bluuebunny/crossref_metadata_2025 huggingface dataset:
Physics-informed neural networks for solving incompressible Navier–Stokes equations in wind engineering
Authors: Cai Kang , Wang Jiayao
Published: December 2024

Despite the substantial advancements made over the past 50 years in solving flow problems using numerical discretization of the Navier–Stokes (NS) equations, seamlessly integrating noisy data into existing algorithms remains a challenge. In addition, mesh generation is intricate, and addressing high-dimensional problems governed by parameterized NS equations is difficult. The resolution of inverse flow problems is notably resource-intensive, often necessitating complex formulations and the development of new computational codes. To address these challenges, a physics-informed neural network (PINN) has been proposed to seamlessly integrate data and mathematical models. This innovative approach has emerged as a multi-task learning framework, where a neural network is tasked with fitting observational data while reducing the residuals of partial differential equations (PDEs). This study offers a comprehensive review of the literature on the application of PINNs in solving two-dimensional and three-dimensional NS equations in structural wind engineering. While PINN has demonstrated efficacy in many applications, significant potential remains for further advancements in solving NS equations in structural wind engineering. This work discusses important areas requiring improvement, such as addressing theoretical limitations, refining implementation processes, and improving data integration strategies. These improvements are essential for the continued success and evolution of PINN in computational fluid dynamics.
Resistivity scaling of porous MoP narrow lines
Authors: Wang Han , Jin Gangtae , Sam Quynh P. , Funni Stephen D. , Panepucci Roberto R. , Kengne Astrid D. , Siddique Saif , Duong Nghiep Khoan , Cheon Yeryun , Kiani Mehrdad T. , Cha Judy J.
Published: December 2024

The resistivity scaling of copper (Cu) interconnects with decreasing dimensions remains a major challenge in the downscaling of integrated circuits. Molybdenum phosphide (MoP) is a triple-point topological semimetal (TSM) with low resistivity and high carrier density. With the presence of topologically protected surface states that should be defect-tolerant and electron backscatter forbidden, MoP nanowires have shown promising resistivity values compared to Cu interconnects at the nanometer scale. In this work, using template-assisted chemical vapor conversion and standard fabrication techniques that are industry-adoptable, we report the fabrication of porous but highly crystalline MoP narrow lines with controlled sizes and dimensions. We examine the influence of porosity, thickness, and cross-section area on the resistivity values of the fabricated MoP lines to further test the feasibility of MoP for interconnect applications. Our work presents a facile approach to synthesizing TSM nanowires with different dimensions and cross sections, enabling experimental investigations of their predicted unconventional resistivity scaling behavior. Finally, our results provide insight into the effects of porosity on the resistivity of these materials on the nanometer scale.
Topology optimization of microchannel structures for enhanced heat flow in liquid cooling garments
Authors: Li Lujia , Xu Jianan , Li Songjing
Published: December 2024

A topology optimization-based design method for liquid cooling garments (LCGs) is proposed, aiming to enhance the heat flow performance of LCG systems by optimizing the internal microchannel structures. The primary objective is to improve flow and heat transfer characteristics in high-temperature environments, ensuring efficient heat dissipation. To achieve this, a novel liquid cooling film replaces traditional fixed hose structures and integrates with a water-cooled heat exchanger, forming a modular system that facilitates rapid assembly. A variable-density topology optimization model is applied to refine the microchannel configurations, examining the effects of fluid domain volume fractions and multi-objective weighting factors. The findings indicate that as the volume fractions increase, the microchannel designs become finer, leading to improved heat dissipation efficiency and reduced pressure drop. Numerical simulations and experimental validations reveal that the topology-optimized (TO) model outperforms traditional designs (TRA and TRB) in terms of heat flow performance, as observed in studies on flow fields, pressure distributions, temperature profiles, and Nusselt numbers. Specifically, the TO model reduces the average temperature by 30.96% compared to TRA and the maximum temperature by 19.46% compared to TRB at a flow rate of 240 ml/min. At a voltage of 8 V and a flow rate of 700 ml/min, the TO-designed LCGs achieve a steady-state temperature of 24 °C, exhibiting superior performance under high-flow scenarios. The TO design also demonstrates faster thermal equilibrium and a reduced temperature gradient, contributing to enhanced wearer comfort. This research confirms the efficacy of topology optimization, offering a theoretical basis and practical framework for developing high-performance LCG systems.
Theoretical investigation of the nonlinear dynamics for cavitation bubbles inside liquid drops
Authors: Qin Yupeng , Wang Zhen , Zou Li
Published: December 2024

The cavitation bubble dynamics inside liquid drops governed by a Rayleigh–Plesset-like equation is investigated theoretically. A strict qualitative analysis is made to determine the bubble dynamic behaviors. Analytical expressions of the collapse times and analytical solutions of the governing equation are derived for different initial conditions. The validity of these analytical solutions is studied by testing numerical algorithms and/or experimental data. As applications of the analytical solutions, analytical expressions in parametric forms for the evolutions of bubble oscillation velocity, oscillation acceleration, kinetic energy, and potential energy are also obtained. Furthermore, the relevant nonlinear bubble dynamic characteristics and motion laws are also revealed based on the obtained results.
Efficient simulations of shock-induced ignition in turbulent flows with a hybrid scheme
Authors: Fan Duosi , Meng Fanzhao , Han Wang , Yang Lijun
Published: December 2024

This study presents efficient simulations of shock-induced ignition in turbulent flows using a hybrid fifth-order weighted essentially non-oscillatory (WENO5) and sixth-order central difference (CD6) scheme (WENO5-CD6), coupled with a novel semi-coupled fourth-order Runge–Kutta (SC-RK4) integrator. The hybrid WENO5-CD6 scheme ensures efficient and accurate capture of both shock waves and broadband turbulent structures by employing sensors to adaptively combine CD6 for smooth regions and WENO5 for discontinuities. The SC-RK4 integrator addresses the challenges of stiff chemical reactions, outperforming traditional Strang splitting methods in near-limit combustion phenomena. The proposed methods are validated against homogeneous reactor and one-dimensional shock-induced ignition benchmarks, showing improved accuracy and efficiency. Simulations of reactive homogeneous isotropic turbulence reveal that increasing turbulent Mach numbers shortens ignition delay due to the pressure-gain effect induced by shocklets. In shock–turbulence interaction cases, the combustion regime transitions from partially to fully premixed flames, with autoignition and flame propagation modes coexisting before transitioning into a broken reaction zone dominated by distributed premixed flame elements. The results highlight the effectiveness of the WENO5-CD6 scheme in reducing computational cost while maintaining accuracy. Moreover, these findings provide insights into the effects of compressible turbulence on ignition delay and reaction wave propagation.
Noise reduction and aerodynamic performance improvement of a multiblade centrifugal fan
Authors: Zhang Hao , Yang Jinwen , Li Bin , Xia Chunwen , Zhang Yufei
Published: December 2024

Multiblade centrifugal fans are widely used in various fields. With the rapid increase in fan performance requirements, improving aerodynamic performance and reducing noise by modifying individual component parameters are no longer sufficient to meet the demands of actual engineering applications. In this work, a combined noise reduction scheme was adopted to reduce the noise level of the fan under different operating conditions while improving its aerodynamic performance. The three-dimensional unsteady flow and acoustic field of the fan were calculated simultaneously via direct computational aeroacoustics based on the lattice Boltzmann method. Experimental data from the performance test bench and the semianechoic chamber were used to validate the accuracy of the numerical simulation results. A curved-type outlet collector, a nonaxisymmetric inlet nozzle, and a variable inlet/outlet angle blade were designed on the basis of the identified acoustic sources. Different modified schemes provide varying benefits under different operating conditions, but their optimal combination not only reduces the noise of the fan but also improves its aerodynamic performance. The simulation and experimental results show that the total pressure efficiency is significantly improved at the same volume flow rate for both operating conditions and that the noise is reduced by 1.5 and 1.4 dBA. The articulation index improved by a maximum of 5.2%. This study provides a valuable reference for the design of multiblade centrifugal fans with wide operating conditions, high efficiency, and low noise.
Quantifying dispersion and light emission for aluminum powder suspensions with varied surface energy
Authors: Key Connor N. , Kuhn Danielle L. , Harland Jill B. , Altman Igor , Pantoya Michelle L.
Published: December 2024

The dust combustion of aluminum (Al) particles post ballistic impact was studied bi-spectrally in the visible (VIS) and near-infrared (NIR) using high-speed imaging. Powders were delivered loosely via a novel sabot design into a chamber and impacted an anvil at speeds of 1050 m/s. Two identically sized Al powders were studied, one was untreated (UN), the other processed using a thermal annealing and quenching treatment called superquenched (SQ). The SQ Al powder had reduced surface energy compared to UN Al powder, which was induced by the annealing–quenching treatment. Particle dispersion and emission during reaction was quantified by introducing a field emission fraction metric that characterizes the burning powder cloud and relates to particle combustibility. In the case of SQ Al, VIS light emission from dispersed powder decays slower compared to UN Al. High-speed NIR imaging shows UN Al agglomerates resulting in high concentrations of unreacted Al. The differences in powder dispersion and emission were attributed to different combustion regimes and further confirmed by x-ray diffraction analysis of post-burn products, which demonstrated different residue phase compositions. This study demonstrates that a field emission fraction is a quantitative analysis tool to simultaneously evaluate dispersion and emission of dust combustion.
The use case of an asymptotic matching method in physics: large-angle pendulum
Authors: Rosales-Vera Marco
Published: December 2024

This paper examines the calculation of the period of a simple pendulum in the case of extremely large amplitude movements. The calculation is carried out using the method of asymptotic matching, which allows obtaining analytical solutions for the pendulum period that contrast very well with the values found through numerical integration. This analysis can be of great use to undergraduate and graduate students in physical sciences, as it provides mathematical tools that are highly useful in the fields of physical and mathematical sciences. These tools can be applied to a range of more complex problems in areas such as quantum mechanics, fluid mechanics, and related fields.
Effects of N2O plasma treatment on the performance and stability of high indium content InGaZnO thin-film transistors
Authors: Nurmamat Patigul , Li Rui , Yang Linyu , Mamat Mamatrishat , Abliz Ablat
Published: December 2024

This study investigates the effects of N2O plasma treatment on the electrical performance and stability of In(2%)GaZnO thin-film transistors (TFTs). The experimental results show that with increasing N2O plasma treatment time, the electrical performance of In(2%)GaZnO TFTs deteriorated, and the threshold voltage (V
th) is positively shifted. Moreover, the optimized In(2%)GaZnO:N2O (4 min) TFTs exhibited the best electrical performance, which include a μ
FE of 22.5 cm2 Vs−1, a small SS value of 0.31 V decade−1, a small V
th of 0.3 V, a low D
it value of 8.5 × 1011 cm−2 eV−1, and a high I
on/I
off of 107. Moreover, a small V
th shift (0.4, 0.6, −0.5 and −0.7 V) in In(2%)GaZnO:N2O (4 min) TFT was observed under the gate bias and light illumination test. X-ray photoelectron spectroscopy and low-frequency noise analysis indicate that this enhanced performance is attributed to the appropriate N2O plasma treatment that can reduce the oxygen vacancy, interface trap density, and other bulk/surface defects due to the formation of metal–nitrogen bonds (especially Ga–N) and N–O bonds. Over all, the N2O plasma treatment simple method has provided a novel approach to achieve high performance and highly stable oxide In(2%)GaZnO TFTs for applications in flat panel displays.
LIDD-YOLO: a lightweight industrial defect detection network
Authors: Luo Shen , Xu Yuanping , Zhang Chaolong , Jin Jin , Kong Chao , Xu Zhijie , Guo Benjun , Tang Dan , Cao Yanlong
Published: December 2024

Surface defect detection is crucial in industrial production, and due to the conveyor speed, real-time detection requires 30–60 frames per second (FPS), which exceeds the capability of most existing methods. This demand for high FPS has driven the need for lightweight detection models. Despite significant advancements in deep learning-based detection that have enabled single-stage models such as the you only look once (YOLO) series to achieve relatively fast detection, existing methods still face challenges in detecting multi-scale defects and tiny defects on complex surfaces while maintaining detection speed. This study proposes a lightweight single-stage detection model called lightweight industrial defect detection network with improved YOLO architecture (LIDD-YOLO) for high-precision and real-time industrial defect detection. Firstly, we propose the large separable kernel spatial pyramid pooling (SPP) module, which is a SPP structure with a separable large kernel attention mechanism, significantly improving the detection rate of multi-scale defects and enhancing the detection rate of small target defects. Secondly, we improved the Backbone and Neck structure of YOLOv8n with dual convolutional (Dual Conv) kernel convolution and enhanced the faster implementation of Cross Stage Partial Bottleneck with 2 Convolutions (C2f) module in the Neck structure with ghost convolution and decoupled fully connected (DFC) attention, reducing the computational and parameter overhead of the model while ensuring detection accuracy. Experimental results on the NEU-DET steel defect datasets and printed circuit board (PCB) defect datasets demonstrate that compared to YOLOv8n, LIDD-YOLO improves the recognition rate of multi-scale defects and small target defects while meeting lightweight requirements. LIDD-YOLO achieves a 3.2% increase in mean average precision (mAP) on the NEU-DET steel defect dataset, reaching 79.5%, and a 2.6% increase in mAP on the small target PCB defect dataset, reaching 93.3%. Moreover, it reduces the parameter count by 20.0% and floating point operations by 15.5%, further meeting the requirements for lightweight and high-precision industrial defect detection models.
ResNet50-3Cur-HGCN: a novel multimodal hybrid curvature space approach to bearing fault diagnosis
Authors: Yi Cancan , Wang Yuchen , Liu Yang , Xiao Han
Published: December 2024

As a consequence of its great load-bearing capacity, low friction loss, and low vibration and impact, bearings are employed extensively in a variety of applications. In response to the current issues in the process of fault signal identification using graph neural networks (GNNs), such as the insufficient expression of node data types, the inadequate exploration of feature information carried by the graph structure, and the singularity of mathematical space operations on graph data, this paper proposes a residual network-50-heterogeneous graph convolutional neural network (ResNet50-HGCN) model based on the combination of ResNet50 and HGCN. The model is trained in a threefold mixed curvature (3 Curvature, 3Cur) space environment for semi-supervised learning, aiming to achieve accurate classification of bearing fault signals. Specifically, first, the time-domain signals and the components of the time–frequency map obtained from the wavelet synchrosqueezing transform are used as the bimodal node information for HGCN. Then, the graph network is merged in the 3Cur space for training and weighted validation, obtaining the predicted category labels of the model under the 3Cur configuration space. Finally, experimental data analysis is conducted, sparse confusion matrices for predicted categories are drawn, and four types of accuracy-related evaluation metrics are calculated. The experimental results show that the proposed ResNet50-3Cur-HGCN classification model outperforms other models in the experiment, achieving an accuracy of 97.71%, which verifies the method’s beneficial effects with regard to precision and efficiency. It also provides a good methodological reference for bearing fault diagnosis approaches centered on GNNs.
Evaluation of impact energy in composites using acoustic emission sensing technique
Authors: Ai Li , Mesaric Tanner , Flowers Sydney , Houck Sydney , Widawsky Joshua , Ziehl Paul
Published: December 2024

A major challenge faced by composite materials is impact, which can result in unexpected damage and degradation. Impact events can cause significant structural damage that may not be immediately visible, leading to a reduction in the material’s mechanical properties and overall performance. This paper presents an impact assessment method using acoustic emission (AE) sensing technology. The primary goal of this approach is to determine the extent of impact damage on composite components by analyzing AE signals produced under operating stress conditions. An advanced algorithm is proposed to predict the probability that the damage falls into various damage categories, providing a detailed assessment of the material’s condition. For validation, a series of composite panels were manufactured and subjected to controlled impact and subsequent compression after impact tests. The AE signals gathered during these tests provided initial validation for the proposed method, showcasing its potential for accurately assessing impact damage. The results demonstrate that AE sensing technology, combined with advanced algorithmic analysis, has the potential to be an effective tool for monitoring the integrity of composite materials and ensuring their reliability in critical applications.
Unveiling the phases of bulk ZrTe5 through magnetotransport phenomena
Authors: Shih Pi-Ju , Yang Cheng-Hsueh , Liao Pin-Chi , Lin Wei-Chen , Chen Fa-Hua , Chen Jeng-Chung , Cao Limin , Chuang Chiashain , Liang Chi-Te
Published: December 2024

We present a straightforward method which may greatly simplify and lower the threshold for determining the phase of the relatively enigmatic quantum material—ZrTe5. In this study, without directly probing the band structure, we identify the topological phase of the three-dimensional (3D) bulk ZrTe5 crystal solely through low-temperature electrical and magnetotransport measurements. A two-dimensional (2D) weak antilocalization (WAL) effect was observed in our bulk ZrTe5 crystal, along with clear Shubnikov–de Haas oscillations. The large prefactor

α

derived from WAL analyses indicates the presence of multiple conducting channels in the bulk ZrTe5 crystal, where each channel is associated with individual 2D ZrTe5 layers. It is the large

α

value provides insights into the topological Dirac semimetal phase inherent to our ZrTe5 crystal. Additionally, we analyze the pronounced linear magnetoresistance and saturation behavior under a perpendicular magnetic field. Our results suggest that bulk ZrTe5 crystals, which exhibit unique layered transport features, serve as a promising platform for further research in quantum phases and transitions in 3D quantum systems.
Elastic limit and relaxation of GaAs/In(Al,Ga)As core/shell nanowires for near-infrared applications
Authors: Chatzopoulou Polyxeni , Hilliard Donovan , Vasileiadis Isaak G , Florini Nikoletta , Devulapalli Vivek , Liebscher Christian H , Lymperakis Liverios , Komninou Philomela , Kehagias Thomas , Dimakis Emmanouil , Dimitrakopulos George P
Published: December 2024

Abstract

In the GaAs/In
x
(Al,Ga)1–x
As core/shell nanowire (CSNW) geometry, narrow cores exhibit significant bandgap reduction and enhanced electron mobility because of their ability to sustain extreme tensile elastic strain. In such an elastic state, the coherency limits and the resulting physical properties of the nanowires are governed by the strain field distribution and plastic relaxation mechanisms. Using atomic-resolution transmission electron microscopy, we determined the three-dimensional strain field, critical misfit, and plastic relaxation relative to the indium content of the shell, while maintaining constant core–shell dimensions. The strain was mapped experimentally in both coherent and plastically relaxed nanowires with a core radius of 10 nm and thick shells and was compared to atomistic and continuum calculations. Our findings reveal that, while axial strains remain uniform, elastic relaxation induces radial and tangential strain gradients. This is attributed to the strain concentration at the sharp interfaces, which persisted even after plastic relaxation. For the pertinent growth conditions, the maximum sustained elastic strain in the cores was observed for the GaAs/In0.5Al0.5As nanowires. The plastic relaxation of nanowires with shells of high indium content involved Frank partials delimiting horizontal intrinsic stacking faults (SFs), misfit dislocations gliding on inclined close-packed planes, and stair-rod dislocations along SF junction lines attributed to nanowire bending. Ab initio calculations showed that the heterojunction remained type I even for the highest elastic strain, despite the existence of strain gradients at the core–shell interface. Our results elucidate the elastoplastic behaviour of CSNWs with narrow cores, offering new perspectives on growth strategies to further push their coherency limits.
Validation of the generalized stochastic microdosimetric model (GSM

2

) over a broad range of LET and particle beam type: a unique model for accurate description of (therapy relevant) radiation qualities
Authors: Bordieri Giulio , Missiaggia Marta , Cartechini Giorgio , Battestini Marco , Bronk Lawrence , Guan Fada , Grosshans David , Rai Priyamvada , Scifoni Emanuele , La Tessa Chiara , Lattanzi Gianluca , Cordoni Francesco G
Published: December 2024

Objective. The present work shows the first extensive validation of the generalized stochastic microdosimetric model (GSM2). This mechanistic and probabilistic model is trained and tested over cell survival experiments conducted with two cell lines (H460 and H1437), three different types of radiation (protons, helium, and carbon ions), spanning a very broad LET range from

1
 

keV

μ

m

−
1

up to more than

300
 

keV

μ

m

−
1

. Currently, the existing mechanistic radiation biophysical models show some limitations in describing cell killing without the addition of ad hoc corrections, especially in the high-LET regime, where the overkill effect is observed. Approach. The experimental irradiation conditions have been accurately reproduced with Monte Carlo simulations using the GEANT4-based TOPAS computational toolkit. We show the main and unique features of GSM

2

, i.e. how it can predict the biological response by considering the full information on the stochasticity of radiation through the microdosimetric spectrum, which is supposed to be the best descriptor of radiation quality. Main results. Well-matching results for different biological endpoints with the natural presence of the overkill effect fully display the predictive power of GSM2. Significance. This study shows the complete generality and flexibility of GSM2 and its ability to successfully predict the cell survival probability from very different particle radiation fields. Consequently, we demonstrate the dependence of the relative biological effectiveness on the whole microdosimetric spectrum, which fully includes the stochasticity inherently given by radiation-matter interaction.
A comprehensive dual energy method for CBCT metal artifact reduction
Authors: Ge Weiwei , Liu Zihao , Cui Hehe , Yuan Xiaogang , Yang Yidong
Published: December 2024

Objective. A major limitation in cone beam CT (CBCT) application is the presence of metal artifacts when scanning metal-embedded objects or high attenuation materials. This study aims to develop a dual-energy based method for effective metal artifact reduction. Approach. The proposed method comprised three steps. Initially, the virtual monoenergetic (VM) projections were generated by combining high- and low-energy projections to mitigate metal artifacts caused by the beam hardening effect. Subsequently, the normalized metal artifact reduction (NMAR) projections were created using the VM projections through the NMAR method. Then, the NMAR CBCT was produced by reintegrating metal into the CBCT reconstructed from NMAR projections. Finally, the iterative reconstruction was employed to obtain the final CBCT, utilizing VM projections and the NMAR CBCT as the initial input. Validation of the proposed method was achieved through Monte Carlo (MC) simulations on digital dental and abdominal phantoms, and CBCT scanning on CIRS Model 062M head and body phantoms. The structural similarity index measurement (SSIM) and the root mean square error (RMSE) calculated within a metal-containing ROI were employed for image quality evaluation. Main Results. Both the MC simulation and phantom scanning demonstrated that the proposed method was superior to the frequency split metal artifact reduction (FSMAR) method in mitigating artifacts and preserving anatomic details around metal. Averaged over four phantoms, the SSIM was enhanced from 99.48% with FSMAR to 99.86% with our proposed method, and the RMSE was reduced from 93.62 HU to 70.75 HU. Furthermore, the proposed method could be implemented with less than two minutes after GPU acceleration. Significance. The proposed dual-energy based metal artifact correction method effectively corrects metal artifacts and preserves tissue details surrounding the metal region by leveraging the strengths of VM, projection interpolation and iterative reconstruction techniques. It has strong potential of clinical implementation due to the superior performance in image quality and process efficiency.
A statistically-based continuum anisotropic constitutive model of fiber-reinforced shape memory hydrogel composites
Authors: Gao Zhaoguo , Hu Yunqiang , Sun Jian , Jia Fei , Liu Yanju , Leng Jinsong
Published: December 2024

Shape memory hydrogel composites (SMHCs) have been developed to enhance the performance of SMHs, serving as smart soft materials with superior shape and performance programmability. The establishment of a constitutive model is crucial for the utilization of SMHCs, yet research in this area remains limited. Herein, based on the transient network theory and the Fung-type elastic model, a micro-macroscopic anisotropic constitutive model for SMHCs incorporating double-network SMHs and the distribution of fibers was developed. Mechanical behaviors and shape memory effects of SMHCs were investigated with three different fiber distributions: unidirectional, planar uniform, and volumetric uniform. The efficacy of model was validated by implementing it into a user-defined materials subroutine. Various parameters of SMHCs, such as ambient temperature, instantaneous shear modulus of the network, and fiber stiffness, were examined for their effects on mechanical behaviors and shape memory effects. The proposed model can capture the shape memory effects of double network SMHCs. Simulation examples involving SMHC-based stents were provided to illustrate the practical implications of our work in SMHCs applications.
A novel body centered cubic 3D auxetic chiral geometry
Authors: Caporale Antonio Maria , Airoldi Alessandro , Novak Nejc
Published: December 2024

Auxetic materials and structures have a negative Poisson’s ratio (PR), which means that they expand under a longitudinal tensile loading and shrink under compressive load. This property gives them an increased shear resistance, damping and energy absorption capabilities. Chiral geometries are among the most effective auxetic structures for their ability to convert the axial loading in the rotation of their internal nodes. In the present work, a novel 3D chiral geometry is presented, and its response is investigated both experimentally and numerically. It is made of spheres placed following a Body Centered Cubic lattice; each one connected to the closest neighbors by eight ligaments. A sample was 3D-printed and mechanically tested in compression exhibiting an auxetic behavior in certain directions. A Finite Element model was then developed, successfully reproducing the outcome of the experimental tests, both in terms of force and PR. Then, a numerical testing campaign was performed on representative units constrained using periodic boundary conditions. This campaign allows to evaluate the mechanical properties of the structure as a function of its geometrical parameters. It shows to be able to exhibit an approach a PR of

−
1

in all the directions. Moreover, the relationship between the sphere’s rotation, PR and instability was investigated.
Research on the characteristics of accurate engineering mathematical model of photovoltaic cells based on grey relational analysis
Authors: Zhou Biying , Zhang Peng , Yin Guofu
Published: December 2024

Traditional photovoltaic (PV) models are characterized by excessive parameters, significant nonlinearity, and transcendental equations, making it challenging to simultaneously satisfy the speed and accuracy criteria for PV array engineering design. To improve traditional PV models and optimize parameters, a precise engineering mathematical model of PV cells is developed. At a temperature of 25 °C and a solar irradiance of 1000 W m−2, compared with actual measurement, the calculated results of the proposed model have an average relative error of 0.22% s. In 5 random settings, compared with the traditional Newton iteration method and the approximate fitting straight line method, this model has an average relative error of 0.23% and 1.37%, respectively. After sensitivity testing on the model parameters, the grey correlation degree method is used to analyze the impact correlation and maximum power point (MPP) of 6 factors, U

mpp
, T, I

mpp
, α, R

sh
, and S. The results show that the proposed engineering mathematical model of PV cells is responsive to different parameters. It effectively demonstrates electrical characteristics under different conditions and highlights the impact of each parameter on the MPP. The findings can provide a foundation for optimizing large-scale solar power generation system.
Design a chaotic circuit using tunable and power efficient memristor emulator circuit for image encryption
Authors: Kumari Usha , Yadav Rekha
Published: December 2024

In a non-linear dynamic system, chaos is a deterministic phenomenon that arises when the state vector trajectories become highly sensitive to the initial conditions, given certain criteria and periodic. The memristor, being the fourth essential component of a two-terminal device, has the potential to overcome the barrier for secure communication against eavesdroppers and manufacturing of duplicate chaotic transrecivers by the untrusted foundaries.It can close a gap among secure manufacturing and reliable communication because its resistance can be programmed by the designer not by the foundary. This property makes the communication system more efficient, reliable secure, and provides more security. In this study, the memristor and analog design of a chaotic transreviver is designed. The memristor model is designed using a Current mirror operational transconductance amplifier (OTA) and an analog multiplier with sinusoidal input having amplitude (V

m
) and input frequency (f). Variations in input frequency, and amplitude have an impact on conductance and resistance state and the OTA parameter g

m
Also affects the V-I response. The research focuses on memristor tunability with a variation of the hysteresis curve using factors such as temperature, amplitude, load resistance, frequency, and incremental and decremental behavior and secure communication using a Chaotic circuit using memristor. The maximum operational frequency that exhibits a pintch hystresis curve is 100 kilohertz, and a power dissipation of 3.1 μW with noise 56 nV/Hz1/2 The results also show the chaotic system are sensitive with their secret key or starting conditions of integrator which is uses for the encryption approach.
Elzaki residual power series approach for semi-analytic approximation of time-fractional nonlinear equations occurring in magneto-acoustic waves
Authors: Kumar Sachit , Joshi Varun , Kapoor Mamta
Published: December 2024

The study of magneto-sound propagation in plasma, capillary gravity water waves, and the travel of long waves under the effect of gravity in shallow water are all important applications of the 5th-order Korteweg–de Vries equation. This research article uses the Elzaki residual power series method(ERPSM), an appropriate innovative technique, to explore time-fractional nonlinear 5th-order Korteweg–de Vries equations. Three instances of the time-fractional 5th-order Korteweg–de Vries equations in order to demonstrate the effectiveness and relevance of the proposed method has been examined. This work's originality is expressed by an analysis of the fractional behavior of the considered equations.There is a discernible difference in the solutions that are produced for various fractional orders, which may have distinct ramifications for further work. Readers can employ the hybrid approaches combining with our proposed scheme as a future study direction to get better results. Additionally, appropriate numerical simulations were setup to confirm the accuracy and dependability of the suggested strategy. The results collected indicate that the suggested approach is highly satisfying and looks at the intricate nonlinear problems that occur in innovation and science.
Exploring the stability of equilibria and Hopf-bifurcation in a tuberculosis model with delayed treatment
Authors: Das Saduri , Sarkar Tapan , Biswas Pankaj
Published: December 2024

Tuberculosis poses a worldwide threat, particularly to low and middle-income nations. The timely screening, identification, and management of TB become problematic in these regions due to resource constraints, inadequate education and awareness, stigma and discrimination, weak healthcare infrastructure, and concurrent health conditions. This delay may lead to postponed diagnosis and treatment. This work presents and examines a mathematical model for tuberculosis that incorporates exogenous reinfection, slow-fast progression, and delay in detection and treatment. More precisely, we examine a scenario where a certain proportion of people with active tuberculosis receive prompt diagnosis and treatment, while the rest experience a delay in detection and appropriate treatment. First, we establish the non-negativity and boundedness of the solutions, and discuss the criteria for the existence of different equilibria. Then, the local stability of the equilibria is analyzed. The threshold value of the time delay which decides the local stability of the disease-free equilibrium (DFE) is obtained. We observe that the model exhibits a Hopf-bifurcation when the time delay crosses a certain threshold value,

τ

0

*

. This reveals that the EEP is stable for

τ
<

τ

0

*

. However, as

τ
>

τ

0

*

, the EEP loses its stability via Hopf-bifurcation, leading to sustained periodic oscillations. Further, by applying center manifold theory, we analytically determine the direction and stability of the Hopf-bifurcation and validate the results numerically. It is observed that the Hopf-bifurcation is supercritical and the bifurcating periodic oscillations are stable. Global stability of the endemic equilibrium point (EEP) under certain conditions is established by choosing a suitable Lyapunov function. Additionally, the system also exhibits a Hopf-bifurcation in the absence of delay and numerical simulations are performed to determine the critical parameter values at which the bifurcation occurs. The impact of treatment delay is significant, as it not only contributes to the emergence of complex dynamical behavior but also significantly influences the stability properties of the system. This delay can lead to critical transitions, such as changes in equilibrium stability and the onset of oscillatory dynamics, depending on the interaction of system parameters.
The investigation of the radiation shielding features of boro-tellurite glasses containing bismuth and titanium via FLUKA code
Authors: Hoşgör G , Tabar E
Published: December 2024

The gamma radiation shielding features of four different boro-tellurite glasses with chemical composition xTiO2-yBi2O3-zB2O3-(100-x-y-z) TeO2 (x = 5, 10 mol%, y = 10,20, 25, and 30 mol% and z = 20 and 30 mol%) were examined using FLUKA Monte Carlo code. The simulations were run for photon energies of 245, 356, 511, 662, 964, 1173, and 1332 keV emitted by 152Eu, 133Ba, 22Na, 137Cs, and 60Co. The obtained results show that the Bi2O3 addition increased the mass attenuation coefficient (MAC) ranges from 0.2559 to 0.3584 cm2 g−1, 0.1454 to 0.1869 cm2 g−1, 0.0992 to 0.1167 cm2 g−1, 0.0803 to 0.0902 cm2 g−1, 0.0620 to 0.0667 cm2 g−1, 0.0549 to 0.0581 cm2 g−1, and 0.0511 to 0.0535 cm2 g−1 for 245, 356, 511, 662, 964, 1173, and 1332 keV, respectively. The photon attenuation parameters, such as half-value layer (HVL), ten-value layer (TVL), and mean free path (MFP), were also studied. The results showed that Bi2O3 substitution positively impacts the produced glasses’ photon attenuation abilities.
FlexRT — A fast and flexible cosmological radiative transfer code for reionization studies. Part I. Code validation
Authors: Cain Christopher , D'Aloisio Anson
Published: December 2024

The wealth of high-quality observational data from the epoch of reionization that will
become available in the next decade motivates further development of modeling techniques for their
interpretation. Among the key challenges in modeling reionization are (1) its multi-scale nature,
(2) the computational demands of solving the radiative transfer (RT) equation, and (3) the large
size of reionization's parameter space. In this paper, we present and validate a new RT code
designed to confront these challenges. FlexRT (Flexible Radiative Transfer) combines
adaptive ray tracing with a highly flexible treatment of the intergalactic ionizing opacity. This
gives the user control over how the intergalactic medium (IGM) is modeled, and provides a way to
reduce the computational cost of a FlexRT simulation by orders of magnitude while still
accounting for small-scale IGM physics. Alternatively, the user may increase the angular and
spatial resolution of the algorithm to run a more traditional reionization simulation.
FlexRT has already been used in several contexts, including simulations of the
Lyman-α forest of high-z quasars, the redshifted 21cm signal from reionization, as well
as in higher resolution reionization simulations in smaller volumes. In this work, we motivate and
describe the code, and validate it against a set of standard test problems from the Cosmological
Radiative Transfer Comparison Project. We find that FlexRT is in broad agreement with a
number of existing RT codes in all of these tests. Lastly, we compare FlexRT to an
existing adaptive ray tracing code to validate FlexRT in a cosmological
reionization simulation.
Simulation of dark scalar particle sensitivity in η rare decay channels at HIAF
Authors: Liu 刘 Yang 洋 , Wang 王 Rong 荣 , Mushtaq Zaiba , Tian 田 Ye 野 , He 何 Xionghong 熊宏 , Qiu 仇 Hao 浩 , Chen 陈 Xurong 旭荣
Published: December 2024

The search for dark portal particles is a prominent topic at the frontier of particle physics. We present a simulation study of an experiment suitable for searching for scalar portal particles at the Huizhou η factory. The high-intensity proton beam from HIAF and a high event-rate spectrometer are suggested to conduct this experiment, both of which are well-suited for the discovery of new physics. Under a conservative estimation,

η events could be produced during a one-month operation of the experiment. The hadronic production of η mesons (

) was simulated at a beam energy of 1.8 GeV using the GiBUU event generator. We searched for light dark scalar particles through rare decay channels, namely

and

. The detection efficiencies of the channels and the spectrometer resolutions were studied in the simulation. We also present the projected upper limits of the decay branching ratios of the dark scalar particle and the projected sensitivities to the model parameters.
Universal thermodynamic relations with constant corrections for five-dimensional de Sitter spacetime*
Authors: Ma 马 Yubo 宇波 , Zheng 郑 Songtao 松涛 , Li 李 Jing 静
Published: December 2024

In this study, we built upon the method proposed by Goon and Penco for analyzing the universality of thermodynamic relations with corrections in de Sitter (dS) black holes. Additionally, based on our analysis of non-linear magnetically charged black holes in dS spacetime, five-dimensional dS hairy spacetime, and five-dimensional charged-dS rotating black holes, we demonstrate the universality of thermodynamic relations in dS black holes. This establishes a universal conjecture relating shifted thermodynamic quantities for arbitrary black-hole backgrounds. We consider that these universal relations will offer new insights into the realm of quantum gravity.
Near-surface Imaging Based on Cross-coherence Method with High-Speed-Train-Induced Vibrations
Authors: Chang Weishuai , wu Hua , Shao Guangzhou
Published: December 2024

High-speed trains (HST) generate seismic waves that can serve as a powerful ambient noise source for near-surface imaging. To image the S-wave velocity of the near-surface using the HST seismic signals, we apply the seismic interferometry and compare the effects of two interferometry techniques: cross-correlation and cross-coherence. After processing the measured data, we recovered the Rayleigh wave data in the 1∼5Hz range from the original HST seismic data. The comparison shows that the cross-coherence technique produces surface wave data with a higher signal-to-noise ratio. We then process the obtained virtual shot gathers using the multi-channel surface wave analysis (MASW) method and invert them to obtain the S-wave velocity structure of the subsurface.
Three-dimensional magnetotelluric inversion using unstructured deformed hexahedral grids
Authors: Li Yangming , Guo Chang’an , Chen Chutong , Wang Kunpeng
Published: December 2024

Topography has a great influence on the inversion and interpretation of magnetotellurics. To improve the reliability of the inversion, the influence of topography must be eliminated, and inversion with topography is an effective solution. At present, three-dimensional electromagnetic inversion is still mostly based on finite difference forward modeling, but it is difficult to simulate complex topography using structured hexahedral grids effectively, and unnecessary densification of the grid extension area will be performed. The finite element method can use arbitrary grids to divide the area and is very suitable for simulating undulating topography. Therefore, this study uses unstructured deformed hexahedral grids to divide the calculation area, which can densify local key areas and reduce the number of grid divisions in the extended areas, ensuring calculation accuracy and relatively reducing the number of calculations. The effectiveness of the method is proved by inverting the theoretical model.
An integrated waterborne seismic-electromagnetic acquisition system and its application in bedrock investigation for cross-river tunneling
Authors: Luo Qiang , Yang Dikun , Ma Jinguo
Published: December 2024

Construction of cross-river tunnels requires an understanding of the geology beneath the riverbed, particularly the solidity of the bedrock that may often be compromised by the weathering process. High-efficiency geophysical technology is demanded before drilling and other intrusive verification. We develop an integrated seismic-electromagnetic acquisition system for towed waterborne surveys by combing the single-channel seismic and towed transient electromagnetic (FloaTEM). The system consists of one towing boat and two floating boats connected and traveling in a line. The front deck of the towing boat houses the transmitting and receiving unit of the seismic system, and the seismic sensors are attached to one side of the boat below the waterline. The back deck contains the boat engine and the control unit of the FloaTEM system, whose transmitter loop and receiver coils are mounted in the two floating boats behind the towing boat. The system was tested at a section of Shunde Waterway near Guangzhou, China. The entire survey of about 7.6 line-km was finished in about 1.3 hours at a speed of 6 km/h. The seismic data and EM inversion model are highly consistent in delineating the three major interfaces below the water surface: water-sediments, sediments-weathered bedrock, and weathered-unweathered bedrock. In addition, the EM method is particularly useful in highlighting the contrast between the weathered and unweathered bedrock because of the difference in water content. The integrated survey revealed that the weathered bedrock layer thickens from the north to the south along the planned tunneling line, which is also favorably verified by the drill holes on the river bank of both sides.
Application of Sparsity-Enhanced Predictive Deconvolution in Offshore Wind Farm Site
Authors: Y Zhang , DeL Wang , B Hu
Published: December 2024

The development of offshore wind power has become an integral part of the global energy transition. Geological surveys targeting the bedrock surface are indispensable in the development process of offshore wind farms, as they directly affect the site selection and design of the wind farms. Single-channel seismic surveying is a towed survey method that offers advantages in exploration efficiency and accuracy. However, strong interference from multiple reflections is a unique challenge in offshore seismic exploration. To address this issue, we propose a sparse-promoting multi-channel predictive deconvolution method. This method begins by establishing a framework for multichannel predictive deconvolution, and then leverages the high redundancy and sparsity benefits of the Shearlet transform to enhance the sparsity of seismic signals. Through the processing of field data, we have verified that our method can effectively suppress multiple reflections, improve signal-to-noise ratio, and enhance the accuracy and efficiency of seismic exploration, providing more accurate and reliable technical support for the preliminary environmental investigation of offshore wind power projects.