• Textile Coloration and Finishing
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• v.17 no.5 s.84
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• pp.26-36
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• 2005

This study was carried to evaluate mechanical characteristics of Poly(ethylene terephthalate) fabrics (by Kawabata evaluation system(KES)) which was systematically treated with $O_2$ low temperature plasma and chitosan acetate solution. Furthermore, surface structure was investigated by SEM, AFM, air permeability and wettability. Tensile energy(WT), shear rigidity(G) and surface roughness(MIU) properties calculated by KES-FB have increased with increasing plasma treatment time, while bending rigidity(G) and energy of compression(WC) value were decreased compared with those of the untreated. SEM photographs showed the identification of chitosan coating but did not confirm the plasma etching structure. Air permeability was decreased according to plasma treatment time with increasing concentrations of chitosan. The water absorption rate made rapid progress by chitosan treatment.

• Food Science of Animal Resources
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• v.33 no.3
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• pp.317-324
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• 2013

Radio-frequency driven atmospheric pressure plasma using argon gas was studied in the inactivation of Campylobacter jejuni in order to investigate its applicability. First, the inactivation study was conducted on an agar surface. C. jejuni NCTC11168 was reduced by more than 7 Log CFU after an 88 s treatment. Another strain, ATCC49943, was studied; however, the inactivation was less efficient, with a 5 Log CFU reduction after a 2 min treatment. Then, chicken breast ham was studied at the $10^6$ CFU inoculation level. The inactivation efficiency was much lower for both strains compared to that on the agar plates. C. jejuni NCTC11168 and ATCC49943 were reduced by 3 Log CFU after a 6 min treatment and by 1.5 Log CFU after a 10 min treatment, respectively. The scanning electron microscopy analysis indicated that C. jejuni cells were deformed or transformed into coccoid form under the plasma treatment. During the plasma treatment, the temperature of the samples did not rise above $43^{\circ}C$, suggesting that heat did not contribute to the inactivation. Meanwhile, water activity significantly decreased after a 10 min treatment (p<0.05). This study conveyed that radio-frequency atmospheric pressure plasma can effectively inactivate C. jejuni with strain-specific variation.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.6
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• pp.624-632
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• 2010

Perfluorocarbons (PFCs) are widely used in semiconductor industry. These gases need to be removed efficiently because of their strong absorption of infrared radiation and long atmospheric lifetimes which cause the global warming effect. To destruct $CF_4$, a waterjet gliding arc plasma was designed and manufactured. The highest $CF_4$ destruction showed at waterjet plasma case, compared to plasma discharge only or water scrubber only, respectively. In addition, it could be known that the $CF_4$ destruction should be associated with the electron and OH radicals. The operating conditions such as waterjet flow rate, initial $CF_4$ concentration, total gas flow rate, specific energy input were investigated experimentally using a plasma waterjet scrubber. Through the parametric studies, the highest $CF_4$ destruction of 94.5% was achieved at 0.2% $CF_4$, 2.1 kJ/L SEI, 20 L/min total gas flow rate and 18.5 mL/min waterjet flow rate.

• Applied Chemistry for Engineering
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• v.21 no.1
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• pp.98-103
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• 2010

The effect of plasma treatment on surface characteristics of polycarbonate (PC) films was investigated using low pressure plasma and atmospheric pressure plasma with oxygen and argon. Untreated PC has a contact angle of $82.31^{\circ}$ with de-ionized water which reduced to $9.17^{\circ}$ as the lowest value after being treated with a low pressure plasma treatment with oxygen. Increase of delivered powers such as RF and AC with a high frequency and gas flow rates was not effective to reduce contact angles dramatically but gave the trend of reducing gradually. The surface of PC treated with plasma shows a low contact angle but the contact angle increases rapidly according to the exposure time in air ambient. Oxygen plasma was more effective to generate the polar functional group regardless of the type of plasma. Conclusively, a low plasma treatment with oxygen is more recommendable when the hydrophilic surface of PC is required.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.544-545
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• 2013

Recently, low-temperature atmospheric-pressure plasmas have been investigated [1,2] for biomedical applications and surface treatments. Experiments for improving hydrophilicity of stainless steel (SUS 304) plate with atmospheric microwave argon and H2O2 mixture plasma jet [3] were carried out and experimental measurements and plasma simulations were conducted for investigating the characteristics of plasma for the process. After 30 s of low power (under 10 W) and low temperature (under $50^{\circ}C$) plasma treatment, the water contact angle decreased rapidly to around $10^{\circ}$ from $75^{\circ}$ and was maintained under $30^{\circ}$ for a day (24 hours). The surface free energy, calculated from the contact angles, increased. The chemical properties of the surface were examined by X-ray Photoelectron Spectroscopy (XPS) and the surface morphology and roughness were examined by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) respectively. The characteristics of plasma sources with several frequencies were investigated by Optical Emission Spectroscopy (OES) measurement and one-dimensional Particle-in-Cell (PIC) simulation and zero-dimensional global simulation [4]. The relation between plasma components and the efficacy of the surface modification were discussed.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.250.2-250.2
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• 2014

Currently, teeth whitening method which is applicable to dental surgery is that physician expertises give medical treatment to teeth directly dealed with a high concentration of hydrogen peroxide and carbamide peroxide. If hydrogen peroxide concentration is too high for treatment of maximized teeth whitening effect [1], it is harmful to the human body [2]. To the maximum effective and no harmful teeth whitening effect in a short period of time at home, we have observed the whitening effect using carbamide peroxide (15%) and a low-temperature atmospheric pressure plasma jet which is regulated by the Food and Drug Administration. The gas supplied conditions of the non-thermal atmospheric pressure plasma jet was with the humidified (0.6%) gas in nitrogen or air at gas flow rate of 1000 sccm. Also, the measurement of chemical species from the jet was carried out using the optical emission spectroscopy (OES), the evidence of increased reactive oxygen species compared to non-humidified plasma jet. We have found that the whitening effect of the plasma is very excellent through this experiment, when bovine teeth are treated in carbamide peroxide (15%) and water vapor (0.2 to 1%). The brightness of whitening teeth was increased up to 2 times longer in the CIE chromaticity coordinates. The colorimetric spectrometer (CM-3500d) can measure color degree of whitening effect.

• Archives of Pharmacal Research
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• v.21 no.6
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• pp.651-656
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• 1998

A sensitive high-performance liquid chromatographic (HPLC) method for the determination of aloesin in plasma was developed. After solid-phase extraction from plasma and derivatization of aloesin and compound AD-1, which was prepared from aloesin as a internal standard, with 9-anthroylnitrile in the presence of quinuclidine, the derivatives were separated on a Inertsil ODS-3 column using acetonitrile/methanol/water (3:1:6) as a mobile phase, and detected fluorimetrically at 460nm with excitation at 360nm. The detection limit of aloesin was 3.2ng/ml in plasma (S/N=3).

• Biomolecules & Therapeutics
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• v.1 no.2
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• pp.204-210
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• 1993

The distribution and excretion of DWC-751, a new cephalosporin, were examined in rats and mice following a single intravenous administration. DWC-751 in plasma and urine was determined by both HPLC and microbiological assay. The plasma concentration of the drug declined biexponentially. The initial and terminal half lives of the drug were 3.0 and 28.3 min, respectively. Binding of the drug to plasma proteins was 42.3%. The distribution volume at steacly-state ($Vd_{ss}$) was only 0.341 ι/kg, which is well correlated with the low n-octanol/water partition coefficient of the drug ($K_{o/w{\cong}0$) Actually, the drug was distributed to liver, kidney and lung with very low organ/plasma concentration ratio. The drug, was excreted mainly via renal excretion, i.e., the total($CL_T$) and apparent renal($CL_{R}$) clearances of the drug were 10.8 and 7.5 ml/min/kg, respectively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.1
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• pp.78-81
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• 2008

A hollow cathode which has extremely stable discharge characteristic has been developed. This is composed of the two separated lanthanum hexaboride(LaB6) of a disk type in the tube as the electron emitters. The way of design is of great advantage to extend the surface discharge area of the LaB6, which is also useful for optimal fixing of the LaB6. The hollow cathode is capable of producing 30 kW(100 V, 300 A) of power continuously. Because the generated plasma beam with the high temperature(above $3000^{\circ}C$) from the hollow cathode passes through the center hole of the two intermediate electrodes, it is designed with the high temperature material of the tungsten and the suitable structure of the water cooling. The combinations of the hollow cathode and the two intermediate electrodes are practically useful for the ion plating plasma beam source.

• Korean Journal of Environmental Biology
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• v.21 no.4
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• pp.352-357
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• 2003

Phenanthrene, one of Polycyclic aromatic hydrocarbons with three aromatic rings, is a ubiquitous contaminant in the environment. Phenanthrene has been identified in ambient air, drinking water and sediment. We examined the effect of phenanthrene on steroid hormones level of olive flounder, Paralichthys olivaceus. Plasma testosterone level was increased significantly in fish exposed to phenanthrene($\geq1.0 \mu M$) at 4th week. However, there was no significant changes of estradiol-17$\beta$ concentration in fish exposed to phenanthrene. The physiological variation in phenanthrene exposed fish was a dramatic increase in plasma cortisol level. It is concluded that chronic exposure of phenanthrene can induce increase of plasma testosterone levels and elevate the plasma cortisol level in flounder, Paralichthys olivaceus.