Miracle-dz/UniFAR-FTUs huggingface dataset:
Hybrid ion acceleration with ultrathin composite foils irradiated by high intensity circularly-polarized laser light

A complete analytical description of ion acceleration in the laser radiation-pressure regime is presented. The combined effects of hot electron and light-pressure phenomena are used to qualitatively and quantitatively describe most recent experimental results in this regime. An essential part of the developed model is exhibited in the calculation of nonlinear laser light reflection and transmission properties, as well as in the spectral characterization of the laser light after interaction. The validity of the analytical model is supported by recent experimental results and by particle-in-cell simulations.
A fully self-consistent calculation for positron states: application to aluminium

A fully self-consistent scheme based on the two-component density-functional theory and an embedded-cluster model within the framework of the discrete variational method has been developed for calculating positron states in solids. As an example, aluminium is tested. The changes of the electronic structures and positron states for an aluminium vacancy due to the electron-positron interaction are presented. The effects of the atomic relaxations on the positron annihilation characteristics are considered. The results are also compared with former calculations and the conventional scheme.
On the Validity of the Bootstrap in Non‐Parametric Functional Regression

Abstract. We consider the functional non‐parametric regression model Y= r(χ)+ɛ, where the response Y is univariate, χ is a functional covariate (i.e. valued in some infinite‐dimensional space), and the error ɛ satisfies E(ɛ | χ) = 0. For this model, the pointwise asymptotic normality of a kernel estimator of r (·) has been proved in the literature. To use this result for building pointwise confidence intervals for r (·), the asymptotic variance and bias of need to be estimated. However, the functional covariate setting makes this task very hard. To circumvent the estimation of these quantities, we propose to use a bootstrap procedure to approximate the distribution of . Both a naive and a wild bootstrap procedure are studied, and their asymptotic validity is proved. The obtained consistency results are discussed from a practical point of view via a simulation study. Finally, the wild bootstrap procedure is applied to a food industry quality problem to compute pointwise confidence intervals.
A model for the infrared emission from the bulge of our Galaxy

A quantitative model for the IR emission from the bulge of the Galaxy is constructed using a sequence of models for circumstellar dust shells around late-type stars. The luminosity function for asymptotic giant branch stars and the distribution function for the dust-shell optical depth are derived. The total bolometric luminosity of the bulge population is 170 million solar luminosities and the total mass loss rate is 0.0083 solar mass/yr. The 12 microns and most of the 25 microns flux from the inner part of M31 can be understood as emission from a bulge population similar to that in the Galaxy. A simple model for the IR emission from late-type stars in the disk of the Galaxy is also given.
Optimization of the occulter for the Solar Orbiter/METIS coronagraph

METIS (Multi Element Telescope for Imaging and Spectroscopy investigation), selected to fly aboard the Solar Orbiter ESA/NASA mission, is conceived to perform imaging (in visible, UV and EUV) and spectroscopy (in EUV) of the solar corona, by means of an integrated instrument suite located on a single optical bench and sharing the same aperture on the satellite heat shield. As every coronagraph, METIS is highly demanding in terms of stray light suppression. Coronagraphs history teaches that a particular attention must be dedicated to the occulter optimization. The METIS occulting system is of particular interest due to its innovative concept. In order to meet the strict thermal requirements of Solar Orbiter, METIS optical design has been optimized by moving the entrance pupil at the level of the external occulter on the S/C thermal shield, thus reducing the size of the external aperture. The scheme is based on an inverted external-occulter (IEO). The IEO consists of a circular aperture on the Solar Orbiter thermal shield. A spherical mirror rejects back the disk-light through the IEO. A breadboard of the occulting assembly (BOA) has been manufactured in order to perform stray light tests in front of two solar simulators (in Marseille, France and in Torino, Italy). A first measurement campaign has been carried on at the Laboratoire d'Astrophysique de Marseille. In this paper we describe the BOA design, the laboratory set-up and the preliminary results.
Unbiased Estimates of Variance Components With Bootstrap Procedures

This article provides general procedures for obtaining unbiased estimates of variance components for any random-model balanced design under any bootstrap sampling plan, with the focus on designs of the type typically used in generalizability theory. The results reported here are particularly helpful when the bootstrap is used to estimate standard errors of estimated variance components. For the p × i design, Wiley (2000) provided formulas for correcting for bias in bootstrap estimates of variance components. This article extends Wiley's results to any design and any bootstrap procedure. There are important differences in approach, however. In particular, in this article unbiased estimates of variance components are obtained directly for any bootstrap sample through the use of modified expected T-term (uncorrected sums of squares) equations.
Multiple scattering of acoustic waves by random distribution of discrete spherical scatterers with the quasicrystalline and Percus–Yevick approximation

In studying the multiple scattering of acoustic waves by random distributions of scatterers with appreciable concentration, the approach of quasicrystalline approximation together with hole correction (QCA–HC) has been a common method. We show that such an approach will give rise to negative attenuation rate indicating a growth of the coherent wave in space which is a nonphysical solution. To derive better results, we employ the solution of the Percus–Yevick equation together with quasicrystalline approximation (QCA–PY) to study multiple scattering of acoustic waves by discrete spherical scatterers. Waterman’s T matrix formalism is used in formulating the multiple scattering problem. Closed form solutions are obtained for the effective propagation constants in the low‐frequency limit. Effective propagation constants at higher frequencies are calculated by numerical methods. The result of QCA–HC for the two‐dimensional case is also discussed.
The effect of fancy rope jumping exercise on creativity of elementary school students

Purpose: To explore the effects of 6 months of moderate intensity fancy rope jumping exercise on the creativity of elementary school students. Methodology: One hundred and forty elementary school students were divided into two major groups, namely, the fancy rope jumping group and the traditional sports group. The Williams Creative Tendency Scale (WCTS) and Torrance Creative Thinking Scale (TTCT) were used to measure the changes of creative tendency and divergent thinking of elementary school students before and after the experiment, and to compare to evaluate the change of creativity of elementary school students by measuring the difference between the experimental group and the control group. Findings: (1) Six months of moderate intensity fancy rope jumping exercise had a positive effect on elementary school students’ creative tendencies and divergent thinking; (2) Six months of moderate fancy rope jumping exercise had a more significant effect on elementary school students’ divergent thinking. Research and practical limitations/implications: This study confirms experimentally that fancy rope jumping helps to enhance the creative tendency and divergent thinking level of elementary school students and promotes the development of their creativity. The limitation of this study is that the sample size is relatively small and not representative and convincing enough. In the follow-up study, we can make the research results more convincing by expanding the research sample size and sampling across regions.
Qualitative analysis and travelling wave solutions for the SI model with vertical transmission

In this note we analyze a spatially structured SI epidemic model with vertical transmission, a logistic effect on vital dynamics and a density dependent incidence. For a bounded spatial domain we show global stability of the endemic state when it is feasible. Then we look at the existence of travelling wave solutions connecting the endemic and the disease free states.
Electromagnetic fields of elementary dipole antennas embedded in stratified general gyrotropic media

Using matrix methods in conjunction with Fourier transformation techniques, the field excited by arbitrarily oriented elementary electric or magnetic dipole sources in the presence of a uniaxial or biaxial stratified gyrotropic medium is obtained in the form of a full dyadic Green's function. Both the permittivity and permeability tensors, being completely unrestricted, assume their most general forms in each layer separately. The singular behavior of the solution in the close vicinity of the source-point is properly taken into account by separate, suitably selected dyadic delta function terms. Using suitably selected upward or downward wave amplitude matrices, the field inside any of the layers is determined. >
The NRAO VLA Sky Survey

The NRAO VLA Sky Survey (NVSS) covers the sky north of J2000.0 δ = -40° (82% of the celestial sphere) at 1.4 GHz. The principal data products are (1) a set of 2326 4° × 4° continuum "cubes" with three planes containing Stokes I, Q, and U images plus (2) a catalog of almost 2 × 106 discrete sources stronger than S ≈ 2.5 mJy. The images all have θ = 45″ FWHM resolution and nearly uniform sensitivity. Their rms brightness fluctuations are σ ≈ 0.45 mJy beam-1 ≈ 0.14 K (Stokes I) and σ ≈ 0.29 mJy beam-1 ≈ 0.09 K (Stokes Q and U). The rms uncertainties in right ascension and declination vary from ≲1″ for the N ≈ 4 × 105 sources stronger than 15 mJy to 7″ at the survey limit. The NVSS was made as a service to the astronomical community. All data products, user software, and updates are being released via the World Wide Web as soon as they are produced and verified.
Assimilation of autoscaled data and regional and local ionospheric models as input sources for real‐time 3‐D International Reference Ionosphere modeling

This paper describes how the joint utilization of autoscaled data such as the F2 peak critical frequency foF2, the propagation factor M(3000)F2, and the electron density profile coming from two reference ionospheric stations (Rome and Gibilmanna), and the regional (Simplified Ionospheric Regional Model Updated) and global (International Reference Ionosphere) ionospheric models can provide a valid tool for obtaining a real‐time three‐dimensional (3‐D) electron density mapping of the ionosphere. Preliminary results of the proposed 3‐D model are shown by comparing the electron density profiles given by the model with the ones measured at three testing ionospheric stations (Athens, Roquetes, and San Vito).
Theories of the nuclei of active galaxies

The underlying source of power in active galaxies and quasars is still debated. X-ray observations of these objects may relate more directly with this power source than observations in other wavebands. Theories of active galactic nuclei are reviewed, together with X-ray production mechanisms, both thermal and non-thermal. Constraints imposed on these theories by present and future observations are discussed and interpreted in terms of some models for specific objects.
First-principles study of two- and one-dimensional honeycomb structures of boron nitride

This paper presents a systematic study of two- and one-dimensional honeycomb structures of boron nitride (BN) using first-principles plane-wave method. In order to reveal dimensionality effects, a brief study of all allotropic forms of three-dimensional (3D) BN crystals and truly one-dimensional atomic BN chains are also included. Two-dimensional (2D) graphenelike BN is a wide band-gap semiconductor with ionic bonding through significant charge transfer from B to N. Phonon-dispersion curves demonstrate the stability of 2D BN flakes. Quasi-one-dimensional (1D) armchair BN nanoribbons are nonmagnetic semiconductors with edge states. Upon passivation of B and N with hydrogen atoms these edge states disappear and the band gap increases. Bare zigzag BN nanoribbons are metallic but become a ferromagnetic semiconductor when both their edges are passivated with hydrogen. However, their magnetic ground state, electronic band structure, and band gap are found to be strongly dependent on whether B or N edge of the ribbon is saturated with hydrogen. Vacancy defects in armchair and zigzag nanoribbons affect also the magnetic state and electronic structure. Harmonic, anharmonic, and plastic regions are deduced in the variation in the total energy of armchair and zigzag nanoribbons as a function of strain. The calculated force constants display a Hookian behavior. In the plastic region the nanoribbon is stretched, whereby the honeycomb structure of hexagons change into different polygons through sequential structural transformations. In order to reveal dimensionality effects these properties are contrasted with those of various 3D BN crystals and 1D BN atomic chain.
Finite matrix crack penetrating a partially debonded circular inhomogeneity

We rigorously solve the problem of a finite matrix crack penetrating a partially debonded circular elastic inhomogeneity under longitudinal shear. The tips of the matrix crack are mutual image points with respect to the inhomogeneity/matrix interface and one tip of the interface crack is located at the intersection point between the matrix crack and the circular interface. Closed-form expressions of mode-III stress intensity factors at all three crack tips as well as displacement jumps across the crack surfaces are obtained. Our results are illustrated in graphical form and verified by comparison with existing results in the literature.
A critique of methods for calculating the dielectric strength of gas mixtures

Three currently available methods for predicting the dielectric strength of gas mixtures are discussed and compared. All are based on the common principle of linear addition of some property of the individual gases in proportion to their concentration in the mixture. The simplest approach uses a weighted sum of the dielectric strengths of the separate gases. The other approaches are based on predicting the limiting reduced field (E/N)*m at which the net ionization coefficient of the mixture (ᾱ/N)m = 0. Wieland’s approximation for ᾱm involves a weighted sum of the ᾱ’s for the separate gases, and requires a knowledge of these over the range (E/N)*w<(E/N)<(E/N)*s, where w and s refer to the weakest and strongest gas involved. It is shown that this approach in general gives a mixture strength which varies monotonically with the fractional concentrations and lies within the above range of E/N. The simplest approach, using weighted linear addition of strengths, and the empirical rule proposed earlier by Takuma .
A burst of outflows from the Serpens cloud core: wide-field submillimetre continuum, CO J=2–1 and optical observations

Wide-field mapping of Serpens in submillimetre continuum emission and CO J=2–1 line emission is here complemented by optical imaging in [S ii] λλ6716, 6731 line emission. Analysis of the 450- and 850-μm continuum data shows at least 10 separate sources, along with fainter diffuse background emission and filaments extending to the south and east of the core. These filaments describe ‘cavity-like’ structures that may have been shaped by the numerous outflows in the region. The dust opacity index, β, derived for the identifiable compact sources is of the order of 1.0±0.2, with dust temperatures in excess of 20 K. This value of β is somewhat lower than for typical class I YSOs; we suggest that the Serpens sources may be ‘warm’, late class 0 or early class I objects. With the combined CO and optical data we also examine, on large scales, the outflows driven by the embedded sources in Serpens. In addition to a number of new Herbig–Haro flows (here denoted HH 455–460), a number of high-velocity CO lobes are observed; these extend radially outwards from the cluster of submillimetre sources in the core. A close association between the optical and molecular flows is also identified. The data suggest that many of the submillimetre sources power outflows. Collectively, the outflows traced in CO support the widely recognized correlation between source bolometric luminosity and outflow power, and imply a dynamical age for the whole protostellar cluster of ∼3×104 yr. Notably, this is roughly equal to the proposed duration of the ‘class 0’ stage in protostellar evolution.
High‐resolution simulation of inviscid flow in general domains

In this paper, a high‐resolution finite volume method for calculating solutions to a hyperbolic conservation law is presented. The method works in two space dimensions on general domains and uses curvilinear meshes. A non‐trivial estimation of gradients needed for the reconstructions is presented. The paper contains examples of numerical solutions of the Euler gas dynamics equations. Copyright © 2005 John Wiley & Sons, Ltd.
A Nearest-Centroid Technique for Evaluating the Minimum-Variance Clustering Procedure.

It was posited that a good cluster solution has two characteristics: (1) it is stable across multiple random samples; and (2) its clusters accurately correspond to the populations from which the sample of data comes. A technique for evaluating a minimum variance cluster solution (Ward, 1963) was presented which deals with these two characteristics of a solution. In this technique, which follows the cross-validation paradigm, two data sets were drawn from a population mixture. One data set was cluster analyzed (by the minimum variance procedure), and the centroid vectors for the solution were calculated. After the other data set was cluster analyzed, its objects were assigned to the nearest centroid calculated in the first data set. The outcome is a kappa statistic which measures the agreement between the minimum variance cluster solution of the second data set and the classifications made by the nearest-centroid assignment rule. Results from Monte Carlo investigations of the technique showed that the new .
Effects of temperature and strain rate on the mechanical properties of hexagonal boron nitride nanosheets

The effect of temperature and strain rate on mechanical properties remains an open topic in research of hexagonal boron nitride (h-BN) nanosheets. To examine these fundamental issues we have performed molecular dynamics simulations to record the stress–strain curves in tensile tests and measure Young's modulus, fracture strength and fracture strain in armchair and zigzag directions. Comparing the results obtained at different temperatures and strain rates we have quantified the effects of the two factors on the tensile properties of the h-BN nanosheets. The influence of crystal orientation is also examined in the present study. It is found that the h-BN nanosheets are basically an anisotropic material whose tensile properties vary substantially with temperature and strain rate. In particular, a yielding platform is observed for the h-BN nanomaterial at relatively low temperature.
Growing evidence for a core formation threshold traced in Herschel Gould Belt survey clouds

It has already been suggested that a threshold in column density - or in visual extinction - may need to be exceeded to form dense cores and then protostars. Based on Herschel Gould Belt survey results in the Aquila and Orion B molecular cloud complexes we observe clear connection between the locations of the detected prestellar cores and their background column density values. This finding appears to support a core formation scenario where such threshold corresponds to the extinction above which interstellar filaments become gravitationally unstable and fragment into cores. In these two actively star-forming regions we find the vast majority of the gravitationally bound prestellar cores above a high column density of about (6-7) × 1021 cm-2 (AV ˜ 6-7). This limit similarly appears in the column density probability distribution function (PDF) of the regions as well. The spatial distribution of the protostars and young stellar objects (YSOs) also shows a tight connection with the densest sites of both clouds, as more than 70 % of them appear above the mentioned AV thresholds. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.
Forecast Uncertainties in Macroeconomic Modeling

Weargue that probability forecasts convey information on the uncertainties that surround macroeconomic forecasts in a straightforward manner that is preferable to other alternatives, including the use of confidence intervals. Probability forecasts obtained using a small benchmark macroeconometric model and a number of other alternatives are presented and evaluated using recursive forecasts generated over the period 1999q1–2001q1. Out-of-sample probability forecasts of inflation and output growth are also provided over the period 2001q2–2003q1, and their implications are discussed in relation to the Bank of England's inflation target and the need to avoid recessions, both as separate events and jointly. The robustness of the results to parameter and model uncertainties is also investigated using Bayesian model-averaging techniques.
Fast algorithm for electromagnetic scattering from two-dimensional conductor of arbitrary geometry

The fast multipole method (FMM) is used to solve the electromagnetic scattering from two-dimensional conducting bodies of arbitrary shape when a iterative method is used to solve the electric field integral equation (EFIE). FMM reduces the complexity of computing the matrix-vector multiplication from O(N/sup 2/)) to O(N/sup 1.5/). Instead of the conjugate gradient (CG) method, in this paper the biconjugate gradient (BiCG) method is used to accelerate the iteration process.
A Review on the Fundamental Aspects of Female-Friendly Prayer Areas in Shopping Centres

Performing the five-time prayer is an obligation for every Muslim, no matter where they are. The provision of prayer rooms in commercial buildings is one of the facilities offered by building managers to accommodate Muslim buyers in most Muslim countries. However, the muṣallá provided is often remote, placed in a small or poorly planned space that most users, especially women, will feel uncomfortable and uncomfortable. This article aims to identify the feasibility of places of worship facilities for women in malls. The method in this study is qualitative with a descriptive-analytical approach. The results showed that the problems that came to the fore included the unresponsiveness of prayer rooms for the needs of women, inadequate entrance locations, uncomfortable ablution places, not being equipped with the necessary facilities, and some even not being child-friendly for parents. From this literature search, several research recommendations to investigate features and facilities in prayer rooms to make the area more responsive to the needs of Muslim female buyers. The results of this research have contributed to the development of Islamic education, namely increasing mutual awareness about the importance of providing decent worship facilities, especially for women.