bluuebunny/crossref_metadata_2025 huggingface dataset:
Maxwell Demon and Einstein–Podolsky–Rosen Steering
Authors: Hu 胡 Meng-Jun 孟军 , Hu 胡 Xiao-Min 晓敏 , Zhang 张 Yong-Sheng 永生
Published: April 2024

Research of Maxwell demon and quantum entanglement is important because of its foundational significance in physics and its potential applications in quantum information. Previous studies on the Maxwell demon have primarily focused on thermodynamics, taking into account quantum correlations. Here we consider from another perspective and ask whether quantum non-locality correlations can be simulated by performing work. The Maxwell demon-assisted Einstein–Podolsky–Rosen (EPR) steering is thus proposed, which implies a new type of loophole. The application of Landauer’s erasure principle suggests that the only way to close this loophole during a steering task is by continuously monitoring the heat fluctuation of the local environment by the participant. We construct a quantum circuit model of Maxwell demon-assisted EPR steering, which can be demonstrated by current programmable quantum processors, such as superconducting quantum computers. Based on this quantum circuit model, we obtain a quantitative formula describing the relationship between energy dissipation due to the work of the demon and quantum non-locality correlation. The result is of great physical interest because it provides a new way to explore and understand the relationship between quantum non-locality, information, and thermodynamics.
R-matrix calculations for opacities: I. Methodology and computations
Authors: Pradhan A K , Nahar S N , Eissner W
Published: April 2024

An extended version of the R-matrix methodology is presented for calculation of radiative parameters for improved plasma opacities. Contrast and comparisons with existing methods primarily relying on the distorted wave approximation are discussed to verify accuracy and resolve outstanding issues, particularly with reference to the opacity project (OP). Among the improvements incorporated are: (i) large-scale Breit–Pauli R-matrix calculations for complex atomic systems including fine structure, (ii) convergent close coupling wave function expansions for the (e + ion) system to compute oscillator strengths and photoionization cross sections, (iii) open and closed shell iron ions of interest in astrophysics and experiments, (iv) a treatment for plasma broadening of autoionizing resonances as function of energy-temperature-density dependent cross sections, (v) a ‘top-up’ procedure to compare convergence with R-matrix calculations for highly excited levels, and (vi) spectroscopic identification of resonances and bound (e + ion) levels. The present R-matrix monochromatic opacity spectra are fundamentally different from OP and lead to enhanced Rosseland and Planck mean opacities. An outline of the work reported in other papers in this series and those in progress is presented. Based on the present re-examination of the OP work, opacities of heavy elements might require revisions in high temperature-density plasma sources.
R-matrix calculations for opacities: III. Plasma broadening of autoionizing resonances
Authors: Pradhan A K
Published: April 2024

A general formulation is employed to study and quantitatively ascertain the effect of plasma broadening of intrinsic autoionizing (AI) resonances in photoionization cross sections. In particular, R-matrix data for iron ions described in the previous paper in the RMOP series (RMOP-II, hereafter RMOP2) are used to demonstrate underlying physical mechanisms due to electron collisions, ion microfields (Stark), thermal Doppler effects, core excitations, and free–free transitions. Breit–Pauli R-matrix cross sections for a large number of bound levels of Fe ions are considered, 454 levels of Fe XVII, 1184 levels of Fe XVIII and 508 levels of Fe XIX. Following a description of theoretical and computational methods, a sample of results is presented to show significant broadening and shifting of AI resonances due to extrinsic plasma broadening as a function of temperature and density. The redistribution of AI resonance strengths broadly preserves their integrated strengths as well as the naturally intrinsic asymmetric shapes of resonance complexes which are broadened, smeared and flattened, eventually dissolving into the bound-free continua.
Ab-initio transport model to study the thermoelectric performance of MoS2, MoSe2, and WS2 monolayers by using Boltzmann transport equation
Authors: Kumari Shweta , Kumar Sandeep , Pratap Surender , Kubakaddi Shrishail S
Published: April 2024

The potential for thermoelectric applications of two-dimensional materials is quite promising. Using ab-initio calculations, we have investigated the electronic band structure, phonon band structure, electronic density of states, and phonon density of states of monolayers MoS2, MoSe2, and WS2. In order to compute the thermoelectric properties of monolayers MoS2, MoSe2, and WS2, we used the ab-initio model suggested by Faghaninia et al (2015 Phys. Rev. B 91 235123). Within this model, by using inputs from density functional theory and considering all relevant elastic and inelastic scattering mechanisms, we have calculated the thermoelectric properties of monolayers MoS2, MoSe2, and WS2 over various ranges of temperature (T) and carrier concentration (n). The obtained results of Seebeck coefficients (S) and figure of merit (ZT) at T = 300 K for both n/p-types of monolayers MoS2, MoSe2, and WS2 are in good agreement with the findings obtained by other models using the Boltzmann transport equation within a constant relaxation time framework.
Large thermoelectric transport in magnetically coupled CrI3/1T-MoS2 vdW heterostructure via spin–charge interconversion
Authors: Singh Anil Kumar , Gao Weibo , Deb Pritam
Published: April 2024

Low-dimensional materials with prominent thermoelectric (TE) effect play a pivotal role in realizing state-of-the-art nanoscale TE devices. The fusion of TE effect with the magnetism through seamless integration of TE and magnetic materials in the 2D limit offers access to control longitudinal as well as transverse TE properties via magnetic proximity effect. Herein, we design a van der Waals (vdW) heterostructure of metallic 1T-MoS2 with promising TE properties and a layer-dependent magnetic CrI3 material. The result highlights exotic electronic and magnetic configurations of the designed monolayer-CrI3/1T-MoS2 vdW heterostructure, which show magnetically-coupled TE characteristics. The observed remarkable magnetic proximity stems from large magnetic anisotropy energy and spin polarization, which are found to be 2.21 meV Cr−1 and 12.30%, respectively. To this end, the semiconducting CrI3 layer with intrinsic magnetism leads to efficient control and tunability of the observed spin-correlated anomalous Nernst effect. Moreover, a large dimensionless figure of merit of ∼6 and a power factor of

∼
3.8
×

10

11

/

τ

∘

 W

m

−
1

K

−
2

s

−
1

near the Fermi level at 300 K endorse the rejuvenated TE effect. The strong relativistic spin–orbit coupling validates the significant correlation of TE properties with intrinsic magnetic configuration. The present study underscores the significance of the magnetic proximity-governed TE effect in vdW heterostructures to engineer low-dimensional TE devices.
Nernst and seebeck effects in
α−T3
lattice
Authors: Yan Ai , Wang Xing , Li Yu-Xian
Published: April 2024

By using the tight-binding Hamiltonian and non-equilibrium Green’s function methods, the Seebeck and Nernst effects of

α
−

T

3

lattice are investigated, in which the lattice interpolates between graphene and the dice lattice via the parameter α. For α = 0 (graphene), flat bands are always present in the band structure. The Seebeck and Nernst coefficients are consistent with those in graphene. When α is non-zero at zero magnetic field, the Seebeck coefficient is an odd function of the Fermi energy. It produces a very large and wide first peak within the band gap for the zigzag boundary. Under the influence of magnetic fields, the first peak of the Seebeck coefficient in the gap region increases with α increasing. The Nernst effect occurs under the influence of a magnetic field. The height of the zeroth peak of the Nernst coefficient increases with α increasing. When α reaches a certain value, the zeroth peak splits. The post-split peak decreases with α increasing for the zigzag boundary, but continues to become wider and higher for the armchair boundary.
Dynamic detection of saturated distribution of activated carbon adsorbed volatile organic compounds based on electrical impedance tomography
Authors: Pang Chaofan , Zhao Tong , Sun Bo , Gao Zengfeng , Wang Yunqian , Li Lu
Published: April 2024

The electrical impedance tomography (EIT) has been achieved for the dynamic detection of the adsorption saturation distribution in activated carbon. Volatile organic compounds (VOCs) emitted by industries pose a serious threat to human health and environmental quality. Therefore, adsorption method is widely used to treat such organic compounds. Activated carbon, as a commonly used adsorbent material, plays a crucial role in the efficient utilization and management of the adsorption process. Traditional adsorption detection methods suffer from information loss and discontinuity. We can obtain the conductivity distribution information during the current passing through the material by measuring the potential changes on the boundary of interest field, and analyze the saturation distribution information of VOCs adsorbed on activated carbon based on the conductivity distribution image. The feasibility of the technology in monitoring the saturation distribution of the adsorption process in activated carbon was verified by principle and simulation. For experimental verification, fixed bed and fluidized bed experiments were carried out, taking into account the special case of impedance change factors of activated carbon particles in the static and flow states. The experimental results confirm that in fixed-bed adsorption, the adsorption impedance change response can be effectively obtained at an excitation frequency of 1.0 MHz, while in a fluidized bed, a good adsorption impedance change response can be achieved at an excitation frequency of 4 kHz. By selecting the appropriate excitation frequency according to the change in the adsorbent’s state, stable imaging of the saturation distribution can be achieved. This study introduces a new method for visualizing the monitoring process of activated carbon adsorption.
Rotating machinery fault classification based on one-dimensional residual network with attention mechanism and bidirectional gated recurrent unit
Authors: Dong Zhilin , Zhao Dezun , Cui Lingli
Published: April 2024

Conventional convolutional neural networks (CNNs) predominantly emphasize spatial features of signals and often fall short in prioritizing sequential features. As the number of layers increases, they are prone to issues such as vanishing or exploding gradients, leading to training instability and subsequent erratic fluctuations in loss values and recognition rates. To address this issue, a novel hybrid model, termed one-dimensional (1D) residual network with attention mechanism and bidirectional gated recurrent unit (BGRU) is developed for rotating machinery fault classification. First, a novel 1D residual network with optimized structure is constructed to obtain spatial features and mitigate the gradient vanishing or exploding. Second, the attention mechanism (AM) is designed to catch important impact characteristics for fault samples. Next, temporal features are mined through the BGRU. Finally, feature information is summarized through global average pooling, and the fully connected layer is utilized to output the final classification result for rotating machinery fault diagnosis. The developed technique which is tested on one set of planetary gear data and three different sets of bearing data, has achieved classification accuracy of 98.5%, 100%, 100%, and 100%, respectively. Compared with other methods, including CNN, CNN-BGRU, CNN-AM, and CNN with an AM-BGRU, the proposed technique has the highest recognition rate and stable diagnostic performance.
Binder-free all-carbon composite supercapacitors
Authors: Jarrar Sabreen , Hussain Shahzad , Haq Atta Ul , Bhattacharya Gourav , Saadeddin Iyad , Servera Llorenc , Ruiz JM , Janem Alaa , Daraghmeh Allan
Published: April 2024

Carbon-based electrode materials have widely been used in supercapacitors. Unfortunately, the fabrication of the supercapacitors includes a polymeric binding material that leads to an undesirable addition of weight along with an increased charge transfer resistance. Herein, binder-free and lightweight electrodes were fabricated using powder processing of carbon nanofibers (CNFs) and graphene nanoplatelets (GNPs) resulting in a hybrid all-carbon composite material. The structural, morphological, and electrochemical properties of the composite electrodes were studied at different concentrations of GNPs. The specific capacitance (Cs) of the CNFs/GNPs composite was improved by increasing the concentration of GNPs. A maximum Cs of around 120 F g−1 was achieved at 90 wt% GNPs which is around 5-fold higher in value than the pristine CNFs in 1 M potassium hydroxides (KOH), which then further increased to 189 F g−1 in 6 M KOH electrolyte. The energy density of around 20 Wh kg−1 with the corresponding power density of 340 W kg−1 was achieved in the supercapacitor containing 90 wt% GNPs. The enhanced electrochemical performance of the composite is related to the presence of a synergistic effect and the CNFs establishing conductive/percolating networks. Such binder-free all-carbon electrodes can be a potential candidate for next-generation energy applications.
Data classification and parameter estimations with deep learning to the simulated time-domain high-frequency gravitational waves detections
Authors: Shi B , Yuan X L , Zheng H , Wang X D , Li J , Jiang Q Q , Li F Y , Wei L F
Published: April 2024

High-frequency gravitational wave (HFGW) detection is a great challenge, as its signal is significantly weak compared with the relevant background noise in the same frequency bands. Therefore, besides designing and running the feasible installation for the experimental weak-signal detection, developing various effective approaches to process the big detected data for extracting the information about the GWs is also particularly important. In this paper, we focus on the simulated time-domain detected data of the electromagnetic response of the GWs in high-frequency band, typically such as Gigahertz. Specifically, we develop an effective deep learning method to implement the classification of the simulated detection data, which includes the strong electromagnetic background noise in the same frequency band, for the parameter estimations of the HFGWs. The simulatively detected data is generated by the transverse first-order electromagnetic responses of the HFGWs passing through a high stationary magnetic field biased by a high-frequency Gaussian beam. We propose a convolutional neural network model to implement the classification of the simulated detection data, whose accuracy can reach more than 90%. With these data being served as the positive sample datasets, the physical parameters of the simulatively detected HFGWs can be effectively estimated by matching the sample datasets with the noise-free template library one by one. The confidence levels of these extracted parameters can reach 95% in the corresponding confidence interval. Through the multiple data experiments, the effectiveness and reliability of the proposed data processing method are verified. The proposed method could be generalized to big data processing for the detection of experimental HFGWs in the future.
Improvement of high sensitivity ICR characteristics and its application in OFDR
Authors: Qi Gaohan , Zhang Shengxiang , Feng Shijie , Fu Yanfeng
Published: April 2024

Coherent optical sensing technology faces significant challenges in practical applications due to the extremely weak signal light, necessitating highly sensitive coherent receivers. A high-sensitivity, highly integrated, and low-noise coherent receiver module based on germanium-silicon photonic chips has been developed. A testing system was constructed to assess the performance of the coherent receiver module, revealing a reception sensitivity of -70dBm, with physical dimensions of 33×40×8.6 mm3 and an output noise voltage of ±4mV. Additionally, a distributed sensing system based on optical frequency domain reflectometry (OFDR) was established to verify the module’s application in OFDR systems, achieving a spatial resolution of 1mm.
Research on transmission and crosstalk characteristics of a new type of through silicon via and multilayer through silicon via
Authors: Su Zhiyuan , Wang Weimin , Wu Yongle
Published: April 2024

In this work, a new type of bar-coaxial ring TSV (B-coaxial ring TSV) structure was proposed. This study used three-dimensional electromagnetic simulation software for analysis. Firstly, the conventional Bar-TSV (B-TSV) structure and the B-coaxial ring TSV structure were modeled, and their S-parameter results were compared. Our results indicated that the B-coaxial ring TSV structure had better transmission characteristics and crosstalk resistance. Secondly, by simulating of the B-coaxial ring TSV structure and the coaxial ring-tapered TSV structure, we proposed how to choose different structures for different application scenarios. Thirdly, the influence of some structural parameters of the B-coaxial ring TSV structure on the transmission performance was studied. Finally, the multilayer TSV structures of conventional B-TSV, B-coaxial ring TSV and coaxial ring-tapered TSV were studied respectively, and their performance was compared and analyzed.
Algorithm Selection and Application for Robot Path Planning Problems
Authors: Chen Xiaojiao , Chen Ling , Fu Lantian , Wang Chengliang
Published: April 2024

This article primarily delves into the investigation of robotic path planning in the presence of obstacles, aiming to ascertain optimal traversal routes. It conducts a thorough categorization and discussion of two critical aspects: the ascertainability of the overall map and the regularity of obstacles. In addressing this inquiry, two obstacle scenarios, namely regular and irregular, are posited. The article scrutinizes the path planning and obstacle circumvention techniques for both scenarios. Regarding regular obstacles, a comparative assessment of the A* algorithm, Floyd’s algorithm, and Dijkstra’s algorithm was conducted, culminating in the selection of the A* algorithm for its superior efficiency. For irregular obstacles, the article proposes a pre-processing approach involving the utilization of Matlab’s iterative pixel point traversal to assess obstacle proportions within nodes, subsequently converting irregular obstacles into a regularized format. To summarize, in scenarios with a known overall map, the article advocates employing the A* algorithm for proficient path planning. In situations where the map is undisclosed but obstacles exhibit regularity, the D* algorithm is recommended. For instances involving irregular obstacles and an undisclosed map, a dynamic method for handling newly incorporated nodes into the map is proposed. This article presents tailored solutions for robotic path planning across diverse conditions, offering concise yet effective problem-solving strategies. In conclusion, this study offers a comprehensive array of solutions for robot path planning in obstructed environments, enabling the selection of apt methodologies based on varying conditions and exigencies.
Development of ultra-low emission prediction model for steel enterprises based on ARIMA
Authors: Li Shaoming , Yue Bin , Ye Maosheng
Published: April 2024

The iron and steel industry is an important raw material industry in the country, but also a large air pollutant emission. In the face of the increasing environmental standards and requirements of the country, promoting the implementation of ultra-low emissions in the steel industry, significantly reducing pollutant emissions, promoting continuous improvement of environmental quality[1], and accelerating green low-carbon transformation and high-quality development are the general trend and industry needs. According to the promotion requirements of ultra-low emission work in Baoshan Base, the ultra-low emission application system was developed to meet the ultra-low emission control requirements. Using the ultra-low emission monitoring data of Nanjing Mei shan the parameters p, d and q were first determined, and then the ultra-low emission differential autoregressive moving average (ARIMA) prediction model was established.
Numerical study on fractal characteristic of blast-induced cracks in deep rock mass
Authors: Wang Peiyu , Zhou Zilong , Fan Jiale , Cheng Ruishan , Cai Xin , Chen Cuigang , Jiao Wencan
Published: April 2024

The quantitative representation on the characteristics of blasting-induced cracks in rock mass is of great significance to guide the fine blasting design in practice. However, the quantitative relation between blasting-induced cracks of rock mass and in-situ stresses is currently lacking. To provide the reference for the fine blasting design to excavate rock mass with different in-situ stresses, the present study adopts the fractal theory to quantitatively represent the characteristics of blasting-induced cracks in rock mass. The effects of in-situ stress levels and lateral coefficients on the modes and fractal dimensions of blasting-induced cracks are investigated by numerical simulation combined with image processing. The results show that with the increase of in-situ stresses and lateral coefficients, the fractal dimensions of blast-induced cracks gradually decrease. In addition, quantitative relations between the fractal dimensions of blasting-induced cracks and in-situ stresses are established to provide the reference for the design of rock blasting.
Optimization and Upgrading of Key Technologies for Lead Electrolysis Equipment Sets
Authors: Peng H D , Deng A M , Zong Y J , Xiong J Z
Published: April 2024

In response to the current key issues in the production of existing lead electrolysis equipment, such as poor verticality of lead cathode, inferior welding quality, short service life of conductive rod and high contact resistance, we have developed several technologies based on the principles of elastoplastic mechanics, bending and shaping, resistance spot welding and neural network control.These technologies include the stiffness-enhanced plate surface embossing, the dynamic multi-eigenvalue fusion of BP neural network resistance welding control, and the efficient rod-plate separation for cathode lead plates and conductive rod. They have been applied in a newly constructed 480kt/a project at a large domestic lead smelting enterprise. The results have demonstrated significant improvements in overall equipment production capacity, reducing the production time from 15s/plate to 11.5s/plate, decreasing the short-circuit rate caused by cathode verticality to 0.43%, and extending the service life of conductive rod by 12.8%.
Increasing of the unit capacity of MF process at Miike Smelter
Authors: Kubo H , Nishiyama F , Torikai S
Published: April 2024

MF (Mitsui Furnace) is a half shaft blast furnace developed by Mitsui Miike Smelter in the 1960’s to treat vertical retort residue. Currently MF mainly treats various secondary wastes (EAF dust, Secondary Fly Ash, etc.) and recovers zinc and lead as crude zinc oxide, copper and silver as matte, meanwhile other elements such as FeO, CaO, SiO2, Al2O3 are concentrated in slag.

There are two steps in the MF process. The first step is pretreatment. In this process, various waste materials are blended in a certain proportion with reductant and dried adding binder in a rotary dryer, then grinded in a rod mill. The grinded materials are made into an oval briquette by briquetting machine. The second step is treatment process. The briquettes fed into the MF are smelted and reduced by blowing air through the tuyeres. By enriching the tuyere air with oxygen generated by the VSA (Vacuum Swing Adsorption) oxygen generator in 2005 and 2012, we have improved the throughput of wastes.

By the improvement of oxygen enrichment in the MF, the unit capacity increased significantly. However shortage of the drying capacity in the pretreatment process became a problem. To ensure sufficient drying capacity, we installed one more rotary drier in series in 2016. Additionally in 2018, we installed a granulator after the rod mill to improve the bulk density in briquette. As a result of these efforts, the treatment amount in the whole MF process has increased.

The MF can treat various kinds of materials containing various non-ferrous metal-valuables. Through these process improvements, we promote the treatment of wastes containing heavy metals and contributes significantly to the recycling of metal resources.
Life cycle assessment and product carbon footprint for SHG zinc production
Authors: Grund Sabina C. , Genderen Eric van
Published: April 2024

The industry’s environmental impact has moved into focus at global level. Regulators, supply chains, and the financial sector need credible, standardized, and transparent information for multiple reasons. These include regulatory targets for limiting emissions, downstream user optimizations, and developing science-based emission reduction strategies. By characterizing environmental impacts, companies can satisfy stakeholder demands and measure progress towards goals. In this paper, an introduction to life cycle assessment (LCA) for reporting on environmental impacts, including the product carbon footprint as global warming potential is given. Average results from the most recent global LCA update for special high-grade zinc production are summarized. Resulting carbon footprint information is then used to derive the zinc industry’s baseline carbon footprint as the starting point for the decarbonization roadmap for the global zinc industry.
A Post-processing Computational Fluid Dynamics System for Turbomachinery
Authors: Chen Jiawei , Pan Zihao , Butala Mark David
Published: April 2024

Computational fluid dynamics applied to the turbomachinery domain require specialized post-processing functionality. For computational fluid dynamics turbomachinery, we have developed a lightweight post-processing software. We have developed a system utilizing the Visualization Toolkit (VTK) for rendering and the Qt toolkit as the cross-platform graphical user interface platform. The system is lightweight, which implements the fundamental postprocessing functions such as iso-surface and cut plane visualization and determines the meridional plane and the constant blade/van height plane. We designed and evaluated two different methods to determine the meridional plane and the constant blade/van height plane and used VTK filters in VTK to obtain necessary scene information. Finally, we visualized these planes by using the VTK visualization pipeline.
Design and implementation of firefighting reconnaissance robot control system based on master-slave control
Authors: Jiang Jiayi , Li Jinqiu , Qin Heran , Ran Yixun , Huang Jiajun , Liu Ruiran
Published: April 2024

In response to issues related to casualties and property damage caused by fires, this paper primarily investigates a deformable wheeled firefighting reconnaissance robot with functions such as fire source detection, obstacle avoidance, and map transmission. The control system of the robot is elaborated, with the main motion control system utilizing STM32 technology. Tests were conducted on the robot’s two motion capabilities (wheeled and legged), obstacle avoidance ability, reconnaissance capability, etc. The results indicate compliance with the design requirements.
Intelligent robotic arm for human pose recognition based on teleoperation system
Authors: Li Mingyue , Qiu Xiangya , Zhu Simeng , Sheng Zeyu , Liu Yi , Zhao Yuxuan , Zhao Xin , You Ran , Wang Siyang , Bi Dexue
Published: April 2024

With the rapid development of skeleton recognition, machine learning and other technologies, we will find that there are great drawbacks in the control of manipulators. Robot teleoperation refers to the inclusion of human operation in the control loop of robot control. When robots deal with complex perception and a large number of tasks, teleoperation is far superior to intelligent programming when making decisions quickly and dealing with extreme situations. The goal of this paper is to build a robotic arm teleoperation system for human motion capture, so as to solve the problems that the control accuracy of the end of the robotic arm is not high and the motion of the robotic arm is greatly affected by the difference between the human arm in the current related research, the master-slave human motion mapping algorithm is designed and extended with machine learning algorithms. We use inertial motion capture to realize teleoperation, so as to avoid the use of the terminal position and orientation control method of the hand controller to form the control command of the remote robot after tedious calculation, and it is convenient for the operator to complete the attitude tracking task in real time. The obtained attitude information has a larger range, higher sensitivity and better dynamic performance.
Application of K-Core analysis based on complex network community structure to rolling bearing fault diagnosis
Authors: Sun Ming , Cai Xin , Gao Bingpeng , Zhang Yongxing
Published: April 2024

A complex network is a method to analyze nonlinear time series on multiple temporal and spatial scales. K-core analysis of several typical nonlinear series was studied, and then based on this, a fast algorithm method was employed to divide the community structure. According to the definition of k-core, the rolling bearings complex network was divided into different cores at the router level, and the main characteristic quantities such as degree distribution and clustering coefficient of every k-core can be analyzed. The results show that there is a corresponding relationship between the characteristic parameters and the community structure of the bearing. The analysis results show that compared with the traditional method, the method of complex network community structure and k-core analysis has a better diagnosis effect.
Research on brake torque design of civil aircraft
Authors: Lu Weiming , Wang Ziyang
Published: April 2024

Brake torque is one of the key parameters of aircraft brake system design. When braking, hydraulic oil enters the brake actuator assembly, the piston on the brake actuator is extended under the action of liquid pressure, the rotor and static brake discs are pressed together, and the friction between the brake discs forms the brake torque. The design of brake torque is too small, which will increase the deceleration distance of the aircraft and can not meet the requirements of the aircraft design field. Excessive brake torque will make the aircraft pause and transition during braking, make passengers feel uncomfortable, and make the aircraft carry unnecessary weight. Generally, the combined torque between the tire and the runway during the RTO or landing stage is called the dynamic brake torque. The torque required to satisfy 25.735 (d)parking brake item in airworthiness CCAR-25-R4 is called the static brake torque. Brake system designers need to calculate the dynamic brake torque and static brake torque requirements, and design brake actuator assembly to meet these requirements.
Design and optimization of high-speed permanent magnet synchronous motors
Authors: Feng Lin , Liu Weibin , Chen Xinwei , Ding Yinshu , Yu Wentao , Li Hongwei
Published: April 2024

In this paper, a 30 kW and 60, 000 r/min high-speed permanent magnet synchronous motor (HSPMSM) was studied. We use the knowledge of motor design to determine the structural dimensions and materials of each part of the machine to create the electromagnetic design of the motor. The FEM model of the motor was created by finite element software, and the no-load and load characteristics for the motor were modeled and analyzed, which verifies the reasonableness of the design of the motor. A genetic algorithm was applied to carry out multi-objective optimization of the motor to obtain the optimized design solution, and the performance of the high-speed motor before and after the optimized design was compared. The simulation results indicate that the rated torque of the motor has been increased through the optimization, while the torque pulsation and the groove torque of the motor have been decreased, which effectively enhances the magnetic characteristic of the designed machine.
Flywheel rotor cross-filter tracking feedback control
Authors: Liu Weibin , Feng Lin , Chen Xinwei , Ding Yinshu , Yu Wentao , Li Hongwei
Published: April 2024

In light of the matter that the fixed-parameter cross-filter circuit cannot satisfy the phase compensation requirement in the full speed range, a cross-feedback tracking control method based on cross-filter feedback, in which the high-pass cutoff frequency varies with the nutation frequency, is proposed. The stability analysis of the designed control method is carried out by using the phase angle margin and the root trajectory diagram, and the results show that the cross-feedback tracking control can increase the phase angle margin and significantly enhance the stability of the system. Simulation results of the magnetic levitation rotor system show that the designed control method possesses the benefits of high stability, rapid response time, and strong anti-jamming ability.
Research on an integrated control strategy for grid-connected and off-grid optical storage microgrids
Authors: Wang Xiulian , Zhang Junhe
Published: April 2024

In order to mitigate the volatility and randomness caused by the switching processes in a photovoltaic storage microgrid, and to enhance its stability, in this paper, the utilization of the PQ+PQ control strategy is proposed for grid-connected operation and the V/f+PQ integrated control strategy is proposed for off-grid operation. Through this approach, a smooth transition from the PQ control of the master inverter to the V/f control is achieved, enabling seamless switching between grid-connected and off-grid modes in the photovoltaic storage microgrid. The proposed integrated control strategy is validated for feasibility and accuracy using a simulation platform built in Matlab/Simulink.
Nanosecond photography observation of the discharge process across the 220 kV/500 kV insulators in lightning impulse
Authors: Liao Minchuan , Zhao Zicai , He Shaomin , Wu Rongrong , Qu Lu , Chen Huaifei
Published: April 2024

Long air gap discharge is the basis for the study of lightning protection and external insulation design of high voltage lines. However, there is a lack of detailed and comprehensive observation of the long air gap discharge process at the ns-level, as well as higher voltage insulator discharge observations. In this paper, the lightning impulse discharge/flashover tests are conducted on 220 kV glass insulators and 500 kV glass/composite insulators. Firstly, the U50% test is performed to determine the U50% value of each insulator under standard lightning impulse, and 1.1U50%, slightly higher than U50%, is applied to ensure the breakdown of the insulator. Subsequently, emICCD is utilized with a very short exposure time (minimum 10 ns) to obtain repeated single shots of discharge images under different delays, exposure times and light intensity gain. These images were spliced together based on time sequence to create a continuous discharge process. The discharge processes of 220 kV glass insulator and 500 kV glass/composite insulator are compared and analyzed. The results show that in the early stage of discharge, the discharge processes at the low voltage end of both 220 kV and 500 kV glass insulators are more intense. Additionally, the downward leader is faster than the upward leader in the discharge process of 500 kV composite insulators.
Semi-global Simulations of Star Formation in Nuclear Rings of Barred Galaxies
Authors: Kim Woong-Tae , Moon Sanghyuk
Published: April 2024

Nuclear rings at the centers of barred galaxies are active in star formation. To understand what determines the star formation rate (SFR) and structure of nuclear rings, we conduct semi-global, magnetohydrodynamic simulations of nuclear rings subject to various mass inflow rates with and without magnetic fields. We adopt the TIGRESS framework of Kim & Ostriker to handle radiative heating and cooling, star formation, and related supernova feedback. Our findings suggest that supernova feedback cannot destroy the nuclear ring completely or halt star formation within it, while both the mass inflow rate and supernova feedback affect the ring star formation rate. The supernova feedback is responsible for small-amplitude SFR fluctuations with a timescale of less than 40 million years, while the SFR variations over longer timescales are due to changes in the mass inflow rates. Magnetic fields seeded by the inflows are amplified in the ring due to rotational shear and supernova feedback, greatly reducing the SFR at late times. Strong magnetic tension in the ring drives radially inward accretion flows from the ring to form a circumnuclear disk in the central region, which is absent in the unmagnetized model.
Achieving Higher Order Accuracy in Space in Hydrodynamic Simulations of Self-Gravitating Gas
Authors: Hanawa Tomoyuki , Mullen Patrick Dean
Published: April 2024

Modern astrophysical simulation codes employ a variety of numerical algorithms capable of achieving higher-order accuracy in both space and time. Albeit they succeed in achieving an effective higher spatial resolution and in suppressing the numerical damping of waves, to our knowledge, all current astrophysical simulations invoking self-gravity are limited to second-order accuracy in space. If we can devise an algorithm to evaluate self-gravity with a higher-order spatial accuracy, we can better the evaluation of the gravitational acceleration and gravitational energy release which dictate the evolution of many astrophysical systems. Herein, we present a numerical algorithm for self-gravitating hydrodynamics capable of achieving fourth-order accuracy for a given density distribution on a Cartesian uniform grid. First, we derive the cell-averaged gravitational potential at fourth-order accuracy from the cell-averaged density by solving the Poisson equation. Next, we obtain the cell average of the product of the density and gravitational acceleration, which differs from the cell-averaged density multiplied by the cell-averaged gravitational acceleration. We then show the verification of the algorithm by applying it to critical test problems: (1) maintaining equilibria of self-gravitating slabs, even upon advection, (2) evolving a polytropic sphere with a massive power-law envelope, and (3) conservation of specific entropy during the propagation of a sound wave.
Natural Light Harvesting Materials: A Study on Optoelectronic Properties of Potential Natural Dyes
Authors: Harshitha D , Mahesh H M , Renuka C G
Published: April 2024

Natural dyes are being highlighted by research and industry trends; the majority of plant species offer abundant sources of colouring compounds. They can be harvested using affordable technology and used in cutting-edge applications. Hence, an examination of the optoelectronic characteristics of Carissa caranda fruit dye has been looked into in this paper. Anthocyanins present in Carissa caranda were extracted by solvent extraction of the fruits with ethanol and methanol solvents, maintaining pH at 7 under room temperature. UV-visible spectroscopy analyzed the dye extracts, and the optoelectronic properties such as optical energy band gap, extinction coefficient, and refractive index, are studied. UV-Vis investigations revealed large absorption peaks in the visible area and obvious band gaps. Carissa caranda natural dye had the lowest direct bandgap of 2.98eV and an indirect bandgap of 1.93eV for ethanolic extraction. It was found that the optical absorption in the dyes obeyed both direct and indirect transitions between the molecular energy levels. FTIR spectroscopy has been used to confirm the composition of the natural dyes. The findings here may be particularly significant for organic electronics applications, including O-LEDs and sensors.
Crystal structure, molecular mechanics and In silico analyses of piperizine derivative against human mammary carcinoma cells inhibition.
Authors: Keshav Kumar H , Ananda S , Dukanya  , Keerthikumara V , Basappa  , Mahendra M
Published: April 2024

In the present study, the single crystal of novel piperazine derivative4-(2, 3-chlorophenyl) piperazine-1-yl) (2-hydroxyphenyl) methanone (KDM) is grown by using the solvent evaporation method. The 3D structure of the molecule is confirmed by the single-crystal X-ray diffraction method. The study revealed that the molecular system is crystallized in the orthorhombic system with space group Pbca
. The supramolecular crystal architecture establishes the stability of a compound via short contacts and halogen-hydrogen interactions. The Hirshfeld surface analysis were performed to evaluate the numerous intermolecular interactions based on the anisotropy of the topology. The Frontier molecular orbital (FMO) analysis and Molecular electrostatic potential (MEP) plots are investigated to understand the electronic structure properties of compounds using Density Functional Theory (DFT). In silico molecular docking, analysis is carried out to predict the best binding pose of the compound in the active site pocket of the BCl-XL/BAK protein-protein interface. Further, in vitro cytotoxicity studies against human breast cancer (MCF-7) cell lines of similarly designed piperazine-based derivatives showed prominent results. The results of the current study revealed that the compounds under investigation possess potential anti-cancer properties.
Tailored Synthesis of CN-PPy Composite for Enhanced Electrochemical Functionality
Authors: Vijaykumar S P , Sapna S , Suresh D S , Ganesha H , Ba Shbil Abdullah
Published: April 2024

This study details the synthesis of pure carbon nitride (CN) and composite polypyrrole through an in-situ polymerization method. The prepared samples were comprehensively characterized using Fourier Transform Infrared Spectroscopy (FT-IR), Field Emission Scanning Electron Microscopy (FESEM), and X-ray Diffraction (XRD). These analyses confirmed the chemical bonding, structural, and morphological characteristics of the products. Electrochemical measurements, conducted through cyclic voltammetry (CV) and Linear Sweep Voltammetry (LSV), revealed significant current rates in both anodic and cathodic peaks, indicating superior electrochemical properties. This work not only details the synthesis process but also provides a thorough understanding of the structural, morphological, and electrochemical aspects, exhibiting the materials’ potential for various applications in electrochemical devices.
Determination of effective atomic number, electron density and Kerma of some ferroelectric materials using mass attenuation coefficients in the energy range 1 keV -100 GeV
Authors: Pushpa A. , Bhagyalaxmi I. B , Shivaleela B. , Shivraj G. G
Published: April 2024

The effective atomic number Zeff and the corresponding effective electron density Nel of ferroelectric materials (BaCoF4, LiNbO3, KNbO3, BaTiO3, PbZrO3, PbTiO3, KNbO3, Bi4Ti3O12, KHPO4, PbBi2Nb2O9, SrBi2Ta2O9, Ba0.73Sr0.27TiO3 and Mg3B7O13Cl) has been calculated in the extended energy region from 1 keV – 100 GeV using WinXCom program. The total photon interaction with coherent and incoherent one can distinguish three energy regions are approximately E<1 keV, 10 keV<E<1 GeV and E>10 GeV. The main photon interaction processes in these regions are photoelectric absorption, incoherent (Compton) scattering and pair production. Zeff and Nel values also have been obtained for different processes such as coherent and incoherent scattering pair production in nuclear and electric field, photoelectric absorption and the variations are shown graphically. The variations are due to the presence of different elements in a compound. The behaviour of the energy dependence of electron density is similar to the energy dependence of effective atomic number. The photoelectric absorption is dominant for total coherent process for Kinetic energy released per unit mass (Kerma). Direct method is one of the method helpful to calculate effective atomic number for all types of materials, for all energies greater than 1 keV.
Ftir, uv-vis and conductivity studies in a copolymer of indole and carbazole
Authors: Raghavendra B , Sankarappa T , Malge Amarkumar , Heerasingh Mohansingh , Devidas Ashwini
Published: April 2024

The copolymer containing different wt% of indole and carbazole were synthesized by following in situ copolymerization method using ammonium persulfate as oxidizer, at room temperature. Crystalline and amorphous phases were noted from XRD patterns of the samples. Structural and optical studies were carried out by FTIR and UV-Vis spectroscopy. Different functional groups in the prepared copolymer have been identified and optical band gaps were determined to vary from 3.83 eV to 3.96 eV and 3.98 eV to 4.13 eV corresponding to direct and indirect transitions. Dc conductivity measured in the temperature range of 300 K to 423 K is observed to be semiconducting type. Two different regions of variation of conductivity with temperature have been observed and the corresponding activation energy was determined. The increase in conductivity and decrease in activation energy with increase of wt% of Cz content in PInCz copolymer is observed. This may be due to decrease of hopping distance of polarons with increase of Cz contents in the copolymer.
Structural, Physical and Optical studies of Sc3+ doped Lithium Aluminum Borate glasses
Authors: Nagaraju J , Eraiah B
Published: April 2024

Optically transparent lithium aluminum borate containing scandium glasses with composition 70B2O3 – 20Li2O – (10 – x) Al2O3 – xSc2O3 (where x= 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 and 0.7 in mol %) were fabricated by conventional melt quenching technique. The non-crystalline nature of the samples was monitored by X-ray diffraction and it confirms non-crystalline nature. Structure of the fabricated glasses are assessed using the Fourier transform infrared spectra. The absorption spectra of these glasses have been recorded in the wavelength range 200 nm – 1100 nm. Direct and indirect optical energy band gaps were calculated from Tauc’s plots. The physical parameters such as refractive index (RI), optical basicity and interaction parameters were determined using proper formulas to know the characteristics of fabricated glass matrix. The results obtained indicate that 0.3 mol% Sc2O3-containing BLASc glass is more suitable for w-LEDs and lasers applications.