Miracle-dz/UniFAR-FTUs huggingface dataset:
Experiments on transitional boundary layers with wake-induced unsteadiness

Hot-wire measurements were carried out in boundary layers developing along a flat plate over which wakes passed periodically. The wakes were generated by cylinders moving on a squirrel cage in front of the plate leading edge. The flow situation studied is an idealization of that occurring on turbomachinery blades where unsteady wakes are generated by the preceding row of blades. The influence of wake-passing frequency on the boundary-layer development and in particular on the transition processes was examined. The hot-wire signals were processed to yield ensemble-average values and the fluctuations could be separated into periodic and stochastic turbulent components. Hot-wire traces are reported as well as time variations of periodic and ensemble-averaged turbulent fluctuations and of the boundary-layer integral parameters, yielding a detailed picture of the flow development. The Reynolds number was relatively low so that in the limiting case of a boundary layer undisturbed by wakes this remained laminar over the full length of the test plate. When wakes passed over the plate, the boundary layer was found to be turbulent quite early underneath the free-stream disturbances due to the wakes, while it remained initially laminar underneath the undisturbed free-stream regions in between. The turbulent boundary-layer stripes underneath the disturbed free stream travel downstream and grow together so that the embedded laminar regions disappear and the boundary layer becomes fully turbulent. The streamwise location where this happens moves upstream with increasing wake-passing frequency, and a clear correlation could be determined in the experiments. The results are also reported in a mean Lagrangian frame by following fluid parcels underneath the disturbed and undisturbed free stream, respectively, as they travel downstream.
Ab initio simulations in liquid caesium at high pressure and temperature

The structure of liquid caesium undergoes a sharp change at around $4\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$ from a simple liquid to a low-coordination complex structure. This mirrors a similar change in the crystal structure at this pressure. Here, we show that both changes are accurately described in good agreement with experiment by density functional theory calculations, which shed light on the nature of the liquid structure and its electronic origins. Analysis of the wave function character shows $s\text{\ensuremath{-}}d$ hybridization, but not $s\text{\ensuremath{-}}d$ transfer, in both solid and liquid at the pressure of the complex Cs-III phase. This implies that a nearly free electron picture is more appropriate than one based on the atomic orbitals. The similarity of $s\text{\ensuremath{-}}d$ hybridization in crystal and liquid phases indicates that hybridization is a general consequence of densification, rather than being induced by a particular crystal structure. The free-electron picture predicts that stable structures will have diffraction peaks associated with the Fermi vector, and this is borne out by comparison with experiment.
Sliding mode parameter adjustment for perturbed linear systems with actuators via invariant ellipsoid method

A methodology for the design of sliding mode controllers for perturbed quasi‐linear systems in the presence of actuators is presented. This technique is based on the invariant ellipsoid method and given in terms of the solution of a set of linear matrix inequalities. The provided methodology allows the design of the controller parameters ensuring global convergence of the states to a suboptimal ellipsoidal region around the origin even in the presence of both matched and unmatched uncertainties/disturbances. A benchmark example illustrates a good workability of the suggested technique. Copyright © 2010 John Wiley & Sons, Ltd.
Underground study of the O 17 (p, γ) F 18 reaction relevant for explosive hydrogen burning

The 17O(p,γ )18F reaction affects the production of key isotopes (e.g., 18F and 18O) in the explosive hydrogen burning that powers classical novae. Under these explosive conditions, the reaction rate is dominated by contributions from a narrow resonance at Ec.m. = 183 keV and by the combined contributions of direct capture and low-energy tails of broad resonances. At present, the astrophysical reaction rate is not well constrained because of the lack of data in the energy region appropriate to classical novae.
Explosions in the early universe

We have constructed a series of simulations of spherically symmetric explosions in an otherwise unperturbed cosmology. The numerical hydrodynamics code includes effects due to electron conductivity, radiative cooling gravity, ion viscosity, and the difference between the electron and ion temperatures. The initial redshift of the explosions has been varied between a redshift of 50 and a redshift of 2. The initial energies of the explosions range from 10/sup 59/ ergs to 10/sup 61/ ergs, appropriate to the energy input from quasars or primeval galaxies. We discuss the evolution of these explosions in terms of the quantities most clearly related to observable effects on the intergalactic medium, including their size, total thermal and kinetic energies, shell temperatures and densities, and mean interior pressure as a function of epoch. In all cases most of the matter passed by the shock is eventually swept up into relatively dense shells. For certain epochs and ranges of energy, nonradial instabilities can occur, of either the Rayleigh-Taylor or the Jeans type, leading to the formation of dense fragments. The former instability is more relevant to low-energy events and may produce the Ly.cap alpha. clouds seen in absorption with large-energy events producing massive shells subject to gravitationalmore » instabilities and possibly the production of bound stellar systems. Most of the simulations were run with the present total matter density equal to 10% of the critical density. For this case final (current) and radii and peculiar velocities of 10/sup 61/-erg explosions are 4.26 Mpc and 19.2 km s/sup -1/, for an initial redshift of 10, and 3.64 Mpc and 10.2 km s/sup -1/, for an initial redshift of 20. « less
The knapsack problem with a minimum filling constraint

We study a knapsack problem with an additional minimum filling constraint, such that the total weight of selected items cannot be less than a given threshold. The problem has several applications in shipping, e‐commerce, and transportation service procurement. When the threshold equals the knapsack capacity, even finding a feasible solution to the problem is NP‐hard. Therefore, we consider the case when the ratio α of threshold to capacity is less than 1. For this case, we develop an approximation scheme that returns a feasible solution with a total profit not less than (1 ‐ ε) times the total profit of an optimal solution for any ε > 0, and with a running time polynomial in the number of items, 1/ε, and 1/(1‐α). © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2013
Machine Learning as a Downscaling Approach for Prediction of Wind Characteristics under Future Climate Change Scenarios

Assessment of climate change impacts on wind characteristics is crucial for the design, operation, and maintenance of coastal and oﬀshore infrastructures. In the present study, the Model Output Statistics (MOS) method was used to downscale a Coupled Model Intercomparison Project Phase 5 (CMIP5) with General Circulation Model (GCM) results for a case study in the North Atlantic Ocean, and a supervised machine learning method (M5’ Decision Tree model) was developed for the ﬁrst time to establish a statistical relationship between predicator and predicant. To do so, the GCM simulation results and altimeter remote sensing data were employed to examine the capabilities of the M5’DT model in predicting future wind speed and identifying spatiotemporal trends in wind characteristics. For this purpose, three classes of M5 ′ models were developed to study the annual, seasonal, and monthly variations of wind characteristics. The developed decision tree (DT) models were employed to statistically downscale the Beijing Normal University Earth System Model (BNU-ESM) global climate model output. The M 5 ′ models are calibrated and successfully validated against the GCM simulation results and altimeter remote sensing data. All the proposed models showed ﬁrm outputs in the training section. Predictions from the monthly model with a 70/30 training to test ratio demonstrated the best model performance. The monthly prediction model highlighted the decreasing trend in wind speed relative to the control period in 2030 to 2040 for the case study location and across all three future climate change scenarios tested within this study. This reduction in wind speed reduces wind energy by 13% to 19%.
Microcavity effects in a spin‐coated polymer two‐layer system

We report on the design and the optical properties of a spin‐coated multilayer organic microcavity. Tri(stilbene)amine blended with polysulfone as the first layer and an oxadiazole derivative (BPBD) blended with polystyrene as the second layer are sandwiched between two planar mirrors. Enhancement of the luminescence and spectrally narrow emission are observed. By means of time resolved luminescence spectroscopy we show that the spontaneous emission rate is increased in the cavity.
Arithmetic constructions of binary self-dual codes

ARITHMETIC CONSTRUCTIONS OF BINARY SELF-DUAL CODES Ying Zhang Ted Chinburg The goal of this thesis is to explore the interplay between binary self-dual codes and the etale cohomology of arithmetic schemes. Three constructions of binary self-dual codes with arithmetic origins are proposed and compared: Construction Q, Construction G and the Equivariant Construction. In this thesis, we prove that up to equivalence, all binary self-dual codes of length at least 4 can be obtained in Construction Q. This inspires a purely combinatorial, non-recursive construction of binary self-dual codes, about which some interesting statistical questions are asked. Concrete examples of each of the three constructions are provided. The search for binary self-dual codes also leads to inspections of the cohomology “ring” structure of the etale sheaf μ2 on an arithmetic scheme where 2 is invertible. We study this ring structure of an elliptic curve over a p-adic local field, using a technique that is developed in the Equivariant Construction.
First-principles study of defect energetics in titanium-doped alumina

First-principles plane-wave pseudopotential calculations were performed to study electronic structures, structural relaxation, and energetics of point defects in Ti-doped ${\mathrm{Al}}_{2}{\mathrm{O}}_{3}. $ Substitutional and interstitial Ti ions with charge compensating intrinsic defects were considered, and their formation energies were evaluated under various atomic chemical potentials. It was found that substitutional ${\mathrm{Ti}}^{4+}$ ions with charge compensating Al vacancies were most stable in the oxidized condition. In contrast, as oxygen chemical potentials decreased, the formation energy of substitutional ${\mathrm{Ti}}^{3+}$ decreased to have the smallest value in the relatively reduced conditions. However, in the intermediate range of oxygen potentials, substitutional ${\mathrm{Ti}}^{3+}$ and ${\mathrm{Ti}}^{4+}$ exhibited similar formation energies, indicating that these Ti defects can coexist in a particular reduction environment.
Stacking of Interferometric Data

Abstract Radio and mm observations play an important role in determining the star formation properties of high redshift galaxies. However, most galaxies at high redshift are too faint to be detected individually at these wavelengths. A way to study this population of galaxies is to use stacking. By averaging the emission of a large number of galaxies detected in optical or near infrared surveys, we can achieve statistical detection. We investigate methods for stacking data from interferometric surveys. Interferometry poses unique challenges in stacking due to the nature of imaging of this data. We have compared directly stacking the uv data with stacking of the imaged data, the latter being the typically used approach. Using simulated data, we find that uv-stacking may provide around 50% less noise and that image based stacking systematically loses around 10% of the flux.
CENTRALIZERS IN RESIDUALLY FINITE TORSION GROUPS

Let G be a residually finite torsion group. We show that, if G has a finite 2-subgroup whose centralizer is finite, then G is locally finite. We also show that, if G has no 2-torsion, and Q is a finite 2-group acting on G in such a way that the centralizer CG(Q) is soluble, or of finite exponent, then G is locally finite.
Permanent Magnet Machines for Traction Applications

This chapter overviews various permanent magnet (PM) brushless machines for traction applications. PM brushless DC and AC machines and drives are firstly compared in terms of constant torque and constant power capabilities, and their controllability. Various stator winding configurations, rotor topologies, and basic and novel machine topologies, including fractional slot PM, stator PM, and variable flux PM machines, as well as their features are highlighted. Then, alternate methods for enhancing the PM excitation torque and reluctance torque components, and thereby improving the torque and power capability, are described, together with methods for reducing the torque ripples and improving the overload, flux weakening, fault-tolerant, and demagnetization withstand capabilities. Keywords: axial field; brushless AC ; brushless dc; constant torque; flux weakening; fractional slot; interior permanent magnet; permanent magnet; radial-field; variable flux
A Novel Algorithm for Action Landmarks Extraction

In this work, we present a new algorithm for extracting action landmarks from proposition landmarks graph. Compared to published approaches, the action landmarks extraction algorithm we proposed can find more disjunctive action landmarks and single action landmarks. We illustrate our ideas with experiments among benchmark domains. The experiments show that the new algorithm is competitive with traditional algorithm for finding action landmarks from relaxed plan graph.
Music cognition and Williams Syndrome

New studies of the musical abilities of individuals with Williams Syndrome (WMS) are presented. WMS is associated with poor spatial, quantitative, and reasoning abilities, coupled with excellent face processing and relatively preserved language abilities. WMS individuals tend to have richer (larger and more colorful) vocabularies than would be expected for their mental age and tend to be more emotionally expressive than normals. There have long been anecdotal reports of increased musicality in WMS (many of them are competent musicians who play from memory) and these are supported by the finding that the planum temporale (PT, a region adjacent to A1) is proportionately enlarged in WMS; in addition, the PT is unusually asymmetric in WMS, with the left side enlarged in a similar fashion to that found in professional musicians. The authors report new studies of rhythm production and memory for music in WMS. The results suggest that this domain of cognitive ability may also be relatively preserved. These findings provide additional evidence that music constitutes a domain‐specific higher‐level system of expertise in humans, perhaps independent of other mental abilities.
Plasma waves in the distant geomagnetic tail: ISEE 3

The plasma wave measurements obtained during ISEE 3's deep passes through the geomagnetic tail found that moderate to intense electric field turbulence occurred in association with the major plasma and magnetic field regions and flow phenomena. In the magnetopause boundary layer the electric field spectral amplitudes are typically sharply peaked at 316 Hz to 562 Hz. The tail lobe region which is upstream of slow shocks and is magnetically connected to the plasma sheet is characterized by wave spectra that peak in the 100- to 316-Hz range and at the electron plasma frequency. Within the plasma sheet, broadband electrostatic noise occurs in regions where the magnetic field strength exceeds 2 nT; this noise can also be found in the plasma sheet boundary layer in association with strong field-aligned plasma flows. As ISEE 3 moved between the different distant tail regions, distinct but often subtle changes occurred in the plasma wave spectra. Occasionally, plasma oscillations indicate that the distant tail contains a population of relatively dense cold electrons.
Concrete Penetration by Eroding Projectiles: Experiments and Analysis.

Abstract : Spherical-nose copper and tantalum rods with aspect ratios between 4.0 and 14.6 were gun launched against 91-cm dia and 91-cm long concrete and simulant reinforced concrete targets with velocities ranging from 0.15 cmlps to 0.19 cm1%s. Targets were instrumented with a sequence of break gages which provided valuable data for characterizing the penetration process. Target hole profiles and projectile residual masses were measured and reported. Analysis of the penetration performance of projectiles was performed within the framework of the modified hydrodynamic theory of penetration. Based on the results of these calculations, the penetration efficiencies of the copper and the tantalum projectiles are compared as functions of impact velocities. Analysis of the penetration resistance of the simulant reinforced concrete targets was based on treating the targets as composites", comprised of layers of concrete proper and reinforcing steel; the results of these calculations are compared with the experimental data. Using this theory, the penetration resistance of a concrete/steel/concrete composite" is investigated as a function of the following parameters: thickness of the surface layer of the concrete, thickness of the steel reinforcement, and impact velocity.
An enhanced ensemble‐based method for computing CNOPs using an efficient localization implementation scheme and a two‐step optimization strategy: formulation and preliminary tests

The ensemble‐based methods for computing conditional nonlinear optimal perturbations (CNOPs) often contain a localization implementation scheme; its computer implementation is very expensive because of huge memory usage or costly repeated calculations. As a result, the lack of efficient algorithms limits the applications of CNOP. To address this issue, an efficient new localization implementation scheme is proposed in this article. The main ideas are to utilize the correlation matrix and to approximate it by a set of selected Gaussian random samples. An enhanced ensemble‐based method is then proposed using the new localization scheme and a newly proposed two‐step optimization strategy. The proposed approach results in a significant speed‐up for overall optimization algorithms for computing the CNOPs and can be applied to complicated nonlinear models. Numerical experiments with a nonlinear model of the viscous Burgers equation show that the proposed new method produces comparable solutions against an existing ensemble‐based method and an adjoint‐based one for computing the CNOPs. In terms of the net growth ratio of norm square, the proposed method slightly outperforms these two existing methods. On the other hand, our numerical experiments show that the proposed method has an advantage on the memory usage and computational cost, which particularly demonstrates its high potential in predictability or sensitivity studies of operational prediction models. Another group of assimilation experiments conducted using the T21L3 quasi‐geostrophic (QG) model further demonstrates its potential for broader applications.
Search for new physics using a precision measurement of the Ke2/Kμ2 branching ratio

A new experiment at J-PARC proposes to test lepton universality and search for new physics beyond the Standard Model (SM) by measuring the ratio, RK = Γ(K+→e+νe)/Γ(K+→μ+νμ) with an accuracy of 0.25%. Experiment E36 will use a stopped K+ beam, a 12-sector iron-core superconducting toroidal magnet, and a 768 element CsI(Tl) calorimeter which will provide completely different systematics than the existing in-flight CERN NA62 and KLOE experiments.
ON THE STOCHASTIC DEPENDENCE STRUCTURE OF THE LIMIT LOGNORMAL PROCESS

The distribution of a single increment of the limit lognormal process of Mandelbrot, several representations of its Mellin transform, and an explicit analytic continuation of the Selberg integral are reviewed. The intermittency invariance of the limit lognormal construction is used to establish a functional Feynman–Kac equation that captures the entire stochastic dependence structure of the limit process. This equation is a general rule of intermittency differentiation that quantifies how the joint distribution of an arbitrary number of increments of the limit process evolves as a function of intermittency. The solution is represented by means of a formal intermittency expansion and shown to be an exactly renormalized expansion in the joint centered moments of the limit process. The expansion coefficients are related to a novel extension of the Selberg integral.
Vibration Control of a Flexible Structure Using ER Dampers

This technical brief addresses the vibration control of a flexible beau structure using ER ( electro-rheological) dampers. A clamped-clamped flexible beam system supported by two short columns is considered. An ER damper which is operated in shear mode is designed on the basis of Bingham model of the ER fluid, and attached to the flexible beam. After deriving the governing equation of motion and associated boundary conditions, a sliding mode controller is formulated to effectively suppress the vibration of the beam caused by external forces. In the formulation of the controller, parameter variations such as frequency deviation are treated to take into account the robustness of control system. The effectiveness of the proposed control system is confirmed by both simulation and experimental results.
Performance of 2 nm gate length carbon nanotube field-effect transistors with source∕drain underlaps

The performance of coaxially gated, zero-Schottky-barrier, carbon nanotube field-effect transistors is investigated for gate lengths down to 2 nm with source and drain underlaps. Such devices can have nearly ideal subthreshold slopes of ∼63mV∕dec and maximum on∕off current ratios of 2.2×106 assuming 0.0–0.4 volt swing. The leakage mechanism is a combination of both intra-band and inter-band tunneling. For a 30 nm long carbon nanotube (CNT) with a 2 nm gate, Cg=3.13aF, the intrinsic switching time, τs=CgVDD∕ION, is 370 fs, and the intrinsic cut-off frequency defined by fT=gm∕(2πCg) is 1.6 THz. The ambipolar leakage current is suppressed by Coulomb blockade. Calculations are performed using a π-bond model and a self-consistent solution of the nonequilibrium Green function equations and Poisson’s equation.
The Effect of Pressure on the Tensile Properties of Several Metals and Other Materials

Tension tests to fracture under superposed hydrostatic pressure reaching to nearly 30 000 kg/cm2 have been conducted on five polycrystalline metals, Ni, Ta, Cb, Mo, and W, two brittle single metallic crystals, Sb and Cu5Zn8, and two brittle amorphous materials, ``Melmac 404'' and B2O3 glass. All these materials exhibit ductility at the highest pressure; the largest increases are for the polycrystalline metals of which the largest is W, which breaks brittely at atmospheric pressure but with 81 percent reduction of area at the highest pressure. The shape of the strain hardening curves varies among the five metals from abrupt rise with long tailing off to long gradual rise with comparatively abrupt falling off, in the order W, Mo, Ta, Cb, and Ni. The character of the fracture varies continuously with pressure and is different for the different metals. Of the brittle single crystals Sb has a reduction of area of 55 percent at the highest pressure. The plastic, Melmac 404, gives the smallest increase of ductil.