Progress on the application of ELM control schemes to ITER scenarios from the non-active phase to DT operation

NASA Astrophysics Data System (ADS)

Loarte, A.; Huijsmans, G.; Futatani, S.; Baylor, L. R.; Evans, T. E.; Orlov, D. M.; Schmitz, O.; Becoulet, M.; Cahyna, P.; Gribov, Y.; Kavin, A.; Sashala Naik, A.; Campbell, D. J.; Casper, T.; Daly, E.; Frerichs, H.; Kischner, A.; Laengner, R.; Lisgo, S.; Pitts, R. A.; Saibene, G.; Wingen, A.

2014-03-01

Progress in the definition of the requirements for edge localized mode (ELM) control and the application of ELM control methods both for high fusion performance DT operation and non-active low-current operation in ITER is described. Evaluation of the power fluxes for low plasma current H-modes in ITER shows that uncontrolled ELMs will not lead to damage to the tungsten (W) divertor target, unlike for high-current H-modes in which divertor damage by uncontrolled ELMs is expected. Despite the lack of divertor damage at lower currents, ELM control is found to be required in ITER under these conditions to prevent an excessive contamination of the plasma by W, which could eventually lead to an increased disruptivity. Modelling with the non-linear MHD code JOREK of the physics processes determining the flow of energy from the confined plasma onto the plasma-facing components during ELMs at the ITER scale shows that the relative contribution of conductive and convective losses is intrinsically linked to the magnitude of the ELM energy loss. Modelling of the triggering of ELMs by pellet injection for DIII-D and ITER has identified the minimum pellet size required to trigger ELMs and, from this, the required fuel throughput for the application of this technique to ITER is evaluated and shown to be compatible with the installed fuelling and tritium re-processing capabilities in ITER. The evaluation of the capabilities of the ELM control coil system in ITER for ELM suppression is carried out (in the vacuum approximation) and found to have a factor of ˜2 margin in terms of coil current to achieve its design criterion, although such a margin could be substantially reduced when plasma shielding effects are taken into account. The consequences for the spatial distribution of the power fluxes at the divertor of ELM control by three-dimensional (3D) fields are evaluated and found to lead to substantial toroidal asymmetries in zones of the divertor target away from the separatrix. Therefore, specifications for the rotation of the 3D perturbation applied for ELM control in order to avoid excessive localized erosion of the ITER divertor target are derived. It is shown that a rotation frequency in excess of 1 Hz for the whole toroidally asymmetric divertor power flux pattern is required (corresponding to n Hz frequency in the variation of currents in the coils, where n is the toroidal symmetry of the perturbation applied) in order to avoid unacceptable thermal cycling of the divertor target for the highest power fluxes and worst toroidal power flux asymmetries expected. The possible use of the in-vessel vertical stability coils for ELM control as a back-up to the main ELM control systems in ITER is described and the feasibility of its application to control ELMs in low plasma current H-modes, foreseen for initial ITER operation, is evaluated and found to be viable for plasma currents up to 5-10 MA depending on modelling assumptions.

Modeling impurity production and transport during ELM transients in a DIII-D lower single null configuration.

NASA Astrophysics Data System (ADS)

Hogan, J.; Fenstermacher, M.; Groth, M.; West, P.; Coster, D.; Thomas, P.

2003-10-01

Better understanding of carbon production and eventual pathways is an important need for ITER. ELM events can provide a significant carbon source, and small scale experiments predict significant dependence of C production rates on incident deuterium flux and surface temperature, quantities which change significantly during an ELM event. Thus, development of better quantitative models has been hampered by lack of sufficient time resolution during ELMs. Recent progress on DIII-D has significantly improved the spectroscopic resolution [1, 2]. Measured CIII evolution during low- and high-density DIII-D LSN ELMy H-modes (type I and type I-III, respectively) has been compared with modeling using the solps5.0/Eirene99 coupled edge code, and the CASTEM- 2000 3-D, time dependent thermal analysis code. The latter provides time-resolved absolute surface temperature distributions for the cases described in [2]. Comparison with observations using the Roth et al annealing model for chemical sputtering finds qualitative agreement. However, the transition in ELM type/frequency as density increases is the most important factor, and this is an input to the calculation given the present state of first principles ELM models. [1] M Fenstermacher et al EPS2003 [2] M Groth et al J Nucl Mater 2003

Experimental validation of coil phase parametrisation on ASDEX Upgrade, and extension to ITER

NASA Astrophysics Data System (ADS)

Ryan, D. A.; Liu, Y. Q.; Kirk, A.; Suttrop, W.; Dudson, B.; Dunne, M.; Willensdorfer, M.; the ASDEX Upgrade team; the EUROfusion MST1 team

2018-06-01

It has been previously demonstrated in Li et al (2016 Nucl. Fusion 56 126007) that the optimum upper/lower coil phase shift ΔΦopt for alignment of RMP coils for ELM mitigation depends sensitively on q 95, and other equilibrium plasma parameters. Therefore, ΔΦopt is expected to vary widely during the current ramp of ITER plasmas, with negative implications for ELM mitigation during this period. A previously derived and numerically benchmarked parametrisation of the coil phase for optimal ELM mitigation on ASDEX Upgrade (Ryan et al 2017 Plasma Phys. Control. Fusion 59 024005) is validated against experimental measurements of ΔΦopt, made by observing the changes to the ELM frequency as the coil phase is scanned. It is shown that the parametrisation may predict the optimal coil phase to within 32° of the experimental measurement for n = 2 applied perturbations. It is explained that this agreement is sufficient to ensure that the ELM mitigation is not compromised by poor coil alignment. It is also found that the phase which maximises ELM mitigation is shifted from the phase which maximizes density pump-out, in contrast to theoretical expectations that ELM mitigation and density pump out have the same ΔΦ ul dependence. A time lag between the ELM frequency response and density response to the RMP is suggested as the cause. The method for numerically deriving the parametrisation is repeated for the ITER coil set, using the baseline scenario as a reference equilibrium, and the parametrisation coefficients given for future use in a feedback coil alignment system. The relative merits of square or sinusoidal toroidal current waveforms for ELM mitigation are briefly discussed.

ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER

DOE PAGES

Baylor, Larry R.; Lang, P. T.; Allen, Steve L.; ...

2014-10-05

The triggering of rapid small edge localized modes (ELMs) by high frequency pellet injection has been proposed as a method to prevent large naturally occurring ELMs that can erode the ITER plasma facing components. Deuterium pellet injection has been used to successfully demonstrate the on-demand triggering of edge localized modes (ELMs) at much higher rates and with much smaller intensity than natural ELMs. The proposed hypothesis for the triggering mechanism of ELMs by pellets is the local pressure perturbation resulting from reheating of the pellet cloud that can exceed the local high-n ballooning mode threshold where the pellet is injected.more » Nonlinear MHD simulations of the pellet ELM triggering show destabilization of high-n ballooning modes by such a local pressure perturbation. A review of the recent pellet ELM triggering results from ASDEX Upgrade (AUG), DIII-D, and JET reveals that a number of uncertainties about this ELM mitigation technique still remain. These include the heat flux impact pattern on the divertor and wall from pellet triggered and natural ELMs, the necessary pellet size and injection location to reliably trigger ELMs, and the level of fueling to be expected from ELM triggering pellets and synergy with larger fueling pellets. The implications of these issues for pellet ELM mitigation in ITER and its impact on the PFCs are presented along with the design features of the pellet injection system for ITER.« less

ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baylor, Larry R.; Lang, P.; Allen, S. L.

2015-08-01

The triggering of rapid small edge localized modes (ELMs) by high frequency pellet injection has been proposed as a method to prevent large naturally occurring ELMs that can erode the ITER plasma facing components (PFCs). Deuterium pellet injection has been used to successfully demonstrate the on-demand triggering of edge localized modes (ELMs) at much higher rates and with much smaller intensity than natural ELMs. The proposed hypothesis for the triggering mechanism of ELMs by pellets is the local pressure perturbation resulting from reheating of the pellet cloud that can exceed the local high-n ballooning mode threshold where the pellet ismore » injected. Nonlinear MHD simulations of the pellet ELM triggering show destabilization of high-n ballooning modes by such a local pressure perturbation.A review of the recent pellet ELM triggering results from ASDEX Upgrade (AUG), DIII-D, and JET reveals that a number of uncertainties about this ELM mitigation technique still remain. These include the heat flux impact pattern on the divertor and wall from pellet triggered and natural ELMs, the necessary pellet size and injection location to reliably trigger ELMs, and the level of fueling to be expected from ELM triggering pellets and synergy with larger fueling pellets. The implications of these issues for pellet ELM mitigation in ITER and its impact on the PFCs are presented along with the design features of the pellet injection system for ITER.« less

Physics of increased edge electron temperature and density turbulence during ELM-free QH-mode operation on DIII-D

NASA Astrophysics Data System (ADS)

Sung, C.; Rhodes, T. L.; Staebler, G. M.; Yan, Z.; McKee, G. R.; Smith, S. P.; Osborne, T. H.; Peebles, W. A.

2018-05-01

For the first time, we report increased edge electron temperature and density turbulence levels ( T˜ e and n˜ e) in Edge Localized Mode free Quiescent H-mode (ELM-free QH-mode) plasmas as compared to the ELMing time period. ELMs can severely damage plasma facing components in fusion plasma devices due to their large transient energy transport, making ELM-free operation a highly sought after goal. The QH-mode is a candidate for this goal as it is ELM-free for times limited only by hardware constraints. It is found that the driving gradients decrease during the QH-mode compared to the ELMing phase, however, a significant decrease in the ExB shearing rate is also observed that taken together is consistent with the increased turbulence. These results are significant as the prediction and control of ELM-free H-mode regimes are crucial for the operation of future fusion devices such as ITER. The changes in the linear growth rates calculated by CGYRO [Candy et al., J. Comput. Phys. 324, 73 (2016)] and the measured ExB shearing rate between ELMing and QH-mode phases are qualitatively consistent with these turbulence changes. Comparison with ELMing and 3D fields ELM suppressed H-mode finds a similar increase in T˜ e and n˜ e, however, with distinctly different origins, the increased driving gradients rather than the changes in the ExB shearing rate in 3D fields ELM suppressed the H-mode. However, linear gyrokinetic calculation results are generally consistent with the increased turbulence in both ELM-controlled discharges.

Validation of the model for ELM suppression with 3D magnetic fields using low torque ITER baseline scenario discharges in DIII-D

NASA Astrophysics Data System (ADS)

Moyer, R. A.; Paz-Soldan, C.; Nazikian, R.; Orlov, D. M.; Ferraro, N. M.; Grierson, B. A.; Knölker, M.; Lyons, B. C.; McKee, G. R.; Osborne, T. H.; Rhodes, T. L.; Meneghini, O.; Smith, S.; Evans, T. E.; Fenstermacher, M. E.; Groebner, R. J.; Hanson, J. M.; La Haye, R. J.; Luce, T. C.; Mordijck, S.; Solomon, W. M.; Turco, F.; Yan, Z.; Zeng, L.; DIII-D Team

2017-10-01

Experiments have been executed in the DIII-D tokamak to extend suppression of Edge Localized Modes (ELMs) with Resonant Magnetic Perturbations (RMPs) to ITER-relevant levels of beam torque. The results support the hypothesis for RMP ELM suppression based on transition from an ideal screened response to a tearing response at a resonant surface that prevents expansion of the pedestal to an unstable width [Snyder et al., Nucl. Fusion 51, 103016 (2011) and Wade et al., Nucl. Fusion 55, 023002 (2015)]. In ITER baseline plasmas with I/aB = 1.4 and pedestal ν * ˜ 0.15, ELMs are readily suppressed with co- I p neutral beam injection. However, reducing the beam torque from 5 Nm to ≤ 3.5 Nm results in loss of ELM suppression and a shift in the zero-crossing of the electron perpendicular rotation ω ⊥ e ˜ 0 deeper into the plasma. The change in radius of ω ⊥ e ˜ 0 is due primarily to changes to the electron diamagnetic rotation frequency ωe * . Linear plasma response modeling with the resistive MHD code m3d-c1 indicates that the tearing response location tracks the inward shift in ω ⊥ e ˜ 0. At pedestal ν * ˜ 1, ELM suppression is also lost when the beam torque is reduced, but the ω ⊥ e change is dominated by collapse of the toroidal rotation v T . The hypothesis predicts that it should be possible to obtain ELM suppression at reduced beam torque by also reducing the height and width of the ωe * profile. This prediction has been confirmed experimentally with RMP ELM suppression at 0 Nm of beam torque and plasma normalized pressure β N ˜ 0.7. This opens the possibility of accessing ELM suppression in low torque ITER baseline plasmas by establishing suppression at low beta and then increasing beta while relying on the strong RMP-island coupling to maintain suppression.

ELM Dynamics in TCV H-modes

NASA Astrophysics Data System (ADS)

Degeling, A. W.; Martin, Y. R.; Lister, J. B.; Llobet, X.; Bak, P. E.

2003-06-01

TCV (Tokamak à Configuration Variable, R = 0.88 m, a < 0.25 m, BT < 1.54 T) is a highly elongated tokamak, capable of producing limited and diverted plasmas, with the primary aim of investigating the effects of plasma shape and current profile on tokamak physics and performance. L-mode to H-mode transitions are regularly obtained in TCV over a wide range of configurations. Under most conditions, the H-mode is ELM-free and terminates in a high density disruption. The conditions required for a transition to an ELMy H-mode were investigated in detail, and a reliable gateway in parameter space for the transition was identified. Once established, the ELMy H-mode is robust to changes in plasma current, elongation, divertor geometry and plasma density over ranges that are much wider than the size of the gateway in these parameters. There exists marked irregularity in the time interval between consecutive ELMs. Transient signatures in the time-series revealing the existence of an underlying chaotic dynamical system are repeatedly observed in a sizable group of discharges [1]. The properties of these signatures (called unstable periodic orbits, or UPOs) are found to vary systematically with parameters such as the plasma current, density and inner plasma — wall gap. A link has also been established between the dynamics of ELMs and sawteeth in TCV: under certain conditions a clear preference is observed in the phase between ELMs and sawtooth crashes, and the ratio of the ELM frequency (felm) to sawtooth frequency (fst) is found to prefer simple rational values (e.g. 1/1, 2/1 or 1/2). An attempt to control the ELM dynamics was made by applying a perturbation signal to the radial field coils used for vertical stabilisation. Phase synchronisation was found with the external perturbation, and felm was found to track limited scans in the driver frequency about the unperturbed value, albeit with intermittent losses in phase lock.

Measurements and modeling of intra-ELM tungsten sourcing and transport in DIII-D

NASA Astrophysics Data System (ADS)

Abrams, T.; Leonard, A. W.; Thomas, D. M.; McLean, A. G.; Makowski, M. A.; Wang, H. Q.; Unterberg, E. A.; Briesemeister, A. R.; Rudakov, D. L.; Bykov, I.; Donovan, D.

2017-10-01

Intra-ELM tungsten erosion profiles in the DIII-D divertor, acquired via W I spectroscopy with high temporal and spatial resolution, are consistent with SDTrim.SP sputtering modeling using measured ion saturation currents and impact energies during ELMs as input and an ad-hoc 2% C2+ impurity flux. The W sputtering profile peaks close to the OSP both during and between ELMs in the favorable BT direction. In reverse BT the W source peaks close to the OSP between ELMs but strongly broadens and shifts outboard during ELMs, heuristically consistent with radially outward ion transport via ExB drifts. Ion impact energies during ELMs (inferred taking the ratio of divertor heat flux to the ion saturation current) are found to be approximately equal to Te,ped, lower than the 4*Te,ped value predicted by the Fundamenski/Moulton free streaming model. These impact energies imply both D main ions and C impurities contribute strongly to W sputtering during ELMs on DIII-D. This work represents progress towards a predictive model to link upstream conditions (i.e., pedestal height) and SOL impurity levels to the ELM-induced W impurity source at both the strike-point and far-target regions in the ITER divertor. Correlations between ELM size/frequency and SOL W fluxes measured via a midplane deposition probe will also be presented. Work supported by US DOE under DE-FC02-04ER54698.

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

NASA Astrophysics Data System (ADS)

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.

ELM Mitigation in Low-rotation ITER Baseline Scenario Plasmas on DIII-D with Deuterium Pellet Injection

NASA Astrophysics Data System (ADS)

Baylor, L. R.

2016-10-01

ELM mitigation using high frequency D2 pellet ELM pacing has been demonstrated in ITER baseline scenario plasmas on DIII D with low rotation obtained with low NBI input torque. The ITER burning plasmas will have relatively low input torque and are expected to have low rotation. ELM mitigation by on-demand pellet ELM triggering has not been observed before in these conditions. New experiments on DIII-D in these conditions with 90 Hz D2 pellets have shown that significant mitigation of the divertor ELM peak heat flux by a factor of 8 is possible without detrimental effects to the plasma confinement. High-Z impurity accumulation is dramatically reduced at all input torques from 0.1 to 2.5 N-m. Fueling with high field side injection of D2 pellets has been employed to demonstrate that density buildup can be obtained simultaneously with ELM mitigation. The implications are that rapid pellet injection remains a promising technique to trigger on-demand ELMs in low rotating plasmas with greatly reduced peak flux while preventing impurity accumulation in ITER. Supported by the US DOE under DE-AC05-00OR22725, DE-FC02-04ER54698.

ELM mitigation studies in JET and implications for ITER

NASA Astrophysics Data System (ADS)

de La Luna, Elena

2009-11-01

Type I edge localized modes (ELMs) remain a serious concern for ITER because of the high transient heat and particle flux that can lead to rapid erosion of the divertor plates. This has stimulated worldwide research on exploration of different methods to avoid or at least mitigate the ELM energy loss while maintaining adequate confinement. ITER will require reliable ELM control over a wide range of operating conditions, including changes in the edge safety factor, therefore a suite of different techniques is highly desirable. In JET several techniques have been demonstrated for control the frequency and size of type I ELMs, including resonant perturbations of the edge magnetic field (RMP), ELM magnetic triggering by fast vertical movement of the plasma column (``vertical kicks'') and ELM pacing using pellet injection. In this paper we present results from recent dedicated experiments in JET focusing on integrating the different ELM mitigation methods into similar plasma scenarios. Plasma parameter scans provide comparison of the performance of the different techniques in terms of both the reduction in ELM size and on the impact of each control method on plasma confinement. The compatibility of different ELM mitigation schemes has also been investigated. The plasma response to RMP and vertical kicks during the ELM mitigation phase shares common features: the reduction in ELM size (up to a factor of 3) is accompanied by a reduction in pedestal pressure (mainly due to a loss of density) with only minor (< 10%) reduction of the stored energy. Interestingly, it has been found that the combined application of RMP and kicks leads to a reduction of the threshold perturbation level (vertical displacement in the case of the kicks) necessary for the ELM mitigation to occur. The implication of these results for ITER will be discussed.

Control of edge localized modes by pedestal deposited impurity in the HL-2A tokamak

NASA Astrophysics Data System (ADS)

Zhang, Y. P.; Mazon, D.; Zou, X. L.; Zhong, W. L.; Gao, J. M.; Zhang, K.; Sun, P.; Dong, C. F.; Cui, Z. Y.; Liu, Yi; Shi, Z. B.; Yu, D. L.; Cheng, J.; Jiang, M.; Xu, J. Q.; Isobe, M.; Xiao, G. L.; Chen, W.; Song, S. D.; Bai, X. Y.; Zhang, P. F.; Yuan, G. L.; Ji, X. Q.; Li, Y. G.; Zhou, Y.; Delpech, L.; Ekedahl, A.; Giruzzi, G.; Hoang, T.; Peysson, Y.; Song, X. M.; Song, X. Y.; Li, X.; Ding, X. T.; Dong, J. Q.; Yang, Q. W.; Xu, M.; Duan, X. R.; Liu, Y.; the HL-2A Team

2018-04-01

Effect of the pedestal deposited impurity on the edge-localized mode (ELM) behaviour has been observed and intensively investigated in the HL-2A tokamak. Impurities have been externally seeded by a newly developed laser blow-off (LBO) system. Both mitigation and suppression of ELMs have been realized by LBO-seeded impurity. Measurements have shown that the LBO-seeded impurity particles are mainly deposited in the pedestal region. During the ELM mitigation phase, the pedestal density fluctuation is significantly increased, indicating that the ELM mitigation may be achieved by the enhancement of the pedestal transport. The transition from ELM mitigation to ELM suppression was triggered when the number of the LBO-seeded impurity exceeds a threshold value. During the ELM suppression phase, a harmonic coherent mode (HCM) is excited by the LBO-seeded impurity, and the pedestal density fluctuation is significantly decreased, the electron density is continuously increased, implying that HCM may reduce the pedestal turbulence, suppress ELMs, increase the pedestal pressure, thus extending the Peeling-Ballooning instability limit. It has been found that the occurance of the ELM mitigation and ELM suppression closely depends on the LBO laser spot diameter.

Broadening of the divertor heat flux footprint with increasing number of ELM filaments in NSTX

NASA Astrophysics Data System (ADS)

Ahn, Joon-Wook

2014-10-01

We report on the broadening (narrowing) of the ELM heat flux footprint with increasing (decreasing) number of filamentary striations from in-depth thermography measurements in NSTX. Edge localized modes (ELMs) represent a challenge to future fusion devices, due to the high heat fluxes on plasma facing surfaces. One ameliorating factor has been that the divertor heat flux characteristic profile width (λq) has been observed to broaden with the size of ELM, as compared with the inter-ELM λq, which keeps the peak heat flux (qpeak) from increasing. In contrast, λq has been observed to narrow during ELMs under certain conditions in NSTX, for both naturally occurring and 3-D fields triggered ELMs. Fast thermographic measurements and detailed analysis demonstrate that the ELM λq increases with the number of observed filamentary striations, i . e . , profile narrowing (broadening) occurs when the number of striations is smaller (larger) than 3-4. With profile narrowing, qpeak at ELM peak times is inversely related (proportional) to λq (the ELM size), exacerbating the heat flux problem. Edge stability analysis shows that NSTX ELMs almost always lie on the current-driven kink/peeling mode side with low toroidal mode number (n = 1--5), consistent with the typical numbers of striations in NSTX (0-8) in comparison 10--15 striations are normally observed in intermediate-n peeling-ballooning ELMs, e.g., from JET. The NSTX characteristics may translate directly to ITER, which is also projected to lie on the low-n kink/peeling stability boundary. This work was supported by the U.S. DOE, Contract DE-AC05-00OR22725 (ORNL) and DE-AC02-09CH11466 (PPPL).

Physics of thermal transport and increased electron temperature turbulence in the edge pedestal of ELM-free, H-mode regimes on DIII-D

NASA Astrophysics Data System (ADS)

Sung, Choongki

2017-10-01

It has been observed, for the first time, that suppression of Edge Localized Modes (ELMs) in tokamak plasmas is accompanied by an increase in electron temperature turbulence. A correlation electron cyclotron emission technique has been utilized to quantify the observed increase: 40% increase in Quiescent H-mode (QH-mode) and 70% increase in 3D field ELM suppressed H-mode. Since reliable ELM-free H-mode operation is essential for future burning plasma experiments, it is crucial to develop a validated predictive capability for these plasmas. Linear stability analysis using TGLF has provided an explanation for the observations and has indicated that the underlying physical mechanisms are different in the two regimes. In QH-mode, profile gradients and the associated linear growth rate are decreased compared to ELMing H-mode. However, the ExB shearing rate is reduced by an even greater factor such that turbulent transport is no longer suppressed by flow shear. In contrast, during 3D field ELM suppressed H-mode, gradients are increased and TGLF predicts that a large increase in linear growth rate is primarily responsible for the increased turbulence. Power balance analysis using ONETWO is also consistent with the changes in electron thermal transport being due to the increased turbulence. These new findings are significant since they i) provide a physics explanation of these changes via TGLF analysis and enable validation of the model in the key pedestal region, and ii) support the hypothesis that turbulent transport partially replaces ELM-dominated transport during ELM-free operation. These results form a basis to develop a predictive understanding of pedestal regulation in ELM suppressed regimes. Supported by the US DOE under DE-FG02-08ER54984, DE-FC02-04ER54698.

A Fast SVD-Hidden-nodes based Extreme Learning Machine for Large-Scale Data Analytics.

PubMed

Deng, Wan-Yu; Bai, Zuo; Huang, Guang-Bin; Zheng, Qing-Hua

2016-05-01

Big dimensional data is a growing trend that is emerging in many real world contexts, extending from web mining, gene expression analysis, protein-protein interaction to high-frequency financial data. Nowadays, there is a growing consensus that the increasing dimensionality poses impeding effects on the performances of classifiers, which is termed as the "peaking phenomenon" in the field of machine intelligence. To address the issue, dimensionality reduction is commonly employed as a preprocessing step on the Big dimensional data before building the classifiers. In this paper, we propose an Extreme Learning Machine (ELM) approach for large-scale data analytic. In contrast to existing approaches, we embed hidden nodes that are designed using singular value decomposition (SVD) into the classical ELM. These SVD nodes in the hidden layer are shown to capture the underlying characteristics of the Big dimensional data well, exhibiting excellent generalization performances. The drawback of using SVD on the entire dataset, however, is the high computational complexity involved. To address this, a fast divide and conquer approximation scheme is introduced to maintain computational tractability on high volume data. The resultant algorithm proposed is labeled here as Fast Singular Value Decomposition-Hidden-nodes based Extreme Learning Machine or FSVD-H-ELM in short. In FSVD-H-ELM, instead of identifying the SVD hidden nodes directly from the entire dataset, SVD hidden nodes are derived from multiple random subsets of data sampled from the original dataset. Comprehensive experiments and comparisons are conducted to assess the FSVD-H-ELM against other state-of-the-art algorithms. The results obtained demonstrated the superior generalization performance and efficiency of the FSVD-H-ELM. Copyright © 2016 Elsevier Ltd. All rights reserved.

New steady-state quiescent high-confinement plasma in an experimental advanced superconducting tokamak.

PubMed

Hu, J S; Sun, Z; Guo, H Y; Li, J G; Wan, B N; Wang, H Q; Ding, S Y; Xu, G S; Liang, Y F; Mansfield, D K; Maingi, R; Zou, X L; Wang, L; Ren, J; Zuo, G Z; Zhang, L; Duan, Y M; Shi, T H; Hu, L Q

2015-02-06

A critical challenge facing the basic long-pulse high-confinement operation scenario (H mode) for ITER is to control a magnetohydrodynamic (MHD) instability, known as the edge localized mode (ELM), which leads to cyclical high peak heat and particle fluxes at the plasma facing components. A breakthrough is made in the Experimental Advanced Superconducting Tokamak in achieving a new steady-state H mode without the presence of ELMs for a duration exceeding hundreds of energy confinement times, by using a novel technique of continuous real-time injection of a lithium (Li) aerosol into the edge plasma. The steady-state ELM-free H mode is accompanied by a strong edge coherent MHD mode (ECM) at a frequency of 35-40 kHz with a poloidal wavelength of 10.2 cm in the ion diamagnetic drift direction, providing continuous heat and particle exhaust, thus preventing the transient heat deposition on plasma facing components and impurity accumulation in the confined plasma. It is truly remarkable that Li injection appears to promote the growth of the ECM, owing to the increase in Li concentration and hence collisionality at the edge, as predicted by GYRO simulations. This new steady-state ELM-free H-mode regime, enabled by real-time Li injection, may open a new avenue for next-step fusion development.

Advanced divertor configurations with large flux expansion

NASA Astrophysics Data System (ADS)

Soukhanovskii, V. A.; Bell, R. E.; Diallo, A.; Gerhardt, S.; Kaye, S.; Kolemen, E.; LeBlanc, B. P.; McLean, A.; Menard, J. E.; Paul, S. F.; Podesta, M.; Raman, R.; Ryutov, D. D.; Scotti, F.; Kaita, R.; Maingi, R.; Mueller, D. M.; Roquemore, A. L.; Reimerdes, H.; Canal, G. P.; Labit, B.; Vijvers, W.; Coda, S.; Duval, B. P.; Morgan, T.; Zielinski, J.; De Temmerman, G.; Tal, B.

2013-07-01

Experimental studies of the novel snowflake divertor concept (D. Ryutov, Phys. Plasmas 14 (2007) 064502) performed in the NSTX and TCV tokamaks are reviewed in this paper. The snowflake divertor enables power sharing between divertor strike points, as well as the divertor plasma-wetted area, effective connection length and divertor volumetric power loss to increase beyond those in the standard divertor, potentially reducing heat flux and plasma temperature at the target. It also enables higher magnetic shear inside the separatrix, potentially affecting pedestal MHD stability. Experimental results from NSTX and TCV confirm the predicted properties of the snowflake divertor. In the NSTX, a large spherical tokamak with a compact divertor and lithium-coated graphite plasma-facing components (PFCs), the snowflake divertor operation led to reduced core and pedestal impurity concentration, as well as re-appearance of Type I ELMs that were suppressed in standard divertor H-mode discharges. In the divertor, an otherwise inaccessible partial detachment of the outer strike point with an up to 50% increase in divertor radiation and a peak divertor heat flux reduction from 3-7 MW/m2 to 0.5-1 MW/m2 was achieved. Impulsive heat fluxes due to Type-I ELMs were significantly dissipated in the high magnetic flux expansion region. In the TCV, a medium-size tokamak with graphite PFCs, several advantageous snowflake divertor features (cf. the standard divertor) have been demonstrated: an unchanged L-H power threshold, enhanced stability of the peeling-ballooning modes in the pedestal region (and generally an extended second stability region), as well as an H-mode pedestal regime with reduced (×2-3) Type I ELM frequency and slightly increased (20-30%) normalized ELM energy, resulting in a favorable average energy loss comparison to the standard divertor. In the divertor, ELM power partitioning between snowflake divertor strike points was demonstrated. The NSTX and TCV experiments are providing support for the snowflake divertor as a viable solution for the outstanding tokamak plasma-material interface issues.

Understanding tungsten divertor sourcing and SOL transport using multiple poloidally-localized sources in DIII-D ELM-y H-mode discharges

NASA Astrophysics Data System (ADS)

Unterberg, Ea; Donovan, D.; Barton, J.; Wampler, Wr; Abrams, T.; Thomas, Dm; Petrie, T.; Guo, Hy; Stangeby, Pg; Elder, Jd; Rudakov, D.; Grierson, B.; Victor, B.

2017-10-01

Experiments using metal inserts with novel isotopically-enriched tungsten coatings at the outer divertor strike point (OSP) have provided unique insight into the ELM-induced sourcing, main-SOL transport, and core accumulation control mechanisms of W for a range of operating conditions. This experimental approach has used a multi-head, dual-facing collector probe (CP) at the outboard midplane, as well as W-I and core W spectroscopy. Using the CP system, the total amount of W deposited relative to source measurements shows a clear dependence on ELM size, ELM frequency, and strike point location, with large ELMs depositing significantly more W on the CP from the far-SOL source. Additionally, high spatial ( 1mm) and ELM resolved spectroscopic measurements of W sourcing indicate shifts in the peak erosion rate. Furthermore, high performance discharges with rapid ELMs show core W concentrations of few 10-5, and the CP deposition profile indicates W is predominantly transported to the midplane from the OSP rather than from the far-SOL region. The low central W concentration is shown to be due to flattening of the main plasma density profile, presumably by on-axis electron cyclotron heating. Work supported under USDOE Cooperative Agreement DE-FC02-04ER54698.

INCREASED SERUM LEVELS OF UREA AND CREATININE ARE SURROGATE MARKERS FOR DISRUPTION OF RETINAL PHOTORECEPTOR EXTERNAL LIMITING MEMBRANE AND INNER SEGMENT ELLIPSOID ZONE IN TYPE 2 DIABETES MELLITUS.

PubMed

Saxena, Sandeep; Ruia, Surabhi; Prasad, Senthamizh; Jain, Astha; Mishra, Nibha; Natu, Shankar M; Meyer, Carsten H; Gilhotra, Jagjit S; Kruzliak, Peter; Akduman, Levent

2017-02-01

To evaluate the role of serum urea and creatinine as surrogate markers for disruption of retinal photoreceptor external limiting membrane (ELM) and inner segment ellipsoid zone (EZ) in Type 2 diabetic retinopathy (DR) using spectral-domain optical coherence tomography, for the first time. One hundred and seventeen consecutive cases of Type 2 diabetes mellitus (diabetes without retinopathy [No DR; n = 39], nonproliferative diabetic retinopathy [NPDR; n = 39], proliferative diabetic retinopathy [PDR; n = 39]) and 40 healthy control subjects were included. Serum levels of urea and creatinine were assessed using standard protocol. Spectral-domain optical coherence tomography was used to grade the disruption of ELM and EZ as follows: Grade 0, no disruption of ELM and EZ; Grade 1, ELM disrupted, EZ intact; Grade 2, ELM and EZ disrupted. Data were analyzed statistically. Increase in serum levels of urea (F = 22.93) and creatinine (F = 15.82) and increased grades of disruption of ELM and EZ (γ = 116.3) were observed with increased severity of DR (P < 0.001). Increase in serum levels of urea (F = 10.45) and creatinine (F = 6.89) was observed with increased grades of disruption of ELM and EZ (P = 0.001). Serum levels of urea and creatinine are surrogate markers for disruption of retinal photoreceptor ELM and EZ on spectral-domain optical coherence tomography in DR.

Adaptive Online Sequential ELM for Concept Drift Tackling

PubMed Central

Basaruddin, Chan

2016-01-01

A machine learning method needs to adapt to over time changes in the environment. Such changes are known as concept drift. In this paper, we propose concept drift tackling method as an enhancement of Online Sequential Extreme Learning Machine (OS-ELM) and Constructive Enhancement OS-ELM (CEOS-ELM) by adding adaptive capability for classification and regression problem. The scheme is named as adaptive OS-ELM (AOS-ELM). It is a single classifier scheme that works well to handle real drift, virtual drift, and hybrid drift. The AOS-ELM also works well for sudden drift and recurrent context change type. The scheme is a simple unified method implemented in simple lines of code. We evaluated AOS-ELM on regression and classification problem by using concept drift public data set (SEA and STAGGER) and other public data sets such as MNIST, USPS, and IDS. Experiments show that our method gives higher kappa value compared to the multiclassifier ELM ensemble. Even though AOS-ELM in practice does not need hidden nodes increase, we address some issues related to the increasing of the hidden nodes such as error condition and rank values. We propose taking the rank of the pseudoinverse matrix as an indicator parameter to detect “underfitting” condition. PMID:27594879

Applying Cost-Sensitive Extreme Learning Machine and Dissimilarity Integration to Gene Expression Data Classification.

PubMed

Liu, Yanqiu; Lu, Huijuan; Yan, Ke; Xia, Haixia; An, Chunlin

2016-01-01

Embedding cost-sensitive factors into the classifiers increases the classification stability and reduces the classification costs for classifying high-scale, redundant, and imbalanced datasets, such as the gene expression data. In this study, we extend our previous work, that is, Dissimilar ELM (D-ELM), by introducing misclassification costs into the classifier. We name the proposed algorithm as the cost-sensitive D-ELM (CS-D-ELM). Furthermore, we embed rejection cost into the CS-D-ELM to increase the classification stability of the proposed algorithm. Experimental results show that the rejection cost embedded CS-D-ELM algorithm effectively reduces the average and overall cost of the classification process, while the classification accuracy still remains competitive. The proposed method can be extended to classification problems of other redundant and imbalanced data.

Spoken language identification based on the enhanced self-adjusting extreme learning machine approach.

PubMed

Albadr, Musatafa Abbas Abbood; Tiun, Sabrina; Al-Dhief, Fahad Taha; Sammour, Mahmoud A M

2018-01-01

Spoken Language Identification (LID) is the process of determining and classifying natural language from a given content and dataset. Typically, data must be processed to extract useful features to perform LID. The extracting features for LID, based on literature, is a mature process where the standard features for LID have already been developed using Mel-Frequency Cepstral Coefficients (MFCC), Shifted Delta Cepstral (SDC), the Gaussian Mixture Model (GMM) and ending with the i-vector based framework. However, the process of learning based on extract features remains to be improved (i.e. optimised) to capture all embedded knowledge on the extracted features. The Extreme Learning Machine (ELM) is an effective learning model used to perform classification and regression analysis and is extremely useful to train a single hidden layer neural network. Nevertheless, the learning process of this model is not entirely effective (i.e. optimised) due to the random selection of weights within the input hidden layer. In this study, the ELM is selected as a learning model for LID based on standard feature extraction. One of the optimisation approaches of ELM, the Self-Adjusting Extreme Learning Machine (SA-ELM) is selected as the benchmark and improved by altering the selection phase of the optimisation process. The selection process is performed incorporating both the Split-Ratio and K-Tournament methods, the improved SA-ELM is named Enhanced Self-Adjusting Extreme Learning Machine (ESA-ELM). The results are generated based on LID with the datasets created from eight different languages. The results of the study showed excellent superiority relating to the performance of the Enhanced Self-Adjusting Extreme Learning Machine LID (ESA-ELM LID) compared with the SA-ELM LID, with ESA-ELM LID achieving an accuracy of 96.25%, as compared to the accuracy of SA-ELM LID of only 95.00%.

Spoken language identification based on the enhanced self-adjusting extreme learning machine approach

PubMed Central

Tiun, Sabrina; AL-Dhief, Fahad Taha; Sammour, Mahmoud A. M.

2018-01-01

Spoken Language Identification (LID) is the process of determining and classifying natural language from a given content and dataset. Typically, data must be processed to extract useful features to perform LID. The extracting features for LID, based on literature, is a mature process where the standard features for LID have already been developed using Mel-Frequency Cepstral Coefficients (MFCC), Shifted Delta Cepstral (SDC), the Gaussian Mixture Model (GMM) and ending with the i-vector based framework. However, the process of learning based on extract features remains to be improved (i.e. optimised) to capture all embedded knowledge on the extracted features. The Extreme Learning Machine (ELM) is an effective learning model used to perform classification and regression analysis and is extremely useful to train a single hidden layer neural network. Nevertheless, the learning process of this model is not entirely effective (i.e. optimised) due to the random selection of weights within the input hidden layer. In this study, the ELM is selected as a learning model for LID based on standard feature extraction. One of the optimisation approaches of ELM, the Self-Adjusting Extreme Learning Machine (SA-ELM) is selected as the benchmark and improved by altering the selection phase of the optimisation process. The selection process is performed incorporating both the Split-Ratio and K-Tournament methods, the improved SA-ELM is named Enhanced Self-Adjusting Extreme Learning Machine (ESA-ELM). The results are generated based on LID with the datasets created from eight different languages. The results of the study showed excellent superiority relating to the performance of the Enhanced Self-Adjusting Extreme Learning Machine LID (ESA-ELM LID) compared with the SA-ELM LID, with ESA-ELM LID achieving an accuracy of 96.25%, as compared to the accuracy of SA-ELM LID of only 95.00%. PMID:29672546

Impact of Te and ne on edge current density profiles in ELM mitigated regimes on ASDEX Upgrade

NASA Astrophysics Data System (ADS)

Dunne, M. G.; Rathgeber, S.; Burckhart, A.; Fischer, R.; Giannone, L.; McCarthy, P. J.; Schneider, P. A.; Wolfrum, E.; the ASDEX Upgrade Team

2015-01-01

ELM resolved edge current density profiles are reconstructed using the CLISTE equilibrium code. As input, highly spatially and temporally resolved edge electron temperature and density profiles are used in addition to data from the extensive set of external poloidal field measurements available at ASDEX Upgrade, flux loop difference measurements, and current measurements in the scrape-off layer. Both the local and flux surface averaged current density profiles are analysed for several ELM mitigation regimes. The focus throughout is on the impact of altered temperature and density profiles on the current density. In particular, many ELM mitigation regimes rely on operation at high density. Two reference plasmas with type-I ELMs are analysed, one with a deuterium gas puff and one without, in order to provide a reference for the behaviour in type-II ELMy regimes and high density ELM mitigation with external magnetic perturbations at ASDEX Upgrade. For type-II ELMs it is found that while a similar pedestal top pressure is sustained at the higher density, the temperature gradient decreases in the pedestal. This results in lower local and flux surface averaged current densities in these phases, which reduces the drive for the peeling mode. No significant differences between the current density measured in the type-I phase and ELM mitigated phase is seen when external perturbations are applied, though the pedestal top density was increased. Finally, ELMs during the nitrogen seeded phase of a high performance discharge are analysed and compared to ELMs in the reference phase. An increased pedestal pressure gradient, which is the source of confinement improvement in impurity seeded discharges, causes a local current density increase. However, the increased Zeff in the pedestal acts to reduce the flux surface averaged current density. This dichotomy, which is not observed in other mitigation regimes, could act to stabilize both the ballooning mode and the peeling mode at the same time.

Adaptive control of nonlinear system using online error minimum neural networks.

PubMed

Jia, Chao; Li, Xiaoli; Wang, Kang; Ding, Dawei

2016-11-01

In this paper, a new learning algorithm named OEM-ELM (Online Error Minimized-ELM) is proposed based on ELM (Extreme Learning Machine) neural network algorithm and the spreading of its main structure. The core idea of this OEM-ELM algorithm is: online learning, evaluation of network performance, and increasing of the number of hidden nodes. It combines the advantages of OS-ELM and EM-ELM, which can improve the capability of identification and avoid the redundancy of networks. The adaptive control based on the proposed algorithm OEM-ELM is set up which has stronger adaptive capability to the change of environment. The adaptive control of chemical process Continuous Stirred Tank Reactor (CSTR) is also given for application. The simulation results show that the proposed algorithm with respect to the traditional ELM algorithm can avoid network redundancy and improve the control performance greatly. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Parameter dependence of ELM loss reduction by magnetic perturbations at low pedestal density and collisionality in ASDEX upgrade

NASA Astrophysics Data System (ADS)

Leuthold, N.; Suttrop, W.; Fischer, R.; Kappatou, A.; Kirk, A.; McDermott, R.; Mlynek, A.; Valovič, M.; Willensdorfer, M.; the ASDEX Upgrade Team; the EUROfusion MST1 Team

2017-05-01

ELM mitigation by magnetic perturbations is studied at low pedestal collisionalities down to ITER-like values ({ν }{e,{PED}}* =0.1) in ASDEX Upgrade. A comprehensive database of ELM energy losses for varying plasma density, heating power, edge safety factor and magnetic perturbation structure has been assembled to investigate parameter dependencies of ELM mitigation. It is found that magnetic perturbations with a toroidal mode number n = 2 can reduce the ELM energy loss normalized to the energy stored in the plasma pedestal from about 30% to less than 5%, i.e. by a factor of six, below an electron pedestal collisionality of {ν }{e,{PED}}* =0.4. At this level of ELM mitigation a significant reduction of the pedestal pressure and, therefore, global plasma confinement occurs. This pedestal pressure reduction is mostly due to a reduction of plasma density, the so-called ‘pump-out’ effect. Refueling by neutral beams and in particular by pellet injection is possible and can re-establish confinement, however, the ELM energy loss increases as well with increasing density.

Balance of the stored energies sustained by the internal and edge transport barriers and effects of ELMs and L-H transitions in JT-60U

NASA Astrophysics Data System (ADS)

Kamada, Y.; Yoshida, M.; Sakamoto, Y.; Koide, Y.; Oyama, N.; Urano, H.; Kamiya, K.; Suzuki, T.; Isayama, A.; JT-60 Team

2009-09-01

To understand key physics processes determining radial profiles of the kinetic plasma parameters in the advanced tokamak operation scenarios, correlations between the edge transport barrier (ETB) and the internal transport barrier (ITB) have been studied in the JT-60U tokamak device. It has been found that the edge pedestal poloidal beta, βp-ped, increases almost linearly with the total poloidal beta, βp-tot, over a wide range of the plasma current for type I ELMing H-mode plasmas, and this dependence becomes stronger with increasing triangularity. This dependence is not due to the profile stiffness, since the dependence is the same regardless of the existence of ITB. As the stored energy inside the ITB-foot radius (WITB) increases, the total thermal stored energy (Wth) increases and then the pedestal stored energy (Wped) increases. On the other hand, as Wped increases, the ELM penetration expands more inwards and finally reaches the ITB-foot radius. At this situation, the ITB-foot radius cannot move outwards because of the erosion by ELMs. Then the fractions of WITB/Wth and Wped/Wth become almost constant. It has also been found that the type I ELM expels/decreases the edge toroidal momentum larger than the edge ion thermal energy. The ELM penetration for the toroidal rotation tends to be deeper than that for the ion temperature and can exceed the ITB-foot radius. The ELM penetration is deeper for CO-rotating plasmas than CTR rotating plasmas. In both cases, the ELM penetration is deeper in the order of the toroidal rotation (Vt), the ion temperature (Ti) and then the electron temperature (Te). The L-H transition also changes the Vt profile more significantly than the Ti profile. At the L-H transition, the pedestal Vt shifts into the CTR-direction deeply and suddenly without a change in Ti, and then the pedestal Vt grows further together with a growth of the pedestal Ti in a slower timescale. Such changes in Vt by ELMs and L-H transitions may affect degradation/evolution of ITBs.

Improving Classification Performance through an Advanced Ensemble Based Heterogeneous Extreme Learning Machines.

PubMed

Abuassba, Adnan O M; Zhang, Dezheng; Luo, Xiong; Shaheryar, Ahmad; Ali, Hazrat

2017-01-01

Extreme Learning Machine (ELM) is a fast-learning algorithm for a single-hidden layer feedforward neural network (SLFN). It often has good generalization performance. However, there are chances that it might overfit the training data due to having more hidden nodes than needed. To address the generalization performance, we use a heterogeneous ensemble approach. We propose an Advanced ELM Ensemble (AELME) for classification, which includes Regularized-ELM, L 2 -norm-optimized ELM (ELML2), and Kernel-ELM. The ensemble is constructed by training a randomly chosen ELM classifier on a subset of training data selected through random resampling. The proposed AELM-Ensemble is evolved by employing an objective function of increasing diversity and accuracy among the final ensemble. Finally, the class label of unseen data is predicted using majority vote approach. Splitting the training data into subsets and incorporation of heterogeneous ELM classifiers result in higher prediction accuracy, better generalization, and a lower number of base classifiers, as compared to other models (Adaboost, Bagging, Dynamic ELM ensemble, data splitting ELM ensemble, and ELM ensemble). The validity of AELME is confirmed through classification on several real-world benchmark datasets.

Improving Classification Performance through an Advanced Ensemble Based Heterogeneous Extreme Learning Machines

PubMed Central

Abuassba, Adnan O. M.; Ali, Hazrat

2017-01-01

Extreme Learning Machine (ELM) is a fast-learning algorithm for a single-hidden layer feedforward neural network (SLFN). It often has good generalization performance. However, there are chances that it might overfit the training data due to having more hidden nodes than needed. To address the generalization performance, we use a heterogeneous ensemble approach. We propose an Advanced ELM Ensemble (AELME) for classification, which includes Regularized-ELM, L2-norm-optimized ELM (ELML2), and Kernel-ELM. The ensemble is constructed by training a randomly chosen ELM classifier on a subset of training data selected through random resampling. The proposed AELM-Ensemble is evolved by employing an objective function of increasing diversity and accuracy among the final ensemble. Finally, the class label of unseen data is predicted using majority vote approach. Splitting the training data into subsets and incorporation of heterogeneous ELM classifiers result in higher prediction accuracy, better generalization, and a lower number of base classifiers, as compared to other models (Adaboost, Bagging, Dynamic ELM ensemble, data splitting ELM ensemble, and ELM ensemble). The validity of AELME is confirmed through classification on several real-world benchmark datasets. PMID:28546808

Plasma core power exhaust in ELMy H-Mode in JET with ITER-Like Wall

NASA Astrophysics Data System (ADS)

Guillemaut, C.; Metzger, C.; Appel, L.; Drewelow, P.; Horvath, L.; Matthews, G. F.; Szepesi, G.; Solano, E. R.; contributors, JET

2018-07-01

The mitigation of target heat load in future steady state fusion devices will require dissipation of a significant amount of power through radiation. Plasma operations relying on ELMy H-modes could be problematic since ELMs may transport substantial amounts of power to the target without significant dissipation. Therefore, estimation of the average ELM power exhaust from the plasma core is crucial to evaluate the potential limitation on the power dissipation in ELMy H-mode regime. A series of more than 50 Type-I ELMy H-mode discharges in JET with ITER-Like Wall (JET-ILW) with a wide range of conditions has been used here to compare the average ELM power to the average input power. The effect of input power, ELM frequency, plasma current, confinement and radiation on ELM power exhaust has been studied and reported in this paper. Good agreement has been found here with previous studies made in carbon machines. This work suggests that it should not be possible to dissipate more than 70%–80% of the input power in Type-I ELMy H-modes in JET-ILW which is consistent with the maximum radiative fraction found experimentally.

Increased electron temperature turbulence during suppression of edge localized mode by resonant magnetic perturbations in the DIII-D tokamak

NASA Astrophysics Data System (ADS)

Sung, C.; Wang, G.; Rhodes, T. L.; Smith, S. P.; Osborne, T. H.; Ono, M.; McKee, G. R.; Yan, Z.; Groebner, R. J.; Davis, E. M.; Zeng, L.; Peebles, W. A.; Evans, T. E.

2017-11-01

The first observation of increased electron temperature turbulence during edge localized mode (ELM) suppression by resonant magnetic perturbations (RMPs) is presented. These are long wavelength fluctuations (kθρs ≤ 0.2, where kθ = poloidal wavenumber and ρs = ion sound gyroradius) observed during H-mode plasmas on the DIII-D. This increase occurs only after ELMs are suppressed and are not observed during the initial RMP application. The T˜ e/Te increases ( >60%) are coincident with changes in normalized density and electron temperature gradients in the region from the top of the pedestal outward to the upper portion of the steep edge gradient. Density turbulence (kθρs ≤ 0.4) in this location was also observed to increase only after ELM suppression. These results are significant since they indicate that increased gradient-driven turbulent transport is one possible mechanism to regulate and maintain ELM-free H-mode operation. Investigation of linear stability of drift wave instabilities using the CGYRO code [Candy et al., J. Comput. Phys. 324, 73 (2016)] shows that the dominant mode moves closer to the electron mode branch from the ion mode branch only after ELMs are suppressed, correlated with the increased turbulence. The increased turbulence during ELM suppression, rather than with the initial RMP application, indicates that the often observed RMP induced "density pump-out" cannot be attributed to long wavelength edge turbulence level changes.

Energetic ion losses caused by magnetohydrodynamic activity resonant and non-resonant with energetic ions in Large Helical Device

NASA Astrophysics Data System (ADS)

Ogawa, Kunihiro; Isobe, Mitsutaka; Toi, Kazuo; Shimizu, Akihiro; Spong, Donald A.; Osakabe, Masaki; Yamamoto, Satoshi; the LHD Experiment Group

2014-09-01

Experiments to reveal energetic ion dynamics associated with magnetohydrodynamic activity are ongoing in the Large Helical Device (LHD). Interactions between beam-driven toroidal Alfvén eigenmodes (TAEs) and energetic ions have been investigated. Energetic ion losses induced by beam-driven burst TAEs have been observed using a scintillator-based lost fast-ion probe (SLIP) in neutral beam-heated high β plasmas. The loss flux of co-going beam ions increases as the TAE amplitude increases. In addition to this, the expulsion of beam ions associated with edge-localized modes (ELMs) has been also recognized in LHD. The SLIP has indicated that beam ions having co-going and barely co-going orbits are affected by ELMs. The relation between ELM amplitude and ELM-induced loss has a dispersed structure. To understand the energetic ion loss process, a numerical simulation based on an orbit-following model, DELTA5D, that incorporates magnetic fluctuations is performed. The calculation result shows that energetic ions confined in the interior region are lost due to TAE instability, with a diffusive process characterizing their loss. For the ELM, energetic ions existing near the confinement/loss boundary are lost through a convective process. We found that the ELM-induced loss flux measured by SLIP changes with the ELM phase. This relation between the ELM amplitude and measured ELM-induced loss results in a more dispersed loss structure.

Density and magnetic fluctuations in type III-ELM pedestal evolution in JET: experimental and numerical characterization

NASA Astrophysics Data System (ADS)

De Masi, G.; Predebon, I.; Spagnolo, S.; Meneses, L.; Delabie, E.; Lupelli, I.; Hillesheim, J. C.; Maggi, C.; Contributors, JET

2018-04-01

Density and magnetic fluctuation measurements in low-β type-III ELM discharges are obtained in the Joint European Torus (JET). They are observed during the inter-ELM pedestal evolution, after the LH transition phase, at about 60-70 kHz. Density fluctuations are measured with a correlation reflectometer system installed on the low-field side and they are localized at the pedestal top. Magnetic fluctuations with a spatial scale k_yρ_i˜ 0.1 are measured through a high resolution coil array. The main features and the relations with local plasma parameters are presented. The nature of these fluctuations is discussed along with linear gyrokinetic simulations. Ion temperature gradient (ITG) modes are the dominant instabilities in the frequency range of interest. In terms of radial localization, typical oscillation frequency and qualitative relation with the possible linear drive, ITG modes are consistent with the experimental density fluctuations measurements. Micro-tearing modes (MTMs), found unstable with a lower growth rate, appear a possible explanation for magnetic fluctuations in terms of typical wavenumbers and direction of propagation.

Broadening of divertor heat flux profile with increasing number of ELM filaments in NSTX

DOE PAGES

Ahn, J. -W.; Maingi, R.; Canik, J. M.; ...

2014-11-13

Edge localized modes (ELMs) represent a challenge to future fusion devices, owing to cyclical high peak heat fluxes on divertor plasma facing surfaces. One ameliorating factor has been that the heat flux characteristic profile width has been observed to broaden with the size of the ELM, as compared with the inter-ELM heat flux profile. In contrast, the heat flux profile has been observed to narrow during ELMs under certain conditions in NSTX. Here we show that the ELM heat flux profile width increases with the number of filamentary striations observed, i.e., profile narrowing is observed with zero or very fewmore » striations. Because NSTX often lies on the long wavelength current-driven mode side of ideal MHD instabilities, few filamentary structures can be expected under many conditions. Lastly, ITER is also projected to lie on the current driven low-n stability boundary, and therefore detailed projections of the unstable modes expected in ITER and the heat flux driven in ensuing filamentary structures is needed.« less

Trends in extreme learning machines: a review.

PubMed

Huang, Gao; Huang, Guang-Bin; Song, Shiji; You, Keyou

2015-01-01

Extreme learning machine (ELM) has gained increasing interest from various research fields recently. In this review, we aim to report the current state of the theoretical research and practical advances on this subject. We first give an overview of ELM from the theoretical perspective, including the interpolation theory, universal approximation capability, and generalization ability. Then we focus on the various improvements made to ELM which further improve its stability, sparsity and accuracy under general or specific conditions. Apart from classification and regression, ELM has recently been extended for clustering, feature selection, representational learning and many other learning tasks. These newly emerging algorithms greatly expand the applications of ELM. From implementation aspect, hardware implementation and parallel computation techniques have substantially sped up the training of ELM, making it feasible for big data processing and real-time reasoning. Due to its remarkable efficiency, simplicity, and impressive generalization performance, ELM have been applied in a variety of domains, such as biomedical engineering, computer vision, system identification, and control and robotics. In this review, we try to provide a comprehensive view of these advances in ELM together with its future perspectives.

Toroidal Rotation and 3D Nonlinear Dynamics in the Peeling-Ballooning Model of ELMs

NASA Astrophysics Data System (ADS)

Snyder, P. B.

2004-11-01

Maximizing the height of the edge transport barrier (or ``pedestal'') while maintaining acceptably small edge localized modes (ELMs) is a critical issue for tokamak performance. The peeling-ballooning model proposes that intermediate wavelength MHD instabilities are responsible for ELMs and impose constraints on the pedestal. Recent studies of linear peeling-ballooning stability have found encouraging agreement with observations [e.g. 1]. To allow more detailed prediction of mode characteristics, including eventually predictions of the ELM energy loss and its deposition, we consider effects of sheared toroidal rotation, as well as 3D nonlinear dynamics. An eigenmode formulation for toroidal rotation shear is developed and incorporated into the framework of the ELITE stability code [2], resolving the low rotation discontinuity in previous high-n results. Rotation shear is found to impact the structure of peeling-ballooning modes, causing radial narrowing and mode shearing. The calculated mode frequency is found to agree with observed rotation in the edge region in the early stages of the ELM crash. Nonlinear studies with the 3D BOUT and NIMROD codes reveal detailed characteristics of the early evolution of these edge instabilities, including the impact of non-ideal effects. The expected linear growth phase is followed by a fast crash event in which poloidally narrow, filamentary structures propagate radially outward from the pedestal region, closely resembling observed ELM events. Comparisons with ELM observations will be discussed. \\vspace0.25em [1] P.B. Snyder et al., Nucl. Fusion 44, 320 (2004); P.B. Snyder et al., Phys. Plasmas 9, 2037 (2002). [2] H.R. Wilson et al., Phys. Plasmas 9, 1277 (2002).

Canopy decline assessment in American elm after inoculation with different doses of Ophiostoma ulmi and O. novo-ulmi

Treesearch

Charles E. Flower; James M. Slavicek; Dale Lesser; Steven Eshita; Cornelia C. Pinchot

2017-01-01

Restoration of American elm (Ulmus americana L.) in natural and urban landscapes necessitates the development of new selections that not only exhibit Dutch elm disease (DED, caused by the fungal pathogen Ophiostoma novo-ulmi and O. ulmi) tolerance, but also an increase the genetic variability of tolerant...

Increased electron temperature turbulence during suppression of edge localized mode by resonant magnetic perturbations in the DIII-D tokamak [Increased electron temperature turbulence during edge localized mode (ELM) suppression by resonant magnetic perturbations (RMPs) in the DIII-D tokamak

DOE PAGES

Sung, Choongki; Wang, G.; Rhodes, Terry L.; ...

2017-11-16

We report the first observation of increased edge electron temperature turbulence correlated with changes in gradients and the ELM suppression time which occurs after the application of resonant magnetic perturbations (RMP) on DIII-D H-mode plasmas. This increase (T ~ e/T e approximately doubles) occurs in the region extending from the top of the pedestal outward to the upper part of the edge steep gradient region. This is significant as it is consistent with increased turbulence driven transport potentially replacing some part of the edge localized mode (ELM) driven transport. However, temperature turbulence does not change with the initial RMP applicationmore » while ELMs are still present, indicating the turbulence changes are not causative in the development of ELM suppression or initial profile evolution with RMP – but rather a response to these effects. This temperature turbulence is broadband and long wavelength, k θρ s < 0.5, where k θ = poloidal wavenumber, ρ s = ion sound gyroradius. As has been reported previously, long wavelength density turbulence (k θρ s < 1.0) in the same location also increases after ELMs were suppressed by the RMP. Since the decrease of the density starts nearly immediately with RMP application, these results suggest that the so-called RMP “density pump-out” is not linked to these long wavelength turbulent transport changes. Comparison with linear stability analysis finds both consistencies and inconsistencies in this important region.« less

Increased electron temperature turbulence during suppression of edge localized mode by resonant magnetic perturbations in the DIII-D tokamak [Increased electron temperature turbulence during edge localized mode (ELM) suppression by resonant magnetic perturbations (RMPs) in the DIII-D tokamak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sung, Choongki; Wang, G.; Rhodes, Terry L.

We report the first observation of increased edge electron temperature turbulence correlated with changes in gradients and the ELM suppression time which occurs after the application of resonant magnetic perturbations (RMP) on DIII-D H-mode plasmas. This increase (T ~ e/T e approximately doubles) occurs in the region extending from the top of the pedestal outward to the upper part of the edge steep gradient region. This is significant as it is consistent with increased turbulence driven transport potentially replacing some part of the edge localized mode (ELM) driven transport. However, temperature turbulence does not change with the initial RMP applicationmore » while ELMs are still present, indicating the turbulence changes are not causative in the development of ELM suppression or initial profile evolution with RMP – but rather a response to these effects. This temperature turbulence is broadband and long wavelength, k θρ s < 0.5, where k θ = poloidal wavenumber, ρ s = ion sound gyroradius. As has been reported previously, long wavelength density turbulence (k θρ s < 1.0) in the same location also increases after ELMs were suppressed by the RMP. Since the decrease of the density starts nearly immediately with RMP application, these results suggest that the so-called RMP “density pump-out” is not linked to these long wavelength turbulent transport changes. Comparison with linear stability analysis finds both consistencies and inconsistencies in this important region.« less

The Relationships Between ELM Suppression, Pedestal Profiles, and Lithium Wall Coatings in NSTX

DOE Office of Scientific and Technical Information (OSTI.GOV)

D.P. Boyle, R. Maingi, P.B. Snyder, J. Manickam, T.H. Osborne, R.E. Bell, B.P. LeBlanc, and the NSTX Team

2012-08-17

Recently in the National Spherical Torus Experiment (NSTX), increasing lithium wall coatings suppressed edge localized modes (ELMs), gradually but not quite monotonically. This work details profile and stability analysis as ELMs disappeared throughout the lithium scan. While the quantity of lithium deposited between discharges did not uniquely determine the presence of ELMs, profile analysis demonstrated that lithium was correlated to wider density and pressure pedestals with peak gradients farther from the separatrix. Moreover, the ELMy and ELM-free discharges were cleanly separated by their density and pedestal widths and peak gradient locations. Ultimately, ELMs were only suppressed when lithium caused themore » density pedestal to widen and shift inward. These changes in the density gradient were directly reflected in the pressure gradient and calculated bootstrap current. This supports the theory that ELMs in NSTX are caused by peeling and/or ballooning modes, as kink/peeling modes are stabilized when the edge current and pressure gradient shift away from the separatrix. Edge stability analysis using ELITE corroborated this picture, as reconstructed equilibria from ELM-free discharges were generally farther from their kink/peeling stability boundaries than ELMy discharges. We conclude that density profile control provided by lithium is the key first step to ELM suppression in NSTX« less

Lithium granule ablation and penetration during ELM pacing experiments at DIII-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lunsford, R.; Bortolon, A.; Roquemore, A. L.

At DIII-D, lithium granules were radially injected into the plasma at the outer midplane to trigger and pace edge localized modes (ELMs). Granules ranging in size from 300 to 1000 microns were horizontally launched into H-mode discharges with velocities near 100 m/s, and granule to granule injection frequencies less than 500 Hz. While the smaller granules were only successful in triggering ELMs approximately 20% of the time, the larger granules regularly demonstrated ELM triggering efficiencies of greater than 80%. A fast visible camera looking along the axis of injection observed the ablation of the lithium granules. We used the durationmore » of ablation as a benchmark for a neutral gas shielding calculation, and approximated the ablation rate and mass deposition location for the various size granules, using measured edge plasma profiles as inputs. In conclusion, this calculation suggests that the low triggering efficiency of the smaller granules is due to the inability of these granules to traverse the steep edge pressure gradient region and reach the top of the pedestal prior to full ablation.« less

Lithium granule ablation and penetration during ELM pacing experiments at DIII-D

DOE PAGES

Lunsford, R.; Bortolon, A.; Roquemore, A. L.; ...

2016-05-25

At DIII-D, lithium granules were radially injected into the plasma at the outer midplane to trigger and pace edge localized modes (ELMs). Granules ranging in size from 300 to 1000 microns were horizontally launched into H-mode discharges with velocities near 100 m/s, and granule to granule injection frequencies less than 500 Hz. While the smaller granules were only successful in triggering ELMs approximately 20% of the time, the larger granules regularly demonstrated ELM triggering efficiencies of greater than 80%. A fast visible camera looking along the axis of injection observed the ablation of the lithium granules. We used the durationmore » of ablation as a benchmark for a neutral gas shielding calculation, and approximated the ablation rate and mass deposition location for the various size granules, using measured edge plasma profiles as inputs. In conclusion, this calculation suggests that the low triggering efficiency of the smaller granules is due to the inability of these granules to traverse the steep edge pressure gradient region and reach the top of the pedestal prior to full ablation.« less

KSC-2009-1090

NASA Image and Video Library

2009-01-09

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, an overhead crane lowers the ICS Exposed Facility, or ICS-EF, onto the Japanese Experiment Module's Experiment Logistics Module-Exposed Section, or ELM-ES, for installation. The ICS-EF is composed of several components, including an antenna, pointing mechanism, frequency converters, high-power amplifier and various sensors including the Earth sensor, Sun sensor and inertial reference unit. The ICS-EF is part of space shuttle Endeavour's payload on the STS-127 mission, targeted for launch on May 15. Photo credit: NASA/Jim Grossmann

KSC-2009-1085

NASA Image and Video Library

2009-01-09

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, workers prepare the ICS Exposed Facility, ICS-EF, to be lifted and installed on the Japanese Experiment Module's Experiment Logistics Module-Exposed Section, or ELM-ES. The ICS-EF is composed of several components, including an antenna, pointing mechanism, frequency converters, high-power amplifier and various sensors including the Earth sensor, Sun sensor and inertial reference unit. The ICS-EF is part of space shuttle Endeavour's payload on the STS-127 mission, targeted for launch on May 15. Photo credit: NASA/Jim Grossmann

Deep Learning Methods for Underwater Target Feature Extraction and Recognition

PubMed Central

Peng, Yuan; Qiu, Mengran; Shi, Jianfei; Liu, Liangliang

2018-01-01

The classification and recognition technology of underwater acoustic signal were always an important research content in the field of underwater acoustic signal processing. Currently, wavelet transform, Hilbert-Huang transform, and Mel frequency cepstral coefficients are used as a method of underwater acoustic signal feature extraction. In this paper, a method for feature extraction and identification of underwater noise data based on CNN and ELM is proposed. An automatic feature extraction method of underwater acoustic signals is proposed using depth convolution network. An underwater target recognition classifier is based on extreme learning machine. Although convolution neural networks can execute both feature extraction and classification, their function mainly relies on a full connection layer, which is trained by gradient descent-based; the generalization ability is limited and suboptimal, so an extreme learning machine (ELM) was used in classification stage. Firstly, CNN learns deep and robust features, followed by the removing of the fully connected layers. Then ELM fed with the CNN features is used as the classifier to conduct an excellent classification. Experiments on the actual data set of civil ships obtained 93.04% recognition rate; compared to the traditional Mel frequency cepstral coefficients and Hilbert-Huang feature, recognition rate greatly improved. PMID:29780407

Pedestal bifurcation and resonant field penetration at the threshold of edge-localized mode suppression in the DIII-D Tokamak.

PubMed

Nazikian, R; Paz-Soldan, C; Callen, J D; deGrassie, J S; Eldon, D; Evans, T E; Ferraro, N M; Grierson, B A; Groebner, R J; Haskey, S R; Hegna, C C; King, J D; Logan, N C; McKee, G R; Moyer, R A; Okabayashi, M; Orlov, D M; Osborne, T H; Park, J-K; Rhodes, T L; Shafer, M W; Snyder, P B; Solomon, W M; Strait, E J; Wade, M R

2015-03-13

Rapid bifurcations in the plasma response to slowly varying n=2 magnetic fields are observed as the plasma transitions into and out of edge-localized mode (ELM) suppression. The rapid transition to ELM suppression is characterized by an increase in the toroidal rotation and a reduction in the electron pressure gradient at the top of the pedestal that reduces the perpendicular electron flow there to near zero. These events occur simultaneously with an increase in the inner-wall magnetic response. These observations are consistent with strong resonant field penetration of n=2 fields at the onset of ELM suppression, based on extended MHD simulations using measured plasma profiles. Spontaneous transitions into (and out of) ELM suppression with a static applied n=2 field indicate competing mechanisms of screening and penetration of resonant fields near threshold conditions. Magnetic measurements reveal evidence for the unlocking and rotation of tearinglike structures as the plasma transitions out of ELM suppression.

Pedestal Bifurcation and Resonant Field Penetration at the Threshold of Edge-Localized Mode Suppression in the DIII-D Tokamak

DOE PAGES

Nazikian, Raffi; Paz-Soldan, Carlos; Callen, James D.; ...

2015-03-12

Rapid bifurcations in the plasma response to slowly varying n=2 magnetic fields are observed as the plasma transitions into and out of edge localized mode (ELM) suppression. The rapid transition to ELM suppression is characterized by an increase in the toroidal rotation and a reduction in the electron pressure gradient at the top of the pedestal which reduces the perpendicular electron flow to near zero. These events occur simultaneously with an increase in the inner wall magnetic response. These observations are consistent strong resonant field penetration of n=2 fields at the onset of ELM suppression, based on extended MHD simulationsmore » using measured plasma profiles. Spontaneous transitions into (and out of) ELM suppression with a static applied n=2 field indicate competing mechanisms of screening and penetration of resonant fields near threshold conditions. Magnetic measurements reveal evidence for the unlocking and rotation of tearing-like structures as the plasma transitions out of ELM suppression.« less

Non-boronized compared with boronized operation of ASDEX Upgrade with full-tungsten plasma facing components

NASA Astrophysics Data System (ADS)

Kallenbach, A.; Dux, R.; Mayer, M.; Neu, R.; Pütterich, T.; Bobkov, V.; Fuchs, J. C.; Eich, T.; Giannone, L.; Gruber, O.; Herrmann, A.; Horton, L. D.; Maggi, C. F.; Meister, H.; Müller, H. W.; Rohde, V.; Sips, A.; Stäbler, A.; Stober, J.; ASDEX Upgrade Team

2009-04-01

After completion of the tungsten coating of all plasma facing components, ASDEX Upgrade has been operated without boronization for 1 1/2 experimental campaigns. This has allowed the study of fuel retention under conditions of relatively low D co-deposition with low-Z impurities as well as the operational space of a full-tungsten device for the unfavourable condition of a relatively high intrinsic impurity level. Restrictions in operation were caused by the central accumulation of tungsten in combination with density peaking, resulting in H-L backtransitions induced by too low separatrix power flux. Most important control parameters have been found to be the central heating power, as delivered predominantly by ECRH, and the ELM frequency, most easily controlled by gas puffing. Generally, ELMs exhibit a positive impact, with the effect of impurity flushing out of the pedestal region overbalancing the ELM-induced W source. The restrictions of plasma operation in the unboronized W machine occurred predominantly under low or medium power conditions. Under medium-high power conditions, stable operation with virtually no difference between boronized and unboronized discharges was achieved. Due to the reduced intrinsic radiation with boronization and the limited power handling capability of VPS coated divertor tiles (≈10 MW m-2), boronized operation at high heating powers was possible only with radiative cooling. To enable this, a previously developed feedback system using (thermo-)electric current measurements as approximate sensor for the divertor power flux was introduced into the standard AUG operation. To avoid the problems with reduced ELM frequency due to core plasma radiation, nitrogen was selected as radiating species since its radiative characteristic peaks at lower electron temperatures in comparison with Ne and Ar, favouring SOL and divertor radiative losses. Nitrogen seeding resulted not only in the desired divertor power load reduction but also in improved energy confinement, as well as in smaller ELMs.

Extreme learning machine for ranking: generalization analysis and applications.

PubMed

Chen, Hong; Peng, Jiangtao; Zhou, Yicong; Li, Luoqing; Pan, Zhibin

2014-05-01

The extreme learning machine (ELM) has attracted increasing attention recently with its successful applications in classification and regression. In this paper, we investigate the generalization performance of ELM-based ranking. A new regularized ranking algorithm is proposed based on the combinations of activation functions in ELM. The generalization analysis is established for the ELM-based ranking (ELMRank) in terms of the covering numbers of hypothesis space. Empirical results on the benchmark datasets show the competitive performance of the ELMRank over the state-of-the-art ranking methods. Copyright © 2014 Elsevier Ltd. All rights reserved.

Supersonic molecular beam injection effects on tokamak plasma applied non-axisymmetric magnetic perturbation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Hyunsun, E-mail: hyunsun@nfri.re.kr; In, Y.; Jeon, Y. M.

The change of tokamak plasma behavior by supersonic molecular beam injection (SMBI) was investigated by applying a three-dimensional magnetic perturbation that could suppress edge localized modes (ELMs). From the time trace of decreasing electron temperature and with increasing plasma density keeping the total confined energy constant, the SMBI seems to act as a cold pulse on the plasma. However, the ELM behaviors were changed drastically (i.e., the symptom of ELM suppression has disappeared). The plasma collisionality in the edge-pedestal region could play a role in the change of the ELM behaviors.

Edge simulations in ELMy H-mode discharges of EAST tokamak

NASA Astrophysics Data System (ADS)

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.

Observation of EHO in NSTX and Theoretical Study of its Active Control Using HHFW Antenna

DOE Office of Scientific and Technical Information (OSTI.GOV)

J.-K. Park, et. al.

2013-01-14

Two important topics in the tokamak ELM control, using the non-axisymmetric (3D) magnetic perturbations, are studied in NSTX and combined envisioning ELM control in the future NSTX-U operation: Experimental observations of the edge harmonic oscillation in NSTX (not necessarily the same as EHOs in DIII-D), and theoretical study of its external drive using the high harmonic fast wave (HHFW) antenna as a 3D field coil. Edge harmonic oscillations were observed particularly well in NSTX ELM-free operation with low n core modes, with various diagnostics confirming n = 4 ~ 6 edge-localized and coherent oscillations in 2 ~ 8kHz frequency range.more » These oscillations seem to have a favored operational window in rotational shear, similarly to EHOs in DIII-D QH modes . However, in NSTX, they are not observed to provide particle or impurity control, possibly due to their weak amplitudes, of a few mm displacements, as measured by reflectometry. The external drive of these modes has been proposed in NSTX, by utilizing audio-frequency currents in the HHFW antenna straps. Analysis shows that the HHFW straps can be optimized to maximize n = 4 ~ 6 while minimizing n = 1 ~ 3. Also, IPEC calculations show that the optimized configuration with only 1kAt current can produce comparable or larger displacements than the observed internal modes. If this optimized external drive can be constructively combined, or further resonated with the internal modes, the edge harmonic oscillations in NSTX may be able to produce sufficient particle control to modify ELMs.« less

The coolest extremely low-mass white dwarfs

NASA Astrophysics Data System (ADS)

Calcaferro, Leila M.; Althaus, Leandro G.; Córsico, Alejandro H.

2018-06-01

Context. Extremely low-mass white dwarf (ELM WD; M⋆ ≲ 0.18-0.20 M⊙) stars are thought to be formed in binary systems via stable or unstable mass transfer. Although stable mass transfer predicts the formation of ELM WDs with thick hydrogen (H) envelopes that are characterized by dominant residual nuclear burning along the cooling branch, the formation of ELM WDs with thinner H envelopes from unstable mass loss cannot be discarded. Aims: We compute new evolutionary sequences for helium (He) core WD stars with thin H envelopes with the main aim of assessing the lowest Teff that could be reached by this type of stars. Methods: We generate a new grid of evolutionary sequences of He-core WD stars with thin H envelopes in the mass range from 0.1554 to 0.2025 M⊙, and assess the changes in both the cooling times and surface gravity induced by a reduction of the H envelope. We also determine, taking into account the predictions of progenitor evolution, the lowest Teff reached by the resulting ELM WDs. Results: We find that a slight reduction in the H envelope yields a significant increase in the cooling rate of ELM WDs. Because of this, ELM WDs with thin H envelopes could cool down to 2500 K, in contrast to their canonical counterparts that cool down to 7000 K. In addition, we find that a reduction of the thickness of the H envelope markedly increases the surface gravity (g) of these stars. Conclusions: If ELM WDs are formed with thin H envelopes, they could be detected at very low Teff. The detection of such cool ELM WDs would be indicative that they were formed with thin H envelopes, thus opening the possibility of placing constraints on the possible mechanisms of formation of this type of star. Last but not least, the increase in g due to the reduction of the H envelope leads to consequences in the spectroscopic determinations of these stars.

The relationships between edge localized modes suppression, pedestal profiles and lithium wall coatings in NSTX

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boyle, D. P.; Maingi, R.; Snyder, P. B.

2011-01-01

Recently in the National Spherical Torus Experiment (NSTX), increasing lithium wall coatings suppressed edge localized modes (ELMs), gradually but not quite monotonically. This work details profile and stability analysis as ELMs disappeared throughout the lithium scan. While the quantity of lithium deposited between discharges did not uniquely determine the presence of ELMs, profile analysis demonstrated that lithium was correlated with wider density and pressure pedestals with peak gradients farther from the separatrix. Moreover, the ELMy and ELM-free discharges were cleanly separated by their density and pedestal widths and peak gradient locations. Ultimately, ELMs were only suppressed when lithium caused themore » density pedestal to widen and shift inward. These changes in the density gradient were directly reflected in the pressure gradient and calculated bootstrap current. This supports the theory that ELMs in NSTX are caused by peeling and/or ballooning modes, as kink/peeling modes are stabilized when the edge current and pressure gradient shift away from the separatrix. Edge stability analysis using ELITE corroborated this picture, as reconstructed equilibria from ELM-free discharges were generally farther from their kink/peeling stability boundaries than ELMy discharges. We conclude that density profile control provided by lithium is the key first step to ELM suppression in NSTX.« less

A comparative analysis of support vector machines and extreme learning machines.

PubMed

Liu, Xueyi; Gao, Chuanhou; Li, Ping

2012-09-01

The theory of extreme learning machines (ELMs) has recently become increasingly popular. As a new learning algorithm for single-hidden-layer feed-forward neural networks, an ELM offers the advantages of low computational cost, good generalization ability, and ease of implementation. Hence the comparison and model selection between ELMs and other kinds of state-of-the-art machine learning approaches has become significant and has attracted many research efforts. This paper performs a comparative analysis of the basic ELMs and support vector machines (SVMs) from two viewpoints that are different from previous works: one is the Vapnik-Chervonenkis (VC) dimension, and the other is their performance under different training sample sizes. It is shown that the VC dimension of an ELM is equal to the number of hidden nodes of the ELM with probability one. Additionally, their generalization ability and computational complexity are exhibited with changing training sample size. ELMs have weaker generalization ability than SVMs for small sample but can generalize as well as SVMs for large sample. Remarkably, great superiority in computational speed especially for large-scale sample problems is found in ELMs. The results obtained can provide insight into the essential relationship between them, and can also serve as complementary knowledge for their past experimental and theoretical comparisons. Copyright © 2012 Elsevier Ltd. All rights reserved.

Impact of target material on D and D2 recycling in DIII-D ELMy H-mode discharges

NASA Astrophysics Data System (ADS)

Bykov, Igor; Hollmann, Eric; Rudakov, Dmitry; Moyer, Richard; Boedo, Jose; Din, Rui; Wang, Huiqian; Unterberg, Ezekeal; Briesemeister, Alexis; Chrobak, Christopher; Abrams, Tyler; Watkins, Jon; Lasnier, Charles; McLean, Adam

2017-10-01

DIII-D operation with W divertor inserts shows molecular recycling flux (measured by Fulcher-a spectroscopy) is reduced between ELMs in comparison with a C divertor where the flux is dominated by D2 molecules (>=90%). This effect is partly explained by the higher reflection probability of atomic D on W. During ELMs, the molecular fraction drops by factor >2 on both C and W targets. To study the effect of higher ion impact energy (Eimp) on transient D re-emission during ELMs we have applied fast electrostatic bias to a DiMES probe equipped with a W and C sample set. A 50% increase of Eimp from 150 eV due to biasing led to transient increase of atomic D re-emission flux on both targets. Similar increase of the D2 flux was only seen on C. Thus, the ratios of atomic and molecular fluxes on C varied in a similar way to those measured during ELMs. This variation in molecular recycling fraction with material has implications for the dynamics of density pedestal recovery between ELMs, the overall global particle balance of the system, and possibly the overall detachment onset conditions transiently due to the ELM particle influx. Supported by the US DOE under DE-FG02-07ER54917, DE-FG02-04ER54758, DE-FC02-04ER54698, DE-FG03-95ER54309, and DE-FG02-04ER54762.

Device-Free Localization via an Extreme Learning Machine with Parameterized Geometrical Feature Extraction.

PubMed

Zhang, Jie; Xiao, Wendong; Zhang, Sen; Huang, Shoudong

2017-04-17

Device-free localization (DFL) is becoming one of the new technologies in wireless localization field, due to its advantage that the target to be localized does not need to be attached to any electronic device. In the radio-frequency (RF) DFL system, radio transmitters (RTs) and radio receivers (RXs) are used to sense the target collaboratively, and the location of the target can be estimated by fusing the changes of the received signal strength (RSS) measurements associated with the wireless links. In this paper, we will propose an extreme learning machine (ELM) approach for DFL, to improve the efficiency and the accuracy of the localization algorithm. Different from the conventional machine learning approaches for wireless localization, in which the above differential RSS measurements are trivially used as the only input features, we introduce the parameterized geometrical representation for an affected link, which consists of its geometrical intercepts and differential RSS measurement. Parameterized geometrical feature extraction (PGFE) is performed for the affected links and the features are used as the inputs of ELM. The proposed PGFE-ELM for DFL is trained in the offline phase and performed for real-time localization in the online phase, where the estimated location of the target is obtained through the created ELM. PGFE-ELM has the advantages that the affected links used by ELM in the online phase can be different from those used for training in the offline phase, and can be more robust to deal with the uncertain combination of the detectable wireless links. Experimental results show that the proposed PGFE-ELM can improve the localization accuracy and learning speed significantly compared with a number of the existing machine learning and DFL approaches, including the weighted K-nearest neighbor (WKNN), support vector machine (SVM), back propagation neural network (BPNN), as well as the well-known radio tomographic imaging (RTI) DFL approach.

Device-Free Localization via an Extreme Learning Machine with Parameterized Geometrical Feature Extraction

PubMed Central

Zhang, Jie; Xiao, Wendong; Zhang, Sen; Huang, Shoudong

2017-01-01

Device-free localization (DFL) is becoming one of the new technologies in wireless localization field, due to its advantage that the target to be localized does not need to be attached to any electronic device. In the radio-frequency (RF) DFL system, radio transmitters (RTs) and radio receivers (RXs) are used to sense the target collaboratively, and the location of the target can be estimated by fusing the changes of the received signal strength (RSS) measurements associated with the wireless links. In this paper, we will propose an extreme learning machine (ELM) approach for DFL, to improve the efficiency and the accuracy of the localization algorithm. Different from the conventional machine learning approaches for wireless localization, in which the above differential RSS measurements are trivially used as the only input features, we introduce the parameterized geometrical representation for an affected link, which consists of its geometrical intercepts and differential RSS measurement. Parameterized geometrical feature extraction (PGFE) is performed for the affected links and the features are used as the inputs of ELM. The proposed PGFE-ELM for DFL is trained in the offline phase and performed for real-time localization in the online phase, where the estimated location of the target is obtained through the created ELM. PGFE-ELM has the advantages that the affected links used by ELM in the online phase can be different from those used for training in the offline phase, and can be more robust to deal with the uncertain combination of the detectable wireless links. Experimental results show that the proposed PGFE-ELM can improve the localization accuracy and learning speed significantly compared with a number of the existing machine learning and DFL approaches, including the weighted K-nearest neighbor (WKNN), support vector machine (SVM), back propagation neural network (BPNN), as well as the well-known radio tomographic imaging (RTI) DFL approach. PMID:28420187

KSC-2009-1086

NASA Image and Video Library

2009-01-09

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, the ICS Exposed Facility, or ICS-EF, is lifted from its stand. It will be installed on the Japanese Experiment Module's Experiment Logistics Module-Exposed Section, or ELM-ES. The ICS-EF is composed of several components, including an antenna, pointing mechanism, frequency converters, high-power amplifier and various sensors including the Earth sensor, Sun sensor and inertial reference unit. The ICS-EF is part of space shuttle Endeavour's payload on the STS-127 mission, targeted for launch on May 15. Photo credit: NASA/Jim Grossmann

KSC-2009-1087

NASA Image and Video Library

2009-01-09

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, workers examine the ICS Exposed Facility, or ICS-EF, after it is lifted from its stand. It will be installed on the Japanese Experiment Module's Experiment Logistics Module-Exposed Section, or ELM-ES. The ICS-EF is composed of several components, including an antenna, pointing mechanism, frequency converters, high-power amplifier and various sensors including the Earth sensor, Sun sensor and inertial reference unit. The ICS-EF is part of space shuttle Endeavour's payload on the STS-127 mission, targeted for launch on May 15. Photo credit: NASA/Jim Grossmann

A novel hybrid model for air quality index forecasting based on two-phase decomposition technique and modified extreme learning machine.

PubMed

Wang, Deyun; Wei, Shuai; Luo, Hongyuan; Yue, Chenqiang; Grunder, Olivier

2017-02-15

The randomness, non-stationarity and irregularity of air quality index (AQI) series bring the difficulty of AQI forecasting. To enhance forecast accuracy, a novel hybrid forecasting model combining two-phase decomposition technique and extreme learning machine (ELM) optimized by differential evolution (DE) algorithm is developed for AQI forecasting in this paper. In phase I, the complementary ensemble empirical mode decomposition (CEEMD) is utilized to decompose the AQI series into a set of intrinsic mode functions (IMFs) with different frequencies; in phase II, in order to further handle the high frequency IMFs which will increase the forecast difficulty, variational mode decomposition (VMD) is employed to decompose the high frequency IMFs into a number of variational modes (VMs). Then, the ELM model optimized by DE algorithm is applied to forecast all the IMFs and VMs. Finally, the forecast value of each high frequency IMF is obtained through adding up the forecast results of all corresponding VMs, and the forecast series of AQI is obtained by aggregating the forecast results of all IMFs. To verify and validate the proposed model, two daily AQI series from July 1, 2014 to June 30, 2016 collected from Beijing and Shanghai located in China are taken as the test cases to conduct the empirical study. The experimental results show that the proposed hybrid model based on two-phase decomposition technique is remarkably superior to all other considered models for its higher forecast accuracy. Copyright © 2016 Elsevier B.V. All rights reserved.

Stabilizing effect of resistivity towards ELM-free H-mode discharge in lithium-conditioned NSTX

NASA Astrophysics Data System (ADS)

Banerjee, Debabrata; Zhu, Ping; Maingi, Rajesh

2017-07-01

Linear stability analysis of the national spherical torus experiment (NSTX) Li-conditioned ELM-free H-mode equilibria is carried out in the context of the extended magneto-hydrodynamic (MHD) model in NIMROD. The purpose is to investigate the physical cause behind edge localized mode (ELM) suppression in experiment after the Li-coating of the divertor and the first wall of the NSTX tokamak. Besides ideal MHD modeling, including finite-Larmor radius effect and two-fluid Hall and electron diamagnetic drift contributions, a non-ideal resistivity model is employed, taking into account the increase of Z eff after Li-conditioning in ELM-free H-mode. Unlike an earlier conclusion from an eigenvalue code analysis of these equilibria, NIMROD results find that after reduced recycling from divertor plates, profile modification is necessary but insufficient to explain the mechanism behind complete ELMs suppression in ideal two-fluid MHD. After considering the higher plasma resistivity due to higher Z eff, the complete stabilization could be explained. A thorough analysis of both pre-lithium ELMy and with-lithium ELM-free cases using ideal and non-ideal MHD models is presented, after accurately including a vacuum-like cold halo region in NIMROD to investigate ELMs.

Plant signals during beetle (Scolytus multistriatus) feeding in American elm (Ulmus americana Planch).

PubMed

Saremba, Brett M; Tymm, Fiona J M; Baethke, Kathy; Rheault, Mark R; Sherif, Sherif M; Saxena, Praveen K; Murch, Susan J

2017-05-04

American Elms were devastated by an outbreak of Dutch Elm Disease is caused by the fungus Ophiostoma novo-ulmi Brasier that originated in Asia and arrived in the early 1900s. In spite of decades of study, the specific mechanisms and disease resistance in some trees is not well understood. the fungus is spread by several species of bark beetles in the genus Scolytus, during their dispersal and feeding. Our objective was to understand elm responses to beetle feeding in the absence of the fungus to identify potential resistance mechanisms. A colony of Scolytus multistriatus was established from wild-caught beetles and beetles were co-incubated with susceptible or resistant American elm varieties in a controlled environment chamber. Beetles burrowed into the auxillary meristems of the young elm shoots. The trees responded to the beetle damage by a series of spikes in the concentration of plant growth regulating compounds, melatonin, serotonin, and jasmonic acid. Spikes in melatonin and serotonin represented a 7,000-fold increase over resting levels. Spikes in jasmonic acid were about 10-fold higher than resting levels with one very large spike observed. Differences were noted between susceptible and resistant elms that provide new understanding of plant defenses.

ELM-induced transient tungsten melting in the JET divertor

NASA Astrophysics Data System (ADS)

Coenen, J. W.; Arnoux, G.; Bazylev, B.; Matthews, G. F.; Autricque, A.; Balboa, I.; Clever, M.; Dejarnac, R.; Coffey, I.; Corre, Y.; Devaux, S.; Frassinetti, L.; Gauthier, E.; Horacek, J.; Jachmich, S.; Komm, M.; Knaup, M.; Krieger, K.; Marsen, S.; Meigs, A.; Mertens, Ph.; Pitts, R. A.; Puetterich, T.; Rack, M.; Stamp, M.; Sergienko, G.; Tamain, P.; Thompson, V.; Contributors, JET-EFDA

2015-02-01

The original goals of the JET ITER-like wall included the study of the impact of an all W divertor on plasma operation (Coenen et al 2013 Nucl. Fusion 53 073043) and fuel retention (Brezinsek et al 2013 Nucl. Fusion 53 083023). ITER has recently decided to install a full-tungsten (W) divertor from the start of operations. One of the key inputs required in support of this decision was the study of the possibility of W melting and melt splashing during transients. Damage of this type can lead to modifications of surface topology which could lead to higher disruption frequency or compromise subsequent plasma operation. Although every effort will be made to avoid leading edges, ITER plasma stored energies are sufficient that transients can drive shallow melting on the top surfaces of components. JET is able to produce ELMs large enough to allow access to transient melting in a regime of relevance to ITER. Transient W melt experiments were performed in JET using a dedicated divertor module and a sequence of IP = 3.0 MA/BT = 2.9 T H-mode pulses with an input power of PIN = 23 MW, a stored energy of ˜6 MJ and regular type I ELMs at ΔWELM = 0.3 MJ and fELM ˜ 30 Hz. By moving the outer strike point onto a dedicated leading edge in the W divertor the base temperature was raised within ˜1 s to a level allowing transient, ELM-driven melting during the subsequent 0.5 s. Such ELMs (δW ˜ 300 kJ per ELM) are comparable to mitigated ELMs expected in ITER (Pitts et al 2011 J. Nucl. Mater. 415 (Suppl.) S957-64). Although significant material losses in terms of ejections into the plasma were not observed, there is indirect evidence that some small droplets (˜80 µm) were released. Almost 1 mm (˜6 mm3) of W was moved by ˜150 ELMs within 7 subsequent discharges. The impact on the main plasma parameters was minor and no disruptions occurred. The W-melt gradually moved along the leading edge towards the high-field side, driven by j × B forces. The evaporation rate determined from spectroscopy is 100 times less than expected from steady state melting and is thus consistent only with transient melting during the individual ELMs. Analysis of IR data and spectroscopy together with modelling using the MEMOS code Bazylev et al 2009 J. Nucl. Mater. 390-391 810-13 point to transient melting as the main process. 3D MEMOS simulations on the consequences of multiple ELMs on damage of tungsten castellated armour have been performed. These experiments provide the first experimental evidence for the absence of significant melt splashing at transient events resembling mitigated ELMs on ITER and establish a key experimental benchmark for the MEMOS code.

Recycling Reduction and Density Control with Lithium Injection in DIII-D

NASA Astrophysics Data System (ADS)

Jackson, G. L.; Chrobak, C. P.; Maingi, R.; Mansfield, D.; Roquemore, A.; McLean, A. G.

2013-10-01

Lithium conditioning has been effective in tokamaks for reducing recycling and providing density control, particularly in NSTX and EAST. Since DIII-D has not injected lithium in more than a decade (and then in only very small amounts, 0.4 g total), a unique opportunity exists to extend this experience and examine the physical effects of lithium in a well-conditioned lithium-free machine. A lithium dropper, developed by PPPL, has recently been installed on DIII-D. By injecting 0.09 g of lithium we have observed reductions in recycling, density, and ELM frequency from the first discharge with significant lithium injection. Although modeling of individual 40 μ m diam. Li granules predicts virtually no penetration beyond the separatrix in auxiliary heated H-mode pulses, LiIII emission was detected in the core plasma, albeit with no increase in radiated power. On subsequent discharges without injection no core Li was detected, and only LiI emission was observed in the SOL and divertor regions. We will present the effects of Li on recycling, ELM frequency, and the edge pedestal, and discuss the long-term observations of lithium on plasma facing components. Work supported by the US Department of Energy under DE-FC02-04ER54698, DE-AC02-09CH11466, and DE-AC52-07NA27344.

A novel method for landslide displacement prediction by integrating advanced computational intelligence algorithms.

PubMed

Zhou, Chao; Yin, Kunlong; Cao, Ying; Ahmed, Bayes; Fu, Xiaolin

2018-05-08

Landslide displacement prediction is considered as an essential component for developing early warning systems. The modelling of conventional forecast methods requires enormous monitoring data that limit its application. To conduct accurate displacement prediction with limited data, a novel method is proposed and applied by integrating three computational intelligence algorithms namely: the wavelet transform (WT), the artificial bees colony (ABC), and the kernel-based extreme learning machine (KELM). At first, the total displacement was decomposed into several sub-sequences with different frequencies using the WT. Next each sub-sequence was predicted separately by the KELM whose parameters were optimized by the ABC. Finally the predicted total displacement was obtained by adding all the predicted sub-sequences. The Shuping landslide in the Three Gorges Reservoir area in China was taken as a case study. The performance of the new method was compared with the WT-ELM, ABC-KELM, ELM, and the support vector machine (SVM) methods. Results show that the prediction accuracy can be improved by decomposing the total displacement into sub-sequences with various frequencies and by predicting them separately. The ABC-KELM algorithm shows the highest prediction capacity followed by the ELM and SVM. Overall, the proposed method achieved excellent performance both in terms of accuracy and stability.

Elm genetic diversity and hybridization in the presence of Dutch elm disease

Treesearch

Johanne Brunet; Raymond P. Guries

2017-01-01

The impact of Dutch elm disease (DED) on the genetic diversity of slippery elm (Ulmus rubra) is summarized and its potential impact on the genetic diversity of other North American native elms, American elm (U. americana), rock elm (U. thomasii), winged elm (U. alata), cedar elm (

Circulating Elastin Fragments Are Not Affected by Hepatic, Renal and Hemodynamic Changes, But Reflect Survival in Cirrhosis with TIPS.

PubMed

Nielsen, M J; Lehmann, J; Leeming, D J; Schierwagen, R; Klein, S; Jansen, C; Strassburg, C P; Bendtsen, F; Møller, S; Sauerbruch, T; Karsdal, M A; Krag, A; Trebicka, J

2015-11-01

Progressive fibrosis increases hepatic resistance and causes portal hypertension with complications. During progressive fibrosis remodeling and deposition of collagens and elastin occur. Elastin remodeling is crucially involved in fibrosis progression in animal models and human data. This study investigated the association of circulating elastin with the clinical outcome in cirrhotic patients with severe portal hypertension receiving transjugular intrahepatic porto-systemic shunt (TIPS). We analyzed portal and hepatic venous samples of 110 cirrhotic patients obtained at TIPS insertion and 2 weeks later. The circulating levels of elastin fragments (ELM) were determined using specific monoclonal ELISA. The relationship of ELM with clinical short-time follow-up and long-term outcome was investigated. Circulating levels of ELM showed a gradient across the liver before TIPS with higher levels in the hepatic vein. Interestingly, the circulating ELM levels remained unchanged after TIPS. The circulating levels of ELM in portal and hepatic veins correlated with platelet counts and inversely with serum sodium. Hepatic venous levels of ELM were higher in CHILD C compared to CHILD A and B and were associated with the presence of ascites. Patients with high levels of ELM in the hepatic veins before TIPS showed poorer survival. In multivariate analysis ELM levels in the hepatic veins and MELD were independent predictors of mortality in these patients. This study demonstrated that circulating levels of ELM are not associated with hemodynamic changes, but might reflect fibrosis remodeling and predict survival in patients with severe portal hypertension receiving TIPS independently of MELD.

Suppressive response of confections containing the extractive from leaves of Morus Alba on postprandial blood glucose and insulin in healthy human subjects

PubMed Central

Nakamura, Mariko; Nakamura, Sadako; Oku, Tsuneyuki

2009-01-01

Background The first aim of this study was to clarify the effective ratio of extractive from leaves of Morus Alba (ELM) to sucrose so as to apply this knowledge to the preparation of confections that could effectively suppress the elevation of postprandial blood glucose and insulin. The second aim was to identify the efficacy of confections prepared with the optimally effective ratio determined from the first study, using healthy human subjects. Methods Ten healthy females (22.3 years, BMI 21.4 kg/m2) participated in this within-subject, repeated measures study. For the first aim of this study, the test solutions containing 30 g of sucrose and 1.2 or 3.0 g of ELM were repeatedly and randomly given to each subject. To identify the practically suppressive effects on postprandial blood glucose and insulin, some confections with added ELM were prepared as follows: Mizu-yokan, 30 g of sucrose with the addition of 1.5 or 3.0 g ELM; Daifuku-mochi, 9.0 g of starch in addition to 30 g of sucrose and 1.5 or 3.0 g ELM; Chiffon-cake, 24 g of sucrose, starch, and 3.0 or 6.0 g of ELM, and were ingested by each subject. Blood and end-expiration were collected at selected periods after test food ingestion. Results When 30 g of sucrose with 1.2 or 3.0 g of ELM were ingested by subjects, the elevations of postprandial blood glucose and insulin were effectively suppressed (p < 0.01), and the most effective ratio of ELM to sucrose was evaluated to be 1:10. AUC (area under the curve) of breath hydrogen excretion for 6 h after the ingestion of an added 3 g of ELM significantly increased (p < 0.01). When AUCs-3h of incremental blood glucose of confections without ELM was 100, that of Mizu-yokan and Daifuku-mochi with the ratio (1:10) of ELM to sucrose was decreased to 53.4 and 58.2, respectively. Chiffon-cake added one-fourth ELM was 29.0. Conclusion ELM-containing confections for which the ratio of ELM and sucrose is one-tenth effectively suppress the postprandial blood glucose and insulin by inhibiting the intestinal sucrase, thus creating a prebiotic effect. The development of confections with ELM can therefore contribute to the prevention and the quality of life for prediabetic and diabetic patients. PMID:19602243

Suppression of type-I ELMs with reduced RMP coil set on DIII-D

DOE PAGES

Orlov, Dmitriy M.; Moyer, Richard A.; Evans, Todd E.; ...

2016-02-19

Recent experiments on DIII-D have demonstrated that having a toroidally-monochromatic spectral content of edge-resonant magnetic perturbations (RMPs) is not a necessary condition for suppression of Edge Localized Modes (ELMs). Robust ELM suppression has been reproducibly obtained on DIII-D during experiments in which various non-axisymmetric coil loops were turned off pseudo-randomly producing a variety of n=1, n=2, and n=3 spectral contributions. It was shown that RMP ELM suppression could be achieved with as few as 5 out of 12 internal coil loops (I-coils) on DIII-D at similar coil currents and with good plasma confinement. Linear MHD plasma response (M3DC1, IPEC, MARS)more » and vacuum (SURFMN, TRIP3D) modeling have been performed in order to understand the effects of the perturbation spectrum on the plasma response and ELM suppression. The results suggest that reduction of the dominant n=3 perturbation field is compensated by increased n=2 field in the plasma that may lead to RMP ELM suppression at lower levels of n=3 perturbative magnetic flux from the I-coils. These results provide additional confidence that ITER may be capable of RMP ELM suppression in the event of multiple internal coil failures.« less

Stabilizing effect of resistivity towards ELM-free H-mode discharge in lithium-conditioned NSTX

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banerjee, Debabrata; Zhu, Ping; Maingi, Rajesh

Linear stability analysis of the national spherical torus experiment (NSTX) Li-conditioned ELM-free H-mode equilibria is carried out in the context of the extended magneto-hydrodynamic (MHD) model in NIMROD. Our purpose is to investigate the physical cause behind edge localized mode (ELM) suppression in experiment after the Li-coating of the divertor and the first wall of the NSTX tokamak. Besides ideal MHD modeling, including finite-Larmor radius effect and two-fluid Hall and electron diamagnetic drift contributions, a non-ideal resistivity model is employed, taking into account the increase of Z eff after Li-conditioning in ELM-free H-mode. And unlike an earlier conclusion from anmore » eigenvalue code analysis of these equilibria, NIMROD results find that after reduced recycling from divertor plates, profile modification is necessary but insufficient to explain the mechanism behind complete ELMs suppression in ideal two-fluid MHD. After considering the higher plasma resistivity due to higher Z eff, the complete stabilization could be explained. Furthermore, a thorough analysis of both pre-lithium ELMy and with-lithium ELM-free cases using ideal and non-ideal MHD models is presented, after accurately including a vacuum-like cold halo region in NIMROD to investigate ELMs.« less

Stabilizing effect of resistivity towards ELM-free H-mode discharge in lithium-conditioned NSTX

DOE PAGES

Banerjee, Debabrata; Zhu, Ping; Maingi, Rajesh

2017-05-12

Linear stability analysis of the national spherical torus experiment (NSTX) Li-conditioned ELM-free H-mode equilibria is carried out in the context of the extended magneto-hydrodynamic (MHD) model in NIMROD. Our purpose is to investigate the physical cause behind edge localized mode (ELM) suppression in experiment after the Li-coating of the divertor and the first wall of the NSTX tokamak. Besides ideal MHD modeling, including finite-Larmor radius effect and two-fluid Hall and electron diamagnetic drift contributions, a non-ideal resistivity model is employed, taking into account the increase of Z eff after Li-conditioning in ELM-free H-mode. And unlike an earlier conclusion from anmore » eigenvalue code analysis of these equilibria, NIMROD results find that after reduced recycling from divertor plates, profile modification is necessary but insufficient to explain the mechanism behind complete ELMs suppression in ideal two-fluid MHD. After considering the higher plasma resistivity due to higher Z eff, the complete stabilization could be explained. Furthermore, a thorough analysis of both pre-lithium ELMy and with-lithium ELM-free cases using ideal and non-ideal MHD models is presented, after accurately including a vacuum-like cold halo region in NIMROD to investigate ELMs.« less

Plant signals during beetle (Scolytus multistriatus) feeding in American elm (Ulmus americana Planch)

PubMed Central

Saremba, Brett M.; Tymm, Fiona J. M.; Baethke, Kathy; Rheault, Mark R.; Sherif, Sherif M.; Saxena, Praveen K.; Murch, Susan J.

2017-01-01

ABSTRACT American Elms were devastated by an outbreak of Dutch Elm Disease is caused by the fungus Ophiostoma novo-ulmi Brasier that originated in Asia and arrived in the early 1900s. In spite of decades of study, the specific mechanisms and disease resistance in some trees is not well understood. the fungus is spread by several species of bark beetles in the genus Scolytus, during their dispersal and feeding. Our objective was to understand elm responses to beetle feeding in the absence of the fungus to identify potential resistance mechanisms. A colony of Scolytus multistriatus was established from wild-caught beetles and beetles were co-incubated with susceptible or resistant American elm varieties in a controlled environment chamber. Beetles burrowed into the auxillary meristems of the young elm shoots. The trees responded to the beetle damage by a series of spikes in the concentration of plant growth regulating compounds, melatonin, serotonin, and jasmonic acid. Spikes in melatonin and serotonin represented a 7,000-fold increase over resting levels. Spikes in jasmonic acid were about 10-fold higher than resting levels with one very large spike observed. Differences were noted between susceptible and resistant elms that provide new understanding of plant defenses. PMID:28448744

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

PubMed

Jones, A Maxwell P; Chattopadhyay, Abhishek; Shukla, Mukund; Zoń, Jerzy; Saxena, Praveen K

2012-05-30

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. 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. 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 electrofusion and viable heterokaryons were produced. Together, these results provide the first evidence of sustained cell division, callus regeneration, and potential application of somatic cell fusion in American elm, suggesting that this source of protoplasts may be ideal for genetic manipulation of this species. The technological advance made with American elm in this study has potential implications in other woody species for fundamental and applied research which require availability of viable protoplasts.

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

PubMed Central

2012-01-01

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 electrofusion and viable heterokaryons were produced. Together, these results provide the first evidence of sustained cell division, callus regeneration, and potential application of somatic cell fusion in American elm, suggesting that this source of protoplasts may be ideal for genetic manipulation of this species. The technological advance made with American elm in this study has potential implications in other woody species for fundamental and applied research which require availability of viable protoplasts. PMID:22646730

Enhancement of Edge Stability with Lithium Wall Coatings in NSTX

NASA Astrophysics Data System (ADS)

Maingi, R.; Bell, R. E.; Leblanc, B. P.; Kaita, R.; Kaye, S. M.; Kugel, H. W.; Mansfield, D. K.; Osborne, T. H.

2008-11-01

ELM reduction or elimination while maintaining high confinement is essential for ITER, which has been designed for H-mode operation. Large ELMs are thought to be triggered by exceeding either edge current density and/or pressure gradient limits (peeling, ballooning modes). Stability calculations show that spherical tori should have access to higher pressure gradients and pedestal heights than higher R/a tokamaks, owing to access to second stability regimes[...1]. An ELM-free regime was recently observed in the NSTX following the application of lithium onto the graphite plasma facing components[......2]. ELMs were eliminated in phases[.....3], with the resulting pressure gradients and pedestal widths increasing substantially. Calculations with TRANSP have shown that the edge bootstrap current increased substantially, consistent with second stability access. These ELM-free discharges have a substantial improvement in energy confinement, up to the global βN˜ 5.5 limit. * Supported by US DOE DE-FG02-04ER54520, DE-AC-76CH03073, and DE-FC02-04ER54698. [.1] P. B. Snyder, et. al., Plasma Phys. Contr. Fusion 46 (2004) A131. [2] H. W. Kugel, et. al., Phys. Plasma 15 (2008) #056118. [3] D. M. Mansfield, et. al., J. Nucl. Materials (2009) submitted.

HOW to Differentiate Dutch Elm Disease from Elm Phloem Necrosis

Treesearch

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...

Pedestal evolution physics in low triangularity JET tokamak discharges with ITER-like wall

NASA Astrophysics Data System (ADS)

Bowman, C.; Dickinson, D.; Horvath, L.; Lunniss, A. E.; Wilson, H. R.; Cziegler, I.; Frassinetti, L.; Gibson, K.; Kirk, A.; Lipschultz, B.; Maggi, C. F.; Roach, C. M.; Saarelma, S.; Snyder, P. B.; Thornton, A.; Wynn, A.; Contributors, JET

2018-01-01

The pressure gradient of the high confinement pedestal region at the edge of tokamak plasmas rapidly collapses during plasma eruptions called edge localised modes (ELMs), and then re-builds over a longer time scale before the next ELM. The physics that controls the evolution of the JET pedestal between ELMs is analysed for 1.4 MA, 1.7 T, low triangularity, δ  =  0.2, discharges with the ITER-like wall, finding that the pressure gradient typically tracks the ideal magneto-hydrodynamic ballooning limit, consistent with a role for the kinetic ballooning mode. Furthermore, the pedestal width is often influenced by the region of plasma that has second stability access to the ballooning mode, which can explain its sometimes complex evolution between ELMs. A local gyrokinetic analysis of a second stable flux surface reveals stability to kinetic ballooning modes; global effects are expected to provide a destabilising mechanism and need to be retained in such second stable situations. As well as an electron-scale electron temperature gradient mode, ion scale instabilities associated with this flux surface include an electro-magnetic trapped electron branch and two electrostatic branches propagating in the ion direction, one with high radial wavenumber. In these second stability situations, the ELM is triggered by a peeling-ballooning mode; otherwise the pedestal is somewhat below the peeling-ballooning mode marginal stability boundary at ELM onset. In this latter situation, there is evidence that higher frequency ELMs are paced by an oscillation in the plasma, causing a crash in the pedestal before the peeling-ballooning boundary is reached. A model is proposed in which the oscillation is associated with hot plasma filaments that are pushed out towards the plasma edge by a ballooning mode, draining their free energy into the cooler plasma there, and then relaxing back to repeat the process. The results suggest that avoiding the oscillation and maximising the region of plasma that has second stability access will lead to the highest pedestal heights and, therefore, best confinement—a key result for optimising the fusion performance of JET and future tokamaks, such as ITER.

Tungsten: an option for divertor and main chamber plasma facing components in future fusion devices

NASA Astrophysics Data System (ADS)

Neu, R.; Dux, R.; Kallenbach, A.; Pütterich, T.; Balden, M.; Fuchs, J. C.; Herrmann, A.; Maggi, C. F.; O'Mullane, M.; Pugno, R.; Radivojevic, I.; Rohde, V.; Sips, A. C. C.; Suttrop, W.; Whiteford, A.; ASDEX Upgrade Team

2005-03-01

The tungsten programme in ASDEX Upgrade is pursued towards a full high-Z device. The spectroscopic diagnostic of W has been extended and refined and the cooling factor of W has been re-evaluated. The W coated surfaces now represent a fraction of 65% of all plasma facing components (24.8 m2). The only two major components that are not yet coated are the strikepoint region of the lower divertor as well as the limiters at the low field side. While extending the W surfaces, the W concentration and the discharge behaviour have changed gradually pointing to critical issues when operating with a W wall: anomalous transport in the plasma centre should not be too low, otherwise neoclassical accumulation can occur. One very successful remedy is the addition of central RF heating at the 20-30% level. Regimes with low ELM activity show increased impurity concentration over the whole plasma radius. These discharges can be cured by increasing the ELM frequency through pellet ELM pacemaking or by higher heating power. Moderate gas puffing also mitigates the impurity influx and penetration, however, at the expense of lower confinement. The erosion yield at the low field side guard limiter can be as high as 10-3 and fast particle losses from NBI were identified to contribute a significant part to the W sputtering. Discharges run in the upper W coated divertor do not show higher W concentrations than comparable discharges in the lower C based divertor. According to impurity transport calculations no strong high-Z accumulation is expected for the ITER standard scenario as long as the anomalous transport is at least as high as the neoclassical one.

Inter-ELM evolution of the pedestal structures in type-I ELMy H-mode plasmas with LHW and NBI heating on EAST

NASA Astrophysics Data System (ADS)

Han, X.; Zang, Q.; Xiao, S.; Wang, T.; Hu, A.; Tian, B.; Li, D.; Zhou, H.; Zhao, J.; Hsieh, C.; Li, M.; Yan, N.; Gong, X.; Hu, L.; Xu, G.; Gao, X.; the EAST Team

2017-04-01

The evolution characteristics of type-I ELMy high-confinement mode pedestal are examined in EAST based on the recently developed Thomson scattering system. The influence of the plasma current on pedestal evolvement has been confirmed experimentally. In the higher I p case (500 kA) the pedestal height shows an increase trend until the onset of next ELM and in the lower I p cases (300 and 400 kA), however, this buildup saturates at the first ˜30% of the ELM cycle. In contrast, the width increases only during the first ˜70% of the ELM cycle and then keeps almost stable in three I p cases, but resulting in different widening size of ˜1.5, 1 and 0.5 cm for 300, 400 and 500 kA respectively. Experimental results show that the pedestal pressure width has good correlation with poloidal beta as {{{Δ }}}{{p}{{e}},\\psi }=0.16\\sqrt{{{β }}{{p}{{o}}{{l}}}}, where the fitting coefficient 0.16 is not changed with different plasma currents but a little larger than that of other machines. For each current level, the pedestal density increases while the pedestal temperature decreases. But with increasing {I}{{p}} platforms, the pedestal height prior to the ELM onset shows a near quadratic (within error bars) increase. Experimental measurements demonstrate that the decrease of {{Δ }}{W}{{E}{{L}}{{M}}} with increasing {ν }{{p}{{e}}{{d}}}* comes mostly from the reduction of the plasma temperature drop, while the pedestal density height keeps relatively stable. Additional injection of LHW has been proved to modify the pedestal structure which should be responsible for the remaining scatter of the experimental data.

Quiescent double barrier regime in the DIII-D tokamak.

PubMed

Greenfield, C M; Burrell, K H; DeBoo, J C; Doyle, E J; Stallard, B W; Synakowski, E J; Fenzi, C; Gohil, P; Groebner, R J; Lao, L L; Makowski, M A; McKee, G R; Moyer, R A; Rettig, C L; Rhodes, T L; Pinsker, R I; Staebler, G M; West, W P

2001-05-14

A new sustained high-performance regime, combining discrete edge and core transport barriers, has been discovered in the DIII-D tokamak. Edge localized modes (ELMs) are replaced by a steady oscillation that increases edge particle transport, thereby allowing particle control with no ELM-induced pulsed divertor heat load. The core barrier resembles those usually seen with a low (L) mode edge, without the degradation often associated with ELMs. The barriers are separated by a narrow region of high transport associated with a zero crossing in the E x B shearing rate.

Elm genetic diversity and hybridization in the presence of Dutch elm disease

USDA-ARS?s Scientific Manuscript database

Dutch elm disease (DED) has devastated native North American elm species for more than 75 years. The impact of DED on the genetic diversity of one native elm species, U. rubra or slippery elm, is summarized and its potential impact on the genetic diversity of the other four North American native elm...

Discovery of stationary operation of quiescent H-mode plasmas with net-zero neutral beam injection torque and high energy confinement on DIII-D [Discovery of stationary operation of quiescent H-mode plasmas with Net-Zero NBI torque and high energy confinement on DIII-D

DOE PAGES

Burrell, Keith H.; Barada, Kshitish; Chen, Xi; ...

2016-03-11

Here, recent experiments in DIII-D have led to the discovery of a means of modifying edge turbulence to achieve stationary, high confinement operation without Edge Localized Mode (ELM) instabilities and with no net 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 excellent tokamak performance, well above the H 98y2 international tokamak energy confinement scaling (H 98y2=1.25), thus meeting an additional confinement challenge that is usually difficult at low torque. The new regime is triggeredmore » 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. An increase in the ExB shearing rate inside of the edge pedestal is a key factor in the confinement increase. 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 β N=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.« less

Discovery of stationary operation of quiescent H-mode plasmas with net-zero neutral beam injection torque and high energy confinement on DIII-D [Discovery of stationary operation of quiescent H-mode plasmas with Net-Zero NBI torque and high energy confinement on DIII-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burrell, Keith H.; Barada, Kshitish; Chen, Xi

Here, recent experiments in DIII-D have led to the discovery of a means of modifying edge turbulence to achieve stationary, high confinement operation without Edge Localized Mode (ELM) instabilities and with no net 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 excellent tokamak performance, well above the H 98y2 international tokamak energy confinement scaling (H 98y2=1.25), thus meeting an additional confinement challenge that is usually difficult at low torque. The new regime is triggeredmore » 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. An increase in the ExB shearing rate inside of the edge pedestal is a key factor in the confinement increase. 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 β N=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.« less

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

Treesearch

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...

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

DOE PAGES

Thome, Kathleen E.; Bongard, Michael W.; Barr, Jayson L.; ...

2016-09-30

H-mode is obtained atmore » $$A\\sim 1.2$$ 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 $${{H}_{98y,2}}\\sim 1$$ . 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 $$\\sim 15\\,\\,\\times $$ higher than that predicted by conventional International Tokamak Physics Activity (ITPA) scalings, and $${{P}_{\\text{LH}}}/{{P}_{\\text{ITPA}08}}$$ increases as $$A\\to 1$$ . Small ELMs are present at low input power $${{P}_{\\text{IN}}}\\sim {{P}_{\\text{LH}}}$$ , with toroidal mode number $$n\\leqslant 4$$ . At $${{P}_{\\text{IN}}}\\gg {{P}_{\\text{LH}}}$$ , they transition to large ELMs with intermediate 5 < n < 15. 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.« less

Effects of Density and Impurity on Edge Localized Modes in Tokamaks

NASA Astrophysics Data System (ADS)

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 2015GB101004, the 100 Talent Program of the Chinese Academy of Sciences, and U.S. Department of Energy Grants DE-FG02-86ER53218 and DE-FC02-08ER54975.

Host responses and metabolic profiles of wood components in Dutch elm hybrids with a contrasting tolerance to Dutch elm disease

PubMed Central

Ďurkovič, Jaroslav; Kačík, František; Olčák, Dušan; Kučerová, Veronika; Krajňáková, Jana

2014-01-01

Background and Aims Changes occurring in the macromolecular traits of cell wall components in elm wood following attack by Ophiostoma novo-ulmi, the causative agent of Dutch elm disease (DED), are poorly understood. The purpose of this study was to compare host responses and the metabolic profiles of wood components for two Dutch elm (Ulmus) hybrids, ‘Groeneveld’ (a susceptible clone) and ‘Dodoens’ (a tolerant clone), that have contrasting survival strategies upon infection with the current prevalent strain of DED. Methods Ten-year-old plants of the hybrid elms were inoculated with O. novo-ulmi ssp. americana × novo-ulmi. Measurements were made of the content of main cell wall components and extractives, lignin monomer composition, macromolecular traits of cellulose and neutral saccharide composition. Key Results Upon infection, medium molecular weight macromolecules of cellulose were degraded in both the susceptible and tolerant elm hybrids, resulting in the occurrence of secondary cell wall ruptures and cracks in the vessels, but rarely in the fibres. The 13C nuclear magnetic resonance spectra revealed that loss of crystalline and non-crystalline cellulose regions occurred in parallel. The rate of cellulose degradation was influenced by the syringyl:guaiacyl ratio in lignin. Both hybrids commonly responded to the medium molecular weight cellulose degradation with the biosynthesis of high molecular weight macromolecules of cellulose, resulting in a significant increase in values for the degree of polymerization and polydispersity. Other responses of the hybrids included an increase in lignin content, a decrease in relative proportions of d-glucose, and an increase in proportions of d-xylose. Differential responses between the hybrids were found in the syringyl:guaiacyl ratio in lignin. Conclusions In susceptible ‘Groeneveld’ plants, syringyl-rich lignin provided a far greater degree of protection from cellulose degradation than in ‘Dodoens’, but only guaiacyl-rich lignin in ‘Dodoens’ plants was involved in successful defence against the fungus. This finding was confirmed by the associations of vanillin and vanillic acid with the DED-tolerant ‘Dodoens’ plants in a multivariate analysis of wood traits. PMID:24854167

Host responses and metabolic profiles of wood components in Dutch elm hybrids with a contrasting tolerance to Dutch elm disease.

PubMed

Durkovič, Jaroslav; Kačík, František; Olčák, Dušan; Kučerová, Veronika; Krajňáková, Jana

2014-07-01

Changes occurring in the macromolecular traits of cell wall components in elm wood following attack by Ophiostoma novo-ulmi, the causative agent of Dutch elm disease (DED), are poorly understood. The purpose of this study was to compare host responses and the metabolic profiles of wood components for two Dutch elm (Ulmus) hybrids, 'Groeneveld' (a susceptible clone) and 'Dodoens' (a tolerant clone), that have contrasting survival strategies upon infection with the current prevalent strain of DED. Ten-year-old plants of the hybrid elms were inoculated with O. novo-ulmi ssp. americana × novo-ulmi. Measurements were made of the content of main cell wall components and extractives, lignin monomer composition, macromolecular traits of cellulose and neutral saccharide composition. Upon infection, medium molecular weight macromolecules of cellulose were degraded in both the susceptible and tolerant elm hybrids, resulting in the occurrence of secondary cell wall ruptures and cracks in the vessels, but rarely in the fibres. The (13)C nuclear magnetic resonance spectra revealed that loss of crystalline and non-crystalline cellulose regions occurred in parallel. The rate of cellulose degradation was influenced by the syringyl:guaiacyl ratio in lignin. Both hybrids commonly responded to the medium molecular weight cellulose degradation with the biosynthesis of high molecular weight macromolecules of cellulose, resulting in a significant increase in values for the degree of polymerization and polydispersity. Other responses of the hybrids included an increase in lignin content, a decrease in relative proportions of d-glucose, and an increase in proportions of d-xylose. Differential responses between the hybrids were found in the syringyl:guaiacyl ratio in lignin. In susceptible 'Groeneveld' plants, syringyl-rich lignin provided a far greater degree of protection from cellulose degradation than in 'Dodoens', but only guaiacyl-rich lignin in 'Dodoens' plants was involved in successful defence against the fungus. This finding was confirmed by the associations of vanillin and vanillic acid with the DED-tolerant 'Dodoens' plants in a multivariate analysis of wood traits. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Particle transport in DIII-D plasmas

NASA Astrophysics Data System (ADS)

Kress, Peter; Mordijck, Saskia

2017-10-01

By analyzing the plasma opacity and density evolution during the ELM cycle in DIII-D H-mode plasmas in which the amount of gas fueling was altered, we find evidence for an inward particle pinch at the plasma edge which seems to become more pronounced at higher density. Furthermore, at the plasma edge we find a correlation between the pedestal density and opacity, which measures neutral penetration depth. The changes in edge opacity during an ELM cycle were calculated by using a detailed time history of measured plasma profiles. At the same time, the density evolution during an ELM cycle was investigated. We find that if the edge density increases through an increase in gas fueling, then opacity increases and neutral fueling penetration depth decreases. We also find that density at the top of the pedestal recovers faster following an ELM when the overall density level is higher, leading to a hollow profile inside of the pedestal top. All these results indicate that there must be an inward particle pinch in the pedestal which will be crucial in the fueling of future burning plasma devices. Supported by US DOE DE-SC0007880, DIII-D Grant Number DE-FC02-04ER54698.

Design and operations of a load-tolerant external conjugate-T matching system for the A2 ICRH antennas at JET

NASA Astrophysics Data System (ADS)

Monakhov, I.; Graham, M.; Blackman, T.; Dowson, S.; Durodie, F.; Jacquet, P.; Lehmann, J.; Mayoral, M.-L.; Nightingale, M. P. S.; Noble, C.; Sheikh, H.; Vrancken, M.; Walden, A.; Whitehurst, A.; Wooldridge, E.; Contributors, JET-EFDA

2013-08-01

A load-tolerant external conjugate-T (ECT) impedance matching system for two A2 ion cyclotron resonance heating (ICRH) antennas was successfully put into operation at JET. The system allows continuous injection of the radio-frequency (RF) power into plasma in the presence of strong antenna loading perturbations caused by edge-localized modes (ELMs). Reliable ECT performance was demonstrated under a variety of antenna loading conditions including H-mode plasmas with radial outer gaps (ROGs) in the range 4-14 cm. The high resilience to ELMs predicted during the circuit simulations was fully confirmed experimentally. Dedicated arc-detection techniques and real-time matching algorithms were developed as a part of the ECT project. The new advanced wave amplitude comparison system has proven highly efficient in detection of arcs both between and during ELMs. The ECT system has allowed the delivery of up to 4 MW of RF power without trips into plasmas with type-I ELMs. Together with the 3 dB system and the ITER-like antenna, the ECT has brought the total RF power coupled to ELMy plasma to over 8 MW, considerably enhancing JET research capabilities. This paper provides an overview of the key design features of the ECT system and summarizes the main experimental results achieved so far.

The temporal relationship between non-respiratory burst activity of expiratory laryngeal motoneurons and phrenic apnoea during stimulation of the superior laryngeal nerve in rat

PubMed Central

Sun, Qi-Jian; Bautista, Tara G; Berkowitz, Robert G; Zhao, Wen-Jing; Pilowsky, Paul M

2011-01-01

Abstract A striking effect of stimulating the superior laryngeal nerve (SLN) is its ability to inhibit central inspiratory activity (cause ‘phrenic apnoea’), but the mechanism underlying this inhibition remains unclear. Here we demonstrate, by stimulating the SLN at varying frequencies, that the evoked non-respiratory burst activity recorded from expiratory laryngeal motoneurons (ELMs) has an intimate temporal relationship with phrenic apnoea. During 1–5 Hz SLN stimulation, occasional absences of phrenic nerve discharge (PND) occurred such that every absent PND was preceded by an ELM burst activity. During 10–20 Hz SLN stimulation, more bursts were evoked together with more absent PNDs, leading eventually to phrenic apnoea. Interestingly, subsequent microinjections of isoguvacine (10 mm, 20–40 nl) into ipsilateral Bötzinger complex (BötC) and contralateral nucleus tractus solitarii (NTS) significantly attenuated the apnoeic response but not the ELM burst activity. Our results suggest a bifurcating projection from NTS to both the caudal nucleus ambiguus and BötC, which mediates the closely related ELM burst and apnoeic response, respectively. We believe that such an intimate timing between laryngeal behaviour and breathing is crucial for the effective elaboration of the different airway protective behaviours elicited following SLN stimulation, including the laryngeal adductor reflex, swallowing and cough. PMID:21320890

Proceedings of the American elm restoration workshop 2016

Treesearch

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.

Divertor, scrape-off layer and pedestal particle dynamics in the ELM cycle on ASDEX Upgrade

NASA Astrophysics Data System (ADS)

Laggner, F. M.; Keerl, S.; Gnilsen, J.; Wolfrum, E.; Bernert, M.; Carralero, D.; Guimarais, L.; Nikolaeva, V.; Potzel, S.; Cavedon, M.; Mink, F.; Dunne, M. G.; Birkenmeier, G.; Fischer, R.; Viezzer, E.; Willensdorfer, M.; Wischmeier, M.; Aumayr, F.; the EUROfusion MST1 Team; the ASDEX Upgrade Team

2018-02-01

In addition to the relaxation of the pedestal, edge localised modes (ELMs) introduce changes to the divertor and scrape-off layer (SOL) conditions. Their impact on the inter-ELM pedestal recovery is investigated, with emphasis on the electron density (n e) evolution. The typical ELM cycle occurring in an exemplary ASDEX Upgrade discharge interval at moderate applied gas puff and heating power is characterised, utilising several divertor, SOL and pedestal diagnostics. In the studied discharge interval the inner divertor target is detached before the ELM crash, while the outer target is attached. The particles and power expelled by the ELM crash lead to a re-attachment of the inner target plasma. After the ELM crash, the outer divertor target moves into a high recycling regime with large n e in front of the plate, which is accompanied by high main chamber neutral fluxes. On similar timescales, the inner target fully detaches and the high field side high density region (HFSHD) is formed reaching up to the high field side midplane. This state evolves again to the pre-ELM state, when the main chamber neutral fluxes are reduced later in the ELM cycle. Neither the timescale of the appearance of the HFSHD nor the increase of the main chamber neutral fluxes fit the timescale of the n e pedestal, which is faster. It is found that during the n e pedestal recovery, the magnetic activity at the low field side midplane is strongly reduced indicating a lower level of fluctuations. A rough estimation of the particle flux across the pedestal suggests that the particle flux is reduced in this period. In conclusion, the evolution of the n e pedestal is determined by a combination of neutral fluxes, HFSHD and reduced particle flux across the pedestal. A reduced particle flux explains the fast, experimentally observed re-establishment of the n e pedestal best, whereas neutrals and HFSHD impact on the evolution of the SOL and separatrix conditions.

Modelling of edge localised modes and edge localised mode control [Modelling of ELMs and ELM control

DOE PAGES

Huijsmans, G. T. A.; Chang, C. S.; Ferraro, N.; ...

2015-02-07

Edge Localised Modes (ELMs) in ITER Q = 10 H-mode plasmas are likely to lead to large transient heat loads to the divertor. In order to avoid an ELM induced reduction of the divertor lifetime, the large ELM energy losses need to be controlled. In ITER, ELM control is foreseen using magnetic field perturbations created by in-vessel coils and the injection of small D2 pellets. ITER plasmas are characterised by low collisionality at a high density (high fraction of the Greenwald density limit). These parameters cannot simultaneously be achieved in current experiments. Thus, the extrapolation of the ELM properties andmore » the requirements for ELM control in ITER relies on the development of validated physics models and numerical simulations. Here, we describe the modelling of ELMs and ELM control methods in ITER. The aim of this paper is not a complete review on the subject of ELM and ELM control modelling but rather to describe the current status and discuss open issues.« less

HOW to Save Dutch Elm Diseased Trees by Pruning

Treesearch

J.R. Allison; G.F. Gregory

1979-01-01

Dutch elm disease (DED), caused by the fungus, Ceratocystis ulmi, is the most devastating shade tree disease in the United States. Healthy elms can become diseased by 1) elm bark beetles that carry the fungus from elm to elm, or 2) through root grafting with already infected trees. Along with wilt symptoms, streaking (sapwood discoloration), a characteristic internal...

Report from the street: elm reintroduction

Treesearch

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...

Dutch elm disease

Treesearch

James W. Walters

1992-01-01

Since its discovery in the United States in 1930, Dutch elm disease has killed thousands of native elms. The three native elms, American, slippery, and rock, have little or no resistance to Dutch elm disease, but individual trees within each species vary in susceptibility to the disease. The most important of these, American elm, is scattered in upland stands but is...

Extreme learning machines: a new approach for modeling dissolved oxygen (DO) concentration with and without water quality variables as predictors.

PubMed

Heddam, Salim; Kisi, Ozgur

2017-07-01

In this paper, several extreme learning machine (ELM) models, including standard extreme learning machine with sigmoid activation function (S-ELM), extreme learning machine with radial basis activation function (R-ELM), online sequential extreme learning machine (OS-ELM), and optimally pruned extreme learning machine (OP-ELM), are newly applied for predicting dissolved oxygen concentration with and without water quality variables as predictors. Firstly, using data from eight United States Geological Survey (USGS) stations located in different rivers basins, USA, the S-ELM, R-ELM, OS-ELM, and OP-ELM were compared against the measured dissolved oxygen (DO) using four water quality variables, water temperature, specific conductance, turbidity, and pH, as predictors. For each station, we used data measured at an hourly time step for a period of 4 years. The dataset was divided into a training set (70%) and a validation set (30%). We selected several combinations of the water quality variables as inputs for each ELM model and six different scenarios were compared. Secondly, an attempt was made to predict DO concentration without water quality variables. To achieve this goal, we used the year numbers, 2008, 2009, etc., month numbers from (1) to (12), day numbers from (1) to (31) and hour numbers from (00:00) to (24:00) as predictors. Thirdly, the best ELM models were trained using validation dataset and tested with the training dataset. The performances of the four ELM models were evaluated using four statistical indices: the coefficient of correlation (R), the Nash-Sutcliffe efficiency (NSE), the root mean squared error (RMSE), and the mean absolute error (MAE). Results obtained from the eight stations indicated that: (i) the best results were obtained by the S-ELM, R-ELM, OS-ELM, and OP-ELM models having four water quality variables as predictors; (ii) out of eight stations, the OP-ELM performed better than the other three ELM models at seven stations while the R-ELM performed the best at one station. The OS-ELM models performed the worst and provided the lowest accuracy; (iii) for predicting DO without water quality variables, the R-ELM performed the best at seven stations followed by the S-ELM in the second place and the OP-ELM performed the worst with low accuracy; (iv) for the final application where training ELM models with validation dataset and testing with training dataset, the OP-ELM provided the best accuracy using water quality variables and the R-ELM performed the best at all eight stations without water quality variables. Fourthly, and finally, we compared the results obtained from different ELM models with those obtained using multiple linear regression (MLR) and multilayer perceptron neural network (MLPNN). Results obtained using MLPNN and MLR models reveal that: (i) using water quality variables as predictors, the MLR performed the worst and provided the lowest accuracy in all stations; (ii) MLPNN was ranked in the second place at two stations, in the third place at four stations, and finally, in the fourth place at two stations, (iii) for predicting DO without water quality variables, MLPNN is ranked in the second place at five stations, and ranked in the third, fourth, and fifth places in the remaining three stations, while MLR was ranked in the last place with very low accuracy at all stations. Overall, the results suggest that the ELM is more effective than the MLPNN and MLR for modelling DO concentration in river ecosystems.

ELM: an Algorithm to Estimate the Alpha Abundance from Low-resolution Spectra

NASA Astrophysics Data System (ADS)

Bu, Yude; Zhao, Gang; Pan, Jingchang; Bharat Kumar, Yerra

2016-01-01

We have investigated a novel methodology using the extreme learning machine (ELM) algorithm to determine the α abundance of stars. Applying two methods based on the ELM algorithm—ELM+spectra and ELM+Lick indices—to the stellar spectra from the ELODIE database, we measured the α abundance with a precision better than 0.065 dex. By applying these two methods to the spectra with different signal-to-noise ratios (S/Ns) and different resolutions, we found that ELM+spectra is more robust against degraded resolution and ELM+Lick indices is more robust against variation in S/N. To further validate the performance of ELM, we applied ELM+spectra and ELM+Lick indices to SDSS spectra and estimated α abundances with a precision around 0.10 dex, which is comparable to the results given by the SEGUE Stellar Parameter Pipeline. We further applied ELM to the spectra of stars in Galactic globular clusters (M15, M13, M71) and open clusters (NGC 2420, M67, NGC 6791), and results show good agreement with previous studies (within 1σ). A comparison of the ELM with other widely used methods including support vector machine, Gaussian process regression, artificial neural networks, and linear least-squares regression shows that ELM is efficient with computational resources and more accurate than other methods.

Impact of inward turbulence spreading on energy loss of edge-localized modes

DOE PAGES

Ma, C. H.; Xu, X. Q.; Xi, P. W.; ...

2015-05-18

Nonlinear two-fluid and gyrofluid simulations show that an edge localized modes(ELM) crash has two phases: fast initial crash of ion temperature perturbation on the Alfvén time scale and slow turbulence spreading. The turbulencetransport phase is a slow encroachment of electron temperature perturbation due to the ELM event into pedestal region. Because of the inward turbulence spreading effect, the energy loss of an ELM decreases when density pedestal height increases. The Landau resonance yields the different cross phase-shift of ions and electrons. A 3 + 1 gyro-Landau-fluid model is implemented in BOUT++ framework. As a result, the gyrofluid simulations show thatmore » the kinetic effects have stabilizing effects on the ideal ballooning mode and the energy loss increases with the pedestal height.« less

Dutch Elm Disease Control: Intensive Sanitation and Survey Economics

Treesearch

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...

Semi-supervised and unsupervised extreme learning machines.

PubMed

Huang, Gao; Song, Shiji; Gupta, Jatinder N D; Wu, Cheng

2014-12-01

Extreme learning machines (ELMs) have proven to be efficient and effective learning mechanisms for pattern classification and regression. However, ELMs are primarily applied to supervised learning problems. Only a few existing research papers have used ELMs to explore unlabeled data. In this paper, we extend ELMs for both semi-supervised and unsupervised tasks based on the manifold regularization, thus greatly expanding the applicability of ELMs. The key advantages of the proposed algorithms are as follows: 1) both the semi-supervised ELM (SS-ELM) and the unsupervised ELM (US-ELM) exhibit learning capability and computational efficiency of ELMs; 2) both algorithms naturally handle multiclass classification or multicluster clustering; and 3) both algorithms are inductive and can handle unseen data at test time directly. Moreover, it is shown in this paper that all the supervised, semi-supervised, and unsupervised ELMs can actually be put into a unified framework. This provides new perspectives for understanding the mechanism of random feature mapping, which is the key concept in ELM theory. Empirical study on a wide range of data sets demonstrates that the proposed algorithms are competitive with the state-of-the-art semi-supervised or unsupervised learning algorithms in terms of accuracy and efficiency.

Evolution patterns and parameter regimes in edge localized modes on the National Spherical Torus Experiment

DOE Data Explorer

Smith, D. R. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Bell, R. E. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Podesta, M. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Smith, D. R. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Fonck, R. J. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); McKee, G. R. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Diallo, A. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Kaye, S. M. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); LeBlanc, B. P. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Sabbagh, S. A. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

2015-09-01

We implement unsupervised machine learning techniques to identify characteristic evolution patterns and associated parameter regimes in edge localized mode (ELM) events observed on the National Spherical Torus Experiment. Multi-channel, localized measurements spanning the pedestal region capture the complex evolution patterns of ELM events on Alfven timescales. Some ELM events are active for less than 100~microsec, but others persist for up to 1~ms. Also, some ELM events exhibit a single dominant perturbation, but others are oscillatory. Clustering calculations with time-series similarity metrics indicate the ELM database contains at least two and possibly three groups of ELMs with similar evolution patterns. The identified ELM groups trigger similar stored energy loss, but the groups occupy distinct parameter regimes for ELM-relevant quantities like plasma current, triangularity, and pedestal height. Notably, the pedestal electron pressure gradient is not an effective parameter for distinguishing the ELM groups, but the ELM groups segregate in terms of electron density gradient and electron temperature gradient. The ELM evolution patterns and corresponding parameter regimes can shape the formulation or validation of nonlinear ELM models. Finally, the techniques and results demonstrate an application of unsupervised machine learning at a data-rich fusion facility.

KSC-2009-1088

NASA Image and Video Library

2009-01-09

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, the ICS Exposed Facility, or ICS-EF, is moved across the floor to the Japanese Experiment Module's Experiment Logistics Module-Exposed Section, or ELM-ES, where it will be installed alongside two other payloads, the SEDA-AP (Space Environment Data Acquisition Equipment-Attached Payload) and MAXI (Monitor of All-sky X-ray Image), already installed. The ICS-EF is composed of several components, including an antenna, pointing mechanism, frequency converters, high-power amplifier and various sensors including the Earth sensor, Sun sensor and inertial reference unit. The ICS-EF is part of space shuttle Endeavour's payload on the STS-127 mission, targeted for launch on May 15. Photo credit: NASA/Jim Grossmann

KSC-2009-1089

NASA Image and Video Library

2009-01-09

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, an overhead crane lowers the ICS Exposed Facility, or ICS-EF, onto the Japanese Experiment Module's Experiment Logistics Module-Exposed Section, or ELM-ES, where it will be installed alongside two other payloads, the SEDA-AP (Space Environment Data Acquisition Equipment-Attached Payload) and MAXI (Monitor of All-sky X-ray Image). The ICS-EF is composed of several components, including an antenna, pointing mechanism, frequency converters, high-power amplifier and various sensors including the Earth sensor, Sun sensor and inertial reference unit. The ICS-EF is part of space shuttle Endeavour's payload on the STS-127 mission, targeted for launch on May 15. Photo credit: NASA/Jim Grossmann

Child abuse potential in mothers with early life maltreatment, borderline personality disorder and depression.

PubMed

Dittrich, Katja; Boedeker, Katja; Kluczniok, Dorothea; Jaite, Charlotte; Hindi Attar, Catherine; Fuehrer, Daniel; Herpertz, Sabine C; Brunner, Romuald; Winter, Sibylle Maria; Heinz, Andreas; Roepke, Stefan; Heim, Christine; Bermpohl, Felix

2018-05-24

Early life maltreatment (ELM), borderline personality disorder (BPD) and major depressive disorder (MDD) have been shown to increase the potential of abuse. Emotion regulation is an identified mediator for the association of ELM and BPD with abuse potential. Until now, there has been no study to account for the co-occurrence of these risk factors in one analysis, although BPD and MDD are known as common sequelae of ELM. This is paired with a lack of studies investigating the effects of abuse potential on child well-being.AimsOur study aims at (a) disentangling the effects of maternal ELM, MDD and BPD on abuse potential; (b) exploring the role of emotion regulation as a mediator; and (c) testing for intergenerational effects of abuse potential on child psychopathology. The research design included 114 mothers with/without ELM, BPD and MDD in remission and their children, all of which were between 5 and 12 years of age. A path analysis was conducted to investigate the multiple associations between our variables. ELM, MDD and BPD were all associated with abuse potential, with emotion regulation acting as a mediator for BPD and MDD. Furthermore, an elevated abuse potential was related to higher psychopathology in the child. History of ELM as well as the common sequelae, BPD and MDD, pose risks for child abuse. Our findings suggest improvement of emotion regulation as a potential target for intervention programs. These programs should also aim at non-substantiated cases because even an elevated abuse potential affected child mental health.Declaration of interestNone.

ELM: AN ALGORITHM TO ESTIMATE THE ALPHA ABUNDANCE FROM LOW-RESOLUTION SPECTRA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bu, Yude; Zhao, Gang; Kumar, Yerra Bharat

We have investigated a novel methodology using the extreme learning machine (ELM) algorithm to determine the α abundance of stars. Applying two methods based on the ELM algorithm—ELM+spectra and ELM+Lick indices—to the stellar spectra from the ELODIE database, we measured the α abundance with a precision better than 0.065 dex. By applying these two methods to the spectra with different signal-to-noise ratios (S/Ns) and different resolutions, we found that ELM+spectra is more robust against degraded resolution and ELM+Lick indices is more robust against variation in S/N. To further validate the performance of ELM, we applied ELM+spectra and ELM+Lick indices to SDSSmore » spectra and estimated α abundances with a precision around 0.10 dex, which is comparable to the results given by the SEGUE Stellar Parameter Pipeline. We further applied ELM to the spectra of stars in Galactic globular clusters (M15, M13, M71) and open clusters (NGC 2420, M67, NGC 6791), and results show good agreement with previous studies (within 1σ). A comparison of the ELM with other widely used methods including support vector machine, Gaussian process regression, artificial neural networks, and linear least-squares regression shows that ELM is efficient with computational resources and more accurate than other methods.« less

Discovery of stationary operation of quiescent H-mode plasmas with net-zero neutral beam injection torque and high energy confinement on DIII-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burrell, K. H.; Chen, X.; Garofalo, A. M.

Recent experiments in DIII-D [J. L. Luxon et al., in Plasma Physics and Controlled Nuclear Fusion Research 1996 (International Atomic Energy Agency, Vienna, 1987), Vol. I, p. 159] have led to the discovery of a means of modifying edge turbulence to achieve stationary, high confinement operation without Edge Localized Mode (ELM) instabilities and with no net 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 excellent tokamak performance, well above the H{sub 98y2} international tokamakmore » energy confinement scaling (H{sub 98y2} = 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 E × B 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. An increase in the E × B shearing rate inside of the edge pedestal is a key factor in the confinement increase. 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 β{sub N} = 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.« less

Levels of circulating MMP-7 degraded elastin are elevated in pulmonary disorders.

PubMed

Kristensen, J H; Larsen, L; Dasgupta, B; Brodmerkel, C; Curran, M; Karsdal, M A; Sand, J M B; Willumsen, N; Knox, A J; Bolton, C E; Johnson, S R; Hägglund, P; Svensson, B; Leeming, D J

2015-11-01

Elastin is a signature protein of the lungs. Matrix metalloproteinase-7 (MMP-7) is important in lung defence mechanisms and degrades elastin. However, MMP-7 activity in regard to elastin degradation has never been quantified serologically in patients with lung diseases. An assay for the quantification of MMP-7 generated elastin fragments (ELM7) was therefore developed to investigate MMP-7 derived elastin degradation in pulmonary disorders such as idiopathic pulmonary fibrosis (IPF) and lung cancer. Monoclonal antibodies (mABs) were raised against eight carefully selected MMP-7 cleavage sites on elastin. After characterisation and validation of the mABs, one mAB targeting the ELM7 fragment was chosen. ELM7 fragment levels were assessed in serum samples from patients diagnosed with IPF (n=123, baseline samples, CTgov reg. NCT00786201), and lung cancer (n=40) and compared with age- and sex-matched controls. The ELM7 assay was specific towards in vitro MMP-7 degraded elastin and the ELM7 neoepitope but not towards other MMP-7 derived elastin fragments. Serum ELM7 levels were significantly increased in IPF (113%, p<0.0001) and lung cancer (96%, p<0.0001) compared to matched controls. MMP-7-generated elastin fragments can be quantified in serum and may reflect pathological lung tissue turnover in several important lung diseases. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Comparison of heat flux measurement techniques during the DIII-D metal ring campaign

NASA Astrophysics Data System (ADS)

Barton, J. L.; Nygren, R. E.; Unterberg, E. A.; Watkins, J. G.; Makowski, M. A.; Moser, A.; Rudakov, D. L.; Buchenauer, D.

2017-12-01

The heat fluxes expected in the ITER divertor raise concerns about the damage tolerances of tungsten, especially due to thermal transients caused by edge localized modes (ELMs) as well as frequent temperature cycling from high to low extremes. Therefore we are motivated to understand the heat flux conditions that can cause not only enhanced erosion but also bulk thermo-mechanical damage to a tungsten divertor. For the metal ring campaign in DIII-D, tungsten-coated TZM tile inserts were installed making two toroidal arrays of metal tile inserts in the lower divertor. This study examines the deposited heat flux on these rings with embedded thermocouples (TCs) sampling at 10 kHz and compares them to Langmuir probe (LP) and infrared thermography (IRTV) heat flux measurements. We see agreement of the TC, LP, and IRTV data within 20% of the heat flux averaged over the entire discharge, and that all three diagnostics suggest parallel heat flux at the OSP location increases linearly with input heating power. The TC and LP heat flux time traces during the discharge trend together during large changes to the average heat flux. By subtracting the LP measured inter-ELM heat flux from TC data, using a rectangular ELM energy pulse shape, and taking the relative size and duration of each ELM from {{D}}α measurements, we extract the ELM heat fluxes from TC data. This over-estimates the IRTV measured ELM heat fluxes by a factor of 1.9, and could be due to the simplicity of the TC heat flux model and the assumed ELM energy pulse shape. ELM heat fluxes deposited on the inserts are used to model tungsten erosion in this campaign. These TC ELM heat flux estimates are used in addition to IRTV, especially in cases where the IRTV view to the metal ring is obstructed. We observe that some metal inserts were deformed due to exposed leading edges. The thermal conditions on these inserts are investigated with the thermal modeling code ABAQUS using our heat flux measurements when these edges were exposed. We discuss how the thermal cycling on the ends of the inserts caused this deformation.

Effect of n = 3 perturbation field amplitudes below the ELM triggering threshold on edge and SOL transport in NSTX

DOE PAGES

J. M. Canik; Lore, J. D.; Ahn, J. -W.; ...

2013-01-12

Here, the pulsed application of n = 3 magnetic perturbation fields with amplitudes below that which triggers ELMs results in distinct, transient responses observable on several edge and divertor diagnostics in NSTX. We refer to these responses as Sub-Threshold Edge Perturbations (STEPs). An analysis of edge measurements suggests that STEPs result in increased transport in the plasma edge and scrape-off layer, which leads to augmentation of the intrinsic strike point splitting due to error fields, i.e., an intensification of the helical divertor footprint flux pattern. These effects are much smaller in magnitude than those of triggered ELMs, and are observedmore » for the duration of the field perturbation measured internal to the vacuum vessel. In addition, STEPs are correlated with changes to the MHD activity, along with transient reductions in the neutron production rate. Ideally the STEPs could be used to provide density control and prevent impurity accumulation, in the same manner that on-demand ELM triggering is used on NSTX, without the impulsive divertor fluxes and potential for damage to plasma facing components associated with ELMs.« less

Investigation of transient melting of tungsten by ELMs in ASDEX Upgrade

NASA Astrophysics Data System (ADS)

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.

Modeling elm growth and Dutch elm disease susceptibility

Treesearch

Alberto Santini; Luisa Ghelardini

2012-01-01

Elm susceptibility to Dutch elm disease (DED) displays strong seasonal variation. The period during which elms can become infected and express DED symptoms is generally restricted to several weeks after growth resumption in spring, although it can vary among species, provenances, and environmental conditions. The reason for this phenomenon is not understood, but the...

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

Treesearch

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....

Edge-localized-modes in tokamaks

DOE PAGES

Leonard, Anthony W.

2014-09-11

Edge-localized-modes (ELMs) are a ubiquitous feature of H-mode in tokamaks. When gradients in the H-mode transport barrier grow to exceed the MHD stability limit the ELM instability grows explosively rapidly transporting energy and particles onto open field lines and material surfaces. Though ELMs provide additional particle and impurity transport through the H-mode transport barrier, enabling steady operation, the resulting heat flux transients to plasma facing surfaces project to large amplitude in future low collisionality burning plasma tokamaks. Measurements of the ELM heat flux deposition onto material surfaces in the divertor and main chamber indicate significant broadening compared to inter-ELM heatmore » flux, with a timescale for energy deposition that is consistent with sonic ion flow and numerical simulation. Comprehensive ELM simulation is highlighting the important physics processes of ELM transport including parallel transport due to magnetic reconnection and turbulence resulting from collapse of the H-mode transport barrier. As a result, encouraging prospects for ELM control and/or suppression in future tokamaks include intrinsic modes of ELM free operation, ELM triggering with frequent small pellet injection and the application of 3D magnetic fields.« less

Edge-localized-modes in tokamaksa)

NASA Astrophysics Data System (ADS)

Leonard, A. W.

2014-09-01

Edge-localized-modes (ELMs) are a ubiquitous feature of H-mode in tokamaks. When gradients in the H-mode transport barrier grow to exceed the MHD stability limit the ELM instability grows explosively, rapidly transporting energy and particles onto open field lines and material surfaces. Though ELMs provide additional particle and impurity transport through the H-mode transport barrier, enabling steady operation, the resulting heat flux transients to plasma facing surfaces project to large amplitude in future low collisionality burning plasma tokamaks. Measurements of the ELM heat flux deposition onto material surfaces in the divertor and main chamber indicate significant broadening compared to inter-ELM heat flux, with a timescale for energy deposition that is consistent with sonic ion flow and numerical simulation. Comprehensive ELM simulation is highlighting the important physics processes of ELM transport including parallel transport due to magnetic reconnection and turbulence resulting from collapse of the H-mode transport barrier. Encouraging prospects for ELM control and/or suppression in future tokamaks include intrinsic modes of ELM free operation, ELM triggering with frequent small pellet injection and the application of 3D magnetic fields.

Operation REDWING 1956

DTIC Science & Technology

1982-08-01

AIRCRAFT UNIT Hq TAU 2 0 1 0 Eniwetok Is. 20 Mar Hq USAF Elm 0 4 0 0 Eniwetok Is. 30 Apr Hq USAF Elm 4 3 2 0 Parry Is. 30 Apr 4g Drop & Cann Elm 15 41 0...0 Eniwrv k Is. 1 5-36 16 Mar i 4 2 5-52 mqý Effects Elm 14 7 8 53 Eniwecck Is. 1 B-52 21 Mar 1 B-47 I B-57 1 B-66 2 F-84F 1 F-101 IBDA Elm 11 35 0 0...Eniwetok Is. 3 B-47 30 Apr Ionosphere Elm 6 12 0 0 Eniwetok Is. 1 C-97 30 Apr * "Navy Effects Elm 8 31 13 0 I A3D "I P2V Early Pe.ietr Elm 16 40 0 0

Is cardiovascular disease in patients with diabetes associated with serum levels of MMP-2, LOX, and the elastin degradation products ELM and ELM-2?

PubMed

Preil, Simone Andrea Rørdam; Thorsen, Anne-Sofie Faarvang; Christiansen, Anne Lindegaard; Poulsen, Mikael Kjær; Karsdal, Morten Asser; Leeming, Diana Julie; Rasmussen, Lars Melholt

2017-11-01

Diabetes mellitus type 2 (T2DM) is a significant risk factor for the development of cardiovascular diseases (CVDs). In a previous microarray study of internal mammary arteries from patients with and without T2DM, we observed several elastin-related genes with altered mRNA-expression in diabetic patients, namely matrix metalloproteinase 2 (MMP-2), lysyl oxidase (LOX) and elastin itself. In this study we investigate whether the serum concentrations of elastin-related proteins correlate to signs of CVD in patients with T2DM. Blood samples from 302 type 2 diabetic patients were analysed for MMP-2, LOX, and the elastin degradation products ELM and ELM2. The results were investigated for correlations to signs of CVD in different vascular territories, as determined by myocardial perfusion scintigraphy, carotid artery thickness and ankle-brachial blood pressure index. T2DM patients with peripheral arterial disease (low ankle-brachial index) (PAD) display higher levels of MMP-2 and ELM compared to patients without PAD. However, none of the proteins or degradation products correlated with myocardial ischemia or a combined measure of CVD-signs, including myocardial ischemia, increased carotid thickness and decreased ankle-brachial blood pressure. Our results suggest that the diabetic environment affects the circulating amounts of MMP-2 and ELM in patients with PAD. However, the same connection could not be seen in diabetic patients with CVD broadly identified in three vascular territories. LOX and ELM-2 did not correlate to any type of CVD. Overall, serum levels of elastin-related molecules are only remotely related to CVD in type 2 diabetes.

Ulmus crassifolia Nutt. Cedar Elm

Treesearch

John J. Stransky; Sylvia M. Bierschenk

1990-01-01

Cedar elm (Ulmus cassifolia) grows rapidly to medium or large size in the Southern United States and northeastern Mexico, where it may sometimes be called basket elm, red elm, southern rock elm, or olmo (Spanish) It usually is found on moist, limestone soils along water courses with other bottomland trees, but it also paws on dry limestone hills. The...

Elm yellows: a widespread and overlooked killer of elm trees across the United States

Treesearch

Charles E. Flower; Nancy Hayes-Plazolles; Cristina Rosa; James M. Slavicek

2017-01-01

The elm yellows phytoplasma (Candidatus Phytoplasma ulmi) is a geographically widespread pathogen that poses a significant threat to most native wild elms in North America (Ulmus americana, U. rubra, U. alata, U. crassifolia, and U. serotina) (Mäurer et al. 1993), as well as to the success of American elm...

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

Treesearch

John Moser; Heino Konrad; Stacy Blomquist; Thomas Kirisits

2010-01-01

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...

Edge localized mode rotation and the nonlinear dynamics of filaments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morales, J. A.; Bécoulet, M.; Garbet, X.

2016-04-15

Edge Localized Modes (ELMs) rotating precursors were reported few milliseconds before an ELM crash in several tokamak experiments. Also, the reversal of the filaments rotation at the ELM crash is commonly observed. In this article, we present a mathematical model that reproduces the rotation of the ELM precursors as well as the reversal of the filaments rotation at the ELM crash. Linear ballooning theory is used to establish a formula estimating the rotation velocity of ELM precursors. The linear study together with nonlinear magnetohydrodynamic simulations give an explanation to the rotations observed experimentally. Unstable ballooning modes, localized at the pedestal,more » grow and rotate in the electron diamagnetic direction in the laboratory reference frame. Approaching the ELM crash, this rotation decreases corresponding to the moment when the magnetic reconnection occurs. During the highly nonlinear ELM crash, the ELM filaments are cut from the main plasma due to the strong sheared mean flow that is nonlinearly generated via the Maxwell stress tensor.« less

Phenylalanine ammonia-lyase activity in suspension cultures of Ulmus pumila and U. campestris treated with spores of Ceratocystis ulmi.

PubMed

Corchete, M P; Diez, J J; Valle, T

1993-12-01

Cell suspension cultures of a Ceratocystis ulmi-resistant (Ulmus pumila) and a -susceptible elm (U.campestris) were established from leaf callus tissue. Treatment of cultures with spores of C.ulmi induced a large increase in the activity of phenylalanine ammonialyase, only in the cells of the resistant species U.pumila with a maximum after 24 h. Inoculated U.pumila cells also excreted a red unidentified chemical into the culture medium. Neither responses were induced in inoculated U.campestris cultures. The results are discussed in relation to the development of the elm cell culture system as a model for studying the differential biochemical mechanisms of disease resistance in elms.

Elm diseases

Treesearch

John W. Peacock

1989-01-01

Dutch elm disease was found in Cleveland, Ohio, in 1930, and is now in most of the contiguous 48 states. The disease is caused by a fungus that has killed millions of wild and planted elms. Losses have been the greatest in the eastern United States. The fungus attacks all elms, but our native species, American, slippery, and rock elm have little or no resistance to the...

HOW to Identify and Manage Dutch Elm Disease

Treesearch

Linda Haugen

1998-01-01

At one time, the American elm was considered to be an ideal street tree because it was graceful, long-lived, fast growing, and tolerant of compacted soils and air pollution. Then Dutch elm disease (DED) was introduced and began devastating the elm population. Estimates of DED losses of elm in communities and woodlands across the U.S. are staggering (figure 1). Because...

Elms and Dutch elm disease: a quick overview

Treesearch

Michael Marcotrigiano

2017-01-01

In the 1930s Dutch elm disease (DED) was accidentally introduced from Europe into the United States. It had a devastating impact on American elm (Ulmus americana) and its relatives in urban and riparian environments. In the United States, the three-part pathosystem for DED is unique in that the affected elm species are North American, the pathogen originated in Asia,...

Hybridization and introgression between the exotic Siberian elm, Ulmus pumila, and the native Field elm, U. minor, in Italy

USDA-ARS?s Scientific Manuscript database

In response to the first Dutch elm disease (DED) pandemic, Siberian elm, Ulmus pumila, was planted to replace the native elm, U. minor, in Italy. The potential for hybridization between these two species is high and repeated hybridization could result in the genetic swamping of the native species an...

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

Treesearch

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...

An analytical expression for ion velocities at the wall including the sheath electric field and surface biasing for erosion modeling at JET ILW

DOE PAGES

Borodkina, I.; Borodin, D.; Brezinsek, S.; ...

2017-04-12

For simulation of plasma-facing component erosion in fusion experiments, an analytical expression for the ion velocity just before the surface impact including the local electric field and an optional surface biasing effect is suggested. Energy and angular impact distributions and the resulting effective sputtering yields were produced for several experimental scenarios at JET ILW mostly involving PFCs exposed to an oblique magnetic field. The analytic solution has been applied as an improvement to earlier ERO modelling of localized, Be outer limiter, RF-enhanced erosion, modulated by toggling of a remote, however magnetically connected ICRH antenna. The effective W sputtering yields duemore » to D and Be ion impact in Type-I and Type-III ELMs and inter-ELM conditions were also estimated using the analytical approach and benchmarked by spectroscopy. The intra-ELM W sputtering flux increases almost 10 times in comparison to the inter-ELM flux.« less

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

Treesearch

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...

Novel insights into the elm yellows phytoplasma genome and into the metagenome of elm yellows-infected elms

Treesearch

Christina Rosa; Paolo Margaria; Scott M. Geib; Erin D. Scully

2017-01-01

In North America, American elms were historically present throughout the northeastern United States and southeastern Canada. The longevity of these trees, their resistance to the harsh urban environment, and their aesthetics led to their wide use in landscaping and streetscaping over several decades. American elms were one of most cultivated plants in the United States...

Constraints to hydraulic acclimation under reduced light in two contrasting Phaseolus vulgaris cultivars.

PubMed

Matzner, Steven L; Rettedal, David D; Harmon, Derek A; Beukelman, MacKenzie R

2014-08-01

Two cultivars of Phaseolus vulgaris L. were grown under three light levels to determine if hydraulic acclimation to light occurs in herbaceous annuals and whether intraspecific trade-offs constrain hydraulic traits. Acclimation occurred in response to reduced light and included decreased stomatal density (SD) and increased specific leaf area (SLA). Reduced light resulted in lower wood density (WD); decreased cavitation resistance, measured as the xylem pressure causing a 50 % reduction in stem conductivity (P50); and increased hydraulic capacity, measured as average leaf mass specific transpiration (E(LM)). Significant or marginally significant trade-offs between P50 and WD, WD and E(LM), and E(LM) and P50 reflected variation due to both genotype and environmental effects. A trade-off between WD and P50 within one cultivar indicated that morphological adjustment was constrained. Coordinated changes in WD, P50, and E(LM) within each cultivar in response to light were consistent with trade-offs constraining plasticity. A water-use efficiency (WUE, measured as δ(13)C) versus hydraulic capacity (E(LM)) trade-off was observed within each cultivar, further indicating that hydraulic trade-offs can constrain acclimation. Larger plants had lower hydraulic capacity (E(LM)) but greater cavitation resistance, WD, and WUE. Distinct hydraulic strategies were observed with the cultivar adapted to irrigated conditions having higher stomatal conductance and stem flow rates. The cultivar adapted to rain-fed conditions had higher leaf area and greater cavitation resistance. Hydraulic trade-offs were observed within the herbaceous P. vulgaris resulting from both genotype and environmental effects. Trade-offs within a cultivar reflected constraints to hydraulic acclimation in response to changing light. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

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

NASA Astrophysics Data System (ADS)

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.

Recovery of copper and cyanide from waste cyanide solutions using emulsion liquid membrane with LIX 7950 as the carrier.

PubMed

Xie, Feng; Wang, Wei

2017-08-01

The feasibility of using emulsion liquid membranes (ELMs) with the guanidine extractant LIX 7950 as the mobile carrier for detoxifying copper-containing waste cyanide solutions has been determined. Relatively stable ELMs can be maintained under suitable stirring speed during mixing ELMs and the external solution. Effective extraction of copper cyanides by ELMs only occurs at pH below 11. High copper concentration in the external phase and high volume ratio of the external phase to ELMs result in high transport rates of copper and cyanide. High molar ratio of cyanide to copper tends to suppress copper extraction. The presence of thiocyanate ion significantly depresses the transport of copper and cyanide through the membrane while the thiosulfate ion produces less impact on copper removal by ELMs. Zinc and nickel cyanides can also be effectively extracted by ELMs. More than 90% copper and cyanide can be effectively removed from alkaline cyanide solutions by ELMs under suitable experimental conditions, indicating the effectiveness of using the designed ELM for recovering copper and cyanide from waste cyanide solutions.

Operating Characteristics in DIII-D ELM-Suppressed RMP H-modes with ITER Similar Shapes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evans, T E; Fenstermacher, M E; Jakubowski, M

2008-10-13

Fast energy transients, incident on the DIII-D divertors due to Type-I edge localized modes (ELMs), are eliminated using small dc currents in a simple set of non-axisymmetric coils that produce edge resonant magnetic perturbations (RMP). In ITER similar shaped (ISS) plasmas, with electron pedestal collisionalities matched to those expected in ITER a sharp resonant window in the safety factor at the 95 percent normalized poloidal flux surface is observed for ELM suppression at q{sub 95}=3.57 with a minimum width {delta}q{sub 95} of {+-}0.05. The size of this resonant window has been increased by a factor of 4 in ISS plasmasmore » by increasing the magnitude of the current in an n=3 coil set along with the current in a separate n=1 coil set. The resonant ELM-suppression window is highly reproducible for a given plasma shape, coil configuration and coil current but can vary with other operating conditions such as {beta}{sub N}. Isolated resonant windows have also been found at other q95 values when using different RMP coil configurations. For example, when the I-coil is operated in an n=3 up-down asymmetric configuration rather than an up-down symmetric configuration a resonant window is found near q{sub 95}=7.4. A Fourier analysis of the applied vacuum magnetic field demonstrates a statistical correlation between the Chirikov island overlap parameter and ELM suppression. These results have been used as a guide for RMP coil design studies in various ITER operating scenarios.« less

H-mode and Edge Physics on the Pegasus ST: Progress and Future Directions

NASA Astrophysics Data System (ADS)

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

2015-11-01

Ohmic H-modes are routinely attained on the Pegasus ST, in part due to the low L-H power threshold PLH arising from low-BT operation at A ~ 1 . Characteristics of H-mode include: improved τe, consistent with H98 ~ 1 edge current and pressure pedestal formation; and the occurrence of ELMs. Experiments in the past year have examined magnetic topology and density dependencies of PLH in detail. PLH exceeds ITER L-H scaling values by 10-20 ×, with PLH /PITPA 08 increasing sharply as A --> 1 . No PLH-minimizing density has been found. Unlike at high- A, PLH is insensitive to limited or diverted magnetic topologies to date. The low BT and modest pedestal values at A ~ 1 afford unique edge diagnostic accessibility to investigate ELMs and their nonlinear dynamics. Jedge (R , t) measured through a Type I ELM shows a complex pedestal collapse and filament ejection. These studies are being extended to higher Ip and longer pulse length with LHI startup to conserve Ohmic V-s and improve MHD stability. A modest-cost upgrade to the facility will enable detailed validation studies of nonlinear ELM dynamics and ELM control. This initiative will upgrade the centerstack, increasing BT by × 3 , Ohmic V-s by × 4 , and pulse lengths to 100 ms at A < 1 . 3 , as well as deploy a comprehensive 3D magnetic perturbation coil system with full poloidal coverage from frame coils and helical centerstack windings. Work supported by US DOE grant DE-FG02-96ER54375.

Development of new Dutch Elm disease-tolerant selections for restoration of the American Elm in urban and forested landscapes

Treesearch

C.C. Pinchot; C.E. Flower; K.S. Knight; C. Marks; R. Minocha; D. Lesser; K. Woeste; P.G. Schaberg; B. Baldwin; D.M. Delatte; T.D. Fox; N. Hayes-Plazolles; B. Held; K. Lehtoma; S. Long; S. Mattix; A. Sipes; J.M. Slavicek

2017-01-01

The goal of our research and development efforts is to restore American elm (Ulmus americana) as a species in both natural and urban landscapes. Accomplishing this goal requires identification/generation of additional American elm cultivars that are tolerant to Dutch elm disease (DED) caused by Ophiostoma ulmi and O. novo-ulmi, and development of methods to reintroduce...

Relative importance of root grafts and bark beetles to the spread of Dutch elm disease

Treesearch

R. A. Cuthbert; W. N., Jr. Cannon; J. W. Peacock

1975-01-01

Root-graft transmission of Dutch elm disease (DED) is sometimes ignored in both research studies and city programs to control DED. Our results indicate that elms adjacent to 1-, 2-, or 3-year-old stumps have a disease rate three to five times higher than elms not adjacent to stumps. We conclude that in Detroit, which has elm plantings typical of many United States...

Association of serum N(ε)-Carboxy methyl lysine with severity of diabetic retinopathy.

PubMed

Mishra, Nibha; Saxena, Sandeep; Shukla, Rajendra K; Singh, Vinita; Meyer, Carsten H; Kruzliak, Peter; Khanna, Vinay K

2016-04-01

To correlate serum levels of N-epsilon-carboxy methyl lysine (N(ε)-CML) with severity of retinopathy, in vivo macular edema and disruption of external limiting membrane (ELM) and photoreceptor ellipsoid zone in type 2 diabetes mellitus (DM). Consecutive cases of type 2 DM [diabetes mellitus with no retinopathy (No DR) (n=20); non- proliferative diabetic retinopathy (NPDR) with diabetic macular edema (n=20); proliferative diabetic retinopathy with diabetic macular edema (PDR) (n=20)] and healthy controls (n=20) between the ages of 40 and 65 years were included (power of study=93.8%). In vivo histology of retinal layers was assessed using spectral domain optical coherence tomography. Every study subject underwent macular thickness analysis using the macular cube 512×128 feature. Disruption of ELM and photoreceptor ellipsoid zone was graded: grade 0, no disruption of ELM and ellipsoid zone; grade 1, ELM disrupted and ellipsoid zone intact; grade 2, both ELM and ellipsoid zone disrupted. Data were statistically analyzed. The mean levels of N(ε)-CML were 31.34±21.23 ng/ml, 73.88±35.01 ng/ml, 91.21±66.65 ng/ml, and 132.08±84.07 ng/ml in control, No DR, NPDR and PDR respectively. N(ε)-CML level was significantly different between the study groups (control, No DR, NPDR and PDR) (p<0.001). Mean logMAR visual acuity decreased with increased levels of N(ε)-CML (p<0.001). The association of N(Ɛ)CML with the grades of disruption was found to be statistically significant (F value=18.48, p<0.001). Univariate analysis was done with N(Ɛ)-CML as a dependent variable. The values of N(Ɛ)-CML were normalized (log10) and were subjected to univariate analysis with fasting blood glucose level, glycosylated hemoglobin, central subfield macular thickness and cube average thickness among the diseased groups (NPDR and PDR) that act as confounders. It was found that none of the variables had significant effect on N(Ɛ)-CML (fasting blood glucose p=0.12, HBA1c p=0.65, central subfield macular thickness p=0.13, cube average thickness p=0.19). N(Ɛ)-CML tends to be a significant and important predictor of grade of ELM and ellipsoid zone disruption in diabetic retinopathy. Increased N(ε)-CML levels are associated with increased severity of diabetic retinopathy, macular edema and structural changes in macula that is ELM and ellipsoid zone disruption, which serves as a prognosticator of visual outcome. Copyright © 2016 Elsevier Inc. All rights reserved.

QUANTITATIVE TESTS OF ELMS AS INTERMEDIATE N PEELING-BALOONING MODES

DOE Office of Scientific and Technical Information (OSTI.GOV)

LAO,LL; SNYDER,PB; LEONARD,AW

2003-03-01

A271 QUANTITATIVE TESTS OF ELMS AS INTERMEDIATE N PEELING-BALOONING MODES. Several testable features of the working model of edge localized modes (ELMs) as intermediate toroidal mode number peeling-ballooning modes are evaluated quantitatively using DIII-D and JT-60U experimental data and the ELITE MHD stability code. These include the hypothesis that ELM sizes are related to the radial widths of the unstable MHD modes, the unstable modes have a strong ballooning character localized in the outboard bad curvature region, and ELM size generally becomes smaller at high edge collisionality. ELMs are triggered when the growth rates of the unstable MHD modes becomemore » significantly large. These testable features are consistent with many ELM observations in DIII-D and JT-60U discharges.« less

Is extreme learning machine feasible? A theoretical assessment (part II).

PubMed

Lin, Shaobo; Liu, Xia; Fang, Jian; Xu, Zongben

2015-01-01

An extreme learning machine (ELM) can be regarded as a two-stage feed-forward neural network (FNN) learning system that randomly assigns the connections with and within hidden neurons in the first stage and tunes the connections with output neurons in the second stage. Therefore, ELM training is essentially a linear learning problem, which significantly reduces the computational burden. Numerous applications show that such a computation burden reduction does not degrade the generalization capability. It has, however, been open that whether this is true in theory. The aim of this paper is to study the theoretical feasibility of ELM by analyzing the pros and cons of ELM. In the previous part of this topic, we pointed out that via appropriately selected activation functions, ELM does not degrade the generalization capability in the sense of expectation. In this paper, we launch the study in a different direction and show that the randomness of ELM also leads to certain negative consequences. On one hand, we find that the randomness causes an additional uncertainty problem of ELM, both in approximation and learning. On the other hand, we theoretically justify that there also exist activation functions such that the corresponding ELM degrades the generalization capability. In particular, we prove that the generalization capability of ELM with Gaussian kernel is essentially worse than that of FNN with Gaussian kernel. To facilitate the use of ELM, we also provide a remedy to such a degradation. We find that the well-developed coefficient regularization technique can essentially improve the generalization capability. The obtained results reveal the essential characteristic of ELM in a certain sense and give theoretical guidance concerning how to use ELM.

1. EXTERIOR VIEW OF ELM CITY PLANT (A. FRANCIS WALKER, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. EXTERIOR VIEW OF ELM CITY PLANT (A. FRANCIS WALKER, 1905-07) FROM SECOND AVENUE ON OPPOSITE SIDE OF ENTRANCE. THIS STRUCTURE WAS ORIGINALLY BUILT AS THE ELM CITY COTTON MILL OF CALLAWAY MILLS. NOTE RESERVOIR IN FOREGROUND. THIS PHOTOGRAPH IS THE LEFT SIDE OF A PANORAMA VIEW THAT INCLUDES HAER Nos. GA-128-2 AND GA-128-3. - Elm City Cotton Mill, 1000 Elm Street, La Grange, Troup County, GA

KSC-08pd3751

NASA Image and Video Library

2008-11-19

CAPE CANAVERAL, Fla. – In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, workers check the mast deployment on the SEDA-AP or Space Environment Data Acquisition equipment--Attached Payload. SEDA-AP will measure space environment in ISS orbit and environmental effects on materials and electronic devices to investigate the interaction with and from the environment at the Kibo exposed facility. The payload will be installed on the Japanese Experiment Module's Experiment Logistics Module-Exposed Section, or ELM-ES. The ELM-ES is one of the final components of the Japan Aerospace Exploration Agency's Kibo laboratory for the International Space Station. It can provide payload storage space and can carry up to three payloads at launch. In addition, the ELM-ES provides a logistics function where it can be returned to the ground aboard the space shuttle. The ELM-ES will be carried aboard space shuttle Endeavour on the STS-127 mission targeted for launch May 15. Photo credit: NASA/Cory Huston

KSC-08pd3750

NASA Image and Video Library

2008-11-19

CAPE CANAVERAL, Fla. – In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, workers deploy the mast on the SEDA-AP or Space Environment Data Acquisition equipment--Attached Payload. SEDA-AP will measure space environment in ISS orbit and environmental effects on materials and electronic devices to investigate the interaction with and from the environment at the Kibo exposed facility. The payload will be installed on the Japanese Experiment Module's Experiment Logistics Module-Exposed Section, or ELM-ES. The ELM-ES is one of the final components of the Japan Aerospace Exploration Agency's Kibo laboratory for the International Space Station. It can provide payload storage space and can carry up to three payloads at launch. In addition, the ELM-ES provides a logistics function where it can be returned to the ground aboard the space shuttle. The ELM-ES will be carried aboard space shuttle Endeavour on the STS-127 mission targeted for launch May 15. Photo credit: NASA/Cory Huston

KSC-08pd3752

NASA Image and Video Library

2008-11-19

CAPE CANAVERAL, Fla. – In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, workers check the mast deployment on the SEDA-AP or Space Environment Data Acquisition equipment--Attached Payload. SEDA-AP will measure space environment in ISS orbit and environmental effects on materials and electronic devices to investigate the interaction with and from the environment at the Kibo exposed facility. The payload will be installed on the Japanese Experiment Module's Experiment Logistics Module-Exposed Section, or ELM-ES. The ELM-ES is one of the final components of the Japan Aerospace Exploration Agency's Kibo laboratory for the International Space Station. It can provide payload storage space and can carry up to three payloads at launch. In addition, the ELM-ES provides a logistics function where it can be returned to the ground aboard the space shuttle. The ELM-ES will be carried aboard space shuttle Endeavour on the STS-127 mission targeted for launch May 15. Photo credit: NASA/Cory Huston

Flambeau Mining Corporation, Ladysmith, Rusk County, Wisconsin. Proposed Open Pit Copper Mine and Waste Containment Area, Draft Environmental Impact Statement.

DTIC Science & Technology

1976-08-01

American elm Lonicera tatarica - tartarian honeysuckle Ulmus rubra - slippery elm Siiibucus canadenis - common elder Ulmus thoiii~sii - cork elm ...community borders the marshes and swamps. 2.060 The predominant species are the trembling aspen (Populus tremuloides), red maple (Acer rubrum), the elms ...succession. The most numerous trees (in descending order) are: white birch, red maple, aspen, sugar maple, black ash, basswood, elm (Ulmus sp.), hemlock

Professors in the Trenches: Deployed Soldiers and Social Science Academics

DTIC Science & Technology

2009-01-01

CGSC Experiential Learning Model, or ELM . The ELM serves as the methodology for both lesson plan design at the Command and General Staff College and as...the experiential learning model ( ELM ) than the U.S. contractors – the ELM methodology, by design, addresses all four learning style preferences. The...Since the CGSC team used the experiential learning model as the way to teach, they modeled the ELM as they taught all their classes. After the first

Ecological Investigation of a Greentree Reservoir in the Delta National Forest, Mississippi.

DTIC Science & Technology

1981-09-01

elm (Ulmus americana) and slippery elm (U. rubra) oc- curred in the study area, with American elm the more abundant species. No distinction was made...spectively, on both areas (see Appendix C for nomenclature). American elm * and water hickory ranked fifth and sixth in importance on the ref- erence area...between these two species; the label "American elm " includes data for both. 18 boundaries, water hickory increment cores were not analyzed. Table 4

Elm leaf beetle performance on ozone-fumigated elm

Treesearch

Jack H. Barger; Richard W. Hall; Alden M. Townsend; Alden M. Townsend

1992-01-01

Leaves (1986) from elm hybrids ('Pioneer', 'Homestead', '970') previously fumigated in open-top chambers with ozone or with charcoal-filtered air (CFA) were evaluated for water and nitrogen content or were fed to adult elm leaf beetles (ELB), Xanthogaleruca = (Pyrrhallta) luteola (Muller), to determine host suitability for beetle fecundity...

Using Dutch elm disease-tolerant elm to restore floodplains impacted by emerald ash borer

Treesearch

Kathleen S. Knight; James M. Slavicek; Rachel Kappler; Elizabeth Pisarczyk; Bernadette Wiggin; Karen. Menard

2012-01-01

American elm (Ulmus Americana L.) was a dominant species in floodplains and swamps of the Midwest before Dutch elm disease (DED) (Ophiostoma ulmi and O.novo-ulmi) reduced its populations. In many areas, ash (Fraxinus spp.) became dominant in these ecosystems. Emerald ash borer (EAB) (...

A Study of Vegetation Development in Relation to Age of River Stabilization Structures Along a Channelized Segment of the Missouri River.

DTIC Science & Technology

1975-01-25

s.ame time period, the first shrub species begin to appear in the sites. Ulmus rubra ( slippery elm ), Celtis occidentalis (hackberry), and Platanus...boxelder), Ulmus americana (American elm ), Ulmus rubra ( slippery elm ), Fra:inus pennsyl- vanica (green ash), and Juglans nigra (black walnut). These may...be replaced by Tilia americana (basswood), the Ulmus americana (American elm ) and Ulmus rubra ( slippery elm ) remaining as co- dominants. Weaver (1960

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

PubMed Central

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 eradication attempts. Widespread use of neonicotinoid insecticides, however, can disrupt ecosystems tipping the ecological balance in favor of herbivores and creating pest outbreaks. PMID:21655275

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

NASA Astrophysics Data System (ADS)

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.

Meta-cognitive online sequential extreme learning machine for imbalanced and concept-drifting data classification.

PubMed

Mirza, Bilal; Lin, Zhiping

2016-08-01

In this paper, a meta-cognitive online sequential extreme learning machine (MOS-ELM) is proposed for class imbalance and concept drift learning. In MOS-ELM, meta-cognition is used to self-regulate the learning by selecting suitable learning strategies for class imbalance and concept drift problems. MOS-ELM is the first sequential learning method to alleviate the imbalance problem for both binary class and multi-class data streams with concept drift. In MOS-ELM, a new adaptive window approach is proposed for concept drift learning. A single output update equation is also proposed which unifies various application specific OS-ELM methods. The performance of MOS-ELM is evaluated under different conditions and compared with methods each specific to some of the conditions. On most of the datasets in comparison, MOS-ELM outperforms the competing methods. Copyright © 2016 Elsevier Ltd. All rights reserved.

Edge-localized mode avoidance and pedestal structure in I-mode plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walk, J. R., E-mail: jrwalk@psfc.mit.edu; Hughes, J. W.; Hubbard, A. E.

I-mode is a high-performance tokamak regime characterized by the formation of a temperature pedestal and enhanced energy confinement, without an accompanying density pedestal or drop in particle and impurity transport. I-mode operation appears to have naturally occurring suppression of large Edge-Localized Modes (ELMs) in addition to its highly favorable scalings of pedestal structure and overall performance. Extensive study of the ELMy H-mode has led to the development of the EPED model, which utilizes calculations of coupled peeling-ballooning MHD modes and kinetic-ballooning mode (KBM) stability limits to predict the pedestal structure preceding an ELM crash. We apply similar tools to themore » structure and ELM stability of I-mode pedestals. Analysis of I-mode discharges prepared with high-resolution pedestal data from the most recent C-Mod campaign reveals favorable pedestal scalings for extrapolation to large machines—pedestal temperature scales strongly with power per particle P{sub net}/n{sup ¯}{sub e}, and likewise pedestal pressure scales as the net heating power (consistent with weak degradation of confinement with heating power). Matched discharges in current, field, and shaping demonstrate the decoupling of energy and particle transport in I-mode, increasing fueling to span nearly a factor of two in density while maintaining matched temperature pedestals with consistent levels of P{sub net}/n{sup ¯}{sub e}. This is consistent with targets for increased performance in I-mode, elevating pedestal β{sub p} and global performance with matched increases in density and heating power. MHD calculations using the ELITE code indicate that I-mode pedestals are strongly stable to edge peeling-ballooning instabilities. Likewise, numerical modeling of the KBM turbulence onset, as well as scalings of the pedestal width with poloidal beta, indicates that I-mode pedestals are not limited by KBM turbulence—both features identified with the trigger for large ELMs, consistent with the observed suppression of large ELMs in I-mode.« less

Edge-localized mode avoidance and pedestal structure in I-mode plasmasa)

NASA Astrophysics Data System (ADS)

Walk, J. R.; Hughes, J. W.; Hubbard, A. E.; Terry, J. L.; Whyte, D. G.; White, A. E.; Baek, S. G.; Reinke, M. L.; Theiler, C.; Churchill, R. M.; Rice, J. E.; Snyder, P. B.; Osborne, T.; Dominguez, A.; Cziegler, I.

2014-05-01

I-mode is a high-performance tokamak regime characterized by the formation of a temperature pedestal and enhanced energy confinement, without an accompanying density pedestal or drop in particle and impurity transport. I-mode operation appears to have naturally occurring suppression of large Edge-Localized Modes (ELMs) in addition to its highly favorable scalings of pedestal structure and overall performance. Extensive study of the ELMy H-mode has led to the development of the EPED model, which utilizes calculations of coupled peeling-ballooning MHD modes and kinetic-ballooning mode (KBM) stability limits to predict the pedestal structure preceding an ELM crash. We apply similar tools to the structure and ELM stability of I-mode pedestals. Analysis of I-mode discharges prepared with high-resolution pedestal data from the most recent C-Mod campaign reveals favorable pedestal scalings for extrapolation to large machines—pedestal temperature scales strongly with power per particle Pnet/n ¯e, and likewise pedestal pressure scales as the net heating power (consistent with weak degradation of confinement with heating power). Matched discharges in current, field, and shaping demonstrate the decoupling of energy and particle transport in I-mode, increasing fueling to span nearly a factor of two in density while maintaining matched temperature pedestals with consistent levels of Pnet/n ¯e. This is consistent with targets for increased performance in I-mode, elevating pedestal βp and global performance with matched increases in density and heating power. MHD calculations using the ELITE code indicate that I-mode pedestals are strongly stable to edge peeling-ballooning instabilities. Likewise, numerical modeling of the KBM turbulence onset, as well as scalings of the pedestal width with poloidal beta, indicates that I-mode pedestals are not limited by KBM turbulence—both features identified with the trigger for large ELMs, consistent with the observed suppression of large ELMs in I-mode.

The impact of the fast ion fluxes and thermal plasma loads on the design of the ITER fast ion loss detector

NASA Astrophysics Data System (ADS)

Kocan, M.; Garcia-Munoz, M.; Ayllon-Guerola, J.; Bertalot, L.; Bonnet, Y.; Casal, N.; Galdon, J.; Garcia-Lopez, J.; Giacomin, T.; Gonzalez-Martin, J.; Gunn, J. P.; Rodriguez-Ramos, M.; Reichle, R.; Rivero-Rodriguez, J. F.; Sanchis-Sanchez, L.; Vayakis, G.; Veshchev, E.; Vorpahl, C.; Walsh, M.; Walton, R.

2017-12-01

Thermal plasma loads to the ITER Fast Ion Loss Detector are studied for QDT = 10 burning plasma equilibrium using the 3D field line tracing. The simulations are performed for a FILD insertion 9-13 cm past the port plasma facing surface, optimized for fast ion measurements, and include the worst-case perturbation of the plasma boundary and the error in the magnetic reconstruction. The FILD head is exposed to superimposed time-averaged ELM heat load, static inter-ELM heat flux and plasma radiation. The study includes the estimate of the instantaneous temperature rise due to individual 0.6 MJ controlled ELMs. The maximum time-averaged surface heat load is lesssim 12 MW/m2 and will lead to increase of the FILD surface temperature well below the melting temperature of the materials considered here, for the FILD insertion time of 0.2 s. The worst-case instantaneous temperature rise during controlled 0.6 MJ ELMs is also significantly smaller than the melting temperature of e.g. Tungsten or Molybdenum, foreseen for the FILD housing.

Stabilizing Effect of Resistivity towards ELM-free H-mode Discharge in Lithium-conditioned NSTX

NASA Astrophysics Data System (ADS)

Banerjee, Debabrata; Zhu, Ping; Maingi, Rajesh

2016-10-01

The stabilizing effect of edge resistivity on the edge localized modes (ELMs) has been recently recovered through analyzing NSTX experimental profiles of Lithium-conditioned ELM-free H-mode discharge. Comparative studies of ELM-free and a reference NSTX ELMy-H mode equilibriums have been performed using both resistive and 2-fluid MHD models implemented in the initial value extended MHD code NIMROD. Our results indicate that in addition to the pedestal profile refinement in electron pressure, the inclusion of enhanced resistivity due to the increase in the effective electric charge number Zeff, which is observed after Lithium-conditioning in experiment, is further required to account for the full stabilization of the low- n edge localized modes. Such a stabilization from the enhanced edge resistivity only becomes effective when the two-fluid diamagnetic and finite-Larmor-radius (FLR) effects are considered in the MHD model. Supported by the National Magnetic Confinement Fusion Program of China under Grant Nos. 2014GB124002 and 2015GB101004, the 100 Talent Program and the President International Fellowship Initiative of the Chinese Academy of Sciences.

Ten-year performance of the United States national elm trial

Treesearch

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...

FRONT ELEVATION OF RESIDENCE, SHOWING ELM DRIVE AND SIDEWALK IN ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

FRONT ELEVATION OF RESIDENCE, SHOWING ELM DRIVE AND SIDEWALK IN THE FOREGROUND. VIEW FACING NORTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Types 8 and 11, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

Establishment and characterization of American elm cell suspension cultures

Treesearch

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...

Novel insights into the Elm Yellows phytoplasma genome and into the metagenome of Elm Yellows-infected elms

USDA-ARS?s Scientific Manuscript database

In North America, American elms were historically present throughout the northeastern United States and southeastern Canada. The longevity of these trees, their resistance to the harsh urban environment, and their aesthetics led to their wide use in landscaping and streetscaping over several decade...

Modeling carbon production and transport during ELMs in DIII-D

NASA Astrophysics Data System (ADS)

Hogan, J.; Wade, M.; Coster, D.; Lasnier, C.

2004-11-01

Large-scale Type I ELM events could provide a significant C source in ITER, and C production rates depend on incident D flux density and surface temperature, quantities which can vary significantly during an ELM event. Recent progress on DIII-D has improved opportunities for code comparison. Fast time-scale measurements of divertor CIII evolution [1] and fast edge CER measurements of C profile evolution during low-density DIII-D LSN ELMy H-modes (type I) [2] have been modeled using the solps5.0/Eirene99 coupled edge code and time dependent thermal analysis codes. An ELM model based on characteristics of MHD peeling-ballooning modes reproduces the pedestal evolution. Qualitative agreement for the CIII evolution during an ELM event is found using the Roth et al annealing model for chemical sputtering and the sensitivity to other models is described. Significant ELM-to-ELM variations in observed maximum divertor target IR temperature during nominally identical ELMs are investigated with models for C emission from micron-scale dust particles. [1] M Groth, M Fenstermacher et al J Nucl Mater 2003, [2] M Wade, K Burrell et al PSI-16

SIGNIFICANCE OF PREOPERATIVE EXTERNAL LIMITING MEMBRANE HEIGHT ON VISUAL PROGNOSIS IN PATIENTS UNDERGOING MACULAR HOLE SURGERY.

PubMed

Geenen, Caspar; Murphy, Declan C; Sandinha, Maria T; Rees, Jon; Steel, David H W

2018-03-05

To investigate the association between the vertical elevation of the external limiting membrane (ELM) and visual outcome in patients undergoing surgery for idiopathic full-thickness macular hole. Retrospective observational study of a consecutive cohort of patients undergoing vitrectomy to treat macular hole. The greatest vertical height of the central ELM above the retinal pigment epithelium (ELM height) was measured on spectral domain optical coherence tomography preoperatively. The relationship of ELM height to other preoperative and postoperative variables, including macular hole width and height, and visual acuity was analyzed. Data from 91 eyes of 91 patients who had undergone successful hole closure were included. The mean ELM height was 220 μm (range 100-394). There were significant correlations between the ELM height and the diameter of the hole, hole height, and worsening preoperative visual acuity. For holes less than 400 μm in width, better postoperative visual acuity was significantly predicted by a lower ELM height. The ELM height varies widely in idiopathic macular hole. It is higher in eyes where the hole is wider and also when the hole itself is higher. For holes of less than 400 μm in width, a lower ELM height is a strong independent predictor of a good postoperative outcome.

Quantitative thickness prediction of tectonically deformed coal using Extreme Learning Machine and Principal Component Analysis: a case study

NASA Astrophysics Data System (ADS)

Wang, Xin; Li, Yan; Chen, Tongjun; Yan, Qiuyan; Ma, Li

2017-04-01

The thickness of tectonically deformed coal (TDC) has positive correlation associations with gas outbursts. In order to predict the TDC thickness of coal beds, we propose a new quantitative predicting method using an extreme learning machine (ELM) algorithm, a principal component analysis (PCA) algorithm, and seismic attributes. At first, we build an ELM prediction model using the PCA attributes of a synthetic seismic section. The results suggest that the ELM model can produce a reliable and accurate prediction of the TDC thickness for synthetic data, preferring Sigmoid activation function and 20 hidden nodes. Then, we analyze the applicability of the ELM model on the thickness prediction of the TDC with real application data. Through the cross validation of near-well traces, the results suggest that the ELM model can produce a reliable and accurate prediction of the TDC. After that, we use 250 near-well traces from 10 wells to build an ELM predicting model and use the model to forecast the TDC thickness of the No. 15 coal in the study area using the PCA attributes as the inputs. Comparing the predicted results, it is noted that the trained ELM model with two selected PCA attributes yields better predication results than those from the other combinations of the attributes. Finally, the trained ELM model with real seismic data have a different number of hidden nodes (10) than the trained ELM model with synthetic seismic data. In summary, it is feasible to use an ELM model to predict the TDC thickness using the calculated PCA attributes as the inputs. However, the input attributes, the activation function and the number of hidden nodes in the ELM model should be selected and tested carefully based on individual application.

Evaluation of extreme learning machine for classification of individual and combined finger movements using electromyography on amputees and non-amputees.

PubMed

Anam, Khairul; Al-Jumaily, Adel

2017-01-01

The success of myoelectric pattern recognition (M-PR) mostly relies on the features extracted and classifier employed. This paper proposes and evaluates a fast classifier, extreme learning machine (ELM), to classify individual and combined finger movements on amputees and non-amputees. ELM is a single hidden layer feed-forward network (SLFN) that avoids iterative learning by determining input weights randomly and output weights analytically. Therefore, it can accelerate the training time of SLFNs. In addition to the classifier evaluation, this paper evaluates various feature combinations to improve the performance of M-PR and investigate some feature projections to improve the class separability of the features. Different from other studies on the implementation of ELM in the myoelectric controller, this paper presents a complete and thorough investigation of various types of ELMs including the node-based and kernel-based ELM. Furthermore, this paper provides comparisons of ELMs and other well-known classifiers such as linear discriminant analysis (LDA), k-nearest neighbour (kNN), support vector machine (SVM) and least-square SVM (LS-SVM). The experimental results show the most accurate ELM classifier is radial basis function ELM (RBF-ELM). The comparison of RBF-ELM and other well-known classifiers shows that RBF-ELM is as accurate as SVM and LS-SVM but faster than the SVM family; it is superior to LDA and kNN. The experimental results also indicate that the accuracy gap of the M-PR on the amputees and non-amputees is not too much with the accuracy of 98.55% on amputees and 99.5% on the non-amputees using six electromyography (EMG) channels. Copyright © 2016 Elsevier Ltd. All rights reserved.

Surface heat loads on the ITER divertor vertical targets

NASA Astrophysics Data System (ADS)

Gunn, J. P.; Carpentier-Chouchana, S.; Escourbiac, F.; Hirai, T.; Panayotis, S.; Pitts, R. A.; Corre, Y.; Dejarnac, R.; Firdaouss, M.; Kočan, M.; Komm, M.; Kukushkin, A.; Languille, P.; Missirlian, M.; Zhao, W.; Zhong, G.

2017-04-01

The heating of tungsten monoblocks at the ITER divertor vertical targets is calculated using the heat flux predicted by three-dimensional ion orbit modelling. The monoblocks are beveled to a depth of 0.5 mm in the toroidal direction to provide magnetic shadowing of the poloidal leading edges within the range of specified assembly tolerances, but this increases the magnetic field incidence angle resulting in a reduction of toroidal wetted fraction and concentration of the local heat flux to the unshadowed surfaces. This shaping solution successfully protects the leading edges from inter-ELM heat loads, but at the expense of (1) temperatures on the main loaded surface that could exceed the tungsten recrystallization temperature in the nominal partially detached regime, and (2) melting and loss of margin against critical heat flux during transient loss of detachment control. During ELMs, the risk of monoblock edge melting is found to be greater than the risk of full surface melting on the plasma-wetted zone. Full surface and edge melting will be triggered by uncontrolled ELMs in the burning plasma phase of ITER operation if current models of the likely ELM ion impact energies at the divertor targets are correct. During uncontrolled ELMs in pre-nuclear deuterium or helium plasmas at half the nominal plasma current and magnetic field, full surface melting should be avoided, but edge melting is predicted.

Effects of two natural medicine formulations on irritable bowel syndrome symptoms: a pilot study.

PubMed

Hawrelak, Jason A; Myers, Stephen P

2010-10-01

The study objective was to assess the effects and tolerability of two novel natural medicine formulations in improving bowel habit and abdominal symptoms in patients with irritable bowel syndrome (IBS). The DA-IBS formula was designed to treat diarrhea-predominant and alternating bowel habit IBS, and the C-IBS formula was designed to treat constipation-predominant IBS. This was a two arm, open-label, uncontrolled pilot study. Subjects were recruited from the greater Lismore area (NSW, Australia) in 2001. The study included 31 patients who fulfilled the Rome II criteria for IBS. Twenty-one (21) patients were classified as suffering from diarrhea-predominant or alternating bowel habit IBS and 10 patients were classified with constipation-predominant IBS. The DA-IBS formula consisted of a mixture of dried, powdered bilberry fruit, slippery elm bark, agrimony aerial parts, and cinnamon quills. The C-IBS formula consisted of a mixture of dried powdered slippery elm bark, lactulose, oat bran, and licorice root. The aim of each formula was to normalize stool frequency and stool consistency. Ingestion of the DA-IBS formula was associated with a small, but significant increase in bowel movement frequency (p = 0.027). Subjects in the DA-IBS group also experienced reductions in straining (p = 0.004), abdominal pain (p = 0.006), bloating (p < 0.0001), flatulence (p = 0.0001), and global IBS symptoms (p = 0.002) during the treatment phase of the trial. Subjects in the C-IBS group experienced a 20% increase in bowel movement frequency (p = 0.016) and significant reductions in straining (p < 0.0001), abdominal pain (p = 0.032), bloating (p = 0.034), and global IBS symptom severity (p = 0.0005), as well as improvements in stool consistency (p < 0.0001). Both formulas were well-tolerated. The DA-IBS formula was not effective in improving bowel habit in individuals with diarrhea-predominant or alternating bowel habit IBS, although it did significantly improve a number of IBS symptoms. The C-IBS formula significantly improved both bowel habit and IBS symptoms in patients with constipation-predominant IBS. Further research is warranted on C-IBS, as a potentially useful therapeutic formula.

Nonlinear fluid simulation of particle and heat fluxes during burst of ELMs on DIII-D with BOUT++ code [Fluid Simulation of Particle and Heat Fluxes during Burst of ELMs on DIID with BOUT++ code

DOE PAGES

Xia, T. Y.; Xu, X. Q.

2015-09-01

In order to study the distribution and evolution of the transient particle and heat fluxes during edge-localized mode (ELM) bursts, a BOUT++ six-field two-fluid model based on the Braginskii equations with non-ideal physics effects is used to simulate pedestal collapse in divertor geometry. We used the profiles from the DIII-D H-mode discharge #144382 with fast target heat flux measurements as the initial conditions for the simulations. Moreover, a flux-limited parallel thermal conduction is used with three values of the flux-limiting coefficientmore » $${{\\alpha}_{j}}$$ , free streaming model with $${{\\alpha}_{j}}=1$$ , sheath-limit with $${{\\alpha}_{j}}=0.05$$ , and one value in between. The studies show that a 20 times increase in $${{\\alpha}_{j}}$$ leads to ~6 times increase in the heat flux amplitude to both the inner and outer targets, and the widths of the fluxes are also expanded. The sheath-limit model of flux-limiting coefficient is found to be the most appropriate one, which shows ELM sizes close to the measurements. The evolution of the density profile during the burst of ELMs of DIII-D discharge #144382 is simulated, and the collapse in width and depth of $${{n}_{\\text{e}}}$$ are reproduced at different time steps. The growing process of the profiles for the heat flux at divertor targets during the burst of ELMs measured by IRTV (infrared television) is also reproduced by this model. The widths of heat fluxes towards targets are a little narrower, and the peak amplitudes are twice the measurements possibly due to the lack of a model of divertor radiation which can effectively reduce the heat fluxes. The magnetic flutter combined with parallel thermal conduction is found to be able to increase the total heat loss by around 33% since the magnetic flutter terms provide the additional conductive heat transport in the radial direction. Finally, the heat flux profile at both the inner and outer targets is obviously broadened by magnetic flutter. The lobe structures near the X-point at LFS are both broadened and elongated due to the magnetic flutter.« less

Gyro-Landau-Fluid Theory and Simulations of Edge-Localized-Modes

NASA Astrophysics Data System (ADS)

Xu, X. Q.

2012-10-01

We report on the theory and simulations of edge-localized-modes (ELMs) using a gyro-Landau-fluid (GLF) extension of the BOUT++ code. Consistent with the two-fluid model (including 1st order FLR corrections), large ELMs, which are low-to-intermediate toroidal mode number (n) peeling-ballooning (P-B) modes, are suppressed by finite Larmor radius (FLR) effects as the ion temperature increases, while small ELMs (at intermediate n's) remain unstable. This result is good news for high ion temperatures in ITER due to the large stabilizing effects of FLR. Because the FLR effects are proportional to both Ti and n, the maximum growth rate is inversely proportional to Ti and the P-B mode is stabilized at high n. Nonlinear gyro-fluid simulations show results similar to those from the two-fluid model, namely that the P-B modes trigger magnetic reconnection, which drives the collapse of the pedestal pressure. Hyper-resistivity limits the radial spreading of ELMs by facilitating magnetic reconnection. The gyro-fluid ion model further limits the radial spreading of ELMs due to FLR-corrected nonlinear ExB convection of the ion gyro-center density. A gyro-fluid ETG model is being developed to self-consistently calculate the hyper-resistivity. Zonal magnetic fields arise from an ELM event and finite beta drift-wave turbulence when electron inertia effects are included. These lead to current generation and self-consistent current transport as a result of ExB convection in the generalized Ohm's law. Because edge plasmas have significant spatial inhomogeneities and complicated boundary conditions, we have developed a fast non-Fourier method for the computation of Landau-fluid closure terms based on an accurate and tunable approximation. The accuracy and the fast computational scaling of the method are demonstrated.

Tree and stand transpiration in a Midwestern bur oak savanna after elm encroachment and restoration thinning

USGS Publications Warehouse

Asbjornsen, H.; Tomer, M.D.; Gomez-Cardenas, M.; Brudvig, L.A.; Greenan, C.M.; Schilling, K.

2007-01-01

Oak savannas, once common in the Midwest, are now isolated remnants within agricultural landscapes. Savanna remnants are frequently encroached by invasive trees to become woodlands. Thinning and prescribed burning can restore savanna structure, but the ecohydrological effects of managing these remnants are poorly understood. In this study, we measured sap flow (Js) to quantify transpiration in an Iowa bur oak (Quercus macrocarpa) savanna woodland encroached by elms (Ulmus americana), and in an adjacent restored savanna after thinning to remove elms, during summer 2004. Savanna oaks had greater mean daily Js (35.9 L dm-2 day-1) than woodland oaks (20.7 L dm-2 day-1) and elms (12.4 L dm-2 day-1). The response of Js to vapor pressure deficit (D) was unexpectedly weak, although oaks in both stands showed negative correlation between daily Js and D for D > 0.4 kPa. An earlier daily peak in Js in the elm trees showed a possible advantage for water uptake. As anticipated, the woodland's stand transpiration was greater (1.23 mm day-1) than the savanna's (0.35 mm day-1), yet the savanna achieved 30% of the woodland's transpiration with only 11% of its sapwood area. The difference in transpiration influenced water table depths, which were 2 m in the savanna and 6.5 m in the woodland. Regionally, row-crop agriculture has increased groundwater recharge and raised water tables, providing surplus water that perhaps facilitated elm encroachment. This has implications for restoration of savanna remnants. If achieving a savanna ecohydrology is an aim of restoration, then restoration strategies may require buffers, or targeting of large or hydrologically isolated remnants. ?? 2007.

Source and Message Factors in Persuasion: A Reply to Stiff's Critique of the Elaboration Likelihood Model.

ERIC Educational Resources Information Center

Petty, Richard E.; And Others

1987-01-01

Answers James Stiff's criticism of the Elaboration Likelihood Model (ELM) of persuasion. Corrects certain misperceptions of the ELM and criticizes Stiff's meta-analysis that compares ELM predictions with those derived from Kahneman's elastic capacity model. Argues that Stiff's presentation of the ELM and the conclusions he draws based on the data…

American elm clones of importance in Dutch elm disease tolerance studies

Treesearch

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...

First Results of ELM Triggering With a Multichamber Lithium Granule Injector Into EAST Discharges

DOE PAGES

Sun, Z.; Lunsford, R.; Maingi, R.; ...

2017-12-12

A critical challenge facing the basic long-pulse H-mode for ITER is to control edge-localized modes (ELMs). A new method using a multichamber lithium (Li) granule injector (LGI) for ELM triggering experiments has been developed in Experimental Advanced Superconducting Tokamak (EAST). First experimental results of the control of ELMs are obtained in EAST with a tungsten divertor. It is found that the injector has good capacities, i.e., allowing good flexibilities in granule size selection, injection rate, and injection velocity. In conclusion, LGI has successfully triggered ELMs during the H-mode. These results indicate the LGI would be a promising method to controlmore » ELMs in long-pulse steady-state tokamaks.« less

First Results of ELM Triggering With a Multichamber Lithium Granule Injector Into EAST Discharges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Z.; Lunsford, R.; Maingi, R.

A critical challenge facing the basic long-pulse H-mode for ITER is to control edge-localized modes (ELMs). A new method using a multichamber lithium (Li) granule injector (LGI) for ELM triggering experiments has been developed in Experimental Advanced Superconducting Tokamak (EAST). First experimental results of the control of ELMs are obtained in EAST with a tungsten divertor. It is found that the injector has good capacities, i.e., allowing good flexibilities in granule size selection, injection rate, and injection velocity. In conclusion, LGI has successfully triggered ELMs during the H-mode. These results indicate the LGI would be a promising method to controlmore » ELMs in long-pulse steady-state tokamaks.« less

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

PubMed

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.

Ideal MHD stability and characteristics of edge localized modes on CFETR

NASA Astrophysics Data System (ADS)

Li, Ze-Yu; Chan, V. S.; Zhu, Yi-Ren; Jian, Xiang; Chen, Jia-Le; Cheng, Shi-Kui; Zhu, Ping; Xu, Xue-Qiao; Xia, Tian-Yang; Li, Guo-Qiang; Lao, L. L.; Snyder, P. B.; Wang, Xiao-Gang; the CFETR Physics Team

2018-01-01

Investigation on the equilibrium operation regime, its ideal magnetohydrodynamics (MHD) stability and edge localized modes (ELM) characteristics is performed for the China Fusion Engineering Test Reactor (CFETR). The CFETR operation regime study starts with a baseline scenario (R  =  5.7 m, B T  =  5 T) derived from multi-code integrated modeling, with key parameters {{β }N},{{β }T},{{β }p} varied to build a systematic database. These parameters, under profile and pedestal constraints, provide the foundation for the engineering design. The long wavelength low-n global ideal MHD stability of the CFETR baseline scenario, including the wall stabilization effect, is evaluated by GATO. It is found that the low-n core modes are stable with a wall at r/a  =  1.2. An investigation of intermediate wavelength ideal MHD modes (peeling ballooning modes) is also carried out by multi-code benchmarking, including GATO, ELITE, BOUT++ and NIMROD. A good agreement is achieved in predicting edge-localized instabilities. Nonlinear behavior of ELMs for the baseline scenario is simulated using BOUT++. A mix of grassy and type I ELMs is identified. When the size and magnetic field of CFETR are increased (R  =  6.6 m, B T  =  6 T), collisionality correspondingly increases and the instability is expected to shift to grassy ELMs.

Numerical Analysis of the Effects of Normalized Plasma Pressure on RMP ELM Suppression in DIII-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orlov, D. M.; Moyer, R.A.; Evans, T. E.

2010-01-01

The effect of normalized plasma pressure as characterized by normalized pressure parameter (beta(N)) on the suppression of edge localized modes (ELMs) using resonant magnetic perturbations (RMPs) is studied in low-collisionality (nu* <= 0.2) H-mode plasmas with low-triangularity ( = 0.25) and ITER similar shapes ( = 0.51). Experimental results have suggested that ELM suppression by RMPs requires a minimum threshold in plasma pressure as characterized by beta(N). The variations in the vacuum field topology with beta(N) due to safety factor profile and island overlap changes caused by variation of the Shafranov shift and pedestal bootstrap current are examined numerically withmore » 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, Poincare sections and field line loss fractions. These differences do not appear to explain the observed threshold in beta(N) for ELM suppression. Linear peeling-ballooning stability analysis with the ELITE code suggests that the ELMs which persist during the RMPs when beta(N) 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.« less

Antibiotic Injections Control Elm Phloem Necrosis in the Urban Ecosystem

Treesearch

T. H. Filer

1976-01-01

When nine American and cedar elms showing symptoms of elm phloem necrosis were given repeated injections of tetracycline antibiotics for several years, all treated trees recovered and appeared healthy by 1976. All but one of the untreated checks died. Of 10 severely infected American elms treated only during the summer of 1972, seven died and the other three showed...

The Italian elm breeding program for Dutch elm disease resistance

Treesearch

Alberto Santini; Francesco Pecori; Luisa Ghelardini

2012-01-01

In the 20th century, elms across Europe and North America were devastated by two pandemics of Dutch elm disease (DED), caused by the introduction of two fungal pathogens: Ophiostoma ulmi, followed by O. novo-ulmi. At the end of 1920s, research into a resistance to DED began in Europe and then in the United States. No...

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

Treesearch

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...

Pressure injection of methyl 2-benzimidazole carbamate hydrochloride solution as a control for Dutch elm disease

Treesearch

Garold F. Gregory; Thomas W. Jones

1973-01-01

A preliminary evaluation of the effectiveness of injecting methyl 2-benzimidazole carbamate hydrochloride solution into elms for prevention or cure of Dutch elm disease is reported. Symptom development was diminished or prevented in elms injected with fungicide before inoculation. Symptom development was arrested in all crown-inoculated diseased trees injected with the...

The ecological role of American elm (Ulmus americana L.) in floodplain forests of northeastern North America

Treesearch

Christian O. Marks

2017-01-01

Before Dutch elm disease, the American elm (Ulmus americana L.) was a leading dominant tree species in the better drained parts of floodplain forests where flooding occurs about 1 percent of the time. Although still common in these habitats today, U. americana now rarely lives long enough to reach the forest canopy because elm...

Development of methods for the restoration of the American elm in forested landscapes

Treesearch

James M. Slavicek

2013-01-01

A project was initiated in 2003 to establish test sites to develop methods to reintroduce the American elm (Ulmus americana L.) in forested landscapes. American elm tree strains with high levels of tolerance to Dutch elm disease (DED) were established in areas where the trees can naturally regenerate and spread. The process of regeneration will...

ELM elimination with Li powder injection in EAST discharges using the tungsten upper divertor

DOE PAGES

Maingi, R.; Hu, J. S.; Sun, Z.; ...

2018-01-05

Here, we report the first successful use of lithium (Li) to eliminate edge-localized modes (ELMs) with tungsten divertor plasma-facing components in the EAST device. Li powder injected into the scrape-off layer of the tungsten upper divertor successfully eliminated ELMs for 3–5 s in EAST. The ELM elimination became progressively more effective in consecutive discharges at constant lithium delivery rates, and the divertor D α baseline emission was reduced, both signatures of improved wall conditioning. A modest decrease in stored energy and normalized energy confinement was also observed, but the confinement relative to H98 remained well above 1, extending the previousmore » ELM elimination results via Li injection into the lower carbon divertor in EAST. These results can be compared with recent observations with lithium pellets in ASDEX-Upgrade that failed to mitigate ELMs, highlighting one comparative advantage of continuous powder injection for real-time ELM elimination.« less

ELM elimination with Li powder injection in EAST discharges using the tungsten upper divertor

NASA Astrophysics Data System (ADS)

Maingi, R.; Hu, J. S.; Sun, Z.; Tritz, K.; Zuo, G. Z.; Xu, W.; Huang, M.; Meng, X. C.; Canik, J. M.; Diallo, A.; Lunsford, R.; Mansfield, D. K.; Osborne, T. H.; Gong, X. Z.; Wang, Y. F.; Li, Y. Y.; EAST Team

2018-02-01

We report the first successful use of lithium (Li) to eliminate edge-localized modes (ELMs) with tungsten divertor plasma-facing components in the EAST device. Li powder injected into the scrape-off layer of the tungsten upper divertor successfully eliminated ELMs for 3-5 s in EAST. The ELM elimination became progressively more effective in consecutive discharges at constant lithium delivery rates, and the divertor D α baseline emission was reduced, both signatures of improved wall conditioning. A modest decrease in stored energy and normalized energy confinement was also observed, but the confinement relative to H98 remained well above 1, extending the previous ELM elimination results via Li injection into the lower carbon divertor in EAST (Hu et al 2015 Phys. Rev. Lett. 114 055001). These results can be compared with recent observations with lithium pellets in ASDEX-Upgrade that failed to mitigate ELMs (Lang et al 2017 Nucl. Fusion 57 016030), highlighting one comparative advantage of continuous powder injection for real-time ELM elimination.

ELM elimination with Li powder injection in EAST discharges using the tungsten upper divertor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maingi, R.; Hu, J. S.; Sun, Z.

Here, we report the first successful use of lithium (Li) to eliminate edge-localized modes (ELMs) with tungsten divertor plasma-facing components in the EAST device. Li powder injected into the scrape-off layer of the tungsten upper divertor successfully eliminated ELMs for 3–5 s in EAST. The ELM elimination became progressively more effective in consecutive discharges at constant lithium delivery rates, and the divertor D α baseline emission was reduced, both signatures of improved wall conditioning. A modest decrease in stored energy and normalized energy confinement was also observed, but the confinement relative to H98 remained well above 1, extending the previousmore » ELM elimination results via Li injection into the lower carbon divertor in EAST. These results can be compared with recent observations with lithium pellets in ASDEX-Upgrade that failed to mitigate ELMs, highlighting one comparative advantage of continuous powder injection for real-time ELM elimination.« less

Development of Japanese experiment module remote manipulator system

NASA Technical Reports Server (NTRS)

Matsueda, Tatsuo; Kuwao, Fumihiro; Motohasi, Shoichi; Okamura, Ryo

1994-01-01

National Space Development Agency of Japan (NASDA) is developing the Japanese Experiment Module (JEM), as its contribution to the International Space Station. The JEM consists of the pressurized module (PM), the exposed facility (EF), the experiment logistics module pressurized section (ELM-PS), the experiment logistics module exposed section (ELM-ES) and the Remote Manipulator System (RMS). The JEMRMS services for the JEM EF, which is a space experiment platform, consists of the Main Arm (MA), the Small Fine Arm (SFA) and the RMS console. The MA handles the JEM EF payloads, the SFA and the JEM element, such as ELM-ES.

Slippery Elm

MedlinePlus

Slippery elm is a tree that is native to eastern Canada and the eastern and central United States. ... whole bark) is used as medicine. People take slippery elm by mouth for coughs, sore throat, colic, diarrhea, ...

Influence of equilibrium shear flow in the parallel magnetic direction on edge localized mode crash

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Y.; Xiong, Y. Y.; Chen, S. Y., E-mail: sychen531@163.com

2016-04-15

The influence of the parallel shear flow on the evolution of peeling-ballooning (P-B) modes is studied with the BOUT++ four-field code in this paper. The parallel shear flow has different effects in linear simulation and nonlinear simulation. In the linear simulations, the growth rate of edge localized mode (ELM) can be increased by Kelvin-Helmholtz term, which can be caused by the parallel shear flow. In the nonlinear simulations, the results accord with the linear simulations in the linear phase. However, the ELM size is reduced by the parallel shear flow in the beginning of the turbulence phase, which is recognizedmore » as the P-B filaments' structure. Then during the turbulence phase, the ELM size is decreased by the shear flow.« less

New Techniques For The Improvement Of The ICRH System ELM Tolerance On JET

NASA Astrophysics Data System (ADS)

Monakhov, I.; Blackman, T.; Walden, A.; Nightingale, M.; Whitehurst, A.; Durodie, F.; Jet Efda Contributors

2003-12-01

Two complementary improvements to the ELM tolerance of the existing A2 antennas on JET are being assessed. The use of external conjugate-T matching of straps of adjacent antenna arrays could reduce the VSWR levels at RF amplifier output during fast load perturbations. The scheme under consideration uses coaxial line-stretchers (trombones) for tuning the conjugate-T to low resistive impedance (3-6 Ohm) with subsequent stub/trombone circuit impedance transformation to 30 Ohms. Another technique is to modify the RF plant protection system logic to reduce the high VSWR trip duration to an absolute minimum corresponding to a typical ELM response (˜1-2ms) without compromising the plant safety. Both projects are presently being tested and could increase the average power delivered by RF plant into ELMy plasmas at JET.

Discriminant analysis to predict the occurrence of ELMS in H-mode discharges

NASA Astrophysics Data System (ADS)

Kardaun, O. J. W. F.; Itoh, S.-I.; Itoh, K.; Kardaun, J. W. P. F.

1993-08-01

After an exposition of its theoretical background, discriminant analysis is applied to the H-mode confinement database to find the region in plasma parameter space in which H-mode with small ELM's (Edge Localized Modes) is likely to occur. The boundary of this region is determined by the condition that the probability of appearance of such a type of H-mode, as a function of the plasma parameters, should be larger than some threshold value and larger than the corresponding probability for other types of H-mode (i.e., H-mode without ELM's or with giant ELM's). In practice, the discrimination has been performed for the ASDEX, JET and JFT-2M tokamaks using four instantaneous plasma parameters (injected power Pinj, magnetic field Bt, plasma current Ip and line averaged electron density ne) and taking also memory effects of the plasma and the distance between the plasma and the wall into account, while using variables that are normalized with respect to machine size. Generally speaking, it is found that there is a substantial overlap between the region of H-mode with small ELM's and the region of the two other types of H-mode. However, the ELM-free and the giant ELM H-modes relatively rarely appear in the region, that, according to the analysis, is allocated to small ELM's. A reliable production of H-mode with only small ELM's seems well possible by choosing this regime in parameter space. In the present study, it was not attempted to arrive at a unified discrimination across the machines. So, projection from one machine to another remains difficult, and a reliable determination of the region where small ELM's occur still requires a training sample from the device under consideration.

Spatial-spectral blood cell classification with microscopic hyperspectral imagery

NASA Astrophysics Data System (ADS)

Ran, Qiong; Chang, Lan; Li, Wei; Xu, Xiaofeng

2017-10-01

Microscopic hyperspectral images provide a new way for blood cell examination. The hyperspectral imagery can greatly facilitate the classification of different blood cells. In this paper, the microscopic hyperspectral images are acquired by connecting the microscope and the hyperspectral imager, and then tested for blood cell classification. For combined use of the spectral and spatial information provided by hyperspectral images, a spatial-spectral classification method is improved from the classical extreme learning machine (ELM) by integrating spatial context into the image classification task with Markov random field (MRF) model. Comparisons are done among ELM, ELM-MRF, support vector machines(SVM) and SVMMRF methods. Results show the spatial-spectral classification methods(ELM-MRF, SVM-MRF) perform better than pixel-based methods(ELM, SVM), and the proposed ELM-MRF has higher precision and show more accurate location of cells.

Endangered Species Management Plan for Fort Hood, Texas: FY06-10

DTIC Science & Technology

2007-05-01

Texas red oak, post oak, Texas ash (Fraxinus texensis), shin oak, blackjack oak (Quercus marilandica), slippery elm (Ulmus rubra), cedar elm ...by Ashe juniper and Texas oak. Other important tree species included live oak, cedar elm (Ulmus crassifolia), Lacey oak (Quercus laceyi), Arizona...0.83 m (Cimprich 2005). Nest substrates include shin oak, Texas red oak, Texas redbud, Ashe juniper, Texas ash, Plateau live oak, cedar elm , rusty

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

Treesearch

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...

Overview of Recent DIII-D Experimental Results

NASA Astrophysics Data System (ADS)

Fenstermacher, Max; DIII-D Team

2017-10-01

Recent DIII-D experiments contributed to the ITER physics basis and to physics understanding for extrapolation to future devices. A predict-first analysis showed how shape can enhance access to RMP ELM suppression. 3D equilibrium changes from ELM control RMPs, were linked to density pumpout. Ion velocity imaging in the SOL showed 3D C2+flow perturbations near RMP induced n =1 islands. Correlation ECE reveals a 40% increase in Te turbulence during QH-mode and 70% during RMP ELM suppression vs. ELMing H-mode. A long-lived predator-prey oscillation replaces edge MHD in recent low-torque QH-mode plasmas. Spatio-temporally resolved runaway electron measurements validate the importance of synchrotron and collisional damping on RE dissipation. A new small angle slot divertor achieves strong plasma cooling and facilitates detachment access. Fast ion confinement was improved in high q_min scenarios using variable beam energy optimization. First reproducible, stable ITER baseline scenarios were established. Studies have validated a model for edge momentum transport that predicts the pedestal main-ion intrinsic velocity value and direction. Work supported by the US DOE under DE-FC02-04ER54698 and DE-AC52-07NA27344.

Toroidal plasma response based ELM control coil design for EU DEMO

NASA Astrophysics Data System (ADS)

Zhou, Lina; Liu, Yueqiang; Wenninger, Ronald; Liu, Yue; Wang, Shuo; Yang, Xu

2018-07-01

Magnetic coil design study is carried out, for the purpose of mitigating or suppressing the edge localized modes (ELMs) in a EU DEMO reference scenario. The coil design, including both the coil geometry and the coil current requirement, is based on criteria derived from the linear, full toroidal plasma response computed by the MARS-F code (Liu et al 2000 Phys. Plasma 7 3681). With a single midplane row of coils, a coil size covering about 30°–50° poloidal angle of the torus is found to be optimal for ELM control using the n  >  2 resonant magnetic perturbation (RMP) field (n is the toroidal mode number). For off-midplane coils, the coils’ poloidal location, as well as the relative toroidal phase (coil phasing) between the upper and lower rows of coils, also sensitively affects the ELM control according to the specified criteria. Assuming that the optimal coil phasing can always be straightforwardly implemented, following a simple analytic model derived from toroidal computations, it is better to place the two off-midplane rows of coils near the midplane, in order to maximize the resonant field amplitude and to have larger effects on ELMs. With the same coil current, the ex-vessel coils can be made as effective as the in-vessel coils, at the expense of increasing the ex-vessel coils’ size. This is however possible only for low-n (n  =  1–3) RMP fields. With these low-n fields, and assuming 300 kAt maximal coil current, the computed plasma displacement near the X-point can meet the 10 mm level, which we use as the conservative indicator for achieving ELM mitigation in EU DEMO. The risk of partial control coil failure in EU DEMO is also assessed based on toroidal modeling, indicating that the large n  =  1 sideband due to coil failure may need to be corrected, if the nominal n  >  1 coil configurations are used for ELM control in EU DEMO.

Lower Mississippi River Environmental Program. Report 2. A Physical Description of Main Stem Levee Borrow Pits along the Lower Mississippi River

DTIC Science & Technology

1988-02-01

Eastern cottonwood, green ash, sugarberry. box elder, bald cypress, willow honey locust, slippery elm , overcup oak and bitter pecan. Principle...vines and understory. Woody vegetation surrounds the borrow pit and consists of American and slippery elms , silver maple, black willow, cottonwood, pin...aquatica Water elm Ulmus rubra Slippery elm Urtica dioica Stinging nettle Vaccinium sp. Blueberry Vaccinium spp. Vaccinum Vernonia altissima Ironweed

Water Resources Development Miami River, Little Miami River, and Mill Creek Basins, Southwest Ohio. Volume 2. Appendices A-G.

DTIC Science & Technology

1981-10-01

the area. Common species include boxelder, black locust, hackberry, tree of heaven, sycamore, Osage orange, black willow, mulberry, slippery elm ...and maple include tulip poplar, white ash, red elm , American elm , black cherry, hackberry, walnut, basswood, buckeye, white oak, shagbark hickory, and...willow. Other canopy species in these communities include buckeye, elm , beech, black locust, hackberry, walnut, and silver maple. The most prevalent

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

Treesearch

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...

Dynamic extreme learning machine and its approximation capability.

PubMed

Zhang, Rui; Lan, Yuan; Huang, Guang-Bin; Xu, Zong-Ben; Soh, Yeng Chai

2013-12-01

Extreme learning machines (ELMs) have been proposed for generalized single-hidden-layer feedforward networks which need not be neuron alike and perform well in both regression and classification applications. The problem of determining the suitable network architectures is recognized to be crucial in the successful application of ELMs. This paper first proposes a dynamic ELM (D-ELM) where the hidden nodes can be recruited or deleted dynamically according to their significance to network performance, so that not only the parameters can be adjusted but also the architecture can be self-adapted simultaneously. Then, this paper proves in theory that such D-ELM using Lebesgue p-integrable hidden activation functions can approximate any Lebesgue p-integrable function on a compact input set. Simulation results obtained over various test problems demonstrate and verify that the proposed D-ELM does a good job reducing the network size while preserving good generalization performance.

Characteristics of the Secondary Divertor on DIII-D

NASA Astrophysics Data System (ADS)

Watkins, J. G.; Lasnier, C. J.; Leonard, A. W.; Evans, T. E.; Pitts, R.; Stangeby, P. C.; Boedo, J. A.; Moyer, R. A.; Rudakov, D. L.

2009-11-01

In order to address a concern that the ITER secondary divertor strike plates may be insufficiently robust to handle the incident pulses of particles and energy from ELMs, we performed dedicated studies of the secondary divertor plasma and scrape-off layer (SOL). Detailed measurements of the ELM energy and particle deposition footprint on the secondary divertor target plates were made with a fast IR camera and Langmuir probes and SOL profile and transport measurements were made with reciprocating probes. The secondary divertor and SOL conditions depended on changes in the magnetic balance and the core plasma density. Larger density resulted in smaller ELMs and the magnetic balance affected how many ELM particles coupled to the secondary SOL and divertor. Particularly striking are the images from a new fast IR camera that resolve ELM heat pulses and show spiral patterns with multiple peaks during ELMs in the secondary divertor.

Enhancement of Helium exhaust by resonant magnetic perturbations in DIII-D

NASA Astrophysics Data System (ADS)

Hinson, E. T.; Schmitz, O.; Collins, C.; Paz-Soldan, C.; Bykov, I.; Moyer, R. A.; Unterberg, E. A.; Briesemeister, A.; McLean, A. G.; Watkins, J.; Wang, H.

2017-10-01

Clear evidence of enhanced He exhaust during RMP ELM suppression has been obtained for the first time in a series of lower single null H-mode discharges with and without RMP in DIII-D. During RMP, reduced midplane He density measurements from CER and faster neutral He decay times after a 100ms He puff provided evidence for faster outward transport. Additionally, during RMP, neutral He pressure in the lower pumping plenum increased, while D2 pressure was similar to the no RMP case. A spectrometer viewing the divertor shelf in the scrape off layer measured consistently increased He-I light during RMP ELM suppression. These two measurements indicate an improved retention of He in the unconfined region, which is important for enhanced He removal. Consequently, the effective helium confinement time, τ*p,He, measured for conditions in this work was reduced by >35% when RMP ELM suppression was obtained. Work supported by US DOE DE-FC02-04ER54698, DE-SC00013911, DE-FG02-07ER54917, DE-AC52-07NA27344, DE-AC05-00OR22725, DE-AC04-94AL85000.

Advances in the steady-state hybrid regime in DIII-D – a fully non-inductive, ELM-suppressed scenario for ITER

DOE PAGES

Petty, Craig C.; Nazikian, Raffi; Park, Jin Myung; ...

2017-07-19

Here, the hybrid regime with beta, collisionality, safety factor and plasma shape relevant to the ITER steady-state mission has been successfully integrated with ELM suppression by applying an odd parity n=3 resonant magnetic perturbation (RMP). Fully non-inductive hybrids in the DIII-D tokamak with high beta (β ≤ 2.8%) and high confinement (98y2 ≤ 1.4) in the ITER similar shape have achieved zero surface loop voltage for up to two current relaxation times using efficient central current drive from ECCD and NBCD. The n=3 RMP causes surprisingly little increase in thermal transport during ELM suppression. Poloidal magnetic flux pumping in hybridmore » plasmas maintains q above 1 without loss of current drive efficiency, except that experiments show that extremely peaked ECCD profiles can create sawteeth. During ECCD, Alfvén eigenmode (AE) activity is replaced by a more benign fishbone-like mode, reducing anomalous beam ion diffusion by a factor of 2. While the electron and ion thermal diffusivities substantially increase with higher ECCD power, the loss of confinement can be offset by the decreased fast ion transport resulting from AE suppression. Extrapolations from DIII-D along a dimensionless parameter scaling path as well as those using self-consistent theory-based modeling show that these ELM-suppressed, fully non-inductive hybrids can achieve the Q = 5 ITER steady-state mission.« less

Lower Mississippi River Environmental Program. Report 3. Bird and Mammal Use of Main Stem Levee Borrow Pits Along the Lower Mississippi River.

DTIC Science & Technology

1986-02-01

overcup oak, tupelo gum, Nuttall oak, American elm , slippery elm , i , hickories, persimmon, silver maple, deciduous holly, swamp privet, and rose mallows...cottonwood, green ash, sugarberry, box elder, deciduous holly, osage orange, swamp privet, hickories, overcup oak, water locust, honey locust, slippery elm ...wood, box elder, osage orange, hickories, honey locust, water locust, slippery elm , swamp privet, sugarberry, persimmon, and rose mallows. Where

Characterizing Tungsten Sourcing and SOL Transport during the Metal Rings Campaign

NASA Astrophysics Data System (ADS)

Thomas, D. M.; Abrams, T.; Unterberg, E. A.; Donovan, D.; Elder, J. D.; Wampler, W. R.; DIII-D Team

2017-10-01

The Metal Rings Campaign on DIII-D utilized two isotopically and poloidally distinct toroidal arrays of tungsten coated inserts in the lower divertor to study W divertor erosion near the outer strike point (OSP) and divertor entrance and subsequent migration in a mixed-material (C-W) environment. In AT hybrid discharges (PAUX = 14 MW, H98 = 1.6, βN = 3.7) with rapid ELMs (fELM 200 Hz, δW/W 0.7%) W impurities are seen to reach the midplane predominantly from the OSP region rather than the divertor entrance (far-SOL). Conversely, in scenarios with less frequent larger ELMs (fELM 60 Hz, δW/W 3.6%), the W impurities are found to transport equally from the OSP and entrance region. ELM-resolved spectroscopic measurements of W sourcing indicate that large ELMs can source W at many times the inter ELM rate. The peak W erosion rate can shift radially outwards consistent with the ELM energy flux, thereby shifting the balance between strikepoint and far-SOL sources. Changes in the peak erosion locations between forward and reversed Bt discharges are consistent with ExB ion drift effects. Evidence for a near-SOL impurity buildup between the divertors driven by the parallel grad-Ti force is also seen. Work supported under USDOE Cooperative Agreement DE-FC02-04ER54698.

Quantitative analysis of external limiting membrane, ellipsoid zone and interdigitation zone defects in patients with macular holes.

PubMed

Houly, Jacques Ramos; Veloso, Carlos Eduardo; Passos, Elke; Nehemy, Márcio Bittar

2017-07-01

To investigate the correlation between the length of external limiting membrane (ELM), ellipsoid zone (EZ) and interdigitation zone (IZ) defects and visual prognosis in patients undergoing macular hole (MH) surgery, using spectral-domain optical coherence tomography (SD-OCT). This is a retrospective, consecutive, observational case series study. Fifty-two eyes of 52 patients with primary MH were evaluated. A quantitative analysis of ELM, EZ and IZ defects was performed preoperatively and at 3 and 6 months postoperatively using SD-OCT. The correlation between pre- and postoperative ELM, EZ and IZ defects and the best-corrected visual acuity (BCVA) was investigated. The lengths of ELM, EZ and IZ defects correlated significantly with BCVA in each study period (P < 0.001). Preoperative measures of these band defects were also associated with visual outcomes 3 and 6 months after surgery (P < 0.05). Considering all preoperative parameters, the length of the ELM defect was the factor most strongly correlated with BCVA at 6 months (β = 0.643, P < 0.012). The integrity of the ELM was the only factor significantly associated with BCVA at 6 months (β = 0.427; P = 0.004). The preoperative length of the ELM defect is the strongest predictor of visual acuity after MH surgery. Postoperative integrity of the ELM is significantly associated with visual restoration after surgical treatment of MH.

Parsimonious extreme learning machine using recursive orthogonal least squares.

PubMed

Wang, Ning; Er, Meng Joo; Han, Min

2014-10-01

Novel constructive and destructive parsimonious extreme learning machines (CP- and DP-ELM) are proposed in this paper. By virtue of the proposed ELMs, parsimonious structure and excellent generalization of multiinput-multioutput single hidden-layer feedforward networks (SLFNs) are obtained. The proposed ELMs are developed by innovative decomposition of the recursive orthogonal least squares procedure into sequential partial orthogonalization (SPO). The salient features of the proposed approaches are as follows: 1) Initial hidden nodes are randomly generated by the ELM methodology and recursively orthogonalized into an upper triangular matrix with dramatic reduction in matrix size; 2) the constructive SPO in the CP-ELM focuses on the partial matrix with the subcolumn of the selected regressor including nonzeros as the first column while the destructive SPO in the DP-ELM operates on the partial matrix including elements determined by the removed regressor; 3) termination criteria for CP- and DP-ELM are simplified by the additional residual error reduction method; and 4) the output weights of the SLFN need not be solved in the model selection procedure and is derived from the final upper triangular equation by backward substitution. Both single- and multi-output real-world regression data sets are used to verify the effectiveness and superiority of the CP- and DP-ELM in terms of parsimonious architecture and generalization accuracy. Innovative applications to nonlinear time-series modeling demonstrate superior identification results.

iELM—a web server to explore short linear motif-mediated interactions

PubMed Central

Weatheritt, Robert J.; Jehl, Peter; Dinkel, Holger; Gibson, Toby J.

2012-01-01

The recent expansion in our knowledge of protein–protein interactions (PPIs) has allowed the annotation and prediction of hundreds of thousands of interactions. However, the function of many of these interactions remains elusive. The interactions of Eukaryotic Linear Motif (iELM) web server provides a resource for predicting the function and positional interface for a subset of interactions mediated by short linear motifs (SLiMs). The iELM prediction algorithm is based on the annotated SLiM classes from the Eukaryotic Linear Motif (ELM) resource and allows users to explore both annotated and user-generated PPI networks for SLiM-mediated interactions. By incorporating the annotated information from the ELM resource, iELM provides functional details of PPIs. This can be used in proteomic analysis, for example, to infer whether an interaction promotes complex formation or degradation. Furthermore, details of the molecular interface of the SLiM-mediated interactions are also predicted. This information is displayed in a fully searchable table, as well as graphically with the modular architecture of the participating proteins extracted from the UniProt and Phospho.ELM resources. A network figure is also presented to aid the interpretation of results. The iELM server supports single protein queries as well as large-scale proteomic submissions and is freely available at http://i.elm.eu.org. PMID:22638578

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

NASA Astrophysics Data System (ADS)

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.

Initial Assessments of E-Learning Modules in Cytotechnology Education.

PubMed

Mukherjee, Maheswari S; Donnelly, Amber D

2018-01-01

Nine E-learning modules (ELMs) were developed in our program using Articulate software. This study assessed our cytotechnology (CT) students' perceptions on the content of the ELMs, and the perceived influence of the ELMs on students' performance during clinical rotations. All CT students watched nine ELMs before the related classroom lecture and group discussion. Following that, students completed nine preclinical rotation surveys. After their clinical rotations, students completed nine postclinical rotation surveys. Statements on the content of the ELMs regarding the quality of the video and audio, duration, navigation, and the materials presented, received positive responses from the majority of the students. While there were a few disagreements and neutral responses, most of the students responded positively saying that the ELMs better prepared them for their role, as well as helped them to better perform their roles during the clinical rotation. The majority of the students recommended developing more EMLs for cytology courses in the future. This study has given hope that the ELMs have potential to enhance our online curriculum and benefit students, within the United States and internationally, who have no easy access to cytology clinical laboratories for hands-on training.

Comparative ELM study between the observation by ECEI and linear/nonlinear simulation in the KSTAR plasmas

NASA Astrophysics Data System (ADS)

Kim, Minwoo; Park, Hyeon K.; Yun, Gunsu; Lee, Jaehyun; Lee, Jieun; Lee, Woochang; Jardin, Stephen; Xu, X. Q.; Kstar Team

2015-11-01

The modeling of the Edge-localized-mode (ELM) should be rigorously pursued for reliable and robust ELM control for steady-state long-pulse H-mode operation in ITER as well as DEMO. In the KSTAR discharge #7328, a linear stability of the ELMs is investigated using M3D-C1 and BOUT + + codes. This is achieved by linear simulation for the n = 8 mode structure of the ELM observed by the KSTAR electron cyclotron emission imaging (ECEI) systems. In the process of analysis, variations due to the plasma equilibrium profiles and transport coefficients on the ELM growth rate are investigated and simulation results with the two codes are compared. The numerical simulations are extended to nonlinear phase of the ELM dynamics, which includes saturation and crash of the modes. Preliminary results of the nonlinear simulations are compared with the measured images especially from the saturation to the crash. This work is supported by NRF of Korea under contract no. NRF-2014M1A7A1A03029865, US DoE by LLNL under contract DE-AC52-07NA27344 and US DoE by PPPL under contract DE-AC02-09CH11466.

Assembly interdependence among the S. cerevisiae bud neck ring proteins Elm1p, Hsl1p and Cdc12p.

PubMed

Thomas, Courtney L; Blacketer, Melissa J; Edgington, Nicholas P; Myers, Alan M

2003-07-15

In Saccharomyces cerevisiae, a complex comprising more than 20 different polypeptides assembles in a ring at the neck between the mother cell and the bud. This complex functions to coordinate cell morphology with cell division. Relatively little is known about this control system, including the physical relationships between the components of the neck ring. This study addressed the assembly interactions of three components of the ring, specifically the protein kinases Elm1p and Hsl1p and the septin Cdc12p. Specific amino acid substitutions in each of these three proteins were identified that either cause or suppress a characteristic phenotype of abnormally elongated cells and delay in the G(2)-M transition. Each protein was fused to green fluorescent protein, and its ability to localize at the neck was monitored in vivo in cells of various genotypes. Localization of Hsl1p to the neck requires Elm1p function. Elm1p localized normally in the absence of Hsl1p, although a specific point mutation in Hsl1p clearly affected Elm1p localization. The cdc12-122 mutation prevented assembly of Elm1p or Hsl1p into the neck ring. Normal assembly of Cdc12p at the neck was dependent upon Elm1p and also, to a smaller extent, on Hsl1p. Ectopic localization of Cdc12p at the bud tip was observed frequently in elm1 mutants and also, to a lesser extent, in hsl1 mutants. Thus, Elm1p is a key factor in the assembly and/or maintenance of Hsl1p, as well as at least one septin, into the bud neck ring. Copyright 2003 John Wiley & Sons, Ltd.

Is extreme learning machine feasible? A theoretical assessment (part I).

PubMed

Liu, Xia; Lin, Shaobo; Fang, Jian; Xu, Zongben

2015-01-01

An extreme learning machine (ELM) is a feedforward neural network (FNN) like learning system whose connections with output neurons are adjustable, while the connections with and within hidden neurons are randomly fixed. Numerous applications have demonstrated the feasibility and high efficiency of ELM-like systems. It has, however, been open if this is true for any general applications. In this two-part paper, we conduct a comprehensive feasibility analysis of ELM. In Part I, we provide an answer to the question by theoretically justifying the following: 1) for some suitable activation functions, such as polynomials, Nadaraya-Watson and sigmoid functions, the ELM-like systems can attain the theoretical generalization bound of the FNNs with all connections adjusted, i.e., they do not degrade the generalization capability of the FNNs even when the connections with and within hidden neurons are randomly fixed; 2) the number of hidden neurons needed for an ELM-like system to achieve the theoretical bound can be estimated; and 3) whenever the activation function is taken as polynomial, the deduced hidden layer output matrix is of full column-rank, therefore the generalized inverse technique can be efficiently applied to yield the solution of an ELM-like system, and, furthermore, for the nonpolynomial case, the Tikhonov regularization can be applied to guarantee the weak regularity while not sacrificing the generalization capability. In Part II, however, we reveal a different aspect of the feasibility of ELM: there also exists some activation functions, which makes the corresponding ELM degrade the generalization capability. The obtained results underlie the feasibility and efficiency of ELM-like systems, and yield various generalizations and improvements of the systems as well.

Statistical Characterization and Classification of Edge-Localized Plasma Instabilities

NASA Astrophysics Data System (ADS)

Webster, A. J.; Dendy, R. O.

2013-04-01

The statistics of edge-localized plasma instabilities (ELMs) in toroidal magnetically confined fusion plasmas are considered. From first principles, standard experimentally motivated assumptions are shown to determine a specific probability distribution for the waiting times between ELMs: the Weibull distribution. This is confirmed empirically by a statistically rigorous comparison with a large data set from the Joint European Torus. The successful characterization of ELM waiting times enables future work to progress in various ways. Here we present a quantitative classification of ELM types, complementary to phenomenological approaches. It also informs us about the nature of ELM processes, such as whether they are random or deterministic. The methods are extremely general and can be applied to numerous other quasiperiodic intermittent phenomena.

VizieR Online Data Catalog: The ELM survey. VI. 11 new ELM WD binaries (Gianninas+, 2015)

NASA Astrophysics Data System (ADS)

Gianninas, A.; Kilic, M.; Brown, W. R.; Canton, P.; Kenyon, S. J.

2016-02-01

We used the 6.5m MMT telescope equipped with the Blue Channel spectrograph, the 200 inch Hale telescope equipped with the Double spectrograph, the Kitt Peak National Observatory 4m telescope equipped with the R-C spectrograph, and more recently with Kitt Peak Ohio State Multi-Object Spectrograph (KOSMOS), to obtain spectroscopy of our 11 targets in several observing runs. We have also been obtaining radial-velocity measurements for candidates from other sources including the Large Sky Area Multi-Object Spectroscopy Telescope (LAMOST). Those 11 new Extremely low-mass white dwarf (ELM WD) binaries bring the total of ELM WDs identified by the ELM Survey up to 73. (4 data files).

Dutch Elm Disease and Methoxychlor

Treesearch

Jack H. Barger

1976-01-01

American elm trees, Ulmus americana L., in Milwaukee, Wisconsin, were sprayed with methoxychlor by helicopter or mist blower once each year for 3 years to control the smaller European elm bark beetle Scolytus multistriatus (Marsham). Twig crotches were collected from sprayed trees each year for bioassay. Methoxychlor residues...

Destruction of the Last Good Magnetic Surface in Diii-D Usn with Elms and C-Coils Shot 115467 due to ELMs Using Maps

NASA Astrophysics Data System (ADS)

Butcher, L.; Ali, H.; Punjabi, A.

2004-11-01

The unperturbed magnetic topology of DIII-D USN shot 115467 in the absence of ELMs and C-coils is described by the symmetric simple map (SSM) with the map parameter k=0.2623 [1]. For this k, the last good surface passes through x=0 and y=0.9995, q_edge=6.48 if six iterations of the SSM are taken to be equivalent to a single toroidal circuit of DIII-D, and the q_edge equals the q_edge in the DIII-D for shot 115467. The low mn map calculates the effects of the m=1, n=+1,-1 internal magnetic perturbation on the trajectories of field lines. We use the low mn map to represent the effects of the ELMs in the DIII-D. We study the changes in the last good surface and its destruction as the amplitude ɛ in the low mn map is increased. This work is supported by NASA SHARP program and DE-FG02-02ER54673. [1] H. Ali, A. Punjabi, A. Boozer, and T. Evans, presented at the 31st European Physical Society Plasma Physics Meeting, London, UK, June 29, 2004, paper P2-172.

American Elm clones of importance in DED tolerance studies

USDA-ARS?s Scientific Manuscript database

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...

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

NASA Astrophysics Data System (ADS)

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 \

Advances in the steady-state hybrid regime in DIII-D—a fully non-inductive, ELM-suppressed scenario for ITER

NASA Astrophysics Data System (ADS)

Petty, C. C.; Nazikian, R.; Park, J. M.; Turco, F.; Chen, Xi; Cui, L.; Evans, T. E.; Ferraro, N. M.; Ferron, J. R.; Garofalo, A. M.; Grierson, B. A.; Holcomb, C. T.; Hyatt, A. W.; Kolemen, E.; La Haye, R. J.; Lasnier, C.; Logan, N.; Luce, T. C.; McKee, G. R.; Orlov, D.; Osborne, T. H.; Pace, D. C.; Paz-Soldan, C.; Petrie, T. W.; Snyder, P. B.; Solomon, W. M.; Taylor, N. Z.; Thome, K. E.; Van Zeeland, M. A.; Zhu, Y.

2017-11-01

The hybrid regime with beta, collisionality, safety factor and plasma shape relevant to the ITER steady-state mission has been successfully integrated with ELM suppression by applying an odd parity n  =  3 resonant magnetic perturbation (RMP). Fully non-inductive hybrids in the DIII-D tokamak with high beta (≤ft< β \\right>   ⩽  2.8%) and high confinement (H98y2  ⩽  1.4) in the ITER similar shape have achieved zero surface loop voltage for up to two current relaxation times using efficient central current drive from ECCD and NBCD. The n  =  3 RMP causes surprisingly little increase in thermal transport during ELM suppression. Poloidal magnetic flux pumping in hybrid plasmas maintains q above 1 without loss of current drive efficiency, except that experiments show that extremely peaked ECCD profiles can create sawteeth. During ECCD, Alfvén eigenmode (AE) activity is replaced by a more benign fishbone-like mode, reducing anomalous beam ion diffusion by a factor of 2. While the electron and ion thermal diffusivities substantially increase with higher ECCD power, the loss of confinement can be offset by the decreased fast ion transport resulting from AE suppression. Extrapolations from DIII-D along a dimensionless parameter scaling path as well as those using self-consistent theory-based modeling show that these ELM-suppressed, fully non-inductive hybrids can achieve the Q fus  =  5 ITER steady-state mission.

The Elaboration Likelihood Model: Implications for the Practice of School Psychology.

ERIC Educational Resources Information Center

Petty, Richard E.; Heesacker, Martin; Hughes, Jan N.

1997-01-01

Reviews a contemporary theory of attitude change, the Elaboration Likelihood Model (ELM) of persuasion, and addresses its relevance to school psychology. Claims that a key postulate of ELM is that attitude change results from thoughtful (central route) or nonthoughtful (peripheral route) processes. Illustrations of ELM's utility for school…

Cephalosporium Wilt of Elm in the Lower Mississippi Valley

Treesearch

T. H. Filer; F. I. McCracken; E. R. Toole

1968-01-01

Dead and dying American elms (Ulmus americana) and cedar elms (U. crassifolia) were observed on the Delta Experimental Forest, Stoneville, Mississippi, and in Desha County, Arkansas, near the Mississippi River (about 30 miles northwest of the experimental forest) during August 1967. The only fungus consistently isolated from these...

77 FR 36206 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-18

... experienced smoke and heat damage from insulation blankets that smoldered after molten debris from a P200 ELMS power panel fell on the insulation blankets. When a contactor in the ELMS panel fails and overheats, the... ELMS contactor breakdown, consequent smoke and heat damage to airplane structure and equipment during...

Ulmus americana is a polyploid complex

USDA-ARS?s Scientific Manuscript database

The elms (the genus Ulmus) are one of the most important tree crops for the $4.7-billion per year nursery industry. The commercial importance of the genus centers on the American elm, Ulmus americana. Once decimated by Dutch Elm Disease, the recent introduction of cultivars resistant to the diseas...

Virtual screening by a new Clustering-based Weighted Similarity Extreme Learning Machine approach

PubMed Central

Kudisthalert, Wasu

2018-01-01

Machine learning techniques are becoming popular in virtual screening tasks. One of the powerful machine learning algorithms is Extreme Learning Machine (ELM) which has been applied to many applications and has recently been applied to virtual screening. We propose the Weighted Similarity ELM (WS-ELM) which is based on a single layer feed-forward neural network in a conjunction of 16 different similarity coefficients as activation function in the hidden layer. It is known that the performance of conventional ELM is not robust due to random weight selection in the hidden layer. Thus, we propose a Clustering-based WS-ELM (CWS-ELM) that deterministically assigns weights by utilising clustering algorithms i.e. k-means clustering and support vector clustering. The experiments were conducted on one of the most challenging datasets–Maximum Unbiased Validation Dataset–which contains 17 activity classes carefully selected from PubChem. The proposed algorithms were then compared with other machine learning techniques such as support vector machine, random forest, and similarity searching. The results show that CWS-ELM in conjunction with support vector clustering yields the best performance when utilised together with Sokal/Sneath(1) coefficient. Furthermore, ECFP_6 fingerprint presents the best results in our framework compared to the other types of fingerprints, namely ECFP_4, FCFP_4, and FCFP_6. PMID:29652912

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

NASA Astrophysics Data System (ADS)

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.

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

PubMed Central

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

2014-01-01

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. PMID:25366885

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

PubMed

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

2014-11-04

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.

Detection of tumor cell-specific mRNA and protein in exosome-like microvesicles from blood and saliva.

PubMed

Yang, Jieping; Wei, Fang; Schafer, Christopher; Wong, David T W

2014-01-01

The discovery of disease-specific biomarkers in oral fluids has revealed a new dimension in molecular diagnostics. Recent studies have reported the mechanistic involvement of tumor cells derived mediators, such as exosomes, in the development of saliva-based mRNA biomarkers. To further our understanding of the origins of disease-induced salivary biomarkers, we here evaluated the hypothesis that tumor-shed secretory lipidic vesicles called exosome-like microvesicles (ELMs) that serve as protective carriers of tissue-specific information, mRNAs, and proteins, throughout the vasculature and bodily fluids. RNA content was analyzed in cell free-saliva and ELM-enriched fractions of saliva. Our data confirmed that the majority of extracellular RNAs (exRNAs) in saliva were encapsulated within ELMs. Nude mice implanted with human lung cancer H460 cells expressing hCD63-GFP were used to follow the circulation of tumor cell specific protein and mRNA in the form of ELMs in vivo. We were able to identify human GAPDH mRNA in ELMs of blood and saliva of tumor bearing mice using nested RT-qPCR. ELMs positive for hCD63-GFP were detected in the saliva and blood of tumor bearing mice as well as using electric field-induced release and measurement (EFIRM). Altogether, our results demonstrate that ELMs carry tumor cell-specific mRNA and protein from blood to saliva in a xenografted mouse model of human lung cancer. These results therefore strengthen the link between distal tumor progression and the biomarker discovery of saliva through the ELMs.

Improved Sanitation Practice for Control of Dutch Elm Disease

Treesearch

Jack H. Barger

1977-01-01

In Detroit, Michigan, 12 plots, each containing about 600 American elm trees, Ulmus americana L., were subjected for 3 years to intensive and conventional sanitation treatments to control Dutch elm disease. In the intensive treatment, three disease surveys were conducted each year; each followed by tree removal within 20 working days. In the...

Bringing Interpretability and Visualization with Artificial Neural Networks

ERIC Educational Resources Information Center

Gritsenko, Andrey

2017-01-01

Extreme Learning Machine (ELM) is a training algorithm for Single-Layer Feed-forward Neural Network (SLFN). The difference in theory of ELM from other training algorithms is in the existence of explicitly-given solution due to the immutability of initialed weights. In practice, ELMs achieve performance similar to that of other state-of-the-art…

Semiochemical-MediatedFlight Strategies of Two Invasive Elm Bark Beetles: A Potential Factor in Competitive Displacement

USDA-ARS?s Scientific Manuscript database

A recent seven-state survey revealed that the newly invasive banded elm bark beetle, Scolytus schevyrewi, was abundant in areas of Colorado and Wyoming, USA, whereas the long-established European elm bark beetle, S. multistriatus was not as abundant. Behavioral trials were conducted by hanging sm...

Genome size variation in elms (Ulmus spp.) and related genera

USDA-ARS?s Scientific Manuscript database

The elms (the genus Ulmus) are one of the most important tree crops for the $4.7-billion per year U.S. nursery industry. Utilization of these plants has been limited in recent decades by diseases introduced from the Old World, especially Dutch elm disease. Past research and breeding have been based ...

Scaling Relationships for ELM Diverter Heat Flux on DIII D

NASA Astrophysics Data System (ADS)

Peters, E. A.; Makowski, M. A.; Leonard, A. W.

2015-11-01

Edge Localized Modes (ELMs) are periodic plasma instabilities that occur during H-mode operation in tokamaks. Left unmitigated, these instabilities result in concentrated particle and heat fluxes at the divertor and stand to cause serious damage to the plasma facing components of tokamaks. The purpose of this research is to find scaling relationships that predict divertor heat flux due to ELMs based on plasma parameters at the time of instability. This will be accomplished by correlating characteristic ELM parameters with corresponding plasma measurements and analyzing the data for trends. One early assessment is the effect of the heat transmission coefficient ? on the in/out asymmetry of the calculated ELM heat fluxes. Using IR camera data, further assessments in this study will continue to emphasize in/out asymmetry in ELMs, as this has important implications for ITER operation. Work supported in part by the US DOE, DE-AC52-07NA27344, DE-FC02-04ER54698, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internships Program (SULI).

Deep Convolutional Extreme Learning Machine and Its Application in Handwritten Digit Classification

PubMed Central

Yang, Xinyi

2016-01-01

In recent years, some deep learning methods have been developed and applied to image classification applications, such as convolutional neuron network (CNN) and deep belief network (DBN). However they are suffering from some problems like local minima, slow convergence rate, and intensive human intervention. In this paper, we propose a rapid learning method, namely, deep convolutional extreme learning machine (DC-ELM), which combines the power of CNN and fast training of ELM. It uses multiple alternate convolution layers and pooling layers to effectively abstract high level features from input images. Then the abstracted features are fed to an ELM classifier, which leads to better generalization performance with faster learning speed. DC-ELM also introduces stochastic pooling in the last hidden layer to reduce dimensionality of features greatly, thus saving much training time and computation resources. We systematically evaluated the performance of DC-ELM on two handwritten digit data sets: MNIST and USPS. Experimental results show that our method achieved better testing accuracy with significantly shorter training time in comparison with deep learning methods and other ELM methods. PMID:27610128

KSC-08pd2916

NASA Image and Video Library

2008-09-24

CAPE CANAVERAL, Fla. - On the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, ramps are in place for the offloading of the primary cargo from the Russian Antonov AH-124-100 cargo airplane. The plane carries the final components of the Japan Aerospace Exploration Agency's Kibo laboratory for the International Space Station: the Kibo Exposed Facility, or EF, and the Experiment Logistics Module Exposed Section, or ELM-ES. The EF provides a multipurpose platform where science experiments can be deployed and operated in the exposed environment. The payloads attached to the EF can be exchanged or retrieved by Kibo's robotic arm, the JEM Remote Manipulator System. The ELM-ES will be attached to the end of the EF to provide payload storage space and can carry up to three payloads at launch. In addition, the ELM-ES provides a logistics function where it can be detached from the EF and returned to the ground aboard the space shuttle. The two JEM components will be carried aboard space shuttle Endeavour on the STS-127 mission targeted for launch in May 2009. Photo credit: NASA/Jim Grossmann

KSC-08pd2915

NASA Image and Video Library

2008-09-24

CAPE CANAVERAL, Fla. - On the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, workers remove material from a cargo box before offloading the primary cargo from the Russian Antonov AH-124-100 cargo airplane. The plane carries the final components of the Japan Aerospace Exploration Agency's Kibo laboratory for the International Space Station: the Kibo Exposed Facility, or EF, and the Experiment Logistics Module Exposed Section, or ELM-ES. The EF provides a multipurpose platform where science experiments can be deployed and operated in the exposed environment. The payloads attached to the EF can be exchanged or retrieved by Kibo's robotic arm, the JEM Remote Manipulator System. The ELM-ES will be attached to the end of the EF to provide payload storage space and can carry up to three payloads at launch. In addition, the ELM-ES provides a logistics function where it can be detached from the EF and returned to the ground aboard the space shuttle. The two JEM components will be carried aboard space shuttle Endeavour on the STS-127 mission targeted for launch in May 2009. Photo credit: NASA/Jim Grossmann

KSC-08pd2914

NASA Image and Video Library

2008-09-24

CAPE CANAVERAL, Fla. - On the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, equipment is removed from the Russian Antonov AH-124-100 cargo airplane to facilitate offloading of the primary cargo, the final components of the Japan Aerospace Exploration Agency's Kibo laboratory for the International Space Station. The components are the Kibo Exposed Facility, or EF, and the Experiment Logistics Module Exposed Section, or ELM-ES. The EF provides a multipurpose platform where science experiments can be deployed and operated in the exposed environment. The payloads attached to the EF can be exchanged or retrieved by Kibo's robotic arm, the JEM Remote Manipulator System. The ELM-ES will be attached to the end of the EF to provide payload storage space and can carry up to three payloads at launch. In addition, the ELM-ES provides a logistics function where it can be detached from the EF and returned to the ground aboard the space shuttle. The two JEM components will be carried aboard space shuttle Endeavour on the STS-127 mission targeted for launch in May 2009. Photo credit: NASA/Jim Grossmann

Deep Convolutional Extreme Learning Machine and Its Application in Handwritten Digit Classification.

PubMed

Pang, Shan; Yang, Xinyi

2016-01-01

In recent years, some deep learning methods have been developed and applied to image classification applications, such as convolutional neuron network (CNN) and deep belief network (DBN). However they are suffering from some problems like local minima, slow convergence rate, and intensive human intervention. In this paper, we propose a rapid learning method, namely, deep convolutional extreme learning machine (DC-ELM), which combines the power of CNN and fast training of ELM. It uses multiple alternate convolution layers and pooling layers to effectively abstract high level features from input images. Then the abstracted features are fed to an ELM classifier, which leads to better generalization performance with faster learning speed. DC-ELM also introduces stochastic pooling in the last hidden layer to reduce dimensionality of features greatly, thus saving much training time and computation resources. We systematically evaluated the performance of DC-ELM on two handwritten digit data sets: MNIST and USPS. Experimental results show that our method achieved better testing accuracy with significantly shorter training time in comparison with deep learning methods and other ELM methods.

ELM mitigation techniques

NASA Astrophysics Data System (ADS)

Evans, T. E.

2013-07-01

Large edge-localized mode (ELM) control techniques must be developed to help ensure the success of burning and ignited fusion plasma devices such as tokamaks and stellarators. In full performance ITER tokamak discharges, with QDT = 10, the energy released by a single ELM could reach ˜30 MJ which is expected to result in an energy density of 10-15 MJ/m2on the divertor targets. This will exceed the estimated divertor ablation limit by a factor of 20-30. A worldwide research program is underway to develop various types of ELM control techniques in preparation for ITER H-mode plasma operations. An overview of the ELM control techniques currently being developed is discussed along with the requirements for applying these techniques to plasmas in ITER. Particular emphasis is given to the primary approaches, pellet pacing and resonant magnetic perturbation fields, currently being considered for ITER.

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

NASA Technical Reports Server (NTRS)

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.

Discovery of Three Pulsating, Mixed-atmosphere, Extremely Low-mass White Dwarf Precursors

NASA Astrophysics Data System (ADS)

Gianninas, A.; Curd, Brandon; Fontaine, G.; Brown, Warren R.; Kilic, Mukremin

2016-05-01

We report the discovery of pulsations in three mixed-atmosphere, extremely low-mass white dwarf (ELM WD, M ≤slant 0.3 M ⊙) precursors. Following the recent discoveries of pulsations in both ELM and pre-ELM WDs, we targeted pre-ELM WDs with mixed H/He atmospheres with high-speed photometry. We find significant optical variability in all three observed targets with periods in the range 320-590 s, consistent in timescale with theoretical predictions of p-mode pulsations in mixed-atmosphere ≈0.18 M ⊙ He-core pre-ELM WDs. This represents the first empirical evidence that pulsations in pre-ELM WDs can only occur if a significant amount of He is present in the atmosphere. Future, more extensive, timeseries photometry of the brightest of the three new pulsators offers an excellent opportunity to constrain the thickness of the surface H layer, which regulates the cooling timescales for ELM WDs. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina), and Ministério da Ciência, Tecnologia e Inovação (Brazil).

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

NASA Astrophysics Data System (ADS)

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.

RMP ELM Suppression in DIII-D Plasmas with ITER Similar Shapes and Collisionalities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evans, T.E.; Fenstermacher, M. E.; Moyer, R.A.

2008-01-01

Large Type-I edge localized modes (ELMs) are completely eliminated with small n = 3 resonant magnetic perturbations (RMP) in low average triangularity, = 0.26, plasmas and in ITER similar shaped (ISS) plasmas, = 0.53, with ITER relevant collisionalities ve 0.2. Significant differences in the RMP requirements and in the properties of the ELM suppressed plasmas are found when comparing the two triangularities. In ISS plasmas, the current required to suppress ELMs is approximately 25% higher than in low average triangularity plasmas. It is also found that the width of the resonant q95 window required for ELM suppression is smaller inmore » ISS plasmas than in low average triangularity plasmas. An analysis of the positions and widths of resonant magnetic islands across the pedestal region, in the absence of resonant field screening or a self-consistent plasma response, indicates that differences in the shape of the q profile may explain the need for higher RMP coil currents during ELM suppression in ISS plasmas. Changes in the pedestal profiles are compared for each plasma shape as well as with changes in the injected neutral beam power and the RMP amplitude. Implications of these results are discussed in terms of requirements for optimal ELM control coil designs and for establishing the physics basis needed in order to scale this approach to future burning plasma devices such as ITER.« less

H-mode pedestal stability and ELMs in Alcator C-Mod

NASA Astrophysics Data System (ADS)

Mossessian, Dmitri

2002-11-01

For steady state H-mode operation, a relaxation mechanism is required to limit build-up of the edge gradient and impurity accumulation. The major relaxation mechanism seen on most of the existing tokamaks - large type I ELMs - drive high particle and energy fluxes that present a significant power load on the divertor plates. On Alcator C-Mod, however, type I ELMs are not observed. Instead, more benign mechanisms - EDA and small grassy ELMs - appear to drive enhanced particle transport at the edge of H-mode plasmas. Both have good energy confinement, no impurity accumulation, and are steady state. In EDA the edge relaxation mechanism is provided by a quasicoherent electromagnetic mode localized in the outer part of the pedestal. Non-linear gyrofluid and linear gyrokinetic simulations, as well as real geometry fluctuation modeling based on fluid equations show the presence of a coherent mode. Based on those results the observed mode is tentatively identified as resistive ballooning. At higher edge pressure gradient the mode is replaced by broadband fluctuations and small irregular ELMs are observed. Based on ideal MHD calculations that include effects of bootstrap current, these ELMs are identified as medium n coupled ideal peeling/ballooning modes. The stability threshold and modes structure of these modes are studied with recently developed linear MHD stability code ELITE and the results are compared with the observed dependence of the ELMs' character on pedestal parameters and plasma shape.

Biology of the invasive banded elm bark beetle (Coleoptera: Scolytidae) in the western United States

Treesearch

Jana C. Lee; Jose F. Negron; Sally J. McElwey; Livy Williams; Jeffrey J. Witcosky; John B. Popp; Steven J. Seybold

2011-01-01

The banded elm bark beetle, Scolytus schevyrewi Semenov (Coleoptera: Scolytidae), native to Asia, was detected in the United States in 2003, and as of 2011 it is known to occur in 28 states and four Canadian provinces. S. schevyrewi infests the same elm (Ulmus spp.) hosts as the longestablished invasive...

Use of culture filtrates of Ceratocystis ulmi as a bioassay to screen for disease tolerant Ulmus americana

Treesearch

Paula M. Pijut; Subash C. Domir; R. Daniel Lineberger; Lawrence R. Schreiber

1990-01-01

Callus cultures of elm (Ulmus americana L.) derived from Dutch elm disease susceptible, intermediate-resistant, and resistant genotypes were exposed to the culture filtrates of three pathogenic isolates of Ceratocystis ulmi, the causal agent of Dutch elm disease. Callus fresh weights, cell viability, and reactions of stem cuttings...

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

ERIC Educational Resources Information Center

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…

Explaining Electronic Learning Management Systems (ELMS) Continued Usage Intentions among Facilitators in Higher Education Institutions (HEIs) in Tanzania

ERIC Educational Resources Information Center

Muries, Bruckse; Masele, Juma James

2017-01-01

This study sought to explain ELMS continued usage intentions among HEIs in Tanzania. The study was guided by main research question, "What explains ELMS continued usage intentions among facilitators in HEIs in Tanzania?" The study used descriptive cross sectional design administered to 264 respondents drawn from five universities…

Co-occurrence of the invasive banded and European elm bark beetles (Coleoptera: Scolytidae) in North America

Treesearch

Janna C. Lee; Ingrid Aguayo; Ray Aslin; Gail Durham; Shakeeb M. Hamud; Beruce D. Moltzan; A. Steve Munson; Jose F. Negron; Travis Peterson; Iral R. Ragenovich; Jeffrey J. Witcosky; Steven J. Seybold

2009-01-01

The invasive European elm bark beetle, Scolytus multistriatus (Marsham), was detected in Massachusetts a century ago, and it now occurs throughout the continental United States and southern Canada. The Asian banded elm bark beetle, Scolytus schevyrewi Semenov, was discovered in the United States in 2003, and now occurs in 28 states...

Challenge inoculations to test for Dutch elm disease tolerance: a summary of Methods used by various researchers

USDA-ARS?s Scientific Manuscript database

A variety of methods have been used by different research groups to “challenge” inoculate American elms (Ulmus americana) with the purpose of determining whether some clones may be resistant to the Dutch elm disease fungus. The methods used by seven research groups are described, along with observat...

Effects of simulated acid rain, ozone and sulfur dioxide on suitability of elms for elm leaf beetle

Treesearch

Richard W. Hall; Jack H. Barger; Alden M. Townsend

1988-01-01

Cuttings from two clonally propagated elm hybrids ('Pioneer' and 'Homestead') were treated with ozone (03), sulfur dioxide (S02), simulated acid rain or left untreated. Fumigants were applied 7 hours per day, 5 days per week for 9 weeks in open-top chambers. Fumigation treatments were: 0.1 ppm 0

Feedback-Driven Mode Rotation Control by Electro-Magnetic Torque

NASA Astrophysics Data System (ADS)

Okabayashi, M.; Strait, E. J.; Garofalo, A. M.; La Haye, R. J.; in, Y.; Hanson, J. M.; Shiraki, D.; Volpe, F.

2013-10-01

The recent experimental discovery of feedback-driven mode rotation control, supported by modeling, opens new approaches for avoidance of locked tearing modes that otherwise lead to disruptions. This approach is an application of electro-magnetic (EM) torque using 3D fields, routinely maximized through a simple feedback system. In DIII-D, it is observed that a feedback-applied radial field can be synchronized in phase with the poloidal field component of a large amplitude tearing mode, producing the maximum EM torque input. The mode frequency can be maintained in the 10 Hz to 100 Hz range in a well controlled manner, sustaining the discharges. Presently, in the ITER internal coils designed for edge localized mode (ELM) control can only be varied at few Hz, yet, well below the inverse wall time constant. Hence, ELM control system could in principle be used for this feedback-driven mode control in various ways. For instance, the locking of MHD modes can be avoided during the controlled shut down of multi hundreds Mega Joule EM stored energy in case of emergency. Feedback could also be useful to minimize mechanical resonances at the disruption events by forcing the MHD frequency away from dangerous ranges. Work supported by the US DOE under DE-AC02-09CH11466, DE-FC-02-04ER54698, DE-FG02-08ER85195, and DE-FG02-04ER54761.

Pruning The ELM Survey: Characterizing Candidate Low-mass White Dwarfs through Photometric Variability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bell, Keaton J.; Winget, D. E.; Montgomery, M. H.

We assess the photometric variability of nine stars with spectroscopic T {sub eff} and log g values from the ELM Survey that locates them near the empirical extremely low-mass (ELM) white dwarf instability strip. We discover three new pulsating stars: SDSS J135512.34+195645.4, SDSS J173521.69+213440.6, and SDSS J213907.42+222708.9. However, these are among the few ELM Survey objects that do not show radial velocity (RV) variations that confirm the binary nature expected of helium-core white dwarfs. The dominant 4.31 hr pulsation in SDSS J135512.34+195645.4 far exceeds the theoretical cut-off for surface reflection in a white dwarf, and this target is likely amore » high-amplitude δ Scuti pulsator with an overestimated surface gravity. We estimate the probability to be less than 0.0008 that the lack of measured RV variations in four of eight other pulsating candidate ELM white dwarfs could be due to low orbital inclination. Two other targets exhibit variability as photometric binaries. Partial coverage of the 19.342 hr orbit of WD J030818.19+514011.5 reveals deep eclipses that imply a primary radius >0.4 R {sub ⊙}—too large to be consistent with an ELM white dwarf. The only object for which our time series photometry adds support to ELM white dwarf classification is SDSS J105435.78−212155.9, which has consistent signatures of Doppler beaming and ellipsoidal variations. We conclude that the ELM Survey contains multiple false positives from another stellar population at T {sub eff}≲9000 K, possibly related to the sdA stars recently reported from SDSS spectra.« less

Connection between plasma response and resonant magnetic perturbation (RMP) edge localized mode (ELM) suppression in DIII-D [Connection between plasma response and RMP ELM suppression in DIII-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wingen, Andreas; Ferraro, Nathaniel M.; Shafer, Morgan W.

Calculations of the plasma response to applied non-axisymmetric fields in several DIII-D discharges show that predicted displacements depend strongly on the edge current density. This result is found using both a linear two-fluid-MHD model (M3D-C1) and a nonlinear ideal-MHD model (VMEC). Furthermore, it is observed that the probability of a discharge being edge localized mode (ELM)-suppressed is most closely related to the edge current density, as opposed to the pressure gradient. It is found that discharges with a stronger kink response are closer to the peeling–ballooning stability limit in ELITE simulations and eventually cross into the unstable region, causing ELMsmore » to reappear. Thus for effective ELM suppression, the RMP has to prevent the plasma from generating a large kink response, associated with ELM instability. Experimental observations are in agreement with the finding; discharges which have a strong kink response in the MHD simulations show ELMs or ELM mitigation during the RMP phase of the experiment, while discharges with a small kink response in the MHD simulations are fully ELM suppressed in the experiment by the applied resonant magnetic perturbation. The results are cross-checked against modeled 3D ideal MHD equilibria using the VMEC code. The procedure of constructing optimal 3D equilibria for diverted H-mode discharges using VMEC is presented. As a result, kink displacements in VMEC are found to scale with the edge current density, similar to M3D-C1, but the displacements are smaller. A direct correlation in the flux surface displacements to the bootstrap current is shown.« less

Connection between plasma response and resonant magnetic perturbation (RMP) edge localized mode (ELM) suppression in DIII-D [Connection between plasma response and RMP ELM suppression in DIII-D

DOE PAGES

Wingen, Andreas; Ferraro, Nathaniel M.; Shafer, Morgan W.; ...

2015-09-03

Calculations of the plasma response to applied non-axisymmetric fields in several DIII-D discharges show that predicted displacements depend strongly on the edge current density. This result is found using both a linear two-fluid-MHD model (M3D-C1) and a nonlinear ideal-MHD model (VMEC). Furthermore, it is observed that the probability of a discharge being edge localized mode (ELM)-suppressed is most closely related to the edge current density, as opposed to the pressure gradient. It is found that discharges with a stronger kink response are closer to the peeling–ballooning stability limit in ELITE simulations and eventually cross into the unstable region, causing ELMsmore » to reappear. Thus for effective ELM suppression, the RMP has to prevent the plasma from generating a large kink response, associated with ELM instability. Experimental observations are in agreement with the finding; discharges which have a strong kink response in the MHD simulations show ELMs or ELM mitigation during the RMP phase of the experiment, while discharges with a small kink response in the MHD simulations are fully ELM suppressed in the experiment by the applied resonant magnetic perturbation. The results are cross-checked against modeled 3D ideal MHD equilibria using the VMEC code. The procedure of constructing optimal 3D equilibria for diverted H-mode discharges using VMEC is presented. As a result, kink displacements in VMEC are found to scale with the edge current density, similar to M3D-C1, but the displacements are smaller. A direct correlation in the flux surface displacements to the bootstrap current is shown.« less

Pruning The ELM Survey: Characterizing Candidate Low-mass White Dwarfs through Photometric Variability

NASA Astrophysics Data System (ADS)

Bell, Keaton J.; Gianninas, A.; Hermes, J. J.; Winget, D. E.; Kilic, Mukremin; Montgomery, M. H.; Castanheira, B. G.; Vanderbosch, Z.; Winget, K. I.; Brown, Warren R.

2017-02-01

We assess the photometric variability of nine stars with spectroscopic Teff and log g values from the ELM Survey that locates them near the empirical extremely low-mass (ELM) white dwarf instability strip. We discover three new pulsating stars: SDSS J135512.34+195645.4, SDSS J173521.69+213440.6, and SDSS J213907.42+222708.9. However, these are among the few ELM Survey objects that do not show radial velocity (RV) variations that confirm the binary nature expected of helium-core white dwarfs. The dominant 4.31 hr pulsation in SDSS J135512.34+195645.4 far exceeds the theoretical cut-off for surface reflection in a white dwarf, and this target is likely a high-amplitude δ Scuti pulsator with an overestimated surface gravity. We estimate the probability to be less than 0.0008 that the lack of measured RV variations in four of eight other pulsating candidate ELM white dwarfs could be due to low orbital inclination. Two other targets exhibit variability as photometric binaries. Partial coverage of the 19.342 hr orbit of WD J030818.19+514011.5 reveals deep eclipses that imply a primary radius >0.4 R⊙—too large to be consistent with an ELM white dwarf. The only object for which our time series photometry adds support to ELM white dwarf classification is SDSS J105435.78-212155.9, which has consistent signatures of Doppler beaming and ellipsoidal variations. We conclude that the ELM Survey contains multiple false positives from another stellar population at Teff ≲ 9000 K, possibly related to the sdA stars recently reported from SDSS spectra.

Impact of bootstrap current and Landau-fluid closure on ELM crashes and transport

NASA Astrophysics Data System (ADS)

Chen, J. G.; Xu, X. Q.; Ma, C. H.; Lei, Y. A.

2018-05-01

Results presented here are from 6-field Landau-Fluid simulations using shifted circular cross-section tokamak equilibria on BOUT++ framework. Linear benchmark results imply that the collisional and collisionless Landau resonance closures make a little difference on linear growth rate spectra which are quite close to the results with the flux limited Spitzer-Härm parallel flux. Both linear and nonlinear simulations show that the plasma current profile plays dual roles on the peeling-ballooning modes that it can drive the low-n peeling modes and stabilize the high-n ballooning modes. For fixed total pressure and current, as the pedestal current decreases due to the bootstrap current which becomes smaller when the density (collisionality) increases, the operational point is shifted downwards vertically in the Jped - α diagram, resulting in threshold changes of different modes. The bootstrap current can slightly increase radial turbulence spreading range and enhance the energy and particle transports by increasing the perturbed amplitude and broadening cross-phase frequency distribution.

Dose-response of urban trees to sulfur dioxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Temple, P.J.

1972-01-01

Controlled fumigation experiments were conducted to determine the dose-response relationships for four species of urban trees exposed to sulfur dioxide. The species chosen were ginkgo, Norway maple, pin oak, and Chinese elm. Results indicated that resistance to SO/sub 2/ increased among the species in the following order: Chinese elm, Norway maple, ginkgo, pin oak. Elm showed almost 100% leaf necrosis at exposures over 2 ppM for 6 hr, and severe chlorosis and necrosis at 0.25 ppM for 30 days. Fifty percent leaf necrosis occurred on Norway maple at 3 ppM for 6 hr, and on ginkgo at 4 ppM formore » 6 hr, and both species developed moderate marginal chlorosis at 0.50 ppM for 30 days. Injury on pin oak was minor, even at 8 ppM for 8 hr, but at 0.50 ppM for 30 days, a slight overall chlorosis developed on the leaves. The relative susceptibilities of the four species were the same in the long-term as in the short-term exposures. The shapes of the dose-response surfaces indicated that durations of exposure and concentration of the pollutant were of equal importance in producing injury on Chinese elm and probably on pin oak, but on Norway maple and ginkgo, concentration of SO/sub 2/ was of greater importance than the duration of exposure.« less

ELM induced divertor heat loads on TCV

NASA Astrophysics Data System (ADS)

Marki, J.; Pitts, R. A.; Horacek, J.; Tskhakaya, D.; TCV Team

2009-06-01

Results are presented for heat loads at the TCV outer divertor target during ELMing H-mode using a fast IR camera. Benefitting from a recent surface cleaning of the entire first wall graphite armour, a comparison of the transient thermal response of freshly cleaned and untreated tile surfaces (coated with thick co-deposited layers) has been performed. The latter routinely exhibit temperature transients exceeding those of the clean ones by a factor ˜3, even if co-deposition throughout the first days of operation following the cleaning process leads to the steady regrowth of thin layers. Filaments are occasionally observed during the ELM heat flux rise phase, showing a spatial structure consistent with energy release at discrete toroidal locations in the outer midplane vicinity and with individual filaments carrying ˜1% of the total ELM energy. The temporal waveform of the ELM heat load is found to be in good agreement with the collisionless free streaming particle model.

VizieR Online Data Catalog: Binary white dwarfs atmospheric parameters (Gianninas+, 2014)

NASA Astrophysics Data System (ADS)

Gianninas, A.; Dufour, P.; Kilic, M.; Brown, W. R.; Bergeron, P.; Hermes, J. J.

2017-04-01

The sample that we analyze includes a total of 61 ELM WD binaries from the ELM Survey (Brown et al. 2013, J/ApJ/769/66). The bulk of this sample is comprised of the 58 ELM WDs listed in Table 3 of Brown et al. (2013, J/ApJ/769/66), but also includes three additional ELM WDs that have been published in separate papers since then. The spectra of these 61 ELM WDs were obtained using five distinct setups on two different telescopes. A total of 57 targets were observed with the 6.5m MMT telescope with the Blue Channel spectrograph (Schmidt et al. 1989PASP..101..713S). The four remaining targets were observed using the Fred Lawrence Whipple Observatory's (FLWO) 1.5m Tilinghast telescope equipped with the FAST spectrograph (Fabricant et al. 1998PASP..110...79F) and the 600 line/mm grating. (2 data files).

Not all triads are created equal: further support for the importance of visual and semantic proximity in object identification.

PubMed

Schweizer, Tom A; Dixon, Mike J; Desmarais, Geneviève; Smith, Stephen D

2002-01-01

Identification deficits were investigated in ELM, a temporal lobe stroke patient with category-specific deficits. We replicated previous work done on FS, a patient with category specific deficits as a result of herpes viral encephalitis. ELM was tested using novel, computer generated shapes that were paired with artifact labels. We paired semantically close or disparate labels to shapes and ELM attempted to learn these pairings. Overall, ELM's shape-label confusions were most detrimentally affected when we used labels that referred to objects that were visually and semantically close. However, as with FS, ELM had as many errors when shapes were paired with the labels "donut," "tire," and "washer" as he did when they were paired with visually and semantically close artifact labels. Two explanations are put forth to account for the anomalous performance by both patients on the triad of donut-tire-washer.

Multilayer Extreme Learning Machine With Subnetwork Nodes for Representation Learning.

PubMed

Yang, Yimin; Wu, Q M Jonathan

2016-11-01

The extreme learning machine (ELM), which was originally proposed for "generalized" single-hidden layer feedforward neural networks, provides efficient unified learning solutions for the applications of clustering, regression, and classification. It presents competitive accuracy with superb efficiency in many applications. However, ELM with subnetwork nodes architecture has not attracted much research attentions. Recently, many methods have been proposed for supervised/unsupervised dimension reduction or representation learning, but these methods normally only work for one type of problem. This paper studies the general architecture of multilayer ELM (ML-ELM) with subnetwork nodes, showing that: 1) the proposed method provides a representation learning platform with unsupervised/supervised and compressed/sparse representation learning and 2) experimental results on ten image datasets and 16 classification datasets show that, compared to other conventional feature learning methods, the proposed ML-ELM with subnetwork nodes performs competitively or much better than other feature learning methods.

Overview of recent and current research on the TCV tokamak

NASA Astrophysics Data System (ADS)

S. Codathe TCV Team

2013-10-01

Through a diverse research programme, the Tokamak à Configuration Variable (TCV) addresses physics issues and develops tools for ITER and for the longer term goals of nuclear fusion, relying especially on its extreme plasma shaping and electron cyclotron resonance heating (ECRH) launching flexibility and preparing for an ECRH and NBI power upgrade. Localized edge heating was unexpectedly found to decrease the period and relative energy loss of edge localized modes (ELMs). Successful ELM pacing has been demonstrated by following individual ELM detection with an ECRH power cut before turning the power back up to trigger the next ELM, the duration of the cut determining the ELM period. Negative triangularity was also seen to reduce the ELM energy release. H-mode studies have focused on the L-H threshold dependence on the main ion species and on the divertor leg length. Both L- and H-modes have been explored in the snowflake configuration with emphasis on edge measurements, revealing that the heat flux to the strike points on the secondary separatrix increases as the X-points approach each other, well before they coalesce. In L-mode, a systematic scan of the auxiliary power deposition profile, with no effect on confinement, has ruled it out as the cause of confinement degradation. An ECRH power absorption observer based on transmitted stray radiation was validated for eventual polarization control. A new profile control methodology was introduced, relying on real-time modelling to supplement diagnostic information; the RAPTOR current transport code in particular has been employed for joint control of the internal inductance and central temperature. An internal inductance controller using the ohmic transformer has also been demonstrated. Fundamental investigations of neoclassical tearing mode (NTM) seed island formation by sawtooth crashes and of NTM destabilization in the absence of a sawtooth trigger were carried out. Both stabilizing and destabilizing agents (electron cyclotron current drive on or inside the q = 1 surface, respectively) were used to pace sawtooth oscillations, permitting precise control of their period. Locking of the sawtooth period to a pre-defined ECRH modulation period was also demonstrated. Sawtooth control has permitted nearly failsafe NTM prevention when combined with backup NTM stabilization by ECRH.

Modelling of plasma-wall interaction and impurity transport in fusion devices and prompt deposition of tungsten as application

NASA Astrophysics Data System (ADS)

Kirschner, A.; Tskhakaya, D.; Brezinsek, S.; Borodin, D.; Romazanov, J.; Ding, R.; Eksaeva, A.; Linsmeier, Ch

2018-01-01

Main processes of plasma-wall interaction and impurity transport in fusion devices and their impact on the availability of the devices are presented and modelling tools, in particular the three-dimensional Monte-Carlo code ERO, are introduced. The capability of ERO is demonstrated on the example of tungsten erosion and deposition modelling. The dependence of tungsten deposition on plasma temperature and density is studied by simulations with a simplified geometry assuming (almost) constant plasma parameters. The amount of deposition increases with increasing electron temperature and density. Up to 100% of eroded tungsten can be promptly deposited near to the location of erosion at very high densities (˜1 × 1014 cm-3 expected e.g. in the divertor of ITER). The effect of the sheath characteristics on tungsten prompt deposition is investigated by using particle-in-cell (PIC) simulations to spatially resolve the plasma parameters inside the sheath. Applying PIC data instead of non-resolved sheath leads in general to smaller tungsten deposition, which is mainly due to a density and temperature decrease towards the surface within the sheath. Two-dimensional tungsten erosion/deposition simulations, assuming symmetry in toroidal direction but poloidally spatially varying plasma parameter profiles, have been carried out for the JET divertor. The simulations reveal, similar to experimental findings, that tungsten gross erosion is dominated in H-mode plasmas by the intra-ELM phases. However, due to deposition, the net tungsten erosion can be similar within intra- and inter-ELM phases if the inter-ELM electron temperature is high enough. Also, the simulated deposition fraction of about 84% in between ELMs is in line with spectroscopic observations from which a lower limit of 50% has been estimated.

Establishment patterns of water-elm at Catahoula Lake, Louisiana

Treesearch

Karen S. Doerr; Sanjeev Joshi; Richard F. Keim

2015-01-01

At Catahoula Lake in central Louisiana, an internationally important lake for water fowl, hydrologic alterations to the surrounding rivers and the lake itself have led to an expansion of water-elm (Planera aquatic J.F. Gmel.) into the lake bed. In this study, we used dendrochronology and aerial photography to quantify the expansion of water-elm in the lake and identify...

Pruning cycles and storm damage: are young American elms failing prematurely?

Treesearch

Chad P. Giblin

2017-01-01

The use of Dutch elm disease-resistant elms as a common replacement tree in municipal planting schedules has amassed a large population of these trees in many cities throughout the eastern half of the United States. Reports from practitioners have suggested that this population is vulnerable to catastrophic losses due to severe canopy failures during wind-loading...

Challenge inoculations to test for Dutch elm disease tolerance: a summary of methods used by various researchers

Treesearch

Linda M. Haugen; Garrett L. Beier; Susan E. Bentz; Raymond P. Guries; James M. Slavicek

2017-01-01

A variety of methods have been used by different research groups to "challenge" inoculate American elms (Ulmus americana) with the purpose of determining whether some clones may be resistant to the Dutch elm disease fungus. The methods used by seven research groups are described, along with observations on complications and benefits...

Host acceptance and larval competition between the invasive banded and European elm bark beetles (Coleoptera: Scolytidae): Potential mechanisms for competitive displacement

Treesearch

J.C. Lee; S.J. Seybold

2009-01-01

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 was initiated to determine whether competitive displacement of S. multistriatus...

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

Treesearch

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...

Observations of ELM stabilization during neutral beam injection in DIII-D

NASA Astrophysics Data System (ADS)

Bortolon, Alessandro; Kramer, Gerrit; Diallo, Ahmed; Knolker, Matthias; Maingi, Rajesh; Nazikian, Raffi; Degrassie, John; Osborne, Thomas

2017-10-01

Edge localized modes (ELMs) are generally interpreted as peeling-ballooning instabilities, driven by the pedestal current and pressure gradient, with other subdominant effects possibly relevant close to marginal stability. We report observations of transient stabilization of type-I ELMs during neutral beam injection (NBI), emerging from a combined dataset of DIII-D ELMy H-mode plasmas with moderate heating obtained through pulsed NBI waveforms. Statistical analysis of ELM onset times indicates that, in the selected dataset, the likelihood of onset of an ELM lowers significantly during NBI modulation pulses, with the stronger correlation found with counter-current NBI. The effect is also found in rf-heated H-modes, where ELMs appear inhibited when isolated diagnostic beam pulses are applied. Coherent average analysis is used to determine how plasma density, temperature, rotation as well as beam ion quantities evolve during a NB modulation cycle, finding relatively small changes ( 3%) of pedestal Te and ne and toroidal and poloidal rotation variations up to 5 km/s. The effect of these changes on pedestal stability will be discussed. Work supported by US DOE under DE-FC02-04ER54698, DE-AC02-09CH11466.

ELM: the status of the 2010 eukaryotic linear motif resource

PubMed Central

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; Paś, 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. PMID:19920119

Divertor power and particle fluxes between and during type-I ELMs in the ASDEX Upgrade

NASA Astrophysics Data System (ADS)

Kallenbach, A.; Dux, R.; Eich, T.; Fischer, R.; Giannone, L.; Harhausen, J.; Herrmann, A.; Müller, H. W.; Pautasso, G.; Wischmeier, M.; ASDEX Upgrade Team

2008-08-01

Particle, electric charge and power fluxes for type-I ELMy H-modes are measured in the divertor of the ASDEX Upgrade tokamak by triple Langmuir probes, shunts, infrared (IR) thermography and spectroscopy. The discharges are in the medium to high density range, resulting in predominantly convective edge localized modes (ELMs) with moderate fractional stored energy losses of 2% or below. Time resolved data over ELM cycles are obtained by coherent averaging of typically one hundred similar ELMs, spatial profiles from the flush-mounted Langmuir probes are obtained by strike point sweeps. The application of simple physics models is used to compare different diagnostics and to make consistency checks, e.g. the standard sheath model applied to the Langmuir probes yields power fluxes which are compared with the thermographic measurements. In between ELMs, Langmuir probe and thermography power loads appear consistent in the outer divertor, taking into account additional load due to radiation and charge exchange neutrals measured by thermography. The inner divertor is completely detached and no significant power flow by charged particles is measured. During ELMs, quite similar power flux profiles are found in the outer divertor by thermography and probes, albeit larger uncertainties in Langmuir probe evaluation during ELMs have to be taken into account. In the inner divertor, ELM power fluxes from thermography are a factor 10 larger than those derived from probes using the standard sheath model. This deviation is too large to be caused by deficiencies of probe analysis. The total ELM energy deposition from IR is about a factor 2 higher in the inner divertor compared with the outer divertor. Spectroscopic measurements suggest a quite moderate contribution of radiation to the target power load. Shunt measurements reveal a significant positive charge flow into the inner target during ELMs. The net number of elementary charges correlates well with the total core particle loss obtained from highly resolved density profiles. As a consequence, the discrepancy between probe and IR measurements is attributed to the ion power channel via a high mean impact energy of the ions at the inner target. The dominant contributing mechanism is proposed to be the directed loss of ions from the pedestal region into the inner divertor.

Single image super-resolution via regularized extreme learning regression for imagery from microgrid polarimeters

NASA Astrophysics Data System (ADS)

Sargent, Garrett C.; Ratliff, Bradley M.; Asari, Vijayan K.

2017-08-01

The advantage of division of focal plane imaging polarimeters is their ability to obtain temporally synchronized intensity measurements across a scene; however, they sacrifice spatial resolution in doing so due to their spatially modulated arrangement of the pixel-to-pixel polarizers and often result in aliased imagery. Here, we propose a super-resolution method based upon two previously trained extreme learning machines (ELM) that attempt to recover missing high frequency and low frequency content beyond the spatial resolution of the sensor. This method yields a computationally fast and simple way of recovering lost high and low frequency content from demosaicing raw microgrid polarimetric imagery. The proposed method outperforms other state-of-the-art single-image super-resolution algorithms in terms of structural similarity and peak signal-to-noise ratio.

An Incremental Type-2 Meta-Cognitive Extreme Learning Machine.

PubMed

Pratama, Mahardhika; Zhang, Guangquan; Er, Meng Joo; Anavatti, Sreenatha

2017-02-01

Existing extreme learning algorithm have not taken into account four issues: 1) complexity; 2) uncertainty; 3) concept drift; and 4) high dimensionality. A novel incremental type-2 meta-cognitive extreme learning machine (ELM) called evolving type-2 ELM (eT2ELM) is proposed to cope with the four issues in this paper. The eT2ELM presents three main pillars of human meta-cognition: 1) what-to-learn; 2) how-to-learn; and 3) when-to-learn. The what-to-learn component selects important training samples for model updates by virtue of the online certainty-based active learning method, which renders eT2ELM as a semi-supervised classifier. The how-to-learn element develops a synergy between extreme learning theory and the evolving concept, whereby the hidden nodes can be generated and pruned automatically from data streams with no tuning of hidden nodes. The when-to-learn constituent makes use of the standard sample reserved strategy. A generalized interval type-2 fuzzy neural network is also put forward as a cognitive component, in which a hidden node is built upon the interval type-2 multivariate Gaussian function while exploiting a subset of Chebyshev series in the output node. The efficacy of the proposed eT2ELM is numerically validated in 12 data streams containing various concept drifts. The numerical results are confirmed by thorough statistical tests, where the eT2ELM demonstrates the most encouraging numerical results in delivering reliable prediction, while sustaining low complexity.

Very short-term reactive forecasting of the solar ultraviolet index using an extreme learning machine integrated with the solar zenith angle.

PubMed

Deo, Ravinesh C; Downs, Nathan; Parisi, Alfio V; Adamowski, Jan F; Quilty, John M

2017-05-01

Exposure to erythemally-effective solar ultraviolet radiation (UVR) that contributes to malignant keratinocyte cancers and associated health-risk is best mitigated through innovative decision-support systems, with global solar UV index (UVI) forecast necessary to inform real-time sun-protection behaviour recommendations. It follows that the UVI forecasting models are useful tools for such decision-making. In this study, a model for computationally-efficient data-driven forecasting of diffuse and global very short-term reactive (VSTR) (10-min lead-time) UVI, enhanced by drawing on the solar zenith angle (θ s ) data, was developed using an extreme learning machine (ELM) algorithm. An ELM algorithm typically serves to address complex and ill-defined forecasting problems. UV spectroradiometer situated in Toowoomba, Australia measured daily cycles (0500-1700h) of UVI over the austral summer period. After trialling activations functions based on sine, hard limit, logarithmic and tangent sigmoid and triangular and radial basis networks for best results, an optimal ELM architecture utilising logarithmic sigmoid equation in hidden layer, with lagged combinations of θ s as the predictor data was developed. ELM's performance was evaluated using statistical metrics: correlation coefficient (r), Willmott's Index (WI), Nash-Sutcliffe efficiency coefficient (E NS ), root mean square error (RMSE), and mean absolute error (MAE) between observed and forecasted UVI. Using these metrics, the ELM model's performance was compared to that of existing methods: multivariate adaptive regression spline (MARS), M5 Model Tree, and a semi-empirical (Pro6UV) clear sky model. Based on RMSE and MAE values, the ELM model (0.255, 0.346, respectively) outperformed the MARS (0.310, 0.438) and M5 Model Tree (0.346, 0.466) models. Concurring with these metrics, the Willmott's Index for the ELM, MARS and M5 Model Tree models were 0.966, 0.942 and 0.934, respectively. About 57% of the ELM model's absolute errors were small in magnitude (±0.25), whereas the MARS and M5 Model Tree models generated 53% and 48% of such errors, respectively, indicating the latter models' errors to be distributed in larger magnitude error range. In terms of peak global UVI forecasting, with half the level of error, the ELM model outperformed MARS and M5 Model Tree. A comparison of the magnitude of hourly-cumulated errors of 10-min lead time forecasts for diffuse and global UVI highlighted ELM model's greater accuracy compared to MARS, M5 Model Tree or Pro6UV models. This confirmed the versatility of an ELM model drawing on θ s data for VSTR forecasting of UVI at near real-time horizon. When applied to the goal of enhancing expert systems, ELM-based accurate forecasts capable of reacting quickly to measured conditions can enhance real-time exposure advice for the public, mitigating the potential for solar UV-exposure-related disease. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Overview of MAST results

NASA Astrophysics Data System (ADS)

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 in solenoid-free start-up. A new proton detector has characterized escaping fusion products. Langmuir probes and a high-speed camera suggest filaments play a role in particle transport in the private flux region whilst coherence imaging has measured scrape-off layer (SOL) flows. BOUT++ simulations show that fluxes due to filaments are strongly dependent on resistivity and magnetic geometry of the SOL, with higher radial fluxes at higher resistivity. Finally, MAST Upgrade is due to begin operation in 2016 to support ITER preparation and importantly to operate with a Super-X divertor to test extended leg concepts for particle and power exhaust.

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

Treesearch

Jana C. Lee; Shakeeb M. Hamud; Jose F. Negron; Jeffrey J. Witcosky; Steven J. Seybold

2010-01-01

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....

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

USDA-ARS?s Scientific Manuscript database

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...

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

Treesearch

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....

Environmental Assessment for Tinker Aerospace Complex Tinker Air Force Base, Oklahoma

DTIC Science & Technology

2008-05-01

Boutelova curtipendula silver bluestem Andropogon saccharoides slippery elm Ulmus rubra sugarberry Celtis laevigata switchgrass...areas; Crutcho Creek, Elm Creek, and Hog Creek. The Crutcho Creek drainage area consists of two additional water bodies, Kulhman Creek and Solider...Crutcho Creek flows to the north and discharges into the North Canadian River; the North Canadian River then discharges into the Arkansas River. Elm

Vegetation in the Flood Plain Adjacent to the Mississippi River between Cairo, Illinois, and St. Paul, Minnesota, and in the Flood Plain of the Illinois River between Grafton, Illinois, and Chicago, and the Possible Impacts That Will Result from the Construction of L & D 26 and the Associated Increase in Barge Traffic,

DTIC Science & Technology

1975-01-20

americana), green ash (Fraxinus lanceolata), pecan (Carya illinoensis), sugarberry (Celtis laevigata), and red mulberry (Morus rubra). Also...cottonwood (Populus deltoides), silver maple (Acer saccharinum), box elder (Acer negundo), and green ash (Frax- inus lanceolata). There is a rather sparse...Amer- ican elm (Ulmus americana), slippery elm (U. rubra), box elder (Acer negundo), sycamore (Platanus occidentalis) green ash (Fraxinus lanceo- lata

Three dimensional nonlinear simulations of edge localized modes on the EAST tokamak using BOUT++ code

NASA Astrophysics Data System (ADS)

Liu, Z. X.; Xu, X. Q.; Gao, X.; Xia, T. Y.; Joseph, I.; Meyer, W. H.; Liu, S. C.; Xu, G. S.; Shao, L. M.; Ding, S. Y.; Li, G. Q.; Li, J. G.

2014-09-01

Experimental measurements of edge localized modes (ELMs) observed on the EAST experiment are compared to linear and nonlinear theoretical simulations of peeling-ballooning modes using the BOUT++ code. Simulations predict that the dominant toroidal mode number of the ELM instability becomes larger for lower current, which is consistent with the mode structure captured with visible light using an optical CCD camera. The poloidal mode number of the simulated pressure perturbation shows good agreement with the filamentary structure observed by the camera. The nonlinear simulation is also consistent with the experimentally measured energy loss during an ELM crash and with the radial speed of ELM effluxes measured using a gas puffing imaging diagnostic.

Empirical Wavelet Transform Based Features for Classification of Parkinson's Disease Severity.

PubMed

Oung, Qi Wei; Muthusamy, Hariharan; Basah, Shafriza Nisha; Lee, Hoileong; Vijean, Vikneswaran

2017-12-29

Parkinson's disease (PD) is a type of progressive neurodegenerative disorder that has affected a large part of the population till now. Several symptoms of PD include tremor, rigidity, slowness of movements and vocal impairments. In order to develop an effective diagnostic system, a number of algorithms were proposed mainly to distinguish healthy individuals from the ones with PD. However, most of the previous works were conducted based on a binary classification, with the early PD stage and the advanced ones being treated equally. Therefore, in this work, we propose a multiclass classification with three classes of PD severity level (mild, moderate, severe) and healthy control. The focus is to detect and classify PD using signals from wearable motion and audio sensors based on both empirical wavelet transform (EWT) and empirical wavelet packet transform (EWPT) respectively. The EWT/EWPT was applied to decompose both speech and motion data signals up to five levels. Next, several features are extracted after obtaining the instantaneous amplitudes and frequencies from the coefficients of the decomposed signals by applying the Hilbert transform. The performance of the algorithm was analysed using three classifiers - K-nearest neighbour (KNN), probabilistic neural network (PNN) and extreme learning machine (ELM). Experimental results demonstrated that our proposed approach had the ability to differentiate PD from non-PD subjects, including their severity level - with classification accuracies of more than 90% using EWT/EWPT-ELM based on signals from motion and audio sensors respectively. Additionally, classification accuracy of more than 95% was achieved when EWT/EWPT-ELM is applied to signals from integration of both signal's information.

Experimental validation of an analytical kinetic model for edge-localized modes in JET-ITER-like wall

NASA Astrophysics Data System (ADS)

Guillemaut, C.; Metzger, C.; Moulton, D.; Heinola, K.; O’Mullane, M.; Balboa, I.; Boom, J.; Matthews, G. F.; Silburn, S.; Solano, E. R.; contributors, JET

2018-06-01

The design and operation of future fusion devices relying on H-mode plasmas requires reliable modelling of edge-localized modes (ELMs) for precise prediction of divertor target conditions. An extensive experimental validation of simple analytical predictions of the time evolution of target plasma loads during ELMs has been carried out here in more than 70 JET-ITER-like wall H-mode experiments with a wide range of conditions. Comparisons of these analytical predictions with diagnostic measurements of target ion flux density, power density, impact energy and electron temperature during ELMs are presented in this paper and show excellent agreement. The analytical predictions tested here are made with the ‘free-streaming’ kinetic model (FSM) which describes ELMs as a quasi-neutral plasma bunch expanding along the magnetic field lines into the Scrape-Off Layer without collisions. Consequences of the FSM on energy reflection and deposition on divertor targets during ELMs are also discussed.

Exploring Short Linear Motifs Using the ELM Database and Tools.

PubMed

Gouw, Marc; Sámano-Sánchez, Hugo; Van Roey, Kim; Diella, Francesca; Gibson, Toby J; Dinkel, Holger

2017-06-27

The Eukaryotic Linear Motif (ELM) resource is dedicated to the characterization and prediction of short linear motifs (SLiMs). SLiMs are compact, degenerate peptide segments found in many proteins and essential to almost all cellular processes. However, despite their abundance, SLiMs remain largely uncharacterized. The ELM database is a collection of manually annotated SLiM instances curated from experimental literature. In this article we illustrate how to browse and search the database for curated SLiM data, and cover the different types of data integrated in the resource. We also cover how to use this resource in order to predict SLiMs in known as well as novel proteins, and how to interpret the results generated by the ELM prediction pipeline. The ELM database is a very rich resource, and in the following protocols we give helpful examples to demonstrate how this knowledge can be used to improve your own research. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

BELM: Bayesian extreme learning machine.

PubMed

Soria-Olivas, Emilio; Gómez-Sanchis, Juan; Martín, José D; Vila-Francés, Joan; Martínez, Marcelino; Magdalena, José R; Serrano, Antonio J

2011-03-01

The theory of extreme learning machine (ELM) has become very popular on the last few years. ELM is a new approach for learning the parameters of the hidden layers of a multilayer neural network (as the multilayer perceptron or the radial basis function neural network). Its main advantage is the lower computational cost, which is especially relevant when dealing with many patterns defined in a high-dimensional space. This brief proposes a bayesian approach to ELM, which presents some advantages over other approaches: it allows the introduction of a priori knowledge; obtains the confidence intervals (CIs) without the need of applying methods that are computationally intensive, e.g., bootstrap; and presents high generalization capabilities. Bayesian ELM is benchmarked against classical ELM in several artificial and real datasets that are widely used for the evaluation of machine learning algorithms. Achieved results show that the proposed approach produces a competitive accuracy with some additional advantages, namely, automatic production of CIs, reduction of probability of model overfitting, and use of a priori knowledge.

Rule Extraction Based on Extreme Learning Machine and an Improved Ant-Miner Algorithm for Transient Stability Assessment.

PubMed

Li, Yang; Li, Guoqing; Wang, Zhenhao

2015-01-01

In order to overcome the problems of poor understandability of the pattern recognition-based transient stability assessment (PRTSA) methods, a new rule extraction method based on extreme learning machine (ELM) and an improved Ant-miner (IAM) algorithm is presented in this paper. First, the basic principles of ELM and Ant-miner algorithm are respectively introduced. Then, based on the selected optimal feature subset, an example sample set is generated by the trained ELM-based PRTSA model. And finally, a set of classification rules are obtained by IAM algorithm to replace the original ELM network. The novelty of this proposal is that transient stability rules are extracted from an example sample set generated by the trained ELM-based transient stability assessment model by using IAM algorithm. The effectiveness of the proposed method is shown by the application results on the New England 39-bus power system and a practical power system--the southern power system of Hebei province.

ELM Triggering with the New PPPL Lithium Granular Injector

NASA Astrophysics Data System (ADS)

Mansfield, D. K.; Roquemore, A. L.; Maingi, R.; Hu, J. S.; Liang, Y.; Sun, Z.; Zhang, L.; Zou, G.

2012-10-01

A Li granular injector based on a high-speed rotating impeller has been developed at PPPL. The injector is capable of injecting spherical particles with diameters up to 1.3 mm and velocities of up to 100 m/s and has several possible applications. Primarily, the injector was developed as a tool to induce ELMs for ELM pacing experiments in plasmas operating in the H-mode. It can also operate as a real-time wall conditioning tool or as a method to resupply Li during a discharge to devices where Li is applied to the PFC's prior to a discharge. The injector is also capable of horizontally injecting small dust particles of any variety for plasma-dust transport studies. The first injector has recently been successfully installed on the EAST tokamak in Hefei, China where ELMs were induced with near 100% efficiency when 0.7mm spheres were injected at ˜ 40m/s into the midplane SOL. The injector will be described and supporting data for ELM triggering will be presented.

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

Treesearch

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...

Archeology and Native American Religion at the Leon River Medicine Wheel.

DTIC Science & Technology

1996-02-01

varieties of plants. The eastern side of including pecan (Carya illinoinensis), slippery elm the facility (East Range) is typified by dense (Ulmus rubra...southern part of the Cross Timbers and Prairies texana), and cedar elm (Ulmus crassifolia). A Vegetation Area. Alired and Mitchell (1955) term variety of...south (West Fort americana), American elm (Ulmus americana), Hood) are generally more open, ranging from TRC MARIAH ASSOCIATES, INC. (662-21

The Extent of Hybridization and Its Impact on the Genetic Diversity and Population Structure of an Invasive Tree, Ulmus Pumila (Ulmaceae)

USDA-ARS?s Scientific Manuscript database

Siberian elm (Ulmus pumila L.), native to East Asia, was introduced in the U.S. in the 1900’s because of its high tolerance to Dutch elm disease (DED). Siberian elm has spread following its introduction and has now become one of the most invasive woody species in the U.S., alongside Russian olive a...

How to assess the efficiency of synchronization experiments in tokamaks

NASA Astrophysics Data System (ADS)

Murari, A.; Craciunescu, T.; Peluso, E.; Gelfusa, M.; Lungaroni, M.; Garzotti, L.; Frigione, D.; Gaudio, P.; Contributors, JET

2016-07-01

Control of instabilities such as ELMs and sawteeth is considered an important ingredient in the development of reactor-relevant scenarios. Various forms of ELM pacing have been tried in the past to influence their behavior using external perturbations. One of the main problems with these synchronization experiments resides in the fact that ELMs are periodic or quasi-periodic in nature. Therefore, after any pulsed perturbation, if one waits long enough, an ELM is always bound to occur. To evaluate the effectiveness of ELM pacing techniques, it is crucial to determine an appropriate interval over which they can have a real influence and an effective triggering capability. In this paper, three independent statistical methods are described to address this issue: Granger causality, transfer entropy and recurrence plots. The obtained results for JET with the ITER-like wall (ILW) indicate that the proposed techniques agree very well and provide much better estimates than the traditional heuristic criteria reported in the literature. Moreover, their combined use allows for the improvement of the time resolution of the assessment and determination of the efficiency of the pellet triggering in different phases of the same discharge. Therefore, the developed methods can be used to provide a quantitative and statistically robust estimate of the triggering efficiency of ELM pacing under realistic experimental conditions.

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

NASA Astrophysics Data System (ADS)

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.

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

PubMed Central

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

Segmentation of dermatoscopic images by frequency domain filtering and k-means clustering algorithms.

PubMed

Rajab, Maher I

2011-11-01

Since the introduction of epiluminescence microscopy (ELM), image analysis tools have been extended to the field of dermatology, in an attempt to algorithmically reproduce clinical evaluation. Accurate image segmentation of skin lesions is one of the key steps for useful, early and non-invasive diagnosis of coetaneous melanomas. This paper proposes two image segmentation algorithms based on frequency domain processing and k-means clustering/fuzzy k-means clustering. The two methods are capable of segmenting and extracting the true border that reveals the global structure irregularity (indentations and protrusions), which may suggest excessive cell growth or regression of a melanoma. As a pre-processing step, Fourier low-pass filtering is applied to reduce the surrounding noise in a skin lesion image. A quantitative comparison of the techniques is enabled by the use of synthetic skin lesion images that model lesions covered with hair to which Gaussian noise is added. The proposed techniques are also compared with an established optimal-based thresholding skin-segmentation method. It is demonstrated that for lesions with a range of different border irregularity properties, the k-means clustering and fuzzy k-means clustering segmentation methods provide the best performance over a range of signal to noise ratios. The proposed segmentation techniques are also demonstrated to have similar performance when tested on real skin lesions representing high-resolution ELM images. This study suggests that the segmentation results obtained using a combination of low-pass frequency filtering and k-means or fuzzy k-means clustering are superior to the result that would be obtained by using k-means or fuzzy k-means clustering segmentation methods alone. © 2011 John Wiley & Sons A/S.

Edge profile analysis of Joint European Torus (JET) Thomson scattering data: Quantifying the systematic error due to edge localised mode synchronisation.

PubMed

Leyland, M J; Beurskens, M N A; Flanagan, J C; Frassinetti, L; Gibson, K J; Kempenaars, M; Maslov, M; Scannell, R

2016-01-01

The Joint European Torus (JET) high resolution Thomson scattering (HRTS) system measures radial electron temperature and density profiles. One of the key capabilities of this diagnostic is measuring the steep pressure gradient, termed the pedestal, at the edge of JET plasmas. The pedestal is susceptible to limiting instabilities, such as Edge Localised Modes (ELMs), characterised by a periodic collapse of the steep gradient region. A common method to extract the pedestal width, gradient, and height, used on numerous machines, is by performing a modified hyperbolic tangent (mtanh) fit to overlaid profiles selected from the same region of the ELM cycle. This process of overlaying profiles, termed ELM synchronisation, maximises the number of data points defining the pedestal region for a given phase of the ELM cycle. When fitting to HRTS profiles, it is necessary to incorporate the diagnostic radial instrument function, particularly important when considering the pedestal width. A deconvolved fit is determined by a forward convolution method requiring knowledge of only the instrument function and profiles. The systematic error due to the deconvolution technique incorporated into the JET pedestal fitting tool has been documented by Frassinetti et al. [Rev. Sci. Instrum. 83, 013506 (2012)]. This paper seeks to understand and quantify the systematic error introduced to the pedestal width due to ELM synchronisation. Synthetic profiles, generated with error bars and point-to-point variation characteristic of real HRTS profiles, are used to evaluate the deviation from the underlying pedestal width. We find on JET that the ELM synchronisation systematic error is negligible in comparison to the statistical error when assuming ten overlaid profiles (typical for a pre-ELM fit to HRTS profiles). This confirms that fitting a mtanh to ELM synchronised profiles is a robust and practical technique for extracting the pedestal structure.

Dynamic ELM and divertor control using resonant toroidal multi-mode magnetic fields in DIII-D and EAST

NASA Astrophysics Data System (ADS)

Sun, Youwen

2017-10-01

A rotating n = 2 Resonant Magnetic Perturbation (RMP) field combined with a stationary n = 3 RMP field has validated predictions that access to ELM suppression can be improved, while divertor heat and particle flux can also be dynamically controlled in DIII-D. Recent observations in the EAST tokamak indicate that edge magnetic topology changes, due to nonlinear plasma response to magnetic perturbations, play a critical role in accessing ELM suppression. MARS-F code MHD simulations, which include the plasma response to the RMP, indicate the nonlinear transition to ELM suppression is optimized by configuring the RMP coils to drive maximal edge stochasticity. Consequently, mixed toroidal multi-mode RMP fields, which produce more densely packed islands over a range of additional rational surfaces, improve access to ELM suppression, and further spread heat loading on the divertor. Beneficial effects of this multi-harmonic spectrum on ELM suppression have been validated in DIII-D. Here, the threshold current required for ELM suppression with a mixed n spectrum, where part of the n = 3 RMP field is replaced by an n = 2 field, is smaller than the case with pure n = 3 field. An important further benefit of this multi-mode approach is that significant changes of 3D particle flux footprint profiles on the divertor are found in the experiment during the application of a rotating n = 2 RMP field superimposed on a static n = 3 RMP field. This result was predicted by modeling studies of the edge magnetic field structure using the TOP2D code which takes into account plasma response from MARS-F code. These results expand physics understanding and potential effectiveness of the technique for reliably controlling ELMs and divertor power/particle loading distributions in future burning plasma devices such as ITER. Work supported by USDOE under DE-FC02-04ER54698 and NNSF of China under 11475224.

Stream-flow forecasting using extreme learning machines: A case study in a semi-arid region in Iraq

NASA Astrophysics Data System (ADS)

Yaseen, Zaher Mundher; Jaafar, Othman; Deo, Ravinesh C.; Kisi, Ozgur; Adamowski, Jan; Quilty, John; El-Shafie, Ahmed

2016-11-01

Monthly stream-flow forecasting can yield important information for hydrological applications including sustainable design of rural and urban water management systems, optimization of water resource allocations, water use, pricing and water quality assessment, and agriculture and irrigation operations. The motivation for exploring and developing expert predictive models is an ongoing endeavor for hydrological applications. In this study, the potential of a relatively new data-driven method, namely the extreme learning machine (ELM) method, was explored for forecasting monthly stream-flow discharge rates in the Tigris River, Iraq. The ELM algorithm is a single-layer feedforward neural network (SLFNs) which randomly selects the input weights, hidden layer biases and analytically determines the output weights of the SLFNs. Based on the partial autocorrelation functions of historical stream-flow data, a set of five input combinations with lagged stream-flow values are employed to establish the best forecasting model. A comparative investigation is conducted to evaluate the performance of the ELM compared to other data-driven models: support vector regression (SVR) and generalized regression neural network (GRNN). The forecasting metrics defined as the correlation coefficient (r), Nash-Sutcliffe efficiency (ENS), Willmott's Index (WI), root-mean-square error (RMSE) and mean absolute error (MAE) computed between the observed and forecasted stream-flow data are employed to assess the ELM model's effectiveness. The results revealed that the ELM model outperformed the SVR and the GRNN models across a number of statistical measures. In quantitative terms, superiority of ELM over SVR and GRNN models was exhibited by ENS = 0.578, 0.378 and 0.144, r = 0.799, 0.761 and 0.468 and WI = 0.853, 0.802 and 0.689, respectively and the ELM model attained lower RMSE value by approximately 21.3% (relative to SVR) and by approximately 44.7% (relative to GRNN). Based on the findings of this study, several recommendations were suggested for further exploration of the ELM model in hydrological forecasting problems.

Environmental Assessment: Demolish 452 at Grand Forks Air Force Base

DTIC Science & Technology

2005-12-01

Data Sheet MSL Mean Sea Level µg/m3 Micrograms Per Meter Cubed NAAQS National Ambient Air Quality Standards NAGPRA Native American Graves...elm, cottonwood, and green ash. Dutch elm disease has killed many of the elms. European buckthorn (a highly invasive exotic species), chokecherry...level, with local relief being less that one foot. Land at the base is relatively flat; with elevations ranging from 880 to 920 ft mean sea level (MSL

ELM control with RMP: plasma response models and the role of edge peeling response

NASA Astrophysics Data System (ADS)

Liu, Yueqiang; Ham, C. J.; Kirk, A.; Li, Li; Loarte, A.; Ryan, D. A.; Sun, Youwen; Suttrop, W.; Yang, Xu; Zhou, Lina

2016-11-01

Resonant magnetic perturbations (RMP) have extensively been demonstrated as a plausible technique for mitigating or suppressing large edge localized modes (ELMs). Associated with this is a substantial amount of theory and modelling efforts during recent years. Various models describing the plasma response to the RMP fields have been proposed in the literature, and are briefly reviewed in this work. Despite their simplicity, linear response models can provide alternative criteria, than the vacuum field based criteria, for guiding the choice of the coil configurations to achieve the best control of ELMs. The role of the edge peeling response to the RMP fields is illustrated as a key indicator for the ELM mitigation in low collisionality plasmas, in various tokamak devices.

A classification scheme for edge-localized modes based on their probability distributions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shabbir, A., E-mail: aqsa.shabbir@ugent.be; Max Planck Institute for Plasma Physics, D-85748 Garching; Hornung, G.

We present here an automated classification scheme which is particularly well suited to scenarios where the parameters have significant uncertainties or are stochastic quantities. To this end, the parameters are modeled with probability distributions in a metric space and classification is conducted using the notion of nearest neighbors. The presented framework is then applied to the classification of type I and type III edge-localized modes (ELMs) from a set of carbon-wall plasmas at JET. This provides a fast, standardized classification of ELM types which is expected to significantly reduce the effort of ELM experts in identifying ELM types. Further, themore » classification scheme is general and can be applied to various other plasma phenomena as well.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solomon, Wayne M.; Snyder, P. B.; Burrell, K. H.

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 asmore » a function of density using constraints imposed by peeling-ballooning and kinetic-ballooning theory are in quantitative agreement with the measurements.« less

Effect of nitrogen seeding on the energy losses and on the time scales of the electron temperature and density collapse of type-I ELMs in JET with the ITER-like wall

NASA Astrophysics Data System (ADS)

Frassinetti, L.; Dodt, D.; Beurskens, M. N. A.; Sirinelli, A.; Boom, J. E.; Eich, T.; Flanagan, J.; Giroud, C.; Jachmich, M. S.; Kempenaars, M.; Lomas, P.; Maddison, G.; Maggi, C.; Neu, R.; Nunes, I.; Perez von Thun, C.; Sieglin, B.; Stamp, M.; Contributors, JET-EFDA

2015-02-01

The baseline type-I ELMy H-mode scenario has been re-established in JET with the new tungsten MKII-HD divertor and beryllium on the main wall (hereafter called the ITER-like wall, JET-ILW). The first JET-ILW results show that the confinement is degraded by 20-30% in the baseline scenarios compared to the previous carbon wall JET (JET-C) plasmas. The degradation is mainly driven by the reduction in the pedestal temperature. Stored energies and pedestal temperature comparable to the JET-C have been obtained to date in JET-ILW baseline plasmas only in the high triangularity shape using N2 seeding. This work compares the energy losses during ELMs and the corresponding time scales of the temperature and density collapse in JET-ILW baseline plasmas with and without N2 seeding with similar JET-C baseline plasmas. ELMs in the JET-ILW differ from those with the carbon wall both in terms of time scales and energy losses. The ELM time scale, defined as the time to reach the minimum pedestal temperature soon after the ELM collapse, is ˜2 ms in the JET-ILW and lower than 1 ms in the JET-C. The energy losses are in the range ΔWELM/Wped ≈ 7-12% in the JET-ILW and ΔWELM/Wped ≈ 10-20% in JET-C, and fit relatively well with earlier multi-machine empirical scalings of ΔWELM/Wped with collisionality. The time scale of the ELM collapse seems to be related to the pedestal collisionality. Most of the non-seeded JET-ILW ELMs are followed by a further energy drop characterized by a slower time scale ˜8-10 ms (hereafter called slow transport events), that can lead to losses in the range ΔWslow/Wped ≈ 15-22%, slightly larger than the losses in JET-C. The N2 seeding in JET-ILW significantly affects the ELMs. The JET-ILW plasmas with N2 seeding are characterized by ELM energy losses and time scales similar to the JET-C and by the absence of the slow transport events.

Impurity confinement and transport in high confinement regimes without edge localized modes on DIII-D [Impurity confinement and transport in high confinement regimes without ELMs on DIII-D

DOE PAGES

Grierson, Brian A.; Burrell, Keith H.; Nazikian, Raffi M.; ...

2015-04-17

Here, impurity transport in the DIII-D tokamak 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 p/τ 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 harmonicmore » 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 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.« less

Identification of Alzheimer's disease and mild cognitive impairment using multimodal sparse hierarchical extreme learning machine.

PubMed

Kim, Jongin; Lee, Boreom

2018-05-07

Different modalities such as structural MRI, FDG-PET, and CSF have complementary information, which is likely to be very useful for diagnosis of AD and MCI. Therefore, it is possible to develop a more effective and accurate AD/MCI automatic diagnosis method by integrating complementary information of different modalities. In this paper, we propose multi-modal sparse hierarchical extreme leaning machine (MSH-ELM). We used volume and mean intensity extracted from 93 regions of interest (ROIs) as features of MRI and FDG-PET, respectively, and used p-tau, t-tau, and Aβ42 as CSF features. In detail, high-level representation was individually extracted from each of MRI, FDG-PET, and CSF using a stacked sparse extreme learning machine auto-encoder (sELM-AE). Then, another stacked sELM-AE was devised to acquire a joint hierarchical feature representation by fusing the high-level representations obtained from each modality. Finally, we classified joint hierarchical feature representation using a kernel-based extreme learning machine (KELM). The results of MSH-ELM were compared with those of conventional ELM, single kernel support vector machine (SK-SVM), multiple kernel support vector machine (MK-SVM) and stacked auto-encoder (SAE). Performance was evaluated through 10-fold cross-validation. In the classification of AD vs. HC and MCI vs. HC problem, the proposed MSH-ELM method showed mean balanced accuracies of 96.10% and 86.46%, respectively, which is much better than those of competing methods. In summary, the proposed algorithm exhibits consistently better performance than SK-SVM, ELM, MK-SVM and SAE in the two binary classification problems (AD vs. HC and MCI vs. HC). © 2018 Wiley Periodicals, Inc.

Maternal sensitivity and the empathic brain: Influences of early life maltreatment.

PubMed

Mielke, Emilia L; Neukel, Corinne; Bertsch, Katja; Reck, Corinna; Möhler, Eva; Herpertz, Sabine C

2016-06-01

One of the most striking characteristics of early life maltreatment (ELM) is the risk of transmission across generations, which could be linked to differences in maternal behavior. Maternal sensitivity includes appropriate and positive affective exchanges between mother and child. Mothers with a history of ELM have been found to show a lower sensitivity representing a significant risk factor for maltreating their own children. 25 mothers with and 28 mothers without sexual and/or physical childhood maltreatment (as assessed with the Childhood Experience of Care and Abuse interview) and their children participated in a standardized mother-child interaction task. Videotaped interactions were rated by two independent trained raters based on the Emotional Availability Scales. In addition, empathic capabilities were assessed with the Interpersonal Reactivity Index. High resolution structural magnetic resonance brain images of the mothers were analyzed with unbiased voxel-based morphometry and correlated with maternal sensitivity. Results indicate that mothers with ELM were less sensitive in the standardized interaction with their own child. In non-maltreated control mothers, maternal sensitivity was positively related to anterior insular grey matter volume, a region which is crucially involved in emotional empathy, while there was a positive association between maternal sensitivity and grey matter volume in parts of the cognitive empathy network such as the superior temporal sulcus and temporal pole region in mothers with ELM. These results implicate that neurostructural alterations associated with poor maternal sensitivity might be a sequelae of ELM and that mothers with ELM may try to compensate deficits in emotional empathy by recruiting brain regions involved in cognitive empathy when interacting with their child. Thus, findings suggest possible coping strategies of mother with ELM to prevent an intergenerational transmission of abuse. Copyright © 2016 Elsevier Ltd. All rights reserved.

Stability and dynamics of the edge pedestal in the low collisionality regime: physics mechanisms for steady-state ELM-free operation

NASA Astrophysics Data System (ADS)

Snyder, P. B.; Burrell, K. H.; Wilson, H. R.; Chu, M. S.; Fenstermacher, M. E.; Leonard, A. W.; Moyer, R. A.; Osborne, T. H.; Umansky, M.; West, W. P.; Xu, X. Q.

2007-08-01

Understanding the physics of the edge pedestal and edge localized modes (ELMs) is of great importance for ITER and the optimization of the tokamak concept. The peeling-ballooning model has quantitatively explained many observations, including ELM onset and pedestal constraints, in the standard H-mode regime. The ELITE code has been developed to efficiently evaluate peeling-ballooning stability for comparison with observation and predictions for future devices. We briefly review recent progress in the peeling-ballooning model, including experimental validation of ELM onset and pedestal height predictions, and nonlinear 3D simulations of ELM dynamics, which together lead to an emerging understanding of the physics of the onset and dynamics of ELMs in the standard intermediate to high collisionality regime. We also discuss new studies of the apparent power dependence of the pedestal, and studies of the impact of sheared toroidal flow. Recently, highly promising low collisionality regimes without ELMs have been discovered, including the quiescent H-mode (QH) and resonant magnetic perturbation (RMP) regimes. We present recent observations from the DIII-D tokamak of the density, shape and rotation dependence of QH discharges, and studies of the peeling-ballooning stability in this regime. We propose a model of the QH-mode in which the observed edge harmonic oscillation (EHO) is a saturated kink/peeling mode which is destabilized by current and rotation, and drives significant transport, allowing a near steady-state edge plasma. The model quantitatively predicts the observed density dependence and qualitatively predicts observed mode structure, rotation dependence and outer gap dependence. Low density RMP discharges are found to operate in a similar regime, but with the EHO replaced by an applied magnetic perturbation.

Tradition and Culture Change in the Oklahoma Delaware Big House Community: 1867-1924.

DTIC Science & Technology

1981-01-01

sore throat Slippery Elm Ulmus fulva xkwikpi Drink from soaked strips of bark used to relieve chills Wild Black Cherry Prunus scrotina mwmfeli Boiled...Berries used to make dye for baskets Pokeberry Phytolacca americana cAk%.ngwtm Tonic given to chickens made from roots Slippery Elm Ulmus fulva xkwilpi...along drainages, forests of elm , ash, and cottonwood trees. The grasslands extended up the rockier col- luvial slopes where they gave way in places to

Validation of the model for ELM suppression with 3D magnetic fields using low torque ITER baseline scenario discharges in DIII-D

DOE PAGES

Moyer, Richard A.; Paz-Soldan, Carlos; Nazikian, Raffi; ...

2017-09-18

Here, experiments have been executed in the DIII-D tokamak to extend suppression of Edge Localized Modes (ELMs) with Resonant Magnetic Perturbations (RMPs) to ITER-relevant levels of beam torque. The results support the hypothesis for RMP ELM suppression based on transition from an ideal screened response to a tearing response at a resonant surface that prevents expansion of the pedestal to an unstable width.

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, U.S.A

Treesearch

C.E. Flower; N. Hayes-Plazolles; J.M. Slavicek; C. Rosa

2018-01-01

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.

Injected mass deposition thresholds for lithium granule instigated triggering of edge localized modes on EAST

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lunsford, R.; Sun, Zhen; Maingi, Rajesh

The ability of an injected lithium granule to promptly trigger an edge localized mode (ELM) has been established in multiple experiments. By horizontally injecting granules ranging in diameter from 200 microns to 1mm in diameter into the low field side of EAST H-mode discharges we have determined that granules with diameter > 600 microns are successful in triggering ELMs more than 95% of the time. Granules were radially injected from the outer midplane with velocities ~ 80 m/s into EAST upper-single null discharges with an ITER like tungsten monoblock divertor. ELM triggering was a prompt response to granule injection, andmore » for granules of a sufficient size there was no evidence of a "trigger lag" phenomenon as observed in full metal machines. We also demonstrated that the triggering efficiency decreased with granule size during dynamic size scans. These granules were individually tracked throughout their injection cycle in order to determine their efficacy at triggering an ELM. Furthermore, by simulating the granule injection with an experimentally benchmarked neutral gas shielding (NGS) model, the ablatant mass deposition required to promptly trigger an ELM is calculated and the fractional mass deposition is determined. Simulated 900 micron granules capable of triggering an ELM show a peaked mass deposition of 3.9 x 10 17 atoms per mm of penetration at a depth of approximately 5 cm past the separatrix.« less

A Novel Online Sequential Extreme Learning Machine for Gas Utilization Ratio Prediction in Blast Furnaces.

PubMed

Li, Yanjiao; Zhang, Sen; Yin, Yixin; Xiao, Wendong; Zhang, Jie

2017-08-10

Gas utilization ratio (GUR) is an important indicator used to measure the operating status and energy consumption of blast furnaces (BFs). In this paper, we present a soft-sensor approach, i.e., a novel online sequential extreme learning machine (OS-ELM) named DU-OS-ELM, to establish a data-driven model for GUR prediction. In DU-OS-ELM, firstly, the old collected data are discarded gradually and the newly acquired data are given more attention through a novel dynamic forgetting factor (DFF), depending on the estimation errors to enhance the dynamic tracking ability. Furthermore, we develop an updated selection strategy (USS) to judge whether the model needs to be updated with the newly coming data, so that the proposed approach is more in line with the actual production situation. Then, the convergence analysis of the proposed DU-OS-ELM is presented to ensure the estimation of output weight converge to the true value with the new data arriving. Meanwhile, the proposed DU-OS-ELM is applied to build a soft-sensor model to predict GUR. Experimental results demonstrate that the proposed DU-OS-ELM obtains better generalization performance and higher prediction accuracy compared with a number of existing related approaches using the real production data from a BF and the created GUR prediction model can provide an effective guidance for further optimization operation.

Radar HRRP Target Recognition Based on Stacked Autoencoder and Extreme Learning Machine

PubMed Central

Liu, Yongxiang; Huo, Kai; Zhang, Zhongshuai

2018-01-01

A novel radar high-resolution range profile (HRRP) target recognition method based on a stacked autoencoder (SAE) and extreme learning machine (ELM) is presented in this paper. As a key component of deep structure, the SAE does not only learn features by making use of data, it also obtains feature expressions at different levels of data. However, with the deep structure, it is hard to achieve good generalization performance with a fast learning speed. ELM, as a new learning algorithm for single hidden layer feedforward neural networks (SLFNs), has attracted great interest from various fields for its fast learning speed and good generalization performance. However, ELM needs more hidden nodes than conventional tuning-based learning algorithms due to the random set of input weights and hidden biases. In addition, the existing ELM methods cannot utilize the class information of targets well. To solve this problem, a regularized ELM method based on the class information of the target is proposed. In this paper, SAE and the regularized ELM are combined to make full use of their advantages and make up for each of their shortcomings. The effectiveness of the proposed method is demonstrated by experiments with measured radar HRRP data. The experimental results show that the proposed method can achieve good performance in the two aspects of real-time and accuracy, especially when only a few training samples are available. PMID:29320453

Radar HRRP Target Recognition Based on Stacked Autoencoder and Extreme Learning Machine.

PubMed

Zhao, Feixiang; Liu, Yongxiang; Huo, Kai; Zhang, Shuanghui; Zhang, Zhongshuai

2018-01-10

A novel radar high-resolution range profile (HRRP) target recognition method based on a stacked autoencoder (SAE) and extreme learning machine (ELM) is presented in this paper. As a key component of deep structure, the SAE does not only learn features by making use of data, it also obtains feature expressions at different levels of data. However, with the deep structure, it is hard to achieve good generalization performance with a fast learning speed. ELM, as a new learning algorithm for single hidden layer feedforward neural networks (SLFNs), has attracted great interest from various fields for its fast learning speed and good generalization performance. However, ELM needs more hidden nodes than conventional tuning-based learning algorithms due to the random set of input weights and hidden biases. In addition, the existing ELM methods cannot utilize the class information of targets well. To solve this problem, a regularized ELM method based on the class information of the target is proposed. In this paper, SAE and the regularized ELM are combined to make full use of their advantages and make up for each of their shortcomings. The effectiveness of the proposed method is demonstrated by experiments with measured radar HRRP data. The experimental results show that the proposed method can achieve good performance in the two aspects of real-time and accuracy, especially when only a few training samples are available.

Injected mass deposition thresholds for lithium granule instigated triggering of edge localized modes on EAST

DOE PAGES

Lunsford, R.; Sun, Zhen; Maingi, Rajesh; ...

2017-12-19

The ability of an injected lithium granule to promptly trigger an edge localized mode (ELM) has been established in multiple experiments. By horizontally injecting granules ranging in diameter from 200 microns to 1mm in diameter into the low field side of EAST H-mode discharges we have determined that granules with diameter > 600 microns are successful in triggering ELMs more than 95% of the time. Granules were radially injected from the outer midplane with velocities ~ 80 m/s into EAST upper-single null discharges with an ITER like tungsten monoblock divertor. ELM triggering was a prompt response to granule injection, andmore » for granules of a sufficient size there was no evidence of a "trigger lag" phenomenon as observed in full metal machines. We also demonstrated that the triggering efficiency decreased with granule size during dynamic size scans. These granules were individually tracked throughout their injection cycle in order to determine their efficacy at triggering an ELM. Furthermore, by simulating the granule injection with an experimentally benchmarked neutral gas shielding (NGS) model, the ablatant mass deposition required to promptly trigger an ELM is calculated and the fractional mass deposition is determined. Simulated 900 micron granules capable of triggering an ELM show a peaked mass deposition of 3.9 x 10 17 atoms per mm of penetration at a depth of approximately 5 cm past the separatrix.« less

A Novel Online Sequential Extreme Learning Machine for Gas Utilization Ratio Prediction in Blast Furnaces

PubMed Central

Li, Yanjiao; Yin, Yixin; Xiao, Wendong; Zhang, Jie

2017-01-01

Gas utilization ratio (GUR) is an important indicator used to measure the operating status and energy consumption of blast furnaces (BFs). In this paper, we present a soft-sensor approach, i.e., a novel online sequential extreme learning machine (OS-ELM) named DU-OS-ELM, to establish a data-driven model for GUR prediction. In DU-OS-ELM, firstly, the old collected data are discarded gradually and the newly acquired data are given more attention through a novel dynamic forgetting factor (DFF), depending on the estimation errors to enhance the dynamic tracking ability. Furthermore, we develop an updated selection strategy (USS) to judge whether the model needs to be updated with the newly coming data, so that the proposed approach is more in line with the actual production situation. Then, the convergence analysis of the proposed DU-OS-ELM is presented to ensure the estimation of output weight converge to the true value with the new data arriving. Meanwhile, the proposed DU-OS-ELM is applied to build a soft-sensor model to predict GUR. Experimental results demonstrate that the proposed DU-OS-ELM obtains better generalization performance and higher prediction accuracy compared with a number of existing related approaches using the real production data from a BF and the created GUR prediction model can provide an effective guidance for further optimization operation. PMID:28796187

A fast and accurate online sequential learning algorithm for feedforward networks.

PubMed

Liang, Nan-Ying; Huang, Guang-Bin; Saratchandran, P; Sundararajan, N

2006-11-01

In this paper, we develop an online sequential learning algorithm for single hidden layer feedforward networks (SLFNs) with additive or radial basis function (RBF) hidden nodes in a unified framework. The algorithm is referred to as online sequential extreme learning machine (OS-ELM) and can learn data one-by-one or chunk-by-chunk (a block of data) with fixed or varying chunk size. The activation functions for additive nodes in OS-ELM can be any bounded nonconstant piecewise continuous functions and the activation functions for RBF nodes can be any integrable piecewise continuous functions. In OS-ELM, the parameters of hidden nodes (the input weights and biases of additive nodes or the centers and impact factors of RBF nodes) are randomly selected and the output weights are analytically determined based on the sequentially arriving data. The algorithm uses the ideas of ELM of Huang et al. developed for batch learning which has been shown to be extremely fast with generalization performance better than other batch training methods. Apart from selecting the number of hidden nodes, no other control parameters have to be manually chosen. Detailed performance comparison of OS-ELM is done with other popular sequential learning algorithms on benchmark problems drawn from the regression, classification and time series prediction areas. The results show that the OS-ELM is faster than the other sequential algorithms and produces better generalization performance.

33 CFR 211.102 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... of Land Or Interests Therein Acquired for Grapevine, Garza-Little Elm, Benbrook, Belton, and Whitney... the Grapevine, Garza-Little Elm, Benbrook, Belton, and Whitney Reservoir projects, Texas, or for the...

33 CFR 211.102 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... of Land Or Interests Therein Acquired for Grapevine, Garza-Little Elm, Benbrook, Belton, and Whitney... the Grapevine, Garza-Little Elm, Benbrook, Belton, and Whitney Reservoir projects, Texas, or for the...

Bidirectional extreme learning machine for regression problem and its learning effectiveness.

PubMed

Yang, Yimin; Wang, Yaonan; Yuan, Xiaofang

2012-09-01

It is clear that the learning effectiveness and learning speed of neural networks are in general far slower than required, which has been a major bottleneck for many applications. Recently, a simple and efficient learning method, referred to as extreme learning machine (ELM), was proposed by Huang , which has shown that, compared to some conventional methods, the training time of neural networks can be reduced by a thousand times. However, one of the open problems in ELM research is whether the number of hidden nodes can be further reduced without affecting learning effectiveness. This brief proposes a new learning algorithm, called bidirectional extreme learning machine (B-ELM), in which some hidden nodes are not randomly selected. In theory, this algorithm tends to reduce network output error to 0 at an extremely early learning stage. Furthermore, we find a relationship between the network output error and the network output weights in the proposed B-ELM. Simulation results demonstrate that the proposed method can be tens to hundreds of times faster than other incremental ELM algorithms.

Injected mass deposition thresholds for lithium granule instigated triggering of edge localized modes on EAST

NASA Astrophysics Data System (ADS)

Lunsford, R.; Sun, Z.; Maingi, R.; Hu, J. S.; Mansfield, D.; Xu, W.; Zuo, G. Z.; Diallo, A.; Osborne, T.; Tritz, K.; Canik, J.; Huang, M.; Meng, X. C.; Gong, X. Z.; Wan, B. N.; Li, J. G.; the EAST Team

2018-03-01

The ability of an injected lithium granule to promptly trigger an edge localized mode (ELM) has been established in multiple experiments. By horizontally injecting granules ranging in diameter from 200 microns to 1 mm in diameter into the low field side of EAST H-mode discharges we have determined that granules with diameter  >600 microns are successful in triggering ELMs more than 95% of the time. It was also demonstrated that below 600 microns the triggering efficiency decreased roughly with granule size. Granules were radially injected from the outer midplane with velocities ~80 m s-1 into EAST upper single null discharges with an ITER like tungsten monoblock divertor. These granules were individually tracked throughout their injection cycle in order to determine their efficacy at triggering an ELM. For those granules of sufficient size, ELM triggering was a prompt response to granule injection. By simulating the granule injection with an experimentally benchmarked neutral gas shielding (NGS) model, the ablatant mass deposition required to promptly trigger an ELM is calculated and the fractional mass deposition is determined.

Eulerian-Lagrangian solution of the convection-dispersion equation in natural coordinates

USGS Publications Warehouse

Cheng, Ralph T.; Casulli, Vincenzo; Milford, S. Nevil

1984-01-01

The vast majority of numerical investigations of transport phenomena use an Eulerian formulation for the convenience that the computational grids are fixed in space. An Eulerian-Lagrangian method (ELM) of solution for the convection-dispersion equation is discussed and analyzed. The ELM uses the Lagrangian concept in an Eulerian computational grid system. The values of the dependent variable off the grid are calculated by interpolation. When a linear interpolation is used, the method is a slight improvement over the upwind difference method. At this level of approximation both the ELM and the upwind difference method suffer from large numerical dispersion. However, if second-order Lagrangian polynomials are used in the interpolation, the ELM is proven to be free of artificial numerical dispersion for the convection-dispersion equation. The concept of the ELM is extended for treatment of anisotropic dispersion in natural coordinates. In this approach the anisotropic properties of dispersion can be conveniently related to the properties of the flow field. Several numerical examples are given to further substantiate the results of the present analysis.

Dynamic divertor control using resonant mixed toroidal harmonic magnetic fields during ELM suppression in DIII-D

NASA Astrophysics Data System (ADS)

Jia, M.; Sun, Y.; Paz-Soldan, C.; Nazikian, R.; Gu, S.; Liu, Y. Q.; Abrams, T.; Bykov, I.; Cui, L.; Evans, T.; Garofalo, A.; Guo, W.; Gong, X.; Lasnier, C.; Logan, N. C.; Makowski, M.; Orlov, D.; Wang, H. H.

2018-05-01

Experiments using Resonant Magnetic Perturbations (RMPs), with a rotating n = 2 toroidal harmonic combined with a stationary n = 3 toroidal harmonic, have validated predictions that divertor heat and particle flux can be dynamically controlled while maintaining Edge Localized Mode (ELM) suppression in the DIII-D tokamak. Here, n is the toroidal mode number. ELM suppression over one full cycle of a rotating n = 2 RMP that was mixed with a static n = 3 RMP field has been achieved. Prominent heat flux splitting on the outer divertor has been observed during ELM suppression by RMPs in low collisionality regime in DIII-D. Strong changes in the three dimensional heat and particle flux footprint in the divertor were observed during the application of the mixed toroidal harmonic magnetic perturbations. These results agree well with modeling of the edge magnetic field structure using the TOP2D code, which takes into account the plasma response from the MARS-F code. These results expand the potential effectiveness of the RMP ELM suppression technique for the simultaneous control of divertor heat and particle load required in ITER.

Impact of resistive MHD plasma response on perturbation field sidebands

DOE PAGES

Orlov, D. M.; Evans, T. E.; Moyer, R. A.; ...

2016-06-03

Here, single fluid linear simulations of a KSTAR RMP ELM suppressed discharge with the M3D-C 1 resistive magnetohydrodynamic code have been performed for the first time. The simulations show that the application of the n = 1 perturbation using the KSTAR in-vessel control coils (IVCC), which apply modest levels of n = 3 sidebands (~20% of the n = 1), leads to levels of n = 3 sideband that are comparable to the n = 1 when plasma response is included. This is due to the reduced level of screening of the rational-surface-resonant n = 3 component relative to themore » rational-surface-resonant n = 1 component. The n = 3 sidebands could play a similar role in ELM suppression on KSTAR as the toroidal sidebands (n = 1, 2, 4) in DIII-D n = 3 ELM suppression with missing I-coil segments. This result may help to explain the uniqueness of ELM suppression with n = 1 perturbations in KSTAR since the effective perturbation is a mixed n = 1/n = 3 perturbation similar to n = 3 ELM suppression in DIII-D.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Medvedev, S. Yu., E-mail: medvedev@a5.kiam.ru; Ivanov, A. A., E-mail: aai@a5.kiam.ru; Martynov, A. A., E-mail: martynov@a5.kiam.ru

The influence of current density and pressure gradient profiles in the pedestal on the access to the regimes free from edge localized modes (ELMs) like quiescent H-mode in ITER is investigated. Using the simulator of MHD modes localized near plasma boundary based on the KINX code, calculations of the ELM stability were performed for the ITER plasma in scenarios 2 and 4 under variations of density and temperature profiles with the self-consistent bootstrap current in the pedestal. Low pressure gradient values at the separatrix, the same position of the density and temperature pedestals and high poloidal beta values facilitate reachingmore » high current density in the pedestal and a potential transition into the regime with saturated large scale kink modes. New version of the localized MHD mode simulator allows one to compute the growth rates of ideal peeling-ballooning modes with different toroidal mode numbers and to determine the stability region taking into account diamagnetic stabilization. The edge stability diagrams computations and sensitivity studies of the stability limits to the value of diamagnetic frequency show that diamagnetic stabilization of the modes with high toroidal mode numbers can help to access the quiescent H-mode even with high plasma density but only with low pressure gradient values at the separatrix. The limiting pressure at the top of the pedestal increases for higher plasma density. With flat density profile the access to the quiescent H-mode is closed even with diamagnetic stabilization taken into account, while toroidal mode numbers of the most unstable peeling-ballooning mode decrease from n = 10−40 to n = 3−20.« less

Generalised ballooning theory of two-dimensional tokamak modes

NASA Astrophysics Data System (ADS)

Abdoul, P. A.; Dickinson, D.; Roach, C. M.; Wilson, H. R.

2018-02-01

In this work, using solutions from a local gyrokinetic flux-tube code combined with higher order ballooning theory, a new analytical approach is developed to reconstruct the global linear mode structure with associated global mode frequency. In addition to the isolated mode (IM), which usually peaks on the outboard mid-plane, the higher order ballooning theory has also captured other types of less unstable global modes: (a) the weakly asymmetric ballooning theory (WABT) predicts a mixed mode (MM) that undergoes a small poloidal shift away from the outboard mid-plane, (b) a relatively more stable general mode (GM) balloons on the top (or bottom) of the tokamak plasma. In this paper, an analytic approach is developed to combine these disconnected analytical limits into a single generalised ballooning theory. This is used to investigate how an IM behaves under the effect of sheared toroidal flow. For small values of flow an IM initially converts into a MM where the results of WABT are recaptured, and eventually, as the flow increases, the mode asymptotically becomes a GM on the top (or bottom) of the plasma. This may be an ingredient in models for understanding why in some experimental scenarios, instead of large edge localised modes (ELMs), small ELMs are observed. Finally, our theory can have other important consequences, especially for calculations involving Reynolds stress driven intrinsic rotation through the radial asymmetry in the global mode structures. Understanding the intrinsic rotation is significant because external torque in a plasma the size of ITER is expected to be relatively low.

A two-step approach for copper and nickel extracting and recovering by emulsion liquid membrane.

PubMed

Bi, Qiang; Xue, Juanqin; Guo, Yingjuan; Li, Guoping; Cui, Haibin

2016-11-01

The recycling of copper and nickel from metallurgical wastewater using emulsion liquid membrane (ELM) was studied. P507 (2-ethylhexyl phosphonic acid-2-ethylhexyl ester) and TBP (tributyl phosphate) were used as carriers for the extraction of copper and nickel by ELMs, respectively. The influence of four emulsion composition variables, namely, the internal phase volume fraction (ϕ), surfactant concentration (Wsurf), internal phase stripping acid concentration (Cio) and the carrier concentration (Cc), and the process variable treat ratio on the extraction efficiencies of copper or nickel were studied. Under the optimum conditions, 98% copper and nickel were recycled by using ELM. The results indicated that ELM extraction is a promising industrial application technology to retrieve valuable metals in low concentration metallurgical wastewater.

Impact of the pedestal plasma density on dynamics of edge localized mode crashes and energy loss scaling

DOE PAGES

Xu, X. Q.; Ma, J. F.; Li, G. Q.

2014-12-29

The latest BOUT++ studies show an emerging understanding of dynamics of edge localized mode(ELM) crashes and the consistent collisionality scaling of ELMenergy losses with the world multi-tokamak database. A series of BOUT++ simulations are conducted to investigate the scaling characteristics of the ELMenergy losses vs collisionality via a density scan. Moreover, the linear results demonstrate that as the pedestal collisionality decreases, the growth rate of the peeling-ballooning modes decreases for high n but increases for low n (1 < n < 5), therefore the width of the growth rate spectrum γ(n) becomes narrower and the peak growth shifts to lowermore » n. For nonlinear BOUT++ simulations show a two-stage process of ELM crash evolution of (i) initial bursts of pressure blob and void creation and (ii) inward void propagation. The inward void propagation stirs the top of pedestal plasma and yields an increasing ELM size with decreasing collisionality after a series of micro-bursts. The pedestal plasma density plays a major role in determining the ELMenergy loss through its effect on the edge bootstrap current and ion diamagnetic stabilization. Finally, the critical trend emerges as a transition (1) linearly from ballooning-dominated states at high collisionality to peeling-dominated states at low collisionality with decreasing density and (2) nonlinearly from turbulence spreading dynamics at high collisionality into avalanche-like dynamics at low collisionality.« less

Cultural Resources Investigations of the Upper Minnesota River (639) Project, Deuel and Grant Counties, South Dakota, and Lac Qui Parle and Yellow Medicine Counties, Minnesota,

DTIC Science & Technology

1984-09-01

10,000 B.P. to 9,000 B.P., the climate was cooler and moister than at present. A regional deciduous forest, dominated by oak, •:- ~ elm and ironwood...deltoides Cottonwood Quercus macrocarpa Bur oak Ulmus americana American elm Celtis occidentalis Hackberry Ribes americanum Black currant Ribes missouriense...occidentalis Wolfberry Viburnum lentago Sheepberry, wild raisin /Ulmus rubra Red elm Crataegus chrysocarpa Hawthorn £ Psedera quinquefolia Virginia creeper

Aquilla Lake, Brazos River Basin, Texas, Pre-Impoundment Environmental Study: Supplement to Design Memorandum Number 9, Master Plan (in Response to: 40CFR 1505.3),

DTIC Science & Technology

1983-06-01

phaeacantha White Prairie Rose Rosa filiolosa Bur Oak Quercus macrocarpa Slippery Elm Ulrnus rubra Elbow-Bush Forestiera pubescens Southen Black-haw Virburnum...It LIST OF PLATES Plate Title Page 1 Above, a cedar elm woodland scene ( -5), herbaceous component consists primarily of Canada...3( 2 Above, view of a pecan parkland (T3-2), herbaceous and shrub components composed primarily of Smilax, June 1980. Below, a mesquite/cedar elm

General Reevaluation Report and Environmental Impact Statement for the Blanchard River, Ottawa, Ohio Flood Protection Project

DTIC Science & Technology

1987-04-01

Black locust Black willow Honey locust Mulberry Slippery elm Box elder Cottonwood Multiflora rose Green ash Hackberry The U.S. Fish and Wildlife Service...flows in the Blanchard River at Ottawa. The Perry Street bridge was removed in 1951 and replaced by a new bridge at Elm Street that is less restrictive...flood plain. The present tree growth commonly consists of a second growth of spe- cies of elm , maple, and oak. All of the Blanchard River basin lies

Cultural Resources Investigation of a Proposed Flood Control Project along the Sheyenne River, at West Fargo, Cass County, North Dakota. Phase I.

DTIC Science & Technology

1988-01-15

cottonwood (Po2ulus salrgenti), sumac (Ehus sp.), peach and sandbar willows (Salix amvdaloides; . terio), and slippery elm (Ulmus rubra). 3.4.2 Bluestem...forest of elm , oak, ash, hackberry, cottonwood, and aspen along the major streams. Archaeological evidence indicates that prehistoric people along the...black willow (Salix nifra), and American elm (Ulmus amicnan). Other components include: boxelder (Acer neaundo), red maple (A. Subrum), silver maple (A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xi, P. W.; Lawrence Livermore National Laboratory, Livermore, California 94550; Xu, X. Q.

We demonstrate that the occurrence of Edge-Localized-Modes (ELM) crashes does not depend only on the linear peeling-ballooning threshold, but also relies on nonlinear processes. Wave-wave interaction constrains the growth time of a mode, thus inducing a shift in the criterion for triggering an ELM crash. An ELM crash requires the P-B growth rate to exceed a critical value γ>γ{sub c}, where γ{sub c} is set by 1/τ{sup ¯}{sub c}, and τ{sup ¯}{sub c} is the averaged mode phase coherence time. For 0

Birds and Dutch elm disease control

USGS Publications Warehouse

DeWitt, J.B.

1958-01-01

Brief, factual review of information on effect of DDT and other insecticides on birds. One program for control of elm disease caused 22% decrease in number of adult birds and 56% mortality of nestlings. Quail fed 3 oz. of DDT per ton of food had 16% reduction in young hatched and 500% increase in defective chicks. Quail fed same dosage during winter and breeding seasons had 30% decrease in fertile eggs and 800% increase in defective chicks. More than 90% of their chicks died in first 6 weeks although fed no insecticide. Almost equally bad results came from feeding Pheasants diets with about 1 oz. DDT per ton. Other common insecticides (chlorinated hydrocarbons) also caused lowered chick survival and higher percentages of crippled chicks. From field data we know that 2 lbs. DDT/acre can affect birds and has even worse effects on cold-blooded animals. Efforts to control elm disease have left as much as 196 lbs. DDT/acre in top 3 inches of soil. Earthworms concentrate DDT in their tissues. Thus the treated areas can be traps for birds and other animals. What can be done? 1) In control of elm disease, use minimum effective amount of insecticide; mist blowers use less than sprayers. 2) Avoid applications during migration and nesting seasons. It has been reported that adequate control can be obtained with dormant sprays and that foliar applications may not be required. Tables of this paper show effects of DDT on reproduction of Quail, relative toxicity to quail of 8 insecticides, and amounts of 7 insecticides required to cause 40% or more decrease in Quail reproduction. These comparisons demonstrate that Aldrin, Endrin, and Dieldrin are 20 to 200 times as toxic as DDT and that Heptachlor and Chlordane are only slightly less toxic than Dieldrin. Methoxychlor and Strobane are less toxic to Quail than is DDT.

Application of the extreme learning machine algorithm for the prediction of monthly Effective Drought Index in eastern Australia

NASA Astrophysics Data System (ADS)

Deo, Ravinesh C.; Şahin, Mehmet

2015-02-01

The prediction of future drought is an effective mitigation tool for assessing adverse consequences of drought events on vital water resources, agriculture, ecosystems and hydrology. Data-driven model predictions using machine learning algorithms are promising tenets for these purposes as they require less developmental time, minimal inputs and are relatively less complex than the dynamic or physical model. This paper authenticates a computationally simple, fast and efficient non-linear algorithm known as extreme learning machine (ELM) for the prediction of Effective Drought Index (EDI) in eastern Australia using input data trained from 1957-2008 and the monthly EDI predicted over the period 2009-2011. The predictive variables for the ELM model were the rainfall and mean, minimum and maximum air temperatures, supplemented by the large-scale climate mode indices of interest as regression covariates, namely the Southern Oscillation Index, Pacific Decadal Oscillation, Southern Annular Mode and the Indian Ocean Dipole moment. To demonstrate the effectiveness of the proposed data-driven model a performance comparison in terms of the prediction capabilities and learning speeds was conducted between the proposed ELM algorithm and the conventional artificial neural network (ANN) algorithm trained with Levenberg-Marquardt back propagation. The prediction metrics certified an excellent performance of the ELM over the ANN model for the overall test sites, thus yielding Mean Absolute Errors, Root-Mean Square Errors, Coefficients of Determination and Willmott's Indices of Agreement of 0.277, 0.008, 0.892 and 0.93 (for ELM) and 0.602, 0.172, 0.578 and 0.92 (for ANN) models. Moreover, the ELM model was executed with learning speed 32 times faster and training speed 6.1 times faster than the ANN model. An improvement in the prediction capability of the drought duration and severity by the ELM model was achieved. Based on these results we aver that out of the two machine learning algorithms tested, the ELM was the more expeditious tool for prediction of drought and its related properties.

Use of a Neural Net to Model the Impact of Optical Coherence Tomography Abnormalities on Vision in Age-related Macular Degeneration.

PubMed

Aslam, Tariq M; Zaki, Haider R; Mahmood, Sajjad; Ali, Zaria C; Ahmad, Nur A; Thorell, Mariana R; Balaskas, Konstantinos

2018-01-01

To develop a neural network for the estimation of visual acuity from optical coherence tomography (OCT) images of patients with neovascular age-related macular degeneration (AMD) and to demonstrate its use to model the impact of specific controlled OCT changes on vision. Artificial intelligence (neural network) study. We assessed 1400 OCT scans of patients with neovascular AMD. Fifteen physical features for each eligible OCT, as well as patient age, were used as input data and corresponding recorded visual acuity as the target data to train, validate, and test a supervised neural network. We then applied this network to model the impact on acuity of defined OCT changes in subretinal fluid, subretinal hyperreflective material, and loss of external limiting membrane (ELM) integrity. A total of 1210 eligible OCT scans were analyzed, resulting in 1210 data points, which were each 16-dimensional. A 10-layer feed-forward neural network with 1 hidden layer of 10 neurons was trained to predict acuity and demonstrated a root mean square error of 8.2 letters for predicted compared to actual visual acuity and a mean regression coefficient of 0.85. A virtual model using this network demonstrated the relationship of visual acuity to specific, programmed changes in OCT characteristics. When ELM is intact, there is a shallow decline in acuity with increasing subretinal fluid but a much steeper decline with equivalent increasing subretinal hyperreflective material. When ELM is not intact, all visual acuities are reduced. Increasing subretinal hyperreflective material or subretinal fluid in this circumstance reduces vision further still, but with a smaller gradient than when ELM is intact. The supervised machine learning neural network developed is able to generate an estimated visual acuity value from OCT images in a population of patients with AMD. These findings should be of clinical and research interest in macular degeneration, for example in estimating visual prognosis or highlighting the importance of developing treatments targeting more visually destructive pathologies. Copyright © 2017 Elsevier Inc. All rights reserved.

Elm-ash-cottonwood forest type bibliography.

Treesearch

Stephen R Shifley; Kenneth M. Brown

1978-01-01

Lists 679 references, arranged by author's names, on the biology, ecology, silviculture and mensuration of the elm-ash-cottonwood type and its component species. Indices for species, subjects, and second authors are appended.

ELM: super-resolution analysis of wide-field images of fluorescent shell structures

NASA Astrophysics Data System (ADS)

Manton, James D.; Xiao, Yao; Turner, Robert D.; Christie, Graham; Rees, Eric J.

2018-07-01

It is often necessary to precisely quantify the size of specimens in biological studies. When measuring feature size in fluorescence microscopy, significant biases can arise due to blurring of its edges if the feature is smaller than the diffraction limit of resolution. This problem is avoided if an equation describing the feature’s entire image is fitted to its image data. In this paper we present open-source software, ELM, which uses this approach to measure the size of spheroidal or cylindrical fluorescent shells with a precision of around 10 nm. This has been used to measure coat protein locations in bacterial spores and cell wall diameter in vegetative bacilli, and may also be valuable in microbiological studies of algae, fungi and viruses. ELM is available for download at https://github.com/quantitativeimaging/ELM.

ELM: super-resolution analysis of wide-field images of fluorescent shell structures.

PubMed

Manton, James; Xiao, Yao; Turner, Robert; Christie, Graham; Rees, Eric

2018-05-04

It is often necessary to precisely quantify the size of specimens in biological studies. When measuring feature size in fluorescence microscopy, significant biases can arise due to blurring of its edges if the feature is smaller than the diffraction limit of resolution. This problem is avoided if an equation describing the feature's entire image is fitted to its image data. In this paper we present open-source software, ELM, which uses this approach to measure the size of spheroidal or cylindrical fluorescent shells with a precision of around 10 nm. This has been used to measure coat protein locations in bacterial spores and cell wall diameter in vegetative bacilli, and may also be valuable in microbiological studies of algae, fungi and viruses. ELM is available for download at https://github.com/quantitativeimaging/ELM. Creative Commons Attribution license.

Online shopping interface components: relative importance as peripheral and central cues.

PubMed

Warden, Clyde A; Wu, Wann-Yih; Tsai, Dungchun

2006-06-01

The Elaboration Likelihood Model (ELM) uses central (more thoughtful) and peripheral (less thoughtful) routes of persuasion to maximize communication effectiveness. This research implements ELM to investigate the relative importance of different aspects of the user experience in online shopping. Of all the issues surrounding online shopping, convenience, access to information, and trust were found to be the most important. These were implemented in an online conjoint shopping task. Respondents were found to use the central route of the ELM on marketing messages that involved issues of minimizing travel, information access, and assurances of system security. Users employed the peripheral ELM route when considering usability, price comparison, and personal information protection. A descriptive model of Web-based marketing components, their roles in the central and peripheral routes, and their relative importance to online consumer segments was developed.

Edge Stability and Performance of the ELM-Free Quiescent H-Mode and the Quiescent Double Barrier Mode on DIII-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

West, W P; Burrell, K H; Casper, T A

2004-12-03

The quiescent H (QH) mode, an edge localized mode (ELM)-free, high-confinement mode, combines well with an internal transport barrier to form quiescent double barrier (QDB) stationary state, high performance plasmas. The QH-mode edge pedestal pressure is similar to that seen in ELMing phases of the same discharge, with similar global energy confinement. The pedestal density in early ELMing phases of strongly pumped counter injection discharges drops and a transition to QH-mode occurs, leading to lower calculated edge bootstrap current. Plasmas current ramp experiment and ELITE code modeling of edge stability suggest that QH-modes lie near an edge current stability boundary.more » At high triangularity, QH-mode discharges operate at higher pedestal density and pressure, and have achieved ITER level values of {beta}{sub PED} and {nu}*. The QDB achieves performance of {alpha}{sub N}H{sub 89} {approx} 7 in quasi-stationary conditions for a duration of 10 tE, limited by hardware. Recently we demonstrated stationary state QDB discharges with little change in kinetic and q profiles (q{sub 0} > 1) for 2 s, comparable to ELMing ''hybrid scenarios'', yet without the debilitating effects of ELMs. Plasma profile control tools, including electron cyclotron heating and current drive and neutral beam heating, have been demonstrated to control simultaneously the q profile development, the density peaking, impurity accumulation and plasma beta.« less

Nonlinear simulations of particle source effects on edge localized mode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, J.; Tang, C. J.; Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064

2015-12-15

The effects of particle source (PS) with different intensities and located positions on Edge Localized Mode (ELM) are systematically studied with BOUT++ code. The results show the ELM size strongly decreases with increasing the PS intensity once the PS is located in the middle or bottom of the pedestal. The effects of PS on ELM depend on the located position of PS. When it is located at the top of the pedestal, peeling-ballooning (P-B) modes can extract more free energy from the pressure gradient and grow up to be a large filament at the initial crash phase and the broadeningmore » of mode spectrum can be suppressed by PS, which leads to more energy loss. When it is located in the middle or bottom of the pedestal, the extraction of free energy by P-B modes can be suppressed, and a small filament is generated. During the turbulence transport phase, the broader mode spectrum suppresses the turbulence transport when PS is located in the middle, while the zonal flow plays an important role in damping the turbulence transport when PS is located at the bottom.« less

Joint multiple fully connected convolutional neural network with extreme learning machine for hepatocellular carcinoma nuclei grading.

PubMed

Li, Siqi; Jiang, Huiyan; Pang, Wenbo

2017-05-01

Accurate cell grading of cancerous tissue pathological image is of great importance in medical diagnosis and treatment. This paper proposes a joint multiple fully connected convolutional neural network with extreme learning machine (MFC-CNN-ELM) architecture for hepatocellular carcinoma (HCC) nuclei grading. First, in preprocessing stage, each grayscale image patch with the fixed size is obtained using center-proliferation segmentation (CPS) method and the corresponding labels are marked under the guidance of three pathologists. Next, a multiple fully connected convolutional neural network (MFC-CNN) is designed to extract the multi-form feature vectors of each input image automatically, which considers multi-scale contextual information of deep layer maps sufficiently. After that, a convolutional neural network extreme learning machine (CNN-ELM) model is proposed to grade HCC nuclei. Finally, a back propagation (BP) algorithm, which contains a new up-sample method, is utilized to train MFC-CNN-ELM architecture. The experiment comparison results demonstrate that our proposed MFC-CNN-ELM has superior performance compared with related works for HCC nuclei grading. Meanwhile, external validation using ICPR 2014 HEp-2 cell dataset shows the good generalization of our MFC-CNN-ELM architecture. Copyright © 2017 Elsevier Ltd. All rights reserved.

The sdA problem - I. Physical properties

NASA Astrophysics Data System (ADS)

Pelisoli, Ingrid; Kepler, S. O.; Koester, D.

2018-04-01

The so-called sdA stars are defined by having H-rich spectra and surface gravities similar to hot subdwarf stars, but effective temperature below the zero-age horizontal branch. Their evolutionary history is an enigma: their surface gravity is too high for main-sequence stars, but too low for single evolution white dwarfs. They are most likely byproducts of binary evolution, including blue-stragglers, extremely-low mass white dwarf stars (ELMs) and their precursors (pre-ELMs). A small number of ELMs with similar properties to sdAs is known. Other possibilities include metal-poor A/F dwarfs, second generation stars, or even stars accreted from dwarf galaxies. In this work, we analyse colours, proper motions, and spacial velocities of a sample of sdAs from the Sloan Digital Sky Survey to assess their nature and evolutionary origin. We define a probability of belonging to the main sequence and a probability of being a (pre-)ELM based on these properties. We find that 7 per cent of the sdAs are more likely to be (pre-)ELMs than main-sequence stars. However, the spacial velocity distribution suggests that over 35 per cent of them cannot be explained as single metal-poor A/F stars.

Relative optical navigation around small bodies via Extreme Learning Machine

NASA Astrophysics Data System (ADS)

Law, Andrew M.

To perform close proximity operations under a low-gravity environment, relative and absolute positions are vital information to the maneuver. Hence navigation is inseparably integrated in space travel. Extreme Learning Machine (ELM) is presented as an optical navigation method around small celestial bodies. Optical Navigation uses visual observation instruments such as a camera to acquire useful data and determine spacecraft position. The required input data for operation is merely a single image strip and a nadir image. ELM is a machine learning Single Layer feed-Forward Network (SLFN), a type of neural network (NN). The algorithm is developed on the predicate that input weights and biases can be randomly assigned and does not require back-propagation. The learned model is the output layer weights which are used to calculate a prediction. Together, Extreme Learning Machine Optical Navigation (ELM OpNav) utilizes optical images and ELM algorithm to train the machine to navigate around a target body. In this thesis the asteroid, Vesta, is the designated celestial body. The trained ELMs estimate the position of the spacecraft during operation with a single data set. The results show the approach is promising and potentially suitable for on-board navigation.

A New Emulsion Liquid Membrane Based on a Palm Oil for the Extraction of Heavy Metals

PubMed Central

Björkegren, Sanna; Fassihi Karimi, Rose; Martinelli, Anna; Jayakumar, Natesan Subramanian; Hashim, Mohd Ali

2015-01-01

The extraction efficiency of hexavalent chromium, Cr(VI), from water has been investigated using a vegetable oil based emulsion liquid membrane (ELM) technique. The main purpose of this study was to create a novel ELM formulation by choosing a more environmentally friendly and non-toxic diluent such as palm oil. The membrane phase so formulated includes the mobile carrier tri-n-octylmethylammonium chloride (TOMAC), to facilitate the metal transport, and the hydrophilic surfactant Tween 80 to facilitate the dispersion of the ELM phase in the aqueous solution. Span 80 is used as surfactant and butanol as co-surfactant. Our results demonstrate that this novel ELM formulation, using the vegetable palm oil as diluent, is useful for the removal of hexavalent chromium with an efficiency of over 99% and is thus competitive with the already existing, yet less environmentally friendly, ELM formulations. This result was achieved with an optimal concentration of 0.1 M NaOH as stripping agent and an external phase pH of 0.5. Different water qualities have also been investigated showing that the type of water (deionized, distilled, or tap water) does not significantly influence the extraction rate. PMID:25915191

Geosmithia-Ophiostoma: a New Fungus-Fungus Association.

PubMed

Pepori, Alessia L; Bettini, Priscilla P; Comparini, Cecilia; Sarrocco, Sabrina; Bonini, Anna; Frascella, Arcangela; Ghelardini, Luisa; Scala, Aniello; Vannacci, Giovanni; Santini, Alberto

2018-04-01

In Europe as in North America, elms are devastated by Dutch elm disease (DED), caused by the alien ascomycete Ophiostoma novo-ulmi. Pathogen dispersal and transmission are ensured by local species of bark beetles, which established a novel association with the fungus. Elm bark beetles also transport the Geosmithia fungi genus that is found in scolytids' galleries colonized by O. novo-ulmi. Widespread horizontal gene transfer between O. novo-ulmi and Geosmithia was recently observed. In order to define the relation between these two fungi in the DED pathosystem, O. novo-ulmi and Geosmithia species from elm, including a GFP-tagged strain, were grown in dual culture and mycelial interactions were observed by light and fluorescence microscopy. Growth and sporulation of O. novo-ulmi in the absence or presence of Geosmithia were compared. The impact of Geosmithia on DED severity was tested in vivo by co-inoculating Geosmithia and O. novo-ulmi in elms. A close and stable relation was observed between the two fungi, which may be classified as mycoparasitism by Geosmithia on O. novo-ulmi. These results prove the existence of a new component in the complex of organisms involved in DED, which might be capable of reducing the disease impact.

Visual Tracking Based on Extreme Learning Machine and Sparse Representation

PubMed Central

Wang, Baoxian; Tang, Linbo; Yang, Jinglin; Zhao, Baojun; Wang, Shuigen

2015-01-01

The existing sparse representation-based visual trackers mostly suffer from both being time consuming and having poor robustness problems. To address these issues, a novel tracking method is presented via combining sparse representation and an emerging learning technique, namely extreme learning machine (ELM). Specifically, visual tracking can be divided into two consecutive processes. Firstly, ELM is utilized to find the optimal separate hyperplane between the target observations and background ones. Thus, the trained ELM classification function is able to remove most of the candidate samples related to background contents efficiently, thereby reducing the total computational cost of the following sparse representation. Secondly, to further combine ELM and sparse representation, the resultant confidence values (i.e., probabilities to be a target) of samples on the ELM classification function are used to construct a new manifold learning constraint term of the sparse representation framework, which tends to achieve robuster results. Moreover, the accelerated proximal gradient method is used for deriving the optimal solution (in matrix form) of the constrained sparse tracking model. Additionally, the matrix form solution allows the candidate samples to be calculated in parallel, thereby leading to a higher efficiency. Experiments demonstrate the effectiveness of the proposed tracker. PMID:26506359

An Automated System for Skeletal Maturity Assessment by Extreme Learning Machines

PubMed Central

Mansourvar, Marjan; Shamshirband, Shahaboddin; Raj, Ram Gopal; Gunalan, Roshan; Mazinani, Iman

2015-01-01

Assessing skeletal age is a subjective and tedious examination process. Hence, automated assessment methods have been developed to replace manual evaluation in medical applications. In this study, a new fully automated method based on content-based image retrieval and using extreme learning machines (ELM) is designed and adapted to assess skeletal maturity. The main novelty of this approach is it overcomes the segmentation problem as suffered by existing systems. The estimation results of ELM models are compared with those of genetic programming (GP) and artificial neural networks (ANNs) models. The experimental results signify improvement in assessment accuracy over GP and ANN, while generalization capability is possible with the ELM approach. Moreover, the results are indicated that the ELM model developed can be used confidently in further work on formulating novel models of skeletal age assessment strategies. According to the experimental results, the new presented method has the capacity to learn many hundreds of times faster than traditional learning methods and it has sufficient overall performance in many aspects. It has conclusively been found that applying ELM is particularly promising as an alternative method for evaluating skeletal age. PMID:26402795

ELM elimination with lithium aerosol injection in upper-single null discharges using the tungsten divertor in EAST

NASA Astrophysics Data System (ADS)

Sun, Z.; Maingi, R.; Hu, J.; Lunsford, R.; Diallo, A.; Tritz, K.; Osborne, T.; Canik, J.; Zuo, G.; Wang, L.; Xu, G.; Gong, X.; EAST Team Team

2017-10-01

A reproducible, fully non-inductive H-mode regime devoid of large ELMs has been achieved by continuous Li injection in EAST into the upper `ITER-like' tungsten divertor, extending previous results on the graphite divertor. These discharges did not suffer from density or impurity accumulation, and maintained constant core radiated power. The new results extend the energy confinement multiplier H98(y,2) 1.2, as compared to H98(y,2) 0.75 previously on the graphite divertor. The observed ELM elimination is correlated with a decrease in particle recycling, as expected from the strong Li coating before the experiment, and real-time Li aerosol injection. In addition, core W concentration was reduced during the Li injection. ELM elimination is likely related to the reduced recycling and density /temperature profile changes. A low-n electromagnetic coherent mode (MCM) at 40kHz became stronger in amplitude and also more coherent. The MCM shows strong magnetic fluctuations as measured by fast Mirnov coils, but weak density fluctuations. As compared to the graphite divertor, Li injection into the tungsten divertor eliminated ELMs at twice the previous auxiliary heating power, and reduced pedestal collisionality.

VizieR Online Data Catalog: The ELM survey. VII. 15 new ELM white dwarf cand. (Brown+, 2016)

NASA Astrophysics Data System (ADS)

Brown, W. R.; Gianninas, A.; Kilic, M.; Kenyon, S. J.; Allende Prieto, C.

2016-05-01

We present observations of 15 new extremely low-mass white dwarf (ELM WD) candidates. Ten objects are selected by color for our targeted spectroscopic ELM Survey program as described in Brown et al. (2012ApJ...744..142B). Five objects come from follow-up spectroscopy of the completed Hypervelocity Star survey. We acquire spectra for the 15 ELM WD candidates using the Blue Channel spectrograph on the 6.5m MMT telescope. We configured the Blue Channel spectrograph to obtain 3650-4500Å spectral coverage with 1.0Å spectral resolution. We acquire additional spectra for 5 objects using the KOSMOS spectrograph on the Kitt Peak National Observatory 4m Mayall telescope on program numbers 2014B-0119 and 2015A-0082. We configured the KOSMOS spectrograph to obtain 3500-6200Å spectral coverage with 2.0Å spectral resolution. We also acquire spectra for objects with g<17mag using the FAST spectrograph on the Fred Lawrence Whipple Observatory 1.5m Tillinghast telescope. We configured the FAST spectrograph to obtain 3500-5500Å spectral coverage with 1.7Å spectral resolution. (3 data files).

Ideal MHD Stability and Characteristics of Edge Localized Modes on CFETR

NASA Astrophysics Data System (ADS)

Li, Zeyu; Chan, Vincent; Xu, Xueqiao; Wang, Xiaogang; Cfetr Physics Team

2017-10-01

Investigation on the equilibrium operation regime, its ideal magnetohydrodynamics (MHD) stability and edge localized modes (ELM) characteristics is performed for China Fusion Engineering Test Reactor (CFETR). The CFETR operation regime study starts with a baseline scenario derived from multi-code integrated modeling, with key parameters varied to build a systematic database. These parameters, under profile and pedestal constraints, provide the foundation for engineering design. The linear stabilities of low-n and intermediate-n peeling-ballooning modes for CFETR baseline scenario are analyzed. Multi-code benchmarking, including GATO, ELITE, BOUT + + and NIMROD, demonstrated good agreement in predicting instabilities. Nonlinear behavior of ELMs for the baseline scenario is simulated using BOUT + + . Instabilities are found both at the pedestal top and inside the pedestal region, which lead to a mix of grassy and type I ELMs. Pedestal structures extending inward beyond the pedestal top are also varied to study the influence on ELM characteristic. Preliminary results on the dependence of the Type-I ELM divertor heat load scaling on machine size and pedestal pressure will also be presented. Prepared by LLNL under Contract DE-AC52-07NA27344 and National Magnetic Confinement Fusion Research Program of China (Grant No. 2014GB110003 and 2014GB107004).

Pheromone Chemistry of the Smaller European Elm Bark Beetle.

ERIC Educational Resources Information Center

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)

Multi-species impurity granule injection and mass deposition projections in NSTX-U discharges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lunsford, R.; Bortolon, A.; Roquemore, A. L.

Here, by employing a neutral gas shielding (NGS) model to characterize impurity granule injection, the ablation rates for three different species of granule: lithium, boron, and carbon, are determined. Utilizing the duration of ablation events recorded on experiments performed at DIII-D to calibrate the NGS model, we quantify the ablation rate with respect to the plasma density profile. The species-specific granule shielding constant is then used to model granule ablation within NSTX-U discharges. Simulations of 300, 500 and 700 micron diameter granules injected at 50 m s –1 are presented for NSTX-U L-mode type plasmas, as well as H-mode dischargesmore » with low natural ELM frequency. Additionally, ablation calculations of 500 micron granules of each species are presented at velocities ranging from 50–150 m s –1. In H-mode discharges these simulations show that the majority of the injected granule is ablated within or just past the edge steep gradient region. At this radial position, the perturbation to the background plasma generated by the ablating granule can lead to conditions advantageous for the rapid triggering of ELM crashes.« less

Multi-species impurity granule injection and mass deposition projections in NSTX-U discharges

DOE PAGES

Lunsford, R.; Bortolon, A.; Roquemore, A. L.; ...

2017-05-16

Here, by employing a neutral gas shielding (NGS) model to characterize impurity granule injection, the ablation rates for three different species of granule: lithium, boron, and carbon, are determined. Utilizing the duration of ablation events recorded on experiments performed at DIII-D to calibrate the NGS model, we quantify the ablation rate with respect to the plasma density profile. The species-specific granule shielding constant is then used to model granule ablation within NSTX-U discharges. Simulations of 300, 500 and 700 micron diameter granules injected at 50 m s –1 are presented for NSTX-U L-mode type plasmas, as well as H-mode dischargesmore » with low natural ELM frequency. Additionally, ablation calculations of 500 micron granules of each species are presented at velocities ranging from 50–150 m s –1. In H-mode discharges these simulations show that the majority of the injected granule is ablated within or just past the edge steep gradient region. At this radial position, the perturbation to the background plasma generated by the ablating granule can lead to conditions advantageous for the rapid triggering of ELM crashes.« less

QUANTITATIVE TESTS OF ELMS AS INTERMEDIATE N PEELING-BALLOONING MODES

DOE Office of Scientific and Technical Information (OSTI.GOV)

LAO, LL; SNYDER, PB; LEONARD, AW

2002-07-01

OAK A271 QUANTITATIVE TESTS OF ELMS AS INTERMEDIATE N PEELING-BALLOONING MODES. Two of the major issues crucial for the design of the next generation tokamak burning plasma devices are the predictability of the edge pedestal height and control of the divertor heat load in H-mode configurations. Both of these are strongly impacted by edge localized modes (ELMs) and their size. A working model for ELMs is that they are intermediate toroidal mode number, n {approx} 5-30, peeling-ballooning modes driven by the large edge pedestal pressure gradient P{prime} and the associated large edge bootstrap current density J{sub BS}. the interplay betweenmore » P{prime} and J{sub BS} as a discharge evolves can excite peeling-ballooning modes over a wide spectrum of n. The pedestal current density plays a dual role by stabilizing the high n ballooning modes via opening access to second stability but providing free energy to drive the intermediate n peeling modes. This makes a systematic evaluation of this model particularly challenging. This paper describes recent quantitative tests of this model using experimental data from the DIII-D and the JT-60U tokamaks. These tests are made possible by recent improvements to the ELITE MHD stability code, which allow an efficient evaluation of the unstable peeling-ballooning modes, as well as by improvements to other diagnostic and analysis techniques. Some of the key testable features of this model are: (1) ELMs are triggered when the growth rates of intermediate n MHD modes become significantly large; (2) ELM sizes are related to the radial widths of the unstable modes; (3) the unstable modes have a strong ballooning character localized in the outboard bad curvature region; (4) at high collisionality, ELM size generally becomes smaller because J{sub BS} is reduced.« less

46. VIEW LOOKING EAST FROM THE OLMSTED ELM IN THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

46. VIEW LOOKING EAST FROM THE OLMSTED ELM IN THE SOUTH LAWN TO THE ROCK GARDEN. (NOTE: HISTORIC ENGLISH YEW ON RIGHT, CRAB APPLE IN CENTER VIEW). - Fairsted, 99 Warren Street, Brookline, Norfolk County, MA

Camp H.M. Smith and Navy Public Works Center Manana Title ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Four-Bedroom, Single-Family Type 10, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

Camp H.M. Smith and Navy Public Works Center Manana Title ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 7, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

Camp H.M. Smith and Navy Public Works Center Manana Title ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 9, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

A hybrid fuzzy logic and extreme learning machine for improving efficiency of circulating water systems in power generation plant

NASA Astrophysics Data System (ADS)

Aziz, Nur Liyana Afiqah Abdul; Siah Yap, Keem; Afif Bunyamin, Muhammad

2013-06-01

This paper presents a new approach of the fault detection for improving efficiency of circulating water system (CWS) in a power generation plant using a hybrid Fuzzy Logic System (FLS) and Extreme Learning Machine (ELM) neural network. The FLS is a mathematical tool for calculating the uncertainties where precision and significance are applied in the real world. It is based on natural language which has the ability of "computing the word". The ELM is an extremely fast learning algorithm for neural network that can completed the training cycle in a very short time. By combining the FLS and ELM, new hybrid model, i.e., FLS-ELM is developed. The applicability of this proposed hybrid model is validated in fault detection in CWS which may help to improve overall efficiency of power generation plant, hence, consuming less natural recourses and producing less pollutions.

ELM suppression in helium plasmas with 3D magnetic fields

DOE PAGES

Evans, T. E.; Loarte, A.; Orlov, D. M.; ...

2017-06-21

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 andmore » an outward shift of the electron pressure gradient peak compared to that in the high-power ELMing phase. Here, the change in the electron pressure gradient peak is primarily due to a drop in the pedestal temperature rather than the pedestal density.« less

Isolation and characterization of microsatellite markers for red elm (Ulmus rubra Muhl.) and cross-species amplification with Siberian elm (Ulmus pumila L.).

PubMed

Zalapa, J E; Brunet, J; Guries, R P

2008-01-01

Ulmus pumila is an elm species, non-native to the USA that hybridizes with Ulmus rubra. In order to study the genetic structure and hybridization patterns between these two elm species, we developed 15 primer pairs for microsatellite loci in U. rubra and tested their cross-amplification in U. pumila. All 15 primers amplified in both species, 11 of which possessed species-specific alleles. Eight loci were polymorphic in U. pumila and eight in U. rubra, each with two to eight alleles per locus. In addition, five primer pairs previously developed in U. laevis and U. carpinifolia (syn. U. minor) cross-amplified and showed polymorphic loci in U. pumila and/or U. rubra. These markers will facilitate the study of genetic structure and gene flow between U. rubra and exotic, invasive U. pumila. © 2007 Blackwell Publishing Ltd No claim to original US government works.

ELM suppression in helium plasmas with 3D magnetic fields

NASA Astrophysics Data System (ADS)

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.

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

DOE PAGES

Gan, K. F.; Ahn, J. -W.; Gray, T. K.; ...

2017-10-26

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 (more » $${{\\lambda}_{\\operatorname{int}}}$$ ) 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. Finally, experimental result of the counter current rotation of strike points splitting is consistent with the counter-current EHO.« less

Population clustering and clonal structure evidence the relict state of Ulmus minor Mill. in the Balearic Islands

PubMed Central

Fuentes-Utrilla, P; Valbuena-Carabaña, M; Ennos, R; Gil, L

2014-01-01

Field elm (Ulmus minor) is a riparian tree that grows in rare, small populations scattered along temporary watercourses in the Balearic Islands, nowadays mostly covered with Mediterranean vegetation. Agriculture and farming on the fertile land along the periodically flooded plains have reduced the elm populations to sparse tree lines along the creek beds. The presence of field elm in this very anthropic landscape has led some authors to consider it as an introduced species in the Balearics. However, pollen data suggest these elms may be the remains of larger populations experiencing continuous population shrinkage during the Holocene, and hence be native to the isles. In this paper, we apply genetic markers to assess whether field elm is or is not indigenous to the Balearic Islands. We compare the genetic variation in nine nuclear microsatellites of six Balearic populations (three in each of the largest islands, Majorca and Minorca) with that of three natural Iberian populations located in two regions, one geologically (Baetic mountains, SE Iberia) and another historically (Catalonia, NE Iberia) related to the islands. Principal coordinates analysis and Bayesian clustering methods reveal a strong genetic differentiation of the Balearic populations from the Iberian ones, and even among islands, which support their native origin. Genotypic variation in the islands is very low and clonal reproduction is very high compared with the mainland, as it is frequently observed in populations of clonal species where sexual reproduction is limited. We discuss the practical implications of these findings for the conservation of elm genetic resources of these findings. PMID:24619184

Formation of Extremely Low-mass White Dwarf Binaries

NASA Astrophysics Data System (ADS)

Sun, M.; Arras, P.

2018-05-01

Motivated by the discovery of several pulsating, extremely low-mass white dwarfs (ELM WDs, mass M ≲ 0.18 M ⊙) that likely have WD companions, this paper discusses binary formation models for these systems. ELM WDs are formed using angular momentum losses by magnetic braking. Evolutionary models are constructed using the Modules for Experiments in Stellar Astrophysics (MESA), with ELM WD progenitors in the range 1.0 ≲ M d/M ⊙ ≲ 1.5 and WD companions in the range 0.4 ≲ M a/M ⊙ ≲ 0.9. A prescription to reduce magnetic braking for thin surface convection zones is included. Upon the thinning of the evolved donor envelope, the donor star shrinks out of contact and mass transfer (MT) ceases, revealing the ELM WD. Systems with low masses have previously been suggested as possible AM CVNs. Systems with high masses, up to the limit M ≃ 0.18 M ⊙ at which shell flashes occur on the WD cooling track, tend to expand out to orbital periods P orb ≳ 15 hr. In between this range, ELM WDs may become pulsators both as pre-WDs and on the WD cooling track. Brickhill’s criterion for convective mode driving is used to estimate the location of the blue edge of the g-mode instability strip. In the appendix, we show that the formation of an ELM WD by unstable MT or a common-envelope event is unlikely. Stable Roche-lobe overflow with conservative MT produces only M ≳ 0.2 M ⊙.

Camp H.M. Smith and Navy Public Works Center Manana Title ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Types 8 and 11, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

Camp H.M. Smith and Navy Public Works Center Manana Title ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

PERKINELMER ELM

EPA Science Inventory

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

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

PubMed Central

2012-01-01

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, transport and primary metabolism. Conclusion Here we present a dataset for a large-scale study of the mechanisms of plant defense against insect eggs in a co-evolved, natural ecological plant–insect system. The EST database analysis provided here is a first step in elucidating the transcriptional responses of elm to elm leaf beetle infestation, and adds further to our knowledge on insect egg-induced transcriptomic changes in plants. The sequences identified in our comparative analysis give many hints about novel defense mechanisms directed towards eggs. PMID:22702658

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

PubMed

Büchel, Kerstin; McDowell, Eric; Nelson, Will; Descour, Anne; Gershenzon, Jonathan; Hilker, Monika; Soderlund, Carol; Gang, David R; Fenning, Trevor; Meiners, Torsten

2012-06-15

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. 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, transport and primary metabolism. Here we present a dataset for a large-scale study of the mechanisms of plant defense against insect eggs in a co-evolved, natural ecological plant-insect system. The EST database analysis provided here is a first step in elucidating the transcriptional responses of elm to elm leaf beetle infestation, and adds further to our knowledge on insect egg-induced transcriptomic changes in plants. The sequences identified in our comparative analysis give many hints about novel defense mechanisms directed towards eggs.

Changes in divertor conditions in response to changing core density with RMPs

DOE PAGES

Briesemeister, Alexis R.; Ahn, Joon -Wook; Canik, John M.; ...

2017-06-07

The effects of changes in core density on divertor electron temperature, density and heat flux when resonant magnetic perturbations (RMPs) are applied are presented, notably a reduction in RMP induced secondary radial peaks in the electron temperature profile at the target plate is observed when the core density is increased, which is consistent with modeling. RMPs is used here to indicated non-axisymmetric magnetic field perturbations, created using in-vessel control coils, which have components which has at least one but typically many resonances with the rotational transform of the plasma. RMPs are found to alter inter-ELM heat flux to the divertormore » by modifying the core plasma density. It is shown that applying RMPs reduces the core density and increases the inter-ELM heat flux to both the inner and outer targets. Using gas puffing to return the core density to the pre-RMP levels more than eliminates the increase in inter-ELM heat flux, but a broadening of the heat flux to the outer target remains. These measurements were made at a single toroidal location, but the peak in the heat flux profile was found near the outer strike point where simulations indicate little toroidal variation should exist and tangentially viewing diagnostics showed no evidence of strong asymmetries. In experiments where divertor Thomson scattering measurements were available it is shown that, local secondary peaks in the divertor electron temperature profile near the target plate are reduced as the core density is increased, while peaks in the divertor electron density profile near the target are increased. Furthermore, these trends observed in the divertor electron temperature and density are qualitatively reproduced by scanning the upstream density in EMC3-Eirene modeling. Measurements are presented showing that higher densities are needed to induce detachment of the outer strike point in a case where an increase in electron temperature, likely due to a change in MHD activity, is seen after RMPs are applied.« less

Changes in divertor conditions in response to changing core density with RMPs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Briesemeister, Alexis R.; Ahn, Joon -Wook; Canik, John M.

The effects of changes in core density on divertor electron temperature, density and heat flux when resonant magnetic perturbations (RMPs) are applied are presented, notably a reduction in RMP induced secondary radial peaks in the electron temperature profile at the target plate is observed when the core density is increased, which is consistent with modeling. RMPs is used here to indicated non-axisymmetric magnetic field perturbations, created using in-vessel control coils, which have components which has at least one but typically many resonances with the rotational transform of the plasma. RMPs are found to alter inter-ELM heat flux to the divertormore » by modifying the core plasma density. It is shown that applying RMPs reduces the core density and increases the inter-ELM heat flux to both the inner and outer targets. Using gas puffing to return the core density to the pre-RMP levels more than eliminates the increase in inter-ELM heat flux, but a broadening of the heat flux to the outer target remains. These measurements were made at a single toroidal location, but the peak in the heat flux profile was found near the outer strike point where simulations indicate little toroidal variation should exist and tangentially viewing diagnostics showed no evidence of strong asymmetries. In experiments where divertor Thomson scattering measurements were available it is shown that, local secondary peaks in the divertor electron temperature profile near the target plate are reduced as the core density is increased, while peaks in the divertor electron density profile near the target are increased. Furthermore, these trends observed in the divertor electron temperature and density are qualitatively reproduced by scanning the upstream density in EMC3-Eirene modeling. Measurements are presented showing that higher densities are needed to induce detachment of the outer strike point in a case where an increase in electron temperature, likely due to a change in MHD activity, is seen after RMPs are applied.« less

Stability analysis of Eulerian-Lagrangian methods for the one-dimensional shallow-water equations

USGS Publications Warehouse

Casulli, V.; Cheng, R.T.

1990-01-01

In this paper stability and error analyses are discussed for some finite difference methods when applied to the one-dimensional shallow-water equations. Two finite difference formulations, which are based on a combined Eulerian-Lagrangian approach, are discussed. In the first part of this paper the results of numerical analyses for an explicit Eulerian-Lagrangian method (ELM) have shown that the method is unconditionally stable. This method, which is a generalized fixed grid method of characteristics, covers the Courant-Isaacson-Rees method as a special case. Some artificial viscosity is introduced by this scheme. However, because the method is unconditionally stable, the artificial viscosity can be brought under control either by reducing the spatial increment or by increasing the size of time step. The second part of the paper discusses a class of semi-implicit finite difference methods for the one-dimensional shallow-water equations. This method, when the Eulerian-Lagrangian approach is used for the convective terms, is also unconditionally stable and highly accurate for small space increments or large time steps. The semi-implicit methods seem to be more computationally efficient than the explicit ELM; at each time step a single tridiagonal system of linear equations is solved. The combined explicit and implicit ELM is best used in formulating a solution strategy for solving a network of interconnected channels. The explicit ELM is used at channel junctions for each time step. The semi-implicit method is then applied to the interior points in each channel segment. Following this solution strategy, the channel network problem can be reduced to a set of independent one-dimensional open-channel flow problems. Numerical results support properties given by the stability and error analyses. ?? 1990.

Stability at high performance in the MAST spherical tokamak

NASA Astrophysics Data System (ADS)

Buttery, R. J.; Akers, R.; Arends, E.; Conway, N. J.; Counsell, G. F.; Cunningham, G.; Gimblett, C. G.; Gryaznevich, M.; Hastie, R. J.; Hole, M. J.; Lehane, I.; Martin, R.; Patel, A.; Pinfold, T.; Sauter, O.; Taylor, D.; Turri, G.; Valovic, M.; Walsh, M. J.; Wilson, H. R.; MAST Team

2004-09-01

The development of reliable H-modes on MAST, together with advances in heating power and a range of high spatial resolution diagnostics, has provided a platform to enable MAST to address some of the most important issues of tokamak stability. In particular the high bgr potential of the spherical tokamak is highlighted with stable operation at bgrN ~ 5-6, bgrT ~ 16% and bgrp up to ~2. Magnetic diagnostic evaluation of the global bgr parameters is independently confirmed by kinetic profile data. Calculations indicate that the bgrN values are in the vicinity of no-wall stability limits. Studies of neoclassical tearing modes (NTMs) have been extended to explore their effects and develop avoidance strategies. Experiments have demonstrated that sawteeth play a strong role in triggering NTMs—by avoiding large sawteeth a much higher bgrN value has been reached. The significance of NTMs is confirmed, with large islands observed using the 300 point Thomson scattering diagnostic, and locking of large n = 1 modes frequently leading to disruptions, which become more rapid at low q95. The role of error fields has been explored. H-mode plasmas are also limited by edge localized modes (ELMs), with confinement degraded as the ELM frequency rises. However, in contrast to the conventional tokamak, the ELMs in high performing regimes on MAST (HIPB98Y2 ~ 1) appear to be type III in nature. Modelling using the ELITE code, which incorporates finite n corrections, identifies instability to peeling modes, consistent with a type III interpretation. It also shows considerable scope to raise pressure gradients before ballooning type modes (perhaps associated with type I ELMs) occur. The calculations show that narrow pedestals can support much stronger pressure gradients than might be expected from simple n = infin ballooning calculations. Finally sawteeth are shown to degrade confinement by ~10-15% in particular cases examined. They are observed not to remove the q = 1 surface in the cases where snakes are present—various physics models of the sawteeth are now being explored. Thus research on MAST is not only demonstrating stable operation at high performance levels and developing methods to control instabilities; it is also providing detailed tests of the stability physics and models applicable to conventional tokamaks, such as ITER.

Confinement & Stability in MAST

NASA Astrophysics Data System (ADS)

Akers, Rob

2001-10-01

Transition to H-mode has been achieved in the MAST spherical tokamak (ST) for both ohmically and neutral beam heated plasmas (P_NBI ~ 0.5-1.5MW), resulting in double-null diverted discharges containing both regular and irregular edge localised modes (ELMs). The observed L-H power threshold is ~10 times higher than predicted by established empirical scalings. L-H transition in MAST is accompanied by a sharp increase in edge density gradient, the efficient conversion of internal electron Bernstein waves into free space waves, the onset and saturation of edge poloidal rotation and a marked decrease in turbulence. During ELM free periods, a reduction in outboard power deposition width is observed using a Langmuir probe array. A novel divertor structure has been installed to counter the resulting increase in target heat-flux by applying a toroidally varying potential to the divertor plasma, theory suggesting that convective broadening of the scrape off layer will take place. Global confinement in H-mode is found to routinely exceed the international IPB(y,2) scaling, even for discharges approaching the Greenwald density. In an attempt to further extend the density range (densities in excess of Greenwald having been achieved for plasma currents up to 0.8MA) a multi-pellet injector has been installed at the low-field-side. In addition, high field side fuelling can be supplied via a gas-feed located at the centre-column mid-plane, this technique having been found to significantly enhance H-mode accessibility and quality. A range of stability issues will be discussed, including vertical displacement events, the rich variety of high frequency MHD seen in MAST and the physics of the Neoclassical Tearing Mode. This work was funded by the UK Department of Trade and Industry and by EURATOM. The NBI equipment is on loan from ORNL and the pellet injector was provided by FOM.

BEDROOM 2. VIEW FACING EAST Camp H.M. Smith and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

BEDROOM 2. VIEW FACING EAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 7, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

BEDROOM 3. VIEW FACING EAST Camp H.M. Smith and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

BEDROOM 3. VIEW FACING EAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Four-Bedroom, Single-Family Type 10, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

MASTER BEDROOM. VIEW FACING NORTH Camp H.M. Smith and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

MASTER BEDROOM. VIEW FACING NORTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Four-Bedroom, Single-Family Type 10, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

BEDROOM 3. VIEW FACING EAST Camp H.M. Smith and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

BEDROOM 3. VIEW FACING EAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 7, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

UTILITY ROOM. VIEW FACING WEST Camp H.M. Smith and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

UTILITY ROOM. VIEW FACING WEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 7, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

OBLIQUE VIEW FROM THE SOUTH Camp H.M. Smith and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

OBLIQUE VIEW FROM THE SOUTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 7, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

BATH. VIEW FACING NORTH Camp H.M. Smith and Navy ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

BATH. VIEW FACING NORTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Four-Bedroom, Single-Family Type 10, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

Suitability of thirteen different host species for elm leaf beetle, Xanthogaleruca luteola (Coleoptera: Chrysomelidae)

Treesearch

Richard W. Hall; Alden M. Townsend; Jack H. Barger

1987-01-01

Thirteen different host species for elm leaf beetle, Xanthogaleruca luteola (Muller), were assayed to determine their relative suitability. Species examined were Ulmus parvifolia Jacq., U. thomasii Sarg., U. laevis Pall., U. wilsoniana Schneid., U....

Hyperparameterization of soil moisture statistical models for North America with Ensemble Learning Models (Elm)

NASA Astrophysics Data System (ADS)

Steinberg, P. D.; Brener, G.; Duffy, D.; Nearing, G. S.; Pelissier, C.

2017-12-01

Hyperparameterization, of statistical models, i.e. automated model scoring and selection, such as evolutionary algorithms, grid searches, and randomized searches, can improve forecast model skill by reducing errors associated with model parameterization, model structure, and statistical properties of training data. Ensemble Learning Models (Elm), and the related Earthio package, provide a flexible interface for automating the selection of parameters and model structure for machine learning models common in climate science and land cover classification, offering convenient tools for loading NetCDF, HDF, Grib, or GeoTiff files, decomposition methods like PCA and manifold learning, and parallel training and prediction with unsupervised and supervised classification, clustering, and regression estimators. Continuum Analytics is using Elm to experiment with statistical soil moisture forecasting based on meteorological forcing data from NASA's North American Land Data Assimilation System (NLDAS). There Elm is using the NSGA-2 multiobjective optimization algorithm for optimizing statistical preprocessing of forcing data to improve goodness-of-fit for statistical models (i.e. feature engineering). This presentation will discuss Elm and its components, including dask (distributed task scheduling), xarray (data structures for n-dimensional arrays), and scikit-learn (statistical preprocessing, clustering, classification, regression), and it will show how NSGA-2 is being used for automate selection of soil moisture forecast statistical models for North America.

Overview of ASDEX Upgrade results

NASA Astrophysics Data System (ADS)

Zohm, H.; Adamek, J.; Angioni, C.; Antar, G.; Atanasiu, C. V.; Balden, M.; Becker, W.; Behler, K.; Behringer, K.; Bergmann, A.; Bertoncelli, T.; Bilato, R.; Bobkov, V.; Boom, J.; Bottino, A.; Brambilla, M.; Braun, F.; Brüdgam, M.; Buhler, A.; Chankin, A.; Classen, I.; Conway, G. D.; Coster, D. P.; de Marné, P.; D'Inca, R.; Drube, R.; Dux, R.; Eich, T.; Engelhardt, K.; Esposito, B.; Fahrbach, H.-U.; Fattorini, L.; Fink, J.; Fischer, R.; Flaws, A.; Foley, M.; Forest, C.; Fuchs, J. C.; Gál, K.; García Muñoz, M.; Gemisic Adamov, M.; Giannone, L.; Görler, T.; Gori, S.; da Graça, S.; Granucci, G.; Greuner, H.; Gruber, O.; Gude, A.; Günter, S.; Haas, G.; Hahn, D.; Harhausen, J.; Hauff, T.; Heinemann, B.; Herrmann, A.; Hicks, N.; Hobirk, J.; Hölzl, M.; Holtum, D.; Hopf, C.; Horton, L.; Huart, M.; Igochine, V.; Janzer, M.; Jenko, F.; Kallenbach, A.; Kálvin, S.; Kardaun, O.; Kaufmann, M.; Kick, M.; Kirk, A.; Klingshirn, H.-J.; Koscis, G.; Kollotzek, H.; Konz, C.; Krieger, K.; Kurki-Suonio, T.; Kurzan, B.; Lackner, K.; Lang, P. T.; Langer, B.; Lauber, P.; Laux, M.; Leuterer, F.; Likonen, J.; Liu, L.; Lohs, A.; Lunt, T.; Lyssoivan, A.; Maggi, C. F.; Manini, A.; Mank, K.; Manso, M.-E.; Mantsinen, M.; Maraschek, M.; Martin, P.; Mayer, M.; McCarthy, P.; McCormick, K.; Meister, H.; Meo, F.; Merkel, P.; Merkel, R.; Mertens, V.; Merz, F.; Meyer, H.; Mlynek, A.; Monaco, F.; Müller, H.-W.; Münich, M.; Murmann, H.; Neu, G.; Neu, R.; Neuhauser, J.; Nold, B.; Noterdaeme, J.-M.; Pautasso, G.; Pereverzev, G.; Poli, E.; Potzel, S.; Püschel, M.; Pütterich, T.; Pugno, R.; Raupp, G.; Reich, M.; Reiter, B.; Ribeiro, T.; Riedl, R.; Rohde, V.; Roth, J.; Rott, M.; Ryter, F.; Sandmann, W.; Santos, J.; Sassenberg, K.; Sauter, P.; Scarabosio, A.; Schall, G.; Schilling, H.-B.; Schirmer, J.; Schmid, A.; Schmid, K.; Schneider, W.; Schramm, G.; Schrittwieser, R.; Schustereder, W.; Schweinzer, J.; Schweizer, S.; Scott, B.; Seidel, U.; Sempf, M.; Serra, F.; Sertoli, M.; Siccinio, M.; Sigalov, A.; Silva, A.; Sips, A. C. C.; Speth, E.; Stäbler, A.; Stadler, R.; Steuer, K.-H.; Stober, J.; Streibl, B.; Strumberger, E.; Suttrop, W.; Tardini, G.; Tichmann, C.; Treutterer, W.; Tröster, C.; Urso, L.; Vainonen-Ahlgren, E.; Varela, P.; Vermare, L.; Volpe, F.; Wagner, D.; Wigger, C.; Wischmeier, M.; Wolfrum, E.; Würsching, E.; Yadikin, D.; Yu, Q.; Zasche, D.; Zehetbauer, T.; Zilker, M.

2009-10-01

ASDEX Upgrade was operated with a fully W-covered wall in 2007 and 2008. Stationary H-modes at the ITER target values and improved H-modes with H up to 1.2 were run without any boronization. The boundary conditions set by the full W wall (high enough ELM frequency, high enough central heating 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 \\beta_{pol,ped}^{1/2} scaling. In the area of MHD instabilities, disruption mitigation experiments using massive Ne injection reach volume averaged values of the total electron density close to those required for runaway suppression in ITER. ECRH at the q = 2 surface was successfully applied to delay density limit disruptions. The characterization of fast particle losses due to MHD has shown the importance of different loss mechanisms 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 threshold in He are more favourable than in H, suggesting that He operation could allow us to assess H-mode operation in the non-nuclear phase of ITER operation.

Reconceptualizing Social Influence in Counseling: The Elaboration Likelihood Model.

ERIC Educational Resources Information Center

McNeill, Brian W.; Stoltenberg, Cal D.

1989-01-01

Presents Elaboration Likelihood Model (ELM) of persuasion (a reconceptualization of the social influence process) as alternative model of attitude change. Contends ELM unifies conflicting social psychology results and can potentially account for inconsistent research findings in counseling psychology. Provides guidelines on integrating…

DINING ROOM. VIEW FACING NORTHWEST Camp H.M. Smith and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DINING ROOM. VIEW FACING NORTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Types 8 and 11, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

BATH. VIEW FACING NORTH Camp H.M. Smith and Navy ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

BATH. VIEW FACING NORTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

BEDROOM 2. VIEW FACING EAST Camp H.M. Smith and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

BEDROOM 2. VIEW FACING EAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

VIEW FROM CENTER OF ELM AVENUE, LOOKING WEST INTO SECTION ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW FROM CENTER OF ELM AVENUE, LOOKING WEST INTO SECTION L. AT LEFT STANDS THE PONDEROUS MCDANIEL MAUSOLEUM, WHICH SHOWS THE INFLUENCE OF FRANK FURNESS ON H. Q. FRENCH’S 1887 DESIGN - Woodlands Cemetery, 4000 Woodlands Avenue, Philadelphia, Philadelphia County, PA

Experimental sand burial affects seedling survivorship, morphological traits, and biomass allocation of Ulmus pumila var. sabulosa in the Horqin Sandy Land, China

NASA Astrophysics Data System (ADS)

Tang, Jiao; Busso, Carlos Alberto; Jiang, Deming; Musa, Ala; Wu, Dafu; Wang, Yongcui; Miao, Chunping

2016-07-01

As a native tree species, Ulmus pumila var. sabulosa (sandy elm) is widely distributed in the Horqin Sandy Land, China. However, seedlings of this species have to withstand various depths of sand burial after emergence because of increasing soil degradation, which is mainly caused by overgrazing, climate change, and wind erosion. An experiment was conducted to evaluate the changes in its survivorship, morphological traits, and biomass allocation when seedlings were buried at different burial depths: unburied controls and seedlings buried vertically up to 33, 67, 100, or 133 % of their initial mean seedling height. The results showed that partial sand burial treatments (i.e., less than 67 % burial) did not reduce seedling survivorship, which still reached 100 %. However, seedling mortality increased when sand burial was equal to or greater than 100 %. In comparison with the control treatment, seedling height and stem diameter increased at least by 6 and 14 % with partial burial, respectively. In the meantime, seedling taproot length, total biomass, and relative mass growth rates were at least enhanced by 10, 15.6, and 27.6 %, respectively, with the partial sand burial treatment. Furthermore, sand burial decreased total leaf area and changed biomass allocation in seedlings, partitioning more biomass to aboveground organs (e.g., leaves) and less to belowground parts (roots). Complete sand burial after seedling emergence inhibited its re-emergence and growth, even leading to death. Our findings indicated that seedlings of sandy elm showed some resistance to partial sand burial and were adapted to sandy environments from an evolutionary perspective. The negative effect of excessive sand burial after seedling emergence might help in understanding failures in recruitments of sparse elm in the study region.

Erosion dynamics of tungsten fuzz during ELM-like heat loading

NASA Astrophysics Data System (ADS)

Sinclair, G.; Tripathi, J. K.; Hassanein, A.

2018-04-01

Transient heat loading and high-flux particle loading on plasma facing components in fusion reactors can lead to surface melting and possible erosion. Helium-induced fuzz formation is expected to exacerbate thermal excursions, due to a significant drop in thermal conductivity. The effect of heating in edge-localized modes (ELMs) on the degradation and erosion of a tungsten (W) fuzz surface was examined experimentally in the Ultra High Flux Irradiation-II facility at the Center for Materials Under Extreme Environment. W foils were first exposed to low-energy He+ ion irradiation at a fluence of 2.6 × 1024 ions m-2 and a steady-state temperature of 1223 K. Then, samples were exposed to 1000 pulses of ELM-like heat loading, at power densities between 0.38 and 1.51 GW m-2 and at a steady-state temperature of 1223 K. Comprehensive erosion analysis measured clear material loss of the fuzz nanostructure above 0.76 GW m-2 due to melting and splashing of the exposed surface. Imaging of the surface via scanning electron microscopy revealed that sufficient heating at 0.76 GW m-2 and above caused fibers to form tendrils to conglomerate and form droplets. Repetitive thermal loading on molten surfaces then led to eventual splashing. In situ erosion measurements taken using a witness plate and a quartz crystal microbalance showed an exponential increase in mass loss with energy density. Compositional analysis of the witness plates revealed an increase in the W 4f signal with increasing energy density above 0.76 GW m-2. The reduced thermal stability of the fuzz nanostructure puts current erosion predictions into question and strengthens the importance of mitigation techniques.

Spatial Distribution and Site-Specific Spraying of Main Sucking Pests of Elm Trees.

PubMed

Karimzadeh, R; Iranipour, S

2017-06-01

Elm trees are important landscape trees and sucking insects weaken the elm trees and produce large amounts of honeydew. The main objectives of this study were to identify main honeydew-producing pests of elm trees and do site-specific spraying against these pests. To map the spatial distribution of the sucking pests in the large scale, the study area was divided into 40 × 40 m grids and one tree was chosen randomly from each grid (a total of 55 trees). These trees were sampled twice a year in 2011 and 2012. Each sample was a 30-cm branch terminal. Eight samples were taken from each tree in four cardinal directions and two canopy levels. The number of sucking insects and leaves of each sample were counted and recorded. Spatial analysis of the data was carried out using geostatistics. Kriging was used for producing prediction maps. Insecticide application was restricted to the regions with populations higher than threshold. To identify within-tree distribution of the honeydew-producing pests, six and four elm trees were chosen in 2011 and 2012 respectively, and sampled weekly. These trees were sampled as described previously. European elm scale (EES), Gossyparia spuria (Modeer) and two species of aphids were the dominant honeydew-producing pests. The results revealed that the effects of direction, canopy level and their interactions on insect populations were not statistically significant (P < 0.05). Site-specific spraying decreased the amount of insecticides used by ca. 20%, while satisfactory control of the sucking pests and honeydew excretion was obtained. Considering the environmental and economic benefits of site-specific spraying, it is worth doing more complementary works in this area.

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

PubMed Central

Perdiguero, Pedro; Venturas, Martin; Cervera, María Teresa; Gil, Luis; Collada, Carmen

2015-01-01

Elms, especially Ulmus minor and U. 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 single nucleotide polymorphisms (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. PMID:26257751

Stability analysis of ELMs in long-pulse discharges with ELITE code on EAST tokamak

NASA Astrophysics Data System (ADS)

Wang, Y. F.; Xu, G. S.; Wan, B. N.; Li, G. Q.; Yan, N.; Li, Y. L.; Wang, H. Q.; Peng, Y.-K. Martin; Xia, T. Y.; Ding, S. Y.; Chen, R.; Yang, Q. Q.; Liu, H. Q.; Zang, Q.; Zhang, T.; Lyu, B.; Xu, J. C.; Feng, W.; Wang, L.; Chen, Y. J.; Luo, Z. P.; Hu, G. H.; Zhang, W.; Shao, L. M.; Ye, Y.; Lan, H.; Chen, L.; Li, J.; Zhao, N.; Wang, Q.; Snyder, P. B.; Liang, Y.; Qian, J. P.; Gong, X. Z.; EAST team

2018-05-01

One challenge in long-pulse and high performance tokamak operation is to control the edge localized modes (ELMs) to reduce the transient heat load on plasma facing components. Minute-scale discharges in H-mode have been achieved repeatedly on Experimental Advanced Superconducting Tokamak (EAST) since the 2016 campaign and understanding the characteristics of the ELMs in these discharges can be helpful for effective ELM control in long-pulse discharges. The kinetic profile diagnostics recently developed on EAST make it possible to perform the pedestal stability analysis quantitatively. Pedestal stability calculation of a typical long-pulse discharge with ELITE code is presented. The ideal linear stability results show that the ELM is dominated by toroidal mode number n around 10–15 and the most unstable mode structure is mainly localized in the steep pressure gradient region, which is consistent with experimental results. Compared with a typical type-I ELM discharge with larger total plasma current (I p = 600 kA), pedestal in the long-pulse H-mode discharge (I p = 450 kA) is more stable in peeling-ballooning instability and its critical peak pressure gradient is evaluated to be 65% of the former. Two important features of EAST tokamak in the long-pulse discharge are presented by comparison with other tokamaks, including a wider pedestal correlated with the poloidal pedestal beta and a smaller inverse aspect ratio and their effects on the pedestal stability are discussed. The effects of uncertainties in measurements on the linear stability results are also analyzed, including the edge electron density profile position, the separatrix position and the line-averaged effective ion charge {Z}{{e}{{f}}{{f}}} value.

Restoration of Outer Retinal Layers After Aflibercept Therapy in Exudative AMD: Prognostic Value.

PubMed

Coscas, Florence; Coscas, Gabriel; Lupidi, Marco; Dirani, Ali; Srour, Mayer; Semoun, Oudy; Français, Catherine; Souied, Eric H

2015-06-01

To evaluate the outer retinal layer (ellipsoid zone [EZ] and external limiting membrane [ELM]) changes following intravitreal aflibercept injections in eyes with treatment-naïve exudative age-related macular degeneration (eAMD) and to correlate these changes with fluid response and visual improvement. A retrospective case series of 50 treatment-naïve eAMD eyes followed-up for 18 months. All patients underwent regular comprehensive ophthalmic examinations. The presence of EZ disruption, ELM disruption, EZ swelling, subretinal hyper-reflective exudation (SHE), central macular thickness (CMT), cystoid spaces, subretinal fluid, and pigmented epithelium detachment were evaluated by two different retinal specialists at baseline and final visits, and correlated with best corrected visual acuity (BCVA) improvement. At 18 months, BCVA, EZ disruption, ELM disruption, EZ swelling and SHE improved significantly (P = 0.001) at 18 months. Improvement of BCVA showed a statistically significant correlation with ELM restoration (P = 0.018), but not with EZ restoration (P = 0.581). Swelling of the EZ decreased from 72% of the cases at baseline to 30% in 18 months while SHE decreased from 52% to 6% in 18 months (P = 0.001). We observed a statistically significant (P = 0.001) reduction between the baseline and final value of CMT. Aflibercept is safe and effective in treating exudative AMD with the restoration of the outer retinal layers. Restoration of the EZ is not statistically correlated with the final BCVA, even though persistent EZ changes could be associated with irreversible decrease in vision. On the contrary, the final status of the ELM is directly correlated with final BCVA. Also, baseline changes in outer retinal layers, especially the ELM, appear to predict photoreceptor restoration and final BCVA, and must be comprehensively analyzed to enable and determine a future prognosis.

Overview of progress in European medium sized tokamaks towards an integrated plasma-edge/wall solution

NASA Astrophysics Data System (ADS)

Meyer, H.; Eich, T.; Beurskens, M.; Coda, S.; Hakola, A.; Martin, P.; Adamek, J.; Agostini, M.; Aguiam, D.; Ahn, J.; Aho-Mantila, L.; Akers, R.; Albanese, R.; Aledda, R.; Alessi, E.; Allan, S.; Alves, D.; Ambrosino, R.; Amicucci, L.; Anand, H.; Anastassiou, G.; Andrèbe, Y.; Angioni, C.; Apruzzese, G.; Ariola, M.; Arnichand, H.; Arter, W.; Baciero, A.; Barnes, M.; Barrera, L.; Behn, R.; Bencze, A.; Bernardo, J.; Bernert, M.; Bettini, P.; Bilková, P.; Bin, W.; Birkenmeier, G.; Bizarro, J. P. S.; Blanchard, P.; Blanken, T.; Bluteau, M.; Bobkov, V.; Bogar, O.; Böhm, P.; Bolzonella, T.; Boncagni, L.; Botrugno, A.; Bottereau, C.; Bouquey, F.; Bourdelle, C.; Brémond, S.; Brezinsek, S.; Brida, D.; Brochard, F.; Buchanan, J.; Bufferand, H.; Buratti, P.; Cahyna, P.; Calabrò, G.; Camenen, Y.; Caniello, R.; Cannas, B.; Canton, A.; Cardinali, A.; Carnevale, D.; Carr, M.; Carralero, D.; Carvalho, P.; Casali, L.; Castaldo, C.; Castejón, F.; Castro, R.; Causa, F.; Cavazzana, R.; Cavedon, M.; Cecconello, M.; Ceccuzzi, S.; Cesario, R.; Challis, C. D.; Chapman, I. T.; Chapman, S.; Chernyshova, M.; Choi, D.; Cianfarani, C.; Ciraolo, G.; Citrin, J.; Clairet, F.; Classen, I.; Coelho, R.; Coenen, J. W.; Colas, L.; Conway, G.; Corre, Y.; Costea, S.; Crisanti, F.; Cruz, N.; Cseh, G.; Czarnecka, A.; D'Arcangelo, O.; De Angeli, M.; De Masi, G.; De Temmerman, G.; De Tommasi, G.; Decker, J.; Delogu, R. S.; Dendy, R.; Denner, P.; Di Troia, C.; Dimitrova, M.; D'Inca, R.; Dorić, V.; Douai, D.; Drenik, A.; Dudson, B.; Dunai, D.; Dunne, M.; Duval, B. P.; Easy, L.; Elmore, S.; Erdös, B.; Esposito, B.; Fable, E.; Faitsch, M.; Fanni, A.; Fedorczak, N.; Felici, F.; Ferreira, J.; Février, O.; Ficker, O.; Fietz, S.; Figini, L.; Figueiredo, A.; Fil, A.; Fishpool, G.; Fitzgerald, M.; Fontana, M.; Ford, O.; Frassinetti, L.; Fridström, R.; Frigione, D.; Fuchert, G.; Fuchs, C.; Furno Palumbo, M.; Futatani, S.; Gabellieri, L.; Gałązka, K.; Galdon-Quiroga, J.; Galeani, S.; Gallart, D.; Gallo, A.; Galperti, C.; Gao, Y.; Garavaglia, S.; Garcia, J.; Garcia-Carrasco, A.; Garcia-Lopez, J.; Garcia-Munoz, M.; Gardarein, J.-L.; Garzotti, L.; Gaspar, J.; Gauthier, E.; Geelen, P.; Geiger, B.; Ghendrih, P.; Ghezzi, F.; Giacomelli, L.; Giannone, L.; Giovannozzi, E.; Giroud, C.; Gleason González, C.; Gobbin, M.; Goodman, T. P.; Gorini, G.; Gospodarczyk, M.; Granucci, G.; Gruber, M.; Gude, A.; Guimarais, L.; Guirlet, R.; Gunn, J.; Hacek, P.; Hacquin, S.; Hall, S.; Ham, C.; Happel, T.; Harrison, J.; Harting, D.; Hauer, V.; Havlickova, E.; Hellsten, T.; Helou, W.; Henderson, S.; Hennequin, P.; Heyn, M.; Hnat, B.; Hölzl, M.; Hogeweij, D.; Honoré, C.; Hopf, C.; Horáček, J.; Hornung, G.; Horváth, L.; Huang, Z.; Huber, A.; Igitkhanov, J.; Igochine, V.; Imrisek, M.; Innocente, P.; Ionita-Schrittwieser, C.; Isliker, H.; Ivanova-Stanik, I.; Jacobsen, A. S.; Jacquet, P.; Jakubowski, M.; Jardin, A.; Jaulmes, F.; Jenko, F.; Jensen, T.; Jeppe Miki Busk, O.; Jessen, M.; Joffrin, E.; Jones, O.; Jonsson, T.; Kallenbach, A.; Kallinikos, N.; Kálvin, S.; Kappatou, A.; Karhunen, J.; Karpushov, A.; Kasilov, S.; Kasprowicz, G.; Kendl, A.; Kernbichler, W.; Kim, D.; Kirk, A.; Kjer, S.; Klimek, I.; Kocsis, G.; Kogut, D.; Komm, M.; Korsholm, S. B.; Koslowski, H. R.; Koubiti, M.; Kovacic, J.; Kovarik, K.; Krawczyk, N.; Krbec, J.; Krieger, K.; Krivska, A.; Kube, R.; Kudlacek, O.; Kurki-Suonio, T.; Labit, B.; Laggner, F. M.; Laguardia, L.; Lahtinen, A.; Lalousis, P.; Lang, P.; Lauber, P.; Lazányi, N.; Lazaros, A.; Le, H. B.; Lebschy, A.; Leddy, J.; Lefévre, L.; Lehnen, M.; Leipold, F.; Lessig, A.; Leyland, M.; Li, L.; Liang, Y.; Lipschultz, B.; Liu, Y. Q.; Loarer, T.; Loarte, A.; Loewenhoff, T.; Lomanowski, B.; Loschiavo, V. P.; Lunt, T.; Lupelli, I.; Lux, H.; Lyssoivan, A.; Madsen, J.; Maget, P.; Maggi, C.; Maggiora, R.; Magnussen, M. L.; Mailloux, J.; Maljaars, B.; Malygin, A.; Mantica, P.; Mantsinen, M.; Maraschek, M.; Marchand, B.; Marconato, N.; Marini, C.; Marinucci, M.; Markovic, T.; Marocco, D.; Marrelli, L.; Martin, Y.; Solis, J. R. Martin; Martitsch, A.; Mastrostefano, S.; Mattei, M.; Matthews, G.; Mavridis, M.; Mayoral, M.-L.; Mazon, D.; McCarthy, P.; McAdams, R.; McArdle, G.; McCarthy, P.; McClements, K.; McDermott, R.; McMillan, B.; Meisl, G.; Merle, A.; Meyer, O.; Milanesio, D.; Militello, F.; Miron, I. G.; Mitosinkova, K.; Mlynar, J.; Mlynek, A.; Molina, D.; Molina, P.; Monakhov, I.; Morales, J.; Moreau, D.; Morel, P.; Moret, J.-M.; Moro, A.; Moulton, D.; Müller, H. W.; Nabais, F.; Nardon, E.; Naulin, V.; Nemes-Czopf, A.; Nespoli, F.; Neu, R.; Nielsen, A. H.; Nielsen, S. K.; Nikolaeva, V.; Nimb, S.; Nocente, M.; Nouailletas, R.; Nowak, S.; Oberkofler, M.; Oberparleiter, M.; Ochoukov, R.; Odstrčil, T.; Olsen, J.; Omotani, J.; O'Mullane, M. G.; Orain, F.; Osterman, N.; Paccagnella, R.; Pamela, S.; Pangione, L.; Panjan, M.; Papp, G.; Papřok, R.; Parail, V.; Parra, F. I.; Pau, A.; Pautasso, G.; Pehkonen, S.-P.; Pereira, A.; Perelli Cippo, E.; Pericoli Ridolfini, V.; Peterka, M.; Petersson, P.; Petrzilka, V.; Piovesan, P.; Piron, C.; Pironti, A.; Pisano, F.; Pisokas, T.; Pitts, R.; Ploumistakis, I.; Plyusnin, V.; Pokol, G.; Poljak, D.; Pölöskei, P.; Popovic, Z.; Pór, G.; Porte, L.; Potzel, S.; Predebon, I.; Preynas, M.; Primc, G.; Pucella, G.; Puiatti, M. E.; Pütterich, T.; Rack, M.; Ramogida, G.; Rapson, C.; Rasmussen, J. Juul; Rasmussen, J.; Rattá, G. A.; Ratynskaia, S.; Ravera, G.; Réfy, D.; Reich, M.; Reimerdes, H.; Reimold, F.; Reinke, M.; Reiser, D.; Resnik, M.; Reux, C.; Ripamonti, D.; Rittich, D.; Riva, G.; Rodriguez-Ramos, M.; Rohde, V.; Rosato, J.; Ryter, F.; Saarelma, S.; Sabot, R.; Saint-Laurent, F.; Salewski, M.; Salmi, A.; Samaddar, D.; Sanchis-Sanchez, L.; Santos, J.; Sauter, O.; Scannell, R.; Scheffer, M.; Schneider, M.; Schneider, B.; Schneider, P.; Schneller, M.; Schrittwieser, R.; Schubert, M.; Schweinzer, J.; Seidl, J.; Sertoli, M.; Šesnić, S.; Shabbir, A.; Shalpegin, A.; Shanahan, B.; Sharapov, S.; Sheikh, U.; Sias, G.; Sieglin, B.; Silva, C.; Silva, A.; Silva Fuglister, M.; Simpson, J.; Snicker, A.; Sommariva, C.; Sozzi, C.; Spagnolo, S.; Spizzo, G.; Spolaore, M.; Stange, T.; Stejner Pedersen, M.; Stepanov, I.; Stober, J.; Strand, P.; Šušnjara, A.; Suttrop, W.; Szepesi, T.; Tál, B.; Tala, T.; Tamain, P.; Tardini, G.; Tardocchi, M.; Teplukhina, A.; Terranova, D.; Testa, D.; Theiler, C.; Thornton, A.; Tolias, P.; Tophøj, L.; Treutterer, W.; Trevisan, G. L.; Tripsky, M.; Tsironis, C.; Tsui, C.; Tudisco, O.; Uccello, A.; Urban, J.; Valisa, M.; Vallejos, P.; Valovic, M.; Van den Brand, H.; Vanovac, B.; Varoutis, S.; Vartanian, S.; Vega, J.; Verdoolaege, G.; Verhaegh, K.; Vermare, L.; Vianello, N.; Vicente, J.; Viezzer, E.; Vignitchouk, L.; Vijvers, W. A. J.; Villone, F.; Viola, B.; Vlahos, L.; Voitsekhovitch, I.; Vondráček, P.; Vu, N. M. T.; Wagner, D.; Walkden, N.; Wang, N.; Wauters, T.; Weiland, M.; Weinzettl, V.; Westerhof, E.; Wiesenberger, M.; Willensdorfer, M.; Wischmeier, M.; Wodniak, I.; Wolfrum, E.; Yadykin, D.; Zagórski, R.; Zammuto, I.; Zanca, P.; Zaplotnik, R.; Zestanakis, P.; Zhang, W.; Zoletnik, S.; Zuin, M.; ASDEX Upgrade, the; MAST; TCV Teams

2017-10-01

Integrating the plasma core performance with an edge and scrape-off layer (SOL) that leads to tolerable heat and particle loads on the wall is a major challenge. The new European medium size tokamak task force (EU-MST) coordinates research on ASDEX Upgrade (AUG), MAST and TCV. This multi-machine approach within EU-MST, covering a wide parameter range, is instrumental to progress in the field, as ITER and DEMO core/pedestal and SOL parameters are not achievable simultaneously in present day devices. A two prong approach is adopted. On the one hand, scenarios with tolerable transient heat and particle loads, including active edge localised mode (ELM) control are developed. On the other hand, divertor solutions including advanced magnetic configurations are studied. Considerable progress has been made on both approaches, in particular in the fields of: ELM control with resonant magnetic perturbations (RMP), small ELM regimes, detachment onset and control, as well as filamentary scrape-off-layer transport. For example full ELM suppression has now been achieved on AUG at low collisionality with n  =  2 RMP maintaining good confinement {{H}\\text{H≤ft(98,\\text{y}2\\right)}}≈ 0.95 . Advances have been made with respect to detachment onset and control. Studies in advanced divertor configurations (Snowflake, Super-X and X-point target divertor) shed new light on SOL physics. Cross field filamentary transport has been characterised in a wide parameter regime on AUG, MAST and TCV progressing the theoretical and experimental understanding crucial for predicting first wall loads in ITER and DEMO. Conditions in the SOL also play a crucial role for ELM stability and access to small ELM regimes. In the future we will refer to the author list of the paper as the EUROfusion MST1 Team.

A fast and precise indoor localization algorithm based on an online sequential extreme learning machine.

PubMed

Zou, Han; Lu, Xiaoxuan; Jiang, Hao; Xie, Lihua

2015-01-15

Nowadays, developing indoor positioning systems (IPSs) has become an attractive research topic due to the increasing demands on location-based service (LBS) in indoor environments. WiFi technology has been studied and explored to provide indoor positioning service for years in view of the wide deployment and availability of existing WiFi infrastructures in indoor environments. A large body of WiFi-based IPSs adopt fingerprinting approaches for localization. However, these IPSs suffer from two major problems: the intensive costs of manpower and time for offline site survey and the inflexibility to environmental dynamics. In this paper, we propose an indoor localization algorithm based on an online sequential extreme learning machine (OS-ELM) to address the above problems accordingly. The fast learning speed of OS-ELM can reduce the time and manpower costs for the offline site survey. Meanwhile, its online sequential learning ability enables the proposed localization algorithm to adapt in a timely manner to environmental dynamics. Experiments under specific environmental changes, such as variations of occupancy distribution and events of opening or closing of doors, are conducted to evaluate the performance of OS-ELM. The simulation and experimental results show that the proposed localization algorithm can provide higher localization accuracy than traditional approaches, due to its fast adaptation to various environmental dynamics.

Three American tragedies: chestnut blight, butternut canker, and Dutch elm disease

Treesearch

Scott E. Schlarbaum; Frederick Hebard; Pauline C. Spaine; Joseph C. Kamalay

1998-01-01

Three North American tree species, American chestnut (Castanea dentata), butternut (Juglans cinerea), and American elm (Ulmus americana), have been devastated by exotic fungal diseases over the last century. American chestnut was eliminated from eastern forests as a dominant species by chestnut blight (...

75. VIEW LOOKING EAST FROM THE OLMSTED ELM IN THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

75. VIEW LOOKING EAST FROM THE OLMSTED ELM IN THE SOUTH LAWN TO THE ROCK GARDEN. VIEW INCLUDES HISTORIC ENGLISH YEW ON RIGHT, CRAB APPLE IN CENTER. (DUPLICATE OF HABS No. MA-1168-46) - Fairsted, 99 Warren Street, Brookline, Norfolk County, MA

VIEW OF FRONT, RECESSED ENTRY. VIEW FACING EAST Camp ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF FRONT, RECESSED ENTRY. VIEW FACING EAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Types 8 and 11, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

DETAIL OF GABLE VENT OVER CARPORT. VIEW FACING SOUTHEAST ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL OF GABLE VENT OVER CARPORT. VIEW FACING SOUTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 9, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

HALL WITH FOYER IN THE BACKGROUND. VIEW FACING NORTH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HALL WITH FOYER IN THE BACKGROUND. VIEW FACING NORTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 7, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

VIEW SHOWING STORAGE AREA IN CARPORT. VIEW FACING NORTH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW SHOWING STORAGE AREA IN CARPORT. VIEW FACING NORTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 9, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

KITCHEN SHOWING THE ORIGINAL CEILINGHEIGHT CABINETS. VIEW FACING SOUTH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

KITCHEN SHOWING THE ORIGINAL CEILING-HEIGHT CABINETS. VIEW FACING SOUTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Four-Bedroom, Single-Family Type 10, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

FOYER SHOWING THE WOOD GRILLE. VIEW FACING NORTHWEST Camp ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

FOYER SHOWING THE WOOD GRILLE. VIEW FACING NORTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

OBLIQUE VIEW FROM THE SOUTH CORNER Camp H.M. Smith ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

OBLIQUE VIEW FROM THE SOUTH CORNER - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

VIEW OF HALLWAY, LOOKING TOWARDS BEDROOMS. VIEW FACING SOUTHEAST ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF HALLWAY, LOOKING TOWARDS BEDROOMS. VIEW FACING SOUTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 9, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

VIEW FROM EAST SIDE OF ELM DRIVE/BIRCH CIRCLE BLOCK, SHOWING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW FROM EAST SIDE OF ELM DRIVE/BIRCH CIRCLE BLOCK, SHOWING SLOPING TOPOGRAPHY. VIEW FACING WEST. - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

Performance evaluation of a second-generation elastic loop mobility system

NASA Technical Reports Server (NTRS)

Melzer, K. J.; Swanson, G. D.

1974-01-01

Tests were conducted to evaluate the mobility performance of a second-generation Elastic Loop Mobility System (ELMS II). Performance on level test lanes and slopes of lunar soil simulant (LSS) and obstacle-surmounting and crevasse-crossing capabilities were investigated. In addition, internal losses and contact pressure distributions were evaluated. To evaluate the soft-soil performance, two basic soil conditions were tested: loose (LSS1) and dense (LSS5). These conditions embrace the spectrum of soil strengths tested during recent studies for NASA related to the mobility performance of the LRV. Data indicated that for the tested range of the various performance parameters, performance was independent of unit load (contact pressure) and ELMS II drum angular velocity, but was influenced by soil strength and ELMS pitch mode. Power requirements were smaller at a given system output for dense soil than for loose soil. The total system output in terms of pull developed or slope-climbing capability was larger for the ELMS II operating in restrained-pitch mode than in free-pitch mode.

Effects of ELMs and disruptions on ITER divertor armour materials

NASA Astrophysics Data System (ADS)

Federici, G.; Zhitlukhin, A.; Arkhipov, N.; Giniyatulin, R.; Klimov, N.; Landman, I.; Podkovyrov, V.; Safronov, V.; Loarte, A.; Merola, M.

2005-03-01

This paper describes the response of plasma facing components manufactured with tungsten (macro-brush) and CFC to energy loads characteristic of Type I ELMs and disruptions in ITER, in experiments conducted (under an EU/RF collaboration) in two plasma guns (QSPA and MK-200UG) at the TRINITI institute. Targets were exposed to a series of repetitive pulses in QSPA with heat loads in a range of 1-2 MJ/m 2 lasting 0.5 ms. Moderate tungsten erosion, of less than 0.2 μm per pulse, was found for loads of ˜1.5 MJ/m 2, consistent with ELM erosion being determined by tungsten evaporation and not by melt layer displacement. At energy densities of ˜1.8 MJ/m 2 a sharp growth of tungsten erosion was measured together with intense droplet ejection. MK-200UG experiments were focused on studying mainly vapor plasma production and impurity transport during ELMs. The conditions for removal of thin metal deposits from a carbon substrate were characterized.

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

PubMed

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.

Divertor scenario development for NSTX Upgrade

NASA Astrophysics Data System (ADS)

Soukhanovskii, V. A.; McLean, A. G.; Meier, E. T.; Rognlien, T. D.; Ryutov, D. D.; Bell, R. E.; Diallo, A.; Gerhardt, S. P.; Kaita, R.; Kolemen, E.; Leblanc, B. P.; Menard, J. E.; Podesta, M.; Scotti, F.

2012-10-01

In the NSTX-U tokamak, initial plans for divertor plasma-facing components (PFCs) include lithium and boron coated graphite, with a staged transition to molybdenum. Steady-state peak divertor heat fluxes are projected to reach 20-30 MW/m^2 in 2 MA, 12 MW NBI-heated discharges of up to 5 s duration, thus challenging PFC thermal limits. Based on the recent NSTX divertor experiments and modeling with edge transport code UEDGE, a favorable basis for divertor power handling in NSTX-U is developed. The snowflake divertor geometry and feedback-controlled divertor impurity seeding applied to the lower and upper divertors are presently envisioned. In the NSTX snowflake experiments with lithium-coated graphite PFCs, the peak divertor heat fluxes from Type I ELMs and between ELMs were significantly reduced due to geometry effects, increased volumetric losses and null-point convective redistribution between strike points. H-mode core confinement was maintained at H98(y,2)<=1 albeit the radiative detachment. Additional CD4 seeding demonstrated potential for a further increase of divertor radiation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solomon, W. M., E-mail: solomon@fusion.gat.com; Bortolon, A.; Grierson, B. A.

A new high pedestal regime (“Super H-mode”) has been predicted and accessed on DIII-D. Super H-mode was first achieved on DIII-D using a quiescent H-mode edge, enabling a smooth trajectory through pedestal parameter space. By exploiting Super H-mode, it has been possible to access high pedestal pressures at high normalized densities. While elimination of Edge localized modes (ELMs) is beneficial for Super H-mode, it may not be a requirement, as recent experiments have maintained high pedestals with ELMs triggered by lithium granule injection. Simulations using TGLF for core transport and the EPED model for the pedestal find that ITER canmore » benefit from the improved performance associated with Super H-mode, with increased values of fusion power and gain possible. Similar studies demonstrate that the Super H-mode pedestal can be advantageous for a steady-state power plant, by providing a path to increasing the bootstrap current while simultaneously reducing the demands on the core physics performance.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solomon, W. M.; Snyder, P. B.; Bortolon, A.

In a new high pedestal regime ("Super H-mode") we predicted and accessed DIII-D. Super H-mode was first achieved on DIII-D using a quiescent H-mode edge, enabling a smooth trajectory through pedestal parameter space. By exploiting Super H-mode, it has been possible to access high pedestal pressures at high normalized densities. And while elimination of Edge localized modes (ELMs) is beneficial for Super H-mode, it may not be a requirement, as recent experiments have maintained high pedestals with ELMs triggered by lithium granule injection. Simulations using TGLF for core transport and the EPED model for the pedestal find that ITER canmore » benefit from the improved performance associated with Super H-mode, with increased values of fusion power and gain possible. In similar studies demonstrate that the Super H-mode pedestal can be advantageous for a steady-state power plant, by providing a path to increasing the bootstrap current while simultaneously reducing the demands on the core physics performance.« less

Efficient DV-HOP Localization for Wireless Cyber-Physical Social Sensing System: A Correntropy-Based Neural Network Learning Scheme

PubMed Central

Xu, Yang; Luo, Xiong; Wang, Weiping; Zhao, Wenbing

2017-01-01

Integrating wireless sensor network (WSN) into the emerging computing paradigm, e.g., cyber-physical social sensing (CPSS), has witnessed a growing interest, and WSN can serve as a social network while receiving more attention from the social computing research field. Then, the localization of sensor nodes has become an essential requirement for many applications over WSN. Meanwhile, the localization information of unknown nodes has strongly affected the performance of WSN. The received signal strength indication (RSSI) as a typical range-based algorithm for positioning sensor nodes in WSN could achieve accurate location with hardware saving, but is sensitive to environmental noises. Moreover, the original distance vector hop (DV-HOP) as an important range-free localization algorithm is simple, inexpensive and not related to the environment factors, but performs poorly when lacking anchor nodes. Motivated by these, various improved DV-HOP schemes with RSSI have been introduced, and we present a new neural network (NN)-based node localization scheme, named RHOP-ELM-RCC, through the use of DV-HOP, RSSI and a regularized correntropy criterion (RCC)-based extreme learning machine (ELM) algorithm (ELM-RCC). Firstly, the proposed scheme employs both RSSI and DV-HOP to evaluate the distances between nodes to enhance the accuracy of distance estimation at a reasonable cost. Then, with the help of ELM featured with a fast learning speed with a good generalization performance and minimal human intervention, a single hidden layer feedforward network (SLFN) on the basis of ELM-RCC is used to implement the optimization task for obtaining the location of unknown nodes. Since the RSSI may be influenced by the environmental noises and may bring estimation error, the RCC instead of the mean square error (MSE) estimation, which is sensitive to noises, is exploited in ELM. Hence, it may make the estimation more robust against outliers. Additionally, the least square estimation (LSE) in ELM is replaced by the half-quadratic optimization technique. Simulation results show that our proposed scheme outperforms other traditional localization schemes. PMID:28085084

Environmental Factors that Influence Physiological Functioning of Eight Bottomland Hardwood Species

NASA Astrophysics Data System (ADS)

Kassahun, Z.; Renninger, H. J.

2017-12-01

With increases in extreme precipitation, flooding, and prolonged drought events in the southeastern United States, bottomland hardwood forests are expected to experience a drastic shift in their productivity and composition. As environmental conditions shift, certain tree species may experience an increase in productivity or could be more negatively affected over more resilient species, leading to a shift in species composition, water use, and carbon uptake. The goals of this research were to use sap flow measurements, leaf phenology, and photosynthetic rates to study species-specific responses to environmental drivers. Sap flow of eight co-occurring hardwood species as well as soil moisture and vapor pressure deficit were measured continuously over the course of a calendar year that included drought conditions and extended saturated soil conditions. We found that cherrybark oak used the most water during the growing season, about 20% more water than the next highest consumer, swamp chestnut oak. Given low, ample or saturated soil moisture conditions, we found that sap flow of winged elm, American elm, cherrybark oak, and shagbark hickory exhibited varying relationships with vapor pressure deficit under the different soil moisture conditions. While the relationship between sap flow and vapor pressure deficit did not differ depending on soil moisture in willow oak, swamp chestnut oak, and green ash. This suggests that winged elm, American elm, cherrybark oak, and shagbark hickory may be more negatively affected by drought conditions while willow oak, swamp chestnut oak, and green ash are more drought tolerant. Regarding leaf phenology, willow oak, cherrybark oak, and shagbark hickory were the first to experience leaf abscission at the end of the growing season when extended drought conditions occurred. In terms of leaf gas exchange, green ash exhibited the highest photosynthesis and transpiration rates, resulting in the lowest water-use efficiency compared with other study species. Taken together, these responses can be used to estimate forest water budgets given stand species composition or to predict individual species resilience or adaptation to a changing climate, which can improve land surface models and identify species in this forest type that will be most successful under future climate conditions.

Limestone Creek, Local Flood Protection, Fayetteville, New York

DTIC Science & Technology

1990-08-01

maple, slippery elm , syca- more, black locust, dogwood, sumac, choke cherry, creeping cucumber, goldenrod and teasel. Wooded areas on the surrounding...CIRCLE C. -AkA- BARKER t LANE IVIALL KEN 4A AVE 2 7rflEE EEOER r ’A CHANIC S ENWOOD LANE Shcoping cc a ttev Center RNE -V ELM STREET GENES STREET...0~i r; 0 i cyO n 0 00.- w ~ 0vwf N - N 9 00 0 , - 00 -l N NO w IV a,0 200 000 -0 a, r. elm ID MW PN0NIN MOJn 0m M e. 0’iamo 0 q0 ON T0 Fw% N..NV

KITCHEN WITH THE FOYER IN BACKGROUND. VIEW FACING SOUTHEAST ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

KITCHEN WITH THE FOYER IN BACKGROUND. VIEW FACING SOUTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Types 8 and 11, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

VIEW OF FRONT, RECESSED ENTRY SHOWING FRONT WALK. VIEW FACING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF FRONT, RECESSED ENTRY SHOWING FRONT WALK. VIEW FACING SOUTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 9, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

DETAIL OF TYPICAL BASEBOARD IN LIVING ROOM. VIEW FACING SOUTH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL OF TYPICAL BASEBOARD IN LIVING ROOM. VIEW FACING SOUTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Four-Bedroom, Single-Family Type 10, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

REAR OBLIQUE VIEW, SHOWING OPEN GRASSY REAR YARD. VIEW FACING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

REAR OBLIQUE VIEW, SHOWING OPEN GRASSY REAR YARD. VIEW FACING NORTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 9, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

REAR VIEW OF THE HOUSE FROM THE NORTHEAST SIDE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

REAR VIEW OF THE HOUSE FROM THE NORTHEAST SIDE - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

DINING ROOM DOOR TO THE CARPORT. VIEW FACING SOUTHEAST ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DINING ROOM DOOR TO THE CARPORT. VIEW FACING SOUTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

OBLIQUE VIEW FROM ACROSS THE WEST, ACROSS THE STREET ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

OBLIQUE VIEW FROM ACROSS THE WEST, ACROSS THE STREET - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

FRONT OBLIQUE SHOWING REAR OF CARPORT STORAGE AREA. VIEW FACING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

FRONT OBLIQUE SHOWING REAR OF CARPORT STORAGE AREA. VIEW FACING SOUTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 9, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

CLOSEUP OF STORAGE AREA IN ENCLOSED CARPORT. VIEW FACING WEST ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CLOSEUP OF STORAGE AREA IN ENCLOSED CARPORT. VIEW FACING WEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Four-Bedroom, Single-Family Type 10, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

REAR ELEVATION SHOWING ENCLOSED CARPORT ON RIGHT SIDE. VIEW FACING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

REAR ELEVATION SHOWING ENCLOSED CARPORT ON RIGHT SIDE. VIEW FACING SOUTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Four-Bedroom, Single-Family Type 10, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

Experimental studies of high-confinement mode plasma response to non-axisymmetric magnetic perturbations in ASDEX Upgrade

NASA Astrophysics Data System (ADS)

Suttrop, W.; Kirk, A.; Nazikian, R.; Leuthold, N.; Strumberger, E.; Willensdorfer, M.; Cavedon, M.; Dunne, M.; Fischer, R.; Fietz, S.; Fuchs, J. C.; Liu, Y. Q.; McDermott, R. M.; Orain, F.; Ryan, D. A.; Viezzer, E.; The ASDEX Upgrade Team; The DIII-D Team; The Eurofusion MST1 Team

2017-01-01

The interaction of externally applied small non-axisymmetric magnetic perturbations (MP) with tokamak high-confinement mode (H-mode) plasmas is reviewed and illustrated by recent experiments in ASDEX Upgrade. The plasma response to the vacuum MP field is amplified by stable ideal kink modes with low toroidal mode number n driven by the H-mode edge pressure gradient (and associated bootstrap current) which is experimentally evidenced by an observable shift of the poloidal mode number m away from field alignment (m  =  qn, with q being the safety factor) at the response maximum. A torque scan experiment demonstrates the importance of the perpendicular electron flow for shielding of the resonant magnetic perturbation, as expected from a two-fluid MHD picture. Two significant effects of MP occur in H-mode plasmas at low pedestal collisionality, ν \\text{ped}\\ast≤slant 0.4 : (a) a reduction of the global plasma density by up to 61 % and (b) a reduction of the energy loss associated with edge localised modes (ELMs) by a factor of up to 9. A comprehensive database of ELM mitigation pulses at low {ν\\ast} in ASDEX Upgrade shows that the degree of ELM mitigation correlates with the reduction of pedestal pressure which in turn is limited and defined by the onset of ELMs, i. e. a modification of the ELM stability limit by the magnetic perturbation.

An experimental study of turbulence by phase-contrast imaging in the DIII-D tokamak

NASA Astrophysics Data System (ADS)

Coda, Stefano

1997-10-01

A CO2-laser imaging system employing the Zernike phase-contrast technique was designed, built, installed, and operated on the DIII-D tokamak. This system measures the line integrals of plasma density fluctuations along 16 vertical chords at the outer edge of the tokamak (0.85

Stationary QH-mode plasmas with high and wide pedestal at low rotation on DIII-D

DOE PAGES

Chen, Xi; Burrell, K. H.; Osborne, T. H.; ...

2016-09-30

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 ExB rotation shear reduces, the transition from standard QH to the wide pedestal QH-mode occurs. And 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 themore » enhanced edge turbulence-driven transport, enabled by the lower edge ExB 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 ExB flow shear in that region and the enhanced pedestal boost the overall confinement by up to 45%. Our 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.« less

Long-term impact of Ophiostoma novo-ulmi on leaf traits and transpiration of branches in the Dutch elm hybrid ‘Dodoens’

PubMed Central

Plichta, Roman; Urban, Josef; Gebauer, Roman; Dvořák, Miloň; Ďurkovič, Jaroslav

2016-01-01

To better understand the long-term impact of Ophiostoma novo-ulmi Brasier on leaf physiology in ‘Dodoens’, a Dutch elm disease-tolerant hybrid, measurements of leaf area, leaf dry mass, petiole anatomy, petiole hydraulic conductivity, leaf and branch water potential, and branch sap flow were performed 3 years following an initial artificial inoculation. Although fungal hyphae were detected in fully expanded leaves, neither anatomical nor morphological traits were affected, indicating that there was no impact from the fungal hyphae on the leaves during leaf expansion. In contrast, however, infected trees showed both a lower transpiration rate of branches and a lower sap flow density. The long-term persistence of fungal hyphae inside vessels decreased the xylem hydraulic conductivity, but stomatal regulation of transpiration appeared to be unaffected as the leaf water potential in both infected and non-infected trees was similarly driven by the transpirational demands. Regardless of the fungal infection, leaves with a higher leaf mass per area ratio tended to have a higher leaf area-specific conductivity. Smaller leaves had an increased number of conduits with smaller diameters and thicker cell walls. Such a pattern could increase tolerance towards hydraulic dysfunction. Measurements of water potential and theoretical xylem conductivity revealed that petiole anatomy could predict the maximal transpiration rate. Three years following fungal inoculation, phenotypic expressions for the majority of the examined traits revealed a constitutive nature for their possible role in Dutch elm disease tolerance of ‘Dodoens’ trees. PMID:26843210

The quiescent H-mode regime for high performance edge localized mode-stable operation in future burning plasmas [The quiescent H-mode regime for high performance ELM-stable operation in future burning plasmas

DOE PAGES

Garofalo, Andrea M.; Burrell, Keith H.; Eldon, David; ...

2015-05-26

For the first time, DIII-D experiments have achieved stationary quiescent H-mode (QH-mode) operation for many energy confinement times at simultaneous ITER-relevant values of beta, confinement, and safety factor, in an ITER similar shape. QH-mode provides excellent energy confinement, even at very low plasma rotation, while operating without edge localized modes (ELMs) and with strong impurity transport via the benign edge harmonic oscillation (EHO). By tailoring the plasma shape to improve the edge stability, the QH-mode operating space has also been extended to densities exceeding 80% of the Greenwald limit, overcoming the long-standing low-density limit of QH-mode operation. In the theory,more » the density range over which the plasma encounters the kink-peeling boundary widens as the plasma cross-section shaping is increased, thus increasing the QH-mode density threshold. Here, the DIII-D results are in excellent agreement with these predictions, and nonlinear MHD analysis of reconstructed QH-mode equilibria shows unstable low n kink-peeling modes growing to a saturated level, consistent with the theoretical picture of the EHO. Furthermore, high density operation in the QH-mode regime has opened a path to a new, previously predicted region of parameter space, named “Super H-mode” because it is characterized by very high pedestals that can be more than a factor of two above the peeling-ballooning stability limit for similar ELMing H-mode discharges at the same density.« less

Application of the Elaboration Likelihood Model of Attitude Change to Assertion Training.

ERIC Educational Resources Information Center

Ernst, John M.; Heesacker, Martin

1993-01-01

College students (n=113) participated in study comparing effects of elaboration likelihood model (ELM) based assertion workshop with those of typical assertion workshop. ELM-based workshop was significantly better at producing favorable attitude change, greater intention to act assertively, and more favorable evaluations of workshop content.…

Laboratory assay of cacodylic acid and ®Meta-Systox-R on Scolytus multistriatus and Pseudopityophthorus sp.

Treesearch

Charles O. Rexrode; James W. Lockyer

1974-01-01

Cacodylic acid and Meta-Systox-R were applied to oak and elm bark beetle diets. Diets containing 900 to 1,000 ppm of cacodylic acid and diets containing 100 to 200 ppm of Meta-Systox-R killed both oak and elm bark beetles.

Formulation and application of methoxychlor for elm bark beetle control

Treesearch

R. A. Cuthbert; J. H. Barger; A. C. Lincoln; P. A. Reed

1973-01-01

American elm trees, Ulmus americana L., were sprayed with different formulations of methoxychlor by mistblower, hydraulic sprayer or helicopter. Twig-crotches were collected from sprayed trees for GLC assay and Scolytus multistriatus (Marsham) bioassay. Hydraulic deposits were heaviest but the mistblower was more efficient in terms...

DINING ROOM SHOWING DOOR TO LANAI AND PASS THRU TO ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DINING ROOM SHOWING DOOR TO LANAI AND PASS THRU TO KITCHEN (RIGHT). VIEW FACING SOUTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 7, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

FRONT OBLIQUE VIEW WITH STREET ON RIGHT HAND SIDE. VIEW ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

FRONT OBLIQUE VIEW WITH STREET ON RIGHT HAND SIDE. VIEW FACING WEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 9, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

MAIN STREET FACING VIEW OF THE HOUSE. THIS VIEW IS ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

MAIN STREET FACING VIEW OF THE HOUSE. THIS VIEW IS FACING SOUTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

UTILITY ROOM WITH CANEC PANEL CEILING AND TONGUE AND GROOVE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

UTILITY ROOM WITH CANEC PANEL CEILING AND TONGUE AND GROOVE WALL BOARDS. VIEW FACING NORTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Four-Bedroom, Single-Family Type 10, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

INTERIOR VIEW OF FOYER WITH ENTRY DOOR ON THE RIGHT. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

INTERIOR VIEW OF FOYER WITH ENTRY DOOR ON THE RIGHT. VIEW FACING EAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 7, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

REAR ELEVATION WITH BASE OF PALM TREE IN FOREGROUND. VIEW ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

REAR ELEVATION WITH BASE OF PALM TREE IN FOREGROUND. VIEW FACING NORTH/NORTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 9, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

FOYER SHOWING WOOD GRILLE AT THE LIVING ROOM AND HALL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

FOYER SHOWING WOOD GRILLE AT THE LIVING ROOM AND HALL TO BEDROOMS. VIEW FACING SOUTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Four-Bedroom, Single-Family Type 10, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

DINING ROOM. NOTE THE RECESSED PULLS ON THE SLIDING DOORS. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DINING ROOM. NOTE THE RECESSED PULLS ON THE SLIDING DOORS. VIEW FACING EAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

MASTER BEDROOM SHOWING THE CLOSET WITH SLIDING DOORS. VIEW FACING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

MASTER BEDROOM SHOWING THE CLOSET WITH SLIDING DOORS. VIEW FACING NORTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Types 8 and 11, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

UTILITY ROOM SHOWING THE JALOUSIE PANEL REAR DOOR. VIEW FACING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

UTILITY ROOM SHOWING THE JALOUSIE PANEL REAR DOOR. VIEW FACING NORTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

VIEW OF LIVING ROOM DOORS SHOWN IN CLOSED POSITION. VIEW ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF LIVING ROOM DOORS SHOWN IN CLOSED POSITION. VIEW FACING WEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 9, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

DETAILED VIEW OF PARTIALLY ENCLOSED LANAI AT THE FRONT OF ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAILED VIEW OF PARTIALLY ENCLOSED LANAI AT THE FRONT OF THE HOUSE - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 7, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

MASTER BATH SHOWING SINK WITH VANITY AND THE MEDICINE CABINET. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

MASTER BATH SHOWING SINK WITH VANITY AND THE MEDICINE CABINET. VIEW FACING WEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

VIEW OF REAR YARD WITH PLUMERIA TREES AND SMALL PALMS. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF REAR YARD WITH PLUMERIA TREES AND SMALL PALMS. VIEW FACING EAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Types 8 and 11, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

LINEN CLOSET IN THE HALL SHOWING THE BUILT IN SHELVES. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

LINEN CLOSET IN THE HALL SHOWING THE BUILT IN SHELVES. VIEW FACING SOUTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 7, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

VIEW OF UTILITY ROOM, SHOWING ORIGINAL REAR DOOR WITH GLASS ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF UTILITY ROOM, SHOWING ORIGINAL REAR DOOR WITH GLASS JALOUSIES. VIEW FACING SOUTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 9, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

FRONT ELEVATION, WITH DRIVEWAY ON LEFT HAND SIDE, AND STREET ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

FRONT ELEVATION, WITH DRIVEWAY ON LEFT HAND SIDE, AND STREET IN FOREGROUND. VIEW FACING NORTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Four-Bedroom, Single-Family Type 10, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

CLOSE UP OF THE RECESSED MAIN ENTRY OF THE UNIT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CLOSE UP OF THE RECESSED MAIN ENTRY OF THE UNIT - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

VIEW OF RECESSED FRONT ENTRY SHOWING DECORATIVE CONCRETE MASONRY UNIT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF RECESSED FRONT ENTRY SHOWING DECORATIVE CONCRETE MASONRY UNIT WALL. VIEW FACING NORTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Four-Bedroom, Single-Family Type 10, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

DETAIL OF ENCLOSED TOP TRACK OF SLIDING DOORS IN LIVING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL OF ENCLOSED TOP TRACK OF SLIDING DOORS IN LIVING ROOM. VIEW FACING NORTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Four-Bedroom, Single-Family Type 10, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

FRONT LEFT OBLIQUE VIEW, WITH ENCLOSED CARPORT SHOWING ON THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

FRONT LEFT OBLIQUE VIEW, WITH ENCLOSED CARPORT SHOWING ON THE LEFT. VIEW FACING EAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Four-Bedroom, Single-Family Type 10, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

Expansion of the American elm restoration effort to the upper Midwest

Treesearch

James M. Slavicek

2007-01-01

The Forestry Sciences Laboratory, Northeastern Research Station, initiated a project in 2003 to restore the American elm in the state of Ohio. This effort has been expanded to the upper Midwest through establishment of a restoration site in Decorah, IA, Eagle Island, WI, and Hastings, MN.

Typification of infrageneric names in Ulmus L.

USDA-ARS?s Scientific Manuscript database

The elms (the genus Ulmus) are one of the most important tree crops for the $4.7billion per year U.S. nursery industry, but utilization of these plants has been limited in recent decades by introduced diseases, especially Dutch elm disease. Research and breeding for disease resistance have been base...

Dynamic Capacity Allocation Algorithms for iNET Link Manager

DTIC Science & Technology

2014-05-01

algorithm that can better cope with severe congestion and misbehaving users and traffic flows. We compare the E-LM with the LM baseline algorithm (B-LM...capacity allocation algorithm that can better cope with severe congestion and misbehaving users and traffic flows. We compare the E-LM with the LM

Investigation of the plasma shaping effects on the H-mode pedestal structure using coupled kinetic neoclassical/MHD stability simulations

NASA Astrophysics Data System (ADS)

Pankin, A. Y.; Rafiq, T.; Kritz, A. H.; Park, G. Y.; Snyder, P. B.; Chang, C. S.

2017-06-01

The effects of plasma shaping on the H-mode pedestal structure are investigated. High fidelity kinetic simulations of the neoclassical pedestal dynamics are combined with the magnetohydrodynamic (MHD) stability conditions for triggering edge localized mode (ELM) instabilities that limit the pedestal width and height in H-mode plasmas. The neoclassical kinetic XGC0 code [Chang et al., Phys. Plasmas 11, 2649 (2004)] is used in carrying out a scan over plasma elongation and triangularity. As plasma profiles evolve, the MHD stability limits of these profiles are analyzed with the ideal MHD ELITE code [Snyder et al., Phys. Plasmas 9, 2037 (2002)]. Simulations with the XGC0 code, which includes coupled ion-electron dynamics, yield predictions for both ion and electron pedestal profiles. The differences in the predicted H-mode pedestal width and height for the DIII-D discharges with different elongation and triangularities are discussed. For the discharges with higher elongation, it is found that the gradients of the plasma profiles in the H-mode pedestal reach semi-steady states. In these simulations, the pedestal slowly continues to evolve to higher pedestal pressures and bootstrap currents until the peeling-ballooning stability conditions are satisfied. The discharges with lower elongation do not reach the semi-steady state, and ELM crashes are triggered at earlier times. The plasma elongation is found to have a stronger stabilizing effect than the plasma triangularity. For the discharges with lower elongation and lower triangularity, the ELM frequency is large, and the H-mode pedestal evolves rapidly. It is found that the temperature of neutrals in the scrape-off-layer (SOL) region can affect the dynamics of the H-mode pedestal buildup. However, the final pedestal profiles are nearly independent of the neutral temperature. The elongation and triangularity affect the pedestal widths of plasma density and electron temperature profiles differently. This provides a new mechanism of controlling the pedestal bootstrap current and the pedestal stability.

Investigation of the plasma shaping effects on the H-mode pedestal structure using coupled kinetic neoclassical/MHD stability simulations

DOE PAGES

Pankin, A. Y.; Rafiq, T.; Kritz, A. H.; ...

2017-06-08

The effects of plasma shaping on the H-mode pedestal structure are investigated. High fidelity kinetic simulations of the neoclassical pedestal dynamics are combined with the magnetohydrodynamic (MHD) stability conditions for triggering edge localized mode (ELM) instabilities that limit the pedestal width and height in H-mode plasmas. We use the neoclassical kinetic XGC0 code [Chang et al., Phys. Plasmas 11, 2649 (2004)] to carry out a scan over plasma elongation and triangularity. As plasma profiles evolve, the MHD stability limits of these profiles are analyzed with the ideal MHD ELITE code [Snyder et al., Phys. Plasmas 9, 2037 (2002)]. In simulationsmore » with the XGC0 code, which includes coupled ion-electron dynamics, yield predictions for both ion and electron pedestal profiles. The differences in the predicted H-mode pedestal width and height for the DIII-D discharges with different elongation and triangularities are discussed. For the discharges with higher elongation, it is found that the gradients of the plasma profiles in the H-mode pedestal reach semi-steady states. In these simulations, the pedestal slowly continues to evolve to higher pedestal pressures and bootstrap currents until the peeling-ballooning stability conditions are satisfied. The discharges with lower elongation do not reach the semi-steady state, and ELM crashes are triggered at earlier times. The plasma elongation is found to have a stronger stabilizing effect than the plasma triangularity. For the discharges with lower elongation and lower triangularity, the ELM frequency is large, and the H-mode pedestal evolves rapidly. It is found that the temperature of neutrals in the scrape-off-layer (SOL) region can affect the dynamics of the H-mode pedestal buildup. But the final pedestal profiles are nearly independent of the neutral temperature. The elongation and triangularity affect the pedestal widths of plasma density and electron temperature profiles differently. This provides a new mechanism of controlling the pedestal bootstrap current and the pedestal stability.« less

Investigation of the plasma shaping effects on the H-mode pedestal structure using coupled kinetic neoclassical/MHD stability simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pankin, A. Y.; Rafiq, T.; Kritz, A. H.

The effects of plasma shaping on the H-mode pedestal structure are investigated. High fidelity kinetic simulations of the neoclassical pedestal dynamics are combined with the magnetohydrodynamic (MHD) stability conditions for triggering edge localized mode (ELM) instabilities that limit the pedestal width and height in H-mode plasmas. We use the neoclassical kinetic XGC0 code [Chang et al., Phys. Plasmas 11, 2649 (2004)] to carry out a scan over plasma elongation and triangularity. As plasma profiles evolve, the MHD stability limits of these profiles are analyzed with the ideal MHD ELITE code [Snyder et al., Phys. Plasmas 9, 2037 (2002)]. In simulationsmore » with the XGC0 code, which includes coupled ion-electron dynamics, yield predictions for both ion and electron pedestal profiles. The differences in the predicted H-mode pedestal width and height for the DIII-D discharges with different elongation and triangularities are discussed. For the discharges with higher elongation, it is found that the gradients of the plasma profiles in the H-mode pedestal reach semi-steady states. In these simulations, the pedestal slowly continues to evolve to higher pedestal pressures and bootstrap currents until the peeling-ballooning stability conditions are satisfied. The discharges with lower elongation do not reach the semi-steady state, and ELM crashes are triggered at earlier times. The plasma elongation is found to have a stronger stabilizing effect than the plasma triangularity. For the discharges with lower elongation and lower triangularity, the ELM frequency is large, and the H-mode pedestal evolves rapidly. It is found that the temperature of neutrals in the scrape-off-layer (SOL) region can affect the dynamics of the H-mode pedestal buildup. But the final pedestal profiles are nearly independent of the neutral temperature. The elongation and triangularity affect the pedestal widths of plasma density and electron temperature profiles differently. This provides a new mechanism of controlling the pedestal bootstrap current and the pedestal stability.« less

Overview of ASDEX Upgrade results

NASA Astrophysics Data System (ADS)

Kallenbach, A.; Adamek, J.; Aho-Mantila, L.; Äkäslompolo, S.; Angioni, C.; Atanasiu, C. V.; Balden, M.; Behler, K.; Belonohy, E.; Bergmann, A.; Bernert, M.; Bilato, R.; Bobkov, V.; Boom, J.; Bottino, A.; Braun, F.; Brüdgam, M.; Buhler, A.; Burckhart, A.; Chankin, A.; Classen, I. G. J.; Conway, G. D.; Coster, D. P.; de Marné, P.; D'Inca, R.; Drube, R.; Dux, R.; Eich, T.; Endstrasser, N.; Engelhardt, K.; Esposito, B.; Fable, E.; Fahrbach, H.-U.; Fattorini, L.; Fischer, R.; Flaws, A.; Fünfgelder, H.; Fuchs, J. C.; Gál, K.; García Muñoz, M.; Geiger, B.; Gemisic Adamov, M.; Giannone, L.; Giroud, C.; Görler, T.; da Graca, S.; Greuner, H.; Gruber, O.; Gude, A.; Günter, S.; Haas, G.; Hakola, A. H.; Hangan, D.; Happel, T.; Hauff, T.; Heinemann, B.; Herrmann, A.; Hicks, N.; Hobirk, J.; Höhnle, H.; Hölzl, M.; Hopf, C.; Horton, L.; Huart, M.; Igochine, V.; Ionita, C.; Janzer, A.; Jenko, F.; Käsemann, C.-P.; Kálvin, S.; Kardaun, O.; Kaufmann, M.; Kirk, A.; Klingshirn, H.-J.; Kocan, M.; Kocsis, G.; Kollotzek, H.; Konz, C.; Koslowski, R.; Krieger, K.; Kurki-Suonio, T.; Kurzan, B.; Lackner, K.; Lang, P. T.; Lauber, P.; Laux, M.; Leipold, F.; Leuterer, F.; Lohs, A.; Luhmann, N. C., Jr.; Lunt, T.; Lyssoivan, A.; Maier, H.; Maggi, C.; Mank, K.; Manso, M.-E.; Maraschek, M.; Martin, P.; Mayer, M.; McCarthy, P. J.; McDermott, R.; Meister, H.; Menchero, L.; Meo, F.; Merkel, P.; Merkel, R.; Mertens, V.; Merz, F.; Mlynek, A.; Monaco, F.; Müller, H. W.; Münich, M.; Murmann, H.; Neu, G.; Neu, R.; Nold, B.; Noterdaeme, J.-M.; Park, H. K.; Pautasso, G.; Pereverzev, G.; Podoba, Y.; Pompon, F.; Poli, E.; Polochiy, K.; Potzel, S.; Prechtl, M.; Püschel, M. J.; Pütterich, T.; Rathgeber, S. K.; Raupp, G.; Reich, M.; Reiter, B.; Ribeiro, T.; Riedl, R.; Rohde, V.; Roth, J.; Rott, M.; Ryter, F.; Sandmann, W.; Santos, J.; Sassenberg, K.; Sauter, P.; Scarabosio, A.; Schall, G.; Schmid, K.; Schneider, P. A.; Schneider, W.; Schramm, G.; Schrittwieser, R.; Schweinzer, J.; Scott, B.; Sempf, M.; Serra, F.; Sertoli, M.; Siccinio, M.; Sigalov, A.; Silva, A.; Sips, A. C. C.; Sommer, F.; Stäbler, A.; Stober, J.; Streibl, B.; Strumberger, E.; Sugiyama, K.; Suttrop, W.; Szepesi, T.; Tardini, G.; Tichmann, C.; Told, D.; Treutterer, W.; Urso, L.; Varela, P.; Vincente, J.; Vianello, N.; Vierle, T.; Viezzer, E.; Vorpahl, C.; Wagner, D.; Weller, A.; Wenninger, R.; Wieland, B.; Wigger, C.; Willensdorfer, M.; Wischmeier, M.; Wolfrum, E.; Würsching, E.; Yadikin, D.; Yu, Q.; Zammuto, I.; Zasche, D.; Zehetbauer, T.; Zhang, Y.; Zilker, M.; Zohm, H.

2011-09-01

The ASDEX Upgrade programme is directed towards physics input to critical elements of the ITER design and the preparation of ITER operation, as well as addressing physics issues for a future DEMO design. After the finalization of the tungsten coating of the plasma facing components, the re-availability of all flywheel-generators allowed high-power operation with up to 20 MW heating power at Ip up to 1.2 MA. Implementation of alternative ECRH schemes (140 GHz O2- and X3-mode) facilitated central heating above ne = 1.2 × 1020 m-3 and low q95 operation at Bt = 1.8 T. Central O2-mode heating was successfully used in high P/R discharges with 20 MW total heating power and divertor load control with nitrogen seeding. Improved energy confinement is obtained with nitrogen seeding both for type-I and type-III ELMy conditions. The main contributor is increased plasma temperature, no significant changes in the density profile have been observed. This behaviour may be explained by higher pedestal temperatures caused by ion dilution in combination with a pressure limited pedestal and hollow nitrogen profiles. Core particle transport simulations with gyrokinetic calculations have been benchmarked by dedicated discharges using variations of the ECRH deposition location. The reaction of normalized electron density gradients to variations of temperature gradients and the Te/Ti ratio could be well reproduced. Doppler reflectometry studies at the L-H transition allowed the disentanglement of the interplay between the oscillatory geodesic acoustic modes, turbulent fluctuations and the mean equilibrium E × B flow in the edge negative Er well region just inside the separatrix. Improved pedestal diagnostics revealed also a refined picture of the pedestal transport in the fully developed H-mode type-I ELM cycle. Impurity ion transport turned out to be neoclassical in between ELMs. Electron and energy transport remain anomalous, but exhibit different recovery time scales after an ELM. After recovery of the pre-ELM profiles, strong fluctuations develop in the gradients of ne and Te. The occurrence of the next ELM cannot be explained by the local current diffusion time scale, since this turns out to be too short. Fast ion losses induced by shear Alfvén eigenmodes have been investigated by time-resolved energy and pitch angle measurements. This allowed the separation of the convective and diffusive loss mechanisms.

Prediction of laser cutting heat affected zone by extreme learning machine

NASA Astrophysics Data System (ADS)

Anicic, Obrad; Jović, Srđan; Skrijelj, Hivzo; Nedić, Bogdan

2017-01-01

Heat affected zone (HAZ) of the laser cutting process may be developed based on combination of different factors. In this investigation the HAZ forecasting, based on the different laser cutting parameters, was analyzed. The main goal was to predict the HAZ according to three inputs. The purpose of this research was to develop and apply the Extreme Learning Machine (ELM) to predict the HAZ. The ELM results were compared with genetic programming (GP) and artificial neural network (ANN). The reliability of the computational models were accessed based on simulation results and by using several statistical indicators. Based upon simulation results, it was demonstrated that ELM can be utilized effectively in applications of HAZ forecasting.

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

PubMed

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.

Counseling Pretreatment and the Elaboration Likelihood Model of Attitude Change.

ERIC Educational Resources Information Center

Heesacker, Martin

1986-01-01

Results of the application of the Elaboration Likelihood Model (ELM) to a counseling context revealed that more favorable attitudes toward counseling occurred as subjects' ego involvement increased and as intervention quality improved. Counselor credibility affected the degree to which subjects' attitudes reflected argument quality differences.…

Effects of inoculation timing on symptom development in Ulmus americana L.

Treesearch

Garrett L. Beier; Benjamin W. Held; Chad P. Giblin; Robert A. Blanchette

2017-01-01

Field inoculation trials are an important component of screening American elms (Ulmus americana) for levels of resistance to Dutch elm disease. A major concern in screening is variability in disease ratings from year to year. Previous studies have demonstrated that timing of inoculation can have a significant impact on disease susceptibility. In...

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

Treesearch

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...

A Disposable Cage for Obtaining Individual Eggs of the Elm Spanworm

Treesearch

A.T. Drooz

1969-01-01

A waxed paper cage in the shape of a paper coffee creamer (tetrahedron) is easy to make, inexpensive, and ideal for collecting individual eggs or small groups of eggs from the egg-mass depositing elm spanworm. The moths and eggs can be readily observed through the translucent waxed paper.

Research News: Emulsion Liquid Membrane Extraction in a Hollow-Fiber Contactor

NASA Technical Reports Server (NTRS)

Wiencek, John M.; Hu, Shih-Yao

2000-01-01

This article describes how ELMs (emulsion liquid membranes) can be used for extraction. The article addresses the disadvantages of ELM extraction in a stirred contactor, and the advantages of SELMs (supported emulsion liquid membranes). The introduction of the article provides background information on liquid-liquid solvent extraction and dispersion-free solvent extraction.

Micropropagation of juvenile and mature American elms from stem nodal sections

Treesearch

Ann M. Chanon; Joseph C. Kamalay; Pablo Jourdan

1997-01-01

A micropropagation system has been established for the regeneration of superior trees of Ulmus americana L., the American elm. The development of a reliable regeneration system is also required as a prelude to genetic transformation of selected genotypes. The effects of explant source, media formulations, and plant growth regulator concentrations on...

Clitocybe tabescens associated with decline and death of Chinese elm and water oak

Treesearch

T. H. Filer; F. I. McCracken

1969-01-01

In 1964, decline symptoms were found on 48 Chinese elms (Ulmus parvifolia) and 2 water oaks (Quercus nigra) in Washington County, Mississippi. Some of their foliage was yellowish, and small lateral branches were dying in parts of the crowns. Large branches later died and the entire crowns were infected.

Characterization of two non-native invasive bark beetles, Scolytus schevyrewi and Scolytus multistriatus (Coleoptera: Curculionidae: Scolytinae)

Treesearch

Patricia L. Johnson; Jane L. Hayes; John E. Rinehart; Walter S. Sheppard

2008-01-01

Scolytus schevyrewi Semenov, the banded elm bark beetle, and S. multistriatus Marsham, the smaller European elm bark beetle, are morphologically similar. Reliance on adult external morphological characters for identification can be problematic because of wide within species variability and the need for good-quality specimens....