bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detecting language change
Authors: Calude Andreea S. , Harper Sally , Miller Steven , Whaanga Hemi 
Published: March 2020

Abstract
The borrowing of words from one language into another is most likely as ancient as language itself. While ample linguistic attention has focused on various linguistic contact scenarios in which words from one language enter productive use into another, their aim has been largely restricted to documenting the words which are borrowed, their frequency, and other situation-specific information. In this paper, we propose new methods for studying loanwords, namely a combination of statistical testing techniques which can be used together to increase knowledge in this area. We illustrate these tools with a case-study of loanwords from an indigenous language (Māori) into a world dominant language (New Zealand English). Using a topic-constrained newspaper corpus in conjunction with quantitative methods, we explore the use of loanwords diachronically and analyse variation in loanword use across newspapers and across writers.
Storytelling and stance-taking in group interaction
Authors: Peplow David 
Published: March 2020

AbstractThis paper looks at two highly prevalent actions in naturally-occurring talk: stance-taking and storytelling. Stance-taking and storytelling have been shown to co-occur often (e.g.Siromaa, 2012), and this is especially the case in reading group talk, a discursive environment in which speakers are engaged in the joint enterprise of assessing the meaning and quality of a shared object: a written narrative text (e.g. a novel). Insights from conversation analysis and dialogic syntax are used to analyse interactional data from several reading group meetings, with a focus on the types of storytelling that are found in this talk, the relationship between the various stories told in sequence in the talk – including the relationship between the written narrative text and the spoken narratives, and the ways in which stance-taking and storytelling are intertwined.
Group field theory and holographic tensor networks: dynamical corrections to the Ryu–Takayanagi formula
Authors: Chirco Goffredo , Goeßmann Alex , Oriti Daniele , Zhang Mingyi 
Published: March 2020

Abstract
We introduce a generalised class of (symmetric) random tensor network states in the framework of group field theory. In this setting, we compute the Rényi entropy for a generic bipartite state via a mapping to the partition function of a topological 3D BF theory, realised as a simple interacting group field theory. The expectation value of the entanglement entropy is calculated by an expansion into stranded Feynman graphs and is shown to be captured by a Ryu–Takayanagi formula. For the simple case of a 3D BF theory, we can prove the linear corrections, given by a polynomial perturbation of the Gaussian measure, to be negligible for a broad class of networks.
Attosecond transient absorption of a continuum threshold
Authors: Birk Paul , Stooß Veit , Hartmann Maximilian , Borisova Gergana D , Blättermann Alexander , Heldt Tobias , Bartschat Klaus , Ott Christian , Pfeifer Thomas 
Published: March 2020

Abstract
The laser-field-modified dipole response of the first ionization threshold of helium is studied by means of attosecond transient absorption spectroscopy. We resolve light-induced time-dependent structures in the photoabsorption spectrum both below and above the ionization threshold. By comparing the measured results to a quantum-dynamical model, we isolate the contributions of the unbound electron to these structures. They originate from light-induced couplings of near-threshold bound and continuum states and light-induced energy shifts of the free electron. The ponderomotive energy, at low laser intensities, is identified as a good approximation for the perturbed continuum response.
Perceptible exciton-to-trion conversion and signature of defect mediated vibronic modes and spin relaxation in nanoscale WS2 exposed to γ-rays
Authors: Sarmah Hemanga Jyoti , Mohanta Dambarudhar , Saha Abhijit 
Published: March 2020

Abstract
In this work, we report manifested optical, optoelectronic and spin–spin relaxation features of a few layered tungsten disulphide (WS2) nanosheets subjected to energetic γ-photons (∼1.3 MeV) emitted from a Co60 source. Upon intense irradiation (dose = 96 kGy), a slight departure from the pure hexagonal phase was realized with the introduction of the trigonal phase at large. Moreover, in the Raman spectra, as a consequence of the radiation-induced effect, an apparent improvement of the E-to-A mode intensity and a reduction in phonon lifetimes have been realized, with the latter being dependent on the linewidths. The emergence of the new peak (D) maxima observable at ∼406 cm−1 in the Raman spectra and ∼680 nm in the photoluminescence (PL) spectra can be attributed to the introduction of defect centres owing to realization of sulphur vacancies (V
S) in the irradiated nanoscale WS2. Additionally, neutral exciton to charged exciton (trion) conversion is anticipated in the overall PL characteristics. The PL decay dynamics, while following bi-exponential trends, have revealed ample improvement in both the fast parameter (0.39 ± 0.01 ns to 1.88 ± 0.03 ns) and the slow parameter (2.36 ± 0.03 ns to 12.1 ± 0.4 ns) after γ-impact. We attribute this to the finite band gap expansion and the incorporation of new localized states within the gap, respectively. A declining exciton annihilation rate is also witnessed. The isotropic nature of the electron paramagnetic resonance spectra as a consequence of γ-exposure would essentially characterize a uniform distribution of the paramagnetic species in the system, while predicting a three-fold improvement of relative spin density at 96 kGy. Exploring defect dynamics and spin dynamics in 2D nanoscale systems does not only strengthen fundamental insight but can also offer ample scope for designing suitable components in the areas of miniaturized optoelectronic and spintronic devices.
Nano-bridged nanosphere lithography
Authors: Luo Lingpeng , Akinoglu Eser Metin , Wu Lihua , Dodge Tyler , Wang Xin , Zhou Guofu , Naughton Michael J , Kempa Krzysztof , Giersig Michael 
Published: March 2020

Abstract
We develop nano-bridged nanosphere lithography (NB-NSL), a modification to the widely used conventional nanosphere lithography (NSL). Nano-bridges between polystyrene (PS) spheres of a pristine NSL template are controllably formed in a two-step process: (i) spin-coating of a dilute styrene solution on top of the template, followed by (ii) oxygen plasma etching of the template. We show that the nanobridge dimensions can be precisely tuned by controlling the pre-processing conditions and the plasma etching time. The resulting lithography templates feature control over the shape and size of the apertures, which determine the morphology of the final nano-island arrays after material deposition and template removal. The unique advantage of NB-NSL is that PS particle templates based on a single PS particle diameter can be utilized for the fabrication of a variation of nano-island shapes and sizes, whereas conventional NSL yields only bowtie-shaped nano-islands, with their size being predetermined by the PS particle diameter of the template.
A holistic system approach for short range passenger aircraft with cryogenic propulsion system
Authors: Boll Martin , Corduan Matthias , Biser Stefan , Filipenko Mykhaylo , Pham Quoc Huang , Schlachter Sonja , Rostek Peter , Noe Mathias 
Published: March 2020

Abstract
Currently, hybrid-electric aircraft are under investigation as one possible solution to reduce the emissions of the aviation industry according to Flightpath 2050 of the European Union. To meet the drive train's requirements on low mass while aiming for highest efficiency, superconducting technologies are regarded as a key enabling technology for drive train powers of several tens of megawatts. Within the German nationally funded project TELOS an exemplary mission profile and the physical measures of a 220-passenger aircraft are used to derive the requirements for a cryogenic-cooled serial hybrid-electric propulsion system. To optimize the total system performance, we subsequently evaluated the superconducting and cryogenic-cooled components by using computationally fast, analytical models. This approach allows quantifying the system performance by using component technologies being available today. In particular, the system performance of geared drive to direct drive propulsion units are compared and the influence of the DC bus voltage and the electric frequencies of the AC circuits on the mass and the efficiency of the drive trains are analysed.
Dynamic loss of HTS field windings in rotating electric machines
Authors: Kails Kevin , Zhang Hongye , Machura Philip , Mueller Markus , Li Quan 
Published: March 2020

Abstract
High-temperature superconducting (HTS) coated conductors (CCs) are frequently applied under complex electromagnetic fields to develop powerful, compact and efficient rotating electric machines. In such electric machines, field windings constructed by HTS CCs are adopted to increase the magnetic loading of the machines. The HTS field windings work with DC currents and due to the time-varying magnetic field environment, dynamic losses occur. In addition to the AC magnetic field, there is a large DC background field, which is caused by the self-field of the HTS field windings. This paper investigates the dynamic loss in HTS CCs using an H-formulation based numerical model for a wide range of combined DC and AC magnetic fields under various load conditions, and two different methods have been used for calculating dynamic loss. The results show that a DC background field plays a vital role to accurately predict the dynamic losses in HTS CCs. A DC background field of 75 mT can triple the dynamic loss as compared to only applying an AC magnetic field. In addition, the theoretical definition for the dynamic region for the case of solely an AC field has been found inapplicable in the case of a DC background field. Finally, a case study is done based on our double claw pole power generator to estimate the dynamic loss in an actual rotating machine, which was found to be 13.3 W. A low dynamic loss was achieved through the generator field winding design, which prevents high magnetic field fluctuations in the winding, since it is located at a distance from the air gap and armature coils. Furthermore, the rotational speed is very low and hence the resultant magnetic field frequency is low as well.
Ultracold ions wake in dusty plasmas
Authors: Sundar Sita , Moldabekov Zhandos A 
Published: March 2020

Abstract
Motivated by the recent experimental realization of ultracold dusty plasma (2019 Sci. Rep. 9 3261), we present the results of particle-in-cell simulation with Monte-Carlo-collisions for wake behind a dust particle due to focusing of ions at superfluid helium temperature (∼2 K). Dynamical screening (wakefield) defines structural and dynamical properties of charged dust particles in plasmas such as phase transition, crystal formation, vibration modes (waves) etc. Here, we delineate in detail the dependence of wake strength on the streaming velocity of ions and on the ion-neutral charge exchange collision frequency (neutrals density) in the ultracold dusty plasma. Lowering the temperature to ultracold level leads to a wake pattern behind a dust particle that completely differs from the wake at normal conditions. For wide range of parameters, most remarkable features of the wakefield are (i) the formation of wake pattern with two maxima split in transverse to ion flow direction in the downstream area, (ii) pronounced inverse V shape of the wakefield closely resembling the wake in quark-gluon plasma and dense quantum plasma (warm dense matter), and (iii) the inter-dust attraction region in transverse direction. The latter shows that molecule-like interaction between dust particles is realized in ultracold dusty plasmas. These observations show a fundamental difference of ultracold dusty plasma physics from well studied complex plasmas at normal conditions.
Extending qubit coherence by adaptive quantum environment learning
Authors: Scerri Eleanor , Gauger Erik M , Bonato Cristian 
Published: March 2020

Abstract
Decoherence, resulting from unwanted interaction between a qubit and its environment, poses a serious challenge towards the development of quantum technologies. Recently, researchers have started analysing how real-time Hamiltonian learning approaches, based on estimating the qubit state faster than the environmental fluctuations, can be used to counteract decoherence. In this work, we investigate how the back-action of the quantum measurements used in the learning process can be harnessed to extend qubit coherence. We propose an adaptive protocol that, by learning the qubit environment, narrows down the distribution of possible environment states. While the outcomes of quantum measurements are random, we show that real-time adaptation of measurement settings (based on previous outcomes) allows a deterministic decrease of the width of the bath distribution, and hence an increase of the qubit coherence. We numerically simulate the performance of the protocol for the electronic spin of a nitrogen-vacancy centre in diamond subject to a dilute bath of 13C nuclear spin, finding a considerable improvement over the performance of non-adaptive strategies.
Extracellular voltage thresholds for maximizing information extraction in primate auditory cortex: implications for a brain computer interface
Authors: Bigelow James , Malone Brian J 
Published: March 2020

Abstract

Objective. Research by Oby (2016 J. Neural. Eng.
13 036009) demonstrated that the optimal threshold for extracting information from visual and motor cortices may differ from the optimal threshold for identifying single neurons via spike sorting methods. The optimal threshold for extracting information from auditory cortex has yet to be identified, nor has the optimal temporal scale for representing auditory cortical activity. Here, we describe a procedure to jointly optimize the extracellular threshold and bin size with respect to the decoding accuracy achieved by a linear classifier for a diverse set of auditory stimuli. Approach. We used linear multichannel arrays to record extracellular neural activity from the auditory cortex of awake squirrel monkeys passively listening to both simple and complex sounds. We executed a grid search of the coordinate space defined by the voltage threshold (in units of standard deviation) and the bin size (in units of milliseconds), and computed decoding accuracy at each point. Main results. The optimal threshold for information extraction was consistently near two standard deviations below the voltage trace mean, which falls significantly below the range of three to five standard deviations typically used as inputs to spike sorting algorithms in basic research and in brain-computer interface (BCI) applications. The optimal binwidth was minimized at the optimal voltage threshold, particularly for acoustic stimuli dominated by temporally dynamic features, indicating that permissive thresholding permits readout of cortical responses with temporal precision on the order of a few milliseconds. Significance. The improvements in decoding accuracy we observed for optimal readout parameters suggest that standard thresholding methods substantially underestimate the information present in auditory cortical spiking patterns. The fact that optimal thresholds were relatively low indicates that local populations of cortical neurons exhibit high temporal coherence that could be leveraged in service of future auditory BCI applications.
Surface modification of PLA scaffold using radio frequency (RF) nitrogen plasma in tissue engineering application
Authors: Mohsenimehr Soad , Khani Mohammad Reza , Fani Nesa , Baghaban Eslaminejad Mohammad Reza , Shokri Babak , Ghassami Amirreza 
Published: March 2020

Abstract
In this study, two models of flat film and three-dimensional porous structure made by 3D printing (scaffolding) of poly lactic acid polymer (PLA) were processed by radio frequency (RF; 13.56 MHz) low-pressure nitrogen, nitrogen/oxygen and nitrogen/hydrogen plasma to improve surface properties requested in tissue engineering. Samples were treated at different RF power (80–150 w) and time processing was 90 s. Optical emission spectroscopy was used to identify the species in plasma. A significant change in hydrophilicity and surface energy measured by contact angle was observed. Aging effect on the wettability of PLA films at two different temperatures was examined. The result showed that the samples, kept at low temperature, have not changed significantly. Morphology and surface roughness were studied by Atomic force microscopy. Chemical components at the surface were investigated by x-ray photoelectron spectroscopy (XPS). Mechanical and thermal effect on the 3D scaffold PLA were carried out by tension test and thermogravimetric analysis respectively to indicate the effects of RF plasma treatment on the samples. The structural order, interconnectivity, and scale of the scaffold holes have been recorded by an optical microscope. Surface treatment by plasma increased biocompatibility of PLA samples without any toxicity. Cell adhesion on scaffolds was approved through MTT and scanning electron microscope (SEM) analysis. MTT essay show there was significant different between N2/O2 (1:1) group than control sample. Plasma surface treatment is a convenient method to reach a perfect substrate with desired hydrophilicity for attaching cells.
Enhancement of temperature coefficient of resistance (TCR) and magnetoresistance (MR) of La0.67–xRExCa0.33MnO3 (x = 0, 0.1; RE = Gd, Nd, Sm) system via rare-earth substitution
Authors: Pal Anand , Nagaraja B S , Rachana K J , Supriya K V , Kekuda Dhananjaya , Rao Ashok , Li Chia-Ruei , Kuo Yung-Kang 
Published: March 2020

Abstract
We investigated the influence of 10% substitution of rare-earth (RE) elements on the crystallographic, transport, and magnetic properties of La0.67–x
RE
x
Ca0.33MnO3(RE = Nd, Sm, and Gd, x = 0.0, 0.1) manganite perovskite compounds. The bulk polycrystalline samples were synthesized using solid-state reaction method. The phase purity and crystal structure of studied samples were confirmed by room temperature X-ray diffraction followed by the Rietveld refinement analysis. A high temperature insulator to low temperature metal phase transition is observed in electrical transport measurement. We observed an enhancement in the temperature coefficient of resistance (TCR) and magnetoresistance (MR) by partially substituting La with RE ions. The maximum TCR ≈ 22% and MR ≈ 96% are observed in Gd doped sample. The magnetic transition temperature, T

c
, decreases from ∼254 K for the pristine sample to about ∼165 K for the Gd-doped sample. Our analysis of electrical and thermal transport data shows that the Small Polaron Hopping (SPH) is predominant at high temperatures conduction mechanism, whereas at low temperatures mechanism is dominated by electron-magnon scattering. The high temperature insulator paramagnetic phase to low temperature metallic ferromagnetic phase transitions are also observed in thermal conductivity and specific heat.
Microstructure evolution and mechanical properties of friction stir processed TiC/7085Al nanocomposites
Authors: Zhou Dongshuai , Wang Jian , Lu Yalin , Bai Zhihao 
Published: March 2020

Abstract
In this paper, homogeneously dispersed TiC nanoparticles and fine-grained composite was successfully achieved by friction stir processing (FSP) of in situ 0.5 wt.% TiC/7085Al nanocomposites with different rotational speed. The effects of the rotational speed on the microstructures and tensile properties were investigated. Experimental results showed that the stir zone (SZ) exhibited equiaxed recrystallized grains with fine size and a high fraction of high-angle grain boundaries (HAGBs) caused by dynamic recrystallization (DRX). Moreover, the tensile strength and elongation of the friction stir processed (FSPed) composite were significantly improved compared with the base composite. With the rotational speed of 1000 rpm, the composite has the smallest grain size and the optimum mechanical properties. The average grain size decreased to 1.61 μm, the yield strength (YS), ultimate tensile strength (UTS) and elongation reached to 345 MPa, 429 MPa and 17.8%, respectively.
Head stabilization in small vertebrates that run at high frequencies with a sprawled posture
Authors: Jorissen Cas , Paillet Eric , Scholliers Jan , Aerts Peter , Goyens Jana 
Published: March 2020

AbstractSmall animals face a large challenge when running. A stable head is key to maintenance of a stable gaze and a good sense of self-motion and spatial awareness. However, trunk undulations caused by the cyclic limb movements result in involuntary head movements. Hence, the head needs to be stabilized. Humans are capable of stabilizing their head up to 2–3 Hz, but small animals run at cycle frequencies that are up to six times higher. We wondered how natural selection has adapted their head stabilization control. We observed that the relative contributions of vision, on the one hand, and vestibular perception and proprioception, on the other hand, remain the same when lizards undergo fast or slow body undulations in an experimental set-up. Lizards also maintain a short phase lag at both low and high undulation frequencies. Hence, we found no indication that they use a different control mechanism at high frequencies. Instead, head stabilization probably remains possible owing to faster reflex pathways and a lower head inertia. Hence, the intrinsic physical and neurological characteristics of lizards seem to be sufficient to enable head stabilization at high frequencies, obviating the need for evolutionary adaptation of the control pathways. These properties are not unique to lizards and might, therefore, also facilitate head stabilization at high frequencies in other small, fast animals.