Real-time identification of the resistive-wall-mode in DIII-D with Kalman filter ELM discrimination

International Nuclear Information System (INIS)

Edgell, D.H.; Fransson, C.M.; Humphreys, D.A.; Ferron, J.R.; Garofalo, A.M.; Kim, J.S.; La Haye, R.J.; Okabayashi, M.; Reimerdes, H.; Strait, E.J.; Turnbull, A.D.

2004-01-01

The resistive-wall-mode (RWM) is a major performance-limiting instability in present-day tokamaks. Active control and stabilization of the mode will almost certainly be essential for the success of advanced tokamaks and for the economic viability of tokamak fusion reactors. High performance tokamak plasmas often experience edge-localized-modes (ELMs) which can interfere with RWM identification and control. If the RWM control scheme reacts to an ELM the RWM may be driven unstable instead of controlled. An algorithm for real-time identification of the RWM with discrimination of ELMs in the DIII-D tokamak has been developed using a combination of matched filter and Kalman filter methods. The algorithm has been implemented in DIII-D's real-time plasma control system (PCS) and is available to drive active mode control schemes

Modeling of ELM Dynamics in ITER

International Nuclear Information System (INIS)

Pankin, A.Y.; Bateman, G.; Kritz, A.H.; Brennan, D.P.; Snyder, P.B.; Kruger, S.

2007-01-01

Edge localized modes (ELMs) are large scale instabilities that alter the H-mode pedestal, reduce the total plasma stored energy, and can result in heat pulses to the divertor plates. These modes can be triggered by pressure driven ballooning modes or by current driven peeling instabilities. In this study, stability analyses are carried out for a series of ITER equilibria that are generated with the TEQ and TOQ equilibrium codes. The H-mode pedestal pressure and parallel component of plasma current density are varied in a systematic way in order to include the relevant parameter space for a specific ITER discharge. Ideal MHD stability codes, DCON, ELITE, and BALOO code, are employed to determine whether or not each ITER equilibrium profile is unstable to peeling or ballooning modes in the pedestal region. Several equilibria that are close to the marginal stability boundary for peeling and ballooning modes are tested with the NIMROD non-ideal MHD code. The effects of finite resistivity are studied in a series of linear NIMROD computations. It is found that the peeling-ballooning stability threshold is very sensitive to the resistivity and viscosity profiles, which vary dramatically over a wide range near the separatrix. Due to the effects of finite resistivity and viscosity, the peeling-ballooning stability threshold is shifted compared to the ideal threshold. A fundamental question in the integrated modeling of ELMy H-mode discharges concerning how much plasma and current density is removed during each ELM crash can be addressed with nonlinear non-ideal MHD simulations. In this study, the NIMROD computer simulations are continued into the nonlinear stage for several ITER equilibria that are marginally unstable to peeling or ballooning modes. The role of two-fluid and finite Larmor radius effects on the ELM dynamics in ITER geometry is examined. The formation of ELM filament structures, which are observed in many existing tokamak experiments, is demonstrated for ITER

Study of Type III ELMs in JET

Energy Technology Data Exchange (ETDEWEB)

Sartori, R [EFDA Close Support Unit, Garching, 2 Boltzmannstrasse, Garching (Germany); Saibene, G [EFDA Close Support Unit, Garching, 2 Boltzmannstrasse, Garching (Germany); Horton, L D [Association Euratom-IPP, MPI fuer Plasmaphysik, 2 Boltzmannstrasse, Garching (Germany); Becoulet, M [Association Euratom-CEA, CE Cadarache, F-13108 St Paul-lez-Durance, CEDEX (France); Budny, R [PPPL, Princeton University, PO Box 451, Princeton, NJ 08543 (United States); Borba, D [Associacao EURATOM/IST, Centro de Fusao Nuclear, 1096 Lisbon, CODEX (Portugal); Chankin, A [Association Euratom-IPP, MPI fuer Plasmaphysik, 2 Boltzmannstrasse, Garching (Germany); Conway, G D [Association Euratom-IPP, MPI fuer Plasmaphysik, 2 Boltzmannstrasse, Garching (Germany); Cordey, G [EURATOM-UKAEA Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); McDonald, D [EURATOM-UKAEA Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Guenther, K [EURATOM-UKAEA Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Hellermann, M G von [FOM-Rijnhuizen, Ass. Euratom-FOM, TEC, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Igithkanov, Yu [Max-Planck-Institute for Plasma Physics, Teilinstitut Greifswald, EURATOM Ass., D-17491, Greifswald (Germany); Loarte, A [EFDA Close Support Unit, Garching, 2 Boltzmannstrasse, Garching (Germany); Lomas, P J [EURATOM-UKAEA Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Pogutse, O [EURATOM-UKAEA Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Rapp, J [EFDA Close Support Unit, Culham, Abingdon OX14 3DB (United Kingdom)

2004-05-01

This paper presents the results of JET experiments aimed at studying the operational space of plasmas with a Type III ELMy edge, in terms of both local and global plasma parameters. In JET, the Type III ELMy regime has a wide operational space in the pedestal n{sub e} - T{sub e} diagram, and Type III ELMs are observed in standard ELMy H-modes as well as in plasmas with an internal transport barrier (ITB). The transition from an H-mode with Type III ELMs to a steady state Type I ELMy H-mode requires a minimum loss power, P{sub TypeI}. P{sub TypeI} decreases with increasing plasma triangularity. In the pedestal n{sub e} - T{sub e} diagram, the critical pedestal temperature for the transition to Type I ELMs is found to be inversely proportional to the pedestal density (T{sub crit} {proportional_to} 1/n) at a low density. In contrast, at a high density, T{sub crit}, does not depend strongly on density. In the density range where T{sub crit} {proportional_to} 1/n, the critical power required for the transition to Type I ELMs decreases with increasing density. Experimental results are presented suggesting a common mechanism for Type III ELMs at low and high collisionality. A single model for the critical temperature for the transition from Type III to Type I ELMs, based on the resistive interchange instability with magnetic flutter, fits well the density and toroidal field dependence of the JET experimental data. On the other hand, this model fails to describe the variation of the Type III n{sub e} - T{sub e} operational space with isotopic mass and q{sub 95}. Other results are instead suggestive of a different physics for Type III ELMs. At low collisionality, plasma current ramp experiments indicate a role of the edge current in determining the transition from Type III to Type I ELMs, while at high collisionality, a model based on resistive ballooning instability well reproduces, in term of a critical density, the experimentally observed q{sub 95} dependence of the

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

Science.gov (United States)

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.

Modeling elm growth and Dutch elm disease susceptibility

Science.gov (United States)

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...

Elms: MHD Instabilities at the transport barrier

Energy Technology Data Exchange (ETDEWEB)

Huysmans, G.T.A

2005-07-01

Significant progress has been made in recent years both on the experimental characterisation of ELMs (edge localized modes) and the theory and modelling of ELMs. The observed maximum pressure gradient is in good agreement with the calculated ideal MHD stability limits due to peeling-ballooning modes. The dependence on plasma current and plasma shape are also reproduced by the ideal MHD model. It will be a challenge to verify experimentally the influence of the extensions to the ideal MHD theory such as the possibly incomplete diamagnetic stabilisation, the influence of shear flow, finite resistivity or the stabilizing influence of the separatrix on peeling modes. The observations of the filamentary structures find their explanation in the theory and simulations of the early non-linear phase of the evolution of ballooning modes. One of the remaining open questions is what determines the size of the ELM and its duration. This is related to the loss mechanism of energy and density. Some heuristic descriptions of possible mechanisms have been proposed in literature but none of the models so far makes quantitative predictions on the ELM size. Also the numerical simulations are not yet advanced to the point where the full ELM crash can be modelled. The theory and simulations of the ELMs are necessary to decide between the possible parameters, such as the collisionality or the parallel transport time, that are proposed for the extrapolation of ELM sizes to ITER.

Elms: MHD Instabilities at the transport barrier

International Nuclear Information System (INIS)

Huysmans, G.T.A.

2005-01-01

Significant progress has been made in recent years both on the experimental characterisation of ELMs (edge localized modes) and the theory and modelling of ELMs. The observed maximum pressure gradient is in good agreement with the calculated ideal MHD stability limits due to peeling-ballooning modes. The dependence on plasma current and plasma shape are also reproduced by the ideal MHD model. It will be a challenge to verify experimentally the influence of the extensions to the ideal MHD theory such as the possibly incomplete diamagnetic stabilisation, the influence of shear flow, finite resistivity or the stabilizing influence of the separatrix on peeling modes. The observations of the filamentary structures find their explanation in the theory and simulations of the early non-linear phase of the evolution of ballooning modes. One of the remaining open questions is what determines the size of the ELM and its duration. This is related to the loss mechanism of energy and density. Some heuristic descriptions of possible mechanisms have been proposed in literature but none of the models so far makes quantitative predictions on the ELM size. Also the numerical simulations are not yet advanced to the point where the full ELM crash can be modelled. The theory and simulations of the ELMs are necessary to decide between the possible parameters, such as the collisionality or the parallel transport time, that are proposed for the extrapolation of ELM sizes to ITER

ELM triggering conditions for the integrated modeling of H-mode plasmas

International Nuclear Information System (INIS)

Pankin, A.Y.; Schnack, D.D.; Bateman, G.; Kritz, A.H.; Brennan, D.P.; Snyder, P.B.; Voitsekhovitch, I.; Kruger, S.; Janeschitz, G.; Onjun, T.; Pacher, G.W.; Pacher, H.D.

2005-01-01

Recent advances in the integrated modeling of ELMy H-mode plasmas are presented. A new model for the H-mode pedestal and for the triggering of ELMs predicts the height, width, and shape of the H-mode pedestal and the frequency and width of ELMs. The model for the pedestal and ELMs is used in the ASTRA integrated transport code to follow the time evolution of tokamak discharges from L-mode through the transition from L-mode to H-mode, with the formation of the H-mode pedestal, and, subsequently, to the triggering of ELMs. Turbulence driven by the ion temperature gradient mode, resistive ballooning mode, trapped electron mode, and electron temperature gradient mode contributes to the anomalous thermal transport at the plasma edge in this model. Formation of the pedestal and the L-H transition is the direct result of E(vector) r x B(vector) flow shear suppression of anomalous transport. The periodic ELM crashes are triggered by MHD instabilities. Two mechanisms for triggering ELMs are considered: ELMs are triggered by ballooning modes if the pressure gradient exceeds the ballooning threshold or by peeling modes if the edge current density exceeds the peeling mode threshold. The BALOO, DCON, and ELITE ideal MHD stability codes are used to derive a new parametric expression for the peeling-ballooning threshold. The new dependence for the peeling-ballooning threshold is implemented in the ASTRA transport code. Results of integrated modeling of DIII-D like discharges are presented and compared with experimental observations. The results from the ideal MHD stability codes are compared with results from the resistive MHD stability code NIMROD. (author)

Slippery Elm

Science.gov (United States)

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, ...

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

Energy Technology Data Exchange (ETDEWEB)

Baylor, Larry R. [ORNL; Lang, P. [EURATOM / UKAEA, Abingdon, UK; Allen, S. L. [Lawrence Livermore National Laboratory (LLNL); Lasnier, C. J. [Lawrence Livermore National Laboratory (LLNL); Meitner, Steven J. [ORNL; Combs, Stephen Kirk [ORNL; Commaux, Nicolas JC [ORNL; Loarte, A. [ITER Organization, Cadarache, France; Jernigan, Thomas C. [ORNL

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 is 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.

A review of models for ELMs

International Nuclear Information System (INIS)

Connor, J.W.

1997-04-01

The improved confinement regime known as the H-mode is often perturbed by the onset of a quasi-periodic series of relaxation oscillations involving bursts of MHD activity and D α emission known as edge localised modes (ELMs). The result in rapid losses of particles and energy from the region near the plasma boundary, reducing the average global energy confinement by 10-20%. Furthermore these transient burst of energy and particles into the scrape-off layer produce high peak heat loads on the divertor plates which must be accommodated by the divertor design. However, the ELMs are efficient, and beneficial, in removing density and impurities. Thus they are deemed necessary for the stationary operation of ITER, preventing the build up of density, impurities and helium ash. It is therefore desirable to be able to control the level and nature of the ELM activity in order to meet these various conflicting conditions; this would be aided by understanding their cause. After describing the phenomenology of ELMs, various theoretical models that have been proposed to explain them are discussed. These fall into three broad classes. Since ELMs are accompanied by bursts of magnetic activity, the first class of models involves the excitation of various MHD instabilities: ideal and resistive ballooning modes, external kink modes and so-called 'peeling modes'. Such models envisage the application of auxiliary heating driving the equilibrium to a state which triggers some such instability, resulting in the loss of plasma, followed by a recovery stage until the cycle is repeated; thus this description of the ELM cycle is merely conceptual. The second class of models involves limit cycle solutions of the transport equations governing the plasma edge region, exploiting the bifurcations inherent in theories of the L-H transition, eg those involving sheared rotation stabilisation. In the third class elements of both types of theory have been combined, with MHD or pressure driven

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

Science.gov (United States)

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

2012-01-01

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

Ulmus crassifolia Nutt. Cedar Elm

Science.gov (United States)

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...

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-12-15

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

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

International Nuclear Information System (INIS)

Kanabar, Deven; Roy, Swati; Ghate, Mahesh; Raj, Piyush; Kundu, Ananya; Kumar, Nitish; Bhavsar, Dhaval; Panchal, Arun; Pradhan, Subrata

2016-01-01

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

Exhaust, ELM and Halo physics using the MAST tokamak

International Nuclear Information System (INIS)

Counsell, G.F.; Ahn, J-W.; Kirk, A.; Helander, P.; Martin, R.; Tabasso, A.; Wilson, H.R.; Cohen, R.H.; Ryutov, D.D.; Yang, Y.

2003-01-01

The scrape-off layer (Sol) and divertor target plasma of a large spherical tokamak (ST) is characterised in detail for the first time. Scalings for the SOL heat flux width in MAST are developed and compared to conventional tokamaks. Modelling reveals the significance of the mirror force to the ST SOL. Core energy losses, including during ELMs, in MAST arrive predominantly (>80%) to the outboard targets in all geometries. Convective transport dominates energy losses during ELMs and MHD analysis suggests ELMs in MAST are Type III even at auxiliary heating powers well above the L-H threshold. ELMs are associated with a poloidally and/or toroidally localised radial efflux at ∼1 km/s well into the far SOL but not with any broadening of the target heat flux width. Toroidally asymmetric divertor biasing experiments have been conducted in an attempt to broaden the target heat flux width, with promising results. During vertical displacement events, the maximum product of the toroidal peaking factor and halo current fraction remains below 0.3, around half the ITER design limit. Evidence is presented that the resistance of the halo current path may have an impact on the distribution of halo current. (author)

ELM frequency dependence on toroidal rotation in the grassy ELM regime in JT-60U

International Nuclear Information System (INIS)

Oyama, N; Kamada, Y; Isayama, A; Urano, H; Koide, Y; Sakamoto, Y; Takechi, M; Asakura, N

2007-01-01

A systematic study of the effect of the level of toroidal plasma rotation at the top of the ion temperature pedestal ( T i ped ) on the edge localised mode (ELM) characteristics in JT-60U has been performed. The level of toroidal plasma rotation was varied by using different combinations of tangential and perpendicular neutral beam injection (NBI). In the grassy ELM regime at high triangularity (δ) and high safety factor (q), the ELM frequency clearly increased up to 1400 Hz, when counter (ctr) plasma rotation was increased. The response of the ELM frequency was independent of poloidal beta (β p ) in the range 0.84 p 0.53. Even in non-rotating plasma with balanced-NBIs, a high ELM frequency of ∼400 Hz was observed without a large energy loss. When the frequency of the plasma rotation in the co-direction of the plasma current became higher than ∼1 kHz, type I ELMs with a frequency of ∼20 Hz was observed. The achieved pedestal pressure and plasma confinement were similar both in plasmas with type I ELMs and in plasmas with grassy ELMs. The energy loss due to grassy ELMs was evaluated from the reduction in the electron temperature, and the ratio of the energy loss to the pedestal stored energy was less than 1%

Exhaust, ELM and halo physics using the MAST tokamak

International Nuclear Information System (INIS)

Counsell, G. F.

2002-01-01

Scalings for the SOL width on MAST extend the parameter range of conventional devices but confirm a negative dependence on power flow across the separatrix. In L-mode and at ELM peaks, >95% of power to the targets arrives to the outboard side. Peak heat flux densities rise by a factor 2∼6 during ELMs and are accompanied by a shift in the strike-point location but by little change in the target heat flux width. Energy loss per ELM as a percentage of pedestal energy and pedestal collisionality appear uncorrelated, possibly because ELMs on MAST are dominated by convective transport. Modelling shows that parallel gradients in the magnitude of the magnetic field in MAST may drive strong upstream flows. Broadening of the target heat flux width by divertor biasing is being explored as a means of reducing target power loading in next-step devices and has facilitated halo current measurements using series resistors. Halo currents are always less than 30% of plasma current and the product of toroidal peaking factor and halo current fraction is ∼50% of the ITER design limit. Varying the series resistance demonstrates that the VDE behaves more as a voltage source than a current source. (author)

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

Science.gov (United States)

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...

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

Science.gov (United States)

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

2017-01-01

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

Theory-based model for the pedestal, edge stability and ELMs in tokamaks

International Nuclear Information System (INIS)

Pankin, A.Y.; Bateman, G.; Brennan, D.P.; Schnack, D.D.; Snyder, P.B.; Voitsekhovitch, I.; Kritz, A.H.; Janeschitz, G.; Kruger, S.; Onjun, T.; Pacher, G.W.; Pacher, H.D.

2006-01-01

An improved model for triggering edge localized mode (ELM) crashes is developed for use within integrated modelling simulations of the pedestal and ELM cycles at the edge of H-mode tokamak plasmas. The new model is developed by using the BALOO, DCON and ELITE ideal MHD stability codes to derive parametric expressions for the ELM triggering threshold. The whole toroidal mode number spectrum is studied with these codes. The DCON code applies to low mode numbers, while the BALOO code applies to only high mode numbers and the ELITE code applies to intermediate and high mode numbers. The variables used in the parametric stability expressions are the normalized pressure gradient and the parallel current density, which drive ballooning and peeling modes. Two equilibria motivated by DIII-D geometry with different plasma triangularities are studied. It is found that the stable region in the high triangularity discharge covers a much larger region of parameter space than the corresponding stability region in the low triangularity discharge. The new ELM trigger model is used together with a previously developed model for pedestal formation and ELM crashes in the ASTRA integrated modelling code to follow the time evolution of the temperature profiles during ELM cycles. The ELM frequencies obtained in the simulations of low and high triangularity discharges are observed to increase with increasing heating power. There is a transition from second stability to first ballooning mode stability as the heating power is increased in the high triangularity simulations. The results from the ideal MHD stability codes are compared with results from the resistive MHD stability code NIMROD

Different ELM regimes at ASDEX upgrade and their linear stability analysis

International Nuclear Information System (INIS)

Burckhart, Andreas O.

2013-01-01

the theory, as the equilibrium becomes more stable against peeling-ballooning modes, the ELM frequency actually increases. Other scenarios in which peeling-ballooning modes are not thought to be the ELM trigger are also examined. In discharges featuring type-II and type-III ELMs the edge pressure gradient and current density are well below the threshold for peeling-ballooning instabilities, consistent with expectations. This indicates that other mechanisms must be present that prevent the kinetic profiles from building up. The behaviour of the analysed type-III ELMs is consistent with the hypothesis that they are driven by resistive interchange modes. The feasibility of triggering ELMs via frozen deuterium pellets is also examined in detail. In discharges performed when the walls of AUG were protected by carbon tiles, pellets triggered ELMs whenever they were injected into an H-mode plasma. In the tungsten-walled AUG, however, it is only possible to trigger ELMs after a specific lag time has elapsed since the previous ELM. This lag time can be significantly reduced, though not eliminated, when injecting nitrogen into the divertor. In the tungsten-walled AUG, with and without nitrogen, it is possible to trigger ELMs via pellets when the pedestal pressure gradient and the edge current density are 20% below the threshold for spontaneous ELMs. Since the ELM-induced collapse of the plasma edge pressure profile is strongest in the unseeded tungsten machine and the profile recovery is slower, the lag time for successful triggering is longer. Recent extrapolations of the ITER pedestal are also tested using the peeling-ballooning model. It is found that the predictions are very optimistic, but that stability could be achieved with temperatures and densities which are 30% lower than in the extrapolations. Some of the results presented in this thesis question the validity of the peeling-ballooning theory. In many of the presented cases, ELMs occur well below the threshold for

Different ELM regimes at ASDEX upgrade and their linear stability analysis

Energy Technology Data Exchange (ETDEWEB)

Burckhart, Andreas O.

2013-12-16

the theory, as the equilibrium becomes more stable against peeling-ballooning modes, the ELM frequency actually increases. Other scenarios in which peeling-ballooning modes are not thought to be the ELM trigger are also examined. In discharges featuring type-II and type-III ELMs the edge pressure gradient and current density are well below the threshold for peeling-ballooning instabilities, consistent with expectations. This indicates that other mechanisms must be present that prevent the kinetic profiles from building up. The behaviour of the analysed type-III ELMs is consistent with the hypothesis that they are driven by resistive interchange modes. The feasibility of triggering ELMs via frozen deuterium pellets is also examined in detail. In discharges performed when the walls of AUG were protected by carbon tiles, pellets triggered ELMs whenever they were injected into an H-mode plasma. In the tungsten-walled AUG, however, it is only possible to trigger ELMs after a specific lag time has elapsed since the previous ELM. This lag time can be significantly reduced, though not eliminated, when injecting nitrogen into the divertor. In the tungsten-walled AUG, with and without nitrogen, it is possible to trigger ELMs via pellets when the pedestal pressure gradient and the edge current density are 20% below the threshold for spontaneous ELMs. Since the ELM-induced collapse of the plasma edge pressure profile is strongest in the unseeded tungsten machine and the profile recovery is slower, the lag time for successful triggering is longer. Recent extrapolations of the ITER pedestal are also tested using the peeling-ballooning model. It is found that the predictions are very optimistic, but that stability could be achieved with temperatures and densities which are 30% lower than in the extrapolations. Some of the results presented in this thesis question the validity of the peeling-ballooning theory. In many of the presented cases, ELMs occur well below the threshold for

ELM triggering conditions for the integrated modeling of H-mode plasmas

International Nuclear Information System (INIS)

Pankin, A.Y.; Schnack, D.D.; Bateman, G.; Kritz, A.H.; Brennan, D.P.; Snyder, P.B.; Voitsekhovitch, I.; Kruger, S.; Janeschitz, G.; Onjun, T.; Pacher, G.W.; Pacher, H.D.

2004-01-01

Recent advances in the integrated modeling of ELMy (edge localized mode) H-mode plasmas are presented. A model for the H-mode pedestal and for the triggering of ELMs predicts the height, width, and shape of the H-mode pedestal and the frequency and width of ELMs. Formation of the pedestal and the L-H transition is the direct result of E r x B flow shear suppression of anomalous transport. The periodic ELM crashes are triggered by either the ballooning or peeling MHD instabilities. The BALOO, DCON, and ELITE ideal MHD stability codes are used to derive a new parametric expression for the peeling-ballooning threshold. The new dependence for the peeling-ballooning threshold is implemented in the ASTRA transport code. Results of integrated modeling of DIII-D like discharges are presented and compared with experimental observations. The results from the ideal MHD stability codes are compared with results from the resistive MHD stability code NIMROD. (authors)

ELMs and the H-mode pedestal in NSTX

International Nuclear Information System (INIS)

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

2005-01-01

We report on the behavior of ELMs in NBI-heated H-mode plasmas in NSTX. It is observed that the size of Type I ELMs, characterized by the change in plasma energy, decreases with increasing line-average density, as observed at conventional aspect ratio. It is also observed that the Type I ELM size decreases as the plasma equilibrium is shifted from a symmetric double-null toward a lower single-null configuration. Type II/III ELMs have also been observed in NSTX, as well as a high-performance regime with small ELMs which we designate Type V. The Type V ELMs are characterized by an intermittent n 1 magnetic pre-cursor oscillation rotating counter to the plasma current; the mode vanishes between Type V ELMs crashes. Without active pumping, the density rises continuously through the Type V phase, albeit at a slower rate than ELM-free discharges

Automated recognition system for ELM classification in JET

International Nuclear Information System (INIS)

Duro, N.; Dormido, R.; Vega, J.; Dormido-Canto, S.; Farias, G.; Sanchez, J.; Vargas, H.; Murari, A.

2009-01-01

Edge localized modes (ELMs) are instabilities occurring in the edge of H-mode plasmas. Considerable efforts are being devoted to understanding the physics behind this non-linear phenomenon. A first characterization of ELMs is usually their identification as type I or type III. An automated pattern recognition system has been developed in JET for off-line ELM recognition and classification. The empirical method presented in this paper analyzes each individual ELM instead of starting from a temporal segment containing many ELM bursts. The ELM recognition and isolation is carried out using three signals: Dα, line integrated electron density and stored diamagnetic energy. A reduced set of characteristics (such as diamagnetic energy drop, ELM period or Dα shape) has been extracted to build supervised and unsupervised learning systems for classification purposes. The former are based on support vector machines (SVM). The latter have been developed with hierarchical and K-means clustering methods. The success rate of the classification systems is about 98% for a database of almost 300 ELMs.

Adaptive Online Sequential ELM for Concept Drift Tackling

Directory of Open Access Journals (Sweden)

Arif Budiman

2016-01-01

Full Text Available 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.

Inter-ELM evolution of the edge current density profile on the ASDEX Upgrade tokamak

International Nuclear Information System (INIS)

Dunne, Michael G.

2014-01-01

The sudden decrease of plasma stored energy and subsequent power deposition on the first wall of a tokamak device due to edge localised modes (ELMs) is potentially detrimental to the success of a future fusion reactor. Understanding and control of ELMs is critical for the longevity of these devices and also to maximise their performance. The commonly accepted picture of ELMs posits a critical pressure gradient and current density in the plasma edge, above which coupled magnetohydrodynamic (MHD) peeling-ballooning modes are driven unstable. Much analysis has been presented in recent years on the spatial and temporal evolution of the edge pressure gradient. However, the edge current density has typically been overlooked due to the difficulties in measuring this quantity. In this thesis, a novel method of current density recovery is presented, using the equilibrium solver CLISTE to reconstruct a high resolution equilibrium utilising both external magnetic and internal edge kinetic data measured on the ASDEX Upgrade (AUG) tokamak. The evolution of the edge current density relative to an ELM crash is presented, showing that a resistive delay in the buildup of the current density is unlikely. An uncertainty analysis shows that the edge current density can be determined with an accuracy consistent with that of the kinetic data used. A comparison with neoclassical theory demonstrates excellent agreement between the current density determined by CLISTE and the calculated profiles. Three ELM mitigation regimes are investigated: Type-II ELMs, ELMs suppressed by external magnetic perturbations (MPs), and Nitrogen seeded ELMs. In the first two cases, the current density is found to decrease as mitigation onsets, indicating a more ballooning-like plasma behaviour. In the latter case, the flux surface averaged current density can decrease while the local current density increases, thus providing a mechanism to suppress both the peeling and ballooning modes.

Inter-ELM evolution of the edge current density profile on the ASDEX Upgrade tokamak

Energy Technology Data Exchange (ETDEWEB)

Dunne, Michael G.

2014-02-15

The sudden decrease of plasma stored energy and subsequent power deposition on the first wall of a tokamak device due to edge localised modes (ELMs) is potentially detrimental to the success of a future fusion reactor. Understanding and control of ELMs is critical for the longevity of these devices and also to maximise their performance. The commonly accepted picture of ELMs posits a critical pressure gradient and current density in the plasma edge, above which coupled magnetohydrodynamic (MHD) peeling-ballooning modes are driven unstable. Much analysis has been presented in recent years on the spatial and temporal evolution of the edge pressure gradient. However, the edge current density has typically been overlooked due to the difficulties in measuring this quantity. In this thesis, a novel method of current density recovery is presented, using the equilibrium solver CLISTE to reconstruct a high resolution equilibrium utilising both external magnetic and internal edge kinetic data measured on the ASDEX Upgrade (AUG) tokamak. The evolution of the edge current density relative to an ELM crash is presented, showing that a resistive delay in the buildup of the current density is unlikely. An uncertainty analysis shows that the edge current density can be determined with an accuracy consistent with that of the kinetic data used. A comparison with neoclassical theory demonstrates excellent agreement between the current density determined by CLISTE and the calculated profiles. Three ELM mitigation regimes are investigated: Type-II ELMs, ELMs suppressed by external magnetic perturbations (MPs), and Nitrogen seeded ELMs. In the first two cases, the current density is found to decrease as mitigation onsets, indicating a more ballooning-like plasma behaviour. In the latter case, the flux surface averaged current density can decrease while the local current density increases, thus providing a mechanism to suppress both the peeling and ballooning modes.

Non-linear simulations of ELMs in ASDEX upgrade

Energy Technology Data Exchange (ETDEWEB)

Lessig, Alexander; Hoelzl, Matthias; Orain, Francois; Guenter, Sibylle [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstrasse 2, 85748 Garching (Germany); Becoulet, Marina; Huysmans, Guido [CEA-IRFM, Cadarache, 13108 Saint-Paul-Lez-Durance (France); Collaboration: the ASDEX Upgrade Team

2016-07-01

Large edge localized modes (ELMs) are a severe concern for the operation of future tokamak devices like ITER or DEMO due to the high transient heat loads induced on divertor targets and wall structures. It is therefore important to study ELMs both theoretically and experimentally in order to obtain a comprehensive understanding of the underlying mechanisms which is necessary for the prediction of ELM properties and the design of ELM mitigation systems. Using the non-linear MHD code JOREK, we have performed first simulations of full ELM crashes in ASDEX Upgrade, taking into account a large number of toroidal Fourier harmonics. The evolution of the toroidal mode spectrum has been investigated. In particular, we confirm the previously observed non-linear drive of linearly sub-dominant low-n components in the early non-linear phase of the ELM crash. Preliminary comparisons of the simulations with experimental observations regarding heat and particle losses, pedestal evolution and heat deposition patterns are shown. On the long run we aim at code validation as well as an improved understanding of the ELM dynamics and possibly a better characterization of different ELM types.

ELMs IN DIII-D HIGH PERFORMANCE DISCHARGES

International Nuclear Information System (INIS)

TURNBULL, A.D; LAO, L.L; OSBORNE, T.H; SAUTER, O; STRAIT, E.J; TAYLOR, T.S; CHU, M.S; FERRON, J.R; GREENFIELD, C.M; LEONARD, A.W; MILLER, R.L; SNYDER, P.B; WILSON, H.R; ZOHM, H

2003-01-01

A new understanding of edge localized modes (ELMs) in tokamak discharges is emerging [P.B. Snyder, et al., Phys. Plasmas, 9, 2037 (2002)], in which the ELM is an essentially ideal magnetohydrodynamic (MHD) instability and the ELM severity is determined by the radial width of the linearly unstable MHD kink modes. A detailed, comparative study of the penetration into the core of the respective linear instabilities in a standard DIII-D ELMing, high confinement mode (H-mode) discharge, with that for two relatively high performance discharges shows that these are also encompassed within the framework of the new model. These instabilities represent the key, limiting factor in extending the high performance of these discharges. In the standard ELMing H-mode, the MHD instabilities are highly localized in the outer few percent flux surfaces and the ELM is benign, causing only a small temporary drop in the energy confinement. In contrast, for both a very high confinement mode (VH-mode) and an H-mode with a broad internal transport barrier (ITB) extending over the entire core and coalesced with the edge transport barrier, the linearly unstable modes penetrate well into the mid radius and the corresponding consequences for global confinement are significantly more severe. The ELM accordingly results in an irreversible loss of the high performance

The effect of ELMs on energy confinement in JET

International Nuclear Information System (INIS)

Zhang, W.; Tubbing, B.J.D.; Ward, D.J.

1998-01-01

The effect of ELMs on energy confinement in JET has been analysed. ELMs are characterized using D α emission which is decomposed into two components, a baseline level with superimposed pulses due to the ELMs. The analysis of the experimental data shows that the D α baseline, which reflects the neutral pressure at the plasma edge, is an important parameter in determining the energy confinement deterioration. The origin of the D α baseline is either from the neutralization of plasma particles which are expelled by the ELM pulses, or from external gas puffing. An ELM severity parameter, taking into account both the D α baseline and the ELM pulses, is defined. The energy confinement time normalized to the energy confinement time of ELM free phase, τ B /τ H , decreases linearly as the ELM severity increases. The results are independent of divertor configurations. (author)

Survey of Type I ELM dynamics measurements

International Nuclear Information System (INIS)

Leonard, A W; Asakura, N; Boedo, J A; Becoulet, M; Counsell, G F; Eich, T; Fundamenski, W; Herrmann, A; Horton, L D; Kamada, Y; Kirk, A; Kurzan, B; Loarte, A; Neuhauser, J; Nunes, I; Oyama, N; Pitts, R A; Saibene, G; Silva, C; Snyder, P B; Urano, H; Wade, M R; Wilson, H R

2006-01-01

This report summarizes Type I edge localized mode (ELM) dynamics measurements from a number of tokamaks, including ASDEX-Upgrade, DIII-D, JET, JT-60U and MAST, with the goal of providing guidance and insight for the development of ELM simulation and modelling. Several transport mechanisms are conjectured to be responsible for ELM transport, including convective transport due to filamentary structures ejected from the pedestal, parallel transport due to edge ergodization or magnetic reconnection and turbulent transport driven by the high edge gradients when the radial electric field shear is suppressed. The experimental observations are assessed for their validation, or conflict, with these ELM transport conjectures

ELM-Induced Plasma Wall Interactions in DIII-D

International Nuclear Information System (INIS)

Rudakov, D.L.; Boedo, J.A.; Yu, J.H.; Brooks, N.H.; Fenstermacher, M.E.; Groth, M.; Hollmann, E.M.; Lasnier, C.J.; McLean, A.G.; Moyer, R.A.; Stangeby, P.C.; Tynan, G.R.; Wampler, W.R.; Watkins, J.G.; West, W.P.; Wong, C.C.; Zeng, L.; Bastasz, R.J.; Buchenauer, D.; Whaley, J.

2008-01-01

Intense transient fluxes of particles and heat to the main chamber components induced by edge localized modes (ELMs) are of serious concern for ITER. In DIII-D, plasma interaction with the outboard chamber wall is studied using Langmuir probes and optical diagnostics including a fast framing camera. Camera data shows that ELMs feature helical filamentary structures localized at the low field side of the plasma and aligned with the local magnetic field. During the nonlinear phase of an ELM, multiple filaments are ejected from the plasma edge and propagate towards the outboard wall with velocities of 0.5-0.7 km/s. When reaching the wall, filaments result in 'hot spots'--regions of local intense plasma-material interaction (PMI) where the peak incident particle and heat fluxes are up to 2 orders of magnitude higher than those between ELMs. This interaction pattern has a complicated geometry and is neither toroidally nor poloidally symmetric. In low density/collisionality H-mode discharges, PMI at the outboard wall is almost entirely due to ELMs. In high density/collisionality discharges, contributions of ELMs and inter-ELM periods to PMI at the wall are comparable. A Midplane Material Evaluation Station (MiMES) has been recently installed in order to conduct in situ measurements of erosion/redeposition at the outboard chamber wall, including those caused by ELMs

Fast dynamics of Type I ELM and transport of ELM pulse in JT-60U

International Nuclear Information System (INIS)

Oyama, N.

2002-01-01

The mitigation of the large ELM heat load on the divertor target is one of the most important issues to be overcome on ITER. Since the ELM heat load strikes the divertor target not as a time-averaged load but as an instantaneous heat pulse, the evaluation of both ELM energy, and the time scale of the collapse and transport is very important. In JT-60U, the detailed dynamic behaviors of the collapse were measured using O-mode reflectometer. The duration of the collapse was within 0.35 ms and the lost pedestal density was recovered quickly within 0.5 ms. The collapse reached 10 cm inside the separatrix, which corresponds to twice the pedestal width of 5 cm. Dedicated edge density measurements on high- and low-field side revealed the poloidal asymmetry of the collapse of density pedestal for the first time. The measurement of SOL flow and heat load to the divertor target by using SOL Mach probe and IRTV showed that convective transport of the SOL plasma gave large contribution to the ELM heat deposition process. (author)

Toroidally asymmetric ELM precursor oscillations in the TCV tokamak

International Nuclear Information System (INIS)

Reimerdes, H.; Pochelon, A.; Guittienne, P.; Weisen, H.; Suttrop, W.

1997-01-01

In TCV ohmic H-modes have been obtained in diverted single-null (SND), double-null (DND), and elongated limited plasma configurations. In ELM-free H-modes the particle density rises continuously until the discharge usually terminates with a high density disruption. Quasi-stationary H-modes have been obtained in the presence of ELMs. The observed ELM spectrum is continuous and ranges from clearly identifiable type III ELMs to low frequency, large ELMs. The necessity of ELMs for particle control of H-mode plasmas while causing high peak-power loads on strike points makes the control of their level and nature desirable and motivates the study of the underlying MHD-instability. Prior to ELMs in TCV coherent magnetic oscillations, that indicate a rapidly growing MHD instability, have been observed. The structure of these precursor oscillation is investigated with TCV's Mirnov probe arrays. In particular an observed toroidal asymmetry in the growth of the instability has to be explained. (author) 2 figs., 6 refs

Hyperparameterization of soil moisture statistical models for North America with Ensemble Learning Models (Elm)

Science.gov (United States)

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.

Effect of pedestal fluctuation on ELM frequency in the EAST tokamak

Science.gov (United States)

Zhong, F. B.; Zhang, T.; Liu, Z. X.; Qu, H.; Liu, H. Q.; Li, G. Q.; Liu, Y.; Gao, W.; Duan, Y. M.; Yang, Y.; Zeng, L.; Xiang, H. M.; Geng, K. N.; Wen, F.; Zhang, S. B.; Gao, X.; the EAST Team

2018-05-01

The dependence of ELM frequency on heating power has been studied on the Experimental Advanced Superconducting Tokamak (EAST). It is found that the ELM frequency (f ELM) generally increases with the power through separatrix (P sep), indicating type-I ELM in these plasmas. However, there are two data points, named ‘abnormal ELM’ in the present paper, which have much lower f ELM than the ‘normal ELM’, while both types of ELM have similar ELM energy losses. The ‘abnormal ELM’ occurs at a phase with increased radiation power due to metal impurity influx events. The increased radiation power cannot explain the much lower f ELM for ‘abnormal ELM’, since the reduction of P sep is weaker than proportional to the observed reduction of the ELM frequency. The ‘abnormal ELM’ feature can be attributed to the enhanced amplitude of a coherent mode in the pedestal region. Comparing the pedestal evolutions for the two types of ELM with similar separatrix power P sep, it is actually found that the more pronounced pedestal coherent mode in the plasma with ‘abnormal ELM’ leads to a slower pressure pedestal recovery during the inter-ELM phase. This experimental result implies that the physical mechanism for ‘abnormal ELM’ is that the more pronounced pedestal fluctuation induces larger outward transport, slows down the pedestal evolution and leads to longer inter-ELM phase, i.e. lower ELM frequency.

ELM Dynamics in TCV H-modes

Science.gov (United States)

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 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.

Manufacture of mineral-insulated conductor for ITER prototype ELM and VS coil

International Nuclear Information System (INIS)

Long, Feng; Wu, Yu; Jin, Huan; Yu, Min; Han, Qiyang; Ling, Feng; Kalish, Michael

2015-01-01

Highlights: • Compaction method is successfully developed for MIC manufacture. • Manufactured MICs show well controlled outer diameter and good electrical properties. • Insulation resistance of all the MICs is higher than 100 GΩ@DC 2500 V. - Abstract: An ITER Organization (IO) Task Agreement (TA) “Final Design and Prototyping of the ITER In-Vessel Coils (IVC) and Feeders” is almost finished by Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). ITER IVCs consist of edge-localized mode (ELM) and vertical stabilization (VS) coils. One prototype Mid-ELM coil complete with 19 brackets brazed with the conductors and one prototype 120° section of upper VS coil with structural components brazed to the conductors have been fabricated. Compaction method is developed successfully for the mineral-insulated conductor (MIC) manufacture. Approximate 110 m Inconel 625 jacket MICs for Mid-ELM prototype coil and 80 m stainless steel 316L jacket MICs for VS prototype coil were manufactured. Most of the copper tubes used for the MICs fabrication failed the ultrasonic testing (UT), but the jacket tubes have good passing rate. Manufacture processes and inspection for the MICs are presented in this paper

Manufacture of mineral-insulated conductor for ITER prototype ELM and VS coil

Energy Technology Data Exchange (ETDEWEB)

Long, Feng, E-mail: longf@ipp.ac.cn [Institute of Plasma Physics of Chinese Academy of Sciences, Hefei 230031 (China); Wu, Yu; Jin, Huan; Yu, Min; Han, Qiyang; Ling, Feng [Institute of Plasma Physics of Chinese Academy of Sciences, Hefei 230031 (China); Kalish, Michael [Princeton Plasma Physics Laboratory, PO Box 451, Princeton, NJ 08543 (United States)

2015-06-15

Highlights: • Compaction method is successfully developed for MIC manufacture. • Manufactured MICs show well controlled outer diameter and good electrical properties. • Insulation resistance of all the MICs is higher than 100 GΩ@DC 2500 V. - Abstract: An ITER Organization (IO) Task Agreement (TA) “Final Design and Prototyping of the ITER In-Vessel Coils (IVC) and Feeders” is almost finished by Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). ITER IVCs consist of edge-localized mode (ELM) and vertical stabilization (VS) coils. One prototype Mid-ELM coil complete with 19 brackets brazed with the conductors and one prototype 120° section of upper VS coil with structural components brazed to the conductors have been fabricated. Compaction method is developed successfully for the mineral-insulated conductor (MIC) manufacture. Approximate 110 m Inconel 625 jacket MICs for Mid-ELM prototype coil and 80 m stainless steel 316L jacket MICs for VS prototype coil were manufactured. Most of the copper tubes used for the MICs fabrication failed the ultrasonic testing (UT), but the jacket tubes have good passing rate. Manufacture processes and inspection for the MICs are presented in this paper.

QUANTITATIVE TESTS OF ELMs AS INTERMEDIATE n PEELING-BALOONING MODES

International Nuclear Information System (INIS)

LAO, LL; SNYDER, PB; LEONARD, AW; OIKAWA, T; OSBORNE, TH; PETRIE, TW; FERRON, JR; GROEBNER, RJ; HORTON, LD; KAMADA, Y; MURAKAMI, M; SAARELMA, S; STJOHN, HE; TURNBULL, AD; WILSON, HR

2003-01-01

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 become significantly large. These testable features are consistent with many ELM observations in DIII-D and JT-60U discharges

Distinguishing deterministic and noise components in ELM time series

International Nuclear Information System (INIS)

Zvejnieks, G.; Kuzovkov, V.N

2004-01-01

Full text: One of the main problems in the preliminary data analysis is distinguishing the deterministic and noise components in the experimental signals. For example, in plasma physics the question arises analyzing edge localized modes (ELMs): is observed ELM behavior governed by a complicate deterministic chaos or just by random processes. We have developed methodology based on financial engineering principles, which allows us to distinguish deterministic and noise components. We extended the linear auto regression method (AR) by including the non-linearity (NAR method). As a starting point we have chosen the nonlinearity in the polynomial form, however, the NAR method can be extended to any other type of non-linear functions. The best polynomial model describing the experimental ELM time series was selected using Bayesian Information Criterion (BIC). With this method we have analyzed type I ELM behavior in a subset of ASDEX Upgrade shots. Obtained results indicate that a linear AR model can describe the ELM behavior. In turn, it means that type I ELM behavior is of a relaxation or random type

MHD stability analysis of ELMs in MAST

International Nuclear Information System (INIS)

Saarelma, S; Hender, T C; Kirk, A; Meyer, H; Wilson, H R; Team, MAST

2007-01-01

In this paper, edge stability analyses of the MAST tokamak plasmas are presented. The analyses show that the experimental equilibrium prior to an edge localized mode (ELM) is unstable against very narrow peeling modes with low growth rate. When the edge pressure gradient becomes steeper, wider peeling-ballooning modes with larger growth rate become unstable. These modes are the likely triggers of ELMs. In the analyses the required pressure increase for destabilization is sensitive to how the X-point is modelled in the equilibrium reconstruction. A 'sharp' X-point approximation is more stable against the peeling-ballooning modes than a 'round' one. An experimental ELM-free single null plasma is significantly more stable against the peeling-ballooning modes than the double null plasma, but this is unlikely to be directly due to the single null geometry but rather due to the different plasma profiles. Sheared toroidal rotation is able to stabilize the peeling-ballooning modes. This suggests the following model for the ELM triggering: the rotation shear keeps the edge stable until the pressure gradient has sufficiently exceeded the stability boundary for the static plasma. When the mode becomes unstable, it starts to grow, ties the flux surfaces together and flattens the rotation profile. This further destabilizes the edge plasma leading to an ELM crash

Peeling mode relaxation ELM model

International Nuclear Information System (INIS)

Gimblett, C. G.

2006-01-01

This paper discusses an approach to modelling Edge Localised Modes (ELMs) in which toroidal peeling modes are envisaged to initiate a constrained relaxation of the tokamak outer region plasma. Relaxation produces both a flattened edge current profile (which tends to further destabilise a peeling mode), and a plasma-vacuum negative current sheet which has a counteracting stabilising influence; the balance that is struck between these two effects determines the radial extent (rE) of the ELM relaxed region. The model is sensitive to the precise position of the mode rational surfaces to the plasma surface and hence there is a 'deterministic scatter' in the results that has an accord with experimental data. The toroidal peeling stability criterion involves the edge pressure, and using this in conjunction with predictions of rE allows us to evaluate the ELM energy losses and compare with experiment. Predictions of trends with the edge safety factor and collisionality are also made

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

Science.gov (United States)

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.

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

International Nuclear Information System (INIS)

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

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

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

Energy Technology Data Exchange (ETDEWEB)

Bu, Yude [School of Mathematics and Statistics, Shandong University, Weihai, 264209, Shandong (China); Zhao, Gang; Kumar, Yerra Bharat [Key Laboratory for Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012 (China); Pan, Jingchang, E-mail: ydbu@bao.ac.cn, E-mail: gzhao@nao.cas.cn [School of Mechanical, Electrical and Information Engineering, Shandong University, Weihai, 264209, Shandong (China)

2016-01-20

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.

ELM induced divertor heat loads on TCV

Energy Technology Data Exchange (ETDEWEB)

Marki, J., E-mail: janos.marki@epfl.c [Centre de Recherches en Physique des Plasmas (CRPP), Ecole Polytechnique Federale de Lausanne (EPFL), Association Euratom - Confederation Suisse, CH-1015 Lausanne (Switzerland); Pitts, R.A. [Centre de Recherches en Physique des Plasmas (CRPP), Ecole Polytechnique Federale de Lausanne (EPFL), Association Euratom - Confederation Suisse, CH-1015 Lausanne (Switzerland); Horacek, J. [Institute of Plasma Physics, Association EUROATOM-IPP.CR, Za Slovankou 3, 182 00 Prague 8 (Czech Republic); Tskhakaya, D. [Association EURATOM-OAW, Institut fuer Theoretische Physik, A-6020 Innsbruck (Austria)

2009-06-15

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 approx3, 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 approx1% 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.

ELM induced divertor heat loads on TCV

Science.gov (United States)

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.

ELM Dynamics in TCV H-modes

International Nuclear Information System (INIS)

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

2003-01-01

TCV (Tokamak a 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

Use of protoplast, cell, and shoot tip culture in an elm germ plasm improvement program

Science.gov (United States)

R. Daniel Lineberger; M.B. Sticklen; P.M. Pijut; Mark A. Kroggel; C.V.M. Fink; S.C. Domir

1990-01-01

An elm germplasm improvement program was established using three distinct approaches: (1) development of protoplast regeneration protocols with the goal of attempting somatic hybridization between Ulmus americana and disease resistant hybrids; (2) evaluation of the extent of somaclonal variation in plants regenerated from protoplasts; and (3)...

Simulation of tungsten armour cracking due to small ELMs in ITER

International Nuclear Information System (INIS)

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

2010-01-01

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

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

Science.gov (United States)

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.

Simulation of tungsten armour cracking due to small ELMs in ITER

Energy Technology Data Exchange (ETDEWEB)

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

2010-12-15

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

ELMs and the role of current-driven instabilities in the edge

International Nuclear Information System (INIS)

Snyder, P.B.; Wilson, H.R.

2001-01-01

Edge localized modes (ELMs) can limit tokamak performance both directly, via large transient heat loads, and indirectly, through constraints placed on the H-mode pedestal height which impact global confinement. Theoretical understanding of the physics of ELMs should allow optimisation of existing experiments, and lead to greater confidence in projections for Next Step devices. However, understanding ELMs has proved challenging, in part because the sharp edge pressure gradients and consequent large bootstrap currents in the pedestal region provide drive for a variety of modes over a wide range of toroidal mode numbers (n). Here we present a brief discussion of ELM phenomenology, focussing primarily on ELMs whose frequency increases with input power. Theories of ELMs will be reviewed, emphasizing those which incorporate current-driven instabilities such as kink or 'peeling' modes. Parallel current plays a dual role in the edge, enhancing second stability access for ballooning modes while providing drive for peeling modes. The strong collisionality dependence of the edge bootstrap current introduces separate density and temperature dependence into pedestal MHD stability. We give a detailed description of recent work on coupled peeling-ballooning modes, including a model for ELM characteristics and temperature pedestal limits. Peeling-ballooning stability analysis of experimental discharges will be discussed, emphasising comparisons of different ELM regimes, such as the comparison between 'giant' and 'grassy' ELM shots on JT-60U. (orig.)

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

Science.gov (United States)

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

2014-11-01

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

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

DEFF Research Database (Denmark)

Dinkel, Holger; Chica, Claudia; Via, Allegra

2011-01-01

The Phospho.ELM resource (http://phospho.elm.eu.org) is a relational database designed to store in vivo and in vitro phosphorylation data extracted from the scientific literature and phosphoproteomic analyses. The resource has been actively developed for more than 7 years and currently comprises ...... sequence alignment used for the score calculation. Finally, special emphasis has been put on linking to external resources such as interaction networks and other databases.......The Phospho.ELM resource (http://phospho.elm.eu.org) is a relational database designed to store in vivo and in vitro phosphorylation data extracted from the scientific literature and phosphoproteomic analyses. The resource has been actively developed for more than 7 years and currently comprises 42...

Gamma irradiating elm billets reduces their attractancy to the smaller elm bark beetle, Scolytus multistriatus (Marsham)

International Nuclear Information System (INIS)

French, J.R.J.; Robinson, P.J.

1982-01-01

Irradiating elm billets with gamma rays had a significant effect in reducing the attractancy of these billets to inflight adults of the smaller elm bark beetle Scolytus multistriatus (Marsham). The temperature at which the fresh billets were stored prior to the beetle exposure had little effect. Irradiated billets, irrespective of storage temperature, had significantly fewer holes than the freshly cut billets. There were significant differences associated with the location of the billets in the field, but these differences were smaller than those associated with irradiation. (orig.) [de

Inter-ELM pedestal structure development in ASDEX upgrade

Energy Technology Data Exchange (ETDEWEB)

Laggner, Florian Martin

2017-06-15

The performance of a magnetically confined, fusion plasma is strongly impacted by the plasma edge, which is the boundary between the hot, confined plasma and the reactor walls. In a tokamak, which uses a toroidally axis-symmetric magnetic field configuration, a regime of improved plasma confinement, the high confinement mode (H-mode), has been observed. The confinement improvement originates from an edge transport barrier (ETB), which is accompanied by steep gradients of the plasma pressure, named pedestal. The maximum sustainable pedestal, i.e. the maximum pressure gradient, is usually set by an ideal magnetohydrodynamic limit, which if exceeded is leading to edge localised modes (ELMs). ELMs are instabilities that relax the pedestal and lead to a loss of the order of 10% from the plasma stored energy. The mechanisms, which set the pedestal structure before an ELM crash, keeping the pedestal stable up to this point, are not fully understood. Here, microturbulent instabilities, e.g. kinetic ballooning modes (KBMs), are expected to play an important role. The presented PhD thesis investigates the temporal development of the pedestal density and temperature profiles in between ELM crashes at the ASDEX Upgrade tokamak. The aims were comparisons of different plasma conditions, i.e. plasma collisionality (ν{sup *}), main isotope species and plasma shapes. Further, the impact of the conditions outside the confined plasma on the pedestal development was investigated. The extensive study of these parameters resulted in one key observation: The pedestal recovers in distinct phases in between ELM crashes with always the same sequence. Immediately after the ELM crash, the electron density (n{sub e}) pedestal is established, followed by the electron temperature (T{sub e}) pedestal. Finally, a period with constant pressure gradient appears, which can vary in duration. For a large range of ν{sup *} it has been found that the onset of radial magnetic fluctuations with

Influence of the plasma pedestal parameters on ELM mitigation at low collisionality

Energy Technology Data Exchange (ETDEWEB)

Leuthold, Nils [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Universitaet Bayreuth, Universitaetsstrasse 30, 95440 Bayreuth (Germany); Suttrop, Wolfgang [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany)

2016-07-01

The control of Edge Localized Modes (ELMs) is of great importance for future fusion devices in order to provide longevity of the plasma facing components and a better overall plasma performance. In recent magnetic perturbation ELM mitigation experiments in ASDEX Upgrade at low pedestal collisionality, the dependence of ELM losses on pedestal parameters is investigated. It is found that the reduction of the stored energy loss associated with ELMs occurs in correlation with a reduction of edge density and edge pedestal pressure induced by the applied magnetic perturbation (''pedestal pump-out''). Significant ELM mitigation occurs at lowest densities, in a region of pedestal n-T parameter space that has not been accessible in ASDEX Upgrade without magnetic perturbations, and which is occupied by type-IV ELMs in DIII-D. The role of magnetic perturbations for ELM mitigation will be discussed in this context and attempts to counteract the confinement loss by increasing neutral beam injection power or pellet injection increases the ELM energy losses.

Impact of ELM filaments on divertor heat flux dynamics in NSTX

Energy Technology Data Exchange (ETDEWEB)

Ahn, J.-W., E-mail: jahn@pppl.gov [Oak Ridge National Laboratory, Oak Ridge (United States); Maingi, R. [Princeton Plasma Physics Laboratory, Princeton (United States); Canik, J.M. [Oak Ridge National Laboratory, Oak Ridge (United States); Gan, K.F. [Institute of Plasma Physics, Chinese Academy of Science, Hefei (China); Gray, T.K. [Oak Ridge National Laboratory, Oak Ridge (United States); McLean, A.G. [Lawrence Livermore National Laboratory, Livermore (United States)

2015-08-15

The ELM induced change in wetted area (A{sub wet}) and peak heat flux (q{sub peak}) of divertor heat flux is investigated as a function of the number of striations, which represent ELM filaments, observed in the heat flux profile in NSTX. More striations are found to lead to larger A{sub wet} and lower q{sub peak}. The typical number of striations observed in NSTX is 0–9, while 10–15 striations are normally observed in other machines such as JET, and the ELM contracts heat flux profile when the number of striations is less than 3–4 but broadens it with more of them. The smaller number of striations in NSTX is attributed to the fact that NSTX ELMs are against kink/peeling boundary with lower toroidal mode number (n = 1–5), while typical peeling–ballooning ELMs have higher mode number of n = 10–20. For ELMs with smaller number of striations, relative A{sub wet} change is rather constant and q{sub peak} change rapidly increases with increasing ELM size, while A{sub wet} change slightly increases leading to a weaker increase of q{sub peak} change for ELMs with larger number of striations, both of which are unfavourable trend for the material integrity of divertor tiles.

ELM-induced transient tungsten melting in the JET divertor

International Nuclear Information System (INIS)

Coenen, J.W.; Clever, M.; Knaup, M.; Arnoux, G.; Matthews, G.F.; Balboa, I.; Meigs, A.; Bazylev, B.; Autricque, A.; Dejarnac, R.; Horacek, J.; Komm, M.; Coffey, I.; Corre, Y.; Gauthier, E.; Devaux, S.; Krieger, K.; Frassinetti, L.; Jachmich, S.; Marsen, S.

2015-01-01

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 I P  = 3.0 MA/B T  = 2.9 T H-mode pulses with an input power of P IN  = 23 MW, a stored energy of ∼6 MJ and regular type I ELMs at ΔW ELM  = 0.3 MJ and f ELM  ∼ 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 mm 3 ) 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

ELM pace making and amelioration at ASDEX upgrade

Energy Technology Data Exchange (ETDEWEB)

Lang, P.T.; Gruber, O.; Haas, G.; Horton, L.D.; Kaufmann, M.; Mertens, V.; Neu, R.; Neuhauser, J.; Puetterich, T.; Schneider, W.; Sihler, C.; Sips, A.C.C.; Suttrop, W.; Treutterer, W. [Max-Planck-Institut fuer Plasmaphysik, Euratom Association, Garching (Germany); Bucalossi, J. [Association Euratom-Confederation Suisse, CRPP-EPFL, Lausanne (Switzerland); Kalvin, S.; Kocsis, G. [Association Euratom, KFKI-RMKI, Budapest (Hungary); Mc Carthy, P.J. [University College Cork, Physics Dept., Association Euratom-DCu, Cork (Ireland)

2004-07-01

Different techniques were tried to trigger ELMs (edge localized mode): injection of cryogenic solid pellets or a super-sonic molecular gas jet composed of deuterium or magnetic triggering, relying on a fast motion of the plasma column in a spatially asymmetric flux configuration. Our investigations prove externally imposed control techniques can change the ELM frequency. Frequency enhancement can result in amelioration of the single ELMs. Moreover, the approach can maintain plasma operation at a high performance level. Both pellet injection and magnetic triggering have been shown their potential to act as useful control tools. This yields the option to choose eventually the most appropriate technique for a given scenario.

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

Science.gov (United States)

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 MHD stability analysis of type I ELMS in ASDEX Upgrade Tokamak

International Nuclear Information System (INIS)

Saarelma, S.

2000-01-01

The ELMs or edge localized modes are plasma instabilities localized in the edge region of a tokamak plasma. They cause periodic expulsions of particles and energy. The ELMs play a significant role in the confinement of the plasma, helium exhaust and diverter erosion. These are crucial issues in tokamak operation and, thus, understanding the underlying physical mechanism behind the ELM phenomenon is very important. The ELMs are classified into three different types based on the plasma conditions, where they are observed, and, on the ELM frequency response to the heating power. In this thesis, type I ELMs which are the most intense and the most damaging to the diverters, are studied. A model for the ELMs presented by Connor et al. is tested in experimental ASDEX Upgrade plasmas. In the Connor model, the ELMs are explained as a result of two instabilities, ballooning and peeling modes. Also a phenomenon called the bootstrap current plays a significant role by being the destabilising trigger to the peeling modes. The method used to study the model is MHD or magnetohydrodynamics. The theory of the ideal MHD equilibrium and the linear stability analysis is described. Inclusion of the bootstrap current to the equilibrium construction is introduced. The equilibria are created using experimental data from plasma shots that display type I ELMs. The stability analysis indicates that the investigated ELM model is a feasible explanation for type I ELMs. The pressure gradient near the plasma edge was found to be close to the ballooning stability boundary as predicted by the model. The peeling mode stability analysis confirms the prediction of the model that as the bootstrap current increases, the plasma becomes unstable for peeling modes with low to intermediate toroidal mode numbers. The mode numbers agree with the experimental results. In the experiments with high triangularity, low ELM frequency and ELM-free periods were observed. This indicates better stability of the plasma

ELM-induced transient tungsten melting in the JET divertor

Science.gov (United States)

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

Probability distribution functions for ELM bursts in a series of JET tokamak discharges

International Nuclear Information System (INIS)

Greenhough, J; Chapman, S C; Dendy, R O; Ward, D J

2003-01-01

A novel statistical treatment of the full raw edge localized mode (ELM) signal from a series of previously studied JET plasmas is tested. The approach involves constructing probability distribution functions (PDFs) for ELM amplitudes and time separations, and quantifying the fit between the measured PDFs and model distributions (Gaussian, inverse exponential) and Poisson processes. Uncertainties inherent in the discreteness of the raw signal require the application of statistically rigorous techniques to distinguish ELM data points from background, and to extrapolate peak amplitudes. The accuracy of PDF construction is further constrained by the relatively small number of ELM bursts (several hundred) in each sample. In consequence the statistical technique is found to be difficult to apply to low frequency (typically Type I) ELMs, so the focus is narrowed to four JET plasmas with high frequency (typically Type III) ELMs. The results suggest that there may be several fundamentally different kinds of Type III ELMing process at work. It is concluded that this novel statistical treatment can be made to work, may have wider applications to ELM data, and has immediate practical value as an additional quantitative discriminant between classes of ELMing behaviour

Structure, stability and ELM dynamics of the H-mode pedestal in DIII-D

International Nuclear Information System (INIS)

Fenstermacher, M.E.; Leonard, A.W.; Osborne, T.H.

2005-01-01

Experiments are described that have increased understanding of the transport and stability physics that set the H-mode edge pedestal width and height, determine the onset of Type-I edge localized modes (ELMs), and produce the nonlinear dynamics of the ELM perturbation in the pedestal and scrape-off layer (SOL). Predictive models now exist for the n e pedestal profile and the p e height at the onset of Type-I ELMs, and progress has been made toward predictive models of the T e pedestal width and nonlinear ELM evolution. Similarity experiments between DIII-D and JET suggested that neutral penetration physics dominates in the relationship between the width and height of the n e pedestal while plasma physics dominates in setting the T e pedestal width. Measured pedestal conditions including edge current at ELM onset agree with intermediate-n peeling-ballooning (P-B) stability predictions. Midplane ELM dynamics data show the predicted (P-B) structure at ELM onset, large rapid variations of the SOL parameters, and fast radial propagation in later phases, similar to features in nonlinear ELM simulations. (author)

THE ELM SURVEY. III. A SUCCESSFUL TARGETED SURVEY FOR EXTREMELY LOW MASS WHITE DWARFS

International Nuclear Information System (INIS)

Brown, Warren R.; Kenyon, Scott J.; Kilic, Mukremin; Allende Prieto, Carlos

2012-01-01

Extremely low mass (ELM) white dwarfs (WDs) with masses ☉ are rare objects that result from compact binary evolution. Here, we present a targeted spectroscopic survey of ELM WD candidates selected by color. The survey is 71% complete and has uncovered 18 new ELM WDs. Of the seven ELM WDs with follow-up observations, six are short-period binaries and four have merger times less than 5 Gyr. The most intriguing object, J1741+6526, likely has either a pulsar companion or a massive WD companion making the system a possible supernova Type Ia or an Ia progenitor. The overall ELM survey has now identified 19 double degenerate binaries with <10 Gyr merger times. The significant absence of short orbital period ELM WDs at cool temperatures suggests that common envelope evolution creates ELM WDs directly in short period systems. At least one-third of the merging systems are halo objects, thus ELM WD binaries continue to form and merge in both the disk and the halo.

Menyoal Elaboration Likelihood Model (ELM dan Teori Retorika

Directory of Open Access Journals (Sweden)

Yudi Perbawaningsih

2012-06-01

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

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

Science.gov (United States)

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.

THE ELM SURVEY. III. A SUCCESSFUL TARGETED SURVEY FOR EXTREMELY LOW MASS WHITE DWARFS

Energy Technology Data Exchange (ETDEWEB)

Brown, Warren R.; Kenyon, Scott J. [Smithsonian Astrophysical Observatory, 60 Garden St., Cambridge, MA 02138 (United States); Kilic, Mukremin [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St., Norman, OK 73019 (United States); Allende Prieto, Carlos, E-mail: wbrown@cfa.harvard.edu, E-mail: skenyon@cfa.harvard.edu, E-mail: kilic@ou.edu, E-mail: callende@iac.es [Instituto de Astrofisica de Canarias, E-38205, La Laguna, Tenerife (Spain)

2012-01-10

Extremely low mass (ELM) white dwarfs (WDs) with masses < 0.25 M{sub Sun} are rare objects that result from compact binary evolution. Here, we present a targeted spectroscopic survey of ELM WD candidates selected by color. The survey is 71% complete and has uncovered 18 new ELM WDs. Of the seven ELM WDs with follow-up observations, six are short-period binaries and four have merger times less than 5 Gyr. The most intriguing object, J1741+6526, likely has either a pulsar companion or a massive WD companion making the system a possible supernova Type Ia or an Ia progenitor. The overall ELM survey has now identified 19 double degenerate binaries with <10 Gyr merger times. The significant absence of short orbital period ELM WDs at cool temperatures suggests that common envelope evolution creates ELM WDs directly in short period systems. At least one-third of the merging systems are halo objects, thus ELM WD binaries continue to form and merge in both the disk and the halo.

An Improved Iris Recognition Algorithm Based on Hybrid Feature and ELM

Science.gov (United States)

Wang, Juan

2018-03-01

The iris image is easily polluted by noise and uneven light. This paper proposed an improved extreme learning machine (ELM) based iris recognition algorithm with hybrid feature. 2D-Gabor filters and GLCM is employed to generate a multi-granularity hybrid feature vector. 2D-Gabor filter and GLCM feature work for capturing low-intermediate frequency and high frequency texture information, respectively. Finally, we utilize extreme learning machine for iris recognition. Experimental results reveal our proposed ELM based multi-granularity iris recognition algorithm (ELM-MGIR) has higher accuracy of 99.86%, and lower EER of 0.12% under the premise of real-time performance. The proposed ELM-MGIR algorithm outperforms other mainstream iris recognition algorithms.

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

International Nuclear Information System (INIS)

Kardaun, O.J.W.F.; Itoh, S.; 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 ELMs (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 (1) larger than some threshold value and (2) larger than the corresponding probability for other types of H-mode (i.e., H-mode without ELMs or with giant ELMs). In practice, the discrimination has been performed for the ASDEX, JET and JFT-2M tokamaks (a) using four instantaneous plasma parameters (injected power P inj , magnetic field B t , plasma current I p and line averaged electron density (n-bar e ) and (b) taking also memory effects of the plasma and the distance between the plasma and the wall into account, while using variables that are normalised with respect to machine size. Generally speaking, it is found that there is a substantial overlap between the region of H-mode with small ELMs 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 ELMs. A reliable production of H-mode with only small ELMs 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 ELMs occur still requires a training sample from the device under consideration. (author) 53 refs

Structural analysis for the joint of the ITER ELM coil

Energy Technology Data Exchange (ETDEWEB)

Zhang, Shanwen, E-mail: zhangshanwen123@163.com [College of Mechanical Engineering Yangzhou University, Yangzhou 225127 (China); Song, Yuntao; Wang, Zhongwei; Ji, Xiang [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 200031 (China); Zhang, Jianfeng [College of Mechanical Engineering Yangzhou University, Yangzhou 225127 (China)

2017-01-15

Highlights: • The FE sub-model method is feasible and rapid for the joint design. • The components meet the static and fatigue criteria. • Nuclear heat is the key factor for the joint design. - Abstract: The joint is an important component of the Edge Localized Modes (ELM) coils in fusion reactor, which is used to connect the ELM coils. Like the ELM coils, the joints work in an environment with high radiation levels, high temperature and high magnetic field. These joints are mainly subject to nuclear heat from the plasma and cyclic electromagnetic (EM) loads induced by the interaction of ELM coil current with magnetic fields. Take the joint of ITER ELM coil for example. In order to assure the structural integrity of joints under these loads, it is necessary to estimate the strength and fatigue of the joints. As a local model, the joint without ELM coil is investigated by the sub-model method. Results show that the finite element sub-model method is feasible and rapid for the joint design. The maximum magnetic flux intensity occurs in the axial direction for the joint local reference, which parallels with the current and corresponds to the toroidal direction of the ITER. The two areas at the top of the Inconel sleeve appear high temperature. For the joint, the conductor, jacket and sleeve can meet the static and fatigue criteria and the joint design is valid and feasible. The thermal load from the nuclear heat is the key factor for the joint design.

Divertor load footprint of ELMs in pellet triggering and pacing experiments at JET

Energy Technology Data Exchange (ETDEWEB)

Frigione, D., E-mail: domenico.frigione@frascati.enea.it [Unità Tecnica Fusione, ENEA C.R. Frascati, via E. Fermi 45, 00044 Frascati (Roma) (Italy); Garzotti, L. [CCFE, Culham Science Centre, OX14 3DB (United Kingdom); Lennholm, M. [EFDA CSU, Culham Science Centre, OX14 3DB (United Kingdom); Alper, B. [CCFE, Culham Science Centre, OX14 3DB (United Kingdom); Artaserse, G. [Unità Tecnica Fusione, ENEA C.R. Frascati, via E. Fermi 45, 00044 Frascati (Roma) (Italy); Bennett, P. [CCFE, Culham Science Centre, OX14 3DB (United Kingdom); Giovannozzi, E. [Unità Tecnica Fusione, ENEA C.R. Frascati, via E. Fermi 45, 00044 Frascati (Roma) (Italy); Eich, T. [Max Planck Institute for Plasma Physics, Garching (Germany); Kocsis, G. [WIGNER RCP RMI, POB 49, 1525 Budapest (Hungary); Lang, P.T. [Max Planck Institute for Plasma Physics, Garching (Germany); Maddaluno, G. [Unità Tecnica Fusione, ENEA C.R. Frascati, via E. Fermi 45, 00044 Frascati (Roma) (Italy); Mooney, R. [CCFE, Culham Science Centre, OX14 3DB (United Kingdom); Rack, M. [Institut für Energieforschung – Plasmaphysik, Forschungszentrum Jülich, 52425 Jülich (Germany); Sips, G. [EFDA CSU, Culham Science Centre, OX14 3DB (United Kingdom); Tvalashvili, G. [CCFE, Culham Science Centre, OX14 3DB (United Kingdom); Viola, B. [Unità Tecnica Fusione, ENEA C.R. Frascati, via E. Fermi 45, 00044 Frascati (Roma) (Italy); Wilkes, D. [CCFE, Culham Science Centre, OX14 3DB (United Kingdom)

2015-08-15

An investigation of pellet pacing and triggering of Edge Localized Modes (ELMs) was carried out in the frame of ELM mitigation studies aimed at reducing their damaging effects on the plasma-facing components (PFCs). The divertor power load footprint of triggered ELMs was compared with gas puffing controlled ELMs. Small pellets, corresponding to a few per cent of the target plasma particle inventory, were used to minimize the fueling effect and the total particle throughput. There is no evidence that pellets can reduce the divertor power load with respect to gas fueling when operating at the same ELM frequency. The line average density and the energy confinement time remained constant when the gas was progressively substituted by pellets. The launch from the Vertical High Field Side (VHFS) confirmed to be more efficient in ELM triggering than from the Low Field Side (LFS) while the power load footprint remained the same both in time evolution and in spatial distribution when changing the injection geometry.

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

Science.gov (United States)

Wang, Jianhui; Qi, Lin; Wang, Xiao

2017-11-01

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

Establishment patterns of water-elm at Catahoula Lake, Louisiana

Science.gov (United States)

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...

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

Science.gov (United States)

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.

Integrated simulation of ELM energy loss determined by pedestal MHD and SOL transport

International Nuclear Information System (INIS)

Hayashi, N.; Takizuka, T.; Ozeki, T.; Aiba, N.; Oyama, N.

2007-01-01

An integrated simulation code TOPICS-IB based on a transport code with a stability code for the peeling-ballooning modes and a scrape-off-layer (SOL) model has been developed to clarify self-consistent effects of edge localized modes (ELMs) and the SOL on the plasma performance. Experimentally observed collisionality dependence of the ELM energy loss is found to be caused by both the edge bootstrap current and the SOL transport. The bootstrap current decreases with an increase in collisionality and intensifies the magnetic shear at the pedestal region. The increase in the magnetic shear reduces the width of eigenfunctions of unstable modes, which results in the reduction of both the area of the ELM enhanced transport and the ELM enhanced transport near the separatrix. On the other hand, when an ELM crash occurs, the energy flows into the SOL and the SOL temperature rapidly increases. The increase in the SOL temperature lowers the ELM energy loss due to the flattening of the radial edge gradient. The parallel electron heat conduction determines how the SOL temperature increases. For higher collisionality, the conduction becomes lower and the SOL electron temperature increases more. By the above two mechanisms, the ELM energy loss decreases with increasing collisionality

Multiclass AdaBoost ELM and Its Application in LBP Based Face Recognition

Directory of Open Access Journals (Sweden)

Yunliang Jiang

2015-01-01

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

Type I ELM filament heat fluxes on the KSTAR main chamber wall

Directory of Open Access Journals (Sweden)

M.-K. Bae

2017-08-01

Full Text Available Heat loads deposited on the first wall by mitigated Type I ELMs are expected to be the dominant contributor to the total thermal plasma wall load of the International Thermonuclear Experimental Reactor (ITER, particularly in the upper main chamber regions during the baseline H-mode magnetic equilibrium, due to the fast radial convective heat propagation of ELM filaments before complete loss to the divertor. Specific Type I ELMing H-mode discharges have been performed with a lower single null magnetic geometry, where the outboard separatrix position is slowly (∼7s scanned over a radial distance of 7cm, reducing the wall probe–separatrix distance to a minimum of ∼9cm, and allowing the ELM filament heat loss to the wall to be analyzed as a function of radial propagation distance. A fast reciprocating probe (FRP head is separately held at fixed position toroidally close and 4.7cm radially in front of the wall probe. This FRP monitors the ELM ion fluxes, allowing an average filament radial propagation speed, found to be independent of ELM energy, of 80–100ms−1 to be extracted. Radial dependence of the peak filament wall parallel heat flux is observed to be exponential, with the decay length of λq, ELM ∼25 ± 4mm and with the heat flux of q∥, ELM= 0.05MWm−2 at the wall, corresponding to q∥ ∼ 7.5MWm−2 at the second separatrix. Along with the measured radial propagation speed and the calculated radial profile of the magnetic connection lengths across the SOL, these data could be utilized to analyze filament energy loss model for the future machines.

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

Directory of Open Access Journals (Sweden)

Xiao-Li Li

2014-01-01

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

H-Mode Turbulence, Power Threshold, ELM, and Pedestal Studies in NSTX

International Nuclear Information System (INIS)

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

2004-01-01

High-confinement mode (H-mode) operation plays a crucial role in NSTX [National Spherical Torus Experiment] research, allowing higher beta limits due to reduced plasma pressure peaking, and long-pulse operation due to high bootstrap current fraction. Here, new results are presented in the areas of edge localized modes (ELMs), H-mode pedestal physics, L-H turbulence, and power threshold studies. ELMs of several other types (as observed in conventional aspect ratio tokamaks) are often observed: (1) large, Type I ELMs, (2) ''medium'' Type II/III ELMs, and (3) giant ELMs which can reduce stored energy by up to 30% in certain conditions. In addition, many high-performance discharges in NSTX have tiny ELMs (newly termed Type V), which have some differences as compared with ELM types in the published literature. The H-mode pedestal typically contains between 25-33% of the total stored energy, and the NSTX pedestal energy agrees reasonably well with a recent international multi-machine scaling. We find that the L-H transition occurs on a ∼100 (micro)sec timescale as viewed by a gas puff imaging diagnostic, and that intermittent quiescent periods precede the final transition. A power threshold identity experiment between NSTX and MAST shows comparable loss power at the L-H transition in balanced double-null discharges. Both machines require more power for the L-H transition as the balance is shifted toward lower single null. High field side gas fueling enables more reliable H-mode access, but does not always lead to a lower power threshold e.g., with a reduction of the duration of early heating. Finally the edge plasma parameters just before the L-H transition were compared with theories of the transition. It was found that while some theories can separate well-developed L- and H-mode data, they have little predictive value

Transition to ELM-free Improved H-mode by Lithium Deposition on NSTX Graphite Divertor Surfaces

International Nuclear Information System (INIS)

Mansfield, D.K.; Kugel, H.W.; Maingi, R.; Bell, M.G.; Bell, R.; Kaita, R.; Kallman, J.; Kaye, S.; LeBlanc, B.; Mueller, D.; Paul, S.; Raman, R.; Roquemore, L.; Sabbagh, S.; Schneider, H.; Skinner, C.H.; Soukhanovskii, V.; Timberlake, J.; Wilgen, J.; Zakharov, L.

2009-01-01

Lithium evaporated onto plasma facing components in the NSTX lower divertor has made dramatic improvements in discharge performance. As lithium accumulated, plasmas previously exhibiting robust Type 1 ELMs gradually transformed into discharges with intermittent ELMs and finally into continuously evolving ELM-free discharges. During this sequence, other discharge parameters changed in a complicated manner. As the ELMs disappeared, energy confinement improved and remarkable changes in edge and scrape-off layer plasma properties were observed. These results demonstrate that active modification of plasma surface interactions can preempt large ELMs.

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

Science.gov (United States)

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.

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

DEFF Research Database (Denmark)

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

structure. To verify the current characteristic of this structure, a mono-polar current filaments model was involved, which can reproduce same pattern commendably. Thus, current transport may dominant in transitional stage and plays an important role in the nonlinear development phase of ELM exhaustive......In far scrape-o layer (SOL), alternating negative and positive burst structures in ion saturation current were detected at the onset of each type-III edge localized mode (ELM) on EAST. Different from the fast streaming phenomenon reported previously, one subsequent positive burst structure appears...... every time in the early phase of ELM. It seems like a quick transitional stage between edge localized mode (MHD) phase and transport phase during the ELM. A pronounced sinusoidal pattern has been observed on the radial magnetic induction signal by Langmuir - magnetic probe, corresponding with almost...

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

DEFF Research Database (Denmark)

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

2010-01-01

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

PROGRESS IN THE PEELING-BALLOONING MODEL OF ELMS: NUMERICAL STUDIES OF 3D NONLINEAR ELM DYNAMICS

International Nuclear Information System (INIS)

SNYDER, P.B.; WILSON, H.R.; XU, X.Q.

2004-01-01

Nonlinear simulations with the 3D electromagnetic two-fluid BOUT code are employed to study the dynamics of edge localized modes (ELMs) driven by intermediate wavelength peeling-ballooning modes. It is found that the early behavior of the modes is similar to expectations from linear, ideal peeling-ballooning mode theory, with the modes growing linearly at a fraction of the Alfven frequency. In the nonlinear phase, the modes grow explosively, forming a number of extended filaments which propagate rapidly from the outer closed flux region into the open flux region toward the outboard wall. Similarities to non-linear ballooning theory, as well as additional complexities are observed. Comparison to observations reveals a number of similarities. Implications of the simulations and proposals for the dynamics of the full ELM crash are discussed

e-Learning Management System (eLMS) -

Data.gov (United States)

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

Integrated simulations of H-mode operation in ITER including core fuelling, divertor detachment and ELM control

Science.gov (United States)

Polevoi, A. R.; Loarte, A.; Dux, R.; Eich, T.; Fable, E.; Coster, D.; Maruyama, S.; Medvedev, S. Yu.; Köchl, F.; Zhogolev, V. E.

2018-05-01

ELM mitigation to avoid melting of the tungsten (W) divertor is one of the main factors affecting plasma fuelling and detachment control at full current for high Q operation in ITER. Here we derive the ITER operational space, where ELM mitigation to avoid melting of the W divertor monoblocks top surface is not required and appropriate control of W sources and radiation in the main plasma can be ensured through ELM control by pellet pacing. We apply the experimental scaling that relates the maximum ELM energy density deposited at the divertor with the pedestal parameters and this eliminates the uncertainty related with the ELM wetted area for energy deposition at the divertor and enables the definition of the ITER operating space through global plasma parameters. Our evaluation is thus based on this empirical scaling for ELM power loads together with the scaling for the pedestal pressure limit based on predictions from stability codes. In particular, our analysis has revealed that for the pedestal pressure predicted by the EPED1  +  SOLPS scaling, ELM mitigation to avoid melting of the W divertor monoblocks top surface may not be required for 2.65 T H-modes with normalized pedestal densities (to the Greenwald limit) larger than 0.5 to a level of current of 6.5–7.5 MA, which depends on assumptions on the divertor power flux during ELMs and between ELMs that expand the range of experimental uncertainties. The pellet and gas fuelling requirements compatible with control of plasma detachment, core plasma tungsten accumulation and H-mode operation (including post-ELM W transient radiation) have been assessed by 1.5D transport simulations for a range of assumptions regarding W re-deposition at the divertor including the most conservative assumption of zero prompt re-deposition. With such conservative assumptions, the post-ELM W transient radiation imposes a very stringent limit on ELM energy losses and the associated minimum required ELM frequency. Depending on

QUANTITATIVE TESTS OF ELMS AS INTERMEDIATE N PEELING-BALLOONING MODES

International Nuclear Information System (INIS)

LAO, LL; SNYDER, PB; LEONARD, AW; OSBORNE, TH; PETRIE, TW; FERRON, JR; GROEBNER, RJ; HORTON, LD; KAMADA, Y; MURAKAMI, M; OIKAWA, T; PEARLSTEIN, LD; SAARELMA, S; STJOHN, HE; THOMAS, DM; TURNBULL, AD; WILSON, HR

2002-01-01

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 ∼ 5-30, peeling-ballooning modes driven by the large edge pedestal pressure gradient P(prime) and the associated large edge bootstrap current density J BS . the interplay between P(prime) and J 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 BS is reduced

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

Science.gov (United States)

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 triggering by energetic particle driven mode in wall-stabilized high-β plasmas

International Nuclear Information System (INIS)

Matsunaga, G.; Aiba, N.; Shinohara, K.; Asakura, N.; Isayama, A.; Oyama, N.

2013-01-01

In the JT-60U high-β plasmas above the no-wall β limit, a triggering of an edge localized mode (ELM) by an energetic particle (EP)-driven mode has been observed. This EP-driven mode is thought to be driven by trapped EPs and it has been named EP-driven wall mode (EWM) on JT-60U (Matsunaga et al 2009 Phys. Rev. Lett. 103 045001). When the EWM appears in an ELMy H-mode phase, ELM crashes are reproducibly synchronized with the EWM bursts. The EWM-triggered ELM has a higher repetition frequency and less energy loss than those of the natural ELM. In order to trigger an ELM by the EP-driven mode, some conditions are thought to be needed, thus an EWM with large amplitude and growth rate, and marginal edge stability. In the scrape-off layer region, several measurements indicate an ion loss induced by the EWM. The ion transport is considered as the EP transport through the edge region. From these observations, the EP contributions to edge stability are discussed as one of the ELM triggering mechanisms. (paper)

THE ELM SURVEY. IV. 24 WHITE DWARF MERGER SYSTEMS

International Nuclear Information System (INIS)

Kilic, Mukremin; Brown, Warren R.; Kenyon, S. J.; Allende Prieto, Carlos; Heinke, Craig O.; Agüeros, M. A.; Kleinman, S. J.

2012-01-01

We present new radial velocity and X-ray observations of extremely low mass (ELM, ∼0.2 M ☉ ) white dwarf (WD) candidates in the Sloan Digital Sky Survey Data Release 7 area. We identify seven new binary systems with 1-18 hr orbital periods. Five of the systems will merge due to gravitational wave radiation within 10 Gyr, bringing the total number of merger systems found in the ELM Survey to 24. The ELM Survey has now quintupled the known merger WD population. It has also discovered the eight shortest period detached binary WD systems currently known. We discuss the characteristics of the merger and non-merger systems observed in the ELM Survey, including their future evolution. About half of the systems have extreme mass ratios. These are the progenitors of the AM Canum Venaticorum systems and Type Ia supernovae. The remaining targets will lead to the formation of extreme helium stars, subdwarfs, or massive WDs. We identify three targets that are excellent gravitational wave sources. These should be detected by the Laser Interferometer Space Antenna like missions within the first year of operation. The remaining targets are important indicators of what the Galactic foreground may look like for gravitational wave observatories.

THE ELM SURVEY. IV. 24 WHITE DWARF MERGER SYSTEMS

Energy Technology Data Exchange (ETDEWEB)

Kilic, Mukremin [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 West Brooks Street, Norman, OK 73019 (United States); Brown, Warren R.; Kenyon, S. J. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Allende Prieto, Carlos [Instituto de Astrofisica de Canarias, E-38205 La Laguna, Tenerife (Spain); Heinke, Craig O. [Department of Physics, CCIS 4-183, University of Alberta, Edmonton, AB, T6G 2E1 (Canada); Agueeros, M. A. [Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States); Kleinman, S. J., E-mail: kilic@ou.edu [Gemini Observatory, 670 North A' ohoku Place, Hilo, HI 96720 (United States)

2012-06-01

We present new radial velocity and X-ray observations of extremely low mass (ELM, {approx}0.2 M{sub Sun }) white dwarf (WD) candidates in the Sloan Digital Sky Survey Data Release 7 area. We identify seven new binary systems with 1-18 hr orbital periods. Five of the systems will merge due to gravitational wave radiation within 10 Gyr, bringing the total number of merger systems found in the ELM Survey to 24. The ELM Survey has now quintupled the known merger WD population. It has also discovered the eight shortest period detached binary WD systems currently known. We discuss the characteristics of the merger and non-merger systems observed in the ELM Survey, including their future evolution. About half of the systems have extreme mass ratios. These are the progenitors of the AM Canum Venaticorum systems and Type Ia supernovae. The remaining targets will lead to the formation of extreme helium stars, subdwarfs, or massive WDs. We identify three targets that are excellent gravitational wave sources. These should be detected by the Laser Interferometer Space Antenna like missions within the first year of operation. The remaining targets are important indicators of what the Galactic foreground may look like for gravitational wave observatories.

Integrated ELM simulation with edge MHD stability and transport of SOL-divertor plasmas

International Nuclear Information System (INIS)

Hayashi, Nobuhiko; Takizuka, Tomonori; Aiba, Nobuyuki; Ozeki, Takahisa; Oyama, Naoyuki

2007-07-01

The effect of the pressure profile on the energy loss caused by edge localized modes (ELMs) has been investigated by using an integrated simulation code TOPICS-IB based on a core transport code with a stability code for the peeling-ballooning modes and a transport model for scrape-off-layer and divertor plasmas. The steep pressure gradient inside the pedestal top is found to broaden the region of the ELM enhanced transport through the broadening of eigenfunctions and enhance the ELM energy loss. The ELM energy loss in the simulation becomes larger than 15% of the pedestal energy, as is shown in the database of multi-machine experiments. (author)

Assessment of erosion of the ITER divertor targets during type I ELMs

Science.gov (United States)

Federici, G.; Loarte, A.; Strohmayer, G.

2003-09-01

This paper presents the results of a preliminary assessment conducted to estimate the thermal response and erosion lifetime of the ITER divertor targets clad either with carbon-fibre composite or tungsten during type I ELMs. The one-dimensional thermal/erosion model, used for the analyses, is briefly described. It includes all the key surface heat transfer processes such as evaporation, melting, and radiation, and their interaction with the bulk thermal response, and it is based on an implicit finite-difference scheme, which allows for temperature-dependent material properties. The cases analysed clarify the influence of several ELM parameters on the heat transfer and erosion processes at the target (i.e. characteristic plasma ELM energy loss from the pedestal, fraction of the energy reaching the divertor, broadening of the strike-points during ELMs, duration and waveform of the ELM heat load) and design/material parameters (i.e. inclination of the target, type and thickness of the armour material, and for tungsten only, fraction of the melt layer loss). Comparison is made between cases where all ELMs are characterized by the same fixed averaged parameters, and cases where instead the characteristic parameters of each ELM are evaluated in a random fashion by using a standard Monte Carlo technique, based on distributions of some of the variables of interest derived from experiments in today's machines. Although uncertainties rule out providing firm quantitative predictions, the results of this study are useful to illustrate trends. Based on the results, the implications on the design and operation are discussed and priorities are determined for the R&D needed to reduce the remaining uncertainties.

Assessment of erosion of the ITER divertor targets during type I ELMs

International Nuclear Information System (INIS)

Federici, G; Loarte, A; Strohmayer, G

2003-01-01

This paper presents the results of a preliminary assessment conducted to estimate the thermal response and erosion lifetime of the ITER divertor targets clad either with carbon-fibre composite or tungsten during type I ELMs. The one-dimensional thermal/erosion model, used for the analyses, is briefly described. It includes all the key surface heat transfer processes such as evaporation, melting, and radiation, and their interaction with the bulk thermal response, and it is based on an implicit finite-difference scheme, which allows for temperature-dependent material properties. The cases analysed clarify the influence of several ELM parameters on the heat transfer and erosion processes at the target (i.e. characteristic plasma ELM energy loss from the pedestal, fraction of the energy reaching the divertor, broadening of the strike-points during ELMs, duration and waveform of the ELM heat load) and design/material parameters (i.e. inclination of the target, type and thickness of the armour material, and for tungsten only, fraction of the melt layer loss). Comparison is made between cases where all ELMs are characterized by the same fixed averaged parameters, and cases where instead the characteristic parameters of each ELM are evaluated in a random fashion by using a standard Monte Carlo technique, based on distributions of some of the variables of interest derived from experiments in today's machines. Although uncertainties rule out providing firm quantitative predictions, the results of this study are useful to illustrate trends. Based on the results, the implications on the design and operation are discussed and priorities are determined for the R and D needed to reduce the remaining uncertainties

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

Directory of Open Access Journals (Sweden)

Josphat Igadwa Mwasiagi

2017-03-01

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

Investigation of dynamics of ELM crashes and their mitigation techniques

Energy Technology Data Exchange (ETDEWEB)

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

2015-08-14

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

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

Science.gov (United States)

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.

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

NARCIS (Netherlands)

Baylor, L.R.; Lang, P.T.; Allen, S.L.; Combs, S.K.; Commaux, N.; Evans, T.E.; Fenstermacher, M.E.; Huijsmans, G.T.A.; Jernigan, T.C.; Lasnier, C.J.; Leonard, A.W.; Loarte, A.; Maingi, R.; Maruyama, S.; Meitner, S.J.; Moyer, R.A.; Osborne, T.H.

2015-01-01

PLASMA-SURFACE INTERACTIONS 21 — Proceedings of the 21st International Conference on Plasma-Surface Interactions in Controlled Fusion Devices Kanazawa, Japan May 26-30, 2014 The triggering of rapid small edge localized modes (ELMs) by high frequency pellet injection has been proposed as a method to

ELM as a trigger mechanism for the transition between two Edge regimes

International Nuclear Information System (INIS)

Pshenov, A.A.; Morozov, D.Kh.

2012-01-01

The possibility of edge regime transitions under the influence of edge-localized modes (ELMs) is investigated. A theoretical model of the process is presented and examined numerically. ELMs appear able to trigger irreversible transitions from one equilibrium to another with different edge temperatures. The results correspond to the recent experimental studies on both DIII-D and JET tokamaks showing type-I and type-II ELMs causing a prolonged collapse of the edge plasma temperature (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Structure of ELMs in MAST and the implications for energy deposition

International Nuclear Information System (INIS)

Kirk, A; Wilson, H R; Akers, R; Conway, N J; Counsell, G F; Cowley, S C; Dowling, J; Dudson, B; Field, A; Lott, F; Lloyd, B; Martin, R; Meyer, H; Price, M; Taylor, D; Walsh, M

2005-01-01

This paper presents a description of the spatial and temporal structure of edge-localized modes (ELMs) observed in the MAST tokamak. Filamentary enhancements of visible light are observed on photographic images of the plasma obtained during ELMs. Comparisons with simulations show that these filaments are consistent with following field lines at the outboard edge of the plasma. The toroidal mode number of these filaments has been extracted from a study of the discrete peaks observed in the ion saturation current recorded by a mid-plane reciprocating probe. A study of the time delay of these peaks with respect to the onset of the ELM has been used to calculate an effective radial velocity for the expansion of the filaments. A comparison of this derived radial velocity as a function of distance from the last closed flux surface with simulations indicates that the filament is accelerating away from the plasma. Evidence for the temporal evolution of the ELM comes from studies of outboard mid-plane Thomson scattering density profiles. In addition, a study of the toroidal velocity as a function of radius shows that during an ELM the strong velocity shear near the edge of the plasma, normally present in H-modes, is strongly reduced. The picture that emerges is that the ELM can be viewed as being composed of filamentary structures that are generated on a 100 μs timescale, accelerate away from the plasma edge, are extended along a field line and have a typical toroidal mode number ∼10. The implications of these filaments for the energy deposition on plasma facing components are discussed

Observation of pre- and postcursor modes of type-I ELMs on JET

International Nuclear Information System (INIS)

Koslowski, H.R.; Perez, C.; Alper, B.; Hender, T.C.; Sharapov, S.E.; Eich, T.; Huysmans, G.T.A.; Smeulders, P.; Westerhof, E.

2003-01-01

Recent observations of MHD activity in type-I ELMy H-mode discharges on JET have revealed two phenomena: (i) the so-called palm tree mode, a new, snake-like MHD mode at the q = 3 surface which is excited by type-I ELMs, and (ii) coherent MHD mode activity as a precursor to the ELM collapse. Both modes are detected by magnetic pick up coils and can also be seen on the edge ECE and SXR measurements. They are located a few cm inside the separatrix. Palm tree modes have been identified in a wide range of plasma conditions, which comprise standard ELMy H-modes, ITER-like plasma shapes, pellet fuelling, and even pure helium plasmas. The mode frequency increases in time and starts to saturate until the mode finally decays. A possible explanation of the palm tree mode is, that it is the remnant of a (3,1)-island created due to edge ergodisation by the ELM perturbation. The type-I ELM precursor modes have toroidal mode numbers n in the range 1 to 14, a kink-like structure, and appear commonly 0.5 - 1 ms before the ELM, but can appear much earlier in some cases. (author)

Plasma shaping and its impact on the pedestal of ASDEX Upgrade: edge stability and inter-ELM dynamics at varied triangularity

Science.gov (United States)

Laggner, F. M.; Wolfrum, E.; Cavedon, M.; Dunne, M. G.; Birkenmeier, G.; Fischer, R.; Willensdorfer, M.; Aumayr, F.; The EUROfusion MST1 Team; The ASDEX Upgrade Team

2018-04-01

The plasma shape, in particular the triangularity (δ), impacts on the pedestal stability. A scan of δ including a variation of heating power (P heat) and gas puff was performed to study the behaviour of edge localised modes (ELMs) and the pre-ELM pedestal stability for different plasma shapes. Generally, at higher δ the pedestal top electron density (n e) is enhanced and the ELM repetition frequency (f ELM) is reduced. For all δ, the pedestal top n e is already fully established to its pre-ELM value during the initial recovery phase of the n e pedestal, which takes place immediately after the ELM crash. The lowering of the f ELM with increasing δ is related to longer pedestal recovery phases, especially the last pre-ELM phase with clamped pedestal gradients (after the recovery phases of the n e and electron temperature (T e) pedestal) is extended. In all investigated discharge intervals, the pre-ELM pedestal profiles are in agreement with peeling-ballooning (PB) theory. Over the investigated range of δ, two well-separated f ELM bands are observed in several discharge intervals. Their occurrence is linked to the inter-ELM pedestal stability. In both kinds of ELM cycles the pedestal evolves similarly, however, the ‘fast’ ELM cycle occurs before the global plasma stored energy (W MHD) increases, which then provides a stabilising effect on the pedestal, extending the inter-ELM period in the case of the ‘slow’ ELM cycle. At the end of a ‘fast’ ELM cycle the n e profile is radially shifted inwards relative to the n e profile at the end of a ‘slow’ ELM cycle, leading to a reduced pressure gradient. The appearance of two f ELM bands suggests that the pedestal becomes more likely PB unstable in certain phases of the inter-ELM evolution. Such a behaviour is possible because the evolution of the global plasma is not rigidly coupled to the evolution of the pedestal structure on the timescales of an ELM cycle.

Contamination of ITER core by high-Z impurities after ELMs

International Nuclear Information System (INIS)

Landman, I.; Janeschitz, G.

2007-01-01

The H-mode confinement in the future tokamak ITER is anticipated to be repetitively worsened by edge localized instabilities (ELMs). At each ELM the deuterium-tritium (DT) plasma lost from the pedestal into the scrape-off layer (SOL) and further onto a divertor armour produces surface erosion. The following contamination of SOL by the eroded and then ionized material species provides the impurities in the pedestal and the core. The fraction of carbon-based material (CBM) must be minimized, because of not acceptable accumulation rate of radioactive tritium inside its bulk. Therefore tungsten-based material (WBM) should be preferable even near the separatrix strike point (SSP) where DT-plasma maximum flux impacts on CBM tiles. However, the presence of highly but not fully ionized W-ions in the confinement region may get dangerous for the device operation, which is due to enhanced heat loss by the line radiation of W-ions. In this work the DT-plasma contamination after the Type I ELMs is simulated with the tokamak integrated modelling code TOKES. The simulations imply some ELM-caused heat flux distribution over the wall as a function of time and poloidal coordinate along the divertor surface. The processes of emission of eroded C- and W-atoms and their ionization in the SOL as well as the multi-fluid transport in the confinement region among D-, T-, He-, C- and W-ions are calculated for the whole ITER discharge with multiple ELMs, different fuelling and auxiliary heating schemes (neutral beams and pellets) and the burning at fusion gain Q<10. The aim is obtaining tolerable ELM energy based on the radiation losses and deterioration of fusion gain caused by the W-impurity that was produced after the ELM. The TOKES calculates self-consistently also both the poloidal field external coil currents and the confined plasma currents and thus the separatrix dynamics, and thus a significant broadening of power footprint compared to the usual assumption of the SOL effective width

Contamination of ITER core by high-Z impurities after ELMs

Energy Technology Data Exchange (ETDEWEB)

Landman, I.; Janeschitz, G. [Forschungszentrum Karlsruhe (Germany). IHM Fusion

2007-07-01

The H-mode confinement in the future tokamak ITER is anticipated to be repetitively worsened by edge localized instabilities (ELMs). At each ELM the deuterium-tritium (DT) plasma lost from the pedestal into the scrape-off layer (SOL) and further onto a divertor armour produces surface erosion. The following contamination of SOL by the eroded and then ionized material species provides the impurities in the pedestal and the core. The fraction of carbon-based material (CBM) must be minimized, because of not acceptable accumulation rate of radioactive tritium inside its bulk. Therefore tungsten-based material (WBM) should be preferable even near the separatrix strike point (SSP) where DT-plasma maximum flux impacts on CBM tiles. However, the presence of highly but not fully ionized W-ions in the confinement region may get dangerous for the device operation, which is due to enhanced heat loss by the line radiation of W-ions. In this work the DT-plasma contamination after the Type I ELMs is simulated with the tokamak integrated modelling code TOKES. The simulations imply some ELM-caused heat flux distribution over the wall as a function of time and poloidal coordinate along the divertor surface. The processes of emission of eroded C- and W-atoms and their ionization in the SOL as well as the multi-fluid transport in the confinement region among D-, T-, He-, C- and W-ions are calculated for the whole ITER discharge with multiple ELMs, different fuelling and auxiliary heating schemes (neutral beams and pellets) and the burning at fusion gain Q<10. The aim is obtaining tolerable ELM energy based on the radiation losses and deterioration of fusion gain caused by the W-impurity that was produced after the ELM. The TOKES calculates self-consistently also both the poloidal field external coil currents and the confined plasma currents and thus the separatrix dynamics, and thus a significant broadening of power footprint compared to the usual assumption of the SOL effective width

Theory and Simulations of ELM Control with a Snowflake Divertor

Energy Technology Data Exchange (ETDEWEB)

Ryutov, D.; Cohen, B.; Cohen, R.; Makowski, M. A.; Menard, J.; Rognlien, T.; Soukhanovskii, V.; Umansky, M.; Xu, X., E-mail: ryutov1@llnl.gov [Lawrence Livermore National Laboratory, Livermore (United States); Kolemen, E. [Princeton Plasma Physics Laboratory, Princeton (United States)

2012-09-15

Full text: This paper is concerned with the use of a snowflake (SF) divertor for the control and mitigation of edge localized modes (ELMs). Our research is focused on the following three issues: 1. Effect of the SF geometry on neoclassical ion orbits near the separatrix, including prompt ion losses and the related control mechanism for the electric field and plasma flow in the pedestal; 2. Influence of the thereby modified flow and of high poloidal plasma beta in the divertor region on plasma turbulence and transport in the snowflake-plus geometry; 3. Reaction of the SF divertor to type-1 ELM events. Neoclassical ion orbits in the vicinity of the SF separatrix are changed due to a much weaker poloidal field near the null and much longer particle dwell-time in this area. This leads to an increase of the prompt ion loss, which then affects the radial electric field profile near the separatrix. The resulting E x B flow shear in the pedestal region affects the onset of ELMs. The electric field and velocity shear are then used as a background for two-fluid simulations of the edge plasma turbulence in a realistic geometry with the 3D BOUT code. A SF-plus geometry is chosen, so that the separatrix topology remains the same as for the standard X-point divertor, whereas the magnetic shear both inside and outside the separatrix increases dramatically. It is found that mesoscale instabilities are suppressed when the geometry is close to a perfect SF. In situations where complete suppression of ELMs is impossible, the SF divertor offers a path to reducing heat loads during ELM events to an acceptable level. Two effects, both related to the weakness of the poloidal field near the SF null, act synergistically in the same favorable direction. The first is the onset of strong, curvature-driven convection in the divertor, triggered by the increase of the poloidal pressure during the ELM and leading to the splitting of the heat flux between all four (as is the case in a SF geometry

Ultrastructure of cells of Ulmus americana cultured in vitro and exposed to the culture filtrate of Ceratocystis ulmi

Science.gov (United States)

Paula M. Pijut; R. Daniel Lineberger; Subhash C. Domir; Jann M. Ichida; Charles R. Krause

1990-01-01

Calli of American elm susceptible and resistant to Dutch elm disease were exposed to a culture filtrate of a pathogenic isolate of Ceratocystis ulmi. Cells from untreated tissue exhibited typical internal composition associated with healthy, actively growing cells. All cells exposed to culture filtrate showed appreciable ultrastructural changes....

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

Science.gov (United States)

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.

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

Energy Technology Data Exchange (ETDEWEB)

Bell, Keaton J.; Winget, D. E.; Montgomery, M. H.; Castanheira, B. G.; Vanderbosch, Z.; Winget, K. I. [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Gianninas, A.; Kilic, Mukremin [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States); Hermes, J. J. [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599 (United States); Brown, Warren R., E-mail: keatonb@astro.as.utexas.edu [Smithsonian Astrophysical Observatory, Cambridge, MA 02138 (United States)

2017-02-01

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 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 {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.

Observation of different phases during an ELM crash with the help of nitrogen seeding

International Nuclear Information System (INIS)

Schneider, P A; Wolfrum, E; Dunne, M G.; Dux, R; Gude, A; Kurzan, B; Pütterich, T; Rathgeber, S K.; Weller, A; Wenninger, R; Vicente, J

2014-01-01

A new method was applied to indirectly obtain information about the features of the crash of the H-mode edge transport barrier in consequence of an edge localized mode (ELM). The method is based on a combination of fast measurements, without spatial resolution, and relatively slow measurements, with high spatial resolution. The comparison of two different ELM scenarios in the full metal tokamak ASDEX Upgrade—a standard scenario and one with additional nitrogen seeding—revealed a two-fold nature of the ELM crash. In the case with additional nitrogen only a part of the standard crash is observed. This suggests the standard ELM crash consists of two or more consecutive events instead of a single distinct one. Some of these events are observed to be suppressed with changes in plasma parameters. The effect of the impurity seeding on different plasma parameters is documented in detail and compared to measurements conducted in machines with a carbon wall. The radial extent of the phases observed during the ELM crash differs in the kinetic profiles, with one instability extending inside the pedestal top and the other being confined to the pedestal region. This picture can explain the differences in the loss of stored energy and the change in ELM frequency which are observed for the analysed pair of discharges. It also suggests that the ELM crash starts at the pedestal top and only then affects the steep gradient region. (paper)

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

Science.gov (United States)

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

2018-01-01

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

The role of edge current-driven modes in ELM activity

Energy Technology Data Exchange (ETDEWEB)

Gimblett, C G; Hastie, R J; Helander, P [EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom)

2006-10-15

We propose a model for edge localized mode (ELM) evolution which goes beyond linear stability arguments by hypothesizing that peeling modes initiate a Taylor relaxation (a constrained minimization of the magnetic energy) of an outer annular plasma region. The relaxation has two effects on peeling mode stability: (a) As the relaxation process proceeds radially inwards it leaves in its wake a Taylor state, which for conventional tokamak ordering is simply a flattened equilibrium toroidal current density. This effect acting in isolation would provide a destabilizing effect (for conventional current profiles the edge current density would increase); (b) The formation of a (negative for conventional current profiles) skin current at the plasma-vacuum interface which has a counteracting stabilizing effect on peeling modes. For a finite relaxed annulus, these two opposing effects can balance and give a configuration that is stable to all possible peeling instabilities. The radial extent of the relaxed region required for stability can be calculated using this balance. This then leads to model predictions for ELM characteristics such as the widths and mode numbers, the magnitude of the attendant energy losses and the natural (deterministic) scatter in these quantities. We compare these model predictions with a number of experimentally observed ELM properties. Further, expanding the governing equations gives analytic expressions for ELM widths in terms of localized edge parameters. Peeling modes can occur even when the critical pressure gradient for the onset of ballooning modes has not been reached. For this reason 'type III' ELMs, which typically occur just above the threshold for L-H transitions, may be best described by this model.

The role of edge current-driven modes in ELM activity

International Nuclear Information System (INIS)

Gimblett, C G; Hastie, R J; Helander, P

2006-01-01

We propose a model for edge localized mode (ELM) evolution which goes beyond linear stability arguments by hypothesizing that peeling modes initiate a Taylor relaxation (a constrained minimization of the magnetic energy) of an outer annular plasma region. The relaxation has two effects on peeling mode stability: (a) As the relaxation process proceeds radially inwards it leaves in its wake a Taylor state, which for conventional tokamak ordering is simply a flattened equilibrium toroidal current density. This effect acting in isolation would provide a destabilizing effect (for conventional current profiles the edge current density would increase); (b) The formation of a (negative for conventional current profiles) skin current at the plasma-vacuum interface which has a counteracting stabilizing effect on peeling modes. For a finite relaxed annulus, these two opposing effects can balance and give a configuration that is stable to all possible peeling instabilities. The radial extent of the relaxed region required for stability can be calculated using this balance. This then leads to model predictions for ELM characteristics such as the widths and mode numbers, the magnitude of the attendant energy losses and the natural (deterministic) scatter in these quantities. We compare these model predictions with a number of experimentally observed ELM properties. Further, expanding the governing equations gives analytic expressions for ELM widths in terms of localized edge parameters. Peeling modes can occur even when the critical pressure gradient for the onset of ballooning modes has not been reached. For this reason 'type III' ELMs, which typically occur just above the threshold for L-H transitions, may be best described by this model

ELMs and constraints on the H-mode pedestal: A model based on peeling-ballooning modes

International Nuclear Information System (INIS)

Snyder, P.B.

2002-01-01

Maximizing the pedestal height while maintaining acceptable ELMs is a key issue for optimizing tokamak performance. We present a model for ELMs and pedestal constraints based upon theoretical analysis of edge instabilities which can limit the pedestal height and drive ELMs. Sharp pedestal pressure gradients drive large bootstrap currents which play a complex dual role in the stability physics. Consequently, the dominant modes are often intermediate-n coupled 'peeling-ballooning' modes, driven both by current and the pressure gradient. A highly efficient new MHD code, ELITE, is used to study these modes, and calculate quantitative stability constraints on the pedestal, including direct constraints on the pedestal height. A model of various ELM types is developed, and quantitatively compared to data from several tokamaks. A number of observations agree with predictions, including ELM onset times, ELM depth, and variation in pedestal height with discharge shape. Projections of pedestal stability constraints for Next Step designs, and nonlinear simulations of peeling-ballooning modes using the BOUT code are also presented. (author)

Modeling of ELM events and their effect on impurity enrichment

International Nuclear Information System (INIS)

Hogan, J.; Colchin, R.; Coster, D.; Baylor, L.; Fenstermacher, M.; Groth, M.; Wade, M.

2003-01-01

Modeling of transient impurity transport during large ELMs is used to explore basic processes which may determine ELM-averaged enrichment. The b2-Eirene code (solps4), used for DIII-D geometry, suggests that a complex sequence can occur during an ELM cycle in which a transiently detached phase, with relatively low enrichment, can occur even under nominally attached conditions. A slower recovery phase then follows, in which the effect of induced scrape-off layer flows can increase in importance. The model results are compared with available fast time-scale measurements. The observed increased enrichment with higher Z is similar to trends in basic particle reflection properties. Neon recycling processes may thus introduce a significant history effect, as illustrated by analysis of continuous, unforced neon accumulation in a DIII-D discharge with a well-characterized operational history

Comparison of the filament behaviour observed during type I ELMs in ASDEX upgrade and MAST

International Nuclear Information System (INIS)

Kirk, A; Ayed, B; Counsell, G F; Lisgo, S; Price, M; Tallents, S; Herrmann, A; Eich, T; Muller, H W; Schmid, A; Wilson, H

2008-01-01

A study of the evolution of the filaments observed during Type I ELMs on ASDEX Upgrade and MAST is presented. The filaments start off rotating toroidally/poloidally with velocities close to that of the pedestal. This velocity then decreases as the filaments propagate radially. On both devices the ion saturation current e-folding lengths of the filaments show a weak, if any, dependence on the size of the ELM (δW ELM /W ped ). On MAST the measured radial velocities of the filaments also show at most a weak dependence on δW ELM /W ped

Energy saving and prediction modeling of petrochemical industries: A novel ELM based on FAHP

International Nuclear Information System (INIS)

Geng, ZhiQiang; Qin, Lin; Han, YongMing; Zhu, QunXiong

2017-01-01

Extreme learning machine (ELM), which is a simple single-hidden-layer feed-forward neural network with fast implementation, has been widely applied in many engineering fields. However, it is difficult to enhance the modeling ability of extreme learning in disposing the high-dimensional noisy data. And the predictive modeling method based on the ELM integrated fuzzy C-Means integrating analytic hierarchy process (FAHP) (FAHP-ELM) is proposed. The fuzzy C-Means algorithm is used to cluster the input attributes of the high-dimensional data. The Analytic Hierarchy Process (AHP) based on the entropy weights is proposed to filter the redundant information and extracts characteristic components. Then, the fusion data is used as the input of the ELM. Compared with the back-propagation (BP) neural network and the ELM, the proposed model has better performance in terms of the speed of convergence, generalization and modeling accuracy based on University of California Irvine (UCI) benchmark datasets. Finally, the proposed method was applied to build the energy saving and predictive model of the purified terephthalic acid (PTA) solvent system and the ethylene production system. The experimental results demonstrated the validity of the proposed method. Meanwhile, it could enhance the efficiency of energy utilization and achieve energy conservation and emission reduction. - Highlights: • The ELM integrated FAHP approach is proposed. • The FAHP-ELM prediction model is effectively verified through UCI datasets. • The energy saving and prediction model of petrochemical industries is obtained. • The method is efficient in improvement of energy efficiency and emission reduction.

Were the chaotic ELMs in TCV the result of an ARMA process?

International Nuclear Information System (INIS)

Degeling, A W; Lister, J B; Martin, Y R; Zvejnieks, G

2004-01-01

The results of a previous paper claiming the demonstration that edge localized mode (ELM) dynamics on TCV are chaotic in a number of cases has recently been called into question, because the statistical test employed was found to also identify linear auto regressive-moving average (ARMA) models as chaotic. The TCV ELM data has therefore been re-examined with an improved method that is able to make this distinction, and the ARMA model is found to be an inappropriate description of the dynamics on TCV. The hypothesis that ELM dynamics are chaotic on TCV in a number of cases is therefore still favoured. (letter to the editor)

Comparison of the spatial and temporal structure of type-I ELMs

International Nuclear Information System (INIS)

Kirk, A; Beurskens, M; Counsell, G F; Fundamenski, W; Lisgo, S; Asakura, N; Kamada, Y; Oyama, N; Boedo, J A; Eich, T; Herrmann, A; Schmid, A; Leonard, A W; Loarte, A; Pitts, R A; Wilson, H R

2008-01-01

A comparison of the spatial and temporal evolution of the filamentary structures observed during type I ELMs is presented from a variety of diagnostics and machines. There is evidence that these filaments can be detected inside the LCFS prior to ELMs. The filaments do not have a circular cross section instead they are elongated in the perpendicular (poloidal) direction and this size appears to increase linearly with the minor radius of the machine. The filaments start off rotating toroidally/poloidally with velocities close to that of the pedestal. This velocity then decreases as the filaments propagate radially. By comparing the results from all measurements and from comparison with models it is most likely that the filaments have at least their initial radial velocity when they are far out into the SOL and before they have interacted with the nearest limiter surface. There is a general consensus that the dominant loss mechanism in the separated filaments is through parallel transport and that the transport to the wall is through the radial propagation of these filaments. Measurements of the filament energy content show that each filament contains up to 2.5% of the energy released by the ELM at the time it separates from the LCFS, assuming Ti = Te. The parallel flux e-folding length measured on DIII-D, AUG and MAST has a weaker scaling with normalised ELM size than appears to be necessary to explain the deficit in the ELM energy arriving in the divertor on JET, assuming a purely exponential decay of the filament energy with time

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

International Nuclear Information System (INIS)

Lemahieu, Nathan; Greuner, Henri; Linke, Jochen; Maier, Hans; Pintsuk, Gerald; Van Oost, Guido; Wirtz, Marius

2015-01-01

Highlights: • Tungsten was first exposed to H or H/He fluxes and then to ELM-like transients. • The influence of particle exposure on the thermal shock behaviour was studied. • There was no deterioration of thermal shock behaviour compared to reference material. • Some combinations of loading conditions resulted in an improved material behaviour. - Abstract: To investigate synergistic effects of high heat flux loading on H and H/He loaded tungsten surfaces, specimens were exposed to a 30 keV steady-state H or H/He beam and subsequently loaded with an electron beam to simulate ELMs. The heat flux during the H and H/He loading was 10.5 MW m"−"2, while a 2 × 10"2"5 m"−"2 fluence was reached. After exposure, all specimens exhibited an altered surface morphology. The H/He samples with a surface temperature of 1000 °C and 1500 °C had a multitude of surface extrusions. Afterwards the particle loaded samples were exposed to 100 ELM-like pulses around the material's damage threshold. Transient heat fluxes of 190 MW m"−"2 and 380 MW m"−"2 were applied at room temperature and 400 °C for a duration of 1 ms. Post-mortem analysis showed no deterioration of thermal shock resistance in comparison with polished material. For some tests the reference specimens roughened or cracked while the H or H/He exposed material had no damage. The H-content and the H/He-induced cavities and/or extrusions are suggested as two potential causes for this change in material behaviour.

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-10-15

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

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

Science.gov (United States)

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...

ELM suppression in low edge collisionality H-mode discharges using n = 3 magnetic perturbations

Energy Technology Data Exchange (ETDEWEB)

Burrell, K H [General Atomics, PO Box 85608, San Diego, CA 92186-9784 (United States); Evans, T E [General Atomics, PO Box 85608, San Diego, CA 92186-9784 (United States); Doyle, E J [University of California, Los Angeles, California (United States); Fenstermacher, M E [Lawrence Livermore National Laboratory, Livermore, California (United States); Groebner, R J [General Atomics, PO Box 85608, San Diego, CA 92186-9784 (United States); Leonard, A W [General Atomics, PO Box 85608, San Diego, CA 92186-9784 (United States); Moyer, R A [University of California, San Diego, California (United States); Osborne, T H; Schaffer, M J; Snyder, P B [General Atomics, PO Box 85608, San Diego, CA 92186-9784 (United States); Thomas, P R [CEA Cadarache EURATOM Association, Cadarache (France); West, W P [General Atomics, PO Box 85608, San Diego, CA 92186-9784 (United States); Boedo, J A [University of California, San Diego, California (United States); Garofalo, A M [Columbia University, New York, New York (United States); Gohil, P; Jackson, G L; La Haye, R J [General Atomics, PO Box 85608, San Diego, CA 92186-9784 (United States); Lasnier, C J [Lawrence Livermore National Laboratory, Livermore, California (United States); Reimerdes, H [Columbia University, New York, New York (United States); Rhodes, T L [University of California, Los Angeles, California (United States); Scoville, J T [General Atomics, PO Box 85608, San Diego, CA 92186-9784 (United States); Solomon, W M [Princeton Plasma Physics Laboratory, Princeton, New Jersey (United States); Thomas, D M [General Atomics, PO Box 85608, San Diego, CA 92186-9784 (United States); Wang, G [University of California, Los Angeles, California (United States); Watkins, J G [Sandia National Laboratories, Albuquerque, New Mexico (United States); Zeng, L [University of California, Los Angeles, California (United States)

2005-12-15

Using resonant magnetic perturbations with toroidal mode number n = 3, we have produced H-mode discharges without edge localized modes (ELMs) which run with constant density and radiated power for periods up to about 2550 ms (17 energy confinement times). These ELM suppression results are achieved at pedestal collisionalities close to those desired for next step burning plasma experiments such as ITER and provide a means of eliminating the rapid erosion of divertor components in such machines which could be caused by giant ELMs. The ELM suppression is due to an enhancement in the edge particle transport which reduces pedestal current density and maximum edge pressure gradient below the threshold for peeling-ballooning modes. These n = 3 magnetic perturbations provide a means of active control of edge plasma transport.

ELM suppression in low edge collisionality H-mode discharges using n = 3 magnetic perturbations

International Nuclear Information System (INIS)

Burrell, K H; Evans, T E; Doyle, E J; Fenstermacher, M E; Groebner, R J; Leonard, A W; Moyer, R A; Osborne, T H; Schaffer, M J; Snyder, P B; Thomas, P R; West, W P; Boedo, J A; Garofalo, A M; Gohil, P; Jackson, G L; La Haye, R J; Lasnier, C J; Reimerdes, H; Rhodes, T L; Scoville, J T; Solomon, W M; Thomas, D M; Wang, G; Watkins, J G; Zeng, L

2005-01-01

Using resonant magnetic perturbations with toroidal mode number n = 3, we have produced H-mode discharges without edge localized modes (ELMs) which run with constant density and radiated power for periods up to about 2550 ms (17 energy confinement times). These ELM suppression results are achieved at pedestal collisionalities close to those desired for next step burning plasma experiments such as ITER and provide a means of eliminating the rapid erosion of divertor components in such machines which could be caused by giant ELMs. The ELM suppression is due to an enhancement in the edge particle transport which reduces pedestal current density and maximum edge pressure gradient below the threshold for peeling-ballooning modes. These n = 3 magnetic perturbations provide a means of active control of edge plasma transport

Nonlinear evolution of the mode structure of ELMs in realistic ASDEX Upgrade geometry

Energy Technology Data Exchange (ETDEWEB)

Krebs, Isabel; Hoelzl, Matthias; Lackner, Karl; Guenter, Sibylle [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstr. 2, Garching (Germany); Collaboration: The ASDEX Upgrade Team

2013-07-01

Edge-localized modes (ELMs) are edge instabilities in H-mode plasmas, which eject particles and energy. The suitability of the H-mode for future fusion reactors depends crucially on the exact ELM dynamics as they can damage plasma facing components if too large. We have simulated ELMs in ASDEX Upgrade geometry using the nonlinear MHD code JOREK. Emphasis was put on the mode structure evolution in the early ELM phase which is characterized by the exponential growth of the unstable toroidal Fourier harmonics followed by a phase of saturation. In the linear phase, toroidal harmonics grow independently, whereas at larger amplitudes, the nonlinear interaction between the toroidal harmonics influences their growth and structure. Prior to mode saturation, the evolution of the mode structure can be reproduced well by a simple quadratic mode-interaction model, which yields a possible explanation for the strong n=1 component of type-I ELMs observed in ASDEX Upgrade. In the linear phase of the simulations, intermediate toroidal mode numbers (n 6-14) are most unstable as predicted by the peeling-ballooning model. But non-linearly, the n=1 component becomes important due to an energy transfer from pairs of linearly dominant toroidal harmonics with neighboring mode numbers to the n=1. The latter thereby changes its spatial structure.

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

Science.gov (United States)

Walton, J. T.

1994-01-01

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

Investigation of transient melting of tungsten by ELMs in ASDEX Upgrade

International Nuclear Information System (INIS)

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

2017-01-01

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. (paper)

Model-based dynamic resistive wall mode identification and feedback control in the DIII-D tokamak

International Nuclear Information System (INIS)

In, Y.; Kim, J.S.; Edgell, D.H.; Strait, E.J.; Humphreys, D.A.; Walker, M.L.; Jackson, G.L.; Chu, M.S.; Johnson, R.; La Haye, R.J.; Okabayashi, M.; Garofalo, A.M.; Reimerdes, H.

2006-01-01

A new model-based dynamic resistive wall mode (RWM) identification and feedback control algorithm has been developed. While the overall RWM structure can be detected by a model-based matched filter in a similar manner to a conventional sensor-based scheme, it is significantly influenced by edge-localized-modes (ELMs). A recent study suggested that such ELM noise might cause the RWM control system to respond in an undesirable way. Thus, an advanced algorithm to discriminate ELMs from RWM has been incorporated into this model-based control scheme, dynamic Kalman filter. Specifically, the DIII-D [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] resistive vessel wall was modeled in two ways: picture frame model or eigenmode treatment. Based on the picture frame model, the first real-time, closed-loop test results of the Kalman filter algorithms during DIII-D experimental operation are presented. The Kalman filtering scheme was experimentally confirmed to be effective in discriminating ELMs from RWM. As a result, the actuator coils (I-coils) were rarely excited during ELMs, while retaining the sensitivity to RWM. However, finding an optimized set of operating parameters for the control algorithm requires further analysis and design. Meanwhile, a more advanced Kalman filter based on a more accurate eigenmode model has been developed. According to this eigenmode approach, significant improvement in terms of control performance has been predicted, while maintaining good ELM discrimination

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

Science.gov (United States)

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

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

DEFF Research Database (Denmark)

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

2013-01-01

-III ELMy H-modes. The energy loss and divertor power load are systematically characterized for these different ELMy H-modes to provide a physics basis for the next-step high-power long-pulse operations in EAST. Both type-I and compound ELMs exhibit good confinement (H98(y,2) ∼ 1). A significant loss......The Experimental Advanced Superconducting Tokamak (EAST) has recently achieved a variety of H-mode regimes with different edge-localized mode (ELM) dynamics, including type-I ELMs, compound ELMs, which are manifested by the onset of a large spike followed by a sequence of small spikes on Dα......-III ELMs. It is remarkable that the new very small ELMy H-modes exhibit even lower target power deposition than type-III ELMs, with the peak heat flux generally below 1 MW m−2. These very small ELMs are usually accompanied by broadband fluctuations with frequencies ranging from 20 to 50 kHz, which may...

Transient thermo-structural and static magnetic characteristics of 1:1 prototype JET ELM control coils

Energy Technology Data Exchange (ETDEWEB)

Kundu, Ananya; Pradhan, Subrata, E-mail: pradhan@ipr.res.in; Ghate, Mahesh; Kanabar, Deven; Roy, Swati; Kumar, Nitish

2017-01-15

3D transient thermo-structural analyses and steady state magnetic field analyses of 1:1 prototyped JET Edge Localized Mode (ELM) coils have been carried out. Temperature distribution within the magnet winding as well as the temperature evolution have also been simulated as a function of pulsed transport currents in both large and small ELM coils as per the operational scenarios. The induced thermal stresses along with the shear stress components acting on the winding elements have also been analyzed. The deformations caused by thermal stresses have been calculated for the case, the conductor bundle and the insulation layers within the coils. In addition to thermo-structural analyses, steady state magnetic field analyses have also been carried out in the current carrying ELM coils. These values have been compared with the experimental values. The experimentally obtained values matches well with those obtained in simulations indicating that the prototyped ELM coils can operate successfully in JET operational scenarios. Additionally, the R & D and technologies developed in the context of JET ELM coils have also been validated with the magnet performances experimentally.

Investigations on the edge kinetic data in regimes with type-I and mitigated ELMs at ASDEX Upgrade

International Nuclear Information System (INIS)

Rathgeber, S.K.; Barrera, L.; Birkenmeier, G.; Fischer, R.; Suttrop, W.

2014-01-01

The behaviour of profiles and gradients of electron density, temperature and pressure at the edge of ASDEX Upgrade was studied in regimes with type-I and small edge localized modes (ELMs) of discharges with and without applied magnetic perturbations (MPs). Estimation of the edge kinetic parameters was performed by means of integrated data analysis for joint reconstruction of electron density and temperature profiles via combination of data from different diagnostics. The MP fields for ELM mitigation were produced by 16 in-vessel coils allowing to execute this survey with large variations in poloidal spectrum and resonant component of the error field. With several dedicated discharges the effect of MPs on the edge kinetic data and ELMs was determined in dependence of heating power, gas puff and MP-coil configuration. Small ELMs are dominant—with and without MPs—in regimes with reduced pedestal top electron temperatures and flattened edge electron pressure gradients compared to type-I ELM phases. Furthermore, application of MPs opens an additional small ELM regime in the high temperature range at reduced electron pressure gradient. (paper)

Effects of ELMs and disruptions on ITER divertor armour materials

Science.gov (United States)

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.

Effects of ELMs and disruptions on ITER divertor armour materials

International Nuclear Information System (INIS)

Federici, G.; Zhitlukhin, A.; Arkhipov, N.; Giniyatulin, R.; Klimov, N.; Landman, I.; Podkovyrov, V.; Safronov, V.; Loarte, A.; Merola, M.

2005-01-01

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

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

Directory of Open Access Journals (Sweden)

Büchel Kerstin

2012-06-01

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

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

Science.gov (United States)

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

Association between haptoglobin gene and insulin resistance in Arab-Americans.

Science.gov (United States)

Burghardt, Kyle J; Masri, Dana El; Dass, Sabrina E; Shikwana, Sara S; Jaber, Linda A

2017-11-01

To analyze associations between variation in the HP gene and lipid and glucose-related measures in Arab-Americans. Secondary analyses were performed based on sex. Genomic DNA was extracted from samples obtained from a previous epidemiological study of diabetes in Arab-Americans. The HP 1 and 2 alleles were analyzed by polymerase chain reaction and gel electrophoresis. Associations were analyzed by linear regression. Associations were identified between the heterozygous haptoglobin 2-1 genotype and insulin resistance, fasting insulin and fasting c-peptide. The effect of sex did not remain significant after adjustment for relevant variables. HP genetic variation may have utility as a biomarker of insulin resistance and diabetes risk in Arab-Americans, however, future prospective studies are needed.

Using ELM-based weighted probabilistic model in the classification of synchronous EEG BCI.

Science.gov (United States)

Tan, Ping; Tan, Guan-Zheng; Cai, Zi-Xing; Sa, Wei-Ping; Zou, Yi-Qun

2017-01-01

Extreme learning machine (ELM) is an effective machine learning technique with simple theory and fast implementation, which has gained increasing interest from various research fields recently. A new method that combines ELM with probabilistic model method is proposed in this paper to classify the electroencephalography (EEG) signals in synchronous brain-computer interface (BCI) system. In the proposed method, the softmax function is used to convert the ELM output to classification probability. The Chernoff error bound, deduced from the Bayesian probabilistic model in the training process, is adopted as the weight to take the discriminant process. Since the proposed method makes use of the knowledge from all preceding training datasets, its discriminating performance improves accumulatively. In the test experiments based on the datasets from BCI competitions, the proposed method is compared with other classification methods, including the linear discriminant analysis, support vector machine, ELM and weighted probabilistic model methods. For comparison, the mutual information, classification accuracy and information transfer rate are considered as the evaluation indicators for these classifiers. The results demonstrate that our method shows competitive performance against other methods.

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

NARCIS (Netherlands)

Versloot, T.W.; de Vries, P.C.; Giroud, C.; Hua, M.D.; Beurskens, M.N.A.; Brix, M.; Eich, T.; Luna, de la E.; Tala, T.; Naulin, V.; Zastrov, K.D.

2010-01-01

The loss of plasma toroidal angular momentum and thermal energy by edge localized modes (ELMs) has been studied in JET. The analysis shows a consistently larger drop in momentum in comparison with the energy loss associated with the ELMs. This difference originates from the large reduction in

ELMs and constraints on the H-mode pedestal: A model based on peeling-ballooning modes

International Nuclear Information System (INIS)

Snyder, P.B.; Ferron, J.R.; Wilson, H.R.

2003-01-01

We propose a model for Edge Localized Modes (ELMs) and pedestal constraint based upon theoretical analysis of instabilities which can limit the pedestal height and drive ELMs. The sharp pressure gradients, and resulting bootstrap current, in the pedestal region provide free energy to drive peeling and ballooning modes. The interaction of peeling-ballooning coupling, ballooning mode second stability, and finite-Larmor-radius effects results in coupled peeling-ballooning modes of intermediate wavelength generally being the limiting instability. A highly efficient new MHD code, ELITE, is used to calculate quantitative stability constraints on the pedestal, including con straits on the pedestal height. Because of the impact of collisionality on the bootstrap current, these pedestal constraints are dependant on the density and temperature separately, rather than simply on the pressure. A model of various ELM types is developed, and quantitatively compared to data. A number of observations agree with predictions, including ELM onset times, ELM depth and variation in pedestal height with collisionality and discharge shape. Stability analysis of series of model equilibria are used both o predict and interpret pedestal trends in existing experiments and to project pedestal constraints for future burning plasma tokamak designs. (author)

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

Science.gov (United States)

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

A quantitative analysis of the effect of ELMs on H-mode thermal energy confinement in DIII-D

International Nuclear Information System (INIS)

Schissel, D.P.; Osborne, T.H.; Carlstrom, T.N.; Zohm, H.

1992-06-01

The desire to reach ignition in future tokamaks the energy confinement time critical parameter. The most promising enhanced (over L-mode) confinement regime is the H-mode, discovered on ASDEX with neutral beam heating, and then confirmed with various auxiliary heating sources on numerous machines. The knowledge of how H-mode τ E depends on different parameters is of chemical importance to the performance predictions for next generation devices. Inter-machine H-mode total and thermal energy confinement (τ th ) scalings, which are being utilized to predict ITER thermal energy confinement, have been created for discharges where the Edge Localized Mode (ELM) instability has not been present. Confinement scaling research hm concentrated on this ELM-free H-mode phase mostly owing to the difficulty of characterizing ELM behavior. To date, long pulse H-mode operation has only been achieved by utilizing ELMs to flush out unpurities and prevent radiative collapse of the discharge. Unfortunately, accompanying the ELMS is a decrease of the plasma stored energy due to the expulsion of particles near the edge of the discharge resulting in a reduction of the steep edge electron density gradient. In order to predict ITER's H-mode τ th in the presence of ELMS, an estimated 25% confinement degradation factor has been applied to the ELM-free predictions. Our work, summarized in this paper, indicates that this 25% reduction factor is too large and instead a value of approximately 15% would be more appropriate

Comparative investigation of ELM control based on toroidal modelling of plasma response to RMP fields

Science.gov (United States)

Liu, Yueqiang

2016-10-01

The type-I edge localized mode (ELM), bursting at low frequency and with large amplitude, can channel a substantial amount of the plasma thermal energy into the surrounding plasma-facing components in tokamak devices operating at the high-confinement mode, potentially causing severe material damages. Learning effective ways of controlling this instability is thus an urgent issue in fusion research, in particular in view of the next generation large devices such as ITER and DEMO. Among other means, externally applied, three-dimensional resonant magnetic perturbation (RMP) fields have been experimentally demonstrated to be successful in mitigating or suppressing the type-I ELM, in multiple existing devices. In this work, we shall report results of a comparative study of ELM control using RMPs. Comparison is made between the modelled plasma response to the 3D external fields and the observed change of the ELM behaviour on multiple devices, including MAST, ASDEX Upgrade, EAST, DIII-D, JET, and KSTAR. We show that toroidal modelling of the plasma response, based on linear and quasi-linear magnetohydrodynamic (MHD) models, provides essential insights that are useful in interpreting and guiding the ELM control experiments. In particular, linear toroidal modelling results, using the MARS-F code, reveal the crucial role of the edge localized peeling-tearing mode response during ELM mitigation/suppression on all these devices. Such response often leads to strong peaking of the plasma surface displacement near the region of weak equilibrium poloidal field (e.g. the X-point), and this provides an alternative practical criterion for ELM control, as opposed to the vacuum field based Chirikov criteria. Quasi-linear modelling using MARS-Q provides quantitative interpretation of the side effects due to the ELM control coils, on the plasma toroidal momentum and particle confinements. The particular role of the momentum and particle fluxes, associated with the neoclassical toroidal

Electromagnetic ELM and inter-ELM filaments detected in the COMPASS Scrape-Off Layer.

Czech Academy of Sciences Publication Activity Database

Spolaore, M.; Kovařík, Karel; Stöckel, Jan; Adámek, Jiří; Dejarnac, Renaud; Ďuran, Ivan; Komm, Michael; Markovič, Tomáš; Martines, E.; Pánek, Radomír; Seidl, Jakub; Vianello, N.

2017-01-01

Roč. 12, August (2017), s. 844-851 ISSN 2352-1791. [PSI 2016 - 22nd International Conference on Plasma Surface Interactions in Controlled Fusion Devices/22./. Roma, 30.05.2016-03.06.2016] R&D Projects: GA MŠk(CZ) 8D15001; GA MŠk(CZ) LM2015045 EU Projects: European Commission(XE) 633053 - EUROfusion Institutional support: RVO:61389021 Keywords : Electromagnetic filaments * ELMs * Scrape-Off Layer * Magnetic fluctuations * Current density Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) http://www.sciencedirect.com/science/article/pii/S2352179116301934

Magnetic diagnostic of SOL-filaments generated by type I ELMs on JET and ASDEX Upgrade

DEFF Research Database (Denmark)

Naulin, Volker; Vianello, N.; Schrittwieser, R.

2011-01-01

to a simple model, motivated by observations. A new diagnostic in the form of a reciprocating probe with three magnetic pickup loops was developed for ASDEX Upgrade (AUG). Measurements during the passage of type-I ELM filaments determine the filaments to be in the scrape off layer (SOL) and to carry currents......This contribution is focused on the magnetic signatures of type I ELM filaments. On JET a limited number of high time resolution magnetic coils were used to derive essential ELM filament parameters. The method uses forward modelling and simultaneous fitting of magnetic pickup coil signals...

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

Directory of Open Access Journals (Sweden)

Jun Zhou

2016-01-01

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

Dutch elm disease control: performance and costs

Science.gov (United States)

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

1980-01-01

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

Study of type III ELMs in JET

NARCIS (Netherlands)

Sartori, R.; Saibene, G.; Horton, L. D.; Becoulet, M.; Budny, R.; Borba, D.; Chankin, A.; Conway, G. D.; Cordey, G.; McDonald, D.; Guenther, K.; von Hellermann, M. G.; Igithkanov, Y.; Loarte, A.; Lomas, P. J.; Pogutse, O.; Rapp, J.

2004-01-01

This paper presents the results of JET experiments aimed at studying the operational space of plasmas with a Type III ELMy edge, in terms of both local and global plasma parameters. In JET, the Type III ELMy regime has a wide operational space in the pedestal n(e)-T-e diagram, and Type III ELMs are

Small ELM regimes with good confinement on JET and comparison to those on ASDEX Upgrade, Alcator C-mod, and JT-60U

International Nuclear Information System (INIS)

Stober, J.; Lomas, P.; Saibene, G.

2005-01-01

Since it is uncertain if ITER operation is compatible with type-I ELMs, the study of alternative H-mode pedestals is an urgent issue. This paper reports on experiments on JET aiming to find scenarios with small ELMs and good confinement, such as the type-II ELMs in ASDEX Upgrade, the enhanced D-alpha H-mode in Alcator C-mod or the grassy ELMs in JT-60U. The study includes shape variations, especially the closeness to a double-null configuration, variations of q 95 , density and beta poloidal. H-mode pedestals without type-I ELMs have been observed only at the lowest currents (≤ 1.2 MA), showing similarities to the observations in the devices mentioned above. These are discussed in detail on the basis of edge fluctuation analysis. For higher currents, only the mixed type-I/II scenario is observed. Although the increased inter-ELM transport reduces the type-I ELM frequency, a single type-I ELM is not significantly reduced in size. Obviously, these results do question the accessibility of such small ELM scenarios on ITER, except perhaps the high beta-poloidal scenario at higher q 95 , which could not be tested at higher currents at JET due to limitations in heating power. (author)

Spatial Distribution and Site-Specific Spraying of Main Sucking Pests of Elm Trees.

Science.gov (United States)

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.

Plasma-edge gradients in L-mode and ELM-free H-mode JET plasmas

International Nuclear Information System (INIS)

Breger, P.; Zastrow, K.-D.; Davies, S.J.; K ig, R.W.T.; Summers, D.D.R.; Hellermann, M.G. von; Flewin, C.; Hawkes, N.C.; Pietrzyk, Z.A.; Porte, L.

1998-01-01

Experimental plasma-edge gradients in JET during the edge-localized-mode (ELM) free H-mode are examined for evidence of the presence and location of the transport barrier region inside the magnetic separatrix. High spatial resolution data in electron density is available in- and outside the separatrix from an Li-beam diagnostic, and in electron temperature inside the separatrix from an ECE diagnostic, while outside the separatrix, a reciprocating probe provides electron density and temperature data in the scrape-off layer. Ion temperatures and densities are measured using an edge charge-exchange diagnostic. A comparison of observed widths and gradients of this edge region with each other and with theoretical expectations is made. Measurements show that ions and electrons form different barrier regions. Furthermore, the electron temperature barrier width (3-4 cm) is about twice that of electron density, in conflict with existing scaling laws. Suitable parametrization of the edge data enables an electron pressure gradient to be deduced for the first time at JET. It rises during the ELM-free phase to reach only about half the marginal pressure gradient expected from ballooning stability before the first ELM. Subsequent type I ELMs occur on a pressure gradient contour roughly consistent with both a constant barrier width model and a ballooning mode envelope model. (author)

An interpretation of the structure of ELMs and the H to L transition on JET

International Nuclear Information System (INIS)

Cripwell, P.; Edwards, A.; Galvao, R.

1989-01-01

Initial studies on JET have described the characteristics of edge fluctuations in X-point plasmas and their effects on energy and particle confinement. In this paper we perform a detailed magnetic analysis of ELMs and their precursors, and make a comparison with the H to L transition. These magnetic results correlate with those of other diagnostics such as the microwave reflectometer and X-point langmuir probes. Localization of ELMs and H to L transition spike is determined with the soft X-ray camera, and particle transport estimated by an H-alpha detector. Finally possible theoretical explanations for ELMs are discussed. (author) 5 refs., 3 figs

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

OpenAIRE

Qing Ye; Hao Pan; Changhua Liu

2015-01-01

A novel semisupervised extreme learning machine (ELM) with clustering discrimination manifold regularization (CDMR) framework named CDMR-ELM is proposed for semisupervised classification. By using unsupervised fuzzy clustering method, CDMR framework integrates clustering discrimination of both labeled and unlabeled data with twinning constraints regularization. Aiming at further improving the classification accuracy and efficiency, a new multiobjective fruit fly optimization algorithm (MOFOA)...

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

Science.gov (United States)

Ye, Qing; Pan, Hao; Liu, Changhua

2015-01-01

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

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

Directory of Open Access Journals (Sweden)

Qing Ye

2015-01-01

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

Mitigation of divertor heat flux by high-frequency ELM pacing with non-fuel pellet injection in DIII-D

Directory of Open Access Journals (Sweden)

A. Bortolon

2017-08-01

Full Text Available Experiments have been conducted on DIII-D investigating high repetition rate injection of non-fuel pellets as a tool for pacing Edge Localized Modes (ELMs and mitigating their transient divertor heat loads. Effective ELM pacing was obtained with injection of Li granules in different H-mode scenarios, at frequencies 3–5 times larger than the natural ELM frequency, with subsequent reduction of strike-point heat flux (Bortolon et al., Nucl. Fus., 56, 056008, 2016. However, in scenarios with high pedestal density (∼6 ×1019m−3, the magnitude of granule triggered ELMs shows a broad distribution, in terms of stored energy loss and peak heat flux, challenging the effectiveness of ELM mitigation. Furthermore, transient heat-flux deposition correlated with granule injections was observed far from the strike-points. Field line tracing suggest this phenomenon to be consistent with particle loss into the mid-plane far scrape-off layer, at toroidal location of the granule injection.

The structure of ELMs and the distribution of transient power loads in MAST

International Nuclear Information System (INIS)

Kirk, A.; Akers, R.; Conway, N.J.; Counsell, G.F.; Dowling, J.; Field, A.; Meyer, H.; Price, M.; Wilson, H.R.; Dudson, B.; Lott, F.; Walsh, M.

2005-01-01

The spatial and temporal structure of edge localised modes (ELMs) and the spatial structure of power loads during one type of disruption on MAST is presented. Filamentary enhancements of visible light are observed on photographic images of the plasma obtained during ELMs. Comparisons with simulations show that these filaments follow field lines at the outboard edge of the plasma. The toroidal mode number of these filaments has been extracted from a study of the discrete peaks observed in the ion saturation current recorded by a mid-plane reciprocating probe. A study of the time delay of these peaks with respect to the onset of the ELM has been used to calculate an effective radial velocity for the expansion of the filaments. A comparison of this derived radial velocity as a function of distance from the last closed flux surface with simulations indicates that the filament is accelerating away from the plasma. Measurements of the time difference between the peaks in the ion saturation current observed at two toroidally separated probes, when compared to these simulations, confirms this picture. A study of the toroidal velocity as a function of radius shows that during an ELM the strong velocity shear near to the edge of the plasma, normally present in H-modes, is strongly reduced. The picture that emerges is that the ELM can be viewed as being composed of filamentary structures that are generated on a 100 μs timescale, accelerate away from the plasma edge, are extended along a field line and have a typical toroidal mode number ∼ 10. Such a structure would be expected from the theory of the non-linear evolution of ballooning modes, which also predicts filament like structures in certain types of disruptions. Evidence for these filaments as a precursor to a certain type of disruption has been obtained from both visible and infrared images. (author)

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

Science.gov (United States)

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.

COMPARISON OF ELM PULSE PROPAGATION IN THE DIII-D SOL AND DIVERTORS WITH AN ION CONVECTION MODEL

International Nuclear Information System (INIS)

FENSTERMACHER, ME; PORTER, GD; LEONARD, AW; BROOKS, NH; BOEDO, JA; COLCHIN, RJ; GRAY, DS; GROEBNER, RJ; GROTH, M; HOGAN, JT; HOLLMANN, EM; LASNIER, CJ; OSBORNE, TH; PETRIE, TW; RUDAKOV, DL; SNYDER, PB; TAKAHASHI, H; WATKINS, JG; ZENG, L; DIII-D TEAM

2003-01-01

OAK-B135 Results from dedicated ELM experiments, performed in DIII-D with fast diagnostics to measure the evolution of Type-I ELM effects in the SOL and divertor, are compared with a simple ion convection model and with initial time-dependent UEDGE simulations. Delays between ELM effects observed in the inner versus the outer divertor regions in the experiments scale, as a function of density, with the difference in ion convection time along field lines from the outer midplane to the divertor targets. The ELM perturbation was modeled as an instantaneous radially uniform increase of diffusion coefficients from the top of the pedestal to the outer SOL. The perturbation was confined to a low field side poloidal zone ± 40 o from the outer midplane. The delays in the simulations are similar to those observed in the experiments

Scaling of ELM and H-mode pedestal characteristics in ITER shape discharges in the DIII-D tokamak

International Nuclear Information System (INIS)

Osborne, T.H.; Groebner, R.J.; Lao, L.L.; Leonard, A.W.; Miller, R.L.; Thomas, D.M.; Waltz, R.E.; Maingi, R.; Porter, G.D.

1997-07-01

The authors have shown a correlation between the H-mode pressure pedestal height and the energy confinement enhancement in ITER shape discharges on DIII-D which is consistent with the behavior of H in different ELM classes. The width of the steep gradient region was found to equally well fit the scalings δ/R ∝ (ρ POL /R) 2/3 and δ/R ∝ (β POL PED /R) 1/2 . The normalized pressure gradient α MHD was found to be relatively constant just before a type I ELM. An estimate of T PED for ITER gave 1 to 5 keV. They also estimate ΔE ELM ≅ 26 MJ for ITER. They identified a distinct class of type III ELM at low density which may play a role in setting H at powers near the H-mode threshold power

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

Energy Technology Data Exchange (ETDEWEB)

Elmore, S., E-mail: Sarah.Elmore@ccfe.ac.uk [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Allan, S.Y.; Fishpool, G.; Kirk, A. [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Kočan, M. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-lez-Durance (France); Tamain, P. [Association Euratom-CEA, CEA/DSM/IRFM, CEA-Cadarache, F-13108 St Paul-lez-Durance Cedex (France); Thornton, A.J. [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)

2015-08-15

Edge-localised modes (ELMs) can carry significant fractions of their energy as far as main chamber plasma-facing components in divertor tokamaks. Since in future devices (e.g. ITER, DEMO) these energies could cause issues for material lifetime and impurity production, the energy and temperature of ions in ELMs needs to be investigated. In MAST, novel divertor measurements of T{sub i} during ELMs have been made using the divertor retarding field energy analyser (RFEA) probe. These measurements have shown instantaneous ion energy distributions corresponding to an effective T{sub i} at 5 cm from the strike point at the target that can be as high as 60 eV and that this decreases with time after the ELM start. This is consistent with the hottest, fastest ions arriving at the target first by parallel transport, followed by the lower end of the ion energy distribution. This analysis will form a basis for future data analysis of fast swept measurements of ion distributions in ELMs.

Stability analysis of ELMs in long-pulse discharges with ELITE code on EAST tokamak

Science.gov (United States)

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.

H-mode pedestal characteristics, ELMs, and energy confinement in ITER shape discharges on DIII-D

International Nuclear Information System (INIS)

Osborne, T.H.; Groebner, R.J.; Lao, L.L.; Leonard, A.W.; Miller, R.L.; Thomas, D.M.; Waltz, R.E.; Maingi, R.; Porter, G.D.

1997-12-01

The H-mode confinement enhancement factor, H, is found to be strongly correlated with the height of the edge pressure pedestal in ITER shape discharges. In discharges with Type I ELMs the pedestal pressure is set by the maximum pressure gradient before the ELM and the width of the H-mode transport barrier. The pressure gradient before Type I ELMs is found to scale as would be expected for a stability limit set by ideal ballooning modes, but with values significantly in excess of that predicted by stability code calculations. The width of the H-mode transport barrier is found to scale equally well with pedestal P(POL)(2/3) or B(POL)(1/2). The improved H value in high B(POL) discharges may be due to a larger edge pressure gradient and wider H-mode transport barrier consistent with their higher edge ballooning mode limit. Deuterium puffing is found to reduce H consistent with the smaller pedestal pressure which results from the reduced barrier width and critical pressure gradient. Type I ELM energy loss is found to be proportional to the change in the pedestal energy

A Regional Guidebook for Applying the Hydrogeomorphic Approach to the Functional Assessment of Forested Wetlands in Alluvial Valleys of East Texas

Science.gov (United States)

2010-10-01

plant species as the low-gradient riverine subclass. However, species such as American elm (Ulmus americana), slippery elm (Ulmus rubra), winged elm ...americana American elm Ulmus crassifolia cedar elm Ulmus rubra slippery elm Ulmus spp. elm Viburnum nudum possumhaw Vitis rotundifolia muscadine...laurel oak (Q. laurifolia), Shumard oak (Q. shumardii), elms (Ulmus sp.), sweetgum (Liquidambar styraciflua), southern magnolia (Magnolia

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

Science.gov (United States)

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.

Cultural Resources in the Southern Lake Erie Basin: A Predictive Study.

Science.gov (United States)

1981-01-01

American elm , black ash, and silver maple; also associated were slippery elm , burr oak, swamp white oak, and bitternut hickory. Another type of swamp...American elm -red maple-black ash association dominated the wetter sites. Associated were slippery elm , burr oak, swamp white oak, and bitternut...americana Red elm ( slippery elm ) U. rubra Balsam fir Abies balsanea Hackberry Celtis occidentalis American hazel Corylus americana Eastern hemlock

Pacing control of sawtooth and ELM oscillations in tokamaks

NARCIS (Netherlands)

Lauret, M.; Lennholm, M.; de Baar, M.R.; Heemels, W.P.M.H.

2016-01-01

In tokamak plasmas, the sawtooth oscillation (ST) and the edge-localized-mode (ELM) are characterized by a phase of a slow evolution of the plasma conditions, followed by a crash-like instability that resets the plasma conditions when certain criteria of the plasma conditions are satisfied.

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

Energy Technology Data Exchange (ETDEWEB)

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

2005-03-01

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

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

Science.gov (United States)

Dunne, M. G.

2017-02-01

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

Role of phytohormones in organogenic ability of elm multiplicated shoots

Czech Academy of Sciences Publication Activity Database

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

2006-01-01

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

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

Directory of Open Access Journals (Sweden)

N.S. Klimov

2017-08-01

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

Elm Farm Organic Research Centre December 2006

OpenAIRE

Sanders, Richard; Whiltley, Andrew; Haigh, Zoe; Clarke, Sarah; Hitchings, Roger; O'Brien, Josie

2006-01-01

The Organic Research Centre. Elm Farm Research Centre Bulletin with Technical Updates from The Organic Advisory Service is a regular publication from The Organic Research Centre. The current issue covers: Report from 2006 Cirencester Conference; Quest for more home produced organic food; in a world where bread matters; Improving wheat with plenty of parents; Unlocking the secrets of the ancient (cereal varieties); Brain food- a good read; Not to late to protect the future: The organic...

Genome-wide analyses of the Dutch elm disease fungi

Science.gov (United States)

Louis. Bernier

2017-01-01

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

Methane penetration in DIII-D ELMing H-mode plasmas

International Nuclear Information System (INIS)

West, W.P.; Lasnier, C.J.; Whyte, D.G.; Isler, R.C.; Evans, T.E.; Jackson, G.L.; Rudakov, D.; Wade, M.R.; Strachan, J.

2003-01-01

Carbon penetration into the core plasma during midplane and divertor methane puffing has been measured for DIII-D ELMing H-mode plasmas. The methane puffs are adjusted to a measurable signal, but global plasma parameters are only weakly affected (line average density, e > increases by E , drops by 6+ density profiles in the core measured as a function of time using charge exchange recombination spectroscopy. The methane penetration factor is defined as the difference in the core content with the puff on and puff off, divided by the carbon confinement time and the methane puffing rate. In ELMing H-mode discharges with ion ∇B drift direction into the X-point, increasing the line averaged density from 5 to 8x10 19 m -3 dropped the penetration factor from 6.6% to 4.6% for main chamber puffing. The penetration factor for divertor puffing was below the detection limit (<1%). Changing the ion ∇B drift to away from the X-point decreased the penetration factor by more than a factor of five for main chamber puffing

Analysis of different responses of ion and electron in six-field two-fluid ELM simulations

Science.gov (United States)

Ma, Chenhao; Xu, Xueqiao

2013-10-01

We report simulation results of a Landau-Fluid (GLF) extension of the BOUT++ six-field two-fluid Braginskii model which contributes to increasing the physics understanding of ELMs. Landau-Fluid closure can fill the gap for parallel dynamics between hot, collisionless pedestal region and cold, collisional SOL region in H-mode plasmas. Our goal is extending the classical parallel heat flux with Landau-Fluid closures and making comparisons with other closure models. Our simulations show that for weakly collisional pedestal plasmas, the calculated growth rate with Landau-Fluid closure introduces more effective damping on the peeling-ballooning modes than that with the classical thermal diffusivity. Further nonlinear simulation shows that ELM size with Landau-Fluid Closure is smaller than that with classical thermal diffusivity. We find an ELM crash has two phases: fast initial crash of ion temperature perturbation on the Alfven time scale and slow turbulence spreading. Turbulence transport phase is a slow encroachment of electron temperature perturbation due to the ELM event into pedestal region which is due to a positive phase shift around π / 2 between electron temperature and potential on pedestal region while ion temperature is in-phase with potential. This work was performed under the auspices of the U.S. DoE by LLNL under Contract DE-AC52-07NA27344 and also supported by the China Scholarship Committee under contract N0.2011601099.

Lateral deflection of the SOL plasma during a giant ELM

International Nuclear Information System (INIS)

Landman, I.S.; Wuerz, H.

2001-01-01

In recent H-mode experiments at JET with giant ELMs a lateral deflection of hot tokamak plasma striking the divertor plate has been observed. This deflection can effect the divertor erosion caused by the hot plasma irradiation. Based on the MHD model for the vapor shield plasma and the hot plasma, the Seebeck effect is analyzed for explanation of the deflection. At t=-∞ both plasmas are at rest and separated by a boundary parallel to the target. The interaction between plasmas develops gradually ('adiabatically') as exp(t/t 0 ) with t 0 ∼10 2 μs the ELM duration time. At inclined impact of the magnetized hot plasma a toroidal current develops in the interaction zone of the plasmas. The JxB force accelerates the interacting plasmas in the lateral direction. The cold plasma motion essentially compensates the current. The magnitude of the hot plasma deflection is comparable to the observed one

Program ELM: A tool for rapid thermal-hydraulic analysis of solid-core nuclear rocket fuel elements

International Nuclear Information System (INIS)

Walton, J.T.

1992-11-01

This report reviews the state of the art of thermal-hydraulic analysis codes and presents a new code, Program ELM, for analysis of fuel elements. ELM is a concise computational tool for modeling the steady-state thermal-hydraulics of propellant flow through fuel element coolant channels in a nuclear thermal rocket reactor with axial coolant passages. The program was developed as a tool to swiftly evaluate various heat transfer coefficient and friction factor correlations generated for turbulent pipe flow with heat addition which have been used in previous programs. Thus, a consistent comparison of these correlations was performed, as well as a comparison with data from the NRX reactor experiments from the Nuclear Engine for Rocket Vehicle Applications (NERVA) project. This report describes the ELM Program algorithm, input/output, and validation efforts and provides a listing of the code

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

Science.gov (United States)

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

Repetitive plasma loads typical for ITER Type-I ELMS; simulation in QSPA Kh-50

International Nuclear Information System (INIS)

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

2005-01-01

The power loads on current tokamaks associated with the Type I ELMs generally do not affect the lifetime of divertor elements. However, the ITER ELMs may lead to unacceptable lifetime; their loads are estimated as QELM(1-3) MJ/m 2 at t = 0.1-1 ms and the repetition frequency of an order of 1 Hz (∼ 400 ELMs during each ITER pulse). Such plasma energy loads expected for ITER ELMs are not achieved in existing tokamaks. Therefore powerful plasma accelerators are used at present for study of plasma-target interaction and for numerical models validation. Quasi-steady-state plasma accelerators (QSPA), which characterized by essentially longer duration of plasma stream generation in comparison with pulsed plasma guns, became especially attractive facilities for investigations of plasma-surface interaction in conditions of high heat loads simulating the ITER disruptions and ELMs. The paper presents experimental study of energy characteristics of the plasma streams generated with quasi-steady-state plasma accelerator QSPA Kh-50 and the main features of plasma interaction with material surfaces in dependence on plasma heat loads. The samples of pure sintered tungsten of EU trademark have been exposed to hydrogen plasma streams produced by the accelerator. To estimate the range of tolerable loads the effects of ELMs on the lifetime of plasma facing components have been experimentally simulated for large numbers of impacts with varying energy density. The experiments were performed with up to 450 pulses of the duration of 0.25 ms and the heat loads in the range of 0.5 - 1.2 MJ/m 2 . At this calorimetry (both at plasma stream and at the target surface), piezo-detectors as well as spectroscopy and interferometry measurements were applied to determine the impacting plasma parameters in different regimes of operation. A threshold character of morphological changes on the tungsten surface under the melting in respect to the pulses number is demonstrated. The number of initial

Menyoal Elaboration Likelihood Model (ELM) dan Teori Retorika

OpenAIRE

Yudi Perbawaningsih

2012-01-01

Abstract: Persuasion is a communication process to establish or change attitudes, which can be understood through theory of Rhetoric and theory of Elaboration Likelihood Model (ELM). This study elaborates these theories in a Public Lecture series which to persuade the students in choosing their concentration of study. The result shows that in term of persuasion effectiveness it is not quite relevant to separate the message and its source. The quality of source is determined by the quality of ...

Menyoal Elaboration Likelihood Model (ELM) Dan Teori Retorika

OpenAIRE

Perbawaningsih, Yudi

2012-01-01

: Persuasion is a communication process to establish or change attitudes, which can be understood through theory of Rhetoric and theory of Elaboration Likelihood Model (ELM). This study elaborates these theories in a Public Lecture series which to persuade the students in choosing their concentration of study. The result shows that in term of persuasion effectiveness it is not quite relevant to separate the message and its source. The quality of source is determined by the quality of the mess...

Genealogical Analysis of the North-American Spring Wheat Varieties with Different Resistance to Pre-harvest Sprouting

Directory of Open Access Journals (Sweden)

Martynov Sergey

2016-12-01

Full Text Available A comparative analysis of genetic diversity of North American spring wheat varieties differing in resistance to pre-harvest sprouting was carried out. For identification of sources of resistance the genealogical profiles of 148 red-grained and 63 white-grained North-American spring wheat varieties with full pedigrees were calculated and estimates were made of pre-harvest sprouting. The cluster structure of the populations of red-grained and white-grained varieties was estimated. Analysis of variance revealed significant differences between the average contributions of landraces in the groups of resistant and susceptible varieties. Distribution of the putative sources of resistance in the clusters indicated that varieties having different genetic basis may have different sources of resistance. For red-grained varieties the genetic sources of resistance to pre-harvest sprouting are landraces Crimean, Hard Red Calcutta, and Iumillo, or Button, Kenya 9M-1A-3, and Kenya-U, or Red Egyptian and Kenya BF4-3B-10V1. Tracking of pedigrees showed these landraces contributed to the pedigrees, respectively, via Thatcher, Kenya-Farmer, and Kenya-58, which were likely donors of resistance for red-grained varieties. For white-grained varieties the sources of resistance were landraces Crimean, Hard Red Calcutta, Ostka Galicyjska, Iumillo, Akakomugi, Turco, Hybrid English, Rough Chaff White and Red King, and putative donors of resistance — Thatcher, RL2265, and Frontana. The genealogical profile of accession RL4137, the most important donor of resistance to pre-harvest sprouting in North American spring wheat breeding programmes, contains almost all identified sources of resistance.

Preliminary investigations of equilibrium reconstruction quality during ELMy and ELM-free phases on JET

International Nuclear Information System (INIS)

Gelfusa, M.; Murari, A.; Peluso, E.; Gaudio, P.; Orsitto, F.P.; Gerasimov, S.

2013-01-01

On JET, the magnetic topology is normally derived from the code EFIT, which solves the Grad–Shafranov equation with constraints imposed by the available measurements, typically the pick-up coils. Both the code and the measurements are expected to perform worse during ELMs. To assess this hypothesis, various statistical indicators, based on the values of the residuals and their probability distribution, have been calculated. They all show that the quality of EFIT reconstructions is clearly better in absence of ELMs. How the responsibility, for the lower quality of the reconstructions, is shared between the measurements and EFIT is a subject under investigation. © 2001 Elsevier Science. All rights reserved

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

Directory of Open Access Journals (Sweden)

GAO Junfeng

2014-04-01

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

THE ELM SURVEY. II. TWELVE BINARY WHITE DWARF MERGER SYSTEMS

International Nuclear Information System (INIS)

Kilic, Mukremin; Brown, Warren R.; Kenyon, S. J.; Prieto, Carlos Allende; Agueeros, M. A.; Heinke, Craig

2011-01-01

We describe new radial velocity and X-ray observations of extremely low-mass white dwarfs (ELM WDs, ∼0.2 M sun ) in the Sloan Digital Sky Survey Data Release 4 and the MMT Hypervelocity Star survey. We identify four new short period binaries, including two merger systems. These observations bring the total number of short period binary systems identified in our survey to 20. No main-sequence or neutron star companions are visible in the available optical photometry, radio, and X-ray data. Thus, the companions are most likely WDs. Twelve of these systems will merge within a Hubble time due to gravitational wave radiation. We have now tripled the number of known merging WD systems. We discuss the characteristics of this merger sample and potential links to underluminous supernovae, extreme helium stars, AM CVn systems, and other merger products. We provide new observational tests of the WD mass-period distribution and cooling models for ELM WDs. We also find evidence for a new formation channel for single low-mass WDs through binary mergers of two lower mass objects.

Fast-ion losses induced by ELMs and externally applied magnetic perturbations in the ASDEX Upgrade tokamak

International Nuclear Information System (INIS)

Garcia-Munoz, M; Rodriguez-Ramos, M; Äkäslompolo, S; De Marne, P; Dunne, M G; Dux, R; Fietz, S; Fuchs, C; Geiger, B; Herrmann, A; Hoelzl, M; Kurzan, B; McDermott, R M; Strumberger, E; Evans, T E; Ferraro, N M; Pace, D C; Lazanyi, N; Nocente, M; Shinohara, K

2013-01-01

Phase-space time-resolved measurements of fast-ion losses induced by edge localized modes (ELMs) and ELM mitigation coils have been obtained in the ASDEX Upgrade tokamak by means of multiple fast-ion loss detectors (FILDs). Filament-like bursts of fast-ion losses are measured during ELMs by several FILDs at different toroidal and poloidal positions. Externally applied magnetic perturbations (MPs) have little effect on plasma profiles, including fast-ions, in high collisionality plasmas with mitigated ELMs. A strong impact on plasma density, rotation and fast-ions is observed, however, in low density/collisionality and q 95 plasmas with externally applied MPs. During the mitigation/suppression of type-I ELMs by externally applied MPs, the large fast-ion bursts observed during ELMs are replaced by a steady loss of fast-ions with a broad-band frequency and an amplitude of up to an order of magnitude higher than the neutral beam injection (NBI) prompt loss signal without MPs. Multiple FILD measurements at different positions, indicate that the fast-ion losses due to static 3D fields are localized on certain parts of the first wall rather than being toroidally/poloidally homogeneously distributed. Measured fast-ion losses show a broad energy and pitch-angle range and are typically on banana orbits that explore the entire pedestal/scrape-off-layer (SOL). Infra-red measurements are used to estimate the heat load associated with the MP-induced fast-ion losses. The heat load on the FILD detector head and surrounding wall can be up to six times higher with MPs than without 3D fields. When 3D fields are applied and density pump-out is observed, an enhancement of the fast-ion content in the plasma is typically measured by fast-ion D-alpha (FIDA) spectroscopy. The lower density during the MP phase also leads to a deeper beam deposition with an inward radial displacement of ≈2 cm in the maximum of the beam emission. Orbit simulations are used to test different models for 3D

Edge stability and performance of the ELM-free quiescent H-mode and the quiescent double barrier mode on DIII-D

International Nuclear Information System (INIS)

West, W.P.; Burrell, K.H.; Snyder, P.B.; Gohil, P.; Lao, L.L.; Leonard, A.W.; Osborne, T.H.; Thomas, D.M.; Casper, T.A.; Lasnier, C.J.; Doyle, E.J.; Wang, G.; Zeng, L.; Nave, M.F.F.

2005-01-01

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 QHmodes lie near an edge current stabilty boundary. At high triangularity, QH-mode discharges operate at higher pedestal density and pressure, and have achieved ITER level values of β PED and ν*. The QDB achieves performance of β N H 89 ∼ 7 in quasi-stationary conditions for a duration of 10 τ E , limited by hardware. Recently we demonstrated stationary state QDB discharges with little change in kinetic and q profiles (q 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. (author)

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

Science.gov (United States)

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

2011-01-01

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

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

Science.gov (United States)

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

Study on the Effects of Diverting Water into Upper Burnt Pocket, Navigation Pool Number 18, Illinois and A Field Test of the Regression Simulation Model Previously Developed on Navigation Pool Number 8.

Science.gov (United States)

1981-03-01

latifolia L. Commuon Cattail ULMACEAE Celtis occidentalis L. Hackberry Ulmus rubra Muhl. Slippery Elm Ulmus americana L. American Elm URTICACEAE...Populus deltoides Marsh. Cottonwood Celtis occidentalis L. Hackberry Ulmus rubra Muhl. Slippery Elm Ulmus americana L. American Elm *Dominant or most...Cryptochironomus sn. Tnta - Tanytarsus sp. Phys - Physa sp. Crcl n Crytoclido elm sp. Epio - Epoicocladius sp. Trun - Truncilla sp, Elnf - Einfeldia sp. Eusi

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

DEFF Research Database (Denmark)

Rørdam Preil, Simone; Faarvang Thorsen, Anne-Sofie; Christiansen, Anne Lindegaard

2017-01-01

BACKGROUND: 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 i......BACKGROUND: 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 m......RNA-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. METHODS: 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. RESULTS: T2DM...

Variability of morphometric caracteristics of one-year seedlings of different half-sib European White Elm (Ulmus effusa Wild. from the Great War Island

Directory of Open Access Journals (Sweden)

Devetaković, J.

2013-12-01

Full Text Available European White Elm is recognized as a rare and endangered species in the forest fund of the Republic of Serbia. During the past century massive drying of elms occurred and the indications of their extinction appeared, which consequently led to a reduction in genetic diversity and the danger of genetic drift. In the area of the Great War Island near Belgrade we found 56 trees of European White Elm that are spatially divided into three subpopulations. In order to assess the genetic potential of European White Elm in the Great War Island and to define adequate conservation measures variability of 14 selected test trees progeny was rated. Results shows that the satisfactory variability within the popoulation exists, which is a good basis for the conservation of genepool available.

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

Directory of Open Access Journals (Sweden)

Wen-jun Chu

2015-01-01

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

PROGRESS IN THE PEELING-BALLOONING MODEL OF ELMS: TOROIDAL ROTATION AND 3D NONLINEAR DYNAMICS

International Nuclear Information System (INIS)

SNYDER, P.B.; WILSON, H.R.; XU, X.Q.; WEBSTER, A.J.

2004-01-01

Understanding the physics of the H-Mode pedestal and edge localized modes (ELMs) is very important to next-step fusion devices for two primary reasons: (1) The pressure at the top of the edge barrier (''pedestal height'') strongly impacts global confinement and fusion performance, and (2) large ELMs lead to localized transient heat loads on material surfaces that may constrain component lifetimes. The development of the peeling-ballooning model has shed light on these issues by positing a mechanism for ELM onset and constraints on the pedestal height. The mechanism involves instability of ideal coupled ''peeling-ballooning'' modes driven by the sharp pressure gradient and consequent large bootstrap current in the H-mode edge. It was first investigated in the local, high-n limit [1], and later quantified for non-local, finite-n modes in general toroidal geometry [2,3]. Important aspects are that a range of wavelengths may potentially be unstable, with intermediate n's (n ∼ 3-30) generally limiting in high performance regimes, and that stability bounds are strongly sensitive to shape [Fig l(a)], and to collisionality (i.e. temperature and density) [4] through the bootstrap current. The development of efficient MHD stability codes such as ELITE [3,2] and MISHKA [5] has allowed detailed quantification of peeling-ballooning stability bounds (e.g. [6]) and extensive and largely successful comparisons with observation (e.g. [2,6-9]). These previous calculations are ideal, static, and linear. Here we extend this work to incorporate the impact of sheared toroidal rotation, and the non-ideal, nonlinear dynamics which must be studied to quantify ELM size and heat deposition on material surfaces

SOLPS5 modelling of the type III ELMing H-mode on TCV

International Nuclear Information System (INIS)

Gulejova, B.; Pitts, R.A.; Wischmeier, M.; Behn, R.; Coster, D.; Horacek, J.; Marki, J.

2007-01-01

Although ohmic H-modes have long been produced on TCV and the effects of ELMs at the divertor target studied in some detail, no attempt has yet been made to model the scrape-off layer (SOL) in these plasmas. This paper describes details of the first such efforts in which simulations of the inter-ELM phases using the coupled fluid-Monte Carlo SOLPS5 code (without drifts) are constrained by careful upstream Thomson scattering and Langmuir probe profiles. Simulated divertor profiles are compared with Langmuir probes and fast IR camera measurements at the targets. To account for the very differing transport rates in the edge pedestal and main SOL regions, radial variation of edge transport coefficients has been introduced in the simulations. Similarly, it is found that transport in the main chamber and divertor regions must be separately adjusted to provide an acceptable code-experiment match

Density profile analysis during an ELM event in ASDEX Upgrade H-modes

International Nuclear Information System (INIS)

Nunes, I.; Manso, M.; Serra, F.; Horton, L.D.; Conway, G.D.; Loarte, A.

2005-01-01

This paper reports results on measurements of the density profiles. Here we analyse the behaviour of the electron density for a set of experiments in type I ELMy H-mode discharges in ASDEX Upgrade where the plasma current, plasma density, triangularity and input power were varied. Detailed measurements of the radial extent of the perturbation on the density profiles caused by the edge localized mode (ELM) crash (ELM affected depth), the velocity of the radial propagation of the perturbation as well as the width and gradient of the density pedestal are determined. The effect of a type I ELM event on the density profiles affects the outermost 20-40% of the plasma minor radius. At the scrape-off layer (SOL) the density profile broadens while in the pedestal region the density decreases resulting in a smaller density gradient. This change in the density profile defines a pivot point around which the density profile changes. The average radial velocity at the SOL is in the range 125-150 ms -1 and approximately constant for all the density layers far from the pivot point. The width of the density pedestal is approximately constant for all the ELMy H-mode discharges analysed, with values between 2 and 3.5 cm. These results are then compared with an analytical model where the width of the density is predominantly set by ionization (neutral penetration model). The width of the density profiles for L-mode discharges is included, since L- and H-mode have different particle transport. No agreement between the experimental results and the model is found

Modelling ELM heat flux deposition on the ITER main chamber wall

Czech Academy of Sciences Publication Activity Database

Kočan, M.; Pitts, R.A.; Lisgo, S.W.; Loarte, A.; Gunn, J. P.; Fuchs, Vladimír

2015-01-01

Roč. 463, July (2015), s. 709-713 ISSN 0022-3115. [International Conference on Plasma-Surface Interactions in Controlled Fusion Devices (PSI)/21./. Kanazawa, 26.05.2014-30.05.2014] Institutional support: RVO:61389021 Keywords : ELM * ITER Subject RIV: JF - Nuclear Energetics OBOR OECD: Nuclear related engineering Impact factor: 2.199, year: 2015

Two-dimensional numerical study of ELMs-induced erosion of tungsten divertor target tiles with different edge shapes

International Nuclear Information System (INIS)

Huang, Yan; Sun, Jizhong; Hu, Wanpeng; Sang, Chaofeng; Wang, Dezhen

2016-01-01

Highlights: • Thermal performance of three edge-shaped divertor tiles was assessed numerically. • All the divertor tiles exposed to type-I ELMs like ITER's will melt. • The rounded edge tile thermally performs the best in all tiles of interest. • The incident energy flux density was evaluated with structural effects considered. - Abstract: Thermal performance of the divertor tile with different edge shapes was assessed numerically along the poloidal direction by a two-dimensional heat conduction model with considering the geometrical effects of castellated divertor tiles on the properties of its adjacent plasma. The energy flux density distribution arriving at the castellated divertor tile surface was evaluated by a two-dimension-in-space and three-dimension-in-velocity particle-in-cell plus Monte Carlo Collisions code and then the obtained energy flux distribution was used as input for the heat conduction model. The simulation results showed that the divertor tiles with any edge shape of interest (rectangular edge, slanted edge, and rounded edge) would melt, especially, in the edge surface region of facing plasma poloidally under typical heat flux density of a transient event of type-I ELMs for ITER, deposition energy of 1 MJ/m"2 in a duration of 600 μs. In comparison with uniform energy deposition, the vaporizing erosion was reduced greatly but the melting erosion was aggravated noticeably in the edge area of plasma facing diveror tile. Of three studied edge shapes, the simulation results indicated that the divertor plate with rounded edge was the most resistant to the thermal erosion.

Characterization of major lithologic units underlying the lower American River using water-borne continuous resistivity profiling, Sacramento, California, June 2008

Science.gov (United States)

Ball, Lyndsay B.; Teeple, Andrew

2013-01-01

The levee system of the lower American River in Sacramento, California, is situated above a mixed lithology of alluvial deposits that range from clay to gravel. In addition, sand deposits related to hydraulic mining activities underlie the floodplain and are preferentially prone to scour during high-flow events. In contrast, sections of the American River channel have been observed to be scour resistant. In this study, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, explores the resistivity structure of the American River channel to characterize the extent and thickness of lithologic units that may impact the scour potential of the area. Likely lithologic structures are interpreted, but these interpretations are non-unique and cannot be directly related to scour potential. Additional geotechnical data would provide insightful data on the scour potential of certain lithologic units. Additional interpretation of the resistivity data with respect to these results may improve interpretations of lithology and scour potential throughout the American River channel and floodplain. Resistivity data were collected in three profiles along the American River using a water-borne continuous resistivity profiling technique. After processing and modeling these data, inverted resistivity profiles were used to make interpretations about the extent and thickness of possible lithologic units. In general, an intermittent high-resistivity layer likely indicative of sand or gravel deposits extends to a depth of around 30 feet (9 meters) and is underlain by a consistent low-resistivity layer that likely indicates a high-clay content unit that extends below the depth of investigation (60 feet or 18 meters). Immediately upstream of the Watt Avenue Bridge, the high-resistivity layer is absent, and the low-resistivity layer extends to the surface where a scour-resistant layer has been previously observed in the river bed.

THE ELM SURVEY. I. A COMPLETE SAMPLE OF EXTREMELY LOW-MASS WHITE DWARFS

International Nuclear Information System (INIS)

Brown, Warren R.; Kilic, Mukremin; Kenyon, Scott J.; Prieto, Carlos Allende

2010-01-01

We analyze radial velocity observations of the 12 extremely low-mass (ELM), with ≤0.25 M sun , white dwarfs (WDs) in the MMT Hypervelocity Star Survey. Eleven of the twelve WDs are binaries with orbital periods shorter than 14 hr; the one non-variable WD is possibly a pole-on system among our non-kinematically selected targets. Our sample is unique: it is complete in a well-defined range of apparent magnitude and color. The orbital mass functions imply that the unseen companions are most likely other WDs, although neutron star companions cannot be excluded. Six of the eleven systems with orbital solutions will merge within a Hubble time due to the loss of angular momentum through gravitational wave radiation. The quickest merger is J0923+3028, a g = 15.7 ELM WD binary with a 1.08 hr orbital period and a ≤130 Myr merger time. The chance of a supernova Ia event among our ELM WDs is only 1%-7%, however. Three binary systems (J0755+4906, J1233+1602, and J2119-0018) have extreme mass ratios and will most likely form stable mass-transfer AM CVn systems. Two of these objects, SDSS J1233+1602 and J2119-0018, are the lowest surface gravity WDs ever found; both show Ca II absorption likely from accretion of circumbinary material. We predict that at least one of our WDs is an eclipsing detached double WD system, important for constraining helium core WD models.

Aquifer test to determine hydraulic properties of the Elm aquifer near Aberdeen, South Dakota

Science.gov (United States)

Schaap, Bryan D.

2000-01-01

The Elm aquifer, which consists of sandy and gravelly glacial-outwash deposits, is present in several counties in northeastern South Dakota. An aquifer test was conducted northeast of Aberdeen during the fall of 1999 to determine the hydraulic properties of the Elm aquifer in that area. An improved understanding of the properties of the aquifer will be useful in the possible development of the aquifer as a water resource. Historical water-level data indicate that the saturated thickness of the Elm aquifer can change considerably over time. From September 1977 through November 1985, water levels at three wells completed in the Elm aquifer near the aquifer test site varied by 5.1 ft, 9.50 ft, and 11.1 ft. From June 1982 through October 1999, water levels at five wells completed in the Elm aquifer near the aquifer test site varied by 8.7 ft, 11.4 ft, 13.2 ft, 13.8 ft, and 19.7 ft. The water levels during the fall of 1999 were among the highest on record, so the aquifer test was affected by portions of the aquifer being saturated that might not be saturated during drier times. The aquifer test was conducted using five existing wells that had been installed prior to this study. Well A, the pumped well, has an operating irrigation pump and is centrally located among the wells. Wells B, C, D, and E are about 70 ft, 1,390 ft, 2,200 ft, and 3,100 ft, respectively, in different directions from Well A. Using vented pressure transducers and programmable data loggers, water-level data were collected at the five wells prior to, during, and after the pumping, which started on November 19, 1999, and continued a little over 72 hours. Based on available drilling logs, the Elm aquifer near the test area was assumed to be unconfined. The Neuman (1974) method theoretical response curves that most closely match the observed water-level changes at Wells A and B were calculated using software (AQTESOLV for Windows Version 2.13-Professional) developed by Glenn M. Duffield of Hydro

The spatial structure of type-I ELMs at the mid-plane in ASDEX Upgrade and a comparison with data from MAST

International Nuclear Information System (INIS)

Kirk, A; Eich, T; Herrmann, A; Muller, H W; Horton, L D; Counsell, G F; Price, M; Rohde, V; Bobkov, V; Kurzan, B; Neuhauser, J; Wilson, H

2005-01-01

The radial extent and spatial structure of type-I edge localized modes (ELMs) in ASDEX Upgrade are investigated using data from a mid-plane manipulator equipped with Langmuir probes and a fast visible imaging camera and are compared to data from MAST. Plasmas with a range of toroidal magnetic fields have been studied. The radial extent of the ELM efflux is found to be largest at the smaller toroidal magnetic field. A study of a series of shots on ASDEX Upgrade with different plasma edge to wall separation suggests that the closeness of the wall does not have a stabilizing effect on the radial extent of the ELM. The data from the mid-plane manipulator and from visible imaging are consistent with non-linear ballooning mode theory, which predicts that the ELM has a filament like structure. On both devices these structures have a poloidal extent of 5-10 cm and a typical toroidal mode number of ∼15 and are found to accelerate away from the plasma edge. The acceleration is ∼3 times larger on MAST than on ASDEX Upgrade

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

Directory of Open Access Journals (Sweden)

Sukumar P.

2015-01-01

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

Theory and theory-based models for the pedestal, edge stability and ELMs in tokamaks

International Nuclear Information System (INIS)

Guzdar, P.N.; Mahajan, S.M.; Yoshida, Z.; Dorland, W.; Rogers, B.N.; Bateman, G.; Kritz, A.H.; Pankin, A.; Voitsekhovitch, I.; Onjun, T.; Snyder, S.

2005-01-01

Theories for equilibrium and stability of H-modes, and models for use within integrated modeling codes with the objective of predicting the height, width and shape of the pedestal at the edge of H-mode plasmas in tokamaks, as well as the onset and frequency of Edge Localized Modes (ELMs), are developed. A theory model for relaxed plasma states with flow, which uses two-fluid Hall-MHD equations, predicts that the natural scale length of the pedestal is the ion skin depth and the pedestal width is larger than the ion poloidal gyro-radius, in agreement with experimental observations. Computations with the GS2 code are used to identify micro-instabilities, such as electron drift waves, that survive the strong flow shear, diamagnetic flows, and magnetic shear that are characteristic of the pedestal. Other instabilities on the pedestal and gyro-radius scale, such as the Kelvin-Helmholtz instability, are also investigated. Time-dependent integrated modeling simulations are used to follow the transition from L-mode to H-mode and the subsequent evolution of ELMs as the heating power is increased. The flow shear stabilization that produces the transport barrier at the edge of the plasma reduces different modes of anomalous transport and, consequently, different channels of transport at different rates. ELM crashes are triggered in the model by pressure-driven ballooning modes or by current-driven peeling modes. (author)

Comparison of edge plasma perturbation during ELM control using one vs. two toroidal rows of RMP coils in ITER similar shaped plasmas on DIII-D

Energy Technology Data Exchange (ETDEWEB)

Fenstermacher, M.E., E-mail: fenstermacher@fusion.gat.co [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States); Evans, T.E.; Osborne, T.H.; Schaffer, M.J.; DeGrassie, J.S.; Gohil, P.; Groebner, R.J. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Moyer, R.A. [University of California, San Diego, 9500 Gilman Dr., La Jolla, California 92093 (United States)

2009-06-15

Large Type-I edge localized modes (ELMs) were suppressed by n = 3 resonant magnetic perturbations (RMPs) from a set of internal coils in plasmas with an ITER similar shape at the ITER pedestal collisionality, nu{sub e}*approx0.1 and low edge safety factor (q{sub 95} approx 3.6), with either a single toroidal row of the internal RMP coils or two poloidally separated rows of coils. ELM suppression with a single row of internal coils was achieved at approximately the same q{sub 95} surface-averaged perturbation field as with two rows of coils, but required higher current per coil. Maintaining complete suppression of ELMs using n = 3 RMPs from a single toroidal row of internal coils was less robust to variations in input neutral beam injection torque than previous ELM suppression cases using both rows of internal coils. With either configuration of RMP coils, maximum ELM size is correlated with the width of the edge region having good overlap of the magnetic islands from vacuum field calculations.

Experimental and numerical simulations of ELM-like transient damage behaviors to different grade tungsten and tungsten alloys

Energy Technology Data Exchange (ETDEWEB)

Liu, Xiang, E-mail: xliu@swip.ac.cn [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, Sichuan (China); Lian, Youyun; Chen, Lei; Chen, Zhenkui; Chen, Jiming; Duan, Xuru [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, Sichuan (China); Fan, Jinlian [Central South University, Changsha 410083 (China); Song, Jiupeng [Xiamen Honglu Tungsten & Molybdenum Industry Co., Ltd, Xiamen (China)

2015-08-15

Transient heat loads, such as plasma disruptions and ELMs, could induce plastic deformations, cracking, melting, even fatigue cracks and creep of tungsten (W) surface. A high purity W, CVD-W coating, TiC dispersion strengthened and K doped tungsten alloys were tested in a 60 kW electron-beam facility by simulating the transient load events under different base temperatures. It was found that CVD-W, W-TiC and W-K alloys have higher crack thresholds than high purity W, meanwhile CVD-W is more sensitive to the crack disappearing at elevated base temperatures. On the other hand, repetitive pulse loading like ELMs can induce serious network cracks even the power density was quite lower than the crack threshold determined by a single shot. The ABAQUS code was used to simulate the crack behaviors of ITER grade pure W by a single shot and a FE-SAFE code was adopted to estimate the fatigue life under ELMs-like loads. A good agreement with experiment results was found.

ELMs and constraints on the H-mode pedestal: peeling-ballooning stability calculation and comparison with experiment

International Nuclear Information System (INIS)

Snyder, P.B.; Ferron, J.R.; Wilson, H.R.

2004-01-01

We review and test the peeling-ballooning model for edge localized modes (ELMs) and pedestal constraints, a model based upon theoretical analysis of magnetohydrodynamic (MHD) instabilities that can limit the pedestal height and drive ELMs. A highly efficient MHD stability code, ELITE, is used to calculate quantitative stability constraints on the pedestal, including constraints on the pedestal height. Because of the impact of collisionality on the bootstrap current, these pedestal constraints are dependent on the density and temperature separately, rather than simply on the pressure. ELITE stability calculations are directly compared with experimental data for a series of plasmas in which the density is varied and ELM characteristics change. In addition, a technique is developed whereby peeling-ballooning pedestal constraints are calculated as a function of key equilibrium parameters via ELITE calculations using series of model equilibria. This technique is used to successfully compare the expected pedestal height as a function of density, triangularity and plasma current with experimental data. Furthermore, the technique can be applied for parameter ranges beyond the purview of present experiments, and we present a brief projection of peeling-ballooning pedestal constraints for burning plasma tokamak designs. (author)

ELM phenomenon as an interaction between bootstrap-current driven peeling modes and pressure-driven ballooning modes

International Nuclear Information System (INIS)

Saarelma, S.; Kurki-Suonio, T.; Guenter, S.; Zehrfeld, H.-P.

2000-01-01

An ELMy ASDEX Upgrade plasma equilibrium is reconstructed taking into account the bootstrap current. The peeling mode stability of the equilibrium is numerically analysed using the GATO [1] code, and it is found that the bootstrap current can drive the plasma peeling mode unstable. A high-n ballooning mode stability analysis of the equilibria revealed that, while destabilizing the peeling modes, the bootstrap current has a stabilizing effect on the ballooning modes. A combination of these two instabilities is a possible explanation for the type I ELM phenomenon. A triangularity scan showed that increasing triangularity stabilizes the peeling modes and can produce ELM-free periods observed in the experiments. (author)

Edge transport barrier formation and ELM phenomenology in the W7-AS stellarator

International Nuclear Information System (INIS)

Grigull, P.; Hirsch, M.; Baldzuhn, J.; Ehmler, H.; Gadelmeier, F.; Giannone, L.; Hartfuss, H.-J.; Hildebrandt, D.; Jaenicke, R.; Kisslinger, J.; Koenig, R.; McCormick, K.; Wagner, F.; Weller, A.; Wendland, Ch.

2001-01-01

In NBI discharges with density ramps in W7-AS, the quiescent H-mode is restricted to the same ranges of the edge rotational transform as in ECRH discharges and occurs above threshold densities ≥10 20 m -3 which increase with heating power. Higher power needs higher density for stabilization. The approach to the quiescent H-mode often occurs, with increasing density and decreasing power flow through the edge, from grassy through dithering states to bursts of ELMs and, in a few cases, quasi-periodic ELMs. This goes parallel with increasing radial gradients of the plasma pressure and E-field at the edge. Higher heating power reduces in particular the T i gradients and hence the E-field gradients, which effect can be compensated by higher density. The correlations found are fairly consistent when an ExB flow shear decorrelation of the turbulent transport is assumed

Actual and imagined first smoking experiences and resisted smoking opportunities of Asian American adolescents.

Science.gov (United States)

Rosario-Sim, Maria G; O'Connell, Kathleen; Lavin, Joanne

2013-01-01

To explore the metamotivational states experienced during first smoking experiences of Asian American adolescents. This survey research investigated the differences among the smokers, resisters, and smoking naives of a convenience sample of 328 Asian Americans, aged 16-19 in New York City (NYC). The study used a demographic questionnaire, Temptation Episode Surveys (First Smoking Occasion, First Resisted Smoking Opportunity, and Opinions on First Smoking Occasion), the Telic/Paratelic State Instrument, and the Rebellious State Scale. Statistical analyses revealed that Asian American adolescents smoked the first time when in paratelic, arousal-seeking states, and when the physical and social environments are permissive to smoking, initiation opportunities such as presence of peers and friends smoking and in places where adults are not present. The first smoking experiences of Asian American adolescents parallel that of smoking cessation when individuals lapse in a highly tempting situation and when the environment is permissive to smoking. This study is the first to use reversal theory pairs as a framework for smoking initiation. Smoking prevention and intervention programs should consider the importance of the physical, social environment, and the psychological states of adolescents when they smoke the first time. © 2012 Wiley Periodicals, Inc.

Hispanic-American Students' Attitudes toward Enrolling in High School Chemistry: A Study of Planned Behavior and Belief-Based Change.

Science.gov (United States)

Crawley, Frank E.; Koballa, Thomas R., Jr.

The study sought to: (1) identify the determinants that motivate Hispanic-American students to enroll in high school chemistry; and (2) determine if providing belief-based information to students and their parents/guardians increases chemistry registration. The Theory of Planned Behavior (TPB) and Elaboration Likelihood Model (ELM) guided the…

Habitat Fragmentation Handbook for Installation Planners: Status and Options

Science.gov (United States)

2006-12-01

slippery elm , sycamore, American elm , black walnut, eastern redbud, and American basswood, • Species composition of herbaceous vegetation of poison ivy...water source (creek, draw, spring, seep). The mature ash juniper stand can include oaks, ashs, elms , or wal- nuts. A juniper/deciduous mix of varying

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

Directory of Open Access Journals (Sweden)

Pedro ePerdiguero

2015-07-01

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

A new intelligent classifier for breast cancer diagnosis based on a rough set and extreme learning machine: RS + ELM

OpenAIRE

KAYA, Yılmaz

2014-01-01

Breast cancer is one of the leading causes of death among women all around the world. Therefore, true and early diagnosis of breast cancer is an important problem. The rough set (RS) and extreme learning machine (ELM) methods were used collectively in this study for the diagnosis of breast cancer. The unnecessary attributes were discarded from the dataset by means of the RS approach. The classification process by means of ELM was performed using the remaining attributes. The Wisconsin B...

Simulation of tungsten erosion and transport near the divertor plate during ELMs by a kinetic method

Energy Technology Data Exchange (ETDEWEB)

Sun, Zhenyue; Sang, Chaofeng; Hu, Wanpeng; Du, Hailong; Wang, Dezhen, E-mail: wangdez@dlut.edu.cn

2016-11-01

Highlights: • A kinetic method is used to simulate tungsten erosion and transport during ELMs. • The erosion of tungsten plate by different species (deuterium and carbon ions) is shown. • The charge states of sputtered tungsten particles are given statistically. - Abstract: Tungsten (W) is fore seen as one of the most important candidates of the plasma-facing materials (PFM) for future fusion devices, due to its beneficial properties. However, the high-Z characteristic makes it a potential contamination to the core plasma. Divertor is the main component that directly contacts the plasma, therefore, it is very important to understand the erosion of W divertor plate and the corresponding transport of the eroded wall impurity, especially during edge localized modes (ELMs). In this work, a one-dimension-in-space and three-dimensions-in-velocity particle-in-cell code (EPPIC1D) is used to simulate the erosion of W divertor plate, and the transport of eroded W impurity near the divertor plate is studied by a Monte Carlo code. Benefiting from the kinetic simulation, energy/particle flux to the target could be calculated accurately, and the erosion of W plate by different species is simulated during ELMs. The trajectories and distributions of eroded W impurity particles are demonstrated, which shows us a basic idea of how these impurity particles are generated and transported. It is found that C{sup 3+} plays a dominated role on the erosion of W divertor plate during ELMs even when its concentration is low. Both W atoms and ions distribute mainly near the divertor plate, indicating only a very small fraction of W impurity particles could escape from divertor region and penetrate into the core plasma.

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-10-15

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

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

International Nuclear Information System (INIS)

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

2011-01-01

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

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

Science.gov (United States)

R. Jay. Stipes

2017-01-01

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

Effect of stationary high heat flux and transient ELMs-like heat loads on the divertor PFCs

Energy Technology Data Exchange (ETDEWEB)

Riccardi, B., E-mail: bruno.riccardi@f4e.europa.eu [Fusion for Energy, ITER Department, Josep Pla, 2, Torres Diagonal Litoral B3, 08019 Barcelona (Spain); Gavila, P. [Fusion for Energy, ITER Department, Josep Pla, 2, Torres Diagonal Litoral B3, 08019 Barcelona (Spain); Giniatulin, R. [Efremov Institute, 196641 St. Petersburg (Russian Federation); Kuznetsov, V. [SRC RF TRINITI, ul. Pushkovykh, vladenie 12, 142190 Troitsk, Moscow Region (Russian Federation); Rulev, R. [Efremov Institute, 196641 St. Petersburg (Russian Federation); Klimov, N.; Kovalenko, D.; Barsuk, V. [SRC RF TRINITI, ul. Pushkovykh, vladenie 12, 142190 Troitsk, Moscow Region (Russian Federation); Koidan, V.; Korshunov, S. [NRC “Kurchatov Institute”, Moscow (Russian Federation)

2013-10-15

The experimental evaluation of the divertor plasma facing components (PFCs) lifetime under transient events, such as edge localized modes (ELMs) and high heat flux (HHF) thermal fatigue expected during ITER normal operations and slow transient events is here presented. The experiments have been performed in the frame of an EU/RF collaboration. For carbon fiber composite material the erosion is caused by PAN fiber damage whilst the erosion of tungsten is determined by the melt layer movement and crack formation. The conclusion of this study is that, in addition to the structural change produced in the armor materials by ELMs-like loads, some mock ups showed also a degradation of the thermal fatigue performances.

Direct Kernel Perceptron (DKP): ultra-fast kernel ELM-based classification with non-iterative closed-form weight calculation.

Science.gov (United States)

Fernández-Delgado, Manuel; Cernadas, Eva; Barro, Senén; Ribeiro, Jorge; Neves, José

2014-02-01

The Direct Kernel Perceptron (DKP) (Fernández-Delgado et al., 2010) is a very simple and fast kernel-based classifier, related to the Support Vector Machine (SVM) and to the Extreme Learning Machine (ELM) (Huang, Wang, & Lan, 2011), whose α-coefficients are calculated directly, without any iterative training, using an analytical closed-form expression which involves only the training patterns. The DKP, which is inspired by the Direct Parallel Perceptron, (Auer et al., 2008), uses a Gaussian kernel and a linear classifier (perceptron). The weight vector of this classifier in the feature space minimizes an error measure which combines the training error and the hyperplane margin, without any tunable regularization parameter. This weight vector can be translated, using a variable change, to the α-coefficients, and both are determined without iterative calculations. We calculate solutions using several error functions, achieving the best trade-off between accuracy and efficiency with the linear function. These solutions for the α coefficients can be considered alternatives to the ELM with a new physical meaning in terms of error and margin: in fact, the linear and quadratic DKP are special cases of the two-class ELM when the regularization parameter C takes the values C=0 and C=∞. The linear DKP is extremely efficient and much faster (over a vast collection of 42 benchmark and real-life data sets) than 12 very popular and accurate classifiers including SVM, Multi-Layer Perceptron, Adaboost, Random Forest and Bagging of RPART decision trees, Linear Discriminant Analysis, K-Nearest Neighbors, ELM, Probabilistic Neural Networks, Radial Basis Function neural networks and Generalized ART. Besides, despite its simplicity and extreme efficiency, DKP achieves higher accuracies than 7 out of 12 classifiers, exhibiting small differences with respect to the best ones (SVM, ELM, Adaboost and Random Forest), which are much slower. Thus, the DKP provides an easy and fast way

Explaining the Effects of Narrative in an Entertainment Television Program: Overcoming Resistance to Persuasion

Science.gov (United States)

Moyer-Guse, Emily; Nabi, Robin L.

2010-01-01

Research has examined the ability of entertainment-education (E-E) programs to influence behavior across a variety of health and social issues. However, less is known about the underlying mechanisms that account for these effects. In keeping with the extended elaboration likelihood model (E-ELM) and the entertainment overcoming resistance model…

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

International Nuclear Information System (INIS)

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

2009-01-01

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, β p -ped, increases almost linearly with the total poloidal beta, β p -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 (W ITB ) increases, the total thermal stored energy (W th ) increases and then the pedestal stored energy (W ped ) increases. On the other hand, as W ped 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 W ITB /W th and W ped /W th 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 (V t ), the ion temperature (T i ) and then the electron temperature (T e ). The L-H transition also changes the V t profile more significantly than the T i profile. At the L-H transition, the pedestal V t shifts into the CTR-direction deeply and suddenly without a change in T i , and then the pedestal V t grows further together with a growth of the pedestal T i in a slower timescale. Such changes in V t by ELMs and L

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

Science.gov (United States)

Busch, Phyllis S.

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

Investigation of ELM [edge localized mode] Dynamics with the Resonant Magnetic Perturbation Effects

International Nuclear Information System (INIS)

Pankin, Alexei Y.; Kritz, Arnold H.

2011-01-01

Topics covered are: anomalous transport and E f- B flow shear effects in the H-mode pedestal; RMP (resonant magnetic perturbation) effects in NSTX discharges; development of a scaling of H-mode pedestal in tokamak plasmas with type I ELMs (edge localized modes); and divertor heat load studies

Investigation of ELM [edge localized mode] Dynamics with the Resonant Magnetic Perturbation Effects

Energy Technology Data Exchange (ETDEWEB)

Pankin, Alexei Y.; Kritz, Arnold H.

2011-07-19

Topics covered are: anomalous transport and E x B flow shear effects in the H-mode pedestal; RMP (resonant magnetic perturbation) effects in NSTX discharges; development of a scaling of H-mode pedestal in tokamak plasmas with type I ELMs (edge localized modes); and divertor heat load studies.

Operational Draft Regional Guidebook for the Functional Assessment of High-gradient Ephemeral and Intermittent Headwater Streams in Western West Virginia and Eastern Kentucky

Science.gov (United States)

2010-07-01

Liriodendron tulipifera tuliptree Ulmus rubra slippery elm Magnolia acuminata cucumber-tree Ulmus thomasii rock elm ERDC/EL TR-10-11 103 Watershed...americana American elm ERDC/EL TR-10-11 41 0 0.5 1 1.5 2 2.5 SRV per 100 feet of stream reach 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Va ria bl e S...canadensis eastern hemlock Juglans nigra black walnut Ulmus americana American elm Liquidambar styraciflua sweetgum Ulmus parvifolia Chinese elm

The triglyceride/high-density lipoprotein cholesterol ratio fails to predict insulin resistance in African-American women: an analysis of Jackson Heart Study.

Science.gov (United States)

Sumner, Anne E; Harman, Jane L; Buxbaum, Sarah G; Miller, Bernard V; Tambay, Anita V; Wyatt, Sharon B; Taylor, Herman A; Rotimi, Charles N; Sarpong, Daniel F

2010-12-01

Compared to whites, insulin-resistant African Americans have worse outcomes. Screening programs that could identify insulin resistance early enough for intervention to affect outcome often rely on triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) levels. Racial differences in TG and HDL-C may compromise the efficacy of these programs in African Americans. A recommendation currently exists to use the TG/HDL-C ratio ≥2.0 to predict insulin resistance in African Americans. The validity of this recommendation needs examination. Therefore, our aim was to determine the ability of TG/HDL-C ratio to predict insulin resistance in African Americans. In 1,903 African Americans [895 men, 1,008 women, age 55 ± 12 years, mean ± standard deviation (SD), range 35-80 years, body mass index (BMI) 31.0 ± 6.4 kg/m(2), range 18.5-55 kg/m(2)] participating in the Jackson Heart Study, a population-based study of African Americans, Jackson, Mississippi tricounty region, insulin resistance was defined by the upper quartile (≥4.43) of homeostasis model assessment of insulin resistance (HOMA-IR). An area under the receiver operating characteristic curve (AUC-ROC) of >0.70 was required for prediction of insulin resistance by TG/HDL-C. The optimal test cutoff was determined by the Youden index. HOMA-IR was similar in men and women (3.40 ± 2.03 vs. 3.80 ± 2.46, P = 0.60). Women had lower TG (94 ± 49 vs. 109 ± 65 mg/dL P Heart Study can help determine the efficacy of screening programs in African-Americans.

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

Directory of Open Access Journals (Sweden)

Devetaković Jovana

2013-01-01

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

Dietary carbohydrate intake, insulin resistance and gastro-oesophageal reflux disease: a pilot study in European- and African-American obese women.

Science.gov (United States)

Pointer, S D; Rickstrew, J; Slaughter, J C; Vaezi, M F; Silver, H J

2016-11-01

Although obesity rates are higher in African-American than European-American women, gastro-oesophageal reflux disease (GERD) and its comorbidities are more prevalent in European-American women. A common denominator for increased adiposity, and consequent insulin resistance, is excess dietary macronutrient intake - which may promote greater prevalence and severity of GERD in women. To investigate whether GERD is more robustly associated with dietary carbohydrate intake, particularly dietary simple carbohydrate intake, and insulin resistance in European-American women. About 144 obese women were assessed at baseline and 16 weeks after consuming a high-fat/low-carbohydrate diet. GERD diagnosis and medication usage was confirmed in medical records with symptoms and medications assessed weekly. About 33.3% (N = 33) of European-American and 20.0% (N = 9) of African-American women had GERD at baseline. Total carbohydrate (r = 0.34, P < 0.001), sugars (r = 0.30, P = 0.005), glycaemic load (r = 0.34, P = 0.001) and HOMA IR (r = 0.30, P = 0.004) were associated with GERD, but only in European-American women. In response to high-fat/low-carbohydrate diet, reduced intake of sugars was associated with reduced insulin resistance. By the end of diet week 10, all GERD symptoms and medication usage had resolved in all women. GERD symptoms and medication usage was more prevalent in European-American women, for whom the relationships between dietary carbohydrate intake, insulin resistance and GERD were most significant. Nevertheless, high-fat/low-carbohydrate diet benefited all women with regard to reducing GERD symptoms and frequency of medication use. © 2016 John Wiley & Sons Ltd.

Transcriptome of American oysters, Crassostrea virginica, in response to bacterial challenge: insights into potential mechanisms of disease resistance.

Science.gov (United States)

McDowell, Ian C; Nikapitiya, Chamilani; Aguiar, Derek; Lane, Christopher E; Istrail, Sorin; Gomez-Chiarri, Marta

2014-01-01

The American oyster Crassostrea virginica, an ecologically and economically important estuarine organism, can suffer high mortalities in areas in the Northeast United States due to Roseovarius Oyster Disease (ROD), caused by the gram-negative bacterial pathogen Roseovarius crassostreae. The goals of this research were to provide insights into: 1) the responses of American oysters to R. crassostreae, and 2) potential mechanisms of resistance or susceptibility to ROD. The responses of oysters to bacterial challenge were characterized by exposing oysters from ROD-resistant and susceptible families to R. crassostreae, followed by high-throughput sequencing of cDNA samples from various timepoints after disease challenge. Sequence data was assembled into a reference transcriptome and analyzed through differential gene expression and functional enrichment to uncover genes and processes potentially involved in responses to ROD in the American oyster. While susceptible oysters experienced constant levels of mortality when challenged with R. crassostreae, resistant oysters showed levels of mortality similar to non-challenged oysters. Oysters exposed to R. crassostreae showed differential expression of transcripts involved in immune recognition, signaling, protease inhibition, detoxification, and apoptosis. Transcripts involved in metabolism were enriched in susceptible oysters, suggesting that bacterial infection places a large metabolic demand on these oysters. Transcripts differentially expressed in resistant oysters in response to infection included the immune modulators IL-17 and arginase, as well as several genes involved in extracellular matrix remodeling. The identification of potential genes and processes responsible for defense against R. crassostreae in the American oyster provides insights into potential mechanisms of disease resistance.

Online sequential condition prediction method of natural circulation systems based on EOS-ELM and phase space reconstruction

International Nuclear Information System (INIS)

Chen, Hanying; Gao, Puzhen; Tan, Sichao; Tang, Jiguo; Yuan, Hongsheng

2017-01-01

Highlights: •An online condition prediction method for natural circulation systems in NPP was proposed based on EOS-ELM. •The proposed online prediction method was validated using experimental data. •The training speed of the proposed method is significantly fast. •The proposed method can achieve good accuracy in wide parameter range. -- Abstract: Natural circulation design is widely used in the passive safety systems of advanced nuclear power reactors. The irregular and chaotic flow oscillations are often observed in boiling natural circulation systems so it is difficult for operators to monitor and predict the condition of these systems. An online condition forecasting method for natural circulation system is proposed in this study as an assisting technique for plant operators. The proposed prediction approach was developed based on Ensemble of Online Sequential Extreme Learning Machine (EOS-ELM) and phase space reconstruction. Online Sequential Extreme Learning Machine (OS-ELM) is an online sequential learning neural network algorithm and EOS-ELM is the ensemble method of it. The proposed condition prediction method can be initiated by a small chunk of monitoring data and it can be updated by newly arrived data at very fast speed during the online prediction. Simulation experiments were conducted on the data of two natural circulation loops to validate the performance of the proposed method. The simulation results show that the proposed predication model can successfully recognize different types of flow oscillations and accurately forecast the trend of monitored plant variables. The influence of the number of hidden nodes and neural network inputs on prediction performance was studied and the proposed model can achieve good accuracy in a wide parameter range. Moreover, the comparison results show that the proposed condition prediction method has much faster online learning speed and better prediction accuracy than conventional neural network model.

Asian American Cultural Resistance.

Science.gov (United States)

Libretti, Tim

1997-01-01

Explores the encounter of Marxism and Asian American literary theory and imagines an Asian American Marxism. To do so requires theorizing race, class, and gender not as substantive categories of antagonisms but as complementary and coordinated elements of a totality of social relations structuring racial patriarchal capitalism. (SLD)

Dynamic behavior of detached recombining plasmas during ELM-like plasma heat pulses in the divertor plasma simulator NAGDIS-II

International Nuclear Information System (INIS)

Uesugi, Y.; Hattori, N.; Nishijima, D.; Ohno, N.; Takamura, S.

2001-01-01

It has been recognized that the ELMs associated with a good confinement at the edge, such as H-mode, must bring an enormous energy to the divertor target plate through SOL and detached plasmas. The understanding of the ELM energy transport through SOL to the divertor target is rather poor at the moment, which leads to an ambiguous estimation of the deposited heat load on the divertor target in ITER. In the present work the ELM-like plasma heat pulse is generated by rf heating in a linear divertor plasma simulator. Energetic electrons with an energy range 10-40 eV are effectively generated by rf heating in low temperature plasmas with (T e )< ∼1 eV. It is observed experimentally that the energetic electrons ionize the highly excited Rydberg atoms quickly, bringing a rapid increase of the ion particle flux to the target, and make the detached plasmas attached to the target. Detailed physical processes about the interaction between the heat pulse with conduction and convection, and detached recombining plasmas are discussed

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

Directory of Open Access Journals (Sweden)

Yadav Basant

2017-03-01

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

Localised Microwave Bursts During ELMs on MAST

Directory of Open Access Journals (Sweden)

Freethy Simon

2015-01-01

Full Text Available Bursts of microwave emission are observed during ELM events on the Mega Ampère Spherical Tokamak. In agreement with observations on other machines, these bursts are up to 3 orders of magnitude more intense than the thermal background, but are electron cyclotron in nature. The peak in microwave emission is ~20μ before the peak in midplane Dα emission. Using the Synthetic Aperture Microwave Imaging radiometer, we are able to demonstrate that these bursts are often highly spatially localised and preferentially occur at the tokamak midplane. It is hypothesised that the localisation is a result of Doppler resonance broadening for electron Bernstein waves and the high perpendicular electron energies could be the result of pitch angle scattering in high collisionality regions of the plasma.

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

DEFF Research Database (Denmark)

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

2014-01-01

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

The role of radial particle pinches in ELM suppression by resonant magnetic perturbations

International Nuclear Information System (INIS)

Stacey, W.M.; Evans, T.E.

2011-01-01

The force balance in the plasma edge in a matched pair of DIII-D (Luxon 2002 Nucl. Fusion 42 6149) tokamak discharges with and without resonant magnetic perturbations (RMPs) is evaluated in order to investigate the effects on particle transport of RMP applied for the purpose of suppressing edge-localized modes (ELMs). Experimental data are used to evaluate the radial and toroidal force balances, which may be written as a pinch-diffusion relation for the radial ion flux to facilitate investigation of transport effects. The radial electric field in the H-mode plasma had a sharp negative dip in the steep gradient region of the edge pedestal, associated with which was a large inward pinch velocity. The main effect of RMP was to make the edge electric field less negative or more positive, reducing this strong negative dip in the radial electric field (even reversing it from negative to positive over some regions), thereby reducing the strong inward particle pinch in the edge of an H-mode discharge, thus causing a reduction in edge density below the ELM threshold.

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

Science.gov (United States)

Li, Yuancheng; Qiu, Rixuan; Jing, Sitong

2018-01-01

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

Ion orbit modelling of ELM heat loads on ITER divertor vertical targets.

Czech Academy of Sciences Publication Activity Database

Gunn, J. P.; Carpentier-Chouchana, S.; Dejarnac, Renaud; Escourbiac, F.; Hirai, T.; Komm, Michael; Kukushkin, A.; Panayotis, S.; Pitts, R.A.

2017-01-01

Roč. 12, August (2017), s. 75-83 ISSN 2352-1791. [International Conference on Plasma Surface Interactions 2016, PSI2016 /22./. Roma, 30.05.2016-03.06.2016] Institutional support: RVO:61389021 Keywords : ITER * Divertor * ELM heat loads Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) http://www.sciencedirect.com/science/article/pii/S2352179116302745

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

Science.gov (United States)

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...

The experiment progress of bracket brazing to SSMIC for the ITER ELM prototype coil

International Nuclear Information System (INIS)

Shi, Yi; Wu, Yu; Jin, Huan; Ren, Zhibin; Han, Houxiang; Qian, Jing; Qian, Li; Liu, Bo

2014-01-01

Highlights: • In this study, the experimental research of brackets brazing to stainless steel jacketed, Mineral Insulated Conductor (SSMIC) of the first Edge Localized Modes (ELMs) prototype coil for ITER has been made. • The technology for controlling the fluidity of silver-based brazing alloy is developed to meet the bracket brazing. • Brazing experiments to find the reason for cracks are carried out and the improved brazing technologies to restrain the cracks in the Inconel 625 jacket with silver-based alloy are developed. - Abstract: The first Edge Localized Modes (ELMs) prototype coil for International Thermonuclear Experimental Reactor (ITER) has been manufactured in the Institute of Plasma Physics, CAS (ASIPP) at 2014. The all 19 brackets need to braze to the stainless steel jacketed, Mineral Insulated Conductor (SSMIC) for transporting the nuclear heating in the brackets to the water-cooled SSMIC. Silver-based alloy is the only candidate brazing filler for the bracket brazing due to the limitation from melting point temperature and strength. In this paper, firstly, the experimental study for controlling the fluidity of silver-based brazing alloy is developed. And then, the brazing experiment of prototype bracket is introduced to develop the brazing process and some cracks in the Inconel 625 jackets surface appeared unexpectedly. The microstructures and tensile performance study of the cracked Inconel 625 jacket were made to explore the reason for cracks and the improved brazing technologies to suppress the cracks are developed. Finally, the bracket brazing experiment for the first ELM prototype coil is carried out, In spite of this, some cracks also appear in the Inconel 625 jackets

The experiment progress of bracket brazing to SSMIC for the ITER ELM prototype coil

Energy Technology Data Exchange (ETDEWEB)

Shi, Yi, E-mail: shiyi@ipp.ac.cn; Wu, Yu; Jin, Huan; Ren, Zhibin; Han, Houxiang; Qian, Jing; Qian, Li; Liu, Bo

2014-11-15

Highlights: • In this study, the experimental research of brackets brazing to stainless steel jacketed, Mineral Insulated Conductor (SSMIC) of the first Edge Localized Modes (ELMs) prototype coil for ITER has been made. • The technology for controlling the fluidity of silver-based brazing alloy is developed to meet the bracket brazing. • Brazing experiments to find the reason for cracks are carried out and the improved brazing technologies to restrain the cracks in the Inconel 625 jacket with silver-based alloy are developed. - Abstract: The first Edge Localized Modes (ELMs) prototype coil for International Thermonuclear Experimental Reactor (ITER) has been manufactured in the Institute of Plasma Physics, CAS (ASIPP) at 2014. The all 19 brackets need to braze to the stainless steel jacketed, Mineral Insulated Conductor (SSMIC) for transporting the nuclear heating in the brackets to the water-cooled SSMIC. Silver-based alloy is the only candidate brazing filler for the bracket brazing due to the limitation from melting point temperature and strength. In this paper, firstly, the experimental study for controlling the fluidity of silver-based brazing alloy is developed. And then, the brazing experiment of prototype bracket is introduced to develop the brazing process and some cracks in the Inconel 625 jackets surface appeared unexpectedly. The microstructures and tensile performance study of the cracked Inconel 625 jacket were made to explore the reason for cracks and the improved brazing technologies to suppress the cracks are developed. Finally, the bracket brazing experiment for the first ELM prototype coil is carried out, In spite of this, some cracks also appear in the Inconel 625 jackets.

Characterisation of the ELM synchronized H-mode edge pedestal in ASDEX upgrade and DIII-D

Energy Technology Data Exchange (ETDEWEB)

Schneider, Philip A.; Wolfrum, Elisabeth; Guenter, Sibylle; Kurzan, Bernd; Zohm, Hartmut [Max Planck Institut fuer Plasmaphysik, EURATOM Association, Garching (Germany); Groebner, Rich; Osborne, Tom H.; Ferron, John; Snyder, Philip B. [General Atomics, San Diego, CA (United States); Dunne, Mike G. [Department of Physics, University College Cork, Association Euratom-DCU, Cork (Ireland); Collaboration: ASDEX Upgrade Team; DIII-D Team

2011-07-01

The results of a large database of edge pedestal data from type-I ELMy H-mode discharges from ASDEX Upgrade and DIII-D are presented. The data from high resolution edge diagnostics of both devices is analysed with the same analysis code in order to avoid systematic differences. Furthermore, sophisticated equilibrium reconstructions are used to asses uncertainties which arise during mapping from 2D real space coordinates to 1D flux coordinates. ELM synchronization allows the study of the pedestal structure at the ELM stability boundary. The pedestal is characterized by its top value, the gradient and the width. A large parameter range is covered by the two devices. Over this parameter range the profile shape of edge electron density differs from that of the temperature, irrespective of the device. However, the resulting electron pressure profile shape remains similar for all analysed H-Mode discharges.

Assessment of beech scale resistance in full- and half-sibling American beech families

Science.gov (United States)

Jennifer L. Koch; David W. Carey; Mary E. Mason; C. Dana Nelson

2010-01-01

A beech bark disease infested American beech tree (Fagus grandifolia Ehrh.) and two uninfested trees were selected in a mature natural stand in Michigan, USA, and mated to form two full-sib families for evaluating the inheritance of resistance to beech scale (Cryptococcus fagisuga Lind.), the insect element of beech bark disease....

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

Energy Technology Data Exchange (ETDEWEB)

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

2003-08-01

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

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

International Nuclear Information System (INIS)

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

2003-01-01

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

Evolution of Edge Pedestal Profiles Between ELMs

Science.gov (United States)

Floyd, J. P.; Stacey, W. M.; Groebner, R. J.

2012-10-01

The measured edge profile evolution in DIII-D discharges is analyzed in terms of the implied thermal diffusivities, ion diffusion coefficients and pinch velocities, using the momentum-balance methodology of Ref. [1], extended to take into account ion orbit loss and X-point loss. The evolution of the density, temperature, rotation and radial electric field profiles in the edge pedestal between edge localized modes (ELMs) provides information of these diffusive and non-diffusive transport processes in the pedestal of H-mode plasmas. This methodology is incorporated in the GTEDGE code developed for DIII-D data interpretation. Using a smaller integration time for the charge exchange recombination measurements than in Ref. [1] allows a more detailed examination of the time evolution of the ion temperature and rotation profiles. 6pt [1] W.M. Stacey and R.J. Groebner, Nucl. Fusion 51, 063024 (2011).

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

Directory of Open Access Journals (Sweden)

Yuancheng Li

Full Text Available 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.

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

Science.gov (United States)

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

2011-12-01

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

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

International Nuclear Information System (INIS)

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

2011-01-01

Experimental simulations for the erosion rate of tungsten targets under ITER edge-localized mode (ELM)-like surface heat loads of 0.75 MJ m - 2 causing surface melting and of 0.45 MJ m - 2 without melting have been performed in the QSPA-Kh50 plasma accelerator. Analytical considerations allow us to conclude that for both energy deposition values the erosion mechanism is solid dust ejection during surface cracking under the action of thermo-stress. Tungsten influx into the ITER containment of N W ∼5×10 18 W per medium size ELM of 0.75 MJ m - 2 and 0.25 ms time duration has been estimated. The radiation cooling power of P rad =150-300 MW due to such influx of tungsten is intolerable: it should cool the ITER core to 1 keV within a few seconds.

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

Directory of Open Access Journals (Sweden)

Hong Men

2018-01-01

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

Evaluation of insulin resistance in two kinds of South American camelids: llamas and alpacas.

Science.gov (United States)

Araya, A V; Atwater, I; Navia, M A; Jeffs, S

2000-10-01

Insulin resistance was evaluated in South American camelids, llamas and alpacas, by use of the minimal model test and the insulin tolerance test. Animals were catheterized for long-term studies and tamed to minimize stress during evaluation. Results indicated a low insulin sensitivity index (SI) = 0 to 0.97, median = 0.39 x 10(-4) min/uIU x ml, about a fifth the value in other mammals and humans. The KITT was between 1.43 and 3.19 %/min, also significantly lower than that reported for humans. Glycosylated hemoglobin concentration was 6%, and HbAlc concentration was 5.5%; red blood cell lifetime, as measured by use of the 51Cr method, was 120 days, similar to the value in humans. We concluded that llamas and alpacas have naturally higher blood glucose concentration than do humans and other mammals during the glucose tolerance test. Using the same mathematical tools to evaluate glucose metabolism as those used in people, South American camelids appear to be resistant to insulin. Thus, the South American camelid may be a useful new animal model for the study of sugar metabolism and various facets of diabetes mellitus, especially protection from the deleterious effects of glycosylation.

Strategy and Resistance: How Native American Students Engage in Accommodation in Mainstream Schools

Science.gov (United States)

Masta, Stephanie

2018-01-01

This article explores the experiences of a group of Native American 8th graders who attend a mainstream school and how they engage in accommodation as an act of agency and resistance to protect and maintain their identities in their school environment. By using tribal critical race theory to examine these experiences, this study raises important…

Seismic design of steel moment resisting frames-European versus American practice

International Nuclear Information System (INIS)

Naqash, M.T.; Matteis, G.D.; Luca, A.D.

2012-01-01

This paper provides an overview on the design philosophy of moment resisting frames (MRF) according to the seismic provisions of Eurocode 8 and American Institute of Steel Construction (AISC). A synopsis of the main recommendations of the two codes is briefly described. Then in order to examine the structural efficiency of the design principles of MRF according to the aforementioned codes, a case study is developed in which spatial and perimeter moment resisting frames of 12, 6 and 3 storeys residential building are considered. In the case of EC8, Ductility Class Medium (DCM) with behaviour factor of 4 and Ductility Class High (DCH) with behaviour factor of 6.5 for 6-storey frames are used, while only DCH is employed in the design of 12 and 3 storey frames. When dealing with AISC/American Society of Civil Engineers (ASCE) code, special moment resisting frame (SMF) with response modification factor of 8 is employed in the design. The outcomes from the design are illustrated in terms of frame performance, section profiles, strength-demand to capacity ratios, drift-demand to capacity ratios and structural weight, thus allowing the understanding of pros and cons of the design criteria and the capacity design rules of the two codes. The main purpose of the current paper is to compare the seismic design rules of the two codes with a parametric analysis developed by a case study in order to let the technician knows about the importance and influence of some important parameters which are given in the capacity design rules of the two codes. This study will be a benchmark for further analysis on the two codes for seismic design of steel structures. (author)

Spectral Kurtosis Entropy and Weighted SaE-ELM for Bogie Fault Diagnosis under Variable Conditions

Directory of Open Access Journals (Sweden)

Zhipeng Wang

2018-05-01

Full Text Available Bogies are crucial for the safe operation of rail transit systems and usually work under uncertain and variable operating conditions. However, the diagnosis of bogie faults under variable conditions has barely been discussed until now. Thus, it is valuable to develop effective methods to deal with variable conditions. Besides, considering that the normal data for training are much more than the faulty data in practice, there is another problem in that only a small amount of data is available that includes faults. Concerning these issues, this paper proposes two new algorithms: (1 A novel feature parameter named spectral kurtosis entropy (SKE is proposed based on the protrugram. The SKE not only avoids the manual post-processing of the protrugram but also has strong robustness to the operating conditions and parameter configurations, which have been validated by a simulation experiment in this paper. In this paper, the SKE, in conjunction with variational mode decomposition (VMD, is employed for feature extraction under variable conditions. (2 A new learning algorithm named weighted self-adaptive evolutionary extreme learning machine (WSaE-ELM is proposed. WSaE-ELM gives each sample an extra sample weight to rebalance the training data and optimizes these weights along with the parameters of hidden neurons by means of the self-adaptive differential evolution algorithm. Finally, the hybrid method based on VMD, SKE, and WSaE-ELM is verified by using the vibration signals gathered from real bogies with speed variations. It is demonstrated that the proposed method of bogie fault diagnosis outperforms the conventional methods by up to 4.42% and 6.22%, respectively, in percentages of accuracy under variable conditions.

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

Science.gov (United States)

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

Design Of JET ELM Control Coils For Operation At 350 C

International Nuclear Information System (INIS)

Zatz, I.J.; Baker, R.; Brooks, A.; Cole, M.; Neilson, G.H.; Lowry, C.; Mardenfeld, M.; Omran, H.; Thompson, V.; Todd, T.

2010-01-01

A study has confirmed the feasibility of designing, fabricating and installing resonant magnetic field perturbation (RMP) coils in JET1 with the objective of controlling edge localized modes (ELM). A system of two rows of in-vessel coils, above the machine midplane, has been chosen as it not only can investigate the physics of and achieve the empirical criteria for ELM suppression, but also permits variation of the spectra allowing for comparison with other experiments. These coils present several engineering challenges. Conditions in JET necessitate the installation of these coils via remote handling, which will impose weight, dimensional and logistical limitations. And while the encased coils are designed to be conventionally wound and bonded, they will not have the usual benefit of active cooling. Accordingly, coil temperatures are expected to reach 350 C during bakeout as well as during plasma operations. These elevated temperatures are beyond the safe operating limits of conventional OFHC copper and the epoxies that bond and insulate the turns of typical coils. This has necessitated the use of an alternative copper alloy conductor C18150 (CuCrZr). More importantly, an alternative to epoxy had to be found. An R and D program was initiated to find the best available insulating and bonding material. The search included polyimides and ceramic polymers. The scope and status of this R and D program, as well as the critical engineering issues encountered to date are reviewed and discussed.

Pedestal width and ELM size identity studies in JET and DIII-D; implications for ITER

Energy Technology Data Exchange (ETDEWEB)

Beurskens, M N A; Lomas, P; Saarelma, S; Balboa, I; Flanagan, J; Giroud, C; Kempenaars, M [EURATOM/UKAEA Fusion Association, Culham Sc. Centre, Abingdon, OX14 3DB (United Kingdom); Osborne, T H; Groebner, R; Leonard, A; Snyder, P B; Bray, B [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Horton, L D [JET-EFDA, Culham Science Centre, OX14 3DB, Abingdon (United Kingdom); Frassinetti, L [Association EURATOM-VR, Alfven Laboratory, School of Electrical Engineering, KTH, Stockholm (Sweden); Nunes, I [Centro de Fusao Nuclear, Associacao EURATOM-IST, Lisboa (Portugal); Crombe, K [Department of Applied Physics, Ghent University, Rozier 44, 9000 Gent (Belgium); Giovannozzi, E [Associazione EURATOM-ENEA Sulla Fusione, Consorzio RFX Padova (Italy); Kohen, N [Association EURATOM-CEA, CEA/DSM/DRFC-Cadarache 13108, St Paul Durance (France); Loarte, A [ITER Organization, CS 90 046, F-13067 Saint Paul lez Durance Cedex (France); Loennroth, J, E-mail: Marc.Beurskens@jet.u [Association EURATOM-Tekes, Helsinki University of Technology (Finland)

2009-12-15

The dependence of the H-mode edge transport barrier width on normalized ion gyroradius (rho* = rho/a) in discharges with type I ELMs was examined in experiments combining data for the JET and DIII-D tokamaks. The plasma configuration as well as the local normalized pressure (beta), collisionality (nu*), Mach number and the ratio of ion and electron temperature at the pedestal top were kept constant, while rho* was varied by a factor of four. The width of the steep gradient region of the electron temperature (T{sub e}) and density (n{sub e}) pedestals normalized to machine size showed no or only a weak trend with rho*. A rho{sup 1/2} or rho{sup 1} dependence of the pedestal width, given by some theoretical predictions, is not supported by the current experiments. This is encouraging for the pedestal scaling towards ITER as it operates at lower rho* than existing devices. Some differences in pedestal structure and ELM behaviour were, however, found between the devices; in the DIII-D discharges, the n{sub e} and T{sub e} pedestal were aligned at high rho* but the n{sub e} pedestal shifted outwards in radius relative to T{sub e} as rho* decreases, while on JET the profiles remained aligned while rho* was scanned by a factor of two. The energy loss at an ELM normalized to the pedestal energy increased from 10% to 40% as rho* increased by a factor of two in the DIII-D discharges but no such variation was observed in the case of JET. The measured pedestal pressures and widths were found to be consistent with the predictions from modelling based on peeling-ballooning stability theory, and are used to make projections towards ITER

Experimental assessment of the effects of ELMs and disruptions on ITER divertor armour materials

International Nuclear Information System (INIS)

Zhitlukhin, A.; Federici, G.; Giniyatulin, R.; Landman, I.; Linke, J.; Loarte, A.; Merola, M.; Podkovyrov, V.; Safronov, V.

2005-01-01

The response of plasma protection materials to thermal energy deposited during simulated Type I Edge Localised Modes (ELMs) and disruptions was studied. The paper describes the design and manufacture of special CFC and tungsten macrobrush targets, the experimental conditions achievable at simulating facilities and results of selected experiments. Experiments are conducted primarily under an EU/RF research collaboration in two plasma guns (QSPA and MK-200UG) located in TRINITI, Troitsk, Russia. The targets were exposed to a large number of repetitive pulses in QSPA plasma gun with heat loads varying in a range of 1-2 MJ/m 2 lasting 0.1-0.5 ms, with the purpose to determine the total expected erosion rate in ITER. MK-200UG experiments were focused on studying mainly vapour plasma production and impurity transport during ELMs. Moderate tungsten erosion less than 0.3 microns per shot was demonstrated for 1.5 MJ/m 2 energy densities. Energy density increasing up to 1.8 MJ/m 2 resulted in sharp growth of tungsten erosion, caused by intensive droplet ejection from irradiated tungsten surface. The program of further experiments is discussed. (author)

Free-Boundary 3D Equilibria and Resistive Wall Instabilities with Extended-MHD

Science.gov (United States)

Ferraro, N. M.

2015-11-01

The interaction of the plasma with external currents, either imposed or induced, is a critical element of a wide range of important tokamak phenomena, including resistive wall mode (RWM) stability and feedback control, island penetration and locking, and disruptions. A model of these currents may be included within the domain of extended-MHD codes in a way that preserves the self-consistency, scalability, and implicitness of their numerical methods. Such a model of the resistive wall and non-axisymmetric coils is demonstrated using the M3D-C1 code for a variety of applications, including RWMs, perturbed non-axisymmetric equilibria, and a vertical displacement event (VDE) disruption. The calculated free-boundary equilibria, which include Spitzer resistivity, rotation, and two-fluid effects, are compared to external magnetic and internal thermal measurements for several DIII-D discharges. In calculations of the perturbed equilibria in ELM suppressed discharges, the tearing response at the top of the pedestal is found to correlate with the onset of ELM suppression. Nonlinear VDE calculations, initialized using a vertically unstable DIII-D equilibrium, resolve in both space and time the currents induced in the wall and on the plasma surface, and also the currents flowing between the plasma and the wall. The relative magnitude of these contributions and the total impulse to the wall depend on the resistive wall time, although the maximum axisymmetric force on the wall over the course of the VDE is found to be essentially independent of the wall conductivity. This research was supported by US DOE contracts DE-FG02-95ER54309, DE-FC02-04ER54698 and DE-AC52-07NA27344.

Magnetohydrodynamic behaviour during core transport barrier experiments with ion Bernstein wave heating in PBX-M: I ELMs fluctuations and crash events

International Nuclear Information System (INIS)

Sesnic, S.; Kaita, R.; Batha, S.H.

1998-01-01

If the ion Bernstein wave (IBW) heating power in an H mode discharge of the PBX-M experiment exceeds a threshold power of about 200 kW, a core transport barrier is created in the central region of the plasma. At lower neutral beam injection (NBI) powers, the core barrier is accompanied by an edge L mode. The high edge localized mode (ELM) repetition frequency (1 kHz) prevents the creation of a strong barrier, so the edge first has to make an H-to-L transition before a strong core transport barrier can be created. At higher NBI powers, the ELM repetition frequency is lowered to less than 200 Hz, which allows the immediate creation of a strong core barrier. Edge localized mode loss, which propagates radially first on a fast (non-diffusive) and then on a slow (diffusive) time-scale all the way to the plasma core, is strongly reduced in the core barrier region. Correlated with the reduced ELM loss, the fluctuations in the core barrier region are also strongly reduced, both during the ELM and during the quite periods between the ELMs. There is strong evidence that the IBW induced poloidal flow shear is responsible for the stabilization of core turbulence and the creation of the core transport barrier. The large perpendicular E x B flow shear component of the measured toroidal velocity in co-injection neutral beam heated discharges seems to be largely cancelled by the ion diamagnetic drift shear produced by large ion pressure gradients in the core barrier region. The value of IBW induced poloidal flow has not been experimentally determined, but its numerical value is found to be a factor of 4 larger than either the toroidal velocity or the ion diamagnetic drift shear components, leaving only IBW induced flow shear as the most probable cause for the turbulence stabilization. The core turbulence suppression and the creation of the core transport barrier is also consistent with expectations from a comparison between the E x B flow shear rate and a rough estimate of the

In Situ Remediation of a TCE-Contaminated Aquifer Using a Short Rotation Woody Crop Groundwater Treatment System

Science.gov (United States)

2006-05-01

eastern cottonwoods, six oaks, two live oak, three cedars, two willows, one hackberry, one pecan , one pine, one American elm, one unidentified...hackberry, 1 pecan , 1 pine, 1 American elm, 1 unidentified elm, and 1 unidentified species. Cores were collected from a height of approximately 1.5 m above...of trees to act as pumps was noted in the late 19th century when eucalyptus trees were planted in Italy and Algeria to dry up marshes (USEPA, 2003

Characteristics of H-mode-like discharges and ELM activities in the presence of {iota}/2{pi} = 1 surface at the ergodic layer in LHD

Energy Technology Data Exchange (ETDEWEB)

Morita, S [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Morisaki, T [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Tanaka, K [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Masuzaki, S [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Goto, M [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Sakakibara, S [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Michael, C [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Narihara, K [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Ohdachi, S [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Sakamoto, R [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Sanin, A [Budker Institute of Nuclear Physics, 630090, Novosibirsk (Russian Federation); Toi, K [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Tokuzawa, T [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Vyacheslavov, L N [Budker Institute of Nuclear Physics, 630090, Novosibirsk (Russian Federation); Watanabe, K Y [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan)

2006-05-15

Magnetic configurations of LHD are characterized by the presence of chaotic magnetic field, the so-called ergodic layer, surrounding the core plasma. H-mode-like discharges have been obtained at an outwardly shifted configuration of R{sub ax} = 4.00 m with a thick ergodic layer, where the {iota}/2{pi} = 1 position is located in the middle of the ergodic layer. A clear density rise and a reduction of magnetic fluctuation were observed. ELM-like H{alpha} bursts also appeared with a radial propagation of density bursts. These H-mode-like discharges can be triggered by changing P{sub NBI}(<12 MW) from three beams to two beams in a density range (4-8) x 10{sup 13} cm{sup -3}. The ELM-like bursts vanished with a small change of the edge rotational transform. A precise profile measurement of the edge density bursts confirmed that ELM-like bursts occur at the {iota}/2{pi} = 1 position.

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

International Nuclear Information System (INIS)

Lemahieu, Nathan; Balden, Martin; Elgeti, Stefan; Greuner, Henri; Linke, Jochen; Maier, Hans; Pintsuk, Gerald; Wirtz, Marius; Van Oost, Guido; Noterdaeme, Jean-Marie

2016-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-11-01

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

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

Science.gov (United States)

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

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

Science.gov (United States)

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

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

Science.gov (United States)

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

Erosion dynamics of tungsten fuzz during ELM-like heat loading

Science.gov (United States)

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.

Dependence of helium transport on plasma current and ELM frequency in H-mode discharges in DIII-D

International Nuclear Information System (INIS)

Wade, M.R.; Hillis, D.L.; Hogan, J.T.; Finkenthal, D.F.; West, W.P.; Burrell, K.H.; Seraydarian, R.P.

1993-05-01

The removal of helium (He) ash from the plasma core with high efficiency to prevent dilution of the D-T fuel mixture is of utmost importance for future fusion devices, such as the International Thermonuclear Experimental Reactor (ITER). A variety of measurements in L-mode conditions have shown that the intrinsic level of helium transport from the core to the edge may be sufficient to prevent sufficient dilution (i.e., τ He /τ E < 5). Preliminary measurements in biased-induced, limited H-mode discharges in TEXTOR suggest that the intrinsic helium transport properties may not be as favorable. If this trend is shown also in diverted H-mode plasmas, then scenarios based on ELMing H-modes would be less desirable. To further establish the database on helium transport in H-mode conditions, recent studies on the DIII-D tokamak have focused on determining helium transport properties in H-mode conditions and the dependence of these properties on plasma current and ELM frequency

Environmental Impact Study of the Northern Section of the Upper Mississippi River. Pool 5.

Science.gov (United States)

1973-11-01

commercially valuable tree species: silver maple (Acer saccharinum), American elm (Ulmus americana), slippery elm (Ulmus rubrea), green ash (Fraxinus...this division is generally birch, elm , and cotton wood, all the cliffs being bordered by cedars. The navigation, as far as the Iowa River is good, but

Environmental Assessment for Physical Fitness Center Tinker Air Force Base, Oklahoma

Science.gov (United States)

2010-04-01

Tinker AFB contains such species as American elm (Ulmus Americana), slippery elm (Ulmus rubra), hackberry (Celtis spp.), and cottonwood (Poplus...The other two major drainages on the Base are Elm Creek and Hog Creek, both of which flow south off Base and join the Little River. The on-Base

Spectroscopic investigation of ELM phenomena in the ASDEX-Upgrade divertor with high time resolution

International Nuclear Information System (INIS)

Field, A.R.; Buechl, K.; Fuchs, C.J.; Fussmann, G.; Herrmann, A.; Lieder, G.; Napiontek, B.; Radtke, R.; Wenzel, U.; Zohm, H.

1993-01-01

Improved tokamak H-mode confinement is associated with the formation of an insulating zone just within the separatrix. At a critical pressure gradient a sudden burst of MHD activity (an ELM) degrades edge confinement, releasing particles and energy into the scrape-off layer (SOL) which is subsequently transported to the divertor. Here, these phenomena are studied using spectroscopic diagnostics and target plate thermography of high spatial and temporal resolution. (author) 3 refs., 6 figs

Spectroscopic investigation of ELM phenomena in the ASDEX-Upgrade divertor with high time resolution

Energy Technology Data Exchange (ETDEWEB)

Field, A R; Buechl, K; Fuchs, C J; Fussmann, G; Herrmann, A; Lieder, G; Napiontek, B; Radtke, R; Wenzel, U; Zohm, H [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

1994-12-31

Improved tokamak H-mode confinement is associated with the formation of an insulating zone just within the separatrix. At a critical pressure gradient a sudden burst of MHD activity (an ELM) degrades edge confinement, releasing particles and energy into the scrape-off layer (SOL) which is subsequently transported to the divertor. Here, these phenomena are studied using spectroscopic diagnostics and target plate thermography of high spatial and temporal resolution. (author) 3 refs., 6 figs.

Latest investigations on fluctuations, ELM filaments and turbulent transport in the SOL of ASDEX Upgrade

Czech Academy of Sciences Publication Activity Database

Müller, H. W.; Adámek, Jiří; Cavazzana, R.; Conway, G.D.; Fuchs, C.; Gunn, J. P.; Herrmann, A.; Horáček, Jan; Ionita, C.; Kallenbach, A.; Kočan, M.; Maraschek, M.; Maszl, C.; Mehlmann, F.; Nold, B.; Peterka, M.; Rohde, V.; Schweinzer, J.; Schrittwieser, R.; Vianello, N.; Wolfrum, E.; Zuin, M.

2011-01-01

Roč. 51, č. 7 (2011), 073023-073023 ISSN 0029-5515 R&D Projects: GA AV ČR KJB100430901 Institutional research plan: CEZ:AV0Z20430508 Keywords : SOL * ASDEX * ELM * tokamak * ball- pen * H-mode Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 4.090, year: 2011 http://iopscience.iop.org/0029-5515/51/7/073023/pdf/0029-5515_51_7_073023.pdf

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

Science.gov (United States)

This study describes a new genus and species of microsporidia which is a pathogen of the elm leaf beetle, Xanthogaleruca luteola Muller, 1776 (Coleoptera: Chrysomelidae). The beetles were collected from Istanbul in Turkey. All developmental stages are uninucleate and in direct contact with the host ...

Early treatment resistance in a Latin-American cohort of patients with schizophrenia.

Science.gov (United States)

Mena, Cristian; Gonzalez-Valderrama, Alfonso; Iruretagoyena, Barbara; Undurraga, Juan; Crossley, Nicolas A

2018-03-08

Failure to respond to antipsychotic medication in schizophrenia is a common clinical scenario with significant morbidity. Recent studies have highlighted that many patients present treatment-resistance from disease onset. We here present an analysis of clozapine prescription patterns, used as a real-world proxy marker for treatment-resistance, in a cohort of 1195 patients with schizophrenia from a Latin-American cohort, to explore the timing of emergence of treatment resistance and possible subgroup differences. Survival analysis from national databases of clozapine monitoring system, national disease notification registers, and discharges from an early intervention ward. Echoing previous studies, we found that around 1 in 5 patients diagnosed with schizophrenia were eventually prescribed clozapine, with an over-representation of males and those with a younger onset of psychosis. The annual probability of being prescribed clozapine was highest within the first year (probability of 0.11, 95% confidence interval of 0.093-0.13), compared to 0.018 (0.012-0.024) between years 1 and 5, and 0.006 (0-0.019) after 5years. Age at psychosis onset, gender, dose of clozapine used, and compliance with hematological monitoring at 12months, was not related to the onset of treatment resistance. A similar pattern was observed in a subgroup of 230 patients discharged from an early intervention ward with a diagnosis of non-affective first episode of psychosis. Our results highlight that treatment resistance is frequently present from the onset of psychosis. Future studies will shed light on the possible different clinical and neurobiological characteristics of this subtype of psychosis. Copyright © 2018. Published by Elsevier B.V.

Harry S. Truman Dam and Reservoir, Missouri, Holocene Adaptations Within the Lower Pomme de Terre River Valley, Missouri. Volume 1.

Science.gov (United States)

1982-06-01

Kucera and Martin 1957). The primary tree species in the seedling-sapling stage (Table 2.6) are white oak and slippery elm with some black oak, hackberry...i’lnius rubra ( slippery elm ) ."ilirz americana (basswood) * HERBS * Arbrosiu artersiifolia (ragweed) Antena*a neglecta (pussytoes) ,Im4nra sp. (sandwort...basswood, and American elm , and slightly higher, increasing amounts of hackberry, slippery elm , and white ash. The undergrowth of the bottomlands is pri

Buffalo Metropolitan Area, New York Water Resources Management. Interim Report on Feasibility of Flood Management in Cazenovia Creek Watershed.

Science.gov (United States)

1977-03-01

Ulmus rubra slippery elm Ulmus thomasii rock elm Pinus strobus white pine Juglans cinerea. butternut Juglans nigra black walnut Carya ovata shagbark...West Seneca X : X : X Town of Elm : X X X Town of Aurora : X : Town of Boston X : Town of Colden : X : 5.i, Table 1 (cont’d) Flood Insurance Status for...grandidentata bigtooth aspen Populus deltoides eastern cottonwood Rhus typhina staghorn. sumc Betula alleghaniesis yellow birch Ulmus americana. American elm

The association between insulin resistance, metabolic variables, and depressive symptoms in Mexican-American elderly: A population-based study.

Science.gov (United States)

Diniz, Breno S; Fisher-Hoch, Susan; McCormick, Joseph

2018-02-01

Depressive symptoms are common among older adults with obesity and diabetes. Nonetheless, the mechanisms for this association are not clear but may involve changes in the insulin cascade signaling. We aimed to investigate the association, and potential mediators, between obesity, insulin resistance, and depressive symptoms among older adults from a homogenous cohort of Mexican-Americans. We included a total of 500 Mexican-American older adults assessed in the Cameron County Health Study. We evaluated depressive symptoms using the Center for Epidemiologic Survey Depression Scale (CES-D). Central obesity was defined by waist circumference. Insulin resistance was evaluated by the HOMA-IR index. We estimated the association between obesity, insulin resistance, and depressive symptoms by carrying out univariate and multivariate regression analyses. In unadjusted regression analysis, HOMA-IR (unstandardized β = 0.31 ± 0.12, P = 0.007), waist circumference (unstandardized β = 0.066 ± 0.0.028, P = 0.017), and Hb1Ac levels (unstandardized β = 0.52 ± 0.24, P = 0.03) were significantly associated with CES-D scores. The association of HOMA-IR and CES-D remained statistically significant after controlling for socio-demographic and clinical variables in multivariate analysis (unstandardized β = 0.28 ± 0.11, P = 0.01). Our results suggest that depressive symptoms are associated with insulin resistance in older Mexican-American adults. In addition, poorer glucose control and obesity are important mediators of this relationship. Additional studies are needed to evaluate whether interventions that increase insulin sensitivity can also reduce depressive symptoms in this population. Copyright © 2017 John Wiley & Sons, Ltd.

Experiments on transient melting of tungsten by ELMs in ASDEX Upgrade

Science.gov (United States)

Krieger, K.; Balden, M.; Coenen, J. W.; Laggner, F.; Matthews, G. F.; Nille, D.; Rohde, V.; Sieglin, B.; Giannone, L.; Göths, B.; Herrmann, A.; de Marne, P.; Pitts, R. A.; Potzel, S.; Vondracek, P.; ASDEX-Upgrade Team; EUROfusion MST1 Team

2018-02-01

Repetitive melting of tungsten by power transients originating from edge localized modes (ELMs) has been studied in ASDEX Upgrade. Tungsten samples were exposed to H-mode discharges at the outer divertor target plate using the divertor manipulator II (DIM-II) system (Herrmann et al 2015 Fusion Eng. Des. 98-9 1496-9). Designed as near replicas of the geometries used also in separate experiments on the JET tokamak (Coenen et al 2015 J. Nucl. Mater. 463 78-84 Coenen et al 2015 Nucl. Fusion 55 023010; Matthews et al 2016 Phys. Scr. T167 7), the samples featured a misaligned leading edge and a sloped ridge respectively. Both structures protrude above the default target plate surface thus receiving an increased fraction of the parallel power flux. Transient melting by ELMs was induced by moving the outer strike point to the sample location. The temporal evolution of the measured current flow from the samples to vessel potential confirmed transient melting. Current magnitude and dependency from surface temperature provided strong evidence for thermionic electron emission as main origin of the replacement current driving the melt motion. The different melt patterns observed after exposures at the two sample geometries support the thermionic electron emission model used in the MEMOS melt motion code, which assumes a strong decrease of the thermionic net current at shallow magnetic field to surface angles (Pitts et al 2017 Nucl. Mater. Energy 12 60-74). Post exposure ex situ analysis of the retrieved samples show recrystallization of tungsten at the exposed surface areas to a depth of up to several mm. The melt layer transport to less exposed surface areas leads to ratcheting pile up of re-solidified debris with zonal growth extending from the already enlarged grains at the surface.

Preliminary Guide to the Onsite Identification and Delineation of the Wetlands of the South Atlantic United States.

Science.gov (United States)

1982-05-01

shield) Ceratophyilum demersum (Coontail) Myriophyllum spp. (Watermilfoil) Nelumbo lutea ( American lotus) Nuphar luteum (Spatterdock) Nymphaea odorata...Overcup oak) Quercus palustris (Pin oak) Quercus phelios (Willow oak) Ulmus americana ( American elm) UlmuS rubra (Slippery elm) c. Atlantic White...var. biflora (Swamp black gum) Persea borbonia (Red bay) Pinus serotina (Pond pine) Smilax laurifolia (Bamboo vine) Sphagnum spp. (Sphagnum moss

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

Directory of Open Access Journals (Sweden)

S Venkatalakshmi

2017-05-01

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

Cross-Modality 2D-3D Face Recognition via Multiview Smooth Discriminant Analysis Based on ELM

Directory of Open Access Journals (Sweden)

Yi Jin

2014-01-01

Full Text Available In recent years, 3D face recognition has attracted increasing attention from worldwide researchers. Rather than homogeneous face data, more and more applications require flexible input face data nowadays. In this paper, we propose a new approach for cross-modality 2D-3D face recognition (FR, which is called Multiview Smooth Discriminant Analysis (MSDA based on Extreme Learning Machines (ELM. Adding the Laplacian penalty constrain for the multiview feature learning, the proposed MSDA is first proposed to extract the cross-modality 2D-3D face features. The MSDA aims at finding a multiview learning based common discriminative feature space and it can then fully utilize the underlying relationship of features from different views. To speed up the learning phase of the classifier, the recent popular algorithm named Extreme Learning Machine (ELM is adopted to train the single hidden layer feedforward neural networks (SLFNs. To evaluate the effectiveness of our proposed FR framework, experimental results on a benchmark face recognition dataset are presented. Simulations show that our new proposed method generally outperforms several recent approaches with a fast training speed.

Numerical simulations for ITER divertor armour erosion and SOL contamination due to disruptions and ELMs

International Nuclear Information System (INIS)

Landman, I.S.; Pestchanyi, S.E.; Bazylev, B.N.

2005-01-01

The divertor armour materials for ITER are going to be tungsten (as brushe or plates) and CFC. Disruptive loads with the heat deposition Q up to 30 MJ/m 2 on the time scale τ of 3 ms or operation with ELMs at repetitive loads of Q ∼ 3 MJ/m 2 and τ ∼ 0.3 ms cause enhanced armour erosion and produce contamination of SOL. Recent numerical investigations of erosion mechanisms with the anisotropic thermomechanics code PEGASUS-3D and the surface melt motion code MEMOS-1.5D as well as hot hydrogen plasma dynamics, heat loads at the armour surface and backward propagation of material plasma in SOL with the radiation-magnetohydrodynamics code FOREV-2D are survived. For CFC targets, the local overheating model is explained and numerically demonstrated. For the tungsten targets the numerical analysis of melt motion erosion of W-brushe and bulk tungsten targets on the base of MEMOS-1.5D calculations is developed and accompanied by numerical results. For validation of the codes at the regimes relevant to ITER disruptions and ELMs, the simulation results are compared with available experiments carried out at plasma guns, electron beam test facilities and the tokamak JET. (author)

Draft Genome Sequences of Two Extensively Drug-Resistant Strains of Mycobacterium tuberculosis Belonging to the Euro-American S Lineage

NARCIS (Netherlands)

Malinga, L.A.; Abeel, T.; Desjardins, C.A.; Dlamini, T.C.; Cassell, G.; Chapman, S.B.; Birren, B.W.; Earl, A.M.; Van der Walt, M.

2016-01-01

We report the whole-genome sequencing of two extensively drug-resistant tuberculosis strains belonging to the Euro-American S lineage. The RSA 114 strain showed single-nucleotide polymorphisms predicted to have drug efflux activity.

A compound structure of ELM based on feature selection and parameter optimization using hybrid backtracking search algorithm for wind speed forecasting

International Nuclear Information System (INIS)

Zhang, Chu; Zhou, Jianzhong; Li, Chaoshun; Fu, Wenlong; Peng, Tian

2017-01-01

Highlights: • A novel hybrid approach is proposed for wind speed forecasting. • The variational mode decomposition (VMD) is optimized to decompose the original wind speed series. • The input matrix and parameters of ELM are optimized simultaneously by using a hybrid BSA. • Results show that OVMD-HBSA-ELM achieves better performance in terms of prediction accuracy. - Abstract: Reliable wind speed forecasting is essential for wind power integration in wind power generation system. The purpose of paper is to develop a novel hybrid model for short-term wind speed forecasting and demonstrates its efficiency. In the proposed model, a compound structure of extreme learning machine (ELM) based on feature selection and parameter optimization using hybrid backtracking search algorithm (HBSA) is employed as the predictor. The real-valued BSA (RBSA) is exploited to search for the optimal combination of weights and bias of ELM while the binary-valued BSA (BBSA) is exploited as a feature selection method applying on the candidate inputs predefined by partial autocorrelation function (PACF) values to reconstruct the input-matrix. Due to the volatility and randomness of wind speed signal, an optimized variational mode decomposition (OVMD) is employed to eliminate the redundant noises. The parameters of the proposed OVMD are determined according to the center frequencies of the decomposed modes and the residual evaluation index (REI). The wind speed signal is decomposed into a few modes via OVMD. The aggregation of the forecasting results of these modes constructs the final forecasting result of the proposed model. The proposed hybrid model has been applied on the mean half-hour wind speed observation data from two wind farms in Inner Mongolia, China and 10-min wind speed data from the Sotavento Galicia wind farm are studied as an additional case. Parallel experiments have been designed to compare with the proposed model. Results obtained from this study indicate that the

Validating the Operational Draft Regional Guidebook for the Functional Assessment of High-Gradient Ephemeral and Intermittent Headwater Streams in Western West Virginia and Eastern Kentucky

Science.gov (United States)

2014-04-01

blackgum, wild black cherry (Prunus serotina), sweet cherry (Prunus avium), slippery elm (Ulmus rubra), sourwood (Oxydendrum arboreum), red maple, and...virginiana), American hornbeam (Carpinus caroliniana), and slippery elm . Buffalo nut (Pyrularia pubera), wild hydrangea (Hydrangea arborescens...Pinus strobus), wild black cherry, boxelder (Acer negundo), sycamore, black locust (Robinia pseudo-acacia), slippery elm , and white ash. The shrub

THE ELM SURVEY. V. MERGING MASSIVE WHITE DWARF BINARIES

International Nuclear Information System (INIS)

Brown, Warren R.; Kenyon, Scott J.; Kilic, Mukremin; Gianninas, A.; Allende Prieto, Carlos

2013-01-01

We present the discovery of 17 low-mass white dwarfs (WDs) in short-period (P ≤ 1 day) binaries. Our sample includes four objects with remarkable log g ≅ 5 surface gravities and orbital solutions that require them to be double degenerate binaries. All of the lowest surface gravity WDs have metal lines in their spectra implying long gravitational settling times or ongoing accretion. Notably, six of the WDs in our sample have binary merger times 0.9 M ☉ companions. If the companions are massive WDs, these four binaries will evolve into stable mass transfer AM CVn systems and possibly explode as underluminous supernovae. If the companions are neutron stars, then these may be millisecond pulsar binaries. These discoveries increase the number of detached, double degenerate binaries in the ELM Survey to 54; 31 of these binaries will merge within a Hubble time.

THE ELM SURVEY. V. MERGING MASSIVE WHITE DWARF BINARIES

Energy Technology Data Exchange (ETDEWEB)

Brown, Warren R.; Kenyon, Scott J. [Smithsonian Astrophysical Observatory, 60 Garden St, Cambridge, MA 02138 (United States); Kilic, Mukremin; Gianninas, A. [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St., Norman, OK, 73019 (United States); Allende Prieto, Carlos, E-mail: wbrown@cfa.harvard.edu, E-mail: skenyon@cfa.harvard.edu, E-mail: kilic@ou.edu, E-mail: alexg@nhn.ou.edu, E-mail: callende@iac.es [Instituto de Astrofisica de Canarias, E-38205, La Laguna, Tenerife (Spain)

2013-05-20

We present the discovery of 17 low-mass white dwarfs (WDs) in short-period (P {<=} 1 day) binaries. Our sample includes four objects with remarkable log g {approx_equal} 5 surface gravities and orbital solutions that require them to be double degenerate binaries. All of the lowest surface gravity WDs have metal lines in their spectra implying long gravitational settling times or ongoing accretion. Notably, six of the WDs in our sample have binary merger times <10 Gyr. Four have {approx}>0.9 M{sub Sun} companions. If the companions are massive WDs, these four binaries will evolve into stable mass transfer AM CVn systems and possibly explode as underluminous supernovae. If the companions are neutron stars, then these may be millisecond pulsar binaries. These discoveries increase the number of detached, double degenerate binaries in the ELM Survey to 54; 31 of these binaries will merge within a Hubble time.

Damage to tungsten macro-brush targets under multiple ELM-like heat loads. Experiments vs. numerical simulations and extrapolation to ITER

Energy Technology Data Exchange (ETDEWEB)

Bazylev, B.; Landman, I. [Forschungszentrum Karlsruhe (Germany). IHM; Janeschitz, G. [Forschungszentrum Karlsruhe (DE). Fusion EURATOM] (and others)

2007-07-01

Operation of ITER at high fusion gain is assumed to be the H-mode. A characteristic feature of this regime is the transient release of energy from the confined plasma onto PFCs by multiple ELMs (about 104 ELMs per ITER discharge), which can play a determining role in the erosion rate and lifetime of these components. The expected energy heat loads on the ITER divertor during Type I ELM are in range 0.5-4 MJ/m{sup 2} in timescales of 0.3-0.6 ms. Tungsten macro-brush armour (W-brushes) is foreseen as one of plasma facing components (PFC) for ITER divertor and dome. During the intense transient events in ITER the surface melting, melt motion, melt splashing and evaporation are seen as the main mechanisms of W erosion. The expected erosion of the ITER plasma facing components under transient energy loads can be properly estimated by numerical simulations validated against target erosion of the experiments at the plasma gun facility QSPA-T. Within the collaboration established between EU fusion programme and the Russian Federation, W-brush targets (produced either from pure tungsten or tungsten with 1% of La{sub 2}O{sub 3}) manufactured according to the EU specifications for the ITER divertor targets, have been exposed to multiple ITER ELM-like loads in plasma gun facilities at TRINITI in the range 0.5 - 2.2 MJ/m2 with pulse duration of 0.5 ms. The measured material erosion data have been used to validate the codes MEMOS and PHEMOBRID. Numerical simulations, including 3D-simulations (codes MEMOS and PHEMOBRID), carried out for the conditions of the QSPA-T experiments with heat loads in the range 0.5-2.2 MJ/m{sup 2} and the timescale 0.5 ms demonstrated a rather good agreement with the data obtained at the plasma gun facility QSPA: melting of brush edges at low heat loads, intense melt motion and bridge formation caused by the Rayleigh-Taylor instability at heat loads Q>1.3 MJ/m{sup 2}. The melt splashing generated by the Kelvin-Helmholtz, and Rayleigh

Effects of ELMs on ITER divertor armour materials

Energy Technology Data Exchange (ETDEWEB)

Zhitlukhin, A. [SRC RF TRINITI, Troitsk, 142190, Moscow Region (Russian Federation)]. E-mail: zhitlukh@triniti.ru; Klimov, N. [SRC RF TRINITI, Troitsk, 142190, Moscow Region (Russian Federation); Landman, I. [Forschungszentrum Karlsruhe, P.O. Box 3640, 76021 Karlsruhe (Germany); Linke, J. [Forschungszentrum Juelich, EURATOM-Association, Juelich (Germany)]. E-mail: j.linke@fz-juelich.de; Loarte, A. [EFDA, Boltzmannstr. 2, 85748 Garching (Germany); Merola, M. [EFDA, Boltzmannstr. 2, 85748 Garching (Germany); Podkovyrov, V. [SRC RF TRINITI, Troitsk, 142190, Moscow Region (Russian Federation); Federici, G. [ITER JWS Garching, Boltzmannstr. 2, 85748 Garching (Germany); Bazylev, B. [Forschungszentrum Karlsruhe, P.O. Box 3640, 76021 Karlsruhe (Germany); Pestchanyi, S. [Forschungszentrum Karlsruhe, P.O. Box 3640, 76021 Karlsruhe (Germany); Safronov, V. [SRC RF TRINITI, Troitsk, 142190, Moscow Region (Russian Federation); Hirai, T. [Forschungszentrum Juelich, EURATOM-Association, Juelich (Germany); Maynashev, V. [SRC RF TRINITI, Troitsk, 142190, Moscow Region (Russian Federation); Levashov, V. [SRC RF TRINITI, Troitsk, 142190, Moscow Region (Russian Federation); Muzichenko, A. [SRC RF TRINITI, Troitsk, 142190, Moscow Region (Russian Federation)

2007-06-15

This paper is concerned with investigation of an erosion of the ITER-like divertor plasma facing components under plasma heat loads expected during the Type I ELMs in ITER. These experiments were carried out on plasma accelerator QSPA at the SRC RF TRINITI under EU/RF collaboration. Targets were exposed by series repeated plasma pulses with heat loads in a range of 0.5-1.5 MJ/m{sup 2} and pulse duration 0.5 ms. Erosion of CFC macrobrushes was determined mainly by sublimation of PAN-fibres that was less than 2.5 {mu}m per pulse. The CFC erosion was negligible at the energy density less than 0.5 MJ/m{sup 2} and was increased to the average value 0.3 {mu}m per pulse at 1.5 MJ/m{sup 2}. The pure tungsten macrobrushes erosion was small in the energy range of 0.5-1.3 MJ/m{sup 2}. The sharp growth of tungsten erosion and the intense droplet ejection were observed at the energy density of 1.5 MJ/m{sup 2}.

Effects of ELMs on ITER divertor armour materials

Science.gov (United States)

Zhitlukhin, A.; Klimov, N.; Landman, I.; Linke, J.; Loarte, A.; Merola, M.; Podkovyrov, V.; Federici, G.; Bazylev, B.; Pestchanyi, S.; Safronov, V.; Hirai, T.; Maynashev, V.; Levashov, V.; Muzichenko, A.

2007-06-01

This paper is concerned with investigation of an erosion of the ITER-like divertor plasma facing components under plasma heat loads expected during the Type I ELMs in ITER. These experiments were carried out on plasma accelerator QSPA at the SRC RF TRINITI under EU/RF collaboration. Targets were exposed by series repeated plasma pulses with heat loads in a range of 0.5-1.5 MJ/m2 and pulse duration 0.5 ms. Erosion of CFC macrobrushes was determined mainly by sublimation of PAN-fibres that was less than 2.5 μm per pulse. The CFC erosion was negligible at the energy density less than 0.5 MJ/m2 and was increased to the average value 0.3 μm per pulse at 1.5 MJ/m2. The pure tungsten macrobrushes erosion was small in the energy range of 0.5-1.3 MJ/m2. The sharp growth of tungsten erosion and the intense droplet ejection were observed at the energy density of 1.5 MJ/m2.

Temperature-stress resistance and tolerance along a latitudinal cline in North American Arabidopsis lyrata.

Directory of Open Access Journals (Sweden)

Guillaume Wos

Full Text Available The study of latitudinal gradients can yield important insights into adaptation to temperature stress. Two strategies are available: resistance by limiting damage, or tolerance by reducing the fitness consequences of damage. Here we studied latitudinal variation in resistance and tolerance to frost and heat and tested the prediction of a trade-off between the two strategies and their costliness. We raised plants of replicate maternal seed families from eight populations of North American Arabidopsis lyrata collected along a latitudinal gradient in climate chambers and exposed them repeatedly to either frost or heat stress, while a set of control plants grew under standard conditions. When control plants reached maximum rosette size, leaf samples were exposed to frost and heat stress, and electrolyte leakage (PEL was measured and treated as an estimate of resistance. Difference in maximum rosette size between stressed and control plants was used as an estimate of tolerance. Northern populations were more frost resistant, and less heat resistant and less heat tolerant, but-unexpectedly-they were also less frost tolerant. Negative genetic correlations between resistance and tolerance to the same and different thermal stress were generally not significant, indicating only weak trade-offs. However, tolerance to frost was consistently accompanied by small size under control conditions, which may explain the non-adaptive latitudinal pattern for frost tolerance. Our results suggest that adaptation to frost and heat is not constrained by trade-offs between them. But the cost of frost tolerance in terms of plant size reduction may be important for the limits of species distributions and climate niches.

Intra-ELM phase modelling of a JET ITER-like wall H-mode discharge with EDGE2D-EIRENE

Energy Technology Data Exchange (ETDEWEB)

Harting, D.M., E-mail: Derek.Harting@ccfe.ac.uk [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Wiesen, S. [Institute of Energy and Climate Research – IEK4, Association EURATOM-FZJ, D-52425 Jülich (Germany); Groth, M. [Aalto University, Association EURATOM-Tekes, Espoo (Finland); Brezinsek, S. [Institute of Energy and Climate Research – IEK4, Association EURATOM-FZJ, D-52425 Jülich (Germany); Corrigan, G.; Arnoux, G. [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Boerner, P. [Institute of Energy and Climate Research – IEK4, Association EURATOM-FZJ, D-52425 Jülich (Germany); Devaux, S.; Flanagan, J. [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Järvinen, A. [Aalto University, Association EURATOM-Tekes, Espoo (Finland); Marsen, S. [Max-Planck-Institut für Plasmaphysik, EURATOM-Association, D-17491 Greifswald (Germany); Reiter, D. [Institute of Energy and Climate Research – IEK4, Association EURATOM-FZJ, D-52425 Jülich (Germany)

2015-08-15

We present the application of an improved EDGE2D-EIRENE SOL transport model for the ELM phase utilizing kinetic correction of the sheath-heat-transmission coefficients and heat-flux-limiting factors used in fluid SOL modelling. With a statistical analysis over a range of similar type-I ELMy H-mode discharges performed at the end of the first JET ITER-like wall campaign, we achieved a fast (Δt = 200 μs) temporal evolution of the outer midplane n{sub e} and T{sub e} profiles and the target-heat and particle-flux profiles, which provides a good experimental data set to understand the characteristics of an ELM cycle. We will demonstrate that these kinetic corrections increase the simulated heat-flux-rise time at the target to experimentally observed times but the power-decay time at the target is still underestimated by the simulations. This longer decay times are potentially related to a change of the local recycling coefficient at the tungsten target plate directly after the heat pulse.

Characterization of subsurface stratigraphy along the lower American River floodplain using electrical resistivity, Sacramento, California, 2011

Science.gov (United States)

Burton, Bethany L.; Powers, Michael H.; Ball, Lyndsay B.

2014-01-01

In July 2011, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, completed a geophysical survey using electrical resistivity along an approximately 6-mile reach of the lower American River in Sacramento, California, to map near-surface lithological variations. This survey is a part of a manifold and comprehensive study of river-flow dynamics and geologic boundary-property knowledge necessary to estimate scour potential and levee erosion risk. Data were acquired on the left (south or west) bank between river mile 5 and 10.7 as well as a short section on the right bank from river mile 5.4 to 6. Thirteen direct-current resistivity profiles and approximately 8.3 miles of capacitively coupled resisistivity data were acquired along accessible areas of the floodplain between the levee and river bank. Capacitively coupled resistivity was used as a reconnaissance tool, because it allowed for greater spatial coverage of data but with lower resolution and depth of investigation than the DC resistivity method. The study area contains Pleistocene-age alluvial deposits, dominated by gravels, sands, silts, and clays, that vary in both lateral extent and depth. Several generations of lithologic logs were used to help interpret resistivity variations observed in the resistivity models.

Investigation on the Scratch Strength of Clear Paints Used in Furniture Industries on the Wood Species Beech, Elm, Alder and Spruce

Directory of Open Access Journals (Sweden)

Mohammad Ghofrani

2014-05-01

Full Text Available In This research, the scratch strength (Cross-Cut Test of clear paints (nitrocellulose lacquers and acid catalyst lacquers of wood species Beech, Elm, Alder and spruce were studied as a function of moisture content (MC of the samples. For this purpose, lumbers (550×110×12 mm were cut from sapwood in tangential surfaces and were air dried for one month according to wood drying procedures. Then, for pre-conditioning of moisture content, at the levels of 8%, 12% and 15%, the samples were placed in three clima rooms. Then, finish applied and strength tests were performed. The results revealed that for acid catalyst lacquers the highest scratch strength (10.4% belongs to Elm wood with 8% moisture content, and the lowest scratch strength (53.6% belongs to Spruce wood with nitrocellulose lacquers having 15% moisture content.

Brief report: Contextual predictors of African American adolescents' ethnic-racial identity affirmation-belonging and resistance to peer pressure.

Science.gov (United States)

Derlan, Chelsea L; Umaña-Taylor, Adriana J

2015-06-01

The current study examined whether contextual factors (i.e., familial cultural socialization, percentage of same-ethnicity friends in high school, and neighborhood ethnic-racial composition) predicted ethnic-racial identity affirmation-belonging and, in turn, resistance to peer pressure to engage in problem behavior. Participants were 250 African American adolescents (M age = 15.57 years; SD = 1.22). Consistent with ecological theory, findings indicated that familial cultural socialization and percentage of same-ethnicity friends predicted greater ethnic-racial identity affirmation-belonging. Furthermore, consistent with notions from social identity theory, youth who reported higher ethnic-racial identity affirmation-belonging also reported greater resistance to peer pressure. Findings highlight the significance of the family and school context, as well as the importance of ethnic-racial identity affirmation-belonging, for African American youths' positive development. Copyright © 2015 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Environmental Assessment for the Aeromedical Evacuation Formal Training Unit, Wright-Patterson Air Force Base

Science.gov (United States)

2012-05-01

pennsylvanica), White Ash (Fraxinus americana), Shingle Oak (Quercus imbricaria), Northern Red Oak (Quercus rubra), Slippery Elm (Ulmus rubra...American Elm (Ulmus americana), Eastern Cottonwood (Populus deltoides), Silver Maple (Acer saccharinum), Sassafras (Sassafras albidum), Post Oak (Quercus

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

Directory of Open Access Journals (Sweden)

R Kavitha

2017-07-01

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

On lateral deflection of the SOL plasma in tokamaks during giant ELMs

International Nuclear Information System (INIS)

Landman, I.S.; Wuerz, H.

2000-06-01

In recent H-mode experiments at JET with giant ELMs a lateral deflection of hot tokamak plasma leaving the scrape-off layer and striking the divertor plate has been observed. This deflection can effect the divertor erosion caused by the hot plasma irradiation, because of enlarging the irradiated area. A simplified MHD model of the vapor shield plasma and of the hot plasma initially formed at time t → -∞ is analyzed. At t = -∞ both plasmas are assumed to stay on rest and to be separated by a boundary, which is parallel to the plate surface. The interaction between plasmas is assumed to develop gradually ('adiabatically') as exp(t/t 0 ) with t 0 ∝ 10 2 μs the ELM duration time. Electrical insulation of the core tokamak plasma is assumed everywhere except for the contact with the divertor. Electric currents are flowing only in the toroidal direction. These currents developing in the interaction zone of the hot plasma and the rather cold target plasma are calculated for inclined impact of the magnetized hot plasma. At such conditions the J x B force in the lateral direction accelerates the interacting plasmas. The motion of the cold plasma and the gradual increase of the plasma interaction intensity are shown to be important for the appropriate deflection magnitude. Adiabatically responding against the increase of the interaction intensity the cold plasma motion compensates significantly the currents thus decreasing the deflection compared to motionless approach. The calculated magnitude of the hot plasma deflection is comparable to the observed one. The results of the modeling are discussed in relation to the experiments. It is shown that sudden switching on of the interaction produces Alfven oscillations of large amplitudes causing much larger amplitudes of the magnetic field induced by the currents than in the adiabatic case. (orig.)

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

Science.gov (United States)

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-04-30

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

Influence of plasma pedestal profiles on access to ELM-free regimes in ITER

Energy Technology Data Exchange (ETDEWEB)

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; Poshekhonov, Yu. Yu., E-mail: naida@a5.kiam.ru [Russian Academy of Sciences, Keldysh Institute of Applied Mathematics (Russian Federation); Konovalov, S. V., E-mail: konoval-sv@nrcki.ru [National Research Nuclear University “MEPhI,” (Russian Federation); Polevoi, A. R., E-mail: alexei.polevoi@iter.org [ITER Organization (France)

2016-05-15

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 reaching 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.

Habitat Development at Eight Corps of Engineers Sites: Feasibility and Assessment.

Science.gov (United States)

1982-10-01

extremely slippery in wet weather, the vegetation should be either dense enough to provide traction to access vehicles or a layer of gravel or other surface...willow, green ash, bottomland oak species such as water oak, cedar elm , and Texas sugarberry and a variety of understory plants such as dewberry, frog...American elm Ulmus americana American holly Ilex opaca Annual pickleweed Salicornia bigj~lovi Arrow arum Peltandra virginica Arrowheads Sagittaria spp

Update on exotic ash collection for hybrid breeding and survey for EAB-resistance in native North American species

Science.gov (United States)

Mary E. Mason; Daniel A. Herms; David W. Carey; Kathleen S. Knight; Nurul I. Faridi; Jennifer. Koch

2011-01-01

Contrary to the high levels of devastation observed on North American ash species infested with emerald ash borer (EAB) (Agrilus planipennis Fairmaire), reports from Asia indicate that EAB-induced destruction of Asian ash species is limited to stressed trees. This indicates that Asian ash species have co-evolved resistance, or at least a high degree...

Flood Tolerance in Plants: A State-of-the-Art Review

Science.gov (United States)

1979-08-01

Q imbriraria Black walnut Juaus nigra Bitternut hickory Carya cordiformi. Red bud Cerc:i n e adensis Box el.der Accr n,ýgundo Slippery elm Jlmus rubra...Liriodendron tl__ipifera), sugar maple (Acer saccharum), white oak (Quercus alba), honey-locust (Gleditsia triacanthos), and Amterican elm (Ulmus americana...only American elm developed adventitious roots (YClcnouky 1964). 37. Accumulation of C02 . Next to lowered 0 concentration,:; the accumulation of toxic

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

Directory of Open Access Journals (Sweden)

Šifrar Kajan, Marjana

2012-09-01

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

Effect of misaligned edges and magnetic field orientation on plasma deposition into gaps during ELMs on ITER

Czech Academy of Sciences Publication Activity Database

Dejarnac, Renaud; Komm, Michael; Gunn, J. P.; Pekarek, Z.

2011-01-01

Roč. 415, č. 1 (2011), S977-S980 ISSN 0022-3115. [International Conference on Plasma-Surface Interactions in Controlled Fusion (PSI19)/19th./. San Diego, 24.05.2010-28.05.2010] Institutional research plan: CEZ:AV0Z20430508 Keywords : Edge modeling * Plasma-wall interactions * ITER * Sheaths * ELMs Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 2.052, year: 2011 http://www.sciencedirect.com/science/article/pii/S0022311510005520

Faith and feminism: how African American women from a storefront church resist oppression in healthcare.

Science.gov (United States)

Abrums, Mary

2004-01-01

It is well documented that racism in the US healthcare system, including the objectification and disparagement of women of color, contributes to disparities in health status. However, it is a mistaken notion to characterize women of color as unknowing victims. In this study, black feminist standpoint epistemology is used in methodological approach and analysis to understand how a small group of African American church-going women use religious beliefs to help them cope with and resist the racism and discriminatory objectification they encounter in healthcare encounters.

Expression for the thermal H-mode energy confinement time under ELM-free conditions

International Nuclear Information System (INIS)

Ryter, F.; Gruber, O.; Kardaun, O.J.W.F.; Menzler, H.P.; Wagner, F.; Schissel, D.P.; DeBoo, J.C.; Kaye, S.M.

1992-07-01

The design of future tokamaks, which are supposed to reach ignition with the H-mode, requires a reliable scaling expression for the H-mode energy confinement time. In the present work, an H-mode scaling expression for the thermal plasma energy confinement time has been developed by combining data from four existing divertor tokamaks, ASDEX, DIII-D, JET and PBX-M. The plasma conditions, which were as similar as possible to ensure a coherent set of data, were ELM-free deuterium discharges heated by deuterium neutral beam injection. By combining four tokamaks, the parametric dependence of the thermal energy confinement on the main plasma parameters, including the three main geometrical variables, was determined. (orig./WL)

Media Literacy and Attitude Change: Assessing the Effectiveness of Media Literacy Training on Children's Responses to Persuasive Messages within the ELM.

Science.gov (United States)

Yates, Bradford L.

This study adds to the small but growing body of literature that examines the effectiveness of media literacy training on children's responses to persuasive messages. Within the framework of the Elaboration Likelihood Model (ELM) of persuasion, this research investigates whether media literacy training is a moderating variable in the persuasion…

Interspecific variation in resistance of Asian, European, and North American birches (Betula spp.) to bronze birch borer (Coleoptera: Buprestidae).

Science.gov (United States)

Nielsen, David G; Muilenburg, Vanessa L; Herms, Daniel A

2011-06-01

Bronze birch borer (Agrilus anxius Gory) is the key pest of birches (Betula spp.) in North America, several of which have been recommended for ornamental landscapes based on anecdotal reports of borer resistance that had not been confirmed experimentally. In a 20-yr common garden experiment initiated in 1979 in Ohio, North American birch species, including paper birch (Betula papyrifera Marshall), 'Whitespire' gray birch (Betula populifolia Marshall), and river birch (Betula nigra L.), were much more resistant to bronze birch borer than species indigenous to Europe and Asia, including European white birch (Betula pendula Roth), downy birch (Betula pubescens Ehrh.), monarch birch (Betula maximowicziana Regel), and Szechuan white birch (Betula szechuanica Jansson). Within 8 yr of planting, every European white, downy, and Szechuan birch had been colonized and killed, although 100% of monarch birch had been colonized and 88% of these plants were killed after nine years. Conversely, 97% of river birch, 76% of paper birch, and 73% Whitespire gray birch were alive 20 yr after planting, and river birch showed no evidence of colonization. This pattern is consistent with biogeographic theory of plant defense: North American birch species that share a coevolutionary history with bronze birch borer were much more resistant than naïve hosts endemic to Europe and Asia, possibly by virtue of evolution of targeted defenses. This information suggests that if bronze birch borer were introduced to Europe or Asia, it could threaten its hosts there on a continental scale. This study also exposed limitations of anecdotal observation as evidence of host plant resistance.

Development of novel ash hybrids to introgress resistance to emerald ash borer into north American ash species

Science.gov (United States)

Jennifer L. Koch; David W. Carey; Mary E. Mason

2008-01-01

Currently, there is no evidence that any of the native North American ash species have any resistance to the emerald ash borer (EAB). This means that the entire ash resource of the eastern United States and Canada is at risk of loss due to EAB. In contrast, outbreaks of EAB in Asian ash species are rare and appear to be isolated responses to stress (Bauer et al. 2005,...

Investigation of erosion mechanisms and erosion products in divertor armour materials under conditions relevant to elms and mitigated disruptions in ITER

International Nuclear Information System (INIS)

Safronov, V.M.; Arkhipov, N.I.; Klimov, N.S.; Kovalenko, D.V.; Moskaleva, A.A.; Podkovyrov, V.L.; Toporkov, D.A.; Zhitlukhin, A.M.; Landman, I.S.; Poznyak, I.M.

2008-01-01

Carbon fibre composite (CFC) and tungsten were irradiated by intense plasma streams at plasma gun facilities MK-200UG and QSPA-T. The targets were tested by plasma loads relevant to Edge Localised Modes (ELM) and mitigated disruptions in ITER. Onset condition of material erosion and properties of erosion products have been studied

White pine blister rust resistance in North American, Asian and european species - results from artificial inoculartion trials in Oregon

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R.A. Sniezko

2013-12-01

Full Text Available Dorena Genetic Resource Center (DGRC has used artificial inoculation trials to evaluate progenies of thousands of Pinus monticola and P. lambertiana selections from Oregon and Washington for resistance to white pine blister rust caused by Cronartium ribicola. In addition, early results are now available for P. albicaulis and P. strobiformis. DGRC has also recently evaluated seed orchard progenies of P. strobus, as well as bulked seedlots from P. armandii and P. peuce. The majority of P. monticola, P. lambertiana, P. albicaulis, and P. strobus progenies are very susceptible to blister rust. However, resistance exists in all these species. P. strobiformis showed relatively high levels of resistance for the eight progenies tested. Resistance in P. armandii was mainly reflected in the very low percentage of cankered seedlings; for P. peuce, the high percentage of cankered seedlings alive three years after inoculation was notable. R-genes are present in some of the North American five-needle pine species, but partial resistance traits (e.g. bark reaction will play a major role in breeding activities for P. monticola and P. lambertiana and will likely be the key to developing durable resistance.

Control of the Resistive Wall Mode in Advanced Tokamak Plasmas on DIII-D

International Nuclear Information System (INIS)

Garofalo, A.M.; Strait, E.J.; Bialek, J.; Frederickson, E.; Gryaznevich, M.; Jensen, T.H.; Johnson, L.C.; La Haye, R.J.; Navratil, G.A.; Lazarus, E.A.; Luce, T.C.; Makowski, M.; Okabayashi, M.; Rice, B.W.; Scoville, J.T.; Turnbull, A.D.; Walker, M.L.

1999-01-01

Resistive wall mode (RWM) instabilities are found to be a limiting factor in advanced tokamak (AT) regimes with low internal inductance. Even small amplitude modes can affect the rotation profile and the performance of these ELMing H-mode discharges. Although complete stabilization of the RWM by plasma rotation has not yet been observed, several discharges with increased beam momentum and power injection sustained good steady-state performance for record time extents. The first investigation of active feedback control of the RWM has shown promising results: the leakage of the radial magnetic flux through the resistive wall can be successfully controlled, and the duration of the high beta phase can be prolonged. The results provide a comparative test of several approaches to active feedback control, and are being used to benchmark the analysis and computational models of active control

Processes and properties of edge-localised instabilities in 2T 2MA plasmas in the Joint European Torus

International Nuclear Information System (INIS)

Webster, A. J.; Webster, S. J.

2014-01-01

During July 2012, 150 almost identical H-mode plasmas were consecutively created in the Joint European Torus, providing a combined total of approximately 8 minutes of steady-state plasma with 15 000 Edge Localised Modes (ELMs). In principle, each of those 15 000 ELMs are statistically equivalent. Here, the changes in edge density and plasma energy associated with those ELMs are explored, using the spikes in Beryllium II (527 nm) radiation as an indicator for the onset of an ELM. Clearly different timescales are observed during the ELM process. Edge temperature falls over a 2 ms timescale, edge density and pressure fall over a 5 ms timescale, and there is an additional 10 ms timescale that is consistent with a resistive relaxation of the plasma's edge. The statistical properties of the energy and density losses due to the ELMs are explored. For these plasmas the ELM energy (δE) is found to be approximately independent of the time between ELMs, despite the average ELM energy (〈δE〉) and average ELM frequency (f) being consistent with the scaling of 〈δE〉∝1/f. Instead, beyond the first 0.02 s of waiting time between ELMs, the energy losses due to individual ELMs are found to be statistically the same. Surprisingly no correlation is found between the energies of consecutive ELMs either. A weak link is found between the density drop and the ELM waiting time. Consequences of these results for ELM control and modelling are discussed

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

Energy Technology Data Exchange (ETDEWEB)

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

2007-07-01

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

African American Educational Leadership in the School Superintendency

Science.gov (United States)

Smith, Eva C.

2013-01-01

African American educational leadership has long been part of American education and African American activism to resist oppression. However, the field of educational leadership has rarely included the contributions of African American leaders, particularly women leaders, into mainstream leadership theory and practices. This omission is difficult…

ELM-induced melting: assessment of shallow melt layer damage and the power handling capability of tungsten in a linear plasma device

Czech Academy of Sciences Publication Activity Database

Morgan, T.W.; van Eden, G.G.; de Kruif, T.M.; van den Berg, A.; Matějíček, Jiří; Chráska, Tomáš; De Temmerman, G.

-, T159 (2014), 014022-014022 ISSN 0031-8949. [International Conference on Plasma-Facing Materials and Components for Fusion Applications/14./. Jülich, 13.05.2013-17.05.2013] Institutional support: RVO:61389021 Keywords : melting * tungsten * ELMs * divertor * ITER * DEMO Subject RIV: JG - Metallurgy Impact factor: 1.126, year: 2014 http://iopscience.iop.org/1402-4896/2014/T159/014022/pdf/1402-4896_2014_T159_014022.pdf

Distribution of Serum Total Homocysteine and Its Association with Diabetes and Cardiovascular Risk Factors of the Insulin Resistance Syndrome in Mexican American Men: The Third National Health and Nutrition Examination Survey

Directory of Open Access Journals (Sweden)

Gillum Richard

2003-08-01

Full Text Available Abstract Background Few data have been published on the association of variables of the insulin resistance syndrome and serum total homocysteine (tHcy, a putative risk factor for cardiovascular morbidity, in representative samples of total populations or in Hispanic Americans. Methods To describe the distributions of serum tHcy concentration and variables associated with insulin resistance in Mexican American men and to assess their association, data from a cross-sectional survey of a large national sample, the Third National Health and Nutrition Examination Survey were analyzed. Analyses were restricted to Mexican American men aged 40–74 years with data on glycated hemoglobin (%, body mass index (BMI, body fat distribution, HDL cholesterol, fasting serum insulin, serum triglycerides and serum tHcy concentrations. Results Cumulative distributions of serum tHcy shifted to the right with increasing age. Log serum tHcy was not associated with prevalence of diagnosed diabetes mellitus or glycated hemoglobin percent or other risk factors other than age. Log serum tHcy concentration showed borderline significant (p = 0.049 positive association with fasting serum insulin concentration independent of age and BMI, only in men aged 60–74. Conclusion No consistent association of tHcy with diabetes prevalence or variables of the insulin resistance syndrome were found in Mexican American men aged 40–74 years. Further research is needed on the associations of serum tHcy concentration with insulin resistance and other components of the insulin resistance syndrome in persons of varying ethnicity.

Improving ELM-Based Service Quality Prediction by Concise Feature Extraction

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Yuhai Zhao

2015-01-01

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

Advances towards QH-mode viability for ELM-stable operation in ITER

International Nuclear Information System (INIS)

Garofalo, A.M.; Burrell, K.H.; DeBoo, J.C.; Schaffer, M.J.; Snyder, P.B.; Solomon, W.M.; Park, J.-K.; Lanctot, M.J.; Reimerdes, H.; McKee, G.R.; Schmitz, L.

2011-01-01

The application of static, non-axisymmetric, nonresonant magnetic fields (NRMFs) to high beta DIII-D plasmas has allowed sustained operation with a quiescent H-mode (QH-mode) edge and both toroidal rotation and neutral beam injected torque near zero. Previous studies have shown that QH-mode operation can be accessed only if sufficient radial shear in the plasma flow is produced near the plasma edge. In past experiments, this flow shear was produced using neutral beam injection (NBI) to provide toroidal torque. In recent experiments, this torque was nearly completely replaced by the torque from applied NRMFs. The application of the NRMFs does not degrade the global energy confinement of the plasma. Conversely, the experiments show that the energy confinement quality increases with lower plasma rotation. Furthermore, the NRMF torque increases plasma resilience to locked modes at low rotation. These results open a path towards QH-mode utilization as an edge-localized mode (ELM)-stable H-mode in the self-heated burning plasma scenario, where toroidal momentum input from NBI may be small or absent.

An ELM Based Online Soft Sensing Approach for Alumina Concentration Detection

Directory of Open Access Journals (Sweden)

Sen Zhang

2015-01-01

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

Range Expansion and the Origin of USA300 North American Epidemic Methicillin-Resistant Staphylococcus aureus

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Lavanya Challagundla

2018-01-01

Full Text Available The USA300 North American epidemic (USA300-NAE clone of methicillin-resistant Staphylococcus aureus has caused a wave of severe skin and soft tissue infections in the United States since it emerged in the early 2000s, but its geographic origin is obscure. Here we use the population genomic signatures expected from the serial founder effects of a geographic range expansion to infer the origin of USA300-NAE and identify polymorphisms associated with its spread. Genome sequences from 357 isolates from 22 U.S. states and territories and seven other countries are compared. We observe two significant signatures of range expansion, including decreases in genetic diversity and increases in derived allele frequency with geographic distance from the Pennsylvania region. These signatures account for approximately half of the core nucleotide variation of this clone, occur genome wide, and are robust to heterogeneity in temporal sampling of isolates, human population density, and recombination detection methods. The potential for positive selection of a gyrA fluoroquinolone resistance allele and several intergenic regions, along with a 2.4 times higher recombination rate in a resistant subclade, is noted. These results are the first to show a pattern of genetic variation that is consistent with a range expansion of an epidemic bacterial clone, and they highlight a rarely considered but potentially common mechanism by which genetic drift may profoundly influence bacterial genetic variation.

Evaluation of two vaccine education interventions to improve pertussis vaccination among pregnant African American women: A randomized controlled trial.

Science.gov (United States)

Kriss, Jennifer L; Frew, Paula M; Cortes, Marielysse; Malik, Fauzia A; Chamberlain, Allison T; Seib, Katherine; Flowers, Lisa; Ault, Kevin A; Howards, Penelope P; Orenstein, Walter A; Omer, Saad B

2017-03-13

Vaccination coverage with tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine in pregnancy or immediately postpartum has been low. Limited data exist on rigorously evaluated interventions to increase maternal vaccination, including Tdap. Tailored messaging based on the Elaboration Likelihood Model (ELM) framework has been successful in improving uptake of some public health interventions. We evaluated the effect of two ELM-based vaccine educational interventions on Tdap vaccination among pregnant African American women, a group of women who tend to have lower vaccine uptake compared with other groups. We conducted a prospective randomized controlled trial to pilot test two interventions - an affective messaging video and a cognitive messaging iBook - among pregnant African American women recruited during routine prenatal care visits. We measured Tdap vaccination during the perinatal period (during pregnancy and immediately postpartum), reasons for non-vaccination, and intention to receive Tdap in the next pregnancy. Among the enrolled women (n=106), 90% completed follow-up. Tdap vaccination in the perinatal period was 18% in the control group; 50% in the iBook group (Risk Ratio [vs. control group]: 2.83; 95% CI, 1.26-6.37), and 29% in the video group (RR: 1.65; 95% CI, 0.66-4.09). From baseline to follow-up, women's reported intention to receive Tdap during the next pregnancy improved in all three groups. Among unvaccinated women, the most common reason reported for non-vaccination was lack of a recommendation for Tdap by the woman's physician. Education interventions that provide targeted information for pregnant women in an interactive manner may be useful to improve Tdap vaccination during the perinatal period. However, larger studies including multiple racial and ethnic groups are needed to evaluate robustness of our findings. clinicaltrials.gov Identifier: NCT01740310. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of effect of Ophiostoma novo-ulmi on four major wood ...

African Journals Online (AJOL)

Evaluation of effect of Ophiostoma novo-ulmi on four major wood species of the elm family in Rasht (North West of Iran) ... the diameter size of vessels and the number of xylary rays in four species: Ulmus carpinifolia, Ulmus glabra, Zelkova carpinifolia and Celtis australis as important factors in host resistance to elm disease.

Evaluating methyl jasmonate for induction of resistance to Fusarium oxysporum, F. circinatum and Ophiostoma novo-ulmi

Energy Technology Data Exchange (ETDEWEB)

Vivas, M.; Martin, J. a.; Gil, L.; Solla, A.

2012-11-01

Damping off is probably the most common disease affecting seedlings in forest nurseries. In south-western Europe, the pitch canker and the Dutch elm disease cause relevant economic looses in forests, mostly in adult trees. The ability of the chemical plant elicitor methyl jasmonate (MeJA) to induce resistance in Pinus pinaster against Fusarium oxysporum and F. circinatum, and in Ulmus minor against Ophiostoma novo-ulmi was examined. In a first experiment, an aqueous solution of MeJA 5 mM was applied to P. pinaster seeds by immersion or spray, and different concentrations of MeJA (0, 0.1, 0.5, 1, 5 and 10 mM) were tested in seedlings before inoculations with F. oxysporum (105 and 107 spores mL{sup -}1). In a second experiment, 6-months-old P. pinaster seedlings were sprayed with 0 and 25 mM of MeJA, and later challenged with mycelium of F. circinatum. Finally, 4-year-old U. minor trees were sprayed with 0, 50 and 100 mM of MeJA and subsequently inoculated with O. novo-ulmi (106 spores mL{sup -}1). MeJA did not protect P. pinaster seeds and seedlings against F. oxysporum, probably because plants were too young for the physiological mechanisms responsible for resistance to be induced. Based on the morphological changes observed in the treated 6-months-old P. pinaster seedlings (reduction of growth and increased resin duct density), there is evidence that MeJA could have activated the mechanisms of resistance. However, 25 mM MeJA did not reduce plant mortality, probably because the spread of the virulent F. circinatum strain within the tree tissues was faster than the formation of effective defense responses. Based on the lack of phenological changes observed in the treated elms, there is no evidence that MeJA would cause induction of resistance. These results suggest that the use of MeJA to prevent F. oxysporum and F. circinatum in P. pinaster seedlings in nurseries and O. novo-ulmi in U. minor trees should be discarded. (Author) 42 refs.

Evaporation and Vapor Shielding of CFC Targets Exposed to Plasma Heat Fluxes Relevant to ITER ELMs

International Nuclear Information System (INIS)

Safronov, V.; Arkhipov, N.I.; Toporkov, D.A.; Zhitlukhin, A.M.; Landman, I.

2007-01-01

Full text of publication follows: Carbon-fibre composite (CFC) is foreseen presently as armour material for the divertor target in ITER. During the transient processes such as instabilities of Edge Localized Modes (ELMs) the target as anticipated will be exposed to the plasma heat loads of a few MJ/m 2 on the time scale of a fraction of ms, which causes an intense evaporation at the target surface and contaminates tokamak plasma by evaporated carbon. The ITER transient loads are not achievable at existing tokamaks therefore for testing divertor armour materials other facilities, in particular plasma guns are employed. In the present work the CFC targets have been tested for ITER at the plasma gun facility MK- 200 UG in Troitsk by ELM relevant heat fluxes. The targets in the applied magnetic field up to 2 T were irradiated by hydrogen plasma streams of diameter 6 - 8 cm, impact ion energy 2 - 3 keV, pulse duration 0.05 ms and energy density varying in the range 0.05 - 1 MJ/m 2 . Primary attention has been focused on the measurement of evaporation threshold and investigation of carbon vapor properties. Fast infrared pyrometer, optical and VUV spectrometers, framing cameras and plasma calorimeters were applied as diagnostics. The paper reports the results obtained on the evaporation threshold of CFC, the evaporation rate of the carbon fibers oriented parallel and perpendicular to the exposed target surface, the velocity of carbon vapor motion along and across the magnetic field lines, and the parameters of carbon plasma such as temperature, density and ionization state measured up to the distance 15 cm at varying plasma load. First experimental results on investigation of the vapor shield onset conditions are presented also. (authors)

Operational conditions and characteristics of ELM-events during H-mode plasmas in the stellarator W7-AS

International Nuclear Information System (INIS)

Hirsch, M.; Grigull, P.; Wobig, H.; Kisslinger, J.; McCormick, K.; Anton, M.; Baldzuhn, J.; Fiedler, S.; Fuchs, Ch.; Geiger, J.; Giannone, L.; Hartfuss, H.-J.; Holzhauer, E.; Hirsch, M.; Jaenicke, R.; Kick, M.; Maassberg, H.; Wagner, F.; Weller, A.

2000-01-01

H-mode operation in the low-shear stellarator W7-AS is achieved for specific plasma edge topologies characterized by three 'operational windows' of the edge rotational transform. An explanation for this strong influence of the magnetic configuration could be the increase of viscous damping if rational surfaces and thus island structures occur within the relevant plasma edge layer, thereby impeding the development of an edge transport barrier. Prior to the final transition to a quiescent state, the plasma edge passes a rich phenomenology of dynamic behaviour such as dithering and ELMs. Plasma edge parameters indicate that a quiescent H-mode occurs if a certain edge pressure is achieved. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-06-15

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

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

International Nuclear Information System (INIS)

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

2009-01-01

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

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

Directory of Open Access Journals (Sweden)

Sen Zhang

2017-01-01

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

The H-mode pedestal, ELMs and TF ripple effects in JT-60U/JET dimensionless identity experiments

International Nuclear Information System (INIS)

Saibene, G.; Oyama, N.; Loennroth, J.; Andrew, Y.; Luna, E. de la; Giroud, C.; Huysmans, G.T.A.; Kamada, Y.; Kempenaars, M.A.H.; Loarte, A.; Donald, D. Mc; Nave, M.M.F.; Meiggs, A.; Parail, V.; Sartori, R.; Sharapov, S.; Stober, J.; Suzuki, T.; Takechi, M.; Toi, K.; Urano, H.

2007-01-01

This paper summarizes results of dimensionless identity experiments in JT-60U and JET, aimed at the comparison of the H-mode pedestal and ELM behaviour in the two devices. Given their similar size, dimensionless matched plasmas are also similar in their dimensional parameters (in particular, the plasma minor radius a is the same in JET and JT-60U). Power and density scans were carried out at two values of I p , providing a q scan (q 95 = 3.1 and 5.1) with fixed (and matched) toroidal field. Contrary to initial expectations, a dimensionless match between the two devices was quite difficult to achieve. In general, p ped in JT-60U is lower than in JET and, at low q, the pedestal pressure of JT-60U with a Type I ELMy edge is matched in JET only in the Type III ELM regime. At q 95 = 5.1, a dimensionless match in ρ*, ν* and β p,ped is obtained with Type I ELMs, but only with low power JET H-modes. These results motivated a closer investigation of experimental conditions in the two devices, to identify possible 'hidden' physics that prevents obtaining a good match of pedestal values over a large range of plasmas parameters. Ripple-induced ion losses of the medium bore plasma used in JT-60U for the similarity experiments are identified as the main difference with JET. The magnitude of the JT-60U ripple losses is sufficient to induce counter-toroidal rotation in co-injected plasma. The influence of ripple losses was demonstrated at q 95 = 5.1: reducing ripple losses by ∼2 (from 4.3 to 1.9 MW) by replacing positive with negative neutral beam injection at approximately constant P in resulted in an increased p ped in JT-60U, providing a good match to full power JET H-modes. At the same time, the counter-toroidal rotation decreased. Physics mechanisms relating ripple losses to pedestal performance are not yet identified, and the possible role of velocity shear in the pedestal stability, as well as the possible influence of ripple on thermal ion transport are briefly

Comparisons of protein profiles of beech bark disease resistant and susceptible American beech (Fagus grandifolia)

Science.gov (United States)

2013-01-01

Background Beech bark disease is an insect-fungus complex that damages and often kills American beech trees and has major ecological and economic impacts on forests of the northeastern United States and southeastern Canadian forests. The disease begins when exotic beech scale insects feed on the bark of trees, and is followed by infection of damaged bark tissues by one of the Neonectria species of fungi. Proteomic analysis was conducted of beech bark proteins from diseased trees and healthy trees in areas heavily infested with beech bark disease. All of the diseased trees had signs of Neonectria infection such as cankers or fruiting bodies. In previous tests reported elsewhere, all of the diseased trees were demonstrated to be susceptible to the scale insect and all of the healthy trees were demonstrated to be resistant to the scale insect. Sixteen trees were sampled from eight geographically isolated stands, the sample consisting of 10 healthy (scale-resistant) and 6 diseased/infested (scale-susceptible) trees. Results Proteins were extracted from each tree and analysed in triplicate by isoelectric focusing followed by denaturing gel electrophoresis. Gels were stained and protein spots identified and intensity quantified, then a statistical model was fit to identify significant differences between trees. A subset of BBD differential proteins were analysed by mass spectrometry and matched to known protein sequences for identification. Identified proteins had homology to stress, insect, and pathogen related proteins in other plant systems. Protein spots significantly different in diseased and healthy trees having no stand or disease-by-stand interaction effects were identified. Conclusions Further study of these proteins should help to understand processes critical to resistance to beech bark disease and to develop biomarkers for use in tree breeding programs and for the selection of resistant trees prior to or in early stages of BBD development in stands. Early

Oil-in-Ice Demonstration 4: Quick Look Report

Science.gov (United States)

2016-11-01

A-3  Figure A-4. Temporary storage tank setup on the deck of USCGC Elm , December 2014 (ELASTEC American Marine 2014...an oil surrogate.  Boot covers work well for slippery surfaces, better than rubber boots. Oil-in-Ice IV Demonstration Quick Look Report 24...RDC | A. Balsley, et al. Public | November 2016 Figure A-4. Temporary storage tank setup on the deck of USCGC Elm , December 2014 (ELASTEC

Surface damage characteristics of CFC and tungsten with repetitive ELM-like pulsed plasma irradiation

Energy Technology Data Exchange (ETDEWEB)

Kikuchi, Y., E-mail: ykikuchi@eng.u-hyogo.ac.jp [Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, 671-2280 Hyogo (Japan); Nishijima, D. [Center for Energy Research, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0417 (United States); Nakatsuka, M.; Ando, K.; Higashi, T.; Ueno, Y.; Ishihara, M.; Shoda, K.; Nagata, M. [Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, 671-2280 Hyogo (Japan); Kawai, T.; Ueda, Y. [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Fukumoto, N. [Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, 671-2280 Hyogo (Japan); Doerner, R.P. [Center for Energy Research, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0417 (United States)

2011-08-01

Surface damage of carbon fiber composite (CFC) and tungsten (W) due to repetitive ELM-like pulsed plasma irradiation has been investigated by using a magnetized coaxial plasma gun. CX2002U CFC and stress-relieved W samples were exposed to repetitive pulsed deuterium plasmas with duration of {approx}0.5 ms, incident ion energy of {approx}30 eV, and surface absorbed energy density of {approx}0.3-0.7 MJ/m{sup 2}. Bright spots on a CFC surface during pulsed plasma exposures were clearly observed with a high-speed camera, indicating a local surface heating. No melting of a W surface was observed under a single plasma pulse exposure at energy density of {approx}0.7 MJ/m{sup 2}, although cracks were formed. Cracking of the W surface grew with repetitive pulsed plasma exposures. Subsequently, the surface melted due to localized heat absorption.

Effects of Density and Impurity on Edge Localized Modes in Tokamaks

Science.gov (United States)

Zhu, Ping

2017-10-01

Plasma density and impurity concentration are believed to be two of the key elements governing the edge tokamak plasma conditions. Optimal levels of plasma density and impurity concentration in the edge region have been searched for in order to achieve the desired fusion gain and divertor heat/particle load mitigation. However, how plasma density or impurity would affect the edge pedestal stability may have not been well known. Our recent MHD theory modeling and simulations using the NIMROD code have found novel effects of density and impurity on the dynamics of edge-localized modes (ELMs) in tokamaks. First, previous MHD analyses often predict merely a weak stabilizing effect of toroidal flow on ELMs in experimentally relevant regimes. We find that the stabilizing effects on the high- n ELMs from toroidal flow can be significantly enhanced with the increased edge plasma density. Here n denotes the toroidal mode number. Second, the stabilizing effects of the enhanced edge resistivity due to lithium-conditioning on the low- n ELMs in the high confinement (H-mode) discharges in NSTX have been identified. Linear stability analysis of the experimentally constrained equilibrium suggests that the change in the equilibrium plasma density and pressure profiles alone due to lithium-conditioning may not be sufficient for a complete suppression of the low- n ELMs. The enhanced resistivity due to the increased effective electric charge number Zeff after lithium-conditioning provides additional stabilization of the low- n ELMs. These new effects revealed in our theory analyses may help further understand recent ELM experiments and suggest new control schemes for ELM suppression and mitigation in future experiments. They may also pose additional constraints on the optimal levels of plasma density and impurity concentration in the edge region for H-mode tokamak operation. Supported by National Magnetic Confinement Fusion Science Program of China Grants 2014GB124002 and 2015GB

Food cravings, food addiction, and a dopamine-resistant (DRD2 A1) receptor polymorphism in Asian American college students.

Science.gov (United States)

Yeh, Joanna; Trang, Amy; Henning, Susanne M; Wilhalme, Holly; Carpenter, Catherine; Heber, David; Li, Zhaoping

2016-01-01

In an era where obesity remains an important public health concern, food addiction has emerged as a possible contributor to obesity. The DRD2 gene is the most studied polymorphism. The aim of this study was to investigate a relationship between food addiction questionnaires, body composition measurements, and a dopamine- resistant receptor polymorphism (DRD2 A1) among Asian Americans. A total of 84 Asian American college students were recruited. Participants underwent body composition measurement via bioelectrical impedance, answered questionnaires (Food Craving Inventory and Power of Food Scale), and had blood drawn for genotyping (PCR). There was no difference in body composition (BMI, percent body fat) between the A1 (A1A1 or A1A2) and A2 (A2A2) groups. There were statistically significant differences in food cravings of carbohydrates and fast food on the Food Craving Inventory between the A1 and A2 groups (p=0.03), but not for sugar or fat. Among Asian college females, there was also a difference on the Power of Food questionnaire (p=0.04), which was not seen among men. 13 out of 55 women also had >30% body fat at a BMI of 21.4 to 28.5 kg/m2. Greater carbohydrate and fast food craving was associated with the DRD2 A1 versus A2 allele among Asian Americans. Further studies examining the ability of dopamine agonists to affect food craving and to reduce body fat in Asian American are warranted. More studies in food addiction among obese Asian Americans are needed with careful definition of obesity, specifically for Asian women.

Ceftaroline-Resistant, Daptomycin-Tolerant, and Heterogeneous Vancomycin-Intermediate Methicillin-Resistant Staphylococcus aureus Causing Infective Endocarditis.

Science.gov (United States)

Nigo, Masayuki; Diaz, Lorena; Carvajal, Lina P; Tran, Truc T; Rios, Rafael; Panesso, Diana; Garavito, Juan D; Miller, William R; Wanger, Audrey; Weinstock, George; Munita, Jose M; Arias, Cesar A; Chambers, Henry F

2017-03-01

We report a case of infective endocarditis (IE) caused by ceftaroline-resistant, daptomycin-tolerant, and heterogeneous vancomycin-intermediate methicillin-resistant S. aureus (MRSA). Resistance to ceftaroline emerged in the absence of drug exposure, and the E447K substitution in the active site of PBP2a previously associated with ceftaroline resistance was identified. Additionally, we present evidence of patient-to-patient transmission of the strain within the same unit. This case illustrates the difficulties in treating MRSA IE in the setting of a multidrug-resistant phenotype. Copyright © 2017 American Society for Microbiology.

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

Energy Technology Data Exchange (ETDEWEB)

Jia, Y.Z., E-mail: jaja880816@aliyun.com [Science and Technology on Reactor Fuel and Materials Laboratory, Nuclear Power Institute of China, Chengdu, Sichuan 610213 (China); Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu, W., E-mail: liuw@mail.tsinghua.edu.cn [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Xu, B.; Qu, S.L. [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Morgan, T.W. [FOM Institute DIFFER-Dutch Institute for Fundamental Energy Research, 5612AJ Eindhoven (Netherlands)

2017-04-15

The surface damage of W under D plasma and ELMs-like transient heat loads was studied by combined stationary and pulsed D plasma. Low-flux transient heat loads will promote blister formation due to the gas expansion inside the blisters. On the contrary, high-flux transient heat loads will mitigate blistering due to the high surface temperature. Therefore, blistering on W surface first increased and then decreased with the increasing transient heat loads. The promotion effect of pulsed plasma on blistering is more obvious on [001] and [110] surfaces than on [111] surface, and the orientation dependence of blisters was mitigated by the transient heat loads. Surface modification induced by transient heat loads only formed on [001] and [110] surfaces, but did not form on [111] surface. The orientation dependence of surface modification was mainly due to the slipping system of dislocations.

Phytoremediation of Groundwater at Air Force Plant 4, Carswell, Texas

Science.gov (United States)

2003-09-01

willows, one hackberry, one mesquite, one pecan , one American elm, one unidentified elm, and one unidentified species. Cores were collected from a height...ability of trees to act as pumps was noted in the late 19th century when Eucalyptus trees were planted in Italy and Algeria to dry up marshes. The...Netherlands, Finland, Denmark, Sweden, Italy , Australia, and the United Kingdom. B-2 If shallow ground water contaminated with low level

A Novel Multimodal Biometrics Recognition Model Based on Stacked ELM and CCA Methods

Directory of Open Access Journals (Sweden)

Jucheng Yang

2018-04-01

Full Text Available Multimodal biometrics combine a variety of biological features to have a significant impact on identification performance, which is a newly developed trend in biometrics identification technology. This study proposes a novel multimodal biometrics recognition model based on the stacked extreme learning machines (ELMs and canonical correlation analysis (CCA methods. The model, which has a symmetric structure, is found to have high potential for multimodal biometrics. The model works as follows. First, it learns the hidden-layer representation of biological images using extreme learning machines layer by layer. Second, the canonical correlation analysis method is applied to map the representation to a feature space, which is used to reconstruct the multimodal image feature representation. Third, the reconstructed features are used as the input of a classifier for supervised training and output. To verify the validity and efficiency of the method, we adopt it for new hybrid datasets obtained from typical face image datasets and finger-vein image datasets. Our experimental results demonstrate that our model performs better than traditional methods.

Comparing 1.5D ONETWO and 2D SOLPS analyses of inter-ELM H-mode plasma in DIII-D

International Nuclear Information System (INIS)

Owen, Larry W.; Canik, John; Groebner, R.; Callen, J.D.; Bonnin, X.; Osborne, T.H.

2010-01-01

A DIII-D inter-ELM H-mode plasma that is in approximate transport equilibrium is analysed with the 1.5D ONETWO core code and the 2D SOLPS code. In order to investigate the importance of core-edge coupling and 2D effects, including divertor fuelling across the X-point and poloidal asymmetries that are not explicitly included in ONETWO, the domain of SOLPS is extended to very near the magnetic axis. Two principal objectives are (1) to determine whether poloidal asymmetries in the plasma distributions are large enough to vitiate a core-type interpretive plasma transport analysis and (2) to determine whether the interpretive transport coefficients and neutral beam power and particle sources from ONETWO, when used in 2D SOLPS full plasma simulations, yield the same quality fits to the measured upstream density and temperature profiles as obtained with ONETWO. Results show that only a small increase in the separatrix value of the particle diffusion coefficient, and no change in the thermal diffusivities from ONETWO was needed to get excellent agreement of the upstream SOLPS density and temperature profiles and the Thomson scattering and CER data. Good agreement of the ONETWO and SOLPS flux surface averaged distributions of the core electron and D+ densities and temperatures are also obtained. Likewise the C6+ density, with a simple chemical sputtering model based on a constant fraction of the divertor D+ flux, the core heat and particle fluxes and the neutral density reveal no 2D effects in the core/pedestal region that would vitiate a 1.5D treatment of the inter-ELM H-mode plasma.

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

Science.gov (United States)

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.

An Overview Of The ITER In-Vessel Coil Systems

International Nuclear Information System (INIS)

Heitzenroeder, P.J.; Brooks, A.W.; Chrzanowski, J.H.; Dahlgren, F.; Hawryluk, R.J.; Loesser, G.D.; Neumeyer, C.; Mansfield, C.; Smith, J.P.; Schaffer, M.; Humphreys, D.; Cordier, J.J.; Campbell, D.; Johnson, G.A.; Martin, A.; Rebut, P.H.; Tao, J.O.; Fogarty, P.J.; Nelson, B.E.; Reed, R.P.

2009-01-01

ELM mitigation is of particular importance in ITER in order to prevent rapid erosion or melting of the divertor surface, with the consequent risk of water leaks, increased plasma impurity content and disruptivity. Exploitable 'natural' small or no ELM regimes might yet be found which extrapolate to ITER but this cannot be depended upon. Resonant Magnetic Perturbation has been added to pellet pacing as a tool for ITER to mitigate ELMs. Both are required, since neither method is fully developed and much work remains to be done. In addition, in-vessel coils enable vertical stabilization and RWM control. For these reasons, in-vessel coils (IVCs) are being designed for ITER to provide control of Edge Localized Modes (ELMs) in addition to providing control of moderately unstable resistive wall modes (RWMs) and the vertical stability (VS) of the plasma.

A genome-wide association study of field and seedling response to stem rust pathogen races reveals combinations of race-specific resistance genes in North American spring wheat

Science.gov (United States)

Stem rust of wheat caused by the fungal pathogen Puccinia graminis f. sp. tritici historically caused major yield losses of wheat worldwide. To understand the genetic basis of stem rust resistance in conventional North American spring wheat, genome-wide association analysis (GWAS) was conducted on a...

Resistência à traça-do-tomateiro em plantas com altos teores de acilaçúcares nas folhas Resistance to the South American tomato pinworm in tomato plants with high foliar acylsugar contents

Directory of Open Access Journals (Sweden)

Álvaro C Gonçalves Neto

2010-06-01

Full Text Available A traça-do-tomateiro foi constatada pela primeira vez no Brasil em 1980 estando hoje dentre as principais pragas da tomaticultura nacional. O controle desta praga é feito principalmente por inseticidas, sendo realizada em casos extremos, até três pulverizações semanais. Acessos silvestres de tomateiro como S. pennellii LA-716 possuem resistência a pragas, mediada pela presença de acilaçúcares nos folíolos. Os objetivos deste trabalho foram obter genótipos de tomateiro com características comerciais e altos teores foliares de acilaçúcares (AA, e avaliar seus níveis de resistência à traça do tomateiro Tuta absoluta. Os genótipos foram obtidos a partir de populações segregantes (F2 oriundas do cruzamento entre AF-8665 (linhagem elite com baixos teores de AA e as linhagens BPX370E-30-275-11-7, BPX370E-30-275-11-8, BPX370E-30-380-68-6 e BPX370E-30-380-68-8 (linhagens pré-comerciais com altos teores, obtidas a partir do cruzamento interespecífico S. lycopersicum x S. pennellii LA-716. Plantas F2 previamente selecionadas com base nos teores de AA foram clonadas e em seguida testadas quanto à resistência à traça-do-tomateiro. Genótipos selecionados para altos teores de AA expressaram menor ovoposição da traça e níveis inferiores de danos causados à planta pela infestação do microlepidóptero do que genótipos (comerciais ou não com baixos teores de AA. Embora genótipos com altos teores de AA tenham sido mais resistentes à traça do que os demais, seus níveis de resistência podem ser dependentes do background genotípico: clones BPX-410H (alto teor de AA mostraram-se em geral ligeiramente mais resistentes do que o dos clones BPX-370G (também alto teor de AA. Os clones BPX-410H-01pl#281, BPX-410H-04pl#348 e BPX-410H-04pl#481 foram superiores nas avaliações de resistência à traça e são recomendados para a continuidade do programa de melhoramento.The South American tomato pinworm was first detected in Brazil

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

National Research Council Canada - National Science Library

Schoengold, Carole

1999-01-01

...; Tests MILL YARD, DIAMOND BEECH, MIGHTY OAK, MIDDLE NOTE, MISSION GHOST, MISSION CYBER, MISTY ECHO, DISKO ELM, MINERAL QUARRY, DISTANT ZENITH, DIAMOND FORTUNE, and HUNTERS TROPHY, 9 October 1985 to 18 September 1992...

A Catskill Flora and Economic Botany, III: Apetalae. Including the Poplars, Willows, Hickories, Birches, Beeches, Oaks, Elms, Nettles, Sorrels, Docks, and Smartweeds. Bulletin No. 443, New York State Museum.

Science.gov (United States)

Brooks, Karl L.

This compendium deals with the ecology and economic importance of the poplars, willows, hickories, birches, beeches, oaks, elms, nettles, sorrels, docks, and smartweeds growing in New York's Catskills. Provided are keys for identifying each plant to species by flowers, foliage, or winter buds. A line drawing accompanies a summary of basic data…

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

Energy Technology Data Exchange (ETDEWEB)

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

2007-06-15

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-08-15

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

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

Science.gov (United States)

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

2015-08-01

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

Optimasi Kandungan Gizi Susu Kambing Peranakan Etawa (PE Menggunakan ELM-PSO Di UPT Pembibitan Ternak Dan Hijauan Makanan Ternak Singosari-Malang

Directory of Open Access Journals (Sweden)

Imam Cholissodin

2017-02-01

Full Text Available Abstrak Susu merupakan salah satu sumber protein hewani yang mengandung semua zat yang dibutuhkan tubuh. Ternak penghasil susu utama di Indonesia yaitu sapi perah, namun produksi susunya belum dapat mencukupi kebutuhan masyarakat. Alternatifnya adalah kambing peranakan etawa (PE. Tingginya kualitas kandungan gizi susu sangat dipengaruhi oleh beberapa faktor salah satunya, yaitu faktor pakan. Bagian peternakan kambing PE di UPT Pembibitan Ternak dan Hijauan Makanan Ternak Singosari-Malang masih menghadapi permasalahan, yaitu rendahnya kemampuan dalam memberikan komposisi pakan terhadap kambing PE. Kekurangan tersebut berpengaruh terhadap kualitas susu yang dihasilkan. Diperlukan pengetahuan rekayasa kandungan gizi susu untuk menentukan komposisi pakan dalam menghasilkan susu premium dengan kandungan gizi optimal. Penulis menggunakan metode Extreme Learning Machine (ELMdan Particle Swarm Optimization (PSO  untuk membuat pemodelan pakan kambing dalam mengoptimasi kandungan gizi susu kambing. Dalam analisa pengujian konvergensi menggunakan metode ELM-PSO yang dilakukan dengan kasus untuk berat badan kambing 32 kg, serta jenis pakan yang digunakan yaitu rumput Odot 70% dan rumput Raja 30% menghasilkan sistem mencapai kestabilan dalam konvergensi pada iterasi ke-20 dengan fitness terbaik yaitu 16.2712. Kata Kunci: Susu Kambing, Optimasi, Artificial Neural Network (ANN, Particle Swarm Optimization (PSO, Genetic Algorithm (GA, Kandungan Nutrisi Pakan. Abstract Milk is one of the animal protein sources which it contains all of the substances needed by human body. The main milk producer cattle in Indonesia is dairy cow, however its milk production has not fulfilled the society needs. The alternative is the goat, the Etawa crossbreed (PE. The high quality of milk nutrients content is greatly influenced by some factors one of them, is the food factor. The PE goat livestock division of the UPT Cattle Breeding and the Cattle Food Greenery in Singosari

Resistant and Refractory Hypertension: Antihypertensive Treatment Resistance vs Treatment Failure

Science.gov (United States)

Siddiqui, Mohammed; Dudenbostel, Tanja; Calhoun, David A.

2017-01-01

Resistant or difficult to treat hypertension is defined as high blood pressure that remains uncontrolled with 3 or more different antihypertensive medications, including a diuretic. Recent definitions also include controlled blood pressure with use of 4 or more medications as also being resistant to treatment. Recently, refractory hypertension, an extreme phenotype of antihypertensive treatment failure has been defined as hypertension uncontrolled with use of 5 or more antihypertensive agents, including a long-acting thiazide diuretic and a mineralocorticoid receptor antagonist. Patients with resistant vs refractory hypertension share similar characteristics and comorbidities, including obesity, African American race, female sex, diabetes, coronary heart disease, chronic kidney disease, and obstructive sleep apnea. Patients with refractory vs resistant hypertension tend to be younger and are more likely to have been diagnosed with congestive heart failure. Refractory hypertension might also differ from resistant hypertension in terms of underlying cause. Preliminary evidence suggests that refractory hypertension is more likely to be neurogenic in etiology (ie, heightened sympathetic tone), vs a volume-dependent hypertension that is more characteristic of resistant hypertension in general. PMID:26514749

Hydrostratigraphic interpretation of test-hole and surface geophysical data, Elkhorn and Loup River Basins, Nebraska, 2008 to 2011

Science.gov (United States)

Hobza, Christopher M.; Bedrosian, Paul A.; Bloss, Benjamin R.

2012-01-01

The Elkhorn-Loup Model (ELM) was begun in 2006 to understand the effect of various groundwater-management scenarios on surface-water resources. During phase one of the ELM study, a lack of subsurface geological information was identified as a data gap. Test holes drilled to the base of the aquifer in the ELM study area are spaced as much as 25 miles apart, especially in areas of the western Sand Hills. Given the variable character of the hydrostratigraphic units that compose the High Plains aquifer system, substantial variation in aquifer thickness and characteristics can exist between test holes. To improve the hydrogeologic understanding of the ELM study area, the U.S. Geological Survey, in cooperation with the Nebraska Department of Natural Resources, multiple Natural Resources Districts participating in the ELM study, and the University of Nebraska-Lincoln Conservation and Survey Division, described the subsurface lithology at six test holes drilled in 2010 and concurrently collected borehole geophysical data to identify the base of the High Plains aquifer system. A total of 124 time-domain electromagnetic (TDEM) soundings of resistivity were collected at and between selected test-hole locations during 2008-11 as a quick, non-invasive means of identifying the base of the High Plains aquifer system. Test-hole drilling and geophysical logging indicated the base-of-aquifer elevation was less variable in the central ELM area than in previously reported results from the western part of the ELM study area, where deeper paleochannels were eroded into the Brule Formation. In total, more than 435 test holes were examined and compared with the modeled-TDEM soundings. Even where present, individual stratigraphic units could not always be identified in modeled-TDEM sounding results if sufficient resistivity contrast was not evident; however, in general, the base of aquifer [top of the aquifer confining unit (ACU)] is one of the best-resolved results from the TDEM

First-wall heat-flux measurements during ELMing H-mode plasma

International Nuclear Information System (INIS)

Lasnier, C.J.; Allen, S.L.; Hill, D.N.; Leonard, A.W.; Petrie, T.W.

1994-01-01

In this report we present measurements of the diverter heat flux in DIII-D for ELMing H-mode and radiative diverter conditions. In previous work we have examined heat flux profiles in lower single-null diverted plasmas and measured the scaling of the peak heat flux with plasma current and beam power. One problem with those results was our lack of good power accounting. This situation has been improved to better than 80--90% accountability with the installation of new bolometer arrays, and the operation of the entire complement of 5 Infrared (IR) TV cameras using the DAPS (Digitizing Automated Processing System) video processing system for rapid inter-shot data analysis. We also have expanded the scope of our measurements to include a wider variety of plasma shapes (e.g., double-null diverters (DND), long and short single-null diverters (SND), and inside-limited plasmas), as well as more diverse discharge conditions. Double-null discharges are of particular interest because that shape has proven to yield the highest confinement (VH-mode) and beta of all DIII-D plasmas, so any future diverter modifications for DIII-D will have to support DND operation. In addition, the proposed TPX tokamak is being designed for double-null operation, and information on the magnitude and distribution of diverter heat flux is needed to support the engineering effort on that project. So far, we have measured the DND power sharing at the target plates and made preliminary tests of heat flux reduction by gas injection

Aging of residual surface resistance of superconducting lead cavities

DEFF Research Database (Denmark)

Danielsen, M.

1972-01-01

Measurements of the residual surface resistance of superconducting lead cavities as a function of time during a period of a month showed an oscillating variation. An explanation of the ageing curves is proposed. ©1972 The American Institute of Physics......Measurements of the residual surface resistance of superconducting lead cavities as a function of time during a period of a month showed an oscillating variation. An explanation of the ageing curves is proposed. ©1972 The American Institute of Physics...

Thr202Ala in thyA Is a Marker for the Latin American Mediterranean Lineage of the Mycobacterium tuberculosis Complex Rather than Para-Aminosalicylic Acid Resistance

KAUST Repository

Feuerriegel, S.

2010-08-30

Single nucleotide polymorphisms (SNPs) involved in the development of resistance represent powerful markers for the rapid detection of first- and second-line resistance in clinical Mycobacterium tuberculosis complex (MTBC) isolates. However, the association between particular mutations and phenotypic resistance is not always clear-cut, and phylogenetic SNPs have been misclassified as resistance markers in the past. In the present study, we investigated the utility of a specific polymorphism in thyA (Thr202Ala) as a marker for resistance to para-aminosalicyclic acid (PAS). Sixty-three PAS-susceptible MTBC strains comprising all major phylogenetic lineages, reference strain H37Rv, and 135 multidrug-resistant (MDR) strains from Germany (comprising 8 PAS-resistant isolates) were investigated for the presence of Thr202Ala. In both strain collections, the Thr202Ala SNP was found exclusively in strains of the Latin American Mediterranean (LAM) lineage irrespective of PAS resistance. Furthermore, PAS MICs (0.5 mg/liter) for selected LAM strains (all containing the SNP) and non-LAM strains (not containing the SNP), as well as the results of growth curve analyses performed in liquid 7H9 medium in the presence of increasing PAS concentrations (0 to 2.0 mg/liter), were identical. In conclusion, our data demonstrate that the Thr202Ala polymorphism in thyA is not a valid marker for PAS resistance but, instead, represents a phylogenetic marker for the LAM lineage of the M. tuberculosis complex. These findings challenge some of the previous understanding of PAS resistance and, as a consequence, warrant further in-depth investigations of the genetic variation in PAS-resistant clinical isolates and spontaneous mutants.

No Effect of Added Sugar Consumed at Median American Intake Level on Glucose Tolerance or Insulin Resistance.

Science.gov (United States)

Lowndes, Joshua; Sinnett, Stephanie S; Rippe, James M

2015-10-23

Excess sugar consumption may promote adverse changes in hepatic and total body insulin resistance. Debate continues over the effects of sugars at more typically consumed levels and whether the identity of the sugar consumed is important. In the present study participants (20-60 years old) were randomly assigned to one of five groups, three that consumed low fat milk with added fructose containing sugars in amounts equivalent to the 50th percentile of fructose consumption (US), one which consumed low-fat milk sweetened with glucose, and one unsweetened low-fat milk control group. The intervention lasted ten weeks. In the entire study population there was less than 1 kg increase in weight (73.6 ±13.0 vs. 74.5 ± 13.3 kg, p 0.05). There were no changes in fasting glucose (49 ± 0.4 vs. 5.0 ± 0.5 mmol/L), insulin (56.9 ± 38.9 vs. 61.8 ± 50.0 pmol/L), or insulin resistance, as measured by the Homeostasis Model Assessment method (1.8 ± 1.3 vs. 2.0 ± 1.5, all p > 0.05). These data suggest that added sugar consumed at the median American intake level does not produce changes in measures of insulin sensitivity or glucose tolerance and that no sugar has more deleterious effects than others.

American Resistance to Establishing a Standing Stability Operations Force

Science.gov (United States)

2010-09-01

reaching impetuously for too many objectives at once... especially when a firm hold on the nettle looked like involving more casualties and a long... root out terrorism and to establish strong, sovereign governments.145 However, as American activities in Afghanistan and Iraq have made clear

Value of American Thoracic Society guidelines in predicting infection or colonization with multidrug-resistant organisms in critically ill patients.

Directory of Open Access Journals (Sweden)

Jianfeng Xie

Full Text Available The incidence rate of infection by multidrug-resistant organisms (MDROs can affect the accuracy of etiological diagnosis when using American Thoracic Society (ATS guidelines. We determined the accuracy of the ATS guidelines in predicting infection or colonization by MDROs over 18 months at a single ICU in eastern China.This prospective observational study examined consecutive patients who were admitted to an intensive care unit (ICU in Nanjing, China. MDROs were defined as bacteria that were resistant to at least three antimicrobial classes, such as methicillin-resistant Staphylococcus aureus (MRSA, vancomycin-resistant enterococci (VRE, Pseudomonas aeruginosa, Acinetobacter baumannii. Screening for MDROs was performed at ICU admission and discharge. Risk factors for infection or colonization with MDROs were recorded, and the accuracy of the ATS guidelines in predicting infection or colonization with MDROs was documented.There were 610 patients, 225 (37% of whom were colonized or infected with MDROs at ICU admission, and this increased to 311 (51% at discharge. At admission, the sensitivity (70.0%, specificity (31.6%, positive predictive value (38.2%, and negative predictive value (63.5%, all based on ATS guidelines for infection or colonization with MDROs were low. The negative predictive value was greater in patients from departments with MDRO infection rates of 31-40% than in patients from departments with MDRO infection rates of 30% or less and from departments with MDRO infection rates more than 40%.ATS criteria were not reliable in predicting infection or colonization with MDROs in our ICU. The negative predictive value was greater in patients from departments with intermediate rates of MDRO infection than in patients from departments with low or high rates of MDRO infection.ClinicalTrials.gov NCT01667991.

Researches on the resistance to Fusarium oxysporum f. sp. dianthi in carnation

International Nuclear Information System (INIS)

Silvy, A.; Pereau-Leroy, P.

1977-01-01

Trials have been undertaken in order to discover in carnation with sexual reproduction some resistances to Fusarium equivalent to which are known previously in certain sorts of carnations with asexual propagation, like Heidi. Only the resistance of horticultural species has been studied. It is a polygenic type and open to improvement by selection or cross between resistant parents, specially Heidi x mignardise, some products of which may be used as 'miniature' varieties. To plan the improvement of american carnations by interspecific cross with these resistant parents is possible. But on account of foreseeable difficulties to preserve the floral characteristics of these varieties an attempt was made to induce resistance characters by exposing american carnations to the γ rays of 60 Co [fr

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

Science.gov (United States)

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

2017-11-01

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

Multilocus sequence typing, biochemical and antibiotic resistance characterizations reveal diversity of North American strains of the honey bee pathogen Paenibacillus larvae.

Science.gov (United States)

Krongdang, Sasiprapa; Evans, Jay D; Pettis, Jeffery S; Chantawannakul, Panuwan

2017-01-01

Paenibacillus larvae is a Gram positive bacterium and the causative agent of the most widespread fatal brood disease of honey bees, American foulbrood (AFB). A total of thirty-three independent Paenibacillus larvae isolates from various geographical origins in North America and five reference strains were investigated for genetic diversity using multilocus sequence typing (MLST). This technique is regarded to be a powerful tool for epidemiological studies of pathogenic bacteria and is widely used in genotyping assays. For MLST, seven housekeeping gene loci, ilvD (dihydroxy-acid dyhydrogenase), tri (triosephosphate isomerase), purH (phospharibosyl-aminoimidazolecarboxamide), recF (DNA replication and repair protein), pyrE (orotate phosphoribosyltransferase), sucC (succinyl coenzyme A synthetase β subunit) and glpF (glycerol uptake facilitator protein) were studied and applied for primer designs. Previously, ERIC type DNA fingerprinting was applied to these same isolates and the data showed that almost all represented the ERIC I type, whereas using BOX-PCR gave an indication of more diversity. All isolates were screened for resistance to four antibiotics used by U.S. beekeepers, showing extensive resistance to tetracycline and the first records of resistance to tylosin and lincomycin. Our data highlight the intraspecies relationships of P. larvae and the potential application of MLST methods in enhancing our understanding of epidemiological relationships among bacterial isolates of different origins.

Multilocus sequence typing, biochemical and antibiotic resistance characterizations reveal diversity of North American strains of the honey bee pathogen Paenibacillus larvae.

Directory of Open Access Journals (Sweden)

Sasiprapa Krongdang

Full Text Available Paenibacillus larvae is a Gram positive bacterium and the causative agent of the most widespread fatal brood disease of honey bees, American foulbrood (AFB. A total of thirty-three independent Paenibacillus larvae isolates from various geographical origins in North America and five reference strains were investigated for genetic diversity using multilocus sequence typing (MLST. This technique is regarded to be a powerful tool for epidemiological studies of pathogenic bacteria and is widely used in genotyping assays. For MLST, seven housekeeping gene loci, ilvD (dihydroxy-acid dyhydrogenase, tri (triosephosphate isomerase, purH (phospharibosyl-aminoimidazolecarboxamide, recF (DNA replication and repair protein, pyrE (orotate phosphoribosyltransferase, sucC (succinyl coenzyme A synthetase β subunit and glpF (glycerol uptake facilitator protein were studied and applied for primer designs. Previously, ERIC type DNA fingerprinting was applied to these same isolates and the data showed that almost all represented the ERIC I type, whereas using BOX-PCR gave an indication of more diversity. All isolates were screened for resistance to four antibiotics used by U.S. beekeepers, showing extensive resistance to tetracycline and the first records of resistance to tylosin and lincomycin. Our data highlight the intraspecies relationships of P. larvae and the potential application of MLST methods in enhancing our understanding of epidemiological relationships among bacterial isolates of different origins.

No Effect of Added Sugar Consumed at Median American Intake Level on Glucose Tolerance or Insulin Resistance

Directory of Open Access Journals (Sweden)

Joshua Lowndes

2015-10-01

Full Text Available Excess sugar consumption may promote adverse changes in hepatic and total body insulin resistance. Debate continues over the effects of sugars at more typically consumed levels and whether the identity of the sugar consumed is important. In the present study participants (20–60 years old were randomly assigned to one of five groups, three that consumed low fat milk with added fructose containing sugars in amounts equivalent to the 50th percentile of fructose consumption (US, one which consumed low-fat milk sweetened with glucose, and one unsweetened low-fat milk control group. The intervention lasted ten weeks. In the entire study population there was less than 1 kg increase in weight (73.6 ±13.0 vs. 74.5 ± 13.3 kg, p < 0.001, but the change in weight was comparable among groups (p > 0.05. There were no changes in fasting glucose (49 ± 0.4 vs. 5.0 ± 0.5 mmol/L, insulin (56.9 ± 38.9 vs. 61.8 ± 50.0 pmol/L, or insulin resistance, as measured by the Homeostasis Model Assessment method (1.8 ± 1.3 vs. 2.0 ± 1.5, all p > 0.05. These data suggest that added sugar consumed at the median American intake level does not produce changes in measures of insulin sensitivity or glucose tolerance and that no sugar has more deleterious effects than others.

Anthelmintic resistance in a herd of alpacas (Vicugna pacos)

Science.gov (United States)

Galvan, Noe; Middleton, John R.; Nagy, Dusty W.; Schultz, Loren G.; Schaeffer, Josh W.

2012-01-01

A herd of alpacas was examined because of a history of severe endoparasitism, anemia, hypoproteinemia, and weight loss. Resistance of gastrointestinal nematodes to albendazole, fenbendazole, and doramectin was documented. This report suggests that anthelmintic resistance may be an emerging problem in South American camelids in North America. PMID:23729829

Preimpoundment Water Quality Study

Science.gov (United States)

1981-12-01

American Elm U. americana Americrn Holly Ilex opaca Persirmnr~ Diospyros virginiana Tulip Rbplar Liriodexniron tul-ipifera Basswoo Tilia americana...Brown Company, Dubuque, Iowa. 977 pp. Roback, S.S. 1963. The genus Xenochironomus (Diptera: Tendipedidae) Kieffer, taxonomy and immature stages...Transactions of the American Entomological Society 88:235-245. Roback, S.S. 1969. The immature stages of the genus Tanypus Meigen (Diptera: Chironomidae

Evaluation of powdery mildew-resistance of grape germplasm and rapid amplified polymorphic DNA markers associated with the resistant trait in Chinese wild Vitis.

Science.gov (United States)

Zhang, J; Zhang, Y; Yu, H; Wang, Y

2014-05-09

The resistance of wild Vitis germplasm, including Chinese and American wild Vitis and Vitis vinifera cultivars, to powdery mildew (Uncinula necator Burr.) was evaluated for two consecutive years under natural conditions. Most of the Chinese and North American species displayed a resistant phenotype, whereas all of the European species were highly susceptible. The Alachua and Conquistador accessions of Vitis rotundifolia species, which originated in North America, were immune to the disease, while Baihe-35-1, one of the accessions of Vitis pseudoreticulata, showed the strongest resistance among all Chinese accessions evaluated. Three rapid amplified polymorphic DNA (RAPD) markers, OPW02-1756, OPO11-964, and OPY13-661, were obtained after screening 520 random primers among various germplasm, and these markers were found to be associated with powdery mildew resistance in Baihe-35-1 and in some Chinese species, but not in any European species. Analysis of F₁ and F₂ progenies of a cross between resistant Baihe-35-1 and susceptible Carignane (V. vinifera) revealed that the three RAPD markers were linked to the powdery resistant trait in Baihe-35-1 plants. Potential applications of the identified RAPD markers for gene mapping, marker-assisted selection, and breeding were investigated in 168 F₂ progenies of the same cross. Characterization of the resistant phenotype of the selected F₂ seedlings for breeding a new disease-resistant grape cultivar is in progress.

New features of L-H transition in limiter H-modes of JIPP T-IIU

International Nuclear Information System (INIS)

Toi, K.; Morita, S.; Kawahata, K.

1992-09-01

In limiter H-modes of JIPP T-IIU, a new type of L-H transition preceded by an ELM is observed. The preceding ELM (pre-ELM) appears just prior to the L-H transition. This type of transition is usually observed in H-modes of JIPP T-IIU. The L-H transition without the pre-ELM is triggered only in the case when a sufficiently large rapid current ramp down is emploied. In H-modes with constant q(a)∼3.5-4.5, coherent magnetic oscillations with m=3/n=1 destabilized during L-phase are further enhanced at the pre-ELM, and suppressed suddenly at the transition. This mode is situated in the region of the transport barrier. Propagation frequency of the m=3/n=1 mode, which may be affected by plasma mass rotation, rises appreciably (by ∼ 10 %) during H-phase with frequent ELMs, but remains unchanged for at least 200 μs after the transition. Behaviours of the m=3/n=1 and m=2/n=1 modes are well explained by quasi-linear resistive tearing mode analysis for modelled toroidal current density profiles slightly detached from the limiter. These experimental results suggest that the transition is controlled by the change of a magnetic field structure relating to the modification of a toroidal current density profile near the edge. The possibility for the development of edge radial electric field as a consequence of the transition is discussed. (author)

Silvicultural and logistical considerations associated with the pending reintroduction of American chestnut

Science.gov (United States)

Douglass F. Jacobs

2010-01-01

Traditional breeding for blight resistance has led to the potential to restore American chestnut (Castanea dentata (Marsh.) Borkh.) to Eastern United States forests using a blight resistant hybrid chestnut tree. With prospects of pending wide-scale reintroduction, restoration strategies based on ecological and biological characteristics of the...

From behind the Veil: Students' Resistance from Different Directions

Science.gov (United States)

Muhtaseb, Ahlam

2007-01-01

In this chapter, critical race and expectancy violation theories are used to deconstruct students' resistance to a female faculty member of color, a Muslim Arab American who wears the traditional Islamic cover. The author provides a narrative of her teaching experience and some techniques she has used to face such resistance.

Plasma current dependence of the edge pedestal height in JET ELM-free H-modes

International Nuclear Information System (INIS)

Nave, M.; Lomas, P.; Gowers, C.

2000-01-01

Models for the suppression of turbulence in the L to H transition, suggest that the width of the H-mode edge barrier is either proportional or is of the order of the ion poloidal Larmor radius. This would require that the width of the edge barrier should depend on the plasma current. This dependence has been clearly verified at JET in experiments designed to control the edge MHD stability of ELM-free hot-ion H-mode plasmas. The effects of isotopic mass and the applicability of several edge barrier models to the hot-ion H-mode plasmas were analysed in using a large database containing both Deuterium-only (DD) and Deuterium-Tritium (DT) plasmas. This database has now been enlarged to include discharges from a plasma shape scan, allowing to study the dependence of the pedestal height on the edge shear. In addition the range of plasma currents was extended up to 6 MA. It is shown that the edge data is best described by a model where the edge barrier width is determined by the fast ions weighted towards the components with largest poloidal Larmor radii. However, it is not possible to eliminate conclusively the thermal ion model. (author)

The main altarpiece of Our Lady of the Elms church in Torre de Juan Abad, Spain: technical study and condition state

Directory of Open Access Journals (Sweden)

Rosario Llamas

2013-01-01

Full Text Available The altarpiece of the church of Our Lady of the Elms, in Campo de Montiel, attributed to Francisco Cano, is a unique masterpiece that represents the essence of the Mannerism or Late Renaissance in the region. Its technical study is one of the objectives of this article that seeks to explain the constructive aspects and identify the materials (wood species, pigments and binders and the techniques used. Simultaneously, we have characterized its current state of preservation, describing in detail the problems identified, both structurally and in terms of the polychromy. We have tried to revalue an important work that got to survive the events of the Spanish Civil War. Generally speaking, it is unpublished information that has been collected and presented here.

Genetic Determinants of High-Level Oxacillin Resistance in Methicillin-Resistant Staphylococcus aureus.

Science.gov (United States)

Pardos de la Gandara, Maria; Borges, Vitor; Chung, Marilyn; Milheiriço, Catarina; Gomes, João Paulo; de Lencastre, Herminia; Tomasz, Alexander

2018-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) strains carry either a mecA - or a mecC -mediated mechanism of resistance to beta-lactam antibiotics, and the phenotypic expression of resistance shows extensive strain-to-strain variation. In recent communications, we identified the genetic determinants associated with the stringent stress response that play a major role in the antibiotic resistant phenotype of the historically earliest "archaic" clone of MRSA and in the mecC -carrying MRSA strain LGA251. Here, we sought to test whether or not the same genetic determinants also contribute to the resistant phenotype of highly and homogeneously resistant (H*R) derivatives of a major contemporary MRSA clone, USA300. We found that the resistance phenotype was linked to six genes ( fruB , gmk , hpt , purB , prsA , and relA ), which were most frequently targeted among the analyzed 20 H*R strains (one mutation per clone in 19 of the 20 H*R strains). Besides the strong parallels with our previous findings (five of the six genes matched), all but one of the repeatedly targeted genes were found to be linked to guanine metabolism, pointing to the key role that this pathway plays in defining the level of antibiotic resistance independent of the clonal type of MRSA. Copyright © 2018 American Society for Microbiology.

Development of a double plasma gun device for investigation of effects of vapor shielding on erosion of PFC materials under ELM-like pulsed plasma bombardment

Science.gov (United States)

Sakuma, I.; Iwamoto, D.; Kitagawa, Y.; Kikuchi, Y.; Fukumoto, N.; Nagata, M.

2012-10-01

It is considered that thermal transient events such as type I edge localized modes (ELMs) could limit the lifetime of plasma-facing components (PFCs) in ITER. We have investigated surface damage of tungsten (W) materials under transient heat and particle loads by using a magnetized coaxial plasma gun (MCPG) device at University of Hyogo. The capacitor bank energy for the plasma discharge is 144 kJ (2.88 mF, 10 kVmax). Surface melting of a W material was clearly observed at the energy density of ˜2 MJ/m2. It is known that surface melting and evaporation during a transient heat load could generate a vapor cloud layer in front of the target material [1]. Then, the subsequent erosion could be reduced by the vapor shielding effect. In this study, we introduce a new experiment using two MCPG devices (MCPG-1, 2) to understand vapor shielding effects of a W surface under ELM-like pulsed plasma bombardment. The capacitor bank energy of MCPG-2 is almost same as that of MCPG-1. The second plasmoid is applied with a variable delay time after the plasmoid produced by MCPG-1. Then, a vapor cloud layer could shield the second plasma load. To verify the vapor shielding effects, surface damage of a W material is investigated by changing the delay time. In the conference, the preliminary experimental results will be shown.[4pt] [1] A. Hassanein et al., J. Nucl. Mater. 390-391, pp. 777-780 (2009).

A cultural contracts perspective: examining American Indian identity negotiations in academia.

Science.gov (United States)

Lamsam, Teresa Trumbly

2014-01-01

Education has played a central role in identity confusion, and to this day, it is used to assimilate American Indians. For those American Indians who persist through doctoral degrees and enter academe, resisting assimilation is especially risky and often tiresome. In this conceptual exploration of identity, Cultural Contracts theory serves to illuminate the path of the American Indian academic journey. Although never applied in an American Indian context, cultural contracts theory may provide a bridge between the seemingly disparate strains of identity research and leave us with a sense of scope and potential for the theory's application.

Effect of Adolescent Obesity on Cardiometabolic Risk in African-Americans and Caucasians

OpenAIRE

Hoffman, Robert P.

2012-01-01

African-Americans have more hypertension, stroke, and type 2 diabetes than do Caucasians. Endothelial dysfunction and insulin resistance are precursors for each. Since these diseases have origins in pediatrics and are associated with obesity, this study was designed to determine if obesity has different effects on endothelial function, insulin sensitivity, and secretion in African-American and Caucasian adolescents. Thirty-three Caucasian and 25 African-Americans (10–18 years old) were subdiv...

Specific Detection and Identification of American Mulberry-Infecting and Italian Olive-Associated Strains of Xylella fastidiosa by Polymerase Chain Reaction.

Science.gov (United States)

Guan, Wei; Shao, Jonathan; Elbeaino, Toufic; Davis, Robert E; Zhao, Tingchang; Huang, Qi

2015-01-01

Xylella fastidiosa causes bacterial leaf scorch in many landscape trees including elm, oak, sycamore and mulberry, but methods for specific identification of a particular tree host species-limited strain or differentiation of tree-specific strains are lacking. It is also unknown whether a particular landscape tree-infecting X. fastidiosa strain is capable of infecting multiple landscape tree species in an urban environment. We developed two PCR primers specific for mulberry-infecting strains of X. fastidiosa based on the nucleotide sequence of a unique open reading frame identified only in mulberry-infecting strains among all the North and South American strains of X. fastidiosa sequenced to date. PCR using the primers allowed for detection and identification of mulberry-infecting X. fastidiosa strains in cultures and in samples collected from naturally infected mulberry trees. In addition, no mixed infections with or non-specific detections of the mulberry-infecting strains of X. fastidiosa were found in naturally X. fastidiosa-infected oak, elm and sycamore trees growing in the same region where naturally infected mulberry trees were grown. This genotype-specific PCR assay will be valuable for disease diagnosis, studies of strain-specific infections in insects and plant hosts, and management of diseases caused by X. fastidiosa. Unexpectedly but interestingly, the unique open reading frame conserved in the mulberry-infecting strains in the U. S. was also identified in the recently sequenced olive-associated strain CoDiRO isolated in Italy. When the primer set was tested against naturally infected olive plant samples collected in Italy, it allowed for detection of olive-associated strains of X. fastidiosa in Italy. This PCR assay, therefore, will also be useful for detection and identification of the Italian group of X. fastidiosa strains to aid understanding of the occurrence, evolution and biology of this new group of X. fastidiosa strains.

Specific Detection and Identification of American Mulberry-Infecting and Italian Olive-Associated Strains of Xylella fastidiosa by Polymerase Chain Reaction.

Directory of Open Access Journals (Sweden)

Wei Guan

Full Text Available Xylella fastidiosa causes bacterial leaf scorch in many landscape trees including elm, oak, sycamore and mulberry, but methods for specific identification of a particular tree host species-limited strain or differentiation of tree-specific strains are lacking. It is also unknown whether a particular landscape tree-infecting X. fastidiosa strain is capable of infecting multiple landscape tree species in an urban environment. We developed two PCR primers specific for mulberry-infecting strains of X. fastidiosa based on the nucleotide sequence of a unique open reading frame identified only in mulberry-infecting strains among all the North and South American strains of X. fastidiosa sequenced to date. PCR using the primers allowed for detection and identification of mulberry-infecting X. fastidiosa strains in cultures and in samples collected from naturally infected mulberry trees. In addition, no mixed infections with or non-specific detections of the mulberry-infecting strains of X. fastidiosa were found in naturally X. fastidiosa-infected oak, elm and sycamore trees growing in the same region where naturally infected mulberry trees were grown. This genotype-specific PCR assay will be valuable for disease diagnosis, studies of strain-specific infections in insects and plant hosts, and management of diseases caused by X. fastidiosa. Unexpectedly but interestingly, the unique open reading frame conserved in the mulberry-infecting strains in the U. S. was also identified in the recently sequenced olive-associated strain CoDiRO isolated in Italy. When the primer set was tested against naturally infected olive plant samples collected in Italy, it allowed for detection of olive-associated strains of X. fastidiosa in Italy. This PCR assay, therefore, will also be useful for detection and identification of the Italian group of X. fastidiosa strains to aid understanding of the occurrence, evolution and biology of this new group of X. fastidiosa strains.

Prevalence of chlorhexidine-resistant methicillin-resistant Staphylococcus aureus following prolonged exposure.

Science.gov (United States)

Schlett, Carey D; Millar, Eugene V; Crawford, Katrina B; Cui, Tianyuan; Lanier, Jeffrey B; Tribble, David R; Ellis, Michael W

2014-08-01

Chlorhexidine has been increasingly utilized in outpatient settings to control methicillin-resistant Staphylococcus aureus (MRSA) outbreaks and as a component of programs for MRSA decolonization and prevention of skin and soft-tissue infections (SSTIs). The objective of this study was to determine the prevalence of chlorhexidine resistance in clinical and colonizing MRSA isolates obtained in the context of a community-based cluster-randomized controlled trial for SSTI prevention, during which 10,030 soldiers were issued chlorhexidine for body washing. We obtained epidemiological data on study participants and performed molecular analysis of MRSA isolates, including PCR assays for determinants of chlorhexidine resistance and high-level mupirocin resistance and pulsed-field gel electrophoresis (PFGE). During the study period, May 2010 to January 2012, we identified 720 MRSA isolates, of which 615 (85.4%) were available for molecular analysis, i.e., 341 clinical and 274 colonizing isolates. Overall, only 10 (1.6%) of 615 isolates were chlorhexidine resistant, including three from the chlorhexidine group and seven from nonchlorhexidine groups (P > 0.99). Five (1.5%) of the 341 clinical isolates and five (1.8%) of the 274 colonizing isolates harbored chlorhexidine resistance genes, and four (40%) of the 10 possessed genetic determinants for mupirocin resistance. All chlorhexidine-resistant isolates were USA300. The overall prevalence of chlorhexidine resistance in MRSA isolates obtained from our study participants was low. We found no association between extended chlorhexidine use and the prevalence of chlorhexidine-resistant MRSA isolates; however, continued surveillance is warranted, as this agent continues to be utilized for infection control and prevention efforts. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Epidemiology of Dysglycemia in Pregnant Oklahoma American Indian Women.

Science.gov (United States)

Azar, Madona; Stoner, Julie A; Dao, Hanh Dung; Stephens, Lancer; Goodman, Jean R; Maynard, John; Lyons, Timothy J

2015-08-01

Minority communities are disproportionately affected by diabetes, and minority women are at an increased risk for glucose intolerance (dysglycemia) during pregnancy. In pregnant American Indian women, the objectives of the study were to use current criteria to estimate the prevalence of first-trimester (Tr1) dysglycemia and second-trimester (Tr2) incidence of gestational diabetes mellitus (GDM) and to explore new candidate measures and identify associated clinical factors. This was a prospective cohort study. In Tr1 we performed a 75-g, 2-hour oral glucose tolerance test (OGTT) and glycated hemoglobin (HbA1c) to determine the following: fasting insulin; homeostasis model assessment of insulin resistance; serum 1,5-anhydroglucitol; noninvasive skin autofluorescence (SCOUT). We defined dysglycemia by American Diabetes Association and Endocrine Society criteria and as HbA1c of 5.7% or greater. In Tr2 in an available subset, we performed a repeat OGTT and SCOUT. Pregnant American Indian women (n = 244 at Tr1; n = 114 at Tr2) participated in the study. The prevalence of dysglycemia at Tr1 and incidence of GDM at Tr2 were measured. At Tr1, one woman had overt diabetes; 36 (15%) had impaired glucose tolerance (American Diabetes Association criteria and/or abnormal HbA1c) and 59 (24%) had GDM-Tr1 (Endocrine Society criteria). Overall, 74 (30%) had some form of dysglycemia. Associated factors were body mass index, hypertension, waist/hip circumferences, SCOUT score, fasting insulin, and homeostasis model assessment of insulin resistance. At Tr2, 114 of the Tr1 cohort underwent a repeat OGTT and SCOUT, and 26 (23%) had GDM. GDM-Tr2 was associated with increased SCOUT scores (P = .029) and Tr1 body mass index, waist/hip circumferences, diastolic blood pressure, fasting insulin, and triglyceride levels. Overall, dysglycemia at Tr1 and/or Tr2 affected 38% of the women. Dysglycemia at some point during pregnancy was common among American Indian women. It was associated with

Vitamin D intake is associated with insulin sensitivity in African American, but not European American, women

Directory of Open Access Journals (Sweden)

Oster Robert A

2010-04-01

Full Text Available Abstract Background The prevalence of type 2 diabetes is higher among African Americans (AA vs European Americans (EA, independent of obesity and other known confounders. Although the reason for this disparity is not known, it is possible that relatively low levels of vitamin D among AA may contribute, as vitamin D has been positively associated with insulin sensitivity in some studies. The objective of this study was to test the hypothesis that dietary vitamin D would be associated with a robust measure of insulin sensitivity in AA and EA women. Methods Subjects were 115 African American (AA and 137 European American (EA healthy, premenopausal women. Dietary intake was determined with 4-day food records; the insulin sensitivity index (SI with a frequently-sampled intravenous glucose tolerance test and minimal modeling; the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR with fasting insulin and glucose; and body composition with dual-energy X-ray absorptiometry. Results Vitamin D intake was positively associated with SI (standardized β = 0.18, P = 0.05 and inversely associated with HOMA-IR (standardized β = -0.26, P = 0.007 in AA, and the relationships were independent of age, total body fat, energy intake, and % kcal from fat. Vitamin D intake was not significantly associated with indices of insulin sensitivity/resistance in EA (standardized β = 0.03, P = 0.74 and standardized β = 0.02, P = 0.85 for SI and HOMA-IR, respectively. Similar to vitamin D, dietary calcium was associated with SI and HOMA-IR among AA but not EA. Conclusions This study provides novel findings that dietary vitamin D and calcium were independently associated with insulin sensitivity in AA, but not EA. Promotion of these nutrients in the diet may reduce health disparities in type 2 diabetes risk among AA, although longitudinal and intervention studies are required.

Beyond the gaze. The changing architecture of security between seduction and camouflage

Directory of Open Access Journals (Sweden)

Elisabetta Brighi

2015-03-01

Full Text Available The site of the new American embassy in London, expected to open in 2017 and currently being built in Nine Elms in the borough of Wandsworth as the river Thames slithers south, stands atop layers of invisible urban archaeology.

Archaeological and Historical Reconnaissance and Literature Search of Cultural Resources within the Pembina River Project, Pembina and Cavalier Counties, North Dakota. Volume 1.

Science.gov (United States)

1982-12-01

Bur oak Ulmus americana American elm Celtis occidentalis Hackberry Menispermum canadense Moonseed Ribes americanum Black currant Ribes missouriense...broken terrain, or at slippery stream crossings and successfully attacked. There is no indication of the use of poison, pits, traps, fire, or communal

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

Science.gov (United States)

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

2016-02-01

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

Interspecific proteomic comparisons reveal ash phloem genes potentially involved in constitutive resistance to the emerald ash borer.

Science.gov (United States)

Whitehill, Justin G A; Popova-Butler, Alexandra; Green-Church, Kari B; Koch, Jennifer L; Herms, Daniel A; Bonello, Pierluigi

2011-01-01

The emerald ash borer (Agrilus planipennis) is an invasive wood-boring beetle that has killed millions of ash trees since its accidental introduction to North America. All North American ash species (Fraxinus spp.) that emerald ash borer has encountered so far are susceptible, while an Asian species, Manchurian ash (F. mandshurica), which shares an evolutionary history with emerald ash borer, is resistant. Phylogenetic evidence places North American black ash (F. nigra) and Manchurian ash in the same clade and section, yet black ash is highly susceptible to the emerald ash borer. This contrast provides an opportunity to compare the genetic traits of the two species and identify those with a potential role in defense/resistance. We used Difference Gel Electrophoresis (DIGE) to compare the phloem proteomes of resistant Manchurian to susceptible black, green, and white ash. Differentially expressed proteins associated with the resistant Manchurian ash when compared to the susceptible ash species were identified using nano-LC-MS/MS and putative identities assigned. Proteomic differences were strongly associated with the phylogenetic relationships among the four species. Proteins identified in Manchurian ash potentially associated with its resistance to emerald ash borer include a PR-10 protein, an aspartic protease, a phenylcoumaran benzylic ether reductase (PCBER), and a thylakoid-bound ascorbate peroxidase. Discovery of resistance-related proteins in Asian species will inform approaches in which resistance genes can be introgressed into North American ash species. The generation of resistant North American ash genotypes can be used in forest ecosystem restoration and urban plantings following the wake of the emerald ash borer invasion.

Experimental estimation of tungsten impurity sputtering due to Type i ELMs in JET-ITER-like wall using pedestal electron cyclotron emission and target Langmuir probe measurements

Czech Academy of Sciences Publication Activity Database

Guillemaut, C.; Jardin, A.; Horáček, Jan; Borodkina, I.; Autricque, A.; Arnoux, G.; Boom, J.; Brezinsek, S.; Coenen, J.W.; De La Luna, E.; Devaux, S.; Eich, T.; Harting, D.; Kirschner, A.; Lipschultz, B.; Matthews, G. F.; Meigs, A.; Moulton, D.; O'Mullane, M.; Stamp, M.

T167, February (2016), s. 014005 ISSN 0031-8949. [International Conference on Plasma-Facing Materials and Components for Fusion Applications, PFMC 2015/15./. Aix-en-Provence, 18.05.2015-22.05.2015] R&D Projects: GA MŠk LG14002 EU Projects: European Commission(XE) 633053 - EUROfusion Institutional support: RVO:61389021 Keywords : tungsten sputtering * edge localized mode * magnetic confinement fusion * ITER * H-mode * ELMs * Langmuir Probes (LP) Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: 1.3 Physical sciences Impact factor: 1.280, year: 2016 http://iopscience.iop.org/issue/1402-4896/2016/T167

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

Energy Technology Data Exchange (ETDEWEB)

Schmid, Andreas

2008-03-18

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

Effect of variation in equilibrium shape on ELMing H-mode performance in DIII-D diverted plasmas

International Nuclear Information System (INIS)

Fenstermacher, M.E.; Osborne, T.H.; Petrie, T.W.

2001-01-01

The changes in the performance of the core, pedestal, scrape-off-layer (SOL), and divertor plasmas as a result of changes in triangularity, δ, up/down magnetic balance, and secondary divertor volume were examined in shape variation experiments using ELMing H mode plasmas on DIII-D. In moderate density, unpumped plasmas, high δ∼0.7 increased the energy in the H mode pedestal and the global energy confinement of the core, primarily due to an increase in the margin by which the edge pressure gradient exceeded the value which would have been expected had it been limited by infinite-n ideal ballooning modes. In addition, a nearly balanced double-null (DN) shape was effective for sharing the peak heat flux in the divertor in these attached plasmas. For detached plasmas good heat flux sharing was obtained for a substantial range of unbalanced DN shapes. Finally, the presence of a second X-point in unbalanced DN shapes did not degrade the plasma performance if it was sufficiently far inside the vacuum vessel. These results indicate that a high δ unbalanced DN shape has some advantages over a single null shape for future high power tokamak operation. (author)

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

International Nuclear Information System (INIS)

Schmid, Andreas

2008-01-01

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

Geographic Variation in Phosphine Resistance Among North American Populations of the Red Flour Beetle (Coleoptera: Tenebrionidae).

Science.gov (United States)

Cato, A J; Elliott, Brent; Nayak, Manoj K; Phillips, Thomas W

2017-06-01

The red flour beetle, Tribolium castaneum (Herbst), is a common stored-product pest found worldwide. Phosphine, hydrogen phosphide (PH3), is the most commonly used fumigant for stored grains, for which genetically based resistance has been recorded for several pest species. This study assessed phosphine resistance in 25 T. castaneum populations from across the United States and Canada using a discriminating dose bioassay. Dose-mortality assays were conducted with adults from seven of these populations to categorize weak and strong resistance phenotypes. Phosphine resistance was detected in 12 out of the 25 populations, and the frequency of resistance within populations varied from 2% in Victoria, TX, to 100% in Red Level, AL. Two resistant populations from Kansas that had been sampled three years earlier were found to have similar resistance frequencies in the current study. None of the four Canadian populations had any detectable resistance among the insects tested. Resistance ratio calculations from LC50 value in resistant populations relative to the LC50 for the laboratory susceptible strain allowed resistance phenotypes to be assigned as either weak resistance, at 5- to 26-fold resistance relative to susceptible, or strong resistance at 95- to 127-fold relative to susceptible. This study suggests that proper resistance assessment techniques can help to determine occurrence of phosphine resistance in populations of T. castaneum and can further characterize the strength of resistance present. These data can be used to support resistance management programs that consider either cessation or modification of phosphine fumigation to control T. castaneum. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Plasma current dependence of the edge pedestal height in JET ELM-free H-modes

International Nuclear Information System (INIS)

Nave, M.F.F; Lomas, P.; Gowers, C.; Guo, H.; Hawkes, N.; Huysmans, G.T.A.; Jones, T.; Parail, V.V.; Rimini, F.; Schunke, B.

2000-01-01

Some models for the suppression of turbulence in the L to H transition, suggest that the width of the H-mode edge barrier is either proportional or is of the order of the thermal or the fast-ion poloidal Larmor radius. This would require that the width of the edge barrier should depend on the plasma current. This dependence has been clearly verified at JET in experiments designed to control the edge MHD stability of ELM-free hot-ion H-mode plasmas. The effects of isotopic mass and the applicability of several edge barrier models to the hot-ion H-mode plasmas were analysed in (Guo H Y et al 2000 Edge transport barrier in JET hot-ion H-modes Nucl. Fusion 40 69) using a large database containing both deuterium-only and deuterium-tritium plasmas. This database has now been enlarged to include discharges from a plasma shape scan, allowing one to study the dependence of the pedestal height on the edge shear. In addition, the range of plasma currents was extended up to 6 MA. It is shown that the edge data are best described by a model where the edge barrier width is determined by the fast ions weighted towards the components with largest poloidal Larmor radii. However, it is not possible to conclusively eliminate the thermal ion model. (author)

Structural Relationships Of Selected Tree Species at Several Mid-Latitude Deciduous Forest Sites in Virginia

Science.gov (United States)

1999-09-01

are included in the deciduous analyses. They are mockernut hickory { Carya tomentosa), American elm {Ulmus americana), pecan { Carya illinoensis ), and...alba, white ash (Fraxinus americana), and pecan ( Carya illinoensis ). A number of these trees have plaques indicating the dates of planting (late 1700s

Environmental and Cultural Impact. Proposed Tennessee Colony Reservoir, Trinity River, Texas. Volume IV. Appendix F.

Science.gov (United States)

1972-01-01

Some other species in this area are hackberry (Celtis laevigata), water oak (Quercus nigra), pecan ( Carya illinoensis ), and American elm (Ulmus...Some upland hickory species ( Carya ) will also be encountered. These areas should be maintained as such in order to prevent erosion of the future

H-mode edge stability of Alcator C-mod plasmas

International Nuclear Information System (INIS)

Mossessian, D.A.; Hubbard, A.; Hughes, J.W.; Greenwald, M.; LaBombard, B.; Snipes, J.A.; Wolfe, S.; Snyder, P.; Wilson, H.; Xu, X.; Nevins, W.

2003-01-01

For steady state H-mode operation, a relaxation mechanism is required to limit build-up of the edge gradient and impurity content. C-Mod sees two such mechanisms - EDA and grassy ELMs, but not large type I ELMs. In EDA the edge relaxation is provided by an edge localized quasi coherent electromagnetic mode that exists at moderate pedestal temperature T 3.5 and does not limit the build up of the edge pressure gradient. The mode is not observed in the ideal MHD stability analysis, but is recorded in the nonlinear real geometry fluctuations modeling based on fluid equations and is thus tentatively identified as a resistive ballooning mode. At high edge pressure gradients and temperatures the mode is replaced by broadband fluctuations (f< 50 kHz) and small irregular ELMs are observed. Based on ideal MHD calculations that include the effects of edge bootstrap current, these ELMs are identified as medium n (10 < n < 50) coupled peeling/ballooning modes. The stability thresholds, its dependence on the plasma shape and the modes structure are studied experimentally and with the linear MHD stability code ELITE. (author)

Physics constraints on tokamak edge operational space and extrapolation to ITER

International Nuclear Information System (INIS)

Igitkhanov, Yu.; Janeschitz, G.; Sugihara, M.; Pacher, H.D.; Post, D.E.; Pacher, G.W.; Pogutse, O.P.

1998-01-01

This paper emphasises the theoretical understanding of the physical processes in the edge tokamak plasma and their attendant uncertainties and constraints. The various operational boundaries are represented in the edge operational space (EOS) diagram, the space of edge density and temperature, defined at the top of the H-mode transport barrier. The EOS is governed by four boundaries representing physical constraints for the edge plasma parameters. The first boundary represents the onset of type I ELM instabilities in terms of a critical pressure gradient for MHD stability at the edge which defines the maximum pedestal temperature for a given density once the width of the H-mode transport barrier at the edge (pedestal width) is known. The ideal ballooning mode is a candidate for this instability. The second boundary defines the boundary between type III ELM's, which are probably resistive MHD modes, and the ELM-free region. (orig.)

Regional Guidebook for Applying the Hydrogeomorphic Approach to Assessing the Functions of Headwater Slope Wetlands on the South Carolina Coastal Plain

Science.gov (United States)

2011-09-01

i.e., swamp bay) ( Persea borbonia) in the overstory or midstory ERDC/EL TR-11-11 20 (Monk 1966, Nelson 1986, Wharton et al. 1977, USACE 1988). In...biflora swamp tupelo Persea borbonia redbay Pinus glabra spruce pine Pinus taeda loblolly pine Quercus laurifolia laurel oak Quercus michauxii swamp... American elm Group 22 Carpinus caroliniana American hornbeam 0.66 Celtis laevigata sugarberry Cornus foemina stiff dogwood Diospyros virginiana

Does Culture Affect how People Receive and Resist Persuasive Messages? Research Proposals about Resistance to Persuasion in Cultural Groups

OpenAIRE

Renata Kolodziej-Smith; Daniel Patrick Friesen; Attila Yaprak

2013-01-01

Abstract Even though persuasion has been a widely researched topic in consumer behavior, the great majority of these studies have involved American consumers and focused on persuasion itself, with very few addressing resistance to persuasive attempts. None has addressed resistance to persuasion in a cross-cultural context. We aim to contribute to closing this gap in the literature with this paper. Specifically, we aim to expand knowledge of the persuasive process by applying the cultural dime...

Modeling of divertor particle and heat loads during application of resonant magnetic perturbation fields for ELM control in ITER

Energy Technology Data Exchange (ETDEWEB)

Schmitz, O., E-mail: o.schmitz@fz-juelich.de [Forschungszentrum Jülich, IEK-4, Association EURATOM-FZJ, Jülich (Germany); Becoulet, M. [CEA/IRFM, Cadarache, 13108 St. Paul-lez-Durance Cedex (France); Cahyna, P. [IPP AS CR, Za Slovankou 3, 18200 Prague 8 (Czech Republic); Evans, T.E. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); Feng, Y. [Max-Planck-Institut für Plasmaphysik, Greifswald (Germany); Frerichs, H.; Kirschner, A. [Forschungszentrum Jülich, IEK-4, Association EURATOM-FZJ, Jülich (Germany); Kukushkin, A. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Laengner, R. [Forschungszentrum Jülich, IEK-4, Association EURATOM-FZJ, Jülich (Germany); Lunt, T. [Max-Planck-Institut für Plasmaphysik, Greifswald (Germany); Loarte, A.; Pitts, R. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Reiser, D.; Reiter, D. [Forschungszentrum Jülich, IEK-4, Association EURATOM-FZJ, Jülich (Germany); Saibene, G. [Fusion for Energy Joint Undertaking, Barcelona (Spain); Samm, U. [Forschungszentrum Jülich, IEK-4, Association EURATOM-FZJ, Jülich (Germany)

2013-07-15

First results from three-dimensional modeling of the divertor heat and particle flux pattern during application of resonant magnetic perturbation fields as ELM control scheme in ITER with the EMC3-Eirene fluid plasma and kinetic neutral transport code are discussed. The formation of a helical magnetic footprint breaks the toroidal symmetry of the heat and particle fluxes. Expansion of the flux pattern as far as 60 cm away from the unperturbed strike line is seen with vacuum RMP fields, resulting in a preferable heat flux spreading. Inclusion of plasma response reduces the radial extension of the heat and particle fluxes and results in a heat flux peaking closer to the unperturbed level. A strong reduction of the particle confinement is found. 3D flow channels are identified as a consistent reason due to direct parallel outflow from inside of the separatrix. Their radial inward expansion and hence the level of particle pump out is shown to be dependent on the perturbation level.

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

Science.gov (United States)

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

2015-08-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-08-15

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

The growing problem of antimicrobial resistance

DEFF Research Database (Denmark)

Holmstrup, Palle; Klausen, Bjarne

2018-01-01

Antibiotic therapy over the years has saved millions of lives, but antimicrobial resistance (AMR) is a current threat to human health. An interesting review on AMR has recently been presented in the Journal of American Medical Association (Marston et al., 2016). The review is authored by five staff...... members at National Institutes of Health in Bethesda, Maryland, and the purpose of the review was to identify factors associated with AMR, the current epidemiology of important resistant organisms, and possible solutions to the AMR problem. This article is protected by copyright. All rights reserved....

Cryopreservation of medicinal plants: role of melatonin

Science.gov (United States)

Many useful plant species found in Canada are of conservation concern. In vitro storage and cryopreservation techniques guarantees safety of these species and have potential applications which may result in sustainable agriculture. Shoot tips of in vitro-grown plantlets of American elm, St John’s Wo...

Growth and Survival of Northern Hardwood Sprouts After Burning

Science.gov (United States)

Donald A. Perala

1974-01-01

Root collar sprouting of nine hardwoods was measured annually after a prescribed burn. Basswood, red oak, and paper birch were the most vigorous sprouters; sugar maple and yellow birch the least; and American elm, bur oak, ironwood and red maple were intermediate. Parent tree diameter influenced spreading.

Site Investigation Report Fort Devens Groups 3,5, and 6. Volume 1 of 2: Report Text

Science.gov (United States)

1996-01-01

and slippery , and samplers were belayed by rope and harness to prevent accidents. Location ABB Environmental Services, Inc. GRP356.SI 6917.07 0 01/19...red maple (Acer rubrum), American elm (Ulmus americana), and white pine (Pinus strobus). Other trees observed include pitch pine (Pinus rigida

Opposition to the American leadership by Brazilian nurses (1934-1938).

Science.gov (United States)

Santos, Tânia Cristina Franco; Lopes, Gertrudes Teixeira; Porto, Fernando; da Fonte, Aline Silva

2008-01-01

A historical social descriptive study whose objective is to describe the circumstances where Bertha Pullen assumes as the dean of Anna Nery Nursing School, to assess the strategies undertaken by Pullen to assure her position of power and prestige in the space of the school and Brazilian nursing; and to discuss about the resistance to the presence and authority of the American dean for the nurses and students, in the struggle for a national identity. Corpus analysis was made by putting photographs into context based on written documents and secondary sources. The second management of Pullen was the reiteration of the American presence in the leadership of the School, despite the resistance of the nurses and students. Thus, we may assume that the second tenure of Pullen did not represent a real need that was felt by the school.

The Association between Mycobacterium Tuberculosis Genotype and Drug Resistance in Peru.

Directory of Open Access Journals (Sweden)

Louis Grandjean

Full Text Available The comparison of Mycobacterium tuberculosis bacterial genotypes with phenotypic, demographic, geospatial and clinical data improves our understanding of how strain lineage influences the development of drug-resistance and the spread of tuberculosis.To investigate the association of Mycobacterium tuberculosis bacterial genotype with drug-resistance. Drug susceptibility testing together with genotyping using both 15-loci MIRU-typing and spoligotyping, was performed on 2,139 culture positive isolates, each from a different patient in Lima, Peru. Demographic, geospatial and socio-economic data were collected using questionnaires, global positioning equipment and the latest national census.The Latin American Mediterranean (LAM clade (OR 2.4, p<0.001 was significantly associated with drug-resistance and alone accounted for more than half of all drug resistance in the region. Previously treated patients, prisoners and genetically clustered cases were also significantly associated with drug-resistance (OR's 2.5, 2.4 and 1.8, p<0.001, p<0.05, p<0.001 respectively.Tuberculosis disease caused by the LAM clade was more likely to be drug resistant independent of important clinical, genetic and socio-economic confounding factors. Explanations for this include; the preferential co-evolution of LAM strains in a Latin American population, a LAM strain bacterial genetic background that favors drug-resistance or the "founder effect" from pre-existing LAM strains disproportionately exposed to drugs.

Asian American Women's Victimization History and In-The-Moment Responses to Partner Violence.

Science.gov (United States)

Nguyen, Hong V; Schacht, Rebecca L; Yang, Joyce P; George, William H; Pantalone, David W

2018-04-01

Between 20% and 50% of Asian American women report experiencing partner violence (PV). Furthermore, nearly half of PV victims experience their first assault between the age of 18 and 24 years, suggesting that Asian American college women may be particularly at risk of PV. Experiencing childhood abuse (CA) may impair women's capacity to perceive risk during a potential PV situation, increasing their risk for revictimization. The purpose of the current study was to examine differences among Asian American college women's ( N = 324) in-the-moment behavioral intention, risk perception, and likelihood to stay in an abusive relationship during a progressively threatening PV scenario, based on victimization history and posttraumatic stress disorder (PTSD) symptoms. We tested three path models, each assessing the relations among CA, PV, PTSD, current and future risk perception, likelihood of staying in the relationship, and one of three behavioral intentions (soothe the perpetrator, escape, and escalation/resistance). As hypothesized, CA history positively predicted PV history and PTSD symptoms. Furthermore, CA and PV predicted more in-the-moment soothe behavioral intentions and fewer escape behavioral intentions which, in turn, predicted diminished current and future risk perception. CA and PV also predicted stronger escalation/resistance behavioral intentions, such that escalation/resistance intentions were associated with higher risk perception during a more violent part of the scenario but lower risk perception during a less violent part of the scenario. Finally, higher risk perception predicted lower likelihood of staying in the relationship. Findings indicate that victimization history is associated with increased risky behavioral intentions among Asian American college women and suggest that targeted interventions to improve assault-exposed Asian American women's awareness of risk cues may be warranted.

Resistance in School and Society: Public and Pedagogical Debates about Eugenics, 1900-1947.

Science.gov (United States)

Selden, Steven

1988-01-01

This article reviews positions of scientists, educators and publicists who resisted eugenics and determinism. The nature nurture controversy is discussed, as well as the impact of eugenics on American classrooms. Specific attention is given to four resisters: Dewey, Bagley, Jennings, and Lippmann. (IAH)

Gypsy moth IPM

Science.gov (United States)

Michael L. McManus; Andrew M. Liebhold

2009-01-01

Over the last 50 years, North American forests have been inundated by a multitude of alien pest invasions. Among these, noteworthy invaders include the hemlock woolly adelgid (Adelges tsugae), emerald ash borer (Agrilus planipennis), chestnut blight and Dutch elm disease. These species have greatly altered both the ecological and...

Winter Iinjury of American chestnut seedlings grown in a common garden at the species' northern range limit

Science.gov (United States)

Paul G. Schaberg; Thomas M. Saielli; Gary J. Hawley; Joshua M. Halman; Kendra M. Gurney

2013-01-01

Hybridization of American chestnut (Castanea dentata) with Chinese chestnut (C. mollissima), followed by backcrossing to American chestnut, is conducted to increase the resistance of resulting stock to chestnut blight, caused by the fungal pathogen Cryphonectria parasitica (Murr.) Barr. Backcross breeding is...

Study of mutual coupling effects in the antenna array of the ICRH plug-in for ITER

International Nuclear Information System (INIS)

Lamalle, P.U.; Messiaen, A.; Dumortier, P.; Durodie, F.; Evrard, M.; Louche, F.

2005-01-01

The performance of the ELM-tolerant 'conjugate T' (CT) matching schemes considered for the ITER ICRH antenna array has been found highly sensitive to the mutual resistances and reactances between antenna straps, which can produce large exchanges of active power between circuit branches. A general analysis is given of the effect of mutual coupling on the matching of a single CT and on the simultaneous matching of several coupled CT circuits. Circuit configurations optimizing the resilience of the system to realistic ELM-induced load variations are given in the case of a single CT. Problems arising from the interaction between several CTs and possible remedies are discussed

African-American Vernacular Dance: Core Culture and Meaning Operatives.

Science.gov (United States)

Hazzard-Gordon, Katrina

1985-01-01

Discusses the role of social dancing in the lives and culture of working class Black Americans. Focuses specifically on four aspects of its meaning: identity (self-esteem), cultural integrity, ingroup-outgroup, and political resistance. Bases argument on sociological, biographical, and fictional works by and about Black culture. (KH)

[Change in drug resistance of Staphylococcus aureus].

Science.gov (United States)

Lin, Yan; Liu, Yan; Luo, Yan-Ping; Liu, Chang-Ting

2013-11-01

To analyze the change in drug resistance of Staphylococcus aureus (SAU) in the PLA general hospital from January 2008 to December 2012, and to provide solid evidence to support the rational use of antibiotics for clinical applications. The SAU strains isolated from clinical samples in the hospital were collected and subjected to the Kirby-Bauer disk diffusion test. The results were assessed based on the 2002 American National Committee for Clinical Laboratory Standards (NCCLS) guidelines. SAU strains were mainly isolated from sputum, urine, blood and wound excreta and distributed in penology, neurology wards, orthopedics and surgery ICU wards. Except for glycopeptide drugs, methicillin-resistant Staphylococcus aureus (MRSA) had a higher drug resistance rate than those of the other drugs and had significantly more resistance than methicillin-sensitive Staphylococcus aureus (MSSA) (P resistance, we discovered a gradual increase in drug resistance to fourteen test drugs during the last five years. Drug resistance rate of SAU stayed at a higher level over the last five years; moreover, the detection ratio of MRSA keeps rising year by year. It is crucial for physicians to use antibiotics rationally and monitor the change in drug resistance in a dynamic way.

Compilation of hydrologic data, Little Elm Creek, Trinity River basin, Texas, 1968

Science.gov (United States)

,

1972-01-01

The U.S. Soil Conservation Service is actively engaged in the installation of flood and soil erosion reducing measures in Texas under the authority of "The Flood Control Act ot 1936 and 1944" and ''Watershed Protection and Flood Prevention Act" (Public Law 566), as amended. In June 1968, the Soil Conservation Service estimated approximately 3,500 structures to be physically and economically feasible for installation in Texas. As of September 30, 1968, 1,271 of these structures had been built. This watershed-development program will have varying but important effects on the surface- and ground-water resources of river basins, especially where a large number of the floodwater-retarding structures are built. Basic hydrologic data are needed to appraise the effects of the structures on water yield and the mode of occurrence of runoff. Hydrologic investigations of these small watersheds were begun by the Geological Survey in 1951 and are now being made in 11 areas (fig. 1). These studies are being made in cooperation with t he Texas Water Development Board, the Soil Conservation Service, the San Antonio River Authority, the city of Dallas, and the Tarrant County Water Control and Improvement District No. 1. The 11 study areas were choson to sample watersheds having different rainfall, topography, geology, and soils. In four of the study areas (Mukewater, North, Little Elm, and Pin Oak Creeks), streamflow and rainfall records were collected prior to construction of the floodwater-retarding structures, thus affording the opportunity for analyses to the conditions before and after" development. Structures have now been built in three of these study areas. A summary of the development of the floodwater-retarding structures on each study area as of September 30, 1968, is shown in table 1.

Obesity-Associated Hypertension: the Upcoming Phenotype in African-American Women.

Science.gov (United States)

Samson, Rohan; Qi, Andrea; Jaiswal, Abhishek; Le Jemtel, Thierry H; Oparil, Suzanne

2017-05-01

The present obesity epidemic particularly affects African-American women. Whether the obesity epidemic will alter the hypertension phenotype in African-American women is entertained. The prevalence of morbid obesity is steadily increasing in African-American women, who are prone to developing hypertension (HTN) even in the absence of obesity. The obesity-associated hypertension phenotype is characterized by marked sympathetic nervous system activation and resistance/refractoriness to antihypertensive therapy. Weight loss achieved through lifestyle interventions and pharmacotherapy has a modest and rarely sustained antihypertensive effect. In contrast, bariatric surgery has a sustained antihypertensive effect, as evidenced by normalization of hypertension or lessening of antihypertensive therapy. The prevalence of HTN and its obesity-associated phenotype is likely to increase in African-American women over the next decades. Obese African-American women may be increasingly referred for bariatric surgery when hypertension remains uncontrolled despite lifestyle interventions and pharmacological therapy for weight loss and blood pressure (BP) control.

A Comprehensive Study of the Tocks Island Lake Project and Alternatives. Part A. Chapters I, II, III. Analysis of Service Areas and Resource Needs.

Science.gov (United States)

1975-06-01

stream or river and relies on water from these sources for subsistence. Species of riparian vegetation include River Birch, American Elm , Sycamore and...a "drought." The concept of drought as discussed earlier, is an elusive and slippery concept; thus it is not appropriate to argue about whether this

Archaeological Testing and Survey: Testing of Three Sites and Survey of a Road Detour within Proposed Project Construction Zones, Burlington Dam Flood Control Project Area, Upper Souris River, North Dakota,

Science.gov (United States)

1980-01-01

reported in Burgess et al. (1973:19). Low bottom species in the study area include American elm (Ulmus americanus), green ash (Fraxinus pennsylvanica...deposits with "Calgon" before water screening. Because of slow permeability clay is very slippery when it becomes wet and can be hazardous to workers. The

Fighting through Resistance: Challenges Faced by African American Women Principals in Predominately White School Settings

Science.gov (United States)

Jackson, Alicia D.

2013-01-01

African American women represented a growing proportion within the field of education in attaining leadership roles as school principals. As the numbers continued to rise slowly, African American women principals found themselves leading in diverse or even predominately White school settings. Leading in such settings encouraged African American…

An Examination of Behavioral Responses to Stereotypical Deceptive Displays.

Science.gov (United States)

Huddleston, Bill M.

A study investigated whether receivers who detect senders behaving deceitfully will automatically become more resistent to the message being presented. By developing predictions derived from the Elaboration Likelihood Model (ELM), the study hypothesized that only noninvolved receivers would respond negatively to deceptive nonverbal cues in a…

Black Willow

Science.gov (United States)

R. M. Krinard

1980-01-01

Black willow and other species of Salix together comprise a majority of the stocking. Cottonwood is the chief associate, particularly in the early stages, but green ash, sycamore, pecan, persimmon, waterlocust, American elm, baldcypress, red maple, sugarberry, box-elder, and in some areas, silver maple are invaders preceding the next successional stage.

Ancestral effect on HOMA-IR levels quantitated in an American population of Mexican origin.

Science.gov (United States)

Qu, Hui-Qi; Li, Quan; Lu, Yang; Hanis, Craig L; Fisher-Hoch, Susan P; McCormick, Joseph B

2012-12-01

An elevated insulin resistance index (homeostasis model assessment of insulin resistance [HOMA-IR]) is more commonly seen in the Mexican American population than in European populations. We report quantitative ancestral effects within a Mexican American population, and we correlate ancestral components with HOMA-IR. We performed ancestral analysis in 1,551 participants of the Cameron County Hispanic Cohort by genotyping 103 ancestry-informative markers (AIMs). These AIMs allow determination of the percentage (0-100%) ancestry from three major continental populations, i.e., European, African, and Amerindian. We observed that predominantly Amerindian ancestral components were associated with increased HOMA-IR (β = 0.124, P = 1.64 × 10(-7)). The correlation was more significant in males (Amerindian β = 0.165, P = 5.08 × 10(-7)) than in females (Amerindian β = 0.079, P = 0.019). This unique study design demonstrates how genomic markers for quantitative ancestral information can be used in admixed populations to predict phenotypic traits such as insulin resistance.

Axes of resistance for tooth movement: does the center of resistance exist in 3-dimensional space?

Science.gov (United States)

Viecilli, Rodrigo F; Budiman, Amanda; Burstone, Charles J

2013-02-01

The center of resistance is considered the most important reference point for tooth movement. It is often stated that forces through this point will result in tooth translation. The purpose of this article is to report the results of numeric experiments testing the hypothesis that centers of resistance do not exist in space as 3-dimensional points, primarily because of the geometric asymmetry of the periodontal ligament. As an alternative theory, we propose that, for an arbitrary tooth, translation references can be determined by 2-dimensional projection intersections of 3-dimensional axes of resistance. Finite element analyses were conducted on a maxillary first molar model to determine the position of the axes of rotation generated by 3-dimensional couples. Translation tests were performed to compare tooth movement by using different combinations of axes of resistance as references. The couple-generated axes of rotation did not intersect in 3 dimensions; therefore, they do not determine a 3-dimensional center of resistance. Translation was obtained by using projection intersections of the 2 axes of resistance perpendicular to the force direction. Three-dimensional axes of resistance, or their 2-dimensional projection intersections, should be used to plan movement of an arbitrary tooth. Clinical approximations to a small 3-dimensional "center of resistance volume" might be adequate in nearly symmetric periodontal ligament cases. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Stabilization of ideal plasma resistive wall modes in cylindrical geometry: The effect of resistive layers

International Nuclear Information System (INIS)

Finn, J.M.

1995-01-01

A cylindrical model with finite beta having an external resonant ideal magnetohydrodynamic instability has been constructed. This resonant mode has a mode rational surface, where the safety factor q equals m/n, within the plasma. In this model, the perturbed radial magnetic field for the ideal mode is nonzero between the mode rational surface and the wall, even though it must vanish at the mode rational surface. This property of the mode is in common with the toroidal external kink. Results are presented showing that in the parameter range for which this ideal mode is stable with a conducting wall but unstable with the wall at infinity, a resistive wall mode persists. However, in the presence of plasma resistivity in a resistive layer about the mode rational surface, this resistive wall mode can be stabilized by a plasma rotation frequency of order a nominal resistive instability growth rate. Furthermore, the stabilization occurs in a large gap in wall position or beta. It is also shown that for the ideal resonant mode, as well as resistive plasma modes and nonresonant ideal plasma modes, there is a maximum value of plasma rotation above which there is no stability gap. Discussions are presented suggesting that these properties may hold for the toroidal external kink. copyright 1995 American Institute of Physics

Survey for the presence of Phytophthora cinnamomi on reclaimed mined lands in Ohio chosen for restoration of the American chestnut

Science.gov (United States)

Shiv Hiremath; Kirsten Lehtoma; Jenise M. Bauman

2013-01-01

We have been planting blight resistant American chestnut seedlings on reclaimed coal mined areas in Southeastern Ohio, which was once within the natural range of the American chestnut. Towards the goal of restoring the American chestnut, we are testing suitable sites that can aid survival, growth and establishment of planted seedlings pre-inoculated with...

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

Science.gov (United States)

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

2009-01-01

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

The effect of microbial inocula on the growth of black locust, Siberian elm and silver maple seedlings

Directory of Open Access Journals (Sweden)

Hajnal-Jafari Timea

2014-01-01

Full Text Available Growth and development of forest plants depend mostly on the soil microbial activity since no mineral or organic fertilizers are applied. Microbial processes can be activated and conditions for plants development improved with the introduction of selected microorganisms in the soil. With the aim of obtaining quality planting material in a shorter period of time, the effects of Azotobacter chroococcum and Streptomyces sp. on the early growth of black locust (Robinia pseudoacacia, Siberian elm (Ulmus pumila and silver-leaf maple (Acer dasycarpum were investigated in this study. Microorganisms were applied individually and in a mixture (1:1. Plant height was measured on the 90th, 120th and 180th day after planting. Plant diameter, as well as the number of actinomycetes and azotobacters was measured at the end of the vegetation period (180 days after planting. Applied microorganisms had a positive effect on the seedling height in all three plant species, with the best effect found in the black locust. Effectiveness of applied microorganisms on seedling diameter was the highest in the silver-leaf maple. The largest number of azotobacters was found in the rhizosphere of black locust. Number of microorganisms from both groups was increased in the inoculated variants. [Projekat Ministarstva nauke Republike Srbije, br. III 43002

Symplectic homoclinic tangles of the ideal separatrix of the DIII-D from type I ELMs

Science.gov (United States)

Punjabi, Alkesh; Ali, Halima

2012-10-01

The ideal separatrix of the divertor tokamaks is a degenerate manifold where both the stable and unstable manifolds coincide. Non-axisymmetric magnetic perturbations remove the degeneracy; and split the separatrix manifold. This creates an extremely complex topological structure, called homoclinic tangles. The unstable manifold intersects the stable manifold and creates alternating inner and outer lobes at successive homoclinic points. The Hamiltonian system must preserve the symplectic topological invariance, and this controls the size and radial extent of the lobes. Very recently, lobes near the X-point have been experimentally observed in MAST [A. Kirk et al, PRL 108, 255003 (2012)]. We have used the DIII-D map [A. Punjabi, NF 49, 115020 (2009)] to calculate symplectic homoclinic tangles of the ideal separatrix of the DIII-D from the type I ELMs represented by the peeling-ballooning modes (m,n)=(30,10)+(40,10). The DIII-D map is symplectic, accurate, and is in natural canonical coordinates which are invertible to physical coordinates [A. Punjabi and H. Ali, POP 15, 122502 (2008)]. To our knowledge, we are the first to symplectically calculate these tangles in physical space. Homoclinic tangles of separatrix can cause radial displacement of mobile passing electrons and create sheared radial electric fields and currents, resulting in radial flows, drifts, differential spinning, and reduction in turbulence, and other effects. This work is supported by the grants DE-FG02-01ER54624 and DE-FG02-04ER54793.

A Comparison of Plasma Performance Between Single-Null and Double-Null Configurations During Elming H-Mode

International Nuclear Information System (INIS)

Petrie, T.W.; Fenstermacher, M.E.; Allen, S.L.; Carlstrom, T.N.; Gohil, P.; Groebner, R.J.; Greenfield, C.M.; Hyatt, A.W.; Lasnier, C.J.; La Haye, R.J.; Leonard, A.W.; Mahdavi, M.A.; Osborne, T.H.; Porter, G.D.; Rhodes, T.L.; Thomas, D.M.; Watkins, J.G.; West, W.P.; Wolf, N.S.

1999-01-01

Tokamak plasma performance generally improves with increased shaping of the plasma cross section, such as higher elongation and higher triangularity. The stronger shaping, especially higher triangularity, leads to changes in the magnetic topology of the divertor. Because there are engineering and divertor physics issues associated with changes in the details of the divertor flux geometry, especially as the configuration transitions from a single-null (SN) divertor to a marginally balanced double-null (DN) divertor, we have undertaken a systematic evaluation of the plasma characteristics as the magnetic geometry is varied, particularly with respect to (1) energy confinement, (2) the response of the plasma to deuterium gas fueling, (3) the operational density range for the ELMing H-mode, and (4) heat flux sharing by the diverters. To quantify the degree of divertor imbalance (or equivalently, to what degree the shape is double-null or single-null), we define a parameter DRSEP. DRSEP is taken as the radial distance between the upper divertor separatrix and the lower divertor separatrix, as determined at the outboard midplane. For example, if DRSEP=O, the configuration is a magnetically balanced DN; if DRSEP = +1.0 cm, the divertor configuration is biased toward the upper divertor. Three examples are shown in Fig. 1. In the following discussions, VB drift is directed toward the lower divertor

The meek cry or the importance of resisting multiple forms

Directory of Open Access Journals (Sweden)

Diego Alejandro Muñoz Gaviria

2011-07-01

Full Text Available First step, seeks to broadly down some of the known theories of resistance. The idea in this item will be the statement configured stress field around the idea of resistance as a political option. In a second step, seeks to identify the key ideas of Paulo Freire around the resistor, as a Latin American perspective able to shed light on the "other" ways to act politically in our territories, from a critical or resistance. Finally, some conclusions are proposed that will synthesize the above and leave open questions for further reflection exercises and thematic depth.

Transcriptome Profiling of Antimicrobial Resistance in Pseudomonas aeruginosa.

Science.gov (United States)

Khaledi, Ariane; Schniederjans, Monika; Pohl, Sarah; Rainer, Roman; Bodenhofer, Ulrich; Xia, Boyang; Klawonn, Frank; Bruchmann, Sebastian; Preusse, Matthias; Eckweiler, Denitsa; Dötsch, Andreas; Häussler, Susanne

2016-08-01

Emerging resistance to antimicrobials and the lack of new antibiotic drug candidates underscore the need for optimization of current diagnostics and therapies to diminish the evolution and spread of multidrug resistance. As the antibiotic resistance status of a bacterial pathogen is defined by its genome, resistance profiling by applying next-generation sequencing (NGS) technologies may in the future accomplish pathogen identification, prompt initiation of targeted individualized treatment, and the implementation of optimized infection control measures. In this study, qualitative RNA sequencing was used to identify key genetic determinants of antibiotic resistance in 135 clinical Pseudomonas aeruginosa isolates from diverse geographic and infection site origins. By applying transcriptome-wide association studies, adaptive variations associated with resistance to the antibiotic classes fluoroquinolones, aminoglycosides, and β-lactams were identified. Besides potential novel biomarkers with a direct correlation to resistance, global patterns of phenotype-associated gene expression and sequence variations were identified by predictive machine learning approaches. Our research serves to establish genotype-based molecular diagnostic tools for the identification of the current resistance profiles of bacterial pathogens and paves the way for faster diagnostics for more efficient, targeted treatment strategies to also mitigate the future potential for resistance evolution. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Effect of iron on pancreatic beta cell function and insulin resistance

African Journals Online (AJOL)

Dr Olaleye

Diabetes mellitus is a metabolic disorder characterized by disturbances .... indices of body fat distribution and obesity in. Mexican American men—the Third National Health and Nutrition ... Mechanisms linking obesity to insulin resistance and.

Quasineutral plasma expansion into infinite vacuum as a model for parallel ELM transport

Science.gov (United States)

Moulton, D.; Ghendrih, Ph; Fundamenski, W.; Manfredi, G.; Tskhakaya, D.

2013-08-01

An analytic solution for the expansion of a plasma into vacuum is assessed for its relevance to the parallel transport of edge localized mode (ELM) filaments along field lines. This solution solves the 1D1V Vlasov-Poisson equations for the adiabatic (instantaneous source), collisionless expansion of a Gaussian plasma bunch into an infinite space in the quasineutral limit. The quasineutral assumption is found to hold as long as λD0/σ0 ≲ 0.01 (where λD0 is the initial Debye length at peak density and σ0 is the parallel length of the Gaussian filament), a condition that is physically realistic. The inclusion of a boundary at x = L and consequent formation of a target sheath is found to have a negligible effect when L/σ0 ≳ 5, a condition that is physically plausible. Under the same condition, the target flux densities predicted by the analytic solution are well approximated by the ‘free-streaming’ equations used in previous experimental studies, strengthening the notion that these simple equations are physically reasonable. Importantly, the analytic solution predicts a zero heat flux density so that a fluid approach to the problem can be used equally well, at least when the source is instantaneous. It is found that, even for JET-like pedestal parameters, collisions can affect the expansion dynamics via electron temperature isotropization, although this is probably a secondary effect. Finally, the effect of a finite duration, τsrc, for the plasma source is investigated. As is found for an instantaneous source, when L/σ0 ≳ 5 the presence of a target sheath has a negligible effect, at least up to the explored range of τsrc = L/cs (where cs is the sound speed at the initial temperature).

"Chinese-Mexicans" and "Blackest Asians": Filipino American Youth Resisting the Racial Binary

Science.gov (United States)

Chutuape, Erica D.

2016-01-01

This study provides a deeper understanding of the interracial connections not just between non-whites and whites, but among non-whites. Filipino American youth attending high school in New York City contended with a dominant bipolar racial discourse that marginalizes the racialized experiences of Asians and Pacific Islanders. However, instead of…

Transcriptomic identification of ADH1B as a novel candidate gene for obesity and insulin resistance in human adipose tissue in Mexican Americans from the Veterans Administration Genetic Epidemiology Study (VAGES.

Directory of Open Access Journals (Sweden)

Deidre A Winnier

Full Text Available Type 2 diabetes (T2D is a complex metabolic disease that is more prevalent in ethnic groups such as Mexican Americans, and is strongly associated with the risk factors obesity and insulin resistance. The goal of this study was to perform whole genome gene expression profiling in adipose tissue to detect common patterns of gene regulation associated with obesity and insulin resistance. We used phenotypic and genotypic data from 308 Mexican American participants from the Veterans Administration Genetic Epidemiology Study (VAGES. Basal fasting RNA was extracted from adipose tissue biopsies from a subset of 75 unrelated individuals, and gene expression data generated on the Illumina BeadArray platform. The number of gene probes with significant expression above baseline was approximately 31,000. We performed multiple regression analysis of all probes with 15 metabolic traits. Adipose tissue had 3,012 genes significantly associated with the traits of interest (false discovery rate, FDR ≤ 0.05. The significance of gene expression changes was used to select 52 genes with significant (FDR ≤ 10(-4 gene expression changes across multiple traits. Gene sets/Pathways analysis identified one gene, alcohol dehydrogenase 1B (ADH1B that was significantly enriched (P < 10(-60 as a prime candidate for involvement in multiple relevant metabolic pathways. Illumina BeadChip derived ADH1B expression data was consistent with quantitative real time PCR data. We observed significant inverse correlations with waist circumference (2.8 x 10(-9, BMI (5.4 x 10(-6, and fasting plasma insulin (P < 0.001. These findings are consistent with a central role for ADH1B in obesity and insulin resistance and provide evidence for a novel genetic regulatory mechanism for human metabolic diseases related to these traits.

Abdominal candidiasis is a hidden reservoir of echinocandin resistance.

Science.gov (United States)

Shields, Ryan K; Nguyen, M Hong; Press, Ellen G; Clancy, Cornelius J

2014-12-01

FKS mutant Candida isolates were recovered from 24% (6/25) of abdominal candidiasis patients exposed to echinocandin. Candida glabrata (29%) and Candida albicans (14%) mutants were identified. Multidrug-resistant bacteria were recovered from 83% of FKS mutant infections. Mutations were associated with prolonged echinocandin exposure (P = 0.01), breakthrough infections (P = 0.03), and therapeutic failures despite source control interventions (100%). Abdominal candidiasis is a hidden reservoir for the emergence of echinocandin-resistant Candida. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

A Regional Guidebook for Conducting Functional Assessments of Wetland and Riparian Forests in the Ouachita Mountains and Crowley’s Ridge Regions of Arkansas

Science.gov (United States)

2006-12-01

Liquidambar styraciflua Gleditsia triacanthos Quercus alba Pinus taeda Juniperus virginiana Quercus pagoda Quercus nigra Prunus serotina Quercus phellos...maple, sugarberry (Celtis laevigata), American elm (Ulmus americana), and persimmon (Diospyros virginiana ). Wetlands of higher terraces typically are...hazels (Hamamelis virginiana , H. vernalis), and highbush blueberry (Vaccinium arboreum). The groundcover layer is usually very diverse and may include

Association between insulin resistance and plasma amino acid profile in non-diabetic Japanese subjects

OpenAIRE

Yamada, Chizumi; Kondo, Masumi; Kishimoto, Noriaki; Shibata, Takeo; Nagai, Yoko; Imanishi, Tadashi; Oroguchi, Takashige; Ishii, Naoaki; Nishizaki, Yasuhiro

2015-01-01

Aims/Introduction Elevation of the branched-chain amino acids (BCAAs), valine, leucine and isoleucine; and the aromatic amino acids, tyrosine and phenylalanine, has been observed in obesity-related insulin resistance. However, there have been few studies on Asians, who are generally less obese and less insulin-resistant than Caucasian or African-Americans. In the present study, we investigated the relationship between homeostasis model assessment of insulin resistance (HOMA-IR) and plasma ami...

Reference ranges for interrupter resistance technique: the Asthma UK Initiative.

NARCIS (Netherlands)

Merkus, P.J.F.M.; Stocks, J.; Beydon, N.; Lombardi, E.; Jones, M.; McKenzie, S.A.; Kivastik, J.; Arets, B.G.; Stanojevic, S.

2010-01-01

Measuring interrupter resistance (R(int)) is an increasingly popular lung function technique and especially suitable for preschool children because it is simple, quick and requires only passive cooperation. A European Respiratory Society (ERS)/American Thoracic Society (ATS) Task Force recently

American Women and American Studies.

Science.gov (United States)

Chmaj, Betty E.

The American Studies Association (ASA) is an interprofessional group, representing a cross-section of persons from American literature, American history, the social sciences, philosophy, archeology, Black Studies, Urban Studies, American Studies, and others. This document by the ASA Commission on the Status of Women includes: (1) a report of the…

Characterization of an IncA/C Multidrug Resistance Plasmid in Vibrio alginolyticus.

Science.gov (United States)

Ye, Lianwei; Li, Ruichao; Lin, Dachuan; Zhou, Yuanjie; Fu, Aisi; Ding, Qiong; Chan, Edward Wai Chi; Yao, Wen; Chen, Sheng

2016-05-01

Cephalosporin-resistant Vibrio alginolyticus was first isolated from food products, with β-lactamases encoded by blaPER-1, blaVEB-1, and blaCMY-2 being the major mechanisms mediating their cephalosporin resistance. The complete sequence of a multidrug resistance plasmid, pVAS3-1, harboring the blaCMY-2 and qnrVC4 genes was decoded in this study. Its backbone exhibited genetic homology to known IncA/C plasmids recoverable from members of the family Enterobacteriaceae, suggesting its possible origin in Enterobacteriaceae. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Review of Reports on Lake Erie-Lake Ontario Waterway, New York. Appendix E. Impact Assessment and Environment Plan.

Science.gov (United States)

1973-10-01

Ostrya virginiana ), American hornbeam or blue beech (Carpinus caroliana), American elm (Ulnus americana), silver maple (Acer saccharinum), red maple...921 4, 13, 780 Pears 7, 519, lt7 (,, 58t, 058 Cherries 7, 75,727 7, 147, 129 Plums and prunes 2. 892.85i 2, 352, 488 Grapes b, 874, 9e,) 8, t 2 4...drained soils), 10 percent peaches, 15-20 percent grapes, and 5 percent plums and prunes . A high per- centage of new plantings, up to 20 percent for

AXL mediates resistance to cetuximab therapy.

Science.gov (United States)

Brand, Toni M; Iida, Mari; Stein, Andrew P; Corrigan, Kelsey L; Braverman, Cara M; Luthar, Neha; Toulany, Mahmoud; Gill, Parkash S; Salgia, Ravi; Kimple, Randall J; Wheeler, Deric L

2014-09-15

The EGFR antibody cetuximab is used to treat numerous cancers, but intrinsic and acquired resistance to this agent is a common clinical outcome. In this study, we show that overexpression of the oncogenic receptor tyrosine kinase AXL is sufficient to mediate acquired resistance to cetuximab in models of non-small cell lung cancer (NSCLC) and head and neck squamous cell carcinoma (HNSCC), where AXL was overexpressed, activated, and tightly associated with EGFR expression in cells resistant to cetuximab (Ctx(R) cells). Using RNAi methods and novel AXL-targeting agents, we found that AXL activation stimulated cell proliferation, EGFR activation, and MAPK signaling in Ctx(R) cells. Notably, EGFR directly regulated the expression of AXL mRNA through MAPK signaling and the transcription factor c-Jun in Ctx(R) cells, creating a positive feedback loop that maintained EGFR activation by AXL. Cetuximab-sensitive parental cells were rendered resistant to cetuximab by stable overexpression of AXL or stimulation with EGFR ligands, the latter of which increased AXL activity and association with the EGFR. In tumor xenograft models, the development of resistance following prolonged treatment with cetuximab was associated with AXL hyperactivation and EGFR association. Furthermore, in an examination of patient-derived xenografts established from surgically resected HNSCCs, AXL was overexpressed and activated in tumors that displayed intrinsic resistance to cetuximab. Collectively, our results identify AXL as a key mediator of cetuximab resistance, providing a rationale for clinical evaluation of AXL-targeting drugs to treat cetuximab-resistant cancers. Cancer Res; 74(18); 5152-64. ©2014 AACR. ©2014 American Association for Cancer Research.

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

Energy Technology Data Exchange (ETDEWEB)

Landman, I.S.; Pestchanyi, S.E.; Bazylev, B.N [Forschungszentrum Karlsruhe (Germany). Inst. for Pulsed Power and Microwave Technology; Safronov, V.M. [Troitsk Inst. for Innovation and Fusion Research (TRINITI) (Russian Federation); Garkusha, I.E. [Kharkov Inst. of Physics and Technology (KIPT) (Ukraine). Inst. of Plasma Physics

2004-08-01

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

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

Science.gov (United States)

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

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

Metal-free, single-polymer device exhibits resistive memory effect

KAUST Repository

Bhansali, Unnat Sampatraj; Khan, Yasser; Cha, Dong Kyu; Almadhoun, Mahmoud N.; Li, Ruipeng; Chen, Long; Amassian, Aram; Odeh, Ihab N.; Alshareef, Husam N.

2013-01-01

All-polymer, write-once-read-many times resistive memory devices have been fabricated on flexible substrates using a single polymer, poly(3,4- ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). Spin-cast or inkjet-printed films of solvent-modified PEDOT:PSS are used as electrodes, while the unmodified or as-is PEDOT:PSS is used as the semiconducting active layer. The all-polymer devices exhibit an irreversible but stable transition from a low resistance state (ON) to a high resistance state (OFF) at low voltages caused by an electric-field-induced morphological rearrangement of PEDOT and PSS at the electrode interface. However, in the metal-PEDOT:PSS-metal devices, we have shown a metal filament formation switching the device from an initial high resistance state (OFF) to the low resistance state (ON). The all-PEDOT:PSS memory device has low write voltages (<3 V), high ON/OFF ratio (>10 3), good retention characteristics (>10 000 s), and stability in ambient storage (>3 months). © 2013 American Chemical Society.

Metal-free, single-polymer device exhibits resistive memory effect

KAUST Repository

Bhansali, Unnat Sampatraj

2013-12-23

All-polymer, write-once-read-many times resistive memory devices have been fabricated on flexible substrates using a single polymer, poly(3,4- ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). Spin-cast or inkjet-printed films of solvent-modified PEDOT:PSS are used as electrodes, while the unmodified or as-is PEDOT:PSS is used as the semiconducting active layer. The all-polymer devices exhibit an irreversible but stable transition from a low resistance state (ON) to a high resistance state (OFF) at low voltages caused by an electric-field-induced morphological rearrangement of PEDOT and PSS at the electrode interface. However, in the metal-PEDOT:PSS-metal devices, we have shown a metal filament formation switching the device from an initial high resistance state (OFF) to the low resistance state (ON). The all-PEDOT:PSS memory device has low write voltages (<3 V), high ON/OFF ratio (>10 3), good retention characteristics (>10 000 s), and stability in ambient storage (>3 months). © 2013 American Chemical Society.

Race Across Borders: Transnationalism and Racial Identity in African-American Fiction, 1929-1945

OpenAIRE

Agbodike, Kanayo Jason

2012-01-01

Race Across Borders: Transnationalism and Racial Identity in African-American Fiction, 1929-1945, examines four African-American literary texts that employ transnational themes and aesthetics as a means of resisting a logic of racial essentialism that governed the production and reception of black literature in the United States during the early 20th century. I examine the ways in which Dark Princess by W. E. B. Du Bois, Their Eyes Were Watching God by Zora Neale Hurston, Banjo: A Story Witho...

Genome-Wide Analysis of Secondary Metabolite Gene Clusters in Ophiostoma ulmi and Ophiostoma novo-ulmi Reveals a Fujikurin-Like Gene Cluster with a Putative Role in Infection

Directory of Open Access Journals (Sweden)

Nicolau Sbaraini

2017-06-01

Full Text Available The emergence of new microbial pathogens can result in destructive outbreaks, since their hosts have limited resistance and pathogens may be excessively aggressive. Described as the major ecological incident of the twentieth century, Dutch elm disease, caused by ascomycete fungi from the Ophiostoma genus, has caused a significant decline in elm tree populations (Ulmus sp. in North America and Europe. Genome sequencing of the two main causative agents of Dutch elm disease (Ophiostoma ulmi and Ophiostoma novo-ulmi, along with closely related species with different lifestyles, allows for unique comparisons to be made to identify how pathogens and virulence determinants have emerged. Among several established virulence determinants, secondary metabolites (SMs have been suggested to play significant roles during phytopathogen infection. Interestingly, the secondary metabolism of Dutch elm pathogens remains almost unexplored, and little is known about how SM biosynthetic genes are organized in these species. To better understand the metabolic potential of O. ulmi and O. novo-ulmi, we performed a deep survey and description of SM biosynthetic gene clusters (BGCs in these species and assessed their conservation among eight species from the Ophiostomataceae family. Among 19 identified BGCs, a fujikurin-like gene cluster (OpPKS8 was unique to Dutch elm pathogens. Phylogenetic analysis revealed that orthologs for this gene cluster are widespread among phytopathogens and plant-associated fungi, suggesting that OpPKS8 may have been horizontally acquired by the Ophiostoma genus. Moreover, the detailed identification of several BGCs paves the way for future in-depth research and supports the potential impact of secondary metabolism on Ophiostoma genus’ lifestyle.

PineElm_SSRdb: a microsatellite marker database identified from genomic, chloroplast, mitochondrial and EST sequences of pineapple (Ananas comosus (L.) Merrill).

Science.gov (United States)

Chaudhary, Sakshi; Mishra, Bharat Kumar; Vivek, Thiruvettai; Magadum, Santoshkumar; Yasin, Jeshima Khan

2016-01-01

Simple Sequence Repeats or microsatellites are resourceful molecular genetic markers. There are only few reports of SSR identification and development in pineapple. Complete genome sequence of pineapple available in the public domain can be used to develop numerous novel SSRs. Therefore, an attempt was made to identify SSRs from genomic, chloroplast, mitochondrial and EST sequences of pineapple which will help in deciphering genetic makeup of its germplasm resources. A total of 359511 SSRs were identified in pineapple (356385 from genome sequence, 45 from chloroplast sequence, 249 in mitochondrial sequence and 2832 from EST sequences). The list of EST-SSR markers and their details are available in the database. PineElm_SSRdb is an open source database available for non-commercial academic purpose at http://app.bioelm.com/ with a mapping tool which can develop circular maps of selected marker set. This database will be of immense use to breeders, researchers and graduates working on Ananas spp. and to others working on cross-species transferability of markers, investigating diversity, mapping and DNA fingerprinting.

Reading "Gatsby"/Performing "Jazz": On Narrative Voice, Race, and Resistance.

Science.gov (United States)

Rogers, Theresa

1998-01-01

Describes an experiment in pairing the novels "The Great Gatsby" (F. Scott Fitzgerald) and "Jazz" (Toni Morrison) in a teacher preparation class. Relates that the students (all European American) initially resisted "Jazz" and accepted "Gatsby" as a timeless classic. Includes responses about another Toni…

Sequence Exchange between Homologous NB-LRR Genes Converts Virus Resistance into Nematode Resistance, and Vice Versa.

Science.gov (United States)

Slootweg, Erik; Koropacka, Kamila; Roosien, Jan; Dees, Robert; Overmars, Hein; Lankhorst, Rene Klein; van Schaik, Casper; Pomp, Rikus; Bouwman, Liesbeth; Helder, Johannes; Schots, Arjen; Bakker, Jaap; Smant, Geert; Goverse, Aska

2017-09-01

Plants have evolved a limited repertoire of NB-LRR disease resistance ( R ) genes to protect themselves against myriad pathogens. This limitation is thought to be counterbalanced by the rapid evolution of NB-LRR proteins, as only a few sequence changes have been shown to be sufficient to alter resistance specificities toward novel strains of a pathogen. However, little is known about the flexibility of NB-LRR R genes to switch resistance specificities between phylogenetically unrelated pathogens. To investigate this, we created domain swaps between the close homologs Gpa2 and Rx1 , which confer resistance in potato ( Solanum tuberosum ) to the cyst nematode Globodera pallida and Potato virus X , respectively. The genetic fusion of the CC-NB-ARC of Gpa2 with the LRR of Rx1 (Gpa2 CN /Rx1 L ) results in autoactivity, but lowering the protein levels restored its specific activation response, including extreme resistance to Potato virus X in potato shoots. The reciprocal chimera (Rx1 CN /Gpa2 L ) shows a loss-of-function phenotype, but exchange of the first three LRRs of Gpa2 by the corresponding region of Rx1 was sufficient to regain a wild-type resistance response to G. pallida in the roots. These data demonstrate that exchanging the recognition moiety in the LRR is sufficient to convert extreme virus resistance in the leaves into mild nematode resistance in the roots, and vice versa. In addition, we show that the CC-NB-ARC can operate independently of the recognition specificities defined by the LRR domain, either aboveground or belowground. These data show the versatility of NB-LRR genes to generate resistance to unrelated pathogens with completely different lifestyles and routes of invasion. © 2017 American Society of Plant Biologists. All Rights Reserved.

Design and preliminary evaluation of an exoskeleton for upper limb resistance training

Science.gov (United States)

Wu, Tzong-Ming; Chen, Dar-Zen

2012-06-01

Resistance training is a popular form of exercise recommended by national health organizations, such as the American College of Sports Medicine (ACSM) and the American Heart Association (AHA). This form of training is available for most populations. A compact design of upper limb exoskeleton mechanism for homebased resistance training using a spring-loaded upper limb exoskeleton with a three degree-of-freedom shoulder joint and a one degree-of-freedom elbow joint allows a patient or a healthy individual to move the upper limb with multiple joints in different planes. It can continuously increase the resistance by adjusting the spring length to train additional muscle groups and reduce the number of potential injuries to upper limb joints caused by the mass moment of inertia of the training equipment. The aim of this research is to perform a preliminary evaluation of the designed function by adopting an appropriate motion analysis system and experimental design to verify our prototype of the exoskeleton and determine the optimal configuration of the spring-loaded upper limb exoskeleton.

ORIGINAL ARTICLES

African Journals Online (AJOL)

Improved resistance to fatigue. 15. 37.5 .... in the prevalence of. AAS use are interesting and prOVide a useful model for trying ... Athletes' projections of anabolic steroid use. elm Sports ... of Mathematical Statistics, L'niver5ity of Cape Town, 1991. 23. ... Test-retest reliability and validity information for a high .school drug use.

Resistive Reduced MHD Modeling of Multi-Edge-Localized-Mode Cycles in Tokamak X-Point Plasmas

Czech Academy of Sciences Publication Activity Database

Orain, F.; Bécoulet, M.; Huijsmans, G.; Dif-Pradalier, G.; Hoelzl, M.; Morales, J.; Garbet, X.; Nardon, E.; Paméla, S.; Passeron, C.; Latu, G.; Fil, A.; Cahyna, Pavel

2015-01-01

Roč. 114, č. 3 (2015), 035001-035001 ISSN 0031-9007 EU Projects: European Commission(XE) 633053 Institutional support: RVO:61389021 Keywords : transport * stabilization * ELMs * JET Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 7.645, year: 2015 http://journals. aps .org/prl/abstract/10.1103/PhysRevLett.114.035001

Cottonwood

Science.gov (United States)

R. M. Krinard

1980-01-01

Cottonwood is pure or comprises a majority of the stocking, but it is associated with other bottomland hardwoods. Eastern, plains, and swamp cottonwood are included under the type name. The chief associates in the younger stages are black and sandbar willow. Sweetgum !s rare. White or green ash, silver maple, and American elm may occur in the northern extremities of...

Field trip on the Kellogg Forest of Michigan State University near Augusta, Michigan