutral atoms have been obtained. The electron capture and loss phenomenon is confirmed to be the origin of the negative ion and neutral atom beams. The equilibrium ratios of different charge components and cross sections have been measured. Our method is general and allows the creation of beams of neutral atoms and negative ions for different species which inherit the characteristics of the positive ion source.

  1. 78 FR 49553 - Three Mile Island, Unit 2; Post Shutdown Decommissioning Activities Report

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-14

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Three Mile Island, Unit 2; Post Shutdown Decommissioning Activities Report AGENCY: Nuclear...) for Three Mile Island, Unit 2 (TMI-2). The PSDAR provides an overview of GPUN's...

  2. Despite the Shutdown, Rescheduled NIH Research Festival Brings Science to the Forefront | Poster

    Cancer.gov

    By Andrea Frydl, Contributing Writer Although it was delayed by almost a month because of the federal shutdown, the NIH Research Festival still took place at the NIH Clinical Center in Bethesda, Md., and attendance was high.

  3. Characteristics of dioxin emissions at startup and shutdown of MSW incinerators.

    PubMed

    Tejima, Hajime; Nishigaki, Masahide; Fujita, Yasuyuki; Matsumoto, Akihiro; Takeda, Nobuo; Takaoka, Masaki

    2007-01-01

    Dioxin concentrations from municipal waste incinerators in Japan and elsewhere often show low concentrations that comply with legal limits (in this paper, the term "dioxin" designates WHO-TEQ: PCDD/Fs+dioxin-like PCB). However, such data is usually generated under normal steady state operational conditions, and there has been little investigation of releases occurring during startup and shutdown. It is important, therefore, to ascertain quantitatively emissions in an unsteady state (startup and shutdown) in order to correctly evaluate the relationship between emissions from a facility and the surrounding environment. The present study aimed to examine dioxin emissions of a continuously operated incinerator at startup and shutdown, and estimating the time period of greatest emission, and the processes causing dioxin generation. The startup process was divided into five stages and the shutdown into two; at each stage, dioxins in the flue gas were measured at the boiler outlet and the stack. From the concentration of dioxins and the flue gas volume at each stage, the amount of dioxins at startup and shutdown were calculated, and these were compared with that under steady state conditions. Dioxin concentration at the stack under steady state conditions was a very low level, while those at startup and shutdown were higher. In the case where dioxin concentration under a steady state is a low level like in this study, it is indicated that the total annual dioxin emission from a facility could be attributed to the startup periods.

  4. Optimal cut-off points of fasting plasma glucose for two-step strategy in estimating prevalence and screening undiagnosed diabetes and pre-diabetes in Harbin, China.

    PubMed

    Bao, Chundan; Zhang, Dianfeng; Sun, Bo; Lan, Li; Cui, Wenxiu; Xu, Guohua; Sui, Conglan; Wang, Yibaina; Zhao, Yashuang; Wang, Jian; Li, Hongyuan

    2015-01-01

    To identify optimal cut-off points of fasting plasma glucose (FPG) for two-step strategy in screening abnormal glucose metabolism and estimating prevalence in general Chinese population. A population-based cross-sectional study was conducted on 7913 people aged 20 to 74 years in Harbin. Diabetes and pre-diabetes were determined by fasting and 2 hour post-load glucose from the oral glucose tolerance test in all participants. Screening potential of FPG, cost per case identified by two-step strategy, and optimal FPG cut-off points were described. The prevalence of diabetes was 12.7%, of which 65.2% was undiagnosed. Twelve percent or 9.0% of participants were diagnosed with pre-diabetes using 2003 ADA criteria or 1999 WHO criteria, respectively. The optimal FPG cut-off points for two-step strategy were 5.6 mmol/l for previously undiagnosed diabetes (area under the receiver-operating characteristic curve of FPG 0.93; sensitivity 82.0%; cost per case identified by two-step strategy ¥261), 5.3 mmol/l for both diabetes and pre-diabetes or pre-diabetes alone using 2003 ADA criteria (0.89 or 0.85; 72.4% or 62.9%; ¥110 or ¥258), 5.0 mmol/l for pre-diabetes using 1999 WHO criteria (0.78; 66.8%; ¥399), and 4.9 mmol/l for IGT alone (0.74; 62.2%; ¥502). Using the two-step strategy, the underestimates of prevalence reduced to nearly 38% for pre-diabetes or 18.7% for undiagnosed diabetes, respectively. Approximately a quarter of the general population in Harbin was in hyperglycemic condition. Using optimal FPG cut-off points for two-step strategy in Chinese population may be more effective and less costly for reducing the missed diagnosis of hyperglycemic condition.

  5. Optimal cut-off points of fasting plasma glucose for two-step strategy in estimating prevalence and screening undiagnosed diabetes and pre-diabetes in Harbin, China.

    PubMed

    Bao, Chundan; Zhang, Dianfeng; Sun, Bo; Lan, Li; Cui, Wenxiu; Xu, Guohua; Sui, Conglan; Wang, Yibaina; Zhao, Yashuang; Wang, Jian; Li, Hongyuan

    2015-01-01

    To identify optimal cut-off points of fasting plasma glucose (FPG) for two-step strategy in screening abnormal glucose metabolism and estimating prevalence in general Chinese population. A population-based cross-sectional study was conducted on 7913 people aged 20 to 74 years in Harbin. Diabetes and pre-diabetes were determined by fasting and 2 hour post-load glucose from the oral glucose tolerance test in all participants. Screening potential of FPG, cost per case identified by two-step strategy, and optimal FPG cut-off points were described. The prevalence of diabetes was 12.7%, of which 65.2% was undiagnosed. Twelve percent or 9.0% of participants were diagnosed with pre-diabetes using 2003 ADA criteria or 1999 WHO criteria, respectively. The optimal FPG cut-off points for two-step strategy were 5.6 mmol/l for previously undiagnosed diabetes (area under the receiver-operating characteristic curve of FPG 0.93; sensitivity 82.0%; cost per case identified by two-step strategy ¥261), 5.3 mmol/l for both diabetes and pre-diabetes or pre-diabetes alone using 2003 ADA criteria (0.89 or 0.85; 72.4% or 62.9%; ¥110 or ¥258), 5.0 mmol/l for pre-diabetes using 1999 WHO criteria (0.78; 66.8%; ¥399), and 4.9 mmol/l for IGT alone (0.74; 62.2%; ¥502). Using the two-step strategy, the underestimates of prevalence reduced to nearly 38% for pre-diabetes or 18.7% for undiagnosed diabetes, respectively. Approximately a quarter of the general population in Harbin was in hyperglycemic condition. Using optimal FPG cut-off points for two-step strategy in Chinese population may be more effective and less costly for reducing the missed diagnosis of hyperglycemic condition. PMID:25785585

  6. Optimal Cut-Off Points of Fasting Plasma Glucose for Two-Step Strategy in Estimating Prevalence and Screening Undiagnosed Diabetes and Pre-Diabetes in Harbin, China

    PubMed Central

    Sun, Bo; Lan, Li; Cui, Wenxiu; Xu, Guohua; Sui, Conglan; Wang, Yibaina; Zhao, Yashuang; Wang, Jian; Li, Hongyuan

    2015-01-01

    To identify optimal cut-off points of fasting plasma glucose (FPG) for two-step strategy in screening abnormal glucose metabolism and estimating prevalence in general Chinese population. A population-based cross-sectional study was conducted on 7913 people aged 20 to 74 years in Harbin. Diabetes and pre-diabetes were determined by fasting and 2 hour post-load glucose from the oral glucose tolerance test in all participants. Screening potential of FPG, cost per case identified by two-step strategy, and optimal FPG cut-off points were described. The prevalence of diabetes was 12.7%, of which 65.2% was undiagnosed. Twelve percent or 9.0% of participants were diagnosed with pre-diabetes using 2003 ADA criteria or 1999 WHO criteria, respectively. The optimal FPG cut-off points for two-step strategy were 5.6 mmol/l for previously undiagnosed diabetes (area under the receiver-operating characteristic curve of FPG 0.93; sensitivity 82.0%; cost per case identified by two-step strategy ¥261), 5.3 mmol/l for both diabetes and pre-diabetes or pre-diabetes alone using 2003 ADA criteria (0.89 or 0.85; 72.4% or 62.9%; ¥110 or ¥258), 5.0 mmol/l for pre-diabetes using 1999 WHO criteria (0.78; 66.8%; ¥399), and 4.9 mmol/l for IGT alone (0.74; 62.2%; ¥502). Using the two-step strategy, the underestimates of prevalence reduced to nearly 38% for pre-diabetes or 18.7% for undiagnosed diabetes, respectively. Approximately a quarter of the general population in Harbin was in hyperglycemic condition. Using optimal FPG cut-off points for two-step strategy in Chinese population may be more effective and less costly for reducing the missed diagnosis of hyperglycemic condition. PMID:25785585

  7. New Method for Accurate Calibration of Micro-Channel Plate based Detection Systems and its use in the Fast Plasma Investigation of NASA's Magnetospheric MultiScale Mission

    NASA Astrophysics Data System (ADS)

    Gliese, U.; Avanov, L. A.; Barrie, A.; Kujawski, J. T.; Mariano, A. J.; Tucker, C. J.; Chornay, D. J.; Cao, N. T.; Zeuch, M.; Pollock, C. J.; Jacques, A. D.

    2013-12-01

    The Fast Plasma Investigation (FPI) of the NASA Magnetospheric MultiScale (MMS) mission employs 16 Dual Electron Spectrometers (DESs) and 16 Dual Ion Spectrometers (DISs) with 4 of each type on each of 4 spacecraft to enable fast (30ms for electrons; 150ms for ions) and spatially differentiated measurements of full the 3D particle velocity distributions. This approach presents a new and challenging aspect to the calibration and operation of these instruments on ground and in flight. The response uniformity and reliability of their calibration and the approach to handling any temporal evolution of these calibrated characteristics all assume enhanced importance in this application, where we attempt to understand the meaning of particle distributions within the ion and electron diffusion regions. Traditionally, the micro-channel plate (MCP) based detection systems for electrostatic particle spectrometers have been calibrated by setting a fixed detection threshold and, subsequently, measuring a detection system count rate plateau curve to determine the MCP voltage that ensures the count rate has reached a constant value independent of further variation in the MCP voltage. This is achieved when most of the MCP pulse height distribution (PHD) is located at higher values (larger pulses) than the detection amplifier threshold. This method is adequate in single-channel detection systems and in multi-channel detection systems with very low crosstalk between channels. However, in dense multi-channel systems, it can be inadequate. Furthermore, it fails to fully and individually characterize each of the fundamental parameters of the detection system. We present a new detection system calibration method that enables accurate and repeatable measurement and calibration of MCP gain, MCP efficiency, signal loss due to variation in gain and efficiency, crosstalk from effects both above and below the MCP, noise margin, and stability margin in one single measurement. The fundamental

  8. HbA1c, fasting and 2-hour plasma glucose in current-, ex-, and non-smokers: a meta-analysis

    PubMed Central

    Soulimane, Soraya; Simon, Dominique; Herman, William H; Lange, Celine; Lee, Crystal MY; Colagiuri, Stephen; Shaw, Jonathan E; Zimmet, Paul Z; Magliano, Dianna; Ferreira, Sandra RS; Dong, Yanghu; Zhang, Lei; Jorgensen, Torben; Tuomilehto, Jaakko; Mohan, Viswanathan; Christensen, Dirk L; Kaduka, Lydia; Dekker, Jacqueline M; Nijpels, Giel; Stehouwer, Coen DA; Lantieri, Olivier; Fujimoto, Wilfred Y; Leonetti, Donna L; McNeely, Marguerite J; Borch-Johnsen, Knut; Boyko, Edward J; Vistisen, Dorte; Balkau, Beverley

    2014-01-01

    Aim The relations between smoking and glycaemic parameters are not well explored. We compare HbA1c, fasting plasma glucose (FPG) and 2-hour plasma glucose (2H-PG) in current-, ex- and never-smokers. Methods This meta-analysis used individual data from 16 886 men and 18 539 women without known diabetes, in 12 DETECT-2 consortium studies and in the French D.E.S.I.R. and TELECOM studies. Means of the three glycaemic parameters in current-, ex- and never-smokers were modelled by linear regression, with study as a random factor. The I2 statistic evaluated heterogeneity among studies. Results HbA1c was 0.10 (95%CI:0.08,0.12) % [1.1 (0.9,1.3) mmol/mol] higher in current-smokers and 0.03 (0.01,0.05) % [0.3 (0.1,0.5) mmol/l] higher in ex-smokers, compared with never-smokers. For FPG, there was no significant difference between current- and never-smokers: −0.004 (−0.03,0.02) mmol/l but FPG was higher in ex-smokers: 0.12 (0.09,0.14) mmol/l. In comparison to never-smokers, 2H-PG was lower: −0.44 (−0.52,−0.37) mmol/l in current-smokers, with no difference for ex-smokers: 0.02 (−0.06,0.09) mmol/l. There was a large and unexplained heterogeneity among studies, with I2 always higher than 50%: after stratification by sex and adjustment for age and BMI, I2 changed little. In this study population, current-smokers had a prevalence of diabetes as screened by HbA1c, 1.30% higher and that screened by 2H-PG, 0.52% lower than in comparison to never-smokers. Conclusion Current-smokers had a higher HbA1c and a lower 2H-PG than never-smokers, across this heterogeneous group of studies; this will effect the chances of smokers being diagnosed with diabetes. PMID:24065153

  9. Ultra-fast LC-ESI-MS/MS method for the simultaneous determination of six highly toxic Aconitum alkaloids from Aconiti kusnezoffii radix in rat plasma and its application to a pharmacokinetic study.

    PubMed

    Liu, Jingjing; Li, Qing; Yin, Yidi; Liu, Ran; Xu, Huarong; Bi, Kaishun

    2014-01-01

    A fast, sensitive, and efficient ultra-fast LC-ESI-MS/MS method was developed for the simultaneous quantitation of six highly toxic Aconitum alkaloids, that is, aconitine, mesaconitine, hypaconitine, benzoylaconine, benzoylmesaconine, and benzoylhypaconine, in rat plasma after oral administration of crude ethanol extracts from Aconiti kusnezoffii radix by ultrasonic extraction, reflux extraction for 1 h, and reflux extraction for 3 h, respectively. The separation of six Aconitum alkaloids and aminopyrine (internal standard) was performed on an InertSustain® C18 column, and the quantification of the analytes was performed on a 4000Q ultra-fast LC-MS/MS system with turbo ion spray source in the positive ion and multiple-reaction monitoring mode. Absolute recoveries ranged within 65.06-85.1% for plasma samples. The intra- and interday precision and accuracy of analytes were satisfactory. The methods were validated with sensitivity reaching the lower LOQ for aconitine, mesaconitine, hypaconitine, benzoylaconine, benzoylmesaconine, and benzoylhypaconine, which were 0.025, 0.025, 0.050, 0.025, 0.025, and 0.100 ng/mL, respectively. The method was successfully applied to a pharmacokinetic study of six Aconitum alkaloids in rat plasma after oral administration of crude ethanol extracts from the raw root of Aconitum kusnezoffii Reichb. by three different extraction processes.

  10. Effect of chromium-enriched yeast on fasting plasma glucose, glycated haemoglobin and serum lipid levels in patients with type 2 diabetes mellitus treated with insulin.

    PubMed

    Racek, Jaroslav; Sindberg, C D; Moesgaard, S; Mainz, Josef; Fabry, Jaroslav; Müller, Luděk; Rácová, Katarína

    2013-10-01

    Chromium is required for a normal insulin function, and low levels have been linked with insulin resistance. The aim of this study was to follow the effect of chromium supplementation on fasting plasma glucose (FPG), glycated haemoglobin (HbA1c) and serum lipids in patients with type 2 diabetes mellitus (DM2) on insulin therapy. Eleven randomly selected patients with DM2 on insulin therapy were supplemented with a daily dose of 100 μg chromium yeast for the first supplementation period of 2 weeks. In the second supplementation period, the chromium dose was doubled and continued for the next 6 weeks. The third phase was a 6-week washout period. After each period, the levels of FPG and HbA1c were compared with the corresponding values at the end of the previous period. Serum triglycerides, total HDL and LDL cholesterol values after supplementation were compared with the baseline values. FPG decreased significantly after the first period of chromium supplementation (p < 0.001), and a tendency to a further reduction was observed after the second supplementation period. Similarly, HbA1c decreased significantly in both periods (p < 0.02 and p < 0.002, respectively). Eight weeks after withdrawal of chromium supplementation, both FPG and HbA1c levels returned to their pre-intervention values. The serum lipid concentrations were not significantly influenced by chromium supplementation. Chromium supplementation could be beneficial in patients with DM2 treated with insulin, most likely due to lowered insulin resistance leading to improved glucose tolerance. This finding needs to be confirmed in a larger study.

  11. Associations of Apolipoprotein A, High-Sensitivity C-Reactive Protein and Fasting Plasma Insulin in Obese Children With and Without Family History of Cardiovascular Disease

    PubMed Central

    Karabouta, Zacharoula; Papandreou, Dimitrios; Makedou, Areti; Rousso, Israel; Athanassiadou, Fani

    2016-01-01

    Background The worldwide prevalence of childhood obesity has increased from 4.2% to 6.7% during the last two decades. Pediatric obesity is a major health problem, which is dramatically increasing in Greece. A variety of inflammatory variables have been also found to associate with cardiometabolic (CV) risk in obese children. The purpose of this study was to identify and examine the effects of possible CV risk factors in obese and non-obese children with and without family history (FH) of cardiovascular disease (CVD). Methods Sixty-eight (68) healthy children and adolescents aged 7 - 13 years participated in the study. Anthropometrical and biochemical indexes were obtained from all children as well as FH of CVD. Results Systolic blood pressure (SBP), total cholesterol (TC), triglyceride (TG), high-sensitivity C-reactive protein (hsCRP), fasting plasma insulin (FPI) and homeostasis model assessment of insulin resistance (HOMA-IR) levels were found statistically significantly higher in the obese group compared to the non-obese one. High-density lipoprotein (HDL) levels were observed to be statistically significantly lower in the obese children compared to their normal peers. Conclusions Apolipoprotein A, hsCRP and FPI levels were significantly higher in the obese children with FH of CVD compared to the ones without FH of CVD. TC and SBP were found to be independently associated with obesity (odds ratio (OR): 1.965, 95% confidence interval (CI): 1.935 - 2.97, P < 0.031 and OR: 1.045, 95% CI: 1.016 - 1.074, P < 0.002, respectively). PMID:27222670

  12. Risk of Future Diabetes in Japanese People with High-normal Fasting Plasma Glucose Levels: A 4-Year Follow-up Study.

    PubMed

    Watanabe, Yoh; Eto, Tanenao; Taniguchi, Shotaro; Terauchi, Yasuo

    2016-01-01

    Objective There is no definite consensus regarding the treatment and guidance for individuals with high-normal fasting plasma glucose levels (FPG;100-109 mg/dL). The present study aimed to determine the risk factors for future diabetes in Japanese people with high-normal FPG. Methods Retrospective cohort studies were conducted from 2008 to 2012, including 15,097 individuals who underwent medical examinations. First, the participants were divided into normal FPG (n=13,065) and high-normal FPG (n=2,032) groups to compare the diabetes incidence. Second, the high FPG group was divided into diabetes onset (n=133) and non-diabetes onset (n=1,899) groups to compare the baseline values. Third, to determine the risk factors for future diabetes in the high-normal FPG group, multivariate analyses were conducted. Results The cumulative incidence during the mean follow-up of 4 years was 94/13,065 (0.72%) and 133/2,032 (6.55%) in the normal FPG and high-normal FPG groups, respectively. Within the high-normal FPG group, the baseline body mass index, waist circumference, triglycerides, FPG, alanine aminotransferase (ALT), and gamma-glutamyl transferase were significantly higher and high-density lipoprotein cholesterol (HDL-C) was significantly lower in the diabetes onset group than in the non-diabetes onset group. Obesity, abdominal obesity, hypertriglyceridemia, low HDL-C, and high ALT were significant risk factors for diabetes according to a multivariate analysis. Conclusion The high-normal FPG group had a higher risk of diabetes than the normal FPG group, particularly when accompanied with obesity, abdominal obesity, hypertriglyceridemia, low HDL-C, and high ALT. Thus, this high risk group should receive appropriate guidance for lifestyle changes to avoid developing diabetes at an early stage. PMID:27580535

  13. Development and validation of a fast and uniform approach to quantify β-lactam antibiotics in human plasma by solid phase extraction-liquid chromatography-electrospray-tandem mass spectrometry.

    PubMed

    Colin, Pieter; De Bock, Lies; T'jollyn, Huybrecht; Boussery, Koen; Van Bocxlaer, Jan

    2013-01-15

    Monitoring of plasma antibiotic concentrations is necessary for individualization of antimicrobial chemotherapy dosing in special patient populations. One of these special populations of interest are the post-bariatric surgery patients. Until today, little is known on the effect of this procedure on drug disposition and efficacy. Therefore, close monitoring of antimicrobial plasma concentrations in these patients is warranted. A fast and uniform ultra-high-performance liquid chromatography (UPLC) method with tandem mass spectrometric detection (MS/MS) has been developed and qualified for the simultaneous quantification of β-lactam antibiotics in human plasma. Compounds included in this multi-component analysis are: amoxicillin, ampicillin, phenoxymethylpenicillin, piperacillin, cefuroxime, cefadroxil, flucloxacillin, meropenem, cefepime, ceftazidime, tazobactam, linezolid and cefazolin. After spiking of five different stable isotope labelled internal standards, plasma samples were prepared for UPLC-MS/MS analysis by mixed-mode solid phase extraction. The developed method was proven to be free of (relative) matrix effects and proved to be reliable for the quantification of 12 out of 13 β-lactam antibiotics. As a proof of concept the method has been applied to plasma samples obtained from a healthy volunteer treated with amoxicillin. The analytical method is suitable for use in a therapeutic drug monitoring setting, providing the clinician with reliable measurements on β-lactam antibiotic plasma concentrations in a timely manner. PMID:23200389

  14. Development and validation of a fast and uniform approach to quantify β-lactam antibiotics in human plasma by solid phase extraction-liquid chromatography-electrospray-tandem mass spectrometry.

    PubMed

    Colin, Pieter; De Bock, Lies; T'jollyn, Huybrecht; Boussery, Koen; Van Bocxlaer, Jan

    2013-01-15

    Monitoring of plasma antibiotic concentrations is necessary for individualization of antimicrobial chemotherapy dosing in special patient populations. One of these special populations of interest are the post-bariatric surgery patients. Until today, little is known on the effect of this procedure on drug disposition and efficacy. Therefore, close monitoring of antimicrobial plasma concentrations in these patients is warranted. A fast and uniform ultra-high-performance liquid chromatography (UPLC) method with tandem mass spectrometric detection (MS/MS) has been developed and qualified for the simultaneous quantification of β-lactam antibiotics in human plasma. Compounds included in this multi-component analysis are: amoxicillin, ampicillin, phenoxymethylpenicillin, piperacillin, cefuroxime, cefadroxil, flucloxacillin, meropenem, cefepime, ceftazidime, tazobactam, linezolid and cefazolin. After spiking of five different stable isotope labelled internal standards, plasma samples were prepared for UPLC-MS/MS analysis by mixed-mode solid phase extraction. The developed method was proven to be free of (relative) matrix effects and proved to be reliable for the quantification of 12 out of 13 β-lactam antibiotics. As a proof of concept the method has been applied to plasma samples obtained from a healthy volunteer treated with amoxicillin. The analytical method is suitable for use in a therapeutic drug monitoring setting, providing the clinician with reliable measurements on β-lactam antibiotic plasma concentrations in a timely manner.

  15. Multiple well-shutdown tests and site-scale flow simulation in fractured rocks.

    PubMed

    Tiedeman, Claire R; Lacombe, Pierre J; Goode, Daniel J

    2010-01-01

    A new method was developed for conducting aquifer tests in fractured-rock flow systems that have a pump-and-treat (P&T) operation for containing and removing groundwater contaminants. The method involves temporary shutdown of individual pumps in wells of the P&T system. Conducting aquifer tests in this manner has several advantages, including (1) no additional contaminated water is withdrawn, and (2) hydraulic containment of contaminants remains largely intact because pumping continues at most wells. The well-shutdown test method was applied at the former Naval Air Warfare Center (NAWC), West Trenton, New Jersey, where a P&T operation is designed to contain and remove trichloroethene and its daughter products in the dipping fractured sedimentary rocks underlying the site. The detailed site-scale subsurface geologic stratigraphy, a three-dimensional MODFLOW model, and inverse methods in UCODE_2005 were used to analyze the shutdown tests. In the model, a deterministic method was used for representing the highly heterogeneous hydraulic conductivity distribution and simulations were conducted using an equivalent porous media method. This approach was very successful for simulating the shutdown tests, contrary to a common perception that flow in fractured rocks must be simulated using a stochastic or discrete fracture representation of heterogeneity. Use of inverse methods to simultaneously calibrate the model to the multiple shutdown tests was integral to the effectiveness of the approach.

  16. Impacts of flare emissions from an ethylene plant shutdown to regional air quality

    NASA Astrophysics Data System (ADS)

    Wang, Ziyuan; Wang, Sujing; Xu, Qiang; Ho, Thomas

    2016-08-01

    Critical operations of chemical process industry (CPI) plants such as ethylene plant shutdowns could emit a huge amount of VOCs and NOx, which may result in localized and transient ozone pollution events. In this paper, a general methodology for studying dynamic ozone impacts associated with flare emissions from ethylene plant shutdowns has been developed. This multi-scale simulation study integrates process knowledge of plant shutdown emissions in terms of flow rate and speciation together with regional air-quality modeling to quantitatively investigate the sensitivity of ground-level ozone change due to an ethylene plant shutdown. The study shows the maximum hourly ozone increments can vary significantly by different plant locations and temporal factors including background ozone data and solar radiation intensity. It helps provide a cost-effective air-quality control strategy for industries by choosing the optimal starting time of plant shutdown operations in terms of minimizing the induced ozone impact (reduced from 34.1 ppb to 1.2 ppb in the performed case studies). This study provides valuable technical supports for both CPI and environmental policy makers on cost-effective air-quality controls in the future.

  17. 46 CFR 154.540 - Quick-closing shut-off valves: Emergency shut-down system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Quick-closing shut-off valves: Emergency shut-down... shut-down system. The quick-closing shut-off valves under §§ 154.530, 154.532, and 154.538 must have an emergency shut-down system that: (a) Closes all the valves; (b) Is actuated by a single control in at...

  18. 46 CFR 154.540 - Quick-closing shut-off valves: Emergency shut-down system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Quick-closing shut-off valves: Emergency shut-down... shut-down system. The quick-closing shut-off valves under §§ 154.530, 154.532, and 154.538 must have an emergency shut-down system that: (a) Closes all the valves; (b) Is actuated by a single control in at...

  19. 46 CFR 154.540 - Quick-closing shut-off valves: Emergency shut-down system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Quick-closing shut-off valves: Emergency shut-down... shut-down system. The quick-closing shut-off valves under §§ 154.530, 154.532, and 154.538 must have an emergency shut-down system that: (a) Closes all the valves; (b) Is actuated by a single control in at...

  20. 46 CFR 154.540 - Quick-closing shut-off valves: Emergency shut-down system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Quick-closing shut-off valves: Emergency shut-down... shut-down system. The quick-closing shut-off valves under §§ 154.530, 154.532, and 154.538 must have an emergency shut-down system that: (a) Closes all the valves; (b) Is actuated by a single control in at...

  1. Experimental Breeder Reactor II inherent shutdown and heat removal tests - test results and analysis

    SciTech Connect

    Planchon, H.P.; Singer, R.M.; Mohr, D.; Feldman, E.E.; Chang, L.K.; Betten, P.R.

    1985-01-01

    A test program is being conducted to demonstrate that a power producing Liquid Metal Reactor (LMR) can passively remove shutdown heat by natural convection; passively reduce power in response to a loss of reactor flow and passively reduce power in response to a loss of the balance of plant heat sink. Measurements and pretest predictions confirm that natural convection is a reliable, predictable method of shutdown heat removal and suggest that safety-related pumps or pony motors are not necessary for safe, shutdown heat removal in a LMR. Measurements from tests in which reactor flow and heat rejection to the balance of plant were perturbed show that reactivity feedbacks can passively control power and temperature. This data is a basis for additional tests including a complete loss-of-flow without scram and a complete loss of heat sink without scram.

  2. Securing the Future of Seversk and Zheleznogorsk After Reactor Shutdown. Conference Handbook

    SciTech Connect

    Hund, Gretchen; Stein, Steven L.

    2005-01-31

    Seversk and Zheleznogorsk, two Russian closed nuclear cities, are home to the last three operating plutonium production reactors in Russia. The reactors are now scheduled for shutdown. Closing these reactors presents the world community with a significant nonproliferation achievement, but at the same time poses environmental, economic, and security challenges for the local communities. This conference is an opportunity for the international community to provide crucial support to facilitate these aspects of the plutonium reactor shutdown. Projects proposed complement the reactor shutdown process or assist with worker transition from plutonium production to nonweapons-related careers. Switzerland graciously offered to host the conference with the participation of both the Federal Atomic Energy Agency, Russian Federation and the United States Department of Energy. The one-and-a-half day event was held in Spiez, Switzerland, 8-9 February 2005. Dr. Alec Baer of Switzerland moderated the conference.

  3. Development of Standardized Probabilistic Risk Assessment Models for Shutdown Operations Integrated in SPAR Level 1 Model

    SciTech Connect

    S. T. Khericha; J. Mitman

    2008-05-01

    Nuclear plant operating experience and several studies show that the risk from shutdown operation during Modes 4, 5, and 6 at pressurized water reactors and Modes 4 and 5 at boiling water reactors can be significant. This paper describes using the U.S. Nuclear Regulatory Commission’s full-power Standardized Plant Analysis Risk (SPAR) model as the starting point for development of risk evaluation models for commercial nuclear power plants. The shutdown models are integrated with their respective internal event at-power SPAR model. This is accomplished by combining the modified system fault trees from the SPAR full-power model with shutdown event tree logic. Preliminary human reliability analysis results indicate that risk is dominated by the operator’s ability to correctly diagnose events and initiate systems.

  4. On-line coupling of physiologically relevant bioaccessibility testing to inductively coupled plasma spectrometry: Proof of concept for fast assessment of gastrointestinal bioaccessibility of micronutrients from soybeans.

    PubMed

    Herrera, Mónica Alejandra; Rosende, María; Arruda, Marco Aurélio Zezzi; Miró, Manuel

    2016-10-01

    In-vitro physiologically relevant gastrointestinal extraction based on the validated Unified BARGE Method (UBM) is in this work hyphenated to inductively coupled plasma optical emission spectrometry in a batch-flow configuration for real-time monitoring of oral bioaccessibility assays with high temporal resolution. A fully automated flow analyzer is designed to foster in-line filtration of gastrointestinal extracts at predefined times (≤15 min) followed by on-line multi-elemental analysis of bioaccessible micro-nutrients, viz., Cu, Fe and Mn, in well-defined volumes of extracts (300 μL) of transgenic and non-transgenic soybean seeds taken as model samples. The hyphenated flow setup allows for recording of temporal extraction profiles to gain full knowledge of the kinetics of the gastrointestinal digestion processes, including element leaching and concomitant precipitation and complexation reactions hindering bioavailability. Simplification of the overall standard procedure is also feasible by identification of steady-state extraction conditions. Our findings indicate that reliable measurement of oral bioaccessible pools of Cu, Fe and Mn in soybean might be obtained in less than 180 min rather than 240 min as endorsed by UBM. Using a matrix-matched external calibration, limits of detection according to the 3s criteria were 0.5 μg/g for Mn, 0.6 μg/g for Cu and 2.3 μg/g for Fe. Trueness of the automatic bioaccessibility method was confirmed by mass balance validation with recoveries ranging from 87 to 116% regardless of the target element and sample. Cu was the micronutrient with the highest oral bioaccessibility ranging from 73% to 83% (7.5-7.9 μg/g) for non-transgenic and transgenic soybeans, respectively, followed by Mn and Fe within the ranges of 29-31% (10.8-11.4 μg/g) and 11-15% (8-14 μg/g), respectively, regardless of transgenesis. The proposed kinetic method is proven suitable for fast and expedient estimation of the nutritional value of

  5. On-line coupling of physiologically relevant bioaccessibility testing to inductively coupled plasma spectrometry: Proof of concept for fast assessment of gastrointestinal bioaccessibility of micronutrients from soybeans.

    PubMed

    Herrera, Mónica Alejandra; Rosende, María; Arruda, Marco Aurélio Zezzi; Miró, Manuel

    2016-10-01

    In-vitro physiologically relevant gastrointestinal extraction based on the validated Unified BARGE Method (UBM) is in this work hyphenated to inductively coupled plasma optical emission spectrometry in a batch-flow configuration for real-time monitoring of oral bioaccessibility assays with high temporal resolution. A fully automated flow analyzer is designed to foster in-line filtration of gastrointestinal extracts at predefined times (≤15 min) followed by on-line multi-elemental analysis of bioaccessible micro-nutrients, viz., Cu, Fe and Mn, in well-defined volumes of extracts (300 μL) of transgenic and non-transgenic soybean seeds taken as model samples. The hyphenated flow setup allows for recording of temporal extraction profiles to gain full knowledge of the kinetics of the gastrointestinal digestion processes, including element leaching and concomitant precipitation and complexation reactions hindering bioavailability. Simplification of the overall standard procedure is also feasible by identification of steady-state extraction conditions. Our findings indicate that reliable measurement of oral bioaccessible pools of Cu, Fe and Mn in soybean might be obtained in less than 180 min rather than 240 min as endorsed by UBM. Using a matrix-matched external calibration, limits of detection according to the 3s criteria were 0.5 μg/g for Mn, 0.6 μg/g for Cu and 2.3 μg/g for Fe. Trueness of the automatic bioaccessibility method was confirmed by mass balance validation with recoveries ranging from 87 to 116% regardless of the target element and sample. Cu was the micronutrient with the highest oral bioaccessibility ranging from 73% to 83% (7.5-7.9 μg/g) for non-transgenic and transgenic soybeans, respectively, followed by Mn and Fe within the ranges of 29-31% (10.8-11.4 μg/g) and 11-15% (8-14 μg/g), respectively, regardless of transgenesis. The proposed kinetic method is proven suitable for fast and expedient estimation of the nutritional value of

  6. Simultaneous quantitation of polygalaxanthone III and four ginsenosides by ultra-fast liquid chromatography with tandem mass spectrometry in rat and beagle dog plasma after oral administration of Kai-Xin-San: application to a comparative pharmacokinetic study.

    PubMed

    Lv, Chunxiao; Li, Qing; Zhang, Xiaowen; He, Bosai; Xu, Huarong; Yin, Yidi; Liu, Ran; Liu, Jingjing; Chen, Xiaohui; Bi, Kaishun

    2014-05-01

    A fast, selective, and quantitative ultra-fast liquid chromatography with tandem mass spectrometry method has been developed and validated for the simultaneous quantitation of polygalaxanthone III, ginsenoside Rb1, ginsenoside Rd, ginsenoside Re, and ginsenoside Rg1 in the plasma of rat and beagle dog after oral administration of Kai-Xin-San. After addition of the internal standard, salidroside, the plasma samples were extracted by liquid-liquid extraction and separated on a Venusil MP C18 column with methanol/0.01% acetic acid water as mobile phase. The tandem mass spectrometric detection was performed in the multiple reaction monitoring with turbo ion spray source in a switching ionization mode. The method was examined, and found to be precise and accurate with the linearity range of the compounds. The intra- and interday precision and accuracy of the analytes were well within acceptance criteria (±15%). The mean extraction recoveries of analytes and internal standard were all >75.0%. The validated method has been successfully applied to comparing pharmacokinetic profiles of analytes in rat and beagle dog plasma. The results indicated that no significant differences were observed in pharmacokinetic parameters of ginsenoside Rg1, while the others had significant differences, which may due to the different mechanisms of absorption and metabolism.

  7. Effects of solid-phase extraction of plasma in measuring gut metabolic hormones in fasted and fed blood of lean and diet-induced obese rats.

    PubMed

    Reidelberger, Roger; Haver, Alvin; Anders, Krista; Apenteng, Bettye; Lanio, Craig

    2016-05-01

    Glucagon-like peptide-1 (GLP-1), peptide YY (3-36) [PYY(3-36)], amylin, ghrelin, insulin, and leptin are thought to act as hormonal signals from periphery to brain to control food intake. Here, we determined the effects of solid-phase extraction of plasma in measuring these hormones in blood of lean and diet-induced obese rats. Individual enzyme-linked immunoassays and a multiplex assay were used to measure active GLP-1, total PYY, active amylin, active ghrelin, insulin, leptin, and total GIP in response to (1) addition of known amounts of the peptides to lean and obese plasma, (2) a large meal in lean and obese rats, and (3) intravenous infusions of anorexigenic doses of GLP-1, PYY(3-36), amylin, and leptin in lean rats. Extraction of lean and obese plasma prior to assays produced consistent recoveries across assays for GLP-1, PYY, amylin, ghrelin, and insulin, reflecting losses inherent to the extraction procedure. Plasma extraction prior to assays generally revealed larger meal-induced changes in plasma GLP-1, PYY, amylin, ghrelin, and insulin in lean and obese rats. Plasma extraction and the multiplex assay were used to compare plasma levels of GLP-1, PYY, and amylin after a large meal with plasma levels produced by IV infusions of anorexigenic doses of GLP-1, PYY(3-36), and amylin. Infusions produced dose-dependent increases in plasma peptide levels, which were well above their postprandial levels. These results do not support the hypothesis that postprandial plasma levels of GLP-1, PYY(3-36), and amylin are sufficient to decrease food intake by an endocrine mechanism.

  8. 78 FR 63309 - New Filing Deadlines for Material Due To Be Submitted During the Federal Government Shutdown

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-23

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION... notice that any material due to be submitted to the Board during the Federal government shutdown will now... shutdown of the Federal government, from October 1, 2013, through October 16, 2013, all deadlines...

  9. Shutdown and Closure of the Experimental Breeder Reactor - II

    SciTech Connect

    Michelbacher, John A.; Baily, Carl E.; Baird, Daniel K.; Henslee, S. Paul; Knight, Collin J.; Rosenberg, Kenneth E.

    2002-07-01

    The Department of Energy mandated the termination of the Integral Fast Reactor (IFR) Program, effective October 1, 1994. To comply with this decision, Argonne National Laboratory-West (ANL-W) prepared a plan providing detailed requirements to maintain the Experimental Breeder Reactor - II (EBR-II) in a radiologically and industrially safe condition, including removal of all irradiated fuel assemblies from the reactor plant, and removal and stabilization of the primary and secondary sodium, a liquid metal used to transfer heat within the reactor plant. The EBR-II is a pool-type reactor. The primary system contained approximately 325 m{sup 3} (86,000 gallons) of sodium and the secondary system contained 50 m{sup 3} (13,000 gallons). In order to properly dispose of the sodium in compliance with the Resource Conservation and Recovery Act (RCRA), a facility was built to react the sodium to a solid sodium hydroxide monolith for burial as a low level waste in a land disposal facility. Deactivation of a liquid metal fast breeder reactor (LMFBR) presents unique concerns. Residual amounts of sodium remaining in circuits and components must be passivated, inerted, or removed to preclude future concerns with sodium-air reactions that could generate potentially explosive mixtures of hydrogen and leave corrosive compounds. The passivation process being implemented utilizes a moist carbon dioxide gas that generates a passive layer of sodium carbonate/sodium bicarbonate over any quantities of residual sodium. Tests being conducted will determine the maximum depths of sodium that can be reacted using this method, defining the amount that must be dealt with later to achieve RCRA clean closure. Deactivation of the EBR-II complex is on schedule for a March, 2002, completion. Each system associated with EBR-II has an associated lay-up plan defining the system end state, as well as instructions for achieving the lay-up condition. A goal of system-by-system lay-up is to minimize

  10. Shutdown and closure of the experimental breeder reactor - II.

    SciTech Connect

    Michelbacher, J. A.; Baily, C. E.; Baird, D. K.; Henslee, S. P.; Knight, C. J.; Rosenberg, K. E.

    2002-09-26

    The Department of Energy mandated the termination of the Integral Fast Reactor (IFR) Program, effective October 1, 1994. To comply with this decision, Argonne National Laboratory-West (ANL-W) prepared a plan providing detailed requirements to maintain the Experimental Breeder Reactor-II (EBR-II) in a radiologically and industrially safe condition, including removal of all irradiated fuel assemblies from the reactor plant, and removal and stabilization of the primary and secondary sodium, a liquid metal used to transfer heat within the reactor plant. The EBR-II is a pool-type reactor. The primary system contained approximately 325 m{sup 3} (86,000 gallons) of sodium and the secondary system contained 50 m{sub 3} (13,000 gallons). In order to properly dispose of the sodium in compliance with the Resource Conservation and Recovery Act (RCRA), a facility was built to react the sodium to a solid sodium hydroxide monolith for burial as a low level waste in a land disposal facility. Deactivation of a liquid metal fast breeder reactor (LMFBR) presents unique concerns. Residual amounts of sodium remaining in circuits and components must be passivated, inerted, or removed to preclude future concerns with sodium-air reactions that could generate potentially explosive mixtures of hydrogen and leave corrosive compounds. The passivation process being implemented utilizes a moist carbon dioxide gas that generates a passive layer of sodium carbonate/sodium bicarbonate over any quantities of residual sodium. Tests being conducted will determine the maximum depths of sodium that can be reacted using this method, defining the amount that must be dealt with later to achieve RCRA clean closure. Deactivation of the EBR-II complex is on schedule for a March, 2002, completion. Each system associated with EBR-II has an associated layup plan defining the system end state, as well as instructions for achieving the layup condition. A goal of system-by-system layup is to minimize surveillance

  11. First demonstration of rapid shutdown using neon shattered pellet injection for thermal quench mitigation on DIII-D

    NASA Astrophysics Data System (ADS)

    Commaux, N.; Shiraki, D.; Baylor, L. R.; Hollmann, E. M.; Eidietis, N. W.; Lasnier, C. J.; Moyer, R. A.; Jernigan, T. C.; Meitner, S. J.; Combs, S. K.; Foust, C. R.

    2016-04-01

    Shattered pellet injection (SPI) is one of the prime candidates for the ITER disruption mitigation system because of its deeper penetration and larger particle flux than massive gas injection (MGI) (Taylor et al 1999 Phys. Plasmas 6 1872) using deuterium (Commaux et al 2010 Nucl. Fusion 50 112001, Combs et al 2010 IEEE Trans. Plasma Sci. 38 400, Baylor et al 2009 Nucl. Fusion 49 085013). The ITER disruption mitigation system will likely use mostly high Z species such as neon because of more effective thermal mitigation and pumping constraints on the maximum amount of deuterium or helium that could be injected. An upgrade of the SPI on DIII-D enables ITER relevant injection characteristics in terms of quantities and gas species. This upgraded SPI system was used on DIII-D for the first time in 2014 for a direct comparison with MGI using identical quantities of neon. This comparison enabled the measurements of density perturbations during the thermal quench (TQ) and radiated power and heat loads to the divertor. It showed that SPI using similar quantities of neon provided a faster and stronger density perturbation and neon assimilation, which resulted in a lower conducted energy to the divertor and a faster TQ onset. Radiated power data analysis shows that this was probably due to the much deeper penetration of the neon in the plasma inducing a higher core radiation than in the MGI case. This experiment shows also that the MHD activity during an SPI shutdown (especially during the TQ) is quite different compared to MGI. This favorable TQ energy dissipation was obtained while keeping the current quench (CQ) duration within acceptable limits when scaled to ITER.

  12. First demonstration of rapid shutdown using neon shattered pellet injection for thermal quench mitigation on DIII-D

    DOE PAGESBeta

    Commaux, Nicolas J. C.; Shiraki, Daisuke; Baylor, Larry R.; Hollmann, E. M.; Eidietis, N. W.; Lasnier, C. J.; Moyer, R. A.; Jernigan, T. C.; Meitner, S. J.; Combs, Stephen Kirk; et al

    2016-03-02

    Shattered pellet injection (SPI) is one of the prime candidates for the ITER disruption mitigation system because of its deeper penetration and larger particle flux than massive gas injection (MGI) (Taylor et al 1999 Phys. Plasmas 6 1872) using deuterium (Commaux et al 2010 Nucl. Fusion 50 112001, Combs et al 2010 IEEE Trans. Plasma Sci. 38 400, Baylor et al 2009 Nucl. Fusion 49 085013). The ITER disruption mitigation system will likely use mostly high Z species such as neon because of more effective thermal mitigation and pumping constraints on the maximum amount of deuterium or helium that couldmore » be injected. An upgrade of the SPI on DIII-D enables ITER relevant injection characteristics in terms of quantities and gas species. This upgraded SPI system was used on DIII-D for the first time in 2014 for a direct comparison with MGI using identical quantities of neon. This comparison enabled the measurements of density perturbations during the thermal quench (TQ) and radiated power and heat loads to the divertor. It showed that SPI using similar quantities of neon provided a faster and stronger density perturbation and neon assimilation, which resulted in a lower conducted energy to the divertor and a faster TQ onset. Radiated power data analysis shows that this was probably due to the much deeper penetration of the neon in the plasma inducing a higher core radiation than in the MGI case. This experiment shows also that the MHD activity during an SPI shutdown (especially during the TQ) is quite different compared to MGI. Furthermore, this favorable TQ energy dissipation was obtained while keeping the current quench (CQ) duration within acceptable limits when scaled to ITER.« less

  13. An initial measurement of a fast neutral spectrum for ion cyclotron range of frequency heated plasma using two-channel compact neutral particle analyzers in KSTAR

    NASA Astrophysics Data System (ADS)

    Kim, S. H.; Wang, S. J.; Park, M.; Kim, S. K.

    2013-11-01

    The accurate measurement of fast neutral particles from high energy ion tails is very important since it is a measure of ion cyclotron range of frequency (ICRF) or neutral beam (NB) ion heating. In KSTAR, fast neutral measurements have been carried out using a compact neutral particle analyzer based on the silicon photo diode since 2010. As a result, the fast neutral spectrum was observed consistent with the ion temperature, diamagnetic energy, and neutron flux in 2011. However, there was fast neutral count beyond the injected neutral beam energy in NB-only heating. Since it is difficult to expect the count unless the temperature is high enough to diffuse the fast ions beyond the beam energy it was required to identify what it is. During the 2012 campaign, the two-channel diode detectors with and without a particle stopper were used to distinguish fast neutral counts and other counts by a hard X-ray or neutrons. As a result, it was confirmed that the high energy component beyond the beam energy originated from a hard X-ray or neutrons. Finally, it was observed that faster neutrals are generated by ICRF heating and enhanced by electron cyclotron heating compared to NB-only heating.

  14. An initial measurement of a fast neutral spectrum for ion cyclotron range of frequency heated plasma using two-channel compact neutral particle analyzers in KSTAR

    SciTech Connect

    Kim, S. H.; Park, M.; Kim, S. K.; Wang, S. J.

    2013-11-15

    The accurate measurement of fast neutral particles from high energy ion tails is very important since it is a measure of ion cyclotron range of frequency (ICRF) or neutral beam (NB) ion heating. In KSTAR, fast neutral measurements have been carried out using a compact neutral particle analyzer based on the silicon photo diode since 2010. As a result, the fast neutral spectrum was observed consistent with the ion temperature, diamagnetic energy, and neutron flux in 2011. However, there was fast neutral count beyond the injected neutral beam energy in NB-only heating. Since it is difficult to expect the count unless the temperature is high enough to diffuse the fast ions beyond the beam energy it was required to identify what it is. During the 2012 campaign, the two-channel diode detectors with and without a particle stopper were used to distinguish fast neutral counts and other counts by a hard X-ray or neutrons. As a result, it was confirmed that the high energy component beyond the beam energy originated from a hard X-ray or neutrons. Finally, it was observed that faster neutrals are generated by ICRF heating and enhanced by electron cyclotron heating compared to NB-only heating.

  15. 40 CFR 63.310 - Requirements for startups, shutdowns, and malfunctions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CATEGORIES National Emission Standards for Coke Oven Batteries § 63.310 Requirements for startups, shutdowns... or operator shall operate and maintain the coke oven battery and its pollution control equipment... operator of a coke oven battery shall develop, according to paragraph (c) of this section, a...

  16. 40 CFR 63.310 - Requirements for startups, shutdowns, and malfunctions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CATEGORIES National Emission Standards for Coke Oven Batteries § 63.310 Requirements for startups, shutdowns... or operator shall operate and maintain the coke oven battery and its pollution control equipment... operator of a coke oven battery shall develop, according to paragraph (c) of this section, a...

  17. 40 CFR 63.310 - Requirements for startups, shutdowns, and malfunctions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CATEGORIES National Emission Standards for Coke Oven Batteries § 63.310 Requirements for startups, shutdowns... or operator shall operate and maintain the coke oven battery and its pollution control equipment... operator of a coke oven battery shall develop, according to paragraph (c) of this section, a...

  18. 40 CFR 63.310 - Requirements for startups, shutdowns, and malfunctions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CATEGORIES National Emission Standards for Coke Oven Batteries § 63.310 Requirements for startups, shutdowns... or operator shall operate and maintain the coke oven battery and its pollution control equipment... operator of a coke oven battery shall develop, according to paragraph (c) of this section, a...

  19. 40 CFR 63.310 - Requirements for startups, shutdowns, and malfunctions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CATEGORIES National Emission Standards for Coke Oven Batteries § 63.310 Requirements for startups, shutdowns... or operator shall operate and maintain the coke oven battery and its pollution control equipment... operator of a coke oven battery shall develop, according to paragraph (c) of this section, a...

  20. 78 FR 38001 - Reconsideration of Certain Startup/Shutdown Issues: National Emission Standards for Hazardous Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-25

    ... . SUPPLEMENTARY INFORMATION: On February 16, 2012, the EPA issued the final MATS and Utility NSPS (77 FR 9304). In...'' (77 FR 71323). The November 30, 2012, action announced, among other things, reconsideration of certain... shutdown (including related technical corrections) (78 FR 24073). During the comment period, the...