• Title, Summary, Keyword: plasma

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Analysis of characteristics of discharge in liquid

  • Kim, Ju-Sung;Min, Boo-Ki;Hong, Young-June;Kang, Seong-Oun;Choi, Eun-Ha
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.209.2-209.2
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    • 2016
  • Up to now, Plasma applications are thought as a leading technology in industrial, chemical and even medical and biological field. Especially, Due to direct discharge in liquid with reaction in ambient solution, plasma in liquid is useful plasma technology. Such as electro-surgery, water purification, radical generation for synthesis. For using those plasma applications efficiently, plasma characteristics should be understood in advance. But discharge in liquid is not much well-known about its characteristics. And plasma discharge in solution is difficult to generate and analysis due to electrolysis, vaporization and radical generation. So, We make stable plasma discharge in solution(saline 0.9%) without input gas. We also analyze new type of plasma source in thermal and electrochemical view. And we check characteristics of plasma in liquid. For example, plasma density and radical density(OH) with optical emission, thermal energy with thermometer, electrical energy with oscilloscope and so on. And we try to explain the bubble and plasma formation with circuit analysis.

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NEW APPLICATIONS OF R.F. PLASMA TO MATERIALS PROCESSING

  • Akashi, Kazuo;Ito, Shigru
    • Journal of the Korean institute of surface engineering
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    • v.29 no.5
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    • pp.371-378
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    • 1996
  • An RF inductively coupled plasma (ICP) torch has been developed as a typical thermal plasma generator and reactor. It has been applied to various materials processings such as plasma flash evaporation, thermal plasma CVD, plasma spraying, and plasma waste disposal. The RF ICP reactor has been generally operated under one atmospheric pressure. Lately the characteristics of low pressure RF ICP is attracting a great deal of attention in the field of plasma application. In our researches of RF plasma applications, low pressure RF ICP is mainly used. In many cases, the plasma generated by the ICP torch under low pressure seems to be rather capacitive, but high density ICP can be easily generated by our RF plasma torch with 3 turns coil and a suitable maching circuiit, using 13.56 MHz RF generator. Plasma surface modification (surface hardening by plasma nitriding and plasma carbo-nitriding), plasma synthesis of AIN, and plasma CVD of BN, B-C-N compound and diamond were practiced by using low pressure RF plasma, and the effects of negative and positive bias voltage impression to the substrate on surface modification and CVD were investigated in details. Only a part of the interesting results obtained is reported in this paper.

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Relationship between Dietary Fatty Acids, Plasma Lipids, and Fatty Acid Compositions of Plasma and RBC in Young Korean Females (한국 일부 여대생의 식이 지방산과 혈장지질, 혈장 및 적혈구 지방산 조성과의 관계)

  • 김양희
    • Journal of Nutrition and Health
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    • v.27 no.2
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    • pp.109-117
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    • 1994
  • This study was conducted to evaluate dietary fat intake and its effect on the plasma lipids and fatty acids composition in plasma and red blood cells(RBC) in 96 healthy Korean female college student. Three-day food intakes were recorded, and fasting blood samples were collected and analyzed for plasma total cholesterol and triglyceride. Fatty acid compositions were determined in plasma and RBC membrane. Oleic acid was the most abundant in diet, followed by palmitic and linoleic acids. Mean daily intake of cholesterol was 219$\pm$127mg, mean plasma cholesterol was 160$\pm$24mg/이 and mean plasma triglyceride was 68$\pm$25mg/dl. Plasma fatty acids were mostly composed of linoleic, palmitic and oleic acids, while palmitic, stearic and arachidonic acids were high in RBC membrane. Plasma triglyceride showed positive correlation with BMI. Among dietary fatty acids, arachidonic acid, EPA and DHA showed negative correlation with plasma total cholesterol. Plasma triglyceride levels were negatively correlated with dietary arachidonic acid, plasma n-6 fatty acids and plasma polyunsaturated fatty acids. Dietary EPA and DHA levels were positively correlated with plasma EPA, dietary n-3/n-6 ratio were positively correlated with plasma n-3 fatty acids and n-3/n-6 ratio. Highly significant correlations were shown between the levels in plasma and RBC for several fatty acids.

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Measurement of characteristics of plasma discharge in liquid

  • Kim, Ju-Sung;Min, Boo-Ki;Kang, Seong-Oun;Choi, Eun-Ha
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.153-153
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    • 2015
  • Application of the plasma is already highlighted as a new technology in the last few years. In these days, there are lots of attempt in various application with plasma in that it is known as an effective treatment to animal, plants, material and so on. Plasma in liquid, one of new plasma applications, has advantages in ability to treat bio-cell or solutions. For example, electro-surgery, water purification, radical generation and so on. Especially, plasma discharge in solutions is very useful technique and difficult to generate due to electrolysis, vaporization and something else. In this study, we have performed plasma discharge and checked sustainability of plasma in solution(saline 0.9%). And we have measured basic characteristics of plasma in liquid. Such as electrical energy and plasma density are calculated from discharging current and voltage. Also, its thermal energy is measured with IR camera.

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Cellular and Molecular Responses of a Filamentous Fungus Neurospora Crassa to Non-thermal Plasma at Atmospheric Pressure

  • Park, Gyung-Soon;Ryu, Young-Hyo;Hong, Young-June;Uhm, Han-Sup;Choi, Eun-H.
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.476-476
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    • 2012
  • Although plasma is an efficient means of microbial sterilization, mechanism of plasma effect on microorganisms still needs to be clarified. In addition, a limited number of studies are available on eukaryotic microorganisms such as yeast and fungi in relation to plasma application. Thus, we investigated cellular and molecular aspects of plasma effects on a filamentous fungus, Neurospora crassa by making use of argon plasma jet at atmospheric pressure. The viability and cell morphology of N. crassa spores exposed to plasma were both significantly reduced depending on the exposure time when treated in water. The intracellular genomic DNA content was dramatically reduced in fungal tissues after a plasma treatment and the transcription factor tah-3 was found to be required for fungal tolerance to a harsh plasma environment.

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Plasma Chemistry Data Research for Plasma Applications

  • Yoon, Jung-Sik
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.77-77
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    • 2012
  • As interest has increased in the interaction between low-temperature plasmas and materials, the role of modeling and simulation of processing in plasma has become important in understanding the effects of charged particles and radicals in plasma applications. Thus in this presentation, we present the theoretical and experimental studies of electron impact cross section for plasma processing gas, such as plasma etching and deposition processes. Also, here the work conducted at the Data Center for Plasma Properties (DCPP) over last 7 years on the systematic synthesis and assessment of fundamental knowledge on low-energy electron interactions with plasma processing gases is briefly summarized and discussed.

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Analysis of Biological Effect of DBD-type Non-thermal Atmospheric Pressure Plasma on Saccharomyces Cerevisiae

  • Park, Gyung-Soon;Baik, Ku-Yeon;Kim, Jung-Gil;Kim, Yun-Jung;Lee, Kyung-Ae;Choi, Eun-Ha;Uhm, Hwan-Sup;Jung, Ran-Ju;Cho, Kwang-Sup
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.337-337
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    • 2011
  • Application of plasma technology on microbial sterilization has been frequently studied. In spite of accumulating number of studies, many have been focused on bacteria. Reports on eukaryotic yeasts and filamentous fungi are limited. In addition, mechanism of plasma effect still needs to be clarified. In this study, we analyzed the effect of non-thermal atmospheric pressure plasma on the budding yeast, Saccharomyces cerevisiae using DBD-type device. When yeast cells were exposed to plasma (at 2 mm distance) and then cultured on YPD-agar plate, number of cells survived (shown as colony) were reduced proportionally to exposure time. More than 50% reduction in number of colonies were observed after twice exposure of 5min. each. Colonies much smaller than those of control (no plasma exposure) were appeared after twice exposure of 5 min. each. It seems that small colonies are resulted from delayed cell growth due to the damage caused by plasma treatment. Microscopic analysis demonstrates that yeast cells treated with plasma for 5 min. twice have more rough and shrinked shape compared to oval shape with smooth surface of control.

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Multi-hole RF CCP 방전에서 방전 주파수가 미치는 영향

  • Lee, Heon-Su;Lee, Yun-Seong;Seo, Sang-Hun;Jang, Hong-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.145-145
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    • 2011
  • Recently, multi-hole electrode RF capacitively coupled plasma discharge is being used in the deposition of microcrystalline silicon for thin film solar cell to increase the speed of deposition. To make efficient multi-hole electrode RF capacitively coupled plasma discharge, the hole diameter is to be designed concerning the plasma parameters. In past studies, the relationship between plasma parameters such as pressures and gas species, and hole diameter for efficient plasma density enhancement is experimentally shown. In the presentation, the relationship between plasma deriving frequency and hole diameter for efficient multi-hole electrode RF capacitively coupled plasma discharge is shown. In usual capacitively coupled plasma discharge, plasma parameter, such as plasma density, plasma impedence and plasma temperature, change as frequency increases. Because of the change, the optimum hole diameter of the multi-hole electrode RF capacitively coupled plasma for high density plasma is thought to be modified when the plasma deriving frequency changes. To see the frequency effect on the multi-hole RF capacitively coupled plasma is discharged and one of its electrode is changed from a plane electrode to a variety of multi-hole electrodes with different hole diameters. The discharge is derived by RF power source with various frequency and the plasma parameter is measured with RF compensated single Langmuir probe. The shrinkage of the hole diameter for efficient discharge is observed as the plasma deriving frequency increases.

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Plasma Engineering for Nano-Materials

  • Kim, Seong-In;Shin, Myoung-Sun;Son, Byung-Koo;Song, Seok-Kyun;Choi, Sun-Yong
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.79-79
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    • 2012
  • A high temperature and a low temperature plasma process technologies were developed and demonstrated for synthesis, hybrid formation, surface treatment and CVD engineering of nano powder. RF thermal plasma is used for synthesis of spherical nano particles in a diameter ranged from 10 nm to 100 nm. A variety of nano particules such as Si, Ni, has been synthesized. The diameter of the nano-particles can be controlled by RF plasma power, pressure, gas flow rate and raw material feed rate. A modified RF thermal plasma also produces nano hybrid materials with graphene. Hemispherical nano-materials such as Ag, Ni, Si, SiO2, Al2O3, size ranged from 30 to 100 nm, has been grown on graphene nanoplatelet surface. The coverage ranged from 0.1 to 0.7 has been achieved uniformly over the graphene surface. Low temperature AC plasma is developed for surface modification of nano-powder. In order to have a three dimensional and lengthy plasma treatment, a spiral type of reactor has been developed. A similar plasma reactor has been modfied for nano plasma CVD process. The reactor can be heated with halogen lamp.

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