• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.815-818
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• 2002

Mn doped hexagonal phase of ZnS has been studied as a yellow-orange phosphor for the application to fluorescent displays operated at low voltages. It was found that luminescence from $Mn^{2+}$ was increased as the Mn concentration was increased up to1.2 mol% of host lattice. This study has been attempted by adding trivalent ions such as $Al^{3+}$ or $Bi^{3+}$ to ZnS:Mn as an agent to do the efficient incorporation of Mn ions into ZnS:Mn lattice, resulting in a significant improvement in the phosphor performance, especially at low voltages.

• 한국식품저장유통학회지
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• 제18권5호
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• pp.811-816
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• 2011

국산 캠벨 얼리 포도과즙을 36 $^{\circ}Brix$로 동결농축한 후 국산 포도로부터 분리된S. cerevisiae S13, D8 균주를 이용하여 아이스와인의 발효를 행하면서 대조균주인 S. cerevisiae Fermivin과 발효특성을 비교하였다. 발효 중 S13과 D8의 경우 Fermivin보다 당도가 다소 빠르게 감소하였으며 빠른 알코올 생성을 보였다. 발효 종료 시점인 9일 후의 알코올 농도는 D8이 15.2%, S13은 14.0%, Fermivin은 12.6%를 나타내었다. 잔존 환원당의 함량은 Fermivin 포도주가 14.0%로 가장 높았으며 D8 포도주는 9.07%, S13 포도 주는 9.77%로 나타났다. 총산 함량은 Fermivin 포도주 약 0.82%에 비하여 D8과 S13 포도주에서 각각 0.97, 0.96%로 다소 높게 나타났으며 pH는 모든 포도주에서 3.65-3.67로 유의적인 차이가 없었다. 아세트알데히드는 D8 포도주가 81.9 ppm으로 다소 높았으며 Fermivin 포도주는 58.8 ppm으로 가장 낮았다. 메탄올 함량은 S13, D8 포도주가 Fermivin 포도주보다 다소 높았으나 과실주의 메탄올 허용 기준치보다는 매우 낮았다. L 값은 6.89-6.99로 일반포도주에 비해 매우 낮게, b 값은 4.37-4.54로 매우 높게 나타났다. 아이스와인의 향과 맛은 S13 포도주가 가장 높은 점수를 받았으며 전반적인 기호도는 D8와 S13 포도주가 Fermivin 포도주보다 높은 점수를 받았다.

• 환경위생공학
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• 제18권1호
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• pp.30-40
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• 2003

The study subjects included the workers who were estimated to have been exposed in a low density of lead-laden glaze from pottery manufacturers. They were evaluated in terms of PbB and PbU as indices of lead concentration in the body, and Hb, Hct, ALAD, and FEP as indices of biochemical lead poisoning. Consequently, the study results revealed the relationship between each of indices and its effectiveness to indicate the degree of occupational lead exposure. 1. The mean of PbB was $22.85{\;}{\mu}g/d{\ell}$(range; $4.2~44.7{\;}{\mu}g/d{\ell}$) and PbU $45.69{\mu}g/d{\ell}$(range; $6.7~87.5{\mu}g/d{\ell}$), to indicate the level of lead exposure in the subjects. 2. While there was a high, linear correlation between PbB, PbU and FEP (r=0.835, r=0.855, respectively), a low correlation existed between PbB and ALAD(r=-0.240). 3. While there was a high, linear correlation between PbU and FEP(r=0.825), a low correlation existed between PbU and ALAD(r=-0.352). The above results suggest that FEP can be used as a highly useful biochemical index of lead poisoning, based on its high correlation with PbB and PbU indicating lead concentration in the body.

• 한국세라믹학회지
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• 제46권2호
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• pp.155-160
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• 2009

The reliability could be one of the essential properties for multilayer ceramic capacitor (MLCC) using in various electronic devices and the concentration and mobility of oxygen vacancy would play important role in the reliability. To investigate the migration behavior of oxygen vacancies, thermally stimulated depolarization current (TSDC) is adopted. In dielectric material of X5R MLCC, the TSD-Current peak observed around 150$^{\circ}C$ and 200$^{\circ}C$ which represented the migration of oxygen vacancy. Substituting Yttrium for Dysprosium in X5R MLCC showed higher migration activation energy and lower TSD current density.

• Mycobiology
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• 제31권3호
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• pp.145-150
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• 2003

This study investigated the morphological differences of P. ostreatus grown in the artificial environmental conditions such as humidity, temperature, ventilation, and watering. Oyster mushroom, which was cultivated on artificial environmental condition, was shown to have different morphology of fruitbodies. The optimum $CO_2$ concentration for good morphology of P.ostreatus was 0.3%. But most fruitbody showed the morphologically low qualities in more than 0.5% of $CO_2$ concentration. In the humidity in excess of 80% at $13{\sim}16^{\circ}C$, the best morphology of P. ostreatus was investigated. The growth of fruitbodies of P. ostreatus in the ventilation system was good at the wind velocity ranging from $0.2{\sim}0.5$ fpms and expouring type. In other conditions, P. ostreatus generally showed the morphology closing to malformation.

• 방사선산업학회지
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• 제8권2호
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• pp.133-140
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• 2014

The sterilization of health care products is widely used to choose conventional Ethylene Oxide gas sterilization in South Korea. But the method has brought serious issues because of the toxic residual gas and global warming of $CO_2$ evacuation after the sterilization process. This study is carried out to confirm the application possibility of gamma sterilization instead of Ethylene Oxide in sanitary aid products. Four kinds of products (gauze, menstrual pad, bandage, menstrual tampon) were treated with gamma irradiation of 15 kGy, then analyzed the achievement of the sterility assurance level (SAL) $10^{-6}$ through BI test. The cytotoxicity of accelerated samples of 6 months elapse evaluated by means of colony forming rate at various concentration of the extracts. pH and UV measurements at extract concentrations were tested according to the MFDS (Ministry of food & drug safety) guideline to verify a stability & safety of product sterilized. The results revealed that the extracts did not show any significant changes in cytoxicity assay as well as pH and UV values by gamma sterilization. All extract concentration was observed high cell viability, pH and UV values were calculated within the acceptable range prescribed by the guideline. It indicates that gamma sterilization could effectively substitute for conventional sterilization such as Ethylene Oxide sterilization in the sanitary aid products.

• 센서학회지
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• 제31권5호
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• pp.337-342
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• 2022

Hydrogen (H₂) gas is widely preferred for use as a renewable energy source owing to its characteristics such as environmental friendliness and a high energy density. However, H₂ can easily reverse or explode due to minor external factors. Therefore, H₂ gas monitoring is crucial, especially when the H₂ concentration is close to the lower explosive limit. In this study, metal oxide materials and their p-n heterojunctions were synthesized by a hydrothermal-assisted dip-coating method. The synthesized thin films were used as sensing materials for H₂ gas. When the H₂ concentration was varied, all metal oxide materials exhibited different gas sensitivities. The performance of the metal oxide gas sensor was analyzed to identify parameters that could improve the performance, such as the choice of the metal oxide material, effect of the p-n heterojunctions, and operating temperature conditions of the gas sensor. The experimental results demonstrated that a CuO/ZnO gas sensor with a p-n heterojunction exhibited a high sensitivity and fast response time (134.9% and 8 s, respectively) to 5% H₂ gas at an operating temperature of 300℃.

• 공업화학
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• 제10권6호
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• pp.863-870
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• 1999

본 연구에서는 촉매로 Co-Mn-Br계를 사용하고, 상대적으로 온화한 반응조건에서 2,6-Dimethylnaphthalene(DMN)의 산화 반응 특성과 촉매가 반응에 미치는 영향을 고찰하였다. 이를 위해 $2{\ell}$의 회분식 반응기를 이용하여 촉매의 농도를 조절하며 실험하였다. 먼저 반응시간에 따른 반응중간생성물의 농도변화를 분석하여 반응경로를 확인하였고, 그 결과 2-formyl-6-naphthoic acid, 2-methyl-6-naphthoic acid, 그리고 2-hydroxymethyl-6-methylnaphthalene이 반응중간물임을 확인할 수 있었다. 또한, 2,6-naphthalene dicarboxylic acid(NDA)의 수율은 Co와 Br의 농도에 많은 영향을 받는다는 것을 알 수 있었고, 제품의 품질 척도 중 하나인 color-b는 Mn의 농도와 밀접한 관련이 있는 것으로 나타났으며, 용매연소는 Mn과 Br의 농도조절로 줄일 수가 있었다. 조촉매로 Ce/Cu 화합물을 첨가함으로 NDA의 수율을 증가시키고 용매연소를 줄이는 결과를 얻을 수 있었다.

• 대한화장품학회지
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• 제32권4호
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• pp.219-225
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• 2006

본 연구는 항유 추출물의 화장품 원료로서의 특성을 알아보기 위하여 항산화, 미백 및 항염 효과와 관련된 다양한 실험을 실시하였다. 30%, 70% 그리고 100% 메탄올로 추출한 각각의 향유 추출물을 대상으로 실험한 결과 DPPH 라디칼 소거 효과는 30%와 70% 추출물들은 0.025% 이상의 농도에서, 100% 추출물은 0.1% 이상의 농도에서 80%의 효과를 나타내었다. 세포내 멜라닌 생성 억제 효과는 각각의 용매별 추출물 모두 0.1% 이상의 농도에서 80%의 효과를 나타내었다. 이후 70% 메탄을 추출물을 대상으로 MPLC를 사용하여 성분 분리 실험을 실시한 결과 4개의 분획들을 얻었고, 이들을 대상으로 실험한 결과 1번, 2번 그리고 3번 분획들에서 항산화(DPPH 라니칼 소거, Mn-SOD 생성 억제), 미백(멜라닌 생성 억제) 그리고 항염($IL-1{\alpha}$, IL-6, COX-2, Total NO 생성 억제)효과를 나타내었다.

• 한국수소및신에너지학회논문집
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• 제27권6호
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• pp.670-676
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• 2016

Hydrogen town in Republic of Korea was established in 2013. Hydrogen as a byproduct produced by various processes of factories is used in hydrogen town facilities. As cell performance is affected by contaminations in fuel gas, various standards about impurities of fuel have been determined by many countries. This study shows performance degradation of single cell with impurities concentrations. Traces of carbon monoxide (CO) and hydrogen sulfide ($H_2S$)can cause considerable cell performance losses. For comparing the performances by poisoning of CO, acceleration test, I-V curve, constant current are performed. Both the CO and $H_2S$ poisoning rate are a function of their concentration. With the higher concentrations the higher poisoning rates are observed. And, it was confirmed that, oxidation behavior and side reaction generation are not affected. Under the lower $H_2S$ concentration condition, the poisoning rate is much higher than that of CO because of its different adsorption intensity. It can be possible that the result of this study can be used for enacting regulation as a baseline data.