• ANNALS OF ANIMAL RESOURCE SCIENCES
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• v.30 no.2
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• pp.69-78
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• 2019

The objective of this study was to investigate the quality properties of sausages added with the atmospheric pressure plasma treated extract of Perilla frutescens Britton var. acuta Kudo (red perilla). The lyophilized powder of red perilla extract treated by atmospheric-pressure plasma contained 7.5 g kg^-1 nitrite. Sausage samples were manufactured with the addition of sodium nitrite (Control), celery powder (Celery), or plasma-treated extract of red perilla (PTP) to obtain nitrite concentration of 70 mg kg^-1. The residual nitrite content was the lowest in PTP during storage for 21 days at 4℃ (p<0.05). The total aerobic bacteria counts were higher in PTP than in Control and Celery during storage at 4℃ (p<0.05). Malondialdehyde content of sausages was significantly lower in PTP than in Control and Celery during storage (p<0.05). PTP showed the lowest L^* value and the highest b^* value among the tested sausage samples during storage (p<0.05). PTP received the low scores in all the sensory properties of sausages because of its inherent color and flavor. The results suggested that the plasma-treated extract of red perilla was an unsuitable natural nitrite source for cured meat products because of its adverse effect on sensory quality. However, natural nitrite source with increased nitrite content can be produced by the treatment of the natural plant extract with atmospheric-pressure plasma.

• Journal of Surface Science and Engineering
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• v.39 no.3
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• pp.142-146
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• 2006

A novel internal-type linear inductive antenna, which we refer to as a double comb-type antenna, was developed for a large-area plasma source with substrate size of $880\;mm{\times}660\;mm$ ($4^{th}$ generation glass size). In this study, effect of plasma confinement by applying multi-polar magnetic field was investigated. High density plasmas of the order of $3.18{\times}10^{11}\;cm^{-3}$ could be obtained with a pressure of 15 mTorr Ar at an inductive power of 5000 W with good plasma stability. This plasma density is higher than that obtained for the conventional double comb-type antenna, possibly due to the plasma confinement, low rf voltage, resulting in high power transfer efficiency. Also, due to the remarkable reduction in the antenna rf voltage and length, a plasma uniformity of less than 3% could be obtained within a substrate area of $880\;mm{\times}660\;mm$ as rf power increased.

• The Korean Journal of Physiology
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• v.23 no.2
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• pp.253-261
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• 1989

Responses of atrial natriuretic peptide (ANP), aldosterone and renin release to acute volume expansion were compared in normotensive Wistar and spontaneously hypertensive rat (SHR) fed low or high-sodium diet (2 or 25 mmol Na/100 g diet). Experimental diets were fed for 6 weeks from 7-week-old and the growth rate was similar in all groups. In the morning of the experiment, catheters were inserted under ether anesthesia in femoral artery for pressure recording and blood collection, femoral vein for saline infusion, and bladder for urine collection. Then, the rats were placed in restraining cages. When the rats were recovered from anesthesia and the arterial pressure became stabilized, control urine and blood samples were collected. Then, 0.9% saline was infused for 30 min for volume expansion (3% BW). Arterial pressure was significantly higher in the high-sodium SHR but there was no difference between the two groups of Wistar rats. Control plasma levels of Na, K, ANP, renin activity, and hematocrit were not different among the 4 groups. However, plasma aldosterone level was significantly higher in the low-sodium groups. Wistar low-sodium rats showed approximately two times higher plasma aldosterone level than the SHR counterpart. Volume expansion produced a marked increase in plasma ANP level, especially in the high-sodium groups. The low-sodium groups of both strains showed approximately two-fold increase in plasma ANP level. Following a volume expansion plasma aldosterone level and renin activity decreased in all groups. There was a significant logarithmic positive correlation between plasma renin activity and aldosterone concentration. The low-sodium rats produced a greater increase in aldosterone release by small increase in plasma renin than did the high-sodium rats. The low- and high-sodium rats produced a similar degree of diuresis and natriuresis after volume expansion. However, SHR produced a greater natriuresis than did the Wistar rats. The above results indicate that regulatory mechanisms of ANP, aldosterone and renin release are different between the normotensive and hypertensive rats, and between the low- and high-sodium groups.

• Textile Coloration and Finishing
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• v.5 no.4
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• pp.29-41
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• 1993

In order to surface Hydrophobilization of Poly(ethylene terephthalate) (PET) fiber samples were treated in the atmosphere of CF$_{4}$ or $C_{2}$F$_{6}$glow discharge. The sample used in this study was PET film which is 75$\mu$m thick made by Teijin, O-Type(Japan). The cleaned samples were placed in plasma reactor made of pyrex glass cylinder, and plasma processing was carried out by glow discharge of CF$_{4}$ or $C_{2}$F$_{6}$ gas, being continuously fed by gas flow and continuously pumped out by a vacuum system. Electric power source for generate plasma state was sustained alternating current(60Hz) and voltage was sustained 600 volt. The duration of plasma treatment varied from 15 to 120 seconds except special case, the monomer gase pressure varied from 0.02 to 0.3 Torr and power range was 10 to 90 watts. The hydrophobic features of changed PET surface were evaluated by contact angle measurement and surface chemical characteristics were analyzed by ESCA. Results can be summerized as follows. 1. The most favorable setting position of substrate was the center area between the two electrodes. 2. $C_{2}$F$_{6}$ discharge current was lower than that of CF$_{4}$ when same voltage was sustained. Treated efficiency between CF$_{4}$ and $C_{2}$F$_{6}$ did not revealed significant differences under same electric power(wattage). 3. When monomer pressure is very low below 0.02 torr, as though substrate is exposed to CF$_{4}$ or $C_{2}$F$_{6}$ plasma, it tend to be hydrophilic through a little of fluorine bond and a great deal of oxidizing reaction. 4. There brought good hydrophobilization when monomer pressure was more 0.1 torr and duration of glow discharge treatment was over 45 seconds. When monomer pressure was too high, discharge current became low. Although prolong the duration, there was no more high hydrophobilization. 5. According to ESCA analysis, there were a little CF bond and a prevailing CF$_{2}$ bond in CF$_{4}$-treated substrate. There were CF$_{3}$, a little CF and a prevailing CF$_{2}$ bond in $C_{2}$F$_{6}$-treated substrate.d substrate.

• Korean Journal of Materials Research
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• v.19 no.3
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• pp.132-136
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• 2009

This study investigates GaAs dry etching in capacitively coupled $BCl_3/N_2$ plasma at a low vacuum pressure (>100 mTorr). The applied etch process parameters were a RIE chuck power ranging from $100{\sim}200W$ on the electrodes and a $N_2$ composition ranging from $0{\sim}100%$ in $BCl_3/N_2$ plasma mixtures. After the etch process, the etch rates, RMS roughness and etch selectivity of the GaAs over a photoresist was investigated. Surface profilometry and field emission-scanning electron microscopy were used to analyze the etch characteristics of the GaAs substrate. It was found that the highest etch rate of GaAs was $0.4{\mu}m/min$ at a 20 % $N_2$ composition in $BCl_3/N_2$ (i.e., 16 sccm $BCl_3/4$ sccm $N_2$). It was also noted that the etch rate of GaAs was $0.22{\mu}m/min$ at 20 sccm $BCl_3$ (100 % $BCl_3$). Therefore, there was a clear catalytic effect of $N_2$ during the $BCl_3/N_2$ plasma etching process. The RMS roughness of GaAs after etching was very low (${\sim}3nm$) when the percentage of $N_2$ was 20 %. However, the surface roughness became rougher with higher percentages of $N_2$.

• Journal of the Korean Vacuum Society
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• v.8 no.4A
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• pp.397-402
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• 1999

The base pressure of the vacuum vessel of KSTAR tokamak is to be ultra high vacuum, $10^{-6}\sim10^{-7}Pa$, to produce a clean plasma with low impurity concentrations. For this purpose, vessel and plasma facing components need to be baked up to $250^{\circ}C$, $350^{\circ}C$ respectively to remove impurities from the plasma-material interaction surfaces. Here the required heating power to be supplied for baking has been calculated according to pre-assumed different temperature profiles (baking scenario and proper baking plan for KSTAR tokamak has been proposed. Mass flow rate and temperature of nitrogen gas for baking has also been calculated.

• Nuclear Engineering and Technology
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• v.56 no.9
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• pp.3961-3968
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• 2024

The Korea Atomic Energy Research Institute (KAERI) is developing a novel Two-Region Arc Plasma Ion Source (TRAP) as a negative hydrogen (deuterium) ion source for a Neutral Beam Injection (NBI) system in a fusion tokamak. The TRAP ion source is based on a two-region configuration, comprising a high energy electron region that creates highly vibrationally excited molecules and a low electron temperature region that generates negative ions by attaching electrons to molecules. This configuration can be achieved by optimizing the filament position and magnetic cusp field. In order to optimize the TRAP configuration, the plasma parameters are investigated under various operating conditions, such as filament position, gas pressure, and arc power. Electron density and temperature are determined using Langmuir probe measurements. In this paper, the detailed experimental results are described and discussed.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.270-270
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• 2012

Low temperature atmospheric pressure plasmas (APPs) have been known to be effective for living cell inactivation in the water [1]. Many earlier research found that pH level of the solution was changed from neutral to acidic after plasma treatment. The importance of the effect of acidity of the solution for cell treatments has already been reported by many experiments. In addition, several studies have demonstrated that the addition of a small amount of oxygen to pure helium results in higher sterilization efficiency of APPs [2]. However, it is not clear yet which species are key factors for the cell treatment. To find key factors, we used GMoo simulation. We elucidate the processes through which pH level in the solution is changed from neutral to acidic after plasma exposure and key components with pH and air variation with using GMoo simulation. First, pH level in a liquid solution is changed by He+ and He(21S) radicals. Second, O3 density decreases as pH level in the solution decreases and air concentration decreases. It can be a method of removing O3 that cause chest pain and damage lung tissue when the density is very high. H2O2, HO2 and NO radicals are found to be key factors for cell inactivation in the solution with pH and air variation.

• The Korean Journal of Ceramics
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• v.7 no.1
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• pp.20-25
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• 2001

PbTiO$_3$ thin films were prepared by low-pressure thermal plasma deposition on (100)Pt/(100)MgO substrates. Mist of source material in which metal alkoxides are dissolved in 2-methoxyethanol was introduced into plasma through heating furnace and deposited onto substrates at $600^{\circ}C$. As-deposited PbTiO$_3$/Pt/MgO thin film prepared at 1.33$\times$10$^4$ Pa was grown epitaxially, but was consisted of many rectangular shaped grains, with many grain boundaries and it was impossible to measure electric properties. As-deposited film prepared at 1.00$\times$10$^4$ Pa showed weak peaks of X-ray diffraction and the film was not grown epitaxially. On the other hand, the film after annealed at $700^{\circ}C$ showed strong diffraction peaks and epitaxial growth was also observed. For annealed film, moreover, no clear grain boundaries were observed. The value of ${\varepsilon}_r$, tan${\delta}$, Pr and Ec of annealed film were 160, 3.2%, 10.4${\mu}$C.cm$^-2$ and 51.2kV.cm$^-1$, respectively. Since the composition, Pb/Ti, measured by EDS attaching to SEM changed point by point, the distribution of composition in annealed film was investigated and found out several relations between composition and electric properties. At stoichiometric composition, Pr and Ec showed the lowest value and they gradually became large as composition deviated from stoichiometric one. Moreover, the value of ${\varepsilon}_r$ became gradually large as the ratio of Ti became high.

• Journal of the Korean Vacuum Society
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• v.22 no.2
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• pp.55-65
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• 2013

Sterilization of Neurospora crassa has been investigated in this research by using a surface air plasma with dielectric barrier discharged (DBD) structure under atmospheric pressure. The sinusoidal alternating current has been used in this experiment with discharge voltage of 1.4~2.3 kV. The phase difference between the voltage and current signals are found to be almost 80 degree due to the capacitive property of dielectric barrier. Temperature on the biomaterials has been minimized by radiating the heat with the air cooling system. It is noted that the substrate temperature remains under 37 degree for plasma exposure time of 10 minutes with operation of cooler system. It is found that the ozone, $O_3$, has been measured to be about 25~30 ppm within 1 cm region and to be about 5 ppm at the 150 cm downstream region away from the suface plasma. It is also noted that the nitric oxide, NO, and nitric dioxide, $NO_2$, are not nearly detected. Germination rate and mitochodrial activity of Neurospora crassa immersed in the deionized water have been found to be drastically decreased as the plasma treatment time and its electrical power are increased in this experiment. Here, the mitochondrial activity has been analyzed by MTT (3-(4,5-dimethy lthiazol-2yl)-2,5-diphenyl-2H-tetrazolium bromide) assay. However, sterilization of Neurospora crassa immersed in the Vogel's minimal media has been found to be low by plasma treatment, which is caused by surrounding background solution. This research shows the sterilization possibility of Neurospora crassa by using the noncontated surface DBD plasma, which is different from the plasma jet. This is mainly attibuted to the reactive species generated by the surface plasma, since they play a major role for inhibition of micobes such as Neurospora crassa.