Miracle-dz/UniFAR-FTUs huggingface dataset:
A Warp in the Large Magellanic Cloud Disk?

We present a study of the shape of the Large Magellanic Cloud (LMC) disk. We use the brightnesses of core helium burning red clump stars identified in V-I, I color-magnitude diagrams of 50 randomly selected LMC fields observed with the Cerro Tololo Inter-American Observatory 0.9 m telescope to measure relative distances to the fields. Random photometric errors and errors in the calibration are controlled to ≲1%. Following correction for reddening measured through the color of the red clump, we solve for the inclination and position angle of the line of nodes of the tilted plane of the LMC, finding i = 35. °8 ± 2. °4 and θ = 145° ± 4°. Our solution requires that we exclude 15 fields in the southwest of the LMC that have red clump magnitudes ∼0.1 mag brighter than the fitted plane. On the basis of these fields, we argue that the LMC disk is warped and twisted, containing features that extend up to 2.5 kpc out of the plane. We argue that alternative ways of producing red clump stars brighter than expected, such as variations in age and metallicity of the stars, are unlikely to explain our observations.
The adiabatic invariant of the n-degree-of-freedom harmonic oscillator

In this graduate-level theoretical paper, we propose a general derivation of the adiabatic invariant of the n-degree-of-freedom harmonic oscillator, available whichever the physical nature of the oscillator and of the parametrical excitation it undergoes. This derivation is founded on the use of the classical Glauber variables and ends up with this simplest result: the oscillator's adiabatic invariant is just the sum of all the semiclassical quanta numbers associated with its different eigenmodes.
Spark plasma sintering and thermal conductivity of carbon nanotube bulk materials

Carbon nanotube (CNT) bulk samples were fabricated by spark plasma sintering (SPS), which, as a rapid consolidation technique, preserved the phase structure and diameter of cylindrical tubules of the CNTs even at high temperatures of up to 2000°C. The thermal conductivity of the resultant bulk samples was measured by the conventional laser-flash method, and the corresponding thermal conductivity was found to be as low as 4.2W∕m∕K at room temperature. This low thermal conductivity of the CNT bulk materials was explained on the basis of multiple physical elements including intensive tube–tube interactions. CNT bulk materials may find potential applications as thermoelectric materials that require low thermal conductivity, but high electrical conductivity.
Full evolution of the 6 and 20 centimeter radio emission from SN 1980K

First detected at 6 cm in 1980 November, only 1 month after optical maximum, and several months later at 20 cm in 1981 March, SN 1980K has now dropped below reasonable monitoring limits of the VLA at these two frequencies. It thus represents the first Type II radio supernova to have been well-studied at centimeter wavelengths from «turn-on» to «turn-off. » It also represents one of the few radio supernovae to have such an extensive, decade-long, multiple-frequency data set. New observations of SN 1980K made with the VLA at 20 and 6 cm from 1984 November through 1990 December ar presented
Infrared reflectivity and lattice fundamentals in anatase TiO 2 s

Polarization-dependent far-infrared reflectivity measurements were carried out on single crystals of anatase TiO2. The results were analyzed to yield the dielectric dispersion properties of anatase in the lattice fundamentals regime. The frequencies ~in cm! of the transverse optical ~TO! and longitudinal optical~LO! zone-center phonons were determined to be 367 ~755! for the TO~LO! of theA2u mode, 262~366! and 435~876! for the Eu modes. The large TO-LO splittings were used to estimate effective charges. @S0163-1829 ~97! 02009-2#
Inelastic electron tunneling study of crystallization effects and defect energies in hafnium oxide gate dielectrics

Changes in phonon spectra and point defect populations that accompany crystallization of HfO2 were investigated by inelastic tunneling across Al/HfO2/SiO2/Si. Spectral features from tetragonal- and monoclinic-HfO2 vibrational modes are observed in annealed films, while they are not detected in as-deposited samples, consistent with selected area electron diffraction analysis. In addition to features indexed as vibrational modes, peaks whose amplitude and energy vary with bias history were detected for p-type Si. We attribute these features to point defect-related states in the HfO2 band gap and find good agreement between their energies and those predicted theoretically for oxygen vacancy levels in HfO2.
Energy considerations for linear instabilities of parallel magnetohydrodynamic flows

A formulation with the flow as the prime source of instability and dissipation as a triggering mechanism is presented as an alternative to the “negative energy” formulation of instabilities of parallel flows. The formulation is based on the linear wave energy equation. The apparent opposition between the “negative energy” wave formulation and the linear wave energy formulation, where the wave energy is always positive, is resolved.
Degrees of greatest common divisors of invariant factors of two regular polynomial matrices

Abstract In a previous paper it was shown that a necessary and sufficient condition for two regular polynomial matrices T and U to have relatively prime determinants is that a certain matrix R be non-singular. This generalization of the resultant of two scalar polynomials is extended to give an expression for the sum of the degrees of the greatest common divisors of all pairs of invariant factors of T and U in terms of the rank of R. Further, if rank R exceeds a given value then specified pairs of factors are relatively prime.
An Algorithm for the Calculation of the Time-Dependent Mixing Height in Coastal Sites

Abstract This paper describes a simple algorithm for the calculation of the time-dependent mixing height h(t) in coastal sites using wind, temperature, momentum flux, and heat flux time series as input data. A stationary expression for the coastal internal boundary layer height is used to avoid the solution of a partial differential equation for the evolution of h as a function of time and fetch, thus reducing the problem to a direct integration in time. The algorithm has been implemented in a previously developed scheme that allows a continuous calculation over the diurnal cycle. The calculated evolution of h(t) is compared with sodar estimates in a coastal site over a few days.
Novel continuously shaped diffractive optical elements enable high efficiency beam shaping

LIMO's unique production technology is capable to manufacture free form surfaces on monolithic arrays larger than 250 mm with high precision and reproducibility. Different kinds of intensity distributions with best uniformities or customized profiles have been achieved by using LIMO's refractive optical elements. Recently LIMO pushed the limits of this lens production technology and was able to manufacture first diffractive optical elements (DOEs) based on continuous relief's profile. Beside for the illumination devices in lithography, DOEs find wide use in optical devices for other technological applications, such as optical communications, laser technologies and data processing. Classic lithographic technologies lead to quantized (step-like) profiles of diffractive micro-reliefs, which cause a decrease of DOE's diffractive efficiency. The newest development of LIMO's microlens fabrication technology allows us to make a step from free programmable microlens profiles to diffractive optical elements with high efficiency. Our first results of this approach are demonstrated in this paper. Diffractive beam splitters with continuous profile are fabricated and investigated. The results of profile measurements and intensity distribution of the diffractive beam splitters are given. The comparison between theoretical simulations and experimental results shows very good correlation.
Multi-exposure imaging for measurements in rubber production

In the paper, the application of high dynamic range and exposure fusion techniques to image-based measurement systems is described. The advantages of such techniques are discussed, and their performances are compared to the original high-contrast images and between them. Results will show the improvements of measurement reliability achieved with the technique presented in the case of length measurements of industrial products characterized by different surface reflectance.
The question of mass in (anti-) de Sitter spacetimes

The possible existence of a non-zero cosmological constant Λ gives rise to controversial interpretations. By Λ we here understand some sort of bare cosmological constant, and not the observed one that should contain modifications coming from the classical or the quantum fluctuations of matter fields. Is Λ a universal constant fixing the geometry of an empty universe, as fundamental as the Planck constant or the speed of light in the vacuum? Is it instead something emerging from a perturbative calculus performed on the metric solution of the Einstein equation and to which it might be given a material status of (dark or bright) ‘energy’? Since a physical quantity like mass originates in a Minkowskian conservation law, we proceed to a group theoretical interpretation of this relation in terms of the two possible Λ-deformations of the Poincaré group, namely the de Sitter and anti de Sitter groups. We use the so-called Garidi mass in order to make clear the asymptotic relations between Minkowskian masses m and their possible dS/AdS counterparts.
Drastic changes in the plasma potential inside a hollow anode during an applied accelerating pulse

We present results which show drastic changes in the parameters of a hollow anode (HA) which serves as a cathode in an electron diode. The HA has a ferroelectric plasma source (FPS) incorporated in it. The applied accelerating pulse causes increase of the potential of the plasma inside the HA up to 7 kV and switches the direction of the current of plasma electrons from the HA and its output grid towards the accelerating gap. It is shown that, in spite of the large positive plasma potential, electron emission occurs due to the dynamics of ion motion in the sheath near the HA grid.
Oscillator strengths for allowed and intercombination transitions in neutral sulfur

A B-spline box-based multi-channel method for treating Rydberg series is applied for systematic calculations of transition probabilities in neutral sulfur for energy levels up to n = 12. Extensive configuration–interaction wavefunctions in close-coupling form are used to represent the atomic levels. Special attention is paid to the treatment of inner-core and core–valence correlations at the same level of accuracy for all states. Non-orthogonal sets of one-electron radial functions are used to account for the strong term dependence of these orbitals. Relativistic effects are included through correction terms of the Breit–Pauli Hamiltonian. The agreement in the length and velocity gauges of the transition data and the accuracy of the binding energies are used to estimate the accuracy of our results, which are also compared with previous theoretical predictions, experimental measurements, and values predicted from astrophysical data.
Discretization error and signal/error correlation in atmospheric data assimilation : (II). The effect of unresolved scales

This paper is the 2nd of a 2-part study of the effects of forward interpolation error and model discretization error on atmospheric data assimilation. Utilizing the generalized Kalman filter developed in part (I), that investigation is here extended to the case where not all scales in the signal are resolvable by the analysis mesh (although they may all be sampled by the observation network). The error in the unresolved scales is thus able to affect the forward interpolation and model discretization errors and the signal/error correlations considered in part (I). In some circumstances, the results are found to be qualitatively similar to those observed when all scales were resolved, but at a much higher error level. This strengthens the corresponding results of part (I) by extending them to the situation where there are unresolved scales. The most important findings of this type are the following. (a) Models, however imperfect, reduce analysis error. (b) The neglect of signal/error correlation can result in a serious underestimate of analysis error. (c) While model truncation error has a blue spectrum, proper inclusion of signal/error correlation has the effect of reddening the spectrum. Other important findings of this paper are the following. (i) The error in the unresolved scales cannot be eliminated by data assimilation. Moreover, the existence of unresolved scales not only increases the magnitude of the forward interpolation and model discretization errors due to errors in these scales, but also produces error in the resolved scales. (ii) While simple models can provide useful information about the mechanisms of analysis error growth and decay, the coupling of these models with very special observation networks (e.g., coincident with the analysis mesh) may yield results which are misleading with respect to more realistic models and networks. (iii) For imperfect models, both the magnitude of the analysis error and the forecast-error correlation structure are much more sensitive to model resolution than to observation network density. DOI: 10.1034/j.1600-0870.1997. t01-4-00004.x
Structure and evolution of an isolated semi‐geostrophic cyclone

The evolution and structure of an indealized low-pressure system is studied within the framework of the semi-geostrophic dynamics and in the limit of uniform potential vorticiy. An isolated cyclone is grown from suitably chosen initial conditions, rather than studying the evolution of a longitudinally periodic train of baroclinic systems. It is shown that the resulting development is able to produce a range of flow features that compare favourably with observationally based conceptual models of cyclogenesis. These features include in particular: (i) the simultaneous occurrence of both a cold and a warm front whose alignment shows some of the characteristics of occluded frontal systems and is skin to the notion of a frontal fracture, (ii) a dry descending air-stream to the rear of the cyclone, (iii) a narrow region of maximum ascent within the warm front an its bent-back portion, (iv) a poleward traveling air-stream ahead of the cold front, and (v) a γ-shaped pattern of vertical lifting comparable with the cloud patterns as commonly observed in satellite pictures. The evolving cyclone is analysed both form Lagrangian and Eulerian viewpoints. It is demonstrated that Lagrangian criteria exist that allow for the objective definition of air-streams and flow patterns within developing cyclones. The structures of cold and warm fronts at low levels are significantly affected by the different nature of the Lagrangian trajectories within each of these regions. In particular, the air parcels in the warm-frontal region are transported rapidly towards the centre of the low, resulting in a low-level warm front with an intrinsically three-dimensional structure and an associated vorticity gradient in the along-front direction.
Improved estimators for generalized linear models with dispersion covariates

This paper addresses the issue of bias reduction of maximum likelihood estimators in generalized linear models with dispersion covariates. For this class of models, we derive general formulae for the second-order biases of maximum likelihood estimators of the linear and dispersion parameters, linear predictors, precision parameters and mean values. Our formulae cover many important and commonly used models and can be viewed as an extension of the results in Cordeiro and McCullagh (1991) and Cordeiro (1993)These formulae are easily implemented by means of supplementary weighted linear regressions. They are also simple enough to be used algebraically to obtain several closed-form expressions in special models. The practical use of such bias corrections is illustrated in a simulation study.
Multi-Angle Digital Holographic Profilometry for Precision Measurements

A novel digital holographic interferometry used for measuring the 3D shape is proposed. The theory analysis and simulation of multi-angle interferometry are described. General holographic interferometry are not able to measure the discontinuous object because of the phase unwrapping. However, in this method, holographic interferograms are generated by object beam and reference beam with different incident angles. Height information of every point at the object surface is extracted independently without the phase unwrapping. The results of simulation demonstrate that this method can be used for measuring the complicated and discontinuous object. It will be useful for the measuring the large and complex discontinuous surfaces often exist in mechanical machining.
Bias-stress-induced creation and removal of dangling-bond states in amorphous silicon thin-film transistors

We report on the threshold voltage shift in amorphous silicon thin‐film transistors, subjected to a gate bias for a prolonged period of time (bias stress). For transistors made with a silicon nitride gate insulator, the threshold voltage shift for low positive bias is due to dangling‐bond‐state creation in the amorphous silicon layer. For low negative bias, the threshold voltage shift is due to the bias‐stress‐induced removal of dangling‐bond states. These results are contrasted with previously published results for oxide transistors, but both results are consistent with a defect pool model for the dangling‐bond states. The difference for oxide and nitride transistors is due to a different zero‐bias Fermi energy position at the interface. For nitride transistors at much larger applied bias, the dominant mechanism changes and the threshold voltage shift is dominated by charge trapping in the gate dielectric. This is found for both large negative and large positive bias.
Typical decision problems in the first-order autoregressive time series

Applied statistical decision theory has wide applications in decision-making fields of studies, such as economic, business management and industrial managements. In this work, following Pratt et al.’s [Introduction to statistical decision theory. 3rd ed. Cambridge, MA: The MIT Press; 2001] approach, we provide theoretical and practical formulations for the calculations of the key decision-making indices expected value of perfect information and expected value of sample information, whenever the unknown state appears to be the first-order autoregressive (AR) time series parameter that assumes a normal prior distribution. A practical procedure is furnished for calculating the decision-making indices. We treat the finite and infinite state spaces for the linear value functions and the quadratic opportunity losses. Interestingly our investigations on the distribution of the mean of the posterior distribution lead us to a general form for the corresponding statistic and its distribution, discussed by Reeves [The distribution of the maximum likelihood estimator of the parameter in the first-order AR series. Biometrika. 1972;59:387–394], Moschopoulos and Canada [The distribution function of a linear combination of chi-squares. Comput Math Appl. 1984;10:383–386], and Roychowdhury and Bhattacharya [On the performance of estimators of parameter in AR model of order one and optimal prediction under asymmetric loss. Model Assist Stat Appl. 2008;3:225–232].
Numerical Investigation of Near-Wall Turbulent Heat Transfer Taking Into Account the Unsteady Heat Conduction in the Solid Wall

The deterministic near-wall turbulence model developed by Kasagi et al. (1984b) is used in a numerical analysis of turbulent heat transfer, in which the unsteady heat conduction inside the wall associated with the turbulent flow unsteadiness is taken into account. Unlike the typical methodology based on Reynolds decomposition, the algebraic expressions for the three fluctuating velocities given by the model are directly introduced into the governing energy equation. From the numerical results of the unsteady conjugate heat transfer, the statistical quantities, such as temperature variance, turbulent heat flux, and turbulent Prandtl number, are obtained for fluids of various Prandtl numbers. It is demonstrated that the near-wall behavior of these quantities is strongly influenced by the thermal properties and thickness of the wall. In addition, the budget of the temperature variance associated with coherent turbulence structure is calculated and, except for dissipation, each budget term is in qualitative agreement with the experiment.
Antiferromagnetic Ising spin glass

Ising magnetic systems exhibiting re-entrant phase transitions from the antiferromagnetic phase to the non-ergodic mixed phase are considered. The phase diagram in external magnetic field is found. It is shown that the temperature derivative of the sublattice magnetisation is continuous at the re-entrant transition temperature. The reversible magnetic susceptibility in the non-ergodic phase with long-range magnetic order depends slightly on temperature, unlike that in the pure spin glass. It appears that the temperature of the transition into the mixed phase increases with increasing magnetic field.
Neutral and Ionised Hydrogen in NGC 4214

Abstract It is not clear at present how the diffuse ionised gas (DIG) component in galaxies is ionised. The leading hypothesis is that ultraviolet photons from star clusters are responsible, but this requires a rather porous interstellar medium if the photons are to travel the large distances (≥ 1 kpc) between the bright clusters and diffuse-emission regions. To examine this hypothesis, we present high-resolution VLA observations of the neutral hydrogen in the Magellanic galaxy NGC 4214, and compare them with an Hα image. The data appear consistent with the idea that enough UV photons escape from supergiant H II regions to ionise the DIG.
Electron collision cross sections at low energies for all transitions between the n=1, 2, 3, 4 and 5 levels of atomic hydrogen

Collision strengths for all transitions among states up to the n=5 level are reported in the energy range below 1.96 Ryd. The R-matrix and no-exchange programs have been used for partial waves with L 9 respectively. The results are analysed in detail highlighting the resonance structure. They are also compared with other results. The effective collision strengths obtained after averaging the collision strengths over a Maxwellian distribution of electron velocities are listed at temperatures below 50000 K. Though the results require an improvement especially in the intermediate energy region, nevertheless they are probably the best available for most of the transitions.
Improving thermoelectric performance of caged compounds through light-element filling

Heavy elements filling have been considered the most effective way to improve the thermoelectric performance of caged compounds such as CoSb3 by reducing kL. Here, we show an opposite example of filling a light element, Na, into CoSb3 for obtaining high thermoelectric figure of merit ZT.ZT=1.25 at 850 K for Na0.48Co4Sb12 is one of the highest values among all reported single-element-filled CoSb3. The Na-filling scatters phonons less effectively but it results in relatively high mobility thus large power factor. This most likely comes from the extra electronic states near the Fermi level induced by Na.