bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing Fundamental Frequency Variation in Speakers With Parkinson's Disease: Effects of Tracking Errors
Authors: Portnova Alena , Fletcher Annalise , Wisler Alan , Borrie Stephanie A.
Published: February 2025

Purpose:

Automatic measurements of fundamental frequency (
F
0) typically contain tracking errors that can be challenging to accurately correct. This study assessed to what degree these errors change
F
0 summary statistics in speakers with Parkinson's disease (PD) and neurotypical adults. In addition, we include a case study examining how the removal of tracking errors influenced our ability to predict a perceptual outcome measure, speech expressiveness, associated with dysarthria and PD. Several different statistical approaches for characterizing
F
0 variability were used to demonstrate the influence of tracking errors.

Method:

Eight speakers with PD and eight neurotypical speakers were recorded reading The Caterpillar passage.
F
0 measurements were extracted in Praat and tracking errors were manually identified. The effect of tracking errors on
F
0 mean and standard deviation was statistically analyzed. Twenty listeners rated speech expressiveness across 80 sentences. The relationship between listener ratings and
F
0 variability was examined using different statistical approaches for characterizing
F
0 variability (with and without tracking errors).

Results:

Measurements of
F
0 standard deviation, but not
F
0 mean, were significantly affected by tracking errors. Relationships between measurements of
F
0 variability and expressiveness were strengthened when tracking errors were removed from data analysis.

Conclusions:

Tracking errors significantly alter
F
0 standard deviation values for both speakers with PD and neurotypical adults. Case study evidence also suggests that tracking errors can reduce the strength of relationships between
F
0 variability and perceptual outcome measures, such as speech expressiveness.
A Case Study on Perspectives of Parents of Children Who Are Deaf or Hard of Hearing: Factors Influencing Quality of Life, an Application of the International Classification of Functioning, Disability and Health Framework
Authors: Kintop Claire , Isaacson Heather
Published: February 2025

Purpose:

This descriptive case study was conducted to explore factors that enhance the quality of life of individuals who are Deaf or Hard of Hearing (DHH) through the application of the International Classification of Functioning, Disability and Health (ICF).

Method:

The perspectives of primary caregivers in two families that had two biological children with sensorineural hearing loss were explored using a semistructured interview. The Bingham Five-Phase Process of Qualitative Data Analysis was utilized to thoroughly analyze and find commonalities between responses. The ICF framework guided theme exploration.

Result:

The results show the highest number of codes emerging as related to processing information and safety, concerns about peer relationships and self-image, and not utilizing technology to its fullest extent. Participants indicated that the presence of environmental supports, both within the school system and through personal advocates, underscores the importance of external factors in mitigating barriers and fostering inclusion for individuals who are DHH.

Conclusions:

The specific codes identified support the overarching themes of participation limitations, personal coping style, and environmental supports that can be considered when working with this population. Further research should be completed to find more qualitative results encompassing a wider variety of individuals in this community.
Optimized Coordination of Electric Vehicles, Distributed Compensation Devices, and Distributed Generation for Risk Mitigation in Radial Distribution Networks
Authors: Zhongbo Chen , Liang Liang , Chao Lu
Published: February 2025

The charging demand of electric vehicles (EVs), intelligent and flexible compensation units, and renewable energy generation are key components of the smart grid framework. This paper aims to evaluate the benefits of coordinating distributed compensation units while mitigating the risks associated with the uncertainties arising from the aggregation of distributed generation and EV charging loads within the smart grid. Linear models for electric spring (ES) were developed to facilitate their integration into collaborative operational strategies. Subsequently, probabilistic load flow (PLF) analysis was combined with branch power flow (BPF) equations to assess voltage fluctuations and the stochastic distribution of energy demand. The proposed methodology aims to optimize coordinated operations for risk mitigation. Finally, case studies were carried out to verify the effectiveness of the proposed optimization model and provide further insights into its practical applications.
Local asymptotics and optimal control for a viscous Cahn-Hilliard-Reaction-Diffusion model for tumor growth
Authors: Trussardi Lara , Davoli Elisa , Rocca Elisabetta , Scarpa Luca
Published: February 2025

In this paper we study nonlocal-to-local asymptotics for a tumor-growth model coupling a viscous Cahn-Hilliard equation describing the tumor proportion with a reaction-diffusion equation for the nutrient phase parameter.
First, we prove that solutions to the nonlocal Cahn-Hilliard system converge, as the nonlocality parameter tends to zero, to solutions to its local counterpart. Second, we provide first-order optimality conditions for an optimal control problem on the local model, accounting also for chemotaxis, and both for regular or singular potentials, without any additional regularity assumptions on the solution operator. The proof is based on an approximation of the local control problem by means of suitable nonlocal ones, and on proving nonlocal-to-local convergence both for the corresponding dual systems and for the associated first-order optimality conditions.
Bericht zum Workshop: Fach- und Erfahrungsaustausch für onkologisch
tätige Sport- und PhysiotherapeutInnen
Authors: Meyer-Schwickerath Corinna , Paratte Jean-Luc , Wiskemann Joachim
Published: February 2025

Am 27. und 28.09.24 fand das erste Therapeut*innentreffen im Rahmen eines
Workshops für onkologisch tätige Sport- und Physiotherapeut*innen am Uniklinikum
in Heidelberg statt. Der Workshop wurde als gemeinsame Veranstaltung der
Stiftung Leben mit Krebs und des Netzwerks OnkoAKtiv von
Sportwissenschaftler*innen des NCT Heidelbergs vorbereitet und durchgeführt.
Ziel des Treffens war die Schaffung eines Raumes für Fach- und
Erfahrungsaustausch sowie die stärkere Vernetzung onkologisch tätiger Sport- und
Physiotherapeut*innen.
Choosing the right wavelengths: how to improve photovoltaics to boost positive emotion
Authors: Thompson Avery
Published: February 2025

Organic photovoltaic devices can collect energy from windows or skylights, but which wavelengths they allow through can have a significant impact on people’s emotional health.
Magnetic electrides: Recent advances in materials realization and application prospects
Authors: Meng Weizhen , Bai Jingbo , Ma Fengxian , Jiao Yalong , Wang Shiyao , Jiang Jiayu , Zhang Xiaoming , Cheng Zhenxiang , Yang Tie
Published: February 2025

The coupling of magnetism in multidimensional inorganic electrides has attracted significant attention in the fields of spintronics, materials science, and chemistry. Inorganic electrides exhibit a wide range of promising applications due to their remarkable properties, such as unique magnetic behavior, low work function, nontrivial topological states, and high electron mobility. Despite the rapid advancements in this emerging field, comprehensive reviews on magnetic inorganic electrides remain scarce. This review aims to provide a thorough analysis of the research progress in magnetic inorganic electrides. We examine the development and preparation methods, classifications, and regulatory mechanisms of magnetism, along with various properties and potential applications. Finally, we discuss the challenges and future prospects for magnetic inorganic electrides, highlighting the potential for breakthroughs in this exciting field.
Room-temperature ferromagnetism and photoluminescence in layer-conjugated 2D Cu-BDC
Authors: Mao Zhimin , Weng Xiaoliang , Li Zelong , Tang Wei , Li Luyan , Fang Hui , Zhang Su-Yun , Zeng Yu-Jia
Published: February 2025

Magnetic metal-organic frameworks (MOFs) hold immense promise as multifunctional materials for next-generation spintronic and optoelectronic devices. Here, we introduce a layered conjugated MOF 2D Cu-BDC, i.e., Cu(BDC)(DMF), synthesized via a simple solution co-deposition method at ambient conditions. Cu-BDC exhibits robust room-temperature ferromagnetism arising from strong coupling between Cu2+ ions and delocalized π-electrons in the ligand, as revealed by magnetic measurements and density functional theory calculations. Ferromagnetic resonance studies further demonstrate a low Gilbert damping factor of 8.4 × 10−3, highlighting its potential for efficient spin transport. In parallel, Cu-BDC MOFs show a high conductivity (σ) of 115.7 S cm−1 at room temperature and efficient photoluminescence (λex = 462 nm) induced by π*-π electron transitions in the temperature range of 100–300 K. This unique integration of magnetic, electronic, and optical properties positions Cu-BDC as a compelling candidate for multifunctional applications in advanced opto-spintronics.
Analgesic effect of simultaneously targeting multiple pain processing brain circuits in an aged humanized mouse model of chronic pain by transcranial focused ultrasound
Authors: Kim Min Gon , Yeh Chih-Yu , Yu Kai , Li Zherui , Gupta Kalpna , He Bin
Published: February 2025

Low-intensity transcranial focused ultrasound (tFUS) has recently been shown to noninvasively and non-pharmacologically modulate pain hypersensitivity with high spatial specificity and deep brain penetration. However, the lack of knowledge about its effectiveness for pain management in older subjects vulnerable to severe pain who are also at increased risk of cognitive impairment, presents significant challenges. Additionally, current opioid pain treatments require hospital visits, limiting unwanted serious side effects with multiple liabilities, and device-based pain treatments are typically administered at medical facilities with bulky and expensive equipment, limiting accessibility and thus highlighting the need for at-home non-pharmacological treatment options. Here, we present a more accessible, noninvasive tFUS pain treatment strategy for senior subjects. This approach involves simultaneously targeting multiple pain-processing circuits using a battery-powered, compact, and low-cost ultrasound analog front end (UAFE). We developed and evaluated the performance of the UAFE capable of generating sufficiently high-amplitude output with significantly lower noise levels compared to a commercial transmitter. Using a humanized sickle mouse model of chronic hyperalgesia, we found that tFUS stimulation targeting multiple pain-processing circuits effectively reduces heat hyperalgesia in aged female mice. In addition to its efficacy, our behavioral-based safety assessment revealed no adverse effects on motor functions. These results suggest that using a battery-powered, compact UAFE to simultaneously target multiple pain-processing circuits can effectively suppress heat pain-related behaviors in aged female sickle mice without negatively impacting motor coordination and balance. This highlights the potential for further development of fully home-based tFUS pain treatment for seniors.
Influence of bias-voltage noise on the inelastic cooper-pair tunneling amplifier (ICTA)
Authors: Martel U. , Albert R. , Blanchet F. , Griesmar J. , Ouellet G. , Therrien H. , Nehra N. , Bourlet N. , Peugeot A. , Hofheinz M.
Published: February 2025

We experimentally show that the inelastic cooper-pair tunneling amplifier (ICTA), implementing a DC-powered parametric amplification scheme, can achieve gain and noise performance similar to that of AC-powered Josephson parametric amplifiers. Using experimental data and simulations, we show that the ICTA has near-quantum-limited noise as long as low-frequency voltage noise, expressed as broadening of the Josephson frequency line, is narrower than the amplification bandwidth. We observe a gain of 20 dB across a 11 MHz bandwidth with noise below 1.7 times the quantum limit when the full width at half maximum of the Josephson frequency linewidth is 5.6 MHz.
Hollow cathode electron properties are consistent with marginally stable turbulence
Authors: Roberts P. J. , Brown Z. A. , Jorns B. A.
Published: February 2025

The scaling of the electron Mach number in a 20 A class hollow cathode plume is characterized experimentally as a function of the local plasma properties. These local properties are inferred from measurements with an incoherent Thomson scattering diagnostic, configured to measure the axial projection of the electron velocity distribution on the cathode centerline. The time-averaged electron temperatures are found to be 1–2 eV for xenon flow rates between 1.35 and 2.25 mg/s and increase above 5 eV at a lower flow rate of 0.45 mg/s. This transition in temperature corresponds to the cathode's transition from the so-called spot mode to the plume mode. The electron Mach number is found to be between 0.2 and 0.8 for all flow rates. The scaling of the Mach number with the ratio of electron temperature to ion temperature is examined, which reveals a non-monotonic relationship that can be approximately described by the assumption of marginally stable wave growth. The possibility of leveraging this assumption as a zero-equation closure for the electron fluid equations is discussed in the context of past experiments.
Flow of hybrid nanofluids between two permeable corrugated curved walls using Yamada–Ota and Xue models with variable viscosity
Authors: Mujahid M. , Abbas Z. , Rafiq M. Y.
Published: February 2025

This article investigates the pressure-driven flow of a magnetized hybrid nanofluid confined between two curved corrugated walls in the presence of slip constraints. The base fluid, water, is augmented with single-walled and multiwalled carbon nanotubes (SWCNTs and MWCNTs) to enhance thermal conductivity, evaluated using the Xue and Yamada–Ota models. The channel geometry is mathematically modeled in an orthogonal curvilinear coordinate system, with sinusoidal functions describing the corrugation grooves and phase differences between the walls. An analytical solution for velocity and temperature profiles is derived using the boundary perturbation method, with the corrugation amplitude as the perturbation parameter. The effects of various physical parameters on the flow fields are thoroughly analyzed and presented using graphs and tables. Additionally, key quantities such as volumetric flow rate, skin friction coefficient, and local Nusselt numbers are numerically computed for different parameter values and comprehensively tabulated. The results reveal a significant reduction in the temperature profile with increasing curvature parameter. Comparisons indicate that the Yamada–Ota model outperforms the Xue model in terms of predictive capability and analytical robustness. Finally, the trapping process is examined in detail through the construction of contour streamlines.
Compliance for enhanced electroadhesion: Designing kirigami patterns for local conformation on rough surfaces
Authors: Shum Jennifer A. , Hernandez Alyssa M. , Schiebel Perrin E. , Jayaram Kaushik , Wood Robert J.
Published: February 2025

We aim to improve the adhesion capabilities of electroadhesive pads on rough surfaces by using geometry-driven compliance to increase effective contact area. We present a kirigami-based approach for enhancing compliance through an exploration of geometric features cut into an adhesive disk. We experimentally test a range of geometries, comparing shear adhesion strength to understand structure–function relationships in our chosen parameter space. Our findings indicate that introducing cuts to form serpentine paths in a disk results in longer effective lengths and enhanced compliance, thus requiring less energy to deform into a rough surface. Leveraging this insight and associated scaling analysis, we conclude that serpentine-like features arranged in a radially symmetric wedge configuration achieve high levels of adhesion, even on rough surfaces, enabling robust adhesion relative to featureless electroadhesive disks.
Determination of mid-infrared optical properties of complex media using partial Mueller matrix ellipsometry
Authors: Yang Chiyu , Wang Xueji , Jacob Zubin , Cai Wenshan , Zhang Zhuomin M.
Published: February 2025

Tailoring optical and radiative properties has attracted significant attention recently due to its importance in advanced energy systems, nanophotonics, electro-optics, and nanomanufacturing. Metamaterials with micro- and nanostructures exhibit exotic radiative properties with tunability across the spectrum, direction, and polarization. Structures made from anisotropic or nanostructured materials have shown polarization-selective absorption bands in the mid-infrared. Characterizing the optical and radiative properties of such materials is crucial for both fundamental research and the development of practical applications. Mueller matrix ellipsometry offers a nondestructive and noninvasive technique for characterizing radiative properties. Although such ellipsometers have long been used to measure optical properties, their operational bandwidth is usually limited to the visible to near-infrared range, leaving the mid-infrared largely unexplored. In this work, a broadband mid-infrared ellipsometer, operating from 2 to 15 μm, is designed and constructed to measure 12 elements of the Mueller matrix. The results may be used to determine the full Mueller matrix under specific conditions. The performance of the ellipsometer is evaluated using nanostructured materials, including a 1D grating and a chiral F-shaped metasurface. The measurement results compared well to those obtained from rigorous-coupled-wave analysis and finite-difference time-domain simulations, suggesting that this setup offers a useful tool in optical property retrieval and the assessment of nanostructured materials.
A numerical reconstruction of the Eqip Sermia iceberg calving-generated impulse wave
Authors: Shi Chuan-Qi , Hu Chao , Liu Hao-Ran , Wang Xiao-Liang , Liu Qing-Quan
Published: February 2025

In recent years, the escalation of climate change has led to a rise in the frequency of icebergs calving into the ocean. These iceberg calving-generated waves (ICGWs) present a significant hazard to passing vessels and coastal infrastructure. The Eqip Sermia ICGWs event possibly represented the most comprehensive record of an ICGWs event to date. However, survey data are limited due to the challenges of field observations. For instance, the three-dimensional shape of the iceberg remains unknown, with only the shape of its cross section being discernible. To investigate this practical event, a fluid–solid coupling model employing the smoothed particle hydrodynamics method is introduced. Through the simulation of a three-dimensional iceberg resembling Eqip Sermia, we are able to replicate the intricate process of ICGW formation, encompassing the iceberg's motion, wave generation process, and the intricate flow dynamics in its immediate vicinity. In particular, our simulation presents the captivating sight of an iceberg submerging into the water and generating splashes upon impact with the water surface. By obtaining detailed data through replication, a more refined analysis of the event is conducted. We explore the impact of different three-dimensional iceberg shapes on wave amplitude and splash height, investigating their distribution patterns across various directions. Moreover, we postulate a potential iceberg shape with a concave outward that closely mirrors the observed ICGWs at Eqip Sermia, drawing from comparisons between maximum wave amplitude values and their respective locations.
Surface coupled locally resonant modes for reinforced and localized acoustofluidic particle manipulation
Authors: Barahimi Behdad , Darbari Sara , Zabetian Targhi Mohammad , Halvaei Iman , Nosrati Reza
Published: February 2025

Acoustofluidics is an efficient, label-free, biocompatible, and low-cost technique for manipulating particles in biological and medical research. Despite its capabilities, challenges in complex patterning and bio-particle trapping remain. However, recent advances have improved the acoustofluidic manipulation flexibility by engineered spatially localized acoustic fields. This study proposes surface-coupled resonant modes using surface acoustic wave-driven ridges at 9.65 MHz within a conventional acoustofluidic channel for reinforced bio-particle manipulation. The amplified localized displacements at the resonating ridge edges and the consequent enhanced localized acoustic fields in the fluid lead to strong local vortices and enhanced acoustic forces in the ridge-included configuration, 2.2 (3.8) times higher than the conventional configuration according to the experiments (simulations). Moreover, the exerted reinforced acoustic forces have reduced the required electric input power to efficiently manipulate target particles in the ridge-included configuration compared with the conventional configuration. The ridge-induced reinforced acoustic forces are directed toward the ridge edges, hindering the target particles from being washed out. The introduced ridge-included acoustofluidic channel is raised as a promising platform for efficient, rapid, and engineerable manipulation of bioparticles, paving the way to attain tunable bioparticle manipulation in compact, low-power, and high-throughput lab-on-a-chip systems.
A drift-flux correlation for pool-type liquid metal two-phase flow based on fluid properties and flow characteristics
Authors: Mou Zhuoya , Zhu Longxiang , Ouyang Yong , Wang Di , Zhang Hong , Wan Lingfeng , Zhang Luteng , Tang Simiao , Pan Liangming
Published: February 2025

Accurately predicting the void fraction introduced into the core through the drift-flux correlation is fundamental for safety assessments of lead-cooled fast reactors under steam generator tube rupture scenarios. Due to the limitations of the applicability of existing drift-flux correlations for gas–water two-phase flow systems and the lack of experimental data, it becomes necessary to develop correlations suitable for gas–liquid metal two-phase flow through experimental studies. Flow measurements are conducted in a liquid metal pool using double-sensor conductivity probes to obtain local two-phase parameters. Results indicate radial profiles of parameters tend to evolve toward a core-peak shape with the increase in superficial gas velocity. The predictive performance of seven drift-flux correlations has been validated against the present data. No available correlations developed for gas–water two-phase flow systems can give accurate predictions for the present study. Although the correlations developed for gas–liquid metal two-phase flow systems provide good predictive performance, inaccuracies in predictions of the distribution parameter and drift velocity exist within the correlations. The study analyzes the effects of fluid properties and two-phase flow characteristics. A drift-flux correlation applicable to pool-type liquid metal two-phase flow is developed based on the limitations of existing correlations. The newly developed drift-flux correlation has been validated with the existing data, with the relative deviations in the void fraction predictions for the present data and other datasets being approximately less than ±15% and ±30%, respectively, and the corresponding mean absolute relative deviations are 5.35% and 18.19%, respectively.
Wavy leading-edge phenomena on circular cylinder flow
Authors: Ferreira Paulo H. , Moura Rodrigo C. , de Araújo Tiago B.
Published: February 2025

The present work explores a bio-inspired modification of a cylinder, incorporating a wavy pattern inspired by humpback whale flipper tubercles. Drawing on prior research on airfoils and wings, the investigation provides valuable insights into the implications of this novel geometry on cylinder flow, contributing to the existing knowledge in the field. A selection of four patterns of waviness (varying in amplitudes and wavelengths) is compared to a smooth (i.e., straight cylinder) model by measuring pressure distribution and aerodynamic forces. The study is conducted in a wind tunnel, considering Reynolds numbers from about 3.9×104 to 1.9×105. Notable findings include a drag coefficient reduction of up to 25% for a model with 12% wavelength and 3% waviness amplitude. Flow visualization reveals the presence of two distinct phenomena: the formation of three-dimensional laminar separation bubbles, and the indications of counter-rotating vortex pairs over the cylinder surface. These flow structures contribute to explain the observed drag variation through changes in the separation line, base pressure, and other associated mechanisms. This study enhances our understanding of the performance of such bio-inspired designs.
Enhanced wicking dynamics of paper-based microfluidics by a nonporous wall
Authors: He Guan-Yu , Tsao Heng-Kwong , Sheng Yu-Jane
Published: February 2025

A paper-based microfluidic device, comprising a nonporous wall and a porous sheet separated by a gap, is investigated through many-body dissipative particle dynamics simulations. The time evolutions of the mean penetration lengths within the gap and the porous sheet are monitored separately, characterized by Lg(t) and Lp(t), respectively. They can be described by Lg2 = Sgt and Lp2 = Spt, consistent with the Lucas–Washburn equation. The influences of gap width (w) and the surface wettability of the nonporous wall (θw) on the imbibition rates Sg and Sp are systematically examined. Due to the presence of the gap, Sp is facilitated to exceed the imbibition rate of isolated paper, and Sp is always larger than Sg. It is found that Sp increases linearly with increasing w but decreases with increasing θw. The enhancement of the imbibition rate results from side imbibition, which introduces extra capillary flow from the gap to the porous sheet, in addition to the capillary flow from the bottom reservoir. The contribution from side imbibition to the liquid absorbed within the porous sheet increases over time and becomes the dominant source, surpassing the direct contribution from the bottom reservoir.
Fluid-membrane interaction of nano rotor based on dynamic mode decomposition
Authors: Du Haowei , Dang Tianjiao , Li Shiqi , Sun Ye , Liu Zhen
Published: February 2025

As the size decreases, the flight Reynolds number of nano rotors decreases, reaching approximately 104 in magnitude, leading to a sharp decline in their aerodynamic efficiency. Therefore, it becomes crucial to improve the aerodynamic performance of nano rotors at low Reynolds numbers through flow control methods. Existing studies have shown that flexible membranes can improve aerodynamic performance of nano rotors, yet the mechanisms behind this improvement remain unclear. This study uses a dynamic mode decomposition (DMD) framework for analyzing the fluid-structure interactions of flexible membrane rotors, enabling simultaneous examination of fluid and structural variables. Results show that the aerodynamic efficiency of flexible membrane rotors has increased by approximately 7.5% compared to non-membrane rotors. DMD analysis reveals that both membrane and non-membrane rotors are dominated by static modes, which contribute over 65% to the flow field, indicating that the primary mechanism driving the improvement in aerodynamic efficiency is attributed to the static deformation of the membrane. Regarding vibration characteristics, differences in rotor structural properties result in distinct forms of vibration, which excite higher-order aerodynamic modes when coupled with the flow field. This effect becomes more pronounced with increasing collective angles, with higher-order modes contributing up to approximately 35% to the flow field. Research shows that the static deformation of flexible membranes improves aerodynamic performance of nano rotors, while their vibration has a significant impact on flight stability.
Efficient enhancement of CO2 separation and capture of the T-C3N2 membranes with modulations of strain, charge, and their synergistic effect
Authors: Hou Qihua , Guo Wentao , Liu Zhiyong , Yong Yongliang , Cui Hongling , Li Xinli , Li Xiaohong , Huang Shaobo
Published: February 2025

The effective separation and capture of CO2 over C2H2 and CH4 via T-C3N2 monolayer membranes modulated by strain, charge, and their synergistic effect was realized by using molecular dynamics simulations and density functional theory calculations. The strained T-C3N2 monolayer exhibits high CO2 permeability of 2.15 × 107 and 2.32 × 107 GPU at 300 K in the CO2/C2H2 and CO2/CH4 separation. The introduction of negative charges is a promising approach for improving CO2 separation performance due to the breaking of trade-off effects, that is, not only the CO2 permeability is enhanced to (2.94–3.07) ×107 GPU but also the selectivity of CO2 relative to C2H2 and CH4 is improved to 4.40 × 1033 and 2.82 × 1022, higher by 1016 and 107 orders of magnitude compared to pure T-C3N2. The synergistic effects of strain and negative charges also effectively enhance CO2 separation performance, and the effectiveness surpasses strain modulation but is slightly weaker than individual charge modulation. The adsorption strength of CO2 on the T-C3N2 surface can be significantly increased by modulation of negative charges. Moreover, the CO2 capture/release on/from the T-C3N2 monolayer could be realized by modulating the process of injection/removal of negative charges. The CO2 uptake capacity reaches 5.26 × 1014 cm−2, which is superior to that of other membrane materials. The demonstrated enhancement of the CO2 separation and capture performance by modulations of strain, charge, and their synergistic effect suggests broad prospects for the applications of the T-C3N2 membranes in the efficient separation and capture of CO2 from low-carbon hydrocarbon gases and carbon capture.
Dynamics of shear-thinning droplet under pulsating flow
Authors: Kumar Robin , Mukhopadhyay Sudipto
Published: February 2025

The breakup of non-Newtonian droplets under steady flow has been investigated extensively. However, non-Newtonian droplets under unsteady or pulsating flows have not been studied. This is relevant for kerosene gel droplets, which are shear thinning in nature and may be subjected to thermo-acoustic instabilities in the rocket combustion chamber. The investigation focuses on the shear-thinning droplet dynamics and breakup subjected to pulsating (sinusoidal) airflow of different amplitudes and frequencies. The volume of fluid multiphase model tracks the liquid–gas interface, and the governing equations are solved using the finite volume method. The shear-thinning behavior is modeled using a power law. Simulations are carried out for a Weber number (We=13) for which the droplet with power law index, n=0.67, does not show a breakup in a steady flow. However, a breakup is exhibited when subjected to a pulsating flow for the same We based on the mean gas speed except for the lowest amplitude (A=0.25) and frequency (f=500 Hz) investigated. Parametric investigations for different n show that the droplet breakup time significantly increases for n>0.8 for the pulsating flow of different amplitudes and frequencies. It is also observed that the change in frequency or amplitude changes the temporal evolution of the droplet viscosity for a constant n. Also, for the same A and f, the droplet with the lower value of n (<0.8) has a higher acceleration as compared to a droplet with a higher value of n (>0.8).
Fluid–structure interaction characteristics between stator–rotor clearance flow and rotor of full tubular pump
Authors: Liu Jianfeng , Jiang Tao , Xi Wang , Lu Weigang
Published: February 2025

Affected by the hydrodynamic pressure difference between the inlet and outlet side of the impeller of a full tubular pump (FTP), stator–rotor clearance flow inevitably exists during the operation of FTP, disturbing the flow field and causing hydraulic friction around the rotor. Based on the fluid–solid interaction method, this paper explored the interaction characteristics between the flow field of the stator–rotor clearance flow and the rotor structure. By conducting numerical simulation and model test, the deformation and stress distribution characteristics of the rotor were investigated and its high-strength stress region was located, where the alteration mechanism of the stator–rotor clearance vortex and the spatiotemporal distribution of velocity field were further deduced. The results show that during the operation of FTP, the maximum deformation region of the rotor was concentrated in the outer ring which showed obvious periodicity and the peak equivalent stress of the rotor was distributed along the bone line of the impeller with the span of 0.1. With the widening of spacing between the stator and the rotor, the accumulation of high momentum fluid both near the stator wall and the rotor wall was increased, and the radial non-uniformity of the clearance flow circulation was aggravated so that part of the mainstream water in the intersection domain deflected inward, magnifying the blade stress and leading to the peak deformation surface of the rotor twirling along the direction of impeller rotation at the speed of 8°/mm. This study investigated the fluid–structure interaction features of FTP, providing reference for future research on performance optimization.
Study on the evolution of coal fracture behavior and stress energy consumption model: Experimental study and implications for in situ coal seam cracking
Authors: Zhang Siqing , Gu Zhoujie , Liu Xiaofei , Zhou Xin , Wang Xiaoran , Tan Ruilin
Published: February 2025

The extent of coal fracturing directly affects the efficacy of coalbed methane extraction. Therefore, we performed an examination of the mechanical properties, energy dynamics, and damage characteristics of coal under varying strain rates (30–120 s−1) using the Split Hopkinson Pressure Bar. The findings reveal that peak strength, strain, average rate of stress increase, energy dissipation, and damage severity in coal specimens exhibits a positive correlation with the strain rate. Conversely, the duration of stress escalation and the average size of fragments demonstrate a negative correlation with strain rate. As the strain rate increases, the cumulative curve of fragments transitions from a concave to a convex configuration, and the degree of coal sample fracturing gradually progresses from type I to II and III. Based on these findings, stress and energy models for coal samples subjected to varied strain rate conditions were developed and validated with experimental data, providing significant insights into the stress and energy dissipation mechanisms critical for coal mining safety. The study introduces an innovative evaluation index, q (0–1, 1–5, >5), for assessing the degree of coal sample fragmentation, which increases with increasing strain rate, reflecting the transition from initial to complete fracturing of coal samples. This discovery holds substantial engineering value for refining new dry ice fracturing techniques in coal mining safety and enhancing the efficiency of gas extraction.
Non-axisymmetric diffuser pipe design to suppress the eccentric jet flow characteristic in a high-pressure angle valve
Authors: Li Haoyang , Lu Hanan , Xu Le , Li Qiushi
Published: February 2025

Angle valves are common flow control devices used in various industrial fields. However, under harsh conditions such as high pressure difference, severe eccentric jet flow phenomenon will occur in the diffuser pipe section, leading to significant erosion and wear on the valve walls. This ultimately results in a short service life for the valves and even safety hazards. Traditionally, some axisymmetric design methods are tried to be employed to suppress the eccentric jet flow. Even though they can play active roles, the control effect is usually limited. To better eliminate the eccentric jet flow characteristic, this paper has proposed a non-axisymmetric diffuser pipe design strategy in a high-pressure angle valve. The main purpose is to use a non-axisymmetric diffuser structure to control the non-uniform pressure distribution in the valve diffuser section. As is known, the asymmetrical structure of an angle valve leads to a non-uniform inflow at the diffuser inlet, resulting in distinct pressure recovery abilities on the two sidewalls and notable eccentric jet flow impacting a single sidewall. Results show that a non-axisymmetric diffuser pipe can improve the non-uniform pressure distribution and help suppress the eccentric jet flow. Specifically, a 2.5° diffuser pipe inclination design has the greatest effect on reducing the degree of eccentricity compared to the prototype valve. Moreover, the pressure recovery rate on the left sidewall becomes higher than that on the right sidewall, and a more uniform pressure distribution across the pipe can be obtained. In the meanwhile, the separation regions on both sidewalls of the diffuser present a similar size. A more uniform distribution of turbulence intensity is also noted near both sidewalls. As a consequence, the eccentric jet flow has been well suppressed in the first diffuser section, which is beneficial for reducing the erosion and wear on the single sidewall and improving the valve service life. In addition, cavitation is produced and developed in the throttle region and collapses in the diffuser pipe. As the turbulent kinetic energy is high in the cavitation zone, it is closely related to cavitation production and collapse. The non-axisymmetric diffuser design has decreased the volume of the cavitation zone on the right sidewall and reduced the hazard of cavitation wear in the local region. The research work might provide useful guidelines for designing reliable and long service-life high-pressure angle valves.
Dynamic response characteristics of bridges under the impact of debris flows in mountainous areas
Authors: Qiu Enxi , Luo Xinyu , Xu Di , Wang Fei , Bai Hao , Liu Jun , Xiong Xiaotian , Peng Zhuang
Published: February 2025

Debris flows pose a significant geological hazard, impacting economic development, transportation infrastructure, and the ecological environment in mountainous regions. To investigate the movement and disaster-causing characteristics of debris flows along the Jiuzhai-Mianyang Expressway, a series of scaled flume experiments were conducted to simulate their impact on bridge piers. These experiments, informed by field investigations of debris flow gullies along the Jiuzhai-Mianyang Expressway, examined the effects of debris flow density, flume angle, and the distance between the debris flow outlet and the bridge pier. The study introduced the Froude number to develop a calculation model for debris flow impact forces. Results showed flow velocities ranging from 0.75 to 6.14 m/s, debris flow depths from 2.7 to 13.4 cm, and maximum impact forces between 1.5 and 74.76 kPa. Flume angle was identified as a critical factor influencing viscous debris flow velocity. Impact patterns varied with flow conditions and fluid properties, exhibiting behaviors such as splashing, climbing, and flowing around obstacles. Furthermore, a refined hydrodynamic model for debris flow impact force, based on experimental data and existing literature, revealed a power function relationship between impact force and the Froude number. This study offers valuable insights for enhancing the safety of transportation infrastructure in the Jiuzhai-Mianyang Expressway and mountainous regions of southwestern China.
Three-dimensional wave structure within the puff of pipe flow
Authors: Wu Puyuan , Gu Dingwei , Jiang Xianyang , Lee Cunbiao
Published: February 2025

Direct numerical simulations are conducted to investigate the puff in pipe flow at various Reynolds numbers. Lagrangian approaches and vortex dynamics analysis are employed to examine the early-stage flow structures. The formation of low-speed streaks and the lift-up of three-dimensional (3D) waves (which is the same as soliton-like coherent structures in the boundary layer) upstream of the puff are observed in a pipe flow using timeline visualizations. The instantaneous vorticity deviation criterion reveals hairpin vortices surrounding 3D waves within the flow field. Vortex formation consistently follows 3D wave development, with the spatial delay influenced by the wave amplitude. The effects of the Reynolds number on the turbulence dynamics are assessed.
Multi-cation synergy improves crystallization and antioxidation of CsSnBr3 for lead-free perovskite light-emitting diodes
Authors: Wang Jie , Han Dongyuan , Ji Huiyu , Zang Ziang , Zhou Jianheng , Wang Ning
Published: February 2025

Tin (Sn) perovskites have emerged as promising alternatives to address the toxicity concerns associated with lead-based (Pb) perovskite light-emitting diodes (PeLEDs). However, the inherent oxidation of Sn perovskite films leads to a serious efficiency roll-off in PeLEDs at increased current densities. Although three-dimensional (3D) CsSnBr3 perovskites exhibit decent carrier mobilities and thermal stability, their rapid crystallization during solution processing results in inadequate surface coverage. This inadequate coverage increases non-radiative recombination and leakage current, thereby hindering Sn PeLED performance. Herein, we present a multi-cation synergistic strategy by introducing the organic cations formamidinium (FA+) and thiophene ethylamine (TEA+) into CsSnBr3 perovskites. The addition of organic cations delays crystallization by forming hydrogen bonds interacting with the CsSnBr3. The smaller FA+ enters the perovskite lattice and improves crystallinity, while the larger TEA⁺ cation enhances surface coverage and passivates defect states. By further optimizing the interface between PEDOT:PSS and perovskite layers through the use of ethanolamine (ETA) and a thin layer of LiF, we achieved a red Sn-based PeLED with an emission wavelength of 670 nm, a maximum luminance of 151 cd m-2, and an external quantum efficiency (EQE) of 0.21%.
A chaos-based lightweight encryption scheme using hash-code and cyclic rotation
Authors: KAYA Yasin , AYDIN Zeynep Gürkaş , Akgül Akif
Published: February 2025

This study introduces a novel lightweight encryption scheme for platforms with limited resources utilizing chaotic systems. We employ a dual logistic map, utilizing the first map to determine cyclic rotation step counts for rows and columns in confusion (permutation) phase, and the second map for the XoR operation in diffusion phase. Input parameters of the first logistic map is derived from only secret key while input parameters of the second logistic map derived from secret key and hash value of plaintext together. Since we use hash value of the plaintext to determine input parameter of the second logistic map, our schema is highly resistant to differential attacks. On average, it produces over %99.57 NPCR value and about %33.45 UACI value in case of one pixel change in the plaintext. It also produces an information entropy value of over 7.9971 on average. Since we use double logistic map, our scheme is resistant to brute force attacks via about 196 bits key length. Firsty, we calculate the hash value of the plaintext which will be used to determine input parameter of the second logistic map. And then we employ cyclic rotation operation for all rows and all columns utilizing key stream generated by the first logistic map at the permutation stage. Subsequently, we performed the XoR operation to the output, utilizing the key stream of the second logistic map which is initialized with the hash value and secret key. Since we need the hash value of the plaintext in the decryption process, we need to save it in the ciphertext. So, we add a new row at the bottom of the ciphertext to make a room for the hash value. We save and distribute it into the matrix by swapping operation and obtain final ciphertext. To decrypt the ciphertext, we follow these steps in reverse order. First, we extract the hash value of the original plaintext from the ciphertext. Then, we apply XOR and cyclic rotation operations. Our test and analysis results demonstrate that our schema is pretty fast, reliable, robust, feasible and successful. It is a good lightweight encryption scheme alternative for resource-limited platforms.
From dark matter minihalos to large-scale radiative feedback: a self-consistent 3D simulation of the first stars and galaxies using neural networks
Authors: Feathers Colton R. , Kulkarni Mihir , Visbal Eli
Published: February 2025

A key obstacle to accurate models of the first stars and galaxies is the vast range of distance scales that must be considered. While star formation occurs on sub-parsec scales within dark matter (DM) minihalos, it is influenced by large-scale baryon-dark matter streaming velocities (v
bc) and Lyman-Werner (LW) radiative feedback which vary significantly on scales of ∼100 Mpc. We present a novel approach to this issue in which we utilize artificial neural networks (NNs) to emulate the Population III (PopIII) and Population II (PopII) star formation histories of many small-scale cells given by a more complex semi-analytic framework based on DM halo merger trees. Within each simulation cell, the NN takes a set of input parameters that depend on the surrounding large-scale environment, such as the cosmic overdensity, δ(x⃗), and v
bc of the cell, then outputs the resulting star formation far more efficiently than is possible with the semi-analytic model. This rapid emulation allows us to self-consistently determine the LW background intensity on ∼100 Mpc scales, while simultaneously including the detailed merger histories (and corresponding star formation histories) of the low-mass minihalos that host the first stars. Comparing with the full semi-analytic framework utilizing DM halo merger trees, our NN emulators yield star formation histories with redshift-averaged errors of ∼7.3% and ∼5.2% for PopII and PopIII, respectively. When compared to a simpler sub-grid star formation prescription reliant on halo mass function integration, we find that the diversity of halo merger histories in our simulation leads to enhanced spatial fluctuations, an earlier transition from PopIII to PopII dominated star formation, and more scatter in star formation histories overall.
Towards a classification of UV completable Higgs inflation in metric-affine gravity
Authors: Mikura Yusuke , Tada Yuichiro
Published: February 2025

Towards a classification of UV completable Higgs inflation in the framework of parity-even
metric-affine gravity, we investigate the particle spectrum of a deformed theory in the large-N
limit. In a simple Higgs inflation model in metric-affine gravity, it is known that its UV cutoff
is much smaller than the Planck scale. While it calls for UV completion, a concrete example has
not yet been found, even with the large-N limit known as a successful technique to complete an
original Higgs inflation defined on the Riemannian geometry. This motivates us to study how small
deformation of the simple Higgs inflation affects the emergence and properties of dynamical fields
particularly in the large-N limit. As a UV theory has to be free of ghosts or tachyons at least
around Minkowski space, we perform the parameter search and find the healthy parameter region
where a new heavy particle can propagate without these pathologies.