Miracle-dz/UniFAR-FTUs huggingface dataset:
Radio emission from supernovae. I. One to twelve year old supernovae

All recorded optical supernovae brighter than 14.0 mag from SN 1970A to SN 1981A were observed in May 1982 using VLA at 6 cm. Apart from the known radio supernovae (SN 1970G, SN 1979C, and SN 1980K), radio emissions were not detected from any of the objects to a limit of about 0.5 mJy. Limits on mass-loss rates from the presupernova systems are established. It is found that Type Ia Sns originate in systems which contain very little circumstellar material at the time of explosion. These systems are very different from those which originate Type Ib Sns. With some exceptions, Type II SNs originate with the high presupernova mass-loss rates expected from red supergiant progenitors with original main-sequence masses greater than about 8 solar masses. 16 references.
Synthesis of discrete-interval binary signals with specified Fourier amplitude spectra

A closed-form solution is presented for the discrete-interval, binary, periodic signal the complex Fourier coefficient spectrum of which optimally approximates in the least squares sense a desired complex Fourier coefficient spectrum. From this solution an efficient numerical procedure is derived for synthesis of discrete-interval, binary, periodic signals the Fourier amplitude spectrum of which is optimal in the same sense. Numerical examples show the practical feasibility of the procedure.
On the Relative Motion of Binary Tropical Cyclones

Abstract The interaction between spatially proximate (binary) tropical cyclones is such that relative rotation in the counterclockwise sense and decreasing separation distance between the two storm centers can be expected. This is referred to as the Fujiwhara effect. This study analyzes this effect for 43 binary tropical cyclone systems which occurred over the western North Pacific, 1949–78. It is shown that most demonstrated mutual interaction according to Fujiwhara expectations. However, there were notable apparent exceptions. Further analysis of these exceptional cases shows that environmental currents in which the storms were embedded had a significant effect on relative motion and masked the Fujiwhara effect. Additionally, it was found that storms exhibiting behavior most in accordance with Fujiwhara expectations were located in or near the Intertropical Convergence Zone. The main conclusion of the study, in confirmation of earlier studies, is that forces relative to environmental steering must be de.
Euclidean fields having a large Lenstra constant

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Slater transition-state band-structure calculations

Slater's transition-state method enables one to calculate excitation energies by means of an artificial state that is halfway between the ground state of an atom or molecule and an excited state. This idea has been adapted to insulators and semiconductors with a band-structure model where a localized hole is created in one cell by removing charge from the top of the valence band and putting it in a delocalized state at the bottom of the conduction band. Significant improvements in calculated band gaps are obtained in most cases over conventional local-density calculations. (c) 2000 The American Physical Society.
CFD Analysis of the HyShot II Scramjet Experiments in the HEG Shock Tunnel

Testing of the HyShot II scramjet configuration was carried out in the High Enthalpy Shock Tunnel Goettingen, HEG, of the German Aerospace Center, DLR. Computational fluid dynamics (CFD) is applied to support the analysis of experimental results and for the prediction of the free stream conditions in the HEG test section. Numerical simulations of the flow in the complete HyShot configuration for fuel on and off conditions were performed. This paper describes the laminar and turbulent modeling approaches for the CFD analysis and presents numerical results and their comparison to the experiment for both the HEG nozzle flow and the turbulent reacting flow in the HyShot Scramjet. The practicability of pressure-length scaling was tested by using further numerical analysis. Limits of applicability of this scaling approach were identified and are discussed in this paper
Signal amplitude and sensitivity of the Kelvin probe force microscopy

When the tip-sample distance is small, Kelvin probe force microscopy is affected by parametric amplification. This is due to the fact that the electric force has two components; the higher one having a frequency exactly twice as high as the lower. The oscillation amplitude may substantially depart from what is usually expected. Those phenomena are analytically modeled and experimentally shown, and the optimal parameter values which must be used for voltage detection are established.
Formation and stability of polarization sheaths of a cross-field beam

A layer of plasma (such as that comoving with the space shuttle) can travel across a magnetic field if it is flanked by ‘‘polarization sheaths’’ that create the E field necessary for E×B drift. Both the spontaneous evolution and the stability of these positive and negative sheaths can be studied by their analogy with the charge configuration in magnetron‐type electron devices. That is, conservation of canonical momentum results in ‘‘Brillouin flow,’’ i.e., shear flows in a pure ion sheath on one side and a pure electron sheath on the other side of the neutral plasma beam. The equilibrium parameters of this flow were obtained and the stability of the equilibria was analyzed. Both the ion and electron sheaths were found to be one‐dimensionally stable and two‐dimensionally unstable in a mode variously known as ‘‘magnetron,’’ ‘‘slipping stream,’’ or ‘‘diocotron. ’’ This mode connects up with the Kelvin–Helmholtz instability in neutral matter. The analytical results were confirmed both qualitatively and quantit.
Effect of Solid Concentration and Particle Size on the Flotation Kinetics and Entrainment of Quartz and Hematite

Despite the importance of solid concentration in froth flotation, its effect on flotation kinetics and entrainment has rarely been studied. In this study, the flotation kinetics and entrainment in quartz and hematite single-mineral flotation systems as a function of the solid concentration and particle size were investigated using dodecylamine acetate as a collector. Kinetics modeling showed that the Gamma distribution achieved the best agreement with the experimental data, whereas the Classical and Klimpel models poorly fit the data (e.g., RMSE). The flotation rate constants (k) of both quartz and hematite at a higher solid concentration showed a concave shape, with the inflexion point at the middle-size range, whereas this trend altered at lower solid concentrations. Overall, quartz exhibited higher equilibrium recoveries (R∞) than hematite, which indicates its better overall rate constants. The degree of water recovery in both the quartz and hematite systems was higher at higher solid concentrations, but the hematite system exhibited higher water R∞ than the quartz system, meaning that the entrainment of gangue could be higher in direct hematite flotation than the reverse one. Therefore, a higher solid concentration is associated with better overall quartz recovery and can reduce hematite loss by entrainment during reverse flotation. An inverse relationship was identified between the solid concentration and particle size in terms of the ratio of water recovery to the concentrate. In the reverse flotation of iron ore, refraining from achieving equilibrium recovery could help limit entrainment, but this was not necessarily the case in direct flotation. No entrainment model or method other than the Warren and Ross model approximated the overall trends of flotation at the finest size range (−38 µm). However, extending the Warren method to polynomial distribution led to an improved fit with the experimental results. In addition to the solid concentration, particle density and size were revealed to be key to developing new entrainment models. Finally, after the fast recovery period (true flotation) was over, the slow recoveries were mainly driven by the slow-floating water fraction.
Aristotle on the unity and disunity of science

Concerns about the unity and disunity of science were as strongly felt in the 4th century BC as they have been in the 20th AD. We know from Plato’s Republic VI and VII that by the middle of the 4th century BC there was a concerted intellectual effort to found such disparate natural investigations as astronomy, harmonics and optics on mathematical foundations. Moreover, we know that by this time these sciences were becoming autonomous enough that they are referred to with speci c names that distinguish them from “natural philosophy”. In the next generation Aristotle’s Analytics makes familiar references to mechanics, optics, astronomy and harmonics as in some sense marrying mathematical and natural science into subaltern sciences. In the generation after Aristotle, Euclid produces the Elements along with works in astronomy, optics and harmonics. On the one hand then, these sciences were becoming uni ed methodologically as branches of the mathematical sciences; on the other hand, they were becoming autonomous “special sciences”—the idea of a single “natural philosophy” was becoming passé. In chapter 5 of Posterior Analytics I, in fact, Aristotle faces just this issue head on.
Proportional hazards regression for cancer screening data

The complication in analysing tumour data is that the tumours detected in a screening programme tend to be slowly progressive, which is the so-called left-truncated sampling that is inherent in screening studies. Under the assumption that all subjects have the same tumour growth function, Ghosh [Proportional hazards regression for cancer studies, Biometrics 64 (2008), pp. 141–148] developed estimation procedures for proportional hazards model. In this note, by modelling growth function as a function of covariates and parameterizing the distribution function of left truncation time, we demonstrate that Ghosh's approach can be extended to the case when each subject has a specific growth function. A simulation study is conducted to demonstrate the potential usefulness of the proposed estimators for the regression parameters in the proportional hazards model.
AN OPTICAL INVESTIGATION OF POWERFUL FAR-INFRARED GALAXIES

The results of long-split spectroscopy of 20 powerful (about 10 to the 12th solar luminosities) far-infrared galaxies (FIRGs) are discussed, and deep narrowband images of the prototypical tepid FIRGs Arp 220 and NGC 6240 are presented. The results show that, as a class, the emission-line spectra of tepid FIRGs are most similar to LINERs, but about half are intermediate between LINERs and low-excitation H II regions. Huge (10,000-100,000-pc) and morphologically spectacular emission-line nebulae resembling the M82 filament system are associated with both NGC 6240 and Arp 220. It is proposed that the model of Chevalier and Clegg (1985) and McCarthy et al. (1987) for M82 be generalized to encompass powerful FIRGs as a class. 43 references.
NONLINEAR ALBEDO-TEMPERATURE COUPLING IN CLIMATE MODELS.

Abstract An analytical study is made of the number, stability and bifurcations of solutions of time-dependent Budyko-type climate models with various nonlinear albedo parameterizations. With Budyko's (1969) albedo, a general stability criterion is derived and it is found that, for the present value of the solar constant, the present climate and ice-covered earth solutions are stable, a spurious solution is unstable and there is an ice-free solution which is stable. A Seller's (1969) type albedo leads to a stable present climate and an ice-covered earth solution as well as an unstable climate. Faegre's (1972) albedo produces a present climate which is unstable and has an incorrect behavior as the solar constant or the infrared flux is changed, as well as a stable warmer climate and an ice-covered earth solution. It is found that latidutinal variations in the albedo way have a profound effect on the number and stability of the solutions.
INERTIAL LIFT ON A MOVING SPHERE IN CONTACT WITH A PLANE WALL IN A SHEAR FLOW

In this paper we calculate the lift force on a smooth sphere rotating and translating in a simple shear flow in contact with a rigid wall. The calculation involves only known creeping flow solutions and is presented in terms of six different coefficients, each arising as a result of a pairwise combination of the translational velocity, rotational velocity, and the imposed shear flow. The results obtained agree well with those of Cherukat and McLaughlin [J. Fluid Mech. 263, 1 (1994a); and (personal communication, 1994b)], extrapolated for the case of zero separation distance. The calculated lift is further integrated into a force and torque balance on a non‐neutrally buoyant rough sphere moving in contact with a plane. It is found that if the shear Reynolds number Re is sufficiently large, the lift force exceeds the gravitational force and the sphere separates from the plane. The increased separation is accompanied by an increase in the translational velocity U of the sphere and a corresponding decrease in.
Preparation and properties of CuInS2 thin films produced by exposing sputtered Cu‐In films to an H2S atmosphere

CuInS2 thin films have been made from copper, indium, and hydrogen sulfide gas using a two‐step technique which involves exposing Cu‐In films produced by sputtering pure copper and pure indium to H2S gas diluted with argon. X‐ray diffraction, Auger electron spectroscopy, optical transmission, and electrical measurements were used to identify and characterize the CuInS2. The resulting films were all p type with resistivity in the range 0.1–500 Ω cm and showed a preferred orientation of the (112) plane parallel to the substrate.
Temperature dependence of nonlinear susceptibilities near ferroelectric phase transition of a lead germanate single crystal

The results of measurements of the linear and nonlinear dielectric susceptibilities of a lead germanate, Pb5Ge3O11, single crystal are presented. The change in the sign of the third-order dielectric susceptibility χ3 as predicted by the thermodynamic theory of the continuous phase transitions is confirmed experimentally. Both the change in the sign of χ3 and the temperature independence, within the temperature range of T⩽TC+8K above the phase transition temperature point, of the nonlinearity coefficient B confirm that the lead germanate belongs to the Landau universality class.
Minimax Rates for Estimating the Variance and its Derivatives in Non–Parametric Regression

In this paper the van Trees inequality is applied to obtain lower bounds for the quadratic risk of estimators for the variance function and its derivatives in non–parametric regression models. This approach yields a much simpler proof compared to previously applied methods for minimax rates. Furthermore, the informative properties of the van Trees inequality reveal why the optimal rates for estimating the variance are not affected by the smoothness of the signal g. A Fourier series estimator is constructed which achieves the optimal rates. Finally, a second–order correction is derived which suggests that the initial estimator of g must be undersmoothed for the estimation of the variance.
A Survey of the Millimeter-Wave Spectrum of Sagittarius B2

More than 60 percent of the millimeter wave spectrum between 70 and 150 GHz of the giant Sgr B2 molecular cloud was surveyed with the Bell Laboratories 7 m telescope at a spectral resolution of 1 MHz. The observations and instrumentation are described, including beam efficiency and beamwidth as functions of frequency, frequency coverage, and rms noise. The catalog used to identify the 457 lines found is summarized, and the analysis of the data to determine column densities and rotational temperatures is discussed. The range of rotational temperatures obtained and their relation to the kinetic temperature, and their implications for the hydrogen density, are considered. More than 300 lines are transitions of 21 molecules, and the results for these are analyzed, giving excitation diagrams for most of them. A partly successful attempt is made to use ratios of the calculated abundances to predict abundances of as yet undetected species. Finally, the spectra for the entire survey are presented.
Polarization dependence of gain in discrete Raman amplifiers with dispersion compensating fibres

Polarization dependence of stimulated Raman scattering is a fundamental physical effect, which influences the design and application of Raman amplifiers for optical networks. We report experimental data of the study of polarization dependence of Raman gain in dispersion compensating fibres (DCF). The investigation displays a strong variation of the polarization dependence of Raman gain versus average polarization mode dispersion (PMD) values of DCF for both co-propagating and counter-propagating pump configurations. The reported data show, for the first time to our knowledge, that, for large PMD values, such a dependence may be as small as to be comparable with the accuracy of the measurements. The results of the study may be used to simplify the design of Raman amplifiers to avoid depolarization of pump sources that are currently used to decrease polarization dependence of Raman gain.
Spatial instability of a swirling jet - Theory and experiment

The spatial instability of a swirling jet is investigated both experimentally and theoretically. A hydrodynamic stability analysis is applied to an inviscid incompressible top-hat jet, with a swirl distribution of solid-body rotation and free vortex in and outside the vortex core, respectively. Both plane and helical instability modes are examined. It is found that the top-hat jet with swirl distribution of Rankine vortex type is unstable in all the modes studied. The higher the positive helicity, the less spatially unstable the jet behavior; the higher the negative helicity, the more spatially unstable this behavior becomes. A comparison is made between theoretical results and experimental data on a low-intensity swirling jet. The trend of the initial growth of the instability waves in the near field is captured.
Birth-and-death processes on the integers with phases and general boundaries

The invariant probability distribution is found for a class of birth-and-death processes on the integers with phases and one or two boundaries. The invariant vector has a matrix geometric form and is found by solving a non-linear matrix equation and then finding an invariant probability distribution on the boundary states. Levy's concept of watching a Markov process in a subset is used to naturally decouple the computation of distributions on the boundary and interior states.
Experimental limits on the existence of strongly interacting massive particles bound to gold nuclei

We report the results from an experimental search for strongly interacting massive particles bound to gold nuclei. A scan for heavy gold isotopes with masses ranging from 186.3 to $325.9 \mathrm{GeV}{/c}^{2}$ was performed on laboratory gold and gold from western Australia using PRIME Lab, the Purdue Accelerator Mass Spectrometer facility. The results provide significant new constraints on current models which predict the existence of such particles with abundance ratios in the range ${10}^{\ensuremath{-}11}\char21{}{10}^{\ensuremath{-}10}. $
Verification and validation for magnetic fusiona)

Dramatic progress in the scope and power of plasma simulations over the past decade has extended our understanding of these complex phenomena. However, as codes embody imperfect models for physical reality, a necessary step toward developing a predictive capability is demonstrating agreement, without bias, between simulations and experimental results. While comparisons between computer calculations and experimental data are common, there is a compelling need to make these comparisons more systematic and more quantitative. Tests of models are divided into two phases, usually called verification and validation. Verification is an essentially mathematical demonstration that a chosen physical model, rendered as a set of equations, has been accurately solved by a computer code. Validation is a physical process which attempts to ascertain the extent to which the model used by a code correctly represents reality within some domain of applicability, to some specified level of accuracy. This paper will cover principles and practices for verification and validation including lessons learned from related fields.
Inferring Marine Atmospheric Boundary Layer Properties from Spectral Characteristics of Satellite-Borne SAR Imagery

Abstract For the commonly observed range of air–sea temperature difference and surface wind speed, the static stability of the atmospheric surface layer can have a significant effect on the mean surface stress and its turbulence-scale horizontal variability. While traditional satellite-borne scatterometers have insufficient horizontal resolution to map this turbulence-scale horizontal variability, satellite-borne synthetic aperture radars (SAR) can. This paper explores the potential for applying existing boundary layer similarity theories to these SAR-derived maps of turbulence-scale horizontal variability in air–sea stress. Two potential approaches for deriving boundary layer turbulence and stability statistics from SAR backscatter imagery are considered. The first approach employs Monin–Obukhov similarity theory, mixed layer similarity theory, and a SAR-based estimate of the atmospheric boundary layer depth to relate the ratio of the mean and standard deviation of the SAR-derived wind speed field to the.
Stability and stabilization of discrete‐time singular Markov jump systems with time‐varying delay

The stochastic stability and stochastic stabilization of time‐varying delay discrete‐time singular Markov jump systems are discussed. For full and partial knowledge of transition probabilities cases, delay‐dependent linear matrix inequalities (LMIs) conditions for the systems to be regular, causal and stochastically stable are given. Sufficient conditions are proposed for the existence of state feedback controller in terms of LMIs. Finally, two numerical examples to illustrate the effectiveness of the method are given. Copyright © 2009 John Wiley & Sons, Ltd.
Testing the “strong” PAHs hypothesis - I. Profile invariance of electronic transitions of interstellar PAH cations

The so-called "strong" Polycyclic Aromatic Hydrocarbons (PAHs) hypothesis postulates that isolated PAHs, which are thought to be the carriers of the Unidentified Infrared Bands, ought to be also responsible for a large number of Diffuse Interstellar Bands (DIBs). In this framework, the spectral profile of such DIBs should be due to unresolved rotational structure of vibronic absorption bands, the rotation of the molecule being by and large governed by the interaction with the interstellar radiation field. In this paper we quantitatively test the above hypothesis against the observational constraint of DIBs profile invariance, by using Monte-Carlo methods to model the photophysics of a prototypical interstellar PAH, namely the ovalene cation (C32H +). Our results show that the predicted rotational band profiles are remarkably insensitive to both the ambient conditions and the assumed values of some poorly known parameters. The present model therefore offers a quantitative link between any given PAH and the observed DIB profiles, providing a valuable tool for molecular identification.