bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of ion irradiation induced phase transformations and oxygen vacancies on the leakage current characteristics of HfO2 thin films deposited on GaAs
Authors: Kumar K Vinod , Arun N , Mangababu A , Mishra A , Ojha Sunil , Pathak A P , Rao S V S Nageswara 
Published: November 2024

Abstract
We report on ion-induced phase transformations, defect dynamics related to oxygen vacancies and the resulting leakage current characteristics of RF sputtered HfO2 thin films grown on GaAs. A systematic growth of HfO2 grains and ion prompted phase transformations of HfO2 to crystalline phases such as monoclinic and tetragonal/orthorhombic (mixed phase) in otherwise amorphous HfO2 thin films have been observed after irradiation. At lower fluences, ion induced enhancement in the dielectric properties of HfO2 thin films resulted in a reduction in the leakage current, whereas ion prompted defect formation at higher fluences caused a systematic increase in the leakage current density. Further, the effects of Poole-Frenkel tunneling and Fowler-Nordheim tunneling on the leakage current have also been investigated. These mechanisms showed the existence of impurities in the as-grown films. Photoluminescence study suggests that the variation in the defect configuration related to O-vacancies and the slight shift in the peak positions due to swift heavy ion irradiation are responsible for the observed changes in electrical characteristics. This study offers worthwhile information for considering the effects of electronic excitation prompted defect annealing and defect creation on the performance of HfO2/GaAs based photonic and optoelectronic devices, particularly, when such devices are operated in a radiation harsh environment.
Pairing phase favored by magnetic frustration
Authors: Krindges A , Morais C V , Schmidt M , Zimmer F M 
Published: November 2024

Abstract
The interplay between magnetic frustration and pairing is investigated by adopting a BCS-like pairing mechanism on the frustrated

J
1

−

J
2

Ising model on the square lattice. The ground-state and thermal phase transitions of the model are analyzed using a fermionic formulation within a CMF method. In this approach, the lattice system is divided into identical clusters, where the intracluster dynamic is exactly solved, and the intercluster interactions are replaced by self-consistent mean fields. We introduce a framework with two pairing couplings: an intracluster local coupling, g, which controls the electron pairing and its mobility within the clusters, and an intercluster coupling, g′, which adjusts the pairing mechanism between clusters. Tuning

g

′

/

g

allows evaluating how the pairing phase evolves from a weak pairing coupling between clusters (clustered system) to a strong one (

g

′

→
g

, homogeneous system). In the range

0
⩽

g

′

/

g
⩽
1

, we find that a gradual increase in

g

′

/

g

favors the pairing phase and induces a change in criticality. In particular, our results reveal the presence of tricriticality for a certain range of

g

′

/

g

. In addition, an increase in competing magnetic interactions weakens the magnetic orders, causing the pairing phase to occur at lower strengths of pairing interactions, especially when

g

′

=
g

. Therefore, our findings support that magnetic frustration favors the pairing phase, contributing to the onset of a superconducting state.
Bearing life prediction method based on novel health indicators and improved similarity curve matching
Authors: Zhang Jing , Zhang Chao , Wu Yangbiao , Liu Guiyi , Ouyang Bing 
Published: November 2024

Abstract
To tackle the issues of low accuracy in similarity curve matching and the challenges in measuring the similarity of degraded curve segments in rolling bearing life prediction methods, we propose a novel bearing remaining useful life (RUL) prediction method utilizing new health indicators (HIs) and improved similarity curve matching techniques. Initially, time and frequency domain features are extracted from the bearing vibration signals. Subsequently, the multi-dimensional features are meticulously screened using monotonicity, Spearman’s correlation, and uncertainty metrics to construct the HI and the HI library for the bearing. Subsequently, the support vector data description combined with the PID search algorithm is employed to ascertain the initial prediction time of the bearing and to construct the corresponding HI library. Following this, both global and local feature capture are conducted using dual dynamic time warping (DDTW) in conjunction with a sliding window to predict the remaining service life of rolling bearings. The proposed method is validated on the PHM2012 and XJTU-SY datasets and benchmarked against the latest research. The results demonstrate that our method significantly enhances the prediction accuracy of the RUL of bearings, underscoring the effectiveness and superiority of the proposed approach.
Shape measurement using a multicore optical fiber sensor with asymmetric dual cores
Authors: Wang Jianjian , Tang Rui , Shang Qiufeng 
Published: November 2024

Abstract
Shape measurement using multicore optical fiber sensors has attracted more attention in many fields due to the good consistency of the fiber cores. Three symmetrically arranged cores in a multicore fiber are usually used to reconstruct shapes by calculating the bending vectors, which will not be achieved when one of the cores is damaged or occupied in actual application. A shape measurement method using a multicore optical fiber sensor with asymmetric dual cores is proposed in this paper. Based on the analysis of the principle of shape reconstruction and the geometric relationship of the asymmetric dual cores in the multicore fiber sensor, the bending vector is decomposed. The mathematical expressions for the bending curvature and orientation of the asymmetric dual cores are derived. The two-dimensional (2D) and three-dimensional (3D) shape reconstruction results in both finite element modeling simulation and shape measurement experiments based on optical frequency domain reflectometry have shown that the proposed method using a multicore fiber sensor with asymmetric dual cores is able to achieve shape measurement; its performance is comparable and even equivalent to the traditional method that uses three symmetrically arranged cores. In the experiment, the maximum relative errors of 2D and 3D reconstructed shapes are 2.653% and 5.139%, respectively. The proposed method, which only needs asymmetric dual cores in the multicore optical fiber sensor for shape reconstruction, will be conducive to solving the limitations of multicore optical fiber sensors in shape measurement applications.
Comparison of contrast-enhanced ultrasound imaging (CEUS) and super-resolution ultrasound (SRU) for the quantification of ischaemia flow redistribution: a theoretical study
Authors: Arthur Lachlan J M B , Voulgaridou Vasiliki , Butler Mairead B , Papageorgiou Georgios , Lu Weiping , McDougall Steven R , Sboros Vassilis 
Published: November 2024

Abstract
The study of microcirculation can reveal important information related to pathology. Focusing on alterations that are represented by an obstruction of blood flow in microcirculatory regions may provide an insight into vascular biomarkers. The current in silico study assesses the capability of contrast enhanced ultrasound (CEUS) and super-resolution ultrasound imaging (SRU) flow-quantification to study occlusive actions in a microvascular bed, particularly the ability to characterise known and model induced flow behaviours. The aim is to investigate theoretical limits with the use of CEUS and SRU in order to propose realistic biomarker targets relevant for clinical diagnosis. Results from CEUS flow parameters display limitations congruent with prior investigations. Conventional resolution limits lead to signals dominated by large vessels, making discrimination of microvasculature specific signals difficult. Additionally, some occlusions lead to weakened parametric correlation against flow rate in the remainder of the network. Loss of correlation is dependent on the degree to which flow is redistributed, with comparatively minor redistribution correlating in accordance with ground truth measurements for change in mean transit time,

dMTT

(CEUS, R = 0.85; GT, R = 0.82) and change in peak intensity,

d
I
p

(CEUS, R = 0.87; GT, R = 0.96). Major redistributions, however, result in a loss of correlation, demonstrating that the effectiveness of time-intensity curve parameters is influenced by the site of occlusion. Conversely, results from SRU processing provides accurate depiction of the anatomy and dynamics present in the vascular bed, that extends to individual microvessels. Correspondence between model vessel structure displayed in SRU maps with the ground truth was

>
91
%

for cases of minor and major flow redistributions. In conclusion, SRU appears to be a highly promising technology in the quantification of subtle flow phenomena due ischaemia induced vascular flow redistribution.
Comparison of automatic and physiologically-based feature selection methods for classifying physiological stress using heart rate and pulse rate variability indices
Authors: Iovino Marta , Lazic Ivan , Loncar-Turukalo Tatjana , Javorka Michal , Pernice Riccardo , Faes Luca 
Published: November 2024

Abstract

Objective. This study evaluates the effectiveness of four machine learning algorithms in classifying physiological stress using heart rate variability (HRV) and pulse rate variability (PRV) time series, comparing an automatic feature selection based on Akaike’s criterion to a physiologically-based feature selection approach. Approach. Linear discriminant analysis, support vector machines, K-nearest neighbors and random forest were applied on ten HRV and PRV indices from time, frequency and information domains, selected with the two feature selection approaches. Data were collected from 127 healthy individuals during different stress conditions (rest, postural and mental stress). Main results. Our results highlight that, while specific stress classification is feasible, distinguishing between postural and mental stress remains challenging. The used classifiers exhibited similar performance, with automatic Akaike Information Criterion-based feature selection proving overall better than the physiology-driven approach. Additionally, PRV-based features performed comparably to HRV-based ones, indicating their potential in outpatient monitoring using wearable devices. Significance. The obtained findings help to determine the most relevant HRV/PRV features for stress classification, potentially useful to highlight different physiological mechanisms involved during both challenges accompanied by a shift in the sympathovagal balance. The proposed approach may have implications for advancing stress assessment methodologies in clinical settings and real-world contexts for well-being evaluation.
Magnetic field sensor based on multiple Fano resonance in metal-insulator-metal waveguide coupled with cross-shape resonator
Authors: Li Zhuang , Chen Fang , Yang Wenxing 
Published: November 2024

Abstract
In this paper, an innovative plasmonic magnetic field sensor (MFS) that exploits a Metal-insulator-Metal (MIM) waveguide configuration with an asymmetric cross-shaped resonator is constructed. The design enables the observation of double Fano resonance in the transmission spectrum, resulting from the coupling between continuous spectrum and discrete spectrum. By incorporating magnetic fluid in the asymmetric cross-shape resonator, the Fano line shapes can be tuned by the external magnetic field. Finite-Difference Time-Domain (FDTD) is used to simulate the spectra response to external magnetic fields and geometrical sizes. The proposed structure exhibits remarkable magnetic field sensitivity of

12.1

p
m
/
O
e

within the detection range of

15

O
e

to

199

O
e
.

The resolution of MIM magnetic field sensors can reach

0.0826

O
e
.

The optimal figure of merit (FOM) and maximum Q factor of the Fano dip are about

6.9
×

10

−
4

/

O
e

and 66.74, respectively. Meanwhile, The proposed Fano resonance MFS has some advantages, including compact size, high sensitivity, and cost-effectiveness. A strong linear relationship between the magnetic field and resonance wavelength indicates that the proposed structure can find potential applications in diverse fields such as magnetic field sensors, aircraft navigation, and even nuclear energy generation.
Molecular dynamics-based study of the effects of grain size and temperature on the nanoscratching groove characteristics of grating polycrystalline layered Al films
Authors: Liu Jiye , Shi Guangfeng , Jiang Ziwei 
Published: November 2024

Abstract
Echelle gratings, a specialized type of diffraction grating, feature a periodic groove pattern that exhibits excellent light-splitting capabilities. These gratings are characterized by a low density of lines per millimeter and a significant blaze angle. The primary substrate for echelle gratings in mechanical scratching is an aluminum film with a layered structure, which is determined by the coating process. However, the unique interlayer structure of the layered aluminum film, combined with the challenges posed by deep and high-precision triangular diffraction grooves, complicates the control of the scratching process. This article aims to investigate the material removal process and the thermal field-assisted scratching mechanism in the nano-scratching of polycrystalline layered aluminum films, with a particular emphasis on the material removal mechanism involved in nano-scratching. It discusses the influence of the thermal field and grain size on the mechanical response and the material removal process, while thoroughly examining their effects on the accuracy of groove formation. The results indicate that as the temperature increases, both the frictional and normal forces exhibit a decreasing trend. Additionally, a reduction in grain size corresponds to smaller frictional and normal forces. This decrease in scratching force contributes to minimizing the deformation of the workpiece during the scratching process, which is advantageous for precise control of groove shape and enhances the scratching quality of large-area gratings. As the temperature increases, the number of atoms removed from the polycrystalline layered aluminum film rises, leading to an enhanced material removal rate. Consequently, the accuracy of the diffraction grating groove also improves. Concurrently, the presence of delaminated grain boundary interfaces impedes the downward propagation of defects such as dislocations and can accommodate these dislocations. As temperature rises, the total length of dislocation lines decreases. Elevated temperatures promote the transformation of the crystal structure into an amorphous state. The grain boundaries and interlayer grain boundaries at the delamination restrict the movement of dislocations. The deformation behavior suggests that grain boundaries significantly contribute to the suppression of strain and stress propagation, resulting in a gradient distribution at the layered grain boundary interface, which further impedes stress transmission. Stress and strain are concentrated not only in the contact area between the tool tip and the substrate but also within the grain boundaries and their adjacent regions.
Impact of nuclear level density and radiative strength function models on the S factors of (α, γ) reactions relevant to p-nuclei production
Authors: Nhu Le N 
Published: November 2024

Abstract
The astrophysical S factors of (α, γ) reactions are crucial inputs to nuclear reaction network simulations for studying p-nuclei production. Previous work revealed considerable discrepancies between theoretical and experimental S factors using different nuclear level densities (NLD) and radiative strength functions (RSF). Accordingly, in this article, we studied the influence of six RSF and four NLD models on the astrophysical S factors of (α, γ) reactions on 16 target nuclei. The microscopic NLD and RSF models under investigation are based on the Hartree–Fock + Bardeen-Cooper-Schrieffer (HFBCS) and Hartree–Fock-Bogulubov (HFB) mean-field calculations. The obtained results have shown that within the α-OMP proposed in Nhu Le and Quang Hung (2022 Phys. Rev. C 105 014602), RSF and NLD models used in the S factor computation yield root mean square (rms) deviations of less than 0.750, and phenomenological NLD and RSF models provide better predictions for astrophysical S factors than microscopic ones in all cases considered. More research is needed on NLD and RSF models to improve prediction accuracy and reduce deviations in calculations of the S factors of radiative α captures.
Advancing non-linear PDE's solutions: modified Yang transform method with Caputo-Fabrizio fractional operator
Authors: Ullah Abd , Ansari Khursheed J , Ullah Aman 
Published: November 2024

Abstract
Nonlinear partial differential equations have a crucial rule in many physical processes. In this paper, a novel approach is used to study nonlinear partial differential equations of fractional order, which is named as Modified Yang Transform (MYT) method. This approach combines Yang transform with the Adomian decomposition method. The fractional order is considered in the Caputo-Fabrizio sense. Convergence analysis of the modified Yang transform to nonlinear fractional order partial differential equations is presented. Additionally, a solution framework for the solution of nonlinear partial differential equation is carried out and some examples are provided to highlight the application of the current method. To illustrate that how the solution behaves for various fractional orders, 2D and 3D graphs are plotted. Various tables are also provided to show the difference between exact and approximate solutions and the values are compared with other methods in the literature. Results and discussion sections are included for each example to explain the graphs, tables and their results.
Unraveling coupling delays through a transfer entropy analysis in stochastic processes and non-linear systems
Authors: Salgado-García R , Rivera Islas A I , Gonzalez-Narvaez R E , Vázquez F , López de Haro M 
Published: November 2024

Abstract
In this work we propose a transfer entropy approach to discern time-delay couplings within non-linear and stochastic coupled systems. We introduce the concept of ‘time-wise transfer entropy’, which quantifies the reduction in future uncertainty for a process Y by considering the values of processes X and Y at a specific past moment. The key advantage of our approach is a reduction in the number of parameters required for estimation when compared to other transfer entropy methodologies. Our proposed time-wise transfer entropy not only lends itself to effective estimation from actual data but also enhances our understanding of the origins of seemingly ‘spurious’ couplings observed in some transfer entropy approaches. To validate our method, we apply it to determine coupling delays in minimal stochastic models where the time-wise transfer entropy can be precisely derived in terms of the Shannon entropy. We further assess the technique performance in coupled non-linear systems with delays, demonstrating its capacity to accurately reproduce the corresponding coupling delays. The developed technique may be useful in the analysis of multifactor non-linear physical systems where complex causal relationships may exist.
Thermoelastic field analysis using differential transform under Moore-Gibson-thompson theory
Authors: Sutar C S , Chaudhari Kamini K , Pimpare Sangita B , Pardeshi Yuvraj 
Published: November 2024

Abstract
Heat conduction has many applications in engineering fields. There are various heat conduction models have been studied in the last few years. The main objective of this research is to study the effect of MGT model on thermoelastic problem. Also, offer a strong tool-the DifferentialTransform Method- for solving the governing partial differential equations with a simpler computation load than existing approaches. This paper presents the mathematical model describing the MooreGibsonThompson (MGT) equation in rectangular plate. This MGT equation is modified into the heat conduction in the rectangular plate. Thermoelastic phenomena play a significant role in heat conduction, particularly in materials that experience both thermal and mechanical stresses. Thus the thermoelastic properties of rectangular plates were also studied using the two-dimensional mathematical model under MGT heat conduction. Goodier's function and Boussinesq harmonic functions techniques have been used to obtain the thermal stresses in rectangular plates. The results have been discussed using graphs drawn by the mathematical software MATLAB.
Splitting of triply quantized vortices in Bose–Einstein condensates of finite temperature
Authors: Yan Jun , Mo Jiexiong , Mo Lichang , Lan Shanquan , Xu Xiaobao , Li Guqiang , He Huandian 
Published: November 2024

Abstract
Utilizing the dissipative Gross–Pitaevskii equation, we investigated the splitting dynamics of triply quantized vortices at finite temperature. Through linear perturbation analysis, we determined the excitation modes of these vortices across various dissipation parameters. We identified three unstable modes with p = 2-, 3- and 4-fold rotational symmetries, revealing a significant dynamic transition of the most unstable mode. That is, as the dissipation parameter increases the most unstable mode transitions from the p = 2 mode to the p = 3 mode. Throughout the entire range of dissipation parameters, the p = 4 unstable mode is never the dominant mode. Subsequently, we performed nonlinear numerical simulations of the vortex splitting process. Under random perturbations we confirmed the dynamical transition, and under specific perturbations we confirmed the instability of the p = 4 mode. Our findings on the finite temperature dependence of the splitting dynamics of triply quantized vortices are expected to be verifiable in experiments.
Components and Anisotropy of 3D QFP Waves During the Early Solar Eruption
Authors: Hu Jialiang , Ye Jing , Chen Yuhao , Mei Zhixing , Xu Shanshan , Lin Jun 
Published: November 2024

Abstract
The propagation of disturbances in the solar atmosphere is inherently three-dimensional (3D), yet comprehensive studies on the spatial structure and dynamics of 3D wave fronts are scarce. Here we conduct high-resolution 3D numerical simulations to investigate filament eruptions, focusing particularly on the 3D structure and genesis of extreme ultraviolet (EUV) waves. Our results demonstrate that the EUV wave front forms a dome-like configuration subdivided into three distinct zones. The foremost zone, preceding the flux rope, consists of fast-mode shock waves that heat the adjacent plasma. Adjacent to either side of the flux rope, the second zone contains expansion waves that cool the nearby plasma. The third zone, at the juncture of the first two, exhibits minimal disturbances. This anisotropic structure of the wave front stems from the configuration and dynamics of the flux rope, which acts as a 3D piston during eruptions—compressing the plasma ahead to generate fast-mode shocks and evacuating the plasma behind to induce expansion waves. This dynamic results in the observed anisotropic wave front. Additionally, with synthetic EUV images from simulation data, the EUV waves are observable in Atmospheric Imaging Assembly 193 and 211 Å, which are identified as the fast-mode shocks. The detection of EUV waves varies with the observational perspective: the face-on view reveals EUV waves from the lower to the higher corona, whereas an edge-on view uncovers these waves only in the higher corona.