Miracle-dz/UniFAR-FTUs huggingface dataset:
Infrared spectroscopy of Sakurai's object

We present near (ground-based) and far (ISO) infrared spectroscopy of Sakurai's object. As in the case of the optical spectrum, between 1996 and 1997 April the near-infrared spectrum underwent a dramatic change to later spectral type, and there is some evidence that the spectrum continued to evolve during 1997. Molecular features of carbon-bearing molecules (CN, C2, CO) — corresponding to those seen in cool carbon stars — are now prominent in the 1–2.5 μ m range, and the 12C/13C ratio is low. The ISO data demonstrate the presence of hot circumstellar dust at a temperature of ∼ 680 K. If the dust shell is optically thin, the dust mass is ∼ 2.8 × 10−8 M⊙.
Multiple shocks around the low{luminosity protostar IRAS 16293{2422 ?

Using the IRAM 30 m and SEST 15 m telescopes we mapped an area covering 300 00 220 00 around IRAS 16293 2422 in the N2H + J =1 ! 0, H2CO J =3 1;3 ! 21;2 ,S iOJ =2 ! 1 J =3 ! 2a ndJ =5 ! 4 molecular transitions. Five positions were also observed in the FIR, between 45 m and 200 m, with the Long Wavelength Spectrometer on board ISO, revealing only (C ii) 158 ma nd (Oi )6 3m emission. All these ob- servations are used to reconstruct the complex morphology of the region, in which several outflows from several sources co-exist. The N2H + line emission is strong and centered on 16293E, a recently discovered low mass and very young protostar situated South-East of IRAS 16293{2422. Only weaker N2H + line emission is associated with the binary system IRAS 16293{2422, presumably because the gas surrounding it is warmer. In addition to the previously known North-East{South-West outflow powered by IRAS 16293{2422, we suggest the existence of a second outflow in this binary system. We also report the discovery of a North-West{South-East flow driven by 16293E. The impact of the outflows with the ambient cloud is probed by the SiO and H2CO maps, which reveal the presence of at least four, possibly six shocked regions. We discuss in some detail the nature of the shocks, deriving densities, temperatures and column densities of the shocked gas of the various observed components. We suggest that the wind and ambient shocks are probed by the high and low velocity components observed in the SiO lines. The morphology of the H2CO, SiO and (O i) line emissions are rather dierent, showing almost all kind of combinations. We discuss the origin of these dierences in terms of the age of the shocks, the pre-shock densities and of the composition of the ices which are partially desorbed by the shocks.
A Critical Comparison of Eulerian-Grid-Based Vlasov Solvers

A common problem with direct Vlasov solvers is ensuring that the distribution function remains positive. A related problem is to guarantee that the numerical scheme does not introduce false oscillations in velocity space. In this paper we use a variety of schemes to assess the importance of these issues and to determine an optimal strategy for Eulerian split approaches to Vlasov solvers. From these tests we conclude that maintaining positivity is less important than correctly dissipating the fine-scale structure which arises naturally in the solution to many Vlasov problems. Furthermore we show that there are distinct advantages to using high-order schemes, i.e., third order rather than second. A natural choice which satisfies all of these requirements is the piecewise parabolic method (PPM), which is applied here to Vlasov's equation for the first time.
A mathematical model of prostate tumor growth and androgen-independent relapse

A mathematical model is developed that investigates polyclonality and decreased apoptosis as mechanisms for the androgen-independent relapse of human prostate cancer. The tumor is treated as a continuum of two types of cells (androgen-dependent and androgen- independent) whose proliferation and apoptotic death rates differ in response to androgen rich and androgen poor conditions. Insight into the tumor's response to therapies which both partially and completely block androgen production is gained by applying a combination of analytical and numerical techniques to the model equations. The analysis predicts that androgen deprivation therapy can only be successful for a small range of the biological parameters no matter how completely androgen production is blocked. Numerical simulations show that the model captures all three experimentally observed phases of human prostate cancer progression including exponential growth prior to treatment, androgen sensitivity immediately following therapy, and the eventual androgen-independent relapse of the tumor. Simulations also agree with experimental evidence that androgen-independent relapse is associated with a decrease in apoptosis without an increase in proliferation.
Optimization and tolerance analysis of QCSE modulators and detectors

This paper describes the design constraints and optimization of multiple-quantum-well (MQW) devices for use as flip-chip bonded devices on silicon circuitry. These devices act as quantum-confined Stark effect (QSCE) modulators and detectors. It is shown that the optimal device thickness depends upon the biasing voltage levels as well as the voltage swing that is available from the silicon circuitry. Lower voltages favor thinner device designs. It was found that, for GaAs-AlGaAs quantum wells, a design in which the modulator and detector are of identical design, a combined efficiency of 0.36 could be achieved with a 5-V swing on the modulators, falling to 0.21 with 2.5 V. By using separate layers for the design of the modulator and detector, the performance could be improved significantly with 0.48 achievable for a 5-V swing. It is shown that optimizing the device to minimize nonuniformity effects makes the optimal design thinner.
Towards a self-consistent model of the keyhole in penetration laser beam welding

The stability of a cylindrical keyhole is investigated using the energy and pressure balance. Non-equilibrium evaporation from the keyhole surface, surface tension, hydrostatic and hydrodynamic pressure in the melt as well as heat conduction into the workplace are considered. In contrast to former investigations, the temperature at the keyhole wall and the radius of the keyhole adjust themselves self-consistently. A threshold for the laser power per thickness of the workpiece is found above which the formation of a stable keyhole commences. For iron, this threshold is 790 W mm-1. The temperature at the keyhole wall exceeds evaporation temperature by approximately 100 K. The keyhole radius exceeds the radius of the laser beam and is at least 1.7 times the laser radius.
A model-based approach to video-based eye tracking

Video-based eye tracking typically relies on tracking the pupil and a first-surface corneal reflection (CR) of an illumination source. The positional difference between these two features is used to determine the observer's eye-in-head orientation. With the use of head-mounted eye trackers, this positional difference is unavoidably affected by relative movements between the eye tracking camera and the subject's eye. Video-based trackers also suffer from problems resulting in poor CR detection, such as spurious reflections being mistaken as the desired CR. We approach these problems by modelling how these features—pupil and CR—are affected by different relative movements of the eye. Optical relationships between the offset of the apparent pupil centre and that of the CR are derived. An experiment was conducted with five observers to support these derivations. Solutions to the aforementioned problems using these offset relationships are provided. The first application compensates for movements of an eye tracking camera with respect to the eye and reduces noise in the final eye orientation data. The second application is prediction of CR locations for artefact removal in the new eye tracking system prototype.
Resolution of redundant manipulators via distance optimization

Abstract Redundant manipulators are useful in practice as they have freedom in addition to that needed for a specific end-effector position. This additional freedom has to be properly resolved, and such redundancy resolution problems have been actively studied over the past decade. The most common scheme for redundancy resolution is achieved at the joint velocity level and does not take into account the presence of obstacles. This work presents a new scheme for redundancy resolution based on maximizing the shortest distance to obstacles. The aim is to resolve the redundancy by reconfiguring the robot to be at the safest pose or furthest from obstacles. The proposed scheme resolves the redundancy at the joint position level and, hence, has the advantage of ensuring collision-free motion. Several numerical examples in two- and three-dimensional spaces demonstrate the effectiveness of the proposed scheme.
Incorporation of ENDF-V neutron cross section data for calculating neutron-induced single event upsets

The authors report on improved methodologies of predicting upset rates of sensitive devices for neutron energies less than 20 MeV and between 20 and 50 MeV in silicon and apply these to predicting the neutron-induced single-event upset (NSEU) in the atmosphere for one of the most SEU-sensitive LSI bipolar RAMs (93L422). The improved method uses the differential cross section in both energy and angle from the most recent Evaluated Neutron Data File (ENDF-V), an extrapolation of the ENDF data to neutron energies in the 20-50-MeV range, and the detailed energy and angular dependence of the energy deposited as ionization in the sensitive volume of the device. The revised conclusions principally are: (a) elastic scattering contribution is reduced from that predicted by previous methods by an energy-dependent factor approaching an order of magnitude at 19 MeV; (b) the contribution due to inelastic scattering processes is dominant, particularly for neutron energies above 10 MeV, as opposed to dominance by the elastic scattering predicted previously; and (c) the previously neglected alpha particle contribution in (n,alpha) reactions is significant for critical charges >
DISCOVERY OF FOUR kpc-SCALE BINARY ACTIVE GALACTIC NUCLEI

We report the discovery of four kpc-scale binary active galactic nuclei (AGNs). These objects were originally selected from the Sloan Digital Sky Survey based on double-peaked [O iii] λλ4959, 5007 emission lines in their fiber spectra. The double peaks could result from pairing active supermassive black holes (SMBHs) in a galaxy merger or could be due to bulk motions of narrow-line region gas around a single SMBH. Deep near-infrared (NIR) images and optical slit spectra obtained from the Magellan 6.5 m and the Apache Point Observatory 3.5 m telescopes strongly support the binary SMBH scenario for the four objects. In each system, the NIR images reveal tidal features and double stellar components with a projected separation of several kpc, while optical slit spectra show two Seyfert 2 nuclei spatially coincident with the stellar components, with line-of-sight velocity offsets of a few hundred km s−1. These objects were drawn from a sample of only 43 objects, demonstrating the efficiency of this technique to find kpc-scale binary AGNs.
Item Parameter Estimation for the MIRT Model

The accuracy of item parameter estimates in the multidimensional item response theory (MIRT) model context is one that has not been researched in great detail. This study examines the ability of two confirmatory factor analysis models specifically for dichotomous data to properly estimate item parameters using common formulae for converting factor loadings and thresholds to discrimination and difficulty indices. The two MIRT estimation methods included in this research, unweighted least squares (ULS) and robust weighted least squares (RWLS), and the unidimensional estimation approach used are accessible in the widely distributed software packages NOHARM, Mplus, and BILOGMG, respectively. These techniques have been assessed in terms of the overall accuracy, bias, and standard error of item parameter estimates under a variety of sample sizes, test lengths, intertrait correlations, pseudo-guessing, and latent trait distribution conditions. Results indicate that there exists a complex relationship between these manipulated factors and the estimation accuracy of these methods. Recommendations for practice in light of these results are provided.
Star cluster evolution with primordial binaries. II, Detailed analysis

The evolution of globular cluster models containing significant numbers of primordial binaries is followed to the point at which the primordial fuel is spent and the behavior reverts to the 'single-star' form. This point is reached after some 30 initial core collapse times when the cluster has expanded by a factor of about five to seven. For N about 1100, the ratio of core radius to virial radius just after core collapse is about 0.12. This ratio then drops linearly in comoving time, reaching the asymptotic single-star value of about 0.05. The core mass drops by a factor of two during this time. The first detailed statistical study of the spatial evolution of the binary population in a star cluster is also reported. The mass fraction of binaries in the core shows a steady, near-linear decrease from 0.5 to 0.1 between 20 and 250 instantaneous half-mass crossing times. Hard binaries are found to harden both through the effects of strong scattering and through the declining energy scale set by the expanding cluster. 23 refs.
Transient Response of Parallel and Counterflow Heat Exchangers

The analysis of the transient behavior of shell and tube heat exchangers has been carried out by many researchers. Compared with the finite-difference procedure, the method presented in this note can be used to calculate directly the transient responses at arbitrary values of z and x, without performing many-step calculations pertinent to the selected time and space steps. Being different from other analytical procedures that can only deal with the transient responses to a step input change, this semi-analytical method can be applied to predicting the transient behavior subject to arbitrary inlet temperatures is shell and tube heat exchangers with parallel or countercurrent flow.
Superconductor–normal–superconductor Josephson junctions fabricated by oxygen implantation into YBa2Cu3O7−δ

We report Josephson junctions in YBa2Cu3O7−δ films, fabricated by oxygen irradiation through a 50 nm wide slit in an implantation mask. After annealing the irradiated microbridges at 500 °C in an oxygen atmosphere, this process creates a homogeneous barrier region with a reduced but finite transition temperature, allowing Josephson coupling in a temperature window of ⩽15 K. Over the entire temperature range of Josephson coupling these junctions show resistively shunted junction behavior. The exponential dependence of the critical current on temperature is in good agreement with conventional superconductor–normal–superconductor proximity effect theory.
Horizontally Issuing Diffusion Flames Characterized by OH-PLIF and Visualizations

Planar laser induced fluorescence and flame visualizations characterized the effect of buoyancy on the behavior of the combustion zone of diffusion jet flames which issued from horizontally-oriented tubes into ambient air. The study focused on the mixing characteristics of propane and ethylene at Reynolds numbers ranging from 300 to 1500 in the near field of the jet (up to X/D=9) and Froude numbers ranging as low as 0.36, based on cold-flow gas properties and conditions. Performing the study with a variety of fuel tube diameters enabled independent control of Froude and Reynolds numbers. The PLIF visualizations revealed the presence of the hydroxyl radical in the mixing layer for all cases. The hydroxyl concentrations were consistently higher in the upper portion of the mixing layer, indicative of more vigorous mixing in this region. The visualizations also revealed the evolution of polycyclic aromatic hydrocarbons which were initially spatially segregated from the portion of the reaction zone containing the hydroxyl radical. The polycyclic aromatic hydrocarbons initiate in fuel-rich regions nearer to the jet core than the hydroxyl radical, though the two regions eventually combine well downstream of the tube exit. Both the hydroxyl radical and the polycyclic aromatic hydrocarbons were more prominent on the upper side of the jet flame. Both propane and ethylene fuels led to qualitatively similar features of the flow field, indicating the important role played by the buoyancy-influenced fluid dynamics of the combustion products. The resulting cross sectional PLIF images were used to produce a three-dimensional representation of the reaction zone, indicating the jet spread and trajectory. The data was empirically correlated and found to collapse when based on the Froude number consistent with the density and temperature of a fully-reacted stoichiometric mixture. Complementary visualizations provided additional insight into the trajectory of the jet flame and revealed features of the reaction zone farther from the tube exit.
Hydrogen effusion from hydrogenated amorphous silicon caused by the deposition of a silicon nitride overlayer

The effect of silicon nitride (SiN) deposition on hydrogenated amorphous silicon (a‐Si:H) has been investigated to find the origin of the difference of a‐Si:H/SiN interface properties caused by the order of deposition. Sheet conductance of the on‐state in inverted staggered (a‐Si:H on SiN) thin‐film transistors (TFTs) increases gradually with the substrate temperature (Tsub) of SiN, but decreases rapidly with the Tsub of SiN in staggered TFTs (SiN on a‐Si:H). Photoluminescence experiments indicated that the degradation in staggered TFTs was due to the creation of defects in a‐Si:H by the deposition of the SiN overlayer. It was shown by Fourier transform infrared attenuated total reflection that the origin of the defects was hydrogen effusion from a‐Si:H.
Foreign Language Anxiety and Student Interpreters’ Learning Outcomes: Implications for the Theory and Measurement of Interpretation Learning Anxiety

Although anxiety has been documented as an important variable in both interpretation performance and second language acquisition, there has been virtually no research on the interconnections between the anxiety reactions induced by these two cross-linguistic / cultural endeavors. A review of the literature on anxiety and interpretation performance finds that most of the existing studies have treated the anxiety induced by interpretation as a transfer of other general types of anxieties, such as trait anxiety, without considering the probable role of second language anxiety in interpretation performance. In order to determine the role of foreign language anxiety in 213 Chinese-English interpretation students’ learning outcomes, which were indexed by the participants’ mid-term exam scores and semester grades, this study employed Spielberger’s (1983) Trait Anxiety Inventory to measure the students’ trait anxiety, while utilizing Horwitz, Horwitz et al.’s (1986) Foreign Language Classroom Anxiety Scale (FLCAS) to measure the participants’ foreign language anxiety. Results of correlation analyses showed that a) trait anxiety was not related to either mid-term exam scores or semester grades, b) foreign language anxiety was significantly and negatively associated with both outcome measures, c) after controlling for the effect of trait anxiety, the relationship between foreign language anxiety and interpretation learning outcomes remained significant, and d) a vast majority of the FLCAS items had significant and negative associations with both outcome measures. Implications for developing a theory of and a measurement instrument for interpretation learning anxiety are suggested.
The role of FA1:Ag+ defects in laser light generation and coadsorption of CO and halogen atoms at the KCl and KBr surface sites. First principles calculations

FA1:Ag+ color center at the low coordination (100) and (110) surface sites of KCl and KBr thin films play an important role in providing tunable laser oscillation and adsorbatesubstrate interactions. Double-well potentials at this site are investigated using ab initio molecular electronic structure calculations. The calculated Stokes shifted (optical transition bands), opticaloptical conversion efficiencies, the probability of orientational destruction, exciton (energy) transfer and Glasner-Tompkins empirical rule suggest that laser light generation is sensitive to (i) the lattice anion, (ii) the coordination number of surface ions, and (iii) the choice of the basis set centered on the anion vacancy. The adsorbate-substrate interactions were found to be dependent on the electronegativity of the adatom and on the lattice anion. Optimised geometries and the coadsorption of CO and (F, Cl, Br, I) on KCl and KBr (100) crystals are presented. Calculated chemisorption energies for CO on the (halogen atom/defect free sites of KCl and KBr (100) crystals) showed that the coadsorption of halogen atom tends to block other adsorbate-substrate interactions at the nearest neighbour sites. Thus if halogen atom coverage increases, the CO prefers to be adsorbed on the K+ site of the KCl and KBr (100) surfaces and on KBr relative to KCl.
Majorization and the Lorenz Order: A Brief Introduction

1 Introduction. - 2 Majorization in IR. - Exercises. - 3 The Lorenz order in the space of distribution functions. - Exercises. - 4 Transformations and their effects. - Exercises. - 5 Multivariate and stochastic majorization. - 1 Multivariate majorization. - 2 Stochastic majorization. - Exercises. - 6 Some related orderings. - 1 Star ordering. - 2 Stochastic dominance. - Exercises. - 7 Some applications. - 1 A geometric inequality of Cesaro. - 2 Matrices with prescribed characteristic roots. - 3 Variability of sample medians and means. - 4 Reliability. - 5 Genetic selection. - 6 Large interactions. - 7 Unbiased tests. - 8 Summation modulo m. - 9 Forecasting. - 10 Ecological diversity. - References. - Author index.
Laboratory evaluation of climbing helmets: assessment of linear acceleration

This study utilized a guided free-fall drop tower and standard test headform to measure the peak linear acceleration (PLA) generated by different climbing helmet models that were impacted at various speeds (2–6 m s−1) and locations (top, front, rear, side). Wide-ranging impact performance was observed for the climbing helmet models selected. Helmets that produced lower PLAs were composed of protective materials, such as expanded polystyrene (EPS) or expanded polypropylene, which were integrated throughout multiple helmet regions including the front, rear and side. Climbing helmets that produced the highest PLAs consisted of a chinstrap, a suspension system, an acrylontrile butadiene styrene (ABS) outer shell, and an EPS inner layer, which was applied only to the top location. Variation in impact protection was attributed not only to helmet model but also impact location. Although head acceleration measurements were fairly similar between helmet models at the top location, impacts to the front, rear, and side led to larger changes in PLA. A 300 g cutoff for PLA was chosen due to its use as a pass/fail threshold in other helmet safety standards, and because it represents a high risk of severe head injury. All seven helmet models had the lowest acceleration values at the top location with PLAs below 300 g at speeds as high as 6 m s−1. Impact performance varied more substantially at the front, rear, and side locations, with some models generating PLAs above 300 g at speeds as low as 3 m s−1. These differences in impact performance represent opportunities for improved helmet design to better protect climbers across a broader range of impact scenarios in the event of a fall or other collision. An understanding of how current climbing helmets attenuate head acceleration could allow manufacturers to enhance next-generation models with innovative and more robust safety features including smart materials.