Miracle-dz/UniFAR-FTUs huggingface dataset:
Data mining in the young open cluster IC 2391

Large-scale astrometric and photometric data bases have been used to search for and confirm stellar membership of the open cluster IC 2391. 125 stars were found that satisfied criteria for membership based on proper motion components and BRI photometry from the United States Naval Observatory B (USNO-B) catalogue and JHK photometry from the Two Micron All Sky Survey (2MASS) catalogue. This listing was compared with others recently published. A distance to the cluster of 147.7 ± 5.5 pc was found with mean proper motion components, from the Tycho2 catalogue of (-25.04 ± 1.53 mas yr -1 ; +23.19±1.23 mas yr -1 ). A revised Trumpler classification of II3r is suggested. Luminosity and mass functions for the candidate stars were constructed and compared with those of field stars and other clusters.
Equation of state of molecular hydrogen and deuterium from shock-wave experiments to 760 kbar

We have carried out single-shock experiments with liquid deuterium to 210 kbar (Troughly-equal4800 K) and reflected experiments to 760 kbar (Troughly-equal7000 K) as well as single-shock experiments with liquid hydrogen to 100 kbar (Troughly-equal3300 K). These data enable us to determine a theoretical spherically symmetric, effective intermolecular pair potential. Calculated solid isotherms are compared with recent static measurements.
Effects of Parallel and Perpendicular Compressive Stresses on the Dielectric and Ferroelectric Properties of Soft PZT Ceramics

Effects of compressive stress on the dielectric and ferroelectric properties of commercial soft PZT ceramics were investigated. The dielectric and ferroelectric properties were measured under compressive stress applied parallel and perpendicular to an electric field direction. The results showed that the dielectric properties; i.e. the dielectric constant (ϵr) and dielectric loss tangent (tan δ), and the ferroelectric characteristics; i.e. the area of ferroelectric hysteresis (P-E) loops, the maximum polarization (Pmax), the coercive field (Ec) and the remanent polarization (Pr), changed significantly with increasing compressive stress. These changes depended greatly on direction of the applied stress. The stress clamping of domain wall, de-ageing and non-180° ferroelectric domain switching processes are responsible for the changes observed. In addition, a significant decrease in those parameters after a full cycle of stress application has been observed and attributed to the de-poling and stress-induced decrease in switchable part of spontaneous polarization at high stress. This study clearly showed that the applied stress has significant influence on the electrical properties of soft PZT ceramics.
ON THE DIFFICULT INTERPLAY BETWEEN LIFE, "COMPLEXITY", AND MATHEMATICAL SCIENCES

This paper presents a revisiting, with developments, of the so-called kinetic theory for active particles, with the main focus on the modeling of nonlinearly additive interactions. The approach is based on a suitable generalization of methods of kinetic theory, where interactions are depicted by stochastic games. The basic idea consists in looking for a general mathematical structure suitable to capture the main features of living, hence complex, systems. Hopefully, this structure is a candidate towards the challenging objective of designing a mathematical theory of living systems. These topics are treated in the first part of the paper, while the second one applies it to specific case studies, namely to the modeling of crowd dynamics and of the immune competition.
Acoustically induced transparency using Fano resonant periodic arrays

A three-dimensional acoustic device, which supports Fano resonance and induced transparency in its response to an incident sound wave, is designed and fabricated. These effects are generated from the destructive interference of closely coupled one broad- and one narrow-band acoustic modes. The proposed design ensures excitation and interference of two spectrally close modes by locating a small pipe inside a wider and longer one. Indeed, numerical simulations and experiments demonstrate that this simple-to-fabricate structure can be used to generate Fano resonance as well as acoustically induced transparency with promising applications in sensing, cloaking, and imaging.
Robust Spacecraft Angular Rate Estimation from Vector Observations Using Interlaced Particle Filtering

A novel algorithm is presented for the estimation of the spacecraft angular rate from vector observations. Belonging to the class of Monte Carlo sequential methods, the new estimator is a particle filter that uses approximate numerical representation techniques for performing the otherwise exact time propagation and measurement update of potentially non-Gaussian probability density functions in inherently nonlinear systems. This paper develops the filter and its implementation in the case of a low Earth orbit spacecraft, acquiring noisy geomagnetic field measurements via a three-axis magnetometer. Because the effective measurement noise in this case is time correlated, a special procedure is developed to account for that correlation in the particle filter implementation. The new estimator copes with the absence of an exact inertia tensor by employing a secondary particle filter that computes a maximum-likelihood estimate of the tensor of inertia, thus avoiding the need to expand the primary filter's state. This renders the new estimator highly efficient and enables its implementation with a remarkably small number of particles. The results of a simulation study are presented, in which the new filter is compared to a recently presented conventional extended Kalman filter. The comparison demonstrates the viability and robustness of the new algorithm and its fast convergence rate.
Non-isothermal droplet spreading/dewetting and its reversal

Axisymmetric non-isothermal spreading/dewetting of droplets on a substrate is studied, wherein the surface tension is a function of temperature, resulting in Marangoni stresses. A lubrication theory is first extended to determine the drop shape for spreading/dewetting limited by slip. It is demonstrated that an apparent angle inferred from a fitted spherical cap shape does not relate to the contact-line speed as it would under isothermal conditions. Also, a power law for the thermocapillary spreading rate versus time is derived. Results obtained with direct numerical simulations (DNS), using a slip length down to $O(10^{-4})$ times the drop diameter, confirm predictions from lubrication theory. The DNS results further show that the behaviour predicted by the lubrication theory – that a cold wall promotes spreading, and a hot wall promotes dewetting – is reversed at sufficiently large contact angles and/or viscosity of the surrounding fluid. This behaviour is summarized in a phase diagram, and a simple model that supports this finding is presented. Although the key results are found to be robust when accounting for heat conduction in the substrate, a critical thickness of the substrate is identified above which wall conduction significantly modifies wetting behaviour.
Pressure and temperature perturbations within a squall-line thunderstorm derived from SESAME dual-Doppler data

Abstract Some dynamic and thermodynamic properties of a convective cell within a squall line that occurred on 6 June 1979 were studied based on dual-Doppler observations. The domain under investigation had a horizontal dimension of 27 km × 27 km with 12 levels in the vertical. The grid spacing used was 1 km. Vertical velocities were computed from the anelastic continuity equation by integrating downward with variational adjustment. Fields of deviation perturbation pressure, density and virtual temperature were recovered from a three-dimensional wind field using the thermodynamic retrieval method. These retrieved fields were then subjected to internal consistency checks to determine the level of confidence. Our findings demonstrate that thermodynamic retrieval is feasible when random errors inherent in the radial wind components are minimized by proper smoothing. Errors in the computation of vertical velocity can be substantially reduced when a variational approach is used with the anelastic continuity equ.
Successful fabrication of high Ku columnar CoPt-SiO2 granular film sputtered under high substrate temperature

High substrate temperature sputtered CoPt-SiO2 granular films with columnar grain structure, high perpendicular uniaxial magnetic anisotropy (Ku⊥), and low stacking faults (SFs) are reported. By introducing a CoCr-SiO2 buffer layer onto a Ru layer, SiO2 segregates to Ru grains boundaries and CoCr grains grow epitaxially onto Ru grains. Consequently, the bumpy surface morphology of the underlayer is maintained even though the temperature of the substrate heating is subsequently elevated to around 400 °C. Therefore, the CoPtCr magnetic grains of the CoPtCr-SiO2 granular recording layer can grow epitaxially with columnar structure upon the CoCr grains of the CoCr-SiO2 buffer layer. For deposition of CoPt-SiO2 (no Cr) granular films at the substrate temperature below 400 °C, the increase of SFs can be suppressed such that Ku⊥ can be kept high at around 6.5 × 106 ergs/cm3 (Kugrain of around 9.0 × 106 ergs/cm3, where Kugrain is referred to uniaxial magneto-crystalline anisotropy of the magnetic grains when oxid.
Electron-impact ionization and recombination of M -shell atomic ions in the argon isonuclear sequence

Electron-impact ionization and recombination cross sections and rate coefficients are calculated for M-shell Ar atomic ions using a configuration-average distorted-wave method. The electron-impact ionization calculations are for all atomic ions in the Ar isonuclear sequence. Ionization contributions include both direct ionization and excitation-autoionization processes. Good agreement is found between theory and experimental crossed-beam measurements for moderately charged ion stages. Comparisons are made with previous theoretical calculations where possible. We also generate rate coefficients for neutral argon ionization, based on recent R-matrix with pseudostates calculations. Electron-impact dielectronic recombination is calculated for all M-shell ions of argon. For Ar{sup 6+} and Ar{sup 7+} the current theoretical results agree well with previous level-resolved distorted-wave calculations. In order to compare with published ionization balance results our dielectronic recombination data are combined with literature values for the higher ion stages and with recent radiative recombination data for all the ion stages. We find significant differences in our equilibrium fractional abundances for the M-shell ions, compared with literature values. We relate these differences to the underlying atomic data.
Life, Mechanism and Purpose

The determination of the place of life in nature has been a major philosophic issue. Some, in their attempt to show the continuity of nature, have resorted to the reductive method and have argued that the living differ in no significant sense from the non-living, unless it be in their complexity; others, in their desire to emphasize the qualitatively varied aspects of nature, have drifted to disjunctive method and have claimed that there is an unbridgeable gap between the living and the non-living. Yet life in its natural setting presents both continuity with the physical world and a distinctive difference from it. One need neither sunder the continuity in nature nor deny the empirically observable qualitative differences. It is this principle that will guide the present discussion of life. To understand life one must first consider the matrix within which it functions.
On stochastic differential equations driven by a Cauchy process and other stable Lévy motions

We consider the class of one-dimensional stochastic differential equations dX t = b(X t -)dZ t , t ≥ 0, where b is a Borel measurable real function and Z is a strictly α-stable Levy process (0 < α ≤ 2). Weak solutions are investigated improving previous results of the author in various ways. In particular, for the equation driven by a strictly 1-stable Levy process, a sufficient existence condition is proven. Also we extend the weak existence and uniqueness exact criteria due to Engelbert and Schmidt for the Brownian case (i.e., a = 2) to the class of equations with a such that 1 < α ≤ 2. The results employ some representation properties with respect to strictly stable Levy processes.
A variational analysis of a non-Newtonian flow in a rotating system

This study deals with the flow of a third grade fluid past an infinite plate. Both fluid and plate are in a state of rigid body rotation. The analysis presented here deals with similarity solutions of the problem and is done in the following way. We consider a Lagrangian formulation which allows us to directly determine conserved quantities leading to a reduction of the resultant systems.
TRANSIENT DYNAMIC RESPONSE ANALYSIS OF ORTHOTROPIC CIRCULAR CYLINDRICAL SHELL UNDER EXTERNAL HYDROSTATIC PRESSURE

Following Flugge's exact derivation for the buckling of cylindrical shells, the equations of motion for transient dynamic loading of orthotropic circular cylindrical shells under external hydrostatic pressure have been formulated. The normal mode theory is used to provide transient dynamic response for the equations of motion. The effect of shell's parameters, external hydrostatic pressure and material properties on the shell response has been studied in detail. A part of tables and figures are given in this paper.
Observation of Satellite Reflections in the Intermediate Phase of Quartz

The intermediate phase (IP) between α and β phases of quartz, which has been reported previously by the present authors, was studied by a fine-beam X-ray Laue method. Then, one could find satellite reflections. The analysis shows that IP has a sinusoidal and displacive modulated structure which is characterized by 6 wave vectors q perpendicular to the a axes. The wave is transversal in the C-plane. The period \(\varLambda{=}q^{-1}\) of the modulation and the associated intensities increase as temperature decreases; i.e. \(\varLambda{=}172{\pm}10\) A on β side and 565±25 A on α side. The satellites are likely owing to the optical mode of the displacive vibration of SiO 4 tetrahedra.
Osmosis and Thermo-Osmosis Through Cellulose Acetate Membranes

Osmotic experiments have been carried out by using aqueous solutions of sucrose and cellulose acetate membranes. Two kinds of experiments have been developed. In the first, osmotic flows have been measured. In the second, the evolution towards steady states has been obtained. In both cases the experiments have been performed by varying the concentration difference. The global osmotic permeabilities were of the order of 10" mol/ms for both membranes.
A nonmonotone line search technique for Newton's method

In this paper a nonmonotone steplength selection rule for Newton’s method is proposed, which can be viewed as a generalization of Armijo’s rule. Numerical results are reported which indicate that the proposed technique may allow a considerable saving both in the number of line searches and in the number of function evaluations.
Bose–Einstein condensation of atomic hydrogen Feynman path integral approach

We study the ground state properties of Bose–Einstein condensation of atomic hydrogen in the Ioffe–Pritchard magnetic trap using many-body Feynman path integral theory, which leads to the calculation of the ground state energy and the wavefunction. We also calculate the size, peak condensate density and the value of the ground state energy, which are in good agreement with the experimental results obtained by laser spectroscopy of the 1S–2S transition.
The motion of long bubbles in polygonal capillaries. Part 2. Drag, fluid pressure and fluid flow

This work determines the pressure–velocity relation of bubble flow in polygonal capillaries. The liquid pressure drop needed to drive a long bubble at a given velocity U is solved by an integral method. In this method, the pressure drop is shown to balance the drag of the bubble, which is determined by the films at the two ends of the bubble. Using the liquid-film results of Part 1 (Wong, Radke & Morris 1995), we find that the drag scales as Ca2/3 in the limit Ca → 0 (Ca μU/σ, where μ is the liquid viscosity and σ the surface tension). Thus, the pressure drop also scales as Ca2/3. The proportionality constant for six different polygonal capillaries is roughly the same and is about a third that for the circular capillary. The liquid in a polygonal capillary flows by pushing the bubble (plug flow) and by bypassing the bubble through corner channels (corner flow). The resistance to the plug flow comes mainly from the drag of the bubble. Thus, the plug flow obeys the nonlinear pressure–velocity relation of the bubble. Corner flow, however, is chiefly unidirectional because the bubble is long. The ratio of plug to corner flow varies with liquid flow rate Q (made dimensionless by σa2/μ, where a is the radius of the largest inscribed sphere). The two flows are equal at a critical flow rate Qc, whose value depends strongly on capillary geometry and bubble length. For the six polygonal capillaries studied, Qc [Lt ] 10−6. For Qc [Lt ] Q [Lt ] 1, the plug flow dominates, and the gradient in liquid pressure varies with Q2/3. For Q [Lt ] Qc, the corner flow dominates, and the pressure gradient varies linearly with Q. A transition at such low flow rates is unexpected and partly explains the complex rheology of foam flow in porous media.
Linear r-Modes below the Sun’s Convective Envelope

Theoretical properties of linear r-modes in a standard solar interior are computed, and the excitation of some by convective overshoot is estimated. The modes oscillate in a resonant cavity usually occupying most of the nonconvecting interior. Most modes concentrate their kinetic energy toward the center of the Sun. Over half the energy usually lies below 0.15 R☉ with an asymptotic limit of 0.11 R☉ for high radial harmonics (R☉ is the solar radius). The oscillation frequencies are very close to the well-known toroidal frequency, σt = 2Ωm[l(l + 1)]-1, deviating by fractional amounts ~ 10-6±1 which are roughly 3 orders of magnitude smaller than deviations found earlier for r-modes in convective layers. An explicit formula for the ratio of divergent motion to curl motion is derived. It shows how rapidly the compressible component changes as a function of r. Compressibility is only ~ 10-6 of the total motion for low l-modes and declines proportionally to ml-3 for high l. A small subset of modes (the lowest radial harmonic of angular states |m| = l) avoid the core which makes them sensitive to convective overshoot. Just one of the giant convection cells detected by Beck et al. can excite such modes to kilometer-size amplitudes with the possibility that far larger displacement amplitudes can accumulate in the mode over time if the interaction between cells and r-modes is found to be strong.
The 13–14 December 2001 IMPROVE-2 Event. Part III: Simulated Microphysical Budgets and Sensitivity Studies

Abstract This paper investigates the microphysical pathways and sensitivities within the Reisner-2 bulk microphysical parameterization (BMP) of the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) for the Improvement of Microphysical Parameterization through Observational Verification Experiment (IMPROVE)-2 field experiment on 13–14 December 2001. A microphysical budget over the windward slope at 1.33-km horizontal grid spacing was calculated, in which the importance of each microphysical process was quantified relative to the water vapor loss (WVL) rate. Over the windward Cascades, the largest water vapor loss was associated with condensation (73% of WVL) and snow deposition (24%), and the windward surface precipitation resulted primarily from accretion of cloud water by rain (27% of WVL), graupel fallout and melt (19%), and snowmelt (6%). Two-thirds of the snow generated aloft spilled over into the lee in an area of model overpredic.
Ion kinetic simulations of the formation and propagation of a planar collisional shock wave in a plasma

Ion kinetic simulations of the formation and propagation of planar shock waves in a hydrogen plasma have been performed at Mach numbers 2 and 5, and compared to fluid simulations. At Mach 5, the shock transition is far wider than expected on the basis of comparative fluid calculations. This enlargement is due to hot ions streaming from the hot plasma into the cold plasma and is found to be limited by the electron preheating layer, essentially because electron–ion collisions slow down these energetic ions very effectively in the cold upstream region. Double‐humped ion velocity distributions formed in the transition region, which are particularly prominent during the shock formation, are found not to be unstable to any electrostatic mode, due to electron Landau damping. At Mach numbers of 2 and below, no such features are seen in velocity space, and there is very little difference between the profiles from the kinetic and fluid simulations.
Resonant acoustic frequencies of a tandem cascade. Part 2. Rotating blade rows

In Part 1 (Woodley & Peake 1999) we described a method for predicting the occurrence of resonant states in a system comprising twin cascades in zero relative motion. We now demonstrate how that work can be extended to account for the case of more practical interest, in which the upstream cascade (rotor) is rotating in the transverse direction relative to the downstream cascade (stator). Time periodicity now forces the temporal frequency of any disturbance to be an integer multiple of the rotor passing frequency in the stator frame, and vice versa, and this leads to the requirement to sum over a discrete set of temporal modes, as well as over the spatial modes already described in Part 1. The mechanisms by which temporal and spatial modes are scattered by the blade rows is made clear by the analytical approach adopted here; the scattering of the incident pressure (and, for the stator, vorticity) fields by each row in its own frame is completed using results similar to those presented in Part 1, and the fields in the two frames then matched across the inter-row gap to provide a single matrix equation. Specimen results for the conditioning of this equation are given, and although it seems more difficult to obtain very strong excitation than it was for zero rotation, the significance of Parker resonance of the stator is again apparent.
Separation of the massless field equations for arbitrary spin in the Robertson–Walker space–time

The massless spin 2 free‐field equation is studied in the Robertson–Walker space–time via the Newman–Penrose formalism and separated by using a Chandrasekhar–Teukolski method. The resulting temporal and angular equations are explicitly integrated. The radial equations are solved in the flat universe case. The closed universe case shows, in principle, the existence of a discrete spectrum of the energy of the massless particles. In the general case of spin greater than 2 the massless field equations are shown to be separable by induction. The separated equations admit the same recurrence structure and analog interpretation properties of the spin 2 and less than 2 cases.