• 한국표면공학회지
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• 제57권1호
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• pp.31-37
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• 2024

The surge in demand for lithium is primarily fueled by the expanding electric vehicle market, the necessity for renewable energy storage, and governmental initiatives aimed at achieving carbon neutrality. This study proposes a straightforward method for lithium extraction utilizing cellulose nanofiber (CNF) via a vacuum filtration process. This approach yields a porous CNF film, showcasing its potential utility as a lithium extractor and indicator. Given its abundance and eco-friendly characteristics, cellulose nanofiber (CNF) emerges as a material offering both economic and environmental advantages over traditional lithium extraction techniques. Hence, this research not only contributes to lithium recovery but also presents a sustainable solution to meet the growing demand for lithium in energy storage technologies.

• 한국식품영양과학회지
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• 제36권3호
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• pp.348-354
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• 2007

반응표면분석법을 이용하여 생강의 추출조건에 따른 기능성을 모니터링하였다. 중심합성계획법에 따라 마이크로웨이브 에너지($30{\sim}150\;watt$), 에탄올 농도($0{\sim}100%$), 추출시간($1{\sim}9$분)을 달리하였을 때 회귀식 $R^{2}$는 추출수율, 전자공여작용, tyrosinase 저해효과 및 polyphenol 함량이 각각 0.9152, 0.9239, 0.9696과 0.9057로 분석되었다. 조건별 추출물의 수율, 전자공여능, tyrosinase 저해효과, polyphenol에 대한 4차원 반응표면을 superimposing하여 얻은 최적 추출조건 범위는 마이크로웨이브 에너지 $0{\sim}80\;watt$, 에탄올 농도 $0{\sim}40%$, 추출시간 $3{\sim}7$분으로 나타났다. 최적 추출조건 범위 내의 임의의 조건인 마이크로웨이브 에너지 50 watt, 에탄올 농도 20%, 추출시간 5분을 각각의 회귀식에 대입하여 얻은 예측값은 추출물의 수율 22.92%, 전자공여능 35.76%, tyrosinase 저해효과 56.52%, polyphenol 함량은 37.68%로 나타났다.

• 한국식품영양과학회지
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• 제44권3호
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• pp.464-469
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• 2015

능이버섯의 수율과 항산화 활성을 측정하여 효율적 추출조건을 예측하기 위해 마이크로웨이브 에너지, 에탄올 농도, 추출시간의 요인 변수를 중심합성법에 따라 설정하여 반응 표면분석을 통해 최적화 조건을 설정하였다. 능이버섯 추출물의 수율, 전자공여작용, 총 폴리페놀 함량, SOD 유사 활성에 대한 반응표면의 회귀식 $R^2$값이 각각 0.97, 0.90, 0.80 및 0.87로, 수율, 전자공여작용 및 SOD 유사 활성이 각각 P<0.001, P<0.05 및 P<0.05 수준에서 유의성이 인정되었다. 능이버섯은 요인 변수에 따라 수율은 마이크로웨이브 에너지의 영향을 가장 많이 받았고, 에탄올 농도에 따른 영향도 있었다. 그 외 종속변수인 전자공여능과 SOD 유사 활성은 에탄올 농도에 따른 영향을 받는 것으로 나타났다. 추출물의 각 특성을 모두 만족시키는 최적의 추출조건의 범위는 superimposing 하여 마이크로웨이브 에너지 78~88 W, 에탄올 농도 39~57%, 추출시간 3.5~9분으로 예측되었다.

• 한국식품영양과학회지
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• 제45권8호
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• pp.1162-1169
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• 2016

본 연구에서는 기능성 홍삼 엑기스 제조를 위해 추출용매, 압력, 온도, 추출시간을 조절하여 가속 용매 추출한 후 기능성 홍삼제품의 지표성분인 진세노사이드 함량, 총페놀화합물 및 벤조피렌 함량 등을 조사하였다. 홍삼 가속 용매 추출 최적화를 위한 독립변수 선택을 위해 에탄올 농도, 압력, 온도 및 추출시간에 따른 기능성 홍삼제품의 지표성분인 진세노사이드 Rb1, Rg1 및 Rg3(20S) 함량의 합을 분석하여 진세노사이드 추출에 가장 최적의 용매를 50% 에탄올로 하고, 영향이 다소 작았던 요인인 압력을 2,500 psi로 설정하였으며, 온도와 추출시간을 독립변수로 설정하였다. 추출 온도 및 시간을 독립변수로 하여 고온고압 처리한 홍삼의 진세노사이드 Rb1, Rg1 및 Rg3(20S) 함량의 합, 총 페놀성 화합물 및 벤조피렌 함량을 측정한 결과, 벤조피렌이 검출되지 않는 조건에서 진세노사이드 Rb1, Rg1 및 Rg3(20S)의 함량 합이 최적화된 조건은 $158^{\circ}C$, 20분임을 확인할 수 있었다. 최적화된 조건에서의 가속 용매 추출 시 초음파 및 환류냉각 추출에 비해 적은 용매로 단시간 추출하면서 진세노사이드 Rb1, Rg1 및 Rg3(20S) 함량 합 및 총폴리페놀 함량이 각각 1.5~2배 및 2.2~5배 높게 추출할 수 있어 효율적인 추출방법이 될 것으로 생각된다.

• Natural Product Sciences
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• 제23권1호
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• pp.9-15
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• 2017

DF formula is comprised of three traditional herbs, Ephedra intermedia, Rheum palmatum and Lithospermum erythrorhizon, and locally used for treating of the metabolic diseases, such as obesity and diabetes in Korea. We tried to optimize the extraction conditions of two major components, (-)-ephedrine and (+)-pseudoephedrine, in DF formula using response surface methodology with Box-Behnken design (BBD). The experimental conditions with 70% for EtOH concentrations, 4.8 hour for extraction hours and 8.7 times for the solvent to material ratio were suggested for the optimized extraction of DF formula with the highest amounts of (-)-ephedrine and (+)-pseudoephedrine in the designed model.

• Natural Product Sciences
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• 제29권2호
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• pp.83-90
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• 2023

To our knowledge, this is the first study aiming to optimize the extraction conditions of total phenolic compounds (TPC) and total flavonoids contents (TFC) from Argania spinosa leaves using Response Surface Methodology (RSM) with a Box-Behnken design (BBD). The optimal conditions obtained were 5% (w/v) solvent-to-solid ratio, 72.33% ethanol concentration, and 10h ours as an extraction time, which resulted in an extract with maximum TPC (131.63 mg GAE/g dw) and TFC (10.66 mg QE/g dw). Under the optimal extraction conditions, the antioxidant activity of the extracts of leaves of argan tree showed a moderate antiradical capacity of DPPH (IC₅₀ = 0,130 mg/mL) and ABTS (IC₅₀ = 0.198 mg/mL). However, the leaves of argan tree showed a very interesting reducing power of Iron (IC₅₀ = 0.448 mg/ml) which is similar to that of the ascorbic acid (IC₅₀ = 0.371 mg/mL).

• 한국산업융합학회 논문집
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• 제2권2호
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• pp.147-153
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• 1999

An in-process extraction method of the ground surface roughness is a bottle-neck and essential field in conventional machining process. We define the D.A.R.F(Dimensionless Average Roughness Factor) that has a roughness characteristic of ground surface. D.A.R.F include the absolute average and the standard deviation values which are the analytic parameters of the AE(Acoustic Emission) signal generated during the grinding operation. The theoretical equation between the surface roughness and the D.A.R.F has been derived from the linear regressive analysis and verified its availability through the experimentation on the surface grinding machine.

• 한국CDE학회논문집
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• 제15권1호
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• pp.33-42
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• 2010

In this study, new medial surface calculation methods using Voronoi diagrams are investigated for the point samples extracted on closed surface models. The medial surface is defined by the closure of all points having more than one closest point on the shape boundary. It is a one of essential geometric information in 3D and can be used in many areas such as 3D shape analysis, dimension reduction, freeform shape deformation, image processing, computer vision, FEM analysis, etc. In industrial parts, the idealized solid parts and shell shapes including sharp edges and vertices are frequently used. Other medial surface extraction methods using Voronoi diagram have inherent separation and branch problems, so that they are not appropriate to the sharp edged objects and have difficulties to be applied to industrial parts. In addition, the branched surfaces on sharp edges in shell shapes should be eliminated to obtain representative medial shapes. In order to avoid separation and branch problems, the new approach by analyzing the shapes and specially sampling on surfaces has been developed.

• 한국식품영양과학회지
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• 제28권5호
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• pp.1087-1091
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• 1999

Microwave extraction system equipped with closed vessels, which is known to rapidly extract target compounds from natural products, was applied to monitor the changes in phenolic compounds, browning color intensity and electron donating ability by using response surface methodology(RSM). Maximum content of phenolic compound was 21.65mg/100ml in 67.88% of ethanol concentration, 145oC of extraction temperature, and 6.24min of extraction time. The phenolic compounds in extracts are dependent on the increase of the extraction temperature and the ethanol concentration. Browning color intensity, which was maximized in 67.21%, 147oC, and 6.02min, was proportional to the increase of the extraction temperature. Maximum value of electron donating ability was 24.50units in 54.33%, 147oC, and 6.11 min. The electron donating ability of extracts was dependent on the increase of extraction temperature and maximized in the range from 50 to 65% of ethanol concentration.

• 제어로봇시스템학회논문지
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• 제22권7호
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• pp.543-551
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• 2016

This paper presents the analysis and implementation of traveling surface characteristics test equipment using optical mice in connection with the velocity estimation of a mobile robot equipped with optical mice. In the traveling surface characteristics test equipment, a traveling surface sample is made to rotate toward stationary optical mice instead of a mobile robot equipped with optical mice moving over a traveling surface. First, the conceptual design and operational principle of the traveling surface characteristics test equipment is explained. Second, the velocity kinematics of the traveling surface characteristics test equipment is formulated; based on this, the parameter setting of the traveling surface characteristics test equipment is described. Third, the implementation of the traveling surface characteristics test equipment is described in detail, including the mechanical design and construction and the hardware and software development. Fourth, using the prototype of the traveling surface characteristics test equipment, the experimental results of the statistical parameter extraction for different traveling surface samples are given. Finally, some potential usages of the traveling surface characteristics test equipment are discussed.