{"title":"Gas Temperature Measurement of Low-Current DC Arc in Air by Shadow Imaging","authors":"Shuqun Wu;Dawei Shi;Yue Guo;Sude Liu;Qiaojue Liu","doi":"10.1109/TPS.2025.3531223","DOIUrl":"https://doi.org/10.1109/TPS.2025.3531223","url":null,"abstract":"The gas temperature of arc plasma is an essential parameter in studies of the motion and extinguishment of arc, the recovery of gas insulation, and electrode erosion caused by arc discharge. This work measured the spatial distribution of the gas temperature by high-speed shadow imaging of the variation of the arc-induced flow field, which was confirmed by the Boltzmann plot method of the emission of the excited states of copper atoms. A typical low-current dc arc from photovoltaic arc faults was generated in the open air. The results showed that the gas temperature near the cathode was higher than that near the anode, which was different from the arc discharge of a high-current dc arc. It was interesting to observe a dispersed high-temperature region in the upper left, away from the cathode, which was independent of the direction of the electrode movement. When the arc current increased, the high-temperature region became elongated and then connected with the cathode. Detailed analysis of the flow field and the radiation light of the arc showed that the high-temperature region was probably caused by the electrode jet phenomenon of arc discharge.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 9","pages":"2342-2350"},"PeriodicalIF":1.5,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effects of Anode Structures on the Laminar Plasma Jet Characteristics Based on Fluent Simulation Method","authors":"Xiuquan Cao;Ling Luo;Yong He;Xing Liu;Yi Zhao;Yufeng Tang","doi":"10.1109/TPS.2025.3598054","DOIUrl":"https://doi.org/10.1109/TPS.2025.3598054","url":null,"abstract":"A Fluent-based simulation model was established to explore the anode current density distribution, as well as the internal temperature and velocity fields with three typical anode structures: cylindrical type, Laval type, and constricted type. First, by analyzing the relevant governing equations and theories of the laminar plasma torch, a numerical simulation model based on Fluent was developed, and its validity was verified through experiments. Then, using the constructed model, the temperature and velocity fields within the plasma torch, along with the anode surface current density distribution, were simulated and analyzed. Finally, based on a comparative analysis of the simulation results, optimization suggestions for the anode structure were proposed. The results indicate that: 1) the error between the simulation results and the experimental results of the constructed simulation model is less than 3%; 2) cylindrical-type anode current density > constricted-type anode current density > Laval-type anode current density; 3) the three typical anode structures have little influence on the temperature field within the plasma torch; however, in the anode outlet area, the outlet center temperature of the cylindrical-type anode structure is the lowest, and the radial temperature gradient is the largest; and the outlet central temperature of the Laval-type structure is slightly lower than that of the constricted-type structure, but its radial temperature gradient is the smallest, which is conducive to the uniform dispersion of the plasma flow temperature; and 4) the velocity field corresponding to the cylindrical-type structure is slightly lower than that corresponding to the Laval-type structure and the constricted-type structure. Moreover, when the Laval-type structure is adopted, the velocity in the anode area is only slightly lower than that of the constricted structure.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 10","pages":"3144-3152"},"PeriodicalIF":1.5,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145290266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Roshni Oommen;Adikiran S B;Akash R.;Gautham G;Aswathi R Nair
{"title":"Gate Tunable Retention in Optoelectronic Synapses Using Oxide Semiconductor Thin Film Transistors","authors":"Roshni Oommen;Adikiran S B;Akash R.;Gautham G;Aswathi R Nair","doi":"10.1109/TNANO.2025.3602073","DOIUrl":"https://doi.org/10.1109/TNANO.2025.3602073","url":null,"abstract":"In this work we propose a biasing scheme to modulate the retention behavior of oxide semiconductor based optoelectronic synapses. The method has been demonstrated using a zinc oxide thin film transistor, which exhibits persistent photoconductivity to UV light. The application of a negative gate bias prevents the recombination of photo-generated carriers, leading to a negligible decay in the post synaptic current and consequently, the retention time could extend beyond <inline-formula><tex-math>$10^{5}$</tex-math></inline-formula>s. The improvement in memory retention is observed in various synaptic functions such as short-term memory, long-term memory, duration-time-dependent plasticity and paired pulse facilitation. A five fold improvement in the % decay of post synaptic current was observed at <inline-formula><tex-math>$V_{gs}$</tex-math></inline-formula> = −5 V, when compared to <inline-formula><tex-math>$V_{gs}$</tex-math></inline-formula> = +5 V. Furthermore, we have assessed the impact of these improved retention properties on the performance of an artificial neural network, designed for pattern recognition of MNIST handwritten digits. The accuracy decayed drastically with time from 96% to nearly 40% at <inline-formula><tex-math>$V_{gs}$</tex-math></inline-formula> = +5 V whereas it drops to only 94% at <inline-formula><tex-math>$V_{gs}$</tex-math></inline-formula> = −5 V.","PeriodicalId":449,"journal":{"name":"IEEE Transactions on Nanotechnology","volume":"24 ","pages":"434-438"},"PeriodicalIF":2.1,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144998258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Semi-Physical Simulation System for Evaluation of Cardiopulmonary Resuscitation Mechanical Compression Parameters Based on Fracture Risk and Blood Perfusion","authors":"Yiming Chen;Yifeng Pan;Jiefeng Xu;Yufeng Hu;Mao Zhang;Peng Zhao","doi":"10.1109/JSEN.2025.3589561","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3589561","url":null,"abstract":"High-quality cardiopulmonary resuscitation (CPR) is a critical determinant of survival following cardiac arrest. In recent years, mechanical compression has become increasingly prevalent in the emergency management of cardiac arrest. The settings of key compression parameters strongly influence the effectiveness of chest compression. This study developed a semi-physical simulation platform and evaluation criteria to assess the optimal parameters for CPR. A multispring system was designed to simulate the risk of sternal fractures during chest compression. In addition, a blood flow model was constructed to simulate blood perfusion. The evaluation criteria, which include quantifying sternal fracture risk and blood perfusion, are used to calculate the compression effect by inputting the compression force and depth data into the evaluation model. Analysis of variance (ANOVA) demonstrated statistically significant impacts of different compression parameters on compression outcomes. The results demonstrated that the mechanical waveform data more accurately reflected the compression dynamics encountered in real-world CPR circumstances. The trapezoidal compression waveform demonstrated clear superiority over triangle and sine waveforms, enhancing blood circulation. This study’s exploration of the trapezoidal waveform fills a gap in American Heart Association (AHA) guidelines. In addition to the waveform, the study confirmed that a compression depth of 50 mm and a frequency of 120 compressions/min yielded the most effective hemodynamic outcomes. These findings validated and expanded upon the AHA guidelines, offering a novel and comprehensive approach by optimizing CPR effectiveness, improving both patient survival rates and the quality of mechanical resuscitation.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 17","pages":"32301-32311"},"PeriodicalIF":4.3,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144990081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Y. Pan;J. C. Cai;Z. X. Su;X. K. Zhang;Z. Zhang;Z. X. Liang;M. Asad;C. Zhang;L. Zeng;X. C. Lin;P. C. Yin;J. Xu;L. N. Yue;H. R. Yin;Y. Xu;G. Q. Zhao;W. X. Wang;Y. Y. Wei
{"title":"Demonstration of a Compact CW 263-GHz Extended Interaction Klystron Frequency Upconverter","authors":"G. Y. Pan;J. C. Cai;Z. X. Su;X. K. Zhang;Z. Zhang;Z. X. Liang;M. Asad;C. Zhang;L. Zeng;X. C. Lin;P. C. Yin;J. Xu;L. N. Yue;H. R. Yin;Y. Xu;G. Q. Zhao;W. X. Wang;Y. Y. Wei","doi":"10.1109/TPS.2025.3598042","DOIUrl":"https://doi.org/10.1109/TPS.2025.3598042","url":null,"abstract":"To realize the miniaturization of RF sources for applications in dynamic nuclear polarization–nuclear magnetic resonance (DNP–NMR) spectroscopy, a compact continuous-wave (CW) 263-GHz extended interaction klystron (EIK) frequency upconverter is designed and proposed in this article, including the high-frequency circuit and a complete compact beam optical system (BOS) based on hybrid permanent magnets. This G-band EIK could be driven by easily accessible W-band signal with power level less than 1 W. A local magnetic field enhancement technology is used in the BOS to allow the beam to be further compressed in the tiny drifting tunnel of output cavity, achieving full cylindrical-beam transmission along the whole hybrid circuit. Particle-in-cell (PIC) simulation results show that the saturated output power of the designed EIK could reach over 250 W at 263 GHz, with an operating beam voltage of 24 kV and a beam current of 0.3 A. In addition, its instantaneous bandwidth is broad enough to meet the requirements of DNP–NMR power source where no instability is observed. The key specifications demonstrate that the designed EIK could stably operate in CW mode. This study is expected to provide new approach for the design of cost-efficient sub-THz EIKs in a compact profile, aiming for DNP–NMR applications and beyond.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 9","pages":"2219-2225"},"PeriodicalIF":1.5,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Kinetic Effects of Nanosecond Discharge on the Ignition Delay of Ethylene–Air Mixtures","authors":"Bin Zhang;Changlin Zou;Shuqun Wu","doi":"10.1109/TPS.2025.3589221","DOIUrl":"https://doi.org/10.1109/TPS.2025.3589221","url":null,"abstract":"This study develops a zero-dimensional kinetic model to investigate the effects of nanosecond pulsed discharge on the ignition characteristics of stoichiometric ethylene–air mixtures. The simulation framework combines ZDPlasKin for plasma kinetics and CHEMKIN for combustion chemistry. At an initial temperature of 1200 K, a pressure of 1.1 atm, and a fixed plasma energy input of 20 mJ/cm<sup>3</sup>, the results show that the nanosecond discharge significantly shortens the ignition delay time compared to autoignition. The ignition enhancement strongly depends on the reduced electric field <inline-formula> <tex-math>$E/N$ </tex-math></inline-formula>, reaching a minimum delay at 200 Td. The primary radicals responsible for promoting ignition—O, H, C<sub>2</sub>H, and C<sub>2</sub>H<sub>3</sub>—are mainly produced through quenching reactions of electronically excited nitrogen species, particularly N<sub>2</sub>(A) and N<sub>2</sub>(<inline-formula> <tex-math>$text{a}^{prime }$ </tex-math></inline-formula>). Path flux analysis reveals that electron collisions contribute significantly to O formation, while H and C<sub>2</sub>H<sub>3</sub> are predominantly formed via N<sub>2</sub> quenching. The variation in radical production with <inline-formula> <tex-math>$E/N$ </tex-math></inline-formula> explains the non monotonic trend of ignition delay time.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 9","pages":"2161-2167"},"PeriodicalIF":1.5,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Numerical Modeling of Streamer Propagation in a Nonuniform Electric Field to Assess the Lightning Impulse Flashover Voltage of Polymeric Insulators","authors":"M. Noorul Haque;K. Sunitha","doi":"10.1109/TPS.2025.3597884","DOIUrl":"https://doi.org/10.1109/TPS.2025.3597884","url":null,"abstract":"Assessing the dielectric withstand strength of every equipment in a power system is crucial for insulation coordination. The flashover voltage (FOV) of polymeric insulators due to a lightning impulse (LI) is computed by modeling the air discharge using air plasma chemistry and the movement of the charged species using the charge transport model. The formation of corona streamers and breakdown (BD) streamers from the anode and cathode under the influence of a nonuniform electric field is analyzed. Charge concentrations are formed due to the accumulation of ions of opposite polarity, and the propagation of BD streamers due to the influence of these space charges (SCs) is illustrated. The final air BD is observed to be a combination of cathode- and anode-directed streamers. The velocity of the streamers decreases as they propagate through the low-field region, and the velocity of the anode-directed streamers is found to be less than that of the cathode-directed streamers. The computed FOVs are in agreement with the experimentally determined FOVs.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 9","pages":"2450-2457"},"PeriodicalIF":1.5,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yong Bo;Xiaolong Pan;Xianmin Guo;Qingqing Deng;Wei Chen;Lixia Yang
{"title":"Research on Electromagnetic Scattering Characteristics of Moving Time-Varying Dusty Plasma Based on Lorentz-SO-FDTD Method","authors":"Yong Bo;Xiaolong Pan;Xianmin Guo;Qingqing Deng;Wei Chen;Lixia Yang","doi":"10.1109/TPS.2025.3574812","DOIUrl":"https://doi.org/10.1109/TPS.2025.3574812","url":null,"abstract":"This article establishes an electromagnetic scattering model for high-speed moving targets covered by a dusty plasma sheath, utilizing the Bhatnagar-Gross–Krook (BGK) collision model of fully ionized dusty plasma. The proposed Lorentz-shift-operator finite-difference time-domain (Lorentz-SO-FDTD) method is employed to compute the backscatter radar cross section (RCS) of complex blunt cone targets at varying velocities. Furthermore, considering the time-varying nature of electron density in dusty plasma, this study investigates the frequency-domain scattering properties of a moving blunt cone target coated with time-varying dusty plasma. The results indicate that the Doppler effect, caused by the target’s motion, influences both the echo signal and the backward RCS. Additionally, the time-varying characteristics of electron density modulate the scattering field of moving targets. The frequency components of the time-varying electron density and their higher order harmonics can be detected in the scattering field spectrum, leading to a reduction in the primary frequency energy of the echo signal spectrum.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 9","pages":"2458-2466"},"PeriodicalIF":1.5,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Electron Trajectories Analysis in Spatial Harmonic Magnetrons Using Epitrochoidal Curve Theory","authors":"Rajendra Kumar Verma;Shivendra Maurya;N. Kanagraj","doi":"10.1109/TPS.2025.3596401","DOIUrl":"https://doi.org/10.1109/TPS.2025.3596401","url":null,"abstract":"The manuscript presents the implementation of epitrochoidal curve theory for the study and analysis of electron trajectories in the boundary conditions of the designed spatial harmonic magnetron (SHM). A model is created based on the epitrochoidal curve theory to study the trajectories of a particle/point with derived equations, offering insights into the understanding of magnetrons by a fundamental theoretical framework. The constants of the theory, namely “a,” “b,” “h,” and their correlation, have been analyzed. Constant “a” controls the expansion radius and thus relates to the dc voltage, constant “b” controls the gyration radius and relates to the magnetic field, and constant “h” controls the periodicity and perturbation of the trajectories and thus relates to the RF voltage. The model provides some derived equations enabling the mapping of these constants within the boundary constraints of the designed SHM to understand certain important phenomena in magnetrons and SHMs. The boundary condition solutions from the model provide the initial guesses of constants, which are further optimized by radial expansion study and trajectory analysis. The trajectories of the generated electron hub reveal the dominance of electron backbombardment phenomena at the cathode when the rotational radial vector rtot < rm mean radius, and anode current collection domination when the stationary radial vector rstat > rm mean radius. Thus, the model highlights the significance of the mean radius and optimizes the ratio of radial expansion constants “a” and “b” and the RF constant “h,” which plays a significant role in the working of magnetron physics. Using the model, the optimum values of the parameters for 22 spokes in SHM have been obtained as <italic>a</i>max = 1.2342, <italic>a</i>min = 0.6996, <italic>b</i>max = 0.0561, <italic>b</i>min = 0.0318, <italic>h</i>max <inline-formula> <tex-math>$= pm 0.2960$ </tex-math></inline-formula>, and <italic>h</i>min <inline-formula> <tex-math>$= =pm 0.0080$ </tex-math></inline-formula>.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 9","pages":"2248-2253"},"PeriodicalIF":1.5,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Deterministic Target-Barrier Coverage With Importance-Aware Sensor Deployment in IIoT","authors":"Chien-Fu Cheng;Wen-Hao Lin","doi":"10.1109/JSEN.2025.3598798","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3598798","url":null,"abstract":"This study addresses the target-barrier coverage problem in a deterministic deployment setting, considering targets with varying levels of importance. Taking the surveillance of oil exploitation infrastructure in the Industrial Internet of Things (IIoT) as an example, different oil-related facilities within the exploitation area may have distinct levels of importance. To prevent potential damage, target-barriers must be constructed around these infrastructures. Targets of higher importance require target-barriers with extended response times, necessitating distance constraints that vary according to importance levels. To the best of our knowledge, this is the first work to address the target-barrier coverage problem while incorporating different levels of target importance. The primary objective is to minimize the number of deployed sensors needed to construct target-barriers in a deterministic manner while ensuring coverage requirements based on target importance. The minimum number of sensors required for target-barrier construction is analytically determined and formally proven. Additionally, the problem is shown to be NP-hard. Finally, simulation results are presented to evaluate the performance of the proposed algorithm.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 19","pages":"37370-37382"},"PeriodicalIF":4.3,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145204545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}