Miracle-dz/UniFAR-FTUs huggingface dataset:
Comparison of MHD-induced rotation damping with NTV predictions on MAST

Plasma rotation in tokamaks is of special interest for its potential stabilizing effect on micro- and macro-instabilities, leading to increased confinement. In MAST, the torque from neutral beam injection can spin the plasma to a core velocity ∼300 km s−1 (Alfvén Mach number ∼0.3). Low density plasmas often exhibit a weakly non-monotonic safety factor profile just above unity. Theory predicts that such equilibria are prone to magneto-hydro-dynamic (MHD) instabilities, which was confirmed by recent observations. The appearance of the mode is accompanied by strong damping of core rotation on a timescale much faster than the momentum confinement time. The mode's saturated structure is estimated using the CASTOR code together with soft x-ray measurements, enabling the calculation of the plasma braking by the MHD mode according to neoclassical toroidal viscosity (NTV) theory. The latter exhibits strong similarities with the torque measured experimentally.
Numerical simulations of the effect of hydrodynamic interactions on diffusivities of integral membrane proteins

Proteins in a biological membrane can be idealized as disks suspended in a thin viscous sheet surrounded by a fluid of lower viscosity (Saffman 1976). To determine the effect of hydrodynamic interactions on protein diffusivities in non-dilute suspensions, we numerically solve the Stokes equations of motion for a system of disks in a bounded periodic two-dimensional fluid using a multipole expansion technique. We consider both free suspensions, in which all the proteins are mobile, and fixed beds, in which a fraction of the proteins are fixed. For free suspensions, we determine both translational and rotational short-time self-diffusivities and the gradient diffusivity as a function of the area fraction of the disks. The translational self- and gradient diffusivities computed in this way grow logarithmically with the number of disks owing to Stokes paradox; to obtain finite values, we renormalize our simulation results by treating long-range interactions in terms of a membrane with an enhanced viscosity in contact with a low-viscosity three-dimensional fluid. The diffusivities in fixed beds require no such adjustment because, at non-dilute area fractions of disks, the Brinkman screening of hydrodynamic interactions is more important that the viscous drag due to the surrounding three-dimensional fluid in limiting the range of hydrodynamic interactions. The diffusivities are determined as functions of the area fractions of both mobile and fixed proteins. We compare our results for diffusivities with experimental measurements of long-time protein self-diffusivity after adjusting our short-time diffusivities calculations in an approximate way to account for effects of hindered diffusion due to volume exclusion, and find very good agreement between the two.
Elimination of hydrogen‐related instabilities in Si/SiO2 structures by fluorine implantation

In this study we have investigated the effect of fluorination on the electrical properties of the Si/SiO2/Al system, including their degradation. Fluorine was introduced by ion implantation into the gate oxide with doses ranging from 109–1015 cm−2. Study of the electron and hole trapping properties of the as‐fabricated system showed that water‐related electron traps and hole traps with small cross section are removed after introduction of fluorine. Hole traps with large cross section related to oxygen vacancies are not affected. Fluorination also suppresses generation of donor‐type interface states and of oxide electron traps generated by vacuum ultraviolet irradiation. The data indicate that the involvement of fluorine is mostly of a catalytic nature. It is proposed that the post‐metallization anneal in the presence of fluorine promotes the elimination of hydrogen available for radiolysis.
Do magnetized winds self-collimate?

We discuss the asymptotic behaviour of steady, axisymmetric, non-relativistic, polytropic, perfect magnetohydrodynamic (MHD) winds from rotating magnetized bodies, which have passed smoothly through three critical surfaces. A quantity defined by ζ≡αρϖ2/η plays a crucial role in the asymptotic domain far from the Alfvenic surface. Here α is the angular velocity of field lines, η is the mass flux per unit flux tube and ρ is the mass density. In general, ζ is a function of the magnetic stream function P and the distance s measured along each field line. In the asymptotic domain, ϖBt≈−ζ and the electric current parallel to the poloidal field is j∥∝−(∂ζ/∂P)sBp, while the perpendicular one is j⊥∝−∂ζ/∂s)P. Also ζ(P,s) as a function of s measures the change of the Poynting energy flow along a given field line and as a function of P measures the total electric current passing within the surface of revolution defined by P and with s fixed. The asymptotic transfield equation reduces to ρvp2/R≈j∥Bt/c, where R is the curvature radius of poloidal field lines. This equation indicates that when viewed from the rotation-axis side, the field geometry is convex (R>0) in the range of field lines with ingoing current (j∥ 0), with a straight, ‘neutral’ field line Pn separating both ranges. For particles to be accelerated by the magnetic stress in both poloidal and toroidal directions, one requires j⊥>0, i.e. (∂ζ/∂s)P<0. When ζ diminishes like ζ∝1/lns with no Poynting flux carried to infinity, an ‘exact’causal solution of the transfield equation shows a quasi-radial structure in the asymptotic domain. If the wind zones in both hemispheres have a convex geometry with j∥ 0 and Bt>0 in the lower, there must exist a large equatorial sheet current that balances the inflow of charges in the wind zones. The conical or cylindrical structure in the whole asymptotic domain, consisting of magnetic surfaces on which finite Poynting flux is carried to infinity with j∥=j⊥=0, imposes severe, probably acausal constraints on the structure in the subasymptotic domains upstream. In summary, the condition of current closure, together with causality, taken into account will not allow all the open field lines emanating from a central object with a realistic source field to bend toward the axis as suggested previously. It is argued that almost all previously developed models or processes claiming magnetic collimation are unsatisfactory with respect to causality and the current-closure condition. Thus magnetized winds as a whole will not collimate the rotation axis without any external help, such as the channelling effects of thick accretion discs and/or confinement resulting from the ambient medium.
Left-distributive quasi-groups

is left-distributive. Such quasigroups arise in various contexts, e.g., groups furnished with an automorphism leaving only the unit fixed [3] [5], totally symmetric quasigroups and Moufang loops [1], and conics [2; 4]. Also a left-distributive quasigroup has an orthogonal complement. Specifically, for aCS define the quasigroup o on S by x o y=x? (a0y). Then 0 is orthogonal to o. In [4] it is shown that there are no left-distributive quasigroups of order 4k+2. It will now be shown that left-distributive quasigroups are intimately connected with the binary operation of conjugation in a group.
Thermal conductivity of tubular and core/shell nanowires

Analytical solution of the Boltzmann transport equation (BTE) for phonon transport in tubular and core-shell nanowire is obtained. Thermal conductivity calculated from the analytical solution of BTE is in excellent agreement with a recently reported numerical model [R. Yang et al., Nano Lett. 5, 1111 (2005)]. Results show that thermal conductivity of tubular and core-shell nanowire can be significantly smaller than the bulk thermal conductivity.
Improving Short-Term Numerical Weather Prediction in the California Coastal Zone by Dynamic Initialization of the Marine Boundary Layer

Abstract Few data are available over the world’s oceans to characterize the initial atmospheric state in numerical models. Objective analysis in these regions is largely based on forecast fields obtained from a global model and used as the background (“first guess”). Unfortunately, global models often do not resolve the marine boundary layer (MBL) structure, which is important for simulating stratus clouds, coastal zone circulations, and electromagnetic wave propagation. Furthermore, initialization of the MBL in the coastal zone and data-sparse oceanic regions poses a challenging mesoscale modeling problem. The goal of this study, therefore, is to improve warm-season short-term mesoscale numerical prediction of California coastal zone meteorology by improving the model initial conditions in the coastal zone and offshore data-void regions. Initialization strategies tested include standard static and dynamic techniques and a new marine boundary layer initialization scheme that uses a dynamic initialization .
Simulated annealing approach to the max cut problem

In this paper we address the problem of partitioning the nodes of a random graph into two sets, so as to maximize the sum of the weights on the edges connecting nodes belonging to different sets. This problem has important real-life counterparts, but has been proven to be NP-complete. As such, a number of heuristic solution techniques have been proposed in literature to address this problem. We propose a stochastic optimization technique, simulated annealing, to find solutions for the max cut problem. Our experiments verify that good solutions to the problem can be found using this algorithm in a reasonable amount of time.
Charge balance and photon collection in polymer based ternary bulk heterojunction photovoltaic devices containing cadmium selenide nanoparticles

Solar cells employing a ternary bulk heterojunction active layer comprised of poly(3-hexylthiophene) (P3HT), 6,6-phenyl C61-butyric acid methyl ester (PCBM) doped with composites constructed from a combination of 2.5 nm CdSe nanoparticles (NP), and methyl viologen (MV) have been examined. It was found that the devices containing the CdSe NP/MV composite exhibit significantly more photocurrent in a region surrounding the absorption peak of the particles (560-660 nm) when compared to pristine P3HT:PCBM devices. For a low ratio of CdSe to PCBM, the photocurrent collection was accompanied by space charge build up that limited the performance of the devices. When the ratio of CdSe to PCBM was raised, the space charge dissipated and performance recovered. JV curve shape analysis suggests that charge balance was achieved; however, electrode selectivity was reduced.
Analytical treatment of polarization-mode dispersion in single-mode fibers by means of the backscattered signal

We present analytical results on the polarization-mode dispersion characteristics of single-mode birefringent fibers based on statistical properties of the backscattered signal. In particular, we calculate exactly the relationship between polarization-mode dispersion characteristics in forward propagation with respect to round-trip propagation in terms of dynamical equations, differential group delays, correlation lengths, and second-order effects. The theory applies to fibers affected by superposition of linear and circular birefringence in both the short-length and the long-length regimes.
Methods for Quantitative Risk Assessment Using Occupational Studies

Abstract Although carcinogenic risk assessment is frequently based on animal bioassay data, occupational studies are generally considered the best source of data for quantitative risk estimation. The model selected for use with occupational study data is required to extrapolate on age, exposure level, and temporal exposure pattern. Relative and absolute risk models are examined, as are alternatives for the definition of a dose (exposure) variable. The models express disease incidence as a function of the chosen exposure variable and convert incidence into estimates of lifetime risk. In this form, predictions of the models can be compared. The methods are illustrated using three examples: arsenic exposure and respiratory cancer, leukemia associated with benzene exposure, and asbestos-induced mesothelioma.
Adjusting the characteristic deviations of guided-mode resonant filters using the cover layer

One method of adjusting the characteristic deviations of Guided mode resonant filters (GMRFs) induced by preparing errors is derived by using the cover layer of GMRFs. The investigations of GMRFs are reported widely for their merits such as high efficiency, narrow bandwidth and low sideband. But there are few reports about the preparation and commercial application of GMRFs. The reason for this is that the characteristics of GMRFs are strict with the error of preparation. The data of this paper shows the linear relationship between the grating depth and the resonant wavelength in the grating depth error range of 0-12 nm. It is shown that the cover layer of GMRFs has adjusting effect on the characteristics of GMRFs. Through choosing material and adjusting the thickness of cover layer, these deviations induced by preparing errors cay be adjusted perfectly.
Failure rate — a unified approach

Aging, of biological and mechanical systems, is well described as ‘deterioration of the power to withstand destruction. ’ The failure-rate concept is the mathematical way of describing aging. Failure rates have been defined for discrete and continuous time and used extensively, particularly in actuarial science and reliability. This paper assumes an arbitrary scale on which an object encounters stress, and develops a theory of failure rate with respect to ‘stress-time’ in analogy with the discrete- and continuous-time cases.
Sensor communication technology towards ambient intelligence

This paper is a review of the fascinating development of sensors and the communication of sensor data. A brief historical introduction is given, followed by a discussion on architectures for sensor networks. Further, realistic specifications on sensor devices suitable for ambient intelligence and ubiquitous computing are given. Based on these specifications, the status and current frontline development are discussed. In total, it is shown that future technology for ambient intelligence based on sensor and actuator devices using standardized Internet communication is within the range of possibilities within five years.
Numerical and experimental determination of ionizing front velocity in a DC point-to-plane corona discharge

The present work is devoted to the comparison between numerical and experimental determination of the velocity profile of an ionizing front (primary streamer) in a DC positive point-to-plane corona discharge in dry air at atmospheric pressure. The inception and propagation of the ionizing front is simulated by a one-dimensional model, using finite differences in a flux-corrected transport numerical scheme, including gamma -effects, and using experimental results concerning the swarm parameters. This model provides the spatio-temporal local field and charge density variations as well as the ionization front velocity. An optical measurement of the velocity is performed with the same discharge parameters, using a photomultiplier and a single-slit device. The technique is based on the experimental fact that, for a 1 cm gap in the 7-9 kV voltage range, the successive primary streamers corresponding to a given gap voltage display identical velocity profiles. As a result of the comparison, it appears that a precise coupling between simulation and experiment is possible. There is a voltage range (8-9 kV) within which good agreement is observed. The front velocity in most of the gap is about 2*107 cm s-1 and the profile presents an increase when the streamer leaves the point electrode and when it reaches the cathode. The possible mechanisms of these accelerations are discussed. The model may be applied to a large variation range for various parameters such as the nature of the gas, pressure, inter-electrode gap and curvature radius of the active electrode.
Consensus problems in continuous-time with time-varying communication delays

Abstract In this paper, we study a consensus problem of continuous time multi-agent system. Multi-agent system has communication network. Each agent gets information of neighbors to achieve consensus. It is assumed that there are delays in communication network. The communication delays are different every communication channels and time-dependent. Furthermore, it is assumed that there are switching topologies and feed-back gains are time variable. Under these assumptions, we show that the entire system is stable. The stability is shown by Lyapunov theorem.
Ionospheric plasma flow over large high-voltage space platforms. II: The formation and structure of plasma wake

Theory and particle simulation results are presented for ionospheric plasma flow over large high‐voltage space platforms at a large angle of attack. Both the transient formation of the space‐charge wake and its steady‐state structure are studied. The wake‐side ion impact and current collection are obtained. It is found that the wake behind a high‐voltage plate is characterized by two ion‐rich sheaths embedded in a quasineutral background wake. The embedded sheath is formed by the ions passing through the sheath around the plate edge and serves as their trajectory path. Depending on the surface potential, the plate dimension, and the angle of attack, the embedded sheath may either extend downstream or curve back to form a ‘‘hook’’ structure. As a result, the plate’s wake‐side surface may receive a high, localized ion flux at the location the embedded sheath strikes.
A Rotated Eigenanalysis of the Correlation between 700 mb Heights and Sea Surface Temperatures in the Pacific and Atlantic

Abstract Associations between Pacific and Atlantic sea surface temperature (SST) and the 700 mb circulation were studied using 30 years (1949-78) of gridded monthly data. The monthly data were grouped into four (nonstandard) seasons for the analysis. The linear correlation between the two fields (SST and 700 mb heights) was analyzed by finding the eigenvalue solution of the mean product matrix of the cross correlations. This technique, introduced by Prohaska, was modified through the use of a varimax rotation. The result is a set of pairs of patterns (one pattern for each medium) which explains part of the linear correlation between the two fields. The number of significant modes (pairs) was determined by a Monte Carlo simulation. One well-known atmospheric teleconnections pattern, referred to as the Pacific/North American (PNA) pattern by Wallace and Gutzler, was found in all seasons; however, seasonal differences were noted. During the warm season, the PNA pattern manifests itself as the Great Plains (G.
Iron K Emission Lines in the Energy Spectra of Low-Mass X-Ray Binaries Observed with ASCA

ASCA archive data of 20 low-mass X-ray binaries (LMXBs) were analyzed to study the iron K emission lines. The LMXBs analyzed here include Z sources, atoll sources, dippers, bursters, and ADC (accretion disk corona) sources. We paid particular attention to reducing systematic errors for the estimation of line parameters, and the combination of SIS and GIS, which have different energy resolutions, was found to be very useful for this purpose. We detected significant iron lines from about one-half of the sources. The line center was 6.56 keV on average, and a finite width of ∼0.5 keV (FWHM) was obtained from six sources; these properties may be common to LMXBs. On the other hand, equivalent width (EW) of the lines showed large scatter among the sources, from less than 10 to 170 eV. These line parameters do not show any correlation with the source categories or luminosities. The iron K lines from LMXBs are likely produced through the radiative recombination of photoionized plasma. We discuss the origin of the line width, which may result from the combination of the line blending, Doppler broadening, and Compton scattering.
A ‘stick-slip’ problem related to the motion of a free jet at low Reynolds numbers

A problem in fluid mechanics which has received some attention recently concerns the emergence of an incompressible Newtonian fluid jet from a uniform tube into an inviscid atmosphere. Both the axisymmetric case of a circular tube and the two-dimensional case of flow from between parallel planes are of interest. When the jet falls vertically under gravity, the motion far downstream is dominated by gravity and the expansion procedures of Clarke (3), and Kaye and Vale (10) give details of the flow in this region. When the flow near the exit is at a high Reynolds number, it is reasonable to expect the flow appropriate to that in an infinite tube to prevail right up to the exit (except, perhaps, near the point of discontinuity of the boundary conditions). With this assumption, Duda and Vrentas(5) use a numerical technique to solve for the flow in the axisymmetric jet beyond the exit, both with and without gravity acting in the axial direction. In the absence of gravity, the jet can be expected to attain a constant width some distance downstream, and at high Reynolds numbers the above assumption is sufficient to allow a mass and momentum balance to determine the contraction ratio of the jet as for the axisymmetric case, and for the two-dimensional case (see Harmon (8)). By treating the dynamics of the jet as those of a boundary layer growing on the free surface, Goren and Wronski (6) and Tillett (18) are able to examine the flow in greater detail.
On a Novel Dual-Grid Level-Set Method for Two-Phase Flow Simulation

In this work, a hypothesis is proposed for two-phase flow simulation: The number of grid points required for the grid-independent solution of the flow field is lesser than that required to capture the grid-independent interface. Based on this, a dual-grid level-set(LS) method (DGLSM) is proposed, where the LS and energy equations are solved on a uniform grid which is twice finer than the continuity and momentum equations. This novel grid arrangement is aimed at improving interface resolution with only a slight increase in computational time. Qualitative and quantitative results of the DGLSM are compared against analytical, experimental, and numerical results on three stringent test problems: dam break, Rayleigh-Taylor instability, and film boiling. The results show that the DGLSM is accurate and robust, even for surface tension-dominant flows. Moreover, the hypothesis is corroborated by showing that the DGLSM is nearly as accurate as the completely refined traditional LS method at substantially less computational expense.
Separated Flow Response to Single Pulse Actuation

The response of a separated flow over a two-dimensional wing to short-duration disturbances from a Lorentz force leading-edge actuator is presented. At a chord Reynolds number of Re=104 and an angle of attack of α=16 deg, the flow is initially laminar but undergoes transition within the separated shear layer.The transient flow structures and lift force measurements were obtained with varying actuator pulse duration, pulse amplitude, and direction of actuation. The peak amplitude of the lift is shown to depend on the pulse duration when the pulse duration is less than 0.5 convective times, after which it saturates. Saturation of the lift amplitude also occurs when the effective actuator pulse amplitude exceeds Cμ=0.05%. Detailed flow structures that develop in the separated shear layer were identified using the finite-time Lyapunov exponent method. The direction of the actuator pulse has a significant influence on the initial development of the shear layer, but the larger-scale envelope of the separated f.