Miracle-dz/UniFAR-FTUs huggingface dataset:
On rational torsion points of central $\mathbb{Q}$-curves(Algebraic Number Theory and Related Topics)

Soit E une Q-courbe centrale sur un corps polyquadratique k. Dans cet article, nous donnons une borne superieure des diviseurs premiers de l'ordre du sous-groupe de torsion k-rationnel E tors (k) (voir Theoremes 1.1 et 1.2). La notion de Q-courbe centrale est une generalisation de celle de courbe elliptique sur Q. Notre resultat est une generalisation du Theoreme de Mazur [12], et c'est une precision des bornes superieures de Merel [15] et Oesterle [17].
Effects of Zonal Flows on Equatorially Trapped Waves

Abstract Linear shallow water equations are employed to study the effects of basic zonal flows on equatorially trapped waves. Analytical solutions are obtained for constant basic zonal flows. It is shown that changes in the wave structures due to the non-Doppler effect of the basic zonal flow are considerable for the Rossby wave, moderate for the westward propagating mixed Rossby–gravity wave, but negligible for the other equatorial waves. The Rossby wave and the westward propagating mixed Rossby–gravity wave possess greater eigenfrequencies and are less trapped in westerlies than in easterlies. The dependence of the Rossby wave structure upon the basic zonal flow is interpreted in terms of potential vorticity conservation. In basic zonal flows with meridional shears, the eigenfrequencies are found to be larger in equatorial easterlies than in equatorial westerlies for the westward propagating waves but smaller for the eastward propagating waves. While the meridional structures of the eastward propagating.
Size-induced structural phase transitions and hyperfine properties of microcrystalline Fe2O3

Microcrystalline particles of Fe2O3 having different sizes (varying between 70 and 5 nm) have been synthesised using a novel three-component micro-emulsion technique. A succession of crystal-size-induced structural transitions was observed. While alpha -Fe2O3 was found to nucleate for a particle size above 30 nm, gamma -Fe2O3 was preferentially formed for a size below 30 nm, whereas amorphous Fe2O3 was formed at a particle size of 5 nm. These structural transformations have been related to the increase in the unit-cell volume that occurs as the particle size is decreased. The size dependence of the lattice parameter is shown to arise from a coupling of the surface energy to the dilatational lattice mode. A model Hamiltonian which incorporates this interaction and displays size-induced phase transitions is defined. The Mossbauer hyperfine field in the microcrystalline samples at 4.2 K was found to be substantially smaller than in the 'bulk'. The hyperfine parameters of the amorphous sample were found to be similar to those pertaining to samples prepared by conventional techniques such as melt quenching. A large anisotropy in the ionic vibrational amplitudes was detected in samples with particles smaller than about 10 nm.
Limit Theorems for Two Classes of Random Matrices with Dependent Entries

In this paper we study random symmetric matrices with dependent entries. Suppose that all entries have zero mean and finite variances, which can be different. Assuming that the average of normalized sums of variances in each row converges to one and the Lindeberg condition holds true, we prove that the empirical spectral distribution of eigenvalues converges to Wigner's semicircle law. The result can be generalized to the class of covariance matrices with dependent entries. In this case expected empirical spectral distribution function converges to the Marchenko--Pastur law.
Infrared properties of nearby radio galaxies

The IRAS data for a sample of nearby radio galaxies (z less than 0.13) are analyzed. Comparison of the infrared, radio, and optical data suggests that most of the long-wavelength infrared emission comes from cool interstellar dust for almost all of the galaxies; these galaxies may contain large amounts (10 to the 8th - 10 to the 10th solar masses) of interstellar matter. About 15 percent of the galaxies show evidence for a hotter thermal component emitting at the shorter IRAS wavelengths; this could be due to dust in the inner regions of the galaxy heated by the active galactic nucleus. 86 refs.
Viscous excretion discs around Be stars

The properties of geometrically thin viscous Keplerian excretion discs around Be stars are analyzed. The inner boundary of the disc is assumed to be located at the equatorial surface of the central star. It is assumed that angular momentum is transferred by some mechanism from the interior to the equatorial surface of the central star and hence matter is supplied at the inner boundary of the disc at a certain rate (excretion rate). The matter drifts outward in the disc because the angular momentum of the matter is exchanged by the effect of viscous stress. For mass excretion rates similar to the mass-loss rate estimated for Be stars, the irradiative heating by the central star is as important for the disc structure as the viscous heating in the disc
PET: Exploring the Myth and the Method

New research tools such as PET can produce dramatic results. But they can also produce dramatic artifacts. Why is PET to be trusted? We examine both the rationale that justifies interpreting PET as measuring brain activity and the strategies for interpreting PET results functionally. We show that functional ascriptions with PET make important assumptions and depend critically on relating PET results to those secured through other research techniques.
Auroral Lyman α and H2 bands from the giant planets: 2. Effect of the anisotropy of the precipitating particles on the interpretation of the “color ratio”

Previous spectral analyses have given evidence of collisionally excited Jovian and (at times) Saturnian H2 Werner bands being absorbed by hydrocarbons at the shortest wavelengths along the auroral ovals, and of a longitudinal dependence of this absorption in the Jovian aurorae. This “color ratio” has been used to estimate the energy of the primary particles. In such estimates, particles are generally assumed to penetrate vertically into the atmosphere. However, the precipitating particle angular distribution is unknown, and a model developed for a diffuse aurora by Prange and Elkhamsi (1991), for instance, predicts quite different possible distributions. We consider here the influence of the angular distribution used in the model, and show that distributions peaking far from vertical may increase the energy derived from a given color ratio by as much as a factor of 3. We discuss previous interpretations of the color ratio longitudinal modulation (variation of the auroral atmosphere structure, or of the incident particle energy) in view of the subsequent increase in energy input. We argue that an interpretation in terms of energy variations only is not consistent with the energy available in the magnetosphere if the aurorae are diffuse, and we discuss this finding in the context of recent Hubble Space Telescope images.
Data-based mechanistic modelling and validation for leaf area index estimation using multi-angular remote-sensing observation time series

Spatially and temporally complete leaf area index (LAI) time series are required for crop growth monitoring, forest biomass estimation, and land surface process simulation studies. Global LAI products currently available include the Moderate Resolution Imaging Spectroradiometer (MODIS) LAI product. However, data quality still needs to be improved, especially with respect to temporal continuity. In this research, a new approach has been developed to estimate LAI time series using the data-based mechanistic (DBM) modelling procedure. Both the nadir viewing reflectance and anisotropic index (ANIX) time series derived from the MODIS product are used in LAI_DBM modelling and estimation, where the ANIX values are used as an auxiliary variable to represent the bidirectional reflectance anisotropy of the vegetation canopy. Both the MOD09GA multi-angular remote-sensing observations and the MOD15A2 LAI products are used in the LAI time series modelling and retrieval procedure. Ground measurements at typical vegetation sites are used to validate the estimated LAI. The preliminary results show that: (1) the new LAI_DBM approach using nadir viewing reflectance observation and ANIX time series can be used to improve the continuity of estimated LAI time series. The disturbance noise introduced by using the MOD09A1 directional reflectance observations directly can thus be reduced. (2) An ANIX time series can represent the vegetation canopy bidirectional reflectance anisotropy information and its dynamic changes. It works well in the retrieval procedure for improving LAI time series estimation. (3) The preliminary retrieval results demonstrate that the estimated LAIs can achieve better time series continuity than the original MODIS LAI product.
Mapping HF waves in the reconnection diffusion region

We study in detail high‐frequency (HF) plasma waves between the electron cyclotron and plasma frequencies within a reconnection diffusion region (DR) encountered by Cluster in the magnetotail using continuous electric field waveforms. We identify three wave types, all observed within the separatrix regions: Langmuir waves (LW), electrostatic solitary waves (ESWs), and electron cyclotron waves (ECWs). This is the first time the ECWs have been observed inside this region. Direct comparison between waveforms and electron distributions are made at the timescale of one energy sweep of the electron detector (125 ms). Based on the wave and electron distribution characteristics, we find that the separatrix region has a stratified spatial structure. The outer part of the region is dominated by LW emissions related to suprathermal electron beams propagating away from the X‐line. Furthest in, nearest to the current sheet, we observe ESWs associated with counterstreaming electron populations. Studying HF waveforms allows for a precise mapping of kinetic boundaries in the reconnection region and helps to improve our understanding of the electron dynamics in the DR.
Identification Methods in Vector‐Error Correction Models: Equivalence Results

In a structural vector‐error correction (VEC) model, it is possible to decompose the shocks into those with permanent and transitory effects on the levels of the variables. Pagan and Pesaran derive the restrictions which the permanent–transitory decomposition of the shocks imposes on the structural VEC model. This paper shows that these restrictions are equivalent to a set of restrictions that are applied in the methods of Gonzalo and Ng and King et al. (KPSW). Using this result, it is shown that the Pagan and Pesaran method can be used to recover the structural shocks with permanent effects identically to those from the Gonzalo and Ng and KPSW methods. In the former case, this is illustrated in the context of Lettau and Ludvigson's consumption model and in the latter case in KPSW's six variable model. There are also two other methods for which the Pagan and Pesaran approach can deliver identical permanent shocks which are also discussed.
Determination of the Twist Angle of GaN Film by High Resolution X-ray Diffraction

As an azimuthal scan method, Φ-scans preformed by X-ray diffraction are usually used to determine the twist angle in GaN films. However, both twist and tilt contribute to full width at half maximum (FWHM) of Φ-scan curves. So far no model has been proposed to distinguish the contributions of tilt and twist to FWHM of these curves. A geometrical model is presented to distinguish their contributions, which is very important to precisely determine the dislocation densities in GaN. Based on this model, FWHM of Φ-scans can be expressed as a simple explicit function of the original twist angle and an additional twist angle induced by tilt. These twist angles are then simply and effectively determined for various GaN films according to this simple function, and are in good agreement with those deduced from ω-scan data fitting.
Cellular automorphisms and self-duality

We catalog up to a type of reducibility all cellular automorphisms of the sphere, projective plane, torus, Klein bottle, and three-crosscaps (Dyck’s) surface. We also show how one can obtain all self-dual embeddings in a surface S given a catalog of all irreducible cellular automorphisms in S.
High-temperature reliability of GaN metal semiconductor field-effect transistor and bipolar junction transistor

High-quality GaN was grown using gas-source molecular beam epitaxy (GSMBE). We fabricated a GaN metal semiconductor field-effect transistor (MESFET) and an n–p–n bipolar junction transistor. The high-temperature reliability of the GaN MESFET and bipolar junction transistor was investigated. That is, the life performance of the FET at 400 °C was examined during continuous current injection at 400 °C. We confirmed that the FET performance did not change at 400 °C for 300 h. No degradation of the metal–semiconductor interface was observed by secondary ion-mass spectrometry and transmission electron microscopy. Furthermore, an n–p–n bipolar junction transistor using GaN grown by GSMBE was demonstrated. The bipolar junction transistor was operated at 300 °C. The reliability of a GaN MESFET and the bipolar junction transistor at high temperature was thus confirmed.
Stability of a characterization by the identical distribution of linear forms

The assumption that two linear statistics are identically distributed can be used to characterize various populations. This is an object of the so-called characterization theorems. But if the assumptions of the characterization theorem are fulfilled only approximately, then may we state that the conclusion of this characterization is also fulfilled approximately? Theorems, in which this kind of problems are considered, are called the stability theorems. According to Eaton's theorem, if under the additional conditions, the two linear statistics and have the same distribution as the monomial X 1, then this monomial has a symmetric stable distribution of order α. The stability estimation in this theorem is investigated in the paper.
Fine-Scale Magnetic Effects on p-Modes and Higher Frequency Acoustic Waves in a Solar Active Region

We present results from a 5 hr time series of simultaneous high-resolution measurements of oscillations in the photosphere and the chromosphere on fine spatial scales for a rapidly evolving solar active region and examine their relation to the vector magnetic field. The photospheric oscillations are determined from Doppler shifts in the Zeeman-insensitive spectral line Fe I 557.6 nm, whereas the chromospheric oscillations are determined from the intensity fluctuations seen in the Ca II K line. The vector magnetic field configurations just prior to and just after the time-series measurements are obtained from the full Stokes inversion of the line profiles of Fe I 630.15 and 630.25 nm. In both the photosphere and the chromosphere, p-mode power is suppressed by the magnetic field, decreasing with increasing field strength. At higher frequencies (above the acoustic cutoff) power is also suppressed at the highest magnetic field strengths in the photosphere and the chromosphere but is enhanced in the photosphere in localized patches ("halos") of intermediate field strength surrounding the patches of highest field strength (as first reported by Brown et al.). The evidence for similar halos in the chromosphere (as first seen by Braun et al. and Toner & LaBonte) and their association with the photospheric halos is less clear. We find seismic evidence, in the forms of suppression of p-mode and higher frequency power and a halo of enhanced higher frequency power, for a developing pore prior to its appearance as a dark patch in Fe I 557.6 nm core intensity. This result shows that p-mode power suppression cannot be due primarily to the greater transparency of the cooler pore atmosphere.
Vortex particle model in a non-Abelian gauge quantum gravity

The search for a quantum theory of gravity has become one of the most well-known problems in theoretical physics. Problems quantizing general relativity because it is not renormalizable have led to a search for a new theory of gravity that, while still agreeing with measured observations, is renormalizable. In this paper, I show that, given a "vortex" model of elementary particles in which rest mass derives from intrinsic spin and polarization, a Yang-Mills force with a R (3,1) SO(3,1) group symmetry predicts post-Newtonian N-body motion such as solar system observations of gravitational behavior as well as binary pulsar precession and orbital speed-up caused by gravitational radiation-reaction. Using a homogeneous, isotropic universe model, I show that this theory does not contradict cosmological observations of Type 1a supernovae, Baryon Acoustic Oscillation, and the Cosmic Microwave Background, including quantities of light elements from Big Bang Nucleosynthesis. In addition, because it is a generic massless Yang-Mills theory, it is a renormalizable quantum theory and makes a testable quantum prediction that mass, energy, and momentum are quantized as integer multiples of a small and previously undetected value.
Sustainable Food Consumption Analysis of Consumer Behaviour towards Organic Food Products

: The Current Scenario Exhibits A Recent Trend In Sustainable Food Consumption Where Consumers Are More Inclined Towards Organic Food Products. Organic Food Products Improve Public Health And Significantly Benefit The Environment As Well As The Economy. In This Regard, This Paper Aims To Conduct A Survey To Analyse Consumer Behaviour Towards Organic Food Products. Furthermore, This Research Assesses How Income Level, Quality Of Product, Environmental Viability, And Effect On Health Influence Consumer Behaviour. Organic Food Products Contribute To The Sustainability Of Food Choices And Their Present Day Significance Lends Value To This Research.
Invariant pattern-recognition filter based on the wavelet transform

A wavelet transformation based optical processor for performing invariant pattern recognition is suggested. It contains a composite filter that consists of several wavelet daughter functions derived from the reference object. The intensity of the correlation peak is determined to be invariant to various deformations of the reference object. Computer simulations show explicitly the promising ability of the new technique.
Two-fluid theory of collisionless magnetic reconnection

Theoretical studies of collisionless reconnection in the framework of two-fluid theory are presented. In the high-β case (β≳1) reconnection is controlled by the whistler mode, leading to decoupling of ions from electrons on scales <c/ωpi. Though reconnection requires electron inertia, the reconnection rate is independent thereof, controlled only by ion inertia. Reconnection is hence much faster than in the absence of the Hall term. In the opposite limit of small β the strong axial field suppresses the whistler mode. Hence ions have to follow the electrons in the narrow reconnection layer δ∼c/ωpe, forming a macroscopic current sheet which strongly reduces the reconnection rate. Theoretical scaling laws are confirmed by numerical simulations.
Measurements in the turbulent wake of a cylinder

An experimental study has been made of the conditions in the turbulent' wake behind a cylinder in an air stream at cylinder Reynolds numbers between 100 and 7000. The measurements include the mean velocity distribution, the distribution of the three components of turbulence, the statistical distribution in time of the turbulent velocity components, and the correlation derivatives in the downstream direction for both the longitudinal and transverse correlations. It is shown that the intensities of the three components of turbulent velocities are nearly equal except at the centre of the wake, where the balance between viscous decay and diffusion from the regions of shear results in a considerably greater intensity for the component at right angles to the direction of flow and also to the axis of the cylinder, i.e. in the direction of diffusion of turbulent energy. An analysis of the energy in the wake proves that complete dynamical similarity in the wake, if it is ever attained, does not occur closer to the cylinder than 1000 diameters, and that the viscous dissipation of energy can be described in terms of a length parameter, nearly constant over the width of the wake and approximately equal to the measured value of Taylor’s scale of micro-turbulence.
Simulation of extremes of diffusions

The authors consider the problem of simulating the times of events such as extremes and barrier crossings in diffusion processes. They develop a rejection sampler based on Shepp [Shepp, Journal of Applied Probability 1979; 16:423–427] for simulating an extreme of a Brownian motion and use it in a general recursive scheme for more complex simulations, including simultaneous simulation of the minimum and maximum and application to more general diffusions. They price exotic options that are difficult to price analytically: a knock‐out barrier option with a modified payoff function, a lookback option that includes discounting at the risk‐free interest rate, and a chooser option where the choice is made at the time of a barrier crossing. The Canadian Journal of Statistics 38: 738–755; 2010 © 2010 Statistical Society of Canada
Observations of the highly variable X-ray source GX 339-4.

Observations with the MIT experiment on the OSO-7 have led to the discovery of an X-ray source, GX 339-4, which varies in intensity by at least a factor of 60 over hundreds of days but shows no evidence of periodic behavior or abrupt intensity changes on time scales from 3 minutes to 13 days. The observations show intense high states, low states with spectra consistent with increased absorption, and off states, when no statistically significant signal is observed. The behavior is unlike that of any previously reported X-ray source.
Equation of state for extrapolation of high‐pressure shock Hugoniot data

An empirical equation of state is proposed for accurate extrapolation of high‐pressure shock Hugoniot states to other thermodynamic states. The proposed equation of state complements the Mie–Gruneisen equation of state and allows extrapolating a reference state to much different energy states where knowledge of the Gruneisen function is still uncertain. Examples are given of extrapolations of porous Hugoniots from corresponding solid Hugoniot data.
The effects of sintering aids upon dielectric microwave properties of columbite niobates, M2+Nb2O6

The columbite niobate ceramics ZnNb2O6, MgNb2O6, CaNb2O6 and CoNb2O6 have low dielectric losses at microwave (1–10 GHz) frequencies, resulting in Qf values between 40 000 and 90 000 GHz, making them suitable materials for use in dielectric resonator applications. However, their temperature coefficient of resonant frequency (τf) values were high, at between −50 and −90 ppm, and the optimum sintering temperatures were found to be between 1150°C and 1350°C. This paper details the doping of these ceramics with 1 wt%V2O5, 1 wt% CeO2, 2 wt% WO3 and 0.5 wt% CuO, in an attempt to reduce the sintering temperature. It was found that in many cases the dopants also had an extremely beneficial effect upon microwave properties, increasing er, and decreasing τf considerably. Although the dopants often had a deleterious effect upon the quality factor (Q), in some cases they caused an increase in Q. Qf values of over 20 000 GHz were often obtained at lower temperatures, even in poorly sintered niobates, and CuO-doped CaNb2O6 yielded Qf values in excess of 65 000 GHz. CoNb2O6+V2O5 or CuO gave 90% sintered and poorly sintered materials with Qf over 10 000 GHz and 25 000 GHz, respectively, at temperatures within low temperature Co-fired ceramic limits.