bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of orifice thickness on the flow field of co-flow jets
Authors: Sundaram Tharika 
Published: May 2023

Abstract
The present study analyses the numerical simulation results of subsonic flow through co-flow orifices. Analysis is done on the effects of modifying orifice thickness on the co-flow jet characteristics. The combined frontal area of the co-flow jet and central jet is maintained constant (20 mm2). The primary orifice diameter (D) is kept as 3mm and the orifice thickness, i.e the co-flow jet is formed as four segments of a concentric circle around the core jet, and the edge distance between them ranges from 0.16D to 0.5D. The 0.16D co-flow is shown to lengthen the potential core of the main jet at nozzle pressure ratios of 1.2, 1.4, 1.6, and 1.8, but the 0.33D co-flow and the 0.5D co-flow shorten the potential core length, enhancing mixing. The present study analyses the Mach numbers that correspond to the Nozzle Pressure ratios of 1.2, 1.4, 1.6, and 1.8, which are 0.517, 0.71, 0.84, and 0.96, respectively. The 0.5D annular gap is found to be more effective which boosts primary jet mixing.
A novel passive micromixer model computational analysis with twist and bend
Authors: Mustafa Md Gulam , Zunaid Mohammad , Gautam Samsher 
Published: May 2023

Abstract
A dynamic mixing model for a microfluidic platform that uses bending and twisting characteristic is proposed in this work. The action of twisting and bending on mixing efficient in the microchannel is tested using Navier-Stokes equations. Micromixers being broadly applied in micro total analysis systems (µTAS). Passive micromixers are largely preferred from their heftiness, serenity of amalgamation and cost effective. However rapid mixing in this model is difficult but can be achieved with a twist in the model and offset. From the past study, we know that with a high Reynolds number mixing efficiency effectively improved. Chaotic advection allows the micromixer model to generate secondary flow which led to a drop in high-pressure drop in the model.
Water quality prediction using CNN
Authors: Vijay Anand M , Sohitha Chennareddy , Saraswathi Galla Neha , Lavanya GV 
Published: May 2023

Abstract
The interaction of solar radiation with the water level concentration and the elements of the water cause the water to have its characteristic hue. The alteration of the color of the water is reflective of the alteration of the water’s properties and the degree to which it is suitable for use. Due to disasters like floods, tsunami in the last few years and water pollution has been an increasing problem. In world the intake of contaminated water causes 40% of deaths. Drinking unclean water is not safe and in order to reduce the issue to a level of extent, prediction of water quality can be done before consuming. The process used in water plants is based on the parameters pH, turbidity, temperature, hardness etc., of water using filtration and the water quality prediction can also be done using IOT by including both hardware and software. This project mainly comprises the primary level of water prediction using machine learning. Based on the color and quality of water the system predicts whether the given water sample is suitable for drinking or any further use. Tensorflow, Keras and CNN are used to train the model to forecast the water quality prediction. This project is cost-effective and works efficiently and can be used as immediate and initial level of water quality check since image processing tool is used. This model of water quality prediction can be checked using mobile captured and Google earth images of water samples.
Sub-millimeter wave nanoantenna-a review
Authors: Mohan Nadar Akila P , Indhumathi K 
Published: May 2023

Abstract
Electromagnetic waves that have a wavelength of less than one millimeter are referred to as sub millimeter waves. In sub millimeter wave-based devices and systems, antennas are critical components that are vital to their operation. Antennas are used in situations when a transition between a directed wave and a free-space wave is needed. Since, electromagnetic characteristics for receiving and transmission of the nano antenna are mutually invertible, the properties of nano antenna are analyzed in sub millimeter wave frequencies and this overcomes the limitations of conventional antenna design. They are very small in size, provide more efficiency, and do not cause health threat. This paper reviews the applications of nano antenna, which operates at sub-millimeter wave frequency, in the field of energy harvesting, space technology, IoT applications, 5G network, smart clothing, bio sensing, communication, etc? Also, the nano antenna fabricated by 3D printing technology is also reviewed. The world’s ever-increasing energy need necessitates the development of alternate energy sources. There is a lot of research and development going on right now to enhance photovoltaic systems so that they can be more efficient, but the constraint is that they can only collect energy from the visible area of the electromagnetic spectrum. As a result, a novel device known as a Nano antenna has been developed to convert heat energy taken from the infrared spectrum into electricity. In the not-too-distant future, it will have an impact on a wide range of fields, such as mobile communication (5G), radar detection, and higher order frequency applications. Space communication, broadband wireless communications, wireless optical communication, and mobile communication will also benefit from its implementation.
Students’ Facial Expression Recognition Based on Multi-head Attention Mechanism
Authors: Dai Xiaojun , Wei Pengcheng , Zeng Yushan , Zhang Qi 
Published: May 2023

Abstract
As there are a far greater number of students in the classroom than teachers, it is difficult for teachers to grasp the learning of all students. Especially during the epidemic period, when online teaching becomes a trend, this problem is more prominent. The issue of how to grasp the learning of each student more comprehensively remains a problem to be solved in teaching. Under such circumstances, students’ facial expression recognition emerges as one of the most important solutions. In this paper, an improved facial expression recognition model based on the multi-head attention mechanism is proposed. The model is tested on two student expression databases, the JAFFE and the OL-SFED, and the recognition rate reaches 99.5% and 100%, respectively. In addition, to compare it with the models developed by other researchers, it is also tested on the RAF-DB, recording the best recognition rate of 90.35% and an average recognition rate of 83.66%, which represents the best level so far.
Modeling of Ship Turning Motion Prediction Based on BP Neural Network
Authors: Zhou Yue , Li Mingjie , Ma Jianwen 
Published: May 2023

Abstract
To more correctly grasp the ship turning performance and provide better references for initial design and safe handling of the ship, combined with the ship turning motion characteristics, a simulation prediction model of the ship turning motion is created by using the BP neural network method, which takes the transverse and longitudinal distance of the ship turning motion as the output. Within that study, the neural network model is trained by utilizing 12 real ship motion data as training examples. This research generates predictions using data from two more real ships as test samples once the training is complete. The discrepancy between the estimated and real ship outcomes is also compared, and the error is examined. The results verify that the constructed prediction model has stronger generalization ability and better accuracy, indicating that the model can successfully realize the simulation prediction for the ship turning motion.
Fault Diagnosis Method Based on CND-SMOTE and BA-SVM Algorithm
Authors: Wang Sheng , Ma Liling , Wang Junzheng 
Published: May 2023

Abstract
The problem of unbalanced data classification has gotten extensive attention in the past few years. Unbalanced sample data makes the fault diagnosis and classification accuracy rate low, and the capability to classify minority-class fault samples is restricted. To address the problem that the classification algorithm in machine learning has the insufficient capability to identify minority class samples for unbalanced sample data classification problems. Therefore, this paper proposes an improved support vector machine (SVM) classification method based on the synthetic minority over-sampling technique (SMOTE). For the sampler, an improved synthetic minority over-sampling technique based on the characteristics of neighborhood distribution (CND-SMOTE) algorithm is used to equilibrate the minority class samples and the majority class samples. For the classifier, the parameter optimization method of support vector machines based on the bat algorithm (BA-SVM) is used to solve the multi-classification problem of faulty samples. Finally, experimental results prove that the CND-SMOTE+BA-SVM algorithm can synthesize high-quality minority fault samples, increase the classification accuracy rate of fault samples, and decrease the time spent on the classification.
TS2VLGNN-based prediction of water temperature at the outlet valve of a valve cooling system
Authors: Zhou Hai-Jia 
Published: May 2023

Abstract
During the operation of a power grid system, devices such as converter valves generate much heat, which leads to a constant increase in the device’s operating temperature, thus significantly reducing the stability and safety of the system. The temperature of the valve cooling system is critical to the stability of the system. In this paper, according to the limitations of traditional multivariate time series prediction methods, such as harrowing feature extraction and poor prediction performance, we propose a model TS2VLGNN to predict the valve cooling system’s outlet water temperature. TS2VLGNN first extracts the features of system variables through the time series-representation learning method TS2Vec and then combines the advantages of LSTM and GNN in multivariable time series prediction. Meanwhile, the GNN module is improved to predict the water temperature at the outlet valve. During the comparative experiment, the model was compared with several models, and the experimental results verified that the TS2VLGNN model has higher prediction performance. Finally, ablation experiments demonstrated each component of the model’s effectiveness.
Study on decoupling control of bearingless motorized spindle
Authors: Meng Jie , He Lihong , Liang Xi 
Published: May 2023

Abstract
Bearingless motorized spindle is a kind of spindle structure that combines a bearingless motor with a motorized spindle. It has the advantages of a motorized spindle and a bearingless motor, which can further improve the speed of the machine tool spindle. However, its complex electromechanical structure and the coupling relationship between the subsystems make it difficult to control its operation process accurately. In this paper, the voltage control decoupling method is used to decouple the torque and suspension system of a bearingless motorized spindle with an independent inverse system, then control the systems. Finally, the control of decoupled bearingless motorized spindle is simulated. The results show that when the speed, rotor radial displacement, and rotor flux change respectively, they will not influence each other. The speed and radial displacement are unaffected after the sudden load is applied. It proves the effectiveness of the decoupling control method.
The Use of Brunel Harmonics of Elliptically Polarized Laser Pulses for High-Resolved Detection of Terahertz and Mid-Infrared Radiation
Authors: Silaev A A , Romanov A A , Vvedenskii N V 
Published: May 2023

Abstract
We study the generation of low-order harmonics during the interaction of helium atoms with intense elliptically-polarized laser pulses in the presence of a static electric field. Based on the solution of the three-dimensional time-dependent Schrödinger equation, the spectra of generated radiation are calculated for various pulse ellipticities, intensities, and static-field strengths. We show the possibility of using the second harmonic generation in the free-electron current density by laser pulses with arbitrary (even circular) polarization for high-resolved measuring the waveforms of terahertz and mid-infrared radiation.
Excitation of Semiconductor Nanosystems by Multy-Frequency Quantum Field
Authors: Tereshchenko I A , Tikhonova O V 
Published: May 2023

Abstract
The formation of Frenkel excitons in a 2D semiconductor nanosystem induced by frequency-multimode non-classical electromagnetic field is investigated. Strong sensitivity of excitation dynamics to the initial states of quantum field modes is found. The possibility to manage the excitation dynamics and controllably enhance a certain excitation channel by varying field frequency detuning and by choosing a proper initial state of the non-classical multimode field is demonstrated. The specific features of the excitation arising due to efficient coupling and energy exchange between initially independent field frequency modes are demonstrated. The polarization response of the considered nanosystem on the multi-frequency field impact is studied and its peculiarities arising due to the quantum features of the affecting non-classical light are found.
Study of a laser method to control the condition of coatings of titanium and magnesium alloys for medical cryo instruments
Authors: Mogilnaya T.Yu. , Pagava L.L. , Petelin N.A. , Medvetskova V.N. , Sagitova E.A. , Krit B.L. 
Published: May 2023

Abstract
The work is devoted to the creation of a laser method for monitoring the virucidal properties of nanocoatings of medical instruments. The relationship between the intensity of the spectra of washes from silver-doped coatings and the concentration of pathogens was studied. Plasmon resonance was obtained using a DFB laser in order to be able to develop this method.
Effects of Laser Irradiation at 1265 nm in Melanoma Cells
Authors: Khokhlova A. V. , Dolgova D. R. , Poludnyakova L. V. , Gilmutdinova A. K. , Zolotovskii I. O. , Saenko Yu. V. , Sokolovskii S. G. , Rafailov E. U. , Stoliarov D. A. , Pogodina E. S. , Ribenek V. A. , Antoneeva I. I. , Fotiadi A. A. 
Published: May 2023

Abstract
Melanoma is the most dangerous type of cancer, with a high rate of metastasis. The conventional method of treating skin melanoma is photodynamic therapy, yet this type of phototherapy has several side effects. In addition, the photosensitizers used are relatively expensive and toxic. Thus, developing methods of treating melanoma cancer using laser only is a promising area of research.
Here we present in vitro effects in melanoma cell culture after 1265 nm laser irradiation exposure.
Nanoscale Sensing Glass Transition of Nanoconfined Polymers Through Thermoplasmonic
Authors: Chernykh E A , Kharintsev S S 
Published: May 2023

Abstract
It is known that downsizing of polymers at the nanoscale causes their physical properties, such as glass formation temperature, to deviate from the corresponding bulk properties. This fact requires the control of such parameters, since today nanoscale polymers are part of the architecture of many devices and are becoming increasingly important in modern technologies. To register temperature parameters in nanosized materials, localized heat sources are required. These can be metal nanostructures that generate heat on a nanoscale under the action of light. Enhanced absorption under conditions of plasmon resonance makes it possible to induce heat at the nanoscale and, therefore, as a result, plasmonic nanostructures can act as nano-heaters. We propose an approach to create enhanced heating of plasmonic nanostructures by nanostructuring the substrate surface (thermostat), which is demonstrated on titanium/silicon nitride (TiN:Si) hybrid structures using Raman thermometry. Using this approach, we detect the local glass transition temperature in nanosized polymers (PMMA and PMMA-DR1) by heating it with a thermoplasmonic metasurface using Raman spectroscopy.
Fragmentation of a trapped bosonic mixture
Authors: Alon O E , Cederbaum L S 
Published: May 2023

Abstract
Fragmentation of bosons and pairs in a trapped imbalanced bosonic mixture is investigated analytically using an exactly solvable model, the generic harmonic-interaction model for mixtures. Closed-form expressions for the eigenvalues and eigenfunctions of the reduced one-particle and two-particle density matrices as a function of all parameters, the masses, numbers of bosons, and the intraspecies and interspecies interactions, are obtained and analyzed. As an application, we consider a system made of N
1 = 100 non-interacting species 1 bosons embedded in a bath made of N
2 = 106 non-interacting species 2 bosons, and show how fragmentation of the system’s bosons and pairs emerges from the system–bath interaction only. Interestingly, the lighter the bosons comprising the bath are the stronger is the system’s fragmentation. Further applications are briefly discussed.
Vacuum Birefringence Measurement via All-Optical Interferometric Schemes
Authors: Ataman Stefan 
Published: May 2023

Abstract
All-optical vacuum birefringence experiments will get increasingly closer to feasibility as multi-petawatt laser facilities become operational around the World. Thus, the availability of focused laser intensities in the order of IL
∼ 1022 −1024 W/cm2 are to be expected in a focused spot size ∼ 3 − 5 μm. With these values, vacuum refraction indices in the order of Δn ∼ 10−11 − 10−9 are possible with an induced phase delay on a counterpropagating optical probe beam in the order of Δφ ∼ 10−9 −10−7 radians. We discuss two all-optical interferometric schemes and detail the Mach-Zender interferometric proposal. We consider this interferometric scheme fed by both classical and non-classical input light and with two detection schemes. We outline scenarios that are likely to lead to a feasible experimental implementation.
The worldline formalism in strong-field QED
Authors: Schubert Christian 
Published: May 2023

Abstract
The worldline formalism provides an alternative to Feynman diagrams that has been found particularly useful for external-field calculations in quantum electrodynamics. Here I summarize its present range of applications, which includes Schwinger pair creation, photon splitting in constant fields and plane-wave backgrounds, as well as non-linear Compton scattering in constant fields.
Optimal Voltage Control of Wind Farm with Distributed Energy Storage System
Authors: Wang Pengda , Shen Feifan , Huang Sheng , Shen Yangwu , Zhang Min , Zhang Yuzhou , Sun Jieyi , Le Xuxin , Pang Jiameng 
Published: May 2023

Abstract
This paper proposes an optimal voltage control method for a wind farm (WF) combined with distributed energy storage systems (DESSs), where the DESSs are connected to the DC sides of wind turbines (WTs). In the proposed control method, the WT units and DESSs can be coordinated to minimize the voltage fluctuation of terminal buses, minimize the distance between the voltage of terminal buses and rated value, and minimize power losses inside the WF collection system. The optimal control (OPC)-based voltage control model is formulated to generate optimal active/reactive power output of WTs and active power output of energy storage units in the WF with DESSs. The DESSs can store active power from WTs to support more capacity of the reactive power output of WTs. The control performance of the proposed voltage control method based on OPC is validated by conducting case studies on the WF with 32*5 MW WTs.
Studies on Three-phase Imbalance Treatment Based on Beidou communication and Commutation Switch
Authors: Guo Jiangtao , Liu Lulu , Wang Tianjun , Jia Junqiang , Wei Maosheng 
Published: May 2023

Abstract
In this paper, genetic algorithm and commutation switch based three-phase imbalanced distribution network are studied. A genetic algorithm-based commutation switch three-phase imbalance management strategy was developed, and the three-phase current distribution station area was established. A mathematical model was developed for the multi-objective optimal commutation based on the minimum imbalance degree and the minimum switching times of the low-voltage load online automatic commutation device during the commutation process. Additionally, the real-time online governance control strategies were balanced. Finally, the effectiveness of the proposed method was verified using simulation studies.
Fault analysis of photovoltaic inverter
Authors: Zhang Xiuqi , Liu Hongqing , Miao Lifang 
Published: May 2023

Abstract
Photovoltaic power generation is one of the main forms of new energy utilization, and the reliable operation of a photovoltaic inverter, as the main component of a photovoltaic power generation system, is of great significance. Studying and mastering the faults of photovoltaic inverter and taking preventive measures is very important to ensure the stable and efficient operation of the photovoltaic power generation system. This paper expounds on the development of photovoltaic power generation and the composition of the photovoltaic power generation system, summarizes the typical faults of a photovoltaic inverter, analyzes the causes of the faults, and on this basis, puts forward the improvement measures to avoid the faults.
Numerical simulation of pneumatic transport of pulverized coal particles in pipelines
Authors: Tian Mingbo , Cheng Zhihai , Kang Zhifeng 
Published: May 2023

Abstract
Coal powder transportation technology is usually used in power plant, chemical industry and other industries. The forces of pulverized coal particles are very complicated and changeable during transportation, this study used pulverized coal particles as transport materials to carry out transport experiments. Computational fluid dynamics (CFD) method was used to model and analyze the flow of pulverized coal particles through the powder feeding pipe in fluidized pneumatic transport, and its gas-solid flow characteristics were numerically simulated. In CFD simulation, discrete phase model is used to analyze the flow behavior of Coal powder. On this basis, the influence of flow characteristics of pulverized coal particles on the formation of output deviation of different pipelines is studied. The deviation from the minimum wind speed is calculated through simulation. The simulation results show that there is a negative correlation between the particle velocity of pulverized coal and the output deviation of the pulverized coal feeding pipe, which provides a reference for further understanding the output deviation characteristics of the pulverized coal feeding pipe.
Analysis of synchronous oscillation of MMC-HVDC in offshore wind farm
Authors: Yan Renwu , Fu Fuwei 
Published: May 2023

Abstract
Due to the special meteorological conditions of offshore wind power generation and the large wind turbines used, offshore doubly-fed wind turbines have larger shafting elastic coefficients than onshore doubly-fed wind turbines. When the offshore wind farm is connected to the grid through MMC-HVDC, two kinds of sub-synchronous oscillations are caused. One is the natural torsional vibration of the wind turbine shaft system, and the other is the sub-synchronous oscillation caused by the interaction between the wind turbine and the devices in the MMC-HVDC converter control system. In view of the above problems, the MMC-HVDC grid connection model of the offshore doubly-fed wind farm is established. The eigenvalue analysis method and participation factor are used to identify the oscillation mode of the interaction between the wind turbine shafting torsional vibration and the converter device, as well as the corresponding strong correlation state variables. According to the correlation of the state variables obtained, the parameter suppression strategy of the CCSC controller based on MMC valve optimization is proposed. The effectiveness of the proposed suppression strategy is verified by PSCAD/EMTDC electromagnetic transient simulation software.