• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.2
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• pp.70-77
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• 2012

The selective catalytic reduction(SCR) system used to reduce NOx in diesel engines requires an NO/$NO_2$ ratio of about 1 in exhaust emissions to realize the fast SCR mode at temperatures lower than $300^{\circ}C$. This study investigated the characteristics of a plasma system as a pre-active apparatus for the fast SCR reaction mode of an SCR system. Plasma was generated by the pulse corona discharge(PCD) method with a four-channel wire-cylinder reactor. This study showed that plasma was easily generated in the exhaust gas by the PCD system, and the peak voltage of the normal state condition for plasma generation was generally 12 kV. The PCD system easily converted NO into $NO_2$ at lower temperatures and the NO/$NO_2$ conversion ratio increased with the discharge current for plasma generation. But the PCD system could not convert NO into $NO_2$ at higher engine speeds and higher engine loads due to the lack of oxygen in exhaust gas. The PCD system also activated the diesel oxidation catalysts(DOC) system to reduce CO emissions.

• Medical Lasers
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• v.8 no.1
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• pp.28-31
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• 2019

Superficial fungal infections with dermatophytes, nondermatophyte molds, or yeasts are treated primarily with topical and/or systemic antifungal agents. Additional or alternative treatment modalities, particularly energy-delivering modalities, however, are used widely to induce fungicidal effects via selective photothermal reactions. In addition to light- or laser-based devices, plasma therapy also has antifungal properties. This report describes a Korean male patient with mycologically confirmed tinea pedis that was treated effectively with two sessions of nitrogen plasma treatment at one-week intervals using a plasma delivering system. Nitrogen plasma was prepared by loading a 0.28-ml inert nitrogen gas/pulse that was activated by a microwave generator. The other treatment settings were a nozzle diameter of 5 mm, pulse energy of 0.75 J, pulse duration of 7 msec, and two passes. One week after the first session of nitrogen plasma treatment, the patient exhibited marked reductions in scale and inflammation. One month after the final treatment, no clinical features of recurrence were found, and successive potassium hydroxide testing revealed negative results.

• Journal of the Korean Society of Combustion
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• v.8 no.1
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• pp.9-16
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• 2003

Carbon soot emission from combustion processes, especially from diesel engines, is a subject of growing concern since soot is known to seriously affect human health. Efforts have been made to oxidize soot particles utilizing Non-Thermal Plasma(NTP) techniques. When oxygen is carried into a plasma device, electrons generated by the plasma dissociate the oxygen, resulting in the formation of oxygen atoms. These highly activated atoms, called O radicals, are known as strong oxidizing agent. This paper presents concentration variations of CO and $CO_2$ at the exit of the plasma device, resulting from the soot oxidation by O radicals, with variations of inlet oxygen concentration, gas temperature, and gas flow rate. Based on the data, Arrehenious rate constants of reactions between C(s)+O and C(s)+O+O were proposed.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2892-2897
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• 2008

Plasma techniques have been proposed to generate a hydrogen enrich gas to investigate a feasibility of plasma techniques on a fuel reforming, we considered a dry reforming and a partial oxidation with methane in the atmospheric pressure. For these experiments, we employed an arc jet plasma reactor. The effects of input power and oxidizer in each process were investigated by product analysis, including carbon monoxide, hydrogen, ethylene, propane, and acetylene as well as methane and carbon dioxide. In both processes, input electrical power activated the reactions significantly. The increased ratio of the carbon dioxide to methane in the dry reforming doesn't affect to a methane conversion, whereas increased ratio of oxidizer to methane in the partial oxidation was very effective for the reaction. Moreover, for a simultaneous treatment of methane and carbon dioxide, a feasibility of a dry reforming combined with partial oxidation also has been investigated.

• Korean Journal of Poultry Science
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• v.29 no.1
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• pp.13-18
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• 2002

This study was conducted to investigate the effects of dietary activated coconut charcoal (ACC) on Performance, e99 quality and Plasma cholesterol level of Plasma in laying hens. One hundred forty four, 47-wk-old, ISA Brown commercial layers were used in a 28-d feeding trial after a 7-d adjustment Period. Four dietary treatments were 0, 0.5, 1.0 and 1.5e% levees of ACC supplemented to a corn-soybean meal basal diet. Egg Production was significantly increased as the levels of ACC increased. However, egg weight was significantly decreased by the addition of ACC in diets. Egg shell breaking strength tended to decrease as the level of ACC increased, however, no significance was found in this respect. As the levels of ACC increased, egg shell thickness decreased significantly. Although not significant, yolk color tended to increase by the addition of ACC. Egg folk index were significantly increased by the addition of ACC In diet. No significant difference was found among four treatments in total cholesterol, HDL cholesterol, and LDL+VLDL cholesterol concentrations in plasma. In conclusion, dietary supplementation of ACC to layer diets could be used to increase egg Production, and yolk index.

• Applied Chemistry for Engineering
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• v.33 no.6
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• pp.624-629
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• 2022

Formaldehyde is an indoor pollutant that is harmful to humans, such as causing respiratory and skin diseases. Nitrogen plasma treatment was performed to introduce nitrogen groups on the surface of the activated carbon fibers (ACFs), and the adsorption characteristics of formaldehyde for the surface-modified ACFs were considered. As the nitrogen gas flow rate increased, the content of nitrogen functional groups introduced to the surface of the ACFs increased by about 7%, and the ratio of nitrogen functional groups to each type present was similar. Ultramicropores increased on the ACFs surface due to the etching effect of plasma treatment. The adsorption efficiency of formaldehyde on the modified ACFs surface was also enhanced. However, under the nitrogen flow rate of 120 sccm or more, the surface of the ACFs was excessively etched, and the specific surface area and the formaldehyde adsorption capacity decreased. Therefore, the content of the nitrogen groups is the main factor in the adsorption of formaldehyde on the nitrogen plasma-treated ACFs, but it can be found that the adsorption efficiency of formaldehyde is improved when the ACFs have a suitable pore structure.

• Journal of the Korean Vacuum Society
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• v.17 no.2
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• pp.113-116
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• 2008

As the integration in semiconductor display develops, semiconductor process becomes multilayer. In order to form several layer patterns, etching process which uses photoresistor (PR) must be performed in multilayer process. Repeated etching processes which take long time and PR residue cause mortal problems in semiconductor. To overcome such problems, we studied about the solution which eliminates PR effectively by using normal dry and wet etching method using plasma activated PR strip solvent in liquid condition. At first, we simulate the device which activates the plasma and make sure whether gas flow in device is uniform or not. Under activated plasma, etching effect is elevated. This improvement reduces etching time as well as display production time of semiconductor process. Generally, increasing etching process increases environmental hazards. Reducing etching process can save the etchant and protect environment as well.

• Clinics in Shoulder and Elbow
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• v.21 no.1
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• pp.3-14
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• 2018

Background: Platelet-rich plasma (PRP) stimulates cell proliferation and enhances matrix gene expression and synthesis. However, there have been no comparative study of the PRP effect on the normal and degenerative tenocytes. The purpose of this study was to compare the effect of PRP on tenocytes from normal and degenerative tendon. Methods: Tendon tissues were obtained from patients undergoing arthroscopic repair (n=9) and from healthy donors (n=3). Tenocytes were cultured with 10% (vol/vol) platelet-poor plasma, PRP activated with calcium, and PRP activated with calcium and thrombin. The total cell number was assessed at days 7 and 14. The expressions of type I and III collagen, decorin, tenascin-C, and scleraxis were evaluated by quantitative real-time reverse transcriptase polymerase chain reaction. The total collagen and glycosaminoglycan (GAG) synthesis was evaluated at days 7 and 14. Results: No differences were observed between the groups at day 7, but cell proliferation was remarkably increased in tenocytes from the degenerative tendon at day 14. In both tenocyte groups, the gene expressions of type I and III collagen were up-regulated. GAG synthesis was greater in the normal tendon, whereas the expressions of decorin and tenascin-C were increased in tenocytes from the degenerative tendon. Tenocytes from the degenerative tendon had higher fold-change of GAG synthesis and a lower collagen III/I ratio than normal tenocytes. Conclusions: PRP promoted the cell proliferation and enhanced the synthesis of tendon matrix in both groups. PRP has a greater positive effect on cell proliferation, matrix gene expression and synthesis in tenocytes from degenerative tendon.

• Carbon letters
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• v.9 no.1
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• pp.23-27
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• 2008

The adsorption and reduction of Cr (VI) to Cr (III) by surface modified activated carbon (AC) in an aqueous solution was studied. The effects of surface modifications on the properties of the carbons were investigated by the analysis of specific surface area, carbon surface pH, acid/base surface values and functional groups. In order to understand the Cr(VI) adsorption and reduction ratio from Cr(VI) to Cr(III), the Cr adsorption capacity of AC was also measured and discussed by using inductively coupled plasma and UV spectrophotometer. The modifications bring about substantial variation in the chemical properties whereas the physical properties such as specific surface area, pore volume and pore size distribution nearly were not changed. Total Cr adsorption efficiency of as-received activated carbon (R-AC) and nitric acid treated activated carbon (N1-AC and N2-AC) were recorded on 98.2, 99.7 and 100%. Cr(III) reduction efficiency of R-AC increased largely from 0.4% to 28.3% compared to N1-AC and N2-AC.

• Journal of the Korean Vacuum Society
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• v.18 no.2
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• pp.97-101
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• 2009

In the modem semiconductor industry, the progress that consumes the most capital and labor is cleansing process. Cleansing process is to remove impurities that can affect the operation of the device and deteriorate its function. Especially, Photoresist (PR) progress that etches the device always requires cleansing at the end of the progress. Also, HDI-PR (High-Dose Ion-implanted Photoresist) created from PR progress is difficult to remove. Thus, in modem IC cleansing, many steps of cleansing are used, including dry and wet cleansing. In this paper, we suggested to combine existing dry-cleansing and wet-cleansing, each represented by plasma cleansing and stripper solution, as Plasma Liquid-Vapor Activation (PLVA). This PLVA method enhances the effect of existing cleansing solution, and decreases the amount of solution and time required to strip. We stripped HDI-PR by activated solution and measured surface hardness and Young's modulus by Nano-indenter. Nano-indenter is the equipment that determines the hardness and the modulus of elasticity by indenting nano-sized tip with specific shape into the surface and measuring weight and z-axis displacement. We measured the change of surface hardness and Young's modulus before and after the cleansing. As a result, we found out that the surface hardness of the sample sharply decreased after the cleansing by plasma-activated PR stripper solution. It can be considered that if physical surface-cleansing process is inserted after this, more effective elimination of HDI-PR is possible.