Miracle-dz/UniFAR-FTUs huggingface dataset:
Measurements in Regions of Shock Wave/Turbulent Boundary Layer Interaction from Mach 3 to 10 for Open and Blind Code Evaluation/Validation

Abstract : Experimental studies have been conducted to examine the characteristics of regions of shock wave/turbulent boundary layer interaction over cone/flare and hollow cylinder/flare configurations in high Reynolds number flows at Mach numbers between 5 and 10 in cold flows and in flows with duplicated flight velocities. Detailed surface pressure and heat transfer measurements have been made through the separated interaction regions as well as upstream and downstream of the interactions for a range of Reynolds numbers under cold wall conditions for total enthalpies duplicating flight. The large scale of the models used in these experiments enabled us to obtain measurements in fully turbulent flows with the length of turbulent flow up to 1,000 boundary layer thicknesses downstream of the beginning of untripped transition. The surface measurements obtained in these studies together with Schlieren and interferometry measurements of the regions of shock wave/boundary layer interaction have been assembled to provide data sets for blind code validation studies.
Scale invariance in jet streams: ER‐2 data around the lower‐stratospheric polar night vortex

High altitude ER‐2 aircraft observations in both hemispheres of the lower‐stratospheric polar night jet stream reveal generalized scale invariance. The scaling exponent has systematic correlation with wind shear and temperature gradient showing across‐jet persistence, along‐jet anti‐persistence, and an overall average value ≈5/9. The analysis provides a natural connection between generalized scale invariance and traditional large‐scale dynamical meteorology. For one mission in the southern hemisphere composite variograms could be constructed for nitrous oxide and ozone, from which it was deduced that the former is a true passive scalar in the lower stratosphere, while sources and sinks are operative for the latter. Copyright © 2004 Royal Meteorological Society
Spectral line polarization with angle-dependent partial frequency redistribution - IV. Scattering expansion method for the Hanle effect

Context. The partial frequency redistribution (PRD) effects in line scattering are necessary ingredients for interpreting the linear polarization observed in strong resonance lines. It is a common practice to use angle-averaged PRD functions for simplicity (obtained by averaging over all scattering angles). It has been established that the use of angle-dependent PRD functions instead of angleaveraged functions is essential for weak fields. Aims. Here we present an efficient iterative method to solve the polarized line radiative transfer equation in weak magnetic fields using angle-dependent PRD functions. Methods. Based on the theory of Stokes vector decomposition for the Hanle effect combined with the Fourier azimuthal expansion of the angle-dependent PRD function, we try to formulate an efficient numerical method of solving the concerned transfer problem in one-dimensional media. This iterative method (referred to as the scattering expansion method, SEM) is based on a series expansion of the polarized source vector in mean number of scatterings (Neumann series expansion). We apply the SEM approach to handle both the exact and various approximate forms of the Hanle scattering redistribution matrix. Results. The SEM is shown to be an efficient method to solve angle-dependent PRD problems involving the Hanle effect. We show that compared to the earlier methods such as the perturbation methods, the SEM is stable and faster. We find that angle-dependent PRD significantly affects the Stokes U parameter.
Rotational Transitions of CO+ Induced by Atomic Hydrogen

The CO+ molecular ion has been observed in photon-dominated regions. Recent modeling has not been able to explain the abundances of CO+ in these regions. The most abundant collision partners are believed to be hydrogen atoms, hydrogen molecules, and electrons. The reactions of these species with CO+ have been studied previously and found to be fast. The only inelastic processes studied before were collisions of CO+ with electrons. Here we investigate the inelastic collisions of CO+ with hydrogen atoms. We argue that this can be done on the lowest triplet electronic state. This implies that CO+ ions, in a hydrogen atom dominated surrounding, experiences a few inelastic collisions before reacting. Rotationally inelastic state-to-state cross sections (j ⩽ 8) are presented together with state-resolved thermal rate coefficients. The results suggest that the rotationally inelastic collision cross sections can be of comparable magnitude to the reactive ones. Implications for the rotational temperature of CO+ in PDRs are discussed. To perform the calculations, a potential energy surface is fitted using the reproducing-kernel Hilbert space method based on multireference configuration-interaction calculations employing the aug-cc-pVQZ basis set.
Sensitivity of the Upper Mesosphere to the Lorenz Energy Cycle of the Troposphere

Abstract The concept of a mechanistic general circulation model that explicitly simulates the gravity wave drag in the extratropical upper mesosphere in a self-consistent fashion is proposed. The methodology consists of 1) a standard spectral dynamical core with high resolution, 2) idealized formulations of radiative and latent heating, and 3) a hydrodynamically consistent turbulent diffusion scheme with the diffusion coefficients based on Smagorinsky’s generalized mixing-length formulation and scaled by the Richardson criterion. The model reproduces various mean and variable features of the wave-driven general circulation from the boundary layer to the mesopause region during January. The dissipation of mesoscale kinetic energy (defined as the frictional heating due to the mesoscale flow) in the extratropical troposphere is found to indicate the tropospheric gravity wave sources relevant for the mesosphere/lower thermosphere. This motivates a sensitivity experiment in which the large-scale differential h.
Ultraviolet Imaging Telescope Images of the Reflection Nebula NGC 7023: Derivation of Ultraviolet Scattering Properties of Dust Grains

The Ultraviolet Imaging Telescope as part of the Astro-1 mission, was used to obtain high-resolution surface brightness distribution data in six ultraviolet wavelength bands for the bright reflection nebula NGC 7023. From the quantitative comparison of the measured surface brightness gradients ratios of nebular to stellar flux, and detail radial surface brightness profiles with corresponding data from the visible, two major conclusions results: (1) the scattering in the near- and far-ultraviolet in this nebula is more strongly forward-directed than in the visible; (2) the dust albedo in the ultraviolet for wavelengths not less than 140 nm is identical to that in the visible, with the exception of the 220 nm bump in the extinction curve. In the wavelengths region of the bump, the albedo is reduced by 25 to 30 percent in comparison with wavelengths regions both shorter and longer. This lower albedo is expected, if the bump is a pure absorption feature.
Linear-quadratic optimal time-varying observers with time-varying guaranteed convergence rate

A well-known method by Anderson and Moore for optimal quadratic feedback design with guaranteed constant convergence rate for linear time-invariant systems is generalised to linear complex-valued time-varying systems and time-varying convergence rates. The resulting method is readily applicable to observer design for state-affine systems and unifies methods developed there with the classical quadratic optimal state estimation and control. A pre-assigned time-varying convergence rate is shown to significantly improve the observer's transients in comparison with a constant one being employed for flux estimation in induction machines.
MULTIPLE‐RECORD SYSTEMS ESTIMATION USING LATENT CLASS MODELS

Capture–recapture methods (also referred to as ‘multiple‐record systems’) have been widely used in enumerating human populations in the fields of epidemiology and public health. In this article, we introduce latent class models into multiple‐record systems to account for unobserved heterogeneity in the population. Two approaches, the full and the conditional likelihood, are proposed to estimate the unknown population abundance. We also suggest rules to diagnose identifiability of the proposed latent class models. The methodologies are illustrated by two real examples: the first is to count the undercount of homelessness in the Adelaide central business district, and the second concerns the incidence of diabetes in a small Italian town.
A COMPLEMENT TO "ON THE UNITARY EQUIVALENCE AMONG THE COMPONENTS OF DECOMPOSITIONS OF REPRESENTATIONS OF INVOLUTIVE BANACH ALGEBRAS AND THE ASSOCIATED DIAGONAL ALGEBRAS"

representation q of an involutive Banach algebra 5 over a measure space (F, u). As shown by several authors in [4], [8], [9], [13] etc., this decomposition cannot be regarded as a decomposition of the unitary equivalence class of 9o into the unitary equivalence classes of q (ry) except for some fairly nice cases, whereas this decompositon is determined only up to unitary equivalence. For instance, some representations can be decomposed in two ways that have no common components as in [8] and some two representations of quite different types can be decomposed into the direct integrals of the same components as in [13]. Therefore it comes into considerations what determines the unitary equivalence relation among the components {gyp( ry); ry EF of the decomposition
Simplified method for seismic risk assessment of buildings with consideration of aleatory and epistemic uncertainty

A simplified method for seismic risk assessment with consideration of aleatory and epistemic uncertainties is proposed based on the widely used closed-form solution for estimating the mean annual frequency of exceeding a limit state (LS). The method for the determination of fragility parameters involves a non-linear static analysis of a set of structural models, which is defined by utilising Latin hypercube sampling, and non-linear dynamic analyses of equivalent single degree-of-freedom models. The set of structural models captures the epistemic uncertainties, whereas the aleatory uncertainty due to the random nature of the ground motion is, as usual, simulated by a set of ground motion records. Although the method is very simple to implement, it goes beyond the widely used assumption of independent effects due to aleatory and epistemic uncertainty. Thus, epistemic uncertainty has a potential influence on both fragility parameters, and not only on dispersion, as has been assumed in some other approximate methods. The proposed method is applied to an example of a four-storey reinforced concrete building, where it is shown that the effects of epistemic uncertainties, in addition to aleatory uncertainty, increase with the severity of the LS, so that, for the near collapse LS, the risk with consideration of both sources of uncertainty is more than double if compared to the risk, which was determined solely by the consideration of aleatory uncertainty.
Velocity dispersion and the stellar population in the central 1.2 parsecs of the Galaxy

New observations of the 2.3 micron absorption band head of CO in integrated stellar light in the central 1.2 pc of the Galaxy are presented. These data confirm that the velocity dispersion of the stars increases toward the Galactic center and totally dominates their systematic rotation at small radii. The velocity dispersion is constant an average value of 125 km/s within about 30 arcsec projected diameter central region. The strength of the CO features decreases in the integrated faint light within the same region. These observations are all consistent with the hypothesis that both the diffuse 2 micron light and the bright 2 micron point sources in the central region are dominated by sources that have little or no CO absorption feature. The observed CO feature at projected distances less than 0.6 pc thus actually arises in stars that are at true radii greater than 0.6 pc. The mass distribution at radius between 3.7 and 0.6 pc from IRS 16 is strong evidence for an increasing mass/2 micron radiation ratio toward the Galactic center. 24 refs.
First-principles calculation of carrier-phonon scattering in n-type Si1−xGex alloys

First-principles calculation of carrier-phonon scattering in n-type Si1−xGex alloys Author(s) Murphy-Armando, Felipe; Fahy, Stephen B. Publication date 2008-07 Original citation MURPHY-ARMANDO, F. & FAHY, S. B. 2008. 'First-principles calculation of carrier-phonon scattering in n-type Si1−xGex alloys'. Physical Review B, 78, 035202. doi:10.1103/PhysRevB.78. 035202 Type of publication Article (peer-reviewed) Link to publisher's version http://link.aps. org/doi/10.1103/PhysRevB.78. 035202 http://dx.doi. org/10.1103/PhysRevB.78. 035202 Access to the full text of the published version may require a subscription. Rights ©2008 The American Physical Society Item downloaded from http://hdl.handle. net/10468/2673
The sensitivity of robust unit root tests

The power properties of the rank-based Dickey–Fuller (DF) unit root test of Granger and Hallman [C. Granger and J. Hallman, Nonlinear transformations of integrated time series, J. Time Ser. Anal. 12 (1991), pp. 207–218] and the range unit root tests of Aparicio et al. [F. Aparicio, A. Escribano, and A. Siplos, Range unit root (RUR) tests: Robust against non-linearities, error distributions, structural breaks and outliers, J. Time Ser. Anal. 27 (2006), pp. 545–576] are considered when applied to near-integrated time series processes with differing initial conditions. The results obtained show the empirical powers of the tests to be generally robust to smaller deviations of the initial condition of the time series from its underlying deterministic component, particularly for more highly stationary processes. However, dramatic decreases in power are observed when either the mean or variance of the deviation of the initial condition is increased. The robustness of the rank- and range-based unit root tests and their higher power results relative to the seminal DF test have both been noted previously in the econometrics literature. These results are questioned by the findings of the present paper.
Optimal Proportional Reinsurance and Ruin Probability

In this paper, we consider optimal proportional reinsurance from an insurer's point of view to maximize the adjustment coefficient. We obtain the explicit expressions for the optimal results in the diffusion approximation case as well as in the jump-diffusion case. Further, we derive a sharper bound on the ruin probability. When the claim sizes are exponentially distributed, we can prove that the Lundberg's inequality also holds for the ruin probability in the diffusion approximation case. Some numerical examples are presented to show that the ruin probability in the diffusion approximation case sometimes underestimates the ruin probability.
Screech tones from free and ducted supersonic jets

It is well known that screech tones from supersonic jets are generated by a feedback loop. The loop consists of three main components. They are the downstream propagating instability wave, the shock cell structure in the jet plume, and the feedback acoustic waves immediately outside the jet. Evidence will be presented to show that the screech frequency is largely controlled by the characteristics of the feedback acoustic waves. The feedback loop is driven by the instability wave of the jet. Thus the tone intensity and its occurrence are dictated by the characteristics of the instability wave. In this paper the dependence of the instability wave spectrum on the azimuthal mode number (axisymmetric or helical/flapping mode, etc.), the jet-to-ambient gas temperature ratio, and the jet Mach number are studied. The results of this study provide an explanation for the observed screech tone mode switch phenomenon (changing from axisymmetric to helical mode as Mach number increases) and the often-cited experimental observation that tone intensity reduces with increase in jet temperature. For ducted supersonic jets screech tones can also be generated by feedback loops formed by the coupling of normal duct modes to instability waves of the jet. The screech frequencies are dictated by the frequencies of the duct modes. Super resonance, resonance involving very large pressure oscillations, can occur when the feedback loop is powered by the most amplified instability wave. It is proposed that the observed large amplitude pressure fluctuations and tone in the test cells of Arnold Engineering Development Center were generated by super resonance. Estimated super-resonance frequency for a Mach 1.3 axisymmetric jet tested in the facility agrees well with measurement.
P2A-3 High Frequency Attenuation and Size Distribution Measurements of Definity and Manipulated Definity Populations

The contrast agent Definitytrade has recently been shown to have substantial nonlinear activity at high ultrasound frequencies (>10 MHz), which has been hypothesized to be associated with the presence of a significant subpopulation of smaller bubbles (<1-2 micrometers). In this study, we characterized the frequency dependant attenuation properties of Definitytrade and populations of Definitytrade that had been modified to preferentially isolate smaller bubbles through decantation or mechanical filtration procedures. A narrowband pulse-echo substitution method was employed with a series of three transducers covering the frequency range from 2 to 50 MHz. 'Native' Definitytrade was found to have a peak in attenuation in the vicinity of 10 MHz and remained high until 50 MHz. This pattern is significantly different from other clinically approved agents and is consistent with recent reports of nonlinear activity at high frequencies. With increasing decantation times, the attenuation peak became more diffuse and occurred at progressively higher frequencies. By 3 hours for example, attenuation continued to rise until 30 MHz. The bubble size distribution, as measured with a coulter counter, underwent preferential skewing towards smaller bubbles with increasing decantation time. Between 30 seconds and 3 hours, the mean bubble diameter went from 3.99 to 0.98 micrometers. Mechanical filtration with 2 and 1 micrometer pores resulted in attenuation that rose until 15 and 40 MHz respectively. This demonstrates that Definitytrade populations can be manipulated to have improve activity at higher frequencies (>10 MHz), which has implications for UMB and IVUS applications
Atlantic Seasonal Hurricane Frequency. Part I: El Niño and 30 mb Quasi-Biennial Oscillation Influences

Abstract This is the first of two papers on Atlantic seasonal hurricane frequency. In this paper, seasonal hurricane frequency as related to E1 Nino events during 1900–82 and to the equatorial Quasi-Biennial Oscillation (QBO) of stratospheric zonal wind from 1950 to 1982 is discussed. It is shown that a substantial negative correlation is typically present between the seasonal number of hurricanes, hurricane days and tropical storms, and moderate or strong (15 cases) El Nin off the South American west coast. A similar negative anomaly in hurricane activity occurs when equatorial winds at 30 mb are from an easterly direction and/or are becoming more easterly with time during the hurricane season. This association of Atlantic hurricane activity with El Nino can also be made with the Southern Oscillation Index. By contrast, seasonal hurricane frequency is slightly above normal in non-El Nino years and substantially above normal when equatorial stratospheric winds blow from a westerly direction and/or are bec.
Room temperature hydrogen detection using Pd-coated GaN nanowires

Multiple GaN nanowires produced by thermal chemical vapor deposition were employed as gas sensors for detection of hydrogen at concentrations from 200–1500 ppm in N2 at 300 K. Palladium coating of the wires improved the sensitivity by a factor of up to 11 at low ppm concentrations relative to uncoated controls. The GaN nanowires showed relative responses of ∼7.4% at 200 ppm and ∼9.1% at 1500 ppm H2 in N2 after a 10 min exposure. Upon removal of hydrogen from the measurement ambient, ∼90% of the initial GaN conductance was recovered within 2 min. Temperature dependent measurements showed a larger relative response and shorter response time at elevated temperature. The adsorption activation energy of the sensor was 2.2 kcal mol−1 at 3000 ppm H2 in N2. These sensors exhibit low power consumption (<0.6 mW) at 300 K.
Dynamical instability for radiating anisotropic collapse

We study the role played by local anisotropy and radiation (in the free-streaming regime) in the onset of dynamical instabilities. In the case of anisotropy we find that, for Newtonian and post-Newtonian approximations, the relevant quantity is the anisotropy of the unperturbed fluid, and that small anisotropies may, in principle, drastically change the stability of the system. The influence of the free-streaming radiation upon stability appears to be qualitatively of the same type as that of radiative diffusion. Some speculations and prospective applications to astrophysical scenarios are presented
Frequency Equations and Modes of Free Vibrations of Rectangular Plates with Various Edge Conditions

This paper considers linear free vibrations of thin isotropic rectangular plates with combinations of the classical boundary conditions of simply supported, clamped and free edges and the mathematically possible condition of guided edges. The total number of plate configurations with the classical boundary conditions are known to be twenty-one. The inclusion of the guided edge condition gives rise to an additional thirty-four plate configurations. Of these additional cases, twenty-one cases have exact solutions for which frequency equations in explicit or transcendental form may be obtained. The frequency equations of these cases are given and, for each case, results of the first nine mode frequencies are tabulated for a range of the plate aspect ratios.
Analysing competing risks data with transformation models

We present a flexible class of marginal models for the cumulative incidence function. The semiparametric transformation model is utilized in a decomposition for the marginal failure probabilities which extends previous work on Farewell's cure model. Novel estimation, inference and prediction procedures are developed, with large sample properties derived from the theory of martingales and U‐statistics. A small simulation study demonstrates that the methods are appropriate for practical use. The methods are illustrated with a thorough analysis of a prostate cancer clinical trial. Simple graphical displays are used to check for the goodness of fit.
A Comment on the Relationship between the Modal and Time-Distance Formulations of Local Helioseismology

The relationship between the time-distance and modal-decomposition approaches to solar active region seismology is clarified through the consideration of the oscillations of a plane-parallel, isentropic polytrope. It is demonstrated by direct construction that a wave packet formed through the superposition of neighboring p-modes interferes constructively along a ray bundle that follows the appropriate WKBJ ray path obtained by using the eikonal approximation. Because the actual power envelope of the solar 5 minute oscillations restricts the excited p-modes to rather low radial orders, the ray bundles are diffuse and sample portions of the solar envelope that are some ≈ 10-30 Mm distant from the nominal WKBJ ray path. This behavior is consistent with the fact that the eikonal approximation becomes valid only in the limiting case of large radial orders (n ≫ 1). The p-mode wave packets that are isolated by employing the time-distance methods must therefore be described either as a superposition of individual p-modes (a wave packet), or as a sum of ray paths (a ray bundle), depending upon which representation proves to be optimal for the given circumstances.