Miracle-dz/UniFAR-FTUs huggingface dataset:
Hot gas in the interstellar medium: A reanalysis of O VI absorption data

The Copernicus O(+5) column densities toward 72 stars provide a rare and valuable tracer of 10(exp 5.5) K gas in the interstellar medium. The original analysis of the data by Jenkins provided important clues about the distribution of interstellar O(+5) ions, but our understanding of the local interstellar medium has since grown substantially. We revisit that work, including the possibility that local hot gas may contribute a significant O(+5) column density to most lines of sight. Our reanalysis also includes slight improvements in the statistics and was found to be reliable when tested on simulated data sets. In the end, we come to conclusions about the distribution of interstellar O(+5) ions that differ considerably from those of the original analysis. With our reanalysis, some theoretical models now show promise. For example, our Local Bubble column density compares favorably with the estimated quantity of O(+5) within the remnant of an ancient local explosion. Similarly, our mean O(+5) column density per feature in more distant regions is like that found in models of hot interstellar bubbles from either stellar winds or ancient supernova explosions in a warm diffuse interstellar environment, suggesting that the hot gas in interstellar space may exist primarily within discrete regions of modest volume occupation rather than in a continuous and pervasive phase.
Adaptive fault‐tolerant control for a class of output‐constrained nonlinear systems

In this work, by incorporating a tan‐type barrier Lyapunov function into the Lyapunov function design, we present a novel adaptive fault‐tolerant control (FTC) scheme for a class of output‐constrained multi‐input single‐output nonlinear systems with actuator failures under the perturbation of both parametric and nonparametric system uncertainties. We show that under the proposed adaptive FTC scheme, exponential convergence of the output tracking error into a small set around zero is guaranteed, while the constraint requirement on the system output will not be violated during operation. In the end, two illustrative examples are presented to demonstrate the effectiveness of the proposed FTC scheme. Copyright © 2015 John Wiley & Sons, Ltd.
Observationally determined silicon II oscillator strengths

Si II oscillator strengths for eight resonance lines from the ground state have been determined using a curve-of-growth analysis of interstellar data from the Copernicus and International Ultraviolet Explorer satellites. The oscillator strengths for 1526 A and 1808 A increase by factors of 3.0 and 1.5, respectively, from previously tabulated values; those for 989 A and 1020 A decrease by factors of 0.55 and 0.60, respectively. These new values result in better silicon abundances for interstellar clouds and resolve a long-standing puzzle in the interpretation of quasar absorption line data.
Predicting the wind noise from the pantograph cover of a train

Finite element and boundary element calculations are combined to predict the flow noise radiated from a 1/10th-scale model of an aerodynamic cover used around the pantograph on a train at 250 km h -1 . The solutions of the unsteady air flow over the cover and the resulting sound propagation are divided into two parts in order to keep the problem tractable. First the unsteady fluid flow is solved using large-eddy simulation (LES). The pressure histories on the cover are then used to predict the radiated sound, using a boundary element method to solve the Helmholtz equation. The result thus leans heavily on assumptions about the coupling of the two solutions, the propagation of sound in a disturbed medium and the efficacy of LES. The predicted sound pressure levels are compared with experimental measurements made in an anechoic wind tunnel.
Geršgorin theorems by Householder's proof

0. The method. Given an mXm matrix A = [ay] of complex numbers, S. Gersgorin [4] proved that every proper value X lies in the union of the m disks Diy where D^ {X| |X-~a«| <Ry i? t= ]C/^| *ï| }• Generalizations of this theorem have appeared in several papers, see for example [l] , [3], [5], [7], [8], and a convenient summary in [6]. The theorem is derivable from the following (older) result, if we set B=A-\I.
Molecular clouds in the outer Galaxy. III. CO studies of individual clouds

Maps of the CO (J = 1 to 0) line have been obtained in order to explore the physical conditions and star-forming activities in 31 molecular clouds in the outer Galaxy. On a large scale, the clouds are found to follow the H I warp. Antenna temperatures (corrected for atmospheric attenuation, ohmic losses, and rear and forward spillover) are shown to decrease somewhat with distance. The results suggest low kinetic temperatures in the clouds and that the CO line is optically thick. Most of the clouds lie between R = 11.5 kpc and R = 14 kpc, are about 40 pc in the longest dimension, and have masses in the 10 to the 4th to 10 to the 5th solar mass range. 33 references.
He(21S, 21P) excitation and positronium formation in positron-helium collisions at intermediate energies

The close-coupling approximation has been used to investigate positronium formation into the n=1 and n=2 levels and helium excitation (11S-21S, 21P) in positron-helium collisions at energies between 31.3 eV and 200 eV. The authors have used a target basis set of the form He(1s, 2s, ks, 2p, kp) and investigated the effect upon excitation due to the addition of the positronium basis set Ps(1s, 2s, 2p). An independent electron model has been combined with a model potential to represent the helium atom. Positronium formation reduces the 21S excitation below 50 eV but the 21P excitation is significantly reduced for all energies up to 150 eV. The present excitation results are in closer agreement with previous close-coupled calculations than with other theoretical methods. The He(n=2) excitation total is in agreement with experimental data below 36 eV. The calculated total positronium formation cross section is in agreement with experiment below 100 eV.
On the Use of Shock-Capturing Schemes for Large-Eddy Simulation

Numerical simulations of freely decaying isotropic fluid turbulence were performed at various Mach numbers (from 0.2 to 1.0) using known shock-capturing Euler schemes (Jameson, TVD-MUSCL, ENO) often employed for aeronautical applications. The objective of these calculations was to evaluate the relevance of the use of such schemes in the large-eddy simulation (LES) context. The potential of the monotone integrated large-eddy simulation (MILES) approach was investigated by carrying out computations without viscous diffusion terms. Although some known physical trends were respected, it is found that the small scales of the simulated flow suffer from high numerical damping. In a quasi-incompressible case, this numerical dissipation is tentatively interpreted in terms of turbulent dissipation, yielding the evaluation of equivalent Taylor micro-scales. The Reynolds numbers based on these are found between 30 and 40, depending on the scheme and resolution (up to 1283). The numerical dissipation is also interpreted in terms of subgrid-scale dissipation in a LES context, yielding equivalent Smagorinsky “constants” which do not level off with time and which remain larger than the commonly accepted values of the classical Smagorinsky constant. On the grounds of tests with either the Smagorinsky or a dynamic model, the addition of explicit subgrid-scale (SGS) models to shock-capturing Euler codes is not recommended.
Regularity aspects and Hamiltonization of non-holonomic systems

We discuss various aspects of the transition from Lagrangian to Hamiltonian equations for systems with general (nonlinear) non-holonomic constraints. The emphasis is first on constructing the reduced dynamics on the constraint submanifold, and then trying to start a Hamiltonization procedure from there. We prove a theorem concerning the regularity which is required to obtain a unique second-order dynamics on the constraint submanifold, and we show that the same condition allows the transition to a Hamiltonian picture. Throughout the analysis, different degrees of generality are discussed.
Difference in formation of ferromagnetic MnAs nanoclusters on III-V semiconducting nanowire templates

The authors report on the differences in ferromagnetic MnAs nanocluster formation on GaAs, GaAs/AlGaAs, GaAs/GaAsP, and InAs nanowire templates by combing selective-area metal-organic vapor phase epitaxy of semiconducting nanowires and endotaxial nanoclustering of MnAs. To characterize the dependences of MnAs nanocluster formation on semiconducting materials of the nanowire templates, GaAs, GaAs/AlGaAs core-shell, and GaAs/GaAsP core-shell nanowires have been grown at 750 °C, whereas InAs nanowires have been grown at 580 °C. MnAs nanoclusters are commonly and most frequently formed at six ridges between two {0-11} crystal facets on hexagonal prisms of III-V semiconducting nanowires. That is presumably because many atomic steps exist between the crystal facets. Here, MnAs nanoclusters are grown “into” the nanowires, as a result of the phenomenon of “endotaxy”. Manganese atoms on the nanowires surface form chemical bonds mainly with arsenic atoms of the nanowires, because only manganese organometallic source and hydrogen are supplied, i.e. no supply of arsenic hydride source during the endotaxy of MnAs. In the case of GaAs/GaAsP core-shell and InAs nanowires, however, MnAs nanoclusters are formed on the top {111}B surfaces of the nanowires, as well as at six ridges of the hexagonal prisms. The results obtained in the current work possibly show that the endotaxy of MnAs depends on the thermal stability of the nanowires and/or the strength of atomic bonds in the host materials of nanowires.
Achievements and Challenges in the Field of sdB Asteroseismology

We review briefly the status of sdB star asteroseismology. We concentrate on the main achievements that have been obtained so far, and we discuss the current challenges that we now face in the field. 1. Current Census and Survey Work Since the initial serendipitous discovery of the first pulsating sdB star EC 14026− 2647 as reported by Kilkenny et al. (1997), immense progress has been made in terms of uncovering additional pulsators. Indeed, ongoing survey work – essentially broadband fast photometry – carried out by several groups in the last decade has so far revealed the existence of at least 34 stars of the EC 14026−2647 type. These are characterized by low-amplitude, multi-periodic, short-period (80−600 s) luminosity variations that are due to low-order and low-degree p-mode oscillations. A second family of pulsating sdB stars was discovered more recently as reported by Green et al. (2003). These are again low-amplitude, multi-periodic pulsators, but with much longer periods (in the range of 2000 to 9000 s), implying the presence of high-order and low-degree g-modes. A total of 31 confirmed pulsators of the kind is now known, after the prototype PG 1716+426. Quite interestingly, three objects identified initially as short-period pulsators of the EC 14026−2647 kind have also been found to exhibit as well long-period oscillations and, thus, represent a hybrid type. These are Balloon 090100001 (Oreiro et al. 2005; Baran et al. 2005), HS 0702+6043 (Schuh et al. 2006), and HS 2201+2610 (Lutz et al., these proceedings). Needless to say, these three EC 14026−2647/PG 1716+426 hybrid pulsators deserve particular attention.
Chaos, Order, and Periodic Orbits in 3:1 Resonant Planetary Dynamics

This study addresses the long-term evolution of possible two-planet extrasolar systems that are initially trapped in 3:1 mean motion resonance. A planar general three-body problem model is used, and its resonant dynamics are examined by computing periodic orbits in a rotating frame, Poincaré maps, and maps of dynamical stability. We computed the families of symmetric resonant periodic orbits that obey bifurcations, giving rise to families of asymmetric periodic orbits. The linear stability of such orbits has also been computed, and their relation to the long-term stability of their nearby phase-space domain has been studied. The maps of dynamical stability reveal a complicated structure in the phase space, where chaos and order coexist and alternate as the initial eccentricities or the phases of the planets change. The regular orbits are classified into various types according to the librating or rotating evolution of the resonant angles. Apsidal symmetric librations are common in the domain of resonant motion, but asymmetric ones are associated exclusively with the existence of asymmetric periodic orbits. Such a stable asymmetric configuration seems to correspond to the companions b and c of the 55 Cnc extrasolar system, which are trapped in the 3:1 mean motion resonance according to the study of McArthur et al. However, a recent study by Fischer et al. shows the existence of a new planet (the companion f) in the system, and that the planets b and c are not in mean motion resonance.
Heat Transfer Around a Cylindrical Protuberance Mounted in a Plane Turbulent Boundary Layer

Heat transfer characteristics around a low aspect ratio cylindrical protuberance placed in a turbulent boundary layer were investigated. The diameters of the protuberance, D, were 40 and 80 mm, and the height to diameter aspect ratio HID ranged from 0.125 to 1.0. The Reynolds numbers based on D ranged from 1.1×10 4 to 1.1×10 5 and the thickness of the turbulent boundary layer at the protuberance location, 8, ranged from 26 to 120 mm for these experiments. In this paper we detail the effects of the boundary layer thickness and the protuberance aspect ratio on heat transfer. The results revealed that the overall heat transfer for the cylindrical protuberance reaches a maximum value when H/δ=0.24.
Lattices Generated by Orbits of Subspaces Under Finite Singular Classical Groups and Its Characteristic Polynomials

Abstract Let be the (2ν + l)-dimensional vector space over the finite field 𝔽 q , and Sp 2ν+l,ν(𝔽 q ) the singular symplectic groups of degree 2ν + l over 𝔽 q . Let ℳ be any orbit of subspaces under Sp 2ν+l,ν(𝔽 q ). Denote by ℒ the set of subspaces which are intersections of subspaces in ℳ and the intersection of the empty set of subspaces of is assumed to be . By ordering ℒ by ordinary or reverse inclusion, two lattices are obtained. This paper studies the inclusion relations between different lattices, a characterization of subspaces contained in a given lattice ℒ, when the lattices form geometric lattice, and the characteristic polynomial of ℒ.
On the facular contrast near the solar limb

We present an improved measurement of the continuum contrast of solar faculae in wavelength bands centered at 800 and 525 nm. Our findings confirm our earlier result that near the extreme solar limb the contrast decreases with decreasing distance to the limb. Parametrizing the contrast function with . delta.I/I = 0.2+. cap alpha. (.mu.-0.2) over the range 0.08< or =. mu. < or =0.2, where . mu. is the cosine of the heliocentric angle, we obtain the best-fit values of . cap alpha. : . cap alpha. /sub red/ = 0.25 +- 0.10, . cap alpha. /sub green/ = 0.30 +- 0.10.
Reexamination of the age-related sensitivity decrease in ISO 7029 : Do the Japanese have better hearing sensitivity?

National Institute of Advanced Industrial Science and Technology,AIST Central 6, 1–1–1 Higashi, Tsukuba, 305–8566 Japan(Received 1 February 2005, Accepted for publication 17 February 2005)Keywords: Hearing sensitivity, Audiometry, Hearing threshold level, Aging eﬀect, ISO standardPACS number: 43.15. +s, 43.66. Cb, 43.66. Sr [DOI: 10.1250/ast.26. 381]1. IntroductionOur hearing sensitivity to tones of various frequenciesdeclines progressively as we become older. ISO 7029 [1]describes a method for calculating expected median values ofhearing thresholds and the expected statistical distributionaround the median. Such calculation is possible for audio-metric frequencies of 125–8,000Hz. The target population isotologically normal persons aged 18–70 years inclusive. Thisstandard is based on an extensive survey by Robinson andSutton [2] and a supplementary formulation by Shipton [3]. The former investigated audiometric data in 25 studies andﬁnally adopted those in seven papers published from 1959 to1970.However, more than 30 years have passed since the ISOstandard source data were published. During those decades,we, living in an industrialized country, have experiencedchanges that may have aﬀected our hearing ability: hearing-conservation actions have been taken, especially in theworkplace. Sanitary and nutritional conditions have alsoimproved. Adverse eﬀects of World War II have diminishedin most countries including Japan. Therefore, we may displaya diﬀerent proﬁle of hearing sensitivity than that shown in theISO standard.This Letter is intended to review the ISO threshold valuesof diﬀerent ages, comparing them to Japanese data publishedafter the Robinson and Sutton survey. A revision of the ISOstandard is proposed based on the results of comparison.2. Comparison of Japanese hearing-threshold data toISO standard valuesAudiometric data reported in two Japanese studies wereemployed for comparison: Okamoto et al. [4] and Kiritaniet al. [5]. They are comparable to ISO 7029 in that: (1) thesubjects showed no obvious symptoms of ear disease; (2) thesubjects represented a wide range of ages — 20–70 and over;and (3) medians of hearing threshold levels were reported.Table 1 summarizes the numbers of subjects in each age bandselected for the comparison. Although both ears were tested,threshold levels of the better ear were reported in Okamotoet al. and left-and-right averages in Kiritani et al.The ISO standard value is expressed as a hearingthreshold deviation, H
Active broadband polymer stabilized liquid crystals

We consider the realization and the electro-optical behaviour of a polymer network stabilized liquid crystal whose reflection band has been broadened. We particularly emphasize the reflective properties (mean value of the selective reflection and bandwidth, and the parameters of broadening) and their evolution with voltage. Broadband active films can be obtained under special conditions of polymerization. A mechanism concerning the broadening of the reflection band is put forward based on inhomogeneous consumption of a chiral monomer within the samples.
Irregular variations in GPS time series by probability and noise analysis

Abstract The character of the topocentric components in ETRF2000(R08) from the Polish ASG-EUPOS system was analysed using skewness and kurtosis derived from the data probability density function. The data from 115 permanent GPS stations with a time span of more than 5 years were used. The main goal of this research was to show that any unmodelled systematics can disrupt the results. The obtained median values of skewness and kurtosis clearly indicate the discrepancies between the assumed normality of the GPS time series distribution and the reality, mainly due to stochastic and/or deterministic parts that are still present in the data. The quadratic relationship between skewness and kurtosis was developed with the empirically determined constants. The noise analysis with the Maximum Likelihood Estimation was also performed with the assumptions of white and white plus power-law noise. The estimated spectral indices for power law noises are close to −1 (flicker noise). The uncertainties of the intraplate velocities with white and white plus power law noise assumptions were calculated. It was shown that these uncertainties can be underestimated up to 5 mm/year. Additionally we made 1000 simulation which were aimed at showing how the values of skewness and kurtosis are changed when some mismodelled part of the data remains in the time series. We assumed different values of trend (1 and 6 mm/year), seasonal amplitudes (1 and 6 mm) and offsets (3 and 10 mm) with flicker noise of 1 mm amplitude to see how the metrics we use are biased.
Sur l'origine des inhomogénéités de taille et de concentration des boucles de dislocation créées par irradiation électronique dans le CdTe

La theorie de la cinetique chimique est reprise et developpee en ecrivant la diffusion des interstitiels vers les surfaces et leur recombinaison sur celles-ci. Les resultats obtenus par cette modelisation montrent que les effets des surfaces sont a l'origine des gradients de concentration en interstitiels libres, lacunes et boucles de dislocation dans la lame ainsi que de la large distribution en taille de ces dernieres. Apres calcul de la vitesse de recombinaison des interstitiels sur les boucles de dislocation, il est montre qu'un flux diffusionnel d'interstitiels peut s'etablir localement vers les boucles de dislocation et qu'un gradient en concentration de lacunes et interstitiels est ainsi engendre autour des defauts etendus, modifiant sensiblement leur dynamique de croissance.
Krasnoselski–Mann iteration for hierarchical fixed-point problems

This paper deals with a method for approximating a solution of the following fixed-point problem: find , where is a Hilbert space, P and T are two nonexpansive mappings on a closed convex subset D and projFix(T) denotes the metric projection on the set of fixed points of T. This amounts to saying that is the fixed point of T which satisfies a variational inequality depending on a given criterion P, namely: find , where NFix(T) denotes the normal cone to the set of fixed points of T. Convergence results for the proposed method are proved. It should be noted that the proposed method can be regarded as a generalized version of Krasnoselski–Mann's iteration for solving a broader class of problems than the original KM algorithm, namely hierarchical fixed-point problems. This class is very interesting because it covers monotone variational inequality on fixed-point sets, minimization problems over equilibrium constraints, hierarchical minimization problems,…. The special aspect of the algorithm together with convergence results makes it an original and theoretically interesting scheme. On the other hand, the framework is general enough and permits us to treat in a unified way several iterative schemes, recovering, developing and improving some known related convergence results in this field.
FRAGMENT MASS DISTRIBUTION OF PLATELIKE OBJECTS

The fragment mass distributions of platelike objects are investigated by conducting two types of experiments. The first is a {open_quotes}sandwich{close_quote}{close_quote} experiment in which thin glass and plaster plates are inserted between two larger stainless steel plates and an iron projectile is dropped onto the target plate at normal incidence. The second is a {open_quotes}lateral impact{close_quote}{close_quote} experiment in which a hypervelocity nylon projectile collides at the side of the plaster plates. There is a discrepancy in the power-law exponent of fragment mass distribution between the sandwich experiment and the lateral impact experiment. A model that agrees with the experimental results is proposed. {copyright} {ital 1997} {ital The American Physical Society}