bluuebunny/crossref_metadata_2025_split huggingface dataset:
A multiple scattering theoretical approach to time delay in high energy core-level photoemission of heteronuclear diatomic molecules
Authors: Tamura Y , Yamazaki K , Ueda K , Hatada K 
Published: April 2022

Abstract
We present analytical expressions of momentum-resolved core-level photoemission time delay in a molecular frame of a heteronuclear diatomic molecule upon photoionization by a linearly polarized soft x-ray attosecond pulse. For this purpose, we start to derive a general expression of photoemission time delay based on the first order time dependent perturbation theory within the one electron and single channel model in the fixed-in-space system (atoms, molecules and crystals) and apply it to the core-level photoemission within the electric dipole approximation. By using multiple scattering theory and applying series expansion, plane wave and muffin-tin approximations, the core-level photoemission time delay

t

is divided into three components,

t
abs

,

t
path

and

t
sc

, which are atomic photoemission time delay, delays caused by the propagation of photoelectron among the surrounding atoms and the scattering of photoelectron by them, respectively. We applied a single scattering approximation to

t
path

and obtained

t

path

(

1

)

(

k
,
θ

)

for a linearly polarized soft x-ray field with polarization vector parallel to the molecular axis for a heteronuclear diatomic molecule, where

θ

is the angle of measured photoelectron from the molecular axis. The core-level photoemission time delay

t

is approximated well with this simplified expression

t

path

(

1

)

(

k
,
θ

)

in the high energy regime (

k

≳

3
.
5

a.u.−1, where

k

is the amplitude of photoelectron momentum

k

), and the validity of this estimated result is confirmed by comparing it with multiple scattering calculations for C 1s core-level photoemission time delay of CO molecules.

t

path

(

1

)

(

k
,
θ

)

shows a characteristic dependence on θ, it becomes zero at θ = 0°, exhibits extended x-ray absorption fine structure type oscillation with period

2
k
R

at θ = 180°, where R is the bondlength, and gives just the travelling time of photoelectron from the absorbing atom to the neighbouring atom at θ = 90°. We confirmed these features also in the numerical results performed by multiple scattering calculations.
Experimental study of the evolution of H

α

line profile in a pulse hydrogen discharge
Authors: Bozhinova I , Pashov A , Iordanova S 
Published: April 2022

Abstract
This study reports on experimental technique for investigation of the dynamics of neutrals in direct current hydrogen discharges at low pressures. It is based on analysis of anomalous broadening of the H

α

emission line profile in a pulsed regime of operation of the source. The application of the technique is relatively simple and it is illustrated in a coaxial discharge tube, but can be readily extended to various discharge sources. The emission line is analyzed by a Fabry-Pérot interferometer and therefore high spectral resolution and fast temporal response can be combined. By observing the evolution of the profile with the pulse duration the experimental technique, extended with numerical modelling, gives opportunity for obtaining useful information about the temporal dependence of the processes responsible for formation of the components of the profile.
Acoustic-based method for identifying surface damage to wind turbine blades by using a convolutional neural network
Authors: Tsai Tung-Chen , Wang Chao-Nan 
Published: April 2022

AbstractDamage to the surface of the blades of a large wind turbine may lead to catastrophic blade failure. Although numerous methods have been proposed for detecting surface damage to wind turbine blades, many of them involve laboratory tests because of the difficulty in acquiring data from a commercial wind farm. This lack of data variety is an obstacle to the development of machine learning approaches for identifying the aforementioned damage. Therefore, we developed a damage detection method for wind turbine blade surfaces that is based on the physical correlation between surface conditions and acoustic signals of operating wind turbines under realistic environmental conditions. In the preprocessing stage of the aforementioned method, the short-time Fourier transform and smoothing techniques are used to analyze real-time spectrograms and the rotor speed. The derived spectrogram and rotor speed are then input into a convolutional neural network (CNN) to classify the wind turbine blade surfaces into two classes: turbines with at least one or no damaged blade. The CNN proposed in this paper is a hybrid network containing a masking module and residual classifier. The masking module suppresses redundant information in the spectrogram, and the residual classifier quantifies the difference between the masked spectrogram and a standard spectrogram. The proposed CNN can be easily trained on a small dataset with a few trainable parameters by using the physical characteristics in the residual classifier. The proposed damage detection method was evaluated using the operational noise of commercial wind turbines; according to the results, this method outperformed approaches proposed in previous studies and exhibited an accuracy of 97.11%.
Influence of twist pitch on hysteretic losses and transport J

c
in overpressure processed high J

c
Bi-2212 round wires
Authors: Oz Y , Davis D , Jiang J , Hellstrom E E , Larbalestier D C 
Published: April 2022

Abstract
Bi-2212 is the only high field, high-temperature superconductor (HTS) available in the macroscopically isotropic, multifilament high J

c
round wire (RW) form capable of generating high uniformity fields with minimum-screening current errors. However, the heat treatment that enables impressively high J

c
(4.2 K, 30 T) values that can attain ∼5000 A mm−2 also produces significant filament bonding (bridging). Filament bridging appears to significantly enhance hysteretic losses of the filaments themselves by coupling neighboring, nominally independent filaments, enabling shielding currents to flow across multiple filaments as though they were one filament of much larger diameter. Wire twisting can be employed to reduce filament-to-filament eddy current coupling losses due to induced currents flowing across the matrix, but twisting is less effective in reducing increased losses from bridging. Here, we compare the twist-pitch dependence of the losses of overpressure processed (OP) high J

c
Bi-2212 RWs with partially bridged filaments to those found in OP Bi-2212 RWs with discrete, not-bridged filaments. We show that filament sub-bundles in standard, partially-bridged wires that have some superconducting connections between filaments can exhibit significant coupling (much larger effective filament diameter), but twisting still reduces their hysteretic losses to values close to or below the ITER Nb3Sn wire loss specification, even though Bi-2212 wires have significantly larger J

c
values. Although it has been reported that twisting can reduce wire J

c
by damaging filaments, we found no reduction in transport J

c
, even for nominal twist pitches of 12 mm in 0.8 mm diameter wires. Evaluation of more-recent, higher J

c
Engi-Mat powder wires showed that their reduced filament bridging and improved longitudinal connectivity significantly improved transport J

c
and reduced the J

c
normalized losses, signaling that J

c
can be further improved without commensurate increase in losses. This important result strengthens the argument for production of high field, low loss HTS magnets made with Bi-2212 RWs.
Waveform of free, hinged and clamped axonemes isolated from C. reinhardtii: influence of calcium
Authors: Gholami A , Ahmad R , Bae A J , Pumir A , Bodenschatz E 
Published: April 2022

Abstract
The beating of cilia and flagella is essential to perform many important biological functions, including generating fluid flows on the cell surface or propulsion of micro-organisms. In this work, we analyze the motion of isolated and demembranated flagella from green algae Chlamydomonas reinhardtii, which act as ATP-driven micro-swimmers. The beating flagella of Chlamydomonas exhibit an asymmetric waveform that is known to involve the superposition of a static component, corresponding to a fixed, intrinsic curvature, and a dynamic wave component traveling from base-to-tip at the fundamental beat frequency, plus higher harmonics. Here, we analyse free, hinged and clamped axonemes using principal component analysis. The axonemal motion is described with a high degree of accuracy, taking into account only the first four dominant eigenmodes. Our analysis suggests that the wave motion can be alternatively described with Fourier modes, with a wavelength λ, larger than the length of the filament L (λ/L ≈ 1.3). Within this representation, we demonstrate that the main base-to-tip traveling wave component coexists with standing waves. Finally, we report the effect of calcium on the constituting wave components and find that the static mode is the most sensitive component to the calcium ion concentration.
Dynamic response of the half-space subjected to a moving point load and thermal stress
Authors: Zhou Xiang , Shui Guoshuang , Su Xiao-Xing 
Published: April 2022

Abstract
Dynamic transient response of the half-space subjected to a moving point load and thermal stress is investigated analytically in this study. By employing the Helmholtz decomposition and introducing a moving coordinate system, the corresponding modified partial differential equations of motion for the transient waves in the half-space are firstly obtained. With one-side and two-side Laplace transformation over the new time and space variables, the second-order partial differential equations of motion in the modified system are then simplified as the ordinary differential equations, whose solutions are thereafter obtained when the boundary condition is satisfied. To get the dynamic response in time domain, the analytical solutions in Laplace domain are inverted using the Cagniard-de Hoop method. Some examples are evaluated and discussed in details for the purpose of examining the effect of the moving load and thermal stress on the transient response of the half-space.
Gravitational shine of dark domain walls
Authors: Babichev E. , Gorbunov D. , Ramazanov S. , Vikman A. 
Published: April 2022

Abstract
Cosmic domain walls are harmless, provided that their tension decreases with expansion of the Universe. This setup can be realized, if the scale of spontaneous symmetry breaking is induced dynamically through the interaction with hot primordial plasma. In that case, the domain wall tension can attain large values in the early Universe without any conflict with observations. Owing to the large initial tension, these topological defects may serve as a powerful source of gravitational waves. We make a preliminary estimate of the gravitational wave spectrum and argue that it is distinct from the spectrum produced by other sources, in particular by domain walls of a constant tension. The resulting gravitational wave signal is in the range accessible by Einstein Telescope, DECIGO, TianQin, LISA, IPTA, or SKA, if the field constituting the domain walls is very feebly coupled with hot primordial plasma and has tiny self-interactions. In particular, one can consider this field for the role of Dark Matter. We discuss various Dark Matter production mechanisms and properties of the emitted gravitational waves associated with them. We find that the conventional freeze-out and freeze-in mechanisms lead to large and perhaps unobservable frequency of gravitational waves. However, the Dark Matter production is also possible at the second order phase transition leading to the domain wall formation or at the inverse phase transition, when the domain walls get dissolved eventually. In both cases, there is essentially no lower bound on the frequency of emitted gravitational waves.
Polarization angle requirements for CMB B-mode experiments. Application to the LiteBIRD satellite
Authors: Vielva P. , Martínez-González E. , Casas F.J. , Matsumura T. , Henrot-Versillé S. , Komatsu E. , Aumont J. , Aurlien R. , Baccigalupi C. , Banday A.J. , Barreiro R.B. , Bartolo N. , Calabrese E. , Cheung K. , Columbro F. , Coppolecchia A. , de Bernardis P. , de Haan T. , de la Hoz E. , De Petris M. , Della Torre S. , Diego-Palazuelos P. , Eriksen H.K. , Errard J. , Finelli F. , Franceschet C. , Fuskeland U. , Galloway M. , Ganga K. , Gervasi M. , Génova-Santos R.T. , Ghigna T. , Gjerløw E. , Gruppuso A. , Hazumi M. , Herranz D. , Hivon E. , Kohri K. , Lamagna L. , Leloup C. , Macias-Perez J. , Masi S. , Matsuda F.T. , Morgante G. , Nakano R. , Nati F. , Natoli P. , Nerval S. , Odagiri K. , Oguri S. , Pagano L. , Paiella A. , Paoletti D. , Piacentini F. , Polenta G. , Puglisi G. , Remazeilles M. , Ritacco A. , Rubino-Martin J.A. , Scott D. , Sekimoto Y. , Shiraishi M. , Signorelli G. , Takakura H. , Tartari A. , Thompson K.L. , Tristram M. , Vacher L. , Vittorio N. , Wehus I.K. , Zannoni M. 
Published: April 2022

Abstract
A methodology to provide the polarization angle requirements for different sets of detectors, at a given frequency of a CMB polarization experiment, is presented. The uncertainties in the polarization angle of each detector set are related to a given bias on the tensor-to-scalar ratio r parameter. The approach is grounded in using a linear combination of the detector sets to obtain the CMB polarization signal. In addition, assuming that the uncertainties on the polarization angle are in the small angle limit (lower than a few degrees), it is possible to derive analytic expressions to establish the requirements. The methodology also accounts for possible correlations among detectors, that may originate from the optics, wafers, etc. The approach is applied to the LiteBIRD space mission. We show that, for the most restrictive case (i.e., full correlation of the polarization angle systematics among detector sets), the requirements on the polarization angle uncertainties are of around 1 arcmin at the most sensitive frequency bands (i.e., ≈ 150 GHz) and of few tens of arcmin at the lowest (i.e., ≈ 40 GHz) and highest (i.e., ≈ 400 GHz) observational bands. Conversely, for the least restrictive case (i.e., no correlation of the polarization angle systematics among detector sets), the requirements are ≈ 5 times
less restrictive than for the previous scenario. At the global and the telescope levels, polarization angle knowledge of a few arcmins is sufficient for correlated global systematic errors and can be relaxed by a factor of two for fully uncorrelated errors in detector polarization angle. The reported uncertainty levels are needed in order to have the bias on r due to systematics below the limit established by the LiteBIRD collaboration.
Generation of unconventional burst-pulse bundle in ytterbium-doped double-clad fiber laser based on self-mode-locked and double passively Q-switched technologies
Authors: Zhou Cheng 
Published: April 2022

Abstract
We experimentally demonstrate the unconventional burst-pulse bundle generation in a linear-cavity ytterbium-doped double-clad fiber laser based on self-mode-locked and double passively-Q-switched technologies. When the pump power is 4421.0 mW, we obtained the burst pulse bundle with proportional pulse qualities. The full width at half maximum (FWHM) of the burst pulse is 2.2 μs, the time interval between the adjacent burst pulse is 2.4 μs and the energy of a single burst pulse is 0.62 μJ. In addition, the maximum burst-pulse energy is 0.85 μJ at the pump power of 4574.0 mW, the minimum FWHM and time interval are 1.7 and 1.4 μs at the pump power of 5387.0 mW. The formation mechanism of the unconventional burst pulse bundle is also discussed in detail.
Laser ablation of Fe2B target enriched in 10B content for boron neutron capture therapy
Authors: Aiyyzhy Kuder O , Barmina Ekaterina V , Zavestovskaya Irina N , Kasatova Anna I , Petrunya Dmitry S , Uvarov Oleg V , Saraykin Vladimir V , Zhilnikova Margarita I , Voronov Valery V , Shafeev Georgy A , Taskaev Sergey Yu , Zelepukin Ivan V , Deyev Sergey M 
Published: April 2022

Abstract
The technique of laser ablation in liquids is applied to produce Boron-containing nanoparticles from ablation of a Fe2B bulk target enriched in 10B isotope. Laser ablation of the target in liquid isopropanol results in partial disproportionation to free Fe and Boron while nanoparticles of Fe2B are also presented. The nanoparticles are magnetic and can be collected using a permanent magnet. The average size of nanoparticles is about 15 nm. The content of 10B in the generated nanoparticles amounts to 76.9%. The nanoparticles are biocompatible and can be used in boron neutron capture therapy.
Relativistic elastic scattering of an electron by a muon in the field of a circularly polarized electromagnetic wave
Authors: Mekaoui Y , Jakha M , Mouslih S , Manaut B , Benbrik R , Taj S 
Published: April 2022

Abstract
Within the framework of quantum electrodynamics, the scattering of an electron by a muon in the presence of a circularly polarized monochromatic laser field is investigated theoretically in the first Born approximation. The expressions for the amplitude and the differential cross section (DCS) are derived analytically by adopting the Furry picture approach in which the calculations are carried out using exact relativistic Dirac-Volkov functions. We begin by studying the process taking into account the relativistic dressing of only the electron without muon. Then, in order to reveal the effect of the muon dressing, we fully consider the relativistic dressing of the electron and muon together in the initial and final states. As a result, the DCS is significantly reduced by the laser field. We find that the effect of laser-dressing of muon becomes noticeable at laser field strengths greater than or equal to

10

9

V cm

−
1

and therefore must be taken into account. The influence of the laser field strength and frequency on the DCS and multiphoton process is revealed. An insightful comparison with the laser-free results is also included.
Continuous 2D trajectory decoding from attempted movement: across-session performance in able-bodied and feasibility in a spinal cord injured participant
Authors: Pulferer Hannah S , Ásgeirsdóttir Brynja , Mondini Valeria , Sburlea Andreea I , Müller-Putz Gernot R 
Published: April 2022

Abstract

Objective. In people with a cervical spinal cord injury (SCI) or degenerative diseases leading to limited motor function, restoration of upper limb movement has been a goal of the brain-computer interface field for decades. Recently, research from our group investigated non-invasive and real-time decoding of continuous movement in able-bodied participants from low-frequency brain signals during a target-tracking task. To advance our setup towards motor-impaired end users, we consequently chose a new paradigm based on attempted movement. Approach. Here, we present the results of two studies. During the first study, data of ten able-bodied participants completing a target-tracking/shape-tracing task on-screen were investigated in terms of improvements in decoding performance due to user training. In a second study, a spinal cord injured participant underwent the same tasks. To investigate the merit of employing attempted movement in end users with SCI, data of the spinal cord injured participant were recorded twice; once within an observation-only condition, and once while simultaneously attempting movement. Main results. We observed mean correlations well above chance level for continuous motor decoding based on attempted movement in able-bodied participants. Additionally, no global improvement over three sessions within five days, both in sensor and in source space, could be observed across all participants and movement parameters. In the participant with SCI, decoding performance well above chance was found. Significance. No presence of a learning effect in continuous attempted movement decoding in able-bodied participants could be observed. In contrast, non-significantly varying decoding patterns may promote the use of source space decoding in terms of generalized decoders utilizing transfer learning. Furthermore, above-chance correlations for attempted movement decoding ranging between those of observation only and executed movement were seen in one spinal cord injured participant, suggesting attempted movement decoding as a possible link between feasibility studies in able-bodied and actual applications in motor impaired end users.
Pattern Inversion as a Pattern Recognition Method for Machine Learning
Authors: Mikhailov Alexei , Karavay Mikhail 
Published: April 2022

Abstract
Artificial neural networks use a lot of coefficients that take a great deal of computing power for their adjustment, especially if deep learning networks are employed. However, there exist coefficients-free extremely fast indexing-based technologies that work, for instance, in Google search engines, in genome sequencing, etc. The paper discusses the use of indexing-based methods for pattern recognition. It is shown that for pattern recognition applications such indexing methods replace with inverse patterns the fully inverted files, which are typically employed in search engines. Not only such inversion provides automatic feature extraction, which is a distinguishing mark of deep learning, but, unlike deep learning, pattern inversion supports almost instantaneous learning, which is a consequence of absence of coefficients. The paper discusses a pattern inversion formalism that makes use on a novel pattern transform and its application for unsupervised instant learning. Examples demonstrate a view-angle independent recognition of three-dimensional objects, such as cars, against arbitrary background, prediction of remaining useful life of aircraft engines, and other applications. In conclusion, it is noted that, in neurophysiology, the function of the neocortical mini-column has been widely debated since 1957. This paper hypothesizes that, mathematically, the cortical mini-column can be described as an inverse pattern, which physically serves as a connection multiplier expanding associations of inputs with relevant pattern classes.
Development of a Face Identification System’s Prototype
Authors: Tkachenko S N , Pichugina A V , Shpilevoy A A , Zakharov A I 
Published: April 2022

Abstract
The paper considers the development of a prototype of a user identification system by face. The system uses face recognition technology built on base points. Neural networks and machine learning methods are used for development of this system. The system is designed using principal component analysis, support vector machine classifier and deep artificial neural networks. We have developed a user-friendly interface. The system has been verified on test images and has been shown sufficient accuracy for identifying people by their photos.
Application of Algorithm of Fuzzy Rule Conclusions in Determination of Animal’s Diseases
Authors: Primova H A , Mukhamedieva D T , Safarova L 
Published: April 2022

Abstract
Today, the detection of non-communicable animal diseases, the analysis of experimental data and the construction of a mathematical model is one of the main problems. In the article a method for determining the type of disease in cattle using a fuzzy inference rule algorithm is discussed. In our country, diseases with ketosis, microelementosis, ostradistraphia and secondary ostradithraphy in livestock, especially cattle, are determined by errors in determining the type of disease due to their similar symptoms. Since the symptoms of these diseases are interrelated and one of them can cause the other, solving this problem using fuzzy rule algorithms helps to reduce the error in determining the type of disease.