bluuebunny/crossref_metadata_2025 huggingface dataset:
A tutorial on optical photothermal infrared (O-PTIR) microscopy
Authors: Prater Craig B. , Kansiz Mustafa , Cheng Ji-Xin
Published: September 2024

This tutorial reviews the rapidly growing field of optical photothermal infrared (O-PTIR) spectroscopy and chemical imaging. O-PTIR is an infrared super-resolution measurement technique where a shorter wavelength visible probe is used to measure and map infrared (IR) absorption with spatial resolution up to 30× better than conventional techniques such as Fourier transform infrared and direct IR laser imaging systems. This article reviews key limitations of conventional IR instruments, the O-PTIR technology breakthroughs, and their origins that have overcome the prior limitations. This article also discusses recent developments in expanding multi-modal O-PTIR approaches that enable complementary Raman spectroscopy and fluorescence microscopy imaging, including wide-field O-PTIR imaging with fluorescence-based detection of IR absorption. Various practical subjects are covered, including sample preparation techniques, optimal measurement configurations, use of IR tags/labels and techniques for data analysis, and visualization. Key O-PTIR applications are reviewed in many areas, including biological and biomedical sciences, environmental and microplastics research, (bio)pharmaceuticals, materials science, cultural heritage, forensics, photonics, and failure analysis.
Lopsided rigid dumbbell rheology from Langevin equation: A graduate tutorial
Authors: Phan-Thien Nhan , Pan Dingyi , Kanso Mona A. , Giacomin Alan Jeffrey
Published: September 2024

The modeling of symmetric rigid dumbbell particles suspended in a Newtonian fluid, as a model of a rigid-rod polymeric solution, has been accomplished exclusively through the diffusion equation, detailed elegantly by Bird et al. [Dynamics of Polymeric Liquids: Kinetic Theory, 2nd ed. (Wiley, NY, 1987), Vol. 2]. In this Tutorial, a straightforward approach for modeling a lopsided rigid dumbbell particle in suspension is presented by the Langevin analysis. The connector force between the dumbbell beads is obtained through the rigidity constraint of the center-to-center vector of the dumbbell using its Langevin equation. By directly averaging via the Langevin equation, the evolution of the center-to-center vector and the configuration tensor are derived. The stress expressions for the dumbbell from the Langevin equation and the diffusion equation for the orientation distribution function of the center-to-center vector of the dumbbell are also derived, and the final expressions agree with the established results from other methods.
A new design of electro-conjugate fluid micropumps with Venturi and teardrop-shaped electrodes
Authors: Lai The Khanh , Dinh Toan , Nguyen Minh Duc , Ngo Ich Long
Published: September 2024

This paper presents a newly designed non-mechanical electro-conjugate fluid (ECF) micropump with a Venturi-shaped collector and teardrop-shaped emitter (VD-ECF micropump). The numerical model using the finite element method was thoroughly validated by comparing it with both experimental data and numerical results. Consequently, the characteristic curves of the VD-ECF micropump are significantly affected by both the emitter angle (θ1) and the collector angle (θ2). The effects of these angles on the flow behaviors in a VD-ECF micropump were first explained. Furthermore, the performance characteristic curves were elaborately constructed for various operating conditions. The operating ranges of pressure difference and flow rate of the VD-ECF micropump are extended, and they peak at θ2 approximately from 25° to 30°. Additionally, the maximum efficiency reaches up to 10%, which is the highest figure recorded to date. The obtained results for the new VD-ECF micropump would significantly contribute to the development of ECF micropumps with precise control. Our work also gives valuable guidelines for designing and manufacturing processes of this type of micropump, which has potential applications in microelectronic cooling systems, micro-actuators, and drug transport mechanisms in medical and biomedical fields.
Ablation characteristics of tungsten with ultra-short laser pulses
Authors: Mittelmann Steffen , Riedlinger Jan , Buchner Benedikt , Schwarz-Selinger Thomas , Mayer Matej , Pretzler Georg
Published: September 2024

In approaches to analyze material composition or in processing tasks using ultra-short laser ablation, it is of particular interest how ablated materials are distributed across the solid angle in front of the interaction region. We found that with our sub-10-fs laser in the regime from 1014W/cm2 to 1017W/cm2, the solid angle of the ablation cone decreases significantly along with the laser intensity in a vacuum environment. For this observation, we used ion-beam analysis to investigate the distribution of tungsten collected on silicon catcher plates arranged across the solid angle of the laser-ablation cone. Moreover, we used other post-mortem tools, such as scanning electron microscopy and confocal laser scanning microscopy, to determine the ablation threshold of Fth=468mJ/cm2 of our tungsten samples. Here, clearly, two laser intensity-dependent ablation regimes can be observed in the detection of a crater depth and a ablation cone angle.
Study on coherent structures in the flow field of single-cell and vortex breakdown tornado-like vortices
Authors: Zhang Dong , Li Zhuoyue , Zhang Di , Gao Nao , Liu Yakun
Published: September 2024

The coherent structures at different height planes within a vortex-breakdown tornado-like flow field are investigated using particle image velocimetry. Proper orthogonal decomposition (POD) of the experimental velocity field reveals that, in the flow field of tornadoes with vortex breakdown, the vortex is a single-cell structure at high altitude, and the main large-scale coherent structure is vortex wandering. At lower altitude, in the plane where vortex breakdown occurs, the coherent motion of vortex size variations intensifies significantly. The mechanisms whereby large-scale coherent motions (vortex wandering and vortex size variations) influence the fluctuating velocity and Reynolds stresses in the vortex flow field within different vortex structures are determined through the low-order reconstruction of modes and analysis of modal stresses. An investigation of numerically synthesized vortex POD modes explains the origins of POD spatial modes for vortex wandering and vortex size variations in single-vortex and vortex-breakdown tornado-like flow fields. Furthermore, by identifying fewer modes in the velocity fields simulated by Burgers' theoretical model, a simplified model capable of representing the fluctuating velocity in single-vortex tornado flow fields is constructed and found to be in good agreement with experimental results.
Interactions between cavitation bubbles and free surfaces of non-Newtonian polymer solutions
Authors: Liu Yang , Zheng Zhi-Ying , He Zhi-Bo , Zeng Tian-Bao , Wang Lu , Cai Wei-Hua , Qi Hong
Published: September 2024

The interaction between cavitation bubbles and free surfaces in non-Newtonian biological fluid holds significant importance for biomedical fields like drug delivery and disease treatment. This paper investigates the influences of elasticity and shear-thinning of non-Newtonian fluid on the interaction between cavitation bubbles and free surfaces by performing visualization experiments on the laser-induced cavitation bubbles near the free surfaces of the water and carboxymethyl cellulose and polyacrylamide solutions with the concentrations of 500–5000 ppm at different dimensionless standoff distances. The results show that the evolutions of free surface in all solutions can be divided into six patterns of water mounds. The elasticity and shear-thinning exhibit significant effects on the four patterns at smaller dimensionless standoff distances (breaking wrinkles, spraying water film, crown, and swallowed water spike) and the evolutions of cavitation bubbles in the corresponding cases. The resultant differences lie in the morphology and migration of bubbles and the stability and morphology of the water spike and water skirt. Combining with the quantitative analyses, it can be concluded that elasticity inhibits the movement and pinch-off of water spike, water skirt expansion, bubble jet motion, and bubble growth and migration within its second period. Conversely, shear-thinning could counteract the inhibitory effects of elasticity in the solutions with lower concentrations, promoting the rise in water spike, water skirt expansion, and bubble jet motion. Finally, the influence mechanisms of elasticity and shear-thinning on the evolution of free surface and cavitation bubble dynamics are revealed from the perspective of the deformation of polymer molecular chains.
Bismuth-related defects in n-type silicon irradiated with protons: A comparison to similar defects formed under electron irradiation
Authors: Emtsev Vadim , Abrosimov Nikolay , Kozlovski Vitalii , Lastovskii Stanislav , Oganesyan Gagik , Poloskin Dmitrii
Published: September 2024

Electrical properties of defects produced in strongly bismuth-doped silicon by 15 MeV protons are investigated in detail. Electrical measurements on irradiated samples by means of the van der Pauw technique are conducted over a wide temperature range of 20–300 K to furnish information on radiation-produced complexes. It is shown that the properties of the dominant bismuth-related defects are the same as earlier found in the electron-irradiated material. These complexes are tentatively identified as bismuth–vacancy pairs being deep donors. Their atomic configuration appears to be radically different from what is known about similar vacancy-related defects with other group-V impurities. These bismuth-related pairs are stable up to T ≈ 300 °C. Some special features of defect formation and annealing processes of radiation defects in bismuth-doped silicon subjected to electron and proton irradiation are discussed. This information may be of advantage in modeling impurity-related complexes containing oversized impurity atoms in silicon.
Large-space and large-time asymptotic properties of vector rogon-soliton and soliton-like solutions for n-component NLS equations
Authors: Weng Weifang
Published: September 2024

In this paper, we analyze the large-space and large-time asymptotic properties of the vector rogon-soliton and soliton-like solutions of the n-component nonlinear Schrödinger equation with mixed nonzero and zero boundary conditions. In particular, we find that these solutions have different decay velocities along different directions of the x axis, that is, the solutions exponentially and algebraically decay along the positive and negative directions of the x axis, respectively. Moreover, we study the change of the acceleration of soliton moving with the increase in time or distance along the characteristic line (i.e., soliton moving trajectory). As a result, we find that the product of the acceleration and distance square tends to some constant value as time increases. These results will be useful to better understand the related multi-wave phenomena and to design physical experiments.
Shock equation of state experiments in MgO up to 1.5 TPa and the effects of optical depth on temperature determination
Authors: Ye Zixuan , Smith Raymond F. , Millot Marius , Sims Melissa , Tsapetis Dimitrios , Shields Michael D. , Singh Saransh , Hari Anirudh , Wicks June K.
Published: September 2024

Laser-driven shock compression enables an experimental study of phase transitions at unprecedented pressures and temperatures. One example is the shock Hugoniot of magnesium oxide (MgO), which crosses the B1–B2-liquid triple point at 400–600 GPa, 10 000–13 000 K (0.86–1.12 eV). MgO is a major component within the mantles of terrestrial planets and has long been a focus of high-pressure research. Here, we combine time-resolved velocimetry and pyrometry measurements with a decaying shock platform to obtain pressure–temperature data on MgO from 300 to 1500 GPa and 9000 to 50 000 K. Pressure–temperature–density Hugoniot data are reported at 1500 GPa. These data represent the near-instantaneous response of an MgO [100] single crystal to shock compression. We report on a prominent temperature anomaly between 400 and 460 GPa, in general agreement with previous shock studies, and draw comparison with equation-of-state models. We provide a detailed analysis of the decaying shock compression platform, including a treatment of a pressure-dependent optical depth near the shock front. We show that if the optical depth of the shocked material is larger than 1 μm, treating the shock front as an optically thick gray body will lead to a noticeable overestimation of the shock temperature.
A numerical hydrodynamic study of the influence of prolate and prolate 45° ellipsoids on laminar flow
Authors: Díaz-Ojeda H. R. , Zhang Yifu , Turnock Stephen , Pérez-Sánchez Julio
Published: September 2024

This paper examines the impact of two tandem configurations of ellipsoids on laminar flow using numerical methods. The first configuration features an ellipsoid in a prolate orientation, while the other employs a prolate ellipsoid tilted at a 45° angle relative to the vertical axis. The study investigates inter-ellipsoid distances ranging from one ellipsoid diameter (1D) to eight diameters (8D) from the ellipsoids' centers and different Reynolds numbers (100, 200, 300, and 400). The presented results focus on hydrodynamic forces, wake symmetry, and wake patterns for different scenarios. The findings reveal that when an angle is present in the ellipsoid, the drag forces between the front and rear ellipsoids tend to approach at smaller separations compared to the prolate orientation case. In these cases, flow separation is asymmetric in the x–y plane but becomes symmetric in the x–z plane at larger ellipsoid spacings. Additionally, the detachment zones are analyzed concerning the angle and Reynolds number. It is observed that up to a distance of approximately 4D, the wake of the front ellipsoid significantly influences the recirculation and hydrodynamics of the rear ellipsoid.
Digital technology and self-care in sexual health
Authors: Ong Jason J. , Tucker Joseph D.
Published: September 2024

This Collection highlights some recent publications in Sexual Health on using technology to optimise sexual health. By leveraging innovations such as rapid diagnostic tools, mobile health (mHealth), self-testing and artificial-intelligence-powered tools, we can empower individuals to take control of their sexual health, reducing risks and enhancing accessibility.
Gypsum form and rate can affect soil physicochemical properties and crop productivity in soils of low electrical conductivity that have been enriched by sodium due to supplementary irrigation
Authors: Carciochi Walter D. , Chevallier Boutell Justo , García Gisela V. , Diovisalvi Natalia V. , Wyngaard Nicolas , Lapaz Olveira Adrián , Reussi Calvo Nahuel I.
Published: September 2024

Context The optimum gypsum form and rate required to ameliorate soil sodicity constraints caused by supplementary irrigation with water containing sodium bicarbonate in humid regions are unknown. Aim Evaluate the short-term effect of different gypsum forms and rates on (i) soil physicochemical properties and (ii) grain yield in a barley (Hordeum vulgare L.)/maize (Zea mays L.) sequence. Methods We conducted two field experiments in the southeastern Argentinean Pampas on soils with low electrical conductivity (0.2 dS m−1), assessing three forms of gypsum (granulated, pelletised, and powdered) applied a month before barley sowing at 2000 kg ha−1. In one experiment, 3000 kg ha−1 was also tested. Soil properties and grain yield were determined at barley and maize harvests (i.e. 7 and 13 months after the gypsum application, respectively). Key results (i) Gypsum did not significantly affect soil physical properties; (ii) powdered gypsum at 3000 kg ha−1 enhanced soil chemical properties at barley harvest, decreasing pH by 7% and exchangeable sodium percentage by 35%, while increasing the exchangeable Ca2+/Na+ ratio by 70% (0.0–0.1 m depth); (iii) powdered gypsum improved soil chemical conditions at deeper soil depths (0.1–0.2 m) at maize harvest; (iv) barley grain yield increased with gypsum application; and (v) maize yield was negatively correlated with soil pH and positively correlated with the Ca2+/Na+ ratio. Conclusions Powdered gypsum can rapidly improve soil chemical properties and increase crop yields. Implications Powdered gypsum, especially at 3000 kg ha−1, could be used to alleviate soil sodicity issues in the short-term.
The development of L1 and L2 reading skills from captioned video viewing
in primary school EFL learners
Authors: Avello Daniela , Muñoz Carmen
Published: September 2024

This investigation explored the extent to which captioned
video viewing (11 episodes) fostered the development of L2 reading skills in
a group of 92 L1-Spanish primary school learners of English (years 4 and 5).
It also assessed the influence of L1- and L2-related factors on students’
reading performance over time. The analyses revealed learners’ significant
improvement in L2 reading skills as a result of the treatment and that
L2-related factors were stronger predictors than L1-related factors. One
interesting finding was that the treatment also enhanced the development of
L1 reading skills, particularly in the case of fifth graders. This outcome
lent support to the idea that in early L2 learning stages, students rely on
their L1 linguistic infrastructure to deal with L2 print.
Multimodal input and L2 pragmatics
Authors: Barón Júlia , Celaya M. Luz , Martínez-Flor Alicia
Published: September 2024

Analyzing the effects of multimodal input in the
acquisition of second/foreign language (L2) pragmatics is a recent area in
research. In this line, the use of eye-tracking to investigate L2
pragmatics remains limited (Godfroid, 2019). This study aimed to explore the
effects of multimodal input on L2 requests among English as a Foreign
Language (EFL) learners, while monitoring them with a webcam eye-tracker.
The study used a multiple-choice discourse completion test at pre and
posttest to evaluate the effects of viewing audio-visual material with or
without captions. Additionally, a subset of participants was
interviewed regarding pragmatic perception. Findings indicate that
participants exposed to captioned videos performed better in the posttest and relied
on captions when viewing, a result corroborated by retrospective
interviews.
The role of language aptitude in learning L2 constructions from captioned
and uncaptioned audiovisual input
Authors: Pattemore Anastasia , del Mar Suárez Maria , Montero Perez Maribel , Muñoz Carmen
Published: September 2024

This chapter discusses the effects of aptitude on
learning L2 grammatical constructions from TV series with or without
captions. Study 1 involved 69 Catalan/Spanish learners of English (EFL) who
watched ten episodes of an English TV series, and targeted grammatical
constructions learning. Study 2 comprised 30 Flemish learners of Spanish
(ELE) who watched two excerpts from a Spanish TV series episode, with
auditory grammaticality judgement pretest-posttest to assess their learning
of subjunctive constructions. Grammatical sensitivity and inference aptitude
was measured using LLAMA F in both studies. Results revealed that groups
without captions relied more on aptitude to handle the demanding processing
of fast-paced TV series. Successful processing of uncaptioned input appeared
to require higher aptitude, whereas captions attenuated the effects of
individual differences.
First-Principles Studies of Structural Evolutions in Cathode Materials LiMO2 (M=Co, Mn, Ni)
Authors: Sun 孙 Yufeng 瑜锋 , Gong 龚 Xin-Gao 新高 , Yang 杨 Ji-Hui 吉辉
Published: September 2024

We explore the structural evolutions of stoichiometric LiMO2 using the first-principles calculations combined with the cluster expansion method. We automatically obtain the ground state structures of the stoichiometric LiMO2 by just considering the cation orderings in the quasi rock-salt structures and the following structural relaxations due to both the atomic size mismatches and the Jahn–Teller distortions. We point out that, on the one hand, the cation orderings are mainly determined by the nearest, the second nearest, and the third nearest cation interactions and can be obtained from the ‘phase diagram’ we have built using the relative strengths of effective cluster interaction (ECI). On the other hand, the structural relaxations are dominated by the crystal field splitting (CFS) energies, i.e., structures with larger CFS energies are more stable. By calculating the ECIs and CFS energies for various structures of LiMO2, we clearly show how ECI and CFS play roles in determining the structural evolution mechanism of these systems.
The acoustic Galton board
Authors: Zhang Xinchao , Zheng Ning , Guo Fenze , Lin Hengze , Shi Qingfan
Published: September 2024

Phononic crystals are a class of materials with periodic structures that influence the propagation characteristics of acoustic waves through periodically arranged structural units. Here, we have developed the acoustic Galton board (AGB), a groundbreaking apparatus that serves as a cost-effective and user-friendly tool for demonstrating phononic crystal properties such as band gaps, Bragg scattering, and local resonance. The device comprises an elastic wave signal generator, an enhanced Galton board featuring a sophisticated pillar-nail array, and a signal receiver. The experimental results we have obtained demonstrate the significant impact of the AGB on elastic wave dispersion, effectively creating bandgaps that impede wave transmission within specific frequency ranges while allowing unhindered propagation in others. Furthermore, the AGB can simulate phononic crystals using both the Bragg scattering mechanism, achieved through the design of periodic rigid pillar-nail arrays, and the locally resonant mechanism, facilitated by the design of pillar-nail arrays with composite material structures. Additionally, the AGB can extend its applications to serve as a simulation tool for elastic metamaterials.
Calculation of thermodynamic properties and transport coefficients of

Ar

/

N
2

–

H
2

–

Si

plasma
Authors: Cheng Zhu , Xianhui Chen , Yunfei Zhang , Weidong Xia , Cheng Wang
Published: September 2024

The composition, thermodynamic properties and transport coefficients of

Ar

–

H
2

–

Si

and

N
2

–

H
2

–

Si

plasma within a temperature range of 300–30 000 K and pressure range of 0.1–10 atm are calculated under the assumptions of local thermal equilibrium (LTE) and local chemical equilibrium (LCE). Taking Debye–Hückel corrections into account, the chemical equilibrium composition and thermodynamic properties of these two plasma systems are derived using the mass action law and classical statistical thermodynamics respectively. The transport coefficients, including viscosity, conductivity, and thermal conductivity, are calculated using the Chapman–Enskog (C–E) method extended to a third-order approximation (second-order for viscosity and heavy particle translational thermal conductivity). Some of the results have been compared with those of other researchers, and there is a good level of agreement. The slight difference arises from the selection of interaction potential. The final calculation reveals that the introduction of silicon vapor significantly alters the thermodynamic properties and transport coefficients of

Ar

/

N
2

–

H
2

–

Si

plasma, even at a small concentration of silicon vapor (1%), the effect on the electrical conductivity cannot be ignored. Furthermore, our calculation results provide the fundamental data for numerical simulations of magnetohydrodynamics (MHD) for the synthesis of silicon nanoparticles and silicon composites.
Mechanical behavior of zirconium hydride phases: insights from molecular dynamics based simulations
Authors: Patil Sanjay , Parashar Avinash
Published: September 2024

This article aims to study the mechanical behavior of zirconium hydride phases, including γ-ZrH, δ-ZrH1.5, and ϵ-ZrH2. Atomistic simulations were performed to analyze the uni-axial tensile behavior of zirconium (Zr) and zirconium hydrides in conjunction with the deformation governing mechanism. The mechanical behavior of Zr and zirconium hydrides was studied with the help of stress–strain curves, dislocation dynamics, and von Mises stress distribution. The atomistic simulation results were subsequently compared with the existing trends in the literature. The hydrogen concentration significantly influences the mechanical properties and deformation governing behavior of zirconium hydrides. Hydride precipitate in the Zr matrix is a barrier to the glissile dislocations, leading to hydrogen embrittlement. This phenomenon intensifies with hydride size and hydrogen concentration, and the effect is more pronounced at lower temperatures.
Terahertz phase imaging of large-aperture liquid crystal modulator with ITO interdigitated electrode
Authors: Le Bourlout A , Pusenkova A , Lafrenière-Greig J , Ropagnol X , Galstian T , Blanchard F
Published: September 2024

We have fabricated and characterized a large-aperture electrooptic phase modulation device operating in the terahertz (THz) frequency range. The device consists of a 1.6 mm thick nematic liquid crystal placed between glass plates with a novel interdigitated electrode design. Using THz time-domain spectroscopy (THz-TDS) coupled with raster scanning imaging, we evaluated phase modulation across a 25 mm diameter LC device and mapped the spatial uniformity of phase shift. Our results confirm the functionality of the LC cell as a controllable quarter-wave plate at 0.26 THz and half-wave plate at 0.52 THz. This work contributes to the development of large-aperture and transmissive LC devices as low-cost phase plates for THz waves and paves the way for future applications in THz modulators.
Room temperature spin injection study across semi-crystalline PVDF-HFP thin films in PVDF-HFP/NiFe bilayers and Ag/(NiFe or Co)/PVDF-HFP/NiFe spin valves
Authors: Roy Jyotirmoy , Ravi Teja Pajjuru , Sahu Savita , S Devadarsan , Basheed G A , Gangineni R B
Published: September 2024

Spin injection across 160 nm thick semi-crystalline Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) is methodically investigated at room temperature in PVDF-HFP/NiFe bilayers and Ag/(NiFe or Co)/PVDF-HFP/NiFe vertical organic spin valves (OSVs) using both the co-planar waveguide ferromagnetic resonance (CPW-FMR: 7–35 GHz) and magnetoresistance (MR) techniques. The structural and microstructural characteristics of PVDF-HFP reveal the formation of mixed non-ferroelectric alpha and ferroelectric beta phases. The spin injection due to the transfer of angular momentum in PVDF-HFP/NiFe is quantified by measuring the spin-mixing conductance (g
↑↓) and the enhancement in Gilbert damping (
α
) parameters from CPW-FMR data. A significant increase in
α
of 26% and g
↑↓ of (2.72 ± 0.45) × 1019 m−2 highlights the efficient spin injection into the PVDF-HFP spacer layer. Further, the MR in OSV structures reveals a room temperature spin injection with a maximum MR of 0.278 ± 0.006% for Ag/Co/PVDF-HFP/NiFe and 0.349 ± 0.039% for the Ag/NiFe/PVDF-HFP/NiFe devices. Furthermore, the spin injection processes are discussed w.r.t to bias voltages, interfaces and microwave frequencies.
A systematic review of data augmentation methods for intelligent fault diagnosis of rotating machinery under limited data conditions
Authors: Ju Zedong , Chen Yinsheng , Qiang Yukang , Chen Xinyi , Ju Chao , Yang Jingli
Published: September 2024

In recent years, research on the intelligent fault diagnosis of rotating machinery has made remarkable progress, bringing considerable economic benefits to industrial production. However, in the industrial environment, the accuracy and stability of the diagnostic model face severe challenges due to the extremely limited fault data. Data augmentation methods have the capability to increase both the quantity and diversity of data without altering the key characteristics of the original data, which is particularly important for the development of intelligent fault diagnosis of rotating machinery under limited data conditions (IFD-RM-LDC). Despite the abundant achievements in research on data augmentation methods, there is a lack of systematic reviews and clear future development directions. Therefore, this paper systematically reviews and discusses data augmentation methods for IFD-RM-LDC. Firstly, existing data augmentation methods are categorized into three groups: synthetic minority over-sampling technique (SMOTE)-based methods, generative model-based methods, and data transformation-based methods. Then, these three methods are introduced in detail and discussed in depth: SMOTE-based methods synthesize new samples through a spatial interpolation strategy; generative model-based methods generate new samples according to the distribution characteristics of existing samples; data transformation-based methods generate new samples through a series of transformation operations. Finally, the challenges faced by current data augmentation methods, including their limitations in generalization, real-time performance, and interpretability, as well as the absence of robust evaluation metrics for generated samples, have been summarized, and potential solutions to address these issues have been explored.
Deep learning-based segmentation for high-dose-rate brachytherapy in cervical cancer using 3D Prompt-ResUNet
Authors: Xue Xian , Sun Lining , Liang Dazhu , Zhu Jingyang , Liu Lele , Sun Quanfu , Liu Hefeng , Gao Jianwei , Fu Xiaosha , Ding Jingjing , Dai Xiangkun , Tao Laiyuan , Cheng Jinsheng , Li Tengxiang , Zhou Fugen
Published: September 2024

Objective. To develop and evaluate a 3D Prompt-ResUNet module that utilized the prompt-based model combined with 3D nnUNet for rapid and consistent autosegmentation of high-risk clinical target volume (HRCTV) and organ at risk (OAR) in high-dose-rate brachytherapy for cervical cancer patients. Approach. We used 73 computed tomography scans and 62 magnetic resonance imaging scans from 135 (103 for training, 16 for validation, and 16 for testing) cervical cancer patients across two hospitals for HRCTV and OAR segmentation. A novel comparison of the deep learning neural networks 3D Prompt-ResUNet, nnUNet, and segment anything model-Med3D was applied for the segmentation. Evaluation was conducted in two parts: geometric and clinical assessments. Quantitative metrics included the Dice similarity coefficient (DSC), 95th percentile Hausdorff distance (HD95%), Jaccard index (JI), and Matthews correlation coefficient (MCC). Clinical evaluation involved interobserver comparison, 4-grade expert scoring, and a double-blinded Turing test. Main results. The Prompt-ResUNet model performed most similarly to experienced radiation oncologists, outperforming less experienced ones. During testing, the DSC, HD95% (mm), JI, and MCC value (mean ± SD) for HRCTV were 0.92 ± 0.03, 2.91 ± 0.69, 0.85 ± 0.04, and 0.92 ± 0.02, respectively. For the bladder, these values were 0.93 ± 0.05, 3.07 ± 1.05, 0.87 ± 0.08, and 0.93 ± 0.05, respectively. For the rectum, they were 0.87 ± 0.03, 3.54 ± 1.46, 0.78 ± 0.05, and 0.87 ± 0.03, respectively. For the sigmoid, they were 0.76 ± 0.11, 7.54 ± 5.54, 0.63 ± 0.14, and 0.78 ± 0.09, respectively. The Prompt-ResUNet achieved a clinical viability score of at least 2 in all evaluation cases (100%) for both HRCTV and bladder and exceeded the 30% positive rate benchmark for all evaluated structures in the Turing test. Significance. The Prompt-ResUNet architecture demonstrated high consistency with ground truth in autosegmentation of HRCTV and OARs, reducing interobserver variability and shortening treatment times.
Assessment of alternative metrics in the application of infrared thermography to detect muscle damage in sports
Authors: Verderber Lukas , da Silva Willian , Aparicio-Aparicio Inmaculada , Germano Andresa M C , Carpes Felipe P , Priego-Quesada Jose Ignacio
Published: September 2024

Objective. The association between muscle damage and skin temperature is controversial. We hypothesize that including metrics that are more sensitive to individual responses by considering variability and regions representative of higher temperature could influence skin temperature outcomes. Here, the objective of the study was to determine whether using alternative metrics (TMAX, entropy, and pixelgraphy) leads to different results than mean, maximum, minimum, and standard deviation (SD) skin temperature when addressing muscle damage using infrared thermography. Approach. Thermal images from four previous investigations measuring skin temperature before and after muscle damage in the anterior thigh and the posterior lower leg were used. The TMAX, entropy, and pixelgraphy (percentage of pixels above 33 °C) metrics were applied. Main results. On 48 h after running a marathon or half-marathon, no differences were found in skin temperature when applying any metric. Mean, minimum, maximum, TMAX, and pixelgraphy were lower 48 h after than at basal condition following quadriceps muscle damage (p < 0.05). Maximum skin temperature and pixelgraphy were lower 48 h after than the basal condition following muscle damage to the triceps sural (p < 0.05). Overall, TMAX strongly correlated with mean (r = 0.85) and maximum temperatures (r = 0.99) and moderately with minimum (r = 0.66) and pixelgraphy parameter (r = 0.64). Entropy strongly correlates with SD (r = 0.94) and inversely moderately with minimum temperature (r = −0.53). The pixelgraphy moderately correlated with mean (r = 0.68), maximum (r = 0.62), minimum (r = 0.58), and TMAX (r = 0.64). Significance. Using alternative metrics does not change skin temperature outcomes following muscle damage of lower extremity muscle groups.
Introduction of a novel longitudinal-flexural-torsional actuator using a magnetostrictive rod
Authors: Karafi Mohammad Reza , Ansari Saeed
Published: September 2024

This paper presents a novel bulk magnetostrictive actuator, utilizing a rod made of Permendur alloy. This actuator demonstrates versatility in accommodating longitudinal, torsional, and flexural deformations. Longitudinal deformation is induced by applying magnetic fields along the material’s axis, exploiting the Joule effect. The axial magnetic field is generated by a coaxial coil surrounding the material. Torsional deformation is achieved by passing current through the magnetostrictive material and applying circumferential magnetic field, following the Wiedeman effect. To induce flexural deformation, a magnetic field is applied at the material’s surface, facilitated by a magnetic coupler. Actuation is executed using DC magnetic fields, granting the actuator control over four degrees of freedom. Numerical analysis conducted utilizing COMSOL software, showed the combined modes and their mutual influences. The actuator’s displacement range reaches a maximum of 12 µms longitudinally, 7 µms flexurally, and 0.15 degrees torsionally. It also exhibits the capability of simultaneous excitation in two or three different modes. The experiments and studies conducted show the potential application of this innovative actuator in precise positioning systems such as microscopes and optical systems.
Loading-unloading contact analysis of functionally graded carbon nanotube reinforced composite (FG-CNTRC)
Authors: Bhadra Rakesh , Jana Tamonash , Mitra Anirban , Sahoo Prasanta
Published: September 2024

The present work deals with a finite element based spherical indentation contact analysis of a functionally graded carbon nanotube reinforced composite (FG-CNTRC) substrate. The gradation in the composite is achieved by varying the distribution of the reinforced CNTs within the matrix material, which is considered to be aluminium in the present study. The finite element modelling and analysis has been performed in finite element software ANSYS platform. The model’s validity has been convincingly substantiated through a comparison with the findings of already published relevant articles from the literature. In the present study, a detailed investigation is conducted for three types of CNT distribution in the substrate: increasing, decreasing, and uniform density with depth. The investigation aims to examine the influence of these distributions on different contact behavioral parameters e.g. contact force, contact area, contact stresses etc The analysis would pave a way for modelling and fabricating appropriate FG-CNTRC substrate for a desired as well as damage resistant surface contact behavior.
A novel design of the electrostatic storage ring using quadrupole deflector
Authors: Jalel Jaafar , Hussein Oday A
Published: September 2024

A novel electrostatic storage ring (ESR) design was created using an electrostatic quadrupole deflector (EQD) and quadrupole doublet lens (QDL). EQD was used to turn the electron beam 90 degrees in order to create an innovative ESR design. The impact of EQD designs on ESR performance was investigated, and the results showed that the performance of ESR was directly affected by the EQD design. The calculations showed that increasing the EQD diameter by 20% led to an enhancement in the electron beam dimensions by 88% for ∆x and 44% for ∆y for the initial angle of the electron beam α = 0.2°. Also, the design achieved its goal of keeping kinetic energy constant, where for an initial kinetic energy of 1000 eV, the difference between the energy of the injected electron beam and the emerging electron beam from the ESR is approximately 1–5 eV, i.e., despite changing the diameter of the EQD, the dimensions of the electron beam improve and the kinetic energy remains constant.
One-dimensional Dunkl quantum mechanics: a path integral approach
Authors: Benchikha A , Hamil B , Lütfüoğlu B C , Khantoul B
Published: September 2024

In the present manuscript, we employ the Feynman path integral method to derive the propagator in one-dimensional Wigner-Dunkl quantum mechanics. To verify our findings we calculate the propagator associated with the free particle and the harmonic oscillator in the presence of the Dunkl derivative. We also deduce the energy spectra and the corresponding bound-state wave functions from the spectral decomposition of the propagator.
Temperature-induced dielectric and electrical behavior of Cs/HPC-copper vanadate nanocomposites
Authors: Al-kalali N A , Abdelghany A M , Bin Anooz S , Abdelaziz M , Oraby A H
Published: September 2024

This study investigates the effects of temperature exposure on the dielectric and electrical properties of Cs/HPC-copper vanadate nanocomposites. The results indicate a direct correlation between the increase in polymer surface roughness and the amount of incorporated copper vanadate nanoparticles. The real dielectric constant and imaginary dielectric constant exhibited a notable increase at lower frequencies, which was attributed to interfacial polarization. At higher frequencies, the decrease was due to space charge polarization. The incorporation of copper vanadate nanoparticles resulted in a significant enhancement of both the real dielectric constant and imaginary dielectric constant highlighting the crucial role of these nanoparticles in the electrical properties of the nanocomposites. The impedance (Z′) and impedance (Z′) measurements indicate a decrease in Z″ with increasing frequency and temperature, suggesting enhanced ionic conductivity and interfacial polarization. The Cole–Cole plots reveal that the dielectric relaxation process in the Cs/HPC-copper vanadate nanoparticles (NPs) follow the non-Debye model. The results provide insights into the charge-transport mechanisms in these nanocomposites and highlight the importance of temperature in controlling their electrical properties.
Exploring uncertainty in glass phase transitions through machine learning
Authors: Qi Rui , Liu Saihua , Yang Chengqiao , Sun Minhua
Published: September 2024

Machine learning methods have shown significant potential and are widely used in modern physics research. However, the uncertainty linked to machine learning, arising from the opacity of its workflow, demands attention and consideration. This study investigates the application of machine learning models in analyzing the glass transition of Cu50Zr50 metallic glass. By employing supervised learning techniques with ResNet50, MobileNetV3, and GoogleNet image extraction models, the study reveals that while machine learning can capture variations in the disordered atomic structure during the transition process, different models may yield divergent results in determining the glass transition temperature. Moreover, variations in atomic sizes within the images can lead to fluctuations in the predicted transition temperatures. These findings highlight the inherent uncertainties associated with using machine learning to analyze continuous phase transitions and stress the importance of ensuring that the extracted structural features align with the physical characteristics of the transition process.
Vibration energy harvester design and experimental study based on double-negative metamaterials
Authors: Chen Ting , Tan Yu , Duan Yongge , Zhou Dengyu , Yan Boqiang
Published: September 2024

This paper proposes an energy harvesting device based on a double-negative metamaterials structure. The negative stiffness behavior of the pre-compressed buckled beam is used to introduce bistability, which broadens the operating frequency band of the energy harvester. Simultaneously, the energy harvester utilizes the stress concentration and tensile-expansion effects inherent in auxetic structures to enhance the output voltage amplitude. Through finite element simulations and dynamic experiments, a comparative analysis of the static and dynamic characteristics of the double-negative buckled beam and auxetic straight beam is performed. Experiments show that, under the excitation of 2.2g acceleration, the working bandwidth and voltage amplitude of the buckled beam increased by 100% and 7.86%, respectively, when juxtaposed with the straight beam, thereby further achieving wide-frequency and high-efficiency energy harvesting.
Classification and reorganization of retired power batteries based on bp and k-means clustering
Authors: Shao Xianrao , Huang Zhili , Wang Dechuan , Sun Zhenning , Jiang Wenrui
Published: September 2024

The article proposes an efficient method for classifying and reorganizing retired power batteries. Firstly, the K-means clustering algorithm is used to enhance electrochemical response consistency in reorganized battery packs by considering the polarization time constant. Secondly, pulse power test parameters and battery health feature parameters estimated by a BP network are utilized for battery classification and reorganization. This approach addresses issues like lengthy grouping time and the inability to determine specific application scenarios. Simulation results show over 97% classification accuracy for individual batteries and good consistency after grouping, indicating high practical value.
The de-icing principle of electrode-to-ice streamers and deep learning-based calculation of ice-melting rate
Authors: Deng Xiaoxu
Published: September 2024

Within the aviation field, dielectric barrier discharge (DBD) plasma stands as a method utilized for de-icing purposes. This paper assesses the ice-melting capability of electrode-to-ice streamers. The methodology employed is predicated upon the phenomenon termed “thermal explosion of the vibrational reservoir”, which manifests an exponential non-linear increase in gas temperature due to the plasma’s thermal instability mechanism. Utilizing a DBD plasma actuator could provide a more comprehensive understanding of the temperature near the streamers. The ice-melting rates are evaluated by utilizing a deep learning-based target segmentation algorithm. The calculated fastest ice-melting rate Rm
is ∼0.97 mm2/s on the plane of the DBD surface, and meanwhile, the highest surface temperature exceeds 200°C. The method of generating these streamers is not exclusively limited to DBD to attain a higher ice-melting rate.
Analysis of the dynamic characteristics of XLPE pellet space charge
Authors: Cheng Lin , Chen Zongrang , Luo Jianyong , Yang Dechao , Liu Nan
Published: September 2024

The accumulation of space charge within XLPE materials can lead to the electric field’s uneven distribution, thereby increasing the risk of insulation problems in cables. However, the damage mechanism of space charge on cable insulation is not understood completely. Therefore, this study is dedicated to analysing the behaviour of space charge accumulation and dissipation in pressed XLPE granular material. The charge movement mechanism within XLPE materials was meticulously analysed with the pulsed electro-acoustic method. Experimental results reveal that the pressed granular XLPE accumulates charges of the same polarity, and that the total charge within the pressed granular XLPE significantly decreases with increasing voltage application time.
Study on reactive power compensation for a grid connected photovoltaic power generation system
Authors: Xie Wei
Published: September 2024

The photovoltaic (PV) industry is developing rapidly, and electricity from decentralized or grid-connected systems is becoming increasingly important. Grid-connected PV systems with active and reactive power compensation can compensate for voltage fluctuation and enhance power system stability. The paper proposes a two-stage, three-phase PV system with reactive power compensation based on the structural properties of conventional PV grid-connected systems. The system achieves maximum power point tracking through real-time detection of PV current and voltage output, load current, and grid voltage and provides active electricity to the grid. It can provide reactive energy required by the grid to compensate for local load reactive current, effectively suppress dynamic voltage fluctuations, improve the electric power quality, and reduce investment outlay. Simulation results are carried out to validate the rationality of the design.
Research on digital twin operation and control method and application of high-voltage cable
Authors: Wang Jian , Liu Bin , Li Danyu
Published: September 2024

A high-voltage cable digital twin operation and control system was established. We analyzed the principles and methods of high-voltage cable digital twin operation and control. Characteristics and construction methods of high-voltage cable digital twin models were studied. We do some analysis on panoramic perception methods for high-voltage cable engineering status. Perception data were collected to analyze the running status of cable lines. High-voltage cable digital twin linkage control technology was built through control interfaces and control strategies. A high-voltage cable digital twin operation and control platform for typical cable tunnels was constructed. The results show that the method based on the research of high-voltage cable digital twin operation and control system can build a digital twin operation and control platform. The system provides good technical support for intelligent operation and control of high-voltage cable projects, which can further improve the stability of cable lines.
A method for analyzing the state of double-column horizontal rotary isolation switch based on image processing
Authors: Li Fupeng
Published: September 2024

When the operating status of electrical equipment in a substation or the operating mode of the power system changes, a series of electrical equipment tripping operations need to be carried out. For traditional substations, personnel need to visually verify the opening and closing status of isolation switches during tripping operations and electrical equipment inspections. This manual operation mode has disadvantages such as low automation level, high labor intensity, and long operation time. The method of indirectly detecting the opening and closing status of isolation switches by installing auxiliary switches on the operating mechanism of control isolation switches also has the drawback of low accuracy. Currently, most inspection robots deployed in substations are used to detect the infrared temperature of electrical equipment and determine if there is an overheating defect, but they cannot automatically identify the opening and closing status of isolation switches and other electrical equipment.