Miracle-dz/UniFAR-FTUs huggingface dataset:
Preload loss of CFRP bolted joint without rotation under transverse and axial loading

There are a large number of CFRP-steel bolted joints with jet nuts subjected to transverse and axial load in aircraft structures, which have passed standard testing of locking characteristics of fasteners under transverse loading conditions. This fastener has a great preload loss and no rotation loosening occurs. Based on the observation, we designed a biaxial loading experiment for CFRP bolted joint, and measured the preload and loosening angle under different initial preload. The biaxial research suggests that compared with the uniaxial loading condition, the preload loss is larger, the rotation is minimal and only appears in the early stage of test, and there are obvious indentations on the surface of CFRP panel. Embedment as an important factor leads to the preload loss due to the weak ability of CFRP panel suffering out of plane load. In order to study the effect of embedment, the relationship between stress S22 and indentation depth under different preload, the relationship between biaxial load amplitude and embedding depth, and the ratio of the preload loss caused by embedding to the total preload loss are revealed by finite element analysis.
Large-Eddy Simulation of a Round Jet in Crossflow

A numerical simulation of a round turbulent jet issuing perpendicularly into a laminar M = 0.2 boundary-layer crossflow is performed at a jet-to-crossflow momentum ratio of 3.3 and a jet Reynolds number of 6930. The mixing behavior of the jet in crossflow is investigated by computing the evolution of a passive scalar. The spatial discretization of the computational domain consists of a block-structured multiblock grid with 58 blocks and a total of 8.9 million cells. The NSMB (Navier-Stokes Multiblock) simulation code uses a finite-volume discretization with a skew-symmetric fourth-order central scheme and a four-stage Runge-Kutta method for time integration. To account for the subgrid scales, the approximate-deconvolution model is employed in a multiblock formulation. Of special interest is the mixing behavior of the jet with the crossflow connected with the complex vortex systems in the mixing region. Results are compared with incompressible large-eddy simulation data and experimental measurements at similar flow parameters. Significant findings comprise the study of the jet development along its trajectory, as well as the upstream influence of the crossflow into the nozzle. Furthermore, the three-dimensional temporal oscillation of the ejected jet body is investigated and an attempt is made to correlate it to the formation of vortices in the mixing region.
Acoustic correlates of consonant gesture timing in English

There is extensive research on the organization of syllable-structure as indexed by the relative timing of the articulators (Browman and Goldstein, 1988; Byrd, 1995; Shaw et al., 2011 inter alia). The research suggests consonants in complex onsets (in words such as scream, stream…) are aligned to a single position called the C-center, the mean of the midpoints of the onset consonants. However, such research typically uses very expensive articulatory equipment (X-ray Microbeam, Electromagnetic Articulography…). This restricts the research to a few laboratories across the world with access to such technology. Here, we explore the possibility of using acoustic measurements, which are cheaper and more accessible, for such research. We conducted an experiment on 6 native speakers of English, who produced 12 repetitions of 24 English words (12 test, 12 filler) that varied in the number of onset consonants (C1, C1C2, C1C2C3) in three different vowel contexts. Paralleling previous studies, the results show that o.
NON-RELATIVISTIC ELECTROMAGNETIC SCATTERING: "REVERSE ENGINEERING" USING THE LORENTZ FORCE FORMULAS - Abstract

For almost a century, velocity dependent scattering problems are solved in the context of Einstein's Special Relativity theory. Most interesting problems involve non-uniform motion, which is heuristically justified by assuming the validity of the "instantaneous velocity" approximation. The present study attempts to provide a consistent postulational foundation by introducing boundary conditions based on the Lorentz force formulas. The methodology used here is dubbed "reverse engineering": Being aware of the relativistic results, we show that they are replicated, (at least) to the first order in β = v/c by the present method. Specific problems are discussed to demonstrate the power of the method, and pave the way to future research in this problem area. Specifically, by realizing that at the boundary we deal with signals, which are derived from waves, only the latter being subject to the wave equations, it is feasible to apply boundary conditions and construct appropriately the scattered waves in space. It is shown that the present approach is also consistent with the Minkowski constitutive relations which are exploited for solving problems where the medium moves parallel with respect to the boundaries.
Evolution of calling songs in the grasshopper subfamily Gomphocerinae (Orthoptera, Acrididae)

The evolution of the calling songs in Gomphocerinae was evaluated via estimating a phylogenetic signal of the song characters and an ancestral character state reconstruction. Analyses of the calling songs in 80 palearctic gomphocerine species allowed us to define 24 characters describing the temporal pattern of the sound and the stridulatory leg‐movement pattern. The ancestral song of Gomphocerinae was shown to consist of numerous short echemes lasting on average 0.9 s; each echeme comprised only one syllable produced by movements of only one leg. The next step of the song evolution could be producing longer echemes or longer echeme‐sequence. Later, echeme duration again decreased, but this was accompanied by increasing of echeme or syllable complexity. The characters describing the echeme structure were found to be conservative in their evolution. By contrast, most characters of the syllable temporal structure were shown to be relatively labile and more likely under natural or sexual selection. Our study shows that the song evolution in Gomphocerinae implied not only increasing but also decreasing complexity of the syllable temporal structure.
Trap state spectroscopy studies and wettability modification of hydroxyapatite nanobioceramics

Sintered hydroxyapatite coatings on titanium-based implants demonstrate beneficial biocompatibility and osteoconductivity. It has been shown that charged surface states and bulk traps located in the vicinity of the surface of the hydroxyapatite coatings strongly influence wettability properties of the hydroxyapatite and may modify biocompatibility of these nanostructured bioceramics. Combination of high-resolution electron state spectroscopy methods, thermostimulated exoelectron emission, and thermoluminescence methods, applied in this work, have allowed studying electron trap energy spectrum of the hydroxyapatite bioceramics.
Global Determinants of Education Reform, 1960 to 2017

Since post-World War II and especially throughout the 1990s, the globalization of a liberal international order propelled a wave of education reforms around the world. However, recent challenges to the legitimacy of the liberal order may undercut the prevalence of education reform across countries. To reveal how global changes are influencing education, we draw on a newly constructed data set of 6,696 education reforms in 147 countries from 1960 to 2017. Using dynamic negative binomial panel regression models, we find declining levels of reform in recent decades. We also find evidence of changing dynamics of influence among prominent organizational actors: World Bank lending is less associated with education reform over time, whereas the influence of international nongovernmental organizations has grown. This suggests a shifting system of governance, where formal coercive pressures become less palatable and the normative influences of civil society grow stronger. Overall, our findings indicate that education reform arises as a macro-global process as much as a response to local needs and conditions.
Convolutional Transformer-Based Few-Shot Learning for Cross-Domain Hyperspectral Image Classification

In cross-domain hyperspectral image (HSI) classification, the labeled samples of the target domain are very limited, and it is a worthy attention to obtain sufficient class information from the source domain to categorize the target domain classes (both the same and new unseen classes). This article investigates this problem by employing few-shot learning (FSL) in a meta-learning paradigm. However, most existing cross-domain FSL methods extract statistical features based on convolutional neural networks (CNNs), which typically only consider the local spatial information among features, while ignoring the global information. To make up for these shortcomings, this article proposes novel convolutional transformer-based few-shot learning (CTFSL). Specifically, FSL is first performed in the classes of source and target domains simultaneously to build the consistent scenario. Then, a domain aligner is set up to map the source and target domains to the same dimensions. In addition, a convolutional transformer (CT) network is utilized to extract local-global features. Finally, a domain discriminator is executed subsequently that can not only reduce domain shift but also distinguish from which domain a feature originates. Experiments on three widely used hyperspectral image datasets indicate that the proposed CTFSL method is superior to the state-of-the-art cross-domain FSL methods and several typical HSI classification methods in terms of classification accuracy.
Optical and Near-Infrared Calibration of AGN Field Stars: An All-Sky Network of Faint Stars Calibrated on the Landolt System

We present a total of 12,436 photometric measures of 371 field stars of 26 quasars in the visible (UBVRI) and 22,276 photometric measures of 122 field stars of 13 quasars in the near-infrared (JHK), giving a total of 34,712 measures. Of these, 115 stars in 12 fields are calibrated in both ranges. One further field, Mrk 421, was calibrated, but on close examination all sources were found to be probably nonstellar; thus these results are not included here. The stars observed cover the range from V = 11 to V = 20 and from K = 9 to K = 17 and are well distributed around the sky north of declination -30°. This represents the initial sample of an extensive catalog of calibrated fields that will cover the northern sky down to declination -30° and that will cover a wide range of Galactic latitudes. These fields will be useful both for photometry of AGNs in the range from B to K and also as faint calibration standards for large telescopes. The median absolute total error on the photometry, including all known error sources, ranges from 0.008 mag in J to 0.034 mag in B. These errors will be greatly reduced with the addition of further data in the future, although the final precision is fundamentally limited by the photometric errors in the existing lists of calibration stars used to calibrate these data.
A Non-oscillatory Eulerian Approach to Interfaces in Multimaterial Flows (the Ghost Fluid Method)

While Eulerian schemes work well for most gas flows, they have been shown to admit nonphysical oscillations near some material interfaces. In contrast, Lagrangian schemes work well at multimaterial interfaces, but suffer from their own difficulties in problems with large deformations and vorticity characteristic of most gas flows. We believe that the most robust schemes will combine the best properties of Eulerian and Lagrangian schemes. In this paper, we propose a new numerical method for treating interfaces in Eulerian schemes that maintains a Heaviside profile of the density with no numerical smearing along the lines of earlier work and most Lagrangian schemes. We use a level set function to track the motion of a multimaterial interface in an Eulerian framework. In addition, the use of ghost cells (actually ghost nodes in our finite difference framework) and a new isobaric fix technique allows us to keep the density profile from smearing out, while still keeping the scheme robust and easy to program with simple extensions to multidimensions and multilevel time integration, e.g., Runge? Kutta methods. In contrast, previous methods used ill-advised dimensional splitting for multidimensional problems and suffered from great complexity when used in conjunction with multilevel time integrators.
Optical and electrical simulations of two-junction III-V nanowires on Si solar cell

A coupled optoelectronic simulation was used to theoretically assess the performance of core-shell GaInP nanowires array (NWA)/Si thin-film two-junction solar cell. Outstanding light harvesting rooted from the strong light trapping and the formation of Fabry-Perot optical cavity in the NWA enables the cell to produce high photocurrent. From the detailed balance calculation, above 32% of efficiency could be obtained at the current matching geometries. Coupled optoelectronic simulation shows that current matching can be easily achieved even under relatively high recombination rate. A promising efficiency of 27.1% is obtained for the proposed cell with appropriate nanowires surface passivation.
Antiparasitic Activities of Compounds Isolated from Aspergillus fumigatus Strain Discovered in Northcentral Nigeria

In this study, we explored a fungal strain UIAU-3F identified as Aspergillus fumigatus isolated from soil samples collected from the River Oyun in Kwara State, Nigeria. In order to explore its chemical diversity, the fungal strain UIAU-3F was cultured in three different fermentation media, which resulted in different chemical profiles, evidenced by LC-ESI-MS-based metabolomics and multivariate analysis. The methanolic extract afforded two known compounds, fumitremorgin C (1) and pseurotin D (2). The in vitro antiparasitic assays of 1 against Trypanosoma cruzi and Plasmodium falciparum showed moderate activity with IC50 values of 9.6 µM and 2.3 µM, respectively, while 2 displayed IC50 values > 50 µM. Molecular docking analysis was performed on major protein targets to better understand the potential mechanism of the antitrypanosomal and antiplasmodial activities of the two known compounds.
Twisted plane wave expansions using hypercomplex methods

The purpose of this paper is to derive various representations of the Dirac delta distribution, including a Bony-type twisted Radon decomposition, from boundary values of monogenic functions. This leads to a new and simpler approach based on the properties of the analogue of the Cauchy kernel in the context of monogenic functions.
Numerical study of instability mechanism in the air-core vortex formation process

Air-core vortices are a ubiquitous phenomenon in the intakes of hydropower stations. Due to the transient and instability of two-phase vorticial flow, the prediction of air-core vortex formation is challenging, and understanding of the instability mechanism remains elusive. In this study, the large eddy simulation (LES) method and a coupled level-set and volume-of-fluid (CLSVOF) method are performed to study air-core vortex formation in a benchmark reservoir with a horizontal intake pipe. The process of air-core vortex formation can be classified into an inception stage, an instability stage, and a stability stage. In the instability stage, the surface vortex repeatedly goes through the process of inception, enhancement, attenuation, and extinction. The movement of the counterrotating secondary vortices and water surface level fluctuation plays a negative role in air-core vortex formation. The additional motion generated by the counterrotating pair drives the pair to the back wall. The main vortex undergoes attenuation due to the stretching/tilting effects induced by the secondary vortex. Water level fluctuations briefly increase the submergence depth, which in turn reduces the vertical velocity gradient and vertical vorticity, destabilizing the vortex. The perturbation of the air-core vortex by water level fluctuations is present only at the beginning of the instability stage.
Inter-subject Registration-based Segmentation of Thoracic-Abdominal Organs in 4 Dimensional Magnetic Resonance Imaging

4 Dimensional Magnetic Resonance Imaging (4D MRI) is currently gaining attention as an imaging modality which is able to capture inter-cycle variability of respiratory motion. Such information is beneficial for example in radiotherapy planning and delivery. In the latter case, there may be a need for organ segmentation, however 4D MRI are of low contrast, which complicates automated organ segmentation. This paper proposes a multi-subject thoracic-abdominal organ segmentation propagation scheme for 4D MRI. The proposed scheme is registration based, hence different combinations of deformation and similarity measures are used. For deformation we used either just an affine transformation or additionally free form deformation on top of an affine transform. For similarity measure, either the sum of squared intensity differences or normalised mutual information is used. Segmentations from multiple subjects are registered to a target MRI and the average segmentation is found. The result of the method is compared with the ground truth which is generated from a semi-automated segmentation method. The results are quantified using the Jaccard index and Hausdorff distance. The results show that using free form deformation with a sum of squared intensity differences similarity measure produces an acceptable segmentation of the organs with an overall Jaccard index of over 0.5. Hence, the proposed scheme can be used as a basis for automated organ segmentation in 4D MRI.
Interplay of chemical expansion, Yb valence, and low temperature thermoelectricity in the YbCu2Si2−xGex solid solution

YbCu2Si2 is a promising low temperature thermoelectric material because of the large broad peak in the Seebeck coefficient near 100 K combined with a low electrical resistivity. This behavior is thought to arise from fluctuating, or intermediate, valence effects due to partial occupation of Yb 4f energy states near the Fermi level. Previous studies of the magnetic properties under pressure have demonstrated that the average Yb valence is sensitive to the contraction of unit cell volume. By forming a solid solution of YbCu2Si2 with YbCu2Ge2, an isostructural compound with a larger unit cell volume, here we examine the subtle effects of lattice expansion on the transport properties and average Yb valence. We observe a shift in the peak of the Seebeck coefficient towards higher temperatures, as well as an enhanced power factor in the solid solutions. At the same time, a reduction in thermal conductivity due to alloy scattering enhances the thermoelectric figure of merit. Chemical pressure effects may thus be.
Bayesian design and analysis of computer experiments: Use of derivatives in surface prediction

This article is concerned with the problem of predicting a deterministic response function yo over a multidimensional domain T, given values of yo and all of its first derivatives at a set of design sites (points) in T. The intended application is to computer experiments in which yo is an output from a computer model of a physical system and each point in T represents a particular configuration of the input parameters. It is assumed that the first derivatives are already available (e.g., from a sensitivity analysis) or can be produced by the code that implements the model. A Bayesian approach in which the random function that represents prior uncertainty about yo is taken to be a stationary Gaussian stochastic process is used. The calculations needed to update the prior given observations of yo and its first derivatives at the design sites are given and are illustrated in a small example. The issue of experimental design is also discussed, in particular the criterion of maximizing the reduction in entropy.
Precise integration methods based on Lagrange piecewise interpolation polynomials

This paper introduces two new types of precise integration methods for dynamic response analysis of structures, namely, the integral formula method and the homogenized initial system method. The applied loading vectors in the two algorithms are simulated by the Lagrange piecewise interpolation polynomials based on the zeros of the first Chebyshev polynomial. Developed on the basis of the integral formula and the Lagrange piecewise interpolation polynomial and combined with the recurrence relationship of some key parameters in the integral computation suggested in this paper with the solving process of linear algebraic equations, the integral formula method has been set up. On the basis of the Lagrange piecewise interpolation polynomial, and transforming the non‐homogenous initial system into the homogeneous dynamic system, the homogenized initial system method without dimensional expanding is presented; this homogenized initial system method avoids the matrix inversion operation and is a general homogenized high‐precision direct integration scheme. The accuracy of the presented time integration schemes is studied and is compared with those of other commonly used schemes; the presented time integration schemes have arbitrary order of accuracy, wider application and are less time consuming. Two numerical examples are also presented to demonstrate the applicability of these new methods. Copyright © 2008 John Wiley & Sons, Ltd.
Two-stream instabilities in electron-positron-ion plasmas

Two-stream instabilities in electron–positron–ion plasmas are studied. The relative motion of the ions with respect to the electron–positron plasma and of the positrons with respect to the electron–ion plasma can give rise to such instabilities. The growth rates depend upon the percentage concentration of different species. A comparison of this work with the two stream instabilities studied previously in pure electron–positron and electron–ion plasmas is also made. The relevance of the present investigation to astrophysical and laboratory plasmas is pointed out.
3D biodistribution of pre-treated MSC in mouse model of liver disease using CryoViz™

‘MERLIN’ (Mesenchymal stem cells to reduce liver inflammation) is an EU FP7-funded project in which BioInVision, Inc. (Cleveland, OH, USA) is partnering with EU establishments that are developing MSC cellular therapy for primary sclerosing cholangitis (PSC), a type of liver disease. MSC have low immunogenicity and possess promising immune modulatory and regulatory capabilities, making them suitable candidates for treating PSC. In MERLIN project, BioInVision’s CryoViz™ cryo-imaging system is being used to study MSC survival under various pre-treatments in a CCL4 liver injury whole mouse model. CryoViz™ consists of a fully automated system for sectioning and tiled microscopic imaging of tissues, providing anatomical brightfield and molecular fluorescence with single cell sensitivity. Umbilical cord-derived MSC (UCMSC) were pre-treated for three days in the presence of pro-/anti-inflammatory cytokines, vitamins and serum-deprivation after which assays were performed to examine their immunogenicity, phenotype, and susceptibility to NK lysis. Subsequently, whole mice intravenously injected with the different pre-treated MSC [no treatment, IFNγ, IFNβ, TGFβ, Starvation, VitB6, (Starvation+VitB6), RA] were frozen and cryo-imaged. Global biodistribution results from CryoViz™ indicate that pretreatment had an effect on cell survival. Localized biodistribution showed preferential distribution in some organs such as the lung and the liver. The cryo-imaging study has revealed that MSC could be optimized to become less immunogenic and more immunomodulatory, which is an important step towards further development of MSC for cellular therapy.