• Polymer Science and Technology
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• v.8 no.4
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• pp.421-426
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• 1997

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.33 no.10
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• pp.30-33
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• 2004

화학 반응에 필요한 고온의 열에너지를 태양열 고집광 기술을 이용하여 화학 에너지로 변화하는 기술을 소개한다.

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.223.2-223
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• 1999

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.421-430
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• 2004

The purpose of this study was to measure and compare the amount of unreacted TEGDMA from pit and fissure sealants cured with three different light sources; conventional halogen light curing unit, plasma arc light curing unit and argon laser. The specimens were eluted in distilled water for different time intervals. The time-related release of TEGDMA were analyzed by reverse-phase high performance liquid chromatography(HPLC). The result of present study can be summarized as follows: 1. The time-related release of TEGDMA decreased with increasing curing time in conventional halogen light, however, that not statistically significant difference(p>0.05). 2. The elution from the specimens cured for 6 and 9 seconds with plasma arc light was similar results corresponding with the time-related TEGBMA release, and was significantly lower than that cured for 3 seconds(p<0.05). 3. The elution of TEGDMA from the specimens cured with argon laser was significantly higher than that cured with halogen and plasma arc light(p<0.05). 4. The elution of TEGDMA from under recommended time of three different light sources were showed to be no statistically significant difference(p>0.05). 5. In time-related release of TEGDMA from recommended time of each light sources, the results correspond to 40 seconds of halogen light and 6 seconds of plasma arc light were similar(p>0.05). 6. The elution of TEGDMA, from over recommended time of three different light sources were showed to be no statistically significant difference(p>0.05). In this study, I suggest that curing time of plasma arc light is 6 and/or 9 seconds in the field of clinical pediatric dentistry claiming its effectiveness in optimal polymerization and reduced chair time.

• Applied Chemistry for Engineering
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• v.10 no.1
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• pp.98-104
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• 1999

In this work, we investigated hydrogen content, bond structure, and electrical properties of a-Si:H films prepared by ECR plasma CVD as a function of pressure. In general, the photo sensitivity of a-Si:H films prepared by CVD method decreases as the deposition rate increases, but the photo sensitivity of a-Si:H films prepared by ECR plasma deposition method increases as the deposition rate increases. In the same condition of microwave power, the ratio of $SiH_4/H_2$, and pressure, though film thickness increases linearly with deposition time and hydrogen content in the film is constant, photo conductivity can be decreased because $SiH_2$ bond is made more than SiH bond in the short reaction time. According to increase pressure in the chamber, SiH bond in the film increase and optical energy gap decrease. So, photo conductivity can be increased. But photo sensitivity decreased as dark conductivity increase. It must be grown in the condition of low pressure and hydrogen gas for taking the a-Si:H film of high quality.

• Journal of the Korean Chemical Society
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• v.36 no.4
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• pp.546-551
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• 1992

Reaction mechanism on the solvent extraction of nickel(Ⅱ) with N-benzylisonitrosoacetylacetone imine(HIAANB) was studied spectrophotometrically. Absorbance was measured by changing the ligand HIAANB concentration in the chloroform organic phase and the pH values in the agueous solution phase. From the absorbance data, the reaction rate was found to be the first order for HIAANB concentration and the inverse first one for [$H^+$]. The rate determining step of the extraction reaction and the rate equation are as follows; $Ni^{2+}$＋HIAANB ${\to}$ Ni-IAANB$^+$＋$H^+$ -d[Ni$^{2+}$] / dt = K'[Ni$^{2+}$][HIAANB]$_0$ / [H$^+$] Calibration curve for the spectrophotometric determination of nickel(Ⅱ) ion in the aqueous solution was linear below the concentration of 1.17 ppm at the optimum experimental condition. And the ligand-to-metal ratio, the relationship between extractability and pH of the aqueous phase, and the effect of diverse ion on the determination of nickel(Ⅱ) ion were examined.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.3
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• pp.233-241
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• 2012

Photodynamic therapy (PDT) is a technique that involves the activation of photosensitizer by light in the presence of tissue oxygen, resulting in the production of reactive radicals capable of inducing cell death. The aim of this study was to evaluate the effect of PDT on Streptococcus mutans in planktonic conditions, previously treated with different photosensitive concentrations of erythrosine, using halogen and LED curing unit as a light source. And we compared the effects of PDT on six strains of S. mutans isolated from oral cavity and reference strain. As a result, S. mutans was susceptible to the combination of hand held photopolymerizer (HHP) and erythrosine. The higher concentration of erythrosine in the presence of light irradiation induced greater effects in reduction of viability of S. mutans. Isolated S. mutans showed a significant reduction in bacterial counts of the groups submitted to PDT compared to the control groups. And they appeared to be similar or slightly lower antimicrobial effect compared with reference strain. However, the difference was not significant (p < 0.05). In conclusion, PDT using erythrosine as a photosensitizing agent and HHP as a light source could be an efficient option for diseases caused by S. mutans.

• Applied Biological Chemistry
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• v.9
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• pp.1-7
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• 1968

The action Spectra for violaxanthin de-epoxidation and zeaxanthin expoxidation in New Zealand spinach leaf segments Tetragonia expansa, were determined at equal incident quanta of $2.0{\times}10^{15}$ quanta $cm^{-2}$ $second^{-1}$. The action spectrum for de-epoxidation had major peaks at approximately 180 and 648 nm. Blue light was slightly more effective than red light and little activity was observed beyond 700 nm. The action spectrum for epoxidation showed major peaks at around 441 and 670 nm. Blue light was more effective than red light and light beyond 700 nm showed definite activity. The net result of de-epoxidation and epoxidation is a cyclic scheme, the violaxanthin cycle, which consumes $O_2$ and photoproducts. The action spectra indicate that the violaxanthin cycle is more active m clue than in red light and therefore could accout for $O_2$ uptake stimulated by blue light. The differences between the action spectra for de-epoxidation suggest that possibly two photosynthetic systems are involved. It was suggested that the violaxanthin cycle may functional a pathway for the consumption of excess photoproducts generated in blue light or the conversion of these photoproducts to other forms of energy.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.459.2-459.2
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• 2014

CdTe계와 CGIS계 태양전지의 광투과층으로 CdS 박막이 많이 사용된다. Cds 박막의 필요한 물성으로는 높은 광투과도와 얇은 두께이다. 광투과층으로 사용되는 CdS 막의 광투과도가 높아야 많은 양의 빛이 손실 없이 투과하여 광흡수층인 CIGS에 도달할 수 있다. 특히, CdS막의 두께가 얇으면 밴드 갭 이상의 에너지를 가지는 파장의 빛도 투과시킬 수 있어 태양전지의 효율의 증가을 얻을 수가 있다. 그러나 CdS 막의 두께가 얇을 경우, pinhole이 생성되는 등 막의 균질성이 문제가 된다. 본 연구에서는 높은 변환 효율을 갖는 CIGS 박막 태양전지 제작에 적합한 chemical bath depostion(츙)법을 이용하여 CdS 박막을 제조하였다. 또한 반응시간, Cd 및 S source 비와 같은 증착 조건에 따른 박막의 특성을 조사하였다.

• Journal of Biosystems Engineering
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• v.22 no.4
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• pp.503-512
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• 1997

최근들어 원예학, 농학, 식물학 등의 분야에서 각종 환경요인에 대한 식물의 생장반응을 연구하기 위한 기초 실험의 상당 부분이 인공광원을 사용한 가운데 이루어지고 있다. 또한 상기의 기초연구 이외에 식물공장에서와 같이 인공광과 태양광의 병용 또는 인공광만을 사용한 식물생산의 상업화에 대한 연구가 활발하게 이루어지고 있는 가운데 조직 배양묘, 접목묘, 실생묘 등을 인공광하에서 효율적으로 생산하기 위한 식물묘 생산의 실용화 연구도 수행되고 있다. 그런데 식물생산과 밀접하게 관련된 광(또는 복사)에 관련된 용어의 정의 또는 단위가 물리학, 조명 공학, 생물학 등의 전문 분야에 따라 서로 다른 경우가 있으며, 식물을 연구 대상으로 삼는 분야에서도 관련 용어와 단위가 뒤섞여 사용되기도 한다. 즉 하나의 용어가 복수의 의미로 사용되거나, 반대로 하나의 정의에 대해서 다수의 용어가 사용되기도 한다. 이러한 경우 단위가 명확하게 표시되지 않으면 사용된 용어의 의미가 애매하게 전달될 수 있다. 그러므로 식물생산과 관련된 용어 또는 단위의 사용에 혼란이 초래되지 않도록 용어와 단위를 통일하는 것이 바람직 할 것으로 판단된다.(중략)