bluuebunny/crossref_metadata_2025 huggingface dataset:
Stenosis severity and heart rate effects on left coronary artery hemodynamics and myocardial oxygen balance: A comprehensive assessment using pressure gradient
Authors: Kumar Pawan , Roy Somnath , Das Prasanta Kumar
Published: February 2024

The estimation of pressure drop across stenotic arteries can provide valuable information about the hemodynamic features. Nevertheless, the temporal behavior of pressure in stenotic arteries is not well reported for realistic pulsatile flows. This research investigates the pressure drop across a left coronary artery model for different degrees of stenotic severity and heart rates. The zones prone to further atherogenic degeneration are identified using time-averaged wall shear stress (TAWSS) and oscillatory shear index (OSI). A unique attempt has been made to quantify the effect of stenosis severity and elevated heart rate on coronary perfusion pressure (CPP) and endocardial viability ratio (EVR), which is an indicator of myocardial oxygen supply-demand balance. We have predicted reductions in both CPP and EVR as stenosis severity increases. The aforementioned metrics exhibit a notable drop when confronted with a moderate stenosis at an increased heart rate, implying that the hemodynamic consequences of a moderate stenosis during an elevated heart rate may be comparable to those of a severe stenosis during a state of rest. The current computational investigation has the potential to reduce the need for in vivo hemodynamic assessments of stenosis. In addition, the wall shear stress-based mechanical parameters, such as TAWSS and OSI, can indicate the atherogenic and thrombogenic regions in the stenosed vessels.
Experimental study on influence of temperature on breakdown in a waveguide cavity
Authors: Tan Nongchao , Wu Ping , Li Juan , Han Zeran , Sun Jun , Ma Ting
Published: February 2024

Radio frequency (RF) breakdown is one of the crucial factors limiting the power capacity of high-power microwave (HPM) generators. In this paper, a waveguide cavity has been designed to study quantitatively the influence of temperature on high-gradient RF breakdown. The two planes of the waveguide cavity are divided into a strong-field side and a weak-field side with the feeding of microwave signals. The temperature of the strong-field side of the waveguide cavity can be adjusted from ambient temperature (25 °C) to 435 °C by loading a resistive wire heater. The breakdown threshold of the waveguide cavity decreases apparently with the increase in the temperature. The breakdown threshold at 408 °C is 751 kV/cm, which is about 150 kV/cm lower than that at ambient temperature. In addition, the higher the temperature, the more pronounced the pulse shortening. Under the same microwave power injection, the averaged pulse width of HPM after passing through the waveguide cavity at 408 °C is equal to 17.6 ns, shortened by about 1/3 compared to that at ambient temperature. The quantitative study of the influence of temperature on the RF breakdown provides a new guideline for exploring breakdown suppression methods in HPM generators.
Plasma sheath tailoring by a magnetic field for three-dimensional plasma etching
Authors: Jüngling Elia , Wilczek Sebastian , Mussenbrock Thomas , Böke Marc , von Keudell Achim
Published: February 2024

Three-dimensional (3D) etching of materials by plasmas is an ultimate challenge in microstructuring applications. A method is proposed to reach a controllable 3D structure by using masks in front of the surface in a plasma etch reactor in combination with local magnetic fields to steer the incident ions in the plasma sheath region toward the surface to reach 3D directionality during etching and deposition. This effect has the potential to be controlled by modifying the magnetic field and/or plasma properties to adjust the relationship between sheath thickness and mask feature size. However, because the guiding length scale is the plasma sheath thickness, which for typical plasma densities is at least tens of micrometers or larger, controlled directional etching and deposition target the field of microstructuring, e.g., of solids for sensors, optics, or microfluidics. In this proof-of-concept study, it is shown that E→×B→ drifts tailor the local sheath expansion, thereby controlling the plasma density distribution and the transport when the plasma penetrates the mask during an RF cycle. This modified local plasma creates a 3D etch profile. This is shown experimentally as well as using 2d3v particle-in-cell/Monte Carlo collisions simulation.
Improved contact of “Spiro-OMeTAD/perovskite” interface by hydrophilic 1, 6-hexanediammonium diiodide molecule and the accelerated charge extraction processes
Authors: Xiao Yuhuan , Yu Xiaohan , Yu Xi , Fang Mei , Li Youzhen , Kong Deming , Zhou Conghua
Published: February 2024

Hydrophilic 1, 6-hexanediammonium diiodide (HDADI) is used to modify the perovskite surface, so as to improve the contact between the “Spiro-OMeTAD/perovskite” interface. It is observed that, after moderate HDADI modification, the wettability of Spiro-OMeTAD/chlorobenzene solution on perovskite is improved. After modified at moderate concentration of HDADI, surface roughness of perovskite film decreases from 19.4 to 15.8 nm, while that of Spiro-OMeTAD (coated on perovskite) decreases from 7.54 to 6.53 nm, indicating better interfacial contact. The improved interfacial contact is due to the hydrophilic nature of the HDADI molecule, and the formed two-dimensional (2D) Dion–Jacobson phase perovskite, as revealed by x-ray diffraction and x-ray photoelectron spectroscopy studies. Photoluminescence and Mott–Schottky studies show that defects are reduced. Accordingly, the charge-extraction rate is accelerated, while recombination is reduced according to transient photovoltaic/photocurrent decay curves tests and impedance spectroscopy. Photo-to-electric power conversion test demonstrates that the modification helps upgrade the power conversion efficiency of perovskite solar cells from 20.25 (±0.85)% to 22.28 (±0.53)% (with a champion efficiency of 23.08%). In addition, device stability has also been prolonged. This study provides an efficient strategy to strengthen the contact between the “Spiro-OMeTAD/perovskite” interface.
Theoretical study of the O(3P) + CN(X2Σ+) → CO(X1Σ+) + N(2D)/N(4S) reactions
Authors: Lu Dandan , Alves Márcio O. , Galvão Breno R. L. , Guo Hua
Published: February 2024

The barrierless exothermic reactions between atomic oxygen and the cyano radical, O(3P) + CN(X2Σ+) → CO(X1Σ+) + N(2D)/N(4S), play a significant role in combustion, astrochemistry, and hypersonic environments. In this work, their dynamics and kinetics are investigated using both wave packet (WP) and quasi-classical trajectory (QCT) methods on recently developed potential energy surfaces of the 12A′, 12A,″ and 14A″ states. The product state distributions in the doublet pathway obtained with the WP method for a few partial waves show extensive internal excitation in the CO product. This observation, combined with highly oscillatory reaction probabilities, signals a complex-forming mechanism. The statistical nature of the reaction is confirmed by comparing the WP results with those from phase space theory. The calculated rate coefficients using the WP (with a J-shifting approximation) and QCT methods exhibit agreement with each other near room temperature, 1.77 × 10−10 and 1.31 × 10−10 cm3 molecule−1 s−1, but both are higher than the existing experimental results. The contribution of the quartet pathway is small at room temperature due to a small entrance channel bottleneck. The QCT rate coefficients are further compared with experimental results above 3000 K, and the agreement is excellent.
Aerodynamic analysis of building with zigzag-patterned façade: Insights from large eddy simulation
Authors: Yu Jianhan , Alrawashdeh Hatem , Li Mingshui
Published: February 2024

High-rise buildings have diverse shapes and configurations to harmonize with the architectural, engineering, environmental, economic, and functional considerations, and aspirations. However, the architectural shape and configuration plays a vital role in determining the aerodynamic characteristics of the surrounding flow field and wind forces acting on the building. This paper numerically investigates the aerodynamic characteristics of the zigzag-patterned building by adopting the three-dimensional large eddy simulation (LES). The flow around a square cylinder in high Reynolds number is used to valid the numerical method. The results show that the zigzag pattern has a little effect on the mean streamwise velocity but significantly influences the fluctuation of streamwise and vertical velocities in the wake region. It is observed that the zigzag pattern on the leeward wall results in a narrower wake region, while on the windward wall, leads to a thinner and longer shear layers and shorter recirculation region. As for the pedestrian level wind, the flow velocity within the separation area is noticeably reduced when incorporating a zigzag pattern on the windward wall. Moreover, the fluctuating pressure coefficient values at the sidewalls of a building with a zigzag windward wall is significantly smaller than that of a smooth configuration building due to the façade pattern's impact in diminishing the curvature of the nearby separation at the leading edge.
Characteristics of branched flows of high-current relativistic electron beams in porous materials
Authors: Jiang K. , Huang T. W. , Li R. , Zhou C. T.
Published: February 2024

Branched flow is a universal phenomenon in which treebranch-like filaments form through traveling waves or particle flows in irregular mediums. Branched flow of high-current relativistic electron beams (REBs) in porous materials has been recently discovered [Jiang et al., Phys. Rev. Lett. 130, 185001 (2023)]. REB branching is accompanied by extreme beam focusing, up to a hundred times the initial value, at predictable caustic locations. The energy coupling efficiency between the beam and porous material surpasses that in homogeneous targets by two orders of magnitude. This paper examines REB branching, focusing on how beam parameters (e.g., Lorentz factor and density) and characteristics of the porous materials (e.g., pore size, skeleton thickness, and density) influence branching patterns. Analyses of the dynamics of individual beam electrons are also provided. The findings pave the way for further understanding REB branching and its potential applications in the future.
GABA
B
receptors induce phasic release from medial habenula terminals through activity-dependent recruitment of release-ready vesicles
Authors: Koppensteiner Peter , Bhandari Pradeep , Önal Cihan , Borges-Merjane Carolina , Le Monnier Elodie , Roy Utsa , Nakamura Yukihiro , Sadakata Tetsushi , Sanbo Makoto , Hirabayashi Masumi , Rhee JeongSeop , Brose Nils , Jonas Peter , Shigemoto Ryuichi
Published: February 2024

GABA
B
receptor (GBR) activation inhibits neurotransmitter release in axon terminals in the brain, except in medial habenula (MHb) terminals, which show robust potentiation. However, mechanisms underlying this enigmatic potentiation remain elusive. Here, we report that GBR activation on MHb terminals induces an activity-dependent transition from a facilitating, tonic to a depressing, phasic neurotransmitter release mode. This transition is accompanied by a 4.1-fold increase in readily releasable vesicle pool (RRP) size and a 3.5-fold increase of docked synaptic vesicles (SVs) at the presynaptic active zone (AZ). Strikingly, the depressing phasic release exhibits looser coupling distance than the tonic release. Furthermore, the tonic and phasic release are selectively affected by deletion of synaptoporin (SPO) and Ca
2+
-dependent activator protein for secretion 2 (CAPS2), respectively. SPO modulates augmentation, the short-term plasticity associated with tonic release, and CAPS2 retains the increased RRP for initial responses in phasic response trains. The cytosolic protein CAPS2 showed a SV-associated distribution similar to the vesicular transmembrane protein SPO, and they were colocalized in the same terminals. We developed the “Flash and Freeze-fracture” method, and revealed the release of SPO-associated vesicles in both tonic and phasic modes and activity-dependent recruitment of CAPS2 to the AZ during phasic release, which lasted several minutes. Overall, these results indicate that GBR activation translocates CAPS2 to the AZ along with the fusion of CAPS2-associated SVs, contributing to persistency of the RRP increase. Thus, we identified structural and molecular mechanisms underlying tonic and phasic neurotransmitter release and their transition by GBR activation in MHb terminals.
Multiscale embedded printing of engineered human tissue and organ equivalents
Authors: Zhang Cheng , Hua Weijian , Mitchell Kellen , Raymond Lily , Delzendehrooy Fatemeh , Wen Lai , Do Changwoo , Chen Jihua , Yang Ying , Linke Gabe , Zhang Zhengyi , Krishnan Mena Asha , Kuss Mitchell , Coulter Ryan , Bandala Erick , Liao Yiliang , Duan Bin , Zhao Danyang , Chai Guangrui , Jin Yifei
Published: February 2024

Creating tissue and organ equivalents with intricate architectures and multiscale functional feature sizes is the first step toward the reconstruction of transplantable human tissues and organs. Existing embedded ink writing approaches are limited by achievable feature sizes ranging from hundreds of microns to tens of millimeters, which hinders their ability to accurately duplicate structures found in various human tissues and organs. In this study, a multiscale embedded printing (MSEP) strategy is developed, in which a stimuli-responsive yield-stress fluid is applied to facilitate the printing process. A dynamic layer height control method is developed to print the cornea with a smooth surface on the order of microns, which can effectively overcome the layered morphology in conventional extrusion-based three-dimensional bioprinting methods. Since the support bath is sensitive to temperature change, it can be easily removed after printing by tuning the ambient temperature, which facilitates the fabrication of human eyeballs with optic nerves and aortic heart valves with overhanging leaflets on the order of a few millimeters. The thermosensitivity of the support bath also enables the reconstruction of the full-scale human heart on the order of tens of centimeters by on-demand adding support bath materials during printing. The proposed MSEP demonstrates broader printable functional feature sizes ranging from microns to centimeters, providing a viable and reliable technical solution for tissue and organ printing in the future.
Monkeypox virus infection of human astrocytes causes gasdermin B cleavage and pyroptosis
Authors: Miranzadeh Mahabadi Hajar , Lin Y. C. James , Ogando Natacha S. , Moussa Eman W. , Mohammadzadeh Nazanin , Julien Olivier , Alto Neal M. , Noyce Ryan S. , Evans David H. , Power Christopher
Published: February 2024

Monkeypox virus (MPXV) infections in humans cause neurological disorders while studies of MPXV-infected animals indicate that the virus penetrates the brain. Pyroptosis is an inflammatory type of regulated cell death, resulting from plasma membrane rupture (PMR) due to oligomerization of cleaved gasdermins to cause membrane pore formation. Herein, we investigated the human neural cell tropism of MPXV compared to another orthopoxvirus, vaccinia virus (VACV), as well as its effects on immune responses and cell death. Astrocytes were most permissive to MPXV (and VACV) infections, followed by microglia and oligodendrocytes, with minimal infection of neurons based on plaque assays. Aberrant morphological changes were evident in MPXV-infected astrocytes that were accompanied with viral protein (I3) immunolabelling and detection of over 125 MPXV-encoded proteins in cell lysates by mass spectrometry. MPXV- and VACV-infected astrocytes showed increased expression of immune gene transcripts (
IL12, IRF3, IL1B, TNFA, CASP1
, and
GSDMB
). However, MPXV infection of astrocytes specifically induced proteolytic cleavage of gasdermin B (GSDMB) (50 kDa), evident by the appearance of cleaved N-terminal-GSDMB (30 kDa) and C-terminal- GSDMB (18 kDa) fragments. GSDMB cleavage was associated with release of lactate dehydrogenase and increased cellular nucleic acid staining, indicative of PMR. Pre-treatment with dimethyl fumarate reduced cleavage of GSDMB and associated PMR in MPXV-infected astrocytes. Human astrocytes support productive MPXV infection, resulting in inflammatory gene induction with accompanying GSDMB-mediated pyroptosis. These findings clarify the recently recognized neuropathogenic effects of MPXV in humans while also offering potential therapeutic options.
Suppressing Zn pulverization with three-dimensional inert-cation diversion dam for long-life Zn metal batteries
Authors: Liao Xuelong , Chen Shan , Chen Jialei , Li Youzeng , Wang Wei , Lu Tiantian , Chen Zhuo , Cao Lixin , Wang Yaxin , Huang Rong , Sun Xiaoting , Lv Runyu , Wang Huan
Published: February 2024

Tremendous attention has been paid to the water-associated side reactions and zinc (Zn) dendrite growth on the electrode–electrolyte interface. However, the Zn pulverization that can cause continuous depletion of active Zn metal and exacerbate hydrogen evolution is severely neglected. Here, we disclose that the excessive Zn feeding that causes incomplete crystallization is responsible for Zn pulverization formation through analyzing the thermodynamic and kinetics process of Zn deposition. On the basis, we introduce 1-ethyl-3-methylimidazolium cations (EMIm
+
) into the electrolyte to form a Galton-board-like three-dimensional inert-cation (3DIC) region. Modeling test shows that the 3DIC EMIm
+
can induce the Zn
2+
flux to follow in a Gauss distribution, thus acting as elastic sites to buffer the perpendicular diffusion of Zn
2+
and direct the lateral diffusion, thus effectively avoiding the local Zn
2+
accumulation and irreversible crystal formation. Consequently, anti-pulverized Zn metal deposition behavior is achieved with an average Coulombic efficiency of 99.6% at 5 mA cm
−2
over 2,000 cycles and superb stability in symmetric cell over 1,200 h at −30 °C. Furthermore, the Zn||KVOH pouch cell can stably cycle over 1,200 cycles at 2 A g
−1
and maintain a capacity of up to 12 mAh.
Genomes, fossils, and the concurrent rise of modern birds and flowering plants in the Late Cretaceous
Authors: Wu Shaoyuan , Rheindt Frank E. , Zhang Jin , Wang Jiajia , Zhang Lei , Quan Cheng , Li Zhiheng , Wang Min , Wu Feixiang , Qu Yanhua , Edwards Scott V. , Zhou Zhonghe , Liu Liang
Published: February 2024

The phylogeny and divergence timing of the Neoavian radiation remain controversial despite recent progress. We analyzed the genomes of 124 species across all Neoavian orders, using data from 25,460 loci spanning four DNA classes, including 5,756 coding sequences, 12,449 conserved nonexonic elements, 4,871 introns, and 2,384 intergenic segments. We conducted a comprehensive sensitivity analysis to account for the heterogeneity across different DNA classes, leading to an optimal tree of Neoaves with high resolution. This phylogeny features a novel Neoavian dichotomy comprising two monophyletic clades: a previously recognized Telluraves (land birds) and a newly circumscribed Aquaterraves (waterbirds and relatives). Molecular dating analyses with 20 fossil calibrations indicate that the diversification of modern birds began in the Late Cretaceous and underwent a constant and steady radiation across the KPg boundary, concurrent with the rise of angiosperms as well as other major Cenozoic animal groups including placental and multituberculate mammals. The KPg catastrophe had a limited impact on avian evolution compared to the Paleocene–Eocene Thermal Maximum, which triggered a rapid diversification of seabirds. Our findings suggest that the evolution of modern birds followed a slow process of gradualism rather than a rapid process of punctuated equilibrium, with limited interruption by the KPg catastrophe. This study places bird evolution into a new context within vertebrates, with ramifications for the evolution of the Earth’s biota.
Measuring L1 Chinese speakers’ anxiety when completing an English as L2 video narration task
Authors: Wang Qiong , Li Shaofeng , East Martin
Published: February 2024

The present study investigated the nature of Chinese as First Language (L1) speakers’ anxiety when completing an
oral task in English as Foreign Language (L2). Chinese second-year university students (n = 96) performed a video
narration task and completed questionnaires measuring their trait anxiety, foreign language anxiety, and task anxiety. Exploratory
factor analysis identified the underlying sub-facets of the task anxiety construct, including language-related difficulties,
environment-related anxiety, setting-related anxiety and physiological symptoms. Language-related difficulties explained the
largest amount of variance and emerged as the most influential factor. Structural equation modelling demonstrated that task
anxiety was an independent construct subject to direct influence from foreign language anxiety and indirect influence from trait
anxiety. Findings suggest that task anxiety is a context-specific construct that warrants distinct attention from teachers and
researchers. Implications for helping students to cope with anxiety in task-based pedagogy and practice are discussed.
Charting literary translator collaborations in digital contexts
Authors: Marin-Lacarta Maialen
Published: February 2024

This study explores collaboration in literary translation, suggesting a wider understanding of the translation
process to also examine collaboration in various stages such as text selection, attracting publishers, self-publishing or
promoting translations. Drawing on ethnographic fieldwork conducted for two research projects, the article outlines five literary
translator collectives that have emerged outside of professional associations and that reflect changes in the publishing field. It
discusses their origins, activities and modes of collaboration. The discussion sheds light on the distinct goals of these
collectives, highlighting the diversity between market-oriented and socially driven approaches, their use of digital tools and the
impact of the collaboration in the translation process and publishing sphere. The article underscores the significance of further
research on literary translator collectives. It serves as a foundational exploration, pointing towards future research avenues
into innovative modes of collaboration among literary translators and their influence on the global publishing landscape.
Psychological Trauma Predicts Obesity in Welsh Secure Mental Health Inpatients
Authors: Davies Joseph Lloyd , Lawrence Daniel , Bagshaw Ruth , Watt Andrew , Mills Shane , Seage Catherine Heidi
Published: February 2024

People in secure psychiatric services experience high levels of exposure to early psychological trauma, are often diagnosed with severe mental illness (SMI) and have increased risk for obesity. Developmental trauma, SMI and obesity are associated with poor physical health outcomes and early death. This study aimed to assess the predictive power of Adverse Childhood Experiences (ACEs), self-harm and psychiatric diagnosis for secure inpatient weight gain and obesity. Data for 248 Welsh patients accommodated in low, medium, and high secure hospitals throughout England and Wales was analyzed. Patient admission bodyweight (in kilograms), bodyweight at the time of audit, and patient BMI at the time of audit was collected. Sex, psychiatric diagnosis, length of current admission, number of ACEs, and frequency of self-harm were also examined. Patients gained significant amounts of weight between admission until the time of the audit (median period = 1 – 2 years) and showed high levels of obesity. Self-harm frequency significantly predicted weight difference. Number of ACEs and diagnosis of schizophrenia significantly predicted patient BMI at the time of audit. The study findings indicate that psychological trauma and the nature of mental illness are important factors driving weight gain and excess morbidity in this vulnerable group.
Generalized binary-encounter-Bethe model for electron impact ionization of atoms
Authors: Wang Yuan-Cheng , Jiao Li Guang , Fritzsche Stephan
Published: February 2024

A generalized binary-encounter-Bethe (GBEB) model is proposed to calculate the partial ionization cross sections of all shells. The present model improves the original version of Kim et al (2000 Phys. Rev.A 62 052710) by incorporating a physically constructed effective charge felt by the ejected electron in the empirical factor, which prevents the selection of specific factors for different shells. A generalized relativistic binary-encounter-Bethe (BEB) formula is also proposed and applied to different inner shells of C, Al, Fe, Ar, Ag, Xe, Sn, Pb, and Bi atoms for impact energies from the thresholds up to 106 keV. The present model improves the partial ionization cross sections in the low-energy region compared to other relativistic BEB models. The GBEB partial and total ionization cross sections of the Xe atom are compared with the original BEB results. The present calculations, combined with the contribution from the direct multiple ionization, show good agreement with the experimental measurements in the intermediate- and high-energy ranges. We conclude that the present GBEB model, without any fitting parameters and ad hoc corrections, improves the BEB prediction of partial and total ionization cross sections for a good variety of atomic targets.
Experimental and theoretical Ritz–Rydberg analysis of the electronic structure of highly charged ions of lead and bismuth by optical spectroscopy
Authors: Rosner Michael K , Rehbehn Nils-Holger , Crespo López-Urrutia José R
Published: February 2024

Intra-configuration fine-structure transitions in highly charged ions (HCIs) result in most cases from changes in the coupling of equivalent electrons. They are multipole forbidden to varying degrees and often occur within the optical range. In HCI with semi-filled

n

d

and

n

f

subshells, electrons can in principle couple to states which are energetically close but with very different total angular momenta, e.g.

0
⩽
J
⩽
10

. This gives rise to metastable states with very long lifetimes that exhibit particularly interesting clock transitions or, as in the case of orbital level crossings, acquire a considerable sensitivity to a possible variation of the fine-structure constant α. We investigate both experimentally and theoretically connecting the ground state and adjacent states of Pb XXII to Pb XXXIV and Bi X to Bi XV, respectively, covering complex couplings of electrons in the

4

f

and

5

d

shells. These and others such as

n

d

and

n

f

, which also contain equivalent electrons, are of interest for frequency metrology using quantum logic spectroscopy, for atomic structure and QED theory tests, and for the search for Dark Matter candidates. We infer their level structure, benchmark calculations from two different electronic structure codes, and lay the groundwork for inferring the wavelengths of forbidden transitions of higher multipolarity in the optical and VUV region.
Critical exponents and fluctuations at BEC in a 2D harmonically trapped ideal gas
Authors: Morales-Amador M I , Romero-Rochín V , Paredes R
Published: February 2024

The critical properties displayed by an ideal 2D Bose gas trapped in a harmonic potential are determined and characterized in an exact numerical fashion. Beyond thermodynamics, addressed in terms of the global pressure and volume which are the appropriate variables of a fluid confined in a non-uniform harmonic potential, the density-density correlation function is also calculated and the corresponding correlation length is found. Evaluation of all these quantities as Bose–Einstein condensation (BEC) is approached manifest its critical continuous phase transition character. The divergence of the correlation length as the critical temperature is reached, unveils the expected spatial scale invariance proper of a critical transition. The logarithmic singularities of this transition are traced back to the non-analytic behavior of the thermodynamic variables at vanishing chemical potential, which is the onset of BEC. The critical exponents associated with the ideal BEC transition in the 2D inhomogeneous fluid reveals its own universality class.
Spin-flip excitation and negative energy dispersion in rotating Bose atoms
Authors: Indra Moumita , Mondal Sandip
Published: February 2024

We investigated the excitation spectra for the rotating Bose system in the fractional quantum Hall effect regime considering short-ranged P

o
¨

schl-Teller and long-ranged Coulomb type interaction. We found the anomalous negative dispersion in the excited spectra for Jain’s second and third series, whereas conventional spin-wave positive dispersion is observed in the case of Jain’s first series. The higher order Jain series display negative curvature with roton minima at lower momenta and exhibit spin-wave excitation similar to conventional ferromagnets at higher momenta. This anomalous spin-flip excitonic state of particle-hole pairs arises due to the merging of two types of spin-reversed modes i.e. spin-wave with no change in Landau level (LL) index and spin-flip with decreasing LL index.
Mechanical properties of bilayer WS2 and Graphene-WS2 Hybrid composites by molecular dynamics simulations
Authors: Wu Fan , Tan Huifeng , Palummo Maurizia , Camilli Luca
Published: February 2024

In the present work, by using molecular dynamics (MD) simulations, we investigate the mechanical properties of different nanostructures that may be core elements in next generation flexible/wearable photovoltaic devices, namely double layer WS2 nanosheets (DLNS), graphene/WS2 (layer) composites and graphene/WS2 nanotube (NT) composites. Our results reveal that the mechanical properties of DLNS deteriorate when compared to those of monolayer WS2. Owing to graphene’s reinforcement action, the mechanical properties of graphene/WS2 (layer) composite with both layers deformed are superior than those of WS2, even though inferior than those of bare graphene. If stress is applied only to the graphene layer, the graphene/WS2 composite retains the most of the strength and toughness of monolayer graphene, decreasing the fracture strength and Young’s modulus by only 9.7% and 16.3%, respectively. Similarly, in the case of the graphene/WS2 NT composite the mechanical strength and toughness experience a reduction compared to monolayer graphene, specifically by 15% and 53% for fracture strength and Young’s modulus, respectively. Considering the market’s keen interest in nanomaterials, particularly van der Waals (vdW) ones, for flexible and wearable photovoltaic devices, the findings presented here will significantly enhance the effective utilization of vdW composites.
A TLOT train gearbox fault diagnosis method based on ridge extraction under variable speed conditions
Authors: Hu Zhongshuo , Li Qiang , Yang Jianwei , Yao Dechen , Wang Jinhai
Published: February 2024

Owing to the rapidly varying working conditions of urban rail trains, the rotational speed conditions constantly shift in a short time span. As a key component of the running gear, the gearbox generates non-stationary vibration signals, making it challenging to monitor its health status. To address this challenge, a tacholess order tracking method (TLOT) based on ridge extraction method is proposed in this paper. This method determines the optimal search starting point using the time-frequency Gini coefficient and extracts the time-varying gearbox meshing frequency components from the time-frequency representation results. Furthermore, the TLOT method is utilized to process the strongly time-varying gearbox signal. In the order domain, multiple frequency components are extracted to reconstruct the signal. Simulation and experimental results demonstrate that the proposed method achieves a superior ridge extraction effect on gearbox experimental signals. It accurately converts unstable signals into angular domain stable signals, enhancing the energy aggregation of time-varying unstable signals in the order domain. This approach addresses the problem of weak harmonic component extraction from gearbox signals and effectively reduces interference in the resonance band, realizing fault diagnosis of the gearbox under unstable working conditions.
Lagrangian particle tracking in the presence of obstructing objects
Authors: Wieneke B , Rockstroh T
Published: February 2024

Volumetric flow measurement techniques have become the state-of-the-art for characterizing a broad range of different flow fields. Still, certain major limitations are present, which hinders the application of these techniques for some of the more complex flow configurations. In particular, flow measurements involving the presence of obstructing objects require time consuming measurement strategies and careful adjustment of the experimental equipment to avoid inaccurate measurement results. Within this study, these limitations are mitigated by the use of a known object’s shape and position in the form of depth maps for commonly used Lagrangian particle tracking schemes like Shake-the-Box (STB) as well as in volume self-calibration methods. The incorporation of these depth maps is computationally inexpensive and straight forward to implement. In order to evaluate the performance of this novel object-aware Lagrangian particle tracking (OA-LPT) approach, synthetic as well as experimental test data is created and the reconstruction quality is evaluated. It is shown, that OA-LPT is capable of providing full flow-field information, whereas the default STB implementation fails to correctly reconstruct particles in the partly-occluded regions.
DFFRLS-FAUKF: accurate and reliable monorail longitudinal slope identification method
Authors: Liu Zechao , Li Jingzhao , Zheng Changlu , Wang Guofeng
Published: February 2024

Monorail cranes have always played an important role in mine auxiliary transportation systems owing to their excellent transportation performance and are therefore a desirable area in which to apply driverless technologies. However, the low-accuracy recognition of monorail track slopes and the poor reliability of recognition results make it difficult and dangerous to implement fully driverless monorail cranes. Aiming to solve these problems, a method for the accurate identification of longitudinal monorail slopes based on the use of a dynamic forgetting factor for recursive least squares (DFFRLS) and a fuzzy adaptive unscented Kalman filter (FAUKF) is proposed. First, acquired acceleration and velocity data are pre-processed using a rolling window. Second, the real-time longitudinal track-curvature value is calculated using the DFFRLS algorithm with the processed data and an established track-curvature model. Finally, based on existing track-curvature values, dynamic recognition of the monorail track slope is realized using the FAUKF algorithm with a fuzzy control factor, improving the accuracy of track gradient recognition. Experiments show that the DFFRLS-FAUKF algorithm improves the accuracy of track-slope recognition by up to 21.26% and 33.93% on average compared with that of DFFRLS with an adaptive extended Kalman filter (DFFRLS-AEKF) or an adaptive unscented Kalman filter (DFFRLS-AUKF).
Interpretable parallel channel encoding convolutional neural network for bearing fault diagnosis
Authors: Tong Qingbin , Du Shouxin , Jiang Xuedong , Lu Feiyu , Feng Ziwei , Liu Ruifang , Xu Jianjun , Huo Jingyi
Published: February 2024

Interpretability plays a crucial role in the application of neural networks for fault diagnosis. Integrating preprocessing methods into neural networks can enhance interpretability while preserving their ‘end-to-end’ characteristics. However, when only redesigning the first layer, subsequent structures still exhibit limited transparency. Additionally, traditional convolution structure is ill-suited for analyzing the readable feature maps derived from vibration signals. To address these challenges, this paper proposes a novel convolution structure for the parameterized signal processing function of the first-layer convolution kernel. This structure incorporates channel mixing for feature augmentation, designs a condensed feature encoder for aggregating and compressing features channel-by-channel, ensures the interpretability of feature map processing, and obtains condensed feature codes to propose smooth activation layer-wise relevance propagation (SA-LRP) method that to perform interpretability analysis. Additionally, cubic feature screening is implemented for diagnostic classification to improve structural fitness. We design experiments using multiple datasets to test various indicators of the structure. The results confirm that connecting our convolution architecture for subsequent analysis outperforms other convolution architectures for the convolution kernel of the first-layer parameterized signal processing function. The interpretability of the model is evaluated through SA-LRP method and validates the interpretability of the model.
Bearing early fault identification and condition monitoring based on dynamic difference index
Authors: Hui Yicong , Zhang Yanchao , Chen Runlin , Liu Gengzhou , Li Zhe , Cui Yahui
Published: February 2024

Bearing condition monitoring is essential for early fault detection and early warning of large equipment, and signal processing techniques are frequently used to analyse nonlinear and nonstationary sequences. Cross-correlation integral is implemented in bearing condition monitoring because it can analyse the non-stationarity of time series in dynamic systems. This paper proposes a dynamic difference index (DDI) due to the difficulty of determining the threshold in the cross-correlation integral and the roughness and operation caused by sequence similarity of 0 or 1. It is a measure of the similarity between the fuzzy autocorrelation integral of a portion of a time series and the cross-correlation between that portion and other portions of the same time series, and it is used to determine the stationarity of the time series. When bearings begin to degrade or develop structural defects, the DDI changes dramatically. The XJTU-SY dataset and IMS Bearing Data were utilised for algorithm validation. First, the algorithm’s efficacy was demonstrated by optimising the effects of various thresholds, distance measures, and time window sizes on DDI and computational efficiency. Secondly, the comparison with common methods and state of the art shows the superiority of the algorithm in detecting early bearing faults, and reveals its appropriate use in practical engineering applications.
Split-based elevational localization of photoacoustic guidewire tip by 1D array probe using spatial impulse response
Authors: Tanaka Tomohiko , Imai Ryo , Takeshima Hirozumi
Published: February 2024

Objective. Photoacoustic emitters on the tip of a therapeutic device have been intensively studied for echo-guided intervention purposes. In this study, a novel method for localizing the guidewire tip emitter in the elevation direction using a 1D array probe is proposed to resolve the issue of the tip potentially deviating from the ultrasound-imaged plane. Approach. Our method uses the ‘interference split’ that appears when the emitter is off-plane. Here, a point source from the emitter splits into two points in images. Based on the split, ‘split-based elevation localization (SEL)’ is introduced to estimate the absolute elevation position of the emitter. Additionally, ‘Signed SEL’ incorporates an asymmetric feature into the 1D probe to obtain the sign of the elevation localization. An attenuative coupler is attached to the half side of the probe to control the interference split. In SEL and Signed SEL, we propose a modeled split matching (MSM) algorithm to localize the tip position. MSM performs pattern matching of a measured split waveform with modeled split waveforms corresponding to all emitter positions in a region of interest. The modeled waveforms are precalculated using the spatial impulse response. The proposed method is numerically and experimentally validated. Main results. Numerical simulations for time-domain wave propagation clearly demonstrated the interference split phenomena. In the experimental validation with a vessel-mimicking phantom, the proposed methods successfully estimated the elevation positions,

y

b

.

SEL exhibited a root-mean-squared error (RMSE) of 2.0 mm for the range of 0 mm ≤

y

b

≤ 30 mm, while Signed SEL estimated the absolute position with an RMSE of 2.4 mm and the sign with an accuracy of 80.8% for the range of −30 mm ≤

y

b

≤ 30 mm. Significance. These results suggest that the proposed method could provide approximate tip positions and help sonographers track it by fanning the probe.
THUBreast: an open-source breast phantom generation software for x-ray imaging and dosimetry
Authors: Wang Jiahao , Liu Yeqi , Hu Ankang , Wu Zhen , Zhang Hui , Li Junli , Qiu Rui
Published: February 2024

Objective. Establishing realistic phantoms of human anatomy is a continuing concern within virtual clinical trials of breast x-ray imaging. However, little attention has been paid to glandular distribution within these phantoms. The principal objective of this study was to develop breast phantoms considering the clinical glandular distribution. Approach. This research introduces an innovative method for integrating glandular distribution information into breast phantoms. We have developed an open-source software, THUBreast
4

4

http://github.com/true02Hydrogen/THUBreast/

, which generates breast phantoms that accurately replicate both the structural texture and glandular distribution, two crucial elements in breast x-ray imaging and dosimetry. To validate the efficacy of THUBreast, we assembled three groups of breast phantoms (THUBreast, patient-based, homogeneous) for irradiation simulation and calculated the power-law exponents (

β

) and mean glandular dose (

D

g

), indicators of texture realism and radiation risk, respectively, utilizing MC-GPU. Main results. Upon the computation of the

D

g

for the THUBreast phantoms, it was found to be in agreement with that absorbed by the phantoms based on patients, with an average deviation of 4%. The estimates of average

D

g

thus obtained were on average 23% less than those computed for the homogeneous phantoms. It was observed that the homogeneous phantoms did overestimate the average

D

g

by 30% when compared to the phantoms based on patients. The mean value of

β

for the images of THUBreast phantoms was found to be 2.92 ± 0.08, which shows a commendable agreement with the findings of prior investigations. Significance. It is evidently clear from the results that THUBreast phantoms have a preliminary good performance in both imaging and dosimetry in terms of indicators of texture realism and glandular dose. THUBreast represents a further step towards developing a powerful toolkit for comprehensive evaluation of image quality and radiation risk.
Diagnostics and characterization of a novel multi gas layer RF atmospheric pressure plasma jet for polymer processing
Authors: Narimisa Mehrnoush , Onyshchenko Yuliia , Sremački Ivana , Nikiforov Anton , Morent Rino , Geyter Nathalie De
Published: February 2024

The quest to employ cold plasma sources at atmospheric pressure in polymer processing has emerged as a potent driving force behind their development. Atmospheric pressure operation of plasma jets provides potential cost reductions as well as easier handling and maintenance. In addition, their unique advantage of remote operation allows the substrate to be placed outside the source boundaries. This latter feature makes it easier to process complex three-dimensional objects and to integrate plasma jets into existing production lines. Although conventional atmospheric pressure plasma jet (APPJ) sources have undergone significant advancements in their design and construction, they have reached their technical and technological thresholds in several domains, thereby also impeding further enhancements in material processing applications. To cope with this issue, this work introduces a promising APPJ (named MPPJ3) working in a three co-axial gas layer geometry, incorporating the capability of aerosol and shield gas introduction leading to a configuration rich in reactive plasma species with controllable size and suitable temperature for polymer processing. A parametric study on the novel MPPJ3 device is carried out and plasma characteristics, such as reactive plasma species and temperatures, are determined by means of optical emission spectroscopy (OES), laser scattering, and infrared (IR) camera imaging whereas the fluid dynamics are analyzed using computational fluid dynamics (CFDs) and Schlieren imaging. The obtained promising results clearly show the flexibility and adaptability of the MPPJ3 device for polymer processing applications.
Experimental and 2D fluid simulation of a streamer discharge in air over a water surface
Authors: Herrmann Antoine , Margot Joëlle , Hamdan Ahmad
Published: February 2024

The high reactivity and attractive properties of streamer discharges make them useful in many applications based on plasma-surface interactions. Therefore, understanding the mechanisms governing the propagation of a streamer discharge as well as its properties is an essential task. This paper presents the development and application of a 2D fluid model to the simulation of discharges triggered at the air-water interface by a pulsed nanosecond high voltage. Experimental characterization using 1 ns-time-resolved imaging reveals rapid transitions from a homogeneous disc to a ring and finally to dots during the discharge process. The simulation enables the determination of the spatio-temporal dynamics of the E-field and electron density, highlighting that the discharge reaches the liquid surface in less than 1 ns, triggering a radial surface discharge. As the discharge propagates along/over the water surface, a sheath forms behind its head. Furthermore, the simulation elucidates the transitions from disc to ring and from ring to dots. The former transition arises from the ionization front’s propagation speed, where an initial disc-like feature changes to a ring due to the decreasing E-field strength. The ring-to-dots transition results from the destabilization caused by radial electron avalanches as the discharge head reaches a radius of ∼1.5 mm. The simulation is further utilized to estimate a charge number and a charge content in the discharge head. This work contributes to a better understanding of discharge propagation in air near a dielectric surface, with the agreement between simulation and experiment validating the model in its present version.
Experimental study on vibration control performance of TMD-STF damper
Authors: Wei Minghai , Lin Kun , Liu Junjie
Published: February 2024

A tuned mass damper (TMD) using shear thickening fluid (STF) as an energy dissipation medium is designed and manufactured. In addition, a TMD incorporating silicone oil (TMD-Si49) is fabricated to compare and analyze the vibration control performance of TMD-STF. Free vibration, forced vibration, and random excitation tests are conducted on a single degree of freedom (SDOF) structure model equipped with TMD-STF and TMD-Si49, respectively. The displacement and acceleration response of the SDOF model are recorded to analyze the vibration control performance of TMD-STF and TMD-Si49 under different load conditions. The results of the free vibration test show that TMD-STF affects the coupling damping ratio of the test model, exhibiting time-varying damping characteristics, but does not impact the coupling frequency ratio. In the forced vibration test, TMD-STF effectively expands the effective frequency range of vibration control performance by approximately 17.0% compared to TMD-Si49. The random excitation test demonstrates that TMD-STF exhibits significantly improved control of acceleration response rather than displacement control. The research findings on TMD-STF provide novel insights for vibration control in engineering structures.