• Applied Chemistry for Engineering
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• v.29 no.5
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• pp.503-509
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• 2018

In this study, we used the ultrasonic extraction process as a method to extract antioxidant substances from kudzu, and measured the content of iso-flavonoids puerarin, daidzein, daidzin contained in kudzu. The response surface methodology which is a statistical analysis method for optimizing the extraction amount of iso-flavonoids from the kudzu and the process condition for maximizing the yield was applied. It is the final objective of this study to effectively derive the condition of the process that matches the target response with a minimum number of experiments and analyze the effect of each process condition on the response. In the response surface methodology, the central composite design was applied and the optimum condition was analyzed, and the three independent variables were set to ultrasonic irradiation time, volume ratio of ethanol/ultrapure water, ultrasonic irradiation power. Using the response surface methodology, the optimum conditions with the maximum extraction yield and the content of iso-flavonoids were evaluated as ultrasonic irradiation time (24.75 min), ethanol / ultrapure water volume ratio (39.75 vol%), ultrasonic irradiation power (592.36 W). The overall satisfaction level appears as high as 0.8938, which is recognized at a significance level within 5%. As a result of analyzing the optimization process, it was confirmed that the ultrasonic irradiation time is the factor that most affects the responses.

• Journal of Food Hygiene and Safety
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• v.38 no.5
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• pp.338-346
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• 2023

The demand for probiotic products has been steadily increasing, and Lactobacillus strains are widely used and are currently the most popular probiotics. Optimizing culture conditions for Lactobacillus production for use as probiotics will enhance their profitability by reducing production costs and time. Statistical analysis using response surface methodology revealed the following optimal sets of independent variables: 22.55 h (cultivation time), 25℃ (cultivation temperature), and 3.41% (w/w, prebiotics concentration) for Lactobacillus acidophilus; 24 h, 30.86℃, and 2% (w/w) for Lactiplantibacillus plantarum; 66.67 h, 35℃, and 3.41% (w/w) for Lacticaseibacillus rhamnosus. Actual outcomes using predicted optimal conditions for Lactobacillus strains have been confirmed to closely match predicted results. This study will provide valuable guidelines for high yield Lactobacillus production.

• Applied Chemistry for Engineering
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• v.31 no.4
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• pp.404-410
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• 2020

In this study, the stability criteria of cosmeceuticals emulsion containing Flos Sophorae Immaturus extracts was established using the Box-Behnken design model (BBD-RSM). As optimization conditions of the emulsification using the BBD-RSM, the amount of surfactant and additive, and emulsification time and speed were used as quantitative factors while mean droplet size (MDS), viscosity and emulsion stability index (ESI) were used as reaction values. According to the result of BBD-RSM, optimum conditions for the emulsification were as follows; the emulsification time and speed of 17.8 min and 5505 rpm, respectively and amounts of the emulsifier and additive of 2.28 and 1.05 wt.%, respectively. Under these conditions, the MDS, viscosity, and ESI after 7 days from the reaction were estimated as 1875.5 nm, 1789.7 cP, and 93.8%, respectively. The average error value from our actual experiments for verifying the conclusions was below 5%, which is mainly due to the fact that the BBD-RSM was applied to the optimized cosmeceuticals emulsification.

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.199-204
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• 2015

Response surface methodology (RSM) in combination with a 17-run central composite design (CCD) was applied to optimize the non-catalytic hydrolysis of lard using subcritical water to produce fatty acids (FA). The effects of three variables including temperature, molar ratio of water to oil and time, and their relationship on FA content were investigated. A quadratic regression model was employed to predict the FA contents. Optimum reaction conditions for maximizing the FA content were obtained as follows: reaction temperature of $288.5^{\circ}C$, molar ratio of water to oil of 39.5 and reaction time of 29.5 min. Under the optimum conditions, the predicted and experimentally obtained FA contents were 97.06% and 96.99%, respectively.

• Korean journal of food and cookery science
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• v.28 no.3
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• pp.275-283
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• 2012

This study was conducted to monitor the quality characteristics of Lespedeza cuneata ethanolic extracts, by a response surface methodology. The independent variables were the extraction temperature ($35{\sim}95^{\circ}C}$), extraction time (2~10 hr), and ethanol concentration (10~90%). The coefficients of the determinations (R2) were 0.8562 (p<0.1), 0.9787 (p<0.01), and 0.8344 (p<0.1) in total polyphenol, total flavonoid, and electron donating ability, respectively. The electron donating ability and nitrite scavenging effect were improved with an increase of ethanol concentration, rather than the extraction temperature. ORAC (Oxygen Radical Absorbance Capacity) with extraction conditions was 1,636.47~2,696.99 ${\mu}moles$ TE/g, and was increased with the increase of extraction temperature and 40~60% of ethanol concentration. Estimated conditions for the maximized extraction including the yield, total polyphenol, electron donating ability, nitrite scavenging effect, and ORAC, were $60{\sim}68^{\circ}C$ in extraction temperature, 6~7 hr in extraction time, and 38~60% in ethanol concentration.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1257-1260
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• 2005

Grinding process has unique characteristics compared with other machining processes. The cutting edges of the grinding wheel don't have uniformity and act differently on the workpiece at each grinding. The response surface analysis is one of various methods for optimizing and evaluating the process parameters to achieve the desired output. In this study, the effect of the grinding parameters on outcomes of the surface grinding was analyzed experimently. To predict the grinding outcomes and to select the grinding conditions before grinding, the second-order response surface models for the grinding force and the surface roughness were developed.

• Journal of Food Hygiene and Safety
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• v.35 no.1
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• pp.83-92
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• 2020

This study investigated the optimal conditions of enzymatic reaction for production of isomaltooligosaccharides (IMO) using rice flour. To manufacture IMO, commercial enzymes (Termamyl 2X, Maltogenase L, Promozyme D2, Fungamyl 800L and Transglucosidase L) were used. The sugar composition and amount of IMO were examined by HPLC with charged aerosol detector (HPLC-CAD) in each manufacturing process. Liquefaction reaction was performed according to different Termamyl 2X concentrations (0.025%, 0.05%, 0.075%, 0.1%) and reaction times (1 h, 2 h). As a result, the reducing sugar content was the highest at 138.26 g/L when 0.075% Termamyl 2X was added for 2 hours. In order to optimize simultaneous saccharification and transglucosylation, experiments on enzyme selection, enzyme concentration and enzyme reaction time were conducted. Reaction with 0.0015% Maltogenase L, 0.05-0.1% Promozyme D2 and 0.1% Tansglucosidase L was effective in decreasing glucose content and increasing content of IMO with a high degree of polymerization. A change in sugar content was observed every 6 hours to determine the optimal reaction time, and the highest IMO was produced after 36 hours of reaction (75.36 g/L). The IMO prepared under optimal conditions showed isomaltose, 35.11 g/L; panose, 11.97 g/L; isomaltotriose, 19.95 g/L; isomaltotetraose, 7.46 g/L; isomaltopentaose, 1.05 g/L at 18 brix and the ratio of IMO in the total sugar was 56.37%.

• Korean Journal of Food Science and Technology
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• v.41 no.6
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• pp.622-627
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• 2009

The objectives of this study were to evaluate a protease suitable for the enzymatic hydrolysis of a snow crab processing by-product (SPB) and to optimize the hydrolysis conditions using response surface methodology (RSM). The SPB was hydrolyzed at $50^{\circ}C$ and pH 7.0-7.2 to obtain various degree of hydrolysis (DH) using Flavourzyme at an enzyme/substrate (E/S) ratio of 3.0%. The reaction progress curve exhibited an initial fast reaction rate followed by a slowing of the rate. The DH was increased to 30% at 90 min with a final DH 32 to 36%. A central composite experimental design having three independent variables (reaction temperature, reaction time, and E/S ratio) with five levels was used to optimize the enzymatic hydrolysis conditions. Based on the DH data, the optimum reaction conditions for the enzymatic hydrolysis of the SPB were a temperature of $51.8^{\circ}C$, reaction time of 4 hr 45 min, and an E/S ratio of 3.8%. It was demonstrated that the enzymatic hydrolysate of SPB could be used as a flavoring agent or a source of precursors for the production of reaction flavors.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1998.05a
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• pp.253-258
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• 1998

연료 전지 시스템에서의 스택은 화학 공장의 반응기에 해당한다. 화학 공장에서 반응 생성물의 생산성을 최적화하기 위해 반응기 해석이 매우 중요한 것과 마찬가지로, 연료 전지 스택의 특성을 해석하고 최적 조건으로 설계 및 운전하는 것은 필수적이다. 스택에서 전기를 생산하는 과정에서 중요한 두 가지 운전 변수는 기체의 조성과 온도이며, 이론적인 해석을 위해서는 유체의 이동시에 열전달 및 각 성분별 물질 수지식과 전기 화학 반응식이 사용될 수 있다.(중략)

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1243-1252
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• 2019

The purpose of this study is to investigate the optimum conditions of biomass pretreatment with potassium hydroxide (KOH) for efficient utilization of cellulose, hemicellulose and lignin from Miscanthus. The optimization of variables was performed by response surface methodology (RSM). The variation ranges of the parameters for the RSM were potassium hydroxide 0.2~0.8 M, reaction temperature 110~190℃ and reaction time 10~90 min. The optimum conditions of alkali pretreatment from Miscanthus were determined as follows: concentration of KOH 0.47 M, reaction temperature 134℃ and reaction time 65 min. At the optimum conditions, the yield of cellulose from the solid fraction after pretreatment was predicted to be 95% by model prediction. Finally, 66.1 ± 1.1% of cellulose were obtained by verification experiment under the optimum conditions. The order contents of solid extraction were hemicellulose 26.4 ± 0.4%, lignin 3.7 ± 0.1% and ash 0.5 ± 0.04%. The yield of ethanol concentration of 96% was obtained using separated saccharification and fermentation.