• 한국식품저장유통학회지
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• 제4권3호
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• pp.251-258
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• 1997

The quality changes of strawberries packaged using low density polyethylene (LDPE) film filled with 3% silver-coated ceramic (WC30) and filled with it and 0.1% chitin (CWC) were investigated during storage at 2$0^{\circ}C$ for 5 days. In gas composition within film bag, CWC and WC30 kept higher CO2 concentration than LDPE without silver-coated ceramic and chitin (CO) did during 5 day storage. The weight loss of strawberries during storage was the smallest in WC30 and the largest in CWC in 5 days. Hardness of strawberries was the highest in WC30 and the lowest in CO during 5 day storage. pH of strwberries was increased a little until 1 day and was not changed after 1 day storage, and soluble solid content was not changed during storage. Vitamin C content was decreased significantly until 2 day storage and decreased a little after 2 days. There is no differences in the change of vitamin C content among the packaging materials. In color measurement, lightness was the highest in WC 30 and in sensory evaluation, all characteristics also had the highest scores in WC30. In conclusion, better quality of straberries was shown in WC30 than in CWC and CO during storage.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1427-1429
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• 2001

Polycrystalline silicon(poly-Si) films are deposited on low temperature glass substrate by Hot-Wire CVD(HWCVD). The structural properties of the poly-Si films are strongly dependent on the wire temperature($T_w$). The films deposited at high $T_w$ of 2000$^{\circ}C$ have superior crystalline properties; average lateral grain sizes are larger than $1{\mu}m$ and there at·e no vertical grain boundaries. The surface of the high $T_w$ samples are naturally textured like pyramid shape. These large grain size and textured surface are believed to give high current density when applied to solar cells. However, the poly-si films are structurally porous and contains high defect density, by which high concentration of C and O resulted within the films by air-penetration after removed from chamber.

• 한국화재소방학회논문지
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• 제25권5호
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• pp.69-75
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• 2011

수산화마그네슘을 첨가한 저밀도 폴리에틸렌-에틸렌 비닐 아세테이트 복합체의 연소성을 시험하였다. 저밀도 폴리에틸렌-에틸렌 비닐 아세테이트에 수산화마그네슘을 40~80 wt% 첨가하여 용융 혼합하고 성형 후 콘칼로리미터(ISO 5660-1)를 이용하여 연소성을 시험하였다. 수산화마그네슘을 첨가한 시편은 첨가하지 않은 시험편에 비하여 그의 플래시오버 가능성이 감소하였다. 이것은 순수한 저밀도 폴리에틸렌-에틸렌비닐 아세테이트에 첨가한 수산화마그네슘의 흡열 분해 때문에 연소 억제성이 향상된 것으로 생각된다. 수산화마그네슘을 첨가한 시험편은 첨가하지 않은 시험편에 비해 낮은 총열방출량과 낮은 CO 발생량을 나타내었고, 수산화마그네슘 함량이 증가할수록 총연기발생량과 비소화면적이 감소하였다.

• 동의생리병리학회지
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• 제22권5호
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• pp.1309-1314
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• 2008

This study was undertaken to elucidate the antioxidant activity of the ethanol (EEPB) and water (WEPB) extracts of Prunus persica branches. The extracts contained a high phenolic content and revealed a potent hydrogen donating activity in DPPH scavenging assay. Compared to $\alpha$-tocopherol, EEPB (p < 0.001) and WEPB (p < 0.05) significantly inhibited $FeCl_2$-ascorbic acid-induced lipid peroxidation, and also exhibited potent antiradical activities against hydroxyl radical, superoxide anion, nitric oxide and peroxynitrite. In copper- and AAPH-mediated human low-density lipoprotein (LDL) oxidation systems, the extracts demonstrated a strong antioxidant function by metal chelating, rather than direct scavenging, action. Furthermore, EEPB at 5 ${\mu}g/mL$ concentration showed 80.77% inhibition of the electrophoretic mobility of LDL, compared to 77.69% for ascorbic acid and 76.92% for BHT. These results suggest that PB branch extracts may protect against oxidative stress-induced diseases.

• 경영과학
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• 제30권1호
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• pp.91-102
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• 2013

This study has an aim to analyze the effects of ADS on conjunctivitis patients among the residents of Seoul, Korea, between 2005 and 2008. For this purpose, the number of medical services provided to conjunctivitis patients on the days of windblown dust storms and the days without any windblown dust storms were analyzed by conducting paired t-test. The interactive effects of the ADS density and the accuracy of ADS forecast on the fluctuation of conjunctivitis cases were also investigated. The results showed that, even with an accurate forecast issued 24 hours prior to the event, the average number of medical services provided for conjunctivitis was higher on the index days than the comparison days. On the other hand, in cases of failure to provide an accurate forecast 24 hours prior to the ADS event, the number of conjunctivitis attacks reported was statistically significantly higher on the index days for 3~5 days after the occurrence of a dust storm in relation to the comparison days. We also found that the rate of increase in asthma treatments on the index days with low level of $PM_{10}$ concentration rather than high $PM_{10}$ level was more significant for all lag days. This study provides evidence that ADS events are significantly associated with conjunctivitis symptoms and the failure to forecast ADS events with low $PM_{10}$ level might aggravate conjunctivitis disease.

• 한국식품영양과학회지
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• 제27권4호
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• pp.675-681
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• 1998

Low density polyethlene(LDPE0 films of 50${\mu}{\textrm}{m}$ thickness were fabricated with addition of antimicrobial agents of Rheum palmatum extract, Coptis chinensis extract, sorbic acid and Ag-substitude inorganic zirconium matrix in 1% concentration. The films were compared in physical properties, tested in antimicrobial activity against some selected microorganisms on the agar plate medium and then applied for packaging fresh curled lettuce and cucumber to preserve their qualities. The films with Rheum palmatum extract, Coptis chinensis extract, and Ag-substituted inorganic zirconium matrix did not show any antimicrobial activity on the disk test against Escherichia coli, Staphylococcus aureus, Leuconostoc mesenteroides, Saccharomyces cerevisiae, Aspergillus niger, Aspergillus oryzae, Penicilluium chrysogenum, while film with sorbic acid did against E. coli, S. aureus and L. mesenteroides. The added antimicrobial agents changed the color and light transmittance of the films, but did not affect their mechanical tensile strength, heat shrinkage and wettability. For the packaged curled lettuce and cucumber stored at 5$^{\circ}C$ and 1$0^{\circ}C$, all the LDPE films impregnated with antimicrobial agents showed the reduced growth of total aerobic bacteria in the vegetables compared with control film without any additive until it reached the level around 108/g. They did not give any negative effect on other quality attributes during storage.

• 한국세라믹학회지
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• 제38권11호
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• pp.973-979
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• 2001

Sn을 도핑한 In$_2$O$_3$(ITO) 박막을 R.F. 마그네트론 반응성 스퍼터링법에 의해서 증착하였다. 동일한 마그네트론 스퍼터링 조건에서 증착위치에 따른 ITO 박막의 저항, 자유 전하 농도 및 이동도 전기적 특성을 조사하였다. 동일한 마그네트론 스퍼터링 조건임에도 불구하고, ITO 박막의 전기적 특성은 증착위치에 따라 불균질성을 나타내었다. 타겟의 중심에 위치한 기판위에 증착된 ITO 박막의 저항은 최소 값인 2~4$\times$$10^{-4}$ $\Omega$.cm인 반면, 중심에서 멀어질수록 박막의 전기 저항은 대칭적으로 증가하였다. ITO 박막의 밀도 측정 결과도 중심에서 이론 밀도 값의 97%에 해당하는 7.0g/$cm^3$를 나타내나, 위치가 중심에서 멀어질수록 박막의 밀도가 대칭적으로 감소하였다. ITO 박막에서 이동도와 전도도는 밀도에 직접적으로 영향을 받는 것이 실험적으로 확인되었다. ITO 박막의 밀도가 7.0g/$cm^3$(이론 밀도의 97%)인 경우, 자유행정거리와 입자크기(=주상의 직경)가 동일한 값을 가지나, 밀도가 이 보다 감소하면 자유행정거리와 입자크기의 차이는 더욱 증가하였다. 이 결과는 ITO 박막의 밀도가 7.0g/$cm^3$인 경우는 입계가 자유 전자의 전도에 중요한 산란 원으로 작용하는 반면, 그 외의 경우는 결정 내의 공격자점, 공공, 기공 등이 다른 산란 원으로 작용하고 있다는 것을 나타낸다.

• 한국습지학회지
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• 제14권2호
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• pp.255-263
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• 2012

하천은 다양한 환경을 가지며 수생생물의 주 서식처로서의 역할을 한다. 식물성 플랑크톤의 분포는 pH, 질소, 인과 같은 수환경에 의해 영향을 받는다. 식물성 플랑크톤의 분포와 수환경간의 관계를 밝히기 위하여, 서울의 도림천 상류 10곳에서 pH, $NO_3{^-}$와 $PO{_4}^{3-}$의 농도 그리고 식물성 플랑크톤을 조사하였다. pH는 5.05 ~ 7.56의 범위에 있었으며, $NO_3{^-}$와 $PO{_4}^{3-}$의 농도는 0.4 ~ 4.9ppm와 0.02 ~ 0.99ppm의 범위에 있었다. 서울대학교로부터 $PO{_4}^{3-}$이 유입되는 것으로 확인되었지만 그 농도는 그리 높지 않았으며, 400m 정도 지나면 거의 모두 정화되었다. $NO_3{^-}/PO{_4}^{3-}$ 비율은 유입되는 $PO{_4}^{3-}$의 영향을 받는 곳을 제외하면 28 ~ 152의 범위로 나타났다. pH, $NO_3{^-}$, $PO{_4}^{3-}$의 농도는 하류로 갈수록 증가하였으며, 이는 한강 본류에서 끌어온 물의 유입뿐만 아니라 비점 오염원으로부터의 유입과 관련되었다. 일반적으로 $NO_3{^-}$의 농도가 3.5ppm 보다 높아지면 식물성 플랑크톤의 밀도가 급격히 증가하였으며, $PO{_4}^{3-}$의 경우는 농도가 0.07ppm 이상이 되어야 증가하는 것으로 나타났다. $NO_3{^-}/PO{_4}^{3-}$ 비율이 50 이상일 때 식물성 플랑크톤의 밀도는 낮게 나타났다.

• 대한한의학회지
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• 제21권4호
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• pp.193-203
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• 2000

Objectives : Hindered barrier function of vascular endothelium has been implicated in the initiation and progression of degenerative vascular diseases such as atherosclerosis. In this study, the effect of Sunghyangchungisan(SHCS) as a protectant against oxidant-induced destruction of endothelial barrier function was assessed. Methods : Toward this end, endothelial cells derived from the human umbilical vein were cultured as monolayers on permeable membrane filters. Endothelial permeability was monitored by measuring transendothelial electrical resistance and movement of low density lipoprotein (LDL) across the endothelial monolayer. Results : Along with increased movement of LDL, $H_2O_2$-induced increase in endothelial permeability was paralleled by a decrease in transendotheliaI electrical resistance. The effect of $H_2O_2$ was mimicked by phorbol 12-myristate 13-acetate (PMA), a potent activator of proteinkinase C. Calphostin-C, a protein kinase C inhibitor, effectively blocked the increase in endothelial permeability induced by $H_2O_2$ or PMA, indicating that activation of protein kinase C is associated with the $H_2O_2-induced$ permeability change. SHCS effectively protected the endothelial monolayer against $H_2O_2-induced$ increase in permeability, whereas, it did not affect PMA-induced change. Forskolin, a potent activator of adenylyl cyclase, antagonized $H_2O_2$ to increase endothelial permeability. In addition, in ${H_2O_2}-treated$ cens, intracenular cAMP concentration was significantly decreased, indicating that impaired cAMP production as well as activation of proteinkinase C is a mechanism underlying ${H_2O_2}>-induced$$H_2O_2$ with regard to its effect on intracellular cAMP content. However, SHCS itself did not affect resting cAMP concentration in endothelial cells. Conclusions : These results suggest that SHCS might operate as an effective protectant against oxidant-induced destruction of endothelial barrier function. The mechanism does not appear to involve direct interaction with protein kinase C- or cAMP-associated signaling mechanism.

• 환경생물
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• 제18권3호
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• pp.299-305
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• 2000

본 연구는 울릉도 성인봉 주변에 생육하고 있는 너도밤나무군락의 섬조릿대하위군락, 전형하위군락, 일색고사리하위군락에 대한 토양단면 및 토양의 이화학적 특성을 조사하여 울릉도 산림토양의 기초자료를 제공하고, 하위군락별 토양특성의 차이를 조사하기 위해 실시되었다. 하위군락별 토양단면의 형태는 하위군락간에 큰 차이를 보이지 않았다. 하위군락간 토양의 이화학적 요인분석에 있어서 0-10cm 토양 깊이에서 Ca함량에서만 유의적인 차이가 나타났을 뿐, 다른 요인들은 하위군락 간에 큰 차이가 없는 것으로 나타났다. 울릉도 성인봉 주변의 토양특성 중 유기물함량은 0-10cm 토양 깊이에서 평균 21.6%로 매우 높게 나타났으며, 전질소함량도 0-10cm 토양 깊이에서 평균 0.74%로 높게 나타났다. 가비중은 0.43g/cm로 매우 낮게 나타났으며, pH는 평균 4.4로 강한 산성토양의 특성을 나타내어 우리나라의 일반 산림 토양과는 매우 다른 특성을 가지고 있는 것으로 나타났다.