pinecone/core-2020-05-10-deduplication huggingface dataset:
Scaling of the coercivity with the geometrical parameters in epitaxial Fe antidot arrays

We studied a series of square lattice antidot arrays, with diameter and lattice parameter from hundreds of nanometers to some microns, fabricated using two lithography techniques in epitaxial Fe(001) ﬁlms. The coercivity increase of each array with respect to its base ﬁlm can be scaled to a simple geometric parameter, irrespective of the lithography technique employed. Magnetic transmission x-ray microscopy studies, in arrays fabricated on polycrystalline Fe ﬁlms deposited on silicon nitride membranes, evidenced the propagation of reversed domains from the edges of the arrays, in agreement with the coercivity analysis of the epitaxial arrays and with micromagnetic models
Flux-weakening operation of open-end winding drive integrating a cost effective high-power charger

In this paper, a three-phase drive with a six-leg Voltage Source Inverter (VSI) and an  open-end winding Interior Permanent Magnet Synchronous Machine (IPMSM) designed for the traction of an electric vehicle is studied in flux-weakening operation. The topology allows the functionality of a high power charger to be obtained, without adding any other supplementary power devices. On the other hand, since there are three independent currents, the control structure has to handle not only the two dq current components but also a zero-sequence current. If neglected, in comparison with wye-coupled three-phase drive, this zero-sequence component can cause a higher maximum peak value of the phase currents, additional stator Joule losses, torque ripple, inverter voltage saturation and IGBT oversizing. The proposed control strategy consists in adapting a conventional method used for wye-connected machines particularly in flux-weakening operation. This strategy allows the closed-loop control of the zero-sequence current to be maintained in the whole speed range and therefore inverter saturation is avoided. Simulations and experimental results are presented and analyzed.FUI SOFRAC
Multi-production of high added market value metabolites from diluted methane emissions via methanotrophic extremophiles

Producción CientíficaThis study constitutes the first-proof-of-concept of a methane biorefinery based on the multi-production of high profit margin substances (ectoine, hydroxyectoine, polyhydroxyalkanoates (PHAs) and exopolysaccharides (EPS)) using methane as the sole carbon and energy source. Two bubble column bioreactors were operated under different magnesium concentrations (0.2, 0.02 and 0.002 g L−1) to validate and optimize this innovative strategy for valorization of CH4 emissions. High Mg2+ concentrations promoted the accumulation of ectoine (79.7–94.2 mg g biomass−1), together with high hydroxyectoine yields (up to 13 mg g biomass−1) and EPS concentrations (up to 2.6 g L culture broth−1). Unfortunately, PHA synthesis was almost negligible (14.3 mg L−1) and only found at the lowest Mg2+ concentration tested. Halomonas, Marinobacter, Methylophaga and Methylomicrobium, previously described as ectoine producers, were dominant in both bioreactors, Methylomicrobium being the only described methanotroph. This study encourages further research on CH4 biorefineries capable of creating value out of GHG mitigation.Ministerio de Economía, Industria y Competitividad (Project CTM2015-70442-RNOVEDAR)Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. E-47-2014-0140696UIC71
Neuropharmacological evaluation of the putative anxiolytic effects of Passiflora edulis Sims, its sub-fractions and flavonoid constituents

Passiflora edulis Sims together with several other plants of the genus Passiflora have been reported to possess anxiolytic properties. It has been suggested recently that flavonoids may be partly responsible for the neuropharmacological activity of these plants but there are still few data reporting the relation between the constituents of these plants and their activity. This work evaluated the anxiolytic/sedative activity of an aqueous extract of Passiflora edulis Sims and bioguided its fractionation using the elevated plus-maze model of anxiety and other complementary pharmacological tests. The aqueous extract presented an anxiolytic-like activity without any significant effect upon the motor activity whilst the total flavonoid fraction (TFF) presented an anxiolytic-like activity but compromised motor activity. Through fractionation of TFF it was possible to isolate and characterize luteolin-7-O-[2-rhamnosylglucoside] which showed an anxiolytic-like activity without compromising motor activity. Copyright © 2006 John Wiley & Sons, Ltd.http://dx.doi.org/10.1002/ptr.199
Population database of STRs in West Africa: a genetic study of TPOX, HUMVWA31/A, HUMTH01, and CYP19

Abstract  Four tetrameric STRs (TPOX, HUMVWA31/A, HUMTH01, and CYP19) were analysed in a West African population (Cabo Verde). No significant deviations from Hardy–Weinberg proportions were observed, either in conventional or exact tests. Pairwise comparisons confirmed allelic independence for all the combinations of loci. Data is provided for the first time about CYP19 in Black populations. In comparisons between African and Afro-American populations, significant frequency differences for several alleles at the TH01 and VWA31/A loci were observed. The allele frequencies provided in this study contribute to a better knowledge of the variability of these markers among the main human groups, especially in the context of Subsaharan African populations.http://dx.doi.org/10.1023/A:100343422115
Pregnancy and its role in breast cancer

Abstract  Early full-term pregnancy is the only recognized factor able to prevent breast cancer. There are several hypotheses to explain the mechanisms of this protection, namely an altered hormonal milieu, a differentiation process or a switch in stem cell properties. To explore them, authors have been using animal models, mainly in rodents. Hormonal administration with estrogen and progesterone was the most widely used process to mimic the mammary changes during pregnancy. We have recently proposed that this enigmatic protective role of a full-term birth in breast cancer is carried out by tumor inhibition mediated by differentiated mammary epithelial cells. This explanation may give a new perspective of breast cancer prevention and treatment.http://dx.doi.org/10.1007/s12156-008-0069-
Multicriteria Approach to Bilevel Optimization

Abstract  In this paper, we study the relationship between bilevel optimization and multicriteria optimization. Given a bilevel optimization problem, we introduce an order relation such that the optimal solutions of the bilevel problem are the nondominated points with respect to the order relation. In the case where the lower-level problem of the bilevel optimization problem is convex and continuously differentiable in the lower-level variables, this order relation is equivalent to a second, more tractable order relation.  Then, we show how to construct a (nonconvex) cone for which we can prove that the nondominated points with respect to the order relation induced by the cone are also nondominated points with respect to any of the two order relations mentioned before. We comment also on the practical and computational implications of our approach.http://dx.doi.org/10.1007/s10957-006-9136-
Landau-Lifshitz sigma-models, fermions and the AdS/CFT correspondence

We define Landau-Lifshitz sigma models on general coset space $G/H$, with $H$
a maximal stability sub-group of $G$. These are non-relativistic models that
have $G$-valued N\"other charges, local $H$ invariance and are classically
integrable. Using this definition, we construct the $PSU(2,2|4)/PS(U(2|2)^2)$
Landau-Lifshitz sigma-model. This sigma model describes the thermodynamic limit
of the spin-chain Hamiltonian obtained from the complete one-loop dilatation
operator of the N=4 super Yang-Mills (SYM) theory. In the second part of the
paper, we identify a number of consistent truncations of the Type IIB
Green-Schwarz action on $AdS_5\times S^5$ whose field content consists of two
real bosons and 4,8 or 16 real fermions. We show that $\kappa$-symmetry acts
trivially in these sub-sectors. In the context of the large spin limit of the
AdS/CFT correspondence, we map the Lagrangians of these sub-sectors to
corresponding truncations of the $PSU(2,2|4)/PS(U(2|2)^2)$ Landau-Lifshitz
sigma-model.Comment: 42 page
Abnormal magnetic behaviour of powder metallurgy austenitic stainless steels sintered in nitrogen

The magnetic response of AISI 304L and AISI 316L obtained through powder metallurgy and sintered in nitrogen were studied. AISI 304L sintered in nitrogen showed a ferromagnetic behaviour in as-sintered state while AISI 316L was paramagnetic. After solution annealing both were paramagnetic. Magnetic behaviour was analysed by using a vibrating sample magnetometer, a magnetic ferritscope and magnetic etching. A microstructural characterization was performed by means of optical metallography, X-ray diffraction, scanning electron microscopy (SEM) and energy dispersive analysis of X-rays (EDS). Some samples when needed were submitted to aged heat treatments at 675 and 875 °C for 90 min, 4, 6, 8 or 48 h. The main microstructural feature found was the presence of a lamellar constituent formed by nitride precipitates and an interlamellar matrix of austenite and/or ferrite. The abnormal magnetic response was explained based on this.Dirección General de Programas y Transferencia de Conocimiento, Ministerio de Ciencia e Innovación, España,  MAT2008-0278
Brief Announcement: Node Sampling Using Centrifugal Random Walks.

We propose distributed algorithms for sampling networks based on a new class of random walks that we call Centrifugal Random Walks (CRW). A CRW is a random walk that starts at a source and always moves away from it. We propose CRW algorithms for connected networks with arbitrary probability distributions, and for grids and networks with regular concentric connectivity with distance based distributions. All CRW sampling algorithms select a node with the exact probability distribution, do not need warm-up, and end in a number of hops bounded by the network diameter
Explaining the behavior of joint and marginal Monte Carlo estimators in latent variable models with independence assumptions

In latent variable models parameter estimation can be implemented by using the joint or the marginal likelihood, based on independence or conditional independence assumptions. The same dilemma occurs within the Bayesian framework with respect to the estimation of the Bayesian marginal (or integrated) likelihood, which is the main tool for model comparison and averaging. In most cases, the Bayesian marginal likelihood is a high dimensional integral that cannot be computed analytically and a plethora of methods based on Monte Carlo integration (MCI) are used for its estimation. In this work, it is shown that the joint MCI approach makes subtle use of the properties of the adopted model, leading to increased error and bias in finite settings. The sources and the components of the error associated with estimators under the two approaches are identified here and provided in exact forms. Additionally, the effect of the sample covariation on the Monte Carlo estimators is examined. In particular, even under independence assumptions the sample covariance will be close to (but not exactly) zero which surprisingly has a severe effect on the estimated values and their variability. To address this problem, an index of the sample's divergence from independence is introduced as a multivariate extension of covariance. The implications addressed here are important in the majority of practical problems appearing in Bayesian inference of multi-parameter models with analogous structures
Strings in gravity with torsion

A theory of gravitation in 4D is presented with strings used in the material
action in $U_4$ spacetime. It is shown that the string naturally gives rise to
torsion. It is also shown that the equation of motion a string follows from the
Bianchi identity, gives the identical result as the Noether conservation laws,
and follows a geodesic only in the lowest order approximation. In addition, the
conservation laws show that strings naturally have spin, which arises not from
their motion but from their one dimensional structure.Comment: 16 page
Linear and quadratic static response functions and structure functions
  in Yukawa liquids

We compute linear and quadratic static density response functions of
three-dimensional Yukawa liquids by applying an external perturbation potential
in molecular dynamics simulations. The response functions are also obtained
from the equilibrium fluctuations (static structure factors) in the system via
the fluctuation-dissipation theorems. The good agreement of the quadratic
response functions, obtained in the two different ways confirms the quadratic
fluctuation-dissipation theorem. We also find that the three-point structure
function may be factorizable into two-point structure functions, leading to a
cluster representation of the equilibrium triplet correlation function
Color kinematic symmetric (BCJ) numerators in a light-like gauge

Color-ordered tree level scattering amplitudes in Yang-Mills theories can be
written as a sum over terms which display the various propagator poles of
Feynman diagrams. The numerators in these expressions which are obtained by
straightforward application of Feynman rules are not satisfying any particular
relations, typically. However, by reshuffling terms, it is known that one can
arrive at a set of numerators which satisfy the same Jacobi identity as the
corresponding color factors. By extending previous work by us we show how this
can be systematically accomplished within a Lagrangian framework. We construct
an effective Lagrangian which yields tree-level color-kinematic symmetric
numerators in Yang-Mills theories in a light-like gauge at five-points. The
five-point effective Lagrangian is non-local and it is zero by Jacobi identity.
The numerators obtained from it respect the original pole structure of the
color-ordered amplitude. We discuss how this procedure can be systematically
extended to higher order.Comment: 36 page
Variational Multi-Time Green's Functions for Nonequilibrium Quantum Fields

The time-dependent variational principle proposed by Balian and Veneroni is used to provide the best approximation to the generating functional for multi-time Green's functions of a set of (bosonic) observables $Q_{\mu)$. By suitably restricting the trial spaces, the computation of the two-time Green's function, obtained by a second order expansion in the sources, is considerably simplified. This leads to a tractable formalism suited to quantum fields out of equilibrium. We propose an illustration on the finite temperature ${\bf\Phi^4}$ theory in curved space and coupled to gravity
Effect of interfacial-active elements addition on the incorporation of micron-sized SiC particles in molten pure aluminum

Ceramic particles generally have poor wettability by liquid metal, leading to a major drawback in fabrication of cast metal matrix composites (MMCs). In this work, the effect of 1 wt. % of Ca, Mg, Si, Ti, Zn and Zr interfacial-active alloying elements was studied on the incorporation of micron-sized SiC particles into the molten pure aluminum using the vortex casting method at 680 1C. The results indicated that Ti, Zr, Zn and Si were not positively effective in improving particulate incorporation, while Ca and especially Mg were very efficient at increasing the incorporation of ceramic particles into the molten Al. Also, it was revealed that Al3Ti, and Al3Zr intermetallic phases were formed for samples containing Ti and Zr, making hybrid MMCs with a higher amount of hardness. Finally, it was found that a reaction layer between Al and SiC particles was formed at the Al/SiC interface for all of the samples, expect for the ones containing Si and Ti, indicating that for most of the samples at 680 1C an exothermic reaction took place between the Al and SiC particles
Comments on the hierarchy problem in effective theories

We discuss aspects of the hierarchy problem in effective theories with light scalars and a large, physical ultraviolet (UV) cutoff. We make two main points: (1) The (naive) fine-tuning observed in an effective theory does not automatically imply that the UV completion is fine tuned. Instead, it gives a type of upper bound on the severity of the actual tuning in the UV completion; the actual tuning can be less severe than the naive tuning or even non-existent. (2) Within an effective theory, there appear to be two types of parameter relations that can alleviate the sensitivity of the scalar mass to the cutoff — relationships among dimensionless couplings or relationships among dimensionful parameters. Supersymmetric models provide symmetry-motivated examples of the former, while scale-invariant models give symmetry-motivated examples of the latter
U(1) lattice gauge theory with a topological action

We investigate the phase diagram of the compact U(1) lattice gauge theory in four dimensions using a non-standard action which is invariant under continuous de-formations of the plaquette angles. Just as for the Wilson action, we find a weakly first order transition, separating a confining phase where magnetic monopoles condense, and a Coulomb phase where monopoles are dilute. We also find a third phase where monopoles are completely absent. However, since the monopoles do not influence the long-distance prop-erties of the Coulomb phase, the physics is smooth across the singularity in the monopole density. The topological action offers an algorithmic advantage for the computation of the free energy
Dark Matter constraints on composite Higgs models

In composite Higgs models the pseudo-Nambu-Goldstone Boson (pNGB) nature of the Higgs field is an interesting alternative for explaining the smallness of the electroweak scale with respect to the beyond the Standard Model scale. In non-minimal models additional pNGB states are present and can be a Dark Matter (DM) candidate, if there is an approximate symmetry suppressing their decay. Here we assume that the low energy effective theory (for scales much below the compositeness scale) corresponds to the Standard Model with a pNGB Higgs doublet and a pNGB DM multiplet. We derive general effective DM Lagrangians for several possible DM representations (under the SM gauge group), including the singlet, doublet and triplet cases. Within this framework we discuss how the DM observables (relic abundance, direct and indirect detection) constrain the dimension-6 operators induced by the strong sector assuming that DM behaves as a Weakly Interacting Particle (WIMP) and that the relic abundance is settled through the freeze-out mechanism. We also apply our general results to two specific cosets: SO(6)/SO(5) and SO(6)/SO(4)×SO(2), which contain a singlet and doublet DM candidate, respectively. In particular we show that if compositeness is a solution to the little hierarchy problem, representations larger than the triplet are strongly disfavored. Furthermore, we find that composite models can have viable DM candidates with much smaller direct detection cross-sections than their non-composite counterparts, making DM detection much more challenging
Resummations and non-perturbative corrections

We consider a generalization of the Borel resummation, which turns out to be equivalent to the standard Borel resummation. We apply it to the simplest large N duality between the pure Chern-Simons theory and the topological string on the resolved conifold, and obtain a simple integral formula for the free energy. Expanding this integral representation around the large radius point at finite string coupling g s , we find that it includes not only the M-theoretic resummation à la Gopakumar and Vafa, but also a non-perturbative correction in g s . Remarkably, the obtained non-perturbative correction is in perfect agreement with a proposal for membrane instanton corrections in arXiv:1306.1734 . Various other examples are also presented
Globally convergent hybridization of particle\ud
swarm optimization using line search-based\ud
derivative-free techniques

The hybrid use of exact and heuristic derivative-free methods for global unconstrained optimization problems is presented. Many real-world problems are modeled by computationally expensive functions, such as problems in simulationbased\ud
design of complex engineering systems. Objective-function values are often provided by systems of partial differential equations, solved by computationally expensive\ud
black-box tools. The objective-function is likely noisy and its derivatives are not provided. On the one hand, the use of exact optimization methods might be computationally too expensive, especially if asymptotic convergence properties are sought. On the other hand, heuristic methods do not guarantee the stationarity of their final solutions. Nevertheless, heuristic methods are usually able to provide an\ud
approximate solution at a reasonable computational cost, and have been widely applied to real-world simulation-based design optimization problems. Herein, an overall\ud
hybrid algorithm combining the appealing properties of both exact and heuristic methods is discussed, with focus on Particle Swarm Optimization (PSO) and line search-based derivative-free algorithms. The theoretical properties of the hybrid algorithm are detailed, in terms of limit points stationarity. Numerical results are presented for a test function and for two real-world optimization problems in\ud
ship hydrodynamics
The effect of the geomagnetic field on cosmic ray energy estimates and large scale anisotropy searches on data from the Pierre Auger Observatory

We present a comprehensive study of the influence of the geomagnetic field on the energy estimation of extensive air showers with a zenith angle smaller than 60 degrees, detected at the Pierre Auger Observatory. the geomagnetic field induces an azimuthal modulation of the estimated energy of cosmic rays up to the similar to 2% level at large zenith angles. We present a method to account for this modulation of the reconstructed energy. We analyse the effect of the modulation on large scale anisotropy searches in the arrival direction distributions of cosmic rays. At a given energy, the geomagnetic effect is shown to induce a pseudo-dipolar pattern at the percent level in the declination distribution that needs to be accounted for
The $qqqq\bar q$ components and hidden flavor contributions to the baryon magnetic moments

The contributions from the $qqqq\bar q$ components to the magnetic moments of the octet as well as the $\Delta^{++}$ and $\Omega^-$ decuplet baryons are calculated for the configurations that are expected to have the lowest energy if the hyperfine interaction depends both on spin and flavor. The contributions from the $u\bar u$, $d\bar d$ and $s\bar s$ components are given separately. It is shown that addition of $qqqq\bar q$ admixtures to the ground state baryons can improve the overall description of the magnetic moments of the baryon octet and decuplet in the quark model without SU(3) flavor symmetry breaking, beyond that of the different constituent masses of the strange and light-flavor quarks. The explicit flavor (and spin) wave functions for all the possible configurations of the $qqqq\bar q$ components with light and strange $q\bar q$ pairs are given for the baryon and octet and decuplet. Admixtures of ~ 10% of the $qqqq\bar q$ configuration where the flavor-spin symmetry is $[4]_{FS}[22]_F[22]_S$, which is likely to have the lowest energy, in particular reduces the deviation from the empirical values of the magnetic moments of the $\Sigma^ -$ and the $\Xi^0$ compared with the quark model