bluuebunny/crossref_metadata_2025 huggingface dataset:
Embodied aesthetics and populist appeal of communist portraits in contemporary Kerala
Authors: Anil Anagha
Published: January 2025

In contrast to their career in the rest of India, the Communist Party of India (Marxist) [CPI (M)] continue to thrive as a highly successful electoral and cultural force in Kerala. Popularly known as the ‘Party’, an important aspect of CPI(M) has been its populist streak even though its official discourse is one that strongly adheres to rule-based reasoning by prioritizing ideological principles in its policies and decisions. The populist streak often manifests through myths and cultic adoration built around its leaders as well as through the occasional branding of Indian judiciary and democracy as bourgeois. It is further characterized by a strong ‘us vs. them’ rhetoric in which the ‘them’ is a powerful other, variously identified as CIA (Central Intelligence Agency of the US), or the media syndicate, or the government of the Indian Union, etc. Usually, the Communist Party is studied only with reference to its history and policies, and it has seldom been interrogated on the affective energies it generates in the everyday. This paper proposes to discuss communist iconography, such as portraits of yesteryear leaders circulated via social media and displayed in communist family homes, as sites where affective energies are generated and realised. Taking its cue from Christopher Pinney’s corpothetics, the paper intends to study this visual practice as an embodied aesthetic engagement, which by invoking filial sentiments, renders the Party felt for its supporters. By drawing on the concept of darshan, the ritualistic and devotional viewing of deities, the paper endeavours to place the affectivity of these portraits in a broader cultural milieu.
How did the Brexit uncertainty impact services exports of UK firms?
Authors: Du Jun , Shepotylo Oleksandr , Yuan Xiaocan
Published: January 2025

This paper examines the impact of Brexit-related uncertainty on the UK’s trade in services, with a focus on how different types of international business policy uncertainty (IBPU) influence export participation and intensity. Leveraging a novel conceptual framework, we integrate multiple layers of uncertainty—including regulatory, legal, and market-based factors—into an analysis of UK firms’ strategic decisions in an open economy. Drawing on firm-level data from Bureau van Dijk’s Orbis database and a synthetic control method, we estimate that Brexit uncertainty led to a 9.2% annual reduction in UK services exports, equivalent to a cumulative loss of USD 146.8 billion between 2016 and 2019. Our findings show that Brexit-related uncertainty disproportionately affected small and medium-sized enterprises (SMEs), while multinational enterprises (MNEs) were more likely to relocate operations outside the UK, exacerbating trade declines. This research highlights the critical role of transparent and predictable regulatory frameworks, risk management policies, and transitional support measures to mitigate the adverse effects of prolonged uncertainty. By identifying the specific mechanisms through which uncertainty shapes export decisions, this study offers key insights for policymakers aiming to foster resilience in the UK’s services trade post-Brexit.
Kinetics of phonon–impurity system of 3He–4He superfluid solutions (review)
Authors: Adamenko I. N. , Rudavskii É. Ya.
Published: January 2025

A review of experimental and theoretical works characterizing the state of the art of the kinetics of 3He–4He solutions is presented. The main emphasis is laid on recent investigations that have removed serious discrepancies that existed between theory and experiment for many years. The results on the velocity and absorption of the first sound, absorption of the second sound, diffusion, viscosity, thermal conductivity, and thermal distribution have been analyzed on the basis of a deeper insight into the kinetics of processes in the 3He–4He solutions. The relation between relaxation processes in the phonon–impurity system and specific features of dispersion of the phonon spectrum in 3He–4He solutions is considered.
Hydrogels: the future of wound care
Authors: Johnson-Groh Mara
Published: January 2025

Stimuli-responsive dressings that respond to wound microenvironments can improve healing outcomes.
Integrated functions of microfluidics and gravimetric sensing enabled by piezoelectric driven microstructures
Authors: Qian Jingui , Wang Yue , Xue Yuhang , Begum Habiba , Fu Yong-Qing , Lee Joshua E.-Y.
Published: January 2025

Micro- and nano-electromechanical systems resonators have been regarded as powerful tools for precision mass detection, and their abilities to measure these in a liquid environment open various opportunities for biosensing, chemical analysis, and environmental monitoring. Apart from overcoming issues of fluidic damping and electrical interfaces, there is a great challenge of bringing microanalytes to these devices with the required precision and scaling for high throughput sensing. Herein, we address the above challenges by proposing a self-excited localized acoustic manipulation methodology based on a piezoelectric micromechanical diaphragm resonator (PMDR). Such a PMDR integrates acoustofluidics and mass sensing functions in tandem on a single device. Particle enrichment is realized within tens of seconds and the limit of detection is enhanced by mitigating common issues such as low capture rate and non-uniform distribution. The developed PMDR is versatile in its applicability to a range of particle sizes and densities for both acoustofluidic actuation and in situ mass sensing. This work addresses long-term technical challenges of inaccurate and inefficient measurement of liquid phase resonance mass sensing with great application potentials in biochemical detection and environmental monitoring.
Evolution modeling and control of networked dynamic games with event-triggering mechanism
Authors: Chen Xiangyong , Feng Jun-e , Xu Wenying , Cao Jinde , Qiu Jianlong
Published: January 2025

This paper mainly focuses on investigating the discrete event dynamic decision-making process with two noncooperative intelligent agents, defined as event dynamic games (EDGs). We introduce a novel state space model and analyze the existence of its equilibrium solution. Additionally, we apply principles of network evolution to address the challenge of event dynamic game network modeling. By providing a normal-form strategic model, we first establish a game tree evolution model, which serves as an extended expression and more accurately captures the impact of changes in event strategies on the game process. Furthermore, we conduct an in-depth analysis of the multi-layered temporal evolution behaviors exhibited by EDGs and develop a corresponding network evolution model. Finally, the validity of the proposed model is demonstrated through application examples, along with a detailed analysis of the cooperative behaviors of nodes during the evolution process.
Wavebreakers in excitable systems and possible applications for corrosion mitigation
Authors: Batista Bruno C. , Romanovskaia Elena , Romanovski Valentin , Scully John R. , Kiss Istvan Z. , Steinbock Oliver
Published: January 2025

Traveling waves of excitation arise from the spatial coupling of local nonlinear events by transport processes. In corrosion systems, these electro-dissolution waves relay local perturbations across large portions of the metal surface, significantly amplifying overall damage. For the example of the magnesium alloy AZ31B exposed to sodium chloride solution, we report experimental results suggesting the existence of a vulnerable zone in the wake of corrosion waves where local perturbations can induce a unidirectional wave pulse or segment. The evolution of these segments, combined with the absence of rotating spiral waves, imply subexcitable dynamics for which the segments' open ends tangentially retract. Using a simple excitable reaction-diffusion model, we identify parameters that replicate these experimental observations. Under these conditions, small protected disks act as wavebreakers, disrupting continuous fronts, which then shrink and disappear. We further explore different placement schemes of these wavebreakers to optimize potential corrosion mitigation. For constant surface coverage, many small wavebreakers prove more effective than a few large ones. A comparison of triangular, square, rectangular, hexagonal, aperiodic Penrose, and random lattice geometries indicates that triangular placements of wavebreakers are generally the optimal choice, while rectangular and random lattices perform poorly. Although wavebreakers were not demonstrated experimentally in this study, these findings provide concrete design guidance for the protection of alloy surfaces prone to wave-mediated corrosion.
Large piezoelectric response in paraelectric region of PMN-32PT near morphotropic phase boundary
Authors: Kangama Moussa , He Zhengwang , Chen Xiaoming , Ding Xiangdong , Lookman Turab , Aktas Oktay
Published: January 2025

We report an effective piezoelectric coefficient of deff = 40 ± 6 pm/V in the paraelectric phase of (1-x)Pb(Mg1/3Nb2/3)O3−(x)PbTiO3 single crystals with x = 0.32 (PMN-32PT), which is near the morphotropic phase boundary (x = 0.30). This value for deff in the paraelectric phase is significantly larger than that for other ferroelectrics measured so far. Our detailed investigation of symmetry-disallowed piezoelectricity indicates bias effects due to alternating current (AC) electric fields (100–800 kHz) and AC field cooling. The application of moderate AC fields (100–350 V/cm) gives rise to a nonlinear response of the piezoelectric effect, leading to an irreversible increase in the piezoelectric coefficient in the paraelectric phase. Along with changes in the elastic properties, the observed poling due to AC electric fields is reminiscent of irreversible ferroelectric–ferroelastic domain wall motion in ferroelectric phases. Such behavior is absent in cubic SrTiO3 where precursor effects are commonly observed at much lower temperatures.
Phase stability and transition behaviors of (BixIn1−x)2Se3 alloy
Authors: Wang Huachun , Cai Xuefen , Li Wei , Wang Bin , Evangelista Igor , Janotti Anderson
Published: January 2025

The Bi2Se3–In2Se3 layered system has garnered significant attention and extensive research due to its versatile properties, yet its structural properties and phase stability remain elusive. Here, using first-principles calculations with van der Waals interactions, we systematically study the phase stability and transition behavior of (BixIn1−x)2Se3 alloys. Our results reveal a contrasting stability profile between Bi2Se3 and In2Se3, with the former exhibiting a distinct preference for the β phase over the α phase, while the latter shows similar stabilities in both phases, thus partially addressing previously reported ground-state inconsistencies. Exploring composition–structure relationships, we demonstrate that Bi incorporation in low concentrations stabilizes the β phase, consistent with early experimental observations. Further analysis based on the cation orbital properties indicates that the preference of Bi for octahedral sites over tetrahedral ones drives the small critical composition for the α→β phase transition. This work enhances our understanding of phase stability in (BixIn1−x)2Se3 alloys, providing insights for future design of monophasic materials and advanced applications.
Microstrip antenna loaded with focusing metasurface for high-gain dual-polarization and bidirectional radiation
Authors: Sun Yibo , Yang Lingling , Wang Jinxiu , Cheng Yongzhi , Luo Hui , Chen Fu , Li Xiangcheng
Published: January 2025

In this paper, we propose a microstrip antenna that incorporates a dual-polarization and bidirectional focusing metasurface (MS) for achieving high-gain transmission in circular polarization (CP) and reflection in linear polarization (LP) radiation, respectively. Initially, we design a MS that enables independent manipulation of the transmitted CP wave at a lower frequency of 8.2 GHz and the reflected LP wave at a higher frequency of 16.2 GHz, respectively. The unit-cell of the MS comprises a combination of an outer bilayered split-ring resonator, along with inner arc-shaped and disk resonators, all separated by a dielectric substrate. Subsequently, a coaxial-fed laminated microstrip antenna is designed that is capable of realizing CP radiation with a gain of approximately 4.9 dBic at 8.2 GHz and LP radiation at 16.2 GHz with a gain of 4.8 dBi, respectively. To improve the radiation performance, we construct a coaxial-fed laminated microstrip antenna integrated with a dual-polarization and bidirectional focusing MS. This configuration enables the antenna to achieve high-gain CP radiation in transmission at 8.2 GHz with a peak gain of 13.1 dBic and high-gain LP radiation in reflection with a peak gain of 14.6 dBi at 16.2 GHz, respectively. The relative bandwidth of the MS antenna is 6.79% (at 8.2 GHz) of the transmitted CP wave and 13.54% (at 16.2 GHz) of the reflective LP wave, respectively. To evaluate the practicality of our proposed design, we fabricated and measured a coaxial-fed laminated microstrip antenna, both with and without the MS. The results obtained from these measurements closely align with our simulations, thereby validating the effectiveness of our proposed dual-polarization and bidirectional MS antenna. This antenna provides a practical solution for achieving dual-polarization radiation and facilitating high-speed information transmission in communication systems.
Study on factors influencing the unbalance of double-split parallel cable current carrying
Authors: Bian Jiayin , Zhang Jue , Yuping Huang , Jiang Shaozhen , Qiu Xuan , Mai Jiayu
Published: January 2025

In recent years, the transmission capacity of a single high-voltage cable has been unable to meet the growing load demand, and double-split parallel cables have become a necessary treatment to improve the transmission capacity requirements. Among them, due to the complex electromagnetic relationship between cables, it may lead to different current-carrying capacity of the same-phase cable line, and this current imbalance will affect the normal operation of power equipment, and in serious cases, it will threaten the safe operation of the power system. This paper first summarizes the factors that may affect the current imbalance degree and then uses Magnet software to carry out finite element simulation analysis of parallel cables to obtain the current-carrying imbalance degree of each phase and finally obtains the influence factor and sensitivity of the current-carrying imbalance degree through comparative analysis, so as to provide effective help for the laying of cables.
Printing quantum dot color conversion layer in etch pits using EHD technology based on mini-LED
Authors: Wang Xinyi , Chen Zhaoyu , Zhou Haojie , Ji Xiaoxiao , Yang Zhu , Liu Li , Yin Luqiao , Zhang Jianhua
Published: January 2025

The rapid development of display technologies has boosted the demand for efficient and high-resolution color conversion techniques. However, conventional approaches such as photolithography and inkjet printing are constrained by limitations in pixel size and material compatibility, making it difficult to meet the demands of industrialization. Due to the low luminescence efficiency of the red quantum dot (QD) material, an innovative quantum dot color conversion (QDCC) layer structure was proposed in this study. The red QD film was prepared in pixel pits below the glass surface using electrohydrodynamic inkjet printing, thus integrating the QD film into the glass substrate. This results in a more vivid and accurate full-color display. The results indicate that the fabricated QDCC layer achieves a pixel size of 216 × 116 μm2, with a maximum external quantum efficiency (EQE) of 5.81% and a luminance of 1 315 205 cd/m2. To improve the performance of the device, the transparent photoresist used for leveling between the LEDs was substituted with a black photoresist. Although the EQE changes to 3.93% and the luminance changes to 1 206 038 cd/m2, the color coordinates move closer to the red region, changing from (0.4396, 0.2089) to (0.4786, 0.2258). This innovative method significantly not only reduces the thickness and weight of the display but also improves its color performance. This research lays the foundation for high-performance displays, paving the way for ultra-thin and energy-efficient display technologies.
The effect of excitation frequency on the flow structure of a plane jet subject to acoustic excitation using particle image velocimetry
Authors: Kumar Sanjay , Murugan Sudharson , Brohi Ali Anwar , Ahmed Zaheer
Published: January 2025

The flow field of plane jets has been studied experimentally under both no-excitation and excitation conditions. The jet pulsation intensity and jet Reynolds number were fixed at 1.0 and 500, respectively, while the excitation frequency increased gradually from 40, 60, and 100 Hz. Acoustic excitation characteristics were determined using hotwire anemometry. Laser-assisted smoke flow visualization techniques were used to render flow features, and an edge detection technique was employed to quantify jet spreading characteristics. The velocity fields were measured using particle image velocimetry. The results show that the velocity pulsation near jet exits exhibited hump-like periodic oscillation signals. Kármán vortex street is generated periodically downstream of plane jet on flow in natural jet flow. These instabilities are replaced with mushroom-shaped coherent vortex structure when jet is under excitation. Higher excitation frequencies intensified these mushroom-shaped structures, which then became puff-like structures and eventually led to vortex breakdown resulting in turbulence eddies. Lagrangian integral time scales and length scales attribute strong vortex stretching effect to vortices breakup phenomenon, which was strong in near field in cases of excitation. In addition, small-length scales of fine turbulence eddies confirmed cascade of turbulent kinetic energy. Flow pulsation magnifies jet spread and vortex's strength. The streamline patterns revealed a two-counter rotating vortex structure in outer shear layers of plane jet flow. Turbulence intensities were significantly higher in near field due to the rapid roll-up of vortices and strong entrainment effect, leading to a higher momentum exchange rate and prominent mixing enhancement significantly during excitation.
Characteristics of a laser-induced bubble near the wedge between the gas–liquid interface and solid wall
Authors: Luo Haotian , Guo Yunji , Xu Sheng , Wen Haocheng , Wu Wangxia , Xiang Gaoming , Wang Bing
Published: January 2025

The dynamics of cavitation bubbles near the wedge region between the free surface and solid wall were experimentally studied using a high-speed camera. In the experiments, the wedge region had different angles θ depending on the solid surface's hydrophobicity. Additionally, the standoff distances of the bubble-solid wall (λw) and bubble-free surface (λs) were varied. Several intriguing results were obtained. First, a competitive mechanism between the free surface and the solid wall during the collapse was observed: the influence of the free surface on the bubble occurred earlier than that of the solid wall. As the collapse progressed, the influence of the solid wall increased. The ratio of the free surface-induced pressure gradient (FPG) to the solid wall-induced pressure gradient (SPG) at the end of the collapse determined the jet direction. Second, altering θ appeared to have minimal influence on the relative ratio (s) between FPG and SPG during bubble collapse. In contrast, variations in λw and λs significantly affected the changing of s, leading to distinct bubble collapse dynamics at varying standoff distances. Finally, the synergistic effects of θ and standoff distances on the jet direction were quantitatively and systematically studied. The distribution of different scale jets was divided based on the value of ζ (Kelvin impulse), and an overall distribution map was provided. This fundamental understanding of the interaction between bubble dynamics and complex boundaries may offer strategies for improving ultrasonic cleaning and reducing cavitation erosion.
Soil erosion on steep hills with varying vegetation patterns
Authors: Aqeel Muhammad , Murtaza Nadir , Ahmed Walli , Pasha Ghufran Ahmed , Ghumman Abdul Razzaq , Ahmed Afzal , Riaz Kashif , Zhao Xianrui
Published: January 2025

Soil erosion on the slope is a major problem in the northern region of Pakistan, causing hill slope instability and landslides. Previous research focused on the assessment of soil erosion in hilly regions caused by intense flooding. However, there is still a gap in investigating the impact of vegetation patterns and densities on the reduction of soil erosion in a hilly region. Therefore, the current research fills this gap with an experimental investigation of various vegetation patterns and densities for the reduction of soil erosion using a physical model of the hilly regions. Experiments were performed under diverse scenarios including two Froude numbers (Fr = 0.17 and 0.20), two vegetation densities (G/d = 2.13 and 1.09, where G: is the gap between two vegetation elements, and d: is the diameter of the vegetation element), and three soil slopes (10°, 15°, and 20°) in a controlled laboratory setting. The findings of the current research indicate a significant contribution of the denser vegetation (G/d  =  1.09, to the reduction of soil erosion. Moreover, a newly modified pattern of vegetation was introduced by modifying the existing patterns of vegetation with gaps and vegetation strips followed by gaps cutting the rate of erosion by between 9% and 12% compared to a regular arrangement under similar scenarios. Consequently, the current research outcomes may be useful in establishing bio-shields as an environmentally friendly method for mitigating soil erosion.
Chirality reversal of vortices induced by surface acoustic waves
Authors: Mi Shuai , Shi Jinxuan , Liu Huibo , Wu Huiliang , Qiao Huifang , Wang Jianing , Dong Jie , Li Xiaolei , Xue Jiangtao , Wang Xiangqian , Wang Jianbo , Liu Qingfang
Published: January 2025

We study the magnetization state and chirality change in the vortex nucleated in the Py disk array in the presence of the surface acoustic wave (SAW) through experiments and simulations. When the magnetic field sweeps across the disk, the presence of the SAW fundamental frequency helps the magnetization to change easily from the buckling to the vortex state. While with the help of the third and fifth harmonics of the acoustic fundamental frequency, besides the changes in magnetic state, some vortices also change their chirality. The reason for this change is that the spin–vorticity coupling induced by the SAW leads to a change in the macroscopic magnetic moment through angular momentum transfer between the mechanical and electron spins. Considering the spin–vorticity coupling equivalent field, called the Barnett field, we simulate the whole process of a vortex under a magnetic field with the help of SAW. The results show that in the presence of a Barnett field, the initial nucleation position and the nucleation process of the vortex are changed, which in turn causes the vortex chirality to change. This work provides ideas for manipulating specific magnetization states and promoting the application of the topological magnetic structure.
Viscosity modeling with the thermodynamic dimension theory: Application to argon fluid
Authors: Ghandili Ali
Published: January 2025

This study extends the recently introduced theory for predicting fluid viscosity by focusing on the thermodynamic dimension (DT) and its relationship to the effective intermolecular potential, Ueff (r, T). The DT describes the degree of freedom in fluid–particle interactions, ranging from three in solids to zero in perfect gases (0 ≤ DT ≤ 3). The DT of fluid varies between these limits depending on temperature and pressure. Unlike traditional models, this method views a fluid as a mix of free particles and temporary clusters (t-clusters), with viscosity resulting from gaseous and solid-like interactions. Viscosity is the sum of dilute gas viscosity and viscosity caused by intermolecular interactions. The theory uses explicit thermodynamic relations to link the Ueff (r, T) to the fluid's equation of state (EoS), giving a unified approach that connects the viscosity equation to the EoS. Argon fluid serves as a case study to demonstrate the model's correctness. The model accurately predicts viscosity throughout a temperature range of 100–1000 K and pressures up to 1000 MPa, with average absolute relative deviations less than 2%. The model's accuracy and computational efficiency enable it to be applied to other simple fluids while upholding the corresponding states principle. These results demonstrate how this theory may be used to unify quantum and classical thermodynamics viewpoints, providing a new framework for understanding and predicting fluid behavior under a variety of circumstances. Because of its accuracy and computational simplicity, the method shows promise for use in fluid mechanics and thermophysical modeling.
The in-depth analysis and validation of momentum dispersion modeling based on direct numerical simulation
Authors: Rao Feixiong , Zhang Shengqi
Published: January 2025

Based on the pore scale prevalence hypothesis (PSPH) in porous media flows, the PSPH model accounts for the effects of momentum dispersion and has been preliminary validated and applied by Rao and Jin [Possibility for survival of macroscopic turbulence in porous media with high porosity, J. Fluid Mech. 937, A17 (2022)]. This paper conducts further in-depth analysis of the PSPH model and validates it across various geometries of homogeneous porous media based on direct numerical simulation (DNS). A detailed analysis of DNS results indicates that the Darcy and Forchheimer terms dominate the flow field with low and high Reynolds numbers, respectively. The Darcy–Forchheimer term effectively approximates the total drag, which consists of both pressure drag and viscous drag throughout the flow field. The contribution of the momentum dispersion term is significant only within the first representative elementary volume adjacent to the boundary, especially at high Reynolds numbers. These findings verify the necessity of Reynolds number-dependent effective viscosity in the PSPH model. Results of the PSPH model are compared with DNS results for isotropic and anisotropic porous media across various geometries. The remarkable consistency between the PSPH model and DNS across a wide range of Reynolds numbers and porosities strongly indicates the potential power of the PSPH model in related industrial applications.
A particle Fokker–Planck method for rarefied gas flows of monatomic mixtures
Authors: Kim Sanghun , Jun Eunji
Published: January 2025

The direct simulation Monte Carlo (DSMC) method is applicable over a wide range of Knudsen numbers. However, the binary collision events make DSMC prohibitively expensive near the continuum regime. To address the computational cost issue in high-density regions, the particle-based Fokker–Planck (FP) method has been studied. In the FP method, particles evolve along independent stochastic paths, so the required cell size and time step do not need to resolve the collisional scale. While several monatomic and diatomic FP models have been proposed, the modeling of gas mixtures has received little attention so far. In this study, two new FP models are proposed to describe monatomic gas mixtures with an arbitrary number of constituents. One is the ellipsoidal statistical FP (ESFP) mixture model, which consistently evolves the relaxation of moments up to shear stress with the Boltzmann collision operator. The other is the ESFP+ mixture model, which includes a nonlinear drift coefficient to match the relaxation of moments up to heat flux with the Boltzmann collision operator. The numerical studies include the relaxation problem, Poiseuille flow, Couette flow, hypersonic flow around a vertical flat plate, and hypersonic flow around a cylinder. The results demonstrate that both the ESFP and ESFP+ models show good agreement with DSMC near equilibrium. However, the ESFP model fails to predict accurate shock structure at high Knudsen numbers, while the ESFP+ model better captures the shock structure.
Roughness effects on flow in Tesla turbine with parametric adjustment of porous layer model
Authors: Pahlavanzadeh Mohammadsadegh , Rusin Krzysztof , Wróblewski Włodzimierz , Rulik Sebastian
Published: January 2025

Momentum diffusion and kinetic energy transfer are critical factors in turbomachinery, which significantly influence the performance of the Tesla turbine. In this investigation, a systematic study was conducted to model surface roughness in flow through the gap between corotating disks of a Tesla turbine. The aim was to define a porous layer instead of a roughness and modify the parameters of the porous material to model real roughness effects. The advantages of the porous layer model lies in its ability to directly simulate the actual roughness effect on flow and independency from equivalent sand-grain roughness. The investigation began with the results of the validation of the porous medium layer (PML) model against experimental tests on a minichannel. The parameters of the PML model were adjusted to achieve the same pressure drop as observed in the experiments. In the next step, the model was implemented in the Tesla turbine analysis. Turbulence closure was k-ω shear stress transport model, which was verified by the results of the large eddy simulation for the case with smooth rotor walls. Three different heights of the porous layer, each with modified parameters, were tested to investigate the effect of roughness height on turbine efficiency and flow parameters. The study demonstrated that the PML roughness model accurately represents the real roughness effect on flow, effectively simulating Tesla turbine performance in the tested cases. Analysis of the results indicates that as the roughness height increases, greater momentum transfer occurs between the operating fluid and the disks.
Cavitating wake dynamics and hydroacoustics performance of marine propeller with a nozzle
Authors: Cheng Zhi , Smoker Brendan , Kashyap Suraj , Burella Giorgio , Jaiman Rajeev K.
Published: January 2025

Using high-fidelity computational fluid dynamics modeling, the current work studies the cavitating turbulent flow of a ducted marine propeller and explores the physical mechanisms underpinning the underwater radiated noise. We employ the standard dynamic large-eddy simulation for the turbulent wake flow and the homogeneous Schnerr–Sauer model for the cavitation process, while the Ffowcs Williams–Hawkings acoustic analogy is used for hydroacoustic modeling. The modeling framework is validated against available experimental data, capturing a distinctive double-helical tip vortex cavitation and its qualitative patterns along the vortex trajectory. In comparison to the noncavitating scenario, the pressure fluctuation on the propeller surface is more ordered but energetic under cavitating conditions due to the periodic nature of the sheet cavity. This is reflected in the thrust spectrum in the form of stronger low-frequency tonal peaks and medium-frequency broadband components, while the high-frequency broadband components are relatively weaker. We show that cavitation enhances the monopole noise source due to fluid displacement by the cavity along with the dipole and quadrupole noise sources associated with the propeller surface and wake turbulence effects. Tonal noise with frequencies corresponding to harmonics of the blade passing frequency is also increased. Cavitating structures increase the hydroacoustic energy of the radiated noise at all orientations, particularly downstream, with an increase in the sound pressure levels by up to 20 dB. Finally, the addition of a duct nozzle inhibits cavitation originating from the propeller surface and its accompanying acoustic energy, although cavitating/vortical structures are now observed at new locations around the nozzle system. As a result, the overall radiated noise power is reduced in the ducted propeller configuration.
Multiphase production prediction of volume fracturing horizontal wells in tight oil reservoir during cyclic water injection
Authors: Wei Bei , Qiao Ruiyi , Hou Jian , Wu Zhongbao , Sun Jiahe , Zhang Yang , Qiang Xuchen , Zhao Ermeng
Published: January 2025

Low-permeability tight reservoirs have emerged as an important part of oil and gas development. Due to the rapid production decline after volume fracturing, water injection is commonly used to supply underground energy. Current rapid production prediction methods cannot account for the impact of imbibition during cyclic water injection and are unable to predict multiphase production. In this study, we established a multiphase production prediction model for cyclic water injection (i.e., huff and puff) after volume fracturing of horizontal wells. The model uses the principle of volume balance to calculate changes of the formation's physical field during the cyclic water injection process. The model employs a three-dimensional imbibition equation to calculate the oil volume of imbibition during the soak period. The model adopts a five-region nonlinear flow model to calculate total liquid production and uses relative permeability for multiphase production splitting. The results show that the model's prediction error is less than 15%. The analysis of model sensitivity factors indicates that the primary influencing factor for multiphase production is the imbibition diffusion coefficient. We have applied the multiphase production prediction method for multiple rounds of cyclic water injection. This study provides a rapid production prediction method for the development of tight oil and gas reservoirs.
The coupling enhancement of air overpressure by aluminium/polytetrafluoroethylene cylindrical shell under inner explosive loading
Authors: Du Jinyi , Guo Lei , He Yuan , Wang Chuanting , Chen Peng , Ma Yue , He Yong
Published: January 2025

To study the reaction behavior of Al/PTFE (Aluminum/Polytetrafluoroethylene) cylindrical shells under inner explosive loading, this paper conducted explosive-driven experiments. The results showed that the flame duration of the reactive samples increased by 448.6% compared to the control group, and the peak overpressure increased by 40% compared to the control group. By comparing the differences between the flame images and overpressure–time curves of different samples, it was found that the anaerobic reaction occurring immediately after detonation significantly enhances the shock wave parameters, particularly the peak overpressure, while the subsequent aerobic reaction has a relatively minor effect on these parameters. To describe the enhancement of the shock wave parameters by the anaerobic reaction, a theoretical model was established from the perspective of shock wave coupling. In this model, the trailing shock wave generated by the Al/PTFE catches up and superimposes the leading shock wave generated by the explosive. During this process of catching up and superposition, the overpressure–time curve of the air shock wave transforms from a double-peak structure to a single-peak structure, and the peak overpressure is enhanced after such transformation. As the explosive mass increases, the air shock wave begins to be enhanced at a distance closer to the explosion center, and the duration of the double-peak structure decreases. Furthermore, as the propagation distance increases, the sample with the highest normalized enhancement rate shows a gradual decrease in the proportion of reactive material. These findings provide a valuable reference for the application of Al/PTFE shells combined with explosives.
First-principles assisted design of high-entropy thermoelectric materials based on half-Heusler alloys
Authors: Zhang Chi , Yan Na , Zhao Changxin , Wei Bingbo
Published: January 2025

The deformation potential theory and semi-classical Boltzmann theory were combined to predict the thermoelectric performances of half-Heusler NaCuTe alloy and Li0.5Na0.5CuSe0.5Te0.5 high-entropy half-Heusler alloy through first-principles calculations. The former was constructed via the congener substitution method from LiCuSe alloy, while the latter was designed by the high-entropy engineering concept. The phonon spectrum and ab initio molecular dynamics simulations indicated that the three alloys display stable intermetallic compounds at ambient temperature. The electrical and thermal transport properties of p-type LiCuSe, NaCuTe, and Li0.5Na0.5CuSe0.5Te0.5 alloys were computed as a function of temperature and carrier concentration. The thermoelectric figure of merit for p-type Li0.5Na0.5CuSe0.5Te0.5 alloy was 1.005 and 3.443 at room temperature and 800 K, whereas that of p-type NaCuTe alloy achieved 2.488 at 800 K, which is obviously superior to most of the recently reported p-type half-Heusler thermoelectric materials. A comprehensive analysis of the phonon lifetime, Grüneisen parameters, phonon group velocities, and primitive cell phonon spectrum revealed that high-entropy engineering could introduce non-equivalent atoms and thus enhance phonon scattering, resulting in the reduction of lattice thermal conductivity. Furthermore, numerical simulations demonstrated that high-entropy engineering could improve the thermoelectric performances of half-Heusler alloys effectively, which provides a unique approach for the optimized design of novel thermoelectric materials.
Diverse plant RNAs coat
Arabidopsis
leaves and are distinct from apoplastic RNAs
Authors: Borniego M. Lucía , Singla-Rastogi Meenu , Baldrich Patricia , Sampangi-Ramaiah Megha Hastantram , Zand Karimi Hana , McGregor Madison , Meyers Blake C. , Innes Roger W.
Published: January 2025

Transgenic expression of a double-stranded RNA in plants can induce silencing of homologous mRNAs in fungal pathogens. Although such host-induced gene silencing is well documented, the molecular mechanisms by which RNAs can move from the cytoplasm of plant cells across the plasma membrane of both the host cell and fungal cell are poorly understood. Indirect evidence suggests that this RNA transfer may occur at a very early stage of the infection process, prior to breach of the host cell wall, suggesting that silencing RNAs might be secreted onto leaf surfaces. To assess whether Arabidopsis plants possess a mechanism for secreting RNA onto leaf surfaces, we developed a protocol for isolating leaf surface RNA separately from intercellular (apoplastic) RNA. This protocol yielded abundant leaf surface RNA that displayed an RNA banding pattern distinct from apoplastic RNA, suggesting that it may be secreted directly onto the leaf surface rather than exuded through stomata or hydathodes. Notably, this RNA was not associated with either extracellular vesicles or protein complexes; however, RNA species longer than 100 nucleotides could be pelleted by ultracentrifugation. Furthermore, pelleting was inhibited by the divalent cation chelator EGTA, suggesting that these RNAs may form condensates on the leaf surface. These leaf surface RNAs are derived almost exclusively from Arabidopsis, but come from diverse genomic sources, including rRNA, tRNA, mRNA, intergenic RNA, microRNAs, and small interfering RNAs, with tRNAs especially enriched. We speculate that endogenous leaf surface RNA plays an important role in the assembly of distinct microbial communities on leaf surfaces.
An improved GAN-based data augmentation model for addressing data scarcity in SRMs
Authors: Yang Huixin , Xiang Zijian , Li Xiang , Zhang Wei
Published: January 2025

In the domain of solid rocket motors (SRMs), acquiring experimental data is a costly endeavor, and fully simulating flight conditions presents significant challenges, making it difficult to gather a sufficient amount of data for each operational scenario. The application of deep learning architectures in the field of SRMs is further complicated by issues of data scarcity and dataset imbalance. To address these challenges, this paper proposes an enhanced generative adversarial network (GAN)-based data augmentation model, referred to as CWGAN-GP-T. This model aims to effectively augment and balance the experimental dataset of SRMs, thereby improving the regression prediction performance of deep learning architectures utilizing SRM data. By leveraging the CWGAN-GP-T framework, pseudo-samples are generated based on the experimental dataset from the SRMs ignition process. The results demonstrate the efficacy of the proposed method in expanding the dataset and ensuring a more balanced distribution of samples across various operating conditions. Comparative experiments are conducted with alternative regression prediction methods and GAN-based data augmentation techniques, validating the superior accuracy of deep convolutional neural networks in predicting the performance of SRMs using datasets augmented by the CWGAN-GP-T method. These findings highlight the exceptional generative capabilities of the proposed model and emphasize its potential impact on advancing research in the field of SRMs.
A whole gamma imaging prototype for higher quantitative imaging of 89Zr-labeled antibodies in a tumor mouse model
Authors: Takyu Sodai , Tashima Hideaki , Takahashi Miwako , Yoshida Eiji , Wakizaka Hidekatsu , Obata Fujino , Akamatsu Go , Nagatsu Kotaro , Sugyo Aya , Sudo Hitomi , Tsuji Atsushi B , Ishibashi Mariko , Imai Yoichi , Parodi Katia , Yamaya Taiga
Published: January 2025

Objective. Positron emission tomography (PET) has become an important clinical modality, but it is limited to imaging the annihilation radiation from positron–electron collisions. Recently, PET imaging with 89Zr, which has a half-life of 3 d, has attracted much attention in immuno-PET to visualize immune cells and cancer cells by targeting specific antibodies on the cell surface. However, 89Zr emits a single gamma ray at 909 keV four times more frequently than positrons, causing image quality (IQ) degradation in conventional PET. To overcome this drawback, use of such single gamma rays for imaging was previously proposed as whole gamma imaging (WGI). In WGI, a single gamma ray is detected by Compton imaging; by inserting a scatter detector ring inside the PET ring, WGI can realize both PET imaging and Compton imaging in one modality. A prototype for WGI was developed and Compton imaging of a mouse after intravenous administration of 89Zr oxalate was demonstrated. However, the Compton imaging of the single gamma ray still presented a challenge due to its low IQ compared to PET. Approach. In this study, the scatter detector insert of the earlier WGI prototype was redesigned with the aim of improving Compton imaging performance. The new prototype produced WGI images by additive averaging of PET and Compton images after optimizing the ratio of each iteration in the image reconstruction. WGI IQ was then evaluated using the NEMA NU4 IQ phantom, and a tumor-burdened mouse was imaged with WGI up to 12 d after 89Zr labeled antibody injection. Main results. Consequently, the Compton imaging performance was improved by lowering the angular resolution measure from 6.7 degrees to 6.4 degrees and the sensitivity from 0.11% to 0.18% compared to the previous prototype WGI. The phantom images with WGI showed a 15% reduction in noise and a 3% increase in contrast recovery under low-statistical conditions compared to images reconstructed by PET data alone. Significance. In-vivo mouse imaging with the new prototype WGI was successfully performed. This successful imaging leads to the expectation that future whole-body WGI imaging will enable more sensitive and better quantitative 89Zr antigen-antibody reaction imaging to be obtained.
Proactive perceptive road: a digital twin-driven intelligent road infrastructure towards proactive road state perception and deduction
Authors: Han Tao , Ma Tao , Xiao Jiangyin
Published: January 2025

The emergence of the digital twin (DT) concept provides a new development direction for the digital transformation and upgrading of road health monitoring and maintenance management. Current road digitization technologies primarily focus on the integration and management of easily perceived and measurable asset and maintenance data. However, they struggle to effectively connect the physical state of the road with various computational and analytical modules, making it difficult to sense and integrate complex, hard-to-measure implicit state information and resulting in an inability to support more comprehensive road condition monitoring and precise maintenance decision-making. This paper introduces the concept of proactive perceptive road (PPR), an intelligent road infrastructure driven by DT technology, capable of actively sensing and deducing explicit and implicit road state information. PPR comprises physical space (air, surface, and internal subspaces) entities and DT models and sensing engines in the virtual space. The paper outlines the application logic and core capabilities of PPR and, based on this, proposes an example architecture for its implementation. Two application case studies are presented—one for monitoring construction quality and another for sensing road structure responses—demonstrating the value and potential of PPR in real-time sensing of implicit road state information. The challenges that remain in practical application are also discussed including perceptual, data, and simulation techniques. The proposed concept of PPR represents the next phase of development, offering insights and methodologies for sensing and extracting complex, implicit structural performance data and road health conditions. The presented cases can serve as references for applying DT in the road sector and guide the development of customized solutions for specific scenarios.
An integrated vibration energy harvesting-storage-injection system based on piezoelectric bistable
Authors: Ye Zhenting , Li Xinxin , Tang Weili , Huang Kexue , Wei Yuming , Mo Fujun
Published: January 2025

Efficiently capturing energy from environmental vibrations remains a significant challenge in sustainable energy systems. This paper presents a novel integrated vibrational energy harvesting-storage-injection system (VEHSIS) to improve energy capture efficiency. The VEHSIS comprises four main components: an energy harvesting module, an energy storage module, an energy injection module, and a microcontroller control module. The VEHSIS employs a four-magnet piezoelectric bi-stable structure, which decreases the height of the potential barriers and thus enables efficient energy harvesting at lower vibration amplitudes. The proposed VEHSIS incorporates a dual-capacitor mode to improve the synchronous electric charge extraction (SECE) circuit and further presents a phase-locked loop circuit and a microcontroller control method to precisely control the synchronous switching of the SECE circuit to optimize energy storage and utilization. By improving the voltage pulse perturbation technique and using the microcontroller to monitor the system status in real-time, the system is enabled to maintain high-energy orbital oscillation output under different conditions. Experimental analysis reveals that the VEHSIS improves harvesting efficiency by 3.2 times after energy injection, providing 827.5 μW in dual piezoelectric cantilever beam mode. Compared to classical energy harvesting systems, the VEHSIS offers a spontaneous energy harvesting method and a significant improvement in energy conversion efficiency, providing a new solution for self-powered devices.