• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.1100-1103
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• 2004

The paper presents the results of using the fundamental and the low frequency harmonic components of leakage current to study aging of EPDM insulator for contaminated condition by kaolin. The largeer the leakage current during 200ms, the higher harmonic component at 60hz. The harmonic component at 60hz and the odd order harmonics is increase relation without Kaolin Conent. Arcing on the surface was always associated with distortion in the leakage current; hence the low frequency components of the leakage currnent can be used as a means to evaluate the surface degration. Both the fundamental and 3rd & 5th harmonics increase dry-band activity.

• 한방안이비인후피부과학회지
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• 제23권3호
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• pp.225-235
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• 2010

Background & Objective : Rejuvenate treatment with oriental medicine is popular these days. However, there are few reports about it. This study was performed to evaluate the effect of derma stamp treatment. Derma stamp is a new clinical equipment for Microneedle System. Methods : Restrospective study was conducted. Ten patients were treated for 5 weeks. Follow-up was performed after the treatment with Janus facial analysis system. Satisfaction degree was asked from the patients. Results and Conclusions : Derma stamp treatment was good for skin aging problems like pore, wrinkle, spot, sebum and porphyrin. Especially oily type had better effect than dry type.

• Journal of the Korean Wood Science and Technology
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• 제24권2호
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• pp.42-45
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• 1996

A residue from the newsprint waste was investigated as a filler in adhesive for bonding southern pine plywood. The residue was prepared by drying the wet residue to 8% moisture content and grinding the dry material using a laboratory Wiley mitt with a 75-${\mu}m$(200-mesh) screen. The residue was compared to a commercial filler commonly used in structural plywood adhesives. A total of 48 three-ply panels. 12.7mm nominal thickness and 0.3 by 0.3 m in size, were fabricated at two press times(4 and 5 min) and three assembly times(20, 40 and 60 min). Evaluations of the residue were carried out by performance tension shear tests after two 4-hour boil accelerated aging tests on plywood. The test results included tension shear strength and estimated wood failure values. All plywood made with the residue filler were comparable to the control-bonded plywood. These results indicate that residue from the newsprint waste streams would be suitable as filler for plywood adhesives.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1993년도 추계학술발표회논문집
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• pp.97-102
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• 1993

The application of epxy composite materials for the outdoor insulating systems has some significant advan-tages compared with conventional inorganic materials, that is low weight in combination with high mechanical strength, small dimensions and design versatility. The paper describes the results of high voltage investigations carried out different aging types of epoxy resin insulator and silicone grease coating. The insulators have been exposed 3000 hours to weather-o-meter and 12 months to outdoor. In this connection, the main study of paper is form the basis of develop-ment of principal technologies of epoxy composites which ard: (1)manufacturing of insulator, (2)high vol-tage testing under dry and wet condition, (3)mechani-cal properties, (4)accelerated weather-ometer test and outdoor exposed, artificial polution.

• 한국대기환경학회지
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• 제16권2호
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• pp.199-208
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• 2000

In this study we investigated on the possibility of platinum and silver catalysts as de-NOx catalyst for activity test of supported metal oxide catalysts. the study was performed with the change of amount of metal and support types. The catalyst was prepared the activity of alumina supported silver catalyst produced by dry and wet impregnation method respectively and the resistance of sulfur for optimum supported silver catalyst,. As a result the activity of alumina supported platinum catalyst was showed at low temperature region but the case of silver catalyst activated at high temperature region. So we finally chose alumina supported silver catalyst as de-NOx target catalyst because alumina supported catalyst showed higher activity than alumina supported platinum catalyst.

• E2M - 전기 전자와 첨단 소재
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• 제10권8호
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• pp.770-777
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• 1997

Some polymer materials including epoxy resin are being instead of porcelain for outdoor insulating materials such as insulators bushings cable terminators and surge arrester housing. And the largest problem to be overcomed is the tracking and erosion of the outdoor polymer material brought about by dry band arcing during prolonged exposure to contaminations. In this paper the effect of surface tension wettability flow rate of contaminants with varying surfactant content and frequency of applied voltage on the tracking breakdown of epoxy insulating materials were investigated. As the flow rate of contaminant is increased the surface resistivity is decreased and the leakage current is increased the time to tracking breakdown is decreased. It is found that time to tracking breakdown depends on the surface tension of contaminant that is difference of wettability. And as the frequency of applied voltage is increased time to tracking breakdown decreased.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.767-770
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• 2000

This study was investigated for searching a cause of flashover failure of polymer insulator and preparing countermeasures. Hydrophobicity, microstructure and chemical structural change of polymer weathershed were studied by polymer characterization methods. In addition, the electrical properties such as power frequency dry flashover voltage/impulse voltage tests, contamination characteristics were carried out. The hydrophobicity of polymer weathershed was decreased significantly and cracks were observed on the surface. Also, the electrical characteristics did not satisfy the KEPCO specification. The failed polymer insulators showed the more leakage current than 4 years service-aged ones. From the result, it can be concluded that the flashover failure of polymer insulator was attributed to the surface aging and severe contamination.

• Journal of Microbiology and Biotechnology
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• 제25권12호
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• pp.2160-2168
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• 2015

The beneficial effects of probiotics are now widely reported, although there are only a few studies on their anti-aging effects. We have found that Lactobacillus plantarum HY7714 (HY7714) improves skin hydration and has anti-photoaging effects, and in the present study, we have further evaluated the anti-aging effect of HY7714 via a randomized, double blind, placebo-controlled clinical trial. The trial included 110 volunteers aged 41 and 59 years who have dry skin and wrinkles. Participants took 1 × 10¹⁰ CFU/day of HY7714 (probiotic group) or a placebo (placebo group) for 12 weeks. Skin hydration, wrinkles, skin gloss, and skin elasticity were measured every 4 weeks during the study period. There were significant increases in the skin water content in the face (p < 0.01) and hands (p < 0.05) at week 12 in the probiotic group. Transepidermal water loss decreased significantly in both groups at weeks 4, 8, and 12 (p < 0.001 compared with baseline), and was suppressed to a greater extent in the face and forearm in the probiotic group at week 12. Volunteers in the probiotic group had a significant reduction in wrinkle depth at week 12, and skin gloss was also significantly improved by week 12. Finally, skin elasticity in the probiotic group improved by 13.17% (p < 0.05 vs. controls) after 4 weeks and by 21.73% (p < 0.01 vs. controls) after 12 weeks. These findings are preliminary confirmation of the anti-aging benefit to the skin of L. plantarum HY7714 as a nutricosmetic agent.

• 유기물자원화
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• 제10권2호
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• pp.132-139
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• 2002

본 연구는 디젤의 오염기간 및 토성이 콤포스팅 처리효율에 미치는 영향을 살펴보고자 실시하였다. 오염경과기간은 15일과 60일로 하였으며 대조실험으로 오염직후의 토양실험도 실시하였다. 연구에 사용된 토양은 실트질양토와 사토이었으며 대상오염물질은 디젤오일이었다. 초기오염농도는 건조질량기준으로 약 10,000mgTPH/kg으로 하였으며, 수분은 각 토성의 수분보유능력의 70%로 조절하였다. 유기물질 보충 및 미생물식종의 목적으로 하수슬러지를 첨가하였으며 토양대 슬러지 혼합비율은 습윤질량비로 1:0.3이었다. 휘발된 TPH양은 초기농도의 0.9-1.8%정도로써 디젤오염토양의 콤포스팅 적용시 디젤은 주로 생물학적인 요인에 의하여 제거되었다. 휘발에 의하여 손실되는 n-alkanes들은 대부분 C10~C17의 성분들이었으며, 특히 C10~C14까지의 성분들이 C15 이상의 성분들보다 휘발이 많이 되었다. 사토의 TPH에 대한 1차반응 분해속도상수 k값은 0.081-0.094/day로 실트질양토의 0.056-0.061/day보다 약 1.5배 정도 높았다. 오염경과기간의 영향을 살펴보면, 60일까지의 오염경과기간으로는 TPH 분해효율의 뚜렷한 차이를 발견할 수 없었다. 이산화탄소회수율은 0.61-0.89이었으며, TPH분해량과 이산화탄소발생량과의 상관계수는 0.90-0.96의 범위에 있었다.

• 한국환경농학회지
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• 제20권4호
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• pp.211-217
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• 2001

본 연구는 경작지 중금속 오염지역의 식물복원을 위한 방안으로, Zn, Cu처리가 담배식물의 생리반응에 영향하는 형태적인 변화와 엽령에 따른 중금속 축적 양상 및 무기이온의 흡수관계를 분석한 결과는 다음과 같다. Zn, Cu에 따른 간장의 생장감소는 1.0 mM이하에서는 작았고, 지상부 건물중보다는 지하부의 건물중을 크게 감소시켰다. 특히 지하부의 건물중은 약 50%가 감소하였다. Zn, Cu처리시 지상 ${\cdot}$ 지하부의 축적은 처리농도가 증가함에 따라 완만히 증가하다가 2.0 mM이상에서는 급격히 증가하였다. 엽령에 따라 Zn은 노화엽에서, Cu는 생장엽에서 축적량이 많았다. 주당 축적량은 2.0 mM에서 Zn은 146,000 mg/kg, Cu는 20,500 mg/kg이었고, 식물수확시기는 Zn은 영양생장기에 Cu는 생식생장기가 적합하였다. Zn, Cu처리에 따른 Mg, Mn, Fe함량은 처리농도가 증가할수록 감소하였다. 지상 ${\cdot}$ 지하부 모두 Zn처리구에서는 Cu함량은 감소하고, Cu처리구에서는 Zn함량은 증가하였다.