bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling with COREDIV Code of JET ILW Configuration
Authors: Zagörski R. , Telesca G. , Fundamenski W. , McCormick K. 
Published: May 2010

AbstractIn this paper we present integrated numerical modeling for the first time applied to AT discharges with tungsten wall using the COREDIV code. We concentrate on numerical simulations of Ne seeded scenarios in the new ILW JET configuration. Results show that the JET operating space might be limited, with tungsten wall, to high density plasmas (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling of Plasma Parameters during High Pressure Gas Injection with a Three Temperature Model
Authors: Baronova E. O. , Vikhrev V. V. 
Published: May 2010

AbstractA three temperature model is constructed to describe dynamics of plasma parameters during argon injection, which is aimed to mitigate disruption consequences. Model predicts fast decrease of electron and ion temperatures, distribution of ionization stages and average ion charge in time, the rate of total radiation losses and time dependent intensities of ArXVII lines, widely used in plasma diagnostics. It was found that rapid drop of electron temperature is not associated with radiation losses (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Edge Stability and Pedestal Profile Sensitivity of Snowflake Diverted Equilibria in the TCV Tokamak
Authors: Medvedev S. Yu. , Ivanov A. A. , Martynov A. A. , Poshekhonov Yu. Yu. , Behn R. , Martin Y. R. , Moret J.‐M. , Piras F. , Pitzschke A. , Pochelon A. , Sauter O. , Villard L. 
Published: May 2010

AbstractA second order null divertor (snowflake) has been successfully created and controlled in the TCV tokamak [1] (F. Piras et al., Plasma Phys. Control. Fusion, 2009). The results of ideal MHD edge stability computations show an enhancement of the edge stability properties of the snowflake equilibria compared to standard x‐point configurations [2] (S. Yu. Medvedev et al., 36th EPS Conference on Plasma Physics, 2009). However, a sensitivity study of the stability limits to variations of the pedestal profiles is essential for making conclusions about possibilities of ELM control in snowflake plasmas. Variations of the edge stability and beta limits for several types of snowflake equilibria, different values of triangularity and various pedestal profiles are investigated (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Edge Plasma in Snowflake Divertor
Authors: Umansky M.V. , Rognlien T.D. , Ryutov D.D. , Snyder P.B. 
Published: May 2010

AbstractThe snowflake divertor (Ryutov 2007, Phys. Plasmas 14, 064502) uses a 2nd order null of the poloidal magnetic field instead of the 1st order null used in the standard divertor. This leads to a number of interesting geometric properties such as stronger fanning of the poloidal flux, stronger magnetic shear in the edge region, larger radiating volume, and larger connection length in the scrape‐off layer. These can potentially lead to new ways for alleviating heat loads on the divertor target plates. Discussion of properties of snowflake is presented, along with results of numerical modeling. Divertor leg volume is larger in snowflake than in the standard x‐point configuration, which leads to larger fraction of radiated power in the divertor. This allows the snowflake to transition to a strongly detached plasma regime more easily than for the standard x‐point. Besides, stronger shearing of the magnetic field in snowflake may be beneficial for controlling magneto‐hydrodynamic instabilities in the edge (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulations of NSTX with a Liquid Lithium Divertor Module
Authors: Stotler D. P. , Maingi R. , Zakharov L.E. , Kugel H.W. , Pigarov A.Yu. , Rognlien T.D. , Soukhanovskii V. A. 
Published: May 2010

AbstractA strategy to develop self‐consistent simulations of the behavior of lithium in the Liquid Lithium Divertor (LLD) module to be installed in NSTX is described. In this initial stage of the plan, the UEDGE edge plasma transport code is used to simulate an existing NSTX shot, with UEDGE's transport coefficients set using midplane and divertor diagnostic data. The LLD is incorporated into the simulations as a reduction in the recycling coefficient over the outer divertor. Heat transfer calculations performed using the resulting heat flux profiles provide preliminary estimates on operating limits for the LLD as well as input data for subsequent steps in the LLD modeling effort (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stabilization of Radiation‐Condensation Instability by Light Impurity Injection
Authors: Pshenov A. A. , Morozov D. Kh. 
Published: May 2010

AbstractAs it has been shown in [1,2], Radiation‐Condensation Instability (RCI) may initiate Microfaceted Asymmetric Radiation from the Edge (MARFE) in tokamaks (see also review papers [3‐5]). Nevertheless, experiments demonstrate the stable regimes with strongly radiated edge plasmas after Ne injection [6‐8] or in siliconized discharges. Two effects destabilize radiative plasmas, the decrease of radiation losses Q with the electron temperature Te increase, and the increase of Q with electron and impurity densities rise. The finite relaxation time of impurity distribution over ionization states [6] as well as the thermal force acting on the growth rate doesn't shift the instability margin. Hence, one can examine the stability margin using the approximation of the coronal equilibrium. Radiation losses of intrinsic impurities like beryllium, carbon and nitrogen usually decrease with the temperature increase at the temperature range typical for the edge (see Fig. 1, curve 1). The situation may be significantly different for impurity mixtures. Radiation losses L ≡ Q /(nenI)normalized by electron and impurity densities ne and nI for the mixture of carbon and neon are shown in Fig. 1, curves 2‐5. One can see that ∂Q/∂T > 0 for practically any temperature at the edge if the concentration ratio nNe/nC ≥ 5. Hence, one can expect the stabilization of RCI by injection of additional impurity and achievement of stable regime with the strongly radiated edge plasmas. The stability of plasmas with few impurity mixtures is examined in the present paper numerically (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Progress on Radiative Transfer Modelling in Optically Thick Divertor Plasmas
Authors: Rosato J. , Reiter D. , Kotov V. , Marandet Y. , Capes H. , Godbert‐Mouret L. , Koubiti M. , Stamm R. 
Published: May 2010

AbstractThe physical model used in the photon transport module of the Monte‐Carlo code EIRENE (www.eirene.de) is presented. A critical assessment of the spectral line broadening mechanisms (which give the shape of the photon‐atom reaction rates) and of their relevance in a transport simulation is carried out (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of Turbulence on Radiative Properties of Tokamak Edge Plasmas
Authors: Rosato J. , Rosmej F. B. , Stamm R. , Kadomtsev M. B. , Levashova M. G. , Lisitsa V. S. 
Published: May 2010

AbstractThe effect of turbulent temperature fluctuations on the radiative losses in tokamak edge and divertor plasmas is investigated. A statistical model is developed. The formalism involves both the probability density function of the fluid quantities and the expression of the emitting energy level population in terms of these quantities. We apply the statistical model to calculations of radiative power losses, successively for lithium and hydrogen radiation. In the former case, the energy level populations are obtained with an analytical collisional‐radiative model accounting for non‐coronal and transport effects. In the hydrogen case, the emitting level population is calculated by a collisional‐radiative code. The role of electron temperature fluctuations is discussed in detail. Application to hydrogen line radiation in JET conditions reveals the significant role of turbulence in the repartition of the radiated energy inside the divertor (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical Aspects of Dust in Fusion Devices
Authors: Krasheninnikov S. I. , Pigarov A. Yu. , Smirnov R. D. , Soboleva T. K. 
Published: May 2010

AbstractIt is known that micro‐particles (dust) exist in fusion devices. However, an impact of dust on plasma contamination, material migration, and performance of fusion devices is still under debate. In burning plasma experiments like ITER dust can also pose safety problems related to it's chemical activity, toxicity, tritium retention, and radioactive content. In order to address all these issues we need to understand the physics of dust generation, dynamics, and transport. In this paper, the results of recent theoretical studies of dust in fusion plasmas are reviewed. Different aspects of the physics of dust in fusion plasmas, including the processes of dust generation, charging, heating, destruction, spinning, forces acting on dust, dust collision with material walls, etc are discussed. The numerical models of these processes have been incorporated into the dust transport code DUSTT, which is capable of tracking of dust particles in fusion devices in 3D geometry. The results of the simulations of dust particle dynamics, transport, and the impact on edge plasma performance are considered. The latest results on nonlinear interactions of dust grain with tokamak plasma as well as remaining gaps in the understanding of physics of dust in fusion devices are discussed (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Acceleration and Redeposition of a Dust Particle in SOL/Divertor Plasma of HL‐2A Tokamak
Authors: Tomita Y. , Kawamura G. , Pan Y.D. , Yan L.W. 
Published: May 2010

AbstractAcceleration of a iron dust particle is studied in the SOL (Scrape‐Off Layer)/divertor plasma of the HL‐2A tokamak in Southwestern Institute of Physics, China, with a single‐null configuration. In this study the simplest model of the dust dynamics is applied: spherical shape of a dust, ion drag force due to Coulomb scattering and drag force due to the plasma ion absorption as dominant forces, and spontaneous charging of a dust particle to the equilibrium charge. In the outer region near the plasma‐facing wall the parallel plasma flow along the magnetic field pushes the dust particle to the divertor plates. It is clarified that the dust particle with a radius of 1mm from the top of the SOL/divertor region is accelerated up to around 100 m/s in a few hundreds milliseconds to the divertor plates. In our model even the small dust particle with 1nm size can overcome the sheath potential and redeposite on the divertor plate (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Linear Polarization of Photons Emitted from Excited Hydrogen Atoms Formed above Metal Surfaces
Authors: Kato D. , Kenmotsu T. , Ohya K. , Tanabe T. 
Published: May 2010

AbstractThis paper presents theoretical results for linear polarization of Lyman‐α and Balmer‐α emission following single electron capture by hydrogen nuclei to excited levels above Mo surfaces. The polarization degrees are evaluated for photons from the hydrogen atoms outgoing along surface normal with translation velocities of 0.05‐1 au. In this geometry, the excited states are aligned with respect to the surface normal (quantization axis). Finite polarization degrees are obtained for electric‐dipole photons emitted at right angle to the surface normal; the linear polarization preferentially along the surface plane at lower translation velocities turns to the surface normal at higher velocities (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron Velocity Distribution at a Sheath Edge in the Presence of Secondary Electron Emission From a Metal Surface
Authors: Inai K. , Ohya K. , Kawamura G. , Tomita Y. 
Published: May 2010

AbstractTo estimate the reduction of the electron temperature at a sheath edge in the presence of secondary electron (SE) emission from tungsten (W) and beryllium (Be), we combined the ELECTRAN code, which calculates SE emission from metals, with a kinetic code that used a particle‐in‐cell (PIC) technique. Because the emitted electrons were accelerated toward the bulk plasma by the sheath electric field, the decrease of the effective temperature of electrons at the sheath edge was attributed to the lower sheath electric field. The electron yield for W (high‐Z) was higher than that for Be (low‐Z). SE emission decreased the sheath electric field. Therefore, the effective temperature of electrons for W is lower than that for Be (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dependency of Tritium Retention in Graphite on Temperature Control of Molecular Dynamics
Authors: Ito A. , Ohya K. , Inai K. , Nakamura H. 
Published: May 2010

AbstractWe have investigated the carbon plasma facing material and hydrogen atom interaction by the use of molecular dynamics simulation to clarify chemical erosion processes on divertor plate. The present paper is our first try at elucidation of temperature dependence by the molecular dynamics. Temperature was controlled by using Langevin thermostat method. As a result, the retention of hydrogen atom achieve steady state, and the CH4 was generated, which was not found MD simulations without a temperature control method. About 30 percent of injected hydrogen atoms are retained. CH4 yields has a peak at 600 K, which accords with experimental results. A dominant path of CH4 generation found by the present molecular dynamics simulation is as follows: a CH is detached from eroded surface and then it grows into CH4 adsorbing hydrogen atoms via CH2 and CH3. In addition, we propose the problem that the hydrogen atom retention and CH𝓍 yields depend on the thermal relaxation time in MD simulation using temperature control methods (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Enthalpy/Entropy Compensation in the Melting of Thermotropic Nitrogen‐Containing Chelating Ligands and Their Lanthanide Complexes: Successes and Failures
Authors: Escande Aude , Guénée Laure , Terazzi Emmanuel , Jensen Thomas B. , Nozary Homayoun , Piguet Claude 
Published: May 2010

AbstractIn this short overview dedicated to the thermodynamics of liquid crystalline chelating nitrogen‐containing ligands and their lanthanide complexes (i.e., lanthanidomesogens), we first go through the initial successes obtained with the introduction of the concept of enthalpy/entropy compensation for rationalizing and programming melting and clearing temperatures in thermotropic mesophases. In the second part, the failures encountered during our attempts for switching from a qualitative toward a quantitative interpretation of the melting processes in polycatenar lanthanidomesogens are discussed, together with the delicate correlations established between the thermodynamic parameters of intermolecular cohesion measured in noncoordinating solvents and those operating in pure mesophases.
Mesomerization of S4‐Symmetric Tetrahedral Chelate Complex [In4(L3)4]: First‐Time Monitored by Temperature‐Dependent 1H NMR Spectroscopy
Authors: Saalfrank Rolf W. , Maid Harald , Scheurer Andreas , Puchta Ralph , Bauer Walter 
Published: May 2010

AbstractVT 1H NMR spectroscopy proved that a non‐dissociative and reversible mesomerization process links the tetranuclear indium(III) complexes meso‐(Δ,Δ,Λ,Λ)(P,P,M,M)‐3 and meso‐(Λ,Λ,Δ,Δ)(M,M,P,P)‐3′. During this process four tandem Bailar twists, resulting in the (Δ)/(Λ) isomerization at the indium centers, and the (P)/(M) inversion of the four coordinating face‐centered, helical ligands (L3)3– are involved. In addition, gas‐phase DFT calculations (B3LYP/LANL2DZp) revealed a C1‐symmetric transition state (+21.9 kcal mol–1) for the mesomerization mechanism which connects 3 and 3′.
Microwave‐Enhanced Rhodium‐Catalyzed [2+2+2] Cycloaddition Reactions To Afford Highly Functionalized Pyridines and Bipyridines
Authors: Garcia Lídia , Pla‐Quintana Anna , Roglans Anna , Parella Teodor 
Published: May 2010

AbstractRhodium(I)‐catalyzed [2+2+2] cycloaddition reactions of N‐tosyl‐, carbon‐, and oxygen‐tethered cyanodiynes in a completely intramolecular fashion have been optimized to afford highly functionalized pyridines by conventional and/or microwave heating. Microwaves have been shown to enhance the process by allowing the reaction to be conducted effectively in short reaction times. The methodology has been extended for the synthesis of bipyridines, either by treating a cyanodiyne with an appended pyridine or by conducting a double [2+2+2] cycloaddition reaction on a dicyanotetrayne scaffold. The choice of the solvent in the microwave heating reaction has been shown to be crucial for the success of the process.
A Novel Polycatechol/Ordered Mesoporous Carbon Composite Film Modified Electrode and Its Electrocatalytic Application
Authors: Bai Jing , Bo Xiangjie , Qi Bin , Guo Liping 
Published: May 2010

AbstractPolycatechol (PCC) was prepared by electropolymerizing catechol (CC) on the surface of an ordered mesoporous carbon (OMC) modified electrode for the first time. Scanning electron microscopy (SEM) and cyclic voltammetry (CV) were used to characterize the structure and electrochemical behaviors of PCC/OMC nanocomposite film. Compared with the bare GC and OMC/GC electrodes, the PCC/OMC/GC electrode exhibits a good electrocatalysis toward the oxidation of NADH at 0.0 V with a high sensitivity (8.7 mA/mM). These make PCC/OMC/GC electrode a promising candidate for stable and efficient electrochemical sensors for the detection of NADH.
Electrocatalytic Performances of Pure and Mixed Hexacyanoferrates of Cu and Pd for the Reduction of Hydrogen Peroxide
Authors: Guadagnini Lorella , Giorgetti Marco , Tarterini Fabrizio , Tonelli Domenica 
Published: May 2010

AbstractA study on the performances of mixed hexacyanoferrates of Cu and Pd (CuPdHCFs), potentiodynamically grown on glassy carbon surfaces, was carried out. Morphological (SEM‐EDX analysis) and electrochemical characterizations were performed, and the electrocatalytic ability of films with various compositions was tested by chronoamperometry. CuPdHCFs were found to display good electrocatalytic performances, with a maximum sensitivity of 45.3 mA M−1 cm−2 at 0.0 V vs. SCE (depending on the Cu and Pd ratio), against the value of 9.1 mA M−1 cm−2 obtained with pure copper hexacyanoferrate (CuHCF). Additionally, mixed hexacyanoferrates showed a higher pH and operational stability. The key role of Cu in Cu‐based hexacyanoferrates was investigated and highlighted.
Stripping Voltammetry of Trace Metals at Bismuth‐Film Electrodes by Batch‐Injection Analysis
Authors: Economou Anastasios , Voulgaropoulos Anastasios 
Published: May 2010

AbstractIn this work, we explore the utility of batch‐injection analysis (BIA) for the determination of trace metals by stripping voltammetry utilising a bismuth‐film electrode (BiFE). This methodology is characterised by experimental simplicity, low cost, rapidity, versatility and low consumption of solutions. The BIA‐stripping voltammetry combination was applied to the determination of Cd(II), Pb(II), Zn(II) and In(III) by anodic stripping voltammetry (ASV) and of Ni(II), Co(II), U(VI) and Al(III) by adsorptive stripping voltammetry (AdSV). Different strategies using stripping voltammetry in combination with BIA have been investigated, such as the use of polymer‐coated BiFEs and the application of the “medium‐exchange” approach. The analytical usefulness of the methodology has been demonstrated for the analysis of real samples.
Porous Bismuth Film Electrodes for Signal Increase in Anodic Stripping Voltammetry
Authors: Urbanová Veronika , Bartoš Martin , Vytřas Karel , Kuhn Alexander 
Published: May 2010

AbstractThe hard sphere template approach has been used to elaborate highly porous bismuth film electrodes. These electrodes of controlled porosity show an increased internal electroactive area that can be used to enhance significantly the signals obtained for the detection of various metals like lead and cadmium by anodic stripping voltammetry. This leads to improved detection limits opening promising applications in the field of trace analysis.
Voltammetric Determination of Aliphatic Phthalate Esters at a Hanging Mercury Drop Minielectrode and a Meniscus Modified Silver Solid Amalgam Electrode
Authors: Qureshi Munawar Saeed , Fischer Jan , Barek Jiří , Sirajuddin  , Bhanger Muhammad Iqbal 
Published: May 2010

AbstractA new simple, fast and sensitive differential pulse voltammetric method was developed for the determination of different aliphatic phthalates. Dibutyl phthalate, diethyl phthalate, didecyl phthalate, and diallyl phthalate can be determined in 0.1 M tetramethylammonium bromide in methanol using a hanging mercury drop minielectrode and a meniscus modified silver solid amalgam electrode. Optimum conditions were found including concentration and composition of supporting electrolyte and solvent, scan rate, pulse amplitude, pulse width, etc. Linear calibration curves were obtained for 10−5 and 10−6 M and for hanging mercury drop minielectrode also for 10−7 M.
Depression and hypertension among Chinese nonagenarians and centenarians
Authors: Wen Zhao , Bi‐Rong Dong , Chang‐Quan Huang , Zhen‐Chan Lu , Yuan Zhuang , Hong‐Mei Wu , Yan‐Ling Zhang , Hui Wang , Ping He 
Published: May 2010

AbstractPurposeIn this study, we explored association between hypertension and depression in the very elderly using a sample ranged in age from 90 to 108 years.MethodsA cross‐sectional study.ResultsThe sample included 687 unrelated Chinese nonagenarians/centenarians (67.4% women, mean age 93.51 years). The mean depression score (measured with brief 23‐item geriatrics depression scale Chinese‐edition (GDS‐CD)) was 8.46 (standard deviation (SD) 3.33 range 0–20). There was no significant difference in depression scores between subjects with and without hypertension and there was also no significant difference in depression prevalence between subjects with and without hypertension. There was no significant difference in prevalence of hypertension between subjects with and without depression and there were also no significant differences in levels of arterial blood pressure (including SBP and DBP). Neither odd ratio (OR) of depression as a function of increased hypertension nor OR of hypertension as a function of increased depression was significant.ConclusionsIn summary, we found that depression was not directly correlated with hypertension among Chinese nonagenarians and centenarians. Copyright © 2010 John Wiley & Sons, Ltd.