• Microbiology and Biotechnology Letters
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• v.32 no.4
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• pp.317-321
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• 2004

We selected a solvent for producing antioxidants from sporophyll of Undaria pinnatOptimum extraction condition for antioxidant ability(Y) of sporophyll of U. pinnatifida was investigated using response surface methodology(RSM). A compound central design was used with variables ($X_1$)temperature($^{\circ}C$) (3.4; 20; 60; 100; 116.6); ($X_2$) pH(1.8; 3; 6; 9; 10.2) and ($X_3$) treatment time(min) (1.7; 10; 30; 50; 58.3). Antioxidant activities were increased with decreasing pH and increasing temperature. The optimal extraction conditions for antioxidant ability(Y) of sporophyll of U. pinnatifida were found to be temperature $51.55^{\circ}C$, pH 4.2 and treatment time 28.2 min. Among the variables tested, pH showed greater significant facin extraction of antioxidants from sporophyll of U. pinnatifida.

• Journal of the Korean Wood Science and Technology
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• v.44 no.4
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• pp.477-493
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• 2016

A single process using hot water (0% green liquor) and green liquor (GL) was investigated for pre-pulping extraction on two types of raw material. The GL was applied at different alkali charges of 0-5% on a dry wood weight basis. The extractions were performed at an H-factor 900 at $180^{\circ}C$. The 0% and 3% GL extraction detected acetic acid (AA) at 10.02 and $9.94g/{\ell}$, extracts derived from hardwood, 2.46 and $3.76g/{\ell}$, extracts derived from softwood, respectively. The single liquid-liquid extraction (LLE) was studied using tri-n-alkylphosphine oxide (TAPO). Response surface methodology (RSM) was employed as an efficient approach for predictive model building and optimization of AA recovery conditions. The extraction of AA was evaluated with a three-level factorial design. Three independent variables, pH (0.5-3.5), temperature ($25-65^{\circ}C$), and residence time (24-48 min) were investigated. Applying the RSM models obtained, the optimal conditions selected of extracts derived from hard- and softwood with a 3% GL were approximately pH 1.4, $26.6^{\circ}C$, 43.8 min and approximately pH 0.7, $25.2^{\circ}C$, 24.6 min, respectively. The predicted and experimental values of AA recovery yield were similar whilst sugar retention was 100%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1514-1519
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• 2009

We fabricated the GaNLED emitting 400 nm wavelength and improved the optical extraction efficiency by making surface patterns on n-GaN layer and ITO layer above p-GaN. In addition, the light reflection metal under the n and p pad is made and the light reflection metal is installed on the backside of the chip. The light extraction efficiency is increased by 20 % with texturing n-GaN layer and 18% with texturing ITO layer at 20 mA. Compared to planar-surface LED, the light extraction efficiency for surface texturing both n-GaN and ITO is increased by 32% at 20mA.

• Journal of IKEEE
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• v.25 no.2
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• pp.322-329
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• 2021

In this study, a method for improving the light extraction efficiency of organic light emitting diodes was presented using the polymer Poly(vinylidenefluoride-co-trifluoroethylene) [P(VDF-TrFE)] having an island surface structure after annealing. Polydimethylsiloxane (PDMS) imprinted on the island-structured P(VDF-TrFE) surface has a spike structure, which improves the external light extraction efficiency aroud 20%. It was confirmed that the produced film showed a low haze characteristic of 8.2, and the Current and external quantum efficiency could be improved without pixel blur due to the excellent transmittance of 93.4%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.244-251
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• 2009

Extraction characteristics of dried jujube and functional properties of corresponding extract were monitored by response surface methodology. Maximum extraction yield of 53.69% was obtained at extraction temperature of $50.35^{\circ}C$, extraction time of 16.69 hr, and ethanol concentration of 72.88%. At extraction temperature, extraction time, and ethanol concentration of $45.80^{\circ}C$, 15.47 hr, and 73.12%, respectively, maximum cyclic adenosine monophosphate content was 8.20 mg/100 g. Maximum total polyphenol content was 18.85 mg/g at extraction temperature, extraction time, and ethanol concentration of $64.91^{\circ}C$, 20.84 hr, and 66.91%, respectively. Maximum total flavonoid content was 0.48 mg/g at extraction temperature, extraction time, and ethanol concentration of $57.36^{\circ}C$, 15.14 hr, and 71.08%, respectively. $IC_{50}$ value of electron donating ability showed maximum level of 32.34 mg/mL at extraction temperature of $48.46^{\circ}C$, extraction time of 19.25 hr, and ethanol concentration of 65.36%. Maximum ascorbic acid equivalent antioxidant capacity was 3.58 mg ascorbic acid equivalent per gram sample at extraction temperature, extraction time, and ethanol concentration of $56.09^{\circ}C$, 21.86 hr, and 65.36%, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.3
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• pp.384-390
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• 2009

Extraction characteristics of citron (Citrus junos Sieb. ex Tanaka) seeds and functional properties of corresponding extract were monitored by response surface methodology (RSM). Maximum extraction yield of 20.23% was obtained at extraction temperature of $50.23^{\circ}C$, extraction time of 3.03 hr, and shaking velocity of 400.06 rpm. At extraction temperature, extraction time, and shaking velocity of $49.88^{\circ}C$, 2.72 hr, and 400.39 rpm, respectively, maximum polyphenol content was 4.37 mg/g. At extraction temperature, extraction time, and shaking velocity of $50.28^{\circ}C$, 3.42 hr, and 399.96 rpm, respectively, maximum electron donating ability (EDA) was 49.69%. Maximum nitrite scavenging activity (NSA) was 47.79% at extraction temperature, extraction time, and shaking velocity of $49.19^{\circ}C$, 0.68 hr, and 602.95 rpm, respectively. Based on superimposition of 3-dimensional RSM with respect to extraction yield, polyphenol, EDA, and NSA, optimum ranges of extraction conditions were extraction temperature of $50^{\circ}C$, extraction time of about 3 hr, and shaking velocity of 400 rpm.

• Food Science and Preservation
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• v.13 no.2
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• pp.252-258
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• 2006

To find the optimum extraction condition of dried omija, central composite experimental design having three independent variable (extraction temperature, extraction time and water ratio) with five levels was conducted for response surface analysis. The maximum of soluble solid was predicted to the extraction conditions of over 25 fold water ratio, $7{\sim}8hr$ and $75^{\circ}C$. Total acid, total phenol, reducing sugar and vitamin C were predicted to respectively 30 fold water ratio, 6 hr, $70^{\circ}C$, 30 fold water ratio, $6{\sim}7\;hrs,\;80^{\circ}C$ and 30 fold water ratio, $6{\sim}8\;hr,\;80^{\circ}C$, 25 fold water ratio, $5{\sim}6hr,\;80^{\circ}C$ extraction condition. Turbidity of extraction condition. Turbidity of extraction condition was 7 over 25 ford water ratio and over $60^{\circ}C$. From the superimposing results of response variables, the optimum extraction condition was predicted 25 folds water ratio, 6 hr and $65{\sim}70^{\circ}C$.

• Journal of Periodontal and Implant Science
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• v.23 no.2
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• pp.261-281
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• 1993

The author transplanted periodontally-diseased teeth which had been treated with citric acid into a clinically healthy extraction sockets and periodontally-affected extraction sockets, and compared with the healing processes within these tissues. Recipient sites were prepared by surgically removing a part of alveolar bone of premolars of adults dogs, placing elastic orthodontic ligatures for 8weeks, thereby inducing periodontal disease. The diseased roots were extracted and transplanted into healthy extraction sockets, and these were designated as control group 1. Diseased roots transplanted into diseased sockets were designated as control group 2. Diseased roots which had been root planed, treated with citric acid and transplanted into healthy sockets were designated as experimental group 1, while identically treated roots which had been transplanted into diseased sockets were designated as experimental group 2. Observations were made at weeks 2, 8 and 12, with following results. 1. At week 2, experimental group 2 showed some inflammatory cell infiltration in the connective tissue above the extraction sockets, while control groups showed less inflammatory or foreign body reactions throughout the experiment. 2. In both control groups, root surface resorption was observed throughout the experiment, while experimental groups showed a little resorption. 3. Control group 1 & 2 showed ankylosis by newly-formed bone ground the resorbed root surfaces, while experimental group 1 & 2 displayed collagen fibers which are not functionally-arranged, with random, loose arrangement or parallel orientation to root surfaces, and newly-formed bone outside of them. 4. In both control groups & experimental groups which had been transplanted into a clinically healthy extraction sockets & periodontally affected extraction sockets groups, histological differences were not significant. 5. Root resorption or ankylosis in control group 1 & 2 had increased quantitatively as experiment progressed. 6. New bone formation developed from the base and lateral wall of extraction sockets. In both control groups & experimental groups, root surfaces lying next to the upper portion of extraction sockets showed little alveolar bone formation and surrounded by connective tissue fiber at weeks 2 & 8, while at weeks 12, they did show alveolar bone formation. 7. At week 12, experimental group 2 showed numerous cells which appeared to be periodontal ligament cells, with functionally arranged connective tissue fibers between the roots and alveolar bone.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.10
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• pp.1334-1340
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• 2007

Extraction characteristics of solid Cheonggukjang and the functional properties of corresponding extracts were monitored by the response surface methodology (RSM). The maximum extraction yield of 12.08% was obtained under the specific extraction conditions, such as microwave power of 132.40 W, ratio of solvent to sample content of 7.57 g/mL and extraction time of 14.11 min. The maximum electron donating ability (EDA) was found as 33.53% at the conditions of 113.26 W microwave power, 16.39 g/mL of ratio of solvent to sample content and 12.67 min extraction time. The maximum superoxide dismutase (SOD) -like activity was 89.62% under the extraction conditions of 61.82 W, 17.06 g/mL and 9.03 min. Based on superimposition of three dimensional RSM with respect to extraction yield, electron donating ability and SOD-like activity obtained under the various extraction conditions, the optimum ranges of extraction conditions were found to be microwave power of $75{\sim}140W$, ratio of solvent to sample content of $3{\sim}12g/mL$ and extraction time of $1{\sim}11min$, respectively.

• Korean Journal of Food Science and Technology
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• v.41 no.1
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• pp.37-41
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• 2009

In this study, supercritical carbon dioxide extraction (SFE) was utilized for the extraction of tocotrienol from grape seeds. The optimal conditions for vitamin E and tocotrienol extraction were determined via response surface methodology (RSM). Central composite design was utilized to assess the effects of oven temperature (30-$50^{\circ}C$, X1), operating pressure (17-25 MPa, X2), and extraction time (1-5 hr, X3) of supercritical fluid extraction. Vitamin E and tocotrienol contents were 8.65 mg/100 g and 7.88 mg/100 g at $40^{\circ}C$, 20MPa and 5 hr, respectively. The predicted extraction condition was validated via actual experimentation. The predicted extraction conditions were $40^{\circ}C$, 3.8 hr, and 20.7MPa. The vitamin E and tocotrienol contents under these conditions were 8.20 mg/100 g and 7.42 mg/100 g, respectively. The vitamin E and tocotrienol contents of solvent extraction with hexane were 8.18 mg/100 g and 7.24 mg/100 g, respectively.