Miracle-dz/UniFAR-FTUs huggingface dataset:
The electromagnetic field in a layered earth induced by an arbitrary stationary current distribution

The subject of this paper is to calculate the fields in a layered earth induced by a current distribution. A general formulation is presented, which contains very few restrictions of the current distribution. For the simplest current distributions (dipole, circular, and rectangular loops) we derive expressions for the fields, which contain a single integral (Sommerfeld type). Numerical computations are presented for the above mentioned sources, and some techniques for increasing the rate of convergence are discussed.
What bends 3C 465

This paper studies the interaction of the prototypical wide-angle tailed radio source 3C 465 with the ambient cluster gas. 3C 465 is attached to the dominant D galaxy NGC 7720 in the cluster Abell 2634. New VLA maps of the radio source are presented which reveal an inner jet and a rapid change of structure at the hot spots at the beginning of each tail. New X-ray maps of the cluster gas are also presented. It is shown that the sharp bend of the flowing radio-luminous plasma between the inner jets and the beginning of the tails cannot be explained by any of the conventional models. Neither galactic motion, buoyancy, gravitational bending, nor dynamic pressure can account for the bending of this source. Attention is also given to new possibilities for the dynamics of this type of radio tailed source: the effect of a current in the jets, and the interaction with cooling clouds in the cluster gas.
Evaporation and combustion of thin films of liquid fuels

We consider the evaporation and subsequent burning of thin films of liquid fuels. Previous studies on liquid films, with and without evaporation, have primarily considered the gas phase to be passive. The new element in this study is the introduction of combustion and the examination of both the liquid and gas phases and their effect on the film's behaviour. For the case of a liquid film burning in quiescent air we show that the problem can be simplified to a single nonlinear evolution equation for the film thickness. All remaining variables, which are simply expressed in terms of the function describing the instantaneous position of the liquid–vapour interface, are subsequently determined. This equation is then solved in order to understand the dynamics of the film in the presence of evaporation and combustion. The planar configuration is discussed first. Predictions for the total evaporation time are obtained, along with the time history of the film thickness, the interfacial surface temperature, the flame standoff distance and its temperature, and the mass burning rate. The dependence of the burning characteristics on the fuel and oxidizer Lewis numbers, which measure the relative importance of thermal and molecular diffusivities, is also determined. Second, we analyse the case of a non-planar interface, where temperature variations along the film's surface cause fluid motion in the liquid that could either dampen or amplify spatial non-uniformities. We show that, while thermocapillarity has the tendency to destabilize the planar interface, combustion acts to reduce this effect. In particular, when the heat release by combustion is substantial, all disturbances are obliterated, the film remains nearly planar and the burning occurs along nearly horizontal surfaces.
Variance Reduction Techniques for Monte Carlo Sampling from Student Distributions

A Monte Carlo design is presented for estimating the variance and cumulative distribution function of translation and scale invariant statistics based on independent Student random variables. One obvious application is studying estimates of the location parameter from a symmetric, possibly long-tailed distribution. The method itself amounts to suppressing some of the variability in the sampled objects by integrating these objects over appropriate regions of the underlying probability space. Indications are that, in cases of interest, the variability is thereby considerably reduced, as is illustrated in an application concerning trimmed and Winsorieed means.
Neutron star properties with unified equations of state of dense matter

Aims. In this paper, we study the global properties of neutron stars (NSs), as predicted by the Brussels-Montreal equations of state (EoSs). These EoSs, which provide a unified description of all regions of a NS, are based on the generalised Skyrme functionals BSk19, BSk20, and BSk21 that were simultaneously fitted to almost all the nuclear mass data and constrained to reproduce various properties of infinite nuclear matter, as obtained from microscopic calculations. Methods. We solved Einstein’s equations of general relativity for both non-rotating and rigidly rotating NSs using these unified EoSs. Results. The NS properties thus obtained are compared with various astrophysical observations. We find that only the stiffest EoS, based on the functional BSk21, is compatible with all the constraints inferred from these observations.
Dense gas discs around T Tauri stars

The circumstellar discs of six T Tauri stars, forming an age sequence from approximately 1 to 10 Myr, have been observed in the molecular line HCO + J = 4 - 3. The dense gas traced by this line lies typically at less than half the radius characteristic of more easily excited CO lines, and the most compact disc solutions have outer radii of only around 100 au. Within the uncertainties set by the disc chemistry, the lowest-mass solutions are found to possess at least 2 to 15 M Jupiter of gas, in all but one of the six systems. The dense gas present within ∼100 au could provide fuel for the zone at tens of au where giants planets may form, and this mass reservoir is sufficient to form such planets. Only the oldest star, LkCa 15 at 8-12 Myr, has a large central cavity lacking in dense material that may reflect gas removal at late times.
The vortical response to penetrative convection and the associated gravity‐wave generation

This study documents the vortical motions that arise due to penetrative convective updraughts. Using an idealized axisymmetric model of dry thermals it is shown that in a stable environment the baroclinic generation of vorticity forms a circulation that opposes updraught overshoot and manifests the first signature of gravity waves emanating from the thermal. Continued baroclinic generation of vorticity of oscillating sign completes the first full wavelength and populates the wave packet. These examples provide an alternate description of the generation of gravity waves by penetrative convection and provide further insight into the morphology of the wave source Copyright © 2008 Royal Meteorological Society
Restoration of turbulence degraded images using improved multi-frame blind deconvolution algorithm

For the restoration of astronomical objects which are degraded mainly by turbulence, an improved multi-frame blind deconvolution method using the generalised expectation-maximisation (GEM) on the basis of the penalised maximum-likelihood estimation method is presented. Experimental results indicate that this method has better performance and costs less time.
Exact and complete electro‐elastic field in a half‐space of piezoelectric medium with a charged surface electrode: Revisit

This note revisits the electro‐elastic coupling behaviors of a transversely isotropic piezoelectric half‐space with a charged surface electrode. A different idea is provided by employing the three‐dimensional (3D) general solution of electro‐elasticity as well as generalized potential theory method. Compared with the previous studies, the method in this study is very simple and straightforward. The potential theory method is successfully extended to non‐axisymmetric case and the electrode can be of any planar configuration. For a charged penny‐shaped electrode, exact and complete 3D analysis is conducted. The validity of the present solutions is achieved numerically and analytically via comparing with those in literature. Some phenomena, which have escaped the attention of previous researchers, are observed. The present solutions are of theoretic and practical significance to serve as benchmarks for numerical codes and simplified studies.
Existence for Nonlinear Volterra Equations in Hilbert Spaces

Existence results for Volterra equations of the form $Bu + a * Au \ni f$ are established. Here A and B are subdifferentials of convex functions on a real Hilbert space.In particular, existence results for the nonlinear differential equation $({d /{dt}})Bu + Au \ni g$, $u(0) = u_0 $ are derived.
Dynamical thermal conductivity of bulk semiconductor crystals

The paper discusses the behavior of the dynamical lattice thermal conductivity κ(Ω) of bulk semiconductor crystals. The calculation approach is based on solving Boltzmann-Peierls phonon transport equation in the frequency domain after excitation by a dynamical temperature gradient, within the framework of the single relaxation time approximation and using modified Debye-Callaway model. Our model allows us to obtain a compact expression for κ(Ω) that captures the leading behavior of the dynamical thermal conduction by phonons. This expression fulfils the causality requirement and leads to a convolution type relationship between the heat flux density current and the temperature gradient in the real space-time domain in agreement with Gurtin-Pipkin theory. The dynamical behavior of κ(Ω) is studied by changing temperature as well as different intrinsic and extrinsic parameters. Our calculations show the cut-off frequency of κ(Ω) to be sensitive to the changes of some of these parameters. The paper investigate.
Improving the Generalized Performance of Deep Embedding for Text-Independent Speaker Verification

In this paper, we propose an effective approach to improve the generalized performance of the speaker embedding system based on a neural network. The deep embedding system, based on x-vector, can obtain a good discriminative capability between different speakers while in the training stage. However, the cross-entropy loss function and the one-hot label limit the generalization ability of this kind of systems. This paper proposes a new training architecture by adding one filler node in the output layer to represent the-of-domain speakers. Moreover, we adopt the attention mechanism in the proposed generalized x-vector system. From the results on the NIST 2010 SRE, we find that the proposed system achieves improved performance for the evaluation of varying duration conditions. On the full length condition, our proposed system obtains a 41.5% and 12.1% relative improvement over the baseline system (i-vector) and the standard x-vector system in equal error rate (EER).
Molecular Identification of Cystoisospora Belli in Patients Infected with the Virus Human Immunodeficiency

Infection with Cystoisospora belli causes severe diarrhea, bile duct involvement, and Extra-intestinal spread in patients with acquired immunodeficiency syndrome (AIDS). This study included eight adult patients with AIDS and chronic diarrhea diagnosed stool cystosisporiasis (oocysts) and / or duodenal biopsies (asexual and sexual stages in epithelium). Identification was carried out at the molecular level using a nested-polymerase chain reaction (PCR) technique that amplifies a fragment of the ribosomal ribonucleic acid (RNA) small subunit gene, using DNA extracted from feces and biopsies. This work allowed us to make the diagnosis of cystosisporiasis through analysis coproparasitological, optimize the DNA extraction protocol from samples fecal and implement the nested -PCR technique for the diagnosis of C. belli in biological samples from infected patients.
CENTRAL LIMIT THEOREMS FOR MULTINOMIAL SUMS

Let $(N_1, \cdots, N_k)$ be a multinomial vector with $n = \sum N_i$ and with parameter $(p_1, \cdots, p_k), \sum p_i = 1$. Let $f_1, \cdots, f_k$ be real-valued functions defined on the integers $\{0, 1, \cdots, n\}$, and let $S_k = \sum^k_{i=1} f_i(N_i)$. Suppose $k \rightarrow \infty$, and as $k \rightarrow \infty$, that $n \rightarrow \infty$ and $\max_{1\leqq i \leqq k}p_i \rightarrow 0$. Conditions on the $\{f_i\}$ are given which guarantee that $S_k$, suitably centered and scaled, has a normal limit in law. An application shows that if $\min_{1\leqq i \leqq k} (np_i)$ is bounded away from zero and the $\{f_i\}$ are polynomials of bounded degree as $k \rightarrow \infty$, that $S_k$ is asymptotically normal provided only that a "uniformly asymptotically negligible" (uan) condition on the $\{f_i\}$ holds. For testing the specified simple hypothesis $p_i = p_i^0$ for all $1 \leqq i \leqq k$, Pearson's "chi-square" statistic and the likelihood ratio statistic can be written in the form of $S_k$. It is shown that these two statistics are asymptotically normal as $k \rightarrow \infty$ provided they satisfy simple conditions which are equivalent to their respective uan conditions.
THE RELATION BETWEEN RAINFALL AND METEOR SHOWERS

Abstract Examination of rainfall figures for a large number of stations shows that there is a tendency for more rain to fall on certain calendar dates than on others. There is a close correspondence between the dates of the rainfall maxima in both the northern and southern hemispheres, and this is difficult to explain on a climatological basis. The effect might, however, be due to an extraterrestrial influence. The rainfall peaks occur approximately 30 days after prominent meteor showers, and it is suggested that they are due to the nucleating effect of meteoritic dust falling into cloud systems in the lower atmosphere, the time difference being accounted for by the rate of fall of the material through the atmosphere. The hypothesis is tested for a particular meteor stream, the Bielids, which is known to have a 6.5-year period. The rainfall 30 days after the meteor shower is found to have a similar period. Furthermore, the phase of the rainfall periodicity is almost identical with that of the meteor showe.
The self-similar cosmological paradigm - A new test and two new predictions

It is demonstrated that the magnetic dipole moments of atomic nuclei and neutron stars are quantitatively related by the fundamental scaling equations of the self-similar cosmological paradigm, and therefore a 16th falsification test has been passed by this theoretical model. Two definitive predictions are also pointed out: (1) the model predicts that the electron will be found to have structure with radius of about 4 x 10 to the -17th cm, at just below the current empirical resolution capability, and (2) the model makes quantitative predictions regarding gravitational microlensing by predicted dark matter candidates. Some possible theoretical implications of cosmological self-similarity are introduced. 14 references.
Effects of Solar Radiation on the Performance of Pyrgeometers with Silicon Domes

Abstract The performance of the Eppley pyrgeometer with a silicon dome presents several anomalies during daytime measurements. These problems are related mainly to the solar heating of the dome, which causes nearly instantaneous fluctuations, about ±1%–2% from the average value, in the longwave irradiance measured by the pyrgeometer during cloudless days. An evaluation of the solar heating effect of the dome made with a set of sun and shade experiments indicates that the pyrgeometer output includes an equivalent of about 3.6% of the incoming solar radiation. In spite of the improvement with the use of silicon instead of KRS-5 domes, the error due to solar heating requires some kind of correction. Sun and shade experiments under a number of wind speed conditions are used to derive an empirical correction that is based on the global solar radiation.
Cooling of a superconductor by quasiparticle tunneling

We have extended the cryogenic cooling method based on tunneling between a superconductor and another metal to the case when both metals are superconducting but when their energy gaps are different; earlier, this method was applied between a superconductor and a normal metal. The electron system of a titanium strip with the superconducting transition temperature Tc2=0.51 K has been cooled from 1.02Tc2 to below 0.7Tc2 by this method, using aluminum as the other superconductor.
Two‐dimensional compact finite difference immersed boundary method

We present a compact finite differences method for the calculation of two‐dimensional viscous flows in biological fluid dynamics applications. This is achieved by using body‐forces that allow for the imposition of boundary conditions in an immersed moving boundary that does not coincide with the computational grid. The unsteady, incompressible Navier–Stokes equations are solved in a Cartesian staggered grid with fourth‐order Runge–Kutta temporal discretization and fourth‐order compact schemes for spatial discretization, used to achieve highly accurate calculations. Special attention is given to the interpolation schemes on the boundary of the immersed body. The accuracy of the immersed boundary solver is verified through grid convergence studies. Validation of the method is done by comparison with reference experimental results. In order to demonstrate the application of the method, 2D small insect hovering flight is calculated and compared with available experimental and computational results. Copyright © 2009 John Wiley & Sons, Ltd.
Recent Star Formation in Several Galaxies of the Tidally Disturbed System HCG 31

High-resolution (0.″7 to 0.″8) Hα images of the Hickson Compact Group 31 (HCG 31) obtained with the WIYN telescope are used in conjunction with broadband optical images from the Hubble Space Telescope (HST) to examine the star formation history and properties of the component galaxies. The high spatial resolution of the WIYN telescope has allowed us to identify a large number of starburst regions from their Hα emission, which traces the recent star birth activity. The HST images of galaxies E and F reveal more detail within the starburst regions in which we have identified numerous super star clusters (SSCs). Photometry of these starburst regions and SSCs in the Hα and optical images indicates that there has been a substantial amount of star formation throughout HGC 31 over the past 10 Myr. The Hα equivalent widths suggest activity within the group as recently as a few megayears ago. There is evidence that galaxy F, the youngest member of the group, is possibly undergoing its initial episode of star formation, as no underlying stellar population has yet been detected.
Humps/Steps Influence on Stability Characteristics of Two-Dimensional Laminar Boundary Layer

The ine uence of two-dimensional humps and steps on the stability characteristics of a two-dimensional laminar boundary layer is investigated by means of direct numerical simulations (DNS). The localized surface irregularity ishereby modeled within theCartesian grid by assigning body forces oversurfacesthat need notcoincidewith grid lines.Comparedtotheuseofabody-e ttedcoordinatesystem,thismethodsavesmemoryandcomputationtime.The method is validated by grid ree nement tests as well as by a comparison with water channel experiments. The DNS results for the steady e ow over a rectangular hump, as well as for an instability wave traveling over a hump, show good agreementwith theexperimental ones. Simulation resultsshow thata localized hump destabilizesthelaminar boundary layer, whereas a forward facing step stabilizes it. The destabilization is stronger when the height or the width of the localized hump are increased. A rounded shape of the hump is less destabilizing than a rectangular shape with sharp corners. The parameter that shows the strongest ine uence on the stability characteristics of the boundary layer is clearly the height of the localized hump.
Generalized Collinearity Diagnostics

Abstract Working in the context of the linear model y = Xβ + e, we generalize the concept of variance inflation as a measure of collinearity to a subset of parameters in β (denoted by β 1, with the associated columns of X given by X 1). The essential idea underlying this generalization is to examine the impact on the precision of estimation—in particular, the size of an ellipsoidal joint confidence region for β 1—of less-than-optimal selection of other columns of the design matrix (X 2), treating still other columns (X 0) as unalterable, even hypothetically. In typical applications, X 1 contains a set of dummy regressors coding categories of a qualitative variable or a set of polynomial regressors in a quantitative variable; X 2 contains all other regressors in the model, save the constant, which is in X 0. If σ 2 V denotes the realized variance of , and σ 2 U is the variance associated with an optimal selection of X 2, then the corresponding scaled dispersion ellipsoids to be compared are ℰ v = {x : x′V .
The properties of the circumnuclear regions in the Circinus galaxy

We analysed the spectra from the XMM-Newton and the three longest Chandra observations of the Circinus Galaxy, the X-ray brightest, Compton-thick Seyfert 2 galaxy, to derive the physical and morphological parameters of the circumnuclear matter. We compare the line and continuum parameters with extensive calculations performed with the well-known photoionisation code CLOUDY. The line spectrum cannot be explained by a single zone, as three different reflecting regions are required. The first has low ionisation, accounting for the prominent iron Kα line, and is likely to be identified with the "torus" envisaged in unification models for Seyfert galaxies; a lower limit of 0.05 pc to the distance of this matter from the nucleus has been estimated, using new constraints on the ionisation state of iron (≤FeX). The second zone is moderately ionised and optically thin (T 0.2), and it accounts for the oxygen to silicon lines. Finally, a third, highly ionised and optically thin reflector is required for the detection of the He-like iron line.
Reactive forcefield for simulating gold surfaces and nanoparticles

We present a ReaxFF reactive forcefield designed to reproduce first-principles density-functional theory (DFT) calculations on gold bulk structures, surfaces, and nanoparticles. We compare the ReaxFF results with those obtained from other atomistic potentials along with results from Perdew-Burke-Ernzerhof--generalized gradient approximation (PBE-GGA) DFT. The new ReaxFF gold force field, which has been trained against various bulk and surface properties calculated by DFT, is subsequently applied to simulated annealing simulations on a range of gold nanoparticles ${\text{Au}}_{n}$ $(n=38,\text{ }236,\text{ }1514)$.
Observations of Vertical Wind Shear Heterogeneity in Convective Boundary Layers

Abstract Dual-Doppler wind syntheses from mobile radar observations obtained during the International H2O Project document some of the spatial variability of vertical wind profiles in convective boundary layers. Much of the variability of popular forecasting parameters such as vertical wind shear magnitude and storm-relative helicity is thought to result from pressure and temperature gradients associated with mesoscale boundaries (e.g., drylines, outflow boundaries, fronts). These analyses also reveal substantial heterogeneity even in the absence of obvious mesoscale wind shifts—in regions many might have classified as “horizontally homogeneous” with respect to these parameters in the past. This heterogeneity is closely linked to kinematic perturbations associated with boundary layer convection. When a mean wind is present, the large spatial variability implies significant temporal variability in the vertical wind profiles observed at fixed locations, with the temporal variability increasing with mean win.