• 대한기계학회논문집B
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• 제22권1호
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• pp.25-33
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• 1998

An experimental study has been carried out to obtain optimal conditions for turbulent mixing of two fluid streams at various angle branches by a flow visualization method. The main purpose of this study is the utilization of flow visualization method as a fast and efficient way to find the optimal mixing conditions when several flow control parameters are superimposed. It is verified that the optimal conditions estimated by flow visualization method have good agreement with the concentration field measurements. The results demonstrate that the diameter ratio is mainly attributed to the mixing phenomena than the branch pipe angle and the Reynolds number. The most striking fact is that there exists the best diameter ratio, d/D.ident. O.17, which requires the minimum momentum ratio in the range of the present experiment. The velocity ratio for the optimal mixing condition has a value within 2 to 16 according to the different flow parameters.

• 한국건축시공학회지
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• 제1권2호
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• pp.174-178
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• 2001

This study was performed to control the thermal crack of the mat footing slab in the multi-purposed buildings. In this study, we executed the mixing design of concrete to satisfy the workability and the quality according to the site conditions. And, we evaluated quantitatively about the possibility of thermal crack by using hydration heat analysis system. Finally, we proposed the optimal mixing conditions, curing methods and curing period which all factors are considered. As a result, the optimal mixing conditions were : W/B 41%, unit binder 375kgf/$\textrm{m}^3$, FA replacement ratio 20%. Lowest thermal stress was 22.0kgf/$\textrm{cm}^2$ and at that time thermal crack index was over 1.5, when the coefficient of thermal conductivity was lowest among the curing conditions. And, the total curing time was estimated at 6.7 days according to curing steps.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.533-538
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• 2001

This study was peformed to control the thermal crack of the mat footing slab in the multi-purposed buildings. In this study, we executed the mixing design of concrete to satisfy the workability and the quality according to the site conditions. And, we evaluated quantitatively about the possibility of thermal crack by using hydration heat analysis system. Finally, we proposed the optimal mixing conditions, curing methods and curing period which all factors are considered. As a results, the optimal mixing conditions were : W/B 41%, unit binder 375kg/$cm^{2}$, FA replacement ratio 20%. Lowest thermal stress was 22.0kgf/$cm^{2}$ and at that time thermal crack index was over 1.5, when the coefficient of thermal conductivity was lowest among the curing conditions. And, the total curing time was estimated at 6.7 days according to curing steps.

• 한국안전학회지
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• 제13권2호
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• pp.109-115
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• 1998

Tri-cresyl phosphate(TCP) was synthesized by reaction of phosphorus chloride with mixed cresol(mixture of m-cresol, p-cresol, and others) in the presence of $AlCl_3$. Some of unwanted products and unreactants colored TCP. In order to separate TCP from these, vaccume distillation was carried twice, but colorless TCP could not be producted. Separation of unwanted materials by 2% NaOH solution was introduced before first and second distillation and optimal separation conditions such as NaOH concentration, mixing volume ratio, mixing time, and rpm were investigated for new batch separation and production of colorless TCP Optimal conditions were 2% NaOH solution, 35% mixing volume ratio of 2% NaOH solution, 1.5 hours of mixing time, and 20 rpm.

• 한국패류학회지
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• 제17권2호
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• pp.95-104
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• 2001

To determine optimal conditions for measurement of the clearance rate in feeding experiment of an intertidal bivalve Glauconome chinensis, effects of starvation, extent of mixing at subsampling, and initial prey concentration were assessed. Experiments were conducted separately for each condition with different treatments. Two-way ANOVAs showed that there were significant differences in clearance rates among different starvation periods (p<0.001), extents of mixing (p = 0.005), and prey concentrations (p < 0.001). Starvation for 1 or 2 days gave rise to 2 to 3-fold increase in the clearance rate. After starvation for 5 days, the clearance rate decreased seriously, implying loss of physiological status. It is suggested that animals should be fed during acclimation. The differences of the clearance rates between gentle and vigorous mixings were significant, but the differences were smaller than that among different incubation times. It was found that vigorous mixing is not necessary. The effect of initial prey concentration was great. However, optimal prey concentration could not be determined at any fixed value. Experiments with multiple concentrations of algal prey are recommended. Optimal incubation time for measurement of the clearance rate of G. chinensis was determined to be 2-4 hours.

• 농업과학연구
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• 제48권3호
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• pp.535-544
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• 2021

When baking, the proper blending or mixing of materials will affect the quality of the product. The mixing strength is important when establishing the optimal conditions for batter, and control of the mixing condition is accordingly an important factor. This study investigated the effects of the mixing speed and time on the quality characteristics of a gluten-free type of rice batter. The batter samples manufactured for this purpose are as follows: control (+) (wheat flour), control (-) (rice flour), T1 (1,800 rpm, 1 min), T2 (1,800 rpm, 2 min), T3 (1,800 rpm, 3 min), T4 (3,600 rpm, 1 min), T5 (3,600 rpm, 2 min), T6 (3,600 rpm, 3 min). In this study, rice flour was used in the T1 to T6 samples. The pH of the batter tended to be higher when the mixing speed was slower and the time was shorter depending on the ultra-high mixing conditions. The moisture content of T3 was highest, and there was no difference according to the ultra-high speed conditions. The specific volumes of the ultra-high mixing treatments were higher than those of the control samples. The relationship between the specific volume, hardness and springiness of rice bread according to the mixing speed and time was weak. Therefore, it is considered that the application of ultra-high speeds when manufacturing gluten-free batter can have a positive effect on improving the production efficiency by reducing the processing time.

• 동아시아식생활학회지
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• 제23권3호
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• pp.320-331
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• 2013

Omija, the major material of omigalsu, has liver protective and antioxidant effects, while mung bean has detoxification effects. A series of studies were conducted to standardize the traditional recipe for omigalsu to develop traditional functional drinks made from Omija extract and mung bean juice. Study 1 was designed to determine the optimal conditions for Omija extraction and mung bean juice. A higher water temperature and longer immersion time was associated with higher, free sugar and organic acid contents of omija extract; however, sensory evaluation revealed that the optimal extraction conditions for the highest acceptability, proper taste and red tone were $23^{\circ}C$ and 18 hrs of immersion. Conversely, the pH of the mung bean juice produced by varying the immersion time (5 hr, 11 hr, 17 hr) was found to be neutral, containing small levels of organic acid and free sugar, and showing a yellow tone. The results of the sensory evaluation also showed that the optimal conditions for taste, flavor and yellowness of mung bean juice was 5-hour-long immersion. Study 2 was designed to determine the optimum mixing ratio of omigalsu concentrate. Sensory evaluation revealed that the contents of sugar and total free sugar were highest when the mixing ratio among omija extract, mung bean juice and sugar was 1:1:20%, indicating that these conditions produced the most attractive color and highest overall acceptability. Study 3 was designed to determine the optimum dilution magnification for omigalsu. Sensory evaluation during summer revealed that the omigalsu produced by mixing 54 g of omigalsu concentrate into 200 cc water of $4^{\circ}C$ or $80^{\circ}C$ was most preferred, while during winter. Overall, the optimum dilution magnification for omigalsu was 4.7~5.4.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2007년도 추계 학술대회논문집
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• pp.49-55
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• 2007

The quality of chaotic mixing in three-dimensional micro channel flow has been numerically studied using Fractional-step method (FSM) and particle tracking techniques such as $Poincar{\acute{e}}$ section and Lyapunov exponents. The flow was driven by pressure distribution and the chaotic mixing was generated by applying alternating current to electrodes embedded on the bottom wall at a first half period and on the top wall at a second half period. The equations governing the velocity and concentration distributions were solved using FSM based on Finite Volume approach. Results showed that the mixing quality depended significantly on the modulation period. The modulation period for the best mixing performance was determined based on the mixing index for various initial conditions of concentration distribution. The optimal values of modulation period obtained by the particle tracking techniques were compared with those from the solution of concentration distribution equation using FSM and CFX software and the comparison showed their good match.

• 융합정보논문지
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• 제12권3호
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• pp.132-140
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• 2022

본 연구에서는 데커신 및 데커시놀 안젤레이트를 이용한 최적의 로션 제조 공정을 확인하기 위하여 연구를 진행하였다. 초기 로션 제형은 3개월 동안 점도(5,208±112 cPs), 함량(99.71±1.01%) 및 pH(5.62)을 유지하는 것을 확인하였다. 제조 공정D 혼합 4의 최적 제조 공정 확인은 22+3 완전 배치 요인법을 이용하였으며, 독립변수로 혼합 온도(40-80℃)와 혼합 시간(10-30 min)으로 종속변수로써 중요품질특성인 함량, pH, 질량편차를 확인하였다. 함량 및 질량편차는 도출된 회귀방적식의 결정계수는 약 0.9였고 p-value값은 0.05보다 작아 모델적합성을 확인하였다. 로션 제조를 위한 최적의 온도조건과 혼합 시간은 61.93℃와 15.85분으로 확인되었다. 혼합4 공정에 있어 혼합 온도(60℃)와 혼합 시간(15 min)에서의 함량은 100.69%, pH는 5.57, 질량편차는 98.07%으로 예측되었고, 실제 검증에서는 각각 100.29±0.98%, 5.57±0.02, 98.27±0.89%으로 예측된 값에 대하여 유사한 결과까지 확인 할 수 있었다.

• 한국수산과학회지
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• 제48권1호
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• pp.36-43
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• 2015

We examined sensory characteristics to determine the optimal conditions for flounder Verasper moseri Jordan et Gilbert sikhe preparation, using response surface methodology. Our aim was to develop the optimum mixing rates and materials for producing highly palatable flounder sikhe. The optimal fermentation temperature, salt concentration, and fermentation period for preparing flounder sikhe of acceptable quality were $11.63^{\circ}C$, 4.66% and 9.12 days, respectively. The optimal percentages of red pepper powder, garlic, monosodium glutamate, ginger, radish and foxtail millet were 16.08%, 7.21%, 2.96%, 3.70%, 10.12% and 13.72% respectively.