Miracle-dz/UniFAR-FTUs huggingface dataset:
Spectral properties and universal behaviour of advecting–diffusing scalar fields in finite-length channels

This paper analyses the relaxation towards the steady state of an advecting–diffusing field in a finite-length channel. The dominant eigenvalue, −-ΛF, of the advection–diffusion operator provides the slowest relaxation time scale for achieving steady state in open flow devices. We focus on parallel flows and analyse how ΛF depends on the velocity profile and the molecular diffusivity. As a result of the universal localization features of the eigenfunction associated with ΛF, we find that ΛF can be predicted analytically based on the local behaviour of the velocity profile near the stagnation points. Microfluidic applications of the theory are also addressed.
Electrical and Optical Properties of Lead Oxide Single Crystals

Single‐crystal platelets (3×3×0.1 mm) of both tetragonal and orthorhombic lead oxide have been grown from dilute NaOH solutions at high pressures using conventional hydrothermal techniques. The predominant yield of the two phases was varied in accord with the P‐T phase diagram of PbO. Electrical measurements include the Hall coefficient and electrical conductivity as a function of temperature, while the corresponding photoeffects and optical absorption with monochromatic radiation were also studied. ``As‐grown'' tetragonal crystals were highly conducting n‐type with σ(300°K) ∼10−3 to 1. 0Ω−1 cm−1, and had Hall mobilities of about 100 cm2V−1 sec−1. In constrast the ``as‐grown'' orthorhombic crystals were rather insulating with σ(300°K) ∼10−5Ω−1 cm−1 and a Hall mobility μe∼50 cm2V−1 sec−1. Heat treatment in air altered both the electrical and optical properties. Photoconductivity was observed in both crystalline forms. The optical measurements indicate band transitions at 1.90 eV and 2.75 eV for the tetragon.
Calculating nonparametric confidence intervals for quantiles using fractional order statistics

In this paper, we provide an easy-to-program algorithm for constructing the preselected 100(1 - alpha)% nonparametric confidence interval for an arbitrary quantile, such as the median or quartile, by approximating the distribution of the linear interpolation estimator of the quantile function Q L ( u ) = (1 - epsilon) X \[ n u ] + epsilon X \[ n u ] + 1 with the distribution of the fractional order statistic Q I ( u ) = Xn u , as defined by Stigler, where n = n + 1 and \[ . ] denotes the floor function. A simulation study verifies the accuracy of the coverage probabilities. An application to the extreme-value problem in flood data analysis in hydrology is illustrated.
Focused ion beam nanolithography on AlF3 at a 10 nm scale

We have investigated the potential use of AlF3 thin films (50 nm thick) as negative inorganic resist layers for focused ion beam nanolithography. We demonstrate that 10 nm-wide lines can be fabricated using a Ga+ beam of 30 keV incident energy. The resist sensitivity of 1010 Ga+/cm is two orders of magnitude lower than for polymethylmethacrylate organic resist. We emphasize that this low sensitivity associated with the exposure mechanism of the resist minimize the influence of the tails of the current distribution within the ion spot.
$L^{2}$-torsion invariants of a surface bundle over $S^{1}$

In the present paper, we introduce L-torsion invariants tkðkb 1Þ for surface bundles over the circle and investigate them from the view point of the mapping class group of a surface. It is conjectured that they converge to the L-torsion for the regular representation of the fundamental group. Further we give an explicit and computable formula of the first two invariants by using the Mahler measure.
The infrared detectors for the wide field camera 3 on HST

We present the performance of the IR detectors developed for the WFC3 project. These are HgCdTe 1Kx1K devices with cutoff wavelength at 1.7 μm and 150K operating temperature. The two selected flight parts, FPA#64 (prime) and FPA#59 (spare) show quantum efficiency higher than 80% at λ=1.6 μm and greater than 40% at λ>1. 1μm, readout noise of ~25 e- rms with double correlated sampling, and mean dark current of ~0.04 e/s/pix at 150K. We also report the results obtained at NASA GSFC/DCL on these and other similar devices in what concerns the QE long-term stability, intra-pixel response, and dark current variation following illumination or reset.
Theory of mountain waves of large amplitude

Rotors are defined as regions containing flow in the opposite direction to the main stream and are shown to exist when the wave amplitude is large enough. Equations are derived for computing rotor flow in an infinitely deep atmosphere. The problem of choosing an appropriate second boundary condition in steady flow over a ridge is complicated when the amplitude is finite because the shape of obstacle obtained depends on the airstream characteristics as well as upon the mathematical form given to it. Probably under some actual conditions the oncoming airstream is modified by the presence of the mountain. Because of the great variety of airstreams and mountains no general case can be illustrated. The particular cases chosen illustrate rotor flow. These particular cases do, however, each represent a set of cases in which all the non-dimensional numbers involved have the same value. Known cases of rotors in the Sierra Nevada and at Cross Fell are cited to illustrate the theory.
Conjugacies adapted to lower semicontinuous functions

Abstract We revisit a remarkable duality devoted to lower semicontinuous functions. We compare its definition in terms of a coupling with its definition in terms of linear-like (or elementary) functions. We consider several variants. Then, we deal with the passage from smoothness to rotundity and the reverse passage and we examine the transfer of boundedness properties to coercivity properties. The relevance of this conjugacy for mathematical programming problems is pointed out.
A model-based diagnostic study of the rapid development phase of the Presidents' Day cyclone

Abstract A model simulation of the rapid development phase of the Presidents' Day cyclone of 19 February 1979 is analyzed in an effort to complement and extend a diagnostic analysis based only on 12-h radiosonde data over the contiguous United States, with a large data-void area over the Atlantic Ocean (Uccellini et al. 1985). As indicated by the SLP and 850 mb absolute vorticity tendencies, rapid cyclogenesis commences between 0300 and 0600 UTC 19 February and proceeds through the remaining 18 h of the simulation. This rapid development phase occurs as stratospheric air [marked by high values of potential vorticity (PV) approaches and subsequently overlies a separate, lower-tropospheric PV maximum confined to the Fast Coast, or during the period when the advection of PV increases in the middle to upper troposphere over the East Coast. The onset of rapid deepening is marked by 1) the transition in the mass divergence profiles over the surface low from a diffuse pattern with two or three divergence maxima .
Approach to thermal equilibrium in a system with adiabatic constraints

The problem of prediction of the equilibrium state in an isolated composite system with an adiabatic internal wall is a delicate problem, whose solution is easily seen to be not entirely determined in the frame of elementary thermodynamics. We show how this indeterminacy can be removed by introducing a suitable kinetic model, in which the influence of the finite velocity of the wall on the change of momentum of the gas molecules impinging on it plays a relevant role. An interesting feature of the entropy behavior of the system is discussed.
Timepix detector at the X-ray Correlation Spectroscopy instrument at LCLS

The Timepix detector can be operated in Time-over-Threshold mode to allow for charge integration measurements as required by short (< 50 fs) x-ray pulses of the Linac Coherent Light Source (LCLS). Initial commissioning activities have started at the X-ray Correlation Spectroscopy (XCS) instrument at LCLS, where speckle patterns have been measured.
Impact of In Vitro Degradation on the Properties of Samples Produced by Additive Production from PLA/PHB-Based Material and Ceramics

The present study deals with preparing a polymer-based material with incorporated ceramics and monitoring changes in properties after in vitro natural degradation. The developed material is a mixture of polymers of polylactic acid and polyhydroxybutyrate in a ratio of 85:15. Ceramic was incorporated into the prepared material, namely 10% hydroxyapatite and 10% tricalcium phosphate of the total volume. The material was processed into a filament form, and types of solid and porous samples were prepared using additive technology. These samples were immersed in three different solutions: physiological solution, phosphate-buffered saline, and Hanks’ solution. Under constant laboratory conditions, changes in solution pH, material absorption, weight loss, changes in mechanical properties, and surface morphology were monitored for 170 days. The average value of the absorption of the solid sample was 7.07%, and the absorption of the porous samples was recorded at 8.33%, which means a difference of 1.26%. The least change in pH from the reference value of 7.4 was noted with the phosphate-buffered saline solution. Computed tomography was used to determine the cross-section of the samples. The obtained data were used to calculate the mechanical properties of materials after degradation. The elasticity modulus for both the full and porous samples degraded in Hanks’ solution (524.53 ± 13.4 MPa) has the smallest deviation from the non-degraded reference sample (536.21 ± 22.69 MPa).
Correlations between CdTe/CdS/SnO2/glass solar cell performance and the interface/surface properties

Surface and interface properties of CdTe/CdS/SnO2/glass heterojunction solar cells are studied by means of x‐ray photoelectron spectroscopy (XPS),secondary ion mass spectroscopy(SIMS), and optical reflectance (OR) techniques. First, n‐type CdS layer was grown by solution growth technique on the SnO2 coated glass substrate and then the p‐type CdTe was deposited on CdS by metal‐organic chemical‐vapor deposition. Despite many other efficiency limiting mechanisms in CdTesolar cells, this article shows that surfaces and interfaces play an important role in determining the cell efficiency. In an attempt to correlate the surface and interface properties to the cell performance, a series of CdTe/CdS solar cells with different conversion efficiencies were fabricated and analyzed. It was found that high efficiency cells possess Te‐rich CdTe surface along with smooth interfaces, as revealed by XPS,SIMS, and OR measurements, while low efficiency cells display near stoichiometric or Cd‐rich CdTe surface and abrupt interfaces. The impact and role of interface/surface properties on CdTesolar cell performance are discussed.
The nature of AFGL 2591 and its associated molecular outflow: infrared and millimeter-wave observations

On presente et on discute les resultats d'une photometrie infrarouge de 2 μm a 160 μm de AFGL 2591 et d'observations 12 CO de son nuage moleculaire associe et de l'ecoulement moleculaire exterieur de grande vitesse. Les observations entre 60 et 160 μm donnent le premier spectre detaille dans l'IR lointain de cette source. La luminosite absorbee entre 2 et 160 μm est de 6,7×10 4 L ○. a une distance de 2 kpc
Visual demonstration of the displacement effect of an ionization chamber within a phantom, at low x-ray energies (< 150 keV)

The publication of an international code of practice for photon and electron dosimetry by the IAEA has demonstrated discrepancies in the correction factors needed for the displacement effects of ion chambers at low and medium X-ray energies, compared with previous recommendations by ICRU and the HPA. The author describes a method for producing an image of a chamber cavity within a phantom, using both silver bromide and radiation-sensitive film, from which it may be deduced that displacement correction factors are likely, in general, to be less than unity. This is in agreement with several Monte Carlo simulation studies but contrary to IAEA recommendations. Although primarily of qualitative interest, the results suggest displacement correction factors, pu, in the range 0.90 < pu < 1.00 within the quality range 2.2 to 5.2 mm Al HVL.
Estimating True Scores Using Group Membership

If two parallel tests were available the reliability could be computed as the correlation between tests, however, two sets of individual values and group means would be observed. The estimation problem is to use all information to obtain a better true score estimate. The general problem of using group status to estimate true scores given multiple measures will be considered in this paper. The linear regression of T on X which is implicitly assumed for equation (1) will hold only under very restricted conditions including normally and independently distributed error and true
The Rank of Jacobian Varieties over the Maximal Abelian Extensions of Number Fields: Towards the Frey–Jarden Conjecture

Abstract Frey and Jarden asked if any abelian variety over a number field $K$ has the infinite Mordell–Weil rank over the maximal abelian extension ${{K}^{\text{ab}}}$ . In this paper, we give an affirmative answer to their conjecture for the Jacobian variety of any smooth projective curve $C$ over $K$ such that $\sharp C\left( {{K}^{\text{ab}}} \right)\,=\,\infty $ and for any abelian variety of $\text{G}{{\text{L}}_{2}}$ -type with trivial character.
A distribution-free two-sample run test applicable to high-dimensional data

We propose a multivariate generalization of the univariate two-sample run test based on the shortest Hamiltonian path. The proposed test is distribution-free in finite samples. While most existing two-sample tests perform poorly or are even inapplicable to high-dimensional data, our test can be conveniently used in high-dimension, low-sample-size situations. We investigate its power when the sample size remains fixed and the dimension of the data grows to infinity. Simulated and real datasets demonstrate our method’s superiority over existing nonparametric two-sample tests.
Optimal Embeddings of Chaotic Attractors from Topological Considerations

Guided by topological considerations, a new method is introduced to obtain optimal delay coordinates for data from chaotic dynamic systems. By determining simultaneously the minimal necessary embedding dimension as well as the proper delay time we achieve optimal reconstructions of attractors. This can be demonstrated, e.g., by reliable dimension estimations from limited data series.
Further relations amongst infinite series and products. II. The evaluation of three-dimensional lattice sums

For pt.I see ibid. vol.20, p.L13-7 (1987). New relations amongst infinite series and infinite products are given. A survey of these and previous results is presented. These relations provide a way of evaluating certain three-dimensional lattice sums in closed form. Over 50 such evaluations are displayed.
Heritage tourism as a revitalization strategy in Antigua, West Indies

In the past 30 to 40 years, tourism has become a popular strategy among governments and communities throughout the world for increasing development. While this strategy does generally achieve increased economic development, it also brings negative impacts to the destinations, many of which the places are unequipped to handle. In Antigua and Barbuda, West Indies the predominance of cruise ship tourism is placing a significant strain on the community and its resources, and yet returning less revenue each year. This thesis investigates current efforts of community leaders to promote heritage tourism as a sustainable means for rejuvenating Antigua's tourism industry. I worked with local community leaders, using participatory research techniques, to construct questionnaires, which I then administered to tourists (cruise ship passengers and resort hotel guests) and residents in Antigua. The tourist questionnaires were designed to gauge current participation in heritage tourism and the potential for future participation in heritage tourism, while the resident questionnaires were designed to collect resident attitudes toward tourism, and to solicit potential solutions to its current decline. The research results indicate that stay-over visitors are better candidates for heritage tourism participation. The results further indicate that indirect marketing of Antigua's historic sites to cruise-ship passengers to encourage their return as hotel guests is roundabout and counterproductive. The results of the resident survey reveal that most Antiguan residents hold the government responsible for reversing the tourism decline. Because the government and Ministry of Tourism are currently supportive of cruise-based tourism, efforts to successfully develop Antigua as a heritage tourism destination will be difficult without significant pressure from the community. This case study is presented not only as a guide for Antigua's tourism planners and developers, but also for any small place that seeks to redefine tourism in its community.
Cohomology of Artin groups of type z An, Bn and applications

We consider two natural embeddings between Artin groups: the group Gz An 1 of type z An 1 embeds into the group GBn of type Bn ; GBn in turn embeds into the classical braid group BrnC1WD GAn of type An . The cohomologies of these groups are related, by standard results, in a precise way. By using techniques developed in previous papers, we give precise formulas (sketching the proofs) for the cohomology of GBn with coefficients over the module aq 1 ;t 1 c; where the action is . q/‐ multiplication for the standard generators associated to the first n 1 nodes of the Dynkin diagram, while is . t/‐multiplication for the generator associated to the last node.
Convergence almost Everywhere of Certain Partial Sums of Fourier Integrals

Suppose that R goes to infinity through a second‐order lacunary set. Let SR denote the Rth spherical partial inverse Fourier integral on Rd. Then SRf converges almost everywhere to f, provided that f satisfies ∫∣f^(ξ)log(8+∣ξ∣)∣2dξ<∞.
Predicting Saturated Liquid Densities of Refrigerants Using the SVRC Framework

Our scaled-variable-reduced-coordinate (SVRC) framework for correlating saturation properties was used to correlate saturated liquid densities of a wide variety of refrigerants at temperatures from the triple point to the critical point. In general, the SVRC model is capable of representing the phase densities of refrigerants within their experimental uncertainties when two adjustable parameters are used for each substance. Beyond precise representation of existing data, the SVRC framework is capable of generalized saturation property predictions. The model yielded average errors of less than 0.5% for the densities, based on a single experimental measurement. This level of accuracy is comparable to that we reported previously for refrigerant vapor pressure predictions.
A True-Field Magnetogram in a Solar Plage Region

The Near-Infrared Magnetograph is used to make the first 2D image of true magnetic field strength in the solar photosphere. The magnitude of the magnetic field vector is derived with a typical formal precision of + or - 75 G (2 sigma) from circularly polarized spectra of a highly Zeeman-sensitive iron line at 6388.6/cm. The true-field map demonstrates that the properties of 'kilogauss' flux tubes vary coherently on a variety of spatial scales within the 1-arcmin field of view. The measured fields span the range 1000-1700 G. The amplitude of the polarized signal implies that the spatial filling factor of the flux tubes can approach 0.3 at the seeing-limited resolution of 2 arcsec. Magnetic field strength and magnetic flux are statistically related in the sense that weak-field areas are weak-flux areas, but strong fields are present in both strong-flux and weak-flux areas. This implies a degree of independence in the relationship between the filling factor of flux tubes and their individual properties, such as field strength, pressure, and temperature.
Neural models for an asymmetric coplanar stripline with an infinitely wide strip

This paper presents a new approach, based on artificial neural networks (ANNs), to determine the characteristic impedance and the effective permittivity of an asymmetric coplanar stripline (ACPS) with an infinitely wide strip. ANNs are trained with five learning algorithms to obtain better performance and faster convergence with simpler structure. The best results for training and test were obtained from the models trained with the Levenberg–Marquardt and the Bayesian regularization algorithms. The results obtained by using the neural model are in very good agreement with the results available in the literature. The neural models presented in this work provide simplicity and accuracy to determine both the parameters of an ACPS. The method is not time consuming and is easily included in a CAD system.
Hybrid PSO – CP technique for the synthesis of non-uniform linear arrays with maximum directivity

A technique to synthesize maximum directivity non-uniform linear layouts subjected to upper bounds on the power pattern is presented. The approach is based on a nested strategy combining an outer particle swarm-based optimization and an inner convex programming solver by taking advantage of the convexity of the synthesis with respect to the excitation coefficients when fixing the array layout. Selected numerical results are discussed to assess the effectiveness, the flexibility, and the limitations of the proposed technique.
EXCITABILITY IN A NONLINEAR OPTICAL CAVITY

We establish a nonlinear optical cavity to be excitable. Excitability in this system is shown to originate from the combined dynamical effects of nonlinear intracavity field saturation and temperature-dependent absorption in the medium on two different time scales. The model may be experimentally realized using optical bistable devices with possible useful applications.
A New Smoothing Method Based on Nonsmooth FB Function for Second-Order Cone Programming

Based on a new smoothing function of the well-known nonsmooth FB (Fischer-Burmeis-ter) function, a smoothing Newton-type method for second-order cone programming problems is presented in this paper. The features of this method are following: firstly, the starting point can be chosen arbitrarily; secondly, at each iteration, only one system of linear equations and one line search are performed; finally, global, strong convergence and Q-quadratic convergent rate are obtained. The numerical results demonstrate the effectiveness of the algorithm.
Entropy Controlled Adaptive Finite Element Simulations for Compressible Gas Flow

The principal idea of the present work consists in using the entropy balance equation in its discrete form as a rationale for controling an optimal amount of artifficial dissipation in Finite Element (FE) compressible gas simulations. The entropy control can be reinterpreted as a nonlinear stability estimate in terms of the so-called modified entropy function. The idea has been practically verified using the Taylor-Galerkin method combined with an artificial viscosity term proposed by Hughes and Johnson, in context ofh-adaptive linear finite elements. The obtained numerical results confirm that the entropy control may indeed provide a basis for the careful balance between stability and higher-order resolution in FE approximations.