Miracle-dz/UniFAR-FTUs huggingface dataset:
Strongly bias-dependent spin injection from Fe into n -type GaAs

We report electrical spin injection into an $n$-doped GaAs $({N}_{d}=1\ifmmode\times\else\texttimes\fi{}{10}^{18}\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3})$ region from an Fe thin film grown by molecular beam epitaxy. The spins are injected through an $n\text{\ensuremath{-}}{\mathrm{Al}}_{0.1}{\mathrm{Ga}}_{0.9}\mathrm{As}$ Schottky barrier on a spin light emitting diode. Spin injection is detected optically via carrier recombination in the layer immediately adjacent to the Schottky barrier, allowing the spin transport to be studied through this important region of interest. A pronounced dependence of injected spin polarization upon applied bias voltage reveals that efficient spin injection occurs across a range of $\ensuremath{\sim}1\phantom{\rule{0.3em}{0ex}}\mathrm{V}$, dropping off sharply to zero at all temperatures. At bias voltages higher than that at which the maximum spin injection occurs, the Schottky barrier resistance is lowered, accompanied by hot electron spin transport in the semiconductor.
Water-drop response to sudden accelerations

The deformation of initially spherical drops of radius r0 subjected to an external flow of velocity u is experimentally examined for a large range of Weber and Bond numbers. Observations of the changes in the response are compared with recent analytical predictions. The data show that beyond a critical Weber number the response ceases to be vibratory and becomes monotonic with time. Subsequently, it is found that, although the response is unstable, the deformation imposed by the external aerodynamic pressure distribution remains the dominant factor. Measurements of the drag coefficient yield a mean value ofCD = 2·5 over a large Reynolds-number range. The time at which Taylor instability occurs is shown to be inversely proportional to Bond number to the one-quarter power. There is little evidence of the instability occurring until a normalized time $t^{*} = (\epsilon^{\frac{1}{2}}\bar{t}u/r_0)$ is approximately unity; here ε is the gas/liquid density ratio (ρ/ρ′) and $\bar{t}$ is the real time.
Rainfall-Rate Assignment Using MSG SEVIRI Data—A Promising Approach to Spaceborne Rainfall-Rate Retrieval for Midlatitudes

Abstract The potential of rainfall-rate assignment using Meteosat Second Generation (MSG) Spinning Enhanced Visible and Infrared Instrument (SEVIRI) data is investigated. For this purpose, a new conceptual model for precipitation processes in connection with midlatitude cyclones is developed, based on the assumption that high rainfall rates are linked to a high optical thickness and a large effective particle radius, whereas low rainfall rates are linked to a low optical thickness and a small effective particle radius. Reflection values in the 0.56–0.71-μm (VIS0.6) and 1.5–1.78-μm (NIR1.6) channels, which provide information about the optical thickness and the effective radius, are considered in lieu of the optical and microphysical cloud properties. An analysis of the relationship between VIS0.6 and NIR1.6 reflection and the ground-based rainfall rate revealed a high correlation between the sensor signal and the rainfall rate. Based on these findings, a method for rainfall-rate assignment as a function o.
Segmentation of images by variational methods: a constructive approach.

Wc give a constructive proob that given a bounded Iunction on a rectangle R, the minimum of the following bunctional is achieved: E(u,B)= IIu — gIV~(R> +1(B), where B is a finite set ob C' curves lii R and u is locally constant in R —B. In image processing, g can be interpreted as an image (g(x,y) is the grey level a! (x,y)) and the curves ob B as the contours of the image, u representing the mean value inside each contour. Following ideas ob Mumbord and Shah, our proob suggests a method br transborming an image into a cartoon.
Normal and reduced phonological space in the production of vowels by deaf adolescents

The production of the vowels /i/,/a/,/c/, and the diphthong /ai/ was investigated spectrographically in the speech of 36 deaf and 4 normally hearing adolescents. The phonological space defined by the maximum and minimum values of F1 and F2 is found to be reduced for many of the deaf subjects. This reduction of phonological space is due primarily to a restricted range of F2 and secondarily to a restricted range of F1. The degree of F2 variation bears a significant positive correlation (0.76) to the intelligibility of the subjects' connected speech. It is suggested that the phonological space reduced most noticeably in the dimension of the second formant is due to the abnormal auditory and visual feedback imposed upon the deaf child: the deaf child's frequency sensitivity is typically worse in the region of the second rather than the first formant; the articulatory gestures of tongue movement, which exert a strong influence on the movement of the second formant, are among the most difficult for the deaf chi.
The Direct Aero-Acoustics Simulation of Flow around a Square Cylinder Using the CE/SE Scheme

The space-time conservation element solution element (CE/SE) method is applied in the classical around square cylinder flow problem for aeroacoustics simulation. The unsteady Navier-Stokes equation and Euler equation are solved to directly numerical simulate the aero-acoustics field aroused in unsteady turbulent flow. The computation domain is decomposed into sound-near field and sound-far field, they are computed and analyzed. Large eddy simulation (LES) is used to compute the acoustic source while the Ffowcs Williams-Hawkings (FW-H) acoustic analogy is applied to this problem also. Comparing the two methods, qualitative agreement is demonstrated using the frequency-spectrum of a monitor point located at (50D,0). The CE/SE method is able to extract more details about the non-linear relation between the flow and sound.
Multifrequency Acousto-Optic Diffraction in Wideband Bragg Cells

A fundamental limit for the dynamic range of acousto-optic signal processor is the intermodulation products (IMPs) generated by nonlinearities in the Bragg cells when simultaneous signals are present. For wideband Bragg cells it was found the dominant contribution of the IMPS is due to acoustic nonlinearities in the Bragg cell medium. A coupled mode analysis is presented for the nonlinear interaction of multiple acoustic waves at different c arrier frequencies. Approximate truncated s eries solutions of the dominant IMPs are derived for two signals case. Experimental results obtained with Te02 and GaP cells are presented.
Lattice Dynamics in CeB6 Studied by Neutron-Scattering and Specific-Heat Measurements.

Lattice dynamics of CeB 6 has been studied by an inelastic neutron scattering experiment. The acoustic and optical modes of dispersion curves are measured in the high symmetry directions of the crystal by the triple-axis spectrometers. Flat low-frequency Ce-modes are similar as in LaB 6 but about 1 meV lower in energy than those in LaB 6 . Those little differences of the flat modes between CeB 6 and LaB 6 explain the so-called magnetic specific heat anomaly at around 40 K in CeB 6 reported previously.
Optimal, Low-Thrust Earth-Orbit Transfers Using Higher-Order Collocation Methods

A trajectory optimization technique based upon higher-order collocation is used to solve optimal, low-thrust, Earth-orbit transfer problems. The optimal control problem solved is defined, and the solution method for solving this problem is described. For several example cases analyzed, a spacecraft is transferred from low Earth orbit to a variety of final mission orbits. A range of thrust accelerations from approximately 1 to 10 - 3 g was used. A comparison is made between the optimal transfers found in this work and the transfers found by using analytical blended control methods. Finally, conclusions drawn from this work are discussed.
Turbulent Exchange Coefficients for Sensible Heat and Water Vapor under Advective Conditions

Abstract Results are presented of micrometeorological measurements made over alfalfa and soybeans under conditions of sensible heat advection at Mead, Neb. The sensible heat advection phenomenon reported here is of a regional rather than a local nature. The exchange coefficient for sensible heat (KH) is found to be generally greater than the exchange coefficient for water vapor (KW). This result contradicts the usual assumption of equality of KH and KW under nonadvection (lapse or unstable) conditions when the net transfer of both sensible heat and water vapor are away from the earth's surface. Under advective conditions, however, heat and water vapor are transferred in opposite directions. Our results are supported by Warhaft's (1976) recently published theoretical analysis in which he concludes that the greatest departure of KH/KW from unity will occur when temperature and humidity gradients are of opposite sign.
Structure of line-emitting accretion disks in active galactic nuclei - Arp 102B

The prime objects of the present self-consistent model of a line-emitting accretion disk able to account for the properties observed in a small class of AGNs are Arp 102B and 3C 390.3, whose double-peaked emission lines have been attributed to a Keplerian disk. Improved calculations of the line profile of a relativistic Keplerian disk, generalized to include a variety of emissivity laws as well as local broadening due to electron scattering or turbulence, are noted to fit Arp 102B; analytic and numerical calculations of the solid angle presented by the outer thin disk to an extended isotropic source of illumination demonstrate that the energy budget requirements for line emission from the disk are also satisfied. 27 refs.
A Statistical Hurricane Intensity Prediction Scheme (SHIPS) for the Atlantic Basin

Abstract A statistical model for predicting intensity changes of Atlantic tropical cyclones at 12, 24, 36, 48, and 72 h is described. The model was developed using a standard multiple regression technique with climatological, persistence, and synoptic predictors. The model developmental sample includes all of the named Atlantic tropical cyclones from 1989 to 1992, with a few additional cases from 1982 to 1988. The sample includes only the times when the storms were over the ocean. The four primary predictors are 1) the difference between the current storm intensity and an estimate of the maximum possible intensity determined from the sea surface temperature, 2) the vertical shear of the horizontal wind, 3) persistence, and 4) the flux convergence of eddy angular momentum evaluated at 200 mb. The sea surface temperature and vertical shear variables are averaged along the track of the storm during the forecast period. The sea surface temperatures along the storm track are determined from monthly climatologi.
An Application of Nonlinear Time Series Forecasting

By means of a real application, it is seen how ARIMA forecasts can be improved when nonlinearities are present. The autocorrelation function (ACF) of the squared residuals provides a convenient tool to check the linearity assumption. Once nonlinearity has been detected, parsimonious bilinear processes seem rather adequate to model it. The detection of nonlinearity and the forecast improvement appear to be rather robust with respect to changes in the linear and bilinear specification. Finally, what bilinear models seem to capture are periods of atypical behavior or sequences of outliers.
α Element Abundances in Mildly Metal-Poor Stars

We present [O/Fe] and other α-elements/Fe ratios in a sample of 24 mildly metal-poor stars. The sample stars are thought to be brighter than 9.0 magnitude and have available uvby photometric data. Also, based on the typical LTE abundance analysis, we find that [Si/Fe] and [Ca/Fe] are correlated with each other. Combining the kinematic data and the metallicity, we can classify the sample stars into three groups. An abundance analysis shows some evidence that these groups are chemically discrete from each other. Further, the general trend of a decreasing overabundance of the α elements with increasing metallicity has been confirmed.
Torque Resistance of a Flow between Rotating Co-Axial Cylinders Having Axial Flow

The writer measured the torque between co-axial cylinder walls exerted by the water flow when the inner cylinder rotates. Furthermore, the writer carried out experiments on the co-axial cylinders having circumferential grooves on its inner cylinder surface. The results obtained are as follows : 1) When grooves and an axial flow are absent, the torque coefficient Cf increases as the clearance between two cylinders increases, and when the peripheral Reynolds number Rw is large, the clearance has little effect on the value of Cf. 2) The axial flow extends the range of laminar state of Rw, where the value of Cf decreases, but when the axial flow increases beyond that range the value of Cf increases again. 3) When there are grooves on the cylinder, it becomes difficult to keep the flow laminar, so that the torque hardly decreases with an increase of the axial flow.
NUMERICAL SIMULATION OF CONDUCTION HEAT TRANSFER IN A SYSTEM OF SLOWLY ROTATING CONCENTRIC SHELLS SEPARATED BY SMALL ANNULAR GAP DISTANCES

Conduction dominated heat transfer in a system of concentric shells with a very small annulus distance and surface eccentricities is studied numerically using IDEAS TMGTM in conjunction with a user-programmed subroutine to model the heat transfer across the gas layer as a function of eccentricity and rotation rate. Sphere diameters range from 30 cm to 40 cm, annular gap sizes range from 0.5 mm to 1 mm, and eccentricities range from 0.05 mm to 0.25 mm. External thermal gradients are found to be attenuated significantly. The inner surface temperature deltas increase by a factor of 4.5, for a doubling in the eccentricity. A correlation for the effective heat transfer across the inner spheres also is presented.
Deuterium Fractionation Along the TMC-1 Ridge

In this paper, we present a model to predict and explain the observed gradients in deuterium fractionation and molecular abundance along the TMC-1 ridge. In TMC-1, gradients in the level of deuterium fractionation are observed for all the molecular species for which the measurement has been made; ${\rm HCO^+}$, ${\rm HC_3N}$, ${\rm C_3H_2}$ and HNC. The model is based on the assumption that the chemical evolution of the TMC-1 ridge has been affected by Alfven waves. The structure of the model and its comparison with observations are discussed. We find that the model qualitatively and somewhat quantitatively reproduces the observations of the aforementioned molecular species. We present predictions of the fractionation gradients along the TMC-1 ridge for other molecules of observational interest.
Stylized Facts of Daily Return Series and the Hidden Markov Model

In two recent papers, Granger and Ding (1995a,b) considered long return series that are first differences of logarithmed price series or price indices. They established a set of temporal and distributional properties for such series and suggested that the returns are well characterized by the double exponential distribution. The present paper shows that a mixture of normal variables with zero mean can generate series with most of the properties Granger and Ding singled out. In that case, the temporal higher-order dependence observed in return series may be described by a hidden Markov model. Such a model is estimated for ten subseries of the well-known S&P 500 return series of about 17,000 daily observations. It reproduces the stylized facts of Granger and Ding quite well, but the parameter estimates of the model sometimes vary considerably from one subseries to the next. The implications of these results are discussed. © 1998 John Wiley & Sons, Ltd.
Finite volume simulation of unsteady shock‐cavitation in compressible water

The present paper extends an established Riemann‐based finite volume hydrocode for compressible pure water to admit change of phase. The thermal and caloric behaviour of water and water vapour is described by a one‐fluid model on the assumption that the two‐phase regime can be described locally within a finite volume cell as a homogeneous mixture that remains in thermodynamic equilibrium. Closure of the equation set is achieved by deriving equations of state for pure fluids and the mixture that cover all possible fluid states. Following a description of the flow model and the numerical method, computations are carried out to demonstrate the potential of the method. Calculations include a one‐dimensional cavitation tube, one‐dimensional condensation front, collapse of a cavitation bubble in water in one dimension, and an unsteady two‐dimensional hypervelocity flow past a cavitating hydrofoil. Copyright © 2012 John Wiley & Sons, Ltd.
Dynamics of ultrasound-induced cavitation bubbles in non-Newtonian liquids and near a rigid boundary

The dynamics of ultrasound-induced cavitation bubbles situated in non-Newtonian liquids and near a rigid boundary are investigated experimentally by acoustic measurements and high-speed photography with up to 4 million frames/s. The non-Newtonian liquids consist of a 0.5% polyacrylamide (PAM) aqueous solution with a strong elastic component and a 0.5% carboxymethylcellulose aqueous solution with a weak elastic component. The maximum velocity of the re-entrant liquid jet and the pressure amplitude of the acoustic transients emitted during first bubble collapse are diminished by the polymer additives. The most significant reduction was found in the elastic PAM solution. It might be caused by an increased resistance to extensional flow which is conferred upon the liquid by the polymer additive. The results are discussed with respect to the mechanisms of cavitation erosion of rigid materials. The material presented may also be useful for comparison with future numerical work.
EFFECTIVENESS OF JAPANESE CORRECTIONAL TREATMENTS FOR JUVENILES

In this article we study effectiveness of training school programs relative to probation on recidivism for Japanese juvenile delinquents with differing criminal experiences—early versus late involvement, and first-time as opposed to repeat. We measure effectiveness by the times elapsed from release to reincarceration in the Juvenile Classification Homes. We employ proportional hazards model to examine the relationship between the form of treatment and the times to reincarceration. The effect of treatment in training school is found to be complex. Institutionalization of the late-starting first-time offenders (N = 5,675) and of the early-starting repeat offenders (N = 158) is associated with significantly longer times to reincarceration. But for the late-starting repeat offenders (N = 946), we do not find any positive effect of training school.
A paradox concerning the extended Stokes series solution for the pressure drop in coiled pipes

While the extended Stokes series (ESS) solution for the laminar pressure drop in coiled pipes predicts that the friction ratio (the ratio of pressure drop in the coiled pipe to that in the straight pipe of the same flow rate) varies asymptotically as one‐fourth power of the Dean number, the existing experimental data largely support a square‐root variation; previous boundary layer analyses also predict a square‐root variation. The subject of this paper is an examination of this paradox. A detailed review shows that the existing set of experimental data can be grouped into various categories depending on the precise flow conditions. It is shown that none of the existing data satisfies the proper experimental conditions required by the ESS method. New experiments reveal that the pressure drop demanded by the ESS solution can actually be observed if they are expressly designed to satisfy the conditions demanded by the ESS solution. The implication is that the domains of initial conditions appropriate to the .
Robust Linear Mixed Models with Normal/Independent Distributions and Bayesian MCMC Implementation

Linear mixed effects models have been widely used in analysis of data where responses are clustered around some random effects, so it is not reasonable to assume independence between observations in the same cluster. In most biological applications, it is assumed that the distributions of the random effects and of the residuals are Gaussian. This makes inferences vulnerable to the presence of outliers. Here, linear mixed effects models with normal/independent residual distributions for robust inferences are described. Specific distributions examined include univariate and multivariate versions of the Student‐ t, the slash and the contaminated normal. A Bayesian framework is adopted and Markov chain Monte Carlo is used to carry out the posterior analysis. The procedures are illustrated using birth weight data on rats in a toxicological experiment. Results from the Gaussian and robust models are contrasted, and it is shown how the implementation can be used for outlier detection. The thick‐tailed distributions provide an appealing robust alternative to the Gaussian process in linear mixed models, and they are easily implemented using data augmentation and MCMC techniques.
Numerical simulation of the unsteady flow over an elliptic cylinder at different orientations

A numerical method is developed for investigating the two‐dimensional unsteady viscous flow over an inclined elliptic cylinder placed in a uniform stream of infinite extent. The direction of the free stream is normal to the cylinder axis and the flow field unsteadiness arises from two effects, the first is due to the flow field development following the start of the motion and the second is due to vortex shedding in the wake region. The time‐dependent flow is governed by the full conservation equations of mass and momentum with no boundary layer approximations. The parameters involved are the cylinder axis ratio, Reynolds number and the angle of attack. The investigation covers a Reynolds number range up to 5000. The minor–major axis ratio of the elliptic cylinder ranges between 0.5 and 0.6, and the angle of attack ranges between 0° and 90°. A series truncation method based on Fourier series is used to reduce the governing Navier–Stokes equations to two coupled infinite sets of second‐order differential equations. These equations are approximated by retaining only a finite number of terms and are then solved by approximating the derivatives using central differences. The results reveal an unusual phenomenon of negative lift occurring shortly after the start of motion. Various comparisons are made with previous theoretical and experimental results, including flow visualizations, to validate the solution methodology. Copyright © 2001 John Wiley & Sons, Ltd.