Miracle-dz/UniFAR-FTUs huggingface dataset:
All-metamaterial-based subwavelength cavities (λ/60) for ultrathin directive antennas

In this letter, we present the characterization and modeling of a metamaterial-based resonant cavity for ultrathin directive printed antennas. A planar artificial magnetic conductor is used for the two reflectors of the Fabry–Perot-type resonant cavity. One reflector behaves as a high impedance surface, and serves as a substrate for the printed antenna. The other reflector is a partially reflective surface used as a transmitting window. The cavity is operated on subwavelength modes, the smallest cavity thickness being of the order of λ∕60. A drastic enhancement of the antenna directivity and gain is obtained over a relatively wide band from 7.5to10. 1GHz, corresponding to a range of cavity thicknesses from ∼λ∕3 to ∼λ∕60. The cavity resonance is seen to be correctly predicted from the standard ray theory approach.
Self-organized calix[4]arenes on Au ( 110 ) − ( 1 × 2 ) : A combined low-energy electron diffraction and scanning tunneling microscopy experimental study with molecular mechanics calculations

We report on self-assembly of calix[4]arenes deposited on $\mathrm{Au}(110)\text{\ensuremath{-}}(1\ifmmode\times\else\texttimes\fi{}2)$. The molecules consist of a macrocycle with four phenol rings linked by methylene groups in the ortho-position. The scanning tunneling microscopy images together with the low-energy electron diffraction patterns allow us to identify the molecular conformer and the unit cell. The intermolecular interactions are rather weak and are governed by $\ensuremath{\pi}$ stacking and van der Waals\char21{}type interactions as deduced from molecular mechanics calculations. The two-dimensional molecular self-ordering is due to a strong interaction with the gold substrate resulting in the replacement of the initial $(1\ifmmode\times\else\texttimes\fi{}2)$ missing row reconstruction by a $(1\ifmmode\times\else\texttimes\fi{}3)$ structure upon molecular adsorption.
Use of the characteristic Raman lines of toluene (C7 H8) as a precise frequency reference on the spectral analysis of gasoline-ethanol blends

In order to reduce some of the toxic emissions produced by internal combustion engines, the fossil-based fuels have been combined with less harmful materials in recent years. However, the fuels used in the automotive industry generally contain different additives, such as toluene, as anti-shock agents and as octane number enhancers. These materials can cause certain negative impact, besides the high volatility implied, on public health or environment due to its chemical composition. Toluene, among several other chemical compounds, is an additive widely used in the commercially-available gasoline-ethanol blends. Despite the negative aspects in terms of toxicity that this material might have, the Raman spectral information of toluene can be used to achieve certain level of frequency calibration without using any additional chemical marker in the sample or any other external device. Moreover, the characteristic and well-defined Raman line of this chemical compound at 1003 cm−1 (even at low v/v content) can be used to quantitatively determine certain aspects of the gasoline-ethanol blend under observation. By using an own-designed Fourier-Transform Raman spectrometer (FT-Raman), we have collected and analyzed different commercially-available and laboratory-prepared gasoline-ethanol blends. By carefully observing the main Raman peaks of toluene in these fuel blends, we have determined the frequency accuracy of the Raman spectra obtained. The spectral information has been obtained in the range of 0 cm−1 to 3500 cm−1 with a spectral resolution of 1.66 cm−1. The Raman spectra obtained presented only reduced frequency deviations in comparison to the standard Raman spectrum of toluene provided by the American Society for Testing and Materials (ASTM).
On the degrees of freedom of scattered fields

Starting from the observation that fields differing less than a prescribed error cannot be resolved as distinct entities, the degrees of freedom of the scattered field are introduced and then computed. The degrees of freedom are shown to be practically equal to the Nyquist number appropriate to the effective (spatial) bandwidth of the scattered field and to the extension of the observation domain. Accordingly, a finite number of elements of information can be used to determine the scattered field to a prescribed approximation error. It is also shown that the field representation can be made in terms of field values and simple sampling functions, provided that a marginal increase in the approximation error is tolerated. The results not only completely justify the use of sampling interpolation for representing scattering fields, but also demonstrate that such representation is practically an optimal one. An algorithm for the reconstruction of scattered fields, given the maximum allowed error, is then produced. >
Evolution of Cluster X-Ray Luminosities and Radii: Results from the 160 Square Degree ROSAT Survey

We searched for cluster X-ray luminosity and radius evolution using our sample of 203 galaxy clusters detected in the 160 deg2 survey with the ROSAT PSPC (Vikhlinin et al.). With such a large area survey, it is possible, for the first time with ROSAT, to test the evolution of luminous clusters, LX > 3 × 1044 ergs s−1 in the 0.5-2 keV band. We detect a factor of 3-4 deficit of such luminous clusters at z > 0.3 compared with the present. The evolution is much weaker or absent at modestly lower luminosities, (1-3) × 1044 ergs s−1. At still lower luminosities, we find no evolution from the analysis of the log N-log S relation. The results in the two upper LX bins are in agreement with the Einstein Extended Medium-Sensitivity Survey evolution result (Gioia et al.; Henry et al.), which was obtained using a completely independent cluster sample. The low-LX results are in agreement with other ROSAT surveys (e.g., Rosati et al.; Jones et al.). We also compare the distribution of core radii of nearby and distant (z > 0.4) luminous (with equivalent temperatures of 4-7 keV) clusters and detect no evolution. The ratio of average core radius for z ~0.5 and z < 0.1 clusters is 0.9 ± 0.1, and the core radius distributions are remarkably similar. A decrease of cluster sizes incompatible with our data is predicted by self-similar evolution models for a high-Ω universe.
A simple numerical verification method for differential equations based on infinite dimensional sequential iteration

: This paper describes a numerical veriﬁcation of solutions for inﬁnite dimensional functional equations based on residual form and sequential iteration. Comparing with other veriﬁcation procedures as typiﬁed by Newton-type iterations, the proposed algorithm can be done at low computational cost, although it needs that the formulated compact map is retrac-tive in some neighborhood of the ﬁxed-point to be veriﬁed. Several computer-assisted proofs for diﬀerential equations, including nonlinear partial diﬀerential equations will be shown
The catalogue of interacting galaxies by Vorontsov-Velyaminov

Abstract This edition unites two parts of the Catalogue of interacting galaxies by B. A. Vorontsov-Velyaminov (1959, 1970, 1977). It contains 852 known interacting VV-systems and 1162 new objects taken from the comments on the galaxies in Morphological Catalogue of galaxies by Vorontsov-Velyaminov et al. (1962, 1963, 1964, 1968, 1974) with numbers from VV853 to VV2014. The classification of interacting galaxies is given in accord with the suggestions of Vorontsov-Velyaminov. The catalogue contains new information for the galaxies included taken from the NEDA-NASA/IPAC extragalactic data base.
Analysing and comparing problem landscapes for black-box optimization via length scale

Optimization problems are of fundamental practical importance and can be found in almost every aspect of human endeavour. Yet remarkably, we have a very limited understanding of the nature of optimization problems and subsequently of how, why and when different algorithms perform well or poorly. The notion of a problem landscape captures the relationship between the objective function and the problem variables. It is clear that the structure of this landscape is vital in understanding optimization problems, however analysis of this structure presents major challenges. Apart from the often high-dimensionality of problem landscapes, information available in the black-box setting is limited to the solutions in the feasible search space and their respective objective function values. Landscape analysis has received some attention in the optimization literature, mainly in evolutionary computation. However there are some important limitations of this work as well as many open issues around its practical utility. This thesis proposes a novel framework and practical techniques for the analysis of optimization problems utilizing information available in the black-box setting. The concept of length scale is proposed as a fundamental feature of both combinatorial and continuous optimization problems. Analytical properties of length scale and its distribution over a given problem are established. Techniques from statistics, set theory, visualisation and machine learning are employed to summarise and interpret sampled length scale values. From the length scale distribution, a problem similarity measure is proposed using the entropic Jeffrey divergence. This provides a means of comparing arbitrary black-box optimization problems, between combinatorial or continuous problems of possibly different dimensionality. An alternative realisation of the framework is also developed for quantifying optimization problem similarity via length scale information, based on the notion of Information Distance from Kolmogorov Complexity Theory. Information Distance is a universal distance measure between two arbitrary objects, and in practice can be approximated by Normalised Compression Distance, which relies on binary representations of the problems of interest
The Crystal Structure of Quartz

Crystal structure of quartz. ---Photographs by the powder method of X-ray crystal analvsis have confirmed the space-lattice proposed by others. A careful study of 30 possible arrangements has shown that the arrangement of atoms which best fits the observed intensities of the lines in the pattern differs somewhat from those previously proposed, maintaining more clearly the identity of the molecule Si${\mathrm{O}}_{2}$. These molecules are obtuse-angled isosceles triangles (angle at Si atom-center, 115\ifmmode^\circ\else\textdegree\fi{} 14\ensuremath{'}; distance between Si and O atom-centers, 1.631 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}8}$ cm) lying in the basal planes of each of three interpenetrating hexagonal space-lattices, so that the crystal may be considered as built up of lay\ifmmode \bar{e}\else \={e}\fi{}rs of molecules, much closer together than adjacent molecules in the same layer.
High speed movies of turbulence in Alcator C-Mod

A high speed (250 kHz), 300 frame charge coupled device camera has been used to image turbulence in the Alcator C-Mod Tokamak. The camera system is described and some of its important characteristics are measured, including time response and uniformity over the field-of-view. The diagnostic has been used in two applications. One uses gas-puff imaging to illuminate the turbulence in the edge/scrape-off-layer region, where D2 gas puffs localize the emission in a plane perpendicular to the magnetic field when viewed by the camera system. The dynamics of the underlying turbulence around and outside the separatrix are detected in this manner. In a second diagnostic application, the light from an injected, ablating, high speed Li pellet is observed radially from the outer midplane, and fast poloidal motion of toroidal striations are seen in the Li+ light well inside the separatrix.
Nonlinear classical diffusion in a contained plasma

The one‐dimensional Cartesian model for the resistive diffusion of a force‐free magnetic field in a plasma of negligible inertia is treated for the case of confinement between rigid walls made of perfect electrical conductors. An exact analysis is given of the general initial‐boundary value problem. The field evolution is driven by a competition between Ohmic loss and the induction effects arising from the tenuous plasma moving to adjust with the diffusing magnetic field. The process is nonlinear and nonlocal. It is shown that the field topology determines whether electrical currents will decay away everywhere or else grow at isolated locations to infinite values in a finite period of time.
Gray-level encoded fringe projection for profile measurements

An encoding algorithm to identify the fringe orders for Fourier transform profilometry is described. Phase unwrapping is then performed with reference to the encoding algorithm. Even though the inspected object is colorful or sensitive to the reflectance variation, unwrapping can be performed without ambiguity. The computation cost is very low, and its unwrapped errors can be confined in a local area.
Quantitative extraction of in-plane surface properties using torsional resonance mode of atomic force microscopy

In the torsional resonance mode of atomic force microscopy (AFM), torsional amplitude and phase shift have been used for in-plane surface property imaging. However, no quantitative relation between torsional amplitude/phase shift and surface properties has yet been established. This paper studies how lateral contact stiffness and viscosity affect the torsional vibration of the cantilever in AFM. A basic methodology to extract in-plane surface properties is described and its effectiveness is demonstrated by quantitatively extracting the lateral contact stiffnesses and viscosities of two different materials: Si(100) and epoxy.
Magnetic and Radiative Variability of Solar Surface Structures. I. Image Decomposition and Magnetic-Intensity Mapping

In order to specify quantitatively the contributions to irradiance variability by specific types of solar surface structure, we analyzed full-disk magnetograms and Ca II K images from the National Solar Observatory and Big Bear Solar Observatory for two sets of several days in early 1992 and mid-1993. These test days were chosen at maxima and minima of the rotational modulation in the Lyα irradiance from the Upper Atmosphere Research Satellite Solar-Stellar Irradiance Comparison Experiment (UARS/SOLSTICE) spectrometer. For the eight days, we isolated active regions, decaying active regions, the enhanced network, the network, and the quiet atmosphere based on their magnetic flux strength and distribution, filling factor, and association with sunspots. Transfer of these image decompositions to Ca II K images gives magnetic flux versus intensity (|B| vs. δK) relationships for four structures with measurable magnetic flux. In the range 30-400 Mx cm-2, these log-log curves are linear with a slope of 0.5, which suggests that the Ca II K residual intensity is proportional to the half-power of the magnetic flux density. The separation into quiet and active Sun structures gives a prediction of the variation of the |B| versus δK relation for the ensemble of our four principal structures from minimum to maximum in the activity cycle of the Sun viewed as a star.
Spectroscopic thermoacoustic imaging of water and fat composition

During clinical studies, thermoacoustic imaging (TAI) failed to reliably identify malignant breast tissue. To increase detection capability, we propose spectroscopic TAI to differentiate samples based on the slope of their dielectric absorption. Phantoms composed of different ratios of water and fat were imaged using excitation frequencies between 2.7 and 3.1 GHz. The frequency-dependent slope of the TA signal was highly correlated with that of its absorption coefficient (R2 = 0.98 and p < 0.01), indicating spectroscopic TAI can distinguish materials based on their intrinsic dielectric properties. This approach potentially enhances cancer detection due to the increased water content of many tumors.
Limnologic Analysis of Gusev Crater Paleolake, Mars

Abstract The survey of the hydrogeologic system formed by Gusev crater and Ma'adim Vallis (Aeolis subquadrangle of Mars) points out evidence for the existence of an ice-covered lake in Gusev crater. A first lake was formed by the drainage of the aquifer in the region surrounding Gusev before the entry of Ma'adim Vallis in the crater. The existence of a former lake in Gusev is deduced from the morphology of the Ma'adim delta. Its comparison with terrestrial Antarctic analogs argues for the presence of an ice-covered lake in Gusev at the time that the southern part of the crater's rampart was breached by Ma'adim first release, and for a subice–lacustrine construction of the valley's delta. Our survey shows that Ma'adim Vallis may have entered Gusev crater as late as Late Hesperian/Early Amazonian as part of a second lake episode. The relationship between the variation of the Gusev lake water-level, the volume of the lake, and the surface of the lake bed is established by our bathymetric model. The elevation of the former lake is deduced from the elevation of the mesa-like structures in the delta of Ma'adim Vallis. Furthermore, the correlation of the crater frequency of Gusev rampart with Mars' stratigraphic age shows that lakes may have occupied Gusev crater over a period of time covering 2 Gyrs. , from the formation of the crater to the last episode of water release from Ma'adim Vallis. Though it is most likely that the lake was episodical, the recurrence of abundant water in Gusev crater makes this site a high priority for missions, either for martian resource exploration, or for the search of life.
Model of soft CP violation using scalars with quark number two.

We propose a model of soft CP violation that evades the strong CP problem and can describe observed CP violation in the neutral kaon sector, both direct and indirect. Our model requires two "duark" mesons carrying quark number two that have complex (CP-violating) bare masses and are coupled to quark pairs. Aside from the existence of these potentially observable new particles with masses of several hundred GeV, we predict a flat unitarity triangle (i.e., no observable direct CP violation in the B-meson sector) and a possibly anomalous branching ratio for the decay mode K+-->pi(+)+nu(nu).
Radial distributions of equatorial phase space density for outer radiation belt electrons

We present the first direct observations of equatorial electron phase space density (PSD) as a function of the three adiabatic invariants throughout the outer radiation belt using data from the Solid State Telescopes on THEMIS‐D. We estimate errors in PSD that result from data fitting and uncertainty in the calculation of the second and third invariants based on performance‐weighted results from seven different magnetic field models. The PSD gradients beyond geosynchronous orbit (GEO) are energy dependent, revealing different source regions for the relativistic and non‐relativistic populations. Specifically, the PSD distribution of outer belt relativistic electrons is peaked near L* ≈ 5.5. These features are typical for the outer belt, based on a survey of a two‐month period from 01 Feb.–31 Mar. 2010. The results are consistent with previous studies, which were based on off‐equatorial observations, but remove the high uncertainties introduced from mapping by using truly equatorial measurements (i.e., within only a few degrees of the magnetic equator) and quantifying the error in PSD. The newly calibrated THEMIS‐SST dataset forms a powerful tool for exploration of the near‐Earth magnetosphere, especially when combined with the upcoming RBSP mission.
Magnetic waves in the core of the earth. II

Abstract Small oscillations of electrically conducting fluid under the influence of magnetic, Archimedean (buoyancy) and Coriolis forces, taking into account Ohmic diffusion, are considered for conditions corresponding to the Earth's fluid core. The significant role played by the nonuniform rotation of the core is stressed. Its effect is investigated by means of greatly simplified planar models. A qualitative picture of the magnetic wave regime probably established in the Earth's core is proposed. On the basis of this picture a simple model of torsional oscillations of the core is constructed.
Stochastic convexity and its applications

Several notions of stochastic convexity and concavity and their properties are studied in this paper. Efficient sample path approaches are developed in order to verify the occurrence of these notions in various applications. Numerous examples are given. The use of these notions in several areas of probability and statistics is demonstrated. In queueing theory, the convexity (as a function of c) of the steady-state waiting time in a GI/D/c queue, and (as a function of the arrival or service rates) in a GI/G/1 queue, is established. Also the convexity of the queue length in the M/M/c case (as a function of the arrival rate) is shown, thus strengthening previous results while simplifying their derivation. In reliability theory, the convexity of the payoff in the success rate of an imperfect repair is obtained and used to find an optimal repair probability. Also the convexity of the damage as a function of time in a cumulative damage shock model is shown. In branching processes, the convexity of the population size as a function of a parameter of the offspring distribution is proved. In non-parametric statistics, the stochastic concavity (or convexity) of the empirical distribution function is established. And, for applications in the theory of probability inequalities, we identify several families of distributions which are convexly parametrized.
Structure and mass function of five intermediate/old open clusters

The UBVRI data of ve northern open star clusters are used to study the mass function (MF), structure and dynamical state of these clusters. The clusters under discussion have ages ranging from 0.6 to 5 Gyr. A comparison of the density proles indicates that the evolution of the core of these clusters is almost the same, whereas the corona of the clusters are probably aected by the external environment and dynamical evolution. For the entire cluster region, the slope of the MF of three clusters (Be 64, Be 69 and King 5) has a value that agrees within the error with the Salpeter value, whereas King 7 and Be 20 show a steeper ( = 2:02 0:24) and almost a flat MF respectively. We nd that the slope of the MF of two clusters (King 5 and King 7) changes signicantly from the inner region to the outer region, becoming steeper at larger radii. The dynamical relaxation time of the clusters under discussion is less than the age of the clusters, which indicates that all of these clusters are dynamically relaxed. Thus the observed mass segregation in three clusters can be attributed to the dynamical evolution of the clusters. The ratio of the clusters' present radius to the limiting radius (determined from the relation given by King 1962) can be representated by an exponent law.
Analysis of large sets of ranking data

Various procedures, mainly graphical are presented for analyzing large sets of ranking data in which the permutations are not equally likely. One method is based on box plots, the others are motivated by a model originally proposed by Mallows. The model is characterised by two parameters corresponding to location and dispersion. Graphical methods based on Q-Q plots are also discussed for comparing two groups of judges. The proposed methods are illustrated on an empirical data set.