Article
Physics, Fluids & Plasmas
A. Saifutdinov, S. S. Sysoev
Summary: Covering the external surface of the cathode improves the current-voltage characteristics of microhollow cathode discharges, allowing the negative glow plasma to occupy more of the discharge volume for better resolution in recording fast electron spectra.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Physical
Bibhuti Bhusan Sahu, Kazuya Nakane, Kenji Ishikawa, Makoto Sekine, Takayoshi Tsutsumi, Taku Gohira, Yoshinobu Ohya, Noriyasu Ohno, Masaru Hori
Summary: This study uses optical emission spectroscopy (OES) to measure the electron temperature and density in dual-frequency pulsed capacitively coupled plasmas (CCPs). The results show that the plasma conditions are dominated by a corona balance and reveal insights into the pulsed discharge.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Physics, Applied
Xu-Cheng Wang, Yuan-Tao Zhang
Summary: Non-thermal plasma technology is a promising solution for decomposing CO (2), and this study proposes a deep neural network (DNN) to describe the discharge characteristics and plasma chemistry of CO (2) pulsed discharge at atmospheric pressure. The DNN is trained using fluid model simulation data and shown to provide accurate results in a fraction of the time compared to traditional simulations. The DNN prediction results indicate the influence of pulse rise rate and plateau duration on discharge current, breakdown voltage, electric field, and product species density. Overall, this study demonstrates the reliability and potential of DNN-based methods in non-thermal plasma applications.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Materials Science, Coatings & Films
Yeong-Min Lim, So-Yeong Park, You He, Young-Hun Hong, Chin-Wook Chung
Summary: A method for improving the plasma uniformity in capacitively coupled plasma (CCP) is developed by using a parallel capacitor. By adjusting the capacitance of the parallel capacitor, the current of other harmonic frequency components in the plasma is greatly reduced, resulting in a more sinusoidal waveform and improved plasma uniformity.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2022)
Article
Physics, Fluids & Plasmas
K. Rasek, F. X. Bronold, H. Fehske
Summary: This study investigates the self-consistent ambipolar charge kinetics across a negatively biased semiconducting plasma-solid interface. By calculating and visualizing, the study shows that the current-voltage characteristic is influenced by the electron microphysics of the semiconductor, indicating that the perfect absorber model commonly used for plasma-solid interfaces cannot be maintained for semiconducting interfaces.
Review
Physics, Applied
Jialin Liu, Lanlan Nie, Dawei Liu, Xinpei Lu
Summary: This paper provides an overview of the research in the field of nitrogen fixation (NF), discussing the main pathway for NO formation in N-2/O-2 mixtures and the involvement of N-2 in the Zeldovich mechanism. It also addresses the high energy consumption obstacle in plasma-assisted NF and the importance of understanding energy flow in the discharge process for improving NF energy efficiency. Furthermore, it discusses various new plasma NF devices reported in recent years.
PLASMA PROCESSES AND POLYMERS
(2023)
Article
Multidisciplinary Sciences
Sangwoo Kim, Jungho Hwang
Summary: This study establishes and validates a numerical methodology to evaluate the maximum current in unipolar corona discharge. The effects of geometric and operation parameters on the maximum currents of different configurations are analyzed and regressed into a single formula.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Applied
Anna Dzimitrowicz, Piotr Jamroz, Piotr Cyganowski, Aleksandra Bielawska-Pohl, Aleksandra Klimczak, Pawel Pohl
Summary: By controlling cold atmospheric pressure plasma (CAPP) treatment, the element composition pattern and phenolic compound content of beetroot juice were altered, inhibiting the proliferation of colorectal adenocarcinoma cell lines while exhibiting non-cytotoxic effects on non-malignant endothelial cells, resulting in a safe-to-consume beetroot juice with improved nutritional quality.
Article
Engineering, Multidisciplinary
Zhendong Yuan, Kouta Suzuki, Yoshiyasu Ehara, Jun Ikeda, Keisuke Yamashiro, Tetsumi Takano
Summary: Harmful substances emitted from marine diesel engines, such as black carbon, have a significant impact on the air environment. Traditional diesel particulate filters are not suitable for collecting high concentration particles from heavy fuel oil emissions. Electrostatic precipitators have advantages of a simpler structure, lower pressure loss, and higher collection efficiency.
IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS
(2022)
Article
Computer Science, Interdisciplinary Applications
Andrea Villa, Roger Schurch, Giacomo Buccella, Luca Barbieri, Christian Laurano, Roberto Malgesini, Daniele Palladini
Summary: Plasma simulation is becoming increasingly important in electrical engineering to replicate technically relevant configurations, such as the evolution of partial discharges. A proper numerical filter can address the challenges caused by high surface conductivity and greatly enhance the performance of simulation algorithms.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Physics, Applied
Ram Krushna Mohanta, Devilal Kumawat, G. Ravi
Summary: This study examines the effects of chamber pressure on the electrical and thermodynamic characteristics of a low-pressure thermal plasma jet. The research investigates various factors, including current-voltage characteristics, arc voltage fluctuations, plasma jet temperature, electron density, and velocity under different chamber pressure conditions. The findings reveal the influence of chamber pressure on different frequencies in the arc voltage spectrum and demonstrate the changes in the plasma jet's temperature, density, and velocity due to the varying chamber pressures.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Engineering, Multidisciplinary
Andrea Villa, Luca Barbieri, Roberto Malgesini, Giacomo Buccella
Summary: This paper aims to simulate plasma-solid interaction in real insulating components using first-principle partial differential equations. A filtering method is applied to allow the use of larger time steps in simulating realistic components. The novel theoretical analysis shows that the filter does not affect the accuracy of the method, as supported by significant numerical experiments.
APPLIED MATHEMATICAL MODELLING
(2021)
Article
Physics, Fluids & Plasmas
A. Ahmed, S. Singha, S. Borthakur, N. K. Neog, T. K. Borthakur, J. Ghosh
Summary: Time-integrated spectroscopic measurements of argon plasma in a coaxial pulsed plasma accelerator revealed the temporal evolution of plasma stream characteristics, including changes in density, excitation temperature, and energy density over time. The study showed a decrease in plasma densities and excitation temperature, as well as a time-dependent decreasing trend in energy density, providing valuable insights for optimizing pulsed plasma accelerators.
PHYSICS OF PLASMAS
(2021)
Article
Plant Sciences
Yuri K. Danilejko, Sergey V. Belov, Alexey B. Egorov, Vladimir I. Lukanin, Vladimir A. Sidorov, Lyubov M. Apasheva, Vladimir Y. Dushkov, Mikhail I. Budnik, Alexander M. Belyakov, Konstantin N. Kulik, Shamil Validov, Denis V. Yanykin, Maxim E. Astashev, Ruslan M. Sarimov, Valery P. Kalinichenko, Alexey P. Glinushkin, Sergey V. Gudkov
Summary: The study demonstrates that water activated by a glow discharge shows antifungal properties and accelerates the growth of grain and fruit crops. In particular, glow-discharge-activated water enhances drought resistance in sorghum culture significantly. The technology developed in this work has the potential for industrial-scale activation of aqueous solutions.
Article
Chemistry, Analytical
Jordi-Roger Riba, Pau Bas-Calopa
Summary: This paper evaluates and compares the sensitivity of two methods for detecting and locating corona discharges, based on a DSLR camera and a portable wideband sonic camera. The results show that the sonic camera can detect and locate corona discharges quickly, simply, and sensitively, even in daylight conditions and at a distance of several meters from the discharge source.
Article
Physics, Fluids & Plasmas
Dongho Lee, Guentae Doh, Holak Kim, Laurent Garrigues, Wonho Choe
Summary: Two distinct discharge modes were observed in a 50 W-class micro-Hall thruster plasma under different operating conditions. In mode B, the thruster showed performance improvements in terms of thrust, specific impulse, and anode efficiency, suggesting that operation is more advantageous in mode B than in mode A for the utilization of such low-power Hall thrusters.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2021)
Article
Multidisciplinary Sciences
Sanghoo Park, Wonho Choe, Hyungyu Lee, Joo Young Park, Jinwoo Kim, Se Youn Moon, Uros Cvelbar
Summary: This study investigates the impact of gas jets on a water surface and the stabilizing effect of weakly ionized gas on cavities. Experimental results demonstrate that plasma bullets generated by weakly ionized gas can exert more force on the water surface through electrohydrodynamic flow, leading to cavity expansion without destabilization.
Article
Materials Science, Ceramics
Hanbyeol Jang, My-Chi Nguyen, Sojung Noh, Woo Kyung Cho, Youngku Sohn, Kiju Yee, Heesoo Jung, Jeongkwon Kim
Summary: UV laser sterilization of ceramic tiles was found to be more effective on vitrified tiles than on porous tiles, and more effective on white and matte tiles than on black and glossy tiles when destroying Bacillus atrophaeus spores. The study evaluated the effects of UV irradiation based on water absorption, tile color, and surface brightness.
CERAMICS INTERNATIONAL
(2022)
Article
Physics, Applied
Holak Kim, Seunghoon Lee, Guentae Doh, Dongho Lee, Wonho Choe
Summary: By tailoring the magnetic field in a cylindrical Hall thruster, this study has demonstrated higher ion current and propellant efficiencies, reduced wall interaction, and observed a large fraction of multiply charged ions.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Applied
Guentae Doh, Holak Kim, Dongho Lee, Sanghoo Park, Stephane Mazouffre, Wonho Choe
Summary: A study was conducted on the structure of the ion acceleration region and the shape of the ion velocity distribution function in cylindrical Hall thruster plasmas, using laser-induced fluorescence spectroscopy on Xe II metastable ions. It was found that ion acceleration mostly takes place outside the discharge channel, with the IVDF close to a single Gaussian distribution inside the channel and becoming asymmetric downstream. The measured ion velocity distributions downstream were in good agreement with double Gaussian distributions, with cold and hot ion groups, showing an R-squared greater than 0.995.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Physics, Fluids & Plasmas
Hyojong Lee, Hyeonjun Lee, Yoon Seong Han, Jiheon Song, E. A. Belli, Wonho Choe, Jisung Kang, Jekil Lee, J. Candy, Jungpyo Lee
Summary: The theoretical analysis and simulation results in this study reveal that the rotation speed has a certain influence on the tungsten impurity accumulation in KSTAR experiment. Beyond a certain threshold, the rotation reduces the inward convection of impurities or changes it to outward convection, providing a means to control impurity accumulation conditionally. Additionally, the rotation amplifies the temperature screening effect. However, this effect is influenced by the radius and collisionality.
PHYSICS OF PLASMAS
(2022)
Article
Physics, Fluids & Plasmas
Jinwoo Kim, Dongho Lee, Guentae Doh, Sanghoo Park, Holak Kim, Wonho Choe
Summary: A diagnostic system was developed for spectrally resolved, three-dimensional tomographic reconstruction of Hall thruster plasmas, successfully reconstructing local intensity profiles of Xe I and Xe II emissions. The system employed 28 virtual cameras and the Phillips-Tikhonov regularization algorithm, achieving a root-mean-square error within an order of 10(-3) even for a 1% difference in azimuthal intensity distribution.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
Dongchang Kim, Jihoon Chung, Deokjae Heo, Seh-Hoon Chung, Giuk Lee, Patrick T. J. Hwang, Min-Kun Kim, Heesoo Jung, Youngho Jin, Jinkee Hong, Sangmin Lee
Summary: As a valuable tool for harvesting energy, triboelectric nanogenerators (TENGs) have advantages over other energy-harvesting methods in terms of their low weight, low cost, and high-power density. To overcome limitations of TENGs, a mechanism that can produce both AC and DC outputs with amplified electrical current has been established. A miniaturized and portable variant of the TENG has also been designed for harvesting mechanical energy in daily-life activities.
ADVANCED ENERGY MATERIALS
(2022)
Article
Chemistry, Physical
Youna Kim, Moonhyun Choi, Jiwoong Heo, Sungwon Jung, Dongwon Ka, Heesoo Jung, Sangmin Lee, Youngho Jin, Jinkee Hong
Summary: This study demonstrates that graphene oxide nanosheets with high surface charge density can provide good protection against chemical warfare agents by reducing their diffusion. The interlayer distance between the graphene oxide nanosheets plays a key role in the barrier effect.
APPLIED SURFACE SCIENCE
(2022)
Article
Engineering, Environmental
Youna Kim, Moonhyun Choi, Jiwoong Heo, Sungwon Jung, Dongwon Ka, Hyeji Lee, Sang Wook Kang, Heesoo Jung, Sangmin Lee, Youngho Jin, Jinkee Hong
Summary: In this study, a multilayer thin film composed of linear polyethylenimine (LPEI) and graphene oxide (GO) was prepared to block the permeation of chemical warfare agents. The protective effect of this film was investigated and it showed high protection efficiency with good breathability. The membrane has potential applications in protective suits and masks.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Engineering, Environmental
Hyungyu Lee, Sanghoo Park, Joo Young Park, Jinwoo Kim, Wonho Choe
Summary: We numerically demonstrate that photolytic processes induced by external UV sources significantly affect the chemical properties of plasma-water systems. Exposure of plasma-treated water (PTW) to UV leads to the photolysis of long-lived species and the formation of hydroxyl radical (OH) and nitric oxide (NO). The concentration of OH and NO in PTW is greatly enhanced under UV exposure, making it an attractive approach to increase the reactivity and applicability of PTW.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Physics, Fluids & Plasmas
Dongho Lee, Jinwoo Kim, Guentae Doh, Changmin Shin, Wonho Choe
Summary: Two-dimensional electron temperature and density profiles in the plume region of a 300 W-class Hall thruster Ar plasmas were successfully obtained using tomographically reconstructed optical emission intensity profiles combined with a collisional-radiative model, and the results were in good agreement with double Langmuir probe measurements.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Physics, Fluids & Plasmas
H. Shin, J. Hwang, Y. Han, G. Shin, H. Lee, K. -B. Chai, Wonho Choe
Summary: In this study, we demonstrate successful ELM suppression and mitigation using an argon-seeded discharge and a three-row resonant magnetic perturbation configuration in KSTAR. The heat flux on the divertor target was reduced by argon seeding, and the particle flux on both targets was significantly reduced. The divertor heat load was further reduced during the RMP grassy-ELM regime, and a highly localized radiation zone near the X-point was observed during divertor detachment.
Article
Materials Science, Multidisciplinary
Holak Kim, Guentae Doh, Wonho Choe
Summary: The production of multiply charged ions in Hall effect plasmas was studied by analyzing factors such as geometry, magnetic field configuration, and magnetic mirror ratio. The co-current configuration of the cylindrical Hall thruster showed the highest fractions of multiply charged ions, with the region of high magnetic flux density having a significant influence on the fraction. However, the fraction of multiply charged ions was not significantly affected by magnetic mirror ratios. The configuration with similar magnetic fields in the cylindrical Hall thruster demonstrated comparable fractions of multiply charged ions and thrust, even with different channel lengths.
CURRENT APPLIED PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Hyunsook Jung, Jihyun Kwon, Heesoo Jung, Kyeong Min Cho, Seung Jung Yu, Sang Myeon Lee, Mingyu Jeon, Sung Gap Im
Summary: In this study, a copolymeric coating with short-chain fluorinated groups was synthesized and directly coated onto a textile fabric via initiated chemical vapor deposition. The coating shows excellent nonwetting ability against hazardous chemical warfare agents and retains its performance even after abrasion and exposure to harsh chemicals.
