Miracle-dz/UniFAR-FTUs huggingface dataset:
Calculation of a two-temperature plasma composition : bases and application to SF6

In this paper we discuss the use of generalized Saha and Guldberg-Waage equations for calculating the composition of a two-temperature SF6 plasma in a pressure range 0.1-1.6 MPa, for an electron temperature in the range 300-20 000 K. We compare two sets of two-temperature laws and we recommend the expressions proposed by the team from Eindhoven. Furthermore, knowing the great influence of the choice of the excitation temperature on the plasma composition, we propose, on the basis of a chemical kinetics approach, a simple general relation allowing the calculation of this temperature versus the electron temperature, the heavy particle temperature and the electron number density. The application of these relations to a real case of a two-temperature SF6 arc plasma gives a realistic radial profile of the electron number density.
Some automated methods of smoothing time-dependent data

Nonparametric function estimation based upon time-dependent data is a challenging problem to both the data analyst and the theoretician. This paper serves as an introduction to the problem and discusses some of the approaches that have been proposed for smoothing autocorrelated data. A principal theme will be accounting for correlation in the data driven choice of a function estimator's smoothing parameter. Data-driven smoothing is considered in various settings including probability density estimation, repeated measures data, and time series trend estimation. Both applications and theoretical issues are addressed, and some open problems will be discussed.
The general low-frequency prediction for asymptotically nonlinear material functions in oscillatory shear

We use a fourth-order fluid expansion to make general predictions for asymptotically nonlinear material functions in oscillatory shear, a characterization protocol sometimes known as medium-amplitude oscillatory shear. The calculation applies to any viscoelastic fluid in the terminal regime defined by the limit of Deborah number much less than one. Two viscous nonlinearities appear at third order, with shear stress scaling as ω3, and are interrelated by a constant multiplicative factor. Two elastic nonlinearities appear at fourth order, with shear stress scaling as ω4, and are also interrelated by a constant multiplicative factor. These nonlinear measures are decoupled from the linear material functions G′ and G″ because they depend on different expansion coefficients. Experimental measurements are presented for all four asymptotic shear material functions using a linear and well-entangled homopolymer of polyisoprene. The experimental observations are consistent with both the predicted frequency scaling .
A Numerical Investigation of the Flow Past a Generic Side Mirror and its Impact on Sound Generation

The case investigated is the flow past a generic side mirror mounted on a flat plate at the Reynolds number of Re(D)=5.2x10(5) based on the mirror diameter. The present work studies both flow and acoustic sources by evaluating two second-order advection schemes, different levels of turbulence modeling, and three different grids. The advection schemes discussed in the present study are a second-order upwind scheme and a monotonic central scheme. The turbulence models investigated cover three levels of modeling. These are the original formulation of the detached eddy simulation (DES) model, the Smagorinsky-Lilly sub-grid scale (SGS) model with near-wall damping, and a dynamic Smagorinsky model. The different grids are as follows: a primary grid where all parameter studies are conducted and a second grid with significantly higher wake resolution and to some extent also increased plate resolution, while maintaining the resolution at the front side of the mirror. The final grid uses a significantly higher plate resolution and a wake resolution similar to that of grid two, but a comparably lower mirror front side resolution as compared with the two other grids. The general outcome of this work is that the estimation of the grid cutoff frequency through a relation of the velocity fluctuation and the grid size matches both the experimental results and trend lines perfectly. Findings from the flow field show that the horseshoe vortex in front of the mirror causes pressure fluctuations with a magnitude exceeding the maximum levels at the rear side of the mirror. Its location and unsteady properties are perfectly captured in the final simulation as compared with the experiments conducted by Daimler-Chrysler. A laminar separation at the front side of the mirror is more or less found for all wall resolved cases except the DES simulation. The third grid fails to predict this flow feature, but it is shown that this effect has no significant effect on either the static pressure sensors at the mirror surface or at the dynamic sensors located downstream of the mirror. The simulation also supports the fundamental frequency based on the eddy convection in the mirror shear layer, which is shown to be twice as high as the frequency peak found in the lateral force spectra.
Enhanced thermoelectric performance in p-type BiSbTe bulk alloy with nanoinclusion of ZnAlO

p-type BiSbTe/x wt % ZnAlO (x=0, 0.25, 0.5, 0.75, and 1.0) composites were prepared by zone melting method. A peak thermoelectric figure of merit (ZT) of 1.33 at 370 K was achieved for the sample with x=0.75, about 34% higher than that of BiSbTe at the same temperature, making these composites more attractive for commercial applications. This enhancement of ZT can be mainly ascribed to a remarkable increase of the electrical conductivity and a simultaneous decrease of the lattice thermal conductivity by the introduction of ZnAlO nanopowder.
The large numbers hypothesis and a relativistic theory of gravitation

A way to reconcile Dirac's large numbers hypothesis and Einstein's theory of gravitation wasrecently suggested by Lau (1985). It is characterized by the conjecture of a time-dependentcosmological term and gravitational term in Einstein's field equations. Motivated by thisconjecture and the large numbers hypothesis, we formulate here a scalar-tensor theory in terms of an action principle. The cosmological term is required to be spatially dependent as well as time dependent in general. The theory developed is applied to a cosmological model compatible with the large numbers' hypothesis. The time-dependent form of the cosmological term and the scalar potential are then deduced. A possible explanation of the smallness of the cosmological term is also given and the possible significance of the scalar field is speculated.
On the microstructure of Si coimplanted with H+ and He+ ions at moderate energies

We report on the microstructure of silicon coimplanted with hydrogen and helium ions at moderate energies. X-ray diffraction investigations in as-implanted samples show the direct correlation between the lattice strain and implanted ion depth profiles. The measured strain is examined in the framework of solid mechanics and its physical origin is discussed. The microstructure evolution of the samples subjected to intermediate temperature annealing (350 °C) is elucidated through transmission electron microscopy. Gas-filled cavities in the form of nanocracks and spherical bubbles appear at different relative concentration, size, and depth location, depending on the total fluence. These different microstructure evolutions are connected with the surface exfoliation behavior of samples annealed at high temperature (700 °C), determining the optimal conditions for thick layer transfer. 1.5 μm thick Si films are then obtained onto glass substrates.
A hydrogen storage layer on the surface of silicon nitride films

Composition, layer structure, and H-retaining stability of 980°C N2-annealed silicon nitride-oxide (ON) stacks were analyzed using high resolution rutherford backscattering, synchrotron x-ray specular reflectometry, and nuclear reaction analysis. The formation of a Si2N2O layer in the near-surface part of N2-annealed nitride films was discovered. The Si2N2O layer can store hydrogen species that are resistant against energetic electron damage due to their reduced diffusion mobility. Although degrading in air, the Si2N2O layer thus provides reliable hydrogen species, which are desirable in the integrated circuit processing of silicon transistors and silicon ONO trap memories.
Sequential sampling designs based on space reduction

In the field of engineering design and optimization, metamodels are widely used to replace expensive simulation models in order to reduce computing costs. To improve the accuracy of metamodels effectively and efficiently, sequential sampling designs have been developed. In this article, a sequential sampling design using the Monte Carlo method and space reduction strategy (MCSR) is implemented and discussed in detail. The space reduction strategy not only maintains good sampling properties but also improves the efficiency of the sampling process. Furthermore, a local boundary search (LBS) algorithm is proposed to efficiently improve the performance of MCSR, which is called LBS-MCSR. Comparative results with several sequential sampling approaches from low to high dimensions indicate that the space reduction strategy generates samples with better sampling properties (and thus better metamodel accuracy) in less computing time.
Stably stratified turbulent channel flows. I. Stratification regimes and turbulence suppression mechanism

Our objective in this study is to study inhomogeneous stratified shear flows using large eddy simulation; stratified pressure-gradient-driven channel flow was selected. The flows can be separated into three regimes: buoyancy affected, buoyancy controlled, and buoyancy dominated flows. The regime boundaries are defined by Richardson and Reynolds numbers based on the friction velocity. Buoyancy affected flows remain actively turbulent and attain a statistical steady state that resembles a lower Reynolds number unstratified flow. Flows in the buoyancy controlled regime are not in equilibrium. In the cases studied, an asymmetry develops with respect to the channel centerline leading to one-sided turbulence. Eventually, the “inactive” half undergoes a transition initiated by the active half and symmetry is restored. At higher Richardson numbers, the flows are buoyancy dominated, the near-wall burst-sweep process is completely disrupted and turbulence production ceases, leading to relaminarization. In relaminar.
Experimental study on passive scalar diffusion in a turbulent shearless mixing-layer by Mie scattering diffusion and PIV

The experiments are run in an inhomogeneous turbulent shearless layer generated in a wind tunnel with two different meshes. A PIV system synchronized simultaneously with a Mie scattering diffusion concentration system is used in order to obtain the velocity and concentration fields at the same instant. We present here some statistical results for both velocity and concentration and also the mean flux. Filtering and subgrid scale modeling are applied to experimental velocity and concentration field in order to check the effect of the length of filter and the accuracy of subgrid model of LES.
Morphogenesis of lamellar polymer crystals

Using a previously developed simulation model we study the changes in morphology of two-dimensional chain crystals caused by annealing. A series of various intermediate crystalline states with different stability exhibiting a non-monotonous evolution of the internal energy and the degree of local order was found. This clearly shows the generic non-equilibrium character of polymer crystals. Thus, the classification scheme of equilibrium thermodynamic phases cannot be used to describe such transient states in polymer crystals. At large length scales the structural changes resemble a liquid-like behaviour while at the same time at small length scales the chains show an improvement of crystalline order. The term morphogenesis reflects this complex kinetic behaviour. In addition, simulations with constant heating rates also demonstrate the importance of relaxation processes in polymer crystals.
LIGHTNING AND THE ORIGIN OF NITRATES FOUND IN PRECIPITATION

No attempt has been made here to establish the relative contribution of the different sources of the atmosphere's budget of nitrogen oxides. However, it appears clear that lightning is only one of many possible sources and its share may have been overestimated, particularly in view of the recent rocket and satellite findings that nitric oxide may be produced at extreme altitudes. It is hoped that further investigations of the composition of the ionosphere and the reactions at the air-water interface of the seas will produce additional information to permit quantitative analysis of the origin of nitrates in precipitation.
Taking advantage of automated assessment of student‐constructed graphs in science

We present a new system for automated scoring of graph construction items that address complex science concepts, feature qualitative prompts, and support a range of possible solutions. This system utilizes analysis of spatial features (e.g., slope of a line) to evaluate potential student ideas represented within graphs. Student ideas are then scored with rubrics based upon the knowledge integration framework (Linn & Eylon, 2011). We tested the effectiveness of this system on graphs constructed by 397 8th–12th grade students preceding, during, and following a curriculum focusing on graphs of motion. Comparison with human-coded responses indicates that the automated scoring system is very accurate (κ = 0.9). Also, ideas represented in constructions were generally similar to those demonstrated in written explanations; although individual students often shifted ideas between items. Learning gains were similar in both written and graph construction formats. Overall, these results suggest that graph construction is a valid and efficient means of evaluating students' complex ideas about data representation in science. We discuss the opportunities for incorporating graph construction into new science content areas, such as graphs representing density. We consider the implications of this system for generating automated, adaptive guidance to support instruction. © 2015 Wiley Periodicals, Inc. J Res Sci Teach 52: 1426–1450, 2015.
Fluctuation conductivity in NdBa/sub 2/Cu/sub 3/O/sub y/ superconductors with the different amounts of 422 phase

Fluctuation conductivity analysis was carried out to characterize NdBa/sub 2/Cu/sub 3/O/sub y/ superconductors with the different amounts of Nd/sub 4/Ba/sub 2/Cu/sub 2/O/sub y/ (Nd422) phase. Samples were prepared by melt-textured process from the mixtures in molar ratios of Nd123: Nd422 = 1:x (x = 0.2, 0.25, 0.3). The conduction dimensionality and the fluctuation amplitude were obtained by analyzing the fluctuation conductivity. The dimension of conduction on excess conductivity showed little variation by the addition of 422 phase. The coherence length and the correlation length obtained by this analysis became larger with increasing amount of 422 phase. The clear evidence was found that the pinning force in the sample was well correlated with the characteristic length of superconductivity.
The Velocity of the Pulse Wave in Man

In an investigation now being carried out by us at Manchester observations are being made, under various conditions, upon the velocity of the pulse wave in man. As a preliminary to this investigation it was thought advisable to study the theory of the transmission of the pulse wave, and the following pages contain the results arrived at, together with an account of experiments upon the velocity of the pulse wave in an isolated human artery.
Limits of validity of three perturbation theories of the specular scattering of light from one-dimensional, randomly rough, dielectric surfaces

The reflectivity of p- and s-polarized light incident upon a one-dimensional, randomly rough, dielectric surface is calculated for several angles of incidence, when the plane of incidence is normal to the generators of the surface, by a second-order small-amplitude perturbation theory, by a second-order self-energy perturbation theory, and by a second-order phase perturbation theory. The wavelength of the incident light is λ = 0.6328 μm, and the dielectric constant of the scattering medium is ∊ = 2.25. The surface roughness is characterized by a rms height δ and a transverse correlation length a. From a comparison of the results of these approximate calculations with those obtained by a numerical simulation approach for each polarization of the incident light, and for several angles of incidence, curves of δ/λ as a function of a/λ are constructed, below which each perturbative method is valid with an error that is smaller than 2.5%. It is found that, for a given value of a/λ, the reflectivity of s- and p-polarized light is given most accurately by the phase perturbation theory and least accurately by small-amplitude perturbation theory.
Determination of the Constancy of the Speed of Light

Kantor’s relativity experiment has been repeated with approximately four times the sensitivity. The experiment measures the speed of light which has passed through moving glass plates by the observation of the shift of interference fringes. It was performed with the interferometric path in vacuum, and with the fringes observed at infinity. The shift predicted by the emission theory used by Kantor was 2.9 fringes. The shift found was less than 0.02 fringe.
Transition scenario of a sphere freely falling in a vertical tube

Abstract The paper presents the results of direct numerical simulations of the fall of a single freely moving sphere in a vertical circular tube. Most results are obtained for the solid–fluid density ratio ${\rho }_{s} / \rho = 2$ . The parametric investigation is carried out depending on the Galileo number defined in Jenny, Dušek & Bouchet J. Fluid Mech. , vol. 508, 2004, pp. 201–239. A qualitatively new scenario is found, as compared to that of an unconfined sphere. The primary bifurcation making the sphere deviate from a vertical fall along the tube axis at a constant velocity is of Hopf type. It sets in at a Galileo number (between 155 and 160) similar to that for an unconfined sphere. We find evidence for two stages of the primary regime: a planar trajectory at $G= 160$ and a helical one (at $G= 165$ and 170). At these Galileo numbers, the regime is perfectly periodic, with a slow period corresponding to a Strouhal number only slightly above 0.01. The dynamics is identified as a periodic wake–wall interaction. The helical regime is found to give way directly to chaos between $G= 170$ and $G= 180$ . This transition is associated with the onset of vortex shedding in the wake of the falling sphere and with a complex interaction between the unsteady wake and the wall marked by intermittent wake extinction. The effect of density ratio is partly investigated at $G= 250$ by considering three density ratios: 2, 3 and 5. A significant change of behaviour is found between the ratios 3 and 5.
Complex permeability of demagnetized microwave ferrites near and above gyromagnetic resonance

A wide variety of microwave ferrite phase-shifting materials have been measured in the demagnetized state. The relative magnetic permeability and loss factor were determined near and above natural gyromagnetic resonance using H/sub 011/ cylindrical dielectric ring resonators. These low-loss dielectric sleeves were dimensioned for accurate magnetic property measurements of single ferrite rod samples at logarithmically sampled resonant frequencies from 2 GHz to 25 GHz. Permeability and magnetic loss factor are computed from the measured resonant frequencies and Q factors of these resonators, with and without the ferrite sample, using exact eigenvalue equations. Generally, the real part of the complex magnetic permeability increases with decreasing saturation magnetization, while the magnetic loss factor increases nonlinearly with increasing saturation. Schloemann's theoretical model for the real part of initial permeability of a cylindrically symmetric domain configuration in the completely demagnetized state shows excellent agreement with measured data when 2/spl pi//spl gamma//spl mu//sub s///spl omega/<0.75. The data allow design optimization of circulators and dual-mode and polarization-insensitive phasers, which are widely used in antenna array systems.
On the adjunction theoretic classification of polarized varieties.

By the Kawamata-Shokurov Base Point Free Theorem, there exists a birational morphism, : M -> X, with X normal and KM ® j L n ~ 2 = 0*jT for an ample line bündle Jf. The structure of (X, tf\ the second reduction of (Jt, &\ was studied in [So 1], [Fa], [FS2], [BFS]. It was shown that X has isolated terminal singularities, and is moreover Gorenstein in even dimensions and 2-Gorenstein in odd dimensions. Further Xis 2-factorial for n ̂ 4 and 2 ·.= (*£)** is 2-Cartier. Note that
Polarization Switching and Domain Wall Motion in Circular and Ring Capacitor Structures in PZT Thin Films

Ferroelectric switching in circular and ring capacitors has been performed using a stroboscopic mode of piezoresponse force microscopy. A simple geometric model incorporating the characteristic domain wall motion is sufficient to describe the switching of circular capacitors but which however breaks down when attempting to describe the ring switching. Analysis of the switching dynamics implies that the domain wall moves faster along the perimeter of both the circle and ring electrode structures.
X-ray absorption toward the red quasar 3C 212

A Roentgen Satellite (ROSAT) X-ray spectrum of the z = 1.049 'red quasar' 3C 212 has a strong low-energy cutoff. The spectrum can be fitted with a power law (of energy index 1.4(+0.8, -0.6) with low-energy photoelectric absorption in excess of the Galactic value that, if at the redhsift of the quasar, would have a column density of (0.9(+0.8, -0.6)) x 10(exp 22) atoms/sq cm. Possible sites for the absorption are a nuclear torus, an intervening damped Lyman-alpha system, or intracluster material (e.g., a cooling flow) around the quasar. The implied absorbing column density is sufficient to redden a normal quasar spectrum to the observed steep optical slope. The observed continuum, if dereddened by this amount, can produce the observed emission line fluxes and ratios. The absence of the graphite lambda-2175 feature in 3C 212 however, requires dust different from the local Milky Way composition, or an intervening absorber with z less than 0.4. Alternative acceptable fits to the X-ray spectrum are (1) a blackbody with a temperature of 0.7 keV (in the quasar frame) modified only by Galactic absorption, and (2) an optically thin thermal plasma with excess absorption. Although a blackbody spectrum would be unprecedented, the model is consistent with all the available X-ray and optical data and cannot be ruled out. We discuss possible observations that can discriminate among the above models.
Full-Wave Analysis of Double Positive/Double Negative Loaded Dipole Antennas

Abstract The influence of material inclusions on the input impedance of loaded dipoles is analytically investigated. Novel and accurate analytical expressions for the input impedance of the loaded dipoles are proposed based on the mode-matching technique. Boundary conditions are also enforced to obtain several simultaneous equations for the discrete modal coefficients inside the radiating region. A study of the input impedance of the whole multi-layered structure is accomplished by the cascade connection of mediums as characterized by their constitutive parameters. Computation is performed to illustrate impedance behavior in terms of geometries and frequency. Derived analytical formulas are successfully validated through a proper comparison with the results obtained with the commercial software CST Microwave Studio (www.cst.com).