Miracle-dz/UniFAR-FTUs huggingface dataset:
What determines the stellar mass functions in globular clusters

We analyze the dependence of stellar mass function slopes for a sample of 17 globular clusters on a variety of cluster parameters. The principal novelty of our approach is the use of appropriate multivariate statistical methods to disentangle the complex situation which is present in this problem: the slopes depend simultaneously on more than one variable, and many cluster parameters are mutually correlated. We find that the mass function slopes in the range M/M(solar) = 0.5-0.8 are largely determined by the position in the Galaxy and to a lesser extent by the cluster metallicity. Clusters closer to the Galactic center or plane have shallower mass function slopes. At a given distance to the Galactic center, clusters closer to the Galactic plane have shallower mass function slopes. At a given R(GC) and/or Z(GP), more metal-rich clusters have shallower mass function slopes. Thus, the monovariate correlations with the position or metallicity are both correct, but only partial, and in terms of slopes, biased descriptions of the situation. We present trivariate least-squares solutions where the mass function slopes can be predicted within the measurement accuracy. This relation can serve as a powerful observational constraint for theories of globular cluster formation and evolution, and it is one of the tightest correlations between globular cluster properties now known.
On the Nature of the Extreme-ultraviolet Late Phase of Solar Flares

Solar flares typically have an impulsive phase that is followed by a gradual phase as best seen in soft X-ray emissions. A recent discovery based on the EUV Variability Experiment observations on board the Solar Dynamics Observatory (SDO) reveals that some flares exhibit a second large peak separated from the first main phase peak by tens of minutes to hours, which is coined as the flare's EUV late phase. In this paper, we address the origin of the EUV late phase by analyzing in detail two late phase flares, an M2.9 flare on 2010 October 16 and an M1.4 flare on 2011 February 18, using multi-passband imaging observations from the Atmospheric Imaging Assembly on board SDO. We find that (1) the late phase emission originates from a different magnetic loop system, which is much larger and higher than the main phase loop system. (2) The two loop systems have different thermal evolution. While the late phase loop arcade reaches its peak brightness progressively at a later time spanning for more than one hour from high to low temperatures, the main phase loop arcade reaches its peak brightness at almost the same time (within several minutes) in all temperatures. (3) Nevertheless, the two loop systems seem to be connected magnetically, forming an asymmetric magnetic quadruple configuration. (4) Further, the footpoint brightenings in UV wavelengths show a systematic delay of about one minute from the main flare region to the remote footpoint of the late phase arcade system. We argue that the EUV late phase is the result of a long-lasting cooling process in the larger magnetic arcade system.
Theoretical and experimental analysis of a base-excited rotor

In this study, the dynamic behavior of a flexible rotor system subjected to support excitation (imposed displacements of its base) is analyzed. The effect of an excitation on lateral displacements is investigated from theoretical and experimental points of view. The study focuses on behavior in bending. A mathematical model with two gyroscopic and parametrical coupled equations is derived using the Rayleigh-Ritz method. The theoretical study is based on both the multiple scales method and the normal form approach. An experimental setup is then developed to observe the dynamic behavior permitting the measurement of lateral displacements when the system's support is subjected to a sinusoidal rotation. The experimental results are favorably compared with the analytical and numerical results.
On knowing about nothing: The processing of zero in single- and multi-digit multiplication

Background: Zero has a special role in calculation: indeed it is not obvious which representation may be invoked in multiplication or division by zero. In particular, zero as an operand, unlike any other operand, makes any quantity disappear. Aims: The study is intended to shed light on the mechanisms mediating the manipulation of zero. Methods & Procedures: Three neuropsychological patients, AF, FV, and FS, are described, whose specific pattern of preserved/impaired performance with single- and multi-digit multiplication shows selective problems with the use of zero (N×0 and 0×N). Outcome & Results: AF's performance in single- and multi-digit multiplication showed a clear dissociation between spared fact-based problems and impaired 0 rule-based problems. FV was totally unable, in multi-digit multiplication, to apply adequately the 0 rule that he could master in simple calculation. Finally, FS showed, within the rule-based problems, a clear-cut dissociation between a preserved performance on N×0 problems and an impaired performance on 0×N problems, a difficulty that almost disappeared in multi-digit multiplications. Conclusions: Overall the reported dissociations indicate that a full grasp of the concept of zero may not be used in routine calculation, and that processing of zero rather appears to rely on a collection of independent, shallow representations.
WRF-Solar: Description and Clear-Sky Assessment of an Augmented NWP Model for Solar Power Prediction

AbstractWRF-Solar is a specific configuration and augmentation of the Weather Research and Forecasting (WRF) Model designed for solar energy applications. Recent upgrades to the WRF Model contribute to making the model appropriate for solar power forecasting and comprise 1) developments to diagnose internally relevant atmospheric parameters required by the solar industry, 2) improved representation of aerosol–radiation feedback, 3) incorporation of cloud–aerosol interactions, and 4) improved cloud–radiation feedback. The WRF-Solar developments are presented together with a comprehensive characterization of the model performance for forecasting during clear skies. Performance is evaluated with numerical experiments using a range of different external and internal treatment of the atmospheric aerosols, including both a model-derived climatology of aerosol optical depth and temporally evolving aerosol optical properties from reanalysis products. The necessity of incorporating the influence of atmospheric aer.
A characterization of epi-convergence in terms of convergence of level sets

Let LSC(X) denote the extended real-valued lower semicontinuous functions on a separable metrizable space X. We show that a sequence (fn) in LSC(X) is epi-convergent o f e LSC(X) if and only for each real a , the level set of height a of f can be recovered as the Painleve-Kuratowski limit of an appropriately chosen sequence of level sets of the fn at heights an approaching a. Assuming the continuum hypothesis, this result fails without separability. An analogous result holds for weakly lower semicontinuous functions defined on a separable Banach space with respect to Mosco epi-convergence.
Philosophy of science: A practical tool for applied geologists in the minerals industry

For applied geologists working in the minerals industry the tasks of problem formulation, observation and data collection, interpretation and modelling invoke various philosophical considerations whether the practitioner is aware of them or not. A primary goal of applied geologists is to build models that accurately predict reality to an acceptable degree. In this paper, we describe the key philosophical frameworks proposed for conducting scientific investigations and relate them to the field of applied geology. We consider the very important differences in the types of problem confronted in experimental sciences (such as physics and chemistry) compared to the historical sciences, such as geology, where the processes studied are unique and only evidential traces of past events are available. The prediction quality of models is likely to be materially improved if the geologist is firmly and consciously practiced in the scientific method. In addition, if the predictions are framed and presented in terms of the underlying science, the quality of decisions made based on those predictions will likewise be improved. The implications for creating additional value to a project or operation can be very significant when geological models are constructed and used by a practitioner with an understanding of the philosophical basis of the activities constituting a scientific investigation. The method of multiple working hypotheses is particularly important when working in historical sciences. We argue that working within the framework of multiple working hypotheses can provide a valuable insurance against the adoption of, or persistence with, flawed models.
TACTICAL DEPRESSURIZATION OF HYDROGEN AND CNG TANKS USING RIFLES AND OTHER PROJECTILES

After a tank has been exposed to crash violence, or an external fire, it might, in some situations, be judged dangerous to move the vessel due to the risk of a sudden tank rupture. Therefore, Swedish rescue services have a long history of using rifles to penetrate and therefore depressurize the vessels. In this paper, some first steps on providing guidance on the selection of ammunition and required stand back distance are presented. The results indicate that a stand back distance on the order of 100 m is required and that the standard 7.62 Ball should only be used for composite CNG-tanks, while stronger ammunitions are needed for steel and composite hydrogen tanks. However, more research is required to provide a more solid scientific underpinning of the tactic guidance.
Coherent structures and dynamics in a neutrally stratified planetary boundary layer flow

Coherent structures and the dynamics of a neutrally stratified planetary boundary layer flow are studied through a large eddy simulation, which includes surface roughness, Coriolis force, and a capping inversion. Quadrant analysis and flow visualization show that low‐speed negative momentum flux (ejection) is the dominant feature throughout most of the boundary layer. The initiation of vortical structures is observed to be associated with vorticity sheets and pressure maxima, which are formed dynamically when low‐speed negative momentum flux collides with either high‐speed negative momentum flux (sweep) or the mean flow. Four dimensional conditional averages are used to study the statistical behavior of ejections and sweeps. The shape, strength, lifetime, and origin of the conditionally sampled structures at three different heights are discussed. Near the surface, sweeps are observed to induce ejections when colliding with the surface. The evolution of sweep‐induced ejections near the wall is discussed.
Experimental observation of the dynamical image potential in extremely low GaAs/AlxGa1−xAs/GaAs tunnel barriers

Tunneling in low‐barrier GaAs/AlxGa1−xAs/GaAs heterostructures has been systematically investigated over a wide range of barrier heights and thicknesses. Measured conductance data have been compared with tunnel conductances calculated with and without the image potential correction. Experimental evidence is found for the validity of the static image correction in the limit of large tunneling times, and for the occurrence of dynamic effects in the limit of short tunneling times.
Study of some systematic trends and non-equilibrium effects in (n,2n) reactions for nuclei far from the symmetry line

Total (n,2n) cross sections at 14.6+or-0.3 MeV for the 84Sr, 86Sr, 88Sr, 93Nb, 113In, 134Ba and 136Ba targets were measured using the activation technique and a Ge(Li) detection system. Isomeric cross section ratios were calculated on the basis of the statistical theory using the shifted Fermi-gas and superconductivity models. Theoretical results are compared with experimental data. In several cases (88Sr, 93Nb, 109Ag, 134Ba, 136Ba and 138Ba) it was not possible to measure total cross sections, and therefore the theoretical prediction of the isomeric cross section ratio was used to determine the total (n,2n) cross section. The cross section data obtained in this work and other recent literature data are analysed in terms of the neutron excess of residual nuclei (N-Z)R at a constant value of the residual excitation energy.
The RSA survey of dwarf galaxies, 1: Optical photometry

We present detailed surface photometry, based on broad B-band charge coupled device (CCD) images, of about 80 dwarf galaxies. Our sample represents approximately 10% of all dwarf galaxies identified in the vicinity of Revised Shapley-Ames (RSA) galaxies on high resolution blue photographic plates, referred to as the RSA survey of dwarf galaxies. We derive global properties and radial surface brightness profiles, and examine the morphologies. The radial surface brightness profiles of dwarf galaxies, whether early or late type, display the same varieties in shape and complexity as those of classical giant galaxies. Only a few are well described by a pure r(exp 1/4) law. Exponential profiles prevail. Features typical of giant disk galaxies, such as exponential profiles with a central depression, lenses, and even, in one case (IC 2041), a relatively prominent bulge are also found in dwarf galaxies. Our data suggest that the central region evolves from being bulge-like, with an r(exp 1/4) law profile, in bright galaxies to a lens-like structure in dwarf galaxies. We prove detailed surface photometry to be a helpful if not always sufficient tool in investigating the structure of dwarf galaxies. In many cases kinematic information is needed to complete the picture. We find the shapes of the surface brightness profiles to be loosely associated with morphological type. Our sample contains several new galaxies with properties intermediate between those of giant and dwarf ellipticals (but no M32-like objects). This shows that such intermediate galaxies exist so that at least a fraction of early-type dwarf ellipticals is structurally related to early-type giants instead of belonging to a totally unrelated, disjunct family. This supports an origin of early-type dwarf galaxies as originally more massive systems that acquired their current morphology as a result of substantial, presumable supernova-driven, mass loss. On the other hand, several early-type dwarfs in our sample are merger candidates. Merger events may lead to anisotropic velocity distributions in systems of any luminosity, including dwarfs. The RSA sample of dwarf galaxies is more likely to contain mergers because, in contrast to earlier dwarf galaxy surveys that have focused on clusters and rich groups of galaxies, the RSA dwarfs are typically located in low density environments. The occurrence of mergers among dwarf galaxies is of interest in connection with the rapid evolution of faint blue galaxy counts at redshift z less than 1 which suggests that dwarf galaxies were about five times more numerous in the recent past. Finally, our sample contains several examples of late-type dwarfs and 'transition' types that are potential precursors of nucleated early-type dwarfs. All the above processes--mass loss, mergers, astration--are likely to have contributed to the formation of the current population of diffuse early-type dwarfs. A few new redshifts of dwarf galaxies are reported in this paper.
Why does a mass on a spring sometimes misbehave

Autoparametric resonance of a mass on a spring was investigated. It is shown that when a spring is loaded so that it stretches to four-thirds of its original rest length, the spring frequency will be double the pendulum frequency and it will not be possible to excite a pure verticcal spring oscillation. (GHT)
Statistical Mechanics of Finite Ising Model

Partition function of finite Ising model (spin=1/2) was exactly obtained by a computer for three dimensional even lattice 4×4×2=32 with periodic boundary condition in the presence of a magnetic field. Specific heat was calculated as a function of temperature. The zeros of the partition functions of the complex temperature plane and magnetic field plane were investigated.
Properties of spiral galaxies from a stochastic star formation model

We have examined the properties of model galaxies produced by the stochastic, self-propagating, star-formation model and compared them with those observed in real galaxies. Observations have shown that a good correlation exists between the morphological type of a spiral galaxy and its rotational velocity, color, and gas fraction. We have shown that the stochastic, self-propagating, star-formation model directly correlates the morphological type with the rotation curve, the most important parameter being the maximum rotational velocity. The relative star-formation rates given by the model lead qualitatively to the observed variation of integrated colors and gas fraction as a function of morphological type, as well as to the observed decrease in the density of regions of recent star formation with radius. We show that this model is also capable of giving spiral arms in red plates and discuss the color profiles across spiral arms. Inclusion of the interaction of star formation and the interstellar gas shows that this model is also capable of inducing spiral ordering in the gas.
On a versatile second‐order multivariate calibration method based on partial least‐squares and residual bilinearization: Second‐order advantage and precision properties

The successful combination of unfolded partial least‐squares (U‐PLS) and residual bilinearization (RBL) constitutes a second‐order multivariate calibration method capable of achieving the second‐order advantage. RBL is performed by varying the test sample scores in order to minimize the residues of a combined U‐PLS/singular value decomposition model (SVD), using a Gauss–Newton (GN) procedure. The sample scores are then employed to predict the analyte concentration, with regression coefficients taken from the calibration step. The technique is able to handle calibration information when only certain analyte concentrations or reference properties are known, as is customary for PLS models. It has been successfully applied to model systems showing linear dependency due to pH equilibria or reaction kinetics, and experimental data aimed at the quantitation of analytes in complex samples. The predictive ability has been compared to those of parallel factor analysis and bilinear least‐squares (BLLS). The precision properties of the U‐PLS/GN‐RBL model have been investigated with the aid of Monte Carlo noise addition, and also by a new theoretical approach to sensitivity calculations. The results show good agreement between theory and simulations, and indicate that the precision and sensitivity of the U‐PLS/GN‐RBL method are comparable to other second‐order multivariate algorithms. Copyright © 2005 John Wiley & Sons, Ltd.
Precipitation in Stratocumulus Clouds: Observational and Modeling Results.

Abstract The spatial and temporal variability of precipitating stratocumulus layers is examined using aircraft observations, satellite retrievals of cloud optical depth, and one-dimensional models that include coalescence and a simple representation of layer turbulence. The aircraft observations show large horizontal variations in cloud thickness and precipitation, with local rain rates 4–5 times larger than the replacement moisture flux, and evidence for precipitation scavenging of small cloud droplets. The satellite observations show that, despite this local water loss, the distribution of cloud optical thickness remains nearly constant over the course of a day, indicating that on larger scales precipitation removal and cloud-top entrainment are in approximate balance with the vapor flux. The authors apply analytic and numerical models of steady-state precipitation to the observed microphysical conditions, and find that the models can match the drop size distributions observed during both heavy and ligh.
A laplace transform representation in a class of renewal queueing and risk processes

For a class of renewal queueing processes characterized by a rational Laplace–Stieltjes transform of the arrival inter-occurrence time distribution, the Laplace–Stieltjes transform of the equilibrium (actual) waiting time distribution is re-expressed in a manner which facilitates explicit inversion under certain conditions. The results are of interest in other contexts as well, as for example in insurance ruin theory. Various analytic properties of these quantities are then obtained as a result.
Evaporation in the transition region during the gradual phase of flares

Previous observations have revealed that small, but sustained, H-alpha blueshifts occur in flare ribbons during the gradual, or late, phase of flares. These blueshifts suggest that there is a gentle evaporation of chromospheric material throughout the late phase of flares, but ambiguities in the interpretation of H-alpha leave open the possibility that these blueshifts are caused by downflowing, rather than upflowing, material. Using both C IV and soft (3.5-8 keV) X-ray data from SMM observations, evidence is found which supports the interpretation of the H-alpha blueshifts as upflows in the range from 4-12 km/s. The blueshifts are interpreted in terms of the reconnection model proposed by Carmichael (1964). The model produces a sustained energy release through-out the late phase which accounts for the prolonged soft X-ray emission after a flare. This energy release comes from the reconnecting magnetic field above the flare site, and some of the energy is transported along field lines mapping to the chromosphere where it drives chromospheric evaporation. 49 refs.
A transmission problem for the reduced wave equation in inhomogeneous media with an infinite interface

In this paper, we consider the transmission problem in Rn (n ≽ 2) for the reduced wave equation in inhomogeneous media with an infinite interface. A new radiation condition involving a surface integral over the interface, which is different from the well-known Rellich-Sommerfeld radiation condition, is introduced to ensure the uniqueness of the solutions. It is then used together with the limiting absorption principle to establish the unique existence of solutions to the problem in the various media.
A Comparison of Variational and Ensemble-Based Data Assimilation Systems for Reanalysis of Sparse Observations

Abstract An observing system experiment, simulating a surface-only observing network representative of the 1930s, is carried out with three- and four-dimensional variational data assimilation systems (3D-VAR and 4D-VAR) and an ensemble-based data assimilation system (EnsDA). It is found that 4D-VAR and EnsDA systems produce analyses of comparable quality and that both are much more accurate than the analyses produced by the 3D-VAR system. The EnsDA system also produces useful estimates of analysis error, which are not directly available from the variational systems.
CHAIN CONDITIONS ON QUOTIENT FINITE DIMENSIONAL MODULES

This paper is motivated by a recent work of C. Faith [9] who has proved that a quotient finite dimensional module which satisfies the ascending chain condition on subdirectly irreducible submodules is Noetherian. A natural question to ask (also raised by Faith [11]) is whether its dual holds true. We answer this in the affirmative, and provide a characterization of Artinian modules dual to Faith's Theorem. We also extend these results to the more general settings of dual Krull dimension and Krull dimension respectively.