cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.11578/1562098
title: TRANSP-based Optimization Towards Tokamak Scenario Development

description: An optimization approach that incorporates the predictive transport code TRANSP is proposed for tokamak scenario development. Optimization methods are often employed to develop open-loop control strategies to aid access to high performance tokamak scenarios. In general, the optimization approaches use control-oriented models, i.e. models that are reduced in complexity and prediction accuracy as compared to physics-oriented transport codes such as TRANSP. In the presented approach, an optimization procedure using the TRANSP code to simulate the tokamak plasma is considered for improved predictive capabilities. As a test case, the neutral beam injection (NBI) power is optimized to develop a control strategy that maximizes the non-inductive current fraction during the ramp-up phase for NSTX-U. Simulation studies towards the achievement of non-inductive ramp up in NSTX-U have already been carried out with the TRANSP code. The optimization-based approach proposed in this work is used to maximize the non-inductive current fraction during ramp-up in NSTX-U, demonstrating that the scenario development task can be automated. An additional test case considers optimization of the current ramp rate in DIII-D for obtaining a stationary plasma characterized bya flat loop voltage profile in the flattop phase.
DOI: 10.11578/1562099
title: Application of transient CHI plasma startup to future ST and AT devices

description: Employment of non-inductive plasma start-up techniques would considerably simplify the design of a spherical tokamak fusion reactor. Transient coaxial helicity injection (CHI) is a promising method, expected to scale favorably to next-step reactors. However, the implications of reactor-relevant parameters on the initial breakdown phase for CHI have not yet been considered. Here, we evaluate CHI breakdown in reactor-like configurations using an extension of the Townsend avalanche theory. We find that a CHI electrode concept in which the outer vessel wall is biased to achieve breakdown, while previously successful on NSTX and HIT-II, may exhibit a severe weakness when scaled up to a reactor. On the other hand, concepts which employ localized biasing electrodes such as those used in QUEST would avoid this issue. Assuming that breakdown can be successfully attained, we then apply scaling relationships to predict plasma parameters attainable in the transient CHI discharge. Assuming the use of 1 Wb of injector flux, we find that plasma currents of 1 MA should be achievable. Furthermore, these plasmas are expected to Ohmically self-heat with more than 1 MW of power as they decay, facilitating efficient hand-off to steady-state heating sources. These optimistic scalings are supported by TSC simulations.
DOI: 10.11578/1562100
title: ELM frequency enhancement and discharge modification through lithium granule injection into EAST H-modes

description: The injection of impurity granules into fusion research discharges can serve as a catalyst for ELM events. For sufficiently low ELM frequencies, and granule sizes above a threshold, this can result in full control of the ELM cycle, referred to as ELM pacing. For this research, we extend the investigation to conditions where the natural ELM frequency is too high for ELM pacing to be realized. Utilizing multiple sizes of lithium granules and classifying their effects by granule size, we demonstrate that ELM mitigation through frequency multiplication can be used at ELM triggering rates that nominally make ELM pacing unrealizable. We find that above a size threshold, injected granules promptly trigger ELMs and commensurately enhance the ELM frequency . Below this threshold size, injection of an individual granule does not always lead to the prompt triggering of an ELM; however, collective ablation in the edge pedestal region does enhance the ELM frequency. Specifically, Li granules too small to individually trigger ELMs were injected into EAST H-mode discharges at frequencies up to 2.3 kHz; collectively the granules were observed to enhance the natural ELM frequency up to 620 Hz, resulting in a ~2.4x multiplication of the natural ELM frequency and a 50% decrease of the ELM size.
DOI: 10.11578/1562101
title: Quasioptical modeling of wave beams with and without mode conversion: II. Numerical simulations of single-mode beams

description: This work continues a series of papers where we propose an algorithm for quasioptical modeling of electromagnetic beams with and without mode conversion. The general theory was reported in the first paper of this series, where a parabolic partial differential equation was derived for the field envelope that may contain one or multiple modes with close group velocities. Here, we present a corresponding code PARADE (PAraxial RAy DEscription) and its test applications to single-mode beams in vacuum and also in inhomogeneous magnetized plasma. The numerical results are compared, respectively, with analytic formulas from Gaussian-beam optics and also with cold-plasma ray tracing. Quasioptical simulations of mode-converting beams are reported in the next, third paper of this series.
DOI: 10.11578/1562102
title: Electron inertial effects on linearly polarized electromagnetic ion cyclotron waves at Earth's magnetosphere

description: We discuss a role of the electron inertial effect on linearly polarized electromagnetic ioncyclotron (EMIC) waves at Earth. The linearly polarized EMIC waves have been previouslysuggested to be generated via mode conversion from the fast compressional wave at the ion-ionhybrid (IIH) resonance. When the electron inertial effects are neglected, the wave normal angleof the mode-converted IIH waves is 90 degrees because the wavevector perpendicular to themagnetic field becomes infinite at the IIH resonance. When the electron inertial effect isconsidered, the mode-converted IIH waves can propagate across the magnetic field lines and thewavelength perpendicular to the magnetic field approaches the electron inertial length scale nearthe Buchsbaum resonance. These waves are referred to as electron inertial waves. Due to theelectron inertial effect, the perpendicular wavenumber to the ambient magnetic field near theIIH resonance remains finite and the wave normal angle is less than 90 degrees. The wave normalangle where the maximum absorption occurs in a dipole magnetic field is 30-80 degrees, whichis consistent with the observed values near the magnetic equator. Therefore, the numericalresults suggest that the linearly polarized EMIC wave generated via mode conversion near theIIH resonance can be detected in between the Buchsbaum and the IIH resonance frequencies,and these waves can have normal angle less than 90 degrees.
DOI: 10.11578/1562103
title: Verification of the global gyrokinetic stellarator code XGC-S for linear ion temperature gradient driven modes

description: XGC (X-point Gyrokinetic Code) is a whole-volume, total-f gyrokinetic particle-in-cell code developed for modelling tokamaks.In recent work, XGC has been extended to model more general 3D toroidal magnetic configurations, such as stellarators.These improvements have resulted in the XGC-S version.In this paper, XGC-S is benchmarked in the reduced delta-f limit for linear electrostatic ion temperature gradient-driven microinstabilities, which can underlie turbulent transport in stellarators.An initial benchmark of XGC-S in tokamak geometry shows good agreement with the XGC1, ORB5, and global GENE codes.A benchmark between XGC-S and the EUTERPE global gyrokinetic code for stellarators has also been performed, this time in geometry of the optimised stellarator Wendelstein 7-X.Good agreement has been found for the mode number spectrum, mode structure, and growth rate.
DOI: 10.11578/1562104
title: Comment on 'Numerical modeling of tokamak breakdown phase driven by pure Ohmic heating under ideal conditions'

description: In this comment, we point out possible critical numerical flaws of recent particle simulation studies (Jiang et al 2016 Nucl. Fusion 56 126017, Peng et al 2018 Nucl. Fusion 58 026007) on the electrical gas breakdown in a simple one-dimensional periodic slab geometry. We show that their observations on the effects of the ambipolar electric fields during the breakdown, such as the sudden reversal of the ion flow direction, could not be real physical phenomena but resulting from numerical artifacts violating the momentum conservation law. We show that an incomplete implementation of the direct-implicit scheme can cause the artificial electric fields and plasma transports resulting in fallacies in simulation results. We also discuss that their simple plasma model without considering poloidal magnetic fields seriously mislead the physical mechanism of the electrical gas breakdown because it cannot reflect important dominant plasma dynamics in the poloidal plane (Yoo et al 2018 Nat. Commun. 9 3523).
DOI: 10.11578/1562105
title: Nonlinear saturation and oscillations of collisionless zonal flows

description: In homogeneous drift-wave (DW) turbulence, zonal flows (ZFs) can be generated via a modulational instability (MI) that either saturates monotonically or leads to oscillations of the ZF energy at the nonlinear stage. This dynamics is often attributed as the predator-prey oscillations induced by ZF collisional damping; however, similar dynamics is also observed in collisionless ZFs, in which case a different mechanism must be involved. Here, we propose a semi-analytic theory that explains the transition between the oscillations and saturation of collisionless ZFs within the quasilinear Hasegawa-Mima model. By analyzing phase-space trajectories of DW quanta (driftons) within the geometrical-optics (GO) approximation, we argue that the parameter that controls this transition is N ~ \gamma_MI/\omega_DW, where \gamma_MI is the MI growth rate and \omega_DW is the linear DW frequency. We argue that at N &lt;&lt; 1, ZFs oscillate due to the presence of so-called passing drifton trajectories, and we derive an approximate formula for the ZF amplitude as a function of time in this regime. We also show that at N &gt;~ 1, the passing trajectories vanish and ZFs saturate monotonically, which can be attributed to phase mixing of higher-order sidebands. A modification of N that accounts for effects beyond the GO limit is also proposed. These analytic results are tested against both quasilinear and fully-nonlinear simulations. They also explain the earlier numerical results by Connaughton et al. [J. Fluid Mech. 654, 207 (2010)] and Gallagher et al. [Phys. Plasmas 19, 122115 (2012)] and offer a revised perspective on what the control parameter is that determines the transition from the oscillations to saturation of collisionless ZFs.
DOI: 10.11578/1562106
title: Formation of solitary zonal structures via the modulational instability of drift waves

description: {\rtf1\ansi\ansicpg1252\cocoartf1561\cocoasubrtf600{\fonttbl\f0\fswiss\fcharset0 Helvetica;}{\colortbl;\red255\green255\blue255;\red0\green0\blue0;}{\*\expandedcolortbl;;\cssrgb\c0\c0\c0;}\margl1440\margr1440\vieww10800\viewh8400\viewkind0\pard\tx887\tx1775\tx2662\tx3550\tx4438\tx5325\tx6213\tx7101\tx7988\tx8876\tx9764\tx10651\tx11539\tx12427\tx13314\tx14202\tx15090\tx15977\tx16865\tx17753\tx18640\tx19528\tx20416\tx21303\tx22191\tx23079\tx23966\tx24854\tx25742\tx26629\tx27517\tx28405\tx29292\tx30180\tx31067\tx31955\tx32843\tx33730\tx34618\tx35506\tx36393\tx37281\tx38169\tx39056\tx39944\tx40832\tx41719\tx42607\tx43495\tx44382\tx45270\tx46158\tx47045\tx47933\tx48821\tx49708\tx50596\tx51484\tx52371\tx53259\tx54147\tx55034\tx55922\tx56810\tx57697\tx58585\tx59472\tx60360\tx61248\tx62135\tx63023\tx63911\tx64798\tx65686\tx66574\tx67461\tx68349\tx69237\tx70124\tx71012\tx71900\tx72787\tx73675\tx74563\tx75450\tx76338\tx77226\tx78113\tx79001\tx79889\tx80776\tx81664\tx82552\tx83439\tx84327\tx85215\tx86102\tx86990\tx87877\tx88765\slleading20\pardirnatural\partightenfactor0\f0\fs38 \cf2 The dynamics of the radial envelope of a weak coherent drift wave is approximately governed by a nonlinear Schr\'f6dinger equation, which emerges as a limit of the modified Hasegawa\'97Mima equation. The nonlinear Schr\'f6dinger equation has well-known soliton solutions, and its modulational instability can naturally generate solitary structures. In this paper, we demonstrate that this simple model can adequately describe the formation of solitary zonal structures in the modified Hasegawa\'97Mima equation, but only when the amplitude of the coherent drift wave is relatively small. At larger amplitudes, the modulational instability produces stationary zonal structures instead. Furthermore, we find that incoherent drift waves with beam-like spectra can also be modulationally unstable to the formation of solitary or stationary zonal structures, depending on the beam intensity. Notably, we show that these drift waves can be modeled as quantumlike particles (\'93driftons\'94) within a recently developed phase-space (Wigner\'97Moyal) formulation, which intuitively depicts the solitary zonal structures as quasi-monochromatic drifton condensates. Quantumlike effects, such as diffraction, are essential to these condensates; hence, the latter cannot be described by wave-kinetic models that are based on the ray approximation.\}
DOI: 10.11578/1562107
title: Quasioptical modeling of wave beams with and without mode conversion: III. Numerical simulations of mode-converting beams

description: This work continues a series of papers where we propose an algorithm for quasioptical modeling of electromagnetic beams with and without mode conversion. The general theory was reported in the first paper of this series, where a parabolic partial differential equation was derived for the field envelope that may contain one or multiple modes with close group velocities. In the second paper, we presented a corresponding code PARADE (PAraxial RAy DEscription) and its test applications to single-mode beams. Here, we report quasioptical simulations of mode-converting beams for the first time. We also demonstrate that PARADE can model splitting of two-mode beams. The numerical results produced by PARADE show good agreement with those of one-dimensional full-wave simulations and also with conventional ray tracing (to the extent that one-dimensional and ray-tracing simulations are applicable).
DOI: 10.21227/5fva-nt27
title: Paper as Substrate for Optogenetic μ­ILED Devices

description: One of the materials that is commonly beingused in electronics applications is paper. It isflexible, cheap, highly available, and allows forsimple manufacturing when paired with methodssuch as screen printing or inkjet printing. Proposedbelow is an optogenetic device that uses paper as thesole substrate, with a screen­printed PCB withAg/AgCl wires. This device was quick and easy tomanufacture, unlike the state of the artoptoelectronic devices that use polymers and rely oncomplex fabrication methods such asphotolithography. Resistivity tests that includedbending and folding of the PCBs have shown thatthe paper­based circuits are flexible, conductive, androbust. The Ag/AgCl wires were able to deliversufficient power to light an LED without the need toincrease voltage input above what is required whendirectly supplying power to the LED. Overall, thisdesign is established as a feasible option for anoptoelectronic device that could be readily made inbulk without using the costly materials or fabricationmethods.
DOI: 10.21227/vayq-m031
title: Paper as Substrate for Optogenetic μ­ILED Devices

description: One of the materials that is commonly beingused in electronics applications is paper. It isflexible, cheap, highly available, and allows forsimple manufacturing when paired with methodssuch as screen printing or inkjet printing. Proposedbelow is an optogenetic device that uses paper as thesole substrate, with a screen­printed PCB withAg/AgCl wires. This device was quick and easy tomanufacture, unlike the state of the artoptoelectronic devices that use polymers and rely oncomplex fabrication methods such asphotolithography. Resistivity tests that includedbending and folding of the PCBs have shown thatthe paper­based circuits are flexible, conductive, androbust. The Ag/AgCl wires were able to deliversufficient power to light an LED without the need toincrease voltage input above what is required whendirectly supplying power to the LED. Overall, thisdesign is established as a feasible option for anoptoelectronic device that could be readily made inbulk without using the costly materials or fabricationmethods.
DOI: 10.5281/zenodo.3424770
title: Data of "Effects of core electron temperature on the competing processes of whistler and electrostatic instabilities in a beam plasma"

description: Data of simulation output for "Effects of core electron temperature on the competing processes of whistler and electrostatic instabilities in a beam plasma", including wave field, energy, temperature and particle phase density.
DOI: 10.5281/zenodo.3424771
title: Data of "Effects of core electron temperature on the competing processes of whistler and electrostatic instabilities in a beam plasma"

description: Data of simulation output for "Effects of core electron temperature on the competing processes of whistler and electrostatic instabilities in a beam plasma", including wave field, energy, temperature and particle phase density.
DOI: 10.17632/d698f2889k.4
title: Data for: Enhanced production of ethyl acetate using co-culture of Wickerhamomyces anomalus and Saccharomyces cerevisiae

description: Reasearch data for this study.
DOI: 10.21227/9eyv-dm09
title: Paper as Substrate for Optogenetic μ­ILED Devices

description: One of the materials that is commonly being used in electronics applications is paper. It is flexible, cheap, highly available, and allows for simple manufacturing when paired with methods such as screen printing or inkjet printing. Proposed below is an optogenetic device that uses paper as the sole substrate, with a screen­printed PCB with Ag/AgCl wires. This device was quick and easy to manufacture, unlike the state of the art optoelectronic devices that use polymers and rely on complex fabrication methods such as photolithography. Resistivity tests that included bending and folding of the PCBs have shown that the paper­based circuits are flexible, conductive, and robust. The Ag/AgCl wires were able to deliver sufficient power to light an LED without the need to increase voltage input above what is required when directly supplying power to the LED. Overall, this design is established as a feasible option for an optoelectronic device that could be readily made in bulk without using the costly materials or fabrication methods.
DOI: 10.21227/e01k-q091
title: Power Density Modification Options on Paper Based Microbial Fuel cell

description: Microbial fuel cells (MFC) are one of the best sources of renewable energy but the power density achieved till now is not enough for present as well as future application purpose. Recent research gives us hope that a high amount of power density can be achieved by doing various modifications at different functional levels on the paper based MFC. This literature survey shows various modifications which are done in Microbial Fuel Cells till now such as improvement in Anode, Cathode and Proton Exchange Membrane, stacking that can be implemented in Paper based Microbial Fuel Cell to improve the power density. We think this survey helps people to understand what research is currently going on for MFC and how high power can be achieved from MFC.
DOI: 10.21227/hbee-nn97
title: Power Density Modification Options on Paper Based Microbial Fuel cell

description: Microbial fuel cells (MFC) are one of the best sources of renewable energy but the power density achieved till now is not enough for present as well as future application purpose. Recent research gives us hope that a high amount of power density can be achieved by doing various modifications at different functional levels on the paper based MFC. This literature survey shows various modifications which are done in Microbial Fuel Cells till now such as improvement in Anode, Cathode and Proton Exchange Membrane, stacking that can be implemented in Paper based Microbial Fuel Cell to improve the power density. We think this survey helps people to understand what research is currently going on for MFC and how high power can be achieved from MFC.
DOI: 10.5281/zenodo.3416054
title: Dataset related to article: "Accuracy of Humanitas Ultrasound Criteria in Assessing Disease Activity and Severity in Ulcerative Colitis: A Prospective Study"

description: This record contains raw data related to article: "Accuracy of Humanitas Ultrasound Criteria in Assessing Disease Activity and Severity in Ulcerative Colitis: A Prospective Study". Colonoscopy [CS] is the standard for assessing disease activity in ulcerative colitis [UC], although invasive and poorly tolerated. Bowel ultrasound [BUS] may be a valid alternative in UC patients; however, the comparative accuracy between BUS and CS is unknown. Methods: Consecutive patients with UC were prospectively assessed by CS and BUS. Colonic wall thickening [CWT &gt;3 mm], colonic wall flow at power Doppler [CWF], colonic wall pattern [CWP], and presence of lymph nodes evaluated at BUS were compared with CS. The endoscopic activity was assessed according to the Mayo endoscopic sub-score [0-3]. All BUS investigations were performed by two independent gastroenterologists and the kappa statistic for agreement was calculated. Ultrasonography-based criteria (Humanitas Ultrasound Criteria [HUC]) were developed. Results: A total of 53 UC patients [56% with left-sided colitis, 19% with pancolitis] were prospectively enrolled. Of these, 22 patients had mucosal healing [Mayo endoscopic sub-score 0-1] and 31 patients were in endoscopic activity. CWT, CWF, hypoechogenic CWP and the presence of lymph nodes significantly correlated with endoscopic activity [p &lt; 0.05]. CWT [p = 0.01] and CWF [p = 0.09] were independent predictors for endoscopic activity. The HUC developed are: [i] the presence of a CWF and CWT &gt; 3 mm; or [ii] the absence of a CWF and CWT &gt; 4.43 mm. They showed high accuracy for the detection of disease activity [sensitivity 0.71, specificity 1.00]. The interobserver agreement for BUS was excellent [kappa 0.86]. Conclusions: BUS is a non-invasive, easy-to-use tool to manage UC patients in clinical practice. HUC were very accurate in assessing disease activity in UC patients.