Miracle-dz/UniFAR-FTUs huggingface dataset:
An Efficient Finite-Difference Method for Simulating Phase Segregation in the Matrix Blocks in Double-Porosity Reservoirs

An efficient finite-difference method is presented for simulating unsteady-state multiphase flow in the matrix blocks (primary porosity) of naturally fractured systems or other reservoirs that have two different porosities. The scheme obtains pressure and saturation distributions in the matrix blocks (rather that average values) by dividing the matrix into subdomains. The method is an extension of the double-porosity concept in which fractures are the continuum for fluid flow and the matrix rock is the primary storage medium that acts as a source term to the fractures. Examples show that this subdivision results in different recoveries from the conventional double-porosity models when phase segregation in the matrix blocks is important to the recovery mechanism. In this formulation, the fracture medium is the major flow path to the wellbore with the matrix subdomains as source terms. The matrix subdomains can be connected to each other or to the fractures in any way desired to conform to the physics of the reservoir. This approach lends itself to an efficient scheme for reducing the system of flow equations to the same structure as conventional single-porosity simulators. The method is presented for a fully implicit, one-dimensional (1D), two-phase (oil/water) simulator.
Effective Professional Development and Change in Practice: Barriers Science Teachers Encounter and Implications for Reform

This study focused on two middle schools in the central US who participated in collaborative, sustained, whole-school professional development in implementing inquiry as part of National Science Education Standards, or standards-based instructional practices. Participants were involved in their second year of the professional development experience. The research question explored was, “What barriers do science teachers encounter when implementing standards-based instruction while participating in effective professional development experiences? ” Qualitative data collected in the form of teacher interviews and classroom observations were utilized and were analyzed using a barrier to reform rubric. Findings indicate that even with effective professional development, science teachers still encounter technical, political, and cultural barriers to implementation. More support is required for professional development efforts to be successful, such as resources and time, as well as administrative buy-in and support. Findings also revealed that even the best intended professional development efforts do not reveal and address existing beliefs for all teachers. Implications for future science education reform stakeholders are discussed.
Total versus quantum correlations in quantum states

On the premises that total correlations in a bipartite quantum state are measured by the quantum mutual information, and that separation of total correlations into quantum and classical parts satisfies an intuitive dominance relation, we examine to what extent various entropic entanglement measures, such as the distillable entanglement, the relative entropy entanglement, the squashed entanglement, the entanglement cost, and the entanglement of formation, can be regarded as consistent measures of quantum correlations. We illustrate that the entanglement of formation often overestimates quantum correlations and thus is too big to be a genuine measure of quantum correlations. This indicates that the entanglement of formation does not quantify the quantum correlations intrinsic to a quantum state, but rather characterizes the pure entanglement needed to build the quantum state via local operations and classical communication. Furthermore, it has the consequence that, if the additive conjecture for the entanglement of formation is true (as is widely believed), then the entanglement cost, which is an operationally defined measure of entanglement with significant physical meaning, cannot be a consistent measure of quantum correlations in the sense that it may exceed total correlations. Alternatively, if the entanglement cost is dominated by total correlations, as our intuition suggests, then we can immediately disprove the additive conjecture. Both scenarios have their counterintuitive and appealing aspects, and a natural challenge arising in this context is to prove or disprove that the entanglement cost is dominated by the quantum mutual information.
Magnetic and atomic short-range order in Cu-rich Cu-Mn

Elastic diffuse neutron scattering from $\text{Cu}\text{\ensuremath{-}}17\phantom{\rule{0.3em}{0ex}}\text{at. }%$ Mn was measured within three planes of reciprocal space, at room temperature and at $11\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ (far above and below the spin-glass temperature of $71\phantom{\rule{0.3em}{0ex}}\mathrm{K}$) to determine the atomic and magnetic short-range order parameters. Using two samples with frozen-in states of thermal equilibrium of 483 and $553\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, respectively, the antiferromagnetic character of the spin glass was found to be robust against changes in the degree of atomic order while the ferromagnetic character is rapidly reduced with lower atomic order. This confirms conclusions of ab initio calculations by Ling et al. [J. Phys.: Condens. Matter 6, 6001 (1994)].
TURBULENT ELLIPTIC WAKES

Abstract This paper describes results of an experimental study on turbulent wake of an elliptic disk set normal to the main flow, whose major diameter is 2·0 or 3·0 minor diameters, Reynolds number being 2·0×10 4 on the basis of the minor diameter D . Two periodic components of velocity fluctuations were found in the wake. One is centred around the minor plane, being due to the alternate shedding of rolled-up, hairpin-like vortices. The other is centred around the major plane, which is likely to be due to a meandering motion of the wake. The axis switching, which is a cross-over of half-widths in the major and minor planes plotted against the streamwise distance, occurred at approximately 4·0 D downstream of the disk. The mechanism of the axis switching is different from that in elliptic jets, and it is proposed that it is due to a difference in the growth rate of the fundamental Fourier modes in the minor and major planes. The structure of the wake is studied by flow visualization and a survey of the time-mean velocity, turbulence intensities and Reynolds shear stresses. Wavelet analysis of the velocity fluctuations disclosed a low-frequency unsteadiness in the wake. This unsteadiness has different representative frequencies in the major and minor planes, being approximately one-fifth of the frequency of the corresponding periodic component in both planes.
Asymptotic Distribution of Statistics in Time Series

Veritable conditions are given for the validity of formal Edgeworth expansions for the distribution of sums X 1 +. + X n , where X i = F(Z i ,., Z i + p − 1) and Z 1 ,Z 2 ,. is a strict sense stationary sequence that can be written as Z j = g(E j − k : k ≥ 0) with an iid sequence (E i ) of innovations. These models include nonlinear functions of ARMA processes (Z i ) as well as certain nonlinear AR processes. The results apply to many statistics in (nonlinear) time series models
Models of intermediate spectral statistics

Based on numerical results it is conjectured that the spectral statistics of certain pseudointegrable billiards have a special form similar to that of the Anderson model at the transition point. A simple theoretical model where such statistics can be obtained analytically is briefly discussed. A few models with similar behavior are considered. In particular, we analytically found the eigenvalue statistics of a Poisson-distributed matrix perturbed by a rank one matrix, which is a good model for spectral statistics of a singular billiard.
Kondo Scattering Observed at a Single Magnetic Impurity

Electron scattering of isolated Ce adatoms on Ag(111) surfaces was studied with a low-temperature scanning tunneling microscope. Tunneling spectra obtained on and near Ce reveal a characteristic dip around the Fermi energy which is absent for nonmagnetic Ag adatoms. This feature is detected over a few atomic diameters around Ce atoms at the surface. The transition matrix element from the localized $f$ electron to the tunnel-current carrying continuum states bears a strong resemblance to discrete autoionized states. We interpret the dip spectrum as a Fano interference for the limit where the $f$ orbital has a very small matrix element.
Electron dichroism - new data and an experimental cross-check

The spin-dependent attenuation of polarized electron beams transmitted through the vapour of chiral molecules was investigated in the electron energy range 0.5 - 10.0 eV. Several target molecules containing at least one atom of high atomic number were used in order to gain information about the role of the spin - orbit interaction in electron dichroism (ED). The results show that for quite different substances with one heavy atom the ED is of the same order of magnitude and that molecules with two heavy atoms do not necessarily show stronger ED. Some of the results indicate that the ED grows with increasing Z of the heavy atom. In some cases the transmission asymmetry reaches its largest values at those energies where resonances in the total cross section occur. In a second experiment it has been shown that an unpolarized electron beam, when transmitted through the vapour of bromocamphor, becomes longitudinally polarized. The value of this polarization and the measured transmission asymmetry correspond to each other, as predicted by theory.
Mass loss in A and B supergiants and the extragalactic distance scale

Des echantillons d'etoiles B5 et A0 du GMN demontrent l'existence de correlations etroites entre la luminosite et les largeurs equivalentes dans les raies Hα et Hβ. Ces correlations impliquent que la perte de masse des supergeantes A et B depend fortement de la luminosite et donc de la masse de l'etoile. Les taux de perte de masse sont plus faibles dans le PNM que dans le GNM. Les differences entre les echantillons dans les deux Nuages peuvent etre dues a des differences de composition chimique des etoiles
Topics in String Duality: D-Branes and Geometry

One of the most striking and surprising aspects of string theory is the vast web of string dualities which relates many seemingly distinct string backgrounds. In this dissertation, I explore several novel dualities between systems of D-branes and closed string flux compactifications. I use geometric transitions to analyze a variety of supersymmetry-breaking D-brane constructions. I additionally present an explanation of the Calabi-Yau fourfold geometries which appear in the computation of superpotentials for D-branes on compact Calabi-Yau threefolds.
New Definition of Conservative Internal Moments in Space Frames

There have been controversy and uncertainties surrounding the rotational behavior of conservative internal bending moments in three-dimensional frames. The two contesting representations of conservative internal bending moments are the quasi-tangential and the semitangential moments, each of which has its own shortcoming from the purely physical point of view. This situation must be rectified, as the correct identification of the nature of internal moments is indispensable for reliable buckling and large displacement analysis of three-dimensional structures. This paper presents a new type of conservative moment that has hitherto never been considered in the literature, and demonstrates that the proposed representation of conservative internal moments can be justified on both physical and rigorous mathematical grounds. Various issues relating to finite rotations and the work done by conservative moments in space are also addressed.
Performance Benchmarking For Taiwan’s International Tourist Hotels

Abstract Jhis study proposes an alternative data envelopment analysis (DEA) method to explore the managerial performance, the input congestion, and the benchmarks of intemational tourist hotels (ITHs) for a small open economy, Taiwan. Several empirical results are shown: (1) most ITHs operate at decreasing returns to scale, indicating that ITHs are facing a highly competitive environment; (2) the intemational chain ITHs are generally more efficient than independent-owned ones; (3) ITHs Iocated in resort areas operate slightly better on average than ones located in metropolitan areas; (4) ITHs that are close to CKS intemational airport operate slightly worse on average than ones far from CKS intemational airport; (5) congestion analysis reveals that inefficient ITHs lack the ability to integrate their resources, especially in the total area of the catering division and the number of guest rooms; and finally, (6) the reference-share measure shows that efficient intemational chain ITHs are able to more easily become benchmarks. The findings show that efficient intemational chain ITHs are more competitive and they should provide examples of operating practice.
CRRES Poynting vector observations of electromagnetic ion cyclotron waves near the plasmapause

Electromagnetic ion cyclotron waves have been observed by the Air Force Geophysics Laboratory triaxial fluxgate magnetometer on the CRRES satellite in the vicinity of the plasmapause. Specific wave events in the 1300–0100 MLT local time sector and over L = 4.8 – 6.7 at magnetic latitudes between ± 20° have been studied with respect to energy propagation. Using the wave magnetic field data and the orthogonal two-component Berkeley electric field experiment data allows the computation of the Poynting vector. Nine events with frequencies below 0.6 Hz have been analyzed. General wave properties showed intensities in the range 4–18 μW m−2. In most events, energy propagation was predominantly away from the equator, supporting the existence of an equatorial source region. There are exceptions and one event, observed 3° from the equator, also showed some propagation back to the equator with equal energy. Four periodic wave packets were seen in another event. This event showed unidirectional propagation away from the equator over all packets with periodicity approximately one-half of the calculated time for a typical bouncing wave packet. Consequently, the periodicity is not the signature of a classical periodic structured Pc 1–2 pulsation event of the type seen on the ground. Generally, the results for these waves with f < fHe+ may be interpreted by assuming an ion cyclotron instability source located near the equator and irregularly emitting wave trains of energy into one or both hemispheres, with minimal reflection at the ionosphere.
Shockwave-boundary layer interference heating analysis.

Interference heating correlations have been developed based on existing wind tunnel test data taken with simple configurations such as wedge/flat plate and compression corner models. For turbulent flow, peak interference heating was first correlated with shock strength (pressure ratio across shock wave) and then as a function of Reynolds number. The peak interference Stanton number was found to exhibit the same Reynolds number and Prandtl number characteristics as the Stanton number variation for undisturbed flow over a flat plate. Similar correlations were developed for laminar flow. Results indicated that for laminar flow at higher Reynolds number, the impinging shockwave may act as a boundary layer trip and cause boundary layer transition resulting in high interference heating. The correlations derived in this study can be used to scale wind tunnel model test data to a full-scale space vehicle at supersonic or hypersonic flight conditions.
The busy period of the migi1 vacation model with a bernoulli schedule

The server busy period for the M|G|1 vacation model with a Bernoulli schedule is studied. Simple expressions are found for (i) the conditional joint distribution of the busy period and number in the system at the end of a busy period given the number in the system at the beginning of the busy period, (ii) the ergodic distribution of the number in the system at a busy period initiation epoch, and (iii) the distribution of the depletion time at service initiation epochs. Expressions in the real domain for the key ingredients of die busy period are also given.
Large deviations analysis of reflected diffusions and constrained stochastic approximation algorithms in convex sets

Let G be a bounded convex set. hen the solution to the Skorokhod problem for a given path 4 may be considered as a reflected version of 4 with respect to G. By use of estimates on the behavior of this deterministic transformation, large deviations type asymptotic estimates for reflected diffusions are shown to hold. Let ll, be the projection onto G and Gaussian sequence. Then from the diffusion results estimates on the asymptotic behavior of recursive algorithms of the type are shown to follow. Let 0 be a stable point of the algorithm, let D be a neighborhood of 0 with respect to G, let A = to be the piecewise linear interpolation of X",tarting at 0 and having interpolation interval E. Then estimates on P{xE(.) E A), the probability of escape from D before time 7; are obtained. This analysis yields an alternative to convergence results on the "asymptotic normality" of errors about 0, which are in any case not applicable if OESG. These and other estimates provided by the large deviations methods are often .
Optimizing the carbonic anhydrase temperature response and stomatal conductance of carbonyl sulfide leaf uptake in the Simple Biosphere model (SiB4)

Abstract. Carbonyl sulfide (COS) is a useful tracer to estimate gross primary production (GPP) because it shares part of the uptake pathway with CO2. COS is taken up in plants through hydrolysis, catalyzed by the enzyme carbonic anhydrase (CA), but is not released. The Simple Biosphere model version 4 (SiB4) simulates COS leaf uptake using a conductance approach. SiB4 applies the temperature response of the RuBisCo enzyme (used for photosynthesis) to simulate the COS leaf uptake, but the CA enzyme might respond differently to temperature. We introduce a new temperature response function for CA in SiB4, based on enzyme kinetics with an optimum temperature. Moreover, we determine Ball–Woodrow–Berry (BWB) model parameters for stomatal conductance (gs) using observation-based estimates of COS flux, GPP, and gs along with meteorological measurements in an evergreen needleleaf forest (ENF) and deciduous broadleaf forest (DBF). We find that CA has optimum temperatures of 20 ∘C (ENF) and 36 ∘C (DBF), which is lower than that of RuBisCo (45 ∘C), suggesting that canopy temperature changes can critically affect CA's catalyzation activity. Optimized values for the BWB offset parameter are similar to the original value (0.010 ± 0.003 mol m−2 s−1), and optimized values for the BWB slope parameter (ENF: 16.4, DBF: 11.4) are higher than the original value (9.0) at both sites. The optimization reduces prior errors on all parameters by more than 50 % at both stations. We apply the optimized gi and gs parameters in SiB4 site simulations, thereby improving the timing and peak of COS assimilation. In addition, we show that SiB4 underestimates the leaf humidity stress under conditions where high vapor pressure deficit (VPD) should limit gs in the afternoon, thereby overestimating gs. Furthermore, global COS biosphere sinks with optimized parameters show smaller COS uptake in regions where the air temperature is over 25 ∘C, mostly in the tropics, and larger uptake in regions where the temperature is below 25 ∘C. This change corresponds with reported deficiencies in the global COS fluxes, such as missing sinks at high latitudes and required sources in the tropics. Using our optimization and additional observations of COS uptake over various climate and plant types, we expect further improvements in global COS biosphere flux estimates.
Constant mean curvature graphs in a strip of ℝ2

We consider the Dirichlet problem for the constant mean curvature surface equation on domains of an infinite strip of the plane. We give sufficient conditions for the existence of smooth solutions provided that the boundary satisfies a certain exterior circle condition. A feature of the work is the use of pieces of nodoids as barriers to make C° and C 1 a priori estimates respectively.
On the shape of flames under strong acoustic forcing: a mean flow controlled by an oscillating flow

A conical flame, in the presence of high-frequency (≈1000 Hz) and high-amplitude acoustic modulation of the cold gases, deforms to a shape which is approximately hemispherical. It is shown that the acoustic level required to produce a hemispherical flame is such that the ratio of acoustic velocity to laminar combustion velocity is about 3. This flame flattening is equivalent to the phenomenon of acoustic restabilization observed for cellular flames propagating in tubes. The transition between the conical flame and a hemispherical flame is described. The surface area of the reaction zone of the flame is found to be unmodified when the flame flattens. The velocity field at the burner outlet is examined with and without a flame. The mean flow lines are strongly deflected when the hemispherical flame is present. We show that the presence of the flame creates an unusual situation where the oscillating flow controls the geometry of the mean flow.
COLLINDER 223: A MODERATELY YOUNG OPEN CLUSTER IN THE CARINA SPIRAL FEATURE

UBV photoelectric data for 110 stars and DDO data for seven stars are discussed originating in the field of the previously unstudied open cluster Collinder 223. These data show that Cr 223 is a genuine open cluster located at a distance of (2900 + or - 270) pc from the sun and 96 pc below the galactic plane. Nearly 40 percent of the sample stars - including one red giant, two blue stragglers, and two suspected variables - are found to be cluster members. The reddening across the cluster is not uniform, the mean value being E(B-V) = 0.26 + or - 0.03 (s.d.). An age of 3.6 x 10 to the 7th yr has been derived, which places Cr 223 within the IC 4665 age group.
Reliability–sensitivity analysis using dimension reduction methods and saddlepoint approximations

Reliability–sensitivity, which is considered as an essential component in engineering design under uncertainty, is often of critical importance toward understanding the physical systems underlying failure and modifying the design to mitigate and manage risk. This paper presents a new computational tool for predicting reliability (failure probability) and reliability–sensitivity of mechanical or structural systems subject to random uncertainties in loads, material properties, and geometry. The dimension reduction method is applied to compute response moments and their sensitivities with respect to the distribution parameters (e.g., shape and scale parameters, mean, and standard deviation) of basic random variables. Saddlepoint approximations with truncated cumulant generating functions are employed to estimate failure probability, probability density functions, and cumulative distribution functions. The rigorous analytic derivation of the parameter sensitivities of the failure probability with respect to the distribution parameters of basic random variables is derived. Results of six numerical examples involving hypothetical mathematical functions and solid mechanics problems indicate that the proposed approach provides accurate, convergent, and computationally efficient estimates of the failure probability and reliability–sensitivity. Copyright © 2012 John Wiley & Sons, Ltd.