Miracle-dz/UniFAR-FTUs huggingface dataset:
Interplanetary Neutral Particle Fluxes Influencing the Earth's Atmosphere and the Terrestrial Environment

Abstract It is well known that the Solar System is swept over by neutral interstellar gases, primarily hydrogen and helium, entering the heliosphere from the upwind side and penetrating inward, even up to the orbit of the Earth. The Earth on its orbit is thus moving through this density field and is intercepting time-variable hydrogen and helium fluxes. Quantitatively, this is associated with a sensitive reaction of the density fields to time-dependent conditions of the solar radiation pressure and the ionizing solar radiations during the solar activity cycle. As we shall show, the density distribution of interstellar hydrogen along the orbit of the Earth is strongly varying during the solar cycle. In connection with the variation of the mean relative velocity of this gas with respect to the orbiting Earth a highly variable hydrogen inflow into the Earth's atmosphere will be induced. There is also an additional source of hydrogen influencing the Earth's environment due to the fact that neutral interstellar hydrogen and helium are neutralizing solar wind protons by charge exchange inside the orbit of the Earth, thereby producing an antisolar flux of keV-energetic hydrogen atoms impinging onto the Earth's atmosphere. These time-variable fluxes could be directly monitored by gas detectors of an advanced technology. They might also be indicated by indirect terrestrial effects. We are investigating the question of whether and how these time-variable inflows could be recognized by careful studies of relevant upper atmospheric reactions. We study particle-induced energy inputs and ionization rates in the upper atmosphere and analyze influences on the hydrogen geocorona. We also study the process of relaxation of the inflowing hydrogen within the terrestrial atmosphere and investigate the reaction of atmospheric hydrogen densities to these variable inflows. While it is shown that the induced short-period variation of upper atmospheric hydrogen densities is of negligible amplitude at the present epoch, long-periodic variations of the hydrogen inflow like those connected with the entrance of the Solar System into a region of increased interstellar density at earlier or later eons clearly give their imprints even at lower heights and could even be reflected in ozone depletions induced by increased hydrogen densities at heights of around 50 km. At present anomalous variations of the geocoronal H-1216 A and He-584 A glows uncorrelated with the solar resonance line illumination indicate a breathing of the geocorona under variable interplanetary gas inflows.
The new robust control using the theory of generalized variable structure

The objective of this paper is the performances comparison of a classical variable structure algorithm (CVS) with the new regulator using the theory of generalized variable structure algorithm (GVS). The GVS control technique takes account the derivatives of control in a non-Kalman state representation. The switching is done on the highest derivative of the control (input), consequently to eliminate the undesirable chatter motion, caused by the discontinuous control law. The performances are compared by considering the time response, the robustness to unmodelled dynamics, and the reduced chattering. The plant is a robotic manipulator studied in two of its degrees of freedom, which is sufficient for examining the validity of the control method and to show clearly the advantages.
An estimate of the velocity correlation tensor - Cosmological implications

The peculiar velocity correlation tensor in the cosmic background radiation is estimated using observations of large-scale streaming motions. Two models are considered, which assume gravitational instability and random phase fluctuations: the CDM (cold dark matter) model representing the standard Omega = 1 CDM dominated universe with adiabatic scale invariant initial fluctuations and the Peebles' baryon isocurvature (PBI) model, an Omega = 0.4 baryon dominated universe with initial isocurvature (entropy) fluctuations. In both cases, the assumed Hubble constant is H = 50 km/sec Mpc. Unlike the CDM model, low Omega, baryon dominated PBI scenarios containing entropy perturbations can lead to correlated velocities over scales exceeding 4,000 km/sec. Predictions of both the CDM and PBI models are discussed. The velocity field in the local standard of rest frame determined by the galaxies themselves is also considered. 27 refs.
Inverse design of transonic airfoils using genetic algorithm and a new parametric shape method

The inverse design of transonic airfoils is carried out using genetic algorithm and different shape parameterization methods. A new technique for airfoil shape parameterization is presented considering the features of the transonic flow. The method is then applied to several airfoil inverse design problems with defined geometry or surface pressure distributions. The influence of parametric shape methods on the accuracy and computational cost of the design process are investigated for inviscid and viscous flow problems. The fitness function evaluation is carried out using an unstructured grid finite volume flow solver. It is shown that the new shape parameterization method is able to reduce the total computational time by about 50% in the inverse design of transonic airfoils, particularly when viscous flow calculations are concerned.
Comparison of Several Novel Annular-Ring Microstrip Patch Antennas for Circular Polarization

Several novel compact circularly-polarized probe-fed annular-ring microstrip patch antennas are examined experimentally and numerically. In order to reduce the antenna size and provide a suitable input impedance match, two techniques are employed; the insertion of strips into the annular ring and placing a cross-slot into the ground plane. The proposed annular-ring patch with a cross-slotted ground plane yields a much smaller size for a given frequency. This novel patch antenna can effectively be reduced by about 55 percent in size compared to conventional annular-ring patch antennas. The antenna displays wide bandwidth and good circular polarization characteristics. The results of a parametric study for three novel strip-loaded annular-ring patch antennas and for the compact circular patch antenna augmented by a narrow annular ring with a cross-slotted ground plane are discussed in this paper.
Studies on the extraction, optical characteristics, and ageing of natural pigments from different flower plants - A Review

: In order to determine the optimal dye removal process, We detailed the colour extraction procedures and solvents used to extract five distinct flowering plants (ethanol and water). Five natural dyes have numerous distinct functional groups present, according to their FTIR spectra. To separate the dyes from their solutions, analytical tests such Vacuum evaporation, column chromatography, and UV spectroscopy were used. Pigment colors in floral extracts were studied using UV-Vis, and the results revealed pronounced bandgaps and higher adsorption maxima in the visible area. One of the pigments under research, Alternanthera ficoidea, has the minimum direct bandgap (1.69 eV) and Absorbed by the material
Exact, explicit solutions for diffraction by hard sound barriers and seamounts

A new method of obtaining exact, explicit solutions for the diffraction of sound waves by truncated wedges is given which, in conjunction with a previous study [I. Tolstoy, IEEE J. Ocean Eng., in press (1989)], can be applied to problems involving two parallel vertices and arbitrary wedge angles θw, θ’w at these vertices. The method combines exact, explicit representations of the field diffracted by a single vertex with the classic multiple scatter algorithm to formulate the interaction between the line vertices. The previous study had demonstrated the method only for cases in which θw, θw were irrational fractions of π, as well as for the rather special case θw=θ’w =2π, i.e., for the hard strip. In the latter case, the calculations were carried out for wavenumbers k such that 1≲kl≤16, where l was the strip width, and were shown to agree with experimental measurements [H. Medwin et al., J. Acoust. Soc. Am. 72, 1005–1013 (1982)]. The present article extends the theory to cover the important remaining cases.
FEATURE EXTRACTION AND ASSESSMENT USING WAVELET PACKETS FOR MONITORING OF MACHINING PROCESSES

Abstract Monitoring of machining processes is a classic and yet unsolved problem in manufacturing engineering. This paper introduces a new method of feature extraction and feature assessment using a wavelet packet transform for monitoring of machining processes. First, the principles of wavelet transforms are briefly described by comparing to the Fourier transform, followed by a discussion on the properties of wavelet transforms and a special wavelet transform algorithm: the wavelet packet transform. Next, based on the wavelet packet transform and signal reconstruction, a new feature extraction method is introduced. To assess the effectiveness of the selected features in both time and frequency domains, four criteria are proposed. Accordingly an automatic feature extraction procedure is developed. The proposed method is tested using two practical examples: chatter monitoring in turning and tool wear monitoring in drilling. Experimental results show that the proposed method is very effective.
Radiative Shocks inside Protogalaxies and the Origin of Globular Clusters

The thermal history of metal-free gas overtaken by radiative shocks with velocities characteristic of gravitationally induced motions inside a typical protogalaxy is studied. This is relevant to suggestions that globular clusters formed within protogalaxies in the compressed gas resulting from such shocks or from a thermal instability. Solutions are obtained for the hydrodynamical equations, along with the rate equations for nonequilibrium ionization, recombination, molecular formation and dissociation, and the equations of radiative transfer for steady-state shocks of velocity 300 km/s in a gas of preshock density 0.1-1/cu cm. It is suggested that the formation of globular clusters is a threshold effect, with the intensity of the UV/soft X-ray field in a protogalaxy as the controlling factor. 27 refs.
Feature motivated polarization scattering matrix decomposition

A method of decomposing the polarization scattering matrix into parts corresponding to nonreciprocal, asymmetric, and symmetric scatterers is presented. The decomposition is used to classify scattering matrices into one of eleven classes. The decomposition and classification scheme is applied to fully polarimetric, millimeter-wave measurement data. Results for a simple array of scatterers and for a truck are shown. <<ETX>>
DETECTION OF A HIGH-ENERGY X-RAY FLARE FROM A SOURCE IN CRUX.

On 1969 A p r i l 16 we c a r r i e d o u t balloon X-ray observations from A u s t r a l i a (energies above 1 8 k e ~ j . We detected a s t r o n g X-ray f l u x i n t h e range 18 t o 36 keV from a source a t k ' = 301&3O, bs = -2k3O. During our observations t h e X-ray f l u x f l a r e d up by about a fact-or of t h r e e . The f l a r e l a s t e d f o r a period of about one and a h a l f hours. There i s a l s o some evidence f o r a f l u x change i n l e s s than 10 minutes. The average observed f l u x was about 2 keV ~ m - ~ s e c ' ~ , which i s a t l e a s t a f a c t o r of seven higher than t h a t observed about one month earlier on 1969 March 20 a t which t i m e no evidence f o r X-ray emission fram t h i s region of t h e sky was found by Lewin, McClintock and Smith. The average f l u x i s about a s high a s t h a t observed by Lewin, Clark and Smith on 1967 October 15 from a source a t 2% = 304.8*1.5', b* = -1.5k2O. This
The use of linear filtering to simplify integrator backstepping control of nonlinear systems

A method is proposed for designing stable controllers with arbitrarily small tracking errors for uncertain mismatched nonlinear systems. This method utilizes the "integrator backstepping" approach but with an important addition, /spl gamma/-1 low pass linear filters, where /spl gamma/ is the relative degree of the output to be controlled. It is shown that these low pass filters allow a design where the model and model error bounds are not differentiated. This method is applied to both Lipschitz and nonLipschitz nonlinearities. The nonLipschitz case requires the use of signum functions and is illustrated with a numerical example.
Stable few-layer MoS2 rectifying diodes formed by plasma-assisted doping

We present a method for making stable MoS2 rectifying diodes using selected-area plasma treatment. The transport and X-ray photoelectron spectroscopic characterizations of MoS2 transistors treated with different plasmas confirm that the rectifying characteristics of MoS2 diodes are attributed to plasma-induced p-doping and p-n junctions in MoS2. Such plasma-doped diodes exhibit high forward/reverse current ratios (∼104 for SF6-treated diodes) and a superior long-term stability. They can play an important role in the development of nanoelectronic devices. In addition, the presented plasma-assisted doping process could be also used for making ambipolar MoS2 transistors and functionalizing other emerging two-dimensional materials.
Rotation numbers for diffeomorphisms and flows

A rotation number is defined for fairly general diffeomorphisms in 2 dimensions and flows in 3 dimensions. An extension to higher dimensionality is sometimes also possible (in particular for Hamiltonian flows) On definit un nombre de rotation pour des diffeomorphismes a 2 dimensions et des flots a trois dimensions assez generaux. Une extension a des dimensions superieures est egalement possible dans certains cas (en particulier pour des flots hamiltoniens)
Eyespace Values in Go

Most of the application of combinatorial game theory to Go has been focussed on late endgame situations and scoring. However, it is also possible to apply it to any other aspect of the game that involves counting. In particular, life-and-death situations often involve counting eyes. Assuming all surrounding groups are alive, a group that has two or more eyes is alive, and a group that has one eye or less is dead. This naturally raises the question of which game-theoretical values can occur for an eyemaking game. We define games that provide a theoretical framework in which this question can be asked precisely, and then give the known results to date. For the single-group case, eyespace values include 0, 1, 2, R 1 2 , R 1 1 2 , R 3 4 , R 1 1 4 , R 1∗, and several ko-related loopy games, as well as some seki-related values. The R 1 2 eye is well-understood in traditional Go theory, and R 1 1 2 only a little less so, but R 3 4 , R 1 1 4 , and R 1∗ may be new discoveries, even though they occur frequently in actual games. For a battle between two or more opposed groups, the theory gets more complicated.
The Angular Distribution and Charged Fraction of Argon Sputtered Tungsten

A polycrystalline tungsten target, with a known texture, was bombarded by a 40 keV Ar+ ion beam. The sputtered particles were collected on a semi-cylindrical collector and the angular distribution for perpendicular sputtering was found to be peaked along the surface normal, which coincided with the 100 direction of the crystallites. By integration the sputtering yield for normal incidence sputtering was found to be 1.6 ± 0.2, which is lower than earlier reported results. For sputtering at an oblique angle, 65°, the yield was found to be 6.1 ± 0.7, which is reasonable since the maximum sputtering yield should be found at about this angle. An attempt was made to measure the fraction of charged sputtered particles with a new and directly quantitative method. The result for normal incidence sputtering was 0.03 ± 0.01. A few assumptions are necessary for the calculation of this value. The possibility to extract microscopical information about the target from quantitatively measured distributions is briefly discussed.
Group Classification of a General Bond-Option Pricing Equation

We carry out group classification of a general bond-option pricing equation. We show that the equation admits a three-dimensional equivalence Lie algebra. We also show that some of the values of the constants which result from group classification give us well-known models in mathematics of finance such as Black-Scholes, Vasicek, and Cox-Ingersoll-Ross. For all such values of these arbitrary constants we obtain Lie point symmetries. Symmetry reductions are then obtained and group invariant solutions are constructed for some cases.
ASYMMETRIES IN THE SPECTRAL LINES OF EVOLVED HALO STARS

We do an initial reconnaissance of asymmetries of spectral lines in metal-poor field stars using high-resolution observations of four red horizontal-branch and 11 red giant branch stars taken with the coude spectrograph at the Canada–France–Hawaii Telescope. We find that (1) the shapes of the line bisectors for metal-poor stars hotter than 4100 K mimic the well-known C shape of bisectors for solar-metallicity stars on the cool side of the granulation boundary while (2) metal-poor stars cooler than 4100 K, or higher up the red giant branch than MV = −1.5, show bisectors with a reversed-C shape, similar to those for solar-metallicity stars on the hot side of the granulation boundary and similar to the reversed-C shape found in a previous study for the M-type supergiant Betelgeuse. The well-documented radial-velocity jitter of high-luminosity stars and the line bisector characteristics vary in concert up the red giant branch; both phenomena are probably signatures of large convection cells.
Edgeworth Series for Lattice Distributions

and identically distributed lattice-valued random variables. We prove that the continuity-corrected Edgeworth series, using Sheppard-adjusted cumulants, is accurate to the same order in n as the usual Edgeworth approximationfor continuous random variables. Finally, as a partial justification of the Sheppard adjustments, it is shown that if a continuous random variable Y is rounded into a discrete part D and a truncation error U, such that Y = D + U, then under suitable limiting conditions the truncation error is approximately uniformly distributed and independent of Y, but not independent of D.
A five‐wave Harten–Lax–van Leer Riemann solver for relativistic magnetohydrodynamics

We present a five-wave Riemann solver for the equations of ideal relativistic magneto-hydrodynamics. Our solver can be regarded as a relativistic extension of the five-wave HLLD Riemann solver initially developed by Miyoshi & Kusano for the equations of ideal magnetohydrodynamics. The solution to the Riemann problem is approximated by a five-wave pattern, comprising two outermost fast shocks, two rotational discontinuities and a contact surface in the middle. The proposed scheme is considerably more elaborate than in the classical case since the normal velocity is no longer constant across the rotational modes. Still, proper closure to the Rankine–Hugoniot jump conditions can be attained by solving a non-linear scalar equation in the total pressure variable which, for the chosen configuration, has to be constant over the whole Riemann fan. The accuracy of the new Riemann solver is validated against one-dimensional tests and multidimensional applications. It is shown that our new solver considerably improves over the popular Harten–Lax–van Leer solver or the recently proposed HLLC schemes.
GT cell formation for minimizing the intercell parts flow

A methodology is proposed to design a GT cell by considering the intercell parts flow in GT cellular manufacturing systems. The problem of GT cell formation is described in a graph using the quantities to be produced in the specified time period and the process routes for producing the products. The objective of this paper is to minimize the total number of parts produced in more than one cell. The problem, formulated as a quadratic assignment problem (QAP), is solved using both Lagrangean relaxation technique and the optimality conditions of quadratic program. Furthermore, in order to obtain the giobal optimal solution rather than the local optimal solution, a branch-and-bound algorithm is employed. Finally, numerical examples are used to show the effectiveness of the solution techniques and GT cell formation procedure. Moreover, a computer simulation is presented, showing the effectiveness of cellular manufacturing systems
Electron distribution functions in the electron diffusion region of magnetic reconnection: Physics behind the fine structures

Highly structured electron distribution functions in the electron diffusion region (EDR) during magnetic reconnection are studied by means of fully kinetic simulations. Four types of structures (striations, arcs, swirls, and rings) in momentum space are analyzed to understand their formation mechanisms. Discrete striations are formed by particles undergoing different numbers of meandering bounces in the EDR and are a result of oscillations in the out‐of‐plane force on meandering electrons. Predictions for the separation between striations and the triangular shape of the distribution are obtained analytically. Arcs and swirls are due to partial remagnetization of accelerated electrons. Near the end of the outflow jet, electron remagnetization gives rise to the ring structure. Understanding the distribution structures is critical to unraveling the kinetic processes occurring in the EDR and will guide the identification of EDRs based on satellite measurements.
Ion distributions near the reconnection sites: Comparison between simulations and THEMIS observations

[1] We study the evolution of ion distribution functions in a magnetotail thin current sheet using as a case study the 26 February 2008 substorm event observed by the THEMIS mission. The observed mushroom-shaped velocity space ion distributions, whereby warmer ions are mostly moving duskward, are shown to appear when the current sheet thickness becomes comparable with thermal ion gyroradius. As magnetic reconnection starts earthward of the THEMIS satellite (probe) P1, these duskward moving warmer ions also start to stream tailward, gradually separating in velocity space from the colder ions that dominate the density moment. Test particle simulations demonstrate that the observed evolution of ion distributions is consistent with cucumber-type trajectories in a current sheet with an X-type configuration.