• Membrane and Water Treatment
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• 제11권2호
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• pp.151-158
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• 2020

ACF preparation from different materials has been attached with great attention during these years. This study was conducted to prepare activated carbon fiber (ACF) from luffa through the processes i.e pre-treatment, pre-oxidation and carbonization activation. Besides, this study also characterizes the ACF and its effect, i.e effect of pre-oxidation time and temperature also activation time and temperature on the compressive strength of ACF were investigated. The results from SEM, BET, FTIR and XRD show that the ACF is very efficient. The products under the optimum conditions had a specific surface area of 478.441 m2 /g with an average pore diameter of 3.783nm, and a pore volume of 0.193 cm3 /g. The surface of the luffa fiber is degummed and exposed, which is beneficial to the subsequent process and the increase of product properties. The compressive strength of HP-ACF was prepared under the optimum conditions, which can reach 0.2461 MPa. ACF is rich in micro-pores and has a good application prospect in the field of environmental protection.

• 한국문화재보존과학회:학술대회논문집
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• 한국문화재보존과학회 2005년도 제22회 학술대회 발표 논문집
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• pp.122-134
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• 2005

XRF, EDX, IR analysis was conducted to figure the effect of Fe to blacken the waterlogged wood. The results showed that investigated soil contained more Fe than normal soil by XRF analysis and wood ash contained more sulfur and Fe than any other element by EDX analysis. C-H and C-O peaks were significantly reduced at the surface of wood where is blackened part of waterlogged wood by IR analysis. The optimum condition to remove Fe from waterlogged wood by EDTA was investigated. To do this, removed concentration of Fe was measured at various concentration of EDTA-2Na. The optimum pH of EDTA-2Na was figured to be 4.1 to 4.3 and as the concentration of EDTA was increasing, extracted concentration of Fe was also increased. In the case of 0.4 wt% of EDTA-2Na, 700ppm of Fe was eliminated and was stabilized after 48 hours time lapse. In the case of EDTA-3Na, the optimum pH was 7 to 8, and 10 ppm of Fe was eliminated at 0.4 wt% of EDTA-3Na. In the case of EDTA-4Na, the optimum pH was 10 to 11, and 120 ppm of Fe was eliminated at 0.4 wt% of EDTA-4Na.

• 한국식품과학회지
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• 제30권4호
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• pp.895-901
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• 1998

폐단백질을 활용하는 방도의 하나로 참깨박으로부터 불용성 단백질의 분리 효율성을 높이고 기능성을 개선하기 위하여 미생물이 생성하는 phytase와 protease를 처리하였다. 이때 참깨박 단백질의 용출을 위한 최적 pH, 최적 온도, 최적 처리시간과 최적 첨가효소량은 pH $10{\sim}12$까지의 알칼리 영역, $60^{\circ}C$, 11시간, phytase 900 unit+protease 60 unit이었다. 효소처리된 참깨박단백질은 거품 형성력과 거품 안정성이 대조구에 비해 크게 증가하였고, 유화력과 유화 안정성 및 유지 흡착력과 수분 흡착력도 효소처리구가 대조구에 비해 매우 증가하였다.

• 열처리공학회지
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• 제30권6호
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• pp.279-284
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• 2017

Mechanical properties of titanium alloy can be improved by controlling microstructure through heat treatment. In this study, Ti-3Al-8V-6Cr-4Mo-4Zr metastable beta titanium alloy, was controlled for excellent mechanical property and sound formability through various high temperature heat treatment and aging conditions and the optimum heat treatment conditions were determined. The specimens were heat-treated at $950^{\circ}C$, followed by various aging treatments from $430^{\circ}C$ to $500^{\circ}C$ for 1 to 24 h. As aging temperature and holding time increased, hardness increased by ${\beta}^{\prime}$ phase formation and precipitation of secondary ${\alpha}$ phase in ${\beta}$ matrix. However, the optimum aging temperature and holding time for mechanical properties were at $450{\sim}470^{\circ}C$ for 8~16 hr. Hardness values of the specimen aged at $450^{\circ}C$ for 8 h were found to be the highest. These results can be effectively applied to fabrication of spring with better formability and mechanical property.

• 한국세라믹학회지
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• 제30권7호
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• pp.589-597
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• 1993

The optimum sol solution for making alumina membrane was synthesized by using sol-gel method with aluminium isopropoxide. Two types of supports were made from the $\alpha$-Al2O3 powder. The porosities of supports could be controlled by the forming methods and the heat treatment conditions. After the support was coated with optimum sol solution and heat-treated at 50$0^{\circ}C$ for 1hour, the thickness of crack-free membrane could be controlled reproductively with dipping time.

• 상하수도학회지
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• 제29권2호
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• pp.183-192
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• 2015

Response surface methodology (RSM) based on a Box-Behnken Design (BBD) was applied to optimize the thermal-alkaline pre-treatment operating conditions for anaerobic digestion of flotation scum in food waste leachate. Three independent variables such as thermal temperature, NaOH concentration and reaction time were evaluated. The maximum methane production of 369.2 mL $CH_4/g$ VS was estimated under the optimum conditions at $62.0^{\circ}C$, 10.1% NaOH and 35.4 min reaction time. A confirmation test of the predicted optimum conditions verified the validity of the BBD with RSM. The analysis of variance indicated that methane production was more sensitive to both NaOH concentration and thermal temperature than reaction time. Thermal-alkaline pretreatment enhanced the improvement of 40% in methane production compared to the control experiment due to the effective hydrolysis and/or solubilization of organic matters. The fractions with molecular weight cut-off of scum in food waste leachate were conducted before and after pre-treatment to estimate the behaviors of organic matters. The experiment results found that thermal-alkaline pre-treatment could reduce the organic matters more than 10kD with increase the organic matters less than 1kD.

• 원예과학기술지
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• 제18권3호
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• pp.395-398
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• 2000

본 연구는 떫은감 "청도반시"를 조기착색과는 9월 21일, 적숙과는 10월 11일에 수확하여 수확시기에 따른 연화정도를 조사하고, 연시제조의 적정온도를 설정하고자 10, 15, $20^{\circ}C$에서의 품질변화를 조사하였다. 경도는 처리온도 15, $20^{\circ}C$에서 처리 2일만에 전체 경도 감소량에 70% 정도 감소되었으며, 6일 이후에는 경도의 감소가 완만하게 되었다. 처리온도 $10^{\circ}C$는 다른 처리온도에 비하여 높은 경도를 나타내어 연시제조에는 효과가 없었다. 가용성탄닌은 수확시기에 관계없이 15, $20^{\circ}C$의 처리구에서 6일째에 급격히 감소하였으나, 무처리구는 가용성탄닌이 약간 감소되었다. 조기수확과의 Hunter 'L', 'b' value는 모든 처리온도에서 2일째까지 증가한 후 감소하였고, 적숙과는 초기부터 감소하기 시작하여 8일째부터는 비교적 일정한 경향을 보였다.

• 아시안잔디학회지
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• 제9권3호
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• pp.253-260
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• 1995

This study is aimed to understand the effects of temperature, light and GA soaking treatment on the seed germination of perennial ryegrass 'Dandy', creeping hentgrass 'Penlinks', tall fescue 'Arid' and Kentucky hluegrass 'Nasaw'. These experiments are carried in vitro, and their results obtained are summarized as the followings ; The optimum temperature for seed germination of perennial ryegrass 'Dandy' was found to he ranged at 20~30$^{\circ}C$, and the optimum temperature for germination of creeping bentgrass 'Penlinks', tall fescue 'Arid' and kentucky bluegrass 'Nasaw' seeds was found to be ranged at 20~25$^{\circ}C$, whereas the germination percentage under the below or above temperature of this range decreased. The germination of perennial ryegrass 'Dandy' and tall fescue 'Arid' seeds showed no effect on light, and while the germination percentage of creeping hentgrass 'Penlinks' increased more highly under the dark condition than under the light condition. The germination percentage decreased according to the higher temperature. The germination of Kentucky bluegrass 'Nasaw' seeds increased more highly under the dark condition than under the light condition at 20~25$^{\circ}C$, whereas the germination percentage under the dark condition at 15$^{\circ}C$ and 30$^{\circ}C$ decreased. In case of GA soaking treatment of seeds, all the cool season turfgrasses tested showed their own promoting effects on seed germination. The early germination of tall fescue 'Arid' was good without the soaking times. Creeping bentgrass 'Penlinks' and perennial ryegrass 'Dandy' had re-spectively the highest germination percentage at 10min and 1hr soaking treatment, and the longer the soaking time, the lesser the germination percentage. Kentucky bluegrass 'Nasaw' obtained the best results at 24has soaking treatment, and the longer the soaking time, the better the ger-mination percentage.

• 산업기술연구
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• 제17권
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• pp.73-77
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• 1997

This study aims to develop the combined septic tank for middle-small scale sewage treatment. The developed process were circular and separate type. The circular combined septic tank was controlled sludge discharge and could be modified the advanced treatment system. The separate combined septic tank was could be applicated wastewater that discharge flow was varied, and was could be maintained F/M ratio constantly. The optimum hydraulic retention time was about 16 hours.

• 환경위생공학
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• 제11권3호
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• pp.37-46
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• 1996

In this study, the effect of pH, Temp, dye concentration, distance of electrode, and the potential on the removal efficiency of dye-wastewater using electrochemical reaction were investigated. Optimum conditions for the electrochemical treatment of dye-wastewater were obtained that pH;7, 8V, electrode distance; 1cm and the reaction time for obtaining above 99% removal efficiency were 10 - 40min at each conditions, From this result, we can determine the instantaneous current efficiency and specific energy consumption, and we can provide the effective data for economical treatment of industrial dye-wastewater.