Miracle-dz/UniFAR-FTUs huggingface dataset:
Mean field kinetic theory description of evaporation of a fluid into vacuum

The evaporation of a liquid slab into vacuum is studied by numerical solutions of the Enskog–Vlasov equation for a fluid of spherical molecules interacting by Sutherland potential. The equation provides a simplified description of the microscopic behavior of the fluid but it has the capability of handling both the liquid and vapor phase, thus eliminating the necessity of postulating ad hoc models for boundary conditions at the vapor-liquid interface. This work focuses on obtaining the structure of the vapor-liquid interface in nonequilibrium conditions as well as the distribution function of evaporating molecules. The results show that the molecules crossing a properly defined vapor-liquid boundary have an almost Maxwellian distribution function and that the vapor phase is reasonably well described by the Boltzmann equation with diffusive boundary condition.
The ionospheric signature of flux transfer events

The author examines the motion of an isolated flux tube connecting the interplanetary and terrestrial magnetic field that has been created by reconnection at the dayside magnetopause. Such tubes should create a distinct localized flow pattern at their feet in the ionosphere. Observational effects are discussed. It is argued that the delay time of the order of a minute or more corresponding to the time for propagation of information from the reconnection site to the ionosphere is important and could control the creation of flux transfer events. It is predicted that magnetic pulsations in the Pc 5 frequency band are likely to be set up on closed flux tubes immediately neighboring the newly connected tubes.
A Generalized dynamic programming principle and hamilton-jacobi-bellman equation

We interpret the following fully nonlinear second-order partial differential equation as the value function of a certain optimal controlled diffusion problem, where is a second order elliptic partial differential operator parametrized by the control variable αϵA: with Here σ,b, and c are functions defined on with values respectively in and is a real function defined on . A particular case of this equation is when . In this case, the equation is the well-known Hamilton-Jacobi-Bellman equation. The problem is formulated as follows: The state equation of the control problem is a classical one. The cost function is described by an adapted solution of a certain backward stochastic differential equation. The paper discusses Bellman's dynamic programming principle for this problem The value function is proved to be a viscosity solution of the above possibly degenerate fully nonlinear equation
Ultrafine Structure in the λ5797 Diffuse Interstellar Absorption Band

High-resolution and high-S/N observations of the strong and relatively narrow λ5797 diffuse interstellar absorption band, recorded with the Ultra-High-Resolution Facility at the 3.9 m Anglo-Australian Telescope and the 0.9 m coudé feed of the Kitt Peak National Observatory, are reported. For selected lines of sight and using resolving powers of up to 600,000, a remarkable degree of intrinsic ultrafine structure is found within the band. There exists an almost exact correspondence between the structure in the spectra recorded toward μ Sgr, ζ Per, and ζ Oph, including one particularly narrow component with a width that is comparable to the widths of atomic and molecular absorption lines along these lines of sight. The results provide a new and extremely exacting test against which theoretical or laboratory candidates can be assessed, and they point to a new approach to studies of diffuse band carrier distributions through their velocity signatures.
Optimization Studies on a Slit Virtual Impactor

This study reports the results of numerical investigations performed on a proposed slit virtual impactor configuration. Simulations were performed using the computational fluid dynamics program CFX-4.4. A detailed numerical investigation was carried out to determine the critical geometrical parameters of the proposed configuration that would optimize the performance for the anticipated operation conditions (specified Reynolds number and major-to-minor flow split ratio). A detailed sensitivity analysis was performed on the optimized configuration to determine its performance characteristics (impactor efficiency and wall loss curves) for (a) operation at different major-to-minor flow split ratios for a constant Reynolds number and (b) operation at different Reynolds numbers but at the same major-to-minor flow split ratio. Finally, the effect of modifying the radius of curvature of the receiving section of the optimized configuration on the impactor performance was studied for the anticipated operation conditions, and the results are reported.
Mean-Field Leader-Follower Games with Terminal State Constraint

We analyze linear McKean-Vlasov forward-backward SDEs arising in leader-follower games with mean-field type control and terminal state constraints on the state process. We establish an existence and uniqueness of solutions result for such systems in time-weighted spaces as well as a convergence result of the solutions with respect to certain perturbations of the drivers of both the forward and the backward component. The general results are used to solve a novel single-player model of portfolio liquidation under market impact with expectations feedback as well as a novel Stackelberg game of optimal portfolio liquidation with asymmetrically informed players.
Constraining the Particle Nature of Dark Matter: Model-independent Tests From the Intersection of Theory and Observation

Dark matter is one of the greatest mysteries of modern astrophysics. It comprises about 83% of the matter density in the Universe and approximately 22% of the total energy density, yet its identity and particle properties are unknown. Gravitational interactions reveal its presence, but it does not readily interact with light or normal matter. The purpose of this dissertation is to provide insight into the particle properties of this exotic type of matter in a model-independent fashion. Dark matter is expected to be its own antiparticle, but the strength of its self-annihilation is not known. It is often assumed to be consistent with that which gives the correct abundance if dark matter were produced as a thermal relic in the early Universe, but that has not been proven. Constraints on the dark matter self-annihilation cross section are found over a wide range of masses, both for the separate cases of monoenergetic neutrino and monoenergetic photon production, and the corresponding limits on the total self-annihilation cross section. This is done by comparing the theoretical flux from a region of annihilating dark matter to observational data of that region. While larger than the thermal relic value, the resulting upper bounds are surprisingly stringent and among the first model-independent limits of their kind. A specific application of residual dark matter annihilations during the time of Big Bang Nucleosynthesis is analyzed, adding a lower limit to the value of the annihilation cross section for a certain mass range to couple with the calculated upper bounds mentioned
Enhanced Hα Emission in Early-Type Galaxies Belonging to Compact Groups

The results of Hα photometry of a sample of early-type galaxies belonging to nearby compact groups are presented. Over 75% of the galaxies in the sample were detected in Hα, a result that we have interpreted as proof of the presence of a warm interstellar medium within them. Comparing the Hα luminosities of the galaxies in our sample with those of a sample of early-type galaxies from the field, we have found that field early-type galaxies are systematically fainter in Hα than the compact group ones for a given B absolute magnitude by Δlog(LHα/LB) ≈ 0.5. We suggest that the excess in the Hα emission within the groups is due to photoionization of gas by Lyman continuum photons emitted by massive stars. Recent massive star formation would be a consequence of the accretion by early-type galaxies of gas from the outer envelopes of gas-rich galaxies experiencing close passages across the group.
Atmospheric Radiocarbon at the End of the Last Glacial: An Estimate Based on AMS Radiocarbon Dates on Terrestrial Macrofossils From Lake Sediments

The main purpose of this work is to reconstruct the atmospheric Δ 14C in the glacial-postglacial transition, 14,000 – 10,000 BP, a range not covered by the tree-ring calibration curve. We measured 14C/12C ratios on series of terrestrial macrofossils from sediments of two Swiss lakes. We selected exclusively plant remains of recognizable terrestrial origin that are not affected by hard water and thus reflect atmospheric 14C concentration. Due to the scarcity of such material, we used accelerator mass spectroscopy. Cores of two lakes were measured to eliminate local effects and to check the reproducibility of results. This required a reliable, 14C-independent correlation of the cores, obtained through local pollen zone boundaries 14C ages were obtained as a function of the depth in the cores. If sedimentation rates are known ages can be converted into Δ 14C values. We also attempted estimating sedimentation rates; calculations are based on the Swedish varve chronology. Results were combined to form an entire data set. The Δ 14C curve shows an increase with time during the Allerød and decreases during Preboreal and Bølling periods. Probabilities for these 14C variations are discussed.
Turbulent Heat Transfer and Friction in Pin Fin Channels With Lateral Flow Ejection

Experiments were conducted to study the effects of lateral flow ejection on the overall heat transfer and pressure drops for turbulent flow through pin fin channels. The two test sections of the investigation were rectangular channels with staggered arrays of six and eight streamwise rows of pins, respectively. The pin length-to-diameter ratio was one and both the streamwise and spanwise pin spacings were 2.5 times the pin diameter. Heat transfer and friction data were obtained for various ejection exit geometries, for ejection ratios between 0 and 1, and for Reynolds numbers between 6,000 and 60,000. The results of the study show that, for any given ejection ratio, the overall Nusselt number increases with increasing Reynolds number. However, the overall Nusselt number is reduced by as much as 25% as the ejection ratio is increased from 0 to 1 over the range of Reynolds number studied. The Nu-Re-{epsilon} relationship, which is insensitive to varying the ejection exit geometry, can be correlated by the equation (Nu/Nu{sub 0}) = (Nu{sub 1}/Nu{sub 0}){sup {epsilon}}, where Nu{sub 0} = c{sub 0}Re{sup m} and Nu{sub 1} = c{sub 1}Re{sup n} are the overall Nusselt numbers in the 0 and 100% lateral flow ejection cases, respectively. Themore » results also show that the overall friction factor is independent of the flow Reynolds number over the range of Reynolds number studied. However, the friction factor is strongly dependent on the ejection ratio as well as the geometries of the straight flow exit and lateral ejection flow exit. « less
Turbulence suppression in a jet by means of a fine ring

Studied are the effects on the velocity field of a fine circular wire ring placed axisymmerically downstream of an air jet of Reynolds number 1.4×104. When placed close to the jet exit (x/Dj<3 where Dj is the jet diameter) the ring caused a pronounced reduction in the rms longitudinal velocity fluctuations, the maximum reduction (of approximately 30% based on the peak value) occurring when the ring is very close to the jet (x/Dj=0.07) and in the shear layer although rings of smaller diameter located in the core also produced the same qualitative effect. The ring also caused a shift in the virtual origin of the mean flow and an increase of the momentum thickness of the shear layer. There resulted a reduction of the magnitude of the fundamental roll‐up frequency, and it saturated later than for the undisturbed flow. The spatial growth rate of the disturbances in the shear layer were also drastically reduced. Spectra showed that vortex pairing was inhibited by the ring and there was an earlier transition to .
Silicon nanowire detectors showing phototransistive gain

Nanowire photodetectors are shown to function as phototransistors with high sensitivity. Due to small lateral dimensions, a nanowire detector can have low dark current while showing large phototransistive gain. Planar and vertical silicon nanowire photodetectors fabricated in a top-down approach using an etching process show a phototransistive gain above 35 000 at low light intensities. Simulations show that incident light can be waveguided into vertical nanowires resulting in up to 40 times greater external quantum efficiency above their physical fill factor. Vertical silicon nanowire phototransistors formed by etching are attractive for low light level detection and for integration with silicon electronics.
Effect of rate and split application of nitrogen on agronomic characteristics, cane yield and juice quality.

A. SREEWAROME, S. SAENSUPO, P. PRAMMANEE and P. WEERATHWORN Mitr Phol Sugarcane Research Center Co. Ltd., 399 Moo 1 Khoksa-at, Phukhieo, Chaiyaphum, Thailand apicharts@mitrphol.com
Time-inhomogeneous discrete stochastic search methods for optimal bernoulli parameters

We present two time-inhomogeneous search processes for finding the optimal Bernoulli parameters, where the performance measure cannot be evaluated exactly but must be estimated through Monte Carlo simulation. At each iteration, two neighbouring alternatives are compared and the one that appears to be better is passed on to the next iteration. The first search process uses an increasing sample size of each configuration at each iteration. The second search process uses a sequential sampling procedure with increasing boundaries as the number of iterations increases. At each iteration the acceptance of a new configuration depends on the iterate number, therefore, the search process turns out to be inhomogeneous Markov chain. We show that if the increase occurs slower than a certain rate, these search processes will converge to the optimal set with probability one.
Convolution kernels of ( n + 1)-fold Marcinkiewicz multipliers on the Heisenberg group

We prove a characterisation, in terms of regularity and cancellation conditions, of the convolution kernels of Marcinkiewicz multiplier operators m (𝔏 1 ,…,𝔏 n , iT ) on the Heisenberg group ℍ n , where 𝔏 1 ,…,𝔏 n are the n partial sub-Laplacians. The necessity of these regularity and cancellation conditions was established by Fraser (2001); here, we prove their sufficiency.
Luminous variables in the Quintuplet cluster

We report observations of variability amongst the stars of the ‘Quintuplet’ cluster located about 30 pc in projection from the centre of the Galaxy. Two of the ﬁve cocoon star members, which may be protostars or peculiar Wolf–Rayet stars, are seen to vary slowly with moderate amplitude (0.4–0.5 mag). The bright star within the ‘Pistol’ H ii region, suspected of being a luminous blue variable (LBV), has in fact been found to show variability, conﬁrming its tentative classiﬁcation. A second nearby presumed LBV also varies. One of the apparent Quintuplet members is likely to be a Mira variable along the same line of sight.
Understanding plasma catalysis through modelling and simulation—a review

Plasma catalysis holds great promise for environmental applications, provided that the process viability can be maximized in terms of energy efficiency and product selectivity. This requires a fundamental understanding of the various processes taking place and especially the mutual interactions between plasma and catalyst. In this review, we therefore first examine the various effects of the plasma on the catalyst and of the catalyst on the plasma that have been described in the literature. Most of these studies are purely experimental. The urgently needed fundamental understanding of the mechanisms underpinning plasma catalysis, however, may also be obtained through modelling and simulation. Therefore, we also provide here an overview of the modelling efforts that have been developed already, on both the atomistic and the macroscale, and we identify the data that can be obtained with these models to illustrate how modelling and simulation may contribute to this field. Last but not least, we also identify future modelling opportunities to obtain a more complete understanding of the various underlying plasma catalytic effects, which is needed to provide a comprehensive picture of plasma catalysis.
Coherent structures and transport properties in magnetized plasmas

A common feature of magnetized plasmas is the presence of fluctuations, which can lead to fully developed turbulence. Often large events—called bursts—emerge from the remaining low-level turbulence, giving an intermittent character to fluctuations; namely the statistical properties of fluctuations are found to depend on the temporal scale over which the investigation is conducted. In magnetized plasmas, the bursts are generally believed to be due to the presence of magnetic-field-aligned structures. Moreover, it has been experimentally shown that the intermittent events detected in the signals are associated with a relevant contribution to the loss of particles from the plasma. All these observations are common to plasmas spanning a wide range of temperature and density and magnetically confined both in linear and toroidal devices. In particular, in high-temperature plasmas for thermonuclear fusion, research aims at devising suitable ways to control transport by acting on the plasma structures, for instance by biasing the plasma edge using electrodes. This paper gives a characterization of the structures found in magnetized plasmas and of their contribution to the particle transport; moreover, the effect of the velocity shear on structures is addressed. Emphasis will be laid on to the most advanced diagnostics allowing the reconstruction of turbulent structures by optical and electrostatic techniques.
The Wide-Field Infrared Explorer (WIRE)

The wide-field infrared explorer (WIRE) is a small spaceborne telescope specifically designed to study the evolution of starburst galaxies. This powerful astronomical instrument will be capable of detecting typical starburst galaxies at a redshift of 0.5, ultraluminous infrared galaxies beyond a redshift of 2, and luminous protogalaxies beyond a redshift of 5. The WIRE survey, to be conducted during a four month period during 1998, will cover over 100 deg2 of high galactic latitude sky at 12 and 25 micrometer. WIRE will measure the ratio of 12 and 25 micrometer flux of detected sources, which is a powerful statistical luminosity indicator. The distribution of starburst galaxy 12-25 micrometer colors as a function of flux density will reveal their evolutionary history and perhaps the presence of protogalaxies at high redshifts. This mission, which is part of the NASA Small Explorer program, takes advantage of recent advances in infrared array detector technology to provide a large sensitivity gain over previously flown missions. During its four-month mission lifetime, WIRE will amass a catalog exceeding the size of the 1983 Infrared Astronomy Satellite (IRAS) Point Source Catalog at flux levels over 500 times fainter than the IRAS Faint Source Catalog. WIRE has been designed to maximize detections of high-redshift starburst galaxies using an extremely small and simple instrument. The 30 cm aperture Cassegrain telescope has no moving parts, no reimaging optics and a wide 33 by 33 arcminute field of view. The optics and detectors are cooled during the mission using a lightweight two-stage solid hydrogen cryostat. The three-axis stabilized spacecraft bus is provided by the Goddard Space Flight Center Small Explorer Project Team. The mission, to be launched in September 1998 using an Orbital Sciences Corporation Pegasus XL Launch Vehicle, is managed by GSFC.
Nonstationary seismic responses of structure with nonlinear stiffness subject to modulated Kanai–Tajimi excitation

A simple structure under earthquake excitation is modeled as a single‐degree‐of‐freedom system with nonlinear stiffness subject to modulated Kanai–Tajimi excitation. The nonstationary responses including the nonstationary probability densities of the system responses and the statistical moments are obtained in semi‐analytical form. By applying the stochastic averaging method based on the generalized harmonic functions, the averaged Fokker–Planck–Kolmogorov(FPK) equation governing the nonstationary probability density of the amplitude is derived. Then, the solution of the FPK equation is approximately expressed by a series expansion in terms of a set of properly selected basis functions with time‐dependent coefficients. According to the Galerkin method, the time‐dependent coefficients are solved from a set of linear first‐order differential equations. Thus, the nonstationary probability densities of the amplitude and the state responses as well as the statistic moments of the amplitude are obtained. Finally, two types of the modulating functions, i.e. constant function and exponential function, are considered to give some semi‐analytical formulae. The proposed procedures are checked against the Monte Carlo simulation. The effects of the structure natural frequency and the intensity of the excitation as well as the ground stiffness on the system responses are discussed. It should be pointed out that the proposed method is good for broadband excitation and light damping. Copyright © 2011 John Wiley & Sons, Ltd.
On the first eigenvalue of the linearized operator of the higher order mean curvature for closed hypersurfaces in space forms

In this paper we derive sharp upper bounds for the ﬁrst positive eigenvalue of the linearized operator of the higher order mean curvature of a closed hypersurface immersed into a Riemannian space form. Our bounds are extrinsic in the sense that they are given in terms of the higher order mean curvatures and the center(s) of gravity of the hypersurface, and they extend previous bounds recently given by Veeravalli [24] for the ﬁrst positive eigenvalue of the Laplacian operator.
The spokes in Saturn's rings: A new approach

We propose that zonal winds in Saturn’s atmosphere cause superrotation of the ionosphere and by virtue of field-aligned currents generate a potential of ∼ 16 kV across the B-ring. Such a potential can momentarily polarize ∼ 1-10µm size ice particles in a radial sense and thus create the spectacular spokes. A resulting current flowing radially through the B-ring would give rise to a power of ∼ 107 W, which is close to that dissipated in an SED burst.
Which method predicts recidivism best?: a comparison of statistical, machine learning and data mining predictive models

Summary. Using criminal population conviction histories of recent offenders, prediction mod els are developed that predict three types of criminal recidivism: general recidivism, violent recidivism and sexual recidivism. The research question is whether prediction techniques from modern statistics, data mining and machine learning provide an improvement in predictive performance over classical statistical methods, namely logistic regression and linear discrim inant analysis. These models are compared on a large selection of performance measures. Results indicate that classical methods do equally well as or better than their modern counterparts. The predictive performance of the various techniques differs only slightly for general and violent recidivism, whereas differences are larger for sexual recidivism. For the general and violent recidivism data we present the results of logistic regression and for sexual recidivism of linear discriminant analysis.