• Journal of Plant Biology
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• v.36 no.4
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• pp.371-375
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• 1993

$ CO_2$ fixation of isolated intact spinach chloroplasts under saturating light began to decrease after 20 min, and stopped completely after 1 h. To identify the lesion sites for the die off, reconstituted chloroplast system was used with chloroplasts collected at several phases of time course. $ CO_2$ fixation was inhibited in the reconstituted chloroplasts made of thylakoids and stroma in the later phases, but showed a higher degree of inhibition by the participation of thylakoids than that of stroma in the later phases. Measurement of photophosphrylation and NADP reduction revealed that a severed thylakoidal damage was occurred at the later phases. This results indicate that the lesion sites for the die off are in the thylakoid.the thylakoid.

• Journal of the Korean Chemical Society
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• v.51 no.2
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• pp.154-159
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• 2007

Biodegradation of Quinoline by free and immobilized Bacillus brevis has been investigated. The rate of quinoline degradation by immobilized Bacillus brevis on coconut shell carbon is faster than the rate by the microorganism immobilized on foam pieces and free cells. A complete removal of 100 ppm of Quinoline in the sample was achieved at a hydraulic retention time of 20 hours with the biocatalyst prepared by immobilizing Bacillus brevis onto coconut shell carbon. The biocatalyst had a reasonable shelf life and desirable recycle capacity.

• Journal of Korean Society of Forest Science
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• v.88 no.1
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• pp.93-100
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• 1999

This study has been carried out to estimate aboveground and soil carbon contents in an average 39-year-old Quercus mongolica and 40-year-old Quercus variabilis stands in Chungju, Chungbuk. Ten sample trees were cut in each forest and soil samples were collected. Aboveground carbon content was estimated by the equation model $Wt=aD^b$ where Wt is oven-dry weight in kg and D is DBH in cm. Total aboveground carbon content was 48.85tonC/ha in Quercus mongolica stand and 57.49tonC/ha in Quercus variabilis stand. The proportion of each tree component to total aboveground carbon content was high in order of bolewood, branches, bolebark, and leaves in the two forests. Aboveground net primary production was estimated at 5.88tonC/ha in Quercus mongolica stand and 5.12tonC/ha in Quercus variabilis stand. Soil carbon content was 67.0tonC/ha in Quercus mongolica stand, 67.8tonC/ha in Quercus variabilis stand, and 54.7tonC/ha in Pinus densiflora stand. There was no significant difference in soil carbon content among the three forests.

• Computational Structural Engineering
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• v.36 no.4
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• pp.8-13
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• 2023

• Computational Structural Engineering
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• v.36 no.4
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• pp.4-7
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• 2023

• Environmental and Resource Economics Review
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• v.6 no.2
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• pp.209-231
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• 1997

본 논문은 전통적인 산업연관분석이 고정투입계수를 시용하고 있어서 상대가격체계의 변화에 따른 경제 주체들의 비용최소화 노력을 모형 내에 반영하지 못하고 있다는 한계를 극복하기 위하여 상대가격체계의 변화에 따라 가변투입계수를 갖는 "반복다중최적화(IMO) 모형"을 이용하여 탄소세 부과가 가격구조에 미치는 영향을 분석하였다. 분석 결과는 고정투입계수모형에 비하여 가격인상효과는 전반적으로 낮게 나타났으며, 특히 에너지집약산업은 고정투입계수모형에 비하여 가격상승률이 낮게 나타난 반면, 기타산업은 가격상승폭이 높게 나타났다. 이러한 결과는 에너지원에 대한 탄소세의 부과효과가 상대가격변화에 적응한 경제주체들의 비용최소화 노력으로 각 산업으로 분산된 결과라 여겨진다.

• Korean Chemical Engineering Research
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• v.49 no.1
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• pp.1-9
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• 2011

Platinum catalysts were prepared by impregnating platinum precursor on titania-, vanadia-, zirconia- and ceria-incorporated silicas followed by hydrogen peroxide treatment. The effects of the oxide incorporation and the hydrogen peroxide treatment in the preparation of the platinum catalysts on their platinum dispersion and catalytic activity in carbon monoxide oxidation were investigated. XRD, TEM, EXAFS, XPS and carbon monoxide chemisorption studies confirmed the high dispersion of platinum even on silica by the oxide incorporation and hydrogen peroxide treatment. However, the type of oxides incorporated on silica caused considerable variances in the adsorption and the catalytic activity in the oxidation of carbon monoxide on them. The incorporation of titania, zirconia and ceria on silica and further hydrogen peroxide treatment enhanced the platinum dispersion, resulting in the improved catalytic activities. Among the catalysts supported on the oxide-incorporated silicas, the platinum catalyst supported on zirconia-incorporated silica exhibited the highest activity because of the highest platinum dispersion due to the formation of Pt-O-Zr bonds.

• KSBB Journal
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• v.6 no.4
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• pp.403-406
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• 1991

Lactic acid production yield was examined for commercial use by immobilizing Rhizopus oryzae with radiation induced polymer. The supporting material was synthesized by the low temperature radiation polymerization method, in which the microorganism was entrapped physically by contacting together in culture broth shaking for 24 hours. Support polymers with 5∼10vol-% monomers were able to increase their catalytic activities, consuming 65g/1 of glucose, producing 56g/1 of lactic acid, thus yielding 88% of product in general. But in free culture, the microorganism consumed almost all carbon sources and produced lactic acid only 60% even after 96 hours. The yield of the experiment under discussion was significantly high compared with conventional immobilization procedure.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.133-133
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• 1999

비정질 탄소막 제조에 있어서 수소가 포함된 반응성 가스를 사용할 경우 제작된 탄소막 내부에는 수소가 포함되게 되며, 이러한 수소원자들은 막의 특성에 중요한 영향을 주는 것으로 알려져 있다. 따라서, 본 연구에서는 비정질 탄소막(a-C:H) 내부에 존재하는 수소가 탄소막의 특성에 미치는 영향을 알아보고, 막 내부에 포함된 수소의 함량과 공정조건 사이의 함수계를 조사함으로써 수소의 함량을 인위적으로 통제할 수 있는 가능성을 제시하고자 한다. 수소가 포함된 비정질 탄소막은 2.45 GHz의 전자기파를 사용하는 electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR-PECVD) 방법과 DC magnetron sputtering 법을 사용하여 제작하였다. 기판으로는 Si(001) wafer를 사용하였으며, 아세톤과 에탄올을 사용하여 표면의 유기성분을 제거하고, 진공챔버속에서 Ar 플라즈마를 발생시켜 sputter etching 방법으로 표면을 세척하였다. ECR-PECVD 방법에서는 반응가스로 메탄(CH4)과 수소(H2)의 혼합가스를 사용하였으며, 혼합가스의 비는 5~50% 범위내에서 변화를 주었다. 수소가스의 유량은 100SCCM으로 고정하였으며, 마이크로웨이브의 power는 360~900W였고, 기판에 가해준 negative DC bias 전압은 0~-500V이었다. DC magnetron sputtering 방법에서는 반응가스로 아세틸린(C2H2) 가스를 사용하였으며, 플라즈마 발생을 용이하게 하기 위해서 Ar 가스와 혼합하여 사용하였다. Ar 가스의 유량은 10SCCM으로 고정하였으며, 아세틸렌 가스의 유량은 5~20SCCM 범위내에서 주입하였다. 이때, 기판에 가해준 negative DC bias 전압은 0~-100V이었다. 제작된 탄소막의 수소 함량을 조사하기 위하여 Fourier Transform Infrared (FTIR) 분광법과 Elastic Recoil Detection Analysis (EFDA) 법을 사용하였으며, 증착율은 SEM 단면촬영과 a-step을 이용하여 측정하였고, 막의 경도는 Micro-Hardness Testing 법을 사용하여 측정하였다.

• Korean Chemical Engineering Research
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• v.61 no.4
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• pp.576-583
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• 2023

This study aimed to investigate the impact of enhancing the electrode conductivity and mitigating the production of hydrogen peroxide - a by-product arising from lactate oxidation - on the performance of lactate electrodes. The electrical conductivity of the electrode was improved by modifying the surface of carbon paper with single-walled carbon nanotubes. Catalase was introduced to effectively eliminate the hydrogen peroxide produced during the lactate oxidation reaction. The carbon paper electrode, with simultaneous immobilization of both lactate oxidase and catalase, yielded a current 1.7 times greater than the electrode where only lactate oxidase was immobilized. The electrode in which lactate oxidase and catalase were co-immobilized on the surface of carbon paper modified with single-walled carbon nanotubes, produced a current of 171 µA, which was more than twice as much current as the carbon paper with only lactate oxidase immobilized. The optimized electrode showed a linear response up to lactate concentration of 20 mM, confirming that it can be used as a sensor electrode.