• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1530-1532
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• 1994

This paper describes the discharge characteristics of liquid nitrogen for plane-plane, needle-plane electrode at variation of gap spacing at atmospheric pressure. The important results obtained from this study are as follows. (1) Breakdown voltage of $LN_2$ for needle-plane electrode is higher than that of for plane-plane electrode and discharge duration tine is longer with increase of gap spacing at atmospheric pressure. (2) The formation of bubbles by evaporation is observed in spite of non-applying source at atmospheric pressure and the creation of corona confirmed for plane-plane electrode results from the bubbles. (3) The applied voltage-discharge magnitude( V-Q) characteristics of $LN_2$ showed hysteresis and the discharge magnitude decreasing and corona voltage increasing proportional to the pulse per second at atmospheric pressure.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.155.1-155.1
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• 2013

The goals of this study are to elucidate the plasma effects on DNA molecules to apply some plasma based applications and also to find out the mechanisms of plasma-induced DNA damage in biomolecule. Nonthermal atmospheric pressure plasma has much potential for medical, agricultural and food applications for the future. The atmospheric pressure plasma jet (APPJ) contains radicals, charged particles, low energy electrons, excited molecules and UV light. It has been started doing experiments using APPJ at the early 21th. And some recent results showed that APPJ has a possibility to apply to new fields like mentioned above. But it is kind of at the very early stages of plasma based application. It is definitely necessary much of theoretical and experimental studies to further understanding to use nonthermal atmospheric pressure plasma in biomedical, agriculture and food parts. Here we introduce a new experimental system to study plasma effects on biomolecules. And we will show some recent results of LEE-induced DNA damage using electron irradiation apparatus under ultra-high vacuum.

• Biomolecules & Therapeutics
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• v.22 no.6
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• pp.477-490
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• 2014

Non-thermal atmospheric-pressure plasma, also named cold plasma, is defined as a partly ionized gas. Therefore, it cannot be equated with plasma from blood; it is not biological in nature. Non-thermal atmospheric-pressure plasma is a new innovative approach in medicine not only for the treatment of wounds, but with a wide-range of other applications, as e.g. topical treatment of other skin diseases with microbial involvement or treatment of cancer diseases. This review emphasizes plasma effects on wound healing. Non-thermal atmospheric-pressure plasma can support wound healing by its antiseptic effects, by stimulation of proliferation and migration of wound relating skin cells, by activation or inhibition of integrin receptors on the cell surface or by its pro-angiogenic effect. We summarize the effects of plasma on eukaryotic cells, especially on keratinocytes in terms of viability, proliferation, DNA, adhesion molecules and angiogenesis together with the role of reactive oxygen species and other components of plasma. The outcome of first clinical trials regarding wound healing is pointed out.

• Applied Chemistry for Engineering
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• v.22 no.3
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• pp.261-265
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• 2011

The sterilization effects of atmospheric pressure plasma with the mixture of argon and oxygen were analyzed. The plasma reactor with the shape of dielectric barrier discharge produced the uniform distribution of glow discharge and generated ozone gas effectively according to the various process parameters. The sterilization for E. coli was affected by power, oxygen ratio in the mixture gas, treatment time and distance between reactor and sample. The concentration of ozone was a major source for the sterilization of E. coli, which was enhanced by the increase of power and oxygen ratio. In this study, the effect of atmospheric pressure plasma treatment for the sterilization was confirmed and its result can deliver the atmospheric pressure plasma treatment as the novel sterilization method instead of conventional methods.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1444-1446
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• 2009

The atmospheric pressure plasma polymerization of acrylate monomers was carried out to have dielectrics with easy preparation and high performance. The effects of discharge power, monomer concentration and deposition time on film properties were investigated using various characterization tools. With proper conditions, smooth dielectric layer of 100nm thickness was obtained. Dielectric property as organic dielectric layer has been studied for future applications in organic thin film transistors(OTFT).

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.880-886
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• 2010

In this study, volatile compounds in liquor distilled from mash produced using koji or nuruk under reduced or atmospheric pressure were analyzed and eventually, the proper starter material and distillation method was selected. Acetaldehyde was detected two or three times more in the liquor distilled under the atmospheric pressure than under the reduced pressure. Furfural was only detected in the liquor distilled under the atmospheric pressure. Esters were detected more in the liquor distilled under the atmospheric pressure than the reduced pressure. Ethyl pelargonate and 2-phenyl ethanol were particularly detected two times more in the liquor distilled under the atmospheric pressure than the reduced pressure. Methanol was detected two times more in the liquor made with nuruk than that with koji. These results suggest that the liquor distilled from the mash produced using koji under the reduced pressure may have the better quality.

• Ocean and Polar Research
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• v.30 no.4
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• pp.453-466
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• 2008

In order to examine the generation mechanism of long ocean waves along the west coast of Korea and to understand the amplification process of the long ocean waves, sea level, atmospheric pressure and wind data observed every minute from 2007 March 29 to 2007 April 1 were analyzed and onedimensional numerical ocean model experiments were performed. An atmospheric pressure jump propagated southeastward from Backryungdo to Yeonggwang along the west coast of Korea with speed of $13{\sim}27\;m/s$ between 2007 March 30 23:00 and 2007 April 1 1:30. Average magnitude of pressure jump was 4.2 hPa. As a moving atmospheric jump propagated from north to south along the coast, long ocean waves were generated and the sea level abnormally rose or fell at Anheung, Kunsan, Wido and Yeonggwang. Average amplitude of sea level rise (or fall) was about 113.6 cm. In a one-dimensional numerical ocean model, nonlinear shallow water equations were numerically integrated and a moving atmospheric pressure jump with traveling speed of 24 m/s was used as an external force. While the atmospheric pressure jump travels over 60 m depth ocean, a long ocean wave is generated. Because the propagation speed of the atmospheric jump is almost equal to that of the long ocean wave, Proudman resonance occurs and the long ocean wave amplifies. As the atmospheric pressure jump moves into the coastal area shallower than 60 m, the speed of the long ocean wave decreases and Proudman resonance effect decreases. However, the amplitude of the long ocean wave increases and wave length becomes shorter because of shoaling effect. When the long ocean wave hits the land boundary, amplitude of the long ocean wave drastically amplifies due to reflection. Data analysis and numerical experiments suggest that the southeastward propagation of an atmospheric pressure jump over the shallow ocean, which is a necessary condition for Proudaman resonance, generated the long ocean waves along the west coast of Korea on 2007 March 31 and the ocean waves amplified due to shoaling effect in the coastal area and reflection at the shore.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.56.2-56.2
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• 2015

Nonthermal Atmospheric Pressure Plasmas and their Applications to Plasma Bioscience and Medicines have been introduced for next generation human healthcare's quantum developments. Various kinds of nonthermal atmospheric pressure plasmas have been introduced and their electron temperature and plasma densities along with reactive oxygen and nitrogen species have been diagnosed and analyzed for biological cell interactions, especially, used in Plasma Bioscience Research Center (PBRC), Korea. Herein, we have also introduced the plasma-initiated ultraviolet photolysis, which might be a generation mechanism for the reactive oxygen and nitrogen species (RONS) intracellular and extracellular regions inside the liquid when the plasma has been bombarded onto the water. Finally we have investigated the interactions of these RONS with the various cancer cells resulting in apoptotic cell death.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.2 s.173
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• pp.448-454
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• 2000

This study was undertaken to investigate tribological characteristics with atmospheric pressure for three alumina ceramics of different purity, such as, 85 %, 95 % and 99.7 %. The wear test was carried out using the wear test device which was designed for this study in air, $10^-2$ Torr and $10^-4$ Torr. The friction coefficient depends entirely on atmospheric pressure and alumina with lower purity than higher purity has been much affected by heat accumulation. The friction surface of ceramics have been protected in the air by the influence of the oxides transferred from STB2. However, the protective layer can not be formed due to the decrease of oxygen in vacuum.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1993.10a
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• pp.58-62
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• 1993

This paper shows the discharge characteristics of liquid nitrogen under plane to plane electrode, needle to plance electrode, inserting teflon insulator in plane to plane electrode at atmospheric pressure. The main experimental device of this paper is cryostat. The important results obtained from this study are sa follows. Breakdown voltage of LN2 under N-P electrode is higher than that of under P-P electrode at atmospheric pressure. Breakdown duration time is longer with increase of electode gap under the P-P, N-P electrodes. The formation of bubbles by evaporation is observed in spite of non-applying source at atmospheric pressure and the creation of corona confirmed. Breakdown voltage and breakdown duration time are in proportion to increase of diameter in case of inserting teflon insulator. Partial discharge characteristics of thickness 0.5[mm] is that 채굼 voltage of teflon insulator rose with increase of diameter in each [pps].