• 한국광물학회지
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• 제27권4호
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• pp.293-299
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• 2014

고준위폐기물의 심지층 처분을 위해 완충재인 벤토나이트가 반드시 필요하고, 지하 환경에서 이 물질의 장기적 특성 변화를 아는 것은 매우 중요하다. 본 실험에서 폐기물 금속용기의 구리코팅 성분이 부식되면서 구리이온 농도가 증가한다고 가정하였을 때, 완충재인 벤토나이트 점토(몬모릴로나이트)의 층간 양이온들의 이온교환 및 용출 특성 등을 실험을 통해 살펴보았다. 용존 구리와 벤토나이트와의 반응실험에서 팽창성 점토의 Na가 선택적으로 먼저 Cu에 의해 치환되었고 Ca는 상대적으로 시간을 두고 이온교환되었다. 그리고 구리로 치환된 몬모릴로나이트는 X-선회절 분석결과 원시료에 비해 층간간격이 다소 줄어든 특징적인 비대칭 회절형태로 관찰되었다. 이러한 실험결과는 지하처분조건에서 고유 벤토나이트 성질의 점진적인 변화를 간접적으로 지시하는 것으로, 향후 다양한 추가실험을 통해 처분장 완충재의 화학적 광물학적 특성 변화를 연구할 계획이다.

• 한국수소및신에너지학회논문집
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• 제26권1호
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• pp.15-20
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• 2015

During the liquefaction of hydrogen, the ortho hydrogen is converted into the para form with heat release that evaporates the liquefied hydrogen into the gaseous one backwards. The ortho-para conversion catalysts are usually used during liquefaction to avoid such boil-off. In order to compare and analyze the performance of the ortho-para hydrogen conversion catalysts, in-situ FT-IR device was designed and manufactured to measure the para hydrogen conversion rate in real-time. $LaFeO_3$ and $La_{0.7}Sr_{0.3}Cu_{0.3}Fe_{0.7}O_3$ perovskite catalysts were prepared by the citrate sol-gel method and their spin conversion characteristics from ortho to para hydrogen were investigated by in-situ FTIR spectroscopy at 17K. It was found that the spin conversion was affected by surface area, particle size, and crystallite size of the catalysts. Thus, the $La_{0.7}Sr_{0.3}Cu_{0.3}Fe_{0.7}O_3$ perovskite catalyst that had higher surface area, higher crystallite size, and smaller particle size than $LaFeO_3$ showed the better spin conversion property of 32.3% at 17K in 120min interaction with the perovskite catalysts.

• 한국콘텐츠학회논문지
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• 제16권7호
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• pp.221-230
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• 2016

대다수의 국민은 부동산정책을 접할 때 정부의 보도자료 보다는 언론기사를 주로 접하며 정보를 얻는다. 하지만 이러한 정보는 언론사의 성향과 독자의 계층에 따라 다른 프레임으로 전달 될 수 있다. 언론사는 정부의 부동산 정책에 대하여 언론사의 성향에 따라 기대와 찬성 또는 우려와 비판의 프레임으로 기사를 보도한다. 따라서 어떤 성향의 언론보도를 접하느냐에 따라 국민의 부동산 정책에 대한 기대와 우려는 바뀌게 될 가능성이 있다. 본 연구에서는 정부의 부동산 정책이 언론사의 성향에 따라 어떤 프레임을 가지고 신문보도에 투영되는지 '부동산 3법에 대한 여야합의 및 국회통과'와 관련된 기사를 분석하여 살펴보았다. 분석결과 보수성향의 언론사는 부동산 3법의 국회통과에 대하여 긍정적 논조의 보도 및 정책에 대한 호의적 전망 프레임의 비율이 높았고, 진보성향의 언론사는 국회통과에 대한 중립적 또는 부정적 논조의 보도 및 정책에 대한 부정적 전망 프레임의 비율이 높은 것으로 나타났다. 이를 통하여 부동산 정책과 관련하여 여야가 합의한 사안이라 하더라도 보수와 진보로 구분되는 언론매체들 사이에 보도프레임에 대하여 차이가 존재하고 있다는 것을 확인하였다.

• 대한본초학회지
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• 제23권4호
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• pp.91-101
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• 2008

Objectives: In this study, we investigated the inhibitory effects of Ampelopsis Radix methanol(AR-M) extract on allergic inflammation in activated human mast cells and its potential therapeutic or toxic effects. Methods: Ampelopsis Radix(AR) was extracted with 80% methanol. HMC-1 cells, a human mast cell line, were treated with different concentrations of AR-M extract, and then stimulated with PMA plus A23187. The cell toxicity of AR-M extract was determined by MTT assay. The concentrations of $PGE_2$ and cytokines were measured by ELISA. The gene expression of COX-2 and its protein levels were determined by RT-PCR and Western blot. The phosphorylation of ERK MAPK and the NF-${\kappa}B$ activation were determined by Western blot. Results: AR-M extract was significantly inhibited the production of PGE2 and inflammatory cytokines(TNF-${\alpha}$, IL-6 and IL-8) in PMA/A23187-stimulated HMC-1 cells. AR-M extract also attenuated the mRNA expression of COX-2 and its protein induction. Furthermore, AR-M extract attenuated PMA/A23187-induced phophorylation of ERK1/2 MAPK and the NF-${\kappa}B$ p65 subunit translocation into nuclear of HMC-1 cells. AR-M extract significantly decreased PMN A23187-induced release of histamine in a dose-dependent manner. Conclusions: These results indicate that Ampelopsis Radix shows the property of anti-allergic inflammation In vitro through suppressing the production of inflammatory mediators released from mast cells, suggesting have a potential for the treatment of allergic diseases.

• 대한기계학회논문집
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• 제9권5호
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• pp.548-554
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• 1985

본 논문에서는 디이젤기관의 연소소음의 저감을 최종목표로 하여 Wiebe의 연 소함수에 의해 근사시킨 열발생속도의 변화가 디이젤기관의 연소소음 및 도시열효율에 미치는 영향에 관하여 수치실험을 통하여 해석검토하였다.

• 생약학회지
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• 제39권2호
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• pp.110-117
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• 2008

In this study, we investigated the anti-inflammatory effects of salidroside (SAL) isolated from the MeOH extract of Acer tegmentosum Maxim heartwood in RAW 264.7 macrophage cells. SAL pretreatment significantly inhibited nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) productions in the lipopolysaccharide (LPS)-induced RAW 264.7 cells. Western blot and RT-PCR analyses revealed that SAL inhibited the LPS-induced expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the protein and mRNA levels in a concentration-dependent manner. In addition, SAL reduced the release and the mRNA expressions of tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) and interleukin-6 (IL-6). Furthermore, nuclear factorkappa B ($NF{-\kappa}B$) luciferase reporter assay was performed to know the involvement of SAL in the production of pro-inflammatory cytokines, we confirmed that LPS-induced transcription activity of $NF{-\kappa}B$ was inhibited by SAL. Taken together, our data indicate that anti-inflammatory property of salidroside might be the result from the inhibition of iNOS, COX-2, $TNF-{\alpha}$ and IL-6 expressions via the down-regulation of $NF{-\kappa}B$ activity.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 연구회
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• pp.101-105
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• 2001

고압용 가교 Polyethylene 절연 케이블의 도체와 절연체 사이, 절연체와 외부 차폐층 사이에는 계면에서의 부분방전을 방지하고 전기적 스트레스를 완화할 목적으로 반도전층이 설계되어 있다. 이 반도전층의 성질은 케이블의 품질과 신뢰성에 매우 중요한 관련이 있다. 일반적으로 반도전층은 압출 성형하는데 Base Polymer에 다량의 카본블랙을 혼합하여 도전화 한다. 절연층과 반도전층간 계면의 평활도는 전력 케이블의 수명과 깊은 관계가 있는데 만약 평활도가 좋지 않으면 전기적 Stress 가 증가하여 전선 수명이 짧아진다. 계면 평활도를 나쁘게 하는 주 요인은 계면의 Void, 반도전층의 돌기와 이물, 탄화물 등이다. 반도전 Compound 제조에 있어서 Carbon Black의 선택과 분산성은 전선수명을 결정하는 중요한 요소이다.

• Macromolecular Research
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• 제12권4호
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• pp.399-406
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• 2004

Glass-like carbon precursors shrink significantly during curing and carbonization, which leads to crack formation and bending. Cured furan resin powder and ethanol were added to furan resin to diminish the weight loss, to suppress the shrinkage and bending, and to readily release the gases evolved during polymerization and curing. Curing and carbonization were controlled by pressure and slow heating to avoid damage to the samples. The effect of the filler and ethanol on the fabrication process was examined by measuring the properties of the glass-like carbon, such as the specific gravity, bending strength, electrical resistivity, and microstructural change. The specific gravities of the filler-added glass-like carbons were higher than those of the ethanol-added samples because of the formation of macropores from the vaporization of ethanol during the curing and polymerization processes. Although the ethanol-added glass-like carbons exhibited lower bending strengths after carbonization than did the filler-added samples, the opposite result was observed after aging at 2,600$^{\circ}C$. We found that the macropores created from ethanol were contracted and removed upon heat treatment. The electrical resistivity of the glass-like carbon aged at 2,600$^{\circ}C$ was lower than those of the samples carbonized at 1,000$^{\circ}C$. We attribute this phenomenon to the fact that aging at high temperature led to well-developed microstructures, the removal of macropores, and the reduction of the surface area.

• 대한화장품학회지
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• 제22권2호
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• pp.132-140
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• 1996

The effect of a novel delivery system, water in oil emulsion containing chitosan hydrogel as a inner phase (W/O-C) was evaluated, and the relationships between the skin permeation, the skin primary irritation and the skin turnover rate of AHAs were discussed. We selected glycolic acid (GA), lactic acid (LA), malic acid (MA), and tartaric acid (TA) as model AHAs. The steady state fluxes of 4 AHAs across the excised hairless mouse skin increased as the molecular weights of the AHAs decreased. (GA>LA>MA>TA). The skin turnover times were shortened in all AHAs, compared with control. The skin permeation and the skin primary irritation of the LA decreased and the skin turnover time increased, as the pH increased. The maximum therapeutic index was obtained with pH 3.8, 0.5 M LA. It was suggested that the skin permeability of LA might be a main factor for prediction of the skin irritation and the skin turnover time. On the other hand, the W/O-C containing pH 3.8, 0.5 M LA indicated a good sustained release property of LA, compared with water in oil emulsion without chitosan hydrogel (W/O) or oil in water emulsion (O/W). The skin permeability and the skin irritation of AHAs from the W/O-C edcreased, compared with W/O or O/W, however the skin turnover time showed almost the same value as W/O or O/W. In conclusion, we suggest that the control of the skin permeation of AHAs would be an important tool for reducing the skin irritation and for maintaining the positive effect of AHAs, and the W/O-C system could be a potential candidate for future cosmetological application of AHAs.

• Journal of Ginseng Research
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• 제36권1호
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• pp.68-77
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• 2012

In this study, we investigated the protective effects of processed Panax ginseng, sun ginseng (SG) against the UVB-irradiation on epidermal keratinocytes and dermal fibroblasts. Pretreatment of SG in HaCaT keratinocytes and human dermal fibroblasts reduced UVB-induced cell damage as seen by reduced lactate dehydrogenase release. We also found that SG restored the UVB-induced decrease in anti-apoptotic gene expression (bcl-2 and bcl-xL) in these cells, indicating that SG has an anti-apoptotic effect and thus can protect cells from cell death caused by strong UVB radiation. In addition, SG inhibited the excessive expression of c-jun and c-fos gene by the UVB in HeCaT cells and human dermal fibroblasts. We also demonstrated that SG may exert an anti-inflammatory activity by reducing the nitric oxide production and inducible nitric oxide synthase mRNA synthesis in HaCaT keratinocytes and human dermal fibroblasts. This was further supported by its inhibitory effects on the elevated cyclooxygenase-2 and tumor necrosis factor-${\alpha}$ transcription which was induced by UVB-irradiation in HaCaT cells. In addition, SG may have anti-aging property in terms of induction of procollagen gene expression and inhibition of the matrix metalloprotease-1 gene expression caused by UVB-exposure. These findings suggest that SG can be a potential agent that may protect against the dermal cell damage caused by UVB.