bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-frequency suppression of inductive coupling between flux qubit and transmission line resonator
Authors: Ashhab Sahel , Ao Ziqiao , Yoshihara Fumiki , Lupascu Adrian , Semba Kouichi 
Published: February 2024

Abstract
We perform theoretical calculations to investigate the naturally occurring high-frequency cutoff in a circuit comprising a flux qubit coupled inductively to a transmission line resonator (TLR). Specifically, a decoupling occurs between the qubit and the high-frequency modes. The coupling strength between the qubit and resonator modes increases with mode frequency ω as

ω

at low frequencies and decreases as

1

/

ω

at high frequencies. This result is similar to those of past studies that considered somewhat similar circuit designs. By avoiding the approximation of ignoring the qubit-TLR coupling in certain steps in the analysis, we obtain effects not captured in previous studies. In particular, we obtain a resonance effect that shifts the TLR mode frequencies close to qubit oscillation frequencies. We derive expressions for the TLR mode frequencies, qubit-TLR coupling strengths and qubit Lamb shift. We identify features in the spectrum of the system that can be used in future experiments to test and validate the theoretical model.
Mechanistic insights of COVID-19 dynamics by considering the influence of neurodegeneration and memory trace
Authors: Joshi Hardik 
Published: February 2024

Abstract
COVID-19 has been declared a global pandemic as it disturbs education, society, agriculture, the economy, poverty, death rate, social development, mental psychology, and many more. Neurodegenerative disease is a brain disorder associated with several pathological factors along with mental psychology. This paper introduces a mathematical model to inspect mechanistic insights into COVID-19 dynamics by considering the influence of neurodegeneration and memory trace. The analysis of the proposed model and the existence and uniqueness of the model are derived using the fixed-point criteria. A numerical experiment is presented to validate the theoretical results and examine the impact of various biological parameters, the influence of neurodegeneration, and memory trace on the transmission dynamics of COVID-19.
An adaptive dynamic window approach for UUV obstacle avoidance planning in 3D environments
Authors: Lin Changjian , Liu Yuhao , Lin Shibo 
Published: February 2024

Abstract
Unmanned Underwater Vehicles (UUVs) are essential equipment for Marine development, widely used in Marine scientific research, Marine resource survey, and Marine security. The autonomous navigation planning ability in unknown environments is a critical indicator for UUV intelligence. This paper focuses on the particularity of UUV motion and the complexity of the underwater environment and proposes an adaptive Dynamic Window Approach (DWA) for UUV obstacle avoidance planning. The adaptive DWA introduces novel heading angle evaluation and adaptive dynamic strategies to solve the problems of poor adaptability of traditional DWA to complex environments and unreasonable path selection in encountering dynamic obstacles and approaching targets. Simulations verify the effectiveness and superiority of the proposed method.
Research on the linear driving characteristics of endoscopic continuous robot
Authors: Niu Yibo , Jin Xiaoyi , He Zhikun , Meng Panpan 
Published: February 2024

Abstract
Due to the way line drive, the continuous endoscope robot will have a certain lag in the process of movement, which will affect the accuracy and flexibility of the operation. In addition, the hysteresis and return difference caused by wire rope transmission will also increase the hysteresis effect of continuous robots. In this paper, the motion characteristics of the continuous endoscopic robot are analyzed, the hysteresis of the robot is modeled theoretically based on the Preisach model, and the effectiveness of the model is verified. Preisach hysteretic nonlinear hyperbola model predicts the bending changes under different positive and negative drives. The experimental results show that the maximum error between the model and the theoretical prediction is 3.18 degrees. The hysteresis model can predict the hysteresis characteristics of the continuous endoscope robot well.
Calculation Model and Accuracy Study of Transformer Standard Oil Preparation
Authors: Li Yanping , Fang Jianjun , Xu Yingjie , Cui Xinyi 
Published: February 2024

Abstract
This article introduces a treatment method, component concentration calculation model, and device for preparing standard oil using transformer oil. The base oil is prepared by deeply purifying the transformer oil and measuring its background value. Based on the target component concentration, the appropriate volume of standard gas is determined, and the background value of the combined oil is used in the component concentration calculation model to determine the theoretical value of the standard oil. The standard oil value that has been prepared is in good agreement with the anticipated target value, thereby simplifying the purification process and cutting down on the processing cost of used transformer oil. Simultaneously, a fully automatic integrated device has been developed for the advanced purification of transformer oil and the production of standard oil. This device comprises a vacuum pump, an oil storage tank, an electromagnetic valve, an oil cylinder, and various sensors, all managed by sophisticated software. The standard oil for transformers can be prepared and stored stably for an extended period. The standard oil output is processed under sealed and unchanging pressure conditions to ensure a consistent concentration of components in the standard oil.
Limiting Factors of Simultaneous Measurement Method for Turbidity and Total Suspended Solids Based on Image Processing Approaches
Authors: Hakiki Rijal , Purnama Irwan , Zevi Yuniati , Muntalif Barti Setiani 
Published: February 2024

Abstract
Image processing is one of the computational approaches that can be applied to measure fluctuations in surface water pollutant concentrations. Identifying factors that can affect and become a limitation in the development of image processing-based simultaneous measurement methods is the focus of the discussion in this article. Nineteen variables have been identified from the three-factor categories of hardware configuration, software settings, and the measured suspension characteristics. Measurements were made on thirty images extracted from video captured with a USB Mechanic-DX-230 camera with a 23-megapixel resolution Panasonic CMOS sensor equipped with a macro lens in 130X magnification on the S-EYE-1.6.0.11 interface. Image frame extraction was performed with VirtualDub2 build 4428/release, followed by digital image processing and analysis with ImageJ 1.46r. The lens’s focal length to the sample cell is 5 cm, setting the brightness parameter minimum of 90 and maximum of 255 and minimum threshold settings of 209 and maximum of 255, which is a controlled factor to achieve the best repeatability rate. It is indicated by a relative standard deviation of up to 6% in the measurement chamber with a dark background. Complying with the stated factors is essential to ensure measurement results’ reliability and validity.
Coordinated control strategy for microgrid based on improved virtual DC motor
Authors: Cheng Xiaoman , Yue Youjun , Zhao Hui , Wang Hongjun 
Published: February 2024

Abstract
The coordinated control strategy based on the improved virtual DC motor (VDCM) is proposed to address the bus voltage fluctuation of an isolated DC microgrid and the power distribution problem of multiple energy storage units. Firstly, the memory converter control process unit is enhanced by adding the VDCM link and low-pass filtering link. Secondly, considering factors such as photovoltaic power, constant-power loads, and battery charging state, six working modes are defined to ensure stable DC bus voltage in each mode. Finally, a simulation model of the isolated DC microgrid is found by using simulation software to verify the validity of this method.
Predefined time backstepping control of photovoltaic grid connected inverter
Authors: Xu Zhao , Ji Yuehui , Chen Jiaqi , Liu Junjie 
Published: February 2024

Abstract
The large-scale grid connection of photovoltaic (PV) systems creates great hazards to the operation of power equipment and has a great impact on the stability and reliability of power systems. To achieve stable control and flexible management of PV grid connection, a predefined time adaptive backstepping control method based on the predefined boundary is proposed. Based on the predefined boundary time-varying function, the user’s predefined boundary design of the control signal is accomplished to ensure the boundedness of the global signal, which is independent of the initial state of the system. The controller with predefined boundaries is designed based on backstepping control, and the estimation and compensation of perturbations are attained based on adaptive control. The global predefined time stability of the predefined boundary of the closed-loop system is certified using the Lyapunov function. Simulation studies attest to the performance of the predefined time control strategy.
The interelectrode breakdown mechanism and discharge characteristics of the electrospray thruster
Authors: Han Xiao , Ye Jifei , Cui Haichao , Yu Chenghao , Song Hang 
Published: February 2024

Abstract
In the actual working process of electric thrusters based on high-voltage electric fields, the discharge breakdown phenomenon is universal and complex, and such phenomena will have a significant impact on the thruster structure, working state and spacecraft system. In order to study the interpolar discharge breakdown characteristics of ionic liquid electrospray thrusters, a basic electrospray model and test system were constructed, and the change curves of discharge characteristic parameters such as breakdown voltage, threshold current, breakdown voltage frequency and so on in the range of 7×10−3~105 Pa with air pressure and transmitter inner diameter were obtained, and the air pressure range that the electrospray model could work in normally was calibrated. The results show that the breakdown voltage characteristic curve of the electrospray model has typical minimum characteristics, and the minimum values all appear around 80 Pa. Lowering the air pressure below 10−2 Pa can effectively increase the breakdown threshold between the poles and the emission current, thereby obtaining a larger voltage regulation range, and when the air pressure is reduced to 7×10−3 Pa, the breakdown can reach more than 3200 V. The 60-μm inner diameter emitter performed better in the discharge experiment, and the breakdown threshold, emission current and operating area range were better than the slightly larger inner diameter emitter under the same working conditions.
Numerical simulation analysis of wind load on an integral bridge with steel-concrete composite girder based on cloud platform
Authors: Liu Hongwei 
Published: February 2024

Abstract
The integral bridge with steel-concrete composite girder will be affected by wind load in the natural environment, so the buffeting effect of wind on the integral bridge with steel-concrete composite girder cannot be ignored. In order to solve the above problems, the numerical simulation analysis on the wind load on integral bridge with steel-concrete composite girder based on cloud platform is carried out. Before the buffeting analysis of the bridge, the wind environment condition should be calculated. Taking the integral bridge with steel-concrete composite girder as an example, based on empirical formula, the influence of girder size change on static wind load and static wind load under different wind speeds are calculated and analyzed. With the help of Davenport fluctuating wind’s power spectrum, the fluctuating wind field of integral bridge with steel-concrete composite girder under certain wind speed is simulated by harmonic synthesis method, the wind load value of integral bridge with steel-concrete composite girder is simulated, and the structural design of bridge is carried out, in order to ensure the scientificity and safety of bridge design. The numerical simulation can correctly react the test law, and can predict the wind resistance of the structure with the existing model.
Numerical study on aerodynamic performance during the process of entering the formation flight
Authors: Wang Xiaobing , Li Yuping , Ma Shang , Liu Guangyuan , Tao Yang 
Published: February 2024

Abstract
. Two or more planes can fly in close formation similar to migratory birds, making use of the wing-tip vortex of the leader plane to increase lift and reduce drag, thereby effectively improving the flying range. By conducting wind tunnel tests and numerical simulations, the aerodynamic performance of formation flight at different relative positions can be obtained, the optimal formation position can thereby be solved. However, significant nonlinear and unsteady aerodynamic characteristics, induced by the interference between the follower plane and the wing-tip vortices of the leader plane, will affect the flight safety of the whole formation. At present, there is no effective prediction methods. Numerical simulations adopting adaptive grid refinement and dynamic overset grid were conducted for the dynamic entering process of the formation flight containing two Ty-154 planes. The aerodynamic characteristics and vortex interferences were analysed considering the effects of approaching direction and speed. The results indicate that there is deterioration of stability at the position where maximum lift gain is reached; Compared to the entering speed, the impact of directions on dynamic aerodynamic characteristics is more significant.
Investigation of the inhibiting effect of environmentally friendly cerium-containing conversion films on the corrosion of zinc coatings
Authors: Peshova M , Bachvarov V 
Published: February 2024

Abstract
In the present work, the inhibiting effect of environmentally friendly cerium and phosphorus-based conversion films on zinc corrosion in 5% NaCl and 1 N Na2SO4 test media was investigated. The films were prepared by immersion and stirring in the passivating/converting solution for time periods of 3,5,7, 10 min., respectively. The chemical composition of the films was determined by EDX analysis. The results of the electrochemical studies showed that in 5% NaCl medium, cerium- and phosphorus-based films exhibited high inhibition effect only during the first days of polarization resistance (Rp) measurement. In 1 N Na2SO4 medium, the Rp of the conversion films was up to 2.5 times higher than that of pure zinc coatings throughout the test period.
Effect of deposition conditions on the structural and mechanical properties of oxynitride TaON coatings for biomedical applications
Authors: Donkov N , Zykova A , Safonov V , Dudin S , Yakovin S , Georgieva B 
Published: February 2024

Abstract
A thorough evaluation was conducted of the structural and nano-mechanical characteristics of oxynitride coatings with TaOxNy structures formed by reactive magnetron sputtering at different flows of the reactive oxygen/nitrogen gasses. Tantalum oxynitrides exhibit a broad range of modifications in their structure and elemental content depending on the conditions of deposition. The TaON structures combine the characteristics exhibited by tantalum nitride, used as a hard material for tribological and mechanical applications, with the excellent dielectric properties of the tantalum oxide. The results discussed point to the deposited tantalum oxynitrides being promising candidates for biomedical applications.
New diffraction-limited laser systems with variable output parameters operating in visible spectral range on copper atomic transitions for advanced material micromachining
Authors: Kostadinov I K , Temelkov K A , Shehadi M , Slaveeva S I , Yankov G P 
Published: February 2024

Abstract
New considerably improved laser systems (LS) featuring beam propagation factor equal to unit, two different laser pulse durations and an average output power from several tens of Watts up to 50 W are reported. Micron-sized machining is also demonstrated.
Experimental study of CO2 dissociation in an expanding dc arc discharge at atmospheric pressure with multiple pin-to-pin electrodes
Authors: Lazarova S , Kolev St , Paunska Ts 
Published: February 2024

Abstract
In the following study, we examine the performance of a new design of the classic gliding arc discharge (GAD) with diverging electrodes between dielectric walls at atmospheric pressure. In the present design, a tungsten pin-to-pin electrode pair ladder replaces the standard curved diverging electrodes. A major problem with the classic GAD design is the surface erosion of the electrodes, which leads to bad repeatability and issues with long-term usage. The new construction provides controlled electrode wear at well-defined points of arc attachment. This ensures stable operation while retaining the arc expansion effect. This new configuration of the discharge is being developed for gas treatment. In the current work, the device was applied for CO2 dissociation. The most significant quantities for this application of the GAD, the CO2 conversion rate and energy efficiency, are measured at different gas flow rates (2–12 Ln/min) and arc currents (50–210 mA). The results are analyzed and compared with previous measurements using the classic GAD at the same conditions.
One-dimensional multi-fluid model of the plasma wall transition
Authors: Gyergyek Tomaž , Kovačič Jernej , Costea Stefan , Kos Leon 
Published: February 2024

Abstract
A one-dimensional multi-fluid model of the plasma wall transition is presented. The plasma is composed of singly charged positive ions, electrons and negative ions. Positive ions are assumed to obey the continuity, momentum transfer and energy transport equation, while the electrons and negative ions are treated by the continuity and momentum transfer equation. For the positive ions the closure is done by assuming that heat flux in the plasma is zero, while both negative species are treated as isothermal, with the pressure gradient term being proportional to the density gradient. The potential drop in the pre-sheath can be determined either by the electrons or the negative ions – depending on their densities in the unperturbed plasma. It is shown how the boundary density of both particle species can be in some cases determined very precisely.
Model of slot antenna for MPECVD of carbon nanostructure
Authors: Vachkov V , Kiss’ovski Zh 
Published: February 2024

Abstract
A model of a slotted waveguide antenna for microwave plasma enhanced chemical vapor deposition (MPECVD) of carbon nanostructures at low pressure is developed. The performance of two slot applicator for the production of dense plasma in the working gas (argon) at a frequency of 2.45 GHz is investigated by EM field simulator. Results show that dimensions of the symmetrical slots (length l ≤ λg/2, width of d = 6-10 mm) and optimized angle (φ=32° with respect to the waveguide central line) have a strong influence on the impedance matching of the waveguide to the dielectric window and plasma column (1.5 < SWR < 2.5), and on the radiation efficiency. The dielectric plate and plasma column density were taken into account in the model in the optimisation of the dimensions of the slots. The mode structure of standing surface waves in the plasma column is investigated at three values of plasma density and results for the radial (n=1) and azimuthal wave numbers (m=3, 4, 5) are in agreement with experimental results.
Application programming interface for electron beam welding of Inconel 718 thin plates
Authors: Koleva L , Koleva E 
Published: February 2024

Abstract
In this paper the simulation of electron beam welding of Inconel 718 thin plates by a moving linear heat source is considered. Neural network models are developed and used for the description of the dependence of the molten pool geometry characteristics on the process parameters - electron beam power, welding velocity, and the plate thickness. Neural network models, based on a multi-layered feedforward neural network, trained with Levenberg-Marquardt error backpropagation algorithm are compared with estimated regression models. The neural networks are trained, tested and validated using a set of experimental data. The resulting models are implemented for developing of an application programming interface for electron beam welding of Inconel 718 thin plates, which is used for prediction, investigation and graphical optimization of the molten pool geometry characteristics of the obtained electron beam welds.
A global centralized magnetic flux leakage small defect detection network
Authors: Chen Yufei , Lang Xianming , Liu Mingyang 
Published: February 2024

Abstract
To solve the problem that magnetic-flux-leakage (MFL) small defects are difficult to accurately detect by machine learning methods, a global centralized magnetic flux leakage small defect detection network (RCFPNet) is proposed. RCFPNet consists of simulation data enhancement, improved feature extraction (backbone), an improved centralized feature pyramid (CFP) and a detection head network. The MFL defect data of various scales and shapes are simulated by ANSYS simulation software and superimposed with the actual detected MFL defects to expand the dataset. The Repvgg module is used to replace the 3*3 convolution of the backbone to improve the detection speed. An improved spatially explicit vision center scheme (EVC) and a global centralized regulation rule (GCR) for feature fusion networks are proposed for feature fusion networks. RCFPNet is based on an improvement of the YOLOv5 network. Experiments have proven that RCFPNet has improved detection speed and accuracy and has achieved good results in the detection of magnetic leakage small defects. Experiments show that when the IOU = 0.5, the accuracy rate of this algorithm is 96.1%, and the reasoning time is 8.9 ms.
The Weight of Tradition at the Beginning of the European Middle Ages
Authors: Gabriele Matthew 
Published: February 2024

Abstract
This chapter confronts how early Christians, especially after the conversion of Constantine, dealt with the problem of time. The work of biblical commentary (exegesis) in this period was often focused on discerning a pattern within sacred history. Here too, however, in order to get back to the past itself, we must work though the historiography, which is heavily shaped by anti-fascist Roman Catholicism of the mid-twentieth century. But once we do, we can see how Augustine built from earlier thinkers, looked around, and saw a world in stasis—an Augustinian Atemporality—with no end in sight.
Epilogue
Authors: Gabriele Matthew 
Published: February 2024

Abstract
This brief epilogue begins with a case study of the historical writing of Fulcher of Chartres, who participated in the so-called First Crusade and then stayed on in Jerusalem under its new Latin kings. After the conquest of Jerusalem by the Christians in 1099, the surety of knowing the pattern of sacred history that developed across the eleventh century seemed to be confirmed. The chapter suggests we see evidence of this in various new currents across twelfth-century Europe. But that surety faded quickly and the intellectual cycle returned, with medievals again looking to the past for answers.