• YAKHAK HOEJI
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• v.38 no.2
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• pp.123-130
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• 1994

Physicochemical properties and hydrolysis kinetics of new some oral cephalosporins were examined in buttered solution and human plasma or rat liver homogenate. The test cephalosporins were 7-[(Z)-2-(2-aminothiazole-4-yl)-2- methoxyiminoacetamido]-3-[4-(2-pyridyl)piperazinyl] thiocarbonylthhiomethyl-3-cephem-4-carboxylic acid (CEN1), 7-[(Z)-2-(2-aminoth iazole-4-yl)-2-methoxyiminoacetamido]-3-[4-(2-pyrimidyl)piperazinyl]th iocarbonylthiomethyl-3-cephem-4-carboxylic acid (CEN2), pivaloyloxymethyl-7-[ (Z)-2-(2-aminothiazole-4-yl)-2-methoxyiminoacetamido]-3-[4-(2-pyridyl)piperazi nyl]thiocarbonylthiomethy1-3-cephem-4-carboxylate (CEN1P), and pivaloyloxymethyl-7-[(Z)-2-(2-aminothiazole-4-yl)-2-methoxyiminoacetamido]-3-[ 4-(2-pyrimidyl)piperazinyl]thiocarbonyl-thiomethyl-3-cephem-4-carboxylate (CEN2P). The partition coefficient(Ko/w) of CEN1P, CEN2P were higher than those of CEN1, CEN2. The calculated pKa values of CEN1, CEN2, CEN1P, and CEN2P were 7.09, 7.75, 4.92, and 5.39, respectively. The hydrolysis of CEN1P and CEN2P were not depend on the composition of pH of the test medium except weak alkaline buffered solution (pH 8.00). CEN1 and CEN2 were very stable in pH 6.80 and 8.00 buffer solutions. CEN1P and CEN2P were rapidly deesterified to CEN1 and CEN2 in human plasma and in rat liver homogenate. Half-lives$(t_{1/2})$ of CEN1 and CEN2 were 3.49 and 4.93 hr in human plasma, 1.47 and 1.26 hr in rat liver homogenate, respectively.

• Korean Journal of Veterinary Research
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• v.36 no.1
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• pp.75-82
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• 1996

Erythrocyte sedimentation rate is influenced by plasma protein, red cell itself and physiological conditions and it is clear that the measurement of erythrocyte sedimentation rate varies with technique and various environmental factors. The effect of temperature, angle of test tube, and osmobility with different percent of NaCl solution on erythrocyte sedimentation rate on sheep was determined by modified Westergren method. In sheep, as the angle of Westergren tube was decreased from $90^{\circ}$ to $45^{\circ}$, erythrocyte sedimentation rate was increased in both diluted plasma and NaCl solutions. As temperature was increased from $4^{\circ}C$ to $20^{\circ}C$ at $45^{\circ}$ angle. erythrocyte sedimentation rate was increased. In ruminants, this modified Westergren methods, erythrocyte 1 : plasma 9 instead of erythrocyte 4 : plasma 6(whole blood), enable them to have meanings as dog therefor, using this method, clinical can determine the erythrocyte sedimentation rate of ruminants for diagnosis. Because erythrocyte sedimentation rate was changed according to the angle of Westergren tube, temperature as erythrocyte diluted with NaCl, this study detected that the change of temperature, the angle of Westergren tube could change erythrocyte sedimentation rate by effecting red cell itself. The increase of osmobility owing to change of NaCl percent resulted in the decrease of rapid erythrocyte sedimentation rate. So this fact indicate that deformibility and the change of red cell volume have meaning in the change of erythrocyte sedimentation rate.

• Polymer(Korea)
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• v.36 no.1
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• pp.65-70
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• 2012

Glycidyl methacrylate (GMA) was used to introduce epoxy groups on the surface of polypropylene (PP) plate, used as a substrate, through plasma-induced graft copolymerization. Emulsion polymerization was applied for graft copolymerization of GMA and was compared with conventional solution polymerization to confirm its effect. Plasma treatment conditions under one atmospheric pressure were fixed as follows; the RF power of 200 W, the treatment time of 30 sec, the Ar gas flow rate of 6 LPM, and the exposure time of treated PP samples in air of 5 min. For graft-copolymerization, GMA concentration, reaction temperature, and reaction time was optimized to maximize the grafting degree of GMA. The maximum grafting degree of GMA was obtained at the condition of 12%-GMA concentration, $90^{\circ}C$ reaction temperature, and 5 hr-reaction time. Analysis results supported that the emulsion polymerization was more effective than the solution polymerization for grafting more GMAs on the surface of PP plate under the same reaction conditions.

• Journal of the Korean Ceramic Society
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• v.32 no.11
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• pp.1301-1307
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• 1995

Pitting corrosion of TiN film deposited on Inconel 600 by plasma assisted chemical vapor deposition (PACVD) was investigated. Cyclic potentiodynamic polarization (CPP) tests were conducted in order to determine the pit nucleation potentials, Enp, of the TiN-deposited sample and the bare Inconel 600 in deaerated NaCl solution at 25, 135 and 20$0^{\circ}C$. The effects of the TiN film thickness, the solution temperature and the Cl- concentration on Enp were studied. Enp of the TiN-deposited sample which had the film thickness above 1${\mu}{\textrm}{m}$ were higher than those of the bare Inconel 600 by 300~600mV at all the solution temperatures, implying the pitting resistance improvement of the TiN film. The morphologies of the pits generated after immersion test were examined with a scaning electron microscopy. The higher was the solution temperature, the more corrosion products, mainly composed of Cr and Ni oxides, were formed.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2001.11a
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• pp.29-30
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• 2001

This paper presents some results of plasma nitriding on hard chromium deposit. The substrates were C45 steel and $30~50{\;}\mu\textrm{m}$ of chromium deposit by electroplating was formed. Plasma nitriding was carried out in a plasma nitriding system with $95NH_3{\;}+{\;}SCH_4$ atmosphere at the pressure about 600 Pa and different temperature from $450^{\circ}C{\;}to{\;}720^{\circ}C$ for various time. Optical microscopy and X-ray diffraction were used to evaluate the characteristics of surface nitride layer formed by nitrogen diffusion from plasma atmosphere inward iCr coating and interface carbide layer formed by carbon diffusion from substrate outward Cr coating. The microhardness was measured using microhareness tester at the load of 100 gf. Corrosion resistance was evaluated using the potentiodynamic measurement in 3.5% NaG solution. A saturated calomel electrode (SiCE) was used as the reference electrode. Fig.1 shows the typical microstructures of top surface and cross-section for nitrided and unnitrided samples. Aaer plasma nitriding a sandwich structure was formed consisting of surface nitride layer, center chromium layer and interface carbide layer. The thickness of nitride and carbide layers was increased with the increase of processing temperature and time. Hardness reached about 1000Hv after nitriding while 900Hv for unnitrided hard chromium deposit. X-ray diffraction indicated that surface nitrided layer was a mixture of $Cr_2N$ and CrN at low temperature and erN at high temperature (Fig.2). Anodic polarization curves showed that plasma nitriding can greatly improve the corrosion resistance of chromium e1ectrodeposit. After plasma nitriding, the corrosion potential moved to noble direction and passive current density was lower by 1 to 4 orders of magnitude compared with chromium deposit(Fig.3).

• Journal of the Korean institute of surface engineering
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• v.54 no.6
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• pp.365-370
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• 2021

In this research, we proceeded with research on plasma resistance of the cleaning process of APS(Atmospheric Plasma Spray)-Y₂O₃ coated parts used for semiconductor and display plasma process equipment. CF₄, O₂, and Ar mixed gas were used for the plasma environment, and respective alconox, surfactant, and piranha solution was used for the cleaning process. After APS-Y₂O₃ was exposed to CF₄ plasma, the surface changed from Y₂O₃ to YF₃ and a large amount of carbon was deposited. For this reason, the plasma corrosion resistance was lowered and contamination particles were generated. We performed a cleaning process to remove the defect-inducing surface YF₃ layer and carbon layer. Among three cleaning solutions, the piranha cleaning process had the highest detergency and the alconox cleaning process had the lowest detergency. Such results could be confirmed through the etching amount, morphology, composition, and accumulated contamination particle analysis results. Piranha cleaning process showed the highest detergency, but due to the very large thickness reduction, the base metal was exposed and a large number of contaminated particles were generated. In contrast, the surfactant cleaning process exhibit excellent properties in terms of surface detergency, etching amount, and accumulated contamination particle analysis.

• Journal of Microbiology and Biotechnology
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• v.29 no.9
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• pp.1401-1411
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• 2019

Mycobacterial cell walls comprise thick and diverse lipids and glycolipids that act as a permeability barrier to antibiotics or other chemical agents. The use of OH radicals from a non-thermal plasma jet (NTPJ) for the inactivation of mycobacteria in aqueous solution was adopted as a novel approach. Addition of water vapor in a nitrogen plasma jet generated OH radicals, which converted to hydrogen peroxide ($H_2O_2$) that inactivated non-pathogenic Mycobacterium smegmatis and pathogenic Mycobacterium tuberculosis H37Rv. A stable plasma plume was obtained from a nitrogen plasma jet with 1.91 W of power, killing Escherichia coli and mycobacteria effectively, whereas addition of catalase decreased the effects of the former. Mycobacteria were more resistant than E. coli to NTPJ treatment. Plasma treatment enhanced intracellular ROS production and upregulation of genes related to ROS stress responses (thiolrelated oxidoreductases, such as SseA and DoxX, and ferric uptake regulator furA). Morphological changes of M. smegmatis and M. tuberculosis H37Rv were observed after 5 min treatment with $N_2+H_2O$ plasma, but not of pre-incubated sample with catalase. This finding indicates that the bactericidal efficacy of NTPJ is related to the toxicity of OH and $H_2O_2$ radicals in cells. Therefore, our study suggests that NTPJ treatment may effectively control pulmonary infections caused by M. tuberculosis and nontuberculous mycobacteria (NTM) such as M. avium or M. abscessus in water.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.4
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• pp.538-546
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• 2008

Large-type goats eating dry forage secreted large volumes of saliva which resulted in the loss of $NaHCO_3$ from the blood and decreased plasma volume (hypovolemia). This research investigated whether or not the loss of $NaHCO_3$ from the blood and hypovolemia brought about by dry forage feeding actually depresses feed intake in large-type goats under free drinking conditions. The present experiment consisted of three treatments (NI, ASI, MI). All treatments in this experiment were carried out under free drinking conditions. In the NI control (NI), a solution was not infused. In the ASI treatment, i.v. infusion of artificial saliva was initiated 2 h before feeding and was continued for a total of 3 h concluding 1 h after the commencement of the feeding perod. In the MI treatment, mannitol solution was infused to replenish only water lost from the blood in the form of saliva. The hematocrit and plasma total protein concentrations during feeding in the NI control were observed to be higher than pre-feeding levels. This indicated that dry forage feeding-induced hypovolemia was caused by the accelerated secretion of saliva during the initial stages of feeding in freely drinking large-type goats. Increases in hematocrit and plasma total protein concentrations due to dry forage feeding were significantly suppressed by the ASI treatment. While hematocrit during feeding in the MI treatment was significantly lower than the NI control, plasma total protein concentrations were not different. From these results, it is clear that the MI treatment was less effective than the ASI treatment in mitigating the decreases in plasma volume brought about by dry forage feeding. This indicates that plasma volume increased during dry forage feeding in the ASI treatment which inhibited production of angiotensin II in the blood. The ASI treatment lessened the levels of suppression on dry forage feeding, but the MI treatment had no effect on it under free drinking conditions. The results indicate that despite the free drinking conditions, increases in saliva secretion during the initial stages of dry forage feeding in large-type goats caused $NaHCO_3$ to be lost from the blood into the rumen which in turn caused a decrease in circulating plasma volume and resulted in activation of the renin-angiotensin system and thus feeding was suppressed.

• Journal of the Korean Ceramic Society
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• v.46 no.3
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• pp.295-300
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• 2009

The crystal structure of surface coatings on Al1050 alloy by PEO (Plasma Electrolytic Oxidation), were investigated. The electrolyte for PEO was Na-Si-P system solution. The main crystalline phase were $\gamma$-alumina and $\alpha$-alumina. Crystallinity was increased with applied voltage and applied time. The dominant crystalline phase were affected not only chemical composition of Al alloy substrate and electrolyte, but also the +/- ratio of applied voltage.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.6
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• pp.59-65
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• 2012

This paper presents a digital control solution which can extract the reactor parameters in atmosphere plasma power supply. The critical issue of the atmosphere plasma power supply is a impedance matching. For the impedance matching, the reactor parameters should be known, but the parameters depend on the reactors. Therefore, the reactor parameters have to measure for the impedance matching. The proposed method is performed by detection of phase difference between inverter voltage and current, and extraction of impedance through active, reactive power.