Miracle-dz/UniFAR-FTUs huggingface dataset:
Geomagnetically trapped anomalous cosmic rays

Since its launch in July 1992, the polar-orbiting satellite SAMPEX has been collecting data on geomagnetically trapped heavy ions, predominantly O, N, and Ne, at energies ≳ 15 MeV/nucleon and in a narrow L shell range near L = 2. Their location, elemental composition, energy spectra, pitch angle distribution, and time variations all support the theory that these particles originated as singly ionized interplanetary anomalous cosmic rays that were stripped of electrons in the Earth's upper atmosphere and subsequently trapped. The O are observed primarily at pitch angles outside the atmospheric loss cones, consistent with a trapped population, and their distribution there is nearly isotropic. The abundances relative to O of the N, possibly Ne, and especially C are lower than the corresponding interplanetary values, which may be indicative of the trapping efficiencies. The distributions of trapped N, O, and Ne in energy and L shell suggest that most of the ions observed at the SAMPEX altitude of ∼600 km are not fully stripped when initially trapped. A comparison of the trapped intensity with the much lower interplanetary intensity of anomalous cosmic rays provides model-dependent estimates of the product of the trapping probability and the average trapped particle lifetime against ionization losses in the residual atmosphere for particles that mirror near the SAMPEX altitude.
Polyamorphic transition of germanium under pressure

Pressure-induced transformations in the atomic and electronic structure of amorphous germanium $(a\ensuremath{-}\mathrm{Ge})$ have been investigated by using x-ray absorption spectroscopy (XAS) combined with energy-scanning x-ray diffraction. Our data show that an abrupt change in the local structure and in the electron states near the Fermi level occurs in evaporated $a\ensuremath{-}\mathrm{Ge}$ at a pressure of about 8 GPa. The transformation is clearly detectable by a change in the shape and energy shift in the near-edge structures and by an increase of the average first-neighbor distance measured by XAS. The occurrence of this polyamorphic transition is discussed in light of the recent advances in the study of multiple dense fluid phases.
Projection pursuit and the solvability condition applied to constructive learning

Single hidden layer neural networks with supervised learning have been successfully applied to approximate unknown functions defined in compact functional spaces. The more advanced results also give rates of convergence, stipulating how many hidden neurons with a given activation function should be used to achieve a specific order of approximation. However, independently of the activation function employed, these connectionist models for function approximation suffer from a severe limitation: all hidden neurons use the same activation function. If each activation function of a hidden neuron is optimally defined for every approximation problem, then better rates of convergence will be achieved. This is exactly the purpose of constructive learning using projection pursuit techniques. Since the training process operates the hidden neurons individually, a pertinent activation function employing automatic smoothing splines can be iteratively developed for each neuron as a function of the learning set. We apply projection pursuit in association with the optimization of the solvability condition, giving rise to a more efficient and accurate computational learning algorithm.
An Euler–Lagrange particle approach for modeling fragments accelerated by explosive detonation

In this paper, a method is proposed for modeling explosive‐driven fragments as spherical particles with a point‐particle approach. Lagrangian particles are coupled with a multimaterial Eulerian solver that uses a three‐dimensional finite volume framework on unstructured grids. The Euler–Lagrange method provides a straightforward and inexpensive alternative to directly resolving particle surfaces or coupling with structural dynamics solvers. The importance of the drag and inviscid unsteady particle forces is shown through investigations of particles accelerated in shock tube experiments and in condensed phase explosive detonation. Numerical experiments are conducted to study the acceleration of isolated explosive‐driven particles at various locations relative to the explosive surface. The point‐particle method predicts fragment terminal velocities that are in good agreement with simulations where particles are fully resolved, while using a computational cell size that is eight times larger. It is determined that inviscid unsteady forces are dominating for particles sitting on, or embedded in, the explosive charge. The effect of explosive confinement, provided by multiple particles, is investigated through a numerical study with a cylindrical C4 charge. Decreasing particle spacing, until particles are touching, causes a 30–50% increase in particle terminal velocity and similar increase in gas impulse. Copyright © 2015 John Wiley & Sons, Ltd.
PARTICLE ACCELERATION AT QUASI-PARALLEL SHOCK WAVES: THEORY AND OBSERVATIONS AT 1 AU

In this paper, we describe a theoretical model for accelerating an arbitrary upstream particle distribution. Only those particles that exceed a prescribed injection energy, Einj, are accelerated via the diffusive shock acceleration (DSA) mechanism, also known as first-order Fermi acceleration. We identify a set of quasi-parallel shocks at 1 AU and use the observed solar wind particle distribution information to construct our upstream distribution, which is then accelerated diffusively at the shock, assuming the observed shock parameters. The injection energy for particles to be accelerated diffusively at a quasi-parallel shock is discussed theoretically. By using the observed upstream solar wind distribution function and the observed shock parameters, we can compute the injection energy that matches the observed downstream accelerated particle spectrum. Like the previous studies of van Nes et al., Lario et al., and Ho et al., this analysis focuses on the acceleration of protons only via the first-order Fermi acceleration mechanism. However, our primary focus is on quasi-parallel shocks and the injection mechanism in the context of DSA with a background thermal solar wind modeled as a Maxwellian or kappa distribution. Our approach allows for a direct test of injection at interplanetary shocks. It has been proposed that an additional seed population of energetic particles is needed to explain the accelerated particle distribution downstream of quasi-parallel shocks. This conclusion is based typically on studies that address the acceleration of heavy ions primarily and do not characterize the injection of protons alone using the DSA mechanism. Through comparisons of Maxwellian and kappa upstream distributions, we find that DSA with injection directly from a thermal Maxwellian distribution, or weak departures therefrom, for protons is responsible for energetic solar particle events associated with quasi-parallel shocks.
Strain‐softening analysis of a spherical cavity

This paper studies the excavation of a spherical cavity subjected to hydrostatic initial stresses in the infinite homogeneous and isotropic rock mass with strain‐softening Mohr–Coulomb (M‐C) and Hoek–Brown (H‐B) behaviors. Numerical solutions of the spherical cavity are obtained and the application to determining stress–strain curve of strain‐softening M‐C and H‐B rock mass is studied. A closed‐form solution for the elastic–brittle–plastic medium is introduced first, and then a numerical procedure that simplifies the strain‐softening process into a series of brittle–plastic ones is presented. The approach is validated against the facts that the strain‐softening process evolves into a brittle–plastic one when the softening slope is very steep, whereas it evolves into an elasto‐plastic one when the softening slope approaches zero. Numerical solutions for the prediction of displacements and stresses around the spherical cavity in the strain‐softening M‐C and H‐B rock mass are presented. On the basis of the analysis of the spherical cavity in strain‐softening rock mass, the stress–strain relationship at an infinitesimal cube around the cavity is obtained and discussed with different evolution laws for the strength parameters considered. Copyright © 2011 John Wiley & Sons, Ltd.
Main divertor flows in Heliotron E: their distribution and dependence on NBI and ECH

In the l = 2/m = 19 Heliotron E heliotron/torsatron device, with a currentless plasma heated by NBI and ECH, the poloidal distributions were measured of diverted plasma flows near the vacuum chamber wall in eight sections of one helical field pitch. A vertical asymmetry of these distributions was observed, contrary to what had been expected from the helical symmetry of the `ideal' (unperturbed) vacuum divertor magnetic configuration. Under NBI conditions, the density normalized divertor plasma flow Jd/e was a rising function of the density normalized absorbed power Pabs/e. This is considered to be a consequence of the power degradation of confinement. With second harmonic ECH, where the main part of the launched power was absorbed in the central region, a similar power dependence as for the NBI was observed. With fundamental ECH, where a considerable fraction of the microwave power was absorbed at the periphery, Jd/e for some areas of the divertor trace distinctly exceeded those obtained under NBI-only conditions with the same Pabs/e. On the other hand, two different time responses (fast and slow) of Jd were observed for the perpendicular NBI and fundamental ECH cases in some particular positions. The slow response is considered to be caused by a diffusion-like outflow of the bulk plasma to the divertor. The fast outflow of particles to the divertor might be caused by a loss of locally trapped high energy electrons and ions.
Two-and Three-Dimensional Modelling Studies of the Big Thompson Storm.

Abstract The Big Thompson storm occurred on 31 July–1 August 1976 over Big Thompson Canyon, Colorado, when a secondary cold frontal surge was accelerated and reached the foothills of the Front Range. Two- and three-dimensional moist compressible cloud models developed by Ogura and Yoshizaki are applied to this storm event. Adopting highly simplified terrain shapes, this study addresses two aspects of the storm. One is the distinct characteristics of the storm structure, as schematically depicted by Carasena et al.; the other is that heavy precipitation occurred in the basin area rather than over the mountain peak area. When the model was initialized in such a way that moisture-rich, low-level, strong easterlies impinged upon the orography, the model predicted the development of a storm that not only caused heavy precipitation at the right location relative to the mountain peak, but also reproduced the observed storm in many aspects, both in two- and three-dimensional (2D and 3D) simulations. The major qua.
How Do Vocational Students Perceive the Use of Telegram for their Online Reading Comprehension?

The advancement of technology encourages English teachers to use online platforms and applications in their English teaching and learning process. There are many apps that can be employed, one of which is Telegram. This study investigates how students perceive the use of Telegram on their reading comprehension and the correlation between the perception and their reading comprehension. For this purpose, 104 students from an Indonesian vocational school from various majors completed an online questionnaire about the use of Telegram for learning English. Besides, a reading test was used to measure the students' reading comprehension. The results portray that the students across departments positively perceived the use of Telegram on their reading comprehension. Furthermore, this study reveals a weak correlation between how the students perceive the use of Telegram and their reading comprehension. It is signified by the correlation between the two variables of interest, . 364, which is significant at the . 000 level. It indicates that the student's perception and reading comprehension for this set of data were significant but had a weak relationship. This may be caused by the reading strategies instructions as the teacher did not provide guidance before the treatment. It yields the pedagogical implication that teachers should train their students to use reading strategies effectively for their online reading comprehension.
Transient anticyclonic eddies and their relationship to atmospheric block persistence

Abstract. Atmospheric blocking is a circulation pattern that describes the presence of large-scale, persistent anticyclones, which have the potential to bring severe impacts at the surface. However, the dynamical behaviour of blocks is still not fully understood. For example, the factors that determine the persistence of blocking events are not clear. In this study, the relationship between blocks and smaller-scale transient anticyclonic eddies is examined, with a particular focus on the impact of transients on the persistence of a block. Analysis is performed in two areas: the Euro-Atlantic and North Pacific, which are locations with both high blocking frequency and potential for severe impacts. Geopotential height anomalies at 500 hPa are used to identify blocking events and the anticyclonic transient eddies. This allows for a Eulerian definition of blocking, as well as a Lagrangian perspective on the eddies. It is found that anticyclonic eddies experience a northward acceleration prior to entering a block, which is indicative of ridge building ahead of the block but could also potentially provide evidence for the previously proposed selective absorption mechanism for block maintenance. A general pattern is found whereby longer blocks interact with more anticyclonic transients than less persistent blocks at all times of the year. This effect is strongest in winter and weakest in summer, which agrees with the fact that blocks are most persistent in winter and least persistent in summer. However, the strength of the anticyclonic eddy that interacts with a block, measured by its maximum 500 hPa geopotential height anomaly, has a more complicated relationship with block persistence. The strength of anticyclonic transient eddies is a more determining factor of block persistence in the North Pacific than in the Euro-Atlantic region. In the North Pacific the longest blocks interact with stronger eddies than the shortest blocks in all seasons except summer, when the reverse is true. By contrast, longer Euro-Atlantic blocks only result from stronger anticyclonic eddies in autumn and winter. We therefore conclude that the number of anticyclonic eddies that interact with a block is most important in determining its persistence, with the strength of the eddies having a more variable effect.
SEMBLANCE AND OTHER COHERENCY MEASURES FOR MULTICHANNEL DATA

The concept of semblance is introduced, along with a descriptive review of several of the more common likeness or coherence measures. Measures are considered from three points of view: the domain in which they are applied, the philosophy of their design, and the manner in which they are used.Crosscorrelation, the most familiar of the likeness criteria, is examined in detail. Differences of design philosophy are noted as expressing themselves by a change in the normalization. Semblance is shown to be related to an energy-normalized crosscorrelation and to share certain features of the summation method or stack which has been used recently as a coherence measure.Several coherence measures, including semblance, are considered in a problem environment--the determination of stacking velocities from multiple ground coverage seismic data. A noise-free synthetic example is studied in order to compare discrimination thresholds of the various methods. Semblance, when properly interpreted, proves to have the greatest power of discrimination among the candidates examined for the particular application.
De invloed van de energie-opname op produktie en reproduktiekenmerken bij (opfok)zeugen

: A total number of 113 first-litter sows and 680 gilts of the Dutch Landrace were used in order to study the effect of energy intake on productive and reproductive characteristics. A high feeding level in normal sows after weaning is essential, not to increase the ovulation rate but rather to improve the condition of the sow and advance oestrus. The experiment with the gilts showed that from the point of view of the cost of the feed consumed and reproductive performance, an energy intake during rearing of more than 2.1 times maintenance will have an adverse effect when adequate protein is given.
LMI-based controller synthesis: A unified formulation and solution

This paper proposes a unified approach to linear controller synthesis that employs various LMI conditions to represent control specifications. We define a comprehensive class of LMIs and consider a general synthesis problem described by any LMI of the class. We show a procedure that reduces the synthesis problem, which is a BMI problem, to solving a certain LMI. The derived LMI condition is equivalent to the original BMI condition and also gives a convex parametrization of all the controllers that solve the synthesis problem. The class contains many of widely-known LMIs (for H∞ norm, H2 norm, etc.), and hence the solution of this paper unifies design methods that have been proposed depending on each LMI. Further, the class also provides LMIs for multi-objective performance measures, which enable a new formulation of controller design through convex optimization. © 1998 John Wiley & Sons, Ltd.
Temperature dependence of the mechanical properties of melt-processed Dy–Ba–Cu–O bulk superconductors evaluated by three point bending tests

Dy–Ba–Cu–O bulk superconductor has an excellent capability of trapping magnetic flux and lower heat conductivity at cryogenic temperatures as compared with Y–Ba–Cu–O bulk superconductor. The Young’s modulus and the bending strength in the range from room temperature to 7 K were measured by the three-point bending tests using specimens cut from a melt-processed Dy–Ba–Cu–O bulk superconductor. They were tested in a helium gas flow type cryostat at Forschungszentrum Karlsruhe and in a liquid nitrogen bath at Iwate University. The Young’s modulus was calculated by either the slope of stress–strain curve or that of the load–deflection curve of the specimen. Although the bending strength measured in the two institutes coincided well, there was a significant discrepancy in the Young’s modulus. The Young’s modulus and bending strength increased with decrease of temperature down to 7 K. The amount of increase in the Young’s modulus and the bending strength were about 32% and 36% of those at room temperature, respectively. The scatter of data for each run was significant and did not depend on temperature. The temperature dependence of the Young’s modulus coincided with that in Y–Ba–Cu–O obtained by ultrasonic velocity. The temperature dependence of the Young’s modulus and the bending strength was discussed from the view point of interatomic distance of the bulk crystal.
Ultraviolet spectrophotometry of 2A 1822-371 - A bulge on the accretion disk

The X-ray source 2A 1822--371 has been observed with the IUE satellite over an 8 hour period. Long and short wavelength exposures of duration 45 or 60 minutes were alternated in order to resolve the 5.57 hr photometric modulation of the star. The data provide evidence that the shape of the 5.57 hr modulation evolves smoothly with energy between extremes defined by the optical and X-ray curves. The far-UV light curve is more deeply modulated than the X-ray light curve. The combined ultraviolet and the UBV band optical data can be fitted with a single blackbody of temperature 2.7 x 10/sup 4/ K, or an optically thick disk model with parameters T/sub asterisk/ = 1.2 x 10/sup 5/ K and R/sub out//R/sub in/approx.30. A single power-law model does not adequately represent the continuum. There is evidence of absorption due to the 2200 A interstellar feature whose depth requires a color excess, E(B--V)approx.0. 1, with 3 sigma upper and lower bounds of 0.29 and 0.01. Emission lines of C IV 1550 A and N V 1240 A are detected in the UV spectrum. The work of Mason et al. and White et al. suggests that the optical and ultraviolet emission arises inmore » an accretion disk, whereas the X-radiation is emitted from a scattering cloud that envelopes a central compact object. In the present paper, the 5.57 hr optical, X-ray and ultraviolet modulation of 2A 1822--371 is intrepreted as the result of partial occultation of the emitting region by a comparison star and a bulge on the outer accretion disk. X-ray heating of the bulge will probably also contribute to the modulation at optical and ultraviolet wavelengths. « less
Topologically free actions and ideals in discrete C*-dynamical systems

A C*-dynamical system is called topologically free if the action satisfies a certain natural condition weaker than freeness. It is shown that if a discrete system is topologically free then the ideal structure of the crossed product algebra is related to that of the original algebra. One consequence is that a minimal topologically free discrete system has a simple reduced crossed product. Sharper results are obtained when the algebra is abelian.
Topological imprint for periodic orbits

The more self-crossing points an orbit has the more complex it is. We introduce the topological imprint to characterize crossing points and focus on the period-doubling cascade. The period-doubling cascade topological imprint determines the topological imprint for orbits in chaotic bands. In addition, there is a closer link between this concept and the braids studied by Lettelier et al (2000 J. Phys. A: Math. Gen. 33 1809–25).
Effects of the Computational Time Step on Numerical Solutions of Turbulent Flow

Effects of large computational time steps on the computed turbulence were investigated using a fully implicit method. In turbulent channel flow computations the largest computational time step in wall units which led to accurate prediction of turbulence statistics was determined. Turbulence fluctuations could not be sustained if the computational time step was near or larger than the Kolmogorov time scale.
Sharp inequalities that generalize the divergence theorem: an extension of the notion of quasi-convexity

Subject to suitable boundary conditions being imposed, sharp inequalities are obtained on integrals over a region Ω of certain special quadratic functions f(E), where E(x) derives from a potential U(x). With E=∇U, it is known that such sharp inequalities can be obtained when f(E) is a quasi-convex function and when U satisfies affine boundary conditions (i.e. for some matrix D, U=Dx on ∂Ω). Here, we allow for other boundary conditions and for fields E that involve derivatives of a variety orders of U. We define a notion of convexity that generalizes quasi-convexity. Q*-convex quadratic functions are introduced, characterized, and an algorithm is given for generating sharply Q*-convex functions. We emphasize that this also solves the outstanding problem of finding an algorithm for generating extremal quasi-convex quadratic functions. We also treat integrals over Ω of special quadratic functions g(J), where J(x) satisfies a differential constraint involving derivatives with, possibly, a variety of orders. The results generalize an example of Kang, and the author in three spatial dimensions where J(x) is a 3×3 matrix-valued field satisfying ∇⋅J=0.