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High-frequency (HF) oil-immersed transformers with small size and light weight have been paid wide attention by researchers. Its oil–paper insulation frequently withstands HF over-voltages at frequencies of several kilohertz and above, resulting in the too early failure of oil–paper insulation. In order to investigate the effect of HF on oil–paper insulation, this article investigates the partial discharge (PD) characteristics of oil–paper insulation under HF stress. The experimental results show that a frequency-induced inflection point is existed near 10 kHz and the PD parameters of HF voltages is much higher than that ac voltages. Besides, the theoretical mechanism is expounded to interpret and understand the formation process of frequency-induced inflection points more easily. It can be found that the change in frequency causes the change in the charge decay time constant and the residual charge on the insulating surface, resulting in the formation of the frequency-induced inflection point at HF. These results might contribute to determine the characteristics of PDs between HF voltages and ac voltages. It can provide references for the research and production of HF transformers. [ABSTRACT FROM AUTHOR]

The space charge effect of transformer insulating paper will distort its internal electric field, and its space charge effect will be more prominent under extremely complex working conditions. At present, the micromechanism of charge transport and electric field distortion characteristics of paperboard are not clear under complex working conditions. So in this article, based on the bipolar carrier transport (BCT) model and the dynamic carrier balance model, the effects of high temperature, aging degree, moisture content, and bent degree on charges accumulation in paperboard are studied under dc high voltage by numerical simulation and the measured data needed for simulation. The results show that the higher temperature strengthens the carrier migration, deepens the injection depth of the charge, and aggravates the distortion of electric field intensity in paperboard. The more extended the aging time of paperboard, the greater the internal trap density and the deeper the trap depth, which lead to charges migration difficultly. Increasing water content in the paperboard will accelerate space charges to reach a steady state, while further increasing it will slow down this process, which is related to the shallow trap getting deeper. When the critical part of paperboard is extruded, many traps are introduced, resulting in charges accumulation seriously. The research results can reference the design of paperboard and the maintenance of transformer insulation system. [ABSTRACT FROM AUTHOR]

The article discusses the International Conference on Plasma Science held in Atlantic City, New Jersey, U.S. in 2017.

The IEEE International Conference on Plasma Science (ICOPS) is held annually, sponsored by the Plasma Science and Applications Committee (PSAC) of the IEEE Nuclear and Plasma Science Society (NPSS). The 47th IEEE NPSS ICOPS was organized ONLINE from December 06 to 10, 2020, by the National Institute of Education, Nanyang Technological University, Singapore. The ICOPS2020 was co-organized together with the 2nd Asia-Pacific Conference on Plasma and Terahertz Science (APCOPTS) which is envisioned as the future Asian version of the ICOPS series of conferences. The ICOPS2020 was initially planned as an onsite physical conference from May 24 to 28, 2020, at Marina Bay Sands, Singapore. However, due to the COVID-19 pandemic, it was shifted to online virtual conference. The conference’s technical program included a wide range of plasma science and technology topics, which ranged from basic and fundamental research to traditional and emerging technology applications. Since the ICOPS2020 was co-organized with APCOPTS, it also had a very strong coverage of fields related to terahertz science and applications. A total of 627 presentations from scientists and participants from over 41 countries were made at ICOPS2020 with a record total registration of 754. All presentations were recorded and were available to the registered participants for 90 days after the conference was over. The program also included a women-in-engineering talk by Jackie Y. Ying from A* Star Singapore and a young professionals networking symposium on “Plasma Entrepreneurship” with the theme “Plasma entrepreneurship—Active translation of cutting-edge research to commercially viable product.” [ABSTRACT FROM AUTHOR]

The objectives of this tutorial are as follows: 1) to help students and researchers develop a basic understanding of how pulsed-power systems are used to create high-energy-density (HED) matter; 2) to develop a basic understanding of a new, compact, and efficient pulsed-power technology called linear transformer drivers (LTDs); 3) to understand why LTDs are an attractive technology for driving HED physics (HEDP) experiments; 4) to contrast LTDs with the more traditional Marxgenerator/ pulse-forming-line approach to driving HEDP experiments; and 5) to briefly review the history of LTD technology as well as some of the LTD-driven HEDP research presently underway at universities and research laboratories across the globe. This invited tutorial is part of the Mini-Course on Charged Particle Beams and High-Powered Pulsed Sources, held in conjunction with the 44th International Conference on Plasma Science in May of 2017. [ABSTRACT FROM AUTHOR]

Surrounding air pollution is one of the important warnings to human health. It is necessary to detect hazardous pollutant gases in the air. The gas sensor is the candidate for such detection. Progress of smart and flexible sensors has been receiving growing curiosity in recent years because of their enormous sensing applications. Such smart and flexible sensors can be manufactured by depositing conducting materials, such as conducting polymer, carbon nanotube (CNT), graphene oxide, and metallic nanoparticles, onto nonconducting polymeric flexible substrates, such as paper, plastic films, and textiles. Most of the flexible polymeric substrates, such as polyethylene, polyester, nylon, and polypropylene, have low surface energy and poor wettability, which weakens the adhesion between conducting material and flexible substrate. Plasma surface modification is a novel technique to enhance surface properties to produce stable composites. This review focuses on various types of plasmas for surface modification and their effects on the surface after plasma treatment to improve the grafting and adhesion of the sensing layer with the substrate. The aim of this article is to systematically overview the development of plasma-enhanced smart and flexible gas sensors to date and to envisage their future progress. [ABSTRACT FROM AUTHOR]

These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal. [ABSTRACT FROM AUTHOR]

These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal. [ABSTRACT FROM AUTHOR]

These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal. [ABSTRACT FROM AUTHOR]

These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal. [ABSTRACT FROM AUTHOR]

These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal. [ABSTRACT FROM AUTHOR]

These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal. [ABSTRACT FROM AUTHOR]

These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal. [ABSTRACT FROM AUTHOR]

This article introduces an optimal design method for a multistage induction coil launcher. Considering the magnetic coupling and the effect of the armature’s resistance, the basic criteria to select the structure of the driving coil and armature are proposed, and the genetic algorithm is introduced to optimize the pending parameters. Based on the principle that the current in the driving coil matches the movement state of the armature, the design method of optimal capacitor parameters is deduced. The results show that the design error is less than 1%. For a multistage induction coil launcher, the optimization is carried out stage by stage. The effect of the stage spacing between driving coils is analyzed, and it is found that changing the direction of the current in driving coils helps to improve the system efficiency. Finally, based on the above optimal design method, a multistage induction coil launcher is designed, and the energy conversion efficiency of the system is close to 40%. [ABSTRACT FROM AUTHOR]

Presents the table of contents for this issue of the publication. [ABSTRACT FROM AUTHOR]

The results presented in this article relate to the work conducted to verify the existence of anode-induced phenomena, predominantly anode vaporization and consequent prebreakdown (PBD) current enhancement due to the impact of positive ions and microparticles over a relatively larger area at the cathode (presumably ion-assisted field (I-F) emission like). The verification of this hypothesis is attempted using a three-electrode arrangement. One electrode is comprised of a needle insulated from and projecting through a plane electrode (collector) of 40-mm diameter. It was surmised that if the positive ion beam from the anode spot (due to electron beam impact) were to be macroscopically diffuse, at least the collector would gather a part of it. However, no currents could be detected in the collector circuit even at voltages close to breakdown. The needle currents continued to display the typical characteristics of PBD currents under alternating voltages. The needle currents depended on the spacing between the needle tip and the plane of the collector and the polytetrafluoroethylene (PTFE) insulation used to prevent emission from the immediate vicinity of the needle evaporated significantly. Typical broad-area electrode behavior displayed by needle currents indicated that I-F emission, if any, is limited to the needle itself, which is certainly broad compared to the positive ion beam. Dependence of the PBD currents and breakdown voltages on the melting point of the anode material lend support to such anode-triggered electrode phenomena. [ABSTRACT FROM AUTHOR]