The Experts below are selected from a list of 22728 Experts worldwide ranked by ideXlab platform
Dong-wha Park - One of the best experts on this subject based on the ideXlab platform.
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High-Efficient Conversion of CO_2 in AC-Pulsed Tornado Gliding Arc Plasma
Plasma Chemistry and Plasma Processing, 2016Co-Authors: Hyun-woo Park, Woo-jae Chung, Dong-wha ParkAbstract:An AC-pulsed tornado gliding arc plasma was employed for CO_2 conversion via CO_2 decomposition and dry reforming reactions. A stable and high-efficient constant arc length Discharge Mode was obtained in this plasma reactor. And then, CO_2 conversion was studied under this Discharge Mode. In the case of CH_4/CO_2 = 0, CO_2 was converted to CO and O_2 via the CO_2 decomposition reaction. Energy efficiency of 29 % was attained at CO_2 conversion of 6 %. With strong reducing agent CH_4 added into CO_2, the main contributor of CO_2 conversion changed from CO_2 decomposition to dry reforming of CH_4. Conversions of CH_4 and CO_2, energy efficiency and energy cost changed sharply at CO_2/CH_4 ratios lower than 1/4, while they changed slowly at CH_4/CO_2 ratios above 1/4. In the case of CH_4/CO_2 = 2/3, energy efficiency of 68 % and syngas energy cost of 1.6 eV/mole were achieved at CH_4 conversion of 29 % and CO_2 conversion of 22 %.
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high efficient conversion of co2 in ac pulsed tornado gliding arc plasma
Plasma Chemistry and Plasma Processing, 2016Co-Authors: Hyun-woo Park, Woo-jae Chung, Dong-wha ParkAbstract:An AC-pulsed tornado gliding arc plasma was employed for CO2 conversion via CO2 decomposition and dry reforming reactions. A stable and high-efficient constant arc length Discharge Mode was obtained in this plasma reactor. And then, CO2 conversion was studied under this Discharge Mode. In the case of CH4/CO2 = 0, CO2 was converted to CO and O2 via the CO2 decomposition reaction. Energy efficiency of 29 % was attained at CO2 conversion of 6 %. With strong reducing agent CH4 added into CO2, the main contributor of CO2 conversion changed from CO2 decomposition to dry reforming of CH4. Conversions of CH4 and CO2, energy efficiency and energy cost changed sharply at CO2/CH4 ratios lower than 1/4, while they changed slowly at CH4/CO2 ratios above 1/4. In the case of CH4/CO2 = 2/3, energy efficiency of 68 % and syngas energy cost of 1.6 eV/mole were achieved at CH4 conversion of 29 % and CO2 conversion of 22 %.
P J Cullen - One of the best experts on this subject based on the ideXlab platform.
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microsecond pulse gas liquid Discharges in atmospheric nitrogen and oxygen Discharge Mode stability and plasma characteristics
Plasma Processes and Polymers, 2021Co-Authors: Sen Wang, Yawei Liu, Renwu Zhou, Feng Liu, Zhi Fang, Kostya Ostrikov, P J CullenAbstract:A plasma's working gas is a significant factor affecting their Discharge characteristics and the induced chemistries during plasma–water interactions. However, the effects on the Discharge Mode and Discharge stability have not been fully investigated. This study focuses on the Discharge Mode transition and stability with nitrogen and oxygen gases. Compared with the oxygen Discharge, the nitrogen Discharge remained stable over a larger voltage range and long duration time. A diffuse Mode Discharge had better stability and lower plasma activity for both nitrogen and oxygen gases, whereas a transient spark Mode in nitrogen and filament Mode in oxygen had lower stability but a higher plasma activity. This study improves the understanding of the physicochemical processes of plasma–water interactions.
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controlled cytotoxicity of plasma treated water formulated by open air hybrid Mode Discharge
Applied Physics Letters, 2017Co-Authors: Daniela Boehm, P J Cullen, Paula BourkeAbstract:Plasma treated liquids (PTLs) provide a means to convey a broad range of effects of relevance for food, environmental, or clinical decontamination, plant growth promotion, and therapeutic applications. Devising the reactive species ingredients and controlling the biological response of PTLs are of great interest. We demonstrate an approach by using an open-air hybrid Mode Discharge (HMD) to control the principal reactive species composition within plasma treated water (PTW), which is then demonstrated to regulate the cytotoxicity of PTW. The cytotoxicity of HMD produced PTW demonstrates a non-monotonic change over the Discharge time. Although hydrogen peroxide and nitrite are not the sole effectors for cell death caused by PTW, using them as principal reactive species indicators, cytotoxicity can be removed and/or enhanced by formulating their concentrations and composition through adjusting the Discharge Mode and time on-line during PTW generation without the addition of additional working gas or chemica...
Sen Wang - One of the best experts on this subject based on the ideXlab platform.
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microsecond pulse gas liquid Discharges in atmospheric nitrogen and oxygen Discharge Mode stability and plasma characteristics
Plasma Processes and Polymers, 2021Co-Authors: Sen Wang, Yawei Liu, Renwu Zhou, Feng Liu, Zhi Fang, Kostya Ostrikov, P J CullenAbstract:A plasma's working gas is a significant factor affecting their Discharge characteristics and the induced chemistries during plasma–water interactions. However, the effects on the Discharge Mode and Discharge stability have not been fully investigated. This study focuses on the Discharge Mode transition and stability with nitrogen and oxygen gases. Compared with the oxygen Discharge, the nitrogen Discharge remained stable over a larger voltage range and long duration time. A diffuse Mode Discharge had better stability and lower plasma activity for both nitrogen and oxygen gases, whereas a transient spark Mode in nitrogen and filament Mode in oxygen had lower stability but a higher plasma activity. This study improves the understanding of the physicochemical processes of plasma–water interactions.
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multiple current peaks in room temperature atmospheric pressure homogenous dielectric barrier Discharge plasma excited by high voltage tunable nanosecond pulse in air
Applied Physics Letters, 2013Co-Authors: Dezheng Yang, Wenchun Wang, Shuai Zhang, Kai Tang, Zhijie Liu, Sen WangAbstract:Room temperature homogenous dielectric barrier Discharge plasma with high instantaneous energy efficiency is acquired by using nanosecond pulse voltage with 20-200 ns tunable pulse width. Increasing the voltage pulse width can lead to the generation of regular and stable multiple current peaks in each Discharge sequence. When the voltage pulse width is 200 ns, more than 5 organized current peaks can be observed under 26 kV peak voltage. Investigation also shows that the organized multiple current peaks only appear in homogenous Discharge Mode. When the Discharge is filament Mode, organized multiple current peaks are replaced by chaotic filament current peaks.
Hyun-woo Park - One of the best experts on this subject based on the ideXlab platform.
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High-Efficient Conversion of CO_2 in AC-Pulsed Tornado Gliding Arc Plasma
Plasma Chemistry and Plasma Processing, 2016Co-Authors: Hyun-woo Park, Woo-jae Chung, Dong-wha ParkAbstract:An AC-pulsed tornado gliding arc plasma was employed for CO_2 conversion via CO_2 decomposition and dry reforming reactions. A stable and high-efficient constant arc length Discharge Mode was obtained in this plasma reactor. And then, CO_2 conversion was studied under this Discharge Mode. In the case of CH_4/CO_2 = 0, CO_2 was converted to CO and O_2 via the CO_2 decomposition reaction. Energy efficiency of 29 % was attained at CO_2 conversion of 6 %. With strong reducing agent CH_4 added into CO_2, the main contributor of CO_2 conversion changed from CO_2 decomposition to dry reforming of CH_4. Conversions of CH_4 and CO_2, energy efficiency and energy cost changed sharply at CO_2/CH_4 ratios lower than 1/4, while they changed slowly at CH_4/CO_2 ratios above 1/4. In the case of CH_4/CO_2 = 2/3, energy efficiency of 68 % and syngas energy cost of 1.6 eV/mole were achieved at CH_4 conversion of 29 % and CO_2 conversion of 22 %.
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high efficient conversion of co2 in ac pulsed tornado gliding arc plasma
Plasma Chemistry and Plasma Processing, 2016Co-Authors: Hyun-woo Park, Woo-jae Chung, Dong-wha ParkAbstract:An AC-pulsed tornado gliding arc plasma was employed for CO2 conversion via CO2 decomposition and dry reforming reactions. A stable and high-efficient constant arc length Discharge Mode was obtained in this plasma reactor. And then, CO2 conversion was studied under this Discharge Mode. In the case of CH4/CO2 = 0, CO2 was converted to CO and O2 via the CO2 decomposition reaction. Energy efficiency of 29 % was attained at CO2 conversion of 6 %. With strong reducing agent CH4 added into CO2, the main contributor of CO2 conversion changed from CO2 decomposition to dry reforming of CH4. Conversions of CH4 and CO2, energy efficiency and energy cost changed sharply at CO2/CH4 ratios lower than 1/4, while they changed slowly at CH4/CO2 ratios above 1/4. In the case of CH4/CO2 = 2/3, energy efficiency of 68 % and syngas energy cost of 1.6 eV/mole were achieved at CH4 conversion of 29 % and CO2 conversion of 22 %.
Zaiping Guo - One of the best experts on this subject based on the ideXlab platform.
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intrinsically optimizing charge transfer via tuning charge Discharge Mode for lithium oxygen batteries
Small, 2019Co-Authors: Wei Liu, Yue Shen, Wang Zhang, Zhaoming Huang, Jintao Meng, Yunhui Huang, Zaiping GuoAbstract:Lithium-oxygen batteries have an ultrahigh theoretical energy density, almost ten times higher than lithium-ion batteries. The poor conductivity of the Discharge product Li2 O2 , however, severely raises the charge overpotential and pulls down the cyclability. Here, a simple and effective strategy is presented for regular formation of lithium vacancies in the Discharge product via tuning charge/Discharge Mode, and their effects on the charge transfer behavior. The effects of the Discharge current density on the lithium vacancies, ionic conductivity, and electronic conductivity of the Discharge product Li2 O2 are systematically investigated via electron spin resonance, spin-alignment echo nuclear magnetic resonance, and tungsten nanomanipulators, respectively. The study by density functional theory indicates that the lithium vacancies in Li2 O2 generated during the Discharge process are highly dependent on the current density. High current can induce a high vacancy density, which enhances the electronic conductivity and reduces the overpotential. Meanwhile, with increasing Discharge current, the morphology of the Li2 O2 changes from microtoroids to thin nanoplatelets, effectively shortening the charge transfer distance and improving the cycling performance. The Li2 O2 grown in fast Discharge Mode is more easily decomposed in the following charging process. The lithium-oxygen battery cycling in fast-Discharge/slow-charge Mode exhibits low overpotential and long cycle life.