Miracle-dz/UniFAR-FTUs huggingface dataset:
Nuclear solid crust on rotating strange quark stars

We calculate in general relativity the thickness, mass, and moment of inertia of the nuclear solid crust that can exist on the surface of a rotating strange quark star suspended out of contact with the quark core by an electric dipole layer on the core surface and the centrifugal force. Aside from the interesting properties of such stars, a particular question of great import to the viability of the strange matter hypothesis is whether strange stars can undergo the observed phenomena of pulsar glitches
A classification of certain finite double coset collections in the exceptional groups

Abstract Let G be an exceptional algebraic group, X a maximal rank reductive subgroup and P a parabolic subgroup. This paper classifies when X\G/P is finite. Finiteness is proven using a reduction to finite groups and character theory. Infiniteness is proven using a dimension criterion that involves root systems.
ON ERGODIC STOCHASTIC CONTROL

We study here ergodic optimal stochastic control problems. After recalling some classical cases where the control system is known to be ergodic like the uniformly nondegenerate case or when there is an exactly controllable det,erniinistic subsystem. we study new intermediate situations. Tiye begin with the one-dimensional case that we essentially solve in full generality. We then consider the periodic case with constant coefiicients and show that ergodicity is equivalent to some stocliastic non resonance condition. Finall we show that the existence of one nondegenerate control is not sufficient for ergodicitj. in dimensions larger than or equal to 2
Transport coefficients from first-principles calculations

We present a method of modeling transport coefficients from first-principles calculations. We introduce the transport distribution that contains all electronic information and from which transport coefficients can easily be calculated. We use this method to analyze Bi 2 Te 3 and calculate its transport coefficients for a comparison with experiment. The transport distribution gives an improved insight into the relationship between transport properties and electronic structure and is a valuable tool in the search for improved thermoelectric materials.
Polytypism of GaAs, InP, InAs, and InSb: An ab initio study

A systematic study of ground state properties of cubic (3$C$) and hexagonal (6$H$, 4$H$, 2$H$) polytypes of normal (nonnitride) III-V compounds is reported using well-converged density-functional calculations within local density approximation, ab initio pseudopotentials, and projector-augmented wave method. Equilibrium results are obtained for lattice parameters, cohesive energies, and bulk moduli. Internal degrees of freedom, i.e., atomic relaxations, are taken into account. Trends with the hexagonality are discussed. Within the axial next-nearest-neighbor Ising (ANNNI) model driving forces of the polytypism as well as the stacking fault formation are derived. The results are compared with available experimental data.
BVRI CCD photometry of Omega Centauri

Color-magnitude diagrams (CMDs) of V vs B-V, V vs V-I, and V vs B-I have been constructed based on 179 BVRI CCD frames of two adjoining 4x2.5-arcmin fields in Omega Cen (NGC 5139) obtained with the 1.54-m Danish La Silla telescope. The spread in the main sequences noted in the three CMDs indicates that the wide range in chemical composition among the evolved stars in this cluster persists as well in the unevolved stars. This result suggests that the abundance variations are primordial. A difference in magnitude between the turnoff and the horizontal branch of 3.8 + or - 0.15 is found which is greater than a previous value. 38 references.
Structure and Evolution of Winter Cyclones in the Central United States and Their Effects on the Distribution of Precipitation. Part I: A Synoptic-Scale Rainband Associated with a Dryline and Lee Trough

Abstract A convective rainband, which was approximately 1500 km in length and affected large areas of the central United States for about 16 h, developed within an evolving winter cyclone. The rainband, which will be referred to as the pre-drytrough rainband, formed approximately 400 km ahead of a developing dryline and lee trough (drytrough, for short) that created an elevated, sloping layer of convective instability. The presence of a deep pool of high-potential-temperature air in the middle troposphere over the south-central United States, advected there from the elevated terrain to the southwest (i.e., an elevated mixed layer), produced a region of warm-air advection downstream of the high terrain. This enhanced the lifting associated with a migrating short wave aloft and generated the pre-drytrough rainband. In previous studies the dryline, the lee trough, the elevated mixed layer, and the low-level jet in the central United States have generally been viewed as isolated features. Here the authors pre.
SINGLE AND DOUBLE IONIZATION OF DIATOMIC MOLECULES IN STRONG LASER FIELDS

Strong-field single ionization and double ionization of two diatomic molecules, O 2 and N2, are studied and compared to Xe and Ar, using an intense ultrashort pulse Ti:sapphire laser in the 2 310 to 8310 W/cm intensity range. N2 behaves like a structureless atom for both single and double ionization. The recently reported suppression of the O 2 1 ion yield compared to Xe 1 is confirmed in our experiment, but we show that the suppression is not due to dissociative recombination. Rather, we conclude that the ionization rate of O 2 is below that predicted by tunneling ionization. We extend the study to the double ionization of O 2 and find a distinctly reduced nonsequential double-ionization rate. We find evidence that electronic structure influences strong-field tunneling ionization in molecules. @S1050-2947 ~98! 50512-4#
Two-Stream Approximations to Radiative Transfer in Planetary Atmospheres: A Unified Description of Existing Methods and a New Improvement

Abstract Existing two-stream approximations to radiative transfer theory for particulate media are shown to be represented by identical forms of coupled differential equations if the intensity is replaced by integrals of the intensity over hemispheres. One set of solutions thus suffices for all methods and provides convenient analytical comparisons. The equations also suggest modifications of the standard techniques so as to duplicate exact solutions for thin atmospheres and thus permit accurate determinations of the effects of typical aerosol layers. Numerical results for the plane albedos of plane-parallel atmospheres (single-scattering albedo = 0.8, 1.0; optical thickness = 0.25, 1, 4. 16; Henyey-Greenstein phase function with asymmetry factor 0.75) are given for conventional and modified Eddington approximations, conventional and modified two-point quadrature schemes, the hemispheric-constant method and the delta-function method, all for comparison with accurate discrete-ordinate solutions. A new two-.
Improved stoichiometry and misfit control in perovskite thin film formation at a critical fluence by pulsed laser deposition

Pulsed laser deposition (PLD) is a good method for growing high-quality functional oxide thin films because of the technical simplicity and the ease with which deposition can be switched from one material to another. However, the repeatability of film quality is often hard to achieve, especially when using several different PLD systems. Here we report the steps that we have taken to grow nearly bulk-equivalent defect-free thin films, with SrTiO3 as an example, by using PLD in a reproducible fashion. The ablation laser fluence was found to have a very strong effect on the lattice constant and defect structure of the films. Nonstoichiometric transfer of material from the ablation target was observed when either the laser fluence or the beam spot area was inadequate.
On the asymptotic distribution of quasinormal-mode frequencies for Schwarzschild black holes

The highly damped quasinormal-mode frequencies of Schwarzschild black holes are discussed. Numerical results obtained from a phase-integral formula derived by Andersson and Linnaeus (1992) are compared with the predictions of an approximate formula given by Nollert (1990). Close agreement between the two independent methods suggests that reliable conclusions regarding the asymptotic behaviour of the quasinormal-mode frequencies may be drawn. For a Schwarzschild black hole with mass M the physical oscillation frequency approaches the asymptotic value (in geometrized units) 0.0437 M-1. Meanwhile, the characteristic damping of the modes increases linearly with the integer index labelling the modes. The asymptotic behaviour is independent of the angular harmonic index l.
Band theory for electronic and magnetic properties of

We report results of calculations that explain in the itinerant-electron picture magnetic and electronic properties of haematite, . For this we use the local approximation to spin-density functional theory and the ASW method incorporating spin - orbit coupling and noncollinear moment arrangements. The insulating character of the compound is obtained correctly and features in the density of states connected with Fe - O hybridization correlate well with experimental features seen in direct and inverse photoemission intensities. The total energy correctly predicts the experimentally observed magnetic order of the ground state, and, using total energies of different magnetic configurations, we can give a rough estimate of the Neel temperature. We also obtain a state showing weak ferromagnetism. The rate of change is calculated for the decrease of the insulating gap when an external magnetic field is applied.
Different choices of scaling in homogenization of diffusion and interfacial exchange in a porous medium

Several choices of scaling are investigated for a coupled system of parabolic partial differential equations in a two‐phase medium at the microscopic scale. This system may be regarded as modelling a reaction–diffusion problem, the Stokes problem of single‐phase flow of a slightly compressible fluid or as a heat conduction problem (with or without interfacial resistance), for example. It is shown that, starting with the same problem on the microscopic scale, different choices of scaling of the diffusion coefficients (resp. permeability or conductivity) and the interfacial‐exchange coefficient lead to different types of macroscopic systems of equations. The characterization of the limit problems in terms of the scaling parameters constitutes a modelling tool because it allows to determine the right type of limit problem. New macroscopic models, not previously dealt with, arise and, for some scalings, classical macroscopic models are recovered. Using the method of two‐scale convergence, a unified approach yielding rigorous proofs is given covering a very broad class of different scalings. Copyright © 2008 John Wiley & Sons, Ltd.
Ensemble Data Assimilation Using a Unified Representation of Model Error

AbstractA natural way to set up an ensemble forecasting system is to use a model with additional stochastic forcing representing the model error and to derive the initial uncertainty by using an ensemble of analyses generated with this model. Current operational practice has tended to separate the problems of generating initial uncertainty and forecast uncertainty. Thus, in ensemble forecasts, it is normal to use physically based stochastic forcing terms to represent model errors, while in generating analysis uncertainties, artificial inflation methods are used to ensure that the analysis spread is sufficient given the observations. In this paper a more unified approach is tested that uses the same stochastic forcing in the analyses and forecasts and estimates the model error forcing from data assimilation diagnostics. This is shown to be successful if there are sufficient observations. Ensembles used in data assimilation have to be reliable in a broader sense than the usual forecast verification methods;.
An alternating direction-based contraction method for linearly constrained separable convex programming problems

The classical alternating direction method (ADM) has been well studied in the context of linearly constrained convex programming and variational inequalities where the involved operator is formed as the sum of two individual functions without crossed variables. Recently, ADM has found many novel applications in diversified areas, such as image processing and statistics. However, it is still not clear whether ADM can be extended to the case where the operator is the sum of more than two individual functions. In this article, we extend the spirit of ADM to solve the general case of the linearly constrained separable convex programming problems whose involved operator is separable into finitely many individual functions. As a result, an alternating direction-based contraction-type method is developed. The realization of tackling this class of problems broadens the applicable scope of ADM substantially.
Birefringence study of the freezing mechanism of lanthanum-modified lead zirconate titanate relaxor ferroelectrics

The temperature dependence of the electric field-induced birefringence and electro-optic coefficient of Pb0.91La0. 09(Zr0.65Ti0.35)0.9775O3 (PLZT) relaxor ferroelectrics were investigated. The remanent birefringence of the poled specimen disappeared around 268 K, thus indicating this to be the freezing temperature. On the other hand, a maximum value of the electro-optic coefficient was observed around 235 K, which is much lower than the freezing temperature. A brief discussion is given on the electro-optic coefficient behavior from the viewpoint of the freezing mechanism of PLZT relaxor ferroelectrics.
APPLICATION OF VARIATIONAL METHODS TO THE THEORY OF THE SCATTERING OF SLOW ELECTRONS BY HYDROGEN MOLECULES

The cross section for the elastic scattering of slow electrons by molecular hydrogen is calculated by use of the variational methods of Hulthen and of Kohn, full allowance being made for electron exchange. The trial wave function is assumed to have a form which in spheroidal coordinates resembles the analogous functions in spherical polar coordinates used in discussing elastic scattering by hydrogen and helium atoms. Quite good agreement is obtained with observed data - an agreement which disappears when exchange is neglected; this is a situation similar to that which arises in the case of helium.
Second order optimality conditions for generalized semi-infinite programming problems

We consider generalized semi-infinite programming problems. Second order necessary and sufficient conditionsfor local optimality are given. The conditions are derived under assumptions such that the feasible set can be described by means of a finite number of optimal value functions. Since we do not require a strict complementary condition for the local reduction these functions are only of class C1 A sufficient condition for optimality is proven under much weaker assumptions.
Dawn‐dusk asymmetry in solar wind ion entry and dayside precipitation: Results from large‐scale simulations

We present the results of numerical studies of the interaction of solar wind ions with the dayside magnetospheric boundary for a southward interplanetary magnetic field and two solar wind speeds (250 and 500 km/s) using the results of global magnetohydrodynamics simulations in conjunction with large‐scale kinetic calculations. Results of these studies show that a dawn‐dusk asymmetry is found in the precipitation of low‐ to middle‐energy ions over the high‐latitude dayside magnetosphere. This asymmetry is consistent with statistical studies of DMSP data showing that ion precipitation from the mantle is predominantly seen over the morning and prenoon sector. Analysis of energy‐latitude spectra and study of individual particle trajectories from the simulations revealed that low‐energy ions can enter the magnetopause at high latitudes in regions where the parallel electric field associated with the magnetopause current is positive and strong enough for the ions to gain energies of the order of the parallel potential drop across the magnetopause. Because the parallel electric field in the Northern Hemisphere is positive in the prenoon sector and negative in the afternoon‐evening sector, solar wind ions reaching the magnetopause in these regions are accelerated toward the ionosphere on the dawnside and outward on the duskside, creating the asymmetry in precipitation. The same dawn‐dusk asymmetry is found in the Southern Hemisphere because both parallel electric field and magnetic field are reversed in direction.
Scour Caused by 2D Horizontal Jets

AbstractAn analysis is presented of the 309 known laboratory data for local scour depth developed by two-dimensional (2D) horizontal jets, which leads to development of a new comprehensive prediction equation. The new equation comprises a number of mutually independent multiplying factors, which account for the effects on local scour depth of the characteristics of the applied jet flow and the bed sediment, as well as the extent of a downstream protective apron. When unitized in terms of the jet thickness, the equation shows that the maximum possible dimensionless local scour depth is equal to three times the jet Froude number expressed in terms of jet velocity and jet thickness. The equation is compared to most of the existing predictive equations by applying each equation to the existing data, the comparison indicating that the new method has superior performance. Indeed, many of the existing predictive equations are shown to perform poorly when judged against the known laboratory data. The known existi.
Stretchability of thin metal films on elastomer substrates

Many flexible electronic surfaces comprise inorganic films on organic substrates. Mechanical failure of such integrated structures of stiff and compliant materials poses a significant challenge. This letter studies the stretchability of metal films on elastomer substrates. Our experiment shows that, when stretched, elastomer-supported metal films rupture at strains larger than those reported for freestanding films. We use a finite element code to simulate the rupture process of metal films. A freestanding metal film ruptures by forming a single neck. By contrast, a metal film on an elastomer substrate may develop an array of necks before rupture. While the pre-rupture necks do not change the electrical conductance appreciably, they elongate the metal film, leading to a large overall rupture strain.
Nonlinear analysis of RC shear walls considering tension-sti(cid:128)ening e(cid:128)ect

An analytical model which can simulate the nonlinear behavior of reinforced concrete (RC) structures (such as panels and shear walls) subjected to in-plane shear and normal stresses is introduced. Based on the concept of equivalent uniaxial strain, constitutive relations of concrete are presented in the axes of orthotropy which coincide with the principal axes of total strain and rotate according to the loading history. The proposed model includes the description of biaxial failure criteria which show compressive strength enhancement and tensile resistance reduction e(cid:128)ects for the stress states of biaxial compression and tension–compression, respectively. After tensile cracking, concrete compressive strength degradation was implemented and the tensile capacity of concrete maintained by the reinforcing steel (tension-sti(cid:128)ening e(cid:128)ect) is considered. Using the concept of average stresses and strains, a criterion is proposed to simulate the tension-sti(cid:128)ening e(cid:128)ect based on the force equilibriums, compatibility conditions, and bond stress-slip relationship between reinforcement and the surrounding concrete. The ﬁnite element model predictions are validated by comparison with available experimental data. In addition, correlation studies between analytical results and experimental values from idealized shear panel tests were conducted. Load–displacement relations of shear panel beams and walls under various stress conditions are then evaluated to verify the soundness of the proposed model. (cid:211) 2001 Elsevier Science Ltd. All rights reserved.
Self‐gravity wakes in Saturn's A ring measured by stellar occultations from Cassini

An azimuthal brightness asymmetry in Saturn's A ring is caused by ephemeral agglomerations that continually form under the mutual gravity of the ring particles only to be torn apart by Keplerian shear. We calculate the shape and spacing of the self‐gravity wakes from Cassini stellar occultations. The wakes are highly flatttened structures, with height/width ratio of 0.15 to 0.37, increasing outward across the A ring. The spacing between wakes increases with their height from a low value in the inner A ring of less than the wake width to >3 times the wake width in the outer third of the ring. The opacity of gaps between wakes also increases in the outer part of the ring where the wakes appear to be less coherent than in the inner and middle A ring. We calculate the vertical opacity of the A ring is 15–35% higher than previously reported.
Determinants Of Muzakki's Level Of Trust Towards The Amil Zakat Institution

The purpose of this study was to find out what factors increased muzakki's trust toward the Amil Zakat Institution (LAZ) with a study on LAZ Harapan Umat. The research with a quantitative approach and using a sample of 70 muzakki, found that the level of muzakki trust was influenced by transparency of financial statements, fund management and religiosity, while accountability had no effect on the level of muzakki trust.
Improved design of a high-voltage vacuum-insulator interface

We have conducted a series of experiments designed to measure the flashover strength of various azimuthally symmetric $45\ifmmode^\circ\else\textdegree\fi{}$ vacuum-insulator configurations. The principal objective of the experiments was to identify a configuration with a flashover strength greater than that of the standard design, which consists of a $45\ifmmode^\circ\else\textdegree\fi{}$ polymethyl-methacrylate (PMMA) insulator between flat electrodes. The thickness $d$ and circumference $C$ of the insulators tested were held constant at 4.318 and 95.74 cm, respectively. The peak voltage applied to the insulators ranged from 0.8 to 2.2 MV. The rise time of the voltage pulse was 40\char21{}60 ns; the effective pulse width [as defined in Phys. Rev. ST Accel. Beams 7, 070401 (2004)] was on the order of 10 ns. Experiments conducted with flat aluminum electrodes demonstrate that the flashover strength of a crosslinked polystyrene (Rexolite) insulator is $(18\ifmmode\pm\else\textpm\fi{}7)%$ higher than that of PMMA. Experiments conducted with a Rexolite insulator and an anode plug, i.e., an extension of the anode into the insulator, demonstrate that a plug can increase the flashover strength by an additional $(44\ifmmode\pm\else\textpm\fi{}11)%$. The results are consistent with the Anderson model of anode-initiated flashover, and confirm previous measurements. It appears that a Rexolite insulator with an anode plug can, in principle, increase the peak electromagnetic power that can be transmitted across a vacuum interface by a factor of $[(1.18)(1.44){]}^{2}=2.9$ over that which can be achieved with the standard design.
A single-shot transmissive spectrometer for hard x-ray free electron lasers

We report hard x-ray single-shot spectral measurements of the Linac Coherent Light Source. The spectrometer is based on a 10 μm thick cylindrically bent Si single crystal operating in the symmetric Bragg geometry to provide dispersion and high transmission simultaneously. It covers a spectral range >1% using the Si(111) reflection. Using the Si(333) reflection, it reaches a resolving power of better than 42 000 and transmits >83% of the incident flux at 8.3 keV. The high resolution enabled the observation of individual spectral spikes characteristic of a self-amplified spontaneous emission x-ray free electron laser source. Potential applications of the device are discussed.