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Sample records for elming h-mode operation

  1. ELMs and the H-mode Pedestal in NSTX

    Energy Technology Data Exchange (ETDEWEB)

    R. Maingi; S.A. Sabbagh; C.E. Bush; E.D. Fredrickson; J.E. Menard; D. Stutman; K. Tritz; M.G. Bell; R.E. Bell; J.A. Boedo; D.A. Gates; D.W. Johnson; R. Kaita; S.M. Kaye; H.W. Kugel; B.P. LeBlanc; D. Mueller; R. Raman; A.L. Roquemore; V.A. Soukhanovskii; T. Stevenson

    2004-07-16

    We report on the behavior of ELMs in NBI-heated H-mode plasmas in NSTX. It is observed that the size of Type I ELMs, characterized by the change in plasma energy, decreases with increasing density, as observed at conventional aspect ratio. It is also observed that the Type I ELM size decreases as the plasma equilibrium is shifted from a symmetric double-null toward a lower single-null configuration. Type III ELMs have also been observed in NSTX, as well as a high-performance regime with small ELMs which we designate Type V. These Type V ELMs are consistent with high bootstrap current operation and density approaching Greenwald scaling. The Type V ELMs are characterized by an intermittent n=1 MHD mode rotating counter to the plasma current. Without active pumping, the density rises continuously through the Type V phase. However, efficient in-vessel pumping should allow density control, based on particle containment time estimates.

  2. QUIESCENT H-MODE, AN ELM-FREE HIGH-CONFINEMENT MODE ON DIII-D WITH POTENTIAL FOR STATIONARY STATE OPERATION

    Energy Technology Data Exchange (ETDEWEB)

    WEST,WP; BURRELL,KH; deGRASSIE,JS; DOYLE,EJ; GREENFIELD,CM; LASNIER,CJ; SNYDER,PB; ZENG,L

    2003-08-01

    OAK-B135 The quiescent H-mode (QH-mode) is an ELM-free and stationary state mode of operation discovered on DIII-D. This mode achieves H-mode levels of confinement and pedestal pressure while maintaining constant density and radiated power. The elimination of edge localized modes (ELMs) and their large divertor loads while maintaining good confinement and good density control is of interest to next generation tokamaks. This paper reports on the correlations found between selected parameters in a QH-mode database developed from several hundred DIII-D counter injected discharges. Time traces of key plasma parameters from a QH-mode discharge are shown. On DIII-D the negative going plasma current (a) indicates that the beam injection direction is counter to the plasma current direction, a common feature of all QH-modes. The D{sub {alpha}} time behavior (c) shows that soon after high powered beam heating (b) is applied, the discharge makes a transition to ELMing H-mode, then the ELMs disappear, indicating the start of the QH period that lasts for the remainder of the high power beam heating (3.5 s). Previously published work showing density and temperature profiles indicates that long-pulse, high-triangularity QH discharges develop an internal transport barrier in combination with the QH edge barrier. These discharges are known as quiescent, double-barrier discharges (QDB). The H-factor (d) and stored energy (c) rise then saturate at a constant level and the measured axial and minimum safety factors remain above 1.0 for the entire QH duration. During QDB operation the performance of the plasma can be very good, with {beta}{sub N}*H{sub 89L} product reaching 7 for > 10 energy confinement times. These discharges show promise that a stationary state can be achieved.

  3. Hybrid H-mode scenario with nitrogen seeding and type III ELMs in JET

    NARCIS (Netherlands)

    Corre, Y.; Joffrin, E.; Monier-Garbet, P.; Andrew, Y.; Arnoux, G.; Beurskens, M.; Brezinsek, S.; Brix, M.; Buttery, R.; Coffey, I.; Crombe, K.; de la Luna, E.; Felton, R.; Giroud, C.; Hacquin, S.; Hobirk, J.; Huber, A.; Imbeaux, F.; Jachmich, S.; Kempenaars, M.; Litaudon, X.; Leggate, H.; Loarer, T.; Maddison, G.; Rachlew, E.; Rapp, J.; Sauter, O.; Savchkov, A.; Telesca, G.; Widdowson, A.; Zastrow, K. D.; Zimmermann, O.

    2008-01-01

    The performance of the 'hybrid' H-mode regime (long pulse operation with high neutron fluency) has been extensively investigated in JET during the 2005-2007 experimental campaign up to normalized pressure beta(N) = 3, toroidal magnetic field B-t = 1.7T, with type I ELMs plasma edge

  4. A stationary long-pulse ELM-absent H-mode regime in EAST

    Science.gov (United States)

    Ye, Y.; Xu, G. S.; Wan, B. N.; Chen, R.; Yan, N.; Guo, H. Y.; Shao, L. M.; Yang, Q. Q.; Wang, H. Q.; Zhang, W.; Xia, T. Y.; Zhang, T.; Li, Y. Y.; Wang, T. F.; Zang, Q.; Hu, Y. J.; Wu, G. J.; Zhang, L.; Hao, B. L.; Wang, L.; Li, Y. L.; Wu, X. Q.; Chen, L.; Lan, H.; Wang, Y. F.; Xu, J. C.; Hu, G. H.; Ding, S. Y.; Zhang, H.; Zhao, N.; Li, J.; The EAST Team

    2017-08-01

    A stationary edge-localized mode (ELM)-absent H-mode regime, with an electrostatic edge coherent mode (ECM) which resides in the pedestal region, has been achieved in the EAST tokamak recently. This regime allows the operation of a nearly fully noninductive long pulse (>15 s), exhibiting a relatively high pedestal and good global energy confinement with {{H}98,y2} near 1.2, and excellent impurity control. Furthermore, this regime is mostly obtained with a 4.6 GHz lower hybrid current drive (LHCD) or counter-current neutral beam injection (NBI), plus electron cyclotron resonance heating, and an extensive lithium wall coating. This stationary ELM-absent H-mode regime transits to a stationary small ELM H-mode regime, and upon additional heating power from the 2.45 GHz LHCD, an ion cyclotron resonant frequency or co-current NBI is applied (under 4.6 GHz LHCD heating background). A slight change of the plasma configuration also makes the small ELMs reappear. The experimental observations suggest that a long-pulse ELM-absent regime can be induced by the ECM, which exhibits strong electrostatic fluctuations and may provide a channel for continuous particle (especially impurities) and heat exhaust across the pedestal. The ECM exists in the collisionality of ν e*   =  2.5-4 and the pressure gradient |\

  5. Comparison of MHD simulation codes for understanding nonlinear ELMs dynamics in KSTAR H-mode plasma

    Science.gov (United States)

    Kim, M.; Lee, J.; Park, H. K.; Yun, G. S.; Xu, X.; Jardin, S. C.; Becoulet, M.

    2017-10-01

    KSTAR electron cyclotron emission imaging (ECEI) systems have contributed to understanding the fundamental physics of ELMs by high-quality 2D and quasi-3D images of ELMs. However, in the highly nonlinear phase of ELM dynamics, the interpretation of ECE signals becomes complicated intrinsically. Theoretical and numerical approaches are necessary to enhance the understanding of ELM physics. Well-established MHD codes (BOUT + + , JOREK, and M3D-C1) are introduced for comparative study with the observations. The nonlinear solutions are obtained using the same equilibrium of the KSTAR H-mode plasma. Each code shows the partial difference in mode evolution, probably, due to the difference in optimized operation window of initial conditions. The nonlinear simulation results show that low- n (n < 5) modes becomes dominant close to pedestal collapse. The mode evolution in the simulations qualitatively matches with the recent ECEI observation just before ELM-crash, or excitation of non-modal solitary perturbation (typically, n = 1) which is highly localized in poloidal and toroidal. Regardless of differences in details, qualitative similarity can provide inspiration to understand the triggering of ELM-crash. This work is supported by NRF of Korea under Contract No. NRF-2014M1A7A1A03029865.

  6. Comparisons of small ELM H-Mode regimes on the Alcator C-Mod and JFT-2M tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Hubbard, A E [MIT Plasma Science and Fusion Center, Cambridge MA, 02139 (United States); Kamiya, K [Japan Atomic Energy Agency, Naka-city, Ibaraki 311-0193 (Japan); Oyama, N [MIT Plasma Science and Fusion Center, Cambridge MA, 02139 (United States); Basse, N [MIT Plasma Science and Fusion Center, Cambridge MA, 02139 (United States); Biewer, T [MIT Plasma Science and Fusion Center, Cambridge MA, 02139 (United States); Edlund, E [MIT Plasma Science and Fusion Center, Cambridge MA, 02139 (United States); Hughes, J W [MIT Plasma Science and Fusion Center, Cambridge MA, 02139 (United States); Lin, L [MIT Plasma Science and Fusion Center, Cambridge MA, 02139 (United States); Porkolab, M [MIT Plasma Science and Fusion Center, Cambridge MA, 02139 (United States); Rowan, W [Fusion Research Center, University of Texas at Austin, TX (United States); Snipes, J [MIT Plasma Science and Fusion Center, Cambridge MA, 02139 (United States); Terry, J [MIT Plasma Science and Fusion Center, Cambridge MA, 02139 (United States); Wolfe, S M [MIT Plasma Science and Fusion Center, Cambridge MA, 02139 (United States)

    2006-05-15

    Comparisons of H-mode regimes were carried out on the Alcator C-Mod and JFT-2M tokamaks. Shapes were matched apart from aspect ratio, which is lower on C-Mod. The high recycling steady H-mode on JFT-2M and enhanced D-alpha (EDA) regime on C-Mod, both of which feature very small or no ELMs, are found to have similar access conditions in q{sub 95} - {nu}* space, occurring for pedestal collisionality {nu}* > 1. Differences in edge fluctuations were found, with lower frequencies but higher mode numbers on C-Mod. In both tokamaks an attractive regime with small ELMs on top of an enhanced D{sub {alpha}} baseline was obtained at moderate {nu}* and higher pressure. The JFT-2M shape favoured the appearance of ELMs on C-Mod and also resulted in the appearance of a lower frequency component of the quasicoherent mode during EDA.

  7. ELM Size & ν⊥ e ~ 0 Location During RMP H-mode Plasmas in DIII-D

    Science.gov (United States)

    Fenstermacher, M. E.; Moyer, R. A.; Osborne, T. H.

    2011-10-01

    Previous studies, examined the correlation between vacuum island overlap region width and edge localized mode (ELM) size during n = 3 resonant magnetic perturbations (RMPs) in DIII-D. For rotating H-mode plasmas it was proposed, that the resonant perturbation components would be screened by plasma response except at locations with the sum of the electron diamagnetic and E × B velocities, ν⊥ e = 0 . One hypothesis for the mechanism of RMP ELM suppression is that the pedestal width is prevented from expanding to the peeling-ballooning instability boundary by plasma modes at a location where vacuum RMP fields penetrate. This would suggest that the ν⊥ e = 0 location would be closer to the plasma edge during ELM suppression than during ELM mitigation. This paper will examine the degree of correlation between ν⊥ e = 0 location and ELM size during RMP H-mode plasmas including those from the previous studies. Work supported by the US DOE under DE-AC52-07NA27344 and DE-FC02-04ER54698.

  8. Effect of ELMs on rotation and momentum confinement in H-mode discharges in JET

    DEFF Research Database (Denmark)

    Versloot, T.W.; de Vries, P.C.; Giroud, C.

    2010-01-01

    The loss of plasma toroidal angular momentum and thermal energy by edge localized modes (ELMs) has been studied in JET. The analysis shows a consistently larger drop in momentum in comparison with the energy loss associated with the ELMs. This difference originates from the large reduction...... in angular frequency at the plasma edge, observed to penetrate into the plasma up to r/a ~ 0.65 during large type-I ELMs. As a result, the time averaged angular frequency is lowered near the top of the pedestal with increasing ELM frequency, resulting in a significant drop in thermal Mach number at the edge....... An increase in profile peaking of ion temperature and angular frequency is observed. At the same time the plasma confinement is reduced while the ratio of confinement times (Rτ = τE/τ) increases noticeably with ELM frequency. This change could be explained by the relatively larger ELM induced losses...

  9. H-mode achievement and edge features in RFX-mod tokamak operation

    Science.gov (United States)

    Spolaore, M.; Cavazzana, R.; Marrelli, L.; Carraro, L.; Franz, P.; Spagnolo, S.; Zaniol, B.; Zuin, M.; Cordaro, L.; Dal Bello, S.; De Masi, G.; Ferro, A.; Finotti, C.; Grando, L.; Grenfell, G.; Innocente, P.; Kudlacek, O.; Marchiori, G.; Martines, E.; Momo, B.; Paccagnella, R.; Piovesan, P.; Piron, C.; Puiatti, M. E.; Recchia, M.; Scarin, P.; Taliercio, C.; Vianello, N.; Zanotto, L.

    2017-11-01

    The RFX-mod experiment is a fusion device designed to operate as a reversed field pinch (RFP), with a major radius R = 2 m and a minor radius a = 0.459 m. Its high versatility recently allowed operating it also as an ohmic tokamak, allowing comparative studies between the two configurations in the same device. The device is equipped with a state of the art MHD mode feedback control system providing a magnetic boundary effective control, by applying resonant or non-resonant magnetic perturbations (MP), both in RFP and in tokamak configurations. In the fusion community the application of MPs is widely studied as a promising tool to limit the impact of plasma filaments and ELMs (edge localized modes) on plasma facing components. An important new research line is the exploitation of the RFX-mod active control system for ELM mitigation studies. As a first step in this direction, this paper presents the most recent achievements in term of RFX-mod tokamak explored scenarios, which allowed the first investigation of the ohmic and edge biasing induced H-mode. The production of D-shaped tokamak discharges and the design and deployment of an insertable polarized electrode were accomplished. Reproducible H-mode phases were obtained with insertable electrode negative biasing in single null discharges, representing an unexplored scenario with this technique. Important modifications of the edge plasma density and flow properties are observed. During the achieved H-mode ELM-like electromagnetic composite filamentary structures are observed. They are characterized by clear vorticity and parallel current density patterns.

  10. Multi-scale gyrokinetic simulations of an Alcator C-Mod, ELM-y H-mode plasma

    Science.gov (United States)

    Howard, N. T.; Holland, C.; White, A. E.; Greenwald, M.; Rodriguez-Fernandez, P.; Candy, J.; Creely, A. J.

    2018-01-01

    High fidelity, multi-scale gyrokinetic simulations capable of capturing both ion ({k}θ {ρ }s∼ { O }(1.0)) and electron-scale ({k}θ {ρ }e∼ { O }(1.0)) turbulence were performed in the core of an Alcator C-Mod ELM-y H-mode discharge which exhibits reactor-relevant characteristics. These simulations, performed with all experimental inputs and realistic ion to electron mass ratio ({({m}i/{m}e)}1/2=60.0) provide insight into the physics fidelity that may be needed for accurate simulation of the core of fusion reactor discharges. Three multi-scale simulations and series of separate ion and electron-scale simulations performed using the GYRO code (Candy and Waltz 2003 J. Comput. Phys. 186 545) are presented. As with earlier multi-scale results in L-mode conditions (Howard et al 2016 Nucl. Fusion 56 014004), both ion and multi-scale simulations results are compared with experimentally inferred ion and electron heat fluxes, as well as the measured values of electron incremental thermal diffusivities—indicative of the experimental electron temperature profile stiffness. Consistent with the L-mode results, cross-scale coupling is found to play an important role in the simulation of these H-mode conditions. Extremely stiff ion-scale transport is observed in these high-performance conditions which is shown to likely play and important role in the reproduction of measurements of perturbative transport. These results provide important insight into the role of multi-scale plasma turbulence in the core of reactor-relevant plasmas and establish important constraints on the the fidelity of models needed for predictive simulations.

  11. Overview of long pulse H-mode operation on EAST

    Science.gov (United States)

    Gong, X.; Garofalo, A. M.; Wan, B.; Li, J.; Qian, J.; Li, E.; Liu, F.; Zhao, Y.; Wang, M.; Xu, H.; EAST Team

    2017-10-01

    The EAST research program aims to demonstrate steady-state long-pulse high-performance H-mode operations with ITER-like poloidal configuration and RF-dominated heating schemes. In the recent experimental campaign, a long pulse fully non-inductive H-mode discharge lasting over 100 seconds using the upper ITER-like tungsten divertor has been achieved in EAST. This scenario used only RF heating and current drive, but also benefitted from an integrated control of the wall conditioning, plasma configuration, divertor heat flux, particle exhaust, impurity management and superconducting coils safety. Maintaining effective coupling of multiple RF heating and current drive sources on EAST is a critical ingredient. This long pulse discharge had good energy confinement, H98,y2 1.1-1.2, and all of the plasma parameters reach a true steady-state. Power balance indicates that the confinement improvement is due partly to a significantly reduced core electron transport inside minor radius rho<0.4. This work was supported by the National Magnetic Confinement Fusion Program of China Contract No. 2015GB10200 and the US Department of Energy Contract No. DE-SC0010685.

  12. Discovery of Stationary Operation of Quiescent H-mode Plasmas with Net-Zero NBI Torque and High Energy Confinement on DIII-D

    Science.gov (United States)

    Burrell, Keith

    2015-11-01

    Experiments this summer in DIII-D have used edge turbulence control to achieve stationary, high confinement operation without Edge Localized Mode (ELM) instabilities and with no external torque input. Eliminating the ELM-induced heat bursts and controlling plasma stability at low rotation represent two of the great challenges for fusion energy. By exploiting edge turbulence in a novel manner, we achieved outstanding tokamak performance, well above the H98 international tokamak energy confinement scaling (H98 =1.25), thus meeting an additional confinement challenge that is usually difficult at low torque. The new regime is triggered in double null plasmas by ramping the injected torque to zero and then maintaining it there. This lowers ExB rotation shear in the plasma edge, allowing low-k, broadband, electromagnetic turbulence to increase. In the H-mode edge, a narrow transport barrier usually grows until MHD instability (a peeling ballooning mode) leads to the ELM heat burst. However, the increased turbulence reduces the pressure gradient, allowing the development of a broader and thus higher transport barrier. A 60% increase in pedestal pressure and 40% increase in energy confinement result. Strong double-null plasma shaping raises the threshold for the ELM instability, allowing the plasma to reach a transport-limited state near but below the explosive ELM stability boundary. The resulting plasmas have burning-plasma-relevant betan =1.6-1.8 and run without the need for extra torque from 3D magnetic fields. To date, stationary conditions have been produced for 2 s or 12 energy confinement times, limited only by external hardware constraints. Stationary operation with improved pedestal conditions is highly significant for future burning plasma devices, since operation without ELMs at low rotation and good confinement is key for fusion energy production. Supported by the US DOE under DE-FC02-04ER54698.

  13. Heat flux pattern in detached L-modes and ELM mitigated H-modes with rotating magnetic perturbations in ASDEX Upgrade

    Science.gov (United States)

    Brida, D.; Lunt, T.; Wischmeier, M.; Bernert, M.; Carralero, D.; Faitsch, M.; Feng, Y.; Sehmer, T.; Sieglin, B.; Suttrop, W.; Wolfrum, E.; The ASDEX Upgrade Team; The MST1 Team

    2017-11-01

    For the first time divertor heat and particle fluxes in high-recycling and detached deuterium L- and H-mode plasmas with rotating magnetic perturbations (MPs) have been measured systematically in the ASDEX Upgrade (AUG) tokamak. The capability to rotate the MP field in AUG enabled us to obtain full two-dimensional profiles of the fluxes from measurements with the divertor triple Langmuir probes. As the divertor detached it was found that the initially non-axisymmetric heat flux became increasingly axisymmetric. In particular no ‘burn-through’ of the lobes was observed in the detached divertor in H-mode. Furthermore, the measurements were compared with simulations of the transport code EMC3-EIRENE as well as a simplified model based on field line tracing.

  14. H-mode pedestal and threshold studies over an expanded operating space on Alcator C-Moda)

    Science.gov (United States)

    Hubbard, A. E.; Hughes, J. W.; Bespamyatnov, I. O.; Biewer, T.; Cziegler, I.; LaBombard, B.; Lin, Y.; McDermott, R.; Rice, J. E.; Rowan, W. L.; Snipes, J. A.; Terry, J. L.; Wolfe, S. M.; Wukitch, S.

    2007-05-01

    This paper reports on studies of the edge transport barrier and transition threshold of the high confinement (H) mode of operation on the Alcator C-Mod tokamak [I. H. Hutchinson et al., Phys. Plasmas 1, 1511 (1994)], over a wide range of toroidal field (2.6-7.86T) and plasma current (0.4-1.7MA). The H-mode power threshold and edge temperature at the transition increase with field. Barrier widths, pressure limits, and confinement are nearly independent of field at constant current, but the operational space at high B shifts toward higher temperature and lower density and collisionality. Experiments with reversed field and current show that scrape-off-layer flows in the high-field side depend primarily on configuration. In configurations with the B ×∇B drift away from the active X-point, these flows lead to more countercurrent core rotation, which apparently contributes to higher H-mode thresholds. In the unfavorable case, edge temperature thresholds are higher, and slow evolution of profiles indicates a reduction in thermal transport prior to the transition in particle confinement. Pedestal temperatures in this case are also higher than in the favorable configuration. Both high-field and reversed-field results suggest that parameters at the L-H transition are influencing the evolution and parameters of the H-mode pedestal.

  15. Particle and power deposition on divertor targets in EAST H-mode plasmas

    DEFF Research Database (Denmark)

    Wang, L.; Xu, G.S.; Guo, H.Y.

    2012-01-01

    ELMs were chosen for analysis in order to reduce the uncertainty resulting from the influence of fast electrons on Langmuir triple-probe evaluation during ELMs. The power deposition obtained from Langmuir triple probes was consistent with that from the divertor infra-red camera during an ELM-free...... significantly broadening the SOL width and plasma-wetted area on the divertor target in both LHCD and LHCD + ICRH H-modes, thus posing a great challenge for the next-step high-power, long-pulse operation in EAST. Increasing the divertor-wetted area was also observed to reduce the peak heat flux and particle...

  16. QUIESCENT DOUBLE BARRIER H-MODE PLASMAS IN THE DIII-D TOKAMAK

    Energy Technology Data Exchange (ETDEWEB)

    K.H. BURRELL; M.E. AUSTIN; D.P. BRENNAN; J.C. DeBOO; E.J. DOYLE; C. FENZI; C. FUCHS; P. GOHIL; R.J. GROEBNER; L.L. LAO; T.C. LUCE; M.A. MAKOWSKI; G.R. McKEE; R.A. MOYER; C.C. PETTY; M. PORKOLAB; C.L.RETTIG; T.L. RHODES; J.C. ROST; B.W. STALLARD; E.J. STRAIT; E.J. SYNAKOWSKI; M.R. WADE; J.G. WATKINS; W.P. WEST

    2000-11-01

    High confinement (H-mode) operation is the choice for next-step tokamak devices based either on conventional or advanced tokamak physics. This choice, however, comes at a significant cost for both the conventional and advanced tokamaks because of the effects of edge localized modes (ELMs). ELMs can produce significant erosion in the divertor and can affect the beta limit and reduced core transport regions needed for advanced tokamak operation. Experimental results from DIII-D [J.L. Luxon, et al., Plasma Phys. and Contr. Nucl. Fusion Research 1986 (International Atomic Energy Agency, Vienna, 1987) Vol. I, p. 159] this year have demonstrated a new operating regime, the quiescent H-mode regime, which solves these problems. We have achieved quiescent H-mode operation which is ELM-free and yet has good density and impurity control. In addition, we have demonstrated that an internal transport barrier can be produced and maintained inside the H-mode edge barrier for long periods of time (>3.5 seconds or >25 energy confinement times {tau}{sub E}), yielding a quiescent double barrier regime. By slowly ramping the input power, we have achieved {beta}{sub N} H{sub 89} = 7 for up to 5 times the {tau}{sub E} of 150 ms. The {beta}{sub N} H{sub 89} values of 7 substantially exceed the value of 4 routinely achieved in standard ELMing H-mode. The key factors in creating the quiescent H-mode operation are neutral beam injection in the direction opposite to the plasma current (counter injection) plus cryopumping to reduce the density. Density and impurity control in the quiescent H-mode is possible because of the presence of an edge magnetic hydrodynamic (MHD) oscillation, the edge harmonic oscillation, which enhances the edge particle transport while leaving the energy transport unaffected.

  17. Quiescent Double Barrier H-Mode Plasmas in the DIII-D Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Burrell, K H; Austin, M E; Brennan, D P; DeBoo, J C; Doyle, E J; Fenzi, C; Fuchs, C; Gohil, P; Greenfield, C M; Groebner, R J; Lao, L L; Luce, T C; Makowski, M A; McKee, G R; Moyer, R A; Petty, C C; Porkolab, M; Rettig, C L; Rhodes, T L; Rost, J C; Stallard, B W; Strait, E J; Synakowski, E J; Wade, M R; Watkins, J G; West, W P

    2000-11-01

    High confinement (H-mode) operation is the choice for next-step tokamak devices based either on conventional or advanced tokamak physics. This choice, however, comes at a significant cost for both the conventional and advanced tokamaks because of the effects of edge localized modes (ELMs). ELMs can produce significant erosion in the divertor and can affect the beta limit and reduced core transport regions needed for advanced tokamak operation. Experimental results from DIII-D this year have demonstrated a new operating regime, the quiescent H-mode regime, which solves these problems. We have achieved quiescent H-mode operation which is ELM-free and yet has good density and impurity control. In addition, we have demonstrated that an internal transport barrier can be produced and maintained inside the H-mode edge barrier for long periods of time (>3.5 seconds or >25 energy confinement times {tau}{sub E}), yielding a quiescent double barrier regime. By slowly ramping the input power, we have achieved {beta}{sub N} H89 = 7 for up to 5 times the {tau}{sub E} of 150 ms. The {beta}{sub N} H89 values of 7 substantially exceed the value of 4 routinely achieved in standard ELMing H-mode. The key factors in creating the quiescent H-mode operation are neutral beam injection in the direction opposite to the plasma current (counter injection) plus cryopumping to reduce the density. Density and impurity control in the quiescent H-mode is possible because of the presence of an edge magnetic hydrodynamic (MHD) oscillation, the edge harmonic oscillation, which enhances the edge particle transport while leaving the energy transport unaffected.

  18. Non-inductive improved H-mode operation at ASDEX Upgrade

    Science.gov (United States)

    Bock, A.; Fable, E.; Fischer, R.; Reich, M.; Rittich, D.; Stober, J.; Bernert, M.; Burckhart, A.; Doerk, H.; Dunne, M.; Geiger, B.; Giannone, L.; Igochine, V.; Kappatou, A.; McDermott, R.; Mlynek, A.; Odstrčil, T.; Tardini, G.; Zohm, H.; The ASDEX Upgrade Team

    2017-12-01

    Recent improvements to the heating and diagnostic systems on the ASDEX Upgrade tokamak allow renewed investigations into non-inductive operation scenarios with improved confinement in a full-metal device. Motivated by this, a scenario with \

  19. Recent results of H-mode confinement study in JT-60U (April-September, 1995)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    Improvement in the performance of energy confinement is one of the most important issues to realize thermonuclear fusion reactors. The H-mode is one of excellent improved confinement modes. From the view point of steady-state operation, the ELMy H-mode is considered to be a principal operation mode in ITER. For the engineering design of the ITER, there still remain issues to be clarified on the H-mode characteristics. These issues are required to be studied on the present tokamaks as ITER physics research needs. In order to satisfy the above request, experiments of the H-mode confinement have been carried out on JT-60U. Recent results of H-mode confinement study in JT-60U during April to September, 1995 are summarized in the present report. The scaling of high T{sub i} H-mode confinement is described in section 2. The time behaviour of transport properties are shown in sections 3 and 4. Result of the non-dimensional transport experiment is presented in section 5. The H-mode transition is investigated in sections 6, 7, 8 and 9; threshold power scaling, parametric study on edge local quantities, effect of edge neutrals, and H-L back transition. The onset condition of ELMs is studied in section 10. (author).

  20. Dynamics and stability of divertor detachment in H-mode plasmas on JET

    Science.gov (United States)

    Field, A. R.; Balboa, I.; Drewelow, P.; Flanagan, J.; Guillemaut, C.; Harrison, J. R.; Huber, A.; Huber, V.; Lipschultz, B.; Matthews, G.; Meigs, A.; Schmitz, J.; Stamp, M.; Walkden, N.; contributors, JET

    2017-09-01

    The dynamics and stability of divertor detachment in {{{N}}}2 seeded, type-I, ELMy H-mode plasmas with dominant NBI heating in the JET ITER-like wall device is studied by means of an integrated analysis of diagnostic data from several systems, classifying data relative to the ELM times. It is thereby possible to study the response of the detachment evolution to the control parameters (SOL input power, upstream density and impurity fraction) prevailing during the inter-ELM periods and the effect of ELMs on the detached divertor. A relatively comprehensive overview is achieved, including the interaction with the targets at various stages of the ELM cycle, the role of ELMs in affecting the detachment process and the overall performance of the scenario. The results are consistent with previous studies in devices with an ITER-like, metal wall, with the important advance of distinguishing data from intra- and inter-ELM periods. Operation without significant degradation of the core confinement can be sustained in the presence of strong radiation from the x-point region (MARFE).

  1. Transport simulation of ELM pacing by pellet injection in tokamak plasmas

    Science.gov (United States)

    Kim, Ki Min; Na, Yong-Su; Hong, Sang Hee; Lang, P. T.; Alper, B.; contributors, JET-EFDA

    2010-05-01

    This paper deals mainly with the numerical simulation on edge localized mode (ELM) pacing by pellet injection that is useful for fuelling and control of plasma profiles to achieve enhanced tokamak operations. The fuelling and pellet-induced ELMs are simulated with a 1.5-dimensional core transport code, which includes a neutral gas shielding model and a grad-B drift model for pellet deposition in H-mode tokamak plasmas. Fuelling and ELM pacing experiments by pellet injections at JET are introduced as a current experimental approach. For the description of ELM triggering by pellet injection based on ideal ballooning mode criteria, three possible models are suggested and discussed on their ELM characteristics, respectively: (i) the density enhanced ELMs in the post-pellet phase, (ii) the modification of the surface averaged pressure profiles in a transport time scale and (iii) the local increase in the pressure (density and/or temperature) gradients perturbed by pellets. Among them, the pellet-induced density perturbation model is adopted, in practice, to carry out an ELM pacing simulation in preparation for future experiments in KSTAR. The numerical simulation shows that the artificially induced ELM by pellets releases the reduced energy bursts, compared with spontaneous ELMs. The energy loss per burst by the pellet-induced ELM turns out to be much smaller than that by the spontaneous ELM as the pellet injection frequency becomes higher in ELM pacing. Based on the simulation results showing good agreement with the general ELM characteristics observed in pellet pacing experiments, the ELM pacing by pellet injection is very promising for mitigating the ELM energy bursts to the divertor by controlling the injection frequency.

  2. Evidence of Zonal-Flow-Driven Limit-Cycle Oscillations during L-H Transition and at H-mode Pedestal of a New Small-ELM Regime in EAST

    DEFF Research Database (Denmark)

    Xu, G.; Wang, H.; Guo, H.

    Small-amplitude edge localized oscillations have been observed, for the first time, in EAST preceding the L-H transition at marginal input power, which manifest themselves as dithering in the divertor D signals at a frequency under 4 kHz, much lower than the GAM frequency. Detailed measurements...... providing a direct evidence of the zonal flows for the L-H transition at marginal input power. Furthermore, near the transition threshold sawtooth heat pulses appear to periodically enhance the dithering, finally triggering the L-H transition after a big sawtooth crash. The zonal flow induced limit...... link between them. A novel predator-prey model, incorporating the evolution of zonal flows, pressure gradient and turbulences at two different frequency ranges, has been developed and successfully reproduced the key features of this newly observed small-ELM regime....

  3. VH mode accessibility and global H-mode properties in previous and present JET configurations

    Energy Technology Data Exchange (ETDEWEB)

    Jones, T.T.C.; Ali-Arshad, S.; Bures, M.; Christiansen, J.P.; Esch, H.P.L. de; Fishpool, G.; Jarvis, O.N.; Koenig, R.; Lawson, K.D.; Lomas, P.J.; Marcus, F.B.; Sartori, R.; Schunke, B.; Smeulders, P.; Stork, D.; Taroni, A.; Thomas, P.R.; Thomsen, K. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

    1994-07-01

    In JET VH modes, there is a distinct confinement transition following the cessation of ELMs, observed in a wide variety of tokamak operating conditions, using both NBI and ICRF heating methods. Important factors which influence VH mode accessibility such as magnetic configuration and vessel conditions have been identified. The new JET pumped divertor configuration has much improved plasma shaping control and power and particle exhaust capability and should permit exploitation of plasmas with VH confinement properties over an even wider range of operating regimes, particularly at high plasma current; first H-modes have been obtained in the 1994 JET operating period and initial results are reported. (authors). 7 refs., 6 figs.

  4. ELM Suppression and performance improvement with a flowing liquid lithium limiter in EAST

    Science.gov (United States)

    Zuo, G. Z.; Hu, J. S.; Maingi, R.; Sun, Z.; Xu, W.; Li, J. G.; Diallo, A.; Lunsford, R.; Osborne, T.; Tritz, K.; EAST Team

    2017-10-01

    Improvements in plasma performance were observed using a second-generation flowing liquid lithium limiter (FLiLi) in EAST. Compared to the H mode discharges without FLiLi, ELM frequency and amplitude were both lower with FLiLi. Also, ELM frequency and amplitude gradually decreased discharge-by-discharge with FLiLi, similar to the gradual ELM mitigation by real-time Li aerosol injection in successive discharges. Moreover, transient ELM-free H-modes with a strong increase of WMHD and H98 were observed for the first time with FLiLi. During the ELM-free phases, MHD activity interpreted from high frequency Mirnov probes differed from activity in the ELMy phases. In addition to the typical low-frequency 50 kHz edge coherent MHD mode (ECM), a second mode 220-240 kHz also was observed in the ELM-free phase. By computing the Li efflux from the FLiLi limiter surface, it was found that the Li efflux from sputtering during discharges and evaporation between discharges was comparable to the typical mass delivery rates used for Li powder injection rate during plasma operation in EAST. Therefore, gradual accumulation of Li in EAST via real time Li efflux from the FLiLi surface produces similar effects to aerosol injection, i.e. reduced recycling, enhanced fluctuations, and ELM mitigation.

  5. Compatibility of separatrix density scaling for divertor detachment with H-mode pedestal operation in DIII-D

    Science.gov (United States)

    Leonard, A. W.; McLean, A. G.; Makowski, M. A.; Stangeby, P. C.

    2017-08-01

    The midplane separatrix density is characterized in response to variations in upstream parallel heat flux density and central density through deuterium gas injection. The midplane density is determined from a high spatial resolution Thomson scattering diagnostic at the midplane with power balance analysis to determine the separatrix location. The heat flux density is varied by scans of three parameters, auxiliary heating, toroidal field with fixed plasma current, and plasma current with fixed safety factor, q 95. The separatrix density just before divertor detachment onset is found to scale consistent with the two-point model when radiative dissipation is taken into account. The ratio of separatrix to pedestal density, n e,sep/n e,ped varies from  ⩽30% to  ⩾60% over the dataset, helping to resolve the conflicting scaling of core plasma density limit and divertor detachment onset. The scaling of the separatrix density at detachment onset is combined with H-mode power threshold scaling to obtain a scaling ratio of minimum n e,sep/n e,ped expected in future devices.

  6. Characterizations of power loads on divertor targets for type-I, compound and small ELMs in the EAST superconducting tokamak

    DEFF Research Database (Denmark)

    Wang, L.; Xu, G.S.; Guo, H.Y.

    2013-01-01

    -III ELMy H-modes. The energy loss and divertor power load are systematically characterized for these different ELMy H-modes to provide a physics basis for the next-step high-power long-pulse operations in EAST. Both type-I and compound ELMs exhibit good confinement (H98(y,2) ∼ 1). A significant loss...... is about 10 MW m−2, as determined from the divertor-embedded triple Langmuir probe system with high time resolution. As expected, type-III ELMs lead to much smaller divertor power loads with a peak heat flux of about 2 MW m−2. Peak power loads for compound ELMs are between those for type-I and type......-III ELMs. It is remarkable that the new very small ELMy H-modes exhibit even lower target power deposition than type-III ELMs, with the peak heat flux generally below 1 MW m−2. These very small ELMs are usually accompanied by broadband fluctuations with frequencies ranging from 20 to 50 kHz, which may...

  7. Advancing the Physics Basis of Quiescent H-mode through Exploration of ITER Relevant Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, W. M. [PPPL; Burrell, K. H. [General Atomics; Fenstermacher, M. E. [LLNL; Garofalo, A. M. [General Atomics; Grierson, B. A. [PPPL; Loarte, A. [ITER; McKee, G. R. [U of Wisc, Madison; Nazikian, R. [PPPL; Snyder, B. P. [General Atomics

    2014-09-01

    Recent experiments on DIII-D have overcome a long-standing limitation in accessing quiescent H-mode (QH-mode), a high confinement state of the plasma that does not exhibit the explosive instabilities associated with edge localized modes (ELMs). In the past, QH-mode was associated with low density operation, but has now been extended to high normalized densities compatible with operation envisioned for ITER. Through the use of strong shaping, QH-mode plasmas have been maintained at high densities, both absolute (ηe ≈ 7 × 1019 m—3) and normalized Greenwald fraction (ηe/ηG > 0:7) . In these plasmas, the pedestal can evolve to very high pressures and current as the density is increased. Calculations of the pedestal height and width from the EPED model are quantitatively consistent with the experimental observed evolution with density. The comparison of the dependence of the maximum density threshold for QH-mode with plasma shape help validate the underlying theoretical peeling-ballooning models describing ELM stability. High density QH-mode operation with strong shaping has allowed stable access to a previously predicted regime of very high pedestal dubbed \\Super H-mode". In general, QH-mode is found to achieve ELM-stable operation while maintaining adequate impurity exhaust, due to the enhanced impurity transport from an edge harmonic oscillation, thought to be a saturated kink- peeling mode driven by rotation shear. In addition, the impurity confinement time is not affected by rotation, even though the energy confinement time and measured E Χ B shear is observed to increase at low toroidal rotation. Together with demonstrations of high beta, high confinement and low q95 for many energy confinement times, these results suggest QH-mode as a potentially attractive operating scenario for ITER's Q=10 mission.

  8. Characteristics of the First H-mode Discharges in NSTX

    Energy Technology Data Exchange (ETDEWEB)

    Maingi, R.; Bell, M.G.; Bell, R.E.; Bush, C.E.; Fredrickson, E.D.; Gates, D.A.; Kaye, S.M.; Kugel, H.W.; LeBlanc, B.P.; Menard, J.E.; Mueller, D.; Sabbagh, S.A.; Stutman, D.; Taylor, G.; Johnson, D.W.; Kaita, R.; Maqueda, R.J.; Ono, M.; Paoletti, F.; Peng, Y-K.M.; Roquemore, A.L.; Skinner, C.H.; Soukhanovskii, V.A.; and Synakowski, E.J.

    2001-05-10

    We report observations of the first low-to-high (L-H) confinement mode transitions in the National Spherical Torus Experiment (NSTX). The H-mode energy confinement time increased over reference L-mode discharges transiently by 100-300%, as high as {approximately}150 ms. This confinement time is {approximately}1.8-2.3 times higher than predicted by a multi-machine ELM-free H-mode scaling. This achievement extends the H-mode window of fusion devices down to a record low aspect ratio (R/a) {approximately} 1.3, challenging both confinement and L-H power thresholds scalings based on conventional aspect ratio tokamaks.

  9. A study on the density shoulder formation in the SOL of H-mode plasmas

    Directory of Open Access Journals (Sweden)

    D. Carralero

    2017-08-01

    Full Text Available The term “shoulder formation” refers to an increase of the density decay length in the scrape-off layer (SOL observed in many tokamaks during L-mode operation when a density threshold is reached. Recent experiments in ASDEX Upgrade (AUG and JET have shown that the shoulder forms when the divertor collisionality in the divertor electrically disconnects filaments from the wall. This leads to a transition from the sheath limited to the inertial regime and to an enhancement of radial particle transport, in good agreement with analytical models. In the present work, the validity of such a mechanism is investigated in the more reactor-relevant H-mode regime. For this, a cold divertor H-mode scenario is developed in AUG using different levels of D puffing and N seeding, in which inter-ELM filaments and SOL density profiles are measured. The basic relation between filament size and divertor collisionality is still valid in H-mode plasmas, albeit an additional condition related to the gas fueling rate has been found for the formation of the shoulder.

  10. ELM-free and inter-ELM divertor heat flux broadening induced by edge harmonics oscillation in NSTX

    Science.gov (United States)

    Gan, K. F.; Ahn, J.-W.; Gray, T. K.; Zweben, S. J.; Fredrickson, E. D.; Scotti, F.; Maingi, R.; Park, J.-K.; Canal, G. P.; Soukhanovskii, V. A.; Mclean, A. G.; Wirth, B. D.

    2017-12-01

    A new n  =  1 dominated edge harmonic oscillation (EHO) has been found in NSTX. The new EHO, rotating toroidally in the counter-current direction and the opposite direction of the neutral beam, was observed during certain inter-ELM and ELM-free periods of H-mode operation. This EHO is associated with a significant broadening of the integral heat flux width ({λ\\operatorname{int}} ) by up to 150%, and a decrease in the divertor peak heat flux by  >60%. An EHO induced filament was also observed by the gas puff imaging diagnostic. The toroidal rotating filaments could change the edge magnetic topology resulting in toroidal rotating strike point splitting and heat flux broadening. Experimental result of the counter current rotation of strike points splitting is consistent with the counter-current EHO.

  11. Rotation Breaking Induced by ELMs on EAST

    DEFF Research Database (Denmark)

    Xiong, H.; Xu, G.; Sun, Y.

    Spontaneous rotation has been observed in LHCD H-mode plasmas with type III ELMs (edge localized modes) on EAST, and it revealed that type III ELMs can induce the loss of both core and edge toroidal rotation. Here we work on the breaking mechanism during the ELMs. Several large tokamaks have...... discovered ELMs' filamentary structures. It revealed that the ELMs are filamentary perturbations of positive density formed along the local field lines close to the LCFS. Currents flowing in the filaments induce magnetic perturbations, which break symmetry of magnetic field strength and lead to deformation...... of magnetic surface, thus generate NTV (neoclassical toroidal viscosity) torque that affects toroidal rotation. We adopt 1cm maximum edge magnetic surface displacement from experimental observation, and our calculation shows that the edge torque is about 0.35 N/m2, and the core very small. The expected...

  12. PERKINELMER ELM

    Science.gov (United States)

    The PerkinElmer Elm (formerly the AirBase CanarIT) is a multi-sensor air quality monitoring device that measures particulate matter (PM), total volatile organic compounds (VOCs), nitrogen dioxide (NO2), and several other atmospheric components. PM, VOCs, and NO2

  13. Enhanced understanding of the MHD dynamics and ELM control experiments in KSTAR

    Science.gov (United States)

    Park, Hyeon K.

    2013-10-01

    In KSTAR, H-mode discharges have been achieved reliably at toroidal fields from 1.4 to 3.5 T with a heating power of ~ 5 MW. Using real-time plasma shape control the flattop time in H-mode has been extended to over ~ 16 s at 600 kA in the 2012 campaign and the extended plasma operation boundary has surpassed the n = 1 no-wall limit with βN /li up to 4.1. In order to achieve a high beta steady state operation in KSTAR, establishment of predictive MHD simulation and first-principle-based control of the harmful MHD are the first steps. Visualization of MHD dynamics via a 2-D Electron Cyclotron Emission Imaging (ECEI) has significantly enhanced the level of understanding of the MHD dynamics. Following the first 2-D ELM measurements in H-mode plasmas in KSTAR the measured 2-D ELM images were compared with synthetic images from the BOUT + + code. The physics of ELMs is characterized based on a wide range of measured mode numbers (n, m) local magnetic shear and pressure gradients. The observed ELM dynamics during control experiments have been enlightening and consistent with the stability models. Near the q ~ 2 surface, the island width and Δ' of the m = 2 tearing mode have been verified through the modified Rutherford model based on the 2-D images. With the aid of a second (toroidally separated) ECEI system installed in the 2012 KSTAR campaign, a 3-D reconstruction of the MHD instabilities has allowed further validation of the computed magnetic field pitch angles, rotation speeds, and toroidal asymmetries of the MHDs Work supported by NRF of Korea under contract No. 20120005920 and the U.S. DoE under contract No. DE-FG-02-99ER54531.

  14. ELM suppression in helium plasmas with 3D magnetic fields

    Science.gov (United States)

    Evans, T. E.; Loarte, A.; Orlov, D. M.; Grierson, B. A.; Knölker, M. M.; Lyons, B. C.; Cui, L.; Gohil, P.; Groebner, R. J.; Moyer, R. A.; Nazikian, R.; Osborne, T. H.; Unterberg, E. A.

    2017-08-01

    Experiments in DIII-D, using non-axisymmetric magnetic perturbation fields in high-purity low toroidal rotation, 4He plasmas have resulted in Type-I edge localized mode (ELM) suppression and mitigation. Suppression is obtained in plasmas with zero net input torque near the L-H power threshold using either electron cyclotron resonant heating (ECRH) or balanced co- and counter-I p neutral beam injection (NBI) resulting in conditions equivalent to those expected in ITER’s non-active operating phase. In low-power ECRH H-modes, periods with uncontrolled density and impurity radiation excursions are prevented by applying n  =  3 non-axisymmetric magnetic perturbation fields. ELM suppression results from a reduction and an outward shift of the electron pressure gradient peak compared to that in the high-power ELMing phase. The change in the electron pressure gradient peak is primarily due to a drop in the pedestal temperature rather than the pedestal density.

  15. Study on divertor particle and heat fluxes from electric probe measurements during ELMy H-modes in KSTAR

    Energy Technology Data Exchange (ETDEWEB)

    Bak, Jun-Gyo, E-mail: jgbak@nfri.re.kr [National Fusion Research Institute, Daejeon (Korea, Republic of); Kim, Heung-Su [National Fusion Research Institute, Daejeon (Korea, Republic of); Bae, Min-Keun; Chung, Kyu-Sun [Hanyang University, Seoul (Korea, Republic of); Hong, Suk-Ho [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2016-11-01

    Highlights: • The characteristics of the particle and heat fluxes were investigated during ELMs in H-modes under the LSN configuration in the KSTAR tokamak.. • There was relation between the ELM amplitude and the ELM frequency as ΔW{sub ELM}/W{sub TOT} ∝ 1/f{sub ELM} in the range of f{sub ELM} ≤ 200 Hz. • The trends of the peak amplitude of the divertor flux near the OSP during ELMs due to the ELM mitigation and the plasma shaping were investigated. • The ELMs were mitigated by MP field, SMBI and ECH. The ELM mitigations due to the MP field and the SMBI were stronger than one due to the ECH. • Finally, the particle flux, evaluated at the far scrape-off layer (SOL) region, was estimated to less than 1% of the divertor particle flux. - Abstract: The characteristics of the divertor particle and heat fluxes are investigated during ELM bursts in ELMy H-mode plasmas with the lower single null (LSN) configuration in Korea Superconducting Tokamak Advanced Research (KSTAR). The particle and heat fluxes are evaluated from the electric probe measurements at the divertor region. It is found that the peak amplitude of the divertor flux during an ELM burst obtained near the outer strike point (OSP) decreases up to about 20% as the ELM frequency increases by a factor of ∼6.5 due to the ELM mitigation and the plasma shaping, which is similar to the trend of the amplitude versus the frequency of the ELM observed in other tokamaks. The ELMs are mitigated by using several methods as magnetic perturbation (MP) field, supersonic molecular beam injection (SMBI) and electron cyclotron heating (ECH) at the edge region. In addition, the particle flux, evaluated at the far scrape-off layer (SOL) region, is less than 1% of the divertor particle flux. In this work, results from the experimental investigations of particle and heat fluxes during ELM bursts from the electric probe measurements at the divertor and far SOL regions are presented.

  16. Power requirements for superior H-mode confinement on Alcator C-Mod: experiments in support of ITER

    Science.gov (United States)

    Hughes, J. W.; Loarte, A.; Reinke, M. L.; Terry, J. L.; Brunner, D.; Greenwald, M.; Hubbard, A. E.; LaBombard, B.; Lipschultz, B.; Ma, Y.; Wolfe, S.; Wukitch, S. J.

    2011-08-01

    Power requirements for maintaining sufficiently high confinement (i.e. normalized energy confinement time H98 >= 1) in H-mode and its relation to H-mode threshold power scaling, Pth, are of critical importance to ITER. In order to better characterize these power requirements, recent experiments on the Alcator C-Mod tokamak have investigated H-mode properties, including the edge pedestal and global confinement, over a range of input powers near and above Pth. In addition, we have examined the compatibility of impurity seeding with high performance operation, and the influence of plasma radiation and its spatial distribution on performance. Experiments were performed at 5.4 T at ITER relevant densities, utilizing bulk metal plasma facing surfaces and an ion cyclotron range of frequency waves for auxiliary heating. Input power was scanned both in stationary enhanced Dα (EDA) H-modes with no large edge localized modes (ELMs) and in ELMy H-modes in order to relate the resulting pedestal and confinement to the amount of power flowing into the scrape-off layer, Pnet, and also to the divertor targets. In both EDA and ELMy H-mode, energy confinement is generally good, with H98 near unity. As Pnet is reduced to levels approaching that in L-mode, pedestal temperature diminishes significantly and normalized confinement time drops. By seeding with low-Z impurities, such as Ne and N2, high total radiated power fractions are possible, along with substantial reductions in divertor heat flux (>4×), all while maintaining H98 ~ 1. When the power radiated from the confined versus unconfined plasma is examined, pedestal and confinement properties are clearly seen to be an increasing function of Pnet, helping to unify the results with those from unseeded H-modes. This provides increased confidence that the power flow across the separatrix is the correct physics basis for ITER extrapolation. The experiments show that Pnet/Pth of one or greater is likely to lead to H98 >= 1 operation

  17. Configuration and Heating Power Dependence of Edge Parameters and H-mode Dynamics in National Spherical Torus Experiment (NSTX)

    Energy Technology Data Exchange (ETDEWEB)

    C.E. Bush; M.G. Bell; R.E. Bell; J. Boedo; E.D. Fredrickson; S.M. Kaye; S. Kubota; B.P. LeBlanc; R. Maingi; R.J. Maqueda; S.A. Sabbagh; V.A. Soukhanovskii; D. Stutman; D.W. Swain; J.B. Wilgen; S.J. Zweben; W.M. Davis; D.A. Gates; D.W. Johnson; R. Kaita; H.W. Kugel; D. Mastrovito; S. Medley; J.E. Menard; D. Mueller; M. Ono; F. Paoletti; S.J. Paul; Y-K.M. Peng; R. Raman; P.G. Roney; A.L. Roquemore; C.H. Skinner; E.J. Synakowski; G. Taylor; the NSTX Team

    2003-01-09

    Edge parameters play a critical role in H-mode (high-confinement mode) access, which is a key component of plasma discharge optimization in present-day toroidal confinement experiments and the design of next-generation devices. Because the edge magnetic topology of a spherical torus (ST) differs from a conventional aspect ratio tokamak, H-modes in STs exhibit important differences compared with tokamaks. The dependence of the NSTX (National Spherical Torus Experiment) edge plasma on heating power, including the L-H transition requirements and the occurrence of edge-localized modes (ELMs), and on divertor configuration is quantified. Comparisons between good L-modes (low-confinement modes) and H-modes show greater differences in the ion channel than the electron channel. The threshold power for the H-mode transition in NSTX is generally above the predictions of a recent ITER (International Thermonuclear Experimental Reactor) scaling. Correlations of transition and ELM phenomena with turbulent fluctuations revealed by Gas Puff Imaging (GPI) and reflectometry are observed. In both single-null and double-null divertor discharges, the density peaks off-axis, sometimes developing prominent ''ears'' which can be sustained for many energy confinement times, tau subscript ''E'', in the absence of ELMs. A wide variety of ELM behavior is observed, and ELM characteristics depend on configuration and fueling.

  18. Extinguishing ELMs in detached radiative divertor plasmas

    Science.gov (United States)

    Pigarov, Alexander; Krasheninnikov, Sergei; Rognlien, Thomas

    2016-10-01

    In order to avoid deleterious effects of ELMs on PFCs in next-step fusion devices it has been suggested to operate with small-sized ELMs naturally extinguishing in the divertor. Our modeling effort is focusing at extinguishing type-I ELMs: conditions for expelled plasma dissipation; efficiency of ELM power handling by detached radiative divertors; and the ELM impact on detachment state. Here time-dependent modeling of a sequence of many ELMs was performed with 2-D edge plasma transport code UEDGE-MB-W which incorporates the Macro-Blob (MB) approach to simulate non-diffusive filamentary transport and various ``Wall'' (W) models for time-dependent hydrogen wall inventory and recycling. Three cases were modeled, in which extinguishing ELMs are achieved due to: (i) intrinsic impurities via graphite sputtering, (ii) extrinsic impurity gas puff (Ne), and (iii) =(i) +(ii). For each case, we performed a series of UEDGE-MB-W runs scanning the deuterium and impurity inventories, pedestal losses and ELM frequency. Temporal variations of the degree of detachment, ionization front shape, recombination sink strength, radiated fraction, peak power loads, OSP, impurity charge states, and in/out asymmetries were analyzed. We discuss the onset of extinguishing ELMs, conditions for not burning through and enhanced plasma recombination as functions of scanned parameters. Efficiencies of intrinsic and extrinsic impurities in ELM extinguishing are compared.

  19. Resonant magnetic perturbation experiments on MAST using external and internal coils for ELM control

    Science.gov (United States)

    Kirk, A.; Nardon, E.; Akers, R.; Bécoulet, M.; De Temmerman, G.; Dudson, B.; Hnat, B.; Liu, Y. Q.; Martin, R.; Tamain, P.; Taylor, D.; MAST Team

    2010-03-01

    Experiments have been performed on MAST using both external (n = 1, 2) and internal (n = 3) resonant magnetic perturbation (RMP) coils. ELM suppression has not been achieved even though vacuum modelling shows that either set of coils can produce a region (ΔΨpol > 0.17), for which the Chirikov parameter is greater than 1, wider than that correlated with ELM suppression in DIII-D. Although complete ELM suppression has not been achieved, application of RMPs has triggered ELMs in ELM free H-mode periods (n = 3) and increased the ELM frequency in regularly ELM-ing discharges (n = 2, 3). In addition, the application of RMPs in an n = 3 configuration has produced large changes to the edge turbulence in L-mode discharges.

  20. H-mode plasmas at very low aspect ratio on the Pegasus Toroidal Experiment

    Science.gov (United States)

    Thome, K. E.; Bongard, M. W.; Barr, J. L.; Bodner, G. M.; Burke, M. G.; Fonck, R. J.; Kriete, D. M.; Perry, J. M.; Reusch, J. A.; Schlossberg, D. J.

    2017-02-01

    H-mode is obtained at A˜ 1.2 in the Pegasus Toroidal Experiment via Ohmic heating, high-field-side fueling, and low edge recycling in both limited and diverted magnetic topologies. These H-mode plasmas show the formation of edge current and pressure pedestals and a doubling of the energy confinement time to {{H}98y,2}˜ 1 . The L-H power threshold {{P}\\text{LH}} increases with density, and there is no {{P}\\text{LH}} minimum observed in the attainable density space. The power threshold is equivalent in limited and diverted plasmas, consistent with the FM3 model. However, the measured {{P}\\text{LH}} is ˜ 15 × higher than that predicted by conventional International Tokamak Physics Activity (ITPA) scalings, and {{P}\\text{LH}}/{{P}\\text{ITPA08}} increases as A\\to 1 . Small ELMs are present at low input power {{P}\\text{IN}}˜ {{P}\\text{LH}} , with toroidal mode number n≤slant 4 . At {{P}\\text{IN}}\\gg {{P}\\text{LH}} , they transition to large ELMs with intermediate 5. The dominant-n component of a large ELM grows exponentially, while other components evolve nonlinearly and can damp prior to the crash. Direct measurements of the current profile in the pedestal region show that both ELM types exhibit a generation of a current-hole, followed by a pedestal recovery. Large ELMs are shown to further expel a current-carrying filament. Small ELM suppression via injection of low levels of helical current into the edge plasma region is also indicated.

  1. Investigation of dynamics of ELM crashes and their mitigation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pankin, Alexei Y. [Tech-X Corporation, Boulder, CO (United States)

    2015-08-14

    The accurate prediction of H-mode pedestal dynamics is critical for planning experiments in existing tokamaks and in the design of future tokamaks such as ITER and DEMO. The main objective of the proposed research is to advance the understanding of the physics of H-mode pedestal. Through advances in coupled kinetic-MHD simulations, a new model for H-mode pedestal and ELM crashes as well as an improved model for the bootstrap current will be developed. ELMmitigation techniques will also be investigated. The proposed research will help design efficient confinement scenarios and reduce transient heat loads on the divertor and plasma facing components. During the last two years, the principal investigator (PI) of this proposal actively participated in physics studies related to the DOE Joint Research Targets. These studies include the modeling of divertor heat load in the DIII-D, Alcator C-Mod, and NSTX tokamaks in 2010, and the modeling of H-mode pedestal structure in the DIII-D tokamak in 2011. It is proposed that this close collaboration with experimentalists from major US tokamaks continue during the next funding period. Verification and validation will be a strong component of the proposed research. During the course of the project, advances will be made in the following areas; Dynamics of the H-mode pedestal buildup and recovery after ELM crashes – The effects of neutral fueling, particle and thermal pinches will be explored; Dynamics of ELM crashes in realistic tokamak geometries – Heat loads associated with ELM crashes will be validated against experimental measurements. An improved model for ELM crashes will be developed; ELM mitigation – The effect of resonant magnetic perturbations on ELMs stability and their evolution will be investigated; Development of a new bootstrap current model – A reduced model for will be developed through careful verification of existing models for bootstrap current against first-principle kinetic neoclassical simulations

  2. HOW to Differentiate Dutch Elm Disease from Elm Phloem Necrosis

    Science.gov (United States)

    Lester Paul Gibson; Arthur R. Hastings; Leon A. LeMadeliene

    1981-01-01

    Dutch elm disease (DED) and elm phloem necrosis are the two most serious diseases of elm in the United States (Figs. 1 and 2). Most native species of elm are susceptible to both diseases. Dutch elm disease is caused by a fungus, Ceratocystis u1mi (Buisman) C. Moreau, and is transmitted by two species of elm bark beetles-the smaller European elm bark beetle, Scolytus...

  3. Edge simulations in ELMy H-mode discharges of EAST tokamak

    Science.gov (United States)

    Xia, T. Y.; Huang, Y. Q.; Xu, X. Q.; Wu, Y. B.; Wang, L.; Zheng, Z.; Liu, J. B.; Zang, Q.; Li, Y. Y.; Zhao, D.

    2017-10-01

    Simulations of ELM crash followed by a coherent mode, leading to transient divertor heat flux on EAST are achieved by the six-field two-fluid model in BOUT + + . Three EAST ELMy H-mode discharges with different pedestal structure, geometry and plasma current Ip are studied. The ELM-driven crash of the profiles in pedestal is reproduced, and the footprints of ELM filaments on targets are comparable with the measurements from divertor probes. A coherent mode is also found in the edge region in all the simulations after the ELM crash. The frequency and poloidal wave number are in the range of the edge coherent mode (ECM) on EAST. The magnetic fluctuations of the mode are smaller than the electric field fluctuations. The detailed comparisons between simulated mode structures with measurements will be reported. Statistical analysis on the simulated turbulent fluctuations shows that both the turbulent and blobby electron anomalous transport can pump the pedestal energy out into SOL, and then flow to divertors. The similar trend of the heat flux width with Ip is obtained in the simulations. The effects of the SOL current driven by LHW on ELMs will be discussed in this paper. This work was performed under the auspices of the US DOE by LLNL under contract DE-AC52-07NA27344. It was supported by the China NSF 11405215 and 11675217.

  4. The 13th International Workshop on H-mode Physics and Transport Barriers (Oxford, UK, 2011) The 13th International Workshop on H-mode Physics and Transport Barriers (Oxford, UK, 2011)

    Science.gov (United States)

    Saibene, G.

    2012-11-01

    as to stimulate and lead the open discussion. Poster sessions were also organized to present specialist papers and provide a venue for continued discussion. The topics selected for this edition of the workshop were: 1. Integrated plasma scenarios for ITER and a reactor: experimental and theoretical studies, including the self-stabilizing transport approach. 2. Edge transport barrier control and plasma performance: physics of 3D stochastic magnetic fields for ELM suppression. 3. H-mode transition physics and H-mode pedestal structure: pedestal dynamics near transitions and requirements for high-confinement access and sustainment. 4. Energetic particle driven instabilities and related physics: H-mode and the transport barrier. 5. Role of and evidence for non-diffusive particle and toroidal momentum transport and impact of fuelling: experiments, theory and modelling. 6. Long-range correlation of plasma turbulence and interaction between edge and core transport. The choice of topics, and the amount of progress in the understanding of the complexity of transport barriers physics reflect the drive in the fusion community towards the preparation for the ITER tokamak operation. More than 100 scientists (including students) attended the three-day workshop, coming from all over the world to present their newest results, discuss with colleagues and enjoy the atmosphere of the beautiful Lady Margaret Hall. The preparation work of the International Advisory Committee (G. Saibene (EU - Chair), R. Groebner (US), T. S Hahm (KO), A. Hubbard (US), K. Ida (Japan), S. Lebedev (RF), N. Oyama (Japan), E Wolfrum (EU)) has been rewarded by the enthusiastic participation of scientists, experimentalist, modellers and theoreticians, and by the high level of the scientific discussion throughout the workshop, during lunch breaks and even at the conference dinner. The Committee is also grateful to EFDA for the support in the organization of the workshop and to the Local Organizing Committee (E

  5. Access to a New Plasma Edge State with High Density and Pressures using Quiescent H-mode

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, Wayne M. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Snyder, P. B. [General Atomics, San Diego, CA (United States); Burrell, K. H. [General Atomics, San Diego, CA (United States); Fenstermacher, M. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Garofalo, A. M. [General Atomics, San Diego, CA (United States); Grierson, B. A. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Loarte, A. [ITER Organization, St. Paul Lez Durance (France); McKee, G. R. [Univ. of Wisconsin, Madison, WI (United States); Nazikian, R [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Osborne, T. H. [General Atomics, San Diego, CA (United States)

    2014-07-01

    A path to a new high performance regime has been discovered in tokamaks that could improve the attractiveness of a fusion reactor. Experiments on DIII-D using a quiescent H-mode edge have navigated a valley of improved edge peeling-ballooning stability that opens up with strong plasma shaping at high density, leading to a doubling of the edge pressure over standard edge localized mode (ELM)ing H-mode at these parameters. The thermal energy confinement time increases both as a result of the increased pedestal height and improvements in the core transport and reduced low-k turbulence. Calculations of the pedestal height and width as a function of density using constraints imposed by peeling-ballooning and kinetic-ballooning theory are in quantitative agreement with the measurements.

  6. ELM mitigation via rotating resonant magnetic perturbations on MAST

    CERN Document Server

    Thornton, A J; Cahyna, P; Chapman, I T; Fishpool, G; Harrison, J R; Liu, Y Q; Kripner, L; Peterka, M

    2014-01-01

    The application of resonant magnetic perturbations (RMPs) produces splitting of the divertor strike point due to the interaction of the RMP field and the plasma field. The application of a rotating RMP field causes the strike point splitting to rotate, distributing the particle and heat flux evenly over the divertor. The RMP coils in MAST have been used to generate a rotating perturbation with a toroidal mode number n=3. The ELM frequency is doubled with the application of the RMP rotating field, whilst maintaining the H mode. During mitigation, the ELM peak heat flux is seen to be reduced by 50% for a halving in the ELM energy and motion of the strike point, consistent with the rotation of the applied RMP field, is seen using high spatial resolution (1.5mm at the target) heat flux profiles measured using infrared (IR) thermography.

  7. ELM Processes and Properties in 2T 2MA JET Plasmas

    CERN Document Server

    Webster, Anthony J; Contributors, EFDA JET

    2013-01-01

    During July 2012, 150 almost identical H-mode plasmas were consecutively created in the Joint European Torus (JET), providing a combined total of approximately 8 minutes of steady-state plasma with 15,000 Edge Localised Modes (ELMs). In principle, each of those 15,000 ELMs are statistically equivalent. Here the changes in edge density and plasma energy associated with those ELMs are explored, using the spikes in Beryllium II (527 nm) radiation as an indicator for the onset of an ELM. Two timescales are found during the ELM process. The first timescale is associated with the density drop, and the second (longer) timescale is associated with a reduction in MHD energy that is consistent with a resistive relaxation of the plasma's edge. The statistical properties of the energy and density losses due to the ELMs are explored. Surprisingly the commonly reported link between ELM energy (E) and ELM frequency (f), of E proportional to 1/f, is not found. Instead beyond the first 0.02 seconds of waiting time between ELM...

  8. Dutch Elm Disease (DED) and the American Elm (Pest Alert)

    Science.gov (United States)

    USDA Forest Service

    1999-01-01

    For decades the American elm was one of our most treasured trees, gracing streets and parks of many cities with beautiful form and dense foliage. The American elm was particularly well suited to urban sites because it grows quickly, is long-lived, and is tolerant of compacted soils and air pollution. However, in most communities Dutch elm disease (DED) killed a...

  9. Castellated tungsten plasma-facing components exposed to H-mode plasma in KSTAR

    Energy Technology Data Exchange (ETDEWEB)

    Hong, S.-H., E-mail: sukhhong@nfri.re.kr [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Department of Electrical Engineering, HanYang University, Seoul 133-791 (Korea, Republic of); Department of Accelerator and Nuclear Fusion Physics and Engineering, University of Science and Technology, Daejeon 305-333 (Korea, Republic of); Lee, H.-H.; Kim, K.M.; Kim, H.T.; Bang, E.-N.; Son, S.H.; Kim, H.K. [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)

    2016-11-01

    Highlights: • Heat load on the misaligned leading edges are studied by COMSOL analysis and infrared (IR) measurements in KSTAR. • 1–3 MW/m{sup 2} of heat flux has been deposited on the blocks during the inter-ELM (edge localized mode) phase in H-mode plasmas. • 1 mm leading edge under 3 MW/m{sup 2} reaches the recrystallization point within 2 s and will be melted within 30 s. • Shaped blocks show much better thermal response meaning that shaping of blocks enhances the heat load handling capability. • A simple COMSOL analysis describes qualitatively heat load patterns on the tungsten blocks of different shapes. - Abstract: Heat load on the misaligned leading edges of tungsten castellated blocks based on tungsten (W), oxygen-free high conductive copper (OFHC-Cu), and copper-chrome-zirconium (CuCrZr) alloy are studied by COMSOL analysis and infrared (IR) measurements in KSTAR. IR measurements show that 1–3 MW/m{sup 2} of heat flux has been deposited on the blocks during the inter-ELM (edge localized mode) phase in H-mode plasmas. COMSOL analysis indicates that the temperature of 1 mm leading edge in KSTAR under 3 MW/m{sup 2} would reach the recrystallization temperature within 2 s and will be melted within 30 s during a long pulse H-mode shot. Rounded and double chamfered blocks show much better thermal response meaning that shaping of divertor block enhances the heat load handling capability. It seems that a simple COMSOL analysis describes heat load patterns on the tungsten blocks of different shapes qualitatively well. Therefore, simple analysis would be useful to make a quick prediction on heat load patterns of blocks with arbitrary shapes.

  10. Langmuir-magnetic probe measurements of ELMs and dithering cycles in the EAST tokamak

    DEFF Research Database (Denmark)

    Yan, Ning; Naulin, Volker; Xu, G. S.

    2014-01-01

    and dithering cycles have been investigated near the threshold power for the transition from the low confinement mode (L-mode) to the high confinement mode (H-mode). A precursor is observed prior to type-III ELM events with chirping frequency (130–70 kHz). It is located inside the separatrix and does not lead...

  11. Building a database for statistical characterization of ELMs on DIII-D

    Science.gov (United States)

    Fritch, B. J.; Marinoni, A.; Bortolon, A.

    2017-10-01

    Edge localized modes (ELMs) are bursty instabilities which occur in the edge region of H-mode plasmas and have the potential to damage in-vessel components of future fusion machines by exposing the divertor region to large energy and particle fluxes during each ELM event. While most ELM studies focus on average quantities (e.g. energy loss per ELM), this work investigates the statistical distributions of ELM characteristics, as a function of plasma parameters. A semi-automatic algorithm is being used to create a database documenting trigger times of the tens of thousands of ELMs for DIII-D discharges in scenarios relevant to ITER, thus allowing statistically significant analysis. Probability distributions of inter-ELM periods and energy losses will be determined and related to relevant plasma parameters such as density, stored energy, and current in order to constrain models and improve estimates of the expected inter-ELM periods and sizes, both of which must be controlled in future reactors. Work supported in part by US DoE under the Science Undergraduate Laboratory Internships (SULI) program, DE-FC02-04ER54698 and DE-FG02- 94ER54235.

  12. ELM control at the L -> H transition by means of pellet pacing in the ASDEX Upgrade and JET all-metal-wall tokamaks

    NARCIS (Netherlands)

    Lang, P. T.; Meyer, H.; Birkenmeier, G.; Burckhart, A.; Carvalho, I. S.; Delabie, E.; Frassinetti, L.; Huijsmans, G.; Kocsis, G.; Loarte, A.; Maggi, C. F.; Maraschek, M.; B. Plöckl,; Rimini, F.; Ryter, F.; Saarelma, S.; Szepesi, T.; Wolfrum, E.; ASDEX Upgrade team,; JET Contributors,

    2015-01-01

    In ITER, pellets are used for ELM pacing and fueling. More importantly, ELM control and in particular control of the first ELM needs to be demonstrated in the non-nuclear phase of ITER during operation in H or He. Whilst D pellets have been established as an ELM control technique in the stationary

  13. Report from the street: elm reintroduction

    Science.gov (United States)

    Tom. Zetterstrom

    2017-01-01

    Since the introduction of Dutch elm disease (DED) to North America, heritage elm preservation was paramount, but elm restoration is held as the long-term solution. Various elm restoration efforts have been advanced and encouraged over the past half century, and all have inspired the euphoria of the "Return of the American Elm." The changing cast of characters...

  14. High Power Fast Wave Coupling and Heating in H-mode Plasmas on DIII-D

    Science.gov (United States)

    Pinsker, R. I.; Buttery, R. J.; Luce, T. C.; Porkolab, M.; Diem, S.; Kaufman, M.; Ryan, P. M.; Hosea, J. C.; Nagy, A.; Perkins, R.; Solomon, W. M.; Maggiora, R.; Milanesio, D.

    2012-10-01

    Up to 2.5 MW of fast wave (FW) heating power has been coupled to the core of ELMing H-mode discharges with βN<=2.5 in conjunction with 3-7 MW of neutral beam injection and 2.6 MW of electron cyclotron heating. Core FW heating efficiency has been found experimentally to approach 100% in the Advanced Inductive regime, consistent with the excellent absorption predicted by ray-tracing models in this high βe regime. Low antenna loading (high rf voltages) characteristic of such regimes makes increasing the FW power challenging. A study of techniques to enhance FW antenna loading has been carried out in DIII-D, with emphasis on maintenance of good confinement. The loading is in absolute agreement with modeling when edge density profiles measured with reflectometry are used in the model. Recent work extending the range of H-mode regimes to which FW heating has been applied and on increasing the FW power coupled to those regimes is described.

  15. Dependence of various SOL widths on plasma current and density in NSTX H-mode plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, J; Maingi, R; Boedo, J; Soukhanovskii, V A

    2009-02-12

    The dependence of various SOL widths on the line-averaged density ({ovr n}{sub e}) and plasma current (l{sub p}) for the quiescent H-mode plasmas with Type-V ELMs in the National Spherical Torus Experiment (NSTX) was investigated. It is found that the heat flux SOL width ({lambda}{sub q}), measured by the IR camera, is virtually insensitive to {ovr n}{sub e} and has a strong negative dependence on l{sub p}. This insensitivity of {lambda}{sub q} to {ovr n}{sub e} is consistent with the scaling law from JET H-mode plasmas that shows a very weak dependence on the upstream density. The electron temperature, ion saturation current density, electron density, and electron pressure decay lengths ({lambda}{sub Te}, {lambda}{sub jsat}, {lambda}{sub ne}, and {lambda}{sub pe}, respectively) measured by the probe showed that {lambda}{sub Te} and {lambda}{sub jsat} have strong negative dependence on l{sub p}, whereas {lambda}{sub ne} and {lambda}{sub pe} revealed only a little or no dependence. The dependence of {lambda}{sub Te} on l{sub p} is consistent with the scaling law in the literature while {lambda}{sub ne} and {lambda}{sub pe} dependence shows a different trend.

  16. ELMs and strike point movements

    NARCIS (Netherlands)

    Solano, E. R.; Jachmich, S.; Villone, F.; Hawkes, N.; Corre, Y.; Alper, B.; Loarte, A.; Pitts, R.A.; Guenther, K.; Korotkov, A.; Stamp, M.; Andrew, P.; Conboy, J.; Bolzonella, T.; Kempenaars, M.; Cenedese, A.; Rachlew, E.

    2008-01-01

    A detailed study of position changes of plasma strike points before and after edge localized modes (ELMs) in JET was carried out. A hypothesis being tested is that in an ELM previously closed edge field lines would open up, releasing plasma current and leading to the formation of a new, smaller

  17. BOUT++ Simulations of Edge Turbulence in Alcator C-Mod's EDA H-Mode

    Science.gov (United States)

    Davis, E. M.; Porkolab, M.; Hughes, J. W.; Labombard, B.; Snyder, P. B.; Xu, X. Q.

    2013-10-01

    Energy confinement in tokamaks is believed to be strongly controlled by plasma transport in the pedestal. The pedestal of Alcator C-Mod's Enhanced Dα (EDA) H-mode (ν* > 1) is regulated by a quasi-coherent mode (QCM), an edge fluctuation believed to reduce particle confinement and allow steady-state H-mode operation. ELITE calculations indicate that EDA H-modes sit well below the ideal peeling-ballooning instability threshold, in contrast with ELMy H-modes. Here, we use a 3-field reduced MHD model in BOUT++ to study the effects of nonideal and nonlinear physics on EDA H-modes. In particular, incorporation of realistic pedestal resistivity is found to drive resistive ballooning modes (RBMs) and increase linear growth rates above the corresponding ideal rates. These RBMs may ultimately be responsible for constraining the EDA pedestal gradient. However, recent high-fidelity mirror Langmuir probe measurements indicate that the QCM is an electron drift-Alfvén wave - not a RBM. Inclusion of the parallel pressure gradient term in the 3-field reduced MHD Ohm's law and various higher field fluid models are implemented in an effort to capture this drift wave-like response. This work was performed under the auspices of the USDoE under awards DE-FG02-94-ER54235, DE-AC52-07NA27344, DE-AC52-07NA27344, and NNSA SSGF.

  18. Dutch elm disease pathogen transmission by the banded elm bark beetle Scolytus schevyrewi

    Science.gov (United States)

    W. R. Jacobi; R. D. Koski; J. F. Negron

    2013-01-01

    Dutch Elm Disease (DED) is a vascular wilt disease of Ulmus species (elms) incited in North America primarily by the exotic fungus Ophiostoma novo-ulmi. The pathogen is transmitted via root grafts and elm bark beetle vectors, including the native North American elm bark beetle, Hylurgopinus rufipes and the exotic smaller European elm bark beetle, Scolytus multistriatus...

  19. Highly radiating type-III ELMy H-mode with low plasma core pollution

    NARCIS (Netherlands)

    Rapp, J.; M.R. de Baar,; Fundamenski, W.; Brix, M.; Felton, R.; Giroud, C.; Huber, A.; Jachmich, S.; Joffrin, E.; Nunes, I.; van Rooij, G. J.; Stamp, M.; Telesca, G.; Zagorski, R.

    2009-01-01

    The impurity seeded type-III ELMy H-mode is proposed as an integrated ITER scenario. At JET this scenario has been demonstrated up to plasma currents of 3 MA with nitrogen as seeding gas. Detached divertor operation is achieved with significantly reduced steady state and transient heat fluxes. By

  20. Radiative type-III ELMy H-mode in all-tungsten ASDEX Upgrade

    NARCIS (Netherlands)

    Rapp, J.; Kallenbach, A.; Neu, R.; Eich, T.; Fischer, R.; Herrmann, A.; Potzel, S.; van Rooij, G. J.; Zielinski, J. J.; ASDEX Upgrade team,

    2012-01-01

    The type-III ELMy H-mode might be the solution for an integrated ITER operation scenario fulfilling the fusion power amplification factor (output fusion power to input heating power) of Q = 10 with simultaneous acceptable steady-state and transient power loads to the plasma-facing components. This

  1. Pellet Fueling of ELM Mitigated ITER Baseline Scenario Plasmas on DIII-D

    Science.gov (United States)

    Baylor, L. R.

    2017-10-01

    ITER has been designed to employ HFS pellet fueling to operate at high density using pellets that produce less than a 10% density perturbation and that penetrate to just beyond the top of the pedestal. DIII-D ITER-like plasmas with ELM mitigation provided by either pellet ELM pacing or RMPs have been fueled with small shallow penetrating HFS pellets. In DIII-D, large natural ELMs dramatically reduce the effective fueling efficiency of the HFS pellets to nearly 0 within the time scale of a few large ELMs. In the ELM paced plasmas, the pellets trigger ELMs that are no more intense than the paced ELMs and the resulting fueling efficiency is >80%. In RMP ELM mitigated plasmas, the efficient fueling from HFS pellets results in pedestal collisionality increases that can reduce the ELM mitigation. New experiments have shown that edge ECH can decrease pedestal collisionality and will be combined with the HFS pellets to better mimic the ITER fueling scenario. These fueling results from pellet pacing and RMP ELM mitigation will be presented and implications for ITER discussed. Supported by the US DOE under DE-AC05-00OR22725, DE-FC02-04ER54698, DE-AC52-07NA27344 & DE-FG02-07ER54917.

  2. The role of MHD instabilities in the improved H-mode scenario

    Energy Technology Data Exchange (ETDEWEB)

    Flaws, Asher

    2009-02-16

    Recently a regime of tokamak operation has been discovered, dubbed the improved H-mode scenario, which simultaneously achieves increased energy confinement and stability with respect to standard H-mode discharges. It has been suggested that magnetohydrodynamic (MHD) instabilities play some role in establishing this regime. In this thesis MHD instabilities were identified, characterised, and catalogued into a database of improved H-mode discharges in order to statistically examine their behaviour. The onset conditions of MHD instabilities were compared to existing models based on previous H-mode studies. Slight differences were found, most notably a reduced {beta}{sub N} onset threshold for the frequently interrupted regime for neoclassical tearing modes (NTM). This reduced threshold is due to the relatively low magnetic shear of the improved H-mode regime. This study also provided a first-time estimate for the seed island size of spontaneous onset NTMs, a phenomenon characteristic of the improved H-mode scenario. Energy confinement investigations found that, although the NTM impact on confinement follows the same model applicable to other operating regimes, the improved H-mode regime acts to mitigate the impact of NTMs by limiting the saturated island sizes for NTMs with toroidal mode number n {>=} 2. Surprisingly, although a significant loss in energy confinement is observed during the sawtooth envelope, it has been found that discharges containing fishbones and low frequency sawteeth achieve higher energy confinement than those without. This suggests that fishbone and sawtooth reconnection may indeed play a role in establishing the high confinement regime. It was found that the time evolution of the central magnetic shear consistently locks in the presence of sawtooth and fishbone reconnection. Presumably this is due to the periodic redistribution of the central plasma current, an effect which is believed to help establish and maintain the characteristic current

  3. Two Efficient Twin ELM Methods With Prediction Interval.

    Science.gov (United States)

    Ning, Kefeng; Liu, Min; Dong, Mingyu; Wu, Cheng; Wu, ZhanSong

    2015-09-01

    In the operational optimization and scheduling problems of actual industrial processes, such as iron and steel, and microelectronics, the operational indices and process parameters usually need to be predicted. However, for some input and output variables of these prediction models, there may exist a lot of uncertainties coming from themselves, the measurement error, the rough representation, and so on. In such cases, constructing a prediction interval (PI) for the output of the corresponding prediction model is very necessary. In this paper, two twin extreme learning machine (TELM) models for constructing PIs are proposed. First, we propose a regularized asymmetric least squares extreme learning machine (RALS-ELM) method, in which different weights of its squared error loss function are set according to whether the error of the model output is positive or negative in order that the above error can be differentiated in the parameter learning process, and Tikhonov regularization is introduced to reduce overfitting. Then, we propose an asymmetric Bayesian extreme learning machine (AB-ELM) method based on the Bayesian framework with the asymmetric Gaussian distribution (AB-ELM), in which the weights of its likelihood function are determined as the same method in RALS-ELM, and the type II maximum likelihood algorithm is derived to learn the parameters of AB-ELM. Based on RALS-ELM and AB-ELM, we use a pair of weights following the reciprocal relationship to obtain two nonparallel regressors, including a lower-bound regressor and an upper-bound regressor, respectively, which can be used for calculating the PIs. Finally, some discussions are given, about how to adjust the weights adaptively to meet the desired PI, how to use the proposed TELMs for nonlinear quantile regression, and so on. Results of numerical comparison on data from one synthetic regression problem, three University of California Irvine benchmark regression problems, and two actual industrial regression

  4. The global build-up to intrinsic ELM bursts seen in divertor full flux loops in Jet

    CERN Document Server

    Chapman, S C; Todd, T N; Watkins, N W; Calderon, F A; Morris, J; Contributors, JET

    2015-01-01

    A global signature of the build-up to an intrinsic ELM is found in the phase of signals measured in full flux azimuthal loops in the divertor region of JET. Full flux loop signals provide a global measurement proportional to the voltage induced by changes in poloidal magnetic flux; they are electromagnetically induced by the dynamics of spatially integrated current density. We perform direct time-domain analysis of the high time-resolution full flux loop signals VLD2 and VLD3. We analyze plasmas where a steady H-mode is sustained over several seconds, during which all the observed ELMs are intrinsic; there is no deliberate intent to pace the ELMing process by external means. ELM occurrence times are determined from the Be II emission at the divertor. We previously found that the occurrence times of intrinsic ELMs correlate with specific phases of the VLD2 and VLD3 signals. Here, we investigate how the VLD2 and VLD3 phases vary with time in advance of the ELM occurrence time. We identify a build-up to the ELM ...

  5. Proceedings of the American elm restoration workshop 2016

    Science.gov (United States)

    Cornelia C. Pinchot; Kathleen S. Knight; Linda M. Haugen; Charles E. Flower; James M. Slavicek

    2017-01-01

    Proceedings from the 2016 American Elm Restoration Workshop in Lewis Center, OH. The published proceedings include 16 papers pertaining to elm pathogens, American elm ecology, and American elm reintroduction.

  6. Simulation of tungsten armour cracking due to small ELMs in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Pestchanyi, S., E-mail: sergey.pestchanyi@ihm.fzk.de [Forschungszentrum Karlsruhe, IHM (Germany); Garkusha, I. [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Landman, I. [Forschungszentrum Karlsruhe, IHM (Germany)

    2010-12-15

    Simulations of tungsten armour cracking under small ELM-like plasma heat load, which does not cause surface melting, have been performed using the PEGASUS-3D code. A dedicated series of experiments have been performed in the QSPA-Kh50 facility for measurements of the unknown tungsten thermophysical properties and for verification of the PEGASUS-3D simulation results. The simulations revealed that a cellular crack network with average mesh size {Lambda} {approx} 0.5 mm formed after first ELMs and the pattern does not change further. With increasing number of repetitive ELMs loads, the average crack width {Delta}(n) has a maximum value {Delta}{sub m}. The ratio of {Delta}{sub m}/{Lambda} is equal to the tungsten thermal expansion at the maximum surface temperature. {Delta}(n) tends to this value exponentially. The number of ELMs n{sub m} needed for {Delta} stabilization depends on the ELMs energy density and time duration, n{sub m} {approx} 300 for the simulated ELMs of 0.45 MJ/m{sup 2} and 0.25 ms duration. The PEGASUS-3D code is prepared for simulations of tungsten armour damage under action of ELMs of various energy deposition and time duration. These parameters of ELMs depend on ITER regimes of operation and on how successful will be the efforts on ELMs mitigation.

  7. Measured vs. Predicted Pedestal Pressure During RMP ELM Control in DIII-D

    Science.gov (United States)

    Zywicki, Bailey; Fenstermacher, Max; Groebner, Richard; Meneghini, Orso

    2017-10-01

    From database analysis of DIII-D plasmas with Resonant Magnetic Perturbations (RMPs) for ELM control, we will compare the experimental pedestal pressure (p_ped) to EPED code predictions and present the dependence of any p_ped differences from EPED on RMP parameters not included in the EPED model e.g. RMP field strength, toroidal and poloidal spectrum etc. The EPED code, based on Peeling-Ballooning and Kinetic Ballooning instability constraints, will also be used by ITER to predict the H-mode p_ped without RMPs. ITER plans to use RMPs as an effective ELM control method. The need to control ELMs in ITER is of the utmost priority, as it directly correlates to the lifetime of the plasma facing components. An accurate means of determining the impact of RMP ELM control on the p_ped is needed, because the device fusion power is strongly dependent on p_ped. With this new collection of data, we aim to provide guidance to predictions of the ITER pedestal during RMP ELM control that can be incorporated in a future predictive code. Work supported in part by US DoE under the Science Undergraduate Laboratory Internship (SULI) program and under DE-FC02-04ER54698, and DE-AC52-07NA27344.

  8. Bifurcation of quiescent H-mode to a wide pedestal regime in DIII-D and advances in the understanding of edge harmonic oscillations

    Science.gov (United States)

    Chen, Xi; Burrell, K. H.; Osborne, T. H.; Barada, K.; Ferraro, N. M.; Garofalo, A. M.; Groebner, R. J.; McKee, G. R.; Petty, C. C.; Porkolab, M.; Rhodes, T. L.; Rost, J. C.; Snyder, P. B.; Solomon, W. M.; Yan, Z.; The DIII-D Team

    2017-08-01

    New experimental studies and modelling of the coherent edge harmonic oscillation (EHO), which regulates the conventional Quiescent H-mode (QH-mode) edge, validate the proposed hypothesis of edge rotational shear in destabilizing the low-n kink-peeling mode as the additional drive mechanism for the EHO. The observed minimum edge E  ×  B shear required for the EHO decreases linearly with pedestal collisionality ν \\text{e}\\ast , which is favorable for operating QH-mode in machines with low collisionality and low rotation such as ITER. In addition, the QH-mode regime in DIII-D has recently been found to bifurcate into a new ‘wide-pedestal’ state at low torque in double-null shaped plasmas, characterized by increased pedestal height, width and thermal energy confinement (Burrell 2016 Phys. Plasmas 23 056103, Chen 2017 Nucl. Fusion 57 022007). This potentially provides an alternate path for achieving high performance ELM-stable operation at low torque, in addition to the low-torque QH-mode sustained with applied 3D fields. Multi-branch low-k and intermediate-k turbulences are observed in the ‘wide-pedestal’. New experiments support the hypothesis that the decreased edge E  ×  B shear enables destabilization of broadband turbulence, which relaxes edge pressure gradients, improves peeling-ballooning stability and allows a wider and thus higher pedestal. The ability to accurately predict the critical E  ×  B shear for EHO and maintain high performance QH-mode at low torque is an essential requirement for projecting QH-mode operation to ITER and future machines.

  9. ELM divertor peak energy fluence scaling to ITER with data from JET, MAST and ASDEX upgrade

    Directory of Open Access Journals (Sweden)

    T. Eich

    2017-08-01

    Full Text Available A newly established scaling of the ELM energy fluence using dedicated data sets from JET operation with CFC & ILW plasma facing components (PFCs, ASDEX Upgrade (AUG operation with both CFC and full-W PFCs and MAST with CFC walls has been generated. The scaling reveals an approximately linear dependence of the peak ELM energy with the pedestal top electron pressure and with the minor radius; a square root dependence is seen on the relative ELM loss energy. The result of this scaling gives a range in parallel peak ELM energy fluence of 10–30MJm−2 for ITER Q= 10 operation and 2.5–7.5MJm−2 for intermediate ITER operation at 7.5MA and 2.65T. These latter numbers are calculated using a numerical regression (ɛII=0.28MJm2ne0.75Te1ΔEELM0.5Rgeo1. A simple model for ELM induced thermal load is introduced, resulting in an expression for the ELM energy fluence of ɛII≅6π pe Rgeo qedge. The relative ELM loss energy in the data is between 2–10% and the ELM energy fluence varies within a range of 100.5 ∼ 3 consistently for each individual device. The so far analysed power load database for ELM mitigation experiments from JET-EFCC and Kicks, MAST-RMP and AUG-RMP operation are found to be consistent with both the scaling and the introduced model, ie not showing a further reduction with respect to their pedestal pressure. The extrapolated ELM energy fluencies are compared to material limits in ITER and found to be of concern.

  10. Domain Adaption Based on ELM Autoencoder

    National Research Council Canada - National Science Library

    Wan-Yu Deng; Yu-Tao Qu; Qian Zhang

    2017-01-01

      We propose a new ELM Autoencoder (ELM-AE) based domain adaption algorithm which describes the subspaces of source and target domain by ELM-AE and then carries out subspace alignment to project different domains into a common new space...

  11. Analysis of the H-mode density limit in the ASDEX upgrade tokamak using bolometry

    Energy Technology Data Exchange (ETDEWEB)

    Bernert, Matthias

    2013-10-23

    The high confinement mode (H-mode) is the operational scenario foreseen for ITER, DEMO and future fusion power plants. At high densities, which are favourable in order to maximize the fusion power, a back transition from the H-mode to the low confinement mode (L-mode) is observed. This H-mode density limit (HDL) occurs at densities on the order of, but below, the Greenwald density. In this thesis, the HDL is revisited in the fully tungsten walled ASDEX Upgrade tokamak (AUG). In AUG discharges, four distinct operational phases were identified in the approach towards the HDL. First, there is a stable H-mode, where the plasma density increases at steady confinement, followed by a degrading H-mode, where the core electron density is fixed and the confinement, expressed as the energy confinement time, reduces. In the third phase, the breakdown of the H-mode and transition to the L-mode, the overall electron density is fixed and the confinement decreases further, leading, finally, to an L-mode, where the density increases again at a steady confinement at typical L-mode values until the disruptive Greenwald limit is reached. These four phases are reproducible, quasi-stable plasma regimes and provide a framework in which the HDL can be further analysed. Radiation losses and several other mechanisms, that were proposed as explanations for the HDL, are ruled out for the current set of AUG experiments with tungsten walls. In addition, a threshold of the radial electric field or of the power flux into the divertor appears to be responsible for the final transition back to L-mode, however, it does not determine the onset of the HDL. The observation of the four phases is explained by the combination of two mechanisms: a fueling limit due to an outward shift of the ionization profile and an additional energy loss channel, which decreases the confinement. The latter is most likely created by an increased radial convective transport at the edge of the plasma. It is shown that the

  12. Short wavelength turbulence generated by shear in the quiescent H-mode edge on DIII–D

    Energy Technology Data Exchange (ETDEWEB)

    Rost, J. C.; Porkolab, M.; Dorris, J. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Burrell, K. H. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)

    2014-06-15

    A region of turbulence with large radial wavenumber (k{sub r}ρ{sub s}>1) is found in the high-shear portion of the plasma edge in Quiescent H-mode (QH-mode) on DIII–D using the Phase Contrast Imaging (PCI) diagnostic. At its peak outside the minimum of the E{sub r} well, the turbulence exhibits large amplitude n{sup ~}/n∼40%, with large radial wavenumber |k{sup ¯}{sub r}/k{sup ¯}{sub θ}|∼11 and short radial correlation length L{sub r}/ρ{sub i}∼0.2. The turbulence inside the E{sub r} well minimum is characterized by the opposite sign in radial wavenumber from that of turbulence outside the minimum, consistent with the expected effects of velocity shear. The PCI diagnostic provides a line-integrated measurement of density fluctuations, so data are taken during a scan of plasma position at constant parameters to allow the PCI to sample a range in k{sub r}/k{sub θ}. Analysis of the Doppler shift and plasma geometry allows the turbulence to be localized to a narrow region 3 mm inside the last closed flux surface, outside the minimum of the E{sub r} well. The turbulence amplitude and radial wavenumber and correlation length are determined by fitting the PCI results with a simple non-isotropic turbulence model with two regions of turbulence. These PCI observations, made in QH-mode, are qualitatively similar to those made in standard edge localized modes (ELM)-free H-mode and between ELMs, suggesting a similar role for large k{sub r} turbulence there.

  13. Short wavelength turbulence generated by shear in the quiescent H-mode edge on DIII-D

    Science.gov (United States)

    Rost, J. C.; Porkolab, M.; Dorris, J.; Burrell, K. H.

    2014-06-01

    A region of turbulence with large radial wavenumber (krρs>1) is found in the high-shear portion of the plasma edge in Quiescent H-mode (QH-mode) on DIII-D using the Phase Contrast Imaging (PCI) diagnostic. At its peak outside the minimum of the Er well, the turbulence exhibits large amplitude n ˜/n˜40%, with large radial wavenumber |k¯r/k¯θ|˜11 and short radial correlation length Lr/ρi˜0.2. The turbulence inside the Er well minimum is characterized by the opposite sign in radial wavenumber from that of turbulence outside the minimum, consistent with the expected effects of velocity shear. The PCI diagnostic provides a line-integrated measurement of density fluctuations, so data are taken during a scan of plasma position at constant parameters to allow the PCI to sample a range in kr/kθ. Analysis of the Doppler shift and plasma geometry allows the turbulence to be localized to a narrow region 3 mm inside the last closed flux surface, outside the minimum of the Er well. The turbulence amplitude and radial wavenumber and correlation length are determined by fitting the PCI results with a simple non-isotropic turbulence model with two regions of turbulence. These PCI observations, made in QH-mode, are qualitatively similar to those made in standard edge localized modes (ELM)-free H-mode and between ELMs, suggesting a similar role for large kr turbulence there.

  14. THE ROLE OF NEUTRALS IN H-MODE PEDESTAL FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    R.J. GROEBNER; M.A. MAHDAVI; A.W. LEONARD; T.H. OSBORNE; G.D. PORTER; R.J. COLCHIN; L.W.OWEN

    2001-11-01

    An analytic model, derived from coupled continuity equations for the electron and neutral deuterium densities, is consistent with many features of edge electron density profiles in the DIII-D tokamak. For an assumed constant particle diffusion coefficient, the model shows that particle transport and neutral fueling produce electron and neutral density profiles that have the same characteristic scale lengths at the plasma edge. For systematic variations of density in H-mode discharges, the model predicts that the width of the electron density transport barrier decreases and the maximum gradient increases, as observed in the experiments. The widths computed from the model agree quantitatively with the experimental widths for conditions in which the model is valid. These results support models of transport barrier formation in which the H-mode particle barrier is driven by the edge particle flux and the width of the barrier is approximately the neutral penetration length.

  15. Charge exchange fluxes of ripple trapped slowing-down ions during L-to-H transition and ELMs

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, W. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Fahrbach, H.U. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Kaufmann, M. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Lackner, K. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Ryter, F. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Zohm, H. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Albrecht, M. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Alexander, M. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Asmussen, K. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Behler, K. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Behringer, K. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Bessenrodt-Weberpals, M. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Bosch, H.S. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Buechl, K. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Carlson, A. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Coster, D. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Blank, H.J. de [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Drube, R. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Dux, R. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Engelhardt, W. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Gehre, O. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

    1995-06-01

    Neutral fluxes from charge exchange with ripple-trapped particles show a remarkably different behaviour during L and H mode; their measurement provides a new diagnostic for the mode discrimination of the plasma. A possible reason for the changes of the fluxes is the action of a radial electric field. This seems to grow steadily after the L-to-H transition with a strong increase (jump in the ms range) at the transition to the quiescent H-mode. During ELMs the fluxes reduce to L-mode level. Measurements with 100 {mu} time resolution show no action in the fluxes piror to the change in the D{sub {alpha}}-signal at the start of type 1 ELM. (orig.)

  16. Improved H mode with flat central q profile on EAST

    Science.gov (United States)

    Liu, Haiqing; Yang, Yao; Gao, Xiang; Zeng, Long; Qian, Jinping; Gong, Xianzu; Wan, Baonian; Ding, Weixing; Brower, David Lyn; EAST Team

    2017-10-01

    High betaN ( 1.8) plasma with good confinement (H98y2 1.1) on EAST tokamak has been reported recently. These ELMy H-mode plasmas with Bt = 1.6T, Ip = 400 kA and q95 4.5 were heated by lower hybrid wave and neutral beam injection. The internal transport barrier (ITB) and edge transport barrier (ETB) are both observed with m/n =1/1 fishbone, which were identified to clamp central q at values close to unity. Implying an improved H-mode with flat central q profile and absence of sawteeth, like other devices. Accurate q profile, key profile for developing scenarios aim at high performance H mode, were derived by Polarimeter-interferometer (POINT) measurement as constraint. Base on the optimized current profile, better confinement (H98y2 1.4) with an electron ITB was obtained also with flat central q profile and absence of sawteeth at high betaP ( 2) regime with Bt = 2.5T, Ip = 400 kA. Both high betaN regime and high betaP regime H mode, are characterized by a stationary flat central q profile q0 >=1, but typically close to 1, absence of sawteeth, H98(y,2) >1 and simultaneously, with ITB. This work is supported by the National Magnetic Confinement Fusion Program of China with Contract No. 2014GB106002 and partly supported by the US D.O.E. contract DESC0010469.

  17. Reciprocating Probe Measurements of L-H Transition in LHCD H-mode on EAST

    DEFF Research Database (Denmark)

    Peng, Liu; Guosheng, Xu; Huiqian, Wang

    2013-01-01

    -H-L transitions were observed during a single shot when the applied LHW power was marginal to the threshold. The floating potential (Vf) had negative spikes corresponding with the Dα signal, and Er oscillation evolved into several intermittent negative spikes just before the L-H transition. In some shots......As the power available in the initial phase of the ITER operation will be limited, accessing the high confinement mode (H-mode) with low heating power will be a critical issue. In the recent experiment on EAST, the H-mode was obtained for the first time with lower hybrid current drive (LHCD) wave...... that the power loss P loss was comparable during the L-H transition, by comparing the adjacent L-mode and H-mode discharge. The Dα emission, Te and ne decreased rapidly in the time scale of about 1 ms, and the radial electric field Er turned positive in this process near the last closed flux surface. Multiple L...

  18. Dutch Elm Disease Control: Intensive Sanitation and Survey Economics

    Science.gov (United States)

    William N., Jr. Cannon; Jack H. Barger; David P. Worley

    1977-01-01

    Recent research has shown that prompt removal of diseased elms reduces the incidence of Dutch elm disease more than sanitation practice that allows diseased elms to remain standing into the dormant season. The key to prompt removal is repeated surveys to detect diseased elms as early as possible. Intensive sanitation can save more elms and cost less than the more...

  19. Dynamical Evolution of Pedestal Parameters in ELMy H-mode in the National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Diallo, A; Kubota, S; Sontag, A; Osborne, T; Podesta, M; Bell, R E; LeBlanc, B P; Menard, J

    2011-07-27

    Characterizations of the pedestal parameter dynamics throughout the edge localized modes(ELM) cycles are performed on the National Spherical Torus Experiment (NSTX, [M. Ono et al., Nucl. Fusion 40, 557 (2000)]). A clear buildup of the pedestal height is observed between ELMs for three di erent plasma currents, which tends to saturate prior to the onset of ELM at low and medium plasma current. Similarly, the pedestal width increases with no clear evidence of saturation during an ELM cycle. The maximum pedestal gradient increases as a function of plasma current, reaches a nominal value after the ELM crash, and remains constant until the end of the ELM cycle. The pedestal height just prior to the onset of ELM is shown to increase quadratically with plasma current. The pedestal width Δ is proportional to the square-root of the poloidal Β at the top of the pedestal. Coherent density uctuations strongly increasing at the plasma edge are observed to be maximum after the ELM crash and to decay during the rest of the ELM cycle. Finally, the pedestal parameters evolution during the ELM cycle as well as the scaling with Ip of the pedestal pressure prior to the onset ELM are found to be qualitatively consistent with the peeling ballooning theory.

  20. Investigation of transient melting of tungsten by ELMs in ASDEX Upgrade

    Science.gov (United States)

    Krieger, K.; Sieglin, B.; Balden, M.; Coenen, J. W.; Göths, B.; Laggner, F.; de Marne, P.; Matthews, G. F.; Nille, D.; Rohde, V.; Dejarnac, R.; Faitsch, M.; Giannone, L.; Herrmann, A.; Horacek, J.; Komm, M.; Pitts, R. A.; Ratynskaia, S.; Thoren, E.; Tolias, P.; ASDEX-Upgrade Team; EUROfusion MST1 Team

    2017-12-01

    Repetitive melting of tungsten by power transients originating from edge localized modes (ELMs) has been studied in the tokamak experiment ASDEX Upgrade. Tungsten samples were exposed to H-mode discharges at the outer divertor target plate using the Divertor Manipulator II system. The exposed sample was designed with an elevated sloped surface inclined against the incident magnetic field to increase the projected parallel power flux to a level were transient melting by ELMs would occur. Sample exposure was controlled by moving the outer strike point to the sample location. As extension to previous melt studies in the new experiment both the current flow from the sample to vessel potential and the local surface temperature were measured with sufficient time resolution to resolve individual ELMs. The experiment provided for the first time a direct link of current flow and surface temperature during transient ELM events. This allows to further constrain the MEMOS melt motion code predictions and to improve the validation of its underlying model assumptions. Post exposure ex situ analysis of the retrieved samples confirms the decreased melt motion observed at shallower magnetic field line to surface angles compared to that at leading edges exposed to the parallel power flux.

  1. Differences in the H-mode pedestal width of temperature and density

    Science.gov (United States)

    Schneider, P. A.; Wolfrum, E.; Groebner, R. J.; Osborne, T. H.; Beurskens, M. N. A.; Dunne, M. G.; Ferron, J. R.; Günter, S.; Kurzan, B.; Lackner, K.; Snyder, P. B.; Zohm, H.; the ASDEX Upgrade Team; the DIII-D Team; EFDA Contributors, JET

    2012-10-01

    A pedestal database was built using data from type-I ELMy H-modes of ASDEX Upgrade, DIII-D and JET. ELM synchronized pedestal data were analysed with the two-line method. The two-line method is a bilinear fit which shows better reproducibility of pedestal parameters than a modified hyperbolic tangent fit. This was tested with simulated and experimental data. The influence of the equilibrium reconstruction on pedestal parameters was investigated with sophisticated reconstructions from CLISTE and EFIT including edge kinetic profiles. No systematic deviation between the codes could be observed. The flux coordinate system is influenced by machine size, poloidal field and plasma shape. This will change the representation of the width in different coordinates, in particular, the two normalized coordinates ΨN and r/a show a very different dependence on the plasma shape. The scalings derived for the pedestal width, Δ, of all machines suggest a different scaling for the electron temperature and the electron density. Both cases show similar dependence with machine size, poloidal magnetic field and pedestal electron temperature and density. The influence of ion temperature and toroidal magnetic field is different on each of \\Delta_{T_\\rme} and \\Delta_{n_\\rme} . In dimensionless form the density pedestal width in ΨN scales with \\rho^{0.6}_{i\\star} , the temperature pedestal width with \\beta_p,ped^{0.5} . Both widths also show a strong correlation with the plasma shape. The shape dependence originates from the coordinate transformation and is not visible in real space. The presented scalings predict that in ITER the temperature pedestal will be appreciably wider than the density pedestal.

  2. Fluctuations during JET discharges with H-mode

    Energy Technology Data Exchange (ETDEWEB)

    Malacarne, M.; Cripwell, P.; Duperrex, P.A.; Edwards, A.W.; Gill, R.D.; Granetz, R.S.; Simonet, F.; Snipes, J.; Weller, A.

    1987-12-01

    The appearance and disappearance of H-mode behaviour in JET Tokamak discharges is associated with characteristic instabilities detected by edge magnetic probes, arrays of soft X-ray diodes and reflectometry: edge disruptive-like modes are observed before L-H transitions whereas H-L transitions are accompanied by large bursts of broad-band activity. Other observed fluctuations, shown to be resonant in the central region of the discharge, are not affected by the transitions. The importance of edge fluctuations and induced transport of a magnetic separatrix configuration is thus emphasised.

  3. Genotype x environment interaction and growth stability of several elm clones resistant to Dutch elm disease

    Science.gov (United States)

    Alberto Santini; Francesco Pecori; Alessia L. Pepori; Luisa Ghelardini

    2012-01-01

    The elm breeding program carried out in Italy at the Institute of Plant Protection - Consiglio Nazionale delle Ricercje (CNR) during the last 40 years aimed to develop Dutch elm disease (DED)-resistant elm selections specific to the Mediterranean environment. The need for genotypes adapted to Mediterranean conditions was evident from the poor performance of the Dutch...

  4. Response of smaller European elm bark beetles to pruning wounds on American elm

    Science.gov (United States)

    Jack H. Barger; William N. Cannon

    1987-01-01

    From 1982 to 1984, inflight smaller European elm bark beetles, Scolytus multistriatus, were captured on American elms, Ulmus americana, that were therapeutically pruned for Dutch elm disease control. Pruning wounds were treated with wound dressing or left untreated to determine effects of the treatments on beetle attraction....

  5. Crossbar H-mode drift-tube linac design with alternative phase focusing for muon linac

    Science.gov (United States)

    Otani, M.; Futatsukawa, K.; Hasegawa, K.; Kitamura, R.; Kondo, Y.; Kurennoy, S.

    2017-07-01

    We have developed a Crossbar H-mode (CH) drift-tube linac (DTL) design with an alternative phase focusing (APF) scheme for a muon linac, in order to measure the anomalous magnetic moment and electric dipole moment (EDM) of muons at the Japan Proton Accelerator Research Complex (J-PARC). The CH-DTL accelerates muons from β = v/c = 0.08 to 0.28 at an operational frequency of 324 MHz. The design and results are described in this paper.

  6. Full-f Neoclassical Simulations toward a Predictive Model for H-mode Pedestal Ion Energy, Particle and Momentum Transport

    Energy Technology Data Exchange (ETDEWEB)

    Battaglia, D. J. [PPPL; Boedo, J. A. [University of California San Diego; Burrell, K. H. [General Atomics; Chang, C. S. [PPPL; Canik, J. M. [ORNL; deGrassie, J. S. [General Atomics; Gerhardt, S. P. [PPPL; Grierson, B. A. [General Atomics; Groebner, R. J. [General Atomics; Maingi, Rajesh [PPPL; Smith, S. P. [General Atomics

    2014-09-01

    Energy and particle transport rates are decoupled in the H-mode edge since the ion thermal transport rate is primarily set by the neoclassical transport of the deuterium ions in the tail of the thermal energy distribution, while the net particle transport rate is set by anomalous transport of the colder bulk ions. Ion orbit loss drives the energy distributions away from Maxwellian, and describes the anisotropy, poloidal asymmetry and local minimum near the separatrix observed in the Ti profile. Non-Maxwellian distributions also drive large intrinsic edge flows, and the interaction of turbulence at the top of the pedestal with the intrinsic edge flow can generate an intrinsic core torque. The primary driver of the radial electric field (Er) in the pedestal and scrapeoff layer (SOL) are kinetic neoclassical effects, such as ion orbit loss of tail ions and parallel electron loss to the divertor. This paper describes the first multi-species kinetic neoclassical transport calculations for ELM-free H-mode pedestal and scrape-off layer on DIII-D using XGC0, a 5D full-f particle-in-cell drift-kinetic solver with self-consistent neutral recycling and sheath potentials. Quantitative agreement between the flux-driven simulation and the experimental electron density, impurity density and orthogonal measurements of impurity temperature and flow profiles is achieved by adding random-walk particle diffusion to the guiding-center drift motion. This interpretative technique quantifies the role of neoclassical, anomalous and neutral transport to the overall pedestal structure, and consequently illustrates the importance of including kinetic effects self-consistently in transport calculations around transport barriers.

  7. Material Surface Damage under High Pulse Loads Typical for ELM Bursts and Disruptions in ITER

    Science.gov (United States)

    Landman, I. S.; Pestchanyi, S. E.; Safronov, V. M.; Bazylev, B. N.; Garkusha, I. E.

    The divertor armour material for the tokamak ITER will probably be carbon manufactured as fibre composites (CFC) and tungsten as either brush-like structures or thin plates. Disruptive pulse loads where the heat deposition Q may reach 102 MJ/m 2 on a time scale Ïä of 3 ms, or operation in the ELMy H-mode at repetitive loads with Q âe 1/4 3 MJ/m2 and Ïä âe 1/4 0.3 ms, deteriorate armour performance. This work surveys recent numerical and experimental investigations of erosion mechanisms at these off-normal regimes carried out at FZK, TRINITI, and IPP-Kharkov. The modelling uses the anisotropic thermomechanics code PEGASUS-3D for the simulation of CFC brittle destruction, the surface melt motion code MEMOS-1.5D for tungsten targets, and the radiation-magnetohydrodynamics code FOREV-2D for calculating the plasma impact and simulating the heat loads for the ITER regime. Experiments aimed at validating these codes are being carried out at the plasma gun facilities MK-200UG, QSPA-T, and QSPA-Kh50 which produce powerful streams of hydrogen plasma with Q = 10–30 MJ/m2 and Ïä = 0.03–0.5 ms. Essential results are, for CFC targets, the experiments at high heat loads and the development of a local overheating model incorporated in PEGASUS-3D, and for the tungsten targets the analysis of evaporation- and melt motion erosion on the base of MEMOS-1.5D calculations for repetitive ELMs.

  8. Electrical testing and performance evaluation of 1:1 prototype JET ELM control coils

    Energy Technology Data Exchange (ETDEWEB)

    Kanabar, Deven, E-mail: deven@ipr.res.in; Roy, Swati; Ghate, Mahesh; Raj, Piyush; Kundu, Ananya; Kumar, Nitish; Bhavsar, Dhaval; Panchal, Arun; Pradhan, Subrata, E-mail: pradhan@ipr.res.in

    2016-12-15

    Highlights: • An appropriate 1:1 prototype Small and Large ELM coils for JET have been successfully manufactured using indigenous technologies. • ELM coils have been tested extensively to verify and validated their performance with respect to operational requirement of JET. • The test results confirm and validate the electrical performance of ELM coils. - Abstract: Magnet Technology Development Division at Institute for Plasma research is engaged in extensive R & D for appropriate technologies towards manufacturing of Edge Localized Mode (ELM) magnets for Large Tokamak such as Joint European Torus (JET) as well as for Steady State Superconducting Tokamak (SST-1). Under this project, manufacturing of 1:1 prototype of Large and Small JET ELM control coils (CC) is completed incorporating indigenously developed manufacturing and insulation technologies. Performance evaluation of both the types of coil has been completed for its current carrying capability and insulation resistance as required by various operational scenarios of JET. Experimental setups, test procedures and measurements for electrical characterization of both type of ELM control coil has been discussed in this paper.

  9. Predictions of H-mode performance in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Budny, R. V.; Andre, R.; Bateman, G.; Halpern, F.; Kessel, C. E.; Kritz, A.; McCune, D.

    2008-03-03

    Time-dependent integrated predictive modeling is carried out using the PTRANSP code to predict fusion power and parameters such as alpha particle density and pressure in ITER H-mode plasmas. Auxiliary heating by negative ion neutral beam injection and ion cyclotron heating of He3 minority ions are modeled, and the GLF23 transport model is used in the prediction of the evolution of plasma temperature profiles. Effects of beam steering, beam torque, plasma rotation, beam current drive, pedestal temperatures, sawtooth oscillations, magnetic diffusion, and accumulation of He ash are treated self-consistently. Variations in assumptions associated with physics uncertainties for standard base-line DT H-mode plasmas (with Ip=15 MA, BTF=5.3 T, and Greenwald fraction=0.86) lead to a range of predictions for DT fusion power PDT and quasi-steady state fusion QDT (≡ PDT/Paux). Typical predictions assuming Paux = 50-53 MW yield PDT = 250- 720 MW and QDT = 5 - 14. In some cases where Paux is ramped down or shut off after initial flat-top conditions, quasi-steady QDT can be considerably higher, even infinite. Adverse physics assumptions such as existence of an inward pinch of the helium ash and an ash recycling coefficient approaching unity lead to very low values for PDT. Alternative scenarios with different heating and reduced performance regimes are also considered including plasmas with only H or D isotopes, DT plasmas with toroidal field reduced 10 or 20%, and discharges with reduced beam voltage. In full-performance D-only discharges, tritium burn-up is predicted to generate central tritium densities up to 1016/m3 and DT neutron rates up to 5×1016/s, compared with the DD neutron rates of 6×1017/s. Predictions with the toroidal field reduced 10 or 20% below the planned 5.3 T and keeping the same q98, Greenwald fraction, and Βη indicate that the fusion yield PDT and QDT will be lower by about a factor of two (scaling as B3.5).

  10. The H-mode power threshold in JET

    Energy Technology Data Exchange (ETDEWEB)

    Start, D.F.H.; Bhatnagar, V.P.; Campbell, D.J.; Cordey, J.G.; Esch, H.P.L. de; Gormezano, C.; Hawkes, N.; Horton, L.; Jones, T.T.C.; Lomas, P.J.; Lowry, C.; Righi, E.; Rimini, F.G.; Saibene, G.; Sartori, R.; Sips, G.; Stork, D.; Thomas, P.; Thomsen, K.; Tubbing, B.J.D.; Von Hellermann, M.; Ward, D.J. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

    1994-07-01

    New H-mode threshold data over a range of toroidal field and density values have been obtained from the present campaign. The scaling with n{sub e} B{sub t} is almost identical with that of the 91/92 period for the same discharge conditions. The scaling with toroidal field alone gives somewhat higher thresholds than the older data. The 1991/2 database shows a scaling of P{sub th} (power threshold) with n{sub e} B{sub t} which is approximately linear and agrees well with that observed on other tokamaks. For NBI and carbon target tiles the threshold power is a factor of two higher with the ion {Nu}B drift away from the target compared with the value found with the drift towards the target. The combination of ICRH and beryllium tiles appears to be beneficial for reducing P{sub th}. The power threshold is largely insensitive to plasma current, X-point height and distance between the last closed flux surface and the limiter, at least for values greater than 2 cm. (authors). 3 refs., 6 figs.

  11. PREFACE: 11th IAEA Technical Meeting on H-mode Physics and Transport Barriers

    Science.gov (United States)

    Takizuka, Tomonori

    2008-07-01

    This volume of Journal of Physics: Conference Series contains papers based on invited talks and contributed posters presented at the 11th IAEA Technical Meeting on H-mode Physics and Transport Barriers. This meeting was held at the Tsukuba International Congress Center in Tsukuba, Japan, on 26-28 September 2007, and was organized jointly by the Japan Atomic Energy Agency and the University of Tsukuba. The previous ten meetings in this series were held in San Diego (USA) 1987, Gut Ising (Germany) 1989, Abingdon (UK) 1991, Naka (Japan) 1993, Princeton (USA) 1995, Kloster Seeon (Germany) 1997, Oxford (UK) 1999, Toki (Japan) 2001, San Diego (USA) 2003, and St Petersburg (Russia) 2005. The purpose of the eleventh meeting was to present and discuss new results on H-mode (edge transport barrier, ETB) and internal transport barrier, ITB, experiments, theory and modeling in magnetic fusion research. It was expected that contributions give new and improved insights into the physics mechanisms behind high confinement modes of H-mode and ITBs. Ultimately, this research should lead to improved projections for ITER. As has been the tradition at the recent meetings of this series, the program was subdivided into six topics. The topics selected for the eleventh meeting were: H-mode transition and the pedestal-width Dynamics in ETB: ELM threshold, non-linear evolution and suppression, etc Transport relations of various quantities including turbulence in plasmas with ITB: rotation physics is especially highlighted Transport barriers in non-axisymmetric magnetic fields Theory and simulation on transport barriers Projections of transport barrier physics to ITER For each topic there was an invited talk presenting an overview of the topic, based on contributions to the meeting and on recently published external results. The six invited talks were: A Leonard (GA, USA): Progress in characterization of the H-mode pedestal and L-H transition N Oyama (JAEA, Japan): Progress and issues in

  12. Non-linear MHD simulations of pellet triggered ELM for ITER plasma scenarios

    Science.gov (United States)

    Futatani, Shimpei; Huijsmans, Guido; Loarte, Alberto; Mantsinen, Mervi; Pamela, Stanislas; Garzotti, Luca

    2017-10-01

    The non-linear MHD simulations with the JOREK code have been performed to study the dependence of the pellet size required to trigger an ELM in ITER plasma, and also the dependency of the threshold on the pedestal plasma pressure when the pellet is injected. Based on the observation that the pedestal pressure leading to spontaneous ELM triggering is 150 kPa by JOREK simulation, pedestal pressure of 75 kPa and 112.5 kPa have been studied. The JOREK simulation results show that it is necessary to increase the pellet size by a factor of 1.5 of the number of particles in the pellet to trigger ELMs for a pedestal pressure of 75 kPa compared to 112.5 kPa in ITER 15MA/5.3T plasma. In these simulations it has also been found that the magnitude of the ELM energy loss is strongly correlated with the pedestal plasma pressure rather than with the size of the pellet that is required for triggering. The JOREK simulation shows the toroidally asymmetric profile of the heat flux on the outer divertor target due to the pellet triggered ELM which is consistent with the experiment observation of JET. The work contributes the estimation of the requirement of the pellet injection condition to control ELMs in ITER 15MA operation scenarios. The views and opinions expressed herein do not necessarily reflect either those of the European Commission or those of the ITER Organization.

  13. The Calibration of High-Speed Camera Imaging System for ELMs Observation on EAST Tokamak

    Science.gov (United States)

    Fu, Chao; Zhong, Fangchuan; Hu, Liqun; Yang, Jianhua; Yang, Zhendong; Gan, Kaifu; Zhang, Bin; East Team

    2016-09-01

    A tangential fast visible camera has been set up in EAST tokamak for the study of edge MHD instabilities such as ELM. To determine the 3-D information from CCD images, Tsai's two-stage technique was utilized to calibrate the high-speed camera imaging system for ELM study. By applying tiles of the passive stabilizers in the tokamak device as the calibration pattern, transformation parameters for transforming from a 3-D world coordinate system to a 2-D image coordinate system were obtained, including the rotation matrix, the translation vector, the focal length and the lens distortion. The calibration errors were estimated and the results indicate the reliability of the method used for the camera imaging system. Through the calibration, some information about ELM filaments, such as positions and velocities were obtained from images of H-mode CCD videos. supported by National Natural Science Foundation of China (No. 11275047), the National Magnetic Confinement Fusion Science Program of China (No. 2013GB102000)

  14. Low Dimensional L-H-ELM Dynamical Model for Ion Temperature Gradient Driven Turbulence

    Science.gov (United States)

    Horton, W.; Hu, G.

    1996-11-01

    The role of self-generated shear flow in pressure gradient driven turbulence is widely reported in simulations, and also manifest itself in toroidal confinement experiments in the L mode, H mode and ELM mode transitions universaly seen at higher auxiliary heating power levels. We present a new d=11 dimensional nonlinear dynamics model derived from the well known two-component FLR fluid equations for the torodial ion temperature gradient (ITG) driven turbulence(W. Horton, D. I. Choi and W. M. Tang, Phys. Fluids 24),1077(1981).. The L mode corresponds to the Lorenz manifold which has d=5 and for which exact solutions are given. The bifurcation for the onset of sheared flows is reported and an example shows a 30% drop in the turbulent thermal flux. As the auxiliary heating power is increased, the steady tilted-cell convection with shear flows is destablized to the ELM-like oscillations. In contrast to the resistive-g mode(W. Horton, G. Hu and G. Laval, Phys. Plasmas 3), (1996)., the ITG model has a well defined finite amplitude oscillation (pump depletion) in the dissipationless limit due to the nonlinear frequency shifts and the linear wave dispersion. We ask the question as to whether there is a closure scheme for reducing the system to yield a thermodynamic model involving the physical energy components as is usually assumed in L-H- ELM modeling.

  15. Application of the H-Mode, a Design and Interaction Concept for Highly Automated Vehicles, to Aircraft

    Science.gov (United States)

    Goodrich, Kenneth H.; Flemisch, Frank O.; Schutte, Paul C.; Williams, Ralph A.

    2006-01-01

    Driven by increased safety, efficiency, and airspace capacity, automation is playing an increasing role in aircraft operations. As aircraft become increasingly able to autonomously respond to a range of situations with performance surpassing human operators, we are compelled to look for new methods that help us understand their use and guide their design using new forms of automation and interaction. We propose a novel design metaphor to aid the conceptualization, design, and operation of highly-automated aircraft. Design metaphors transfer meaning from common experiences to less familiar applications or functions. A notable example is the "Desktop metaphor" for manipulating files on a computer. This paper describes a metaphor for highly automated vehicles known as the H-metaphor and a specific embodiment of the metaphor known as the H-mode as applied to aircraft. The fundamentals of the H-metaphor are reviewed followed by an overview of an exploratory usability study investigating human-automation interaction issues for a simple H-mode implementation. The envisioned application of the H-mode concept to aircraft is then described as are two planned evaluations.

  16. Generation of American elm trees with tolerance to Dutch elm disease through controlled crosses and selection

    Science.gov (United States)

    James M. Slavicek; Kathleen S. Knight

    2012-01-01

    The goal of our research and development efforts is to generate new and/or improved selections of the American elm (Ulmus americana L.) with tolerance/resistance to Dutch elm disease (DED). The approaches we are taking for this effort include: 1) controlled breeding using known DED -tolerant selections, 2) controlled breeding using DED-tolerant...

  17. American elm clones of importance in Dutch elm disease tolerance studies

    Science.gov (United States)

    Linda M. Haugen; Susan E. Bentz

    2017-01-01

    We present the background and characteristics of American elm clones that are commercially available or of interest in research on Dutch elm disease (DED) tolerance in the United States. The characteristics of interest include origin, ploidy level, whether available in nursery trade, evidence of DED tolerance, and other comments. The list includes 10 named commercially...

  18. Integrated core–SOL–divertor modelling for ITER including impurity: effect of tungsten on fusion performance in H-mode and hybrid scenario

    NARCIS (Netherlands)

    Zagorski, R.; Voitsekhovitch, I.; Ivanova-Stanik, I.; Kochl, F.; Belo, da Silva Ares; Fable, E.; Garcia, J.; Garzotti, L.; Hobirk, J.; Hogeweij, G. M. D.; Joffrin, E.; Litaudon, X.; Polevoi, A. R.; Telesca, G.; JET Contributors,

    2015-01-01

    The compatibility of two operational constraints—operation above the L–H power threshold and at low power to divertor—is examined for ITER long pulse H-mode and hybrid scenarios in integrated core–scrape off layer (SOL)–divertor modelling including impurities (intrinsic Be, He, W and seeded Ne). The

  19. Comparison of hybrid and baseline ELMy H-mode confinement in JET with the carbon wall

    NARCIS (Netherlands)

    Beurskens, M. N. A.; Frassinetti, L.; Challis, C.; Osborne, T.; Snyder, P. B.; Alper, B.; Angioni, C.; Bourdelle, C.; Buratti, P.; Crisanti, F.; Giovannozzi, E.; Giroud, C.; Groebner, R.; Hobirk, J.; Jenkins, I.; Joffrin, E.; Leyland, M. J.; Lomas, P.; Mantica, P.; McDonald, D.; Nunes, I.; Rimini, F.; Saarelma, S.; Voitsekhovitch, I.; P. de Vries,; Zarzoso, D.

    2013-01-01

    The confinement in JET baseline type I ELMy H-mode plasmas is compared to that in so-called hybrid H-modes in a database study of 112 plasmas in JET with the carbon fibre composite (CFC) wall. The baseline plasmas typically have beta(Nu) similar to 1.5-2, H-98 similar to 1, whereas the hybrid

  20. Measurements of the edge current evolution and comparison with neoclassical calculations during MAST H-modes using motional Stark effect

    NARCIS (Netherlands)

    de Bock, M. F. M.; Citrin, J.; Saarelma, S.; Temple, D.; Conway, N. J.; Kirk, A.; Meyer, H.; Michael, C. A.

    2012-01-01

    Edge localized modes (ELMs), that are present in most tokamak H-(high confinement) modes, can cause significant damage to plasma facing components in fusion reactors. Controlling ELMs is considered necessary and hence it is vital to understand the underlying physics. The stability of ELMs is

  1. Establishment and characterization of American elm cell suspension cultures

    Science.gov (United States)

    Steven M. Eshita; Joseph C. Kamalay; Vicki M. Gingas; Daniel A. Yaussy

    2000-01-01

    Cell suspension cultures of Dutch elm disease (DED)-tolerant and DED-susceptible American elms clones have been established and characterized as prerequisites for contrasts of cellular responses to pathogen-derived elicitors. Characteristics of cultured elm cell growth were monitored by A700 and media conductivity. Combined cell growth data for all experiments within a...

  2. The banded elm bark beetle: A new threat to elms in North America

    Science.gov (United States)

    Jose F. Negron; Jeffrey J. Witcosky; Robert J. Cain; James R. LaBonte; Donald A. Duerr; Sally J. McElwey; Jana C. Lee; Steven J. Seybold

    2005-01-01

    An exotic bark beetle from Asia, the banded elm bark beetle, Scolytus schevyrewi, has been discovered in 21 states of the United States. Although its point of entry is not known, a survey of museum specimens suggests that it has been in the US for at least 10 years. It is most abundant in western states, attacks primarily American and Siberian elms, and carries spores...

  3. Simulations with current constraints of ELM-induced tungsten melt motion in ASDEX Upgrade

    Science.gov (United States)

    Thorén, E.; Bazylev, B.; Ratynskaia, S.; Tolias, P.; Krieger, K.; Pitts, R. A.; Pestchanyi, S.; Komm, M.; Sieglin, B.; the EUROfusion MST1 Team; the ASDEX Upgrade Team

    2017-12-01

    Melt motion simulations of recent ASDEX Upgrade experiments on transient-induced melting of a tungsten leading edge during ELMing H-mode are performed with the incompressible fluid dynamics code MEMOS 3D. The total current flowing through the sample was measured in these experiments providing an important constraint for the simulations since thermionic emission is considered to be responsible for the replacement current driving melt motion. To allow for a reliable comparison, the description of the space-charge limited regime of thermionic emission has been updated in the code. The effect of non-periodic aspects of the spatio-temporal heat flux in the temperature distribution and melt characteristics as well as the importance of current limitation are investigated. The results are compared with measurements of the total current and melt profile.

  4. Dutch elm disease control: performance and costs

    Science.gov (United States)

    William N., Jr. Cannon; David P. Worley

    1976-01-01

    Municipal programs to suppress Dutch elm disease have had highly variable results. Performance as measured by tree mortality was unrelated to control strategies. Costs for control programs were 37 to 76 percent less than costs without control programs in the 15-year time-span of the study. Only those municipalities that conducted a high-performance program could be...

  5. Spatial decoupling of the n = 1 plasma response during n = 2 RMP ELM suppression on DIII-D

    Science.gov (United States)

    King, J. D.; Strait, E. J.; Buttery, R. J.; La Haye, R. J.; Paz-Soldan, C.; Nazikian, R.

    2015-11-01

    Experiments in the DIII-D tokamak show a strong n = 1 mode appears when edge localized modes (ELM) are suppressed via an applied n = 2 resonant magnetic perturbation (RMP). The poloidal structure of this n = 1 mode, as it unlocks from the vacuum vessel wall, is discussed. An n = 2 mode is found to be entrained by the rotating RMP and an estimate of the modes m is presented. Previous work suggests these n = 1, 2 modes are magnetic island structures located at the top of the H-mode pedestal. The width of these islands is estimated to be 2 ~ 3 cm and the calculated confinement degradation due to their presence is 8 ~ 12%, which is close to the 13 ~ 14% measured between the ELMing and RMP suppressed states. This suggests island energy transport may be sufficient to explain the change in peeling-ballooning stability during RMP induced ELM suppression. Work supported by the US Department of Energy under, DE-FC02-04ER54698, DE-AC02-09CH11466.

  6. E- to H-mode Transition in Inductively Coupled Xenon Discharge Lamp

    Science.gov (United States)

    Nazri, Ahmad; Inui, Shuji; Motomura, Hideki; Jinno, Masafumi; Aono, Masaharu

    In this paper the phenomena of mode transition and hysteresis in xenon ICP (Inductively Coupled Plasma) discharge are studied. Xenon has been used as an alternative for mercury since there are environmental issues related to mercury. The transition from E-mode (electrostatic mode) discharge to H-mode (electromagnetic mode) discharge in a xenon cylindrical tube was investigated. RF energy at 13.56 MHz was induced to the tube through matching network. In this study, all the transitions occurred at a certain threshold input power which is a function of the xenon pressure. Hysteresis was observed as the input power was varied from 1 to 100 W. When the input power is increased the discharge starts in E-mode changes into H-mode, whereas when the input power is decreased the H-mode turns into the E-mode or there is a sudden switch-off as the function of the gas pressures. Mode transition is determined by sudden and huge change of luminance. H-mode is characterized by a much higher luminance and plasma density. Luminance and optical emission spectra were recorded. At high pressure more power is required to transform the discharge mode compared to low pressure. Continuum visible emission was obtained only in H-mode. At H-mode, many ionic and atomic spectrum are observed compared to E-mode. With high luminance and continuum visible emission that obtained from H-mode xenon ICP discharge, xenon is one of the most suitable alternatives in developing mercury-free light sources.

  7. Plasma auto-biasing during Ohmic H-mode in the STOR-M tokamak

    Science.gov (United States)

    Zhang, W.; Xiao, C.; Hirose, A.

    1993-03-01

    Application of a short current pulse on a nominal Ohmic discharge in the STOR-M tokamak triggers the Ohmic H-mode characterized by reduced H sub alpha radiation, increased electron density, and reduced edge density/magnetic fluctuations. Measurements of plasma floating potential at the plasma edge and in the scrape-off layer indicate that the Ohmic H-mode is accompanied by negative plasma autobiasing which leads to a steeper radial electric field profile at the edge. Since the duration of the current pulse is shorter than the resistive skin time of about 1 ms, preferential edge heating is expected, which is believed to be responsible for changes in the edge discharge condition favorable for inducing the Ohmic H-mode. The electron density profile becomes steeper at the edge during the H-mode, and clear formation of a density pedestal has been seen. The evolution of the density profile suggests the presence of particle pinch. It is found that the electrostatic modes are dominant in the scrape-off layer while electromagnetic modes dominate in the main plasma. A similar H-mode is induced by external negative electrode biasing.

  8. Plasma autobiasing during Ohmic H-mode in the STOR-M tokamak

    Science.gov (United States)

    Zhang, W.; Xiao, C.; Hirose, A.

    1993-11-01

    Application of a short current pulse on a nominal Ohmic discharge in the STOR-M tokamak (Saskatchewan Torus-Modified) [Phys. Fluids B 4, 3277 (1992)] triggers the Ohmic H-mode characterized by reduced Hα radiation, increased electron density, and reduced edge density/magnetic fluctuations. Measurements of plasma floating potential at the plasma edge and in the scrape-off layer indicate that the Ohmic H-mode is accompanied by negative plasma autobiasing, which leads to a steeper radial electric field profile at the edge. Since the duration of the current pulse (≤20 kA, 100 μsec) is shorter than the resistive skin time (≂1 msec), preferential edge heating is expected, which is believed to be responsible for changes in the edge discharge condition favorable for inducing the Ohmic H-mode. The electron density profile becomes steeper at the edge during the H-mode, and clear formation of a density pedestal has been seen. The evolution of the density profile suggests the presence of particle pinch. An improved confinement phase (ICP) is induced by external negative electrode biasing. The ICP reveals some similarities as compared to the current pulse induced H-mode. It is found that the electrostatic modes are dominant in the scrape-off layer while electromagnetic modes dominate in the plasma edge during the normal Ohmic discharges.

  9. Do mites phoretic on elm bark beetles contribute to the transmission of Dutch elm disease?

    Science.gov (United States)

    Moser, John C; Konrad, Heino; Blomquist, Stacy R; Kirisits, Thomas

    2010-02-01

    Dutch elm disease (DED) is a destructive vascular wilt disease of elm (Ulmus) trees caused by the introduced Ascomycete fungus Ophiostoma novo-ulmi. In Europe, this DED pathogen is transmitted by elm bark beetles in the genus Scolytus. These insects carry phoretic mites to new, suitable habitats. The aim of this study was to record and quantify conidia and ascospores of O. novo-ulmi on phoretic mites on the three elm bark beetle species Scolytus multistriatus, Scolytus pygmaeus, and Scolytus scolytus. Spores of O. novo-ulmi were found on four of the ten mite species phoretic on Scolytus spp. These included Elattoma fraxini, Proctolaelaps scolyti, Pseudotarsonemoides eccoptogasteri, and Tarsonemus crassus. All four species had spores attached externally to their body surfaces. However, T. crassus carried most spores within its sporothecae, two paired pocket-like structures adapted for fungal transmission. Individuals of Pr. scolyti also had O. novo-ulmi conidia and ascospores frequently in their digestive system, where they may remain viable. While E. fraxini and P. eccoptogasteri rarely had spores attached to their bodies, large portions of Pr. scolyti and T. crassus carried significant numbers of conidia and/or ascospores of O. novo-ulmi. P. scolyti and T. crassus, which likely are fungivores, may thus contribute to the transmission of O. novo-ulmi, by increasing the spore loads of individual Scolytus beetles during their maturation feeding on twigs of healthy elm trees, enhancing the chance for successful infection with the pathogen. Only S. scolytus, which is the most efficient vector of O. novo-ulmi in Europe, carried high numbers of Pr. scolyti and T. crassus, in contrast to S. multistriatus and S. pygmaeus, which are known as less efficient vectors. The high efficiency of S. scolytus in spreading Dutch elm disease may be partly due to its association with these two mites and the hyperphoretic spores of O. novo-ulmi they carry.

  10. Do mites phoretic on elm bark beetles contribute to the transmission of Dutch elm disease?

    Science.gov (United States)

    Moser, John C.; Konrad, Heino; Blomquist, Stacy R.; Kirisits, Thomas

    2010-02-01

    Dutch elm disease (DED) is a destructive vascular wilt disease of elm ( Ulmus) trees caused by the introduced Ascomycete fungus Ophiostoma novo-ulmi. In Europe, this DED pathogen is transmitted by elm bark beetles in the genus Scolytus. These insects carry phoretic mites to new, suitable habitats. The aim of this study was to record and quantify conidia and ascospores of O. novo-ulmi on phoretic mites on the three elm bark beetle species Scolytus multistriatus, Scolytus pygmaeus, and Scolytus scolytus. Spores of O. novo-ulmi were found on four of the ten mite species phoretic on Scolytus spp. These included Elattoma fraxini, Proctolaelaps scolyti, Pseudotarsonemoides eccoptogasteri, and Tarsonemus crassus. All four species had spores attached externally to their body surfaces. However, T. crassus carried most spores within its sporothecae, two paired pocket-like structures adapted for fungal transmission. Individuals of Pr. scolyti also had O. novo-ulmi conidia and ascospores frequently in their digestive system, where they may remain viable. While E. fraxini and P. eccoptogasteri rarely had spores attached to their bodies, large portions of Pr. scolyti and T. crassus carried significant numbers of conidia and/or ascospores of O. novo-ulmi. P. scolyti and T. crassus, which likely are fungivores, may thus contribute to the transmission of O. novo-ulmi, by increasing the spore loads of individual Scolytus beetles during their maturation feeding on twigs of healthy elm trees, enhancing the chance for successful infection with the pathogen. Only S. scolytus, which is the most efficient vector of O. novo-ulmi in Europe, carried high numbers of Pr. scolyti and T. crassus, in contrast to S. multistriatus and S. pygmaeus, which are known as less efficient vectors. The high efficiency of S. scolytus in spreading Dutch elm disease may be partly due to its association with these two mites and the hyperphoretic spores of O. novo-ulmi they carry.

  11. New Edge Coherent Mode Providing Continuous Transport in Long Pulse H-mode Plasmas

    DEFF Research Database (Denmark)

    Wang, H.Q.; Xu, G.S.; Wan, B.N.

    2014-01-01

    An electrostatic coherent mode near the electron diamagnetic frequency (20–90 kHz) is observed in the steep-gradient pedestal region of long pulse H-mode plasmas in the Experimental Advanced Super-conducting Tokamak, using a newly developed dual gas-puff-imaging system and diamond-coated reciproc......An electrostatic coherent mode near the electron diamagnetic frequency (20–90 kHz) is observed in the steep-gradient pedestal region of long pulse H-mode plasmas in the Experimental Advanced Super-conducting Tokamak, using a newly developed dual gas-puff-imaging system and diamond......-coated reciprocating probes. The mode propagates in the electron diamagnetic direction in the plasma frame with poloidal wavelength of ∼8 cm. The mode drives a significant outflow of particles and heat as measured directly with the probes, thus greatly facilitating long pulse H-mode sustainment. This mode shows...

  12. Modelling of transitions between L- and H-mode in JET high plasma current plasmas and application to ITER scenarios including tungsten behaviour

    Science.gov (United States)

    Koechl, F.; Loarte, A.; Parail, V.; Belo, P.; Brix, M.; Corrigan, G.; Harting, D.; Koskela, T.; Kukushkin, A. S.; Polevoi, A. R.; Romanelli, M.; Saibene, G.; Sartori, R.; Eich, T.; Contributors, JET

    2017-08-01

    separatrix remains unchanged (or even slightly decreases) following the H-mode transition. JINTRAC modelling of H-mode transitions for the ITER 15 MA / 5.3 T high Q DT scenarios with the same modelling assumptions as those being derived from JET experiments has been carried out. The modelling finds that it is possible to access high Q DT conditions robustly for additional heating power levels of P AUX  ⩾  53 MW by optimising core and edge plasma fuelling in the transition from L-mode to high Q DT H-mode. An initial period of low plasma density, in which the plasma accesses the H-mode regime and the alpha heating power increases, needs to be considered after the start of the additional heating, which is then followed by a slow density ramp. Both the duration of the low density phase and the density ramp-rate depend on boundary and operational conditions and can be optimised to minimise the resistive flux consumption in this transition phase. The modelling also shows that fuelling schemes optimised for a robust access to high Q DT H-mode in ITER are also optimum for the prevention of the contamination of the core plasma by tungsten during this phase.

  13. Two-Dimensional Visualization of Growth and Burst of the Edge-Localized Filaments in KSTAR H-Mode Plasmas

    NARCIS (Netherlands)

    Yun, G. S.; Lee, W.; Choi, M. J.; Lee, J.; Park, H. K.; Tobias, B.; Domier, C.W.; N C Luhmann Jr.,; Donne, A. J. H.; Lee, J. H.

    2011-01-01

    The filamentary nature and dynamics of edge-localized modes (ELMs) in the KSTAR high-confinement mode plasmas have been visualized in 2D via electron cyclotron emission imaging. The ELM filaments rotating with a net poloidal velocity are observed to evolve in three distinctive stages: initial linear

  14. UF-CHERS Measurements of Ion Temperature and Toroidal Rotation Fluctuations Associated with the Edge Harmonic Oscillation in Quiescent H-mode Plasmas

    Science.gov (United States)

    Truong, D. D.; Fonck, R. J.; McKee, G. R.; Yan, Z.; Grierson, B. A.

    2016-10-01

    The UF-CHERS (Ultra Fast CHarge Exchange Recombination Spectroscopy) diagnostic at DIII-D measures local, long-wavelength ion temperature and toroidal velocity fluctuations at turbulence-relevant spatiotemporal scales from emission of the CVI n=8 ->7 transition. During Quiescent H-mode (QH-mode) plasmas, which offer ELM-free improved confinement, UF-CHERS measurements observed coherent, low frequency (fo 10kHz) pedestal oscillations in Ti and vtor at the Edge Harmonic Oscillation (EHO) frequency while several modes between 35-75 kHz are suppressed when the EHO appears. Although broadband ion temperature and density fluctuations were reduced by the EHO, the toroidal rotation showed increased fluctuation amplitude. Investigating ion temperature and toroidal fluctuations associated with the EHO may provide insights into the saturated instability driving the EHO. Supported by DOE Grants DE-FG02-08ER54999, DE-FC02-04ER54698, and NSF GRFP Grant DGE-1256259.

  15. Height preference of Scolytus schevyrewi Semenov, the banded elm bark beetle of American elm, Ulmus americana

    Science.gov (United States)

    S. McElwey; J. F. Negron; J. Withrow

    2007-01-01

    Scolytus schevyrewi Semenov, the banded elm bark beetle, was first detected in North America in April 2003 in Colorado and Utah by the Rapid Detection and Response Pilot Project sponsored by APHIS and USDA Forest Service, Forest Health Protection. It was captured in Lindgren funnel traps baited with a-pinene, ethanol, and the Ips typographus...

  16. Ubiquity of non-diffusive momentum transport in JET H-modes

    NARCIS (Netherlands)

    Weisen, H.; Camenen, Y.; Salmi, A.; Versloot, T. W.; de Vries, P. C.; Maslov, M.; Tala, T.; Beurskens, M.; Giroud, C.; JET-EFDA Contributors,

    2012-01-01

    A broad survey of the experimental database of neutral beam heated baseline H-modes and hybrid scenarios in the JET tokamak has established the ubiquity of non-diffusive momentum transport mechanisms in rotating plasmas. As a result of their presence, the normalized angular frequency gradient R

  17. Momentum transport studies in JET H-mode discharges with an enhanced toroidal field ripple

    NARCIS (Netherlands)

    de Vries, P. C.; Versloot, T. W.; Salmi, A.; Hua, M. D.; Howell, D. H.; Giroud, C.; Parail, V.; Saibene, G.; Tala, T.

    2010-01-01

    In this study, enhancement of the toroidal field (TF) ripple has been used as a tool in order to reveal the impact of the momentum pinch on the rotation profiles in H-mode JET discharges. The analysis showed that flatter rotation profiles were obtained in discharges with a high TF ripple, attributed

  18. American elm (Ulmus americana) in restoration plantings: a review

    Science.gov (United States)

    Kathleen S. Knight; Linda M. Haugen; Cornelia C. Pinchot; Paul G. Schaberg; James M. Slavicek

    2017-01-01

    The development of disease-tolerant American elm (Ulmus americana) trees has led to a need for reintroduction and restoration methods for the species. Here we review the current state of experimental work to inform reintroduction biology and restoration ecology of American elm. Much of this work is ongoing, and within several years the results will...

  19. Extended MHD Effects on RMPs and ELMs

    Science.gov (United States)

    Strauss, H. R.; Park, G.-Y.; Chang, C. S.; Sugiyama, L.; Breslau, J.; Maingi, R.

    2008-11-01

    M3D studies of Resonant Magnetic Perturbations (RMP) in DIII-D equilibria indicate that in the absence of plasma rotation, the vacuum RMP magnetic field penetrates the plasma and causes the magnetic field to be stochastic in a wide layer. Parallel thermal conduction cools the plasma in the stochastic layer. When the plasma rotates toroidally and / or poloidally, with sufficient speed, the RMP penetrates only a thin edge layer. The pressure gradient is reduced in this layer, which can stabilize Edge Localized Modes (ELMs). This resembles the behavior of RMPs when there is high edge collisionality, ν*> 1. There is advection of density at the edge, as well as some density reduction in the plasma core, but not the large density pump out that has been observed at low edge collisionality ν*ballooning modes. Resistive modes can be stabilized by two fluid drifts. The stabilization depends on edge collsionality. It is possible that the RMP cools the edge and increases collisionality, destabilizing the resistive ELMs.

  20. External kink modes as a model for MHD activity associated with ELMs

    Energy Technology Data Exchange (ETDEWEB)

    Manickam, J.

    1992-01-01

    Tokamak plasmas in the high confinement mode of operation are known to exhibit edge localized activity referred to as ELMs. A model is proposed for the underlying cause in terms of the external kink mode. The build up of the current density near the plasma edge is shown to decrease the shear in the safety-factor, q, profile and lead to destabilization of the kink mode. The role of the plasma geometry and equilibrium profiles is discussed.

  1. Scrape-off layer ion temperature measurements at the divertor target during type III and type I ELMs in MAST measured by RFEA

    CERN Document Server

    Elmore, S; Fishpool, G; Kirk, A; Thornton, A J; Walkden, N R; Harrison, J R

    2016-01-01

    In future nuclear fusion reactors high heat load events, such as edge-localised modes (ELMs), can potentially damage divertor materials and release impurities into the main plasma, limiting plasma performance. The most difficult to handle are type I ELMs since they carry the largest fraction of energy from the plasma and therefore deposit the largest heat flux at the target and on first wall materials. Knowing the temperature of the ions released from ELM events is important since it determines the potential sputtering they would cause from plasma facing materials. To make measurements of Ti by retarding field energy analyser (RFEA) during type I ELMs a new operational technique has been used to allow faster measurements to be made; this is called the fast swept technique (FST).

  2. Impact of perturbative, non-axisymmetric impurity fueling on Alcator C-Mod H-modes

    Science.gov (United States)

    Reinke, M. L.; Lore, J. D.; Terry, J.; Brunner, D.; LaBombard, B.; Lipschultz, B.; Hubbard, A.; Hughes, J. W.; Mumgaard, R.; Pitts, R. A.

    2017-12-01

    Experiments on Alcator C-Mod have been performed to investigate the impact of toroidally localized impurity injection on H-mode exhaust scenarios. Results help to inform sub-divertor gas injector designs, in particular that of the ITER machine, for which this work was primarily undertaken. In repeated EDA H-modes, the amount of N2 injected into the private flux region was scanned up to levels which strongly impacted normalized energy confinement, H98, and led to an H/L back-transition. Repeated scans increased the toroidal peaking of the gas injection, reducing from five equally spaced locations to a single toroidal and poloidal injector. Results show the impact on the pedestal and core plasma is similar between all cases as long as the total gas injection rate is held constant. An influence on toroidally localized impurity spectroscopy is shown, demonstrating a complication in using such data in interpreting experiments and supporting boundary modeling in cases where there are localized extrinsic or intrinsic impurity sources. These results, along with prior work in this area on Alcator C-Mod, form a comprehensive set of L-mode and H-mode data to be used for validation of 3D boundary physics codes.

  3. An ELM-Based Approach for Estimating Train Dwell Time in Urban Rail Traffic

    Directory of Open Access Journals (Sweden)

    Wen-jun Chu

    2015-01-01

    Full Text Available Dwell time estimation plays an important role in the operation of urban rail system. On this specific problem, a range of models based on either polynomial regression or microsimulation have been proposed. However, the generalization performance of polynomial regression models is limited and the accuracy of existing microsimulation models is unstable. In this paper, a new dwell time estimation model based on extreme learning machine (ELM is proposed. The underlying factors that may affect urban rail dwell time are analyzed first. Then, the relationships among different factors are extracted and modeled by ELM neural networks, on basis of which an overall estimation model is proposed. At last, a set of observed data from Beijing subway is used to illustrate the proposed method and verify its overall performance.

  4. Ex situ conservation of genetic resources of field elm (Ulmus minor Mill and European white elm (Ulmus laevis Pall

    Directory of Open Access Journals (Sweden)

    Aleksić Jelena

    2004-01-01

    Full Text Available Principles of the conservation of genetic resources of elms (Ulmus spp do not differ fundamentally from the general principles accepted for the conservation of genetic resources of other common Noble Hardwoods. Efficient conservation can best be achieved through appropriate combination of in situ and ex situ methods, which have distinct advantages. Besides that, ex situ conservation is employed when emergency measures are needed for rare endangered populations and when populations are too small to be managed in situ (e.g. risks of genetic drift and inbreeding. The aim of our research is ex situ conservation of genetic resources of field elm {Ulmus minor Mill and European white elm (Ulmus laevis Pall through establishment of field genebanks. Sampling was conducted in one population of field elm and one population of white elm. Plant material (buds from 8 trees of field elm and 10 trees of white elm was used for in vitro production of clones. Obtained clones will be used for establishment of field genebanks on the experimental estate of the Institute of Lowland Forestry and Environment.

  5. Studies of the pedestal structure and inter-ELM pedestal evolution in JET with the ITER-like wall

    Science.gov (United States)

    Maggi, C. F.; Frassinetti, L.; Horvath, L.; Lunniss, A.; Saarelma, S.; Wilson, H.; Flanagan, J.; Leyland, M.; Lupelli, I.; Pamela, S.; Urano, H.; Garzotti, L.; Lerche, E.; Nunes, I.; Rimini, F.; Contributors, JET

    2017-11-01

    The pedestal structure of type I ELMy H-modes has been analysed for JET with the ITER-like Wall (JET-ILW). The electron pressure pedestal width is independent of ρ * and increases proportionally to  √β pol,PED. Additional broadening of the width is observed, at constant β pol, PED, with increasing ν * and/or neutral gas injection and the contribution of atomic physics effects in setting the pedestal width cannot as yet be ruled out. Neutral penetration alone does not determine the shape of the edge density profile in JET-ILW. The ratio of electron density to electron temperature scale lengths in the edge transport barrier region, η e, is of order 2-3 within experimental uncertainties. Existing understanding, represented in the stationary linear peeling-ballooning mode stability and the EPED pedestal structure models, is extended to the dynamic evolution between ELM crashes in JET-ILW, in order to test the assumptions underlying these two models. The inter-ELM temporal evolution of the pedestal structure in JET-ILW is not unique, but depends on discharge conditions, such as heating power and gas injection levels. The strong reduction in p e,PED with increasing D 2 gas injection at high power is primarily due to clamping of \

  6. Impact of impurity seeding and divertor conditions on transitions, pedestal structure and ELMs

    Science.gov (United States)

    Dunne, M. G.

    2017-02-01

    Future devices will require a high scrape-off later (SOL) density and impurity seeding to avoid high-Z sputtering. However, these operational parameters are not included in present-day scaling laws, making extrapolations to larger devices difficult. As such, understanding the physics of such effects is vital in order to design the operational scenarios most favorable to high fusion gain. This review presents the favorable lowering of L-H transition power by changing to metal walled devices and sumarises the effects currently thought to be responsible for how SOL geometry can play a role in determining this threshold. Experimental observations on changes to the pedestal structure with main ion fuelling and low-, medium-, and high-Z impurity seeding are presented. These results, from several devices, show that main ion fuelling or high density operation can result in a lower pedestal top pressure, and hence reduced stored energy, while impurity seeding can recover this lost pressure. Particular focus is given to nitrogen seeded discharges and the recovery of pedestal parameters (notably high {{T}\\text{e,\\text{ped}}} ) in JET and AUG since the changeover to metal walls in these devices. Lithium seeding is also emerging as a strong actuator in pedestal dynamics, with results ranging from a prolonged inter-ELM period to completely ELM-free scenarios on different devices. ELM dynamics are also presented in each section, with nitrogen seeding offering a probe into the structure of the ELM and demonstrating the difference between the initial ELM crash, likely due to a sharp MHD event, and a prolonged second phase, the origin of which remains unkown. Finally, modelling of the pedestal in impurity seeded scenarios reveals a common effect in the position of the density profile. Either through mode excitation near to the separatrix or an altered fuelling profile, seeding of impurities results in an inward shift of the density profile. This inward shift improves MHD stability

  7. Operations Charioteer, Musketeer, Touchstone, Cornerstone, Aqueduct, Sculpin and Julin. Tests Mill Yard, Diamond Beech, Mighty Oak, Middle Note Mission Ghost, Mission Cyber, Misty Echo, Disko Elm, Mineral Quarry, Distant Zenith, Diamond Fortune, and Hunters Trophy

    National Research Council Canada - National Science Library

    Schoengold, Carole

    1999-01-01

    This report is a personnel-oriented history of DoD participation in underground nuclear weapons testing up to and during Operations Charioteer, Musketeer, Touchstone, Cornerstone, Aqueduct, Sculpin, and Julin...

  8. e-Learning Management System (eLMS) -

    Data.gov (United States)

    Department of Transportation — DOT's electronic Learning Management System (eLMS) is a state-of-the-art web-based system that meets the needs of training administrators, learners, and managers and...

  9. Pheromone Chemistry of the Smaller European Elm Bark Beetle.

    Science.gov (United States)

    Beck, Keith

    1978-01-01

    Discusses the aggregation pheromone of the smaller European elm bark beetle, Scolytus multistriatus (Marsham), with emphasis on information that could be used in the classroom as a practical application of organic chemistry. (Author/GA)

  10. Long-term time series prediction using OP-ELM.

    Science.gov (United States)

    Grigorievskiy, Alexander; Miche, Yoan; Ventelä, Anne-Mari; Séverin, Eric; Lendasse, Amaury

    2014-03-01

    In this paper, an Optimally Pruned Extreme Learning Machine (OP-ELM) is applied to the problem of long-term time series prediction. Three known strategies for the long-term time series prediction i.e. Recursive, Direct and DirRec are considered in combination with OP-ELM and compared with a baseline linear least squares model and Least-Squares Support Vector Machines (LS-SVM). Among these three strategies DirRec is the most time consuming and its usage with nonlinear models like LS-SVM, where several hyperparameters need to be adjusted, leads to relatively heavy computations. It is shown that OP-ELM, being also a nonlinear model, allows reasonable computational time for the DirRec strategy. In all our experiments, except one, OP-ELM with DirRec strategy outperforms the linear model with any strategy. In contrast to the proposed algorithm, LS-SVM behaves unstably without variable selection. It is also shown that there is no superior strategy for OP-ELM: any of three can be the best. In addition, the prediction accuracy of an ensemble of OP-ELM is studied and it is shown that averaging predictions of the ensemble can improve the accuracy (Mean Square Error) dramatically. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Deep Network Based on Stacked Orthogonal Convex Incremental ELM Autoencoders

    Directory of Open Access Journals (Sweden)

    Chao Wang

    2016-01-01

    Full Text Available Extreme learning machine (ELM as an emerging technology has recently attracted many researchers’ interest due to its fast learning speed and state-of-the-art generalization ability in the implementation. Meanwhile, the incremental extreme learning machine (I-ELM based on incremental learning algorithm was proposed which outperforms many popular learning algorithms. However, the incremental algorithms with ELM do not recalculate the output weights of all the existing nodes when a new node is added and cannot obtain the least-squares solution of output weight vectors. In this paper, we propose orthogonal convex incremental learning machine (OCI-ELM with Gram-Schmidt orthogonalization method and Barron’s convex optimization learning method to solve the nonconvex optimization problem and least-squares solution problem, and then we give the rigorous proofs in theory. Moreover, in this paper, we propose a deep architecture based on stacked OCI-ELM autoencoders according to stacked generalization philosophy for solving large and complex data problems. The experimental results verified with both UCI datasets and large datasets demonstrate that the deep network based on stacked OCI-ELM autoencoders (DOC-IELM-AEs outperforms the other methods mentioned in the paper with better performance on regression and classification problems.

  12. Pedestal properties of H-modes with negative triangularity using the EPED-CH model

    Science.gov (United States)

    Merle, A.; Sauter, O.; Medvedev, S. Yu

    2017-10-01

    The EPED model has been designed to predict the pedestal height and width from a minimal set of parameters and using the stability of the pedestal region for global MHD peeling-ballooning (P-B) modes as well as local kinetic ballooning modes (KBMs). This approach has been validated for type-I ELMy H-modes and quiescent H-modes (QH) but can also be used for other types of H-modes where it usually sets an upper limit on the achievable pedestal height. Using the recently developed EPED-like model called EPED-CH and based on the equilibrium codes CHEASE and CAXE and the MHD stability code KINX, we investigate in this work the effect of negative triangularity on the pedestal structure. Our simulation results confirm the experimental results from TCV where a reduction of the pedestal height was observed when going from positive to negative top triangularity. This was interpreted as a degradation of the peeling-ballooning stability due to the closed access to the second stability region for ballooning modes in the case of negative triangularity. This effect is further enhanced by the coupling to the KBM stability criterion in EPED simulations. The novel concept of the negative triangularity tokamak (a DEMO-sized machine) is also investigated. Again a strong reduction of the pedestal height and width is observed going from positive to negative triangularity for up-down symmetric equilibria. The pedestal height is also reduced going to more up-down asymmetric cases. The beneficial effect of the global β value on the pedestal height, which is linked to the second stability access, is strongly reduced for negative triangularity.

  13. Novel Feature of H-Mode Induced by CT Injection on STOR-M Tokamak

    Science.gov (United States)

    Sen, S.; Xiao, C.; Hirose, A.

    2000-10-01

    A novel feature of the H-mode induced by compact torus injection on STOR-M tokamak is observed. There is almost no change in the radial electric-field profiles during and after the L-H transition. The usual hypothesis of the E X B shear stabilization mechanism is therefore unlikely to play a role in this transition. A new mechanism of the stabilization of microinstabilities by parallel flow is suggested as the plausible cause for the transition to this improved regime.

  14. Characteristics of EGAMs in EAST tokamak under ICRF H-mode

    Science.gov (United States)

    di Liu, Ah; Zhou, Chu; Zhang, Xiao Hui; Hu, Jian Qiang; Li, Hong; Lan, Tao; Xie, Jing Lin; Yu, Chang Xuan; Liu, Wan Dong

    2012-10-01

    Doppler reflectometer is common plasma diagnostic used in magnetic confinement devices to measure density fluctuations and poloidal flow velocity. Two set of Doppler reflectometer (Q-band & V-band)were installed on EAST tokamak for the first time. A coherence mode with frequency of 20˜50kHz was observed both on Doppler reflectometer and magnetic coils during ICRF H-mode on EAST. It appeared as zero-symmetric peaks in the spectrum of Doppler backscattering phase signal, implying that the density fluctuation has a standing wave structure with frequency not changing with the plasma rotation. The toroidal mode number is zero according to the magnetic coils. This feather was not observed on ECE and soft-X signals and there isn't obvious relationship between the mode appearance and the neutrons and hard-X signals. Unlike the usual Geodesic Acoustic modes (GAM) in the edge plasma under L-mode, it was found that the mode only appeared in the core regime under H-mode through the ray-tracing code. The mode is suspected to be the energetic ion induced GAM.

  15. Divertor heat flux simulations in ELMy H-mode discharges of EAST

    Science.gov (United States)

    Xia, T. Y.; Xu, X. Q.; Wu, Y. B.; Huang, Y. Q.; Wang, L.; Zheng, Z.; Liu, J. B.; Zang, Q.; Li, Y. Y.; Zhao, D.; EAST Team

    2017-11-01

    This paper presents heat flux simulations for the ELMy H-mode on the Experimental Advanced Superconducting Tokamak (EAST) using a six-field two-fluid model in BOUT++. Three EAST ELMy H-mode discharges with different plasma currents I p and geometries are studied. The trend of the scrape-off layer width λq with I p is reproduced by the simulation. The simulated width is only half of that derived from the EAST scaling law, but agrees well with the international multi-machine scaling law. Note that there is no radio-frequency (RF) heating scheme in the simulations, and RF heating can change the boundary topology and increase the flux expansion. Anomalous electron transport is found to contribute to the divertor heat fluxes. A coherent mode is found in the edge region in simulations. The frequency and poloidal wave number kθ are in the range of the edge coherent mode in EAST. The magnetic fluctuations of the mode are smaller than the electric field fluctuations. Statistical analysis of the type of turbulence shows that the turbulence transport type (blobby or turbulent) does not influence the heat flux width scaling. The two-point model differs from the simulation results but the drift-based model shows good agreement with simulations.

  16. ROLE OF NEUTRALS IN CORE FUELING AND PEDESTAL STRUCTURE IN H-MODE DIII-D DISCHARGES

    Energy Technology Data Exchange (ETDEWEB)

    WOLF, NS; PETRIE, TW; PORTER, GD; ROGNLIEN, TD; GROEBNER, RJ; MAKOWSKI, MA

    2002-10-01

    OAK A271 ROLE OF NEUTRALS IN CORE FUELING AND PEDESTAL STRUCTURE IN H-MODE DIII-D DISCHARGES. The 2-D fluid code UEDGE was used to analyze DIII-D experiments to determine the role of neutrals in core fueling, core impurities, and also the H-mode pedestal structure. The authors compared the effects of divertor closure on the fueling rate and impurity density of high-triangularity, H-mode plasmas. UEDGE simulations indicate that the decrease in both deuterium core fueling ({approx} 15%-20%) and core carbon density ({approx} 15%-30%) with the closed divertor compared to the open divertor configuration is due to greater divertor screening of neutrals. They also compared UEDGE results with a simple analytic model of the H-mode pedestal structure. The model predicts both the width and gradient of the transport barrier in n{sub e} as a function of the pedestal density. The more sophisticated UEDGE simulations of H-mode discharges corroborate the simple analytic model, which is consistent with the hypothesis that fueling processes play a role in H-mode transport barrier formation.

  17. ELM: the status of the 2010 eukaryotic linear motif resource.

    Science.gov (United States)

    Gould, Cathryn M; Diella, Francesca; Via, Allegra; Puntervoll, Pål; Gemünd, Christine; Chabanis-Davidson, Sophie; Michael, Sushama; Sayadi, Ahmed; Bryne, Jan Christian; Chica, Claudia; Seiler, Markus; Davey, Norman E; Haslam, Niall; Weatheritt, Robert J; Budd, Aidan; Hughes, Tim; Pas, Jakub; Rychlewski, Leszek; Travé, Gilles; Aasland, Rein; Helmer-Citterich, Manuela; Linding, Rune; Gibson, Toby J

    2010-01-01

    Linear motifs are short segments of multidomain proteins that provide regulatory functions independently of protein tertiary structure. Much of intracellular signalling passes through protein modifications at linear motifs. Many thousands of linear motif instances, most notably phosphorylation sites, have now been reported. Although clearly very abundant, linear motifs are difficult to predict de novo in protein sequences due to the difficulty of obtaining robust statistical assessments. The ELM resource at http://elm.eu.org/ provides an expanding knowledge base, currently covering 146 known motifs, with annotation that includes >1300 experimentally reported instances. ELM is also an exploratory tool for suggesting new candidates of known linear motifs in proteins of interest. Information about protein domains, protein structure and native disorder, cellular and taxonomic contexts is used to reduce or deprecate false positive matches. Results are graphically displayed in a 'Bar Code' format, which also displays known instances from homologous proteins through a novel 'Instance Mapper' protocol based on PHI-BLAST. ELM server output provides links to the ELM annotation as well as to a number of remote resources. Using the links, researchers can explore the motifs, proteins, complex structures and associated literature to evaluate whether candidate motifs might be worth experimental investigation.

  18. One-dimensional modelling of limit-cycle oscillation and H-mode power scaling

    DEFF Research Database (Denmark)

    Wu, Xingquan; Xu, Guosheng; Wan, Baonian

    2015-01-01

    To understand the connection between the dynamics of microscopic turbulence and the macroscale power scaling in the L-I-H transition in magnetically confined plasmas, a new time-dependent, one-dimensional (in radius) model has been developed. The model investigates the radial force balance equation...... at the edge region of the plasma and applies the quenching effect of turbulence via the E x B flow shear rate exceeding the shear suppression threshold. By slightly ramping up the heating power, the spatio-temporal evolution of turbulence intensity, density and pressure profiles, poloidal flow and E x B flow...... and the turbulence intensity depending on which oscillation of the diamagnetic flow or poloidal flow is dominant. Specifically, by including the effects of boundary conditions of density and temperature, the model results in a linear dependence of the H-mode access power on the density and magnetic field...

  19. ELM-KNN for photometric redshift estimation of quasars

    Science.gov (United States)

    Zhang, Yanxia; Tu, Yang; Zhao, Yongheng; Tian, Haijun

    2017-06-01

    We explore photometric redshift estimation of quasars with the SDSS DR12 quasar sample. Firstly the quasar sample is separated into three parts according to different redshift ranges. Then three classifiers based on Extreme Learning Machine (ELM) are created in the three redshift ranges. Finally k-Nearest Neighbor (kNN) approach is applied on the three samples to predict photometric redshifts of quasars with multiwavelength photometric data. We compare the performance with different input patterns by ELM-KNN with that only by kNN. The experimental results show that ELM-KNN is feasible and superior to kNN (e.g. rms is 0.0751 vs. 0.2626 for SDSS sample), in other words, the ensemble method has the potential to increase regressor performance beyond the level reached by an individual regressor alone and will be a good choice when facing much more complex data.

  20. Use Correlation Coefficients in Gaussian Process to Train Stable ELM Models

    Science.gov (United States)

    2015-05-22

    Curves for training and testing accuracies of different ELMs changing with L on Treasury Dataset 4 Experiments In this section, we use 12 UCI and KEEL ...sci2s.ugr.es/ keel /datasets.php Use Correlation Coefficients in Gaussian Process 407 classification than other methods. The StaELM models are stable...marize kernel-based ELMs. Section 3 introduces our proposed StaELM. Exper- imental simulations are presented in Section 4. Finally, we conclude this

  1. Ten-year performance of the United States national elm trial

    Science.gov (United States)

    Jason J. Griffin; William R. Jacobi; E. Gregory McPherson; Clifford S. Sadof; James R. McKenna; Mark L. Gleason; Nicole Ward Gauthier; Daniel A. Potter; David R. Smitley; Gerard C. Adams; Ann Brooks Gould; Christian R. Cash; James A. Walla; Mark C. Starrett; Gary Chastagner; Jeff L. Sibley; Vera A. Krischik; Adam F. Newby

    2017-01-01

    Ulmus americana (American elm) was an important urban tree in North America prior to the introduction of the Dutch elm disease pathogen in 1930. Subsequently, urban and community forests were devastated by the loss of large canopies. Tree improvement programs produced disease tolerant American and Eurasian elm cultivars and introduced them into the...

  2. Physics and performance of the I-mode regime over an expanded operating space on Alcator C-Mod

    Science.gov (United States)

    Hubbard, A. E.; Baek, S.-G.; Brunner, D.; Creely, A. J.; Cziegler, I.; Edlund, E.; Hughes, J. W.; LaBombard, B.; Lin, Y.; Liu, Z.; Marmar, E. S.; Reinke, M. L.; Rice, J. E.; Sorbom, B.; Sung, C.; Terry, J.; Theiler, C.; Tolman, E. A.; Walk, J. R.; White, A. E.; Whyte, D.; Wolfe, S. M.; Wukitch, S.; Xu, X. Q.; the Alcator C-Mod Team

    2017-12-01

    New results on the I-mode regime of operation on the Alcator C-Mod tokamak are reported. This ELM-free regime features high energy confinement and a steep temperature pedestal, while particle confinement remains at L-mode levels, giving stationary density and avoiding impurity accumulation. I-mode has now been obtained over nearly all of the magnetic fields and currents possible in this high field tokamak (I p 0.55-1.7 MA, B T 2.8-8 T) using a configuration with B  ×  ∇ B drift away from the X-point. Results at 8 T confirm that the L-I power threshold varies only weakly with B T, and that the power range for I-mode increases with B T; no 8 T discharges transitioned to H-mode. Parameter dependences of energy confinement are investigated. Core transport simulations are giving insight into the observed turbulence reduction, profile stiffness and confinement improvement. Pedestal models explain the observed stability to ELMs, and can simulate the observed weakly coherent mode. Conditions for I-H transitions have complex dependences on density as well as power. I-modes have now been maintained in near-DN configurations, leading to improved divertor power flux sharing. Prospects for I-mode on future fusion devices such as ITER and ARC are encouraging. Further experiments on other tokamaks are needed to improve confidence in extrapolation.

  3. Menyoal Elaboration Likelihood Model (ELM dan Teori Retorika

    Directory of Open Access Journals (Sweden)

    Yudi Perbawaningsih

    2012-06-01

    Full Text Available Abstract: Persuasion is a communication process to establish or change attitudes, which can be understood through theory of Rhetoric and theory of Elaboration Likelihood Model (ELM. This study elaborates these theories in a Public Lecture series which to persuade the students in choosing their concentration of study. The result shows that in term of persuasion effectiveness it is not quite relevant to separate the message and its source. The quality of source is determined by the quality of the message, and vice versa. Separating the two routes of the persuasion process as described in the ELM theory would not be relevant. Abstrak: Persuasi adalah proses komunikasi untuk membentuk atau mengubah sikap, yang dapat dipahami dengan teori Retorika dan teori Elaboration Likelihood Model (ELM. Penelitian ini mengelaborasi teori tersebut dalam Kuliah Umum sebagai sarana mempersuasi mahasiswa untuk memilih konsentrasi studi studi yang didasarkan pada proses pengolahan informasi. Menggunakan metode survey, didapatkan hasil yaitu tidaklah cukup relevan memisahkan pesan dan narasumber dalam melihat efektivitas persuasi. Keduanya menyatu yang berarti bahwa kualitas narasumber ditentukan oleh kualitas pesan yang disampaikannya, dan sebaliknya. Memisahkan proses persuasi dalam dua lajur seperti yang dijelaskan dalam ELM teori menjadi tidak relevan.

  4. Intra- and interspecific hybridization in invasive Siberian elm

    Science.gov (United States)

    Although numerous studies have examined the invasion history of herbaceous plants, few studies have investigated the invasion biology of woody plants. In this study, we determined whether inter-specific hybridization was necessary before invasiveness could evolve in the Siberian elm, Ulmus pumila. P...

  5. Role of phytohormones in organogenic ability of elm multiplicated shoots

    Czech Academy of Sciences Publication Activity Database

    Malá, J.; Gaudinová, Alena; Dobrev, Petre; Eder, Josef; Cvikrová, Milena

    2006-01-01

    Roč. 50, č. 1 (2006), s. 8-14 ISSN 0006-3134 Institutional research plan: CEZ:AV0Z5038910; CEZ:AV0Z50380511 Keywords : auxin * cytokinins * multiplication of elm Subject RIV: GK - Forestry Impact factor: 1.198, year: 2006

  6. Genome-wide analyses of the Dutch elm disease fungi

    Science.gov (United States)

    Louis. Bernier

    2017-01-01

    The Ascomycete fungi Ophiostoma ulmi and O. novo-ulmi are the pathogens respectively responsible for the two successive pandemics of Dutch elm disease (DED) since the early 1900s. The advent of the highly fit and virulent O. novo-ulmi was a landmark event in the evolution of DED during the last 100 years....

  7. Phase Contrast Imaging Measurements of Edge Turbulence Across an H-mode Transition

    Science.gov (United States)

    Rost, J. C.; Marinoni, A.; Porkolab, M.; Burrell, K. H.

    2013-10-01

    The Phase Contrast Imaging (PCI) diagnostic on DIII-D provides a line-integrated measurement of density fluctuations. Analysis of previous PCI data taken during QH mode plasmas has revealed turbulence with short radial wavelengths and high frequencies which is generated by the well in the radial electric field Er. Application of these results allows us to study the rapid evolution in turbulence at an L-H transition. The dominant effect of the L-H transition on turbulence is a 70% drop in fluctuation amplitude. However high frequency fluctuations are seen to arise on the same time scale as the L-H transition (i.e. a few ms). Interpretation of the 2d spectrum S (k , f) of the PCI data of the line-integrated fluctuation, especially the Doppler shift and the ratio S (kpci / S (-kpci) , indicates that the high frequency fluctuations are located on the inner edge of the Er well. There is in addition a region of turbulence the PCI detects which is located outside the minimum of the Er well. This ongoing work will provide quantitative information on the evolution of the Er well at high time resolution across the L-H transition, important to understanding the interaction between turbulence and flow shear at the H-mode transition. Work supported by the US Department of Energy under DE-FG02-94ER54235 and DE-FC02-04ER54698.

  8. Modification of argon impurity transport by electron cyclotron heating in KSTAR H-mode plasmas

    Science.gov (United States)

    Hong, Joohwan; Henderson, S. S.; Kim, Kimin; Seon, C. R.; Song, Inwoo; Lee, H. Y.; Jang, Juhyeok; Park, Jae Sun; Lee, S. G.; Lee, J. H.; Lee, Seung Hun; Hong, Suk-Ho; Choe, Wonho

    2017-03-01

    Experiments with a small amount of Ar gas injection as a trace impurity were conducted in the Korea Superconducting Tokamak Advanced Research (KSTAR) H-mode plasma ({{B}\\text{T}}   =  2.8 T, {{I}\\text{P}}   =  0.6 MA, and {{P}\\text{NBI}}   =  4.0 MW). 170 GHz electron cyclotron resonance heating (ECH) at 600 and 800 kW was focused along the mid-plane with a fixed major radial position of R   =  1.66 m. The emissivity of the Ar16+ (3.949 {\\mathring{\\text{A}}} ) and Ar15+ (353.860 {\\mathring{\\text{A}}} ) spectral lines were measured by x-ray imaging crystal spectroscopy (XICS) and a vacuum UV (VUV) spectrometer, respectively. ECH reduces the peak Ar15+ emission and increases the Ar16+ emission, an effect largest with 800 kW. The ADAS-SANCO impurity transport code was used to evaluate the Ar transport coefficients. It was found that the inward convective velocity found in the plasma core without ECH was decreased with ECH, while diffusion remained approximately constant resulting in a less-peaked Ar density profile. Theoretical results from the NEO code suggest that neoclassical transport is not responsible for the change in transport, while the microstability analysis using GKW predicts a dominant ITG mode during both ECH and non-ECH plasmas.

  9. Modeling of argon seeding in ASDEX Upgrade H-mode plasma with SOLPS5.0

    Directory of Open Access Journals (Sweden)

    L.Y. Xiang

    2017-08-01

    Full Text Available SOLPS modeling of Ar seeding in ASDEX Upgrade H-mode plasma shows that the divertor compression of Ar increases with the seeding rate when the inner divertor is detached and the outer divertor is attached. This results from the redistribution of the Ar density as the inner divertor detaches. During the detachment of the inner divertor, the parallel friction and thermal forces on Ar increase in the inner divertor and decrease in the outer divertor. The net force of the two directs Ar from the low field side to the high field side of the plasma along the field line. The net force is found to be stronger after the detachment of the inner divertor in the simulation. Although the divertor compression of Ar increases, the ratio of radiated power by Ar inside the divertor over that inside the separatrix does not increase after the detachment. This is because the radiation efficiency, i.e. the radiated per Ar particle on average decreases with the seeding rate in the divertor and increases inside the separatrix. The radiation efficiency in the simulation is determined by the characteristic cooling curve of Ar and the transport effects.

  10. Towards understanding ELM mitigation by resonant magnetic perturbations in MAST

    Science.gov (United States)

    Chapman, Ian

    2012-10-01

    MAST is equipped with 18 in-vessel coils for use in Resonant Magnetic Perturbation (RMP) ELM control experiments. These coils give considerable flexibility since they allow a range of toroidal mode numbers (up to n=6) and also allow improved alignment of the magnetic perturbations with the plasma equilibrium by allowing the phase of the applied field to be varied during the shot. This is complemented by modelling advances to understand the plasma response to applied fields, the resultant torque and three-dimensional displacement. The application of n>=3 RMPs in MAST results in up to a factor of eight increase in ELM frequency and the released energy per ELM dropping four-fold. The benefits of high-n RMPs include reduced core rotation braking and reduced effect on the L-H transition power with RMPs. During ELM mitigation, lobe structures near the X-point are observed for the first time in visible-light imaging of the plasma edge. These lobes, that were previously predicted, are correlated with RMP penetration and only appear when enhanced particle transport or increased ELM frequency is observed. The number and location of the lobes is well described by vacuum modelling. The toroidal corrugation of the plasma edge due to n=3 RMPs is also measured and found to be 5% of the minor radius. The electron pressure gradient drops and the pedestal width increases when RMPs are applied, which would normally suggest improved stability to peeling-ballooning modes, yet the ELMs are more frequent, or destabilised. This dichotomy is resolved with a model which suggests that the critical pressure gradient to trigger an ELM is degraded by the RMPs, due to both the presence of the lobes and the non-axisymmetric plasma corrugation. A quasi-linear code, MARS-Q code has been used to investigate the effects of the penetration process and plasma response on the observed structures. These computations quantify several factors affecting the dynamics of the RMP field penetration, in

  11. Time-Dependent Simulations of Fast-Wave Heated High-Non-Inductive-Fraction H-Mode Plasmas in the National Spherical Torus Experiment Upgrade

    Science.gov (United States)

    Taylor, Gary; Bertelli, Nicola; Gerhardt, Stefan P.; Hosea, Joel C.; Mueller, Dennis; Perkins, Rory J.; Poli, Francesca M.; Wilson, James R.; Raman, Roger

    2017-10-01

    30 MHz fast-wave heating may be an effective tool for non-inductively ramping low-current plasmas to a level suitable for initiating up to 12 MW of neutral beam injection on the National Spherical Tokamak Experiment Upgrade (NSTX-U). Previously on NSTX 30 MHz fast wave heating was shown to efficiently and rapidly heat electrons; at the NSTX maximum axial toroidal magnetic field (BT(0)) of 0.55 T, 1.4 MW of 30 MHz heating increased the central electron temperature from 0.2 to 2 keV in 30 ms and generated an H-mode plasma with a non-inductive fraction (fNI) ˜ 0.7 at a plasma current (Ip) of 300 kA. NSTX-U will operate at BT(0) up to 1 T, with up to 4 MW of 30 MHz power (Prf). Predictive TRANSP free boundary transport simulations, using the TORIC full wave spectral code to calculate the fast-wave heating and current drive, have been run for NSTX-U Ip = 300 kA H-mode plasmas. Favorable scaling of fNI with 30 MHz heating power is predicted, with fNI ≥ 1 for Prf ≥ 2 MW.

  12. Simultaneous induction of jasmonic acid and disease-responsive genes signifies tolerance of American elm to Dutch elm disease

    Science.gov (United States)

    Sherif , S. M.; Shukla, M. R.; Murch, S. J.; Bernier, L.; Saxena, P. K.

    2016-01-01

    Dutch elm disease (DED), caused by three fungal species in the genus Ophiostoma, is the most devastating disease of both native European and North American elm trees. Although many tolerant cultivars have been identified and released, the tolerance mechanisms are not well understood and true resistance has not yet been achieved. Here we show that the expression of disease-responsive genes in reactions leading to tolerance or susceptibility is significantly differentiated within the first 144 hours post-inoculation (hpi). Analysis of the levels of endogenous plant defense molecules such as jasmonic acid (JA) and salicylic acid (SA) in tolerant and susceptible American elm saplings suggested SA and methyl-jasmonate as potential defense response elicitors, which was further confirmed by field observations. However, the tolerant phenotype can be best characterized by a concurrent induction of JA and disease-responsive genes at 96 hpi. Molecular investigations indicated that the expression of fungal genes (i.e. cerato ulmin) was also modulated by endogenous SA and JA and this response was unique among aggressive and non-aggressive fungal strains. The present study not only provides better understanding of tolerance mechanisms to DED, but also represents a first, verified template for examining simultaneous transcriptomic changes during American elm-fungus interactions. PMID:26902398

  13. Metal impurity transport control in JET H-mode plasmas with central ion cyclotron radiofrequency power injection

    DEFF Research Database (Denmark)

    Valisa, M.; Carraro, L.; Predebon, I.

    2011-01-01

    The scan of ion cyclotron resonant heating (ICRH) power has been used to systematically study the pump out effect of central electron heating on impurities such as Ni and Mo in H-mode low collisionality discharges in JET. The transport parameters of Ni and Mo have been measured by introducing a t...

  14. Gyrokinetic Studies of Resonant Magnetic Perturbation Effect on Microturbulence in DIII-D H-Mode Pedestal

    Science.gov (United States)

    Holod, Ihor; Lin, Zhihong; Taimourzadeh, Sam; Nazikian, Raffi; Spong, Donald; Wingen, Andreas

    2016-10-01

    Vacuum Resonant Magnetic Perturbation (RMP) applied to otherwise axisymmetric plasmas for the purpose of ELM mitigation produce in general a combination of non resonant effects preserving closed flux surfaces (kink response) and resonant effects that introduce magnetic islands. The effect of the plasma kink response on the stability and transport of edge turbulence is studied using the gyrokinetic code GTC for a DIII-D discharge with applied n=2 vacuum RMP. Three reference equilibria were modeled using VMEC code, based on DIII-D shot 158103: axisymmetric (no RMP) equilibrium, n=2 RMP, and artificially amplified RMPx10 equilibria. Gyrokinetic simulations reveal no increase of growth rates for electrostatic driftwave instability and electromagnetic kinetic-ballooning mode in the presence of the RMP. The effect of RMP on zonal flow damping is found to be insufficient to modify turbulent transport. Therefore, the plasma kink response to the RMP cannot account for the change in the turbulence level seen in experiments with suppressed ELMs. These results demonstrate that other physics must be controlling the transition in confinement responsible for ELM suppression. Work is supported by General Atomics subcontract 4500055243, U.S. DOE Grant DE-SC0010416 and DE-SC0013804, and by General Atomics collaboration agreement under DOE Grant DE-FG03-94ER54271.

  15. EDGE2D-EIRENE modelling of near SOL E r: possible impact on the H-mode power threshold

    Science.gov (United States)

    Chankin, A. V.; Delabie, E.; Corrigan, G.; Harting, D.; Maggi, C. F.; Meyer, H.; Contributors, JET

    2017-04-01

    Recent EDGE2D-EIRENE simulations of JET plasmas showed a significant difference between radial electric field (E r) profiles across the separatrix in two divertor configurations, with the outer strike point on the horizontal target (HT) and vertical target (VT) (Chankin et al 2016 Nucl. Mater. Energy, doi: 10.1016/j.nme.2016.10.004). Under conditions (input power, plasma density) where the HT plasma went into the H-mode, a large positive E r spike in the near scrape-off layer (SOL) was seen in the code output, leading to a very large E × B shear across the separatrix over a narrow region of a fraction of a cm width. No such E r feature was obtained in the code solution for the VT configuration, where the H-mode power threshold was found to be twice as high as in the HT configuration. It was hypothesised that the large E × B shear across the separatrix in the HT configuration could be responsible for the turbulence suppression leading to an earlier (at lower input power) L-H transition compared to the VT configuration. In the present work these ideas are extended to cover some other experimental observations on the H-mode power threshold variation with parameters which typically are not included in the multi-machine H-mode power threshold scalings, namely: ion mass dependence (isotope H-D-T exchange), dependence on the ion ∇B drift direction, and dependence on the wall material composition (ITER-like wall versus carbon wall in JET). In all these cases EDGE2D-EIRENE modelling shows larger positive E r spikes in the near SOL under conditions where the H-mode power threshold is lower, at least in the HT configuration.

  16. Recrystallization and grain growth induced by ELMs-like transient heat loads in deformed tungsten samples

    Science.gov (United States)

    Suslova, A.; El-Atwani, O.; Sagapuram, D.; Harilal, S. S.; Hassanein, A.

    2014-11-01

    Tungsten has been chosen as the main candidate for plasma facing components (PFCs) due to its superior properties under extreme operating conditions in future nuclear fusion reactors such as ITER. One of the serious issues for PFCs is the high heat load during transient events such as ELMs and disruption in the reactor. Recrystallization and grain size growth in PFC materials caused by transients are undesirable changes in the material, since the isotropic microstructure developed after recrystallization exhibits a higher ductile-to-brittle transition temperature which increases with the grain size, a lower thermal shock fatigue resistance, a lower mechanical strength, and an increased surface roughening. The current work was focused on careful determination of the threshold parameters for surface recrystallization, grain growth rate, and thermal shock fatigue resistance under ELM-like transient heat events. Transient heat loads were simulated using long pulse laser beams for two different grades of ultrafine-grained tungsten. It was observed that cold rolled tungsten demonstrated better power handling capabilities and higher thermal stress fatigue resistance compared to severely deformed tungsten. Higher recrystallization threshold, slower grain growth, and lower degree of surface roughening were observed in the cold rolled tungsten.

  17. Mexican Hat Wavelet Kernel ELM for Multiclass Classification.

    Science.gov (United States)

    Wang, Jie; Song, Yi-Fan; Ma, Tian-Lei

    2017-01-01

    Kernel extreme learning machine (KELM) is a novel feedforward neural network, which is widely used in classification problems. To some extent, it solves the existing problems of the invalid nodes and the large computational complexity in ELM. However, the traditional KELM classifier usually has a low test accuracy when it faces multiclass classification problems. In order to solve the above problem, a new classifier, Mexican Hat wavelet KELM classifier, is proposed in this paper. The proposed classifier successfully improves the training accuracy and reduces the training time in the multiclass classification problems. Moreover, the validity of the Mexican Hat wavelet as a kernel function of ELM is rigorously proved. Experimental results on different data sets show that the performance of the proposed classifier is significantly superior to the compared classifiers.

  18. Mexican Hat Wavelet Kernel ELM for Multiclass Classification

    Directory of Open Access Journals (Sweden)

    Jie Wang

    2017-01-01

    Full Text Available Kernel extreme learning machine (KELM is a novel feedforward neural network, which is widely used in classification problems. To some extent, it solves the existing problems of the invalid nodes and the large computational complexity in ELM. However, the traditional KELM classifier usually has a low test accuracy when it faces multiclass classification problems. In order to solve the above problem, a new classifier, Mexican Hat wavelet KELM classifier, is proposed in this paper. The proposed classifier successfully improves the training accuracy and reduces the training time in the multiclass classification problems. Moreover, the validity of the Mexican Hat wavelet as a kernel function of ELM is rigorously proved. Experimental results on different data sets show that the performance of the proposed classifier is significantly superior to the compared classifiers.

  19. Recent Trends in ELM and MLELM: A review

    Directory of Open Access Journals (Sweden)

    R. Manju Parkavi

    2017-01-01

    Full Text Available Extreme Learning Machine (ELM is a high effective learning algorithm for the single hidden layer feed forward neural networks. Compared with the existing neural network learning algorithm it solves the slow training speed and over-fitting problems. It has been used in different fields and applications such as biomedical engineering, computer vision, remote sensing, chemical process and control and robotics. It has better generalization stability, sparsity, accuracy, robustness, optimal control and fast learning rate This paper introduces a brief review about ELM and MLELM, describing the principles and latest research progress about the algorithms, theories and applications. Next, Multilayer Extreme Learning Machine (MLELM and other state-of-the-art classifiers are trained on this suitable training feature vector for classification of data. Deep learning has the advantage of approximating the complicated function and mitigating the optimization difficulty associated with deep models. Multilayer extreme learning machine is a learning algorithm of an Artificial Neural Network (ANN which takes to be good for deep learning and extreme learning machine. This review presents a comprehensive view of these advances in ELM and MLELM which may be worthy of exploring in the future.

  20. Modeling of Plasma Pressure Effects on ELM Suppression With RMP in DIII-D

    Science.gov (United States)

    Orlov, D. M.; Moyer, R. A.; Mordijck, S.; Evans, T. E.; Osborne, T. H.; Snyder, P. B.; Unterberg, E. A.; Fenstermacher, M. E.

    2009-11-01

    Resonant magnetic perturbations (RMPs) are used to control the pedestal pressure gradient in both low and high (ν3^*) DIII-D plasmas. In this work we have analyzed several discharges with different levels of triangularity, different neutral beam injection power levels, and with, βN ranging from 1.5 to 2.3. The field line integration code TRIP3D was used to model the magnetic perturbation in ELMing and ELM suppressed phases during the RMP pulse. The results of this modeling showed very little effect of βN on the structure of the vacuum magnetic field during ELM suppression using n=3 RMPs. Kinetic equilibrium reconstructions showed a decrease in bootstrap current during RMP. Linear peeling-ballooning stability analysis performed with the ELITE code suggested that the ELMs, which persist during RMP, i.e. ELMing still is observed, are not Type I ELMs. Identification of these Dα spikes is an ongoing work.

  1. RMSE-ELM: Recursive Model Based Selective Ensemble of Extreme Learning Machines for Robustness Improvement

    Directory of Open Access Journals (Sweden)

    Bo Han

    2014-01-01

    Full Text Available For blended data, the robustness of extreme learning machine (ELM is so weak because the coefficients (weights and biases of hidden nodes are set randomly and the noisy data exert a negative effect. To solve this problem, a new framework called “RMSE-ELM” is proposed in this paper. It is a two-layer recursive model. In the first layer, the framework trains lots of ELMs in different ensemble groups concurrently and then employs selective ensemble approach to pick out an optimal set of ELMs in each group, which can be merged into a large group of ELMs called candidate pool. In the second layer, selective ensemble approach is recursively used on candidate pool to acquire the final ensemble. In the experiments, we apply UCI blended datasets to confirm the robustness of our new approach in two key aspects (mean square error and standard deviation. The space complexity of our method is increased to some degree, but the result has shown that RMSE-ELM significantly improves robustness with a rapid learning speed compared to representative methods (ELM, OP-ELM, GASEN-ELM, GASEN-BP, and E-GASEN. It becomes a potential framework to solve robustness issue of ELM for high-dimensional blended data in the future.

  2. Identification of characteristic ELM evolution patterns with Alfven-scale measurements and unsupervised machine learning analysis

    Science.gov (United States)

    Smith, David R.; Fonck, R. J.; McKee, G. R.; Diallo, A.; Kaye, S. M.; Leblanc, B. P.; Sabbagh, S. A.

    2016-10-01

    Edge localized mode (ELM) saturation mechanisms, filament dynamics, and multi-mode interactions require nonlinear models, and validation of nonlinear ELM models requires fast, localized measurements on Alfven timescales. Recently, we investigated characteristic ELM evolution patterns with Alfven-scale measurements from the NSTX/NSTX-U beam emission spectroscopy (BES) system. We applied clustering algorithms from the machine learning domain to ELM time-series data. The algorithms identified two or three groups of ELM events with distinct evolution patterns. In addition, we found that the identified ELM groups correspond to distinct parameter regimes for plasma current, shape, magnetic balance, and density pedestal profile. The observed characteristic evolution patterns and corresponding parameter regimes suggest genuine variation in the underlying physical mechanisms that influence the evolution of ELM events and motivate nonlinear MHD simulations. Here, we review the previous results for characteristic ELM evolution patterns and parameter regimes, and we report on a new effort to explore the identified ELM groups with 2D BES measurements and nonlinear MHD simulations. Supported by U.S. Department of Energy Award Numbers DE-SC0001288 and DE-AC02-09CH11466.

  3. Fast measurements of the electron temperature and parallel heat flux in ELMy H-mode on the COMPASS tokamak

    Czech Academy of Sciences Publication Activity Database

    Adámek, Jiří; Seidl, Jakub; Komm, Michael; Weinzettl, Vladimír; Pánek, Radomír; Stöckel, Jan; Hron, Martin; Háček, Pavel; Imríšek, Martin; Vondráček, Petr; Horáček, Jan; Devitre, A.

    2017-01-01

    Roč. 57, č. 2 (2017), č. článku 022010. ISSN 0029-5515 R&D Projects: GA ČR(CZ) GA15-10723S; GA MŠk(CZ) LM2015045; GA MŠk(CZ) 8D15001 EU Projects: European Commission(XE) 633053 - EUROfusion Institutional support: RVO:61389021 Keywords : COMPASS * divertor * ELM * scrape-off layer * ball-pen probe * power decay length Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.307, year: 2016 http://iopscience.iop.org/ article /10.1088/0029-5515/57/2/022010

  4. A Short-Term Photovoltaic Power Prediction Model Based on an FOS-ELM Algorithm

    Directory of Open Access Journals (Sweden)

    Jidong Wang

    2017-04-01

    Full Text Available With the increasing proportion of photovoltaic (PV power in power systems, the problem of its fluctuation and intermittency has become more prominent. To reduce the negative influence of the use of PV power, we propose a short-term PV power prediction model based on the online sequential extreme learning machine with forgetting mechanism (FOS-ELM, which can constantly replace outdated data with new data. We use historical weather data and historical PV power data to predict the PV power in the next period of time. The simulation result shows that this model has the advantages of a short training time and high accuracy. This model can help the power dispatch department schedule generation plans as well as support spatial and temporal compensation and coordinated power control, which is important for the security and stability as well as the optimal operation of power systems.

  5. Phospho.ELM: a database of phosphorylation sites--update 2011

    DEFF Research Database (Denmark)

    Dinkel, Holger; Chica, Claudia; Via, Allegra

    2011-01-01

    The Phospho.ELM resource (http://phospho.elm.eu.org) is a relational database designed to store in vivo and in vitro phosphorylation data extracted from the scientific literature and phosphoproteomic analyses. The resource has been actively developed for more than 7 years and currently comprises ...

  6. ELM-ART--An Interactive and Intelligent Web-Based Electronic Textbook

    Science.gov (United States)

    Weber, Gerhard; Brusilovsky, Peter

    2016-01-01

    This paper present provides a broader view on ELM-ART, one of the first Web-based Intelligent Educational systems that offered a creative combination of two different paradigms--Intelligent Tutoring and Adaptive Hypermedia technologies. The unique dual nature of ELM-ART contributed to its long life and research impact and was a result of…

  7. Co-occurence of Two Invasive Species: The Banded and European Elm Bark Beetles (Coleoptera: Scolytidae)

    Science.gov (United States)

    The invasive European elm bark beetle, Scolytus multistriatus (Marsham), was first detected a century ago and now occurs in most of the continental United States. The invasive banded elm bark beetle, Scolytus schevyrewi Semenov, native to Asia, was discovered in the United States in 2003 and is now...

  8. Study of density fluctuation in L-mode and H-mode plasmas on JFT-2M by microwave reflectometer

    Energy Technology Data Exchange (ETDEWEB)

    Shinohara, Kouji [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    1997-08-01

    We propose the model which can explain the runaway phase. The model takes account of the scattered wave which is caused by the density fluctuation near the cut-off layer. We should take a new approach instead of the conventional phase measurement in order to derive the information of the density fluctuation from the data with the runaway phase. The complex spectrum and the rotary spectrum analyses are useful tools to analyze such data. The density fluctuation in L-mode and H-mode plasmas is discussed by using this new approach. We have observed that the reduction of the density fluctuation is localized in the edge region where the sheared electric field is produced. The fluctuations in the range of frequency lower than 100 kHz are mainly reduced. Two interesting features have been observed. One is the detection of the coherent mode around 100 kHz in H-mode. This mode appears about 10 ms after L to H transition. The timing corresponds to the formation of a steep density and temperature gradient in the edge region. The other is the enhancement of the fluctuations with the frequency higher than 300 kHz in H-mode in contrast to the reduction of the fluctuations with the frequency lower than 100 kHz. The Doppler shift is observed in the complex auto-power spectrum of the reflected wave when the plasma is actively moved. We have confirmed that the movement of the plasma is appropriately measured by using the low pass filter. The reflectometer can be used to measure the density profile by using a low pass filter even when the runaway phase phenomenon occurs. (author). 150 refs.

  9. The quasi-coherent signature of enhanced D{sub {alpha}} H-mode in Alcator C-Mod

    Energy Technology Data Exchange (ETDEWEB)

    Snipes, J.A.; LaBombard, B.; Greenwald, M.; Hutchinson, I.H.; Irby, J.; Lin, Y.; Mazurenko, A.; Porkolab, M. [MIT Plasma Science and Fusion Center, Cambridge, MA 02139 (United States)

    2001-04-01

    The steady-state H-mode regime found at moderate to high density in Alcator C-Mod, known as enhanced D{sub {alpha}} (EDA) H-mode, appears to be maintained by a continuous quasi-coherent (QC) mode in the steep edge gradient region. Large amplitude density and magnetic fluctuations with typical frequencies of about 100 kHz are driven by the QC mode. These fluctuations are measured in the steep edge gradient region by inserting a fast-scanning probe containing two poloidally separated Langmuir probes and a poloidal field pick-up coil. As the probe approaches the plasma edge, clear magnetic fluctuations were measured within about 2 cm of the last-closed flux surface (LCFS). The mode amplitude falls off rapidly with distance from the plasma centre with an exponential decay length of k{sub r} approx. 1.5 cm{sup -1}, measured 10 cm above the outboard midplane. The root-mean-square amplitude of the fluctuation extrapolated to the LCFS was B-tilde{sub {theta}} approx. 5 G. The density fluctuations, on the other hand, were visible on the Langmuir probe only when it was within a few millimetres of the LCFS. The potential and density fluctuations were sufficiently in phase to enhance particle transport at the QC mode frequency. These results show that the QC signature of the EDA H-mode is an electromagnetic mode that appears to be responsible for the enhanced particle transport in the plasma edge. (author). Letter-to-the-editor.

  10. Pellet fuelling of plasmas with ELM mitigation by resonant magnetic perturbations in MAST

    CERN Document Server

    Valovic, M; Garzotti, L; Gurl, C; Kirk, A; Naylor, G; Patel, A; Scannell, R; Thornton, A J

    2013-01-01

    Shallow fuelling pellets are injected from the high field side into plasmas in which ELMs have been mitigated using external magnetic perturbation coils. The data are compared with ideal assumptions in the ITER fuelling model, namely that mitigated ELMs are not affected by fuelling pellets. Firstly it is shown that during the pellet evaporation an ELM is triggered, during which the amount particle loss could be larger (factor ~1.5) than the particle loss during an ELM which was not induced by pellet. Secondly, a favourable example is shown in which post-pellet particle losses due to mitigated ELMs are similar to the non-pellet case, however unfavourable counter-examples also exist.

  11. Phylogeography: English elm is a 2,000-year-old Roman clone.

    Science.gov (United States)

    Gil, Luis; Fuentes-Utrilla, Pablo; Soto, Alvaro; Cervera, M Teresa; Collada, Carmen

    2004-10-28

    The outbreak of Dutch elm disease in the 1970s ravaged European elm populations, killing more than 25 million trees in Britain alone; the greatest impact was on Ulmus procera, otherwise known as the English elm. Here we use molecular and historical information to show that this elm derives from a single clone that the Romans transported from Italy to the Iberian peninsula, and from there to Britain, for the purpose of supporting and training vines. Its highly efficient vegetative reproduction and its inability to set seeds have preserved this clone unaltered for 2,000 years as the core of the English elm population--and the preponderance of this susceptible variety may have favoured a rapid spread of the disease.

  12. Multiclass AdaBoost ELM and Its Application in LBP Based Face Recognition

    Directory of Open Access Journals (Sweden)

    Yunliang Jiang

    2015-01-01

    Full Text Available Extreme learning machine (ELM is a competitive machine learning technique, which is simple in theory and fast in implementation; it can identify faults quickly and precisely as compared with traditional identification techniques such as support vector machines (SVM. As verified by the simulation results, ELM tends to have better scalability and can achieve much better generalization performance and much faster learning speed compared with traditional SVM. In this paper, we introduce a multiclass AdaBoost based ELM ensemble method. In our approach, the ELM algorithm is selected as the basic ensemble predictor due to its rapid speed and good performance. Compared with the existing boosting ELM algorithm, our algorithm can be directly used in multiclass classification problem. We also carried out comparable experiments with face recognition datasets. The experimental results show that the proposed algorithm can not only make the predicting result more stable, but also achieve better generalization performance.

  13. An Heuristic Drift-Based Model of the Power Scrape-Off Width in H-Mode Tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Robert J. Goldston

    2011-02-28

    An heuristic model for the plasma scrape-off width in H-mode plasmas is introduced. Grad B and curv B drifts into the SOL are balanced against sonic parallel flows out of the SOL, to the divertor plates. The overall mass flow pattern posited is a modification for open field lines of Pfirsch-Shlüter flows to include sinks to the divertors. These assumptions result in an estimated SOL width of 2aρp/R. They also result in a first-principles calculation of the particle confinement time of H-mode plasmas, qualitatively consistent with experimental observations. It is next assumed that anomalous perpendicular electron thermal diffusivity is the dominant source of heat flux across the separatrix, investing the SOL width, defined above, with heat from the main plasma. The separatrix temperature is calculated based on a two-point model balancing power input to the SOL with Spitzer-Härm parallel thermal conduction losses to the divertor. This results in an heuristic closed-form prediction for the power scrape-off width that is in remarkable quantitative agreement both in absolute magnitude and in scaling with recent experimental data. Further work should include full numerical calculations, including all magnetic and electric drifts, as well as more thorough comparison with experimental data.

  14. Study on H-mode access at low density with lower hybrid current drive and lithium-wall coatings on the EAST superconducting tokamak

    DEFF Research Database (Denmark)

    Xu, G.S.; Wan, B.N.; Li, J.G.

    2011-01-01

    The first high-confinement mode (H-mode) with type-III edge localized modes at an H factor of HIPB98(y,2) ~ 1 has been obtained with about 1 MW lower hybrid wave power on the EAST superconducting tokamak. The first H-mode plasma appeared after wall conditioning by lithium (Li) evaporation before...... plasma breakdown and the real-time injection of fine Li powder into the plasma edge. The threshold power for H-mode access follows the international tokamak scaling even in the low density range and a threshold in density has been identified. With increasing accumulation of deposited Li the H......, which is considered the main mechanism for the H-mode power threshold reduction by the Li wall coatings....

  15. Beta limits in H-modes and VH-modes in JET

    Energy Technology Data Exchange (ETDEWEB)

    Smeulders, P.; Hender, T.C.; Huysmans, G.; Marcus, F.; Ali-Arshad, S.; Alper, B.; Balet, B.; Bures, M.; Deliyanakis, N.; Esch, H. de; Fshpool, G.; Jarvis, O.N.; Jones, T.T.C.; Ketner, W.; Koenig, R.; Lawson, K.; Lomas, P.; O`Brien, D.; Sadler, G.; Stok, D.; Stubberfield, P.; Thomas, P.; Thomen, K.; Wesson, J. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Nave, M.F. [Universidade Tecnica, Lisbon (Portugal). Inst. Superior Tecnico

    1994-07-01

    In Hot-ion H- and VH-modes, the highest achieved beta was about 10% below the Troyon value in the best case of discharge 26087. The operational space of the high beta discharges obtained before March 1992 has been explored as function of the parameters H{sub ITER89P}, {beta}{sub n}, q{sub 95}, I{sub p}. Also, a limiting envelope on the fusion reactivity as a function of the average plasma pressure and beta has been observed with R{sub DD} related to {beta}{sub {phi}}{sup 2}.B{sub {phi}}{sup 4}. MHD stability analysis shows that the JET VH modes at the edge are in the second region for ballooning mode stability. The dependence of ballooning stability and the n=1 external kink on the edge current density is analyzed. (authors). 6 figs., 6 refs.

  16. Turbulence at the transition to the high density H-mode in Wendelstein 7-AS plasmas

    DEFF Research Database (Denmark)

    Basse, N.P.; Zoletnik, S.; Baumel, S.

    2003-01-01

    Recently a new improved confinement regime was found in the Wendelstein 7-AS (W7-AS) stellarator (Renner H. et al 1989 Plasma Phys. Control. Fusion 31 1579). The discovery of this high density high confinement mode (HDH-mode) was facilitated by the installation of divertor modules. In this paper......, measurements of short wavelength density fluctuations in the HDH-mode using collective scattering of infrared light are presented. These measurements will be contrasted to fluctuations during normal confinement operation (NC-mode). The autopower spectra of the measurements show a consistent increase...... of the fluctuation level associated with the transition from NC- to HDH-mode. Correlation calculations on a 20 mus timescale between magnetic and density fluctuations lead to the result that the fluctuations are correlated in NC- but not in HDH-mode. Finally, a comparative analysis between the enhanced D-alpha H...

  17. Study of ELM Density Turbulence using the Upgraded Phase Contrast Imaging on DIII-D

    Science.gov (United States)

    Rost, J. C.; Davis, E. M.; Marinoni, A.; Porkolab, M.; Burrell, K. H.

    2016-10-01

    Recent studies of the turbulent density fluctuations accompanying ELMs in mixed ELM-type discharges have exploited the expanded wavenumber range of the upgraded Phase Contrast Imaging (PCI) diagnostic. The PCI data demonstrate the difference between the fluctuations generated by Type I ELMs, which are broadband in frequency and wavelength, and those generated by Type III ELMs, which are similar in amplitude but restricted to long wavelengths, suggesting that turbulence may play a significant role in Type I ELM transport. The high frequency response of PCI makes it ideal for studying the ELM-associated density fluctuations, which are observed at frequencies up to several MHz, evolve on time scales of 10s of μs, and persist after the magnetic component of the ELM has decayed away. The upgraded PCI, with independent systems for long and short wavelength detection (k < 5 cm-1 and 1 < k < 30 cm-1 respectively), demonstrated coverage of the full wavenumber range of interest. Work supported in part by the US Department of Energy under DE-FG02-94ER54235, DE-FC02-04ER54698, and DE-FC02-99ER54512.

  18. Effect of resonant magnetic perturbations on ELMs in connected double null plasmas in MAST

    CERN Document Server

    Kirk, A; Chapman, I T; Harrison, J; Nardon, E; Scannell, R; Thornton, A J

    2013-01-01

    The application of resonant magnetic perturbations (RMPs) with a toroidal mode number of n=3 to connected double null plasmas in the MAST tokamak produces up to a factor of 9 increase in Edge Localized Mode (ELM) frequency and reduction in plasma energy loss associated with type-I ELMs. A threshold current for ELM mitigation is observed above which the ELM frequency increases approximately linearly with current in the coils. The effect of the RMPs is found to be scenario dependent. In one scenario the mitigation is only due to a large density pump out event and if the density is recovered by gas puffing a return to type I ELMs is observed. In another scenario sustained ELM mitigation can be achieved irrespective of the amount of fuelling. Despite a large scan of parameters complete ELM suppression has not been achieved. The results have been compared to modelling performed using either the vacuum approximation or including the plasma response. The requirement for a resonant condition, that is an optimum align...

  19. The Prediction of Yarn Elongation of Kenyan Ring-Spun Yarn using Extreme Learning Machines (ELM

    Directory of Open Access Journals (Sweden)

    Josphat Igadwa Mwasiagi

    2017-03-01

    Full Text Available The optimization of the manufacture of cotton yarns involves several processes, while the prediction of yarn quality parameters forms an important area of investigation. This research work concentrated on the prediction of cotton yarn elongation. Cotton lint and yarn samples were collected in textile factories in Kenya.The collected samples were tested under standard testing conditions. Cotton lint parameters, machine parameters and yarn elongation were used to design yarn elongation prediction models. The elongation prediction models used three network training algorithms, including backpropagation (BP, an extreme learning machine (ELM, and a hybrid of differential evolution (DE and an ELM referred to as DE-ELM. The prediction models recorded a mean squared error (mse value of 0.001 using 11, 43 and 2 neurons in the hidden layer for the BP, ELM and DE-ELM models respectively. The ELM models exhibited faster training speeds than the BP algorithms, but required more neurons in the hidden layer than other models. The DEELM hybrid algorithm was faster than the BP algorithm, but slower than the ELM algorithm.

  20. Distributed Learning over Massive XML Documents in ELM Feature Space

    Directory of Open Access Journals (Sweden)

    Xin Bi

    2015-01-01

    Full Text Available With the exponentially increasing volume of XML data, centralized learning solutions are unable to meet the requirements of mining applications with massive training samples. In this paper, a solution to distributed learning over massive XML documents is proposed, which provides distributed conversion of XML documents into representation model in parallel based on MapReduce and a distributed learning component based on Extreme Learning Machine for mining tasks of classification or clustering. Within this framework, training samples are converted from raw XML datasets with better efficiency and information representation ability and taken to distributed learning algorithms in Extreme Learning Machine (ELM feature space. Extensive experiments are conducted on massive XML documents datasets to verify the effectiveness and efficiency for both classification and clustering applications.

  1. Development of room temperature crossbar-H-mode cavities for proton and ion acceleration in the low to medium beta range

    Directory of Open Access Journals (Sweden)

    G. Clemente

    2011-11-01

    Full Text Available The crossbar H-mode (CH cavity is an accelerating structure operated in the H_{21(0} mode. The robustness of the crossbar geometry allows one to realize room temperature as well as superconducting linac cavities. The shunt impedance characteristics of this structure are attractive to develop proton and heavy ion linacs in the low and medium beta range. A first room temperature eight-cell prototype has proven the feasibility of the crossbar design in terms of mechanical construction, copper plating, and cooling. An innovative rf coupling concept has been developed where two CH cavities are connected by a two gap E_{010}-mode resonator which, at the same time, provides transverse focusing by a quadrupole triplet. The concept has been applied in the design of the new FAIR proton linac and a scaled model of the second cavity of this injector has been built and tested too. The full scale prototype is now under construction at the University of Frankfurt. In this paper, the room temperature CH cavity development as well as the general layout of the FAIR proton injector (70 MeV, 325 MHz, 70 mA is presented and discussed.

  2. Effect of progressively increasing lithium conditioning on edge transport and stability in high triangularity NSTX H-modes

    Energy Technology Data Exchange (ETDEWEB)

    Maingi, R., E-mail: rmaingi@pppl.gov [Princeton Plasma Physics Laboratory, 100 Stellarator Road, Princeton, NJ 08543 (United States); Canik, J.M. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Bell, R.E. [Princeton Plasma Physics Laboratory, 100 Stellarator Road, Princeton, NJ 08543 (United States); Boyle, D.P. [Princeton University, Princeton, NJ (United States); Diallo, A.; Kaita, R.; Kaye, S.M.; LeBlanc, B.P. [Princeton Plasma Physics Laboratory, 100 Stellarator Road, Princeton, NJ 08543 (United States); Sabbagh, S.A. [Columbia University, New York, NY (United States); Scotti, F.; Soukhanovskii, V.A. [Lawrence Livermore National Laboratory, Livermore, CA (United States)

    2017-04-15

    A sequence of H-mode discharges with increasing levels of pre-discharge lithium evaporation (‘dose’) was conducted in high triangularity and elongation boundary shape in NSTX. Energy confinement increased, and recycling decreased with increasing lithium dose, similar to a previous lithium dose scan in medium triangularity and elongation plasmas. Data-constrained SOLPS interpretive modeling quantified the edge transport change: the electron particle diffusivity decreased by 10–30x. The electron thermal diffusivity decreased by 4x just inside the top of the pedestal, but increased by up to 5x very near the separatrix. These results provide a baseline expectation for lithium benefits in NSTX-U, which is optimized for a boundary shape similar to the one in this experiment.

  3. Generation of Non-Inductive H-Mode Plasmas with 30 MHz Fast Wave Heating in NSTX-U

    Science.gov (United States)

    Taylor, G.; Bertelli, N.; Gerhardt, S. P.; Hosea, J. C.; Mueller, D.; Perkins, R. J.; Poli, F. M.; Wilson, J. R.; Raman, R.

    2016-10-01

    A Fusion Nuclear Science Facility based on a spherical tokamak must generate the plasma current (Ip) with little or no central solenoid field. The NSTX-U non-inductive (NI) plasma research program is addressing this goal by developing NI start-up, ramp-up and sustainment scenarios separately. 4 MW of 30 MHz fast wave power is predicted to ramp Ip to 400 kA, a level sufficient to avoid significant shine-through of 90 keV ions from neutral beam injection. In 2010, experiments in NSTX demonstrated that 1.4 MW of 30 MHz high-harmonic fast wave (HHFW) power could generate an Ip = 300 kA H-mode discharge with a NI Ip fraction, fNI, around 0.7 at the maximum axial toroidal field (BT(0)) in NSTX of 0.55 T. NSTX-U is a major upgrade of NSTX that will eventually allow the generation of plasmas with BT(0) up to 1 T. Full wave simulations of 30 MHz HHFW heating in NSTX-U predict reduced FW power loss in the plasma edge as BT(0) is increased. HHFW experiments this year aim to couple 3 - 4 MW of 30 MHz HHFW power into an Ip = 250 - 350 kA plasma with BT(0) up to 0.75 T to generate a fNI = 1 H-mode plasma. These experiments should benefit from the improved fast wave coupling predicted at higher BT(0) in NSTX-U. Work supported by USDOE Contract No. DE-AC02-09CH11466.

  4. Non-linear simulations of ELMs in ASDEX Upgrade including diamagnetic drift effects

    Energy Technology Data Exchange (ETDEWEB)

    Lessig, Alexander; Hoelzl, Matthias; Krebs, Isabel; Franck, Emmanuel; Guenter, Sibylle [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstrasse 2, 85748 Garching (Germany); Orain, Francois; Morales, Jorge; Becoulet, Marina [CEA-IRFM, Cadarache, 13108 Saint-Paul-Lez-Durance (France); Huysmans, Guido [ITER Organization, 13067 Saint-Paul-Lez-Durance (France)

    2015-05-01

    Large edge localized modes (ELMs) are a severe concern for ITER due to high transient heat loads on divertor targets and wall structures. Using the non-linear MHD code JOREK, we have performed ELM simulations for ASDEX Upgrade (AUG) including diamagnetic drift effects. The influence of diamagnetic terms onto the evolution of the toroidal mode spectrum for different AUG equilibria and the non-linear interaction of the toroidal harmonics are investigated. In particular, we confirm the diamagnetic stabilization of high mode numbers and present new features of a previously introduced quadratic mode coupling model for the early non-linear evolution of the mode structure. Preliminary comparisons of full ELM crashes with experimental observations are shown aiming at code validation and the understanding of different ELM types. Work is ongoing to include toroidal and neoclassical poloidal rotation in our simulations.

  5. Cracking behavior of tungsten armor under ELM-like thermal shock loads: A computational study

    National Research Council Canada - National Science Library

    Li, Muyuan; Werner, Ewald; You, Jeong-Ha

    2015-01-01

    In this work, the cracking behavior of tungsten under edge-localized mode (ELM)-like thermal shock loads was investigated on the basis of a rigorous computational fracture mechanical analysis combined with the finite element method...

  6. Distance Based Multiple Kernel ELM: A Fast Multiple Kernel Learning Approach

    Directory of Open Access Journals (Sweden)

    Chengzhang Zhu

    2015-01-01

    Full Text Available We propose a distance based multiple kernel extreme learning machine (DBMK-ELM, which provides a two-stage multiple kernel learning approach with high efficiency. Specifically, DBMK-ELM first projects multiple kernels into a new space, in which new instances are reconstructed based on the distance of different sample labels. Subsequently, an l2-norm regularization least square, in which the normal vector corresponds to the kernel weights of a new kernel, is trained based on these new instances. After that, the new kernel is utilized to train and test extreme learning machine (ELM. Extensive experimental results demonstrate the superior performance of the proposed DBMK-ELM in terms of the accuracy and the computational cost.

  7. Research on Pattern Recognition Method of Blockage Signal in Pipeline Based on LMD Information Entropy and ELM

    Directory of Open Access Journals (Sweden)

    Jingzong Yang

    2017-01-01

    Full Text Available Aiming at the nonstationary and nonlinear characteristics of acoustic impulse response signal in pipeline blockage and the difficulty in identifying the different degrees of blockage, this paper proposed a pattern recognition method based on local mean decomposition (LMD, information entropy theory, and extreme learning machine (ELM. Firstly, the impulse response signals of pipeline extracted in different operating conditions were decomposed with LMD method into a series of product functions (PFs. Secondly, based on the information entropy theory, the appropriate energy entropy, singular spectrum entropy, power spectrum entropy, and Hilbert spectrum entropy were extracted as the input feature vectors. Finally, ELM was introduced for classification of pipeline blockage. Through the analysis of acoustic impulse response signal collected under the condition of health and different degrees of blockages in pipeline, the results show that the proposed method can well characterize the state information. Also, it has a great advantage in terms of accuracy and it is time consuming when compared with the support vector machine (SVM and BP (backpropagation model.

  8. Surface EMG signals based motion intent recognition using multi-layer ELM

    Science.gov (United States)

    Wang, Jianhui; Qi, Lin; Wang, Xiao

    2017-11-01

    The upper-limb rehabilitation robot is regard as a useful tool to help patients with hemiplegic to do repetitive exercise. The surface electromyography (sEMG) contains motion information as the electric signals are generated and related to nerve-muscle motion. These sEMG signals, representing human's intentions of active motions, are introduced into the rehabilitation robot system to recognize upper-limb movements. Traditionally, the feature extraction is an indispensable part of drawing significant information from original signals, which is a tedious task requiring rich and related experience. This paper employs a deep learning scheme to extract the internal features of the sEMG signals using an advanced Extreme Learning Machine based auto-encoder (ELMAE). The mathematical information contained in the multi-layer structure of the ELM-AE is used as the high-level representation of the internal features of the sEMG signals, and thus a simple ELM can post-process the extracted features, formulating the entire multi-layer ELM (ML-ELM) algorithm. The method is employed for the sEMG based neural intentions recognition afterwards. The case studies show the adopted deep learning algorithm (ELM-AE) is capable of yielding higher classification accuracy compared to the Principle Component Analysis (PCA) scheme in 5 different types of upper-limb motions. This indicates the effectiveness and the learning capability of the ML-ELM in such motion intent recognition applications.

  9. Effect of Island Overlap on ELM Suppression by Resonant Magnetic Perturbations in DIII-D

    Energy Technology Data Exchange (ETDEWEB)

    Fenstermacher, M E; Evans, T E; Osborne, T H; Schaffer, M J; Aldan, M P; deGrassie, J S; Gohil, P; Joseph, I; Moyer, R A; Snyder, P B; Groebner, R J; Jakubowski, M; Leonard, A W; Schmitz, O

    2007-11-08

    Recent DIII-D [J.L. Luxon, et al., Nucl. Fusion 43, 1813 (2003)] experiments show a correlation between the extent of overlap of magnetic islands induced in the edge plasma by perturbation coils and complete suppression of Type-I edge localized modes (ELMs) in plasmas with ITER-like electron pedestal collisionality {nu}*{sub e} {approx} 0.1, flux surface shape and low edge safety factor (q{sub 95} {approx} 3.6). With fixed n = 3 resonant magnetic perturbation (RMP) strength, ELM suppression is obtained only in a finite window in the edge safety factor (q{sub 95}) consistent with maximizing the resonant component of the applied helical field. ELM suppression is obtained over an increasing range of q{sub 95} by either increasing the n = 3 RMP strength, or by adding n = 1 perturbations to 'fill in' gaps between islands across the edge plasma. The suppression of Type-I ELMs correlates with a minimum width of the edge region having magnetic islands with Chirikov parameter >1.0, based on vacuum calculations of RMP mode components excluding the plasma response or rotational shielding. The fraction of vacuum magnetic field lines that are lost from the plasma, with connection length to the divertor targets comparable to an electron-ion collisional mean free path, increases throughout the island overlap region in the ELM suppressed case compared with the ELMing case.

  10. Identification and control of nonlinear system based on Laguerre-ELM Wiener model

    Science.gov (United States)

    Tang, Yinggan; Han, Zhenzhen; Liu, Fucai; Guan, Xinping

    2016-09-01

    In this paper, a new Wiener model is presented for identification and control of single-input single-output (SISO) nonlinear systems. The proposed Wiener model consists of a linear Laguerre filter in cascaded with an extreme learning machine (ELM) neural network (called Laguerre-ELM Wiener model). Laguerre filter can approximate a stable linear system to any degree of accuracy with a small number of Laguerre filters, which provides a parsimony structure and high level accuracy simultaneously. To determine the appropriated number of Laguerre filters in Laguerre-ELM Wiener model, Lipschitz quotient criterion is adapted to determine the order of linear part. A generalized ELM algorithm is proposed to estimate the parameters of Laguerre-ELM Wiener model. Once the unknown nonlinear system is identified using Laguerre-ELM Wiener model, a generalized predictive control (GPC) algorithm is designed for control of nonlinear system. The advantage of the proposed control method is that it transfers a nonlinear control problem to a linear one by inserting the inverse of static nonlinear section. Simulation results demonstrate the effectiveness of the proposed identification and control algorithms.

  11. Identification of maturity of cuiguan pear based on RobustICA and PSO-ELM

    Science.gov (United States)

    Zhang, Yu; Huang, Yongmei; Lin, Min; Liu, Huijun; Zhou, Xinqi

    2017-08-01

    In order to improve the stability of extreme learning machine (ELM), it was proposed to use the combination of robust independent component analysis (RobustICA) and particle swarm optimization ELM algorithm. It was applied to identify the maturity of cuiguan pear at different growing periods. First the two order derivative and the discrete wavelet transform were adopted to remove the background noise and compression spectra. Then RobustICA was used to decompose the spectra to extract independent components and mixed coefficient matrices. Finally, by using particle swarm optimization, the best input layer weight and hidden layer deviation were obtained and adjusted the number of hidden layer nodes to get the best ELM model to differentiate maturity. The method was used to identify the maturity of cuiguan pear at four different stages, and has strong robustness. The results showed that RobustICA-PSO-ELM had better discrimination ability compared with RobustICA - ELM and ELM, and the accuracy increases from 75% to 94.4%.

  12. Adaptive Control of Nonlinear Discrete-Time Systems by Using OS-ELM Neural Networks

    Directory of Open Access Journals (Sweden)

    Xiao-Li Li

    2014-01-01

    Full Text Available As a kind of novel feedforward neural network with single hidden layer, ELM (extreme learning machine neural networks are studied for the identification and control of nonlinear dynamic systems. The property of simple structure and fast convergence of ELM can be shown clearly. In this paper, we are interested in adaptive control of nonlinear dynamic plants by using OS-ELM (online sequential extreme learning machine neural networks. Based on data scope division, the problem that training process of ELM neural network is sensitive to the initial training data is also solved. According to the output range of the controlled plant, the data corresponding to this range will be used to initialize ELM. Furthermore, due to the drawback of conventional adaptive control, when the OS-ELM neural network is used for adaptive control of the system with jumping parameters, the topological structure of the neural network can be adjusted dynamically by using multiple model switching strategy, and an MMAC (multiple model adaptive control will be used to improve the control performance. Simulation results are included to complement the theoretical results.

  13. Electron heat transport in EAST steady-state H-mode discharges with a weak electron internal transport barrier

    Science.gov (United States)

    Du, H.; Ding, S.; Chen, J.; Wang, Y.; Lian, H.; Liu, H.; Zang, Q.; Lyu, B.; Duan, Y.; Xu, G.; Qian, J.; Gong, X.

    2017-10-01

    The global confinement (H98) increases with the internal inductance (1.0 1.2) in the recent steady-state H-mode discharges, which exhibit a weak electron ITB started at ρ = 0.4 in EAST. After turning off ECRH, the stored energy decreases by 30% in 2.5 s. Calculations suggest that both the lower hybrid electron heating and driven current move from the core to large radii after turning off ECRH. Power balance analysis show that the LH deposition profile shift from just inside the ITB to outside the ITB after ECRH termination appears to be responsible for the marked drop in stored energy. The slow stored energy decrease is believed to be connected to the long plasma current profile relaxation time. Linear gyrokinetic simulations indicate increasing low-k instability growth rate from small to large radii, which is consistent with the reduced diffusivity within the ITB. The calculations also show that the CTEM dominate within the ITB, ETG modes grow rapidly outside this region, and that ITG modes dominate near the pedestal top. Work supported by the NNSF of China #11575248.

  14. Reduced turbulence and H-mode confinement in L-mode negative triangularity discharges on DIII-D

    Science.gov (United States)

    Marinoni, A.; Austin, M. E.; Walker, M. L.; Hyatt, A. W.; Petty, C. C.; Thome, K. H.; Porkolab, M.; Rost, J. C.; Davis, E. M.; McKee, G. R.; Rhodes, T. L.; Sung, C.; Sauter, O.; DIII-D Team; MIT-PSFC Collaboration

    2017-10-01

    DIII-D has produced inner-wall limited plasmas with an L-mode edge at negative triangularity characterized by confinement and fluctuation levels comparable to those in H-mode plasmas at positive triangularity. On TCV, similar plasmas at low collisionality and with pure electron heating showedimproved energy confinement, as compared to matched discharges at positive triangularity, due to modifications to the toroidal precession drift of trapped electrons. The recent DIII-D experiment used both ECH and NBI heating, thus exploring a more reactor relevant regime where Te Ti. Compared to matched positive triangularity discharges, the intensity of density and temperaturefluctuations is reduced at negative triangularity both in ECH and in NBI dominated phases. Preliminary TGLF runs indicate the discharges are dominated by TEM modes. More detailed analysis will explore the role of the toroidal precession drift in this new regime. Work supported by US DOE under DE-FG02-94ER54235 and DE-FC02-04ER54698.

  15. Observations of highly sheared turbulence in the H-mode pedestal using Phase Contrast Imaging on DIII-D

    Science.gov (United States)

    Rost, J. C.; Marinoni, A.; Davis, E. M.; Porkolab, M.; Burrell, K. H.

    2017-10-01

    Highly sheared turbulence with short radial correlation lengths has been measured near the top of the H-mode pedestal, in addition to the previously measured highly-sheared turbulence measured in the Er well. Turbulence in regions of large velocity shear is characterized by radial correlation lengths shorter than the poloidal wavelength (L 200 kHz). The phase contrast imaging (PCI) diagnostic on DIII-D is ideally suited to measuring this density turbulence due to the measurement geometry and high frequency bandwidth. Radial localization is achieved by optical filtering, varying the ExB profile, and shifting the plasma position. Reconfiguration of the Er well, such as at the L-H transition or the transition to wide pedestal QH-mode, shows a near-instantaneous change (t < 1 ms) to the sheared turbulence in the Er well ( 1 cm inside the separatrix). In contrast, the sheared turbulence near the top of the pedestal ( 2 cm inside the separatrix) varies over times scales of tens of ms, consistent with pedestal evolution. Work supported by the US Department of Energy under DE-FG02-94ER54235 and DE-FC02-04ER54698.

  16. Initial Characterization of L-mode and H-mode Edge Turbulence in NSTX-U using Beam Emission Spectroscopy

    Science.gov (United States)

    Kriete, David; Fonck, Raymond; McKee, George; Smith, David

    2016-10-01

    Turbulence in L-mode and H-mode plasmas in NSTX-U has been measured using the upgraded 2D BES system. Plasma discharges exhibit a broadband turbulence spectrum up to 150 kHz. In addition, a broadband feature centered at 100 kHz is observed in the early, low density L-mode phase of a discharge with high neutral beam heating, but not in the late, high density L-mode phase of a discharge with low neutral beam heating. Normalized density fluctuation power reduces after the L-H transition by a factor of 10 in the outer edge region, and 5 in the inner edge region. More detailed characterization results, including correlation lengths, decorrelation times, and flow dynamics across the L-H transition, will be presented. Due to discontinuation of the photodiode currently used in BES detectors, the capacitances of several modern, PIN photodiodes have been measured to assess their suitability for BES measurements. The BES preamplifier board layout has been redesigned to test each of the potential replacement diodes. The redesign also enables automated fabrication and assembly of the preamplifiers, simplifying future expansions to the BES system. Finally, the design specifications of a survey spectrometer for impurity measurements with BES detectors will be discussed. This work is supported by US DOE Award Numbers DE-SC0001288 and DE-AC02-09CH11466.

  17. Outward particle transport by coherent mode in the H-mode pedestal in the Experimental Advanced Superconducting Tokamak (EAST)

    Science.gov (United States)

    Zhang, T.; Han, X.; Gao, X.; Liu, H. Q.; Shi, T. H.; Liu, J. B.; Liu, Y.; Kong, D. F.; Liu, Z. X.; Qu, H.; Xiang, H. M.; Geng, K. N.; Wang, Y. M.; Wen, F.; Zhang, S. B.; Ling, B. L.; the EAST Team

    2017-06-01

    A coherent mode (CM) in the edge pedestal region has been observed on different fluctuation quantities, including density fluctuation, electron temperature fluctuation and magnetic fluctuation in H mode plasma on the Experimental Advanced Superconducting Tokamak (EAST) tokamak. Measurements at different poloidal positions show that the local poloidal wavenumber is smallest at the outboard midplane and will increase with poloidal angle. This poloidal asymmetry is consistent with the flute-like assumption (i.e. k// ˜ 0) from which the toroidal mode number of the mode has been estimated as between 12 and 17. It was further found that the density fluctuation amplitude of the CM also demonstrated poloidal asymmetry. The appearance of a CM can clearly decrease or even stop the increase in the edge density, while the disappearance of a CM will lead to an increase in the pedestal density and density gradient. Statistical analysis showed there was a trend that as the CM mode amplitude increased, the rate of increase of the edge density decreased and the particle flux (Γdiv) onto the divertor plate increased. The CM sometimes showed burst behavior, and these bursts led bursts on Γdiv with a time of about 230 μs, which is close to the time for particle flow from the outer midplane to the divertor targets along the scrape-off layer magnetic field line. This evidence showed that the CM had an effect on the outward transport of particles.

  18. Time and materials needed to survey, inject systemic fungicides, and install root-graft barriers for Dutch elm disease management

    Science.gov (United States)

    William N., Jr. Cannon; Jack H. Barger; Charles J. Kostichka; Charles J. Kostichka

    1986-01-01

    Dutch elm disease control practice in 15 communities showed a wide range of time and material required to apply control methods. The median time used for each method was: sanitation survey, 9.8 hours per square mile; symptom survey, 96 hours per thousand elms; systemic fungicide injection, 1.4 hours per elm; and root-graft barrier installation, 2.2 hours per barrier (5...

  19. First observation of a new zonal-flow cycle state in the H-mode transport barrier of the experimental advanced superconducting Tokamak

    DEFF Research Database (Denmark)

    Xu, G.S.; Wang, H. Q.; Wan, B. N.

    2012-01-01

    A new turbulence-flow cycle state has been discovered after the formation of a transport barrier in the H-mode plasma edge during a quiescent phase on the EAST superconducting tokamak. Zonal-flow modulation of high-frequency-broadband (0.05-1MHz) turbulence was observed in the steep-gradient regi...

  20. Towards cooperative guidance and control of highly automated vehicles: H-Mode and Conduct-by-Wire.

    Science.gov (United States)

    Flemisch, Frank Ole; Bengler, Klaus; Bubb, Heiner; Winner, Hermann; Bruder, Ralph

    2014-01-01

    This article provides a general ergonomic framework of cooperative guidance and control for vehicles with an emphasis on the cooperation between a human and a highly automated vehicle. In the twenty-first century, mobility and automation technologies are increasingly fused. In the sky, highly automated aircraft are flying with a high safety record. On the ground, a variety of driver assistance systems are being developed, and highly automated vehicles with increasingly autonomous capabilities are becoming possible. Human-centred automation has paved the way for a better cooperation between automation and humans. How can these highly automated systems be structured so that they can be easily understood, how will they cooperate with the human? The presented research was conducted using the methods of iterative build-up and refinement of framework by triangulation, i.e. by instantiating and testing the framework with at least two derived concepts and prototypes. This article sketches a general, conceptual ergonomic framework of cooperative guidance and control of highly automated vehicles, two concepts derived from the framework, prototypes and pilot data. Cooperation is exemplified in a list of aspects and related to levels of the driving task. With the concept 'Conduct-by-Wire', cooperation happens mainly on the guidance level, where the driver can delegate manoeuvres to the automation with a specialised manoeuvre interface. With H-Mode, a haptic-multimodal interaction with highly automated vehicles based on the H(orse)-Metaphor, cooperation is mainly done on guidance and control with a haptically active interface. Cooperativeness should be a key aspect for future human-automation systems. Especially for highly automated vehicles, cooperative guidance and control is a research direction with already promising concepts and prototypes that should be further explored. The application of the presented approach is every human-machine system that moves and includes high

  1. Parametric dependencies of the experimental tungsten transport coefficients in ICRH and ECRH assisted ASDEX Upgrade H-modes

    Science.gov (United States)

    Sertoli, M.; Angioni, C.; Odstrcil, T.; ASDEX Upgrade Team; Eurofusion MST1 Team

    2017-11-01

    The profiles of the W transport coefficients have been experimentally calculated for a large database of identical ASDEX Upgrade H-mode discharges where only the radio-frequency (RF) power characteristics have been varied [Angioni et al., Nucl. Fusion 57, 056015 (2017)]. Central ion cyclotron resonance heating (ICRH) in the minority heating scheme has been compared with central and off-axis electron cyclotron resonance heating (ECRH), using both localized and broad heat deposition profiles. The transport coefficients have been calculated applying the gradient-flux relation to the evolution of the intrinsic W density in-between sawtooth cycles as measured using the soft X-ray diagnostic. For both ICRH and ECRH, the major player in reducing the central W density peaking is found to be the reduction of inward pinch and, in the case of ECRH, the rise of an outward convection. The impurity convection increases, from negative to positive, almost linearly with RF-power, while no appreciable changes are observed in the diffusion coefficient, which remains roughly at neoclassical levels independent of RF power or background plasma conditions. The ratio vW/DW is consistent with the equilibrium ∇ n W / n W prior to the sawtooth crash, corroborating the separate estimates of diffusion and convection. These experimental findings are slightly different from previous results obtained analysing the evolution of impurity injections over many sawtooth cycles. Modelling performed using the drift-kinetic code NEO and the gyro-kinetic code GKW (assuming axisymmetry) overestimates the diffusion coefficient and underestimates the experimental positive convection. This is a further indication that magneto-hydrodynamic/neoclassical models accounting for 3D effects may be needed to characterize impurity transport in sawtoothing tokamak plasmas.

  2. ELM Behavior in High- βp EAST-Demonstration Plasmas on DIII-D

    Science.gov (United States)

    Li, G. Q.; Gong, X. Z.; Garofalo, A. M.; Lao, L. L.; Meneghini, O.; Snyder, P. B.; Ren, Q. L.; Ding, S. Y.; Guo, W. F.; Qian, J. P.; Wan, B. N.; Xu, G. S.; Holcomb, C. T.; Solomon, W. M.

    2015-11-01

    In the DIII-D high- βp EAST-demonstration experiment, for several similar discharges when the experimental parameters such as the toroidal magnetic field or ECH power are varied slightly, the changes in ELM frequency response are observed to be much larger. Kinetic EFIT equilibrium reconstructions for these discharges have been performed, which suggest that the ELM frequency changes are likely due to the variations of pedestal width, height, and edge current density. Kinetic profile analyses further indicate that the strong ITB that are located at large minor radii (rho=0.6 ~0.7) in these discharges are affecting the pedestal structure. The ITB could broaden the pedestal width and decrease the pedestal height, thus changing the ELM frequency and size. With the GATO and ELITE MHD codes, the linear growth rates and mode structures of these ELMs are analyzed. The impact of ITB on the ELMs behavior will be discussed. Work supported by China MOST under 2014GB106001 and 2015GB102001 and US DOE under DE-FC02-04ER54698 and DE-FG03-95ER54309.

  3. [Dynamic Detection of Fresh Jujube Based on ELM and Visible/Near Infrared Spectra].

    Science.gov (United States)

    Yang, Yi; Zhang, Shu-juan; He, Yong

    2015-07-01

    Jujube was rich in nutrition and variety. In different varieties, there were very different from the market price to the qualities of internal and external. In order to realize the rapid and non-destructive detection of fresh jujubes' classification, Ban jujube, Jixin jujube and Xiang jujube were selected as research objects to collect their visible/near infrared spectral data dynamically. A combination of Moving Smoothing and Multiplicative Scatter Correction (MSC) was applied as the pretreatment method. After the pretreatment, the characteristic wavelengths extracted by Successive Projections Algorithm (SPA) were 980 nm, 1860, 1341, 1386, 2096, 1831, 1910, 1628, 441, 768 and 601 nm, respectively. And the importance reduced in accordance with the order. The 11 characteristic wavelengths were adopted as input variable to established Extreme Learning Machine (ELM) classification model, which was used for prediction. Comparing the ELM model's classification accuracy with other methods' classification accuracy such as Partial Least Squares Discriminant Analysis (PLS-DA) and Least Squares Support Vecor Machines (LS-SVM), the result indicated that: the R2 and the RMSEC of the SPA-ELM model was 0.97238 and 0.018724, respectively. The classification accuracy of the SPA-ELM model was 100% as good as the SPA-PLS-DA and SPA-LS-SVM. ELM was an effective classification method. This study provides a new theoretical basis for detection of fresh jujubes' classification.

  4. Compound feature selection and parameter optimization of ELM for fault diagnosis of rolling element bearings.

    Science.gov (United States)

    Luo, Meng; Li, Chaoshun; Zhang, Xiaoyuan; Li, Ruhai; An, Xueli

    2016-11-01

    This paper proposes a hybrid system named as HGSA-ELM for fault diagnosis of rolling element bearings, in which real-valued gravitational search algorithm (RGSA) is employed to optimize the input weights and bias of ELM, and the binary-valued of GSA (BGSA) is used to select important features from a compound feature set. Three types fault features, namely time and frequency features, energy features and singular value features, are extracted to compose the compound feature set by applying ensemble empirical mode decomposition (EEMD). For fault diagnosis of a typical rolling element bearing system with 56 working condition, comparative experiments were designed to evaluate the proposed method. And results show that HGSA-ELM achieves significant high classification accuracy compared with its original version and methods in literatures. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  5. Tungsten erosion under plasma heat loads typical for ITER type I Elms and disruptions

    Energy Technology Data Exchange (ETDEWEB)

    Garkusha, I.E. [Institute of Plasma Physics of the NSC KIPT, 61108 Kharkov (Ukraine)]. E-mail: garkusha@ipp.kharkov.ua; Bandura, A.N. [Institute of Plasma Physics of the NSC KIPT, 61108 Kharkov (Ukraine); Byrka, O.V. [Institute of Plasma Physics of the NSC KIPT, 61108 Kharkov (Ukraine); Chebotarev, V.V. [Institute of Plasma Physics of the NSC KIPT, 61108 Kharkov (Ukraine); Landman, I.S. [Forschungszentrum Karlsruhe, IHM, 76021 Karlsruhe (Germany); Makhlaj, V.A. [Institute of Plasma Physics of the NSC KIPT, 61108 Kharkov (Ukraine); Marchenko, A.K. [Institute of Plasma Physics of the NSC KIPT, 61108 Kharkov (Ukraine); Solyakov, D.G. [Institute of Plasma Physics of the NSC KIPT, 61108 Kharkov (Ukraine); Tereshin, V.I. [Institute of Plasma Physics of the NSC KIPT, 61108 Kharkov (Ukraine); Trubchaninov, S.A. [Institute of Plasma Physics of the NSC KIPT, 61108 Kharkov (Ukraine); Tsarenko, A.V. [Institute of Plasma Physics of the NSC KIPT, 61108 Kharkov (Ukraine)

    2005-03-01

    The behavior of pure sintered tungsten under repetitive plasma heat loads of {approx}1 MJ/m{sup 2} (which is relevant to ITER ELMs) and 25 MJ/m{sup 2} (ITER disruptions) is studied with the quasi-steady-state plasma accelerator QSPA Kh-50. The ELM relevant heat loads have resulted in formation of two kinds of crack networks, with typical sizes of 10-20 {mu}m and {approx}1 mm, at the surface. Tungsten preheating to 600 deg. C indicates that fine intergranular cracks are probably caused by thermal stresses during fast resolidification of the melt, whereas large cracks are the result of ductile-to-brittle transition. For several hundreds of ELM-like exposures, causing surface melting, the melt motion does not dominate the profile of the melt spot. The disruption relevant experiments demonstrated that melt motion became the main factor of tungsten damage.

  6. Tungsten erosion under plasma heat loads typical for ITER type I ELMs and disruptions

    Science.gov (United States)

    Garkusha, I. E.; Bandura, A. N.; Byrka, O. V.; Chebotarev, V. V.; Landman, I. S.; Makhlaj, V. A.; Marchenko, A. K.; Solyakov, D. G.; Tereshin, V. I.; Trubchaninov, S. A.; Tsarenko, A. V.

    2005-03-01

    The behavior of pure sintered tungsten under repetitive plasma heat loads of ˜1 MJ/m 2 (which is relevant to ITER ELMs) and 25 MJ/m 2 (ITER disruptions) is studied with the quasi-steady-state plasma accelerator QSPA Kh-50. The ELM relevant heat loads have resulted in formation of two kinds of crack networks, with typical sizes of 10-20 μm and ˜1 mm, at the surface. Tungsten preheating to 600 °C indicates that fine intergranular cracks are probably caused by thermal stresses during fast resolidification of the melt, whereas large cracks are the result of ductile-to-brittle transition. For several hundreds of ELM-like exposures, causing surface melting, the melt motion does not dominate the profile of the melt spot. The disruption relevant experiments demonstrated that melt motion became the main factor of tungsten damage.

  7. Analytical Redundancy Design for Aeroengine Sensor Fault Diagnostics Based on SROS-ELM

    Directory of Open Access Journals (Sweden)

    Jun Zhou

    2016-01-01

    Full Text Available Analytical redundancy technique is of great importance to guarantee the reliability and safety of aircraft engine system. In this paper, a machine learning based aeroengine sensor analytical redundancy technique is developed and verified through hardware-in-the-loop (HIL simulation. The modified online sequential extreme learning machine, selective updating regularized online sequential extreme learning machine (SROS-ELM, is employed to train the model online and estimate sensor measurements. It selectively updates the output weights of neural networks according to the prediction accuracy and the norm of output weight vector, tackles the problems of singularity and ill-posedness by regularization, and adopts a dual activation function in the hidden nodes combing neural and wavelet theory to enhance prediction capability. The experimental results verify the good generalization performance of SROS-ELM and show that the developed analytical redundancy technique for aeroengine sensor fault diagnosis based on SROS-ELM is effective and feasible.

  8. Enhancement of ELM by Clustering Discrimination Manifold Regularization and Multiobjective FOA for Semisupervised Classification.

    Science.gov (United States)

    Ye, Qing; Pan, Hao; Liu, Changhua

    2015-01-01

    A novel semisupervised extreme learning machine (ELM) with clustering discrimination manifold regularization (CDMR) framework named CDMR-ELM is proposed for semisupervised classification. By using unsupervised fuzzy clustering method, CDMR framework integrates clustering discrimination of both labeled and unlabeled data with twinning constraints regularization. Aiming at further improving the classification accuracy and efficiency, a new multiobjective fruit fly optimization algorithm (MOFOA) is developed to optimize crucial parameters of CDME-ELM. The proposed MOFOA is implemented with two objectives: simultaneously minimizing the number of hidden nodes and mean square error (MSE). The results of experiments on actual datasets show that the proposed semisupervised classifier can obtain better accuracy and efficiency with relatively few hidden nodes compared with other state-of-the-art classifiers.

  9. Enhancement of ELM by Clustering Discrimination Manifold Regularization and Multiobjective FOA for Semisupervised Classification

    Directory of Open Access Journals (Sweden)

    Qing Ye

    2015-01-01

    Full Text Available A novel semisupervised extreme learning machine (ELM with clustering discrimination manifold regularization (CDMR framework named CDMR-ELM is proposed for semisupervised classification. By using unsupervised fuzzy clustering method, CDMR framework integrates clustering discrimination of both labeled and unlabeled data with twinning constraints regularization. Aiming at further improving the classification accuracy and efficiency, a new multiobjective fruit fly optimization algorithm (MOFOA is developed to optimize crucial parameters of CDME-ELM. The proposed MOFOA is implemented with two objectives: simultaneously minimizing the number of hidden nodes and mean square error (MSE. The results of experiments on actual datasets show that the proposed semisupervised classifier can obtain better accuracy and efficiency with relatively few hidden nodes compared with other state-of-the-art classifiers.

  10. The observation of small ELM post-cursor mode in EAST

    Science.gov (United States)

    Nan, ZHAO; Ning, YAN; Guosheng, XU; Zhengxiong, WANG; Ran, CHEN; Huiqian, WANG; Liang, WANG; Siye, DING; Linming, SHAO; Liang, CHEN; Guanghai, HU; Wei, ZHANG

    2018-02-01

    A ‘post-cursor’ quasi-coherent mode with frequency ∼50 kHz has been observed following the crash of small edge localized modes (ELMs) in the Experimental Advanced Superconducting Tokamak by using a reciprocating Langmuir probe system inserted at the outboard midplane. This mode with strong potential and magnetic perturbations propagates in the electron-diamagnetic drift direction in the laboratory frame. In addition, these quasi-coherent fluctuations appear to be modulated by a MHD mode with lower frequency (∼5 kHz). The bi-coherence analysis shows that the post-cursor mode and the MHD mode have nonlinear interaction through three-wave coupling. The understanding on post-cursor mode can enhance our knowledge of ELMs and pedestal physics, and give new insight into the ELM process itself.

  11. Improving germination of red elm (Ulmus rubra), gray alder (Alnus incana), and buffaloberry (Shepherdia canadensis) seeds with gibberellic acid

    Science.gov (United States)

    Brenda Morales; Charles Barden; Cheryl Boyer; Jason Griffin; Lillian Fisher; Joni Thompson

    2012-01-01

    Red elm (Ulmus rubra), gray alder (Alnus incana), and buffaloberry (Shepherdia canadensis) are considered important plants for many Native American tribes in the United States. Native Americans use these 3 species for a variety of traditional and medicinal purposes. For example, red elm is still the preferred firewood for the cultural ceremonies of several tribes....

  12. The Glenwood Estate: our 32-year experience using Arbotect® 20-S to control Dutch elm disease

    Science.gov (United States)

    William L. MacDonald; Mark L. Double; Cameron M. Stauder; Kemp. Winfree

    2017-01-01

    We report a case study that demonstrates the successful use of the fungicide Arbotect® 20-S to protect American elms (Ulmus americana) from Dutch elm disease at a historic site in Charleston, WV. Standard injection protocols were used every 3 to 4 years to deliver the chemical into the root flares. Twelve of the original 16 trees remain 34 years...

  13. Some Guides to Discovery About Elm Trees, Owls, Cockroaches, Earthworms, Cement and Concrete.

    Science.gov (United States)

    Busch, Phyllis S.

    The introduction emphasizes the need for environmental and conservation education, and advocates an inquiry approach. Outdoor resources available to every school are listed. Detailed suggestions are made for investigating cement and concrete, cockroaches, earthworms, elm trees, and owls. In each case general background information and a list of…

  14. Statistical correlations between GLC assay and smaller European elm bark beetle bioassay

    Science.gov (United States)

    Jack H. Barger; Roy A. Cuthbert; Donald G. Seegrist

    1973-01-01

    American elm trees, Ulmus americana L., were sprayed with methoxychlor by helicopter or mist blower, and twig crotches were collected from sprayed trees for bioassay of Scolytus multistriatus (Marsham) and GLC assay. Correlations established between the 2 assays were dependent on method of application and amount of methoxychlor...

  15. Multigrades Classification Model of Magnesite Ore Based on SAE and ELM

    Directory of Open Access Journals (Sweden)

    Yachun Mao

    2017-01-01

    Full Text Available Magnesite is an important raw material for extracting magnesium metal and magnesium compound; how precise its grade classification exerts great influence on the smelting process. Thus, it is increasingly important to determine fast and accurately the grade of magnesite. In this paper, a method based on stacked autoencoder (SAE and extreme learning machine (ELM was established for the classification model of magnesite. Stacked autoencoder (SAE was firstly used to reduce the dimension of magnesite spectrum data and then neutral network model of extreme learning machine (ELM was adopted to classify the data. Two improved extreme learning machine (ELM models were employed for better classification, namely, accuracy extreme learning machine (AELM and integrated accuracy (IELM to build up the classification models. The grade classification through traditional methods such as chemical approaches, artificial methods, and BP neutral network model was compared to that in this paper. Results showed that the classification model of magnesite ore through stacked autoencoder (SAE and extreme learning machine (ELM is better in terms of speed and accuracy; thus, this paper provides a new way for the grade classification of magnesite ore.

  16. Surface damage of W exposed to combined stationary D plasma and ELMs-like pulsed plasma

    NARCIS (Netherlands)

    Jia, Y. Z.; Liu, W.; Xu, B.; Qu, S. L.; Morgan, T. W.

    2017-01-01

    The surface damage of W under D plasma and ELMs-like transient heat loads was studied by combined stationary and pulsed D plasma. Low-flux transient heat loads will promote blister formation due to the gas expansion inside the blisters. On the contrary, high-flux transient heat loads will mitigate

  17. An elm EST database for identifying leaf beetle egg-induced defense genes

    Directory of Open Access Journals (Sweden)

    Büchel Kerstin

    2012-06-01

    Full Text Available Abstract Background Plants can defend themselves against herbivorous insects prior to the onset of larval feeding by responding to the eggs laid on their leaves. In the European field elm (Ulmus minor, egg laying by the elm leaf beetle ( Xanthogaleruca luteola activates the emission of volatiles that attract specialised egg parasitoids, which in turn kill the eggs. Little is known about the transcriptional changes that insect eggs trigger in plants and how such indirect defense mechanisms are orchestrated in the context of other biological processes. Results Here we present the first large scale study of egg-induced changes in the transcriptional profile of a tree. Five cDNA libraries were generated from leaves of (i untreated control elms, and elms treated with (ii egg laying and feeding by elm leaf beetles, (iii feeding, (iv artificial transfer of egg clutches, and (v methyl jasmonate. A total of 361,196 ESTs expressed sequence tags (ESTs were identified which clustered into 52,823 unique transcripts (Unitrans and were stored in a database with a public web interface. Among the analyzed Unitrans, 73% could be annotated by homology to known genes in the UniProt (Plant database, particularly to those from Vitis, Ricinus, Populus and Arabidopsis. Comparative in silico analysis among the different treatments revealed differences in Gene Ontology term abundances. Defense- and stress-related gene transcripts were present in high abundance in leaves after herbivore egg laying, but transcripts involved in photosynthesis showed decreased abundance. Many pathogen-related genes and genes involved in phytohormone signaling were expressed, indicative of jasmonic acid biosynthesis and activation of jasmonic acid responsive genes. Cross-comparisons between different libraries based on expression profiles allowed the identification of genes with a potential relevance in egg-induced defenses, as well as other biological processes, including signal transduction

  18. Numerical analysis of the effects of normalized plasma pressure on RMP ELM suppression in DIII-D

    Science.gov (United States)

    Orlov, D. M.; Moyer, R. A.; Evans, T. E.; Mordijck, S.; Osborne, T. H.; Fenstermacher, M. E.; Snyder, P. B.; Unterberg, E. A.

    2010-03-01

    The effect of normalized plasma pressure as characterized by normalized pressure parameter (βN) on the suppression of edge localized modes (ELMs) using resonant magnetic perturbations (RMPs) is studied in low-collisionality (ν* vacuum field topology with βN due to safety factor profile and island overlap changes caused by variation of the Shafranov shift and pedestal bootstrap current are examined numerically with the field line integration code TRIP3D. The results show very small differences in the vacuum field structure in terms of the Chirikov (magnetic island overlap) parameter, Poincaré sections and field line loss fractions. These differences do not appear to explain the observed threshold in βN for ELM suppression. Linear peeling-ballooning stability analysis with the ELITE code suggests that the ELMs which persist during the RMPs when βN is below the observed threshold are not type I ELMs, because the pedestal conditions are deep within the stable regime for peeling-ballooning modes. These ELMs have similarities to type III ELMs or low density ELMs.

  19. Observation of Abrupt- and Fast-rising SOL Current during Trigger Phase of ELMs in DIII-D Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    H. Takahashi; E.D. Fredrickson; M.J. Schaffer; M.E. Austin; N.H. Brooks; T.E. Evans; G.L. Jackson; L.L. Lao; J.G. Watkins

    2005-06-27

    Extensive studies to date of edge localized modes (ELMs) have sought their origin inside the separatrix, i.e., MHD instability from steep gradients in the plasma edge, and examined their consequences outside the separatrix, i.e., transport of heat and particles in the scrape-off-layer (SOL) and divertors. Recent measurement by a high-speed scrape-off-layer current (SOLC) diagnostic may indicate that the ELM trigger process lies, in part, in the SOL. Thermoelectrically driven SOLC precedes, or co-evolves with, other parameters of the ELM process, and thus can potentially play a causal role: error field generated by non-axisymmetric SOLC, flowing in the immediate vicinity (approximately 1 cm) of the plasma edge, may contribute toward destabilizing MHD modes. The SOLC, observed concurrently with MHD activity, including ELMs, has been reported elsewhere.

  20. ELM - A SIMPLE TOOL FOR THERMAL-HYDRAULIC ANALYSIS OF SOLID-CORE NUCLEAR ROCKET FUEL ELEMENTS

    Science.gov (United States)

    Walton, J. T.

    1994-01-01

    ELM is a simple computational tool for modeling the steady-state thermal-hydraulics of propellant flow through fuel element coolant channels in nuclear thermal rockets. Written for the nuclear propulsion project of the Space Exploration Initiative, ELM evaluates the various heat transfer coefficient and friction factor correlations available for turbulent pipe flow with heat addition. In the past, these correlations were found in different reactor analysis codes, but now comparisons are possible within one program. The logic of ELM is based on the one-dimensional conservation of energy in combination with Newton's Law of Cooling to determine the bulk flow temperature and the wall temperature across a control volume. Since the control volume is an incremental length of tube, the corresponding pressure drop is determined by application of the Law of Conservation of Momentum. The size, speed, and accuracy of ELM make it a simple tool for use in fuel element parametric studies. ELM is a machine independent program written in FORTRAN 77. It has been successfully compiled on an IBM PC compatible running MS-DOS using Lahey FORTRAN 77, a DEC VAX series computer running VMS, and a Sun4 series computer running SunOS UNIX. ELM requires 565K of RAM under SunOS 4.1, 360K of RAM under VMS 5.4, and 406K of RAM under MS-DOS. Because this program is machine independent, no executable is provided on the distribution media. The standard distribution medium for ELM is one 5.25 inch 360K MS-DOS format diskette. ELM was developed in 1991. DEC, VAX, and VMS are trademarks of Digital Equipment Corporation. Sun4 and SunOS are trademarks of Sun Microsystems, Inc. IBM PC is a registered trademark of International Business Machines. MS-DOS is a registered trademark of Microsoft Corporation.

  1. AN ELM FOR BI-CLASSIFICATION OF VERTICALLY BUNDLED ELECTRICITY MARKET PRICES

    Directory of Open Access Journals (Sweden)

    S Anbazhagan

    2018-10-01

    Full Text Available Electricity price forecasting is a challenging problem owing to the very great volatility of price which depends on many factors. This is especially prominent for both producers and consumers where a versatile price forecasting is crucial. This paper contributes an extreme learning machine (ELM to classify the prices. These price classifications are essential since all market players do not know the precise value of future prices in their deciding procedure. In this paper, bi-classification model is proposed for prices utilizing the pre-specified price threshold. Three alternative classification models based on neural networks (NNs are also proposed in bi-classification of prices. The performance of the proposed models is compared in terms of classification error and accuracy. The simulation results show that the ELM classification model is superior compared to three other classification models based on NNs. The performances of our models are evaluated using real data from vertically unbundled mainland Spain power system market.

  2. Fault Diagnosis for Analog Circuits by Using EEMD, Relative Entropy, and ELM.

    Science.gov (United States)

    Xiong, Jian; Tian, Shulin; Yang, Chenglin

    2016-01-01

    This paper presents a novel fault diagnosis method for analog circuits using ensemble empirical mode decomposition (EEMD), relative entropy, and extreme learning machine (ELM). First, nominal and faulty response waveforms of a circuit are measured, respectively, and then are decomposed into intrinsic mode functions (IMFs) with the EEMD method. Second, through comparing the nominal IMFs with the faulty IMFs, kurtosis and relative entropy are calculated for each IMF. Next, a feature vector is obtained for each faulty circuit. Finally, an ELM classifier is trained with these feature vectors for fault diagnosis. Via validating with two benchmark circuits, results show that the proposed method is applicable for analog fault diagnosis with acceptable levels of accuracy and time cost.

  3. Fault Diagnosis for Analog Circuits by Using EEMD, Relative Entropy, and ELM

    Directory of Open Access Journals (Sweden)

    Jian Xiong

    2016-01-01

    Full Text Available This paper presents a novel fault diagnosis method for analog circuits using ensemble empirical mode decomposition (EEMD, relative entropy, and extreme learning machine (ELM. First, nominal and faulty response waveforms of a circuit are measured, respectively, and then are decomposed into intrinsic mode functions (IMFs with the EEMD method. Second, through comparing the nominal IMFs with the faulty IMFs, kurtosis and relative entropy are calculated for each IMF. Next, a feature vector is obtained for each faulty circuit. Finally, an ELM classifier is trained with these feature vectors for fault diagnosis. Via validating with two benchmark circuits, results show that the proposed method is applicable for analog fault diagnosis with acceptable levels of accuracy and time cost.

  4. Observation of Current Structures at Type-III ELM Onset on EAST

    DEFF Research Database (Denmark)

    Yan, Ning; Naulin, Volker; Xu, G.

    In far scrape-o layer (SOL), alternating negative and positive burst structures in ion saturation current were detected at the onset of each type-III edge localized mode (ELM) on EAST. Different from the fast streaming phenomenon reported previously, one subsequent positive burst structure appears...... structure. To verify the current characteristic of this structure, a mono-polar current filaments model was involved, which can reproduce same pattern commendably. Thus, current transport may dominant in transitional stage and plays an important role in the nonlinear development phase of ELM exhaustive...... crash. As current structure can only be observed in far SOL region of EAST, it maybe conceivable to consider the current origin from local condition rather than release from inside of the pedestal. Our observation may potentially provide support evidence for the recent theory prediction that the error...

  5. An AST-ELM Method for Eliminating the Influence of Charging Phenomenon on ECT

    Directory of Open Access Journals (Sweden)

    Xiaoxin Wang

    2017-12-01

    Full Text Available Electrical capacitance tomography (ECT is a promising imaging technology of permittivity distributions in multiphase flow. To reduce the effect of charging phenomenon on ECT measurement, an improved extreme learning machine method combined with adaptive soft-thresholding (AST-ELM is presented and studied for image reconstruction. This method can provide a nonlinear mapping model between the capacitance values and medium distributions by using machine learning but not an electromagnetic-sensitive mechanism. Both simulation and experimental tests are carried out to validate the performance of the presented method, and reconstructed images are evaluated by relative error and correlation coefficient. The results have illustrated that the image reconstruction accuracy by the proposed AST-ELM method has greatly improved than that by the conventional methods under the condition with charging object.

  6. Diagnostics Method for Analog Circuits Based on Improved KECA and Minimum Variance ELM

    Science.gov (United States)

    Yuan, Zhijie; He, Yigang; Yuan, Lifen

    2017-09-01

    Kernel entropy component analysis(KECA) is a new method for data transformation and dimensionality reduction. However it is sensitive to a single kernel radius. By analysis of the relation of statistics in the kernel feature space, improved KECA introduces two kernel radii and an adjusting factor to make KECA less sensitive to kernel radius. A method for fault diagnosis of analog circuits based on the combination of improved KECA and minimum variance extreme learning machine(ELM)is presented. Through wavelet decomposition of sampled signals, features are extracted. Improved KECA for feature dimension reduction is used. Then the fault patterns are classified by minimum variance ELM. Case studies on two analog circuits demonstrating our diagnostics method are presented.

  7. Neonicotinoid Insecticide Imidacloprid Causes Outbreaks of Spider Mites on Elm Trees in Urban Landscapes

    Science.gov (United States)

    Szczepaniec, Adrianna; Creary, Scott F.; Laskowski, Kate L.; Nyrop, Jan P.; Raupp, Michael J.

    2011-01-01

    Background Attempts to eradicate alien arthropods often require pesticide applications. An effort to remove an alien beetle from Central Park in New York City, USA, resulted in widespread treatments of trees with the neonicotinoid insecticide imidacloprid. Imidacloprid's systemic activity and mode of entry via roots or trunk injections reduce risk of environmental contamination and limit exposure of non-target organisms to pesticide residues. However, unexpected outbreaks of a formerly innocuous herbivore, Tetranychus schoenei (Acari: Tetranychidae), followed imidacloprid applications to elms in Central Park. This undesirable outcome necessitated an assessment of imidacloprid's impact on communities of arthropods, its effects on predators, and enhancement of the performance of T. schoenei. Methodology/Principal Findings By sampling arthropods in elm canopies over three years in two locations, we document changes in the structure of communities following applications of imidacloprid. Differences in community structure were mostly attributable to increases in the abundance of T. schoenei on elms treated with imidacloprid. In laboratory experiments, predators of T. schoenei were poisoned through ingestion of prey exposed to imidacloprid. Imidacloprid's proclivity to elevate fecundity of T. schoenei also contributed to their elevated densities on treated elms. Conclusions/Significance This is the first study to report the effects of pesticide applications on the arthropod communities in urban landscapes and demonstrate that imidacloprid increases spider mite fecundity through a plant-mediated mechanism. Laboratory experiments provide evidence that imidacloprid debilitates insect predators of spider mites suggesting that relaxation of top-down regulation combined with enhanced reproduction promoted a non-target herbivore to pest status. With global commerce accelerating the incidence of arthropod invasions, prophylactic applications of pesticides play a major role in

  8. Phospho.ELM: A database of experimentally verified phosphorylation sites in eukaryotic proteins

    DEFF Research Database (Denmark)

    Diella, F.; Cameron, S.; Gemund, C.

    2004-01-01

    Background: Post-translational phosphorylation is one of the most common protein modifications. Phosphoserine, threonine and tyrosine residues play critical roles in the regulation of many cellular processes. The fast growing number of research reports on protein phosphorylation points to a general...... instances for 556 phosphorylated proteins. Conclusion: Phospho. ELM will be a valuable tool both for molecular biologists working on protein phosphorylation sites and for bioinformaticians developing computational predictions on the specificity of phosphorylation reactions....

  9. Dutch elm disease: an overview of the biology and management regimens

    Science.gov (United States)

    R. Jay. Stipes

    2017-01-01

    Much of the information on the Dutch elm disease (DED) topic was generated by a large group of dedicated scientists, in several different agencies, primarily in the United States and Europe, over the last century. My work on the fungicidal management is but a modest contribution to the whole. It goes without saying that much more work needs to be done to open up new...

  10. Neonicotinoid insecticide imidacloprid causes outbreaks of spider mites on elm trees in urban landscapes.

    Directory of Open Access Journals (Sweden)

    Adrianna Szczepaniec

    Full Text Available BACKGROUND: Attempts to eradicate alien arthropods often require pesticide applications. An effort to remove an alien beetle from Central Park in New York City, USA, resulted in widespread treatments of trees with the neonicotinoid insecticide imidacloprid. Imidacloprid's systemic activity and mode of entry via roots or trunk injections reduce risk of environmental contamination and limit exposure of non-target organisms to pesticide residues. However, unexpected outbreaks of a formerly innocuous herbivore, Tetranychus schoenei (Acari: Tetranychidae, followed imidacloprid applications to elms in Central Park. This undesirable outcome necessitated an assessment of imidacloprid's impact on communities of arthropods, its effects on predators, and enhancement of the performance of T. schoenei. METHODOLOGY/PRINCIPAL FINDINGS: By sampling arthropods in elm canopies over three years in two locations, we document changes in the structure of communities following applications of imidacloprid. Differences in community structure were mostly attributable to increases in the abundance of T. schoenei on elms treated with imidacloprid. In laboratory experiments, predators of T. schoenei were poisoned through ingestion of prey exposed to imidacloprid. Imidacloprid's proclivity to elevate fecundity of T. schoenei also contributed to their elevated densities on treated elms. CONCLUSIONS/SIGNIFICANCE: This is the first study to report the effects of pesticide applications on the arthropod communities in urban landscapes and demonstrate that imidacloprid increases spider mite fecundity through a plant-mediated mechanism. Laboratory experiments provide evidence that imidacloprid debilitates insect predators of spider mites suggesting that relaxation of top-down regulation combined with enhanced reproduction promoted a non-target herbivore to pest status. With global commerce accelerating the incidence of arthropod invasions, prophylactic applications of pesticides

  11. Neonicotinoid insecticide imidacloprid causes outbreaks of spider mites on elm trees in urban landscapes.

    Science.gov (United States)

    Szczepaniec, Adrianna; Creary, Scott F; Laskowski, Kate L; Nyrop, Jan P; Raupp, Michael J

    2011-01-01

    Attempts to eradicate alien arthropods often require pesticide applications. An effort to remove an alien beetle from Central Park in New York City, USA, resulted in widespread treatments of trees with the neonicotinoid insecticide imidacloprid. Imidacloprid's systemic activity and mode of entry via roots or trunk injections reduce risk of environmental contamination and limit exposure of non-target organisms to pesticide residues. However, unexpected outbreaks of a formerly innocuous herbivore, Tetranychus schoenei (Acari: Tetranychidae), followed imidacloprid applications to elms in Central Park. This undesirable outcome necessitated an assessment of imidacloprid's impact on communities of arthropods, its effects on predators, and enhancement of the performance of T. schoenei. By sampling arthropods in elm canopies over three years in two locations, we document changes in the structure of communities following applications of imidacloprid. Differences in community structure were mostly attributable to increases in the abundance of T. schoenei on elms treated with imidacloprid. In laboratory experiments, predators of T. schoenei were poisoned through ingestion of prey exposed to imidacloprid. Imidacloprid's proclivity to elevate fecundity of T. schoenei also contributed to their elevated densities on treated elms. This is the first study to report the effects of pesticide applications on the arthropod communities in urban landscapes and demonstrate that imidacloprid increases spider mite fecundity through a plant-mediated mechanism. Laboratory experiments provide evidence that imidacloprid debilitates insect predators of spider mites suggesting that relaxation of top-down regulation combined with enhanced reproduction promoted a non-target herbivore to pest status. With global commerce accelerating the incidence of arthropod invasions, prophylactic applications of pesticides play a major role in eradication attempts. Widespread use of neonicotinoid insecticides

  12. Segmentation and abnormality detection of cervical cancer cells using fast elm with particle swarm optimization

    Directory of Open Access Journals (Sweden)

    Sukumar P.

    2015-01-01

    Full Text Available Cervical cancer arises when the anomalous cells on the cervix mature unmanageable obviously in the renovation sector. The most probably used methods to detect abnormal cervical cells are the routine and there is no difference between the abnormal and normal nuclei. So that the abnormal nuclei found are brown in color while normal nuclei are blue in color. The spread or cells are examined and the image denoising is performed based on the Iterative Decision Based Algorithm. Image Segmentation is the method of paneling a digital image into compound sections. The major utilize of segmentation is to abridge or modify the demonstration of an image. The images are segmented by applying anisotropic diffusion on the Denoised image. Image can be enhanced using dark stretching to increase the quality of the image. It separates the cells into all nuclei region and abnormal nuclei region. The abnormal nuclei regions are further classified into touching and non-touching regions and touching regions undergoes feature selection process. The existing Support Vector Machines (SVM is classified few nuclei regions but the time to taken for execution is high. The abnormality detected from the image is calculated as 45% from the total abnormal nuclei. Thus the proposed method of Fast Particle Swarm Optimization with Extreme Learning Machines (Fast PSO-ELM to classify all nuclei regions further into touching region and separated region. The iterative method for to training the ELM and make it more efficient than the SVM method. In experimental result, the proposed method of Fast PSO-ELM may shows the accuracy as above 90% and execution time is calculated based on the abnormality (ratio of abnormal nuclei regions to all nuclei regions image. Therefore, Fast PSO-ELM helps to detect the cervical cancer cells with maximum accuracy.

  13. Deuterium charge exchange recombination spectroscopy from the top of the pedestal to the scrape off layer in H-mode plasmas

    Science.gov (United States)

    Haskey, S. R.; Grierson, B. A.; Stagner, L.; Burrell, K. H.; Chrystal, C.; Groebner, R. J.; Ashourvan, A.; Pablant, N. A.

    2017-10-01

    Recent completion of the thirty two channel main-ion (deuterium) charge exchange recombination spectroscopy (CER) diagnostic on DIII-D [J.L. Luxon, Nucl. Fusion 42 (2002) 614] enables detailed comparisons between impurity and main-ion temperature, density, and toroidal rotation. Sixteen sightlines cover the core of the plasma and another sixteen are densely packed towards the edge, providing high resolution measurements of the pedestal and steep gradient edge region of H-mode plasmas. The complexities of the Dα spectrum require fitting with a comprehensive model, as well as using iterative collisional radiative modeling to determine the underlying thermal deuterium ion properties. Large differences in the structure and magnitude of impurity (C6+) and main-ion (D+) toroidal rotation profiles are seen in the H-mode pedestal. Additionally the D+ temperature can be half the value of the C6+ temperature at the separatrix and shows more of a pedestal structure. Typically only the impurity properties are measured and the main-ion properties are either assumed to be the same, or inferred using neoclassical models, which require validation in the steep gradient region. These measured differences have implications for transport model validation, intrinsic rotation studies, pedestal stability, and the boundary conditions for scrape off layer and plasma material interactions studies.

  14. Simulation of the ELMs triggering by lithium pellet on EAST tokamak using BOUT + +

    Science.gov (United States)

    Wang, Y. M.; Xu, X. Q.; Wang, Z.; Sun, Z.; Hu, J. S.; Gao, X.

    2017-10-01

    A new lithium granule injector (LGI) was developed on EAST. Using the LGI, lithium granules can be efficiently injected into EAST tokamak with the granule radius 0.2-1 mm and the granules velocity 30-110 m/s. ELM pacing was realized during EAST shot #70123 at time window from 4.4-4.7s, the average velocity of the pellet was 75 m/s and the average injection rate is at 99Hz. The BOUT + + 6-field electromagnetic turbulence code has been used to simulate the ELM pacing process. A neutral gas shielding (NGS) model has been implemented during the pellet ablation process. The neutral transport code is used to evaluate the ionized electron and Li ion densities with the charge exchange as a dominant factor in the neutral cloud diffusion process. The snapshot plasma profiles during the pellet ablation and toroidal symmetrization process are used in the 6-field turbulence code to evaluate the impact of the pellets on ELMs. Destabilizing effects of the peeling-ballooning modes are found with lithium pellet injection, which is consistent with the experimental results. A scan of the pellet size, shape and the injection velocity will be conducted, which will benefit the pellet injection design in both the present and future devices. Prepared by LLNL under Contract DE-AC52-07NA27344 and this work is supported by the National Natural Science Fonudation of China (Grant No. 11505221) and China Scholarship Council (Grant No. 201504910132).

  15. Feature Optimize and Classification of EEG Signals: Application to Lie Detection Using KPCA and ELM

    Directory of Open Access Journals (Sweden)

    GAO Junfeng

    2014-04-01

    Full Text Available EEG signals had been widely used to detect liars recent years. To overcome the shortcomings of current signals processing, kernel principal component analysis (KPCA and extreme learning machine (ELM was combined to detect liars. We recorded the EEG signals at Pz from 30 randomly divided guilty and innocent subjects. Each five Probe responses were averaged within subject and then extracted wavelet features. KPCA was employed to select feature subset with deduced dimensions based on initial wavelet features, which was fed into ELM. To date, there is no perfect solution for the number of its hidden nodes (NHN. We used grid searching algorithm to select simultaneously the optimal values of the dimension of feature subset and NHN based on cross- validation method. The best classification mode was decided with the optimal searching values. Experimental results show that for EEG signals from the experiment of lie detection, KPCA_ELM has higher classification accuracy with faster training speed than other widely-used classification modes, which is especially suitable for online EEG signals processing system.

  16. Intermediate-k density and magnetic field fluctuations during inter-ELM pedestal evolution in MAST

    Science.gov (United States)

    Hillesheim, J. C.; Dickinson, D.; Roach, C. M.; Saarelma, S.; Scannell, R.; Kirk, A.; Crocker, N. A.; Peebles, W. A.; Meyer, H.; the MAST Team

    2016-01-01

    Measurements of local density and magnetic field fluctuations near the pedestal top, conditionally averaged over the edge localized mode (ELM) cycle, have been made in Mega Amp Spherical Tokamak (MAST). A Doppler backscattering (DBS) system installed at MAST was used to measure intermediate-k ≤ft({{k}\\bot}{ρi}≈ 3~\\text{to}~4\\right) density fluctuations at the top of the pedestal. A novel diagnostic technique combining DBS with cross-polarization scattering (CP-DBS) enabled magnetic field fluctuations to also be locally measured at similar wave numbers. Polarization isolation and other effects for CP-DBS are discussed. Both measurements were used in a series of high-β ≤ft({βn}≈ 4.0\\right. -4.5) MAST plasmas with large type-I ELMs with an ˜ 8~\\text{to}~9~\\text{ms} period where microtearing modes (MTMs) had been predicted to be unstable in similar conditions (Dickinson 2012 Phys. Rev. Lett. 108 135002). The measured density fluctuation level increased by a factor of about 4 between 2 and 4 ms after the ELM, which was correlated with the recovery of the density profile while the temperature pedestal height continued to increase slowly. Magnetic field fluctuations showed different temporal behaviors, slowly increasing throughout the ELM cycle as the local β increased. Linear GS2 calculations show both MTM and electron temperature gradient (ETG) modes unstable at similar wave numbers as the measurements (although with more overlap between ETG wave numbers and diagnostic spectral resolution) at the top of the pedestal, along with kinetic ballooning modes are unstable lower in the pedestal (at larger wavelengths). The inferred ratio of fluctuation levels from experiment was ≤ft(δ B/B\\right)/≤ft(δ n/n\\right)≈ 1/20 . The comparable ratios from GS2 were ≤ft(δ B/B\\right)/≤ft(δ n/n\\right)≈ 0.4 for the MTM and ≤ft(δ B/B\\right)/≤ft(δ n/n\\right)≈ 0.02 for the ETG. Both the experimental wave number range and the fluctuation ratio

  17. Dendrometric, phytopathological and entomological characteristics of a wych elm tree on mt. Goč

    Directory of Open Access Journals (Sweden)

    Medarević Milan

    2011-01-01

    Full Text Available Valuable broadleaves, including also wych elms, belong to the category of rare tree species in the growing stock of Serbia. The conservation of Serbian forest diversity and the genetic potential of these tree species require a multidisciplinary study. In this respect, we undertook a dendrometric and health analysis of a wych elm tree on Goč, as it is a rarity by its dimensions, not only from the local, but also from the regional aspects. The tree is 266 years old, its diameter at breast height is 2.09 m, height 42.1 m, and volume (d>3 cm 56.35 m3. Current height increment culminated early, at the age of 20-30 years, attaining 0.5 m, and current diameter increment at the age of 40-50 years when its value was 14.4 mm. The above data point to a high productivity of this elm tree and to favourable site and stand conditions of its development. On the other hand, its current diameter increment and height over the last period (1.7 mm, and 0.03 m respectively indicate that the tree was in the phase of physiological dying. 10 species of fungi were identified on the tree (facultative parasites or saprophytes, the most significant being Armillaria mellea and Aurantioporus fissilis, which caused central heartwood decay. Other fungi developed saprophytically in the dead part of the stem or in dead branches. Eight insect species (secondary and tertiary pests were identified, including the two most dangerous elm beetles (Scolytus scolytus and S. multistriatus. Together with the species Saperda punctata and Cerambyx scopolii, they accelerated the dying process of twigs and branches, as well as of the whole tree. Ambrosia beetle Xyleborus monographus infested the stem and the large dead branches and caused minor technical damage in wood. The species Dorcus paralelopipedus, Oryctes nasicornis and Valgus hemipterus supported the faster progress of wood-rotting fungi and thus contributed to physiological weakening and shortened the life cycle of the study elm tree.

  18. Control of yeast-mycelium dimorphism in vitro in Dutch elm disease fungi by manipulation of specific external stimuli.

    Science.gov (United States)

    Naruzawa, Erika Sayuri; Bernier, Louis

    2014-11-01

    Dutch elm disease (DED) fungi exhibit yeast-mycelium dimorphism both in planta and in vitro. However, previously published data on the transition between these two growth forms in vitro were mostly obtained from a single strain. We examined the effect of six factors on yeast-mycelium dimorphism in vitro in ten strains of Ophiostoma ulmi, Ophiostoma novo-ulmi and Ophiostoma himal-ulmi. Nitrogen sources, calcium, and yeast extract, altogether with inhibitors of phosphodiesterase (caffeine) and dioxygenases (propyl gallate and salicylic acid) were tested in defined culture media. Morphological response to manipulation of several of these factors varied according to the strain of Ophiostoma being analysed. Responses ranged from no statistical differences in morphological transitions to stimulation or reversion of yeast-mycelium dimorphism with the treatments that were tested. These results suggest that different mechanisms and pathways operate in the control of the yeast-mycelium transition in DED pathogens. Oxylipins could be involved in the yeast-to-mycelium transition, since the addition of a dioxygenase inhibitor, salicylic acid, reduced mycelium production in all strains that were tested. Copyright © 2014 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  19. Inhibition of phenylpropanoid biosynthesis increases cell wall digestibility, protoplast isolation, and facilitates sustained cell division in American elm (Ulmus americana

    Directory of Open Access Journals (Sweden)

    Jones A Maxwell P

    2012-05-01

    Full Text Available Abstract Background Protoplast technologies offer unique opportunities for fundamental research and to develop novel germplasm through somatic hybridization, organelle transfer, protoclonal variation, and direct insertion of DNA. Applying protoplast technologies to develop Dutch elm disease resistant American elms (Ulmus americana L. was proposed over 30 years ago, but has not been achieved. A primary factor restricting protoplast technology to American elm is the resistance of the cell walls to enzymatic degradation and a long lag phase prior to cell wall re-synthesis and cell division. Results This study suggests that resistance to enzymatic degradation in American elm was due to water soluble phenylpropanoids. Incubating tobacco (Nicotiana tabacum L. leaf tissue, an easily digestible species, in aqueous elm extract inhibits cell wall digestion in a dose dependent manner. This can be mimicked by p-coumaric or ferulic acid, phenylpropanoids known to re-enforce cell walls. Culturing American elm tissue in the presence of 2-aminoindane-2-phosphonic acid (AIP; 10-150 μM, an inhibitor of phenylalanine ammonia lyase (PAL, reduced flavonoid content, decreased tissue browning, and increased isolation rates significantly from 11.8% (±3.27 in controls to 65.3% (±4.60. Protoplasts isolated from callus grown in 100 μM AIP developed cell walls by day 2, had a division rate of 28.5% (±3.59 by day 6, and proliferated into callus by day 14. Heterokaryons were successfully produced using electrofusion and fused protoplasts remained viable when embedded in agarose. Conclusions This study describes a novel approach of modifying phenylpropanoid biosynthesis to facilitate efficient protoplast isolation which has historically been problematic for American elm. This isolation system has facilitated recovery of viable protoplasts capable of rapid cell wall re-synthesis and sustained cell division to form callus. Further, isolated protoplasts survived

  20. Data-Driven Dynamic Modeling for Prediction of Molten Iron Silicon Content Using ELM with Self-Feedback

    Directory of Open Access Journals (Sweden)

    Ping Zhou

    2015-01-01

    Full Text Available Silicon content ([Si] for short of the molten metal is an important index reflecting the product quality and thermal status of the blast furnace (BF ironmaking process. Since the online detection of [Si] is difficult and larger time delay exists in the offline assay procedure, quality modeling is required to achieve online estimation of [Si]. Focusing on this problem, a data-driven dynamic modeling method is proposed using improved extreme learning machine (ELM with the help of principle component analysis (PCA. First, data-driven PCA is introduced to pick out the most pivotal variables from multitudinous factors to serve as the secondary variables of modeling. Second, a novel data-driven ELM modeling technology with good generalization performance and nonlinear mapping capability is presented by applying a self-feedback structure on traditional ELM. The feedback outputs at previous time together with input variables at different time constitute a dynamic ELM structure which has a storage ability to tackle data in different time and overcomes the limitation of static modeling of traditional ELM. At last, industrial experiments demonstrate that the proposed method has a better modeling and estimating accuracy as well as a faster learning speed when compared with different modeling methods with different model structures.

  1. Synergistic effects of ELMs and steady state H and H/He irradiation on tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Lemahieu, Nathan, E-mail: n.lemahieu@fz-juelich.de [Institute for Energy and Climate Research, Forschungszentrum Jülich, 52425 Jülich (Germany); Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41 B4, 9000 Gent (Belgium); Institute of Interfacial Process Engineering and Plasma Technology IGVP, Universität Stuttgart, Pfaffenwaldring 31, 70569 Stuttgart (Germany); Greuner, Henri [Max Planck Institute for Plasma Physics, Boltzmannstraße 2, 85748 Garching (Germany); Linke, Jochen [Institute for Energy and Climate Research, Forschungszentrum Jülich, 52425 Jülich (Germany); Maier, Hans [Max Planck Institute for Plasma Physics, Boltzmannstraße 2, 85748 Garching (Germany); Pintsuk, Gerald [Institute for Energy and Climate Research, Forschungszentrum Jülich, 52425 Jülich (Germany); Van Oost, Guido [Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41 B4, 9000 Gent (Belgium); Wirtz, Marius [Institute for Energy and Climate Research, Forschungszentrum Jülich, 52425 Jülich (Germany)

    2015-10-15

    Highlights: • Tungsten was first exposed to H or H/He fluxes and then to ELM-like transients. • The influence of particle exposure on the thermal shock behaviour was studied. • There was no deterioration of thermal shock behaviour compared to reference material. • Some combinations of loading conditions resulted in an improved material behaviour. - Abstract: To investigate synergistic effects of high heat flux loading on H and H/He loaded tungsten surfaces, specimens were exposed to a 30 keV steady-state H or H/He beam and subsequently loaded with an electron beam to simulate ELMs. The heat flux during the H and H/He loading was 10.5 MW m{sup −2}, while a 2 × 10{sup 25} m{sup −2} fluence was reached. After exposure, all specimens exhibited an altered surface morphology. The H/He samples with a surface temperature of 1000 °C and 1500 °C had a multitude of surface extrusions. Afterwards the particle loaded samples were exposed to 100 ELM-like pulses around the material's damage threshold. Transient heat fluxes of 190 MW m{sup −2} and 380 MW m{sup −2} were applied at room temperature and 400 °C for a duration of 1 ms. Post-mortem analysis showed no deterioration of thermal shock resistance in comparison with polished material. For some tests the reference specimens roughened or cracked while the H or H/He exposed material had no damage. The H-content and the H/He-induced cavities and/or extrusions are suggested as two potential causes for this change in material behaviour.

  2. On the asymmetries of ELM divertor power deposition in JET and ASDEX Upgrade

    DEFF Research Database (Denmark)

    Eich, T.; Kallenbach, A.; Fundamenski, W.

    2009-01-01

    An analytical expression was derived for describing the divertor target power during ELMs based on the model discussed in [W. Fundamenski, R.A. Pitts, Plasma Phys. Control. Fus. 48 (2006) 109] where the power load arises from a Maxwellian distribution of particles released into the SOL region....... The paper discusses a comparable simple extension of the model by introducing a non-zero characteristic velocity of the Maxwellian distributed particles. This way the experimentally observed temporal evolution as well as the in/out energy imbalance can be described. The extended model named free...

  3. Host Acceptance and Larval Competition between the Invasive Banded and European Elm Bark Beetles, Scolytus schevyrewi and S. multistriatus (Coleoptera: Scolytidae): Potential Mechanisms for Competitive Displacement

    Science.gov (United States)

    A recent survey revealed that the newly invasive banded elm bark beetle, Scolytus schevyrewi, was much more abundant than the long-established European elm bark beetle, S. multistriatus, in areas of Colorado and Wyoming, USA. This study sought to determine whether competitive displacement of S. mul...

  4. Variability of morphometric characteristics of the leaves of European white elm from the area of Great War Island

    Directory of Open Access Journals (Sweden)

    Devetaković Jovana

    2013-01-01

    Full Text Available The European White Elm (Ulmus effusa Willd. is indicated as a rare and endangered species in the growing stock of the Republic of Serbia. In the area of Great War Island, its natural populations were reduced to 56 registered trees, which occur in three spatially isolated subpopulations. On the basis of the research conducted on the level of variability of adaptible morphometric characteristics of leaves from 14 selected test trees of European White Elm, it can be concluded that the degree of interpopulation variability is satisfactory, which is a good basis for the conservation of the available gene pool.

  5. Intrusion detection system using Online Sequence Extreme Learning Machine (OS-ELM) in advanced metering infrastructure of smart grid.

    Science.gov (United States)

    Li, Yuancheng; Qiu, Rixuan; Jing, Sitong

    2018-01-01

    Advanced Metering Infrastructure (AMI) realizes a two-way communication of electricity data through by interconnecting with a computer network as the core component of the smart grid. Meanwhile, it brings many new security threats and the traditional intrusion detection method can't satisfy the security requirements of AMI. In this paper, an intrusion detection system based on Online Sequence Extreme Learning Machine (OS-ELM) is established, which is used to detecting the attack in AMI and carrying out the comparative analysis with other algorithms. Simulation results show that, compared with other intrusion detection methods, intrusion detection method based on OS-ELM is more superior in detection speed and accuracy.

  6. Comparison of H-mode plasma simulations using toroidal velocity models depending on plasma current density and ion temperature in presence of an ITB

    Directory of Open Access Journals (Sweden)

    Boonyarit Chatthong

    2014-06-01

    Full Text Available Two different approaches for predicting plasma toroidal velocity (v are developed and used in self-consistent simulations of H-mode plasmas with the presence of ITB using BALDUR integrated predictive modelling code. In the first approach, the toroidal velocity depends on the plasma current density; while in the second approach the toroidal velocity is directly proportional to the ion temperature. The profile of v is used to calculate the ExB flow shear which is a main mechanism for plasma transport suppression, leading to the ITB formation. In all simulations, the core transport model is a combination of NCLASS neoclassical transport and semi-empirical Mixed Bohm/gyro-Bohm model that includes the ITB effects. The boundary condition is set at top of the pedestal and is estimated using a pedestal model based on a combination of magnetic and flow shear stabilization pedestal width scaling and an infinite-n ballooning pressure gradient. Two toroidal velocity models are used to simulate the time evolution of plasma temperature and density profiles of 10 JET discharges. The root mean square error (RMSE is used to compare simulation results of those 10 JET discharges with experimental data. It is found that RMSE of Ti , Te , ne are 28.1%, 31.8%, and 15.0% for the first toroidal velocity model and 25.5%, 30.2%, and 15.1% for the second toroidal velocity model, respectively. Furthermore, this suite of codes is used to predict the ITER performance under standard type I ELMy H-mode. It is found that the simulation yields formation of a narrow ITB near r/a = 0.7 in the simulation using the current density dependent model and a wide ITB from r/a = 0.5 to 0.8 in the simulation using the ion temperature dependent model. The average of central ion temperature, total fusion power output and alpha power are predicted to be 36 keV, 159 MW and 492 MW for the current density dependent model and 49 keV, 218 MW and 786 MW for the ion temperature dependent

  7. Design assessment for manufacturability of supporting structures for IWS and ELM coil of ITER vacuum vessel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu-Gyeong, E-mail: aspirany@hhi.co.kr [Hyundai Heavy Industries Co., Ltd., Dong-gu, Ulsan (Korea, Republic of); Hong, Yun-Seok; Kwon, Tae-Hoon; Jung, Yung-Jin [Hyundai Heavy Industries Co., Ltd., Dong-gu, Ulsan (Korea, Republic of); Ahn, Hee-Jae; Kim, Byung-Chul; Lee, Young-Ju [National Fusion Research Institute, 113 Gwahangno, Yuseong-gu, Daejeon-si 305-333 (Korea, Republic of)

    2013-10-15

    Highlights: ► A “bridge type” welding method was proposed for IWS rib and ELM coil supports. ► This method could reduce the welding distortion and increase the manufacturability. ► Structural integrity of proposed design was assessed for both P and S type damages. ► Results show that the proposed designs meet the design criteria of RCC-MR. -- Abstract: A vacuum vessel is one of the core facilities of ITER (International Thermonuclear Experimental Reactor) and basically all-welded structure. Korea is responsible for the procurement of sector 1 and 6 of the main vessel. Accordingly, the design review for the fabrication is in progress by ITER Korea and Hyundai Heavy Industries. Due to anticipated manufacturing problems such as the welding distortion, the design of some components of main vessel, IWS (In-Wall Shield) supporting rib and ELM (Edge Localized Mode) coil support, needs to be modified. To release the risk of welding distortion, the welding method called “bridge type” is suggested and the shape of weld joint is adjusted to secure the manufacturability of the issued components. The elastic and limit analyses with fatigue evaluation have been performed under the most critical loading condition to verify the structural integrity of modified design. Analysis results show that the proposed designs meet the design criteria of RCC-MR. The design deviation requests have been submitted to ITER Organization and ANB (Agreed Notified Body) for approval and their verification is currently in progress.

  8. Assessing the suitability of extreme learning machines (ELM for groundwater level prediction

    Directory of Open Access Journals (Sweden)

    Yadav Basant

    2017-03-01

    Full Text Available Fluctuation of groundwater levels around the world is an important theme in hydrological research. Rising water demand, faulty irrigation practices, mismanagement of soil and uncontrolled exploitation of aquifers are some of the reasons why groundwater levels are fluctuating. In order to effectively manage groundwater resources, it is important to have accurate readings and forecasts of groundwater levels. Due to the uncertain and complex nature of groundwater systems, the development of soft computing techniques (data-driven models in the field of hydrology has significant potential. This study employs two soft computing techniques, namely, extreme learning machine (ELM and support vector machine (SVM to forecast groundwater levels at two observation wells located in Canada. A monthly data set of eight years from 2006 to 2014 consisting of both hydrological and meteorological parameters (rainfall, temperature, evapotranspiration and groundwater level was used for the comparative study of the models. These variables were used in various combinations for univariate and multivariate analysis of the models. The study demonstrates that the proposed ELM model has better forecasting ability compared to the SVM model for monthly groundwater level forecasting.

  9. Divertor Heat Flux Control with 3D Stochastic Magnetic Fields during ELM Suppression

    Science.gov (United States)

    Orlov, Dm; Moyer, Ra; Bykov, Io; Evans, Te; Wu, W.; Loarte, A.; Teklu, A.; Watkins, Jg; Wang, H.; Lyons, Bc; Trevisan, Gl; Makowski, Ma; Lasnier, C.; Fenstermacher, Me

    2017-10-01

    Experiments in DIII-D have been performed to modify the divertor heat and particle flux pattern during suppression of ELMs with resonant magnetic perturbation (RMP) fields. In this work, we assessed the impact of small current modulations in a subset of DIII-D I-coils on pedestal profiles, transport and stability as well as divertor conditions. Different I-coil subset ramps were performed allowing for a slow transition of the divertor footprints from n =3 to n =2 and n =1 distributions. We obtained long periods of RMP ELM suppression with slow I-coil quartet ramps. Strong divertor particle flux splitting was observed in these discharges as well as modulation of the divertor heat flux due to changes in toroidal spectrum of applied perturbation. Experimental results are compared to the TRIP3D modeling and to linear M3D-C1 simulations to understand the role of the plasma response on quantitative predictions of the divertor flux splitting. Work supported by US DOE under DE-FC02-04ER54698 and DE-FG02-05ER54809.

  10. ELM BASED CAD SYSTEM TO CLASSIFY MAMMOGRAMS BY THE COMBINATION OF CLBP AND CONTOURLET

    Directory of Open Access Journals (Sweden)

    S Venkatalakshmi

    2017-05-01

    Full Text Available Breast cancer is a serious life threat to the womanhood, worldwide. Mammography is the promising screening tool, which can show the abnormality being detected. However, the physicians find it difficult to detect the affected regions, as the size of microcalcifications is very small. Hence it would be better, if a CAD system can accompany the physician in detecting the malicious regions. Taking this as a challenge, this paper presents a CAD system for mammogram classification which is proven to be accurate and reliable. The entire work is decomposed into four different stages and the outcome of a phase is passed as the input of the following phase. Initially, the mammogram is pre-processed by adaptive median filter and the segmentation is done by GHFCM. The features are extracted by combining the texture feature descriptors Completed Local Binary Pattern (CLBP and contourlet to frame the feature sets. In the training phase, Extreme Learning Machine (ELM is trained with the feature sets. During the testing phase, the ELM can classify between normal, malignant and benign type of cancer. The performance of the proposed approach is analysed by varying the classifier, feature extractors and parameters of the feature extractor. From the experimental analysis, it is evident that the proposed work outperforms the analogous techniques in terms of accuracy, sensitivity and specificity.

  11. Simulation of residual thermostress in tungsten after repetitive ELM-like heat loads

    Energy Technology Data Exchange (ETDEWEB)

    Pestchanyi, S., E-mail: serguei.pestchanyi@kit.edu [Karlsruhe Institute of Technology, IHM (Germany); Garkusha, I. [Institute of Plasma Physics of the NSC KIPT, Kharkov (Ukraine); Landman, I. [Karlsruhe Institute of Technology, IHM (Germany)

    2011-10-15

    Brittle destruction of tungsten armour under action of edge localised modes of plasma instabilities (ELMs) in ITER is an important issue determining the lifetime of the divertor. Besides, cracking of the armour produces tungsten dust with characteristic size of 1-10 {mu}m flying from the armour surface with velocities up to 10 m/s. Influx of the tungsten dust into the ITER confinement decreases the temperature of the plasma, reduces the thermonuclear gain and even may run the confinement into disruption. This paper describes experiments in QSPA-Kh50 plasma gun and modeling, which has been performed for providing more insight into the physics of tungsten cracking under action of ELMs and for confirmation of the important result on stabilization of the crack development at the tungsten armour surface, predicted in our previous paper - the same authors, 2010. The threshold value of energy density deposition for start of tungsten cracking has been measured as 0.3 MJ/m{sup 2} after 5-10 shots. From analytical considerations three times smaller threshold value has been predicted with increasing number of shots.

  12. First report of 'Candidatus Phytoplasma trifolii'-related strain of 16SrVI-A phytoplasma subgroup, associated with elm yellows disease in American elm (Ulmus americana L.) in Ohio, USA

    Science.gov (United States)

    Charles Elliot Flower; Nancy L Hayes-Plazolles; Cristina Rosa; James M Slavicek

    2017-01-01

    During the investigation of the sudden and early onset of yellowing and mortality of American elm (Ulmus americana L.) trees at the USDA Forest Service Northern Research Station in Delaware, OH, a phytoplasma of the clover proliferation group (16SrVI) was detected as the putative causal agent of the disease outbreak.

  13. ELM server

    DEFF Research Database (Denmark)

    Puntervoll, Pål; Linding, Rune; Gemünd, Christine

    2003-01-01

    no comprehensive collection of small functional sites/motifs comparable to the globular domain resources, yet these are as important for the function of multidomain proteins. Short linear peptide motifs are used for cell compartment targeting, protein-protein interaction, regulation by phosphorylation, acetylation...

  14. Slippery Elm

    Science.gov (United States)

    ... infections and inflammation, syphilis, herpes, and for expelling tapeworms. It is also used for protecting against stomach ... Diarrhea. Gout. Hemorrhoids. Herpes. Rheumatism. Stomach ulcers. Syphilis. Tapeworm. Toothache. Urinary tract infections. Other conditions. More evidence ...

  15. Morphological Characteristics and Water-Use Efficiency of Siberian Elm Trees (Ulmus pumila L. within Arid Regions of Northeast Asia

    Directory of Open Access Journals (Sweden)

    Go Eun Park

    2016-11-01

    Full Text Available The Siberian elm (Ulmus pumila L. is one of the most commonly found tree species in arid areas of northeast Asia. To understand the morphological and physiological characteristics of Siberian elms in arid regions, we analyzed leaves from seven study sites (five arid or semi-arid and two mesic in China, Mongolia and the Republic of Korea, which covered a wide range of average annual precipitation (232 mm·year−1 to 1304 mm·year−1 under various aridity indexes (AI and four different microenvironments: sand dune, steppe, riverside and forest. The traits of Siberian elms varied widely along different annual precipitation (P and AI gradients. Tree height (H, leaf size (LS and stomatal area per unit leaf area (AS/AL decreased with increasing AI, whereas leaf mass per unit leaf area (LMA and water-use efficiency (WUE increased significantly. In addition, trees at the five arid sites showed significant differences in LS, LMA and AS/AL but not in H and WUE. Thus, our study indicated that indigenous Siberian elm trees in arid areas have substantially altered their morphological and physiological characteristics to avoid heat stress and increase water conservation in comparison to mesic areas. However, their changes differed depending on the surrounding microenvironment even in arid areas. Trees in sand dunes had a smaller LS, higher LMA, thicker leaf cuticle layer and higher stomatal density and AS than those in steppes and near a riverside.

  16. Analytic stability criteria for edge MHD oscillations in high performance ELM free tokamak regimes

    Science.gov (United States)

    Brunetti, D.; Graves, J. P.; Lazzaro, E.; Mariani, A.; Nowak, S.; Cooper, W. A.; Wahlberg, C.

    2018-01-01

    A new dispersion relation, and associated stability criteria, is derived for low-n external kink and infernal modes, and is applied to modelling the stability properties of quiescent H-mode like regimes. The analysis, performed in toroidal geometry with large edge pressure gradients associated with a local flattening of the safety factor, includes a pedestal, sheared toroidal rotation and a vacuum region separating the plasma from an ideal metallic wall. The external kink-infernal modes found here exhibit similarities with experimentally observed edge harmonic oscillations.

  17. Analysis of ELM stability with extended MHD models in JET, JT-60U and future JT-60SA tokamak plasmas

    Science.gov (United States)

    Aiba, N.; Pamela, S.; Honda, M.; Urano, H.; Giroud, C.; Delabie, E.; Frassinetti, L.; Lupelli, I.; Hayashi, N.; Huijsmans, G.; JET Contributors, the; Research Unit, JT-60SA

    2018-01-01

    The stability with respect to a peeling–ballooning mode (PBM) was investigated numerically with extended MHD simulation codes in JET, JT-60U and future JT-60SA plasmas. The MINERVA-DI code was used to analyze the linear stability, including the effects of rotation and ion diamagnetic drift ({ω }* {{i}}), in JET-ILW and JT-60SA plasmas, and the JOREK code was used to simulate nonlinear dynamics with rotation, viscosity and resistivity in JT-60U plasmas. It was validated quantitatively that the ELM trigger condition in JET-ILW plasmas can be reasonably explained by taking into account both the rotation and {ω }* {{i}} effects in the numerical analysis. When deuterium poloidal rotation is evaluated based on neoclassical theory, an increase in the effective charge of plasma destabilizes the PBM because of an acceleration of rotation and a decrease in {ω }* {{i}}. The difference in the amount of ELM energy loss in JT-60U plasmas rotating in opposite directions was reproduced qualitatively with JOREK. By comparing the ELM affected areas with linear eigenfunctions, it was confirmed that the difference in the linear stability property, due not to the rotation direction but to the plasma density profile, is thought to be responsible for changing the ELM energy loss just after the ELM crash. A predictive study to determine the pedestal profiles in JT-60SA was performed by updating the EPED1 model to include the rotation and {ω }* {{i}} effects in the PBM stability analysis. It was shown that the plasma rotation predicted with the neoclassical toroidal viscosity degrades the pedestal performance by about 10% by destabilizing the PBM, but the pressure pedestal height will be high enough to achieve the target parameters required for the ITER-like shape inductive scenario in JT-60SA.

  18. Estimation of in-situ bioremediation system cost using a hybrid Extreme Learning Machine (ELM)-particle swarm optimization approach

    Science.gov (United States)

    Yadav, Basant; Ch, Sudheer; Mathur, Shashi; Adamowski, Jan

    2016-12-01

    In-situ bioremediation is the most common groundwater remediation procedure used for treating organically contaminated sites. A simulation-optimization approach, which incorporates a simulation model for groundwaterflow and transport processes within an optimization program, could help engineers in designing a remediation system that best satisfies management objectives as well as regulatory constraints. In-situ bioremediation is a highly complex, non-linear process and the modelling of such a complex system requires significant computational exertion. Soft computing techniques have a flexible mathematical structure which can generalize complex nonlinear processes. In in-situ bioremediation management, a physically-based model is used for the simulation and the simulated data is utilized by the optimization model to optimize the remediation cost. The recalling of simulator to satisfy the constraints is an extremely tedious and time consuming process and thus there is need for a simulator which can reduce the computational burden. This study presents a simulation-optimization approach to achieve an accurate and cost effective in-situ bioremediation system design for groundwater contaminated with BTEX (Benzene, Toluene, Ethylbenzene, and Xylenes) compounds. In this study, the Extreme Learning Machine (ELM) is used as a proxy simulator to replace BIOPLUME III for the simulation. The selection of ELM is done by a comparative analysis with Artificial Neural Network (ANN) and Support Vector Machine (SVM) as they were successfully used in previous studies of in-situ bioremediation system design. Further, a single-objective optimization problem is solved by a coupled Extreme Learning Machine (ELM)-Particle Swarm Optimization (PSO) technique to achieve the minimum cost for the in-situ bioremediation system design. The results indicate that ELM is a faster and more accurate proxy simulator than ANN and SVM. The total cost obtained by the ELM-PSO approach is held to a minimum

  19. Cellulomonas xylanilytica sp. nov., a cellulolytic and xylanolytic bacterium isolated from a decayed elm tree.

    Science.gov (United States)

    Rivas, Raúl; Trujillo, Martha E; Mateos, P F; Martínez-Molina, E; Velázquez, Encarna

    2004-03-01

    A Gram-positive, aerobic, non-motile bacterium was isolated from a decayed elm tree. Phylogenetic analysis based on 16S rDNA sequences revealed 99.0 % similarity to Cellulomonas humilata. Chemotaxonomic data that were determined for this isolate included cell-wall composition, fatty acid profiles and polar lipids; the results supported the placement of strain XIL11(T) in the genus Cellulomonas. The DNA G+C content was 73 mol%. The results of DNA-DNA hybridization with C. humilata ATCC 25174(T), in combination with chemotaxonomic and physiological data, demonstrated that isolate XIL11(T) should be classified as a novel Cellulomonas species. The name Cellulomonas xylanilytica sp. nov. is proposed, with strain XIL11(T) (=LMG 21723(T)=CECT 5729(T)) as the type strain.

  20. Experimental study of plasma energy transfer and material erosion under ELM-like heat loads

    Energy Technology Data Exchange (ETDEWEB)

    Garkusha, I.E., E-mail: garkusha@ipp.kharkov.u [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine); Makhlaj, V.A.; Chebotarev, V.V. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine); Landman, I. [Forschungszentrum Karlsruhe, IHM, 76021 Karlsruhe (Germany); Tereshin, V.I.; Aksenov, N.N.; Bandura, A.N. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine)

    2009-06-15

    Main features of plasma-surface interaction and energy transfer to tokamak plasma facing components are studied at different heat loads in ELM simulation experiments with the plasma gun QSPA Kh-50. Repetitive plasma exposures of tungsten, graphite and different combined W-C targets were performed at the pulse duration of 0.25 ms and the heat loads varied in the range 0.2-2.5 MJ/m{sup 2}. The onset of vapor shield in front of the surface was investigated. The evaporation is immediately followed by a saturation of surface heat load if further increasing the impact energy. The presence of graphite essentially decreases the heat flux to the nearby tungsten surface, which is due to the carbon vapor shield. Droplet splashing at the tungsten surface and formation of hot spots on the graphite surface are discussed.

  1. Damage to preheated tungsten targets after multiple plasma impacts simulating ITER ELMs

    Energy Technology Data Exchange (ETDEWEB)

    Garkusha, I.E. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine)], E-mail: garkusha@ipp.kharkov.ua; Bandura, A.N.; Byrka, O.V.; Chebotarev, V.V. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine); Landman, I. [Forschungszentrum Karlsruhe, IHM, 76021 Karlsruhe (Germany); Makhlaj, V.A. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine); Pestchanyi, S. [Forschungszentrum Karlsruhe, IHM, 76021 Karlsruhe (Germany); Tereshin, V.I. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine)

    2009-04-30

    The behavior of a preheated at 650 deg. C tungsten targets under repetitive ELM-like plasma pulses is studied in simulation experiments with the quasi-stationary plasma accelerator QSPA Kh-50. The targets have been exposed up to 350 pulses of the duration 0.25 ms and the surface heat loads either 0.45 MJ/m{sup 2} or 0.75 MJ/m{sup 2}, which is below and above the melting threshold, respectively. The development of surface morphology of the exposed targets as well as cracking and swelling at the surface is discussed. First comparisons of obtained experimental results with corresponding numerical simulations of the code PEGASUS-3D are presented.

  2. Tungsten melt layer erosion due to J x B force under conditions relevant to ITER ELMs

    Energy Technology Data Exchange (ETDEWEB)

    Garkusha, I.E. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine)]. E-mail: garkusha@ipp.kharkov.ua; Bazylev, B.N. [Forschungszentrum Karlsruhe, IHM, 76021 Karlsruhe (Germany); Bandura, A.N. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine); Byrka, O.V. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine); Chebotarev, V.V. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine); Landman, I.S. [Forschungszentrum Karlsruhe, IHM, 76021 Karlsruhe (Germany); Kulik, N.V. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine); Makhlaj, V.A. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine); Petrov, Yu.V. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine); Solyakov, D.G. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine); Tereshin, V.I. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine)

    2007-06-15

    The behavior of tungsten under repetitive hydrogen plasma impacts causing surface melting in conditions of an applied J x B force of up to 20 MN/m{sup 3} is studied with the plasma accelerator QSPA Kh-50. Tungsten samples of EU trademark have been exposed to up to 100 pulses simulating ITER ELMs of the energy load 0.7 MJ/m{sup 2} and the duration 0.25 ms. An electric current J flows across the magnetic field B of 1.4 T, and the resulting J x B force produces a displacement of the melt with formation of an erosion crater and an inclination of the surface profile along the force. Surface morphology and the damage by surface cracks are discussed. Comparisons of experimental results with numerical simulations of the code MEMOS-1.5D are presented.

  3. Damage to preheated tungsten targets after multiple plasma impacts simulating ITER ELMs

    Science.gov (United States)

    Garkusha, I. E.; Bandura, A. N.; Byrka, O. V.; Chebotarev, V. V.; Landman, I.; Makhlaj, V. A.; Pestchanyi, S.; Tereshin, V. I.

    2009-04-01

    The behavior of a preheated at 650 °C tungsten targets under repetitive ELM-like plasma pulses is studied in simulation experiments with the quasi-stationary plasma accelerator QSPA Kh-50. The targets have been exposed up to 350 pulses of the duration 0.25 ms and the surface heat loads either 0.45 MJ/m 2 or 0.75 MJ/m 2, which is below and above the melting threshold, respectively. The development of surface morphology of the exposed targets as well as cracking and swelling at the surface is discussed. First comparisons of obtained experimental results with corresponding numerical simulations of the code PEGASUS-3D are presented.

  4. Experimental study of plasma energy transfer and material erosion under ELM-like heat loads

    Science.gov (United States)

    Garkusha, I. E.; Makhlaj, V. A.; Chebotarev, V. V.; Landman, I.; Tereshin, V. I.; Aksenov, N. N.; Bandura, A. N.

    2009-06-01

    Main features of plasma-surface interaction and energy transfer to tokamak plasma facing components are studied at different heat loads in ELM simulation experiments with the plasma gun QSPA Kh-50. Repetitive plasma exposures of tungsten, graphite and different combined W-C targets were performed at the pulse duration of 0.25 ms and the heat loads varied in the range 0.2-2.5 MJ/m 2. The onset of vapor shield in front of the surface was investigated. The evaporation is immediately followed by a saturation of surface heat load if further increasing the impact energy. The presence of graphite essentially decreases the heat flux to the nearby tungsten surface, which is due to the carbon vapor shield. Droplet splashing at the tungsten surface and formation of hot spots on the graphite surface are discussed.

  5. Tungsten melt layer erosion due to J × B force under conditions relevant to ITER ELMs

    Science.gov (United States)

    Garkusha, I. E.; Bazylev, B. N.; Bandura, A. N.; Byrka, O. V.; Chebotarev, V. V.; Landman, I. S.; Kulik, N. V.; Makhlaj, V. A.; Petrov, Yu. V.; Solyakov, D. G.; Tereshin, V. I.

    2007-06-01

    The behavior of tungsten under repetitive hydrogen plasma impacts causing surface melting in conditions of an applied J × B force of up to 20 MN/m3 is studied with the plasma accelerator QSPA Kh-50. Tungsten samples of EU trademark have been exposed to up to 100 pulses simulating ITER ELMs of the energy load 0.7 MJ/m2 and the duration 0.25 ms. An electric current J flows across the magnetic field B of 1.4 T, and the resulting J × B force produces a displacement of the melt with formation of an erosion crater and an inclination of the surface profile along the force. Surface morphology and the damage by surface cracks are discussed. Comparisons of experimental results with numerical simulations of the code MEMOS-1.5D are presented.

  6. Advertisement Click-Through Rate Prediction Based on the Weighted-ELM and Adaboost Algorithm

    Directory of Open Access Journals (Sweden)

    Sen Zhang

    2017-01-01

    Full Text Available Accurate click-through rate (CTR prediction can not only improve the advertisement company’s reputation and revenue, but also help the advertisers to optimize the advertising performance. There are two main unsolved problems of the CTR prediction: low prediction accuracy due to the imbalanced distribution of the advertising data and the lack of the real-time advertisement bidding implementation. In this paper, we will develop a novel online CTR prediction approach by incorporating the real-time bidding (RTB advertising by the following strategies: user profile system is constructed from the historical data of the RTB advertising to describe the user features, the historical CTR features, the ID features, and the other numerical features. A novel CTR prediction approach is presented to address the imbalanced learning sample distribution by integrating the Weighted-ELM (WELM and the Adaboost algorithm. Compared to the commonly used algorithms, the proposed approach can improve the CTR significantly.

  7. High-Speed Monitoring of Dust Particles in ITER ELMs Simulation Experiments with QSPA Kh-50

    Directory of Open Access Journals (Sweden)

    Vadym A. Makhlaj

    2013-01-01

    Full Text Available Dust generation under powerful plasma stream impacts has been studied in ITER ELM simulation experiments with QSPA Kh-50 plasma accelerator. Repetitive plasma exposures of tungsten have been performed by 0.25 ms plasma pulses and the heat load varied in the range (0.1÷1.1 MJm-2. Main characteristics of dust particles such as a number of ejected particles, their velocity, angular distribution and start time from the surface are investigated. Dust particles have not been observed under heat load below the cracking threshold. Quantity of dust particles rises with increasing heat load. Average velocities of dust particles are found to be strongly dependent on their start time from the surface after beginning of plasma-surface interaction. Maximal velocity achieved a few tens of meters per second.

  8. Beryllium layer response to ITER-like ELM plasma pulses in QSPA-Be

    Directory of Open Access Journals (Sweden)

    N.S. Klimov

    2017-08-01

    Full Text Available Material migration in ITER is expected to move beryllium (Be eroded from the first wall primarily to the tungsten (W divertor region and to magnetically shadowed areas of the wall itself. This paper is concerned with experimental study of Be layer response to ELM-like plasma pulses using the new QSPA-Be plasma gun (SRC RF TRINITI. The Be layers (1→50µm thick are deposited on special castellated Be and W targets supplied by the ITER Organization using the Thermionic Vacuum Arc technique. Transient deuterium plasma pulses with duration ∼0.5ms were selected to provide absorbed energy densities on the plasma stream axis for a 30° target inclination of 0.2 and 0.5MJm−2, the first well below and the second near the Be melting point. This latter value is close to the prescribed maximum energy density for controlled ELMs on ITER. At 0.2MJm−2 on W, all Be layer thicknesses tested retain their integrity up to the maximum pulse number, except at local defects (flakes, holes and cracks and on tile edges. At 0.5MJm−2 on W, Be layer melting and melt layer agglomeration are the main damage processes, they happen immediately in the first plasma impact. Melt layer movement was observed only near plasma facing edges. No significant melt splashing is observed in spite of high plasma pressure (higher than expected in ITER. Be layer of 10µm thick on Be target has higher resistance to plasma irradiation than 1 and 55µm, and retain their integrity up to the maximum pulse number at 0.2MJm−2. For 1µm and 55µm thick on Be target significant Be layer losses were observed at 0.2MJm−2.

  9. HEART RATE VARIABILITY CLASSIFICATION USING SADE-ELM CLASSIFIER WITH BAT FEATURE SELECTION

    Directory of Open Access Journals (Sweden)

    R Kavitha

    2017-07-01

    Full Text Available The electrical activity of the human heart is measured by the vital bio medical signal called ECG. This electrocardiogram is employed as a crucial source to gather the diagnostic information of a patient’s cardiopathy. The monitoring function of cardiac disease is diagnosed by documenting and handling the electrocardiogram (ECG impulses. In the recent years many research has been done and developing an enhanced method to identify the risk in the patient’s body condition by processing and analysing the ECG signal. This analysis of the signal helps to find the cardiac abnormalities, arrhythmias, and many other heart problems. ECG signal is processed to detect the variability in heart rhythm; heart rate variability is calculated based on the time interval between heart beats. Heart Rate Variability HRV is measured by the variation in the beat to beat interval. The Heart rate Variability (HRV is an essential aspect to diagnose the properties of the heart. Recent development enhances the potential with the aid of non-linear metrics in reference point with feature selection. In this paper, the fundamental elements are taken from the ECG signal for feature selection process where Bat algorithm is employed for feature selection to predict the best feature and presented to the classifier for accurate classification. The popular machine learning algorithm ELM is taken for classification, integrated with evolutionary algorithm named Self- Adaptive Differential Evolution Extreme Learning Machine SADEELM to improve the reliability of classification. It combines Effective Fuzzy Kohonen clustering network (EFKCN to be able to increase the accuracy of the effect for HRV transmission classification. Hence, it is observed that the experiment carried out unveils that the precision is improved by the SADE-ELM method and concurrently optimizes the computation time.

  10. H/He irradiation on tungsten exposed to ELM-like thermal shocks

    Energy Technology Data Exchange (ETDEWEB)

    Lemahieu, Nathan, E-mail: Nathan.Lemahieu@UGent.be [Institute for Energy and Climate Research, Forschungszentrum Jülich, 52425 Jülich (Germany); Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41 B4, 9000 Gent (Belgium); Institute of Interfacial Process Engineering and Plasma Technology IGVP, Universität Stuttgart, Pfaffenwaldring 31, 70569 Stuttgart (Germany); Balden, Martin; Elgeti, Stefan; Greuner, Henri [Max Planck Institute for Plasma Physics, Boltzmannstraße 2, 85748 Garching (Germany); Linke, Jochen [Institute for Energy and Climate Research, Forschungszentrum Jülich, 52425 Jülich (Germany); Maier, Hans [Max Planck Institute for Plasma Physics, Boltzmannstraße 2, 85748 Garching (Germany); Pintsuk, Gerald; Wirtz, Marius [Institute for Energy and Climate Research, Forschungszentrum Jülich, 52425 Jülich (Germany); Van Oost, Guido [Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41 B4, 9000 Gent (Belgium); Noterdaeme, Jean-Marie [Max Planck Institute for Plasma Physics, Boltzmannstraße 2, 85748 Garching (Germany); Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41 B4, 9000 Gent (Belgium)

    2016-11-01

    Highlights: • After ELM-like thermal shocks, tungsten was exposed to H/He particle fluxes. • The influence of combined loading conditions on the damage behaviour was studied. • Roughened surfaces do not alter H/He induced surface modifications. • Cracks interact with the particle flux, resulting in phenomena such as crack bridging. - Abstract: ELM-like thermal shocks and H/He particle exposure were subsequently applied on tungsten samples. Polished test specimens underwent in the JUDITH 1 electron beam facility 100 transient thermal events with a duration of 1 ms. The absorbed heat flux was 0.4 GW m{sup −2} and 1.5 GW m{sup −2}, which is above the material's damage threshold. These experiments were done at room temperature and with the samples heated to 400 °C base temperature. Depending on the loading conditions the test specimens have either a crack network or showed surface roughening. The samples were then loaded in the GLADIS facility at different surface temperatures with a mixed H/He beam with a flux of 3.7 × 10{sup 21} m{sup −2} s{sup −1}. Post-mortem analysis showed that the roughened surface did not alter the H/He induced surface modifications. In contrast to that on the test specimens that exhibited crack formation, phenomena such as bubble creation along the crack edge, formation of a shallow layer of nano-structures covering the crack opening, and the emerging of a porous structure which partially fills the crack are observed.

  11. Estimation of the dust production rate from the tungsten armour after repetitive ELM-like heat loads

    Science.gov (United States)

    Pestchanyi, S.; Garkusha, I.; Makhlaj, V.; Landman, I.

    2011-12-01

    Experimental simulations for the erosion rate of tungsten targets under ITER edge-localized mode (ELM)-like surface heat loads of 0.75 MJ m-2 causing surface melting and of 0.45 MJ m-2 without melting have been performed in the QSPA-Kh50 plasma accelerator. Analytical considerations allow us to conclude that for both energy deposition values the erosion mechanism is solid dust ejection during surface cracking under the action of thermo-stress. Tungsten influx into the ITER containment of NW~5×1018 W per medium size ELM of 0.75 MJ m-2 and 0.25 ms time duration has been estimated. The radiation cooling power of Prad=150-300 MW due to such influx of tungsten is intolerable: it should cool the ITER core to 1 keV within a few seconds.

  12. Semiochemical-mediated flight strategies of two invasive elm bark beetles: a potential factor in competitive displacement.

    Science.gov (United States)

    Lee, Jana C; Hamud, Shakeeb M; Negrón, José F; Witcosky, Jeffrey J; Seybold, Steven J

    2010-04-01

    A seven-state survey showed that the recently detected invasive Asian banded elm bark beetle, Scolytus schevyrewi Semenov, was abundant in areas of Colorado and Wyoming, whereas the long-established European elm bark beetle, S. multistriatus (Marsham), was not as abundant. In one of a series of studies to evaluate whether S. schevyrewi is competitively displacing S. multistriatus in their North American zone of sympatry, we characterized long-range flight responses infested or uninfested to small cut logs of American, Chinese, and Siberian elm, Ulmus americana, U. parvifolia, and U. pumila. Trials were conducted in Colorado and Wyoming to test the flight response of S. schevyrewi; in California to test the response of S. multistriatus; and in Nevada to test the responses of both species simultaneously. Studies with S. schevyrewi showed that males and females aggregated toward Ulmus spp. host volatiles but provided no evidence of a putative aggregation pheromone during the 0- to 48- or 48- to 96-h period of infestation. In contrast, S. multistriatus was attracted to U. pumila over unbaited controls, more to U. pumila infested with conspecific females than without, and more during the 48- to 96- versus 0- to 48-h period of infestation. This confirmed that male and female S. multistriatus aggregated toward host volatiles and that females produced an aggregation pheromone. In a cross-attraction study, S. schevyrewi displayed neither flight preference nor interruption to U. pumila infested with conspecifics, heterospecifics, or a mix of both species. Response of S. multistriatus was too low to draw conclusions. Although S. multistriatus aggregates moderately to host volatiles and strongly to female-derived pheromones emitted after a few days, S. multistriatus may have a relative disadvantage by selecting elm hosts more slowly than S. schevyrewi, which aggregates very strongly to host volatiles. The differential long-range host location strategy may be one factor in a

  13. Damage to Preheated Tungsten Targets after Multiple Plasma Impacts Simulating ITER ELMs

    Energy Technology Data Exchange (ETDEWEB)

    Garkusha, I.E.; Bandura, A.N.; Byrka, O.V.; Chebotarev, V.V.; Makhlay, V.A.; Tereshin, V.I. [Kharkov Inst. of Physics and Technology, Inst. of Plasma Physics of National Science Center, Akademicheskaya street, 1, 61108 Kharkov (Ukraine); Landman, I.; Pestchanyi, S. [FZK-Forschungszentrum Karlsruhe, Association Euratom-FZK, Technik und Umwelt, Postfach 3640, D-7602 1 Karlsruhe (Germany)

    2007-07-01

    Full text of publication follows: The energy loads onto ITER divertor surfaces associated with the Type I ELMs are expected to be up to 1 MJ/m{sup 2} during 0.1-0.5 ms, with the number of pulses about 103 per discharge. Tungsten is a candidate material for major part of the surface, but its brittleness can result in substantial macroscopic erosion after the repetitive heat loads. To minimize the brittle destruction, tungsten may be preheated above the ductile-to-brittle transition temperature. In this work the behavior of preheated tungsten targets under repetitive ELM-like plasma pulses is studied in simulation experiments with the quasi-stationary plasma accelerator QSPA Kh-50. The targets have been exposed up to 450 pulses of the duration 0.25 ms and the heat loads either 0.45 MJ/m{sup 2} or 0.75 MJ/m{sup 2}, which is respectively below and above the melting threshold. During the exposures the targets were permanently kept preheated at 650 deg. C by a heater at target backside. In the course of exposures the irradiated surfaces were examined after regular numbers of pulses using the SEM and the optical microscopy. The profilometry, XRD, microhardness and weight loss measurements have been performed, as well as comparisons of surface damages after the heat loads both below and above the melting threshold. It is obtained that macro-cracks do not develop on the preheated surface. After the impacts with surface melting, a fine mesh of intergranular microcracks has appeared. The width of fine intergranular cracks grows with pulse number, achieving 1-1.5 microns after 100 pulses, and after 210 pulses the crack width increases up to 20 microns, which is comparable with grain sizes. Threshold changes in surface morphology resulting in corrugation structures and pits on the surface as well as importance of surface tension in resulted 'micro-brush' structures are discussed. Further evolution of the surface pattern is caused by loss of separated grains on exposed

  14. Comparison of SVM, RF and ELM on an Electronic Nose for the Intelligent Evaluation of Paraffin Samples

    Directory of Open Access Journals (Sweden)

    Hong Men

    2018-01-01

    Full Text Available Paraffin odor intensity is an important quality indicator when a paraffin inspection is performed. Currently, paraffin odor level assessment is mainly dependent on an artificial sensory evaluation. In this paper, we developed a paraffin odor analysis system to classify and grade four kinds of paraffin samples. The original feature set was optimized using Principal Component Analysis (PCA and Partial Least Squares (PLS. Support Vector Machine (SVM, Random Forest (RF, and Extreme Learning Machine (ELM were applied to three different feature data sets for classification and level assessment of paraffin. For classification, the model based on SVM, with an accuracy rate of 100%, was superior to that based on RF, with an accuracy rate of 98.33–100%, and ELM, with an accuracy rate of 98.01–100%. For level assessment, the R2 related to the training set was above 0.97 and the R2 related to the test set was above 0.87. Through comprehensive comparison, the generalization of the model based on ELM was superior to those based on SVM and RF. The scoring errors for the three models were 0.0016–0.3494, lower than the error of 0.5–1.0 measured by industry standard experts, meaning these methods have a higher prediction accuracy for scoring paraffin level.

  15. Comparison of SVM, RF and ELM on an Electronic Nose for the Intelligent Evaluation of Paraffin Samples

    Science.gov (United States)

    Men, Hong; Fu, Songlin; Yang, Jialin; Cheng, Meiqi; Shi, Yan

    2018-01-01

    Paraffin odor intensity is an important quality indicator when a paraffin inspection is performed. Currently, paraffin odor level assessment is mainly dependent on an artificial sensory evaluation. In this paper, we developed a paraffin odor analysis system to classify and grade four kinds of paraffin samples. The original feature set was optimized using Principal Component Analysis (PCA) and Partial Least Squares (PLS). Support Vector Machine (SVM), Random Forest (RF), and Extreme Learning Machine (ELM) were applied to three different feature data sets for classification and level assessment of paraffin. For classification, the model based on SVM, with an accuracy rate of 100%, was superior to that based on RF, with an accuracy rate of 98.33–100%, and ELM, with an accuracy rate of 98.01–100%. For level assessment, the R2 related to the training set was above 0.97 and the R2 related to the test set was above 0.87. Through comprehensive comparison, the generalization of the model based on ELM was superior to those based on SVM and RF. The scoring errors for the three models were 0.0016–0.3494, lower than the error of 0.5–1.0 measured by industry standard experts, meaning these methods have a higher prediction accuracy for scoring paraffin level. PMID:29346328

  16. OP-Triplet-ELM: Identification of real and pseudo microRNA precursors using extreme learning machine with optimal features.

    Science.gov (United States)

    Pian, Cong; Zhang, Jin; Chen, Yuan-Yuan; Chen, Zhi; Li, Qin; Li, Qiang; Zhang, Liang-Yun

    2016-02-01

    MicroRNAs (miRNAs) are a set of short (21-24 nt) non-coding RNAs that play significant regulatory roles in the cells. Triplet-SVM-classifier and MiPred (random forest, RF) can identify the real pre-miRNAs from other hairpin sequences with similar stem-loop (pseudo pre-miRNAs). However, the 32-dimensional local contiguous structure-sequence can induce a great information redundancy. Therefore, it is essential to develop a method to reduce the dimension of feature space. In this paper, we propose optimal features of local contiguous structure-sequences (OP-Triplet). These features can avoid the information redundancy effectively and decrease the dimension of the feature vector from 32 to 8. Meanwhile, a hybrid feature can be formed by combining minimum free energy (MFE) and structural diversity. We also introduce a neural network algorithm called extreme learning machine (ELM). The results show that the specificity ([Formula: see text])and sensitivity ([Formula: see text]) of our method are 92.4% and 91.0%, respectively. Compared with Triplet-SVM-classifier, the total accuracy (ACC) of our ELM method increases by 5%. Compared with MiPred (RF) and miRANN, the total accuracy (ACC) of our ELM method increases nearly by 2%. What is more, our method commendably reduces the dimension of the feature space and the training time.

  17. VizieR Online Data Catalog: Subdwarf A stars vs ELM WDs radial velocities (Brown+, 2017)

    Science.gov (United States)

    Brown, W. R.; Kilic, M.; Gianninas, A.

    2017-11-01

    Our sample is comprised of 11 subdwarf A-type (sdA) stars suspected of being eclipsing binaries (S. O. Kepler 2015, private communication) and 11 previously unpublished extremely low mass (ELM) white dwarf (WD) candidates that have sdA-like temperatures summarized in Table 1. We obtain time-series spectroscopy for all 22 objects and time-series optical photometry for 21 objects. We also obtain JHK infrared photometry for 6 objects. We obtain time-series spectroscopy for 20 of the 22 objects with the 6.5m MMT telescope. We obtain spectra for the two brightest objects with the 1.5m Tillinghast telescope at Fred Lawrence Whipple Observatory. We obtain additional spectra for six objects with the 4m Mayall telescope at Kitt Peak National Observatory. The spectra were mostly acquired in observing runs between 2014 December and 2016 December. We search the Catalina Surveys Data Release 2 (Drake+ 2009, J/ApJ/696/870) and find time-series V-band photometry for 21 of the 22 objects. Six objects show significant eclipses. (3 data files).

  18. Improving ELM-Based Service Quality Prediction by Concise Feature Extraction

    Directory of Open Access Journals (Sweden)

    Yuhai Zhao

    2015-01-01

    Full Text Available Web services often run on highly dynamic and changing environments, which generate huge volumes of data. Thus, it is impractical to monitor the change of every QoS parameter for the timely trigger precaution due to high computational costs associated with the process. To address the problem, this paper proposes an active service quality prediction method based on extreme learning machine. First, we extract web service trace logs and QoS information from the service log and convert them into feature vectors. Second, by the proposed EC rules, we are enabled to trigger the precaution of QoS as soon as possible with high confidence. An efficient prefix tree based mining algorithm together with some effective pruning rules is developed to mine such rules. Finally, we study how to extract a set of diversified features as the representative of all mined results. The problem is proved to be NP-hard. A greedy algorithm is presented to approximate the optimal solution. Experimental results show that ELM trained by the selected feature subsets can efficiently improve the reliability and the earliness of service quality prediction.

  19. An ELM Based Online Soft Sensing Approach for Alumina Concentration Detection

    Directory of Open Access Journals (Sweden)

    Sen Zhang

    2015-01-01

    Full Text Available The concentration of alumina in the electrolyte is of great significance during the production of aluminum; it may affect the stability of aluminum reduction cell and the current efficiency. However, the concentration of alumina is hard to be detected online because of the special circumstance in the aluminum reduction cell. At present, there is lack of fast and accurate soft sensing methods for alumina concentration and existing methods can not meet the needs for online measurement. In this paper, a novel soft sensing method based on a modified extreme learning machine (MELM for online measurement of the alumina concentration is proposed. The modified ELM algorithm is based on the enhanced random search which is called incremental extreme learning machine in some references. It randomly chooses the input weights and analytically determines the output weights without manual intervention. The simulation results show that the approach can give more accurate estimations of alumina concentration with faster learning speed compared with other methods such as BP and SVM.

  20. [Effect of lactic acid bacteria isolated from Tibetan Plateau on silage fermentation quality of Elms nutans].

    Science.gov (United States)

    Zhang, Hongmei; Ke, Wencan; Jing, Peixin; Zhang, Juan; Chen, Ming; Yu, Yingwen; Guo, Xusheng

    2015-10-04

    In order to detect the effect of lactic acid bacteria isolated from Tibetan Plateau on silage fermentation quality of Elms nutans. We used 3 isolated lactic acid bacteria with better growth at low temperatures of 10 and 15 degrees C at ensiling of Elymus nutans. Subsequently, effects of the selected lactic acid bacteria on fermentation profiles of Elymus nutans silages stored at 15 and 25 degrees C were evaluated by using the same species of commercial inoculants as the control. PP-6 isolated from Tibetan Plateau could ferment raffinose, lactose, sorbitol, melibiose and sucrose, and LS-5 could ferment cottonseed sugar, laetrile, rhamnose, lactose, sorbitol, xylose, arabinose, melibiose and sucrose, but the same species of commercial strains could not use these sugars. Inoculation of these three strains into Elymus nutans at 15 and 25 degrees C ensiled for 50 d, we found that LS-5 significantly reduced silage pH, propionic acid concentration and ratio of ammonia nitrogen/total nitrogen at 15 degrees C (P silage quality of Elymus nutans growing on the Qinghai-Tibetan Plateau at low temperature, but these strains have no obvious advantages at 25 degrees C in comparison with the commercial inoculants.

  1. Automated melanoma recognition in dermoscopic images based on extreme learning machine (ELM)

    Science.gov (United States)

    Rahman, Md. Mahmudur; Alpaslan, Nuh

    2017-03-01

    Melanoma is considered a major health problem since it is the deadliest form of skin cancer. The early diagnosis through periodic screening with dermoscopic images can significantly improve the survival rate as well as reduce the treatment cost and consequent suffering of patients. Dermoscopy or skin surface microscopy provides in vivo inspection of color and morphologic structures of pigmented skin lesions (PSLs), rendering higher accuracy for detecting suspicious cases than it is possible via inspecting with naked eye. However, interpretation of dermoscopic images is time consuming and subjective, even for trained dermatologists. Therefore, there is currently a great interest in the development of computeraided diagnosis (CAD) systems for automated melanoma recognition. However, the majority of the CAD systems are still in the early development stage with lack of descriptive feature generation and benchmark evaluation in ground-truth datasets. This work is focusing on by addressing the various issues related to the development of such a CAD system with effective feature extraction from Non-Subsampled Contourlet Transform (NSCT) and Eig(Hess) histogram of oriented gradients (HOG) and lesion classification with efficient Extreme Learning Machine (ELM) due to its good generalization abilities and a high learning efficiency and evaluating its effectiveness in a benchmark data set of dermoscopic images towards the goal of realistic comparison and real clinical integration. The proposed research on melanoma recognition has huge potential for offering powerful services that would significantly benefit the present Biomedical Information Systems.

  2. Design of a resonant magnetic perturbation ELM suppression system for JET

    Energy Technology Data Exchange (ETDEWEB)

    Agarici, G. [Association EURATOM-CEA, CEA/DSM/DRFC, CEA Cadarache, F-13108, St Paul-lez-Durance (France)], E-mail: gilbert.agarici@cea.fr; Becoulet, M.; Nardon, E.; Saille, A.; Thomas, P.R.; Verger, J.M. [Association EURATOM-CEA, CEA/DSM/DRFC, CEA Cadarache, F-13108, St Paul-lez-Durance (France)

    2007-10-15

    The suppression of ELMs with a resonant magnetic perturbation (RMP), as demonstrated in DIIID experiments [T. Evans, et al., Suppression of large edge localized modes with edge resonant magnetic fields in high confinement DIII-D plasmas, Nucl. Fusion 45 (2005) 595-607], and widely published [K.H. Burrell, et al., Plasma Phys. Control., Fusion 47 (2005) B37-B52 ; M. Becoulet, et al., Edge localized modes control by stochastic magnetic field, Nucl. Fusion 45 (2005) 1284-1292], is an attractive solution to the problem of divertor target erosion in ITER. Ideally, the RMP should be strong at the plasma edge and weak in the core, which requires the installation of the RMP coils as close as possible to the plasma. In both ITER and JET, an installation of the RMP coils within the vacuum vessel would subject the coils to neutron irradiation, tritium contamination and all the problems of furnishing cooling and electrical services, across many interfaces. So for JET, it has been proposed to install an 'ITER prototype' RMP system located ex-vessel.

  3. Prompt triggering of edge localized modes through lithium granule injection on EAST

    Science.gov (United States)

    Lunsford, Robert; Sun, Z.; Hu, J. S.; Xu, W.; Zuo, G. Z.; Gong, X. Z.; Wan, B. N.; Li, J. G.; Huang, M.; Maingi, R.; Diallo, A.; Tritz, K.; the EAST Team

    2017-10-01

    We report successful triggering of edge localized mode (ELMs) in EAST with Lithium (Li) micropellets, and the observed dependence of ELM triggering efficiency on granule size. ELM control is essential for successful ITER operation throughout the entire campaign, relying on magnetic perturbations for ELM suppression and ELM frequency enhancement via pellet injection. To separate the task of fueling from ELM pacing, we initiate the prompt generation of ELMs via impurity granule injection. Lithium granules ranging in size from 200 - 1000 microns are mechanically injected into upper-single null EAST long pulse H-mode discharges. The injections are monitored for their effect on high Z impurity accumulation and to assess the pressure perturbation required for reliable ELM triggering. We have determined that granules of diameter larger than 600 microns (corresponding to 5.2 x 1018 Li atoms) are successful at triggering ELMs more than 90% of the time. The triggering efficiency drops precipitously to less than 40% as the granule size is reduced to 400 microns (1.5 x 1018 Li atoms), indicating a triggering threshold has been crossed. Using this information an optimal impurity granule size which will regularly trigger a prompt ELM in these EAST discharges is determined. Coupling these results with alternate discharge scenarios on EAST and similar experiments performed on DIII-D provides the possibility of extrapolation to future devices.

  4. Repetitive Plasma Loads Typical for ITER Type-I ELMS: Simulation in QSPA Kh-50

    Science.gov (United States)

    Tereshin, V. I.; Bandura, A. N.; Byrka, O. V.; Chebotarev, V. V.; Garkusha, I. E.; Landman, I.; Makhlaj, V. A.; Solyakov, D. G.; Tsarenko, A. V.

    2006-01-01

    The paper presents energy characteristics of the plasma streams generated with quasi-steady-state plasma accelerator QSPA Kh-50 and the main features of plasma interaction with tungsten surfaces in dependence on plasma heat loads. The samples of pure sintered tungsten of EU trademark have been exposed to hydrogen plasma streams. The experiments were performed with up to 450 pulses (pulse duration of 0.25 ms) and the surface heat loads in the range of (0.45 - 1.2) MJ/m2. A threshold character of morphological changes on the melt tungsten surface with the pulses number is demonstrated. The number of initial exposures without formation of corrugations and pits is about 200, which does not depend on the target heat load magnitude. Further increase of the exposures results in the corrugation structures becoming dominant. The melt layer disintegrates into a set of droplets remaining at the surface. Such evolution seems to be driven by the surface tension forces within the fine cells of crack network. Finally a stabilization of the surface pattern occurs. The onset of intensive evaporation at molten tungsten surface under the repetitive heat loads has also been studied. The evaporation can result in enhanced mass losses: increase of the heat load from 0.75 to 1.1 MJ/m2 rises mass losses for one order of magnitude and causes bubble structures at the surface. Due to evaporation, the erosion crater grows with the rate of 0.04 μm/pulse. It was obtained, that for ELM-like repetitive loads the melt motion driven by plasma pressure gradient did not contribute significantly to the erosion profile.

  5. Role of E  ×  B on in-out divertor asymmetry in high recycling/partial detachment regimes under L-mode and H-mode conditions

    Science.gov (United States)

    Du, Hailong; Sang, Chaofeng; Wang, Liang; Bonnin, Xavier; Wang, Huiqian; Sun, Jizhong; Wang, Dezhen

    2017-11-01

    The role of the E  ×  B electric drift on background plasma and carbon impurity in-out divertor asymmetry was estimated under L-mode and H-mode conditions in the high recycling regime and partial detachment regime by using the edge plasma code SOLPS5.1. It was found that the poloidal electric drift E r  ×  B also may play a dominant role during H-mode discharge in high recycling regime, instead of the radial electric drift E θ   ×  B. Moreover, it also was found that during H-mode with partial detachment both components can play simultaneously a crucial role in inducing the in-out asymmetry. Their synergistic effect can make the asymmetry much more obvious than that with either of them separately. However, E θ   ×  B in partial detachment during L-mode can play a main role in inducing in-out asymmetry, rather than E r  ×  B. Besides, the role of E  ×  B components on carbon (C) impurity in-out asymmetry was also addressed. Simulation results reveal that E r  ×  B or E θ   ×  B individually have a very small effect on C impurity ions in-out asymmetry, especially E θ   ×  B, while their synergistic effect makes the impurity ions exhibit a much more remarkable in-out asymmetry. Moreover, it was found that the E r  ×  B and E θ   ×  B drift flows in the private flux region could play a crucial role in inducing C impurity in-out asymmetry, rather than the parallel flow or electric drift flow in the upstream SOL region when only considering E  ×  B.

  6. Observation of a new turbulence-driven limit-cycle state in H-modes with lower hybrid current drive and lithium-wall conditioning in the EAST superconducting tokamak

    DEFF Research Database (Denmark)

    Wang, H.Q.; Xu, G.S.; Guo, H.Y.

    2012-01-01

    The first high confinement H-mode plasma has been obtained in the Experimental Advanced Superconducting Tokamak (EAST) with about 1 MW lower hybrid current drive after wall conditioning by lithium evaporation and real-time injection of Li powder. Following the L–H transition, a small-amplitude, low...... correlated with each other, with nearly no phase differences poloidally and toroidally, and finite phase difference radially, thus providing strong evidence for zonal flows. The growth, saturation and disappearance of the zonal flows are strongly correlated with those of the high-frequency turbulence....... And the measurements demonstrate that the energy gain of zonal flows is of the same order as the energy loss of turbulence. This strongly suggests the interactions between zonal flows and high-frequency turbulences at the pedestal during the limit-cycle state....

  7. Massive sequencing of Ulmus minor's transcriptome provides new molecular tools for a genus under the constant threat of Dutch elm disease

    Directory of Open Access Journals (Sweden)

    Pedro ePerdiguero

    2015-07-01

    Full Text Available Elms, especially Ulmus minor and Ulmus americana, are carrying out a hard battle against Dutch elm disease (DED. This vascular wilt disease, caused by Ophiostoma ulmi and O. novo-ulmi, appeared in the twentieth century and killed millions of elms across North America and Europe. Elm breeding and conservation programmes have identified a reduced number of DED tolerant genotypes. In this study, three U. minor genotypes with contrasted levels of tolerance to DED were exposed to several biotic and abiotic stresses in order to (i obtain a de novo assembled transcriptome of U. minor using 454 pyrosequencing, (ii perform a functional annotation of the assembled transcriptome, (iii identify genes potentially involved in the molecular response to environmental stress, and (iv develop gene-based markers to support breeding programmes. A total of 58,429 putative unigenes were identified after assembly and filtering of the transcriptome. 32,152 of these unigenes showed homology with proteins identified in the genome from the most common plant model species. Well-known family proteins and transcription factors involved in abiotic, biotic or both stresses were identified after functional annotation. A total of 30,693 polymorphisms were identified in 7,125 isotigs, a large number of them corresponding to SNPs (27,359. In a subset randomly selected for validation, 87 % of the SNPs were confirmed. The material generated may be valuable for future Ulmus gene expression, population genomics and association genetics studies, especially taking into account the scarce molecular information available for this genus and the great impact that DED has on elm populations.

  8. Non-Ideal ELM Stability and Non-Axisymmetric Field Penetration Calculations with M3D-C1

    Science.gov (United States)

    Ferraro, N. M.; Chu, M. S.; Snyder, P. B.; Jardin, S. C.; Luo, X.

    2009-11-01

    Numerical studies of ELM stability and non-axisymmetric field penetration in diverted DIII-D and NSTX equilibria are presented, with resistive and finite Larmor radius effects included. These results are obtained with the nonlinear two-fluid code M3D-C1, which has recently been extended to allow linear non-axisymmetric calculations. Benchmarks of M3D-C1 with ideal codes ELITE and GATO show good agreement for the linear stability of peeling-ballooning modes in the ideal limit. New calculations of the resistive stability of ideally stable DIII-D equilibria are presented. M3D-C1 has also been used to calculate the linear response to non-axisymmetric external fields; these calculations are benchmarked with Surfmn and MARS-F. New numerical methods implemented in M3D-C1 are presented, including the treatment of boundary conditions with C^1 elements in a non-rectangular mesh.

  9. Cracking behavior of tungsten armor under ELM-like thermal shockloads II: A revised prediction for crack appearance map

    Directory of Open Access Journals (Sweden)

    Muyuan Li

    2016-12-01

    Full Text Available In this work, the surface cracking features of tungsten armor under thermal shock loads by edge-localized mode (ELM were investigated by means of computational fracture mechanics analysis. For the simulation it was assumed that a small crack was initiated at low temperature after the shut-off of thermal load in contrast to the previous studies where the presence of a crack before thermal loading was assumed. The threshold power density for surface cracking was predicted to range between 0.3 and 0.6GW/m2 while the threshold of base temperature lay between 200 and 400°C. The theoretically predicted damage map agreed well with the experimental data from electron beam irradiation tests. The current simulation model turned out to match better to the real experimental observation than the previous predictions where the threshold base temperature lies roughly between 400 and 600°C.

  10. Experimental investigation of vapor shielding effects induced by ELM-like pulsed plasma loads using the double plasma gun device

    Science.gov (United States)

    Sakuma, I.; Kikuchi, Y.; Kitagawa, Y.; Asai, Y.; Onishi, K.; Fukumoto, N.; Nagata, M.

    2015-08-01

    We have developed a unique experimental device of so-called double plasma gun, which consists of two magnetized coaxial plasma gun (MCPG) devices, in order to clarify effects of vapor shielding on material erosion due to transient events in magnetically confined fusion devices. Two ELM-like pulsed plasmas produced by the two MCPG devices were injected into a target chamber with a variable time difference. For generating ablated plasmas in front of a target material, an aluminum foil sample in the target chamber was exposed to a pulsed plasma produced by the 1st MCPG device. The 2nd pulsed plasma was produced with a time delay of 70 μs. It was found that a surface absorbed energy measured by a calorimeter was reduced to ∼66% of that without the Al foil sample. Thus, the reduction of the incoming plasma energy by the vapor shielding effect was successfully demonstrated in the present experiment.

  11. Experimental investigation of vapor shielding effects induced by ELM-like pulsed plasma loads using the double plasma gun device

    Energy Technology Data Exchange (ETDEWEB)

    Sakuma, I., E-mail: eu13z002@steng.u-hyogo.ac.jp; Kikuchi, Y.; Kitagawa, Y.; Asai, Y.; Onishi, K.; Fukumoto, N.; Nagata, M.

    2015-08-15

    We have developed a unique experimental device of so-called double plasma gun, which consists of two magnetized coaxial plasma gun (MCPG) devices, in order to clarify effects of vapor shielding on material erosion due to transient events in magnetically confined fusion devices. Two ELM-like pulsed plasmas produced by the two MCPG devices were injected into a target chamber with a variable time difference. For generating ablated plasmas in front of a target material, an aluminum foil sample in the target chamber was exposed to a pulsed plasma produced by the 1st MCPG device. The 2nd pulsed plasma was produced with a time delay of 70 μs. It was found that a surface absorbed energy measured by a calorimeter was reduced to ∼66% of that without the Al foil sample. Thus, the reduction of the incoming plasma energy by the vapor shielding effect was successfully demonstrated in the present experiment.

  12. NSTX Plasma Response to Lithium Coated Divertor

    Energy Technology Data Exchange (ETDEWEB)

    H.W. Kugel, M.G. Bell, J.P. Allain, R.E. Bell, S. Ding, S.P. Gerhardt, M.A. Jaworski, R. Kaita, J. Kallman, S.M. Kaye, B.P. LeBlanc, R. Maingi, R. Majeski, R. Maqueda, D.K. Mansfield, D. Mueller, R. Nygren, S.F. Paul, R. Raman, A.L. Roquemore, S.A. Sabbagh, H. Schneider, C.H. Skinner, V.A. Soukhanovskii, C.N. Taylor, J.R. Timberlak, W.R. Wampler, L.E. Zakharov, S.J. Zweben, and the NSTX Research Team

    2011-01-21

    NSTX experiments have explored lithium evaporated on a graphite divertor and other plasma facing components in both L- and H- mode confinement regimes heated by high-power neutral beams. Improvements in plasma performance have followed these lithium depositions, including a reduction and eventual elimination of the HeGDC time between discharges, reduced edge neutral density, reduced plasma density, particularly in the edge and the SOL, increased pedestal electron and ion temperature, improved energy confinement and the suppression of ELMs in the H-mode. However, with improvements in confinement and suppression of ELMs, there was a significant secular increase in the effective ion charge Zeff and the radiated power in H-mode plasmas as a result of increases in the carbon and medium-Z metallic impurities. Lithium itself remained at a very low level in the plasma core, <0.1%. Initial results are reported from operation with a Liquid Lithium Divertor (LLD) recently installed.

  13. Análisis comparativo de la disponibilidad léxica en español como lengua extranjera (ELE y lengua materna (ELM

    Directory of Open Access Journals (Sweden)

    Šifrar Kajan, Marjana

    2012-09-01

    Full Text Available El objetivo del presente trabajo es comparar la disponibilidad léxica de los estudiantes eslovenos de ELE con la disponibilidad léxica de los estudiantes españoles de ELM, y detectar las diferencias o similitudes léxicas entre los hablantes extranjeros y nativos de español en diez campos semánticos: partes del cuerpo, la ropa, la casa, alimentos y bebidas, la ciudad, el campo, medios de transporte, los animales, juegos y distracciones, y profesiones y oficios. Quedan así expuestas las grandes discrepancias entre el léxico más disponible en ELE y ELM, y en relación con el Plan Curricular. A partir de los resultados se propone la aplicación pedagógica de la planificación léxica en la enseñanza de ELE.

  14. [Determination of process variable pH in solid-state fermentation by FT-NIR spectroscopy and extreme learning machine (ELM)].

    Science.gov (United States)

    Liu, Guo-hai; Jiang, Hui; Xiao, Xia-hong; Zhang, Dong-juan; Mei, Cong-li; Ding, Yu-han

    2012-04-01

    Fourier transform near-infrared (FT-NIR) spectroscopy was attempted to determine pH, which is one of the key process parameters in solid-state fermentation of crop straws. First, near infrared spectra of 140 solid-state fermented product samples were obtained by near infrared spectroscopy system in the wavelength range of 10 000-4 000 cm(-1), and then the reference measurement results of pH were achieved by pH meter. Thereafter, the extreme learning machine (ELM) was employed to calibrate model. In the calibration model, the optimal number of PCs and the optimal number of hidden-layer nodes of ELM network were determined by the cross-validation. Experimental results showed that the optimal ELM model was achieved with 1040-1 topology construction as follows: R(p) = 0.961 8 and RMSEP = 0.104 4 in the prediction set. The research achievement could provide technological basis for the on-line measurement of the process parameters in solid-state fermentation.

  15. Preliminary assessment of potential well yields and the potential for artificial recharge of the Elm and Middle James aquifers in the Aberdeen area, South Dakota

    Science.gov (United States)

    Emmons, P.J.

    1987-01-01

    A complex hydrologic system exists in the glacial drift overlying the bedrock in the Aberdeen, South Dakota, area. The hydrologic system has been subdivided into three aquifers: the Elm, Middle James, and Deep James. These sand-and-gravel outwash aquifers generally are separated from each other by till or other fine-grained sediments. The Elm aquifer is the uppermost and largest of the aquifers and underlies about 204 sq mi of the study area. The maximum altitude of the top of the Elm aquifer is 1,400 ft and the minimum altitude of the bottom is 1,225 ft. The Middle James aquifer underlies about 172 sq mi of the study area. The maximum altitude of the top of the Middle James aquifer is 1,250 ft and the minimum altitude of the bottom is 1 ,150 ft. The lower-most Deep James aquifer was not evaluated. The quality of the water from the Elm and Middle James aquifer varies considerably throughout the study area. The predominant chemical constituents in the water from the aquifers are sodium and sulfate ions; however, calcium, magnesium, bicarbonate, or chloride may dominate locally. The calculated theoretical total well yield from the Elm and Middle James aquifers ranges from a minimum of 64 cu ft/sec, which may be conservative, to a maximum of 640 cu ft/sec. Based on available data, yields of 100 to 150 cu ft/sec probably can be obtained from properly sited and constructed wells. The feasibility of artificially recharging an aquifer, using the technique of water spreading, depends on the geologic and hydraulic characteristics of the aquifer and of the sediments overlying the aquifer through which the recharge water must percolate. The sites suitable for artificial recharge in the study area were defined as those areas where the average aquifer thickness was > 20 ft and the average thickness of the fine-grained sediments overlying the aquifer was < 10 ft. Using these criteria, about 14 sq mi of the study area are suitable for artificial recharge. Infiltration rates in

  16. Characterization of type-I ELM induced filaments in the far scrape-off layer of ASDEX upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Andreas

    2008-03-18

    This thesis focuses on the characterization of filaments and their propagation in the ASDEX Upgrade tokamak. The aim is to provide experimental measurements for understanding the filament formation process and their temporal evolution, and to provide a comprehensive database for an extrapolation to future fusion devices. For this purpose, a new magnetically driven probe for filament measurements has been developed and installed in ASDEX Upgrade. The probe carries several Langmuir probes and a magnetic coil in between. The Langmuir probes allow for measurements of the radial and poloidal/toroidal propagation of filaments as well as for measurements of filament size, density, and their radial (or temporal) evolution. The magnetic coil on the filament probe allows for measurements of currents in the filaments. A set of 7 coils, measuring 3 field components at different positions along the filament, has been used to measure the magnetic signature during an ELM. The aim was, on the one hand, to study which role filaments play for the magnetic structure, and on the other hand if the parallel currents predicted by the sheath damped model could be verified. Filament temperatures have been derived and the corresponding heat transport mechanisms have been studied. (orig.)

  17. Description and phylogeny of a new microsporidium from the elm leaf beetle, Xanthogaleruca luteola Muller, 1766 (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Bekircan, Çağrı; Bülbül, Ufuk; Güler, Halil I; Becnel, James J

    2017-02-01

    This study describes a new genus and species of microsporidia which is a pathogen of the elm leaf beetle, Xanthogaleruca luteola Muller, 1776 (Coleoptera: Chrysomelidae). The beetles were collected from Istanbul in Turkey. All developmental stages are uninucleate and in direct contact with the host cell cytoplasm. Giemsa-stained mature spores are oval in shape and measured 3.40 ± 0.37 μm in length and 1.63 ± 0.20 μm in width. These uninucleate spores have an isofilar polar filament with 11 turns. The spore wall was trilaminar (75 to 115 nm) with a rugose, electron-dense exospore (34 to 45 nm) and a thickened, electron-lucent endospore (65 to 80 nm) overlaying the plasmalemma. Morphological, ultrastructural, and molecular features indicate that the described microsporidium is dissimilar to all known microsporidian taxa and confirm that it has different taxonomic characters than other microsporidia infecting X. luteola and is named here as Rugispora istanbulensis n. gen., n. sp.

  18. Heybridge: A late Iron Age and Roman settlement. Excavations at Elms Farm 1993-5. Volume 2

    Directory of Open Access Journals (Sweden)

    Mark Atkinson

    2015-12-01

    Full Text Available The Late Iron Age, Roman and early Saxon settlement at Elms Farm, Heybridge, Essex was excavated in the mid-1990s, in advance of the construction of a large housing estate by Bovis Homes Ltd. The total development area comprised c. 29 hectares, of which some 18ha were subject to varying degrees of investigation by the Essex County Council Field Archaeology Unit (ECC FAU. The large-scale of the excavations is matched by the substantial and important artefact assemblage recovered, which included 6.4 tonnes of Late Iron Age and Roman pottery, 2,910 Roman coins and over 9000 animal bones. Together this has enabled an appreciation of the development of the settlement over time and space, of the changing functions, status and economy of individual areas and the settlement as a whole, and the issues of transition, change and finally decline. The site revealed evidence for activity from the Bronze Age to the post-medieval period. The evidence for the earliest settlement dates to the Late Iron Age period (mid 1st century BC and is rather fragmentary in nature. However a centrally located shrine, with a series of strip-plots to the north and south were tentatively identified. This settlement was remodelled around the mid 1st century AD, with the creation of a formal infrastructure of metalled roads, as well as a new temple precinct on the earlier sacred site and a reworking of the strip-plots into enclosures. This remodelling spanned the Late Iron Age/early Roman transition period, although the new road network is tentatively dated to the decade or two preceding the Roman conquest. To the north of the settlement area were a number of burials, pyre sites and pyre debris dumps. Early Roman cremations were added to this area slightly later. Some of the pyre sites exhibit higher-status elements, and at least one may have been 'aristocratic', suggesting the presence of a local elite. Reconstruction of settlement at Heybridge by Roger Massey-Ryan The later 1st

  19. A Fault Diagnosis Method of High Voltage Circuit Breaker Based on Moving Contact Motion Trajectory and ELM

    Directory of Open Access Journals (Sweden)

    Weihua Niu

    2016-01-01

    Full Text Available In order to avoid the deficiencies of conventional high voltage circuit breaker mechanical properties detection methods, a new algorithm based on image block matching with diamond search strategy is presented in this paper. The motion of auxiliary mark on the pull rod or shaft is firstly recorded by a high-speed and high-definition digital camera when the circuit breaker is open or close. Then the motion trajectory is acquired through diamond image block matching method. The mechanical parameters, such as travel and open and close velocity, are calculated according to the travel-time curve of the circuit breaker. Finally, evaluation model is constructed taking mechanical parameters characteristic values as inputs of ELM. Comparing to the existing techniques, our method is a noncontact measurement based on computer vision. It is easy and convenient for practical application since it need not any electrical and mechanical connection to the breaker. Another advantage of our method is that it can obtain the line and angle displacement simultaneously. The experiment results on the circuit breaker of 220 kv show that our method is effective for breaker mechanical properties detection.

  20. Surface modifications on toughened, fine-grained, recrystallized tungsten with repetitive ELM-like pulsed plasma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Y., E-mail: ykikuchi@eng.u-hyogo.ac.jp [Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, 671-2280 Hyogo (Japan); Sakuma, I.; Kitagawa, Y.; Asai, Y.; Onishi, K.; Fukumoto, N.; Nagata, M. [Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, 671-2280 Hyogo (Japan); Ueda, Y. [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kurishita, H. [Institute for Materials Research, Tohoku University, Ibaraki 311-1313 (Japan)

    2015-08-15

    Surface modifications of toughened, fine-grained, recrystallized tungsten (TFGR W) materials with 1.1 wt.% TiC and 3.3 wt.% TaC dispersoids due to repetitive ELM-like pulsed (∼0.15 ms) helium plasma irradiation have been investigated by using a magnetized coaxial plasma gun. No surface cracking at the center part of the TFGR W samples exposed to 20 plasma pulses of ∼0.3 MJ m{sup −2} was observed. The suppression of surface crack formation due to the increase of the grain boundary strength by addition of TiC and TaC dispersoids was confirmed in comparison with a pure W material. On the other hand, surface cracks and small pits appeared at the edge part of the TFGR W sample after the pulsed plasma irradiation. Erosion of the TiC and TaC dispersoids due to the pulsed plasma irradiation could cause the small pits on the surface, resulting in the surface crack formation.

  1. Vapor shielding effects on energy transfer from plasma-gun generated ELM-like transient loads to material surfaces

    Science.gov (United States)

    Kikuchi, Y.; Sakuma, I.; Asai, Y.; Onishi, K.; Isono, W.; Nakazono, T.; Nakane, M.; Fukumoto, N.; Nagata, M.

    2016-02-01

    Energy transfer processes from ELM-like pulsed helium (He) plasmas with a pulse duration of ˜0.1 ms to aluminum (Al) and tungsten (W) surfaces were experimentally investigated by the use of a magnetized coaxial plasma gun device. The surface absorbed energy density of the He pulsed plasma on the W surface measured with a calorimeter was ˜0.44 MJ m-2, whereas it was ˜0.15 MJ m-2 on the Al surface. A vapor layer in front of the Al surface exposed to the He pulsed plasma was clearly identified by Al neutral emission line (Al i) measured with a high time resolution spectrometer, and fast imaging with a high-speed visible camera filtered around the Al i emission line. On the other hand, no clear evaporation in front of the W surface exposed to the He pulsed plasma was observed in the present condition. Discussions on the reduction in the surface absorbed energy density on the Al surface are provided by considering the latent heat of vaporization and radiation cooling due to the Al vapor cloud.

  2. Surface modifications on toughened, fine-grained, recrystallized tungsten with repetitive ELM-like pulsed plasma irradiation

    Science.gov (United States)

    Kikuchi, Y.; Sakuma, I.; Kitagawa, Y.; Asai, Y.; Onishi, K.; Fukumoto, N.; Nagata, M.; Ueda, Y.; Kurishita, H.

    2015-08-01

    Surface modifications of toughened, fine-grained, recrystallized tungsten (TFGR W) materials with 1.1 wt.% TiC and 3.3 wt.% TaC dispersoids due to repetitive ELM-like pulsed (∼0.15 ms) helium plasma irradiation have been investigated by using a magnetized coaxial plasma gun. No surface cracking at the center part of the TFGR W samples exposed to 20 plasma pulses of ∼0.3 MJ m-2 was observed. The suppression of surface crack formation due to the increase of the grain boundary strength by addition of TiC and TaC dispersoids was confirmed in comparison with a pure W material. On the other hand, surface cracks and small pits appeared at the edge part of the TFGR W sample after the pulsed plasma irradiation. Erosion of the TiC and TaC dispersoids due to the pulsed plasma irradiation could cause the small pits on the surface, resulting in the surface crack formation.

  3. Organic compounds in Elm Fork Trinity River water used for public supply near Carrollton, Texas, 2002-05

    Science.gov (United States)

    Ging, Patricia B.; Delzer, Gregory C.; Hamilton, Pixie A.

    2009-01-01

    Organic compounds studied in this U.S. Geological Survey (USGS) assessment generally are man-made, including pesticides, solvents, gasoline hydrocarbons, personal-care and domestic-use products, refrigerants, and propellants. A total of 103 of 277 compounds were detected at least once among the 30 samples of source water for a community water system on the Elm Fork Trinity River near Carrollton, Texas, collected approximately monthly during 2002-05. The diversity of compounds detected indicates a variety of different sources and uses (including wastewater discharge, industrial, agricultural, domestic, and others) and different pathways (including overland runoff and groundwater discharge) to drinking-water supplies. Nine compounds were detected year-round in source-water samples, including chloroform, methyl tert-butyl ether (MTBE), and selected herbicide compounds commonly used in the Trinity River Basin and in other urban areas across the United States. About 90 percent of the 42 compounds detected most frequently in source water (in at least 20 percent of the samples) also were detected most frequently in finished water (after treatment but before distribution). Concentrations for all detected compounds in source and finished water generally were less than 0.1 microgram per liter and always less than human-health benchmarks, which are available for about one-half of the detected compounds.

  4. A Hybrid DE-RGSO-ELM for Brain Tumor Tissue Categorization in 3D Magnetic Resonance Images

    Directory of Open Access Journals (Sweden)

    K. Kothavari

    2014-01-01

    Full Text Available Medical diagnostics, a technique used for visualizing the internal structures and functions of human body, serves as a scientific tool to assist physicians and involves direct use of digital imaging system analysis. In this scenario, identification of brain tumors is complex in the diagnostic process. Magnetic resonance imaging (MRI technique is noted to best assist tissue contrast for anatomical details and also carries out mechanisms for investigating the brain by functional imaging in tumor predictions. Considering 3D MRI model, analyzing the anatomy features and tissue characteristics of brain tumor is complex in nature. Henceforth, in this work, feature extraction is carried out by computing 3D gray-level cooccurence matrix (3D GLCM and run-length matrix (RLM and feature subselection for dimensionality reduction is performed with basic differential evolution (DE algorithm. Classification is performed using proposed extreme learning machine (ELM, with refined group search optimizer (RGSO technique, to select the best parameters for better simplification and training of the classifier for brain tissue and tumor characterization as white matter (WM, gray matter (GM, cerebrospinal fluid (CSF, and tumor. Extreme learning machine outperforms the standard binary linear SVM and BPN for medical image classifier and proves better in classifying healthy and tumor tissues. The comparison between the algorithms proves that the mean and standard deviation produced by volumetric feature extraction analysis are higher than the other approaches. The proposed work is designed for pathological brain tumor classification and for 3D MRI tumor image segmentation. The proposed approaches are applied for real time datasets and benchmark datasets taken from dataset repositories.

  5. Visualization of the operational space of edge-localized modes through low-dimensional embedding of probability distributions.

    Science.gov (United States)

    Shabbir, A; Verdoolaege, G; Kardaun, O J W F; Noterdaeme, J M

    2014-11-01

    Information visualization aimed at facilitating human perception is an important tool for the interpretation of experiments on the basis of complex multidimensional data characterizing the operational space of fusion devices. This work describes a method for visualizing the operational space on a two-dimensional map and applies it to the discrimination of type I and type III edge-localized modes (ELMs) from a series of carbon-wall ELMy discharges at JET. The approach accounts for stochastic uncertainties that play an important role in fusion data sets, by modeling measurements with probability distributions in a metric space. The method is aimed at contributing to physical understanding of ELMs as well as their control. Furthermore, it is a general method that can be applied to the modeling of various other plasma phenomena as well.

  6. Investigation Of A Transient Energetic Charge Exchange Fux Enhancement ('spike-on-tail') Observed In Neutral-beam-heated H-mode Discharges In The National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Medley et al, S S

    2011-08-04

    In the National Spherical Torus Experiment (NSTX), a large increase in the charge exchange neutral flux localized at the Neutral Beam (NB) injection full energy is measured by the E||B (superimposed parallel electric and magnetic fields) Neutral Particle Analyzer (NPA). Termed the High-Energy Feature (HEF), it appears on the NB-injected energetic ion spectrum only in discharges where tearing or kink-type modes (f < 50 kHz) are absent, Toroidal Alfvén Eigenmode (TAE) activity (f ~ 50 - 150 kHz) is weak and Global Alfvén Eigenmode (GAE) activity (f ~ 400 – 1000 kHz) is robust. Compressional Alfvén eigenmode (CAE) activity (f > 1000 kHz) is usually sporadic or absent during the HEF event. The HEF exhibits growth times of Δt ~ 20 - 80 ms, durations of ~ 100 – 600 ms and peak-to-base flux ratios up to H = Fmax /Fmin ~ 10. In infrequent cases, a slowing down distribution below the HEF energy can develop that continues to evolve over periods > 100 ms, a time scale long compared with the typical fast ion equilibration times. HEFs are Transient energetic charge exchange flux enhancement ('spike-on-tail') 2 observed only in H-mode (not L-mode) discharges with injected power Pb ≥ 4 MW and in the pitch range χ = vll /v ~ 0.7 – 0.9; i.e. only for passing particles. Increases of ~ 10 - 30 % in the measured neutron yield and total stored energy that are observed to coincide with the feature appear to be driven by concomitant broadening of measured Te(r), Ti(r) and ne(r) profiles and not the HEF itself. While the HEF has minimal impact on plasma performance, it nevertheless poses a challenging wave-particle interaction phenomenon to understand. Candidate mechanisms for HEF formation are developed based on quasilinear theory of wave-particle interaction. The only mechanism found to lead to the large NPA flux ratios, H = Fmax /Fmin , observed in NSTX is the quasilinear evolution of the energetic ion distribution, Fb(E,χ,r), in phase space and the concomitant

  7. Elm leaves 'warned' by insect egg deposition reduce survival of hatching larvae by a shift in their quantitative leaf metabolite pattern.

    Science.gov (United States)

    Austel, Nadine; Eilers, Elisabeth J; Meiners, Torsten; Hilker, Monika

    2016-02-01

    Plants may take insect eggs on their leaves as a warning of future herbivory and intensify their defence against feeding larvae. Responsible agents are, however, largely unknown, and little knowledge is available on this phenomenon in perennial plants. We investigated how egg deposition affects the anti-herbivore defence of elm against the multivoltine elm leaf beetle. Prior egg deposition caused changes in the quality of feeding-damaged leaves that resulted in increased larval mortality and reduced reproductive capacity of the herbivore by harming especially female larvae. Chemical analyses of primary and secondary leaf metabolites in feeding-damaged, egg-free (F) and feeding-damaged, egg-deposited (EF)-leaves revealed only small differences in concentrations when comparing metabolites singly. However, a pattern-focused analysis showed clearly separable patterns of (F) and (EF)-leaves because of concentration differences in especially nitrogen and phenolics, of which robinin was consumed in greater amounts by larvae on (EF) than on (F)-leaves. Our study shows that insect egg deposition mediates a shift in the quantitative nutritional pattern of feeding-damaged leaves, and thus might limit the herbivore's population growth by reducing the number of especially female herbivores. This may be a strategy that pays off in a long run particularly in perennial plants against multivoltine herbivores. © 2015 John Wiley & Sons Ltd.

  8. Characteristics of edge-localized modes in the experimental advanced superconducting tokamak (EAST)

    DEFF Research Database (Denmark)

    Jiang, M.; Xu, G.S.; Xiao, C.

    2012-01-01

    confinement modes (H-modes) were obtained with 1 MW lower hybrid wave power in conjunction with wall conditioning by lithium (Li) evaporation and real-time Li powder injection. The ELMs in EAST at this heating power are mostly type-III ELMs. They were observed close to the H-mode threshold power and produced...

  9. Development of a double plasma gun device for investigation of effects of vapor shielding on erosion of PFC materials under ELM-like pulsed plasma bombardment

    Science.gov (United States)

    Sakuma, I.; Iwamoto, D.; Kitagawa, Y.; Kikuchi, Y.; Fukumoto, N.; Nagata, M.

    2012-10-01

    It is considered that thermal transient events such as type I edge localized modes (ELMs) could limit the lifetime of plasma-facing components (PFCs) in ITER. We have investigated surface damage of tungsten (W) materials under transient heat and particle loads by using a magnetized coaxial plasma gun (MCPG) device at University of Hyogo. The capacitor bank energy for the plasma discharge is 144 kJ (2.88 mF, 10 kVmax). Surface melting of a W material was clearly observed at the energy density of ˜2 MJ/m2. It is known that surface melting and evaporation during a transient heat load could generate a vapor cloud layer in front of the target material [1]. Then, the subsequent erosion could be reduced by the vapor shielding effect. In this study, we introduce a new experiment using two MCPG devices (MCPG-1, 2) to understand vapor shielding effects of a W surface under ELM-like pulsed plasma bombardment. The capacitor bank energy of MCPG-2 is almost same as that of MCPG-1. The second plasmoid is applied with a variable delay time after the plasmoid produced by MCPG-1. Then, a vapor cloud layer could shield the second plasma load. To verify the vapor shielding effects, surface damage of a W material is investigated by changing the delay time. In the conference, the preliminary experimental results will be shown.[4pt] [1] A. Hassanein et al., J. Nucl. Mater. 390-391, pp. 777-780 (2009).

  10. Pedestal and confinement properties under shape and magnetic topology variation on Alcator C-Mod

    Science.gov (United States)

    Hughes, J. W.; Lipschultz, B.; Whyte, D.; Marmar, E. S.; Greenwald, M.; Hubbard, A. E.; McDermott, R. M.

    2008-11-01

    Recent work on Alcator C-Mod has examined the influence of magnetic topology and equilibrium shape on edge pedestal structure and plasma confinement. H-mode pedestal parameters show a striking sensitivity to the ion ∇B drift direction, relative to the active x-point position, with considerable variability observed when the distance between separatrices is on the order of the pedestal width (˜5mm) or less, i.e. very near double null (DN). Near DN H-modes can have improved confinement factors (H98>1) as a result of elevated pedestal temperature (Tped), with the edge regulated by benign small edge-localized modes (ELMs) or continuous modes. Such operational regimes with no large ELMs are desirable for ITER and other future devices. Discharges with L-mode-like particle confinement, yet with H98 1 and Tped 1keV, were maintained steady-state by operating with high current, strong shaping and unfavorable ∇B drift direction, while holding input power below the L-H threshold to prevent particle barrier formation. The pedestal and confinement properties of these improved ELM-free regimes will be compared to those of typical H-modes.

  11. Experimental investigation of heat transport and divertor loads of fusion plasmas in all metal ASDEX upgrade and JET

    Energy Technology Data Exchange (ETDEWEB)

    Sieglin, Bernhard A.

    2014-04-28

    This work presents divertor heat load studies conducted at two of the largest tokamaks currently in operation, ASDEX Upgrade and the Joint European Torus (JET). A commonly agreed empirical scaling for the power fall-off length in H-mode obtained in carbon devices is validated in JET with the ILW. Bohm and Gyro-Bohm like models are identified as possible candidates describing the divertor broadening. Quantities for the assessment of the thermal load induced by transient heat loads are defined. JET with the ILW exhibits an on average longer ELM duration as compared to the carbon wall. For identical pedestal conditions the ELM durations in both cases are found to be the same within error bars. The energy fluency is found to depend mainly on the pedestal pressure with a weak dependence on the relative loss in stored energy. This is noteworthy since the current extrapolation to ITER assumes a linear dependence on the relative ELM size.

  12. Overview of Initial NSTX-U Experimental Operations

    Science.gov (United States)

    Battaglia, Devon; the NSTX-U Team

    2016-10-01

    Initial operation of the National Spherical Torus Experiment Upgrade (NSTX-U) has satisfied a number of commissioning milestones, including demonstration of discharges that exceed the field and pulse length of NSTX. ELMy H-mode operation at the no-wall βN limit is obtained with Boronized wall conditioning. Peak H-mode parameters include: Ip = 1 MA, BT0 = 0.63 T, WMHD = 330 kJ, βN = 4, βN/li = 6, κ = 2.3, τE , tot >50 ms. Access to high-performance H-mode scenarios with long MHD-quiescent periods is enabled by the resilient timing of the L-H transition via feedback control of the diverting time and shape, and correction of the dominant n =1 error fields during the Ip ramp. Stationary L-mode discharges have been realized up to 1 MA with 2 s discharges achieved at Ip = 650 kA. The long-pulse L-mode discharges enabled by the new central solenoid supported initial experiments on error field measurements and correction, plasma shape control, controlled discharge ramp-down, L-mode transport and fast ion physics. Increased off-axis current drive and reduction of fast ion instabilities has been observed with the new, more tangential neutral beamline. The initial results support that access to increased field, current and heating at low-aspect-ratio expands the regimes available to develop scenarios, diagnostics and predictive models that inform the design and optimization of future burning plasma tokamak devices, including ITER. Work Supported by U.S. DOE Contract No. DE-AC02-09CH11466.

  13. First use of three-dimensional equilibrium, stability and transport calculations for interpretation of ELM triggering with magnetic perturbations in NSTX

    Science.gov (United States)

    Canik, J. M.; Hirshman, S. P.; Sanchez, R.; Maingi, R.; Ahn, J.-W.; Bell, R. E.; Diallo, A.; Gerhardt, S. P.; LeBlanc, B. P.; Menard, J. E.; Park, J.-K.; Podesta, M.; Sabbagh, S. A.

    2012-05-01

    The application of non-axisymmetric magnetic perturbations has been demonstrated to destabilize edge-localized modes (ELMs) in the National Spherical Torus Experiment. A model 3D equilibrium has been calculated for these experiments using the VMEC code, which assumes nested flux surfaces and therefore that resonant perturbations are shielded. First, a free-boundary equilibrium is calculated using the NSTX coil set, with pressure and current profiles matched to a standard 2D reconstruction, but with up-down symmetry enforced. A new equilibrium is then calculated with the n = 3 field applied at a level consistent with experiment. This equilibrium is then used as the basis of further calculations using codes developed for analysis of stellarator plasmas. The neoclassical transport due to the 3D fields is calculated to be small compared with the experimental transport rates. Initial stability analysis has been performed, and indicates a modest degradation in ballooning stability with 3D fields applied. A new 3D equilibrium is also calculated using the SIESTA code, which allows for the formation of islands and stochastic regions. A comparison of the field structure between the SIESTA calculation and the assumption of fully penetrated vacuum perturbation indicates smaller island sizes and very small stochastic transport in the SIESTA case.

  14. Leadership jellemvonások és lean menedzsment – elmélet és gyakorlat = Leadership attributes and lean management in theory and practice

    OpenAIRE

    Gelei, Andrea; Losonci, Dávid; Báthory, Zsuzsanna; Toarniczky, Andrea

    2012-01-01

    A műhelytanulmány két kutatási kérdést vizsgál. Egyrészt kiemelt szakirodalom alapján megvizsgálja, hogy az elméleti ajánlások milyen vezetési stílust és vezetői stílusjegyeket fogalmaznak meg követendőnek egy lean vállalat számára. Másrészt megvizsgálja, hogy a lean menedzsment gyakorlatának alkalmazásában fejlettebb vállalatok vezetői valóban az irodalom által javasolt, kívánatosnak tekintett vezetői stílusjegyeket tekintik-e pozitívnak. Vizsgálatunkat a Versenyképesség Kutató Központ 2009-...

  15. Elm Tree (Ulmus parvifolia) Bark Bioprocessed with Mycelia of Shiitake (Lentinus edodes) Mushrooms in Liquid Culture: Composition and Mechanism of Protection against Allergic Asthma in Mice.

    Science.gov (United States)

    Kim, Sung Phil; Lee, Sang Jong; Nam, Seok Hyun; Friedman, Mendel

    2016-02-03

    Mushrooms can break down complex plant materials into smaller, more digestible and bioactive compounds. The present study investigated the antiasthma effect of an Ulmus parvifolia bark extract bioprocessed in Lentinus edodes liquid mycelium culture (BPUBE) against allergic asthma in chicken egg ovalbumin (OVA)-sensitized/challenged mice. BPUBE suppressed total IgE release from U266B1 cells in a dose-dependent manner without cytotoxicity. Inhibitory activity of BPUBE against OVA-specific IgE secretion in bronchoalveolar lavage fluid (BALF) was observed in OVA-sensitized/challenged asthmatic mice. BPUBE also inhibited OVA-specific IgG and IgG1 secretion into serum from the allergic mice, suggesting the restoration of a Th2-biased immune reaction to a Th1/Th2-balanced status, as indicated by the Th1/Th2 as well as regulatory T cell (Treg) cytokine profile changes caused by BPUBE in serum or BALF. Inflammatory cell counts in BALF and lung histology showed that leukocytosis and eosinophilia induced by OVA-sensitization/challenge were inhibited by the oral administration of BPUBE. Amelioration of eosinophil infiltration near the trachea was associated with reduced eotaxin and vascular cell adhesion molecule-1 (VCAM-1) levels. Changes in proinflammatory mediator levels in BALF suggest that BPUBE decreased OVA-sensitization-induced elevation of leukotriene C4 (LTC4) and prostaglandin D2 (PGD2). The finding that asthma-associated biomarker levels of OVA-sensitized/challenged mice were much more inhibited with BPUBE treatment than NPUBE (not-bioprocessed Ulmus parvifolia extract) treatment suggested the production of new bioactive compounds by the mushroom mycelia that may be involved in enhancing the observed antiasthmatic properties. The possible relation of the composition determined by proximate analysis and GC/MS to observed bioactivity is discussed. The results suggest that the elm tree (Ulmus parvifolia) bark bioprocessed with mycelia of shiitake (Lentinus edodes

  16. V-ELMpiRNAPred: Identification of human piRNAs by the voting-based extreme learning machine (V-ELM) with a new hybrid feature.

    Science.gov (United States)

    Pian, Cong; Chen, Yuan-Yuan; Zhang, Jin; Chen, Zhi; Zhang, Guang-Le; Li, Qiang; Yang, Tao; Zhang, Liang-Yun

    2017-02-01

    Piwi-interacting RNAs (piRNAs) were recently discovered as endogenous small noncoding RNAs. Some recent research suggests that piRNAs may play an important role in cancer. So the precise identification of human piRNAs is a significant work. In this paper, we introduce a series of new features with 80 dimension called short sequence motifs (SSM). A hybrid feature vector with 1444 dimension can be formed by combining 1364 features of [Formula: see text]-mer strings and 80 features of SSM features. We optimize the 1444 dimension features using the feature score criterion (FSC) and list them in descending order according to the scores. The first 462 are selected as the input feature vector in the classifier. Moreover, eight of 80 SSM features appear in the top 20. This indicates that these eight SSM features play an important part in the identification of piRNAs. Since five of the above eight SSM features are associated with nucleotide A and G ('A*G', 'A**G', 'A***G', 'A****G', 'A*****G'). So, we guess there may exist some biological significance. We also use a neural network algorithm called voting-based extreme learning machine (V-ELM) to identify real piRNAs. The Specificity (Sp) and Sensitivity (Sn) of our method are 95.48% and 94.61%, respectively in human species. This result shows that our method is more effective compared with those of the piRPred, piRNApredictor, Asym-Pibomd, Piano and McRUMs. The web service of V-ELMpiRNAPred is available for free at http://mm20132014.wicp.net:38601/velmprepiRNA/Main.jsp .

  17. New Edge Localized Modes at Marginal Input Power with Dominant RF-heating and Lithium-wall Conditioning in EAST

    DEFF Research Database (Denmark)

    Wang, H.; Xu, G.; Guo, H.

    The EAST tokamak has achieved, for the rst time, the ELMy H-mode at a connement improvement factor HITER89P 1:7, with dominant RF heating and active wall conditioning by lithium evaporation and real-time injection of Li powder. During the H-mode phase, a new small-ELM regime has been observed...... of zonal flows. New observations have also been made on the type-III ELMs. Measurements from Mach probes have demonstrated a decreasing co-current rotation during type-III ELMs. These suggest that the type-III ELMs may transport substantial particles, energy and momentum out of the plasma. Each type...

  18. Spatial Operations

    Directory of Open Access Journals (Sweden)

    Anda VELICANU

    2010-09-01

    Full Text Available This paper contains a brief description of the most important operations that can be performed on spatial data such as spatial queries, create, update, insert, delete operations, conversions, operations on the map or analysis on grid cells. Each operation has a graphical example and some of them have code examples in Oracle and PostgreSQL.

  19. Operational amplifiers

    CERN Document Server

    Dostal, Jiri

    1993-01-01

    This book provides the reader with the practical knowledge necessary to select and use operational amplifier devices. It presents an extensive treatment of applications and a practically oriented, unified theory of operational circuits.Provides the reader with practical knowledge necessary to select and use operational amplifier devices. Presents an extensive treatment of applications and a practically oriented, unified theory of operational circuits

  20. Overview of EAST experiments on the development of high-performance steady-state scenario

    Science.gov (United States)

    Wan, B. N.; Liang, Y. F.; Gong, X. Z.; Li, J. G.; Xiang, N.; Xu, G. S.; Sun, Y. W.; Wang, L.; Qian, J. P.; Liu, H. Q.; Zhang, X. D.; Hu, L. Q.; Hu, J. S.; Liu, F. K.; Hu, C. D.; Zhao, Y. P.; Zeng, L.; Wang, M.; Xu, H. D.; Luo, G. N.; Garofalo, A. M.; Ekedahl, A.; Zhang, L.; Zhang, X. J.; Huang, J.; Ding, B. J.; Zang, Q.; Li, M. H.; Ding, F.; Ding, S. Y.; Lyu, B.; Yu, Y. W.; Zhang, T.; Zhang, Y.; Li, G. Q.; Xia, T. Y.; the EAST Team; Collaborators

    2017-10-01

    The EAST research program aims to demonstrate steady-state long-pulse advanced high-performance H-mode operations with ITER-like poloidal configuration and RF-dominated heating schemes. Since the 2014 IAEA FEC, EAST has been upgraded with all ITER-relevant auxiliary heating and current drive systems, enabling the investigation of plasma profile control by the coupling/integration of various auxiliary heating combinations. Fully non-inductive steady-state H-mode plasma (H 98,y2  >  1.1) was extended over 60 s for the first time with sole RF heating plus good power coupling and impurity and particle control. By means of the 4.6 GHz and 2.45 GHz LHCD systems, H-mode can be obtained and maintained at relatively high density, even up to n e ~ 4.5  ×  1019 m-3, where a current drive effect is still observed. Significant progress has been achieved on EAST, including: (i) demonstration of a steady-state scenario (fully non-inductive with V loop ~ 0.0 V at high β P ~ 1.8 and high-performance in upper single-null (ɛ ~ 1.6) configuration with the tungsten divertor; (ii) discovery of a stationary H-mode regime with no/small ELM using 4.6 GHz LHCD, and; (iii) achievement of ELM suppression in slowly rotating H-mode plasma with n  =  1 and 2 RMP compatible with long-pulse operations. The new advances in scenario development provide an integrated solution in achieving long-pulse steady-state operations on EAST.

  1. Chemical Agent Monitor (CAM) follow-on operational test and evaluation simulant test strategy. Final report, May 1988-April 1989

    Energy Technology Data Exchange (ETDEWEB)

    Seitzinger, A.T.; Grasso, P.S.; Guelta, M.A.

    1990-06-01

    This report was intended to provide technical guidance to the U.S. Army Armor and Engineering (A E) Board in the area of simulant use for the Chemical Agent Monitor (CAM) Follow-on Operational Test and Evaluation (FOT E). The Operational Science Branch (Op Sci Br) was requested to support the A E Board in their effort to design an FOT E for the CAM using methyl salicylate (MS) as the H mode (mustard agent) simulant. Personnel from Op Sci Br were asked to design contamination technology and monitoring methods to test the machine/man interface and use doctrine, and analyze how well data is collected and evaluated.

  2. Overview of MAST results

    Science.gov (United States)

    Chapman, I. T.; Adamek, J.; Akers, R. J.; Allan, S.; Appel, L.; Asunta, O.; Barnes, M.; Ben Ayed, N.; Bigelow, T.; Boeglin, W.; Bradley, J.; Brünner, J.; Cahyna, P.; Carr, M.; Caughman, J.; Cecconello, M.; Challis, C.; Chapman, S.; Chorley, J.; Colyer, G.; Conway, N.; Cooper, W. A.; Cox, M.; Crocker, N.; Crowley, B.; Cunningham, G.; Danilov, A.; Darrow, D.; Dendy, R.; Diallo, A.; Dickinson, D.; Diem, S.; Dorland, W.; Dudson, B.; Dunai, D.; Easy, L.; Elmore, S.; Field, A.; Fishpool, G.; Fox, M.; Fredrickson, E.; Freethy, S.; Garzotti, L.; Ghim, Y. C.; Gibson, K.; Graves, J.; Gurl, C.; Guttenfelder, W.; Ham, C.; Harrison, J.; Harting, D.; Havlickova, E.; Hawke, J.; Hawkes, N.; Hender, T.; Henderson, S.; Highcock, E.; Hillesheim, J.; Hnat, B.; Holgate, J.; Horacek, J.; Howard, J.; Huang, B.; Imada, K.; Jones, O.; Kaye, S.; Keeling, D.; Kirk, A.; Klimek, I.; Kocan, M.; Leggate, H.; Lilley, M.; Lipschultz, B.; Lisgo, S.; Liu, Y. Q.; Lloyd, B.; Lomanowski, B.; Lupelli, I.; Maddison, G.; Mailloux, J.; Martin, R.; McArdle, G.; McClements, K.; McMillan, B.; Meakins, A.; Meyer, H.; Michael, C.; Militello, F.; Milnes, J.; Morris, A. W.; Motojima, G.; Muir, D.; Nardon, E.; Naulin, V.; Naylor, G.; Nielsen, A.; O'Brien, M.; O'Gorman, T.; Ono, Y.; Oliver, H.; Pamela, S.; Pangione, L.; Parra, F.; Patel, A.; Peebles, W.; Peng, M.; Perez, R.; Pinches, S.; Piron, L.; Podesta, M.; Price, M.; Reinke, M.; Ren, Y.; Roach, C.; Robinson, J.; Romanelli, M.; Rozhansky, V.; Saarelma, S.; Sangaroon, S.; Saveliev, A.; Scannell, R.; Schekochihin, A.; Sharapov, S.; Sharples, R.; Shevchenko, V.; Silburn, S.; Simpson, J.; Storrs, J.; Takase, Y.; Tanabe, H.; Tanaka, H.; Taylor, D.; Taylor, G.; Thomas, D.; Thomas-Davies, N.; Thornton, A.; Turnyanskiy, M.; Valovic, M.; Vann, R.; Walkden, N.; Wilson, H.; van Wyk, F.; Yamada, T.; Zoletnik, S.; MAST; MAST Upgrade Teams

    2015-10-01

    The Mega Ampère Spherical Tokamak (MAST) programme is strongly focused on addressing key physics issues in preparation for operation of ITER as well as providing solutions for DEMO design choices. In this regard, MAST has provided key results in understanding and optimizing H-mode confinement, operating with smaller edge localized modes (ELMs), predicting and handling plasma exhaust and tailoring auxiliary current drive. In all cases, the high-resolution diagnostic capability on MAST is complemented by sophisticated numerical modelling to facilitate a deeper understanding. Mitigation of ELMs with resonant magnetic perturbations (RMPs) with toroidal mode number nRMP = 2, 3, 4, 6 has been demonstrated: at high and low collisionality; for the first ELM following the transition to high confinement operation; during the current ramp-up; and with rotating nRMP = 3 RMPs. nRMP = 4, 6 fields cause less rotation braking whilst the power to access H-mode is less with nRMP = 4 than nRMP = 3, 6. Refuelling with gas or pellets gives plasmas with mitigated ELMs and reduced peak heat flux at the same time as achieving good confinement. A synergy exists between pellet fuelling and RMPs, since mitigated ELMs remove fewer particles. Inter-ELM instabilities observed with Doppler backscattering are consistent with gyrokinetic simulations of micro-tearing modes in the pedestal. Meanwhile, ELM precursors have been strikingly observed with beam emission spectroscopy (BES) measurements. A scan in beta at the L-H transition shows that pedestal height scales strongly with core pressure. Gyro-Bohm normalized turbulent ion heat flux (as estimated from the BES data) is observed to decrease with increasing tilt of the turbulent eddies. Fast ion redistribution by energetic particle modes depends on density, and access to a quiescent domain with ‘classical’ fast ion transport is found above a critical density. Highly efficient electron Bernstein wave current drive (1 A W-1) has been achieved

  3. Operational Draft Regional Guidebook for the Functional Assessment of High-gradient Ephemeral and Intermittent Headwater Streams in Western West Virginia and Eastern Kentucky

    Science.gov (United States)

    2010-07-01

    Liquidambar styraciflua) are common forest species across the reference domain (Strausbaugh and Core 1978; USDA 2009). Common shrub species associated with...canadensis eastern hemlock Juglans nigra black walnut Ulmus americana American elm Liquidambar styraciflua sweetgum Ulmus parvifolia Chinese elm

  4. Effects of Density and Impurity on Edge Localized Modes in Tokamaks

    Science.gov (United States)

    Zhu, Ping

    2017-10-01

    Plasma density and impurity concentration are believed to be two of the key elements governing the edge tokamak plasma conditions. Optimal levels of plasma density and impurity concentration in the edge region have been searched for in order to achieve the desired fusion gain and divertor heat/particle load mitigation. However, how plasma density or impurity would affect the edge pedestal stability may have not been well known. Our recent MHD theory modeling and simulations using the NIMROD code have found novel effects of density and impurity on the dynamics of edge-localized modes (ELMs) in tokamaks. First, previous MHD analyses often predict merely a weak stabilizing effect of toroidal flow on ELMs in experimentally relevant regimes. We find that the stabilizing effects on the high- n ELMs from toroidal flow can be significantly enhanced with the increased edge plasma density. Here n denotes the toroidal mode number. Second, the stabilizing effects of the enhanced edge resistivity due to lithium-conditioning on the low- n ELMs in the high confinement (H-mode) discharges in NSTX have been identified. Linear stability analysis of the experimentally constrained equilibrium suggests that the change in the equilibrium plasma density and pressure profiles alone due to lithium-conditioning may not be sufficient for a complete suppression of the low- n ELMs. The enhanced resistivity due to the increased effective electric charge number Zeff after lithium-conditioning provides additional stabilization of the low- n ELMs. These new effects revealed in our theory analyses may help further understand recent ELM experiments and suggest new control schemes for ELM suppression and mitigation in future experiments. They may also pose additional constraints on the optimal levels of plasma density and impurity concentration in the edge region for H-mode tokamak operation. Supported by National Magnetic Confinement Fusion Science Program of China Grants 2014GB124002 and 2015GB

  5. Operating Systems

    Indian Academy of Sciences (India)

    computer networks and also in Internet security concepts. Keywords. Operating systems, file sys- tems, time-shared systems. GENERAL I ARTICLE. Operating Systems. 1. Objectives and Evolution. M Suresh Babu. In this article we examine the objectives and fun.ctions of operating systems, and then we trace the evolution ...

  6. Operating systems

    CERN Document Server

    Tsichritzis, Dionysios C; Rheinboldt, Werner

    1974-01-01

    Operating Systems deals with the fundamental concepts and principles that govern the behavior of operating systems. Many issues regarding the structure of operating systems, including the problems of managing processes, processors, and memory, are examined. Various aspects of operating systems are also discussed, from input-output and files to security, protection, reliability, design methods, performance evaluation, and implementation methods.Comprised of 10 chapters, this volume begins with an overview of what constitutes an operating system, followed by a discussion on the definition and pr

  7. Schwartz operators

    Science.gov (United States)

    Keyl, M.; Kiukas, J.; Werner, R. F.

    2016-05-01

    In this paper, we introduce Schwartz operators as a non-commutative analog of Schwartz functions and provide a detailed discussion of their properties. We equip them, in particular, with a number of different (but equivalent) families of seminorms which turns the space of Schwartz operators into a Fréchet space. The study of the topological dual leads to non-commutative tempered distributions which are discussed in detail as well. We show, in particular, that the latter can be identified with a certain class of quadratic forms, therefore making operations like products with bounded (and also some unbounded) operators and quantum harmonic analysis available to objects which are otherwise too singular for being a Hilbert space operator. Finally, we show how the new methods can be applied by studying operator moment problems and convergence properties of fluctuation operators.

  8. Discriminant analysis of plasma fusion data

    Science.gov (United States)

    Kardaun, O. J. W. F.; Kardaun, J. W. P. F.; Itoh, Sanae-I.; Itoh, Kimitaka

    1992-06-01

    Discriminant analysis is a branch of statistics with applications in many fields. One of these (a relatively new one) is nuclear fusion research, where one is interested in various types of plasma discharges produced in toroidal devices. In many instances, one has a small number, say 2 or 3, of different types of discharges under investigation. For instance, L-mode and H-mode discharges (L stands for Low confinement, and H for High confinement), or: H-mode discharges without ELM's, with 'small' ELM's, and with 'large' (giant) ELM's. The abbreviation ELM's stands for Edge Localized Modes, which are detected by light recording instruments. They enhance the outward transport of the plasma, including the plasma impurities, but if they are large, they produce a heavy heat load on material contacts of the plasma with the wall. There are typically 4 or 5 continuous variables, for instance plasma current Ip, magnetic field B(sub t), plasma electron density n(sub e), input heating power P(inj), that influence the type of discharge ('shot') that will occur. In addition, there may be a few (2 or 3) discrete variables that are physically expected to be important. Finally, there are a number of wall conditioning aspects, which influence the type of shots that will be produced. In the framework of the ITER project, a collaborative effort between Europe, GUS, Japan and the USA, an international fusion reactor device is being designed which is due to operate at the beginning of the next century. In this context, a database (ITERH.DB1) has been assembled containing plasma confinement data of about 1000 H-mode discharges from 6 different tokamaks. These data have been released for general use by plasma physicists and other interested scientists. We will use part of these data to illustrate various discriminant analysis techniques. Several discriminant analysis methods have been applied and compared to predict the type of ELM's in H-mode discharges: (1) quadratic discriminant

  9. Warehousing Operations.

    Science.gov (United States)

    Marine Corps Inst., Washington, DC.

    Developed as part of the Marine Corps Institute (MCI) correspondence training program, this course on warehousing operations is designed to provide instruction in the procedures used in warehousing operations. Introductory materials include specific information for MCI students and a study guide (guidelines to complete the course). The 22-hour…

  10. Operational Sequencing

    DEFF Research Database (Denmark)

    Nielsen, Thomas Rosendal; Hustvedt, Kjersti

    2017-01-01

    by Bakhtinian theory, Brian Edmiston developed a solution to this in the 1990s: the principle of ‘dialogic sequencing’. Aiming to escape the conflict between relativism and absolutism, we present an alternative to Edmiston’s approach, based on Niklas Luhmann’s theory of ‘operational closure’: operational...

  11. Correlation analysis for energy losses, waiting times and durations of type I edge-localized modes in the Joint European Torus

    Science.gov (United States)

    Shabbir, A.; Verdoolaege, G.; Hornung, G.; Kardaun, O. J. W. F.; Zohm, H.; Contributors, JET

    2017-03-01

    Several important ELM control techniques are in large part motivated by the empirically observed inverse relationship between average ELM energy loss and ELM frequency in a plasma. However, to ensure a reliable effect on the energy released by the ELMs, it is important that this relation is verified for individual ELM events. Therefore, in this work the relation between ELM energy loss ≤ft({{W}\\text{ELM}}\\right) and waiting time ≤ft(Δ {{t}\\text{ELM}}\\right) is investigated for individual ELMs in a set of ITER-like wall plasmas in JET. A comparison is made with the results from a set of carbon-wall and nitrogen-seeded ITER-like wall JET plasmas. It is found that the correlation between W ELM and Δ {{t}\\text{ELM}} for individual ELMs varies from strongly positive to zero. Furthermore, the effect of the extended collapse phase often accompanying ELMs from unseeded JET ILW plasmas and referred to as the slow transport event (STE) is studied on the distribution of ELM durations, and on the correlation between W ELM and Δ {{t}\\text{ELM}} . A high correlation between W ELM and Δ {{t}\\text{ELM}} , comparable to CW plasmas is only found in nitrogen-seeded ILW plasmas. Finally, a regression analysis is performed using plasma engineering parameters as predictors for determining the region of the plasma operational space with a high correlation between W ELM and Δ {{t}\\text{ELM}} .

  12. Physics Basis and Simulation of Burning Plasma Physics for the Fusion Ignition Research Experiment (FIRE)

    Energy Technology Data Exchange (ETDEWEB)

    C.E. Kessel; D. Meade; S.C. Jardin

    2002-01-18

    The FIRE [Fusion Ignition Research Experiment] design for a burning plasma experiment is described in terms of its physics basis and engineering features. Systems analysis indicates that the device has a wide operating space to accomplish its mission, both for the ELMing H-mode reference and the high bootstrap current/high beta advanced tokamak regimes. Simulations with 1.5D transport codes reported here both confirm and constrain the systems projections. Experimental and theoretical results are used to establish the basis for successful burning plasma experiments in FIRE.

  13. DIII-D Edge Plasma, Disruptions, and Radiative Processes. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Boedo, J. A.; Luckhardt, S.C.; Moyer, R. A.

    2001-01-01

    The scientific goal of the UCSD-DIII-D Collaboration during this period was to understand the coupling of the core plasma to the plasma-facing components through the plasma boundary (edge and scrape-off layer). To achieve this goal, UCSD scientists studied the transport of particles, momentum, energy, and radiation from the plasma core to the plasma-facing components under normal (e.g., L-mode, H-mode, and ELMs), and off-normal (e.g., disruptions) operating conditions.

  14. Reactor operation

    CERN Document Server

    Shaw, J

    2013-01-01

    Reactor Operation covers the theoretical aspects and design information of nuclear reactors. This book is composed of nine chapters that also consider their control, calibration, and experimentation.The opening chapters present the general problems of reactor operation and the principles of reactor control and operation. The succeeding chapters deal with the instrumentation, start-up, pre-commissioning, and physical experiments of nuclear reactors. The remaining chapters are devoted to the control rod calibrations and temperature coefficient measurements in the reactor. These chapters also exp

  15. Impurity confinement and transport in high confinement regimes without edge localized modes on DIII-D

    Energy Technology Data Exchange (ETDEWEB)

    Grierson, B. A., E-mail: bgriers@pppl.gov; Nazikian, R. M.; Solomon, W. M. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Burrell, K. H.; Garofalo, A. M.; Belli, E. A.; Staebler, G. M.; Evans, T. E.; Smith, S. P.; Chrobak, C. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Fenstermacher, M. E. [Lawerence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States); McKee, G. R. [Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53796 (United States); Orlov, D. M. [Center for Energy Research, University of California San Diego, 9500 Gilman Dr., La Jolla, California 92093-0417 (United States); Chrystal, C. [University of California San Diego, 9500 Gilman Dr., La Jolla, California 92093-0417 (United States)

    2015-05-15

    Impurity transport in the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] is investigated in stationary high confinement (H-mode) regimes without edge localized modes (ELMs). In plasmas maintained by resonant magnetic perturbation (RMP), ELM-suppression, and QH-mode, the confinement time of fluorine (Z = 9) is equivalent to that in ELMing discharges with 40 Hz ELMs. For selected discharges with impurity injection, the impurity particle confinement time compared to the energy confinement time is in the range of τ{sub p}/τ{sub e}≈2−3. In QH-mode operation, the impurity confinement time is shown to be smaller for intense, coherent magnetic, and density fluctuations of the edge harmonic oscillation than weaker fluctuations. Transport coefficients are derived from the time evolution of the impurity density profile and compared to neoclassical and turbulent transport models NEO and TGLF. Neoclassical transport of fluorine is found to be small compared to the experimental values. In the ELMing and RMP ELM-suppressed plasma, the impurity transport is affected by the presence of tearing modes. For radii larger than the mode radius, the TGLF diffusion coefficient is smaller than the experimental value by a factor of 2–3, while the convective velocity is within error estimates. Low levels of diffusion are observed for radii smaller than the tearing mode radius. In the QH-mode plasma investigated, the TGLF diffusion coefficient is higher inside of ρ=0.4 and lower outside of 0.4 than the experiment, and the TGLF convective velocity is more negative by a factor of approximately 1.7.

  16. Operator theory

    CERN Document Server

    2015-01-01

    A one-sentence definition of operator theory could be: The study of (linear) continuous operations between topological vector spaces, these being in general (but not exclusively) Fréchet, Banach, or Hilbert spaces (or their duals). Operator theory is thus a very wide field, with numerous facets, both applied and theoretical. There are deep connections with complex analysis, functional analysis, mathematical physics, and electrical engineering, to name a few. Fascinating new applications and directions regularly appear, such as operator spaces, free probability, and applications to Clifford analysis. In our choice of the sections, we tried to reflect this diversity. This is a dynamic ongoing project, and more sections are planned, to complete the picture. We hope you enjoy the reading, and profit from this endeavor.

  17. Peace Operations

    National Research Council Canada - National Science Library

    Proks, Josef

    2000-01-01

    Peace operations are more and more important in the contemporary world. The end of the Cold War increased not only possibilities of solving disputes by the international community but also by the number and diversity of threats and issues...

  18. Operational Resilience

    Science.gov (United States)

    2014-10-16

    the so-called Threat Image Pro 51 April 2014 Operational Stress on Internet and eCommerce THE WALL STREET JOURNAL. TECH TECHNOLOGY Massive OpenSSL...8217!;:;a.L~ and · ...... -n ... ,.,. ... ,. 53 September 24, 2014 Operational Stress on Internet and eCommerce ::;:\\\\ t?nQCldQt?~ . REVIEWS... Benefits of Convergence and Integration  Similar activities are bound by same risk drivers  Allows for better alignment between risk-based activities

  19. Operative Links

    DEFF Research Database (Denmark)

    Wistoft, Karen; Højlund, Holger

    2012-01-01

    educational goals, learning content, or value clarification. Health pedagogy is often a matter of retrospective rationalization rather than the starting point of planning. Health and risk behaviour approaches override health educational approaches. Conclusions: Operational links between health education......, health professionalism, and management strategies pose the foremost challenge. Operational links indicates cooperative levels that facilitate a creative and innovative effort across traditional professional boundaries. It is proposed that such links are supported by network structures, shared semantics...

  20. Applied Operations Research: Operator's Assistant

    Science.gov (United States)

    Cole, Stuart K.

    2015-01-01

    NASA operates high value critical equipment (HVCE) that requires trouble shooting, periodic maintenance and continued monitoring by Operations staff. The complexity HVCE and information required to maintain and trouble shoot HVCE to assure continued mission success as paper is voluminous. Training on new HVCE is commensurate with the need for equipment maintenance. LaRC Research Directorate has undertaken a proactive research to support Operations staff by initiation of the development and prototyping an electronic computer based portable maintenance aid (Operator's Assistant). This research established a goal with multiple objectives and a working prototype was developed. The research identified affordable solutions; constraints; demonstrated use of commercial off the shelf software; use of the US Coast Guard maintenance solution; NASA Procedure Representation Language; and the identification of computer system strategies; where these demonstrations and capabilities support the Operator, and maintenance. The results revealed validation against measures of effectiveness and overall proved a substantial training and capability sustainment tool. The research indicated that the OA could be deployed operationally at the LaRC Compressor Station with an expectation of satisfactorily results and to obtain additional lessons learned prior to deployment at other LaRC Research Directorate Facilities. The research revealed projected cost and time savings.

  1. Enhanced Confinement Scenarios Without Large Edge Localized Modes in Tokamaks: Control, Performance, and Extrapolability Issues for ITER

    Energy Technology Data Exchange (ETDEWEB)

    Maingi, R [PPPL

    2014-07-01

    Large edge localized modes (ELMs) typically accompany good H-mode confinement in fusion devices, but can present problems for plasma facing components because of high transient heat loads. Here the range of techniques for ELM control deployed in fusion devices is reviewed. The two baseline strategies in the ITER baseline design are emphasized: rapid ELM triggering and peak heat flux control via pellet injection, and the use of magnetic perturbations to suppress or mitigate ELMs. While both of these techniques are moderately well developed, with reasonable physical bases for projecting to ITER, differing observations between multiple devices are also discussed to highlight the needed community R & D. In addition, recent progress in ELM-free regimes, namely Quiescent H-mode, I-mode, and Enhanced Pedestal H-mode is reviewed, and open questions for extrapolability are discussed. Finally progress and outstanding issues in alternate ELM control techniques are reviewed: supersonic molecular beam injection, edge electron cyclotron heating, lower hybrid heating and/or current drive, controlled periodic jogs of the vertical centroid position, ELM pace-making via periodic magnetic perturbations, ELM elimination with lithium wall conditioning, and naturally occurring small ELM regimes.

  2. Operation Context

    DEFF Research Database (Denmark)

    Stüben, Henning; Tietjen, Anne

    2006-01-01

    Abstract: This paper seeks to challenge the notion of context from an operational perspective. Can we grasp the forces that shape the complex conditions for an architectural or urban design within the notion of context? By shifting the gaze towards the agency of architecture, contextual analysis...

  3. Operating Systems

    Indian Academy of Sciences (India)

    The process concept and concurrency are at the heart of modern operating systems (OS). A process is the unit of work in a computer system. A process must be in main memory during execution. To improve the utilization of central processing unit. (CPU) as well as the speed of its response to its users, the computer must ...

  4. Operational Circulars

    CERN Multimedia

    2003-01-01

    Operational Circular N° 4 - April 2003 Conditions for use by members of the CERN personnel of vehicles belonging to or rented by CERN - This circular has been drawn up. Operational Circular N° 5 - October 2000 Use of CERN computing facilities - Further details on the personal use of CERN computing facilities Operational Circular N° 5 and its Subsidiary Rules http://cern.ch/ComputingRules defines the rules for the use of CERN computing facilities. One of the basic principles governing such use is that it must come within the professional duties of the user concerned, as defined by the user's divisional hierarchy. However, personal use of the computing facilities is tolerated or allowed provided : a) It is in compliance with Operational Circular N° 5 and not detrimental to official duties, including those of other users; b) the frequency and duration is limited and there is a negligible use of CERN resources; c) it does not constitute a political, commercial and/or profit-making activity; d) it is not...

  5. Operation REDWING

    Science.gov (United States)

    1956-08-10

    of all camp messing and housing ed after several surgical operations for a ruptur- facilities, consulting with Departments concern- ed appendix...of pillow slips existed for short periods. LAUNDRY. Laundry service for decontaminating radio- A completely outfitted laundry was opera- active

  6. Your Lung Operation: After Your Operation

    Medline Plus

    Full Text Available ... Surgeons Education Patients and Family Skills Programs Your Lung Operation Your Lung Operation DVD After Your Operation Back to Your Lung Operation Your Lung Operation DVD Welcome Your Lung ...

  7. Operation Poorman

    Energy Technology Data Exchange (ETDEWEB)

    Pruvost, N.; Tsitouras, J.

    1981-03-18

    The objectives of Operation Poorman were to design and build a portable seismic system and to set up and use this system in a cold-weather environment. The equipment design uses current technology to achieve a low-power, lightweight system that is configured into three modules. The system was deployed in Alaska during wintertime, and the results provide a basis for specifying a mission-ready seismic verification system.

  8. Your Lung Operation: After Your Operation

    Medline Plus

    Full Text Available ... of Your Lung Operation After Your Operation Your Discharge and Recovery Complete Video After Your Operation Guidance ... Day of Your Lung Operation Read Next Your Discharge and Recovery Back to Top Find A Surgeon ...

  9. Your Lung Operation: After Your Operation

    Medline Plus

    Full Text Available ... State Legislation State Advocacy Resources Chapter Advocacy Lobby Day Grant Program State Legislation Tracked by the College ... Your Lung Operation Preparing for Your Operation The Day of Your Lung Operation After Your Operation Your ...

  10. Development of ITER non-activation phase operation scenarios

    Science.gov (United States)

    Kim, S. H.; Poli, F. M.; Koechl, F.; Militello-Asp, E.; Polevoi, A. R.; Budny, R.; Casper, T. A.; Loarte, A.; Luce, T. C.; Na, Y.-S.; Romanelli, M.; Schneider, M.; Snipes, J. A.; de Vries, P. C.; The ITPA Topical Group on Integrated Operation Scenarios

    2017-08-01

    Non-activation phase operations in ITER in hydrogen (H) and helium (He) will be important for commissioning of tokamak systems, such as diagnostics, heating and current drive (HCD) systems, coils and plasma control systems, and for validation of techniques necessary for establishing operations in DT. The assessment of feasible HCD schemes at various toroidal fields (2.65-5.3 T) has revealed that the previously applied assumptions need to be refined for the ITER non-activation phase H/He operations. A study of the ranges of plasma density and profile shape using the JINTRAC suite of codes has indicated that the hydrogen pellet fuelling into He plasmas should be utilized taking the optimization of IC power absorption, neutral beam shine-through density limit and H-mode access into account. The EPED1 estimation of the edge pedestal parameters has been extended to various H operation conditions, and the combined EPED1 and SOLPS estimation has provided guidance for modelling the edge pedestal in H/He operations. The availability of ITER HCD schemes, ranges of achievable plasma density and profile shape, and estimation of the edge pedestal parameters for H/He plasmas have been integrated into various time-dependent tokamak discharge simulations. In this work, various H/He scenarios at a wide range of plasma current (7.5-15 MA) and field (2.65-5.3 T) have been developed for the ITER non-activation phase operation, and the sensitivity of the developed scenarios to the used assumptions has been investigated to provide guidance for further development. Extended from Preprint: 2016 Int. Conf. on Fusion Energy (Kyoto, Japan, 2016) TH/P2-22.

  11. Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, S. C., E-mail: S.C.Chapman@warwick.ac.uk [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry (United Kingdom); Max Planck Institute for the Physics of Complex Systems, Dresden (Germany); Dendy, R. O. [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry (United Kingdom); Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxfordshire (United Kingdom); JET-EFDA, Culham Science Centre, Abingdon, Oxfordshire (United Kingdom); Todd, T. N.; Webster, A. J.; Morris, J. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxfordshire (United Kingdom); JET-EFDA, Culham Science Centre, Abingdon, Oxfordshire (United Kingdom); Watkins, N. W. [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry (United Kingdom); Max Planck Institute for the Physics of Complex Systems, Dresden (Germany); Centre for the Analysis of Time Series, London School of Economics, London (United Kingdom); Department of Engineering and Innovation, Open University, Milton Keynes (United Kingdom); Calderon, F. A. [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry (United Kingdom); JET-EFDA, Culham Science Centre, Abingdon, Oxfordshire (United Kingdom)

    2014-06-15

    A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM.

  12. Operator theory, operator algebras and applications

    CERN Document Server

    Lebre, Amarino; Samko, Stefan; Spitkovsky, Ilya

    2014-01-01

    This book consists of research papers that cover the scientific areas of the International Workshop on Operator Theory, Operator Algebras and Applications, held in Lisbon in September 2012. The volume particularly focuses on (i) operator theory and harmonic analysis (singular integral operators with shifts; pseudodifferential operators, factorization of almost periodic matrix functions; inequalities; Cauchy type integrals; maximal and singular operators on generalized Orlicz-Morrey spaces; the Riesz potential operator; modification of Hadamard fractional integro-differentiation), (ii) operator algebras (invertibility in groupoid C*-algebras; inner endomorphisms of some semi group, crossed products; C*-algebras generated by mappings which have finite orbits; Folner sequences in operator algebras; arithmetic aspect of C*_r SL(2); C*-algebras of singular integral operators; algebras of operator sequences) and (iii) mathematical physics (operator approach to diffraction from polygonal-conical screens; Poisson geo...

  13. Your Lung Operation: After Your Operation

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  15. The quiescent double barrier regime in the DIII-D tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, E. J.; Baylor, L. R.; Burrell, K. H.; Casper, T. A.; DeBoo, J. C.; Ernst, D. R.; Garofalo, A. M.; Gohil, P.; Greenfield, C. M.; Groebner, R. J.; Hyatt, A. W.; Jackson, G. L.; Jernigan, T. C.; Kinsey, J. E.; Lao, L. L.; Lasnier, C. J.; Leboeuf, J-N; Makowski, M.; McKee, G. R.; Moyer, R. A.; Murakami, M.; Osborne, T. H.; Peebles, W. A.; Porkolab, M.; Porter, G. D.; Rhodes, T. L.; Rost, J. C.; Rudakov, D.; Staebler, G. M.; Stallard, B. W.; Strait, E. J.; Sydora, R. D.; Synakowski, E. J.; Wade, M. R.; Wang, G.; Watkins, J. G.; West, W. P.; Zeng, L.

    2001-12-01

    Experiments on the DIII-D tokamak have identified a new sustained high-performance operating mode, termed the quiescent double barrier (QDB) regime. The QDB regime combines internal transport barriers (ITBs) with a quiescent, edge localized mode (ELM)-free H-mode edge, termed QH-mode, giving rise to separate core and edge transport barriers. These double barriers have been maintained for {>}3.5 s (~25τE), demonstrating a long-pulse, quasi-steady-state capability. The combination of core ITBs and edge H-mode temperature pedestals results in high-performance plasmas; a βN H89 product of 7 has been maintained for 10 τE, other peak (non-simultaneous) parameters include Ti≤17 keV, βN≤2.9% m T MA-1, H89≤2.6, β≤3.8%, τE≤ 160 ms, and DD neutron rate Sn≤5.5×10¹⁵ s-1. These results address a major issue with tokamak plasmas: how to sustain long-pulse, high-performance H-mode plasmas without ELMs, yet retaining the density and impurity control hitherto provided by ELMs. In these QDB plasmas ELMs are replaced by continuous benign MHD activity in the edge, which enhances particle transport. A signature of operation with a QH-mode edge appears to be very large radial electric fields in the edge and scrape-off layer (SOL). In the core, simulations and modelling replicate many of the features of the observed transport and fluctuation behaviour, including the ion temperature profile and turbulence correlation lengths. Slow high-Z impurity accumulation (τ ≥ 500 ms) is observed in the centre of many QDB plasmas, and is the subject of ongoing analysis. To date the QDB regime has only been obtained in plasmas with counter-NBI (injection anti-parallel to the plasma current), and with divertor cryopumping to control the density.

  16. High confinement dissipative divertor operation on Alcator C-Mod

    Energy Technology Data Exchange (ETDEWEB)

    Goetz, J.A.; LaBombard, B.; Lipschultz, B.; Pitcher, C.S.; Terry, J.L.; Boswell, C.; Gangadhara, S.; Pappas, D.; Weaver, J.; Welch, B.; Boivin, R.L.; Bonoli, P.; Fiore, C.; Granetz, R.; Greenwald, M.; Hubbard, A.; Hutchinson, I.; Irby, J.; Marmar, E.; Mossessian, D.; Porkolab, M.; Rice, J.; Rowan, W.L.; Schilling, G.; Snipes, J.; Takase, Y.; Wolfe, S.; Wukitch, S. [Plasma Science Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    1999-05-01

    Alcator C-Mod [I. H. Hutchinson {ital et al.}, Phys. Plasmas {bold 1}, 1511 (1994)] has operated a High-confinement-mode (H-mode) plasma together with a dissipative divertor and low core Z{sub eff}. The initially attached plasma is characterized by steady-state enhancement factor, H{sub ITER89P} [P. N. Yushmanov {ital et al.}, Nucl. Fusion {bold 30}, 1999 (1990)], of 1.9, central Z{sub eff} of 1.1, and a radiative fraction of {approximately}50{percent}. Feedback control of a nitrogen gas puff is used to increase radiative losses in both the core/edge and divertor plasmas in almost equal amounts. Simultaneously, the core plasma maintains H{sub ITER89P} of 1.6 and Z{sub eff} of 1.4 in this nearly 100{percent} radiative state. The power and particle flux to the divertor plates have been reduced to very low levels while the core plasma is relatively unchanged by the dissipative nature of the divertor. {copyright} {ital 1999 American Institute of Physics.}

  17. Your Lung Operation: After Your Operation

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  18. Your Lung Operation: After Your Operation

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    Full Text Available ... to Participate Resources Webinars for Young Surgeons YFA E-News Resident and Associate Society Resident and Associate ... ACS Leader International Exchange Scholar Program Resources RAS E-News Medical Students Operation Giving Back Operation Giving ...

  19. Your Lung Operation: After Your Operation

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    Full Text Available ... Participate Resources Webinars for Young Surgeons YFA E-News Resident and Associate Society Resident and Associate Society ... Leader International Exchange Scholar Program Resources RAS E-News Medical Students Operation Giving Back Operation Giving Back ...

  20. Impacts of microtopographic snow redistribution and lateral subsurface processes on hydrologic and thermal states in an Arctic polygonal ground ecosystem: a case study using ELM-3D v1.0

    Science.gov (United States)

    Bisht, Gautam; Riley, William J.; Wainwright, Haruko M.; Dafflon, Baptiste; Yuan, Fengming; Romanovsky, Vladimir E.

    2018-01-01

    Microtopographic features, such as polygonal ground, are characteristic sources of landscape heterogeneity in the Alaskan Arctic coastal plain. Here, we analyze the effects of snow redistribution (SR) and lateral subsurface processes on hydrologic and thermal states at a polygonal tundra site near Barrow, Alaska. We extended the land model integrated in the E3SM to redistribute incoming snow by accounting for microtopography and incorporated subsurface lateral transport of water and energy (ELM-3D v1.0). Multiple 10-year-long simulations were performed for a transect across a polygonal tundra landscape at the Barrow Environmental Observatory in Alaska to isolate the impact of SR and subsurface process representation. When SR was included, model predictions better agreed (higher R2, lower bias and RMSE) with observed differences in snow depth between polygonal rims and centers. The model was also able to accurately reproduce observed soil temperature vertical profiles in the polygon rims and centers (overall bias, RMSE, and R2 of 0.59 °C, 1.82 °C, and 0.99, respectively). The spatial heterogeneity of snow depth during the winter due to SR generated surface soil temperature heterogeneity that propagated in depth and time and led to ˜ 10 cm shallower and ˜ 5 cm deeper maximum annual thaw depths under the polygon rims and centers, respectively. Additionally, SR led to spatial heterogeneity in surface energy fluxes and soil moisture during the summer. Excluding lateral subsurface hydrologic and thermal processes led to small effects on mean states but an overestimation of spatial variability in soil moisture and soil temperature as subsurface liquid pressure and thermal gradients were artificially prevented from spatially dissipating over time. The effect of lateral subsurface processes on maximum thaw depths was modest, with mean absolute differences of ˜ 3 cm. Our integration of three-dimensional subsurface hydrologic and thermal subsurface dynamics in the E3SM

  1. Impacts of microtopographic snow redistribution and lateral subsurface processes on hydrologic and thermal states in an Arctic polygonal ground ecosystem: a case study using ELM-3D v1.0

    Directory of Open Access Journals (Sweden)

    G. Bisht

    2018-01-01

    Full Text Available Microtopographic features, such as polygonal ground, are characteristic sources of landscape heterogeneity in the Alaskan Arctic coastal plain. Here, we analyze the effects of snow redistribution (SR and lateral subsurface processes on hydrologic and thermal states at a polygonal tundra site near Barrow, Alaska. We extended the land model integrated in the E3SM to redistribute incoming snow by accounting for microtopography and incorporated subsurface lateral transport of water and energy (ELM-3D v1.0. Multiple 10-year-long simulations were performed for a transect across a polygonal tundra landscape at the Barrow Environmental Observatory in Alaska to isolate the impact of SR and subsurface process representation. When SR was included, model predictions better agreed (higher R2, lower bias and RMSE with observed differences in snow depth between polygonal rims and centers. The model was also able to accurately reproduce observed soil temperature vertical profiles in the polygon rims and centers (overall bias, RMSE, and R2 of 0.59 °C, 1.82 °C, and 0.99, respectively. The spatial heterogeneity of snow depth during the winter due to SR generated surface soil temperature heterogeneity that propagated in depth and time and led to ∼ 10 cm shallower and  ∼ 5 cm deeper maximum annual thaw depths under the polygon rims and centers, respectively. Additionally, SR led to spatial heterogeneity in surface energy fluxes and soil moisture during the summer. Excluding lateral subsurface hydrologic and thermal processes led to small effects on mean states but an overestimation of spatial variability in soil moisture and soil temperature as subsurface liquid pressure and thermal gradients were artificially prevented from spatially dissipating over time. The effect of lateral subsurface processes on maximum thaw depths was modest, with mean absolute differences of ∼ 3 cm. Our integration of three-dimensional subsurface hydrologic and

  2. Space station operations management

    Science.gov (United States)

    Cannon, Kathleen V.

    1989-01-01

    Space Station Freedom operations management concepts must be responsive to the unique challenges presented by the permanently manned international laboratory. Space Station Freedom will be assembled over a three year period where the operational environment will change as significant capability plateaus are reached. First Element Launch, Man-Tended Capability, and Permanent Manned Capability, represent milestones in operational capability that is increasing toward mature operations capability. Operations management concepts are being developed to accomodate the varying operational capabilities during assembly, as well as the mature operational environment. This paper describes operations management concepts designed to accomodate the uniqueness of Space Station Freedoom, utilizing tools and processes that seek to control operations costs.

  3. Foreign Operation Methods

    DEFF Research Database (Denmark)

    Welch, Lawrence S.; Benito, Gabriel R. G.; Petersen, Bent

    Introduction and theory -- Introduction -- Theoretical approaches -- Modes of operation -- Franchising -- Licensing -- Management contracts -- International subcontracting -- Project operations -- Exports -- Alliances -- Foreign direct investment -- Strategies -- Mode switching and stretching...

  4. Saxton Transportation Operations Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Saxton Transportation Operations Laboratory (Saxton Laboratory) is a state-of-the-art facility for conducting transportation operations research. The laboratory...

  5. Review. Reproductive ecology of riparian elms

    National Research Council Canada - National Science Library

    López-Almansa, Juan Carlos

    2004-01-01

    ... de la ecología reproductiva en el género Ulmus, del que hay poca información disponible. Las especies del género Ulmus se reproducen, al igual que ocurre en otras especies riparias o sub-riparias, tanto sexual coma vegetativamente...

  6. Your Lung Operation: After Your Operation

    Medline Plus

    Full Text Available ... Surgical Skills for Exposure in Trauma Advanced Trauma Life Support Advanced Trauma Operative Management Basic Endovascular Skills for Trauma Disaster Management and Emergency Preparedness Rural ...

  7. Your Lung Operation: After Your Operation

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    Full Text Available ... Stay Up to Date with ACS Association Management Jobs Events Find a Surgeon Patients and Family Contact My Profile Shop ( 0 ) Cart Donate American College of Surgeons Education Patients and Family Skills Programs Your Lung Operation Your Lung Operation DVD ...

  8. FY-2013 FES (Fusion Energy Sciences) Joint Research Target Report

    Energy Technology Data Exchange (ETDEWEB)

    Fenstermacher, M. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Garofalo, A. M. [General Atomics, San Diego, CA (United States); Gerhardt, S. P. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Hubbard, A. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Maingi, R. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Whyte, D. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2013-09-30

    The H-mode confinement regime is characterized by a region of good thermal and particle confinement at the edge of the confined plasma, and has generally been envisioned as the operating regime for ITER and other next step devices. This good confinement is often interrupted, however, by edge-localized instabilities, known as ELMs. On the one hand, these ELMs provide particle and impurity flushing from the plasma core, a beneficial effect facilitating density control and stationary operation. On the other hand, the ELMs result in a substantial fraction of the edge stored energy flowing in bursts to the divertor and first wall; this impulsive thermal loading would result in unacceptable erosion of these material surfaces if it is not arrested. Hence, developing and understanding operating regimes that have the energy confinement of standard H-mode and the stationarity that is provided by ELMs, while at the same time eliminating the impulsive thermal loading of large ELMs, is the focus of the 2013 FES Joint Research Target (JRT): Annual Target: Conduct experiments and analysis on major fusion facilities, to evaluate stationary enhanced confinement regimes without large Edge Localized Modes (ELMs), and to improve understanding of the underlying physical mechanisms that allow acceptable edge particle transport while maintaining a strong thermal transport barrier. Mechanisms to be investigated can include intrinsic continuous edge plasma modes and externally applied 3D fields. Candidate regimes and techniques have been pioneered by each of the three major US facilities (C-Mod, D3D and NSTX). Coordinated experiments, measurements, and analysis will be carried out to assess and understand the operational space for the regimes. Exploiting the complementary parameters and tools of the devices, joint teams will aim to more closely approach key dimensionless parameters of ITER, and to identify correlations between edge fluctuations and transport. The role of rotation will be

  9. ROV, Remote Operated Vehicle

    OpenAIRE

    Patiris, Ioannis

    2015-01-01

    The purpose of this thesis is to show the basic principles of a Remote Operated Vehicle. The aim is also to document in detail how a small scale remote operated vehicle is constructed from the start. This thesis provides theoretical information about remote operated vehicles, as well as ex-plains the construction of hobbyist Remote Operated Vehicle as I carried it out. In the theoretical part information about the history, classification and the cables used in modern Re-mote Operated Vehi...

  10. The design and implementation of a randomized controlled trial of a risk reduction and human immunodeficiency virus prevention videogame intervention in minority adolescents: PlayForward: Elm City Stories.

    Science.gov (United States)

    Fiellin, Lynn E; Kyriakides, Tassos C; Hieftje, Kimberly D; Pendergrass, Tyra M; Duncan, Lindsay R; Dziura, James D; Sawyer, Benjamin G; Fiellin, David A

    2016-08-01

    To address the need for risk behavior reduction and human immunodeficiency virus prevention interventions that capture adolescents "where they live," we created a tablet-based videogame to teach skills and knowledge and influence psychosocial antecedents for decreasing risk and preventing human immunodeficiency virus infection in minority youth in schools, after-school programs, and summer camps. We developed PlayForward: Elm City Stories over a 2-year period, working with researchers, commercial game designers, and staff and teens from community programs. The videogame PlayForward provides an interactive world where players, using an avatar, "travel" through time, facing challenges such as peer pressure to drink alcohol or engage in risky sexual behaviors. Players experience how their choices affect their future and then are able to go back in time and change their choices, creating different outcomes. A randomized controlled trial was designed to evaluate the efficacy of PlayForward. Participants were randomly assigned to play PlayForward or a set of attention/time control games on a tablet at their community-based program. Assessment data were collected during face-to-face study visits and entered into a web-based platform and unique real-time "in-game" PlayForward data were collected as players engaged in the game. The innovative methods of this randomized controlled trial are described. We highlight the logistical issues of conducting a large-scale trial using mobile technology such as the iPad(®), and collecting, transferring, and storing large amounts of in-game data. We outline the methods used to analyze the in-game data alone and in conjunction with standardized assessment data to establish correlations between behaviors during gameplay and those reported in real life. We also describe the use of the in-game data as a measure of fidelity to the intervention. In total, 333 boys and girls, aged 11-14 years, were randomized over a 14-month period: 166 were

  11. The design and implementation of a randomized controlled trial of a risk reduction and human immunodeficiency virus prevention videogame intervention in minority adolescents: PlayForward: Elm City Stories

    Science.gov (United States)

    Fiellin, Lynn E; Kyriakides, Tassos C; Hieftje, Kimberly D; Pendergrass, Tyra M; Duncan, Lindsay R; Dziura, James D; Sawyer, Benjamin G; Fiellin, David A

    2016-01-01

    Background To address the need for risk behavior reduction and HIV prevention interventions that capture adolescents “where they live,” we created a tablet-based videogame to teach skills and knowledge and influence psychosocial antecedents for decreasing risk and preventing HIV infection in minority youth in schools, after-school programs, and summer camps. Methods We developed PlayForward: Elm City Stories over a 2-year period, working with researchers, commercial game designers, and staff and teens from community programs. The videogame PlayForward provides an interactive world where players, using an avatar, “travel” through time, facing challenges such as peer pressure to drink alcohol or engage in risky sexual behaviors. Players experience how their choices affect their future and then are able to go back in time and change their choices, creating different outcomes. A randomized controlled trial was designed to evaluate the efficacy of PlayForward. Participants were randomly assigned to play PlayForward or a set of attention/time control games on a tablet at their community-based program. Assessment data were collected during face-to-face study visits and entered into a web-based platform and unique real-time “in-game” PlayForward data were collected as players engaged in the game. The innovative methods of this randomized controlled trial are described. We highlight the logistical issues of conducting a large-scale trial using mobile technology such as the iPad®, and collecting, transferring, and storing large amounts of in-game data. We outline the methods used to analyze the in-game data alone and in conjunction with standardized assessment data to establish correlations between behaviors during gameplay and those reported in real life. We also describe the use of the in-game data as a measure of fidelity to the intervention. Results In total, 333 boys and girls, aged 11–14 years, were randomized over a 14-month period: 166 were assigned to

  12. Overview of ASDEX Upgrade results

    DEFF Research Database (Denmark)

    Zohm, H.; Adamek, J.; Angioni, C.

    2009-01-01

    and low enough power density arriving at the target plates) require significant scenario development, but will apply to ITER as well. D retention has been reduced and stationary operation with saturated wall conditions has been found. Concerning confinement, impurity ion transport across the pedestal...... is neoclassical, explaining the strong inward pinch of high-Z impurities in between ELMs. In improved H-mode, the width of the temperature pedestal increases with heating power, consistent with a scaling. In the area of MHD instabilities, disruption mitigation experiments using massive Ne injection reach volume...... for NTMs, TAEs and also beta-induced Alfven eigenmodes (BAEs). Specific studies addressing the first ITER operational phase show that O1 ECRH at the HFS assists reliable low-voltage breakdown. During ramp-up, additional heating can be used to vary li to fit within the ITER range. Confinement and power...

  13. Operating System Security

    CERN Document Server

    Jaeger, Trent

    2008-01-01

    Operating systems provide the fundamental mechanisms for securing computer processing. Since the 1960s, operating systems designers have explored how to build "secure" operating systems - operating systems whose mechanisms protect the system against a motivated adversary. Recently, the importance of ensuring such security has become a mainstream issue for all operating systems. In this book, we examine past research that outlines the requirements for a secure operating system and research that implements example systems that aim for such requirements. For system designs that aimed to

  14. Space Station operations

    Science.gov (United States)

    Gray, R. H.

    1985-01-01

    An evaluation of the success of the Space Station will be based on the service provided to the customers by the Station crew, the productivity of the crew, and the costs of operation. Attention is given to details regarding Space Station operations, a summary of operational philosophies and requirements, logistics and resupply operations, prelaunch processing and launch operations, on-orbit operations, aspects of maintainability and maintenance, habitability, and questions of medical care. A logistics module concept is considered along with a logistics module processing timeline, a habitability module concept, and a Space Station rescue mission.

  15. Computer algebra and operators

    Science.gov (United States)

    Fateman, Richard; Grossman, Robert

    1989-01-01

    The symbolic computation of operator expansions is discussed. Some of the capabilities that prove useful when performing computer algebra computations involving operators are considered. These capabilities may be broadly divided into three areas: the algebraic manipulation of expressions from the algebra generated by operators; the algebraic manipulation of the actions of the operators upon other mathematical objects; and the development of appropriate normal forms and simplification algorithms for operators and their actions. Brief descriptions are given of the computer algebra computations that arise when working with various operators and their actions.

  16. Your Lung Operation: After Your Operation

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  17. Your Lung Operation: After Your Operation

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    Full Text Available ... for Excellence in Trauma Surgery Advanced Trauma Life Support Verification, Review, and Consultation Program for Hospitals Trauma ... Skills for Exposure in Trauma Advanced Trauma Life Support Advanced Trauma Operative Management Basic Endovascular Skills for ...

  18. Your Lung Operation: After Your Operation

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    Full Text Available ... Education Trauma Education Achieving Zero Preventable Deaths Trauma Systems Conference Advanced Surgical Skills for Exposure in Trauma Advanced Trauma Life Support Advanced Trauma Operative Management Basic Endovascular Skills for Trauma Disaster Management and ...

  19. Your Lung Operation: After Your Operation

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  20. Your Lung Operation: After Your Operation

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  1. Research Progress and Future Plan of the KSTAR

    Science.gov (United States)

    Oh, Yeong-Kook; Park, H. K.; Yoon, S. W.; Kwag, J. G.; Chu, Y.; Park, K. R.; Kstar Team Team; Kstar Research Collaborators Collaboration

    2017-10-01

    Unique capabilities of the Korean Superconducting Tokamak Advanced Research (KSTAR) have been fully capitalized for steady state operation of high beta plasmas and fundamental physics research. The KSTAR is ideal for study of the tokamak plasma symmetry on stability and confinement study owing to the lowest error field and magnetic ripple. Versatile magnetic perturbation tool with n=1,2 in-vessel control coils has been extensively used in control of the harmful MHD such as the ELMs and toroidal rotation through NTV. Advanced 2D/3D microwave imaging diagnostics for undisputed measurements for theory and modeling. In 2016 and 2017 campaigns, KSTAR has achieved a record long operation (34s) of a ELM-crash free as well as long ELMy (70s) H-mode operation. A predictive capability as well as the underlying physics of the resonant magnetic perturbation (RMP) have been demonstrated. This talk will address the advances in research and vision toward the high beta long pulse operation in KSTAR together with the upgrade plan. This work is supported by MSIP of Korea under KSTAR project and NRF of Korea under Contract No. NRF-2014M1A7A1A03029865.

  2. Training and Tactical Operationally Responsive Space Operations

    Science.gov (United States)

    Sorensen, B.; Strunce, R., Jr.

    Current space assets managed by traditional space system control resources provide communication, navigation, intelligence, surveillance, and reconnaissance (ISR) capabilities using satellites that are designed for long life and high reliability. The next generation Operationally Responsive Space (ORS) systems are aimed at providing operational space capabilities which will provide flexibility and responsiveness to the tactical battlefield commander. These capabilities do not exist today. The ORS communication, navigation, and ISR satellites are being designed to replace or supplement existing systems in order to enhance the current space force. These systems are expected to rapidly meet near term space needs of the tactical forces. The ORS concept includes new tactical satellites specifically designed to support contingency operations such as increased communication bandwidth and ISR imagery over the theater for a limited period to support air, ground, and naval force mission. The Concept of Operations (CONOPS) that exists today specifies that in addition to operational control of the satellite, the tasking and scheduling of the ORS tactical satellite for mission data collection in support of the tactical warfighter will be accomplished within the Virtual Mission Operations Center (VMOC). This is very similar to what is currently being accomplished in a fixed Mission Operations Center on existing traditional ISR satellites. The VMOC is merely a distributed environment and the CONOPS remain virtually the same. As a result, there is a significant drawback to the current ORS CONOPS that does not account for the full potential of the ORS paradigm for supporting tactical forces. Although the CONOPS approach may be appropriate for experimental Tactical Satellites (TacSat), it ignores the issues associated with the In-Theater Commander's need to own and operate his dedicated TacSat for most effective warfighting as well as the Warfighter specific CONOPS. What is needed

  3. Boiler operator's handbook

    CERN Document Server

    Heselton, Ken

    2004-01-01

    Containing key information for operators and managers of large and small plants, this is an indispensable guide for those at advanced and early stages of their careers, as well as for managers interested in reducing operating expenses.

  4. Crew Transportation Operations Standards

    Science.gov (United States)

    Mango, Edward J.; Pearson, Don J. (Compiler)

    2013-01-01

    The Crew Transportation Operations Standards contains descriptions of ground and flight operations processes and specifications and the criteria which will be used to evaluate the acceptability of Commercial Providers' proposed processes and specifications.

  5. Vessel Operator System

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Operator cards are required for any operator of a charter/party boat and or a commercial vessel (including carrier and processor vessels) issued a vessel permit from...

  6. Successful reefer container operations

    National Research Council Canada - National Science Library

    2003-01-01

    Explains the different types of reefer container operation, including Cold Treatment, Controlled Atmosphere, and Super Freezer, and the procedures that should be followed in order to ensure correct operation...

  7. Major operations and activities

    Energy Technology Data Exchange (ETDEWEB)

    Black, D.G.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the major operations and activities on the site. These operations and activities include site management, waste management, environmental restoration and corrective actions, and research and technology development.

  8. Ranking Operations Management conferences

    NARCIS (Netherlands)

    Steenhuis, H.J.; de Bruijn, E.J.; Gupta, Sushil; Laptaned, U

    2007-01-01

    Several publications have appeared in the field of Operations Management which rank Operations Management related journals. Several ranking systems exist for journals based on , for example, perceived relevance and quality, citation, and author affiliation. Many academics also publish at conferences

  9. Star operations and Pullbacks

    OpenAIRE

    Fontana, Marco; Park, Mi Hee

    2003-01-01

    In this paper we study the star operations on a pullback of integral domains. In particular, we characterize the star operations of a domain arising from a pullback of ``a general type'' by introducing new techniques for ``projecting'' and ``lifting'' star operations under surjective homomorphisms of integral domains. We study the transfer in a pullback (or with respect to a surjective homomorphism) of some relevant classes or distinguished properties of star operations such as $v-, t-, w-, b...

  10. Radial transport of poloidal momentum in ASDEX Upgrade in L-mode and H-mode

    DEFF Research Database (Denmark)

    Mehlmann, F.; Schrittwieser, R.; Naulin, Volker

    2012-01-01

    A reciprocating probe was used for localized measurements of the radial transport of poloidal momentum in the scrape-off layer (SOL) of ASDEX Upgrade (AUG). The probe measured poloidal and radial electric field components and density. We concentrate on three components of the momentum transport: ......: Reynolds stress, convective momentum flux and triple product of the fluctuating components of density, radial and poloidal electric field. For the evaluation we draw mainly on the probability density functions (PDFs)....

  11. Possible influence of near SOL plasma on the H-mode power threshold

    Directory of Open Access Journals (Sweden)

    A.V. Chankina

    2017-08-01

    Full Text Available A strong effect of divertor configuration on the threshold power for the L-H transition (PLH was observed in recent JET experiments in the new ITER-like Wall (ILW [1–3]. Following a series of EDGE2D-EIRENE code simulations with Be impurity and drifts a possible mechanism for the PLH variation with the divertor geometry is proposed. Both experiment and code simulations show that in the configuration with lower neutral recycling near the outer strike point (OSP, electron temperature (Te peaks near the OSP prior to the L-H transition, while in the configuration with higher OSP recycling Te peaks further out in the scrape-off layer (SOL and the plasma stays in the L-mode at the same input power. Code results show large positive radial electric field (Er in the near SOL under lower recycling conditions leading to a large E×B shear across the separatrix which may trigger earlier (at lower input power edge turbulence suppression and lower PLH. Suppressed Te‘s at OSP in configurations with strike points on vertical targets (VT were observed earlier and explained by a geometrical effect of neutral recycling near this particular position, whereas in configurations with strike points on horizontal targets (HT the OSP appears to be more open for neutrals (see e.g. review paper [4].

  12. Momentum losses by charge exchange with neutral particles in H-mode discharges at JET

    NARCIS (Netherlands)

    Versloot, T. W.; de Vries, P. C.; Giroud, C.; Brix, M.; von Hellermann, M. G.; Lomas, P. J.; Moulton, D.; Mullane, M. O.; Nunes, I. M.; Salmi, A.; Tala, T.; Voitsekhovitch, I.; Zastrow, K. D.

    2011-01-01

    The effect of a neutral density background on the toroidal angular momentum and kinetic energy profiles has been investigated in JET. Under equivalent conditions but with increasing gas fuelling during the flat top phase, it has been observed that both the edge rotation and temperature decrease. The

  13. Understanding ECH density pump-out in DIII-D H-mode plasmas

    Science.gov (United States)

    Wang, X.; Mordijck, S.; Doyle, E. J.; Rhodes, T. L.; Zeng, L.; McKee, G. R.; Austin, M. E.; Meneghini, O.; Staebler, G. M.; Smith, S. P.

    2017-11-01

    In this paper, we show that the often observed ‘density pump-out’ with electron cyclotron heating (ECH) (Angioni et al 2004 Nucl. Fusion 44 827, 2009 Plasma Phys. Control. Fusion 51 124017), at low density and/or collisionality is the result of an increase in turbulence drive at the plasma edge (Angioni et al 2004 Nucl. Fusion 44 827, 2005 Phys. Plasmas 12 040701, Mordijck et al 2015 Nucl. Fusion 43 113025). Prior results were limited to comparison of steady-state conditions, before and after the ECH was applied, and thus failed to capture the dynamics of the density pump-out. In this paper, we find, similar to prior results, that when the plasma reaches a new equilibrium after ECH is applied, gyro-kinetic simulations indicate that the plasma has transitioned from the ion temperature gradient (ITG) to a trapped electron mode (TEM) regime around mid-radius. However, this transition from ITG to TEM only occures in the core after 100 ms. The pump-out on the other hand, starts immediately and is strongest around ρ ∼ 0.8 . Linear gyrokinetic simulations with TGLF show that there is an increase in turbulence drive simultaneously with the density pump-out and the doppler backscattering (DBS) measures an instant increase in density fluctuations at the same radial location. On the other hand, around mid-radius the DBS measures no increase in density fluctuations. All these calculations along with experimental measurements show that the density pump-out is not the result of a change in turbulence type (i.e. not caused by a change from ITG to TEM), but the result of a change in turbulence drive (an increase in linear growth rates), which is later followed by the ITG to TEM transition. This highlights the need for studying not just the equilibrium conditions after a transition, but also the time-dependent changes.

  14. On L to H-mode transitions of the tokamak and entropy reduction

    Directory of Open Access Journals (Sweden)

    Rastović Danilo

    2006-01-01

    Full Text Available In an ideal case, it is assumed that the models for tokamak and stellarator plasma behaviour lead to the theory of invariant manifolds by Rastović [Chaos, Solitons & Fractals, 2007]. But, at the present state of knowledge a more realistic concept for describing L to H transitions and edge localized modes is the reduction of entropy and appropriate methods.

  15. Organizing for Operational Deception

    Science.gov (United States)

    2010-05-20

    capability to apply operational art on a large scale during the Battle of Kursk . Previous success had been demonstrated by individual tactical...tasks require different organizational designs. FM 3-0 does not recognize any unique Battle Command requirements for MILDEC, by placing it under the...staff, operations, organization, complexity, doctrine, network centric, group tasks, information, operations, battle command 16. SECURITY

  16. Blowout recovery operations : the capping operation

    Energy Technology Data Exchange (ETDEWEB)

    Miller, M.; Badick, M. [Safety BOSS, Calgary, AB (Canada)

    2001-07-01

    Capping is generally the final work done at a wellhead. A properly planned capping operation is one of the easiest aspects of a recovery process that should be completed in one or two days. The objective is to establish a safe and reliable casing attachment and seal that is designed to suit the activities that follow. The movement of equipment on and off the wellhead is among the higher risk objectives of a recovery operation, so it is crucial that the job be done right the first time. This paper focused on blowout recovery operations and covered the operations from the point where a sound pipe or a reliable casing flange has been established to the point of installing a conventional wellhead, a diverter system blowout preventer (BOP) stack suitable for shutting in the well, continuing to flow the well, or proceeding with a killing operation. The advantages and disadvantages of many capping options were discussed along with the procedures for installing a wellhead or BOP. The choices for wellheads, diverter systems and BOP stack configurations depend on whether the well can be shut-in, killed or if it must be flowed while an offset well is drilled. The choices presented in this paper included, slip rams, casing bowls, and snubbing.

  17. MHD stability analysis and global mode identification preparing for high beta operation in KSTAR

    Science.gov (United States)

    Park, Y. S.; Sabbagh, S. A.; Berkery, J. W.; Jiang, Y.; Ahn, J. H.; Han, H. S.; Bak, J. G.; Park, B. H.; Jeon, Y. M.; Kim, J.; Hahn, S. H.; Lee, J. H.; Ko, J. S.; in, Y. K.; Yoon, S. W.; Oh, Y. K.; Wang, Z.; Glasser, A. H.

    2017-10-01

    H-mode plasma operation in KSTAR has surpassed the computed n = 1 ideal no-wall stability limit in discharges exceeding several seconds in duration. The achieved high normalized beta plasmas are presently limited by resistive tearing instabilities rather than global kink/ballooning or RWMs. The ideal and resistive stability of these plasmas is examined by using different physics models. The observed m/ n = 2/1 tearing stability is computed by using the M3D-C1 code, and by the resistive DCON code. The global MHD stability modified by kinetic effects is examined using the MISK code. Results from the analysis explain the stabilization of the plasma above the ideal MHD no-wall limit. Equilibrium reconstructions used include the measured kinetic profiles and MSE data. In preparation for plasma operation at higher beta utilizing the planned second NBI system, three sets of 3D magnetic field sensors have been installed and will be used for RWM active feedback control. To accurately determine the dominant n-component produced by low frequency unstable RWMs, an algorithm has been developed that includes magnetic sensor compensation of the prompt applied field and the field from the induced current on the passive conductors. Supported by US DOE Contracts DE-FG02-99ER54524 and DE-SC0016614.

  18. Stochastic phase transition operator.

    Science.gov (United States)

    Yamanobe, Takanobu

    2011-07-01

    In this study a Markov operator is introduced that represents the density evolution of an impulse-driven stochastic biological oscillator. The operator's stochastic kernel is constructed using the asymptotic expansion of stochastic processes instead of solving the Fokker-Planck equation. The Markov operator is shown to successfully approximate the density evolution of the biological oscillator considered. The response of the oscillator to both periodic and time-varying impulses can be analyzed using the operator's transient and stationary properties. Furthermore, an unreported stochastic dynamic bifurcation for the biological oscillator is obtained by using the eigenvalues of the product of the Markov operators.

  19. Operational symmetries basic operations in physics

    CERN Document Server

    Saller, Heinrich

    2017-01-01

    This book describes the endeavour to relate the particle spectrum with representations of operational electroweak spacetime, in analogy to the atomic spectrum as characterizing representations of hyperbolic space. The spectrum of hyperbolic position space explains the properties of the nonrelativistic atoms; the spectrum of electroweak spacetime is hoped to explain those of the basic interactions and elementary particles. In this book, the theory of operational symmetries is developed from the numbers, from Plato’s and Kepler’s symmetries over the simple Lie groups to their applications in nonrelativistic, special relativistic and general relativistic quantum theories with the atomic spectrum for hyperbolic position and, in first attempts, the particle spectrum for electroweak spacetime. The standard model of elementary particles and interactions is characterized by a symmetry group. In general, as initiated by Weyl and stressed by Heisenberg, quantum theory can be built as a theory of operation groups an...

  20. Stabilizing effects of resistivity on low-n edge localized modes in NSTX

    CERN Document Server

    Banerjee, Debabrata; Maingi, Rajesh

    2016-01-01

    The stabilizing effects of enhanced edge resistivity on the low-n edge localized modes (ELMs) are reported for the first time in the context of ELM suppression in H-mode discharge due to Lithium-conditioning in the National Spherical Torus Experiment (NSTX). Here n is the toroidal mode number. Linear stability analysis of the corresponding experimental equilibrium suggests that the change in the equilibrium plasma density profile alone due to Lithium-conditioning may be insufficient for a complete suppression of ELMs. The enhanced resistivity due to the increased effective electric charge number Z eff after Lithium-conditioning can account for additional stabi- lization effect necessary for full ELM suppression. Remarkably, such a stabilizing effect of enhanced edge resistivity on the low-n ELMs only exists when two-fluid effects are considered in the MHD model.

  1. Your Lung Operation: After Your Operation

    Medline Plus

    Full Text Available ... Trauma Operative Management Basic Endovascular Skills for Trauma Disaster Management and Emergency Preparedness Rural Trauma Team Development ... 202-5001 (E) postmaster@facs.org Copyright © 1996-2018 by the American College of Surgeons, Chicago, IL ...

  2. Your Lung Operation: After Your Operation

    Medline Plus

    Full Text Available ... Trauma and EMS Cancer and Research Health Information Technology Scope of Practice Pediatric Issues Other Federal Legislative ... for after the operation including review of attached equipment and ways for you to actively participate to prevent high-risk complications such as pneumonia and deep vein thrombosis. ... and Associates Medical Students International Surgeons Media ACS Links About ACS ...

  3. Your Lung Operation: After Your Operation

    Medline Plus

    Full Text Available ... Program Resources Clinical Congress App Clinical Congress 2018 Future Clinical Congresses MyCME About MyCME About MyCME Claim ... Surgical Skills for Exposure in Trauma Advanced Trauma Life Support Advanced Trauma Operative Management Basic Endovascular Skills ...

  4. Cask fleet operations study

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    The Nuclear Waste Policy Act of 1982 assigned to the Department of Energy's (DOE) Office of Civilian Waste Management the responsibility for disposing of high-level waste and spent fuel. A significant part of that responsibility involves transporting nuclear waste materials within the federal waste management system; that is, from the waste generator to the repository. The lead responsibility for transportation operations has been assigned to Oak Ridge Operations, with Oak Ridge National Laboratory (ORNL) providing technical support through the Transportation Operations Support Task Group. One of the ORNL support activities involves assessing what facilities, equipment and services are required to assure that an acceptable, cost-effective and safe transportation operations system can be designed, operated and maintained. This study reviews, surveys and assesses the experience of Nuclear Assurance Corporation (NAC) in operating a fleet of spent-fuel shipping casks to aid in developing the spent-fuel transportation system.

  5. Operations management system

    Science.gov (United States)

    Brandli, A. E.; Eckelkamp, R. E.; Kelly, C. M.; Mccandless, W.; Rue, D. L.

    1990-01-01

    The objective of an operations management system is to provide an orderly and efficient method to operate and maintain aerospace vehicles. Concepts are described for an operations management system and the key technologies are highlighted which will be required if this capability is brought to fruition. Without this automation and decision aiding capability, the growing complexity of avionics will result in an unmanageable workload for the operator, ultimately threatening mission success or survivability of the aircraft or space system. The key technologies include expert system application to operational tasks such as replanning, equipment diagnostics and checkout, global system management, and advanced man machine interfaces. The economical development of operations management systems, which are largely software, will require advancements in other technological areas such as software engineering and computer hardware.

  6. Operational Modal Analysis Tutorial

    OpenAIRE

    Brincker, Rune; ANDERSEN, Palle

    2007-01-01

    In this paper the basic principles in operational modal testing and analysis are presented and discussed. A brief review of the techniques for operational modal testing and identification is presented, and it is argued, that there is now a wide range of techniques for effective identification of modal parameters of practical interest - including the mode shape scaling factor - with a high degree of accuracy. It is also argued that the operational technology offers the user a number of advanta...

  7. Network operating system

    Science.gov (United States)

    1985-01-01

    Long-term and short-term objectives for the development of a network operating system for the Space Station are stated. The short-term objective is to develop a prototype network operating system for a 100 megabit/second fiber optic data bus. The long-term objective is to establish guidelines for writing a detailed specification for a Space Station network operating system. Major milestones are noted. Information is given in outline form.

  8. Purge ventilation operability

    Energy Technology Data Exchange (ETDEWEB)

    Marella, J.R.

    1995-04-10

    A determination of minimum requirements for purge exhaust ventilation system operability has been performed. HLWE and HLW Regulatory Program personnel have evaluated the various scenarios of equipment conditions and HLWE has developed the requirements for purge exhaust systems. This report is provided to document operability requirements to assist Tank Farm personnel to determine whether a system is operable/inoperable and to define required compensatory actions.

  9. Operator interface for vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Bissontz, Jay E

    2015-03-10

    A control interface for drivetrain braking provided by a regenerative brake and a non-regenerative brake is implemented using a combination of switches and graphic interface elements. The control interface comprises a control system for allocating drivetrain braking effort between the regenerative brake and the non-regenerative brake, a first operator actuated control for enabling operation of the drivetrain braking, and a second operator actuated control for selecting a target braking effort for drivetrain braking. A graphic display displays to an operator the selected target braking effort and can be used to further display actual braking effort achieved by drivetrain braking.

  10. Miscellaneous Industrial Mineral Operations

    Data.gov (United States)

    Department of Homeland Security — This map layer includes miscellaneous industrial minerals operations in the United States. The data represent commodities covered by the Minerals Information Team...

  11. Implications for Operations

    Science.gov (United States)

    Arduini, G.; Lamont, M.; Pieloni, T.; Rumolo, G.

    The HL-LHC will introduce a number of novel operational features and challenges including luminosity leveling. After a brief recap of the possible leveling techniques, the potential impact of the operational regime on overall efficiency is discussed. A breakdown of the operational cycle and the standard operational year, together with a discussion of fault time is presented. The potential performance is then explored and estimates of the required machine availability and efficiency for 250 fb-1 per year are given. Finally the e-cloud challenges, scrubbing runs requirements, and machine development potential are outlined.

  12. PLATO administers operator training

    Energy Technology Data Exchange (ETDEWEB)

    Buehner, R.E.

    1979-02-15

    Baltimore Gas and Electric Co. is committed to an in-depth training program for substation operators. For the past two years, one important part of the training program has been a computer-based educational system with a CRT touch-response graphic display that is interactive with the trainee. This system, known as PLATO, reproduces a training situation so realistic that the operator becomes completely involved with the lesson. When used for pretraining prior to substation operating experience, it provides a hands-on insight into operating practices without jeopardizing personnel or equipment, or degrading customer service.

  13. Cyberspace Operations in Support of Counterinsurgency Operations

    Science.gov (United States)

    2013-04-10

    5% GSM – Global System for Mobile Communication CDMA – Code Division Multiple Access Table 1 4 their operations. as access to technology and the...discussions by insurgent organizations. the proliferation of cellular-based technologies, particularly 3G (the third generation of mobile ...Growth GSM Providers (Licensed) 4 4 0 GSM Subscribers 14,855,235 17,558,265 15% Internet Service Providers 7 7 0 CDMA Subscribers 96,947 134,092 27

  14. Operational Transformation In Co-Operative Editing

    Directory of Open Access Journals (Sweden)

    Mandeep Kaur

    2015-08-01

    Full Text Available Cooperative Editing Systems in real-time allows a virtual team to view and edit a shared document at the same time. The document shared must be synchronized in order to ensure consistency for all the participants. This paper describes the Operational Transformation the evolution of its techniques its various applications major issues and achievements. In addition this paper will present working of a platform where two users can edit a code programming file at the same time.

  15. Restoring ecosystem resilience to urban forests using Dutch elm disease-tolerant American elm trees

    Science.gov (United States)

    Charles E. Flower; Cornelia C. Pinchot; James M. Slavicek

    2017-01-01

    Urban forests contribute significantly to human health and environmental quality (Sanesi et al. 2011). As such, maintaining healthy urban forests resilient to pollution (atmospheric and soil), high temperatures, compacted soils, and poor drainage is critical. However, these forests have been hard hit by development, pests, and pathogens, consequently reshaping their...

  16. Operations Program Executive

    Science.gov (United States)

    Fague, M. A.

    1982-01-01

    Ground Resource Operations Program executive (GROPE) is control program for binding system of programs into single, easily operated entity. It relieves user from complexity arising from decomposition of large application into number of interacting program units. System simplifies job control, data management, and recordkeeping for interacting programs.

  17. Orthogonality and Hecke operators

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Permanent link: http://www.ias.ac.in/article/fulltext/pmsc/119/03/0283-0286. Keywords. Hecke operator; eigenvalue; orthogonality; Atkin–Lehner theory. Abstract. In this article we analyze orthogonality relations between old forms and the connection to the theory of Hecke operators. Author Affiliations.

  18. Health care operations management

    NARCIS (Netherlands)

    Carter, M.W.; Hans, Elias W.; Kolisch, R.

    2012-01-01

    Health care operations management has become a major topic for health care service providers and society. Operations research already has and further will make considerable contributions for the effective and efficient delivery of health care services. This special issue collects seven carefully

  19. Elliptic Quadratic Operator Equations

    OpenAIRE

    Ganikhodjaev, Rasul; Mukhamedov, Farrukh; Saburov, Mansoor

    2017-01-01

    In the present paper is devoted to the study of elliptic quadratic operator equations over the finite dimensional Euclidean space. We provide necessary and sufficient conditions for the existence of solutions of elliptic quadratic operator equations. The iterative Newton-Kantorovich method is also presented for stable solutions.

  20. Operation plan : Alviso System

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is the operation plan for ponds A2W, A3W, A7, A14, and A16 in the Alviso System at San Francisco Bay NWR Complex. Operating instructions for both winter and...

  1. Distributed Operating Systems

    NARCIS (Netherlands)

    Tanenbaum, A.S.; van Renesse, R.

    1985-01-01

    Distributed operating systems have many aspects in common with centralized ones, but they also differ in certain ways. This paper is intended as an introduction to distributed operating systems, and especially to current university research about them. After a discussion of what constitutes a

  2. UN Peacebuilding Operations

    African Journals Online (AJOL)

    rary UN peace operations are mandated to manage post-conflict peacebuilding transitions that ... UN military units? And can it remain relevant during all the phases of a UN peacebuilding operation? This paper will analyse this question by first defining and developing .... achievement of the overall peacebuilding objective.

  3. Orthogonality and Hecke operators

    Indian Academy of Sciences (India)

    E-mail: winfried@mathi.uni-heidelberg.de; christian.f.weiss@web.de. MS received 16 January 2006; revised 21 April 2009. Abstract. In this article we analyze orthogonality relations between old forms and the connection to the theory of Hecke operators. Keywords. Hecke operator; eigenvalue; orthogonality; Atkin–Lehner ...

  4. Operating room manager game

    NARCIS (Netherlands)

    Hans, Elias W.; Nieberg, T.

    2007-01-01

    The operating room (OR) department of a hospital forms the heart of the organization, where the single largest cost is incurred. This document presents and reports on the “Operating Room Manager Game,” developed to give insight into managing a large hospital's OR department at various levels of

  5. Subgradient Projection Operators

    OpenAIRE

    Pauwels, Benoit

    2014-01-01

    Several algebraic and topological properties of subgradient projection operators are investigated and various examples are provided. Connections with Moreau's proximity operator are also made and acceleration schemes for subgradient projection algorihms are discussed. Finally continuity, nonexpansiveness, monotonicity, differentiability, and epi-convergence properties are investigated.

  6. with unary operators

    Directory of Open Access Journals (Sweden)

    Sergio Arturo Celani

    2006-01-01

    Full Text Available We characterize the simple and subdirectly irreducible distributive algebras in some varieties of distributive lattices with unary operators, including topological and monadic positive modal algebras. Finally, for some varieties of Heyting algebras with operators we apply these results to determine the simple and subdirectly irreducible algebras.

  7. UN Peacebuilding Operations

    African Journals Online (AJOL)

    published a Post-Conflict Reconstruction: Task Framework in 2002, in which they identify three stages, namely: the ..... building operation. The UN Department of Peacekeeping Operations (DPKO) has participated in the development of the guidelines on the use of military and civil defence assets to support United Nations ...

  8. operation zitadelle (kursk)

    African Journals Online (AJOL)

    Administrator

    Until the coining of the concept of operational art and the identification of the .... concepts. During the Second World War Eisenhower was provided with subordinates such as Bradley and Patton, freeing his hand to concentrate on what to ... with warlike operations in contrast to administrative and logistic functions, training.

  9. Crane and Excavator Operator.

    Science.gov (United States)

    Marine Corps Inst., Washington, DC.

    Developed as part of the Marine Corps Institute (MCI) correspondence training program, this course on crane and excavator operation is designed to enable the crane and excavator operator to perform his/her duties more proficiently. Introductory materials include specific information for MCI students, a course introduction, and a study guide…

  10. Operant-Box Sociology

    Science.gov (United States)

    Dimond, Stuart J.

    1971-01-01

    Sketches a model which considers society a teacher which instructs like an operant box..." The author contends that the family, the school, the play group, the adolescent gang, the office, the prison, the mental hospital, each reward, instruct and control the individual who learns by operant means what the institution teaches." (Author/AL)

  11. Operational Modal Analysis Tutorial

    DEFF Research Database (Denmark)

    Brincker, Rune; Andersen, Palle

    In this paper the basic principles in operational modal testing and analysis are presented and discussed. A brief review of the techniques for operational modal testing and identification is presented, and it is argued, that there is now a wide range of techniques for effective identification of ...... estimation, vibration level estimation and fatigue analysis....

  12. The non-linear evolution of edge localized modes

    Energy Technology Data Exchange (ETDEWEB)

    Wenninger, Ronald

    2013-01-09

    Edge localized modes (ELMs) are instabilities in the edge of tokamak plasmas in the high confinement regime (H-mode). Without them the edge transport in ordinary H-mode plasmas is too low to establish a stationary situation. However in a future device large unmitigated ELMs are believed to cause divertor power flux densities far in excess of tolerable material limits. Hence the size of energy loss per ELM and the resulting ELM frequency must be controlled. To proceed in understanding how the ELM size is determined and how ELM mitigation methods work it is necessary to characterize the non-linear evolution of pedestal erosion. In order to achieve this experimental data is compared to the results of ELM simulations with the code JOREK (reduced MHD, non-linear) applying a specially developed synthetic magnetic diagnostic. The experimental data are acquired by several fast sampling diagnostics at the experiments ASDEX Upgrade and TCV at a large number of toroidal/poloidal positions. A central element of the presented work is the detailed characterization of dominant magnetic perturbations during ELMs. These footprints of the instability can be observed most intensely in close temporal vicinity to the onset of pedestal erosion. Dominant magnetic perturbations are caused by current perturbations located at or inside the last closed flux surface. In ASDEX Upgrade under certain conditions dominant magnetic perturbations like other H-mode edge instabilities display a similarity to solitons. Furthermore - as expected - they are often observed to be correlated to a perturbation of electron temperature. In TCV it is possible to characterize the evolution of the toroidal structure of dominant magnetic perturbations. Between growing above the level of background fluctuations and the maximum perturbation level for all time instance a similar toroidal structure is observed. This rigid mode-structure is an indication for non-linear coupling. Most frequently the dominant toroidal

  13. The Impact Of Lithium Wall Coatings On NSTX Discharges And The Engineering Of The Lithium Tokamak eXperiment (LTX)

    Energy Technology Data Exchange (ETDEWEB)

    R. Majeski, H. Kugel and R. Kaita

    2010-03-18

    Recent experiments on the National Spherical Torus eXperiment (NSTX) have shown the benefits of solid lithium coatings on carbon PFC's to diverted plasma performance, in both Land H- mode confinement regimes. Better particle control, with decreased inductive flux consumption, and increased electron temperature, ion temperature, energy confinement time, and DD neutron rate were observed. Successive increases in lithium coverage resulted in the complete suppression of ELM activity in H-mode discharges. A liquid lithium divertor (LLD), which will employ the porous molybdenum surface developed for the LTX shell, is being installed on NSTX for the 2010 run period, and will provide comparisons between liquid walls in the Lithium Tokamak eXperiment (LTX) and liquid divertor targets in NSTX. LTX, which recently began operations at the Princeton Plasma Physics Laboratory, is the world's first confinement experiment with full liquid metal plasma-facing components (PFCs). All materials and construction techniques in LTX are compatible with liquid lithium. LTX employs an inner, heated, stainless steel-faced liner or shell, which will be lithium-coated. In order to ensure that lithium adheres to the shell, it is designed to operate at up to 500 - 600 oC to promote wetting of the stainless by the lithium, providing the first hot wall in a tokamak to operate at reactor-relevant temperatures. The engineering of LTX will be discussed.

  14. Operant conditioning in invertebrates.

    Science.gov (United States)

    Brembs, Björn

    2003-12-01

    Learning to anticipate future events on the basis of past experience with the consequences of one's own behavior (operant conditioning) is a simple form of learning that humans share with most other animals, including invertebrates. Three model organisms have recently made significant contributions towards a mechanistic model of operant conditioning, because of their special technical advantages. Research using the fruit fly Drosophila melanogaster implicated the ignorant gene in operant conditioning in the heat-box, research on the sea slug Aplysia californica contributed a cellular mechanism of behavior selection at a convergence point of operant behavior and reward, and research on the pond snail Lymnaea stagnalis elucidated the role of a behavior-initiating neuron in operant conditioning. These insights demonstrate the usefulness of a variety of invertebrate model systems to complement and stimulate research in vertebrates.

  15. Assessing Operational Situations

    DEFF Research Database (Denmark)

    Zhang, Xinxin

    In spite of the high level of automation commonly applied to today’s engineering system, humans’ skill and knowledge still plays a central role in the systems’ daily operation, critical decision making, and accident management. The complexity of the engineered system poses great challenge for human...... operators to perceive and understand the operational situation. The research domain of situation awareness approaches the operational challenges from the human cognition perspective while the presented thesis aims at supporting situation assessment from the system perspective. The thesis has reviewed...... different perspectives on situation awareness in the human factor studies and uses the knowledge reflectively for system representation and analysis. The human cognitive activities during complex plant operation and how they perceive a situation and what kind of knowledge has to be established in the human...

  16. Operations Between Functions

    DEFF Research Database (Denmark)

    Gardner, Richard J.; Kiderlen, Markus

    A structural theory of operations between real-valued (or extended-real-valued) functions on a nonempty subset A of Rn is initiated. It is shown, for example, that any operation ∗ on a cone of functions containing the constant functions, which is pointwise, positively homogeneous, monotonic......, and associative, must be one of 40 explicitly given types. In particular, this is the case for operations between pairs of arbitrary, or continuous, or differentiable functions. The term pointwise means that (f ∗g)(x) = F(f(x), g(x)), for all x ∈ A and some function F of two variables. Several results in the same...... spirit are obtained for operations between convex functions or between support functions. For example, it is shown that ordinary addition is the unique pointwise operation between convex functions satisfying the identity property, i.e., f ∗ 0 = 0 ∗ f = f, for all convex f, while other results classify Lp...

  17. Sustainable Building Operation

    DEFF Research Database (Denmark)

    Jensen, Jesper Ole

    2009-01-01

    Energy-savings in the existing building stock have becomes a main goal in national and international policies. Often focus is on building-renovations, whereas the potential of sustainable building operation to a large extent has been neglected. Nevertheless, international research as well...... as practical experiences from Danish housing estates indicates that there are large potentials for energy savings by focusing on the operation of the buildings. We suggest that in order to achieve sustainability in the existing housing, renovation and operations should be seen as integrated parts...... and that sustainable building operation can pave the way for sustainable building renovation. This paper discusses the use of sustainability building operation in Danish housing estates: Which tools, methods and technologies is being used, where are the barriers and where are the potentials? We define sustainable...

  18. Modern operating systems

    CERN Document Server

    Tanenbaum, Andrew S

    2015-01-01

    Modern Operating Systems, Fourth Edition, is intended for introductory courses in Operating Systems in Computer Science, Computer Engineering, and Electrical Engineering programs. It also serves as a useful reference for OS professionals ' The widely anticipated revision of this worldwide best-seller incorporates the latest developments in operating systems (OS) technologies. The Fourth Edition includes up-to-date materials on relevant'OS. Tanenbaum also provides information on current research based on his experience as an operating systems researcher. ' Modern Operating Systems, Third Editionwas the recipient of the 2010 McGuffey Longevity Award. The McGuffey Longevity Award recognizes textbooks whose excellence has been demonstrated over time.'http://taaonline.net/index.html " Teaching and Learning Experience This program will provide a better teaching and learning experience-for you and your students. It will help: ' *Provide Practical Detail on the Big Picture Concepts: A clear and entertaining writing s...

  19. Noncommutative operational calculus

    Directory of Open Access Journals (Sweden)

    Henry E. Heatherly

    1999-12-01

    Full Text Available Oliver Heaviside's operational calculus was placed on a rigorous mathematical basis by Jan Mikusinski, who constructed an algebraic setting for the operational methods. In this paper, we generalize Mikusi'{n}ski's methods to solve linear ordinary differential equations in which the unknown is a matrix- or linear operator-valued function. Because these functions can be zero-divisors and do not necessarily commute, Mikusi'{n}ski's one-dimensional calculus cannot be used. The noncommuative operational calculus developed here,however, is used to solve a wide class of such equations. In addition, we provide new proofs of existence and uniqueness theorems for certain matrix- and operator valued Volterra integral and integro-differential equations. Several examples are given which demonstrate these new methods.

  20. Aircraft operations management manual

    Science.gov (United States)

    1992-01-01

    The NASA aircraft operations program is a multifaceted, highly diverse entity that directly supports the agency mission in aeronautical research and development, space science and applications, space flight, astronaut readiness training, and related activities through research and development, program support, and mission management aircraft operations flights. Users of the program are interagency, inter-government, international, and the business community. This manual provides guidelines to establish policy for the management of NASA aircraft resources, aircraft operations, and related matters. This policy is an integral part of and must be followed when establishing field installation policy and procedures covering the management of NASA aircraft operations. Each operating location will develop appropriate local procedures that conform with the requirements of this handbook. This manual should be used in conjunction with other governing instructions, handbooks, and manuals.

  1. Integrated formal operations plan

    Energy Technology Data Exchange (ETDEWEB)

    Cort, G.; Dearholt, W.; Donahue, S.; Frank, J.; Perkins, B.; Tyler, R.; Wrye, J.

    1994-01-05

    The concept of formal operations (that is, a collection of business practices to assure effective, accountable operations) has vexed the Laboratory for many years. To date most attempts at developing such programs have been based upon rigid, compliance-based interpretations of a veritable mountain of Department of Energy (DOE) orders, directives, notices, and standards. These DOE dictates seldom take the broad view but focus on highly specialized programs isolated from the overall context of formal operations. The result is a confusing array of specific, and often contradictory, requirements that produce a patchwork of overlapping niche programs. This unnecessary duplication wastes precious resources, dramatically increases the complexity of our work processes, and communicates a sense of confusion to our customers and regulators. Coupled with the artificial divisions that have historically existed among the Laboratory`s formal operations organizations (quality assurance, configuration management, records management, training, etc.), this approach has produced layers of increasingly vague and complex formal operations plans, each of which interprets its parent and adds additional requirements of its own. Organizational gridlock ensues whenever an activity attempts to implement these bureaucratic monstrosities. The integrated formal operations plan presented is to establish a set of requirements that must be met by an integrated formal operations program, assign responsibilities for implementation and operation of the program, and specify criteria against which the performance of the program will be measured. The accountable line manager specifies the items, processes, and information (the controlled elements) to which the formal operations program specified applies. The formal operations program is implemented using a graded approach based on the level of importance of the various controlled elements and the scope of the activities in which they are involved.

  2. The Battle for Crete (Operation Mercury): An Operational Analysis

    Science.gov (United States)

    2001-05-18

    NAVAL WAR COLLEGE Newport, R.I. The Battle for Crete (Operation Mercury ): An Operational Analysis by Kenneth J. Cox Lieutenant Colonel, U.S. Army...Title (Include Security Classification): The Battle for Crete (Operation Mercury ): An Operational Analysis (UNCLASSIFIED) 9. Personal Authors...Security Classification of this page Unclassified 3 ABSTRACT The Battle for Crete (Operation Mercury ): An Operational Analysis In May

  3. Scientific Operation of LIGO

    Science.gov (United States)

    Sanders, Gary H.

    2003-04-01

    LIGO construction has been completed. The three interferometers at the two LIGO observatory sites (Livingston, Louisiana and Hanford, Washington) have been operated successfully as power-recycled Michelson interferometers with Fabry-Perot arm cavities. Commissioning of the interferometers has progressed to operating them simultaneously in this final optical configuration. Initial coincidence operation between the observatory sites has provided a full test of the detector hardware and software subsystems, and full operation of the data acquisition and data analysis systems. The LIGO Laboratory and the LIGO Scientific Collaboration are working together to exploit the early series of interleaved engineering and science runs to commission the detector and data systems, to provide a detailed characterization of the detector and to produce the first scientific results from LIGO. The operation of LIGO is also coordinated with operation of the GEO 600 detector, the TAMA 300 detector and the Allegro resonant mass detector. The status of this early operation, including the first science run during 2002, and the resulting data study will be presented. The support of the US National Science Foundation under Cooperative Agreement No. PHY - 0107417 is gratefully acknowledged.

  4. Magellan Telescopes operations 2008

    Science.gov (United States)

    Osip, David J.; Phillips, Mark M.; Palunas, Povilas; Perez, Frank; Leroy, M.

    2008-07-01

    The twin 6.5m Magellan Telescopes have been in routine operations at the Las Campanas Observatory in the Chilean Andes since 2001 and 2002 respectively. The telescopes are owned and operated by Carnegie for the benefit of the Magellan consortium members (Carnegie Institution of Washington, Harvard University, the University of Arizona, Massachusetts Institute of Technology, and the University of Michigan). This paper provides an up to date review of the scientific, technical, and administrative structure of the 'Magellan Model' for observatory operations. With a modest operations budget and a reasonably small staff, the observatory is operated in the "classical" mode, wherein the visiting observer is a key member of the operations team. Under this model, all instrumentation is supplied entirely by the consortium members and the various instrument teams continue to play a critical support role beyond initial deployment and commissioning activities. Here, we present a critical analysis of the Magellan operations model and suggest lessons learned and changes implemented as we continue to evolve an organizational structure that can efficiently deliver a high scientific return for the investment of the partners.

  5. Basic operator theory

    CERN Document Server

    Gohberg, Israel

    2001-01-01

    rii application of linear operators on a Hilbert space. We begin with a chapter on the geometry of Hilbert space and then proceed to the spectral theory of compact self adjoint operators; operational calculus is next presented as a nat­ ural outgrowth of the spectral theory. The second part of the text concentrates on Banach spaces and linear operators acting on these spaces. It includes, for example, the three 'basic principles of linear analysis and the Riesz­ Fredholm theory of compact operators. Both parts contain plenty of applications. All chapters deal exclusively with linear problems, except for the last chapter which is an introduction to the theory of nonlinear operators. In addition to the standard topics in functional anal­ ysis, we have presented relatively recent results which appear, for example, in Chapter VII. In general, in writ­ ing this book, the authors were strongly influenced by re­ cent developments in operator theory which affected the choice of topics, proofs and exercises. One ...

  6. Stirling machine operating experience

    Energy Technology Data Exchange (ETDEWEB)

    Ross, B. [Stirling Technology Co., Richland, WA (United States); Dudenhoefer, J.E. [Lewis Research Center, Cleveland, OH (United States)

    1994-09-01

    Numerous Stirling machines have been built and operated, but the operating experience of these machines is not well known. It is important to examine this operating experience in detail, because it largely substantiates the claim that stirling machines are capable of reliable and lengthy operating lives. The amount of data that exists is impressive, considering that many of the machines that have been built are developmental machines intended to show proof of concept, and are not expected to operate for lengthy periods of time. Some Stirling machines (typically free-piston machines) achieve long life through non-contact bearings, while other Stirling machines (typically kinematic) have achieved long operating lives through regular seal and bearing replacements. In addition to engine and system testing, life testing of critical components is also considered. The record in this paper is not complete, due to the reluctance of some organizations to release operational data and because several organizations were not contacted. The authors intend to repeat this assessment in three years, hoping for even greater participation.

  7. Global Operations Networks

    DEFF Research Database (Denmark)

    In the current context of global economic liberalisation and technological advancements, industrial companies are less likely to generate value in the traditional vertically integrated chain. Instead, they are doing so by means of elaborate cross-border and cross-organisational networks. As a rule...... and processes in global operations networks, and • Trajectories and reconfiguration of global operations networks. The themes are intended to incorporate elements which in combination provide a comprehensive multidisciplinary view on operations networks. Behind these themes lay clusters of questions and topics...

  8. Computer system operation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Jae; Lee, Hae Cho; Lee, Ho Yeun; Kim, Young Taek; Lee, Sung Kyu; Park, Jeong Suk; Nam, Ji Wha; Kim, Soon Kon; Yang, Sung Un; Sohn, Jae Min; Moon, Soon Sung; Park, Bong Sik; Lee, Byung Heon; Park, Sun Hee; Kim, Jin Hee; Hwang, Hyeoi Sun; Lee, Hee Ja; Hwang, In A. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1993-12-01

    The report described the operation and the trouble shooting of main computer and KAERINet. The results of the project are as follows; 1. The operation and trouble shooting of the main computer system. (Cyber 170-875, Cyber 960-31, VAX 6320, VAX 11/780). 2. The operation and trouble shooting of the KAERINet. (PC to host connection, host to host connection, file transfer, electronic-mail, X.25, CATV etc.). 3. The development of applications -Electronic Document Approval and Delivery System, Installation the ORACLE Utility Program. 22 tabs., 12 figs. (Author) .new.

  9. Scenario development toward high beta steady-state operation at KSTAR

    Science.gov (United States)

    Yoon, S. W.; Jeon, Y. M.; Kim, H. S.; Woo, M. H.; Hahn, S. H.; Bae, Y. S.; Kang, J. S.; Na, Y. S.; Oh, Y. K.; Park, H. K.; Kstar Team

    2017-10-01

    Solving issues for high-beta long-pulse operation is one of the essential topics for superconducting tokamaks and sustainment of a fully non-inductive H-mode discharge with high performance is successfully demonstrated upto record-long 70 seconds at KSTAR. Typical plasma parameters are 0.4MA(Ip) , max 5MW (NBI +ECH), βp 3, fBS 0.5, H98 1.3 and in a wide range of q95 = 6 12. Though an internal transport barrier is not identified yet, the developed scenario has many features in common with the so called ``high βp discharge' at DIII-D. The thermal confinement is sensitive on the deposition layer of the central ECH heating 1MW and it correlates with MHD activities in the range of TAE frequency (100 200kHz) suggesting strong interaction TAE with fast ion transport. Based on the transport/stability analysis on the present discharge, improved performance is also estimated with higher NBI +ECH heating power envisaged in near future. Ulsan National Institute of Science and Technology.

  10. EEI: Operation Involvement

    Science.gov (United States)

    Eberhart, Jonathan

    1976-01-01

    Describes the operation of Educational Expeditions International (EEI), a private organization which links interested amateurs with professional researchers on exploratory adventures. EEI funds scientists and their studies for which amateurs pay for the privilege of joining. (CP)

  11. Operating plan FY 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    This document is the first edition of Argonne`s new Operating Plan. The Operating Plan complements the strategic planning in the Laboratory`s Institutional Plan by focusing on activities that are being pursued in the immediate fiscal year, FY 1998. It reflects planning that has been done to date, and it will serve in the future as a resource and a benchmark for understanding the Laboratory`s performance. The heart of the Institutional Plan is the set of major research initiatives that the Laboratory is proposing to implement in future years. In contrast, this Operating Plan focuses on Argonne`s ongoing R&D programs, along with cost-saving measures and other improvements being implemented in Laboratory support operations.

  12. Title V Operating Permits

    Science.gov (United States)

    This site will provide basic information on clean air permitting under the title V operating permits program, provide access to state and regional permitting programs, and maintain access to proposed and final regulatory requirements.

  13. Operable Unit Boundaries

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset consists of operable unit data from multiple Superfund sites in U.S. EPA Region 8. These data were acquired from multiple sources at different times and...

  14. Nuclear material operations manual

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, R.P.

    1981-02-01

    This manual provides a concise and comprehensive documentation of the operating procedures currently practiced at Sandia National Laboratories with regard to the management, control, and accountability of nuclear materials. The manual is divided into chapters which are devoted to the separate functions performed in nuclear material operations-management, control, accountability, and safeguards, and the final two chapters comprise a document which is also issued separately to provide a summary of the information and operating procedures relevant to custodians and users of radioactive and nuclear materials. The manual also contains samples of the forms utilized in carrying out nuclear material activities. To enhance the clarity of presentation, operating procedures are presented in the form of playscripts in which the responsible organizations and necessary actions are clearly delineated in a chronological fashion from the initiation of a transaction to its completion.

  15. Crushed Stone Operations

    Data.gov (United States)

    Department of Homeland Security — This map layer includes crushed stone operations in the United States. These data were obtained from information reported voluntarily to the USGS by the aggregate...

  16. Emergency Operations Center

    Science.gov (United States)

    EOC serves as the response operational focal point. A communication and coordination hub designed to increase data management and coordination abilities, provides communication support for Watch Officer, Homeland Security, regional and field assets.

  17. Payroll Operational Data Store

    Data.gov (United States)

    Social Security Administration — The Payroll ODS will provide a single repository of payroll data to produce accurate and timely financial reports to support operating, budget, and policy decisions.

  18. Adaptively Compressed Exchange Operator

    CERN Document Server

    Lin, Lin

    2016-01-01

    The Fock exchange operator plays a central role in modern quantum chemistry. The large computational cost associated with the Fock exchange operator hinders Hartree-Fock calculations and Kohn-Sham density functional theory calculations with hybrid exchange-correlation functionals, even for systems consisting of hundreds of atoms. We develop the adaptively compressed exchange operator (ACE) formulation, which greatly reduces the computational cost associated with the Fock exchange operator without loss of accuracy. The ACE formulation does not depend on the size of the band gap, and thus can be applied to insulating, semiconducting as well as metallic systems. In an iterative framework for solving Hartree-Fock-like systems, the ACE formulation only requires moderate modification of the code, and can be potentially beneficial for all electronic structure software packages involving exchange calculations. Numerical results indicate that the ACE formulation can become advantageous even for small systems with tens...

  19. Administrative & Operational Circulars - Reminder

    CERN Multimedia

    HR Department

    2011-01-01

    All Administrative and Operational Circulars are available on the intranet site of the Human Resources Department at the following address: http://cern.ch/hr-docs/admincirc/admincirc.asp Department Head Office  

  20. LCOGT network observatory operations

    Science.gov (United States)

    Pickles, Andrew; Hjelstrom, Annie; Boroson, Todd; Burleson, Ben; Conway, Patrick; De Vera, Jon; Elphick, Mark; Haworth, Brian; Rosing, Wayne; Saunders, Eric; Thomas, Doug; White, Gary; Willis, Mark; Walker, Zach

    2014-08-01

    We describe the operational capabilities of the Las Cumbres Observatory Global Telescope Network. We summarize our hardware and software for maintaining and monitoring network health. We focus on methodologies to utilize the automated system to monitor availability of sites, instruments and telescopes, to monitor performance, permit automatic recovery, and provide automatic error reporting. The same jTCS control system is used on telescopes of apertures 0.4m, 0.8m, 1m and 2m, and for multiple instruments on each. We describe our network operational model, including workloads, and illustrate our current tools, and operational performance indicators, including telemetry and metrics reporting from on-site reductions. The system was conceived and designed to establish effective, reliable autonomous operations, with automatic monitoring and recovery - minimizing human intervention while maintaining quality. We illustrate how far we have been able to achieve that.

  1. Features of the repetition frequency of edge localized modes in EAST

    DEFF Research Database (Denmark)

    Jiang, M.; Xiao, C.; Xu, G.S.

    2012-01-01

    This paper presents the features of the edge localized modes (ELMs) observed in the 2010 experimental campaign on the Experimental Advanced Superconducting Tokamak (EAST). The first high-confinement mode (H-mode) at an H-factor of HIPB98(y, 2)~1 has been obtained with about 1 MW lower hybrid wave...

  2. Operational Law Handbook 2002

    Science.gov (United States)

    2002-03-26

    its duly elected Head of Government. FOAA 00, § 508. Congress requires special notification to Congress before obligating funds for Colombia , Haiti...additional funding specifically for, enhanced support to Colombia and Peru. The additional support is similar that provided to Mexico under Section 1031...ROC Rear Operations Center ROE Rules of Engagement ROM Refuel on the Move ROZ Rear Operations Zone RP Release Point RSC SJA Regional Support

  3. Operational Waste Volume Projection

    Energy Technology Data Exchange (ETDEWEB)

    STRODE, J.N.

    1999-08-24

    Waste receipts to the double-shell tank system are analyzed and wastes through the year 2018 are projected based on assumption as of July 1999. A computer simulation of site operations is performed, which results in projections of tank fill schedules, tank transfers, evaporator operations, tank retrieval, and aging waste tank usage. This projection incorporates current budget planning and the clean-up schedule of the Tri-Party Agreement.

  4. Operational Risk Modeling

    OpenAIRE

    Gabriela ANGHELACHE; Ana Cornelia OLTEANU

    2011-01-01

    Losses resulting from operational risk events from a complex interaction between organizational factors, personal and market participants that do not fit a simple classification scheme. Taking into account past losses (ex. Barings, Daiwa, etc.) we can say that operational risk is a major financial losses in the banking sector, although until recently have been underestimated, considering that they are generally minor, note setting survival of a bank.

  5. Operational Risk Measurement

    OpenAIRE

    Gabriela ANGHELACHE; Ana-Cornelia OLTEANU (PUIU); Alina-Nicoleta RADU

    2010-01-01

    Beginning with the fact that performant strategies of the financial institutions have programmes and management procedures for the banking risks, which have as main objective to minimize the probability of risk generation and the bank’s potential exposure, this paper wants to present the operational risk measurement. Therefore, the first part presents the conceptual approach of the operational risks through the point of view of the financial institutions exposed to this type of risk. The seco...

  6. Operational Risk Modeling

    Directory of Open Access Journals (Sweden)

    Gabriela ANGHELACHE

    2011-06-01

    Full Text Available Losses resulting from operational risk events from a complex interaction between organizational factors, personal and market participants that do not fit a simple classification scheme. Taking into account past losses (ex. Barings, Daiwa, etc. we can say that operational risk is a major financial losses in the banking sector, although until recently have been underestimated, considering that they are generally minor, note setting survival of a bank.

  7. Quality in drilling operations

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, E.; Gervais, I. [Sedco Forex Jacintoport Facility, Channelview, TX (United States); Le Moign, Y.; Pangarkar, S.; Stibbs, B. [Sedco Forex, Montrouge (France); McMorran, P. [Sedco Forex, Pau (France); Nordquist, E. [Dubai Petroleum Company, Dubai (United Arab Emirates); Pittman, T. [Sedco Forex, Perth (Australia); Schindler, H. [Sedco Forex, Dubai (United Arab Emirates); Scott, P. [Woodside Offshore Petroleum Pty. Ltd., Perth (Australia)

    1996-12-31

    Driven by cost and profitability pressures, quality has taken on new meaning and importance in the oil field during the past decade. In drilling operations, new initiatives have led to cooperative team efforts between operators and drilling contractors to enhance quality. In this article examples are given of how one drilling contractor, by adopting a quality culture, is reaping major benefits for its clients as well as its employees. 22 figs., 19 refs.

  8. Education of Operational Art

    Science.gov (United States)

    2012-12-06

    Armed Forces, Allied Officers, and interagency members receive a graduate-level education in the development of solutions to operational and...approach accounts for chance and chaos when opposing systems interact. Plans utilizing operational art are non-linear, but express depth. Actions of an...coalition forces attempted forward movement, they faced additional unknown deep-buried or house-borne IEDs at intersections and choke points for vehicular

  9. Operational waste volume projection

    Energy Technology Data Exchange (ETDEWEB)

    Koreski, G.M.

    1996-09-20

    Waste receipts to the double-shell tank system are analyzed and wastes through the year 2015 are projected based on generation trends of the past 12 months. A computer simulation of site operations is performed, which results in projections of tank fill schedules, tank transfers, evaporator operations, tank retrieval, and aging waste tank usage. This projection incorporates current budget planning and the clean-up schedule of the Tri-Party Agreement. Assumptions were current as of June 1996.

  10. Pipeline system operability review

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Kjell [Det Norske Veritas (Norway); Davies, Ray [CC Technologies, Dublin, OH (United States)

    2005-07-01

    Pipeline operators are continuously working to improve the safety of their systems and operations. In the US both liquid and gas pipeline operators have worked with the regulators over many years to develop more systematic approaches to pipeline integrity management. To successfully manage pipeline integrity, vast amounts of data from different sources needs to be collected, overlaid and analyzed in order to assess the current condition and predict future degradation. The efforts undertaken by the operators has had a significant impact on pipeline safety, nevertheless, during recent years we have seen a number of major high profile accidents. One can therefore ask how effective the pipeline integrity management systems and processes are. This paper will present one methodology 'The Pipeline System Operability Review' that can evaluate and rate the effectiveness of both the management systems and procedures, as well as the technical condition of the hardware. The result from the review can be used to compare the performance of different pipelines within one operating company, as well as benchmark with international best practices. (author)

  11. Divertor detachment

    Science.gov (United States)

    Krasheninnikov, Sergei

    2015-11-01

    The heat exhaust is one of the main conceptual issues of magnetic fusion reactor. In a standard operational regime the large heat flux onto divertor target reaches unacceptable level in any foreseeable reactor design. However, about two decades ago so-called ``detached divertor'' regimes were found. They are characterized by reduced power and plasma flux on divertor targets and look as a promising solution for heat exhaust in future reactors. In particular, it is envisioned that ITER will operate in a partly detached divertor regime. However, even though divertor detachment was studied extensively for two decades, still there are some issues requiring a new look. Among them is the compatibility of detached divertor regime with a good core confinement. For example, ELMy H-mode exhibits a very good core confinement, but large ELMs can ``burn through'' detached divertor and release large amounts of energy on the targets. In addition, detached divertor regimes can be subject to thermal instabilities resulting in the MARFE formation, which, potentially, can cause disruption of the discharge. Finally, often inner and outer divertors detach at different plasma conditions, which can lead to core confinement degradation. Here we discuss basic physics of divertor detachment including different mechanisms of power and momentum loss (ionization, impurity and hydrogen radiation loss, ion-neutral collisions, recombination, and their synergistic effects) and evaluate the roles of different plasma processes in the reduction of the plasma flux; detachment stability; and an impact of ELMs on detachment. We also evaluate an impact of different magnetic and divertor geometries on detachment onset, stability, in- out- asymmetry, and tolerance to the ELMs. Supported by the U.S. Department of Energy Office of Science, Office of Fusion Energy Sciences under Award Number DE-DE-FG02-04ER54739 at UCSD.

  12. Stationary QH-mode plasmas with high and wide pedestal at low rotation on DIII-D

    Science.gov (United States)

    Chen, Xi; Burrell, K. H.; Osborne, T. H.; Solomon, W. M.; Barada, K.; Garofalo, A. M.; Groebner, R. J.; Luhmann, N. C.; McKee, G. R.; Muscatello, C. M.; Ono, M.; Petty, C. C.; Porkolab, M.; Rhodes, T. L.; Rost, J. C.; Snyder, P. B.; Staebler, G. M.; Tobias, B. J.; Yan, Z.; the DIII-D Team

    2017-02-01

    A stationary, quiescent H-mode (QH-mode) regime with a wide pedestal and improved confinement at low rotation has been discovered on DIII-D with reactor relevant edge parameters and no ELMs. As the injected neutral beam torque is ramped down and the edge E  ×  B rotation shear reduces, the transition from standard QH to the wide pedestal QH-mode occurs. At the transition, the coherent edge harmonic oscillations (EHO) that usually regulate the standard QH edge cease and broadband edge MHD modes appear along with a rapid increase in the pedestal pressure height (by  ⩽60%) and width (by  ⩽50%). We posit that the enhanced edge turbulence-driven transport, enabled by the lower edge E  ×  B flow shear due to lower torque reduces the pedestal gradient and, combined with the high edge instability limit provided by the balanced double-null plasma shape, permits the development of a broader and thus higher pedestal that is turbulence-transport-limited. Even with the significantly enhanced pedestal pressure, the edge operating point is below the peeling ballooning mode stability boundary and thus without ELMs. Improved transport in the outer core region (0.8  ⩽  ρ  ⩽0.9) owing to increased E  ×  B flow shear in that region and the enhanced pedestal boost the overall confinement by up to 45%. These findings advance the physics basis for developing stationary ELM-free high-confinement operation at low rotation for future burning plasma where similar collisionality and rotation levels are expected.

  13. Using fractional order method to generalize strengthening generating operator buffer operator and weakening buffer operator

    OpenAIRE

    Wu, L.; Liu, S.; Yang, Yingjie

    2016-01-01

    Traditional integer order buffer operator is extended to fractional order buffer operator, the corresponding relationship between the weakening buffer operator and the strengthening buffer operator is revealed. Fractional order buffer operator not only can generalize the weakening buffer operator and the strengthening buffer operator, but also realize tiny adjustment of buffer effect. The effectiveness of GM(1,1) with the fractional order buffer operator is validated by six cases.

  14. Operator representations of frames

    DEFF Research Database (Denmark)

    Christensen, Ole; Hasannasab, Marzieh

    2017-01-01

    The purpose of this paper is to consider representations of frames {fk}k∈I in a Hilbert space ℋ of the form {fk}k∈I = {Tkf0}k∈I for a linear operator T; here the index set I is either ℤ or ℒ0. While a representation of this form is available under weak conditions on the frame, the analysis...... of the properties of the operator T requires more work. For example it is a delicate issue to obtain a representation with a bounded operator, and the availability of such a representation not only depends on the frame considered as a set, but also on the chosen indexing. Using results from operator theory we show...... that by embedding the Hilbert space ℋ into a larger Hilbert space, we can always represent a frame via iterations of a bounded operator, composed with the orthogonal projection onto ℋ. The paper closes with a discussion of an open problem concerning representations of Gabor frames via iterations of a bounded...

  15. DIII-D research to address key challenges for ITER and fusion energy

    Science.gov (United States)

    Buttery, R. J.; the DIII-D Team

    2015-10-01

    DIII-D has made significant advances in the scientific basis for fusion energy. The physics mechanism of resonant magnetic perturbation (RMP) edge localized mode (ELM) suppression is revealed as field penetration at the pedestal top, and reduced coil set operation was demonstrated. Disruption runaway electrons were effectively quenched by shattered pellets; runaway dissipation is explained by pitch angle scattering. Modest thermal quench radiation asymmetries are well described NIMROD modelling. With good pedestal regulation and error field correction, low torque ITER baselines have been demonstrated and shown to be compatible with an ITER test blanket module simulator. However performance and long wavelength turbulence degrade as low rotation and electron heating are approached. The alternative QH mode scenario is shown to be compatible with high Greenwald density fraction, with an edge harmonic oscillation demonstrating good impurity flushing. Discharge optimization guided by the EPED model has discovered a new super H-mode with doubled pedestal height. Lithium injection also led to wider, higher pedestals. On the path to steady state, 1 MA has been sustained fully noninductively with βN = 4 and RMP ELM suppression, while a peaked current profile scenario provides attractive options for ITER and a βN = 5 future reactor. Energetic particle transport is found to exhibit a critical gradient behaviour. Scenarios are shown to be compatible with radiative and snowflake divertor techniques. Physics studies reveal that the transition to H mode is locked in by a rise in ion diamagnetic flows. Intrinsic rotation in the plasma edge is demonstrated to arise from kinetic losses. New 3D magnetic sensors validate linear ideal MHD, but identify issues in nonlinear simulations. Detachment, characterized in 2D with sub-eV resolution, reveals a radiation shortfall in simulations. Future facility development targets burning plasma physics with torque free electron heating, the

  16. Global Operations Coevolution

    DEFF Research Database (Denmark)

    Slepniov, Dmitrij; Wæhrens, Brian Vejrum; Gubi, Ebbe

    2013-01-01

    systemic approach to control and coordination, which emphasizes not only short-term operational efficiency, but also increasingly long-term strategic effectiveness. The findings advance coevolutionary perspectives on the integration of globally dispersed business systems spanning multiple levels......Companies are actively seeking competitive advantage through their choice of location and ownership of operations. The purpose of this chapter is to uncover hidden effects of this development and propose how companies can respond to them. The chapter draws on a case study of a Danish industrial...... equipment firm and describes how its operations configuration has been changing over time. The chapter identifies the key determinants of this change and uncovers some of its hidden effects. The chapter closes with propositions for how to respond to these effects through the development of a distinct...

  17. Operations management for construction

    CERN Document Server

    March, Chris

    2009-01-01

    Students studying construction management and related subjects need to have a broad understanding of the major aspects of controlling the building processes. Operations Management for Construction is one of three textbooks (Business Organisation, Operations Management and Finance Control) written to systematically cover the field. Focusing on construction sites and operations which are challenging to run, Chris March explores issues such as the setting up of the site, the deciding of the methodology of construction, and the sequence of work and resourcing. As changing and increasing regulations affect the way sites are managed, he also considers the issues and methods of successful administering, safety, quality and environment. Finally, the contractor's responsibility to the environment, including relationships with third parties, selection of materials, waste management and sustainability is discussed. Chris March has a wealth of practical experience in the construction industry, as well as considerable exp...

  18. Operations Strategy in practice

    DEFF Research Database (Denmark)

    Rytter, Niels Gorm; Koch, Christian; Boer, Harry

    2005-01-01

    In this paper, we describe and illustrate a new, action-based longitudinal case study approach, which aims at helping scholars narrow the gap between the theory and practice of Operations Strategy (OS). First, we elaborate on the need for new research methods for studying OS in practice. Then, we...... present the two research strategies underpinning the approach proposed here: action research and longitudinal case study. Next, we illustrate the use of the method and exemplify it using a recent study of OS in practice. Then, based on this experience we present and discuss the advantages...... and disadvantages of the method. Finally, we draw conclusions on its potential for operations strategy and operations management studies....

  19. Theory of linear operations

    CERN Document Server

    Banach, S

    1987-01-01

    This classic work by the late Stefan Banach has been translated into English so as to reach a yet wider audience. It contains the basics of the algebra of operators, concentrating on the study of linear operators, which corresponds to that of the linear forms a1x1 + a2x2 + ... + anxn of algebra.The book gathers results concerning linear operators defined in general spaces of a certain kind, principally in Banach spaces, examples of which are: the space of continuous functions, that of the pth-power-summable functions, Hilbert space, etc. The general theorems are interpreted in various mathematical areas, such as group theory, differential equations, integral equations, equations with infinitely many unknowns, functions of a real variable, summation methods and orthogonal series.A new fifty-page section (``Some Aspects of the Present Theory of Banach Spaces'''') complements this important monograph.

  20. Bascoms operation for pilonidalcyste

    DEFF Research Database (Denmark)

    Bertelsen, C.A.; Jørgensen, Lars Nannestad

    2008-01-01

    INTRODUCTION: Treatment of pilonidal fistula often results in impaired wound healing and recurrence. After wide excision of the fistula, impaired healing and recurrence occur in up to 69% and 10-29% of cases, respectively. Based on these facts we decided to implement Bascom's cleft-lift operation......-29) months. 39 (93%) patients did not experience recurrence while the 3 cases of recurrence were observed after 5, 8 and 9 months. CONCLUSION: Bascom's operation seems to reduce postoperative pain, complications, and the risk of recurrence compared with simple excision with or without primary wound closure...

  1. Energy Operation Model

    Energy Technology Data Exchange (ETDEWEB)

    2017-04-27

    Energy Operation Model (EOM) simulates the operation of the electric grid at the zonal scale, including inter-zonal transmission constraints. It generates the production cost, power generation by plant and category, fuel usage, and locational marginal price (LMP) with a flexible way to constrain the power production by environmental constraints, e.g. heat waves, drought conditions). Different from commercial software such as PROMOD IV where generator capacity and heat rate efficiency can only be adjusted on a monthly basis, EOM calculates capacity impacts and plant efficiencies based on hourly ambient conditions (air temperature and humidity) and cooling water availability for thermal plants. What is missing is a hydro power dispatch.

  2. Operation for gigantincisionalhernie

    DEFF Research Database (Denmark)

    Eriksson, Axelina; Krag, Christen; Jørgensen, Lars Nannestad

    2014-01-01

    Incisional hernia is a common complication to laparotomy impacting negatively on quality of life, risk of emergency surgery and cosmesis. The operation of giant incisional hernia (cross diameter of hernia defect > 20 cm) is a high risk procedure and the surgical techniques are not based on high...... level evidence. Mesh placement is possible onlay, inlay, sublay or intraperitoneal. These operations are most often performed as open procedures, or in combination with endoscopic techniques. These procedures should be centralized to few centers to improve quality and allow robust research....

  3. SOFIA mission operations

    Science.gov (United States)

    Waddell, Patrick G.; Davidson, Jacqueline A.

    2002-02-01

    The SOFIA Airborne Observatory will operate a 2.5 m aperture telescope with the goal of obtaining over 960 successful science hours per year at a nominal altitude of 12.5 km and covering a wavelength range from 0.3 mm to 1.6 mm. The observatory platform is comprised of a Boeing 747SP with numerous significant modifications. The ground and flight mission operations architectures and plans are tailored to keep the telescope emissivity low and achieve high observing efficiency.

  4. The operator's emotional stability

    Science.gov (United States)

    Zilberman, P. B.

    1975-01-01

    An attempt is made to provide a psychological interpretation of the concept of emotional stability in connection with other psychics qualities of an operator's personality. Emotional stability is understood as a person's capacity to control his emotional state for the purpose of maintaining the necessary level of work performance under extreme stress conditions. By modeling the operator's sensorimotor activity and by comparing the productivity indicators under ordinary conditions with those obtained during work involving an emotional load, the level of emotional stability can be determined.

  5. The Nanvix Operating System

    OpenAIRE

    Penna, Pedro Henrique

    2017-01-01

    Nanvix is an operating system created by Pedro H. Penna for educational purposes. It was designed from scratch to be small and simple, and yet modern and fully featured, so that it could help enthusiasts in operating systems, to learn about kernel hacking. The first release of Nanvix came out in early 2011, and since then the system has undergone through several changes. This paper details the internals of Nanvix 1.2. All previous and future releases are available at www.github.com/ppenna/nan...

  6. Topics in Operator Theory

    CERN Document Server

    Ball, Joseph A; Helton, JWilliam; Rodman, Leiba; Spitkovsky, Iiya

    2010-01-01

    This is the first volume of a collection of original and review articles on recent advances and new directions in a multifaceted and interconnected area of mathematics and its applications. It encompasses many topics in theoretical developments in operator theory and its diverse applications in applied mathematics, physics, engineering, and other disciplines. The purpose is to bring in one volume many important original results of cutting edge research as well as authoritative review of recent achievements, challenges, and future directions in the area of operator theory and its applications.

  7. Evidence and modeling of 3D divertor footprint induced by lower hybrid waves on EAST with tungsten divertor operations

    Science.gov (United States)

    Feng, W.; Wang, L.; Rack, M.; Liang, Y.; Guo, H. Y.; Xu, G. S.; Xu, J. C.; Liu, J. B.; Sun, Y. W.; Jia, M. N.; Yang, Q. Q.; Zhang, B.; Zou, X. L.; Liu, H.; Zhang, T.; Ding, F.; Chen, J. B.; Duan, Y. M.; Zheng, X. W.; Dai, S. Y.; Deng, G. Z.; Chen, R.; Hu, G. H.; Yan, N.; Si, H.; Liu, S. C.; Xu, S.; Wang, M.; Li, M. H.; Ding, B. J.; Wingen, A.; Huang, J.; Gao, X.; Luo, G. N.; Gong, X. Z.; Garofalo, A. M.; Li, J.; Wan, B. N.; the EAST team

    2017-12-01

    Three dimensional (3D) divertor particle flux footprints induced by the lower hybrid wave (LHW) have been systematically investigated in the EAST superconducting tokamak during the recent experimental campaign. We find that the striated particle flux (SPF) peaks away from the strike point (SP) closely fit the pitch of the edge magnetic field line for different safety factors q 95, as predicted by a field line tracing code taking into account the helical current filaments (HCFs) in the scrape-off-layer (SOL). As LHW power increases, it requires the fuelling to be increased e.g. by super molecular beam injection (SMBI), to maintain a similar plasma density, which may be attributed to the pump-out effect due to LHW, and may thus be beneficial for EAST steady state operations. The 3D SPF structure is observed with a LHW power threshold (P LHW ~ 0.9 MW). The ratio of the particle fluxes between SPF and outer strike point (OSP), i.e. {{Γ }ion,SPF}/{{Γ }ion,OSP} , increases with the LHW power. Upon transition to divertor detachment, the particle flux at the main OSP decreases, as expected, however, the particle flux at SPF continues increasing, in contrast to the RMP-induced striations that vanish with increasing divertor density. In addition, we also find that the in–out asymmetry of the 3D particle flux footprint pattern exhibits a clear dependence on the toroidal field direction (B  ×    ∇   B  ↓  and B  ×    ∇   B↑). Experiments using neon impurity seeding show a promising capability in 3D particle and heat flux control on EAST. LHW-induced particle and heat flux striations are also present in the H-mode plasmas, reducing the peak heat flux and erosion at the main strike point, thus facilitating long-pulse operation with a new steady-state H-mode over 60 s being recently achieved in EAST.

  8. Systemic Operational Design: Enhancing the Joint Operation Planning Process

    National Research Council Canada - National Science Library

    Delacruz, Victor J

    2007-01-01

    Operational level commanders and their staffs require relevant and current joint doctrine that articulates the critical function of operational design and its role in the Joint Operation Planning Process (JOPP...

  9. Digital Operating Room assistant

    NARCIS (Netherlands)

    Geudon, A.C.P.

    2016-01-01

    The Operating Room (OR) is a complex environment, where a large variety of patients and diseases can be treated and many unexpected events occur (such as emergency surgeries and unexpected progress of procedures). In practice, OR assistants support OR processes as well as they can, in order to

  10. ATC operational error analysis.

    Science.gov (United States)

    1972-01-01

    The primary causes of operational errors are discussed and the effects of these errors on an ATC system's performance are described. No attempt is made to specify possible error models for the spectrum of blunders that can occur although previous res...

  11. Simplifying Operational Design

    Science.gov (United States)

    2012-05-01

    Terraine’s spider web metaphor reflects the complex, highly interactive operating environment that appropriately should be analyzed through a...describing it as, “not prescriptive or a checklist , design is based on critical thinking, conceptual planning, visualization, emergence of a hypothesis

  12. Space Operations Learning Center

    Science.gov (United States)

    Lui, Ben; Milner, Barbara; Binebrink, Dan; Kuok, Heng

    2012-01-01

    The Space Operations Learning Center (SOLC) is a tool that provides an online learning environment where students can learn science, technology, engineering, and mathematics (STEM) through a series of training modules. SOLC is also an effective media for NASA to showcase its contributions to the general public. SOLC is a Web-based environment with a learning platform for students to understand STEM through interactive modules in various engineering topics. SOLC is unique in its approach to develop learning materials to teach schoolaged students the basic concepts of space operations. SOLC utilizes the latest Web and software technologies to present this educational content in a fun and engaging way for all grade levels. SOLC uses animations, streaming video, cartoon characters, audio narration, interactive games and more to deliver educational concepts. The Web portal organizes all of these training modules in an easily accessible way for visitors worldwide. SOLC provides multiple training modules on various topics. At the time of this reporting, seven modules have been developed: Space Communication, Flight Dynamics, Information Processing, Mission Operations, Kids Zone 1, Kids Zone 2, and Save The Forest. For the first four modules, each contains three components: Flight Training, Flight License, and Fly It! Kids Zone 1 and 2 include a number of educational videos and games designed specifically for grades K-6. Save The Forest is a space operations mission with four simulations and activities to complete, optimized for new touch screen technology. The Kids Zone 1 module has recently been ported to Facebook to attract wider audience.

  13. Splunk operational intelligence cookbook

    CERN Document Server

    Diakun, Josh; Mock, Derek

    2014-01-01

    This book is intended for users of all levels who are looking to leverage the Splunk Enterprise platform as a valuable operational intelligence tool. The recipes provided in this book will appeal to individuals from all facets of a business - IT, Security, Product, Marketing, and many more!

  14. Operation for ensidig recurrensparese

    DEFF Research Database (Denmark)

    Melchiors, Jacob; Rasmussen, Niels

    2009-01-01

    voice analysis. MATERIAL AND METHODS: Retrospective cohort study of 42 consecutively operated patients from 1996 to 2006. Twenty-eight patients were treated with a hydroxyapatite prosthesis, which was inserted into the larynx (VoCom), nine patients had a silicone bead oil injected into the paretic vocal...

  15. Operational Area Environmental Evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Bailey-White, Brenda Eileen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nagy, Michael David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wagner, Katrina Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Goodman, Thomas Richard [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Herring, Allen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Catechis, Christopher S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kinghorn, Aubrianna Nicole [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Johnson, Ellie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Barthel, Michael David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Casaus, Benito [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-08-01

    The Operational Area Environmental Evaluation update provides a description of activities that have the potential to adversely affect natural and cultural resources, including soil, air, water, biological, ecological, and historical resources. The environmental sensitivity of an area is evaluated and summarized, which may facilitate informed management decisions as to where development may be prohibited, restricted, or subject to additional requirements.

  16. Basic Water Treatment Operation.

    Science.gov (United States)

    Ontario Ministry of the Environment, Toronto.

    This manual was developed for use at workshops designed to introduce the fundamentals of water treatment plant operations. The course consists of lecture-discussions and hands-on activities. Each of the fourteen lessons in this document has clearly stated behavioral objectives to tell the trainee what he should know or do after completing that…

  17. A cleaner operation

    Energy Technology Data Exchange (ETDEWEB)

    Marti, A. [Martin Engineering (United States)

    1999-06-01

    Developments in belt cleaners provide the opportunity to improve the operation of conveyor systems. However, these products cannot be developed solely in a laboratory but must undergo trial installations in real conditions. This paper describes the trail of UK Martin Engineering`s new belt cleaner and tensioner system at the Detroit Edison Monroe Power Plant. 5 photos.

  18. Sales and operations planning

    DEFF Research Database (Denmark)

    Kjellsdotter, Linea; Dukovska-Popovska, Iskra; Kaipia, Riikka

    2013-01-01

    This paper explores how the use of sales and operations planning (S&OP) may deal with the challenges set by the planning environment by investigating S&OP at four Scandinavian industrial food producers. Variables connected to the product and market, e.g. perishability, customer service elements...

  19. Sales and operations planning

    DEFF Research Database (Denmark)

    Kjellsdotter, Linea; Dukovska-Popovska, Iskra; Kaipia, Riikka

    2015-01-01

    This paper investigates sales and operations planning (S&OP) at four Scandinavian industrial food producers in order to explore how the use of S&OP might help leaders to deal with the challenges set by the planning environment. Variables connected to the product and market, e.g., frequency of new...

  20. Concept of Operations: Essence

    Energy Technology Data Exchange (ETDEWEB)

    Hutton, William J.

    2014-04-01

    This concept of operations is designed to give the reader a brief overview of the National Rural Electric Cooperative Association’s Essence project and a description of the Essence device design. The data collected by the device, how the data are used, and how the data are protected are also discussed in this document.