bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recombination of oxygen atoms on the surface of oxidized polycrystalline nickel—temperature and pressure dependences
Authors: Paul Domen , Mozetič Miran , Zaplotnik Rok , Ekar Jernej , Vesel Alenka , Primc Gregor , Đonlagič Denis 
Published: June 2023

Abstract
The recombination of neutral oxygen atoms in the ground state on the oxidized nickel samples was studied experimentally in the range of pressures where the maximum density occurs in weakly ionized low-pressure oxygen plasma, i.e. between 40 and 200 Pa. The recombination coefficient was determined in the flowing afterglow. The source of oxygen atoms was plasma sustained in a quartz tube of inner diameter 4.7 mm by a microwave discharge in the surfatron mode. The recombination coefficient was determined in the afterglow chamber, which was a Pyrex tube with an inner diameter of 36 mm. The density of oxygen atoms in the afterglow chamber was varied by adjusting the discharge power, the gas flow, the pressure, and the position of a recombinator. Such flexibility of the experimental system enabled adjustment of the temperature of the oxidized nickel samples independently from the O-atom density in its vicinity or other parameters. The density of oxygen atoms in the afterglow chamber at various system parameters was determined by the Šorli method, which is reliable, and has an accuracy of about 20%. The recombination coefficient was determined by calorimetry. The coefficient was inversely proportional to the square root of the pressure and exponentially to the sample temperature. Systematic measurements performed at various pressures and temperatures enabled empirical formula, which were explained qualitatively by recombination kinetics.
The surface tension of Ga2O3 melt measured by a drop-weight method in an optical floating-zone furnace
Authors: Wu Dan , Li Cheng , Ma Keke , Wang Jiabin , Xia Ning , Yan Yuchao , Jin Zhu , Zhang Hui , Yang Deren 
Published: June 2023

Abstract
The surface tension of Ga2O3 melt is successfully measured using a drop-weight method in an optical floating-zone furnace that we have developed. The method is verified to be feasible by measuring the surface tension value of TiO2 melt and then comparing it with values in previous reports determined by other methods. We find that the surface tension of Si-doped Ga2O3 melt increases with the decrease in the Si doping concentration and reaches 527.9 mN m−1 for pure Ga2O3 melt. The surface tension of the unintentionally doped Ga2O3 melt is also measured to be 519.3 mN m−1 in the presence of some common contaminants appearing in Czochralski and edge-defined film-fed growth methods, including Ir, Al, and Si.
Development and validation of a probabilistic multistage algorithm for damage localization in piezo-monitored structures
Authors: De Luca Alessandro , Perfetto Donato , Polverino Antonio , Minardo Aldo , Caputo Francesco 
Published: June 2023

Abstract
All structures during operating life can be affected by faults induced by accidental events and operational conditions. Structural health monitoring systems can provide quasi-real-time diagnosis of the structure, thus enabling the condition-based maintenance approach. By means of piezoelectric transducers (PZTs) and ultrasonic guided waves (UGW), the structural integrity can be easily interrogated, even though laborious post-processing techniques are required to correctly interpret sensed data. This work aims to devise a new automatic diagnosis framework based on the propagation of UGW for thin-walled structures fault detection and localisation. Specifically, a fully automated damage identification algorithm was developed through a numerical dataset obtained by finite element simulations, and then validated experimentally. The case of study consisted of a square-shaped aluminium plate equipped with a five PZTs network. Five different damage positions and three different damage sizes were considered. The originality of the proposed algorithm lies in the data processing methodology as well as in its capability to detect damages located inside and outside the sensors network, even close to the panel edges. Algorithm provides, in less than 15 s, indications on the possible damage location and related probability position with a reduced dispersion with respect to other algorithms proposed in literature. A clear image is created displaying the damage position map. The visualisation of the damage position map on the surface of the monitored part allows successful damage imaging and would enable operators to address more efficiently the inspection procedures only in the highlighted areas, reducing maintenance and repair expenses.
What it could feel like to press on an auxetic: effect of Poisson’s ratio on the indenter
Authors: Attard Daphne , Gatt Ruben , Caruana-Gauci Roberto , Grima-Cornish James N , Cauchi Reuben , Sillato Darren , Cerasola Dario , Ficarra Giovanni , Bezzina Daniel S , Formosa Cynthia , Gatt Alfred , Grima Joseph N 
Published: June 2023

Abstract
The behaviour of an indenter having a hard inner core and a softer outer shell, meant to emulate a human finger, pressing upon a sample covered with an isotropic negative/zero/positive Poisson’s top protective layer was investigated through static finite-element simulations. It was shown that if the material being indented had a comparable Young’s modulus to the outer shell of the indenter, a very negative Poisson’s ratio (NPR) results in more pronounced deformations and stresses within the indenter due to the auxetic material offering a higher resistance to indentation. Pressing of an auxetic material with Poisson’s ratio of −0.90 having the same Young’s modulus as that of the softer outer core of the indenter (1 MPa), was found to result in stresses in the indenter which were approximately double to those measured when pressing a conventional material with same Young’s modulus having Poisson’s ratio +0.45. This indicates that auxetics with a very high NPR may feel more uncomfortable when pressed with a finger compared to materials of the same Young’s modulus having a conventional positive Poisson’s ratio (PPR). However, it was also shown that in such scenarios, the auxetic protective layer being indented could be made much thinner whilst still retaining the same functionality. In fact, the simulations suggest that a conventional material with Poisson’s ratio +0.45 indents more than five times as much as an auxetic material with Poisson’s ratio of −0.90 having the same Young’s modulus of 1 MPa. It was also shown that in situations where the material being indented had a much higher Young’s modulus to that of the indenter, the deformations and stresses within the indenter are practically identical irrespective of the Poisson’s ratio, i.e. a human finger is unlikely to be able to perceive the difference between an auxetic and a conventional PPR material.
Low frequency sound insulation performance of membrane-type acoustic metamaterial with eccentric mass block
Authors: Cai Tong , Huang Shuang , Guo Hui , Sun Pei , Yuan Tao 
Published: June 2023

Abstract
To improve the sound insulation performance in the low frequency band of membrane-type acoustic metamaterial (MAM), membrane-type acoustic metamaterial with eccentric mass block (MAMEM) is used as the object in this paper. The influence of composite mass block on the low frequency sound insulation performance of MAMEM is also studied. Firstly, a mathematical model of sound insulation based on MAMEM was conducted. Secondly, the elastic layer is introduced into the mass block of the MAMEM to form a membrane-type acoustic metamaterial with eccentric composite mass block (MAMECM) structure. The study shows that the peak sound insulation frequency of the structure is obtained with a left shift of 70 Hz, and the introduction of the elastic layer will be beneficial to realize the low frequency regulation of the structural band gap. Thirdly, the influence of the thickness of the elastic and metal layers on the sound insulation of the MAMECM was discussed. The study shows that when the thickness of the metal layer is 1 mm and the thickness of the elastic layer is 10.7 mm, the peak sound insulation reaches 70 dB at this frequency. The peak frequency of sound insulation can reach 260 Hz, which is 140 Hz lower than the MAM at the same mass. Moreover, under the premise that the total mass of composite material blocks remains unchanged, the sound insulation peak frequency of sound transmission loss (STL) curve will shift to the left when the thickness of metal layer is smaller, and the sound insulation at the peak frequency is larger. Finally, the accuracy of the results is verified by experiments.
Large dynamic range terahertz phase modulator based on graphene-metal hybrid metasurface
Authors: Wang Hong , Hu Fangrong , Xu Xinlong , Gong Yumin , Jiang Mingzhu , Zhang Longhui , Zou Yingchang 
Published: June 2023

Abstract
Terahertz (THz) dynamic phase modulator is indispensable in THz wireless communications, high-resolution imaging and radar systems. However, up to now, it is difficult to achieve dynamic tunable phase shift of more than 150 degrees in single-layer transmission mode. In this work, we proposed a THz dynamic large phase modulator based on graphene-metal hybrid metasurface. The simulation results show that, when the Fermi level of graphene changes from 0 eV to 0.86 eV, the phase shift exceeds 176 degrees. By modifying the structural parameters, a phase shift of 170 degrees can be achieved in a bandwidth of 50 GHz. We investigated the physical mechanism of the dynamic phase modulator, and established the relationship between phase shift and Fermi level theoretically. This study paves a new way for realizing dynamic large phase modulation, which is very important for the THz broadband wireless communication, high-resolution imaging and radar system.
Negative differential resistance in Si nanostructure: role of interface traps
Authors: Chakrabarty Sudipta , Hossain Syed Minhaz 
Published: June 2023

Abstract
Negative differential resistance (NDR) has been observed in I-V characteristics measured between two aluminum (Al) pads deposited on a layer containing Silicon nanostructures. This feature has been observed for suitable bias range and specific direction of voltage sweep. NDR has been found to show up within a specific range of lower and upper threshold voltages for each of the samples studied in this work. The amount of NDR has been found to depend on voltage scan rate and bias range. The observed phenomena have been explained using the dynamics of charge trapping and detrapping at the surface/interface defect states present at the boundary of the nanostructured silicon and the oxide layer. An equivalent circuit designed by incorporation of suitable resistance and capacitance representing the trap assisted charge transport within the aluminum-Silicon nanostructure junctions has produced similar I-V characteristics as obtained in the experimental results. Repeatability of NDR shows the potential of the device to be used in oscillators.
Research on damage characteristics and microscopic appearance of ReBCO tapes after DC overcurrent
Authors: Yang Zili , Xu Ying , Li Xianhao , Yang Zhixing , Zhang Zitong , Ding Xuan , Zhou Difan , Peng Shuhao 
Published: June 2023

Abstract
With the expansion of the power grid, the use of DC transmission technology is becoming increasingly prevalent. This has led to higher transmission voltage levels, which in turn have brought to the fore the issue of large short-circuit currents. The existing circuit limiter’s performance is insufficient to meet the growing demand. Superconducting fault current limiter, which based on ReBCO tapes, is considered to be the solution to the problem of large short-circuit current. However, the failure mode of ReBCO tapes under DC overcurrent remains to be studied. In the superconducting state, the current flows mainly through the superconducting layer. Therefore, it is necessary to investigate the overcurrent characteristics of the superconducting layer after overcurrent. In this work, the damage characteristics and microscopic appearance of ReBCO tapes after overcurrent were investigated. The magnetic field distribution characteristics and the microscopic appearance of the superconducting layers of ReBCO tapes with different degrees of critical current recession were investigated, and the chemical elements of the superconducting layers were analyzed. The results show that large-area pits were found on superconducting layer after overcurrent, the element types and mass proportions did not change. Overcurrent affects the superconductivity of the tape mainly by changing the physical structure of the superconducting layer.
Single-step detection of toxic airborne metallic nanoparticles using Goos–Hänchen effect in photonic Bragg grating structures
Authors: Ghasemi Fatemeh , Adinehpour Sara , Razi Sepehr 
Published: June 2023

Abstract
A real-time photonic crystal sensor is suggested for the detection of airborne heavy metal nanoparticles (HMNPs). The sensor consists of a sandwiched sampling cell between two stacks of alternating TiO2 and Si-Ge layers, forming the core of the device. The sensor’s performance is based on monitoring changes in both the intensity and phase of a probe beam as it propagates through the core. By analyzing the fluctuations in intensity, central frequency, and full width at half maximum (FWHM) of the resonant mode within the transmittance spectrum bandgap, or by monitoring the phase changes at the angle of maximum transmittance that may result in a remarkable Goos–Hänchen (GH) shift in transmittance, the sensor can identify the pollutant nanoparticles. Tuning the thicknesses of the slabs and the number of unit cells in the photonic crystal can dynamically shift the resonant mode and bandgap edges, allowing for easy adjustment of the sensor’s responsivity. Furthermore, the optical response of the sensor can be tuned through external parameters such as the incident angle of the probe light or an externally applied electric field. Additionally, the sensor exhibits sensitivity not only to changes in the extent of the sample but also to the shape of the present HMNPs. These characteristics make the proposed configuration cost-effective, user-friendly, and suitable for HMNPs detection without the need for complex sample preparation, data analyses or additional tools/accessories.
Predictive uncertainty on astrophysics recovery from multifield cosmology
Authors: Andrianomena Sambatra , Hassan Sultan 
Published: June 2023

Abstract
We investigate how the constraints on the density parameter (Ωm), the power spectrum amplitude (σ
8) and the supernova feedback parameters (A
SN1 and A
SN2) vary when exploiting information from multiple fields in cosmology. We make use of a convolutional neural network to retrieve the salient features from different combinations of field maps from IllustrisTNG in the CAMELS project. The fields considered are neutral hydrogen (HI), gas density (Mgas), magnetic fields (B) and gas metallicity (Z). We estimate the predictive uncertainty — sum of the squares of aleatoric and epistemic uncertainties — of the parameters inferred by our model by using Monte Carlo dropout, a Bayesian approximation. Results show that in general, the performance of the model improves as the number of channels of its input is increased. In the best setup which includes all fields (four channel input, Mgas-HI-B-Z) the model achieves R
2 > 0.96 on all parameters. Similarly, we find that the predictive uncertainty, which is dominated by the aleatoric uncertainty, decreases as more fields are used to train the model in general. The uncertainties obtained by dropout variational inference are overestimated on all parameters in our case, in that the predictive uncertainty is much larger than the actual squared error, which is the square of the difference between the ground truth and prediction. After calibration, which consists of a simple σ scaling method, the average deviation of the predictive uncertainty from the actual error goes down to 25% at most (on A
SN1).
Infiltration of tumor spheroids by activated immune cells
Authors: Mukherjee Mrinmoy , Chepizhko Oleksandr , Chiara Lionetti Maria , Zapperi Stefano , La Porta Caterina A M , Levine Herbert 
Published: June 2023

Abstract
Recent years have seen a tremendous growth of interest in understanding the role that the adaptive immune system could play in interdicting tumor progression. In this context, it has been shown that the density of adaptive immune cells inside a solid tumor serves as a favorable prognostic marker across different types of cancer. The exact mechanisms underlying the degree of immune cell infiltration is largely unknown. Here, we quantify the temporal dynamics of the density profile of activated immune cells around a solid tumor spheroid. We propose a computational model incorporating immune cells with active, persistent movement and a proliferation rate that depends on the presence of cancer cells, and show that the model able to reproduce semi-quantitatively the experimentally measured infiltration profile. Studying the density distribution of immune cells inside a solid tumor can help us better understand immune trafficking in the tumor micro-environment, hopefully leading towards novel immunotherapeutic strategies.
Polarized laser speckle images produced by calibrated polystyrene microspheres suspensions: comparison between backscattering and transmission experimental configurations
Authors: Loutfi Hadi , Pellen Fabrice , Le Jeune Bernard , Le Brun Guy , Abboud Marie 
Published: June 2023

Abstract
In this paper, we analyze polarized laser speckle images produced by calibrated polystyrene microspheres suspensions and discuss the results obtained while considering two different experimental configurations for light detection: speckle-transmission setup and speckle-backscattering one. The degree of light polarization (DOP) and speckle grain size (dx) were monitored in both cases. Results show that, when backscattered photons are detected, the degree of circular polarization allows a fine monitoring of the variation of scatterers concentration in a sample. A helicity flipping is detected as the scatterers concentration increases, showing that a transition from a simple scattering regime to a multiple scattering one is taking place. When transmitted scattered photons are detected dx is a better parameter than DOP for following changes in scattering regime: dx values initially increase slightly then decrease as the scattering coefficient increases. The observed maximum corresponds to the shift from a simple to a multiple scattering regime.
Compact entanglement concentration for three-electron-spin W states with error-detected parity-check gates
Authors: Fan Gang , Ren Xue-Mei , Fang-Fang Du  
Published: June 2023

Abstract
We present a compact entanglement concentration protocol (ECP) for unknown less-entangled three-electron-spin W states, resorting to the interaction rules between the circularly polarized photon and cavity-quantum-dot (QD) system. In the first step of our ECP, the parties utilize two less-entangled three-electron-spin systems not only to obtain one partially entangled three-electron-spin system with two unknown parameters if the odd-parity occurs with the parity-check gate (PCG) but also to get one entangled two-electron-spin system if the even-parity occurs. By exploiting the above three-electron-spin and two-electron-spin systems as the resource for the second step of our ECP, the parties can obtain a standard three-electron-spin W state if the odd parity occurs. Meanwhile, the systems in the even-parity instance can be used as the resource in the next round of our ECP. As the imperfect performances originated from the side leakage and the limited coupling strength of the cavity-QD system can be reflected by clicking the single-photon detectors, the fidelity of the PCG is unit, in principle, immune to strong coupling-strength restriction. Moreover, the success of our ECP not only is heralded by the detectors but also its efficiency further is improved by repeating the operation processes. Therefore, our ECP is useful in the quantum communication network.
Intelligent machine plus production line digital twin model construction technology
Authors: Ke Guo , Dashun Zhang , Liqin Miao , Jing Wang , Juan Du , Shubo Li , Huan Qiao , Lizhong Sun 
Published: June 2023

Abstract
Digital twin is one of the key technology of intelligent digital manufacturing field, the related research is still in the initial stage This article in complex parts machining production line as the research object, from the geometric physical behavior rules four aspects to explore the digital twin modeling technology of production line Through the geometric model and the size of the physical model visualization expression line shape Based on the three-layer model of geometric physical behavior, the digital twin behavior model is constructed to describe the operation failure rule of the machine and unit. Driven by real-time information collection and fusion technology, closed-loop control and iterative optimization are realized Finally, the application value of digital twin technology in intelligent monitoring information feedback decision control is demonstrated through the intelligent control system of machining production line.
A backlash identification and compensation method for high-speed aircraft angular rate control
Authors: Lyu Huitao , Zhang Yi , Gong Zheng , Chen Yongliang 
Published: June 2023

Abstract
This paper focus on the hysteresis phenomenon of the roll angular rate control resulting from the backlash of the actuators for a high-speed aircraft in real flight. First, the backlash is analyzed in the time and frequency domain, and then the backlash parameters are identified using the statistic method. Second, based on the inverse backlash model, the L
1 adaptive controller with the backlash compensation is designed. Third, two simulation tests with and without the backlash compensation are conducted and the simulation results are compared which show the effectiveness of the backlash-compensation-based controller.
The impact analysis of the un-commanded brake caused by pedal jamming on the aircraft
Authors: Jian Li 
Published: June 2023

Abstract
The rudder brake pedal unit is an important part of aircraft flight control system, also is the human machine interface for pilots to control the aircraft rudder and brake. By applying forces at different positions and directions on the pedals, the pilot can realize the rudder control and brake control functions respectively. This paper takes the rudder brake pedal control unit of civil aircraft as the research object. The research process is as follows. Firstly, an analysis about the influence on the compression of brake sensor by operating pedal when the brake pedal jamming is carried out using CATIA. Secondly, the forces acted on aircraft during rolling on the ground are analyzed and the ground dynamic equations are presented. Finally, through the simulation on the engineering simulator of a certain aircraft, the influence of differential brake caused by brake pedal jamming on the aircraft speed after V1 (take-off decision speed) in the take-off phase is verified. The research results of this study show that, the impact of un-commanded differential brake caused by rudder brake pedal jamming on the safety of the aircraft must be considered during the aircraft design process, and effective measures must be taken to avoid the occurrence of un-commanded deceleration after V1 in the take-off phase.